1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 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 unsigned int debug_infrun
= 0;
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 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)
1838 /* Don't start a new step-over if we already have an in-line
1839 step-over operation ongoing. */
1840 if (step_over_info_valid_p ())
1843 /* Steal the global thread step over chain. As we try to initiate displaced
1844 steps, threads will be enqueued in the global chain if no buffers are
1845 available. If we iterated on the global chain directly, we might iterate
1847 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1848 global_thread_step_over_chain_head
= NULL
;
1850 infrun_debug_printf ("stealing global queue of threads to step, length = %d",
1851 thread_step_over_chain_length (threads_to_step
));
1853 bool started
= false;
1855 /* On scope exit (whatever the reason, return or exception), if there are
1856 threads left in the THREADS_TO_STEP chain, put back these threads in the
1860 if (threads_to_step
== nullptr)
1861 infrun_debug_printf ("step-over queue now empty");
1864 infrun_debug_printf ("putting back %d threads to step in global queue",
1865 thread_step_over_chain_length (threads_to_step
));
1867 global_thread_step_over_chain_enqueue_chain (threads_to_step
);
1871 for (thread_info
*tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1873 struct execution_control_state ecss
;
1874 struct execution_control_state
*ecs
= &ecss
;
1875 step_over_what step_what
;
1876 int must_be_in_line
;
1878 gdb_assert (!tp
->stop_requested
);
1880 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1882 if (tp
->inf
->displaced_step_state
.unavailable
)
1884 /* The arch told us to not even try preparing another displaced step
1885 for this inferior. Just leave the thread in THREADS_TO_STEP, it
1886 will get moved to the global chain on scope exit. */
1890 /* Remove thread from the THREADS_TO_STEP chain. If anything goes wrong
1891 while we try to prepare the displaced step, we don't add it back to
1892 the global step over chain. This is to avoid a thread staying in the
1893 step over chain indefinitely if something goes wrong when resuming it
1894 If the error is intermittent and it still needs a step over, it will
1895 get enqueued again when we try to resume it normally. */
1896 thread_step_over_chain_remove (&threads_to_step
, tp
);
1898 step_what
= thread_still_needs_step_over (tp
);
1899 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1900 || ((step_what
& STEP_OVER_BREAKPOINT
)
1901 && !use_displaced_stepping (tp
)));
1903 /* We currently stop all threads of all processes to step-over
1904 in-line. If we need to start a new in-line step-over, let
1905 any pending displaced steps finish first. */
1906 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1908 global_thread_step_over_chain_enqueue (tp
);
1912 if (tp
->control
.trap_expected
1916 internal_error (__FILE__
, __LINE__
,
1917 "[%s] has inconsistent state: "
1918 "trap_expected=%d, resumed=%d, executing=%d\n",
1919 target_pid_to_str (tp
->ptid
).c_str (),
1920 tp
->control
.trap_expected
,
1925 infrun_debug_printf ("resuming [%s] for step-over",
1926 target_pid_to_str (tp
->ptid
).c_str ());
1928 /* keep_going_pass_signal skips the step-over if the breakpoint
1929 is no longer inserted. In all-stop, we want to keep looking
1930 for a thread that needs a step-over instead of resuming TP,
1931 because we wouldn't be able to resume anything else until the
1932 target stops again. In non-stop, the resume always resumes
1933 only TP, so it's OK to let the thread resume freely. */
1934 if (!target_is_non_stop_p () && !step_what
)
1937 switch_to_thread (tp
);
1938 reset_ecs (ecs
, tp
);
1939 keep_going_pass_signal (ecs
);
1941 if (!ecs
->wait_some_more
)
1942 error (_("Command aborted."));
1944 /* If the thread's step over could not be initiated because no buffers
1945 were available, it was re-added to the global step over chain. */
1948 infrun_debug_printf ("[%s] was resumed.",
1949 target_pid_to_str (tp
->ptid
).c_str ());
1950 gdb_assert (!thread_is_in_step_over_chain (tp
));
1954 infrun_debug_printf ("[%s] was NOT resumed.",
1955 target_pid_to_str (tp
->ptid
).c_str ());
1956 gdb_assert (thread_is_in_step_over_chain (tp
));
1959 /* If we started a new in-line step-over, we're done. */
1960 if (step_over_info_valid_p ())
1962 gdb_assert (tp
->control
.trap_expected
);
1967 if (!target_is_non_stop_p ())
1969 /* On all-stop, shouldn't have resumed unless we needed a
1971 gdb_assert (tp
->control
.trap_expected
1972 || tp
->step_after_step_resume_breakpoint
);
1974 /* With remote targets (at least), in all-stop, we can't
1975 issue any further remote commands until the program stops
1981 /* Either the thread no longer needed a step-over, or a new
1982 displaced stepping sequence started. Even in the latter
1983 case, continue looking. Maybe we can also start another
1984 displaced step on a thread of other process. */
1990 /* Update global variables holding ptids to hold NEW_PTID if they were
1991 holding OLD_PTID. */
1993 infrun_thread_ptid_changed (process_stratum_target
*target
,
1994 ptid_t old_ptid
, ptid_t new_ptid
)
1996 if (inferior_ptid
== old_ptid
1997 && current_inferior ()->process_target () == target
)
1998 inferior_ptid
= new_ptid
;
2003 static const char schedlock_off
[] = "off";
2004 static const char schedlock_on
[] = "on";
2005 static const char schedlock_step
[] = "step";
2006 static const char schedlock_replay
[] = "replay";
2007 static const char *const scheduler_enums
[] = {
2014 static const char *scheduler_mode
= schedlock_replay
;
2016 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2017 struct cmd_list_element
*c
, const char *value
)
2019 fprintf_filtered (file
,
2020 _("Mode for locking scheduler "
2021 "during execution is \"%s\".\n"),
2026 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2028 if (!target_can_lock_scheduler ())
2030 scheduler_mode
= schedlock_off
;
2031 error (_("Target '%s' cannot support this command."), target_shortname
);
2035 /* True if execution commands resume all threads of all processes by
2036 default; otherwise, resume only threads of the current inferior
2038 bool sched_multi
= false;
2040 /* Try to setup for software single stepping over the specified location.
2041 Return true if target_resume() should use hardware single step.
2043 GDBARCH the current gdbarch.
2044 PC the location to step over. */
2047 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2049 bool hw_step
= true;
2051 if (execution_direction
== EXEC_FORWARD
2052 && gdbarch_software_single_step_p (gdbarch
))
2053 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2061 user_visible_resume_ptid (int step
)
2067 /* With non-stop mode on, threads are always handled
2069 resume_ptid
= inferior_ptid
;
2071 else if ((scheduler_mode
== schedlock_on
)
2072 || (scheduler_mode
== schedlock_step
&& step
))
2074 /* User-settable 'scheduler' mode requires solo thread
2076 resume_ptid
= inferior_ptid
;
2078 else if ((scheduler_mode
== schedlock_replay
)
2079 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2081 /* User-settable 'scheduler' mode requires solo thread resume in replay
2083 resume_ptid
= inferior_ptid
;
2085 else if (!sched_multi
&& target_supports_multi_process ())
2087 /* Resume all threads of the current process (and none of other
2089 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2093 /* Resume all threads of all processes. */
2094 resume_ptid
= RESUME_ALL
;
2102 process_stratum_target
*
2103 user_visible_resume_target (ptid_t resume_ptid
)
2105 return (resume_ptid
== minus_one_ptid
&& sched_multi
2107 : current_inferior ()->process_target ());
2110 /* Return a ptid representing the set of threads that we will resume,
2111 in the perspective of the target, assuming run control handling
2112 does not require leaving some threads stopped (e.g., stepping past
2113 breakpoint). USER_STEP indicates whether we're about to start the
2114 target for a stepping command. */
2117 internal_resume_ptid (int user_step
)
2119 /* In non-stop, we always control threads individually. Note that
2120 the target may always work in non-stop mode even with "set
2121 non-stop off", in which case user_visible_resume_ptid could
2122 return a wildcard ptid. */
2123 if (target_is_non_stop_p ())
2124 return inferior_ptid
;
2126 return user_visible_resume_ptid (user_step
);
2129 /* Wrapper for target_resume, that handles infrun-specific
2133 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2135 struct thread_info
*tp
= inferior_thread ();
2137 gdb_assert (!tp
->stop_requested
);
2139 /* Install inferior's terminal modes. */
2140 target_terminal::inferior ();
2142 /* Avoid confusing the next resume, if the next stop/resume
2143 happens to apply to another thread. */
2144 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2146 /* Advise target which signals may be handled silently.
2148 If we have removed breakpoints because we are stepping over one
2149 in-line (in any thread), we need to receive all signals to avoid
2150 accidentally skipping a breakpoint during execution of a signal
2153 Likewise if we're displaced stepping, otherwise a trap for a
2154 breakpoint in a signal handler might be confused with the
2155 displaced step finishing. We don't make the displaced_step_finish
2156 step distinguish the cases instead, because:
2158 - a backtrace while stopped in the signal handler would show the
2159 scratch pad as frame older than the signal handler, instead of
2160 the real mainline code.
2162 - when the thread is later resumed, the signal handler would
2163 return to the scratch pad area, which would no longer be
2165 if (step_over_info_valid_p ()
2166 || displaced_step_in_progress (tp
->inf
))
2167 target_pass_signals ({});
2169 target_pass_signals (signal_pass
);
2171 target_resume (resume_ptid
, step
, sig
);
2173 target_commit_resume ();
2175 if (target_can_async_p ())
2179 /* Resume the inferior. SIG is the signal to give the inferior
2180 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2181 call 'resume', which handles exceptions. */
2184 resume_1 (enum gdb_signal sig
)
2186 struct regcache
*regcache
= get_current_regcache ();
2187 struct gdbarch
*gdbarch
= regcache
->arch ();
2188 struct thread_info
*tp
= inferior_thread ();
2189 const address_space
*aspace
= regcache
->aspace ();
2191 /* This represents the user's step vs continue request. When
2192 deciding whether "set scheduler-locking step" applies, it's the
2193 user's intention that counts. */
2194 const int user_step
= tp
->control
.stepping_command
;
2195 /* This represents what we'll actually request the target to do.
2196 This can decay from a step to a continue, if e.g., we need to
2197 implement single-stepping with breakpoints (software
2201 gdb_assert (!tp
->stop_requested
);
2202 gdb_assert (!thread_is_in_step_over_chain (tp
));
2204 if (tp
->suspend
.waitstatus_pending_p
)
2207 ("thread %s has pending wait "
2208 "status %s (currently_stepping=%d).",
2209 target_pid_to_str (tp
->ptid
).c_str (),
2210 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2211 currently_stepping (tp
));
2213 tp
->inf
->process_target ()->threads_executing
= true;
2216 /* FIXME: What should we do if we are supposed to resume this
2217 thread with a signal? Maybe we should maintain a queue of
2218 pending signals to deliver. */
2219 if (sig
!= GDB_SIGNAL_0
)
2221 warning (_("Couldn't deliver signal %s to %s."),
2222 gdb_signal_to_name (sig
),
2223 target_pid_to_str (tp
->ptid
).c_str ());
2226 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2228 if (target_can_async_p ())
2231 /* Tell the event loop we have an event to process. */
2232 mark_async_event_handler (infrun_async_inferior_event_token
);
2237 tp
->stepped_breakpoint
= 0;
2239 /* Depends on stepped_breakpoint. */
2240 step
= currently_stepping (tp
);
2242 if (current_inferior ()->waiting_for_vfork_done
)
2244 /* Don't try to single-step a vfork parent that is waiting for
2245 the child to get out of the shared memory region (by exec'ing
2246 or exiting). This is particularly important on software
2247 single-step archs, as the child process would trip on the
2248 software single step breakpoint inserted for the parent
2249 process. Since the parent will not actually execute any
2250 instruction until the child is out of the shared region (such
2251 are vfork's semantics), it is safe to simply continue it.
2252 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2253 the parent, and tell it to `keep_going', which automatically
2254 re-sets it stepping. */
2255 infrun_debug_printf ("resume : clear step");
2259 CORE_ADDR pc
= regcache_read_pc (regcache
);
2261 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2262 "current thread [%s] at %s",
2263 step
, gdb_signal_to_symbol_string (sig
),
2264 tp
->control
.trap_expected
,
2265 target_pid_to_str (inferior_ptid
).c_str (),
2266 paddress (gdbarch
, pc
));
2268 /* Normally, by the time we reach `resume', the breakpoints are either
2269 removed or inserted, as appropriate. The exception is if we're sitting
2270 at a permanent breakpoint; we need to step over it, but permanent
2271 breakpoints can't be removed. So we have to test for it here. */
2272 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2274 if (sig
!= GDB_SIGNAL_0
)
2276 /* We have a signal to pass to the inferior. The resume
2277 may, or may not take us to the signal handler. If this
2278 is a step, we'll need to stop in the signal handler, if
2279 there's one, (if the target supports stepping into
2280 handlers), or in the next mainline instruction, if
2281 there's no handler. If this is a continue, we need to be
2282 sure to run the handler with all breakpoints inserted.
2283 In all cases, set a breakpoint at the current address
2284 (where the handler returns to), and once that breakpoint
2285 is hit, resume skipping the permanent breakpoint. If
2286 that breakpoint isn't hit, then we've stepped into the
2287 signal handler (or hit some other event). We'll delete
2288 the step-resume breakpoint then. */
2290 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2291 "deliver signal first");
2293 clear_step_over_info ();
2294 tp
->control
.trap_expected
= 0;
2296 if (tp
->control
.step_resume_breakpoint
== NULL
)
2298 /* Set a "high-priority" step-resume, as we don't want
2299 user breakpoints at PC to trigger (again) when this
2301 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2302 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2304 tp
->step_after_step_resume_breakpoint
= step
;
2307 insert_breakpoints ();
2311 /* There's no signal to pass, we can go ahead and skip the
2312 permanent breakpoint manually. */
2313 infrun_debug_printf ("skipping permanent breakpoint");
2314 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2315 /* Update pc to reflect the new address from which we will
2316 execute instructions. */
2317 pc
= regcache_read_pc (regcache
);
2321 /* We've already advanced the PC, so the stepping part
2322 is done. Now we need to arrange for a trap to be
2323 reported to handle_inferior_event. Set a breakpoint
2324 at the current PC, and run to it. Don't update
2325 prev_pc, because if we end in
2326 switch_back_to_stepped_thread, we want the "expected
2327 thread advanced also" branch to be taken. IOW, we
2328 don't want this thread to step further from PC
2330 gdb_assert (!step_over_info_valid_p ());
2331 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2332 insert_breakpoints ();
2334 resume_ptid
= internal_resume_ptid (user_step
);
2335 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2342 /* If we have a breakpoint to step over, make sure to do a single
2343 step only. Same if we have software watchpoints. */
2344 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2345 tp
->control
.may_range_step
= 0;
2347 /* If displaced stepping is enabled, step over breakpoints by executing a
2348 copy of the instruction at a different address.
2350 We can't use displaced stepping when we have a signal to deliver;
2351 the comments for displaced_step_prepare explain why. The
2352 comments in the handle_inferior event for dealing with 'random
2353 signals' explain what we do instead.
2355 We can't use displaced stepping when we are waiting for vfork_done
2356 event, displaced stepping breaks the vfork child similarly as single
2357 step software breakpoint. */
2358 if (tp
->control
.trap_expected
2359 && use_displaced_stepping (tp
)
2360 && !step_over_info_valid_p ()
2361 && sig
== GDB_SIGNAL_0
2362 && !current_inferior ()->waiting_for_vfork_done
)
2364 displaced_step_prepare_status prepare_status
2365 = displaced_step_prepare (tp
);
2367 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2369 infrun_debug_printf ("Got placed in step-over queue");
2371 tp
->control
.trap_expected
= 0;
2374 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
2376 /* Fallback to stepping over the breakpoint in-line. */
2378 if (target_is_non_stop_p ())
2379 stop_all_threads ();
2381 set_step_over_info (regcache
->aspace (),
2382 regcache_read_pc (regcache
), 0, tp
->global_num
);
2384 step
= maybe_software_singlestep (gdbarch
, pc
);
2386 insert_breakpoints ();
2388 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2390 /* Update pc to reflect the new address from which we will
2391 execute instructions due to displaced stepping. */
2392 pc
= regcache_read_pc (get_thread_regcache (tp
));
2394 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2397 gdb_assert_not_reached (_("Invalid displaced_step_prepare_status "
2401 /* Do we need to do it the hard way, w/temp breakpoints? */
2403 step
= maybe_software_singlestep (gdbarch
, pc
);
2405 /* Currently, our software single-step implementation leads to different
2406 results than hardware single-stepping in one situation: when stepping
2407 into delivering a signal which has an associated signal handler,
2408 hardware single-step will stop at the first instruction of the handler,
2409 while software single-step will simply skip execution of the handler.
2411 For now, this difference in behavior is accepted since there is no
2412 easy way to actually implement single-stepping into a signal handler
2413 without kernel support.
2415 However, there is one scenario where this difference leads to follow-on
2416 problems: if we're stepping off a breakpoint by removing all breakpoints
2417 and then single-stepping. In this case, the software single-step
2418 behavior means that even if there is a *breakpoint* in the signal
2419 handler, GDB still would not stop.
2421 Fortunately, we can at least fix this particular issue. We detect
2422 here the case where we are about to deliver a signal while software
2423 single-stepping with breakpoints removed. In this situation, we
2424 revert the decisions to remove all breakpoints and insert single-
2425 step breakpoints, and instead we install a step-resume breakpoint
2426 at the current address, deliver the signal without stepping, and
2427 once we arrive back at the step-resume breakpoint, actually step
2428 over the breakpoint we originally wanted to step over. */
2429 if (thread_has_single_step_breakpoints_set (tp
)
2430 && sig
!= GDB_SIGNAL_0
2431 && step_over_info_valid_p ())
2433 /* If we have nested signals or a pending signal is delivered
2434 immediately after a handler returns, might already have
2435 a step-resume breakpoint set on the earlier handler. We cannot
2436 set another step-resume breakpoint; just continue on until the
2437 original breakpoint is hit. */
2438 if (tp
->control
.step_resume_breakpoint
== NULL
)
2440 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2441 tp
->step_after_step_resume_breakpoint
= 1;
2444 delete_single_step_breakpoints (tp
);
2446 clear_step_over_info ();
2447 tp
->control
.trap_expected
= 0;
2449 insert_breakpoints ();
2452 /* If STEP is set, it's a request to use hardware stepping
2453 facilities. But in that case, we should never
2454 use singlestep breakpoint. */
2455 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2457 /* Decide the set of threads to ask the target to resume. */
2458 if (tp
->control
.trap_expected
)
2460 /* We're allowing a thread to run past a breakpoint it has
2461 hit, either by single-stepping the thread with the breakpoint
2462 removed, or by displaced stepping, with the breakpoint inserted.
2463 In the former case, we need to single-step only this thread,
2464 and keep others stopped, as they can miss this breakpoint if
2465 allowed to run. That's not really a problem for displaced
2466 stepping, but, we still keep other threads stopped, in case
2467 another thread is also stopped for a breakpoint waiting for
2468 its turn in the displaced stepping queue. */
2469 resume_ptid
= inferior_ptid
;
2472 resume_ptid
= internal_resume_ptid (user_step
);
2474 if (execution_direction
!= EXEC_REVERSE
2475 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2477 /* There are two cases where we currently need to step a
2478 breakpoint instruction when we have a signal to deliver:
2480 - See handle_signal_stop where we handle random signals that
2481 could take out us out of the stepping range. Normally, in
2482 that case we end up continuing (instead of stepping) over the
2483 signal handler with a breakpoint at PC, but there are cases
2484 where we should _always_ single-step, even if we have a
2485 step-resume breakpoint, like when a software watchpoint is
2486 set. Assuming single-stepping and delivering a signal at the
2487 same time would takes us to the signal handler, then we could
2488 have removed the breakpoint at PC to step over it. However,
2489 some hardware step targets (like e.g., Mac OS) can't step
2490 into signal handlers, and for those, we need to leave the
2491 breakpoint at PC inserted, as otherwise if the handler
2492 recurses and executes PC again, it'll miss the breakpoint.
2493 So we leave the breakpoint inserted anyway, but we need to
2494 record that we tried to step a breakpoint instruction, so
2495 that adjust_pc_after_break doesn't end up confused.
2497 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2498 in one thread after another thread that was stepping had been
2499 momentarily paused for a step-over. When we re-resume the
2500 stepping thread, it may be resumed from that address with a
2501 breakpoint that hasn't trapped yet. Seen with
2502 gdb.threads/non-stop-fair-events.exp, on targets that don't
2503 do displaced stepping. */
2505 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2506 target_pid_to_str (tp
->ptid
).c_str ());
2508 tp
->stepped_breakpoint
= 1;
2510 /* Most targets can step a breakpoint instruction, thus
2511 executing it normally. But if this one cannot, just
2512 continue and we will hit it anyway. */
2513 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2518 && tp
->control
.trap_expected
2519 && use_displaced_stepping (tp
)
2520 && !step_over_info_valid_p ())
2522 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2523 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2524 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2527 read_memory (actual_pc
, buf
, sizeof (buf
));
2528 displaced_debug_printf ("run %s: %s",
2529 paddress (resume_gdbarch
, actual_pc
),
2530 displaced_step_dump_bytes
2531 (buf
, sizeof (buf
)).c_str ());
2534 if (tp
->control
.may_range_step
)
2536 /* If we're resuming a thread with the PC out of the step
2537 range, then we're doing some nested/finer run control
2538 operation, like stepping the thread out of the dynamic
2539 linker or the displaced stepping scratch pad. We
2540 shouldn't have allowed a range step then. */
2541 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2544 do_target_resume (resume_ptid
, step
, sig
);
2548 /* Resume the inferior. SIG is the signal to give the inferior
2549 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2550 rolls back state on error. */
2553 resume (gdb_signal sig
)
2559 catch (const gdb_exception
&ex
)
2561 /* If resuming is being aborted for any reason, delete any
2562 single-step breakpoint resume_1 may have created, to avoid
2563 confusing the following resumption, and to avoid leaving
2564 single-step breakpoints perturbing other threads, in case
2565 we're running in non-stop mode. */
2566 if (inferior_ptid
!= null_ptid
)
2567 delete_single_step_breakpoints (inferior_thread ());
2577 /* Counter that tracks number of user visible stops. This can be used
2578 to tell whether a command has proceeded the inferior past the
2579 current location. This allows e.g., inferior function calls in
2580 breakpoint commands to not interrupt the command list. When the
2581 call finishes successfully, the inferior is standing at the same
2582 breakpoint as if nothing happened (and so we don't call
2584 static ULONGEST current_stop_id
;
2591 return current_stop_id
;
2594 /* Called when we report a user visible stop. */
2602 /* Clear out all variables saying what to do when inferior is continued.
2603 First do this, then set the ones you want, then call `proceed'. */
2606 clear_proceed_status_thread (struct thread_info
*tp
)
2608 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2610 /* If we're starting a new sequence, then the previous finished
2611 single-step is no longer relevant. */
2612 if (tp
->suspend
.waitstatus_pending_p
)
2614 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2616 infrun_debug_printf ("pending event of %s was a finished step. "
2618 target_pid_to_str (tp
->ptid
).c_str ());
2620 tp
->suspend
.waitstatus_pending_p
= 0;
2621 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2626 ("thread %s has pending wait status %s (currently_stepping=%d).",
2627 target_pid_to_str (tp
->ptid
).c_str (),
2628 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2629 currently_stepping (tp
));
2633 /* If this signal should not be seen by program, give it zero.
2634 Used for debugging signals. */
2635 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2636 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2638 delete tp
->thread_fsm
;
2639 tp
->thread_fsm
= NULL
;
2641 tp
->control
.trap_expected
= 0;
2642 tp
->control
.step_range_start
= 0;
2643 tp
->control
.step_range_end
= 0;
2644 tp
->control
.may_range_step
= 0;
2645 tp
->control
.step_frame_id
= null_frame_id
;
2646 tp
->control
.step_stack_frame_id
= null_frame_id
;
2647 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2648 tp
->control
.step_start_function
= NULL
;
2649 tp
->stop_requested
= 0;
2651 tp
->control
.stop_step
= 0;
2653 tp
->control
.proceed_to_finish
= 0;
2655 tp
->control
.stepping_command
= 0;
2657 /* Discard any remaining commands or status from previous stop. */
2658 bpstat_clear (&tp
->control
.stop_bpstat
);
2662 clear_proceed_status (int step
)
2664 /* With scheduler-locking replay, stop replaying other threads if we're
2665 not replaying the user-visible resume ptid.
2667 This is a convenience feature to not require the user to explicitly
2668 stop replaying the other threads. We're assuming that the user's
2669 intent is to resume tracing the recorded process. */
2670 if (!non_stop
&& scheduler_mode
== schedlock_replay
2671 && target_record_is_replaying (minus_one_ptid
)
2672 && !target_record_will_replay (user_visible_resume_ptid (step
),
2673 execution_direction
))
2674 target_record_stop_replaying ();
2676 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2678 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2679 process_stratum_target
*resume_target
2680 = user_visible_resume_target (resume_ptid
);
2682 /* In all-stop mode, delete the per-thread status of all threads
2683 we're about to resume, implicitly and explicitly. */
2684 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2685 clear_proceed_status_thread (tp
);
2688 if (inferior_ptid
!= null_ptid
)
2690 struct inferior
*inferior
;
2694 /* If in non-stop mode, only delete the per-thread status of
2695 the current thread. */
2696 clear_proceed_status_thread (inferior_thread ());
2699 inferior
= current_inferior ();
2700 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2703 gdb::observers::about_to_proceed
.notify ();
2706 /* Returns true if TP is still stopped at a breakpoint that needs
2707 stepping-over in order to make progress. If the breakpoint is gone
2708 meanwhile, we can skip the whole step-over dance. */
2711 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2713 if (tp
->stepping_over_breakpoint
)
2715 struct regcache
*regcache
= get_thread_regcache (tp
);
2717 if (breakpoint_here_p (regcache
->aspace (),
2718 regcache_read_pc (regcache
))
2719 == ordinary_breakpoint_here
)
2722 tp
->stepping_over_breakpoint
= 0;
2728 /* Check whether thread TP still needs to start a step-over in order
2729 to make progress when resumed. Returns an bitwise or of enum
2730 step_over_what bits, indicating what needs to be stepped over. */
2732 static step_over_what
2733 thread_still_needs_step_over (struct thread_info
*tp
)
2735 step_over_what what
= 0;
2737 if (thread_still_needs_step_over_bp (tp
))
2738 what
|= STEP_OVER_BREAKPOINT
;
2740 if (tp
->stepping_over_watchpoint
2741 && !target_have_steppable_watchpoint ())
2742 what
|= STEP_OVER_WATCHPOINT
;
2747 /* Returns true if scheduler locking applies. STEP indicates whether
2748 we're about to do a step/next-like command to a thread. */
2751 schedlock_applies (struct thread_info
*tp
)
2753 return (scheduler_mode
== schedlock_on
2754 || (scheduler_mode
== schedlock_step
2755 && tp
->control
.stepping_command
)
2756 || (scheduler_mode
== schedlock_replay
2757 && target_record_will_replay (minus_one_ptid
,
2758 execution_direction
)));
2761 /* Calls target_commit_resume on all targets. */
2764 commit_resume_all_targets ()
2766 scoped_restore_current_thread restore_thread
;
2768 /* Map between process_target and a representative inferior. This
2769 is to avoid committing a resume in the same target more than
2770 once. Resumptions must be idempotent, so this is an
2772 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2774 for (inferior
*inf
: all_non_exited_inferiors ())
2775 if (inf
->has_execution ())
2776 conn_inf
[inf
->process_target ()] = inf
;
2778 for (const auto &ci
: conn_inf
)
2780 inferior
*inf
= ci
.second
;
2781 switch_to_inferior_no_thread (inf
);
2782 target_commit_resume ();
2786 /* Check that all the targets we're about to resume are in non-stop
2787 mode. Ideally, we'd only care whether all targets support
2788 target-async, but we're not there yet. E.g., stop_all_threads
2789 doesn't know how to handle all-stop targets. Also, the remote
2790 protocol in all-stop mode is synchronous, irrespective of
2791 target-async, which means that things like a breakpoint re-set
2792 triggered by one target would try to read memory from all targets
2796 check_multi_target_resumption (process_stratum_target
*resume_target
)
2798 if (!non_stop
&& resume_target
== nullptr)
2800 scoped_restore_current_thread restore_thread
;
2802 /* This is used to track whether we're resuming more than one
2804 process_stratum_target
*first_connection
= nullptr;
2806 /* The first inferior we see with a target that does not work in
2807 always-non-stop mode. */
2808 inferior
*first_not_non_stop
= nullptr;
2810 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2812 switch_to_inferior_no_thread (inf
);
2814 if (!target_has_execution ())
2817 process_stratum_target
*proc_target
2818 = current_inferior ()->process_target();
2820 if (!target_is_non_stop_p ())
2821 first_not_non_stop
= inf
;
2823 if (first_connection
== nullptr)
2824 first_connection
= proc_target
;
2825 else if (first_connection
!= proc_target
2826 && first_not_non_stop
!= nullptr)
2828 switch_to_inferior_no_thread (first_not_non_stop
);
2830 proc_target
= current_inferior ()->process_target();
2832 error (_("Connection %d (%s) does not support "
2833 "multi-target resumption."),
2834 proc_target
->connection_number
,
2835 make_target_connection_string (proc_target
).c_str ());
2841 /* Basic routine for continuing the program in various fashions.
2843 ADDR is the address to resume at, or -1 for resume where stopped.
2844 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2845 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2847 You should call clear_proceed_status before calling proceed. */
2850 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2852 struct regcache
*regcache
;
2853 struct gdbarch
*gdbarch
;
2855 struct execution_control_state ecss
;
2856 struct execution_control_state
*ecs
= &ecss
;
2859 /* If we're stopped at a fork/vfork, follow the branch set by the
2860 "set follow-fork-mode" command; otherwise, we'll just proceed
2861 resuming the current thread. */
2862 if (!follow_fork ())
2864 /* The target for some reason decided not to resume. */
2866 if (target_can_async_p ())
2867 inferior_event_handler (INF_EXEC_COMPLETE
);
2871 /* We'll update this if & when we switch to a new thread. */
2872 previous_inferior_ptid
= inferior_ptid
;
2874 regcache
= get_current_regcache ();
2875 gdbarch
= regcache
->arch ();
2876 const address_space
*aspace
= regcache
->aspace ();
2878 pc
= regcache_read_pc_protected (regcache
);
2880 thread_info
*cur_thr
= inferior_thread ();
2882 /* Fill in with reasonable starting values. */
2883 init_thread_stepping_state (cur_thr
);
2885 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2888 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2889 process_stratum_target
*resume_target
2890 = user_visible_resume_target (resume_ptid
);
2892 check_multi_target_resumption (resume_target
);
2894 if (addr
== (CORE_ADDR
) -1)
2896 if (pc
== cur_thr
->suspend
.stop_pc
2897 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2898 && execution_direction
!= EXEC_REVERSE
)
2899 /* There is a breakpoint at the address we will resume at,
2900 step one instruction before inserting breakpoints so that
2901 we do not stop right away (and report a second hit at this
2904 Note, we don't do this in reverse, because we won't
2905 actually be executing the breakpoint insn anyway.
2906 We'll be (un-)executing the previous instruction. */
2907 cur_thr
->stepping_over_breakpoint
= 1;
2908 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2909 && gdbarch_single_step_through_delay (gdbarch
,
2910 get_current_frame ()))
2911 /* We stepped onto an instruction that needs to be stepped
2912 again before re-inserting the breakpoint, do so. */
2913 cur_thr
->stepping_over_breakpoint
= 1;
2917 regcache_write_pc (regcache
, addr
);
2920 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2921 cur_thr
->suspend
.stop_signal
= siggnal
;
2923 /* If an exception is thrown from this point on, make sure to
2924 propagate GDB's knowledge of the executing state to the
2925 frontend/user running state. */
2926 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2928 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2929 threads (e.g., we might need to set threads stepping over
2930 breakpoints first), from the user/frontend's point of view, all
2931 threads in RESUME_PTID are now running. Unless we're calling an
2932 inferior function, as in that case we pretend the inferior
2933 doesn't run at all. */
2934 if (!cur_thr
->control
.in_infcall
)
2935 set_running (resume_target
, resume_ptid
, true);
2937 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
2938 gdb_signal_to_symbol_string (siggnal
));
2940 annotate_starting ();
2942 /* Make sure that output from GDB appears before output from the
2944 gdb_flush (gdb_stdout
);
2946 /* Since we've marked the inferior running, give it the terminal. A
2947 QUIT/Ctrl-C from here on is forwarded to the target (which can
2948 still detect attempts to unblock a stuck connection with repeated
2949 Ctrl-C from within target_pass_ctrlc). */
2950 target_terminal::inferior ();
2952 /* In a multi-threaded task we may select another thread and
2953 then continue or step.
2955 But if a thread that we're resuming had stopped at a breakpoint,
2956 it will immediately cause another breakpoint stop without any
2957 execution (i.e. it will report a breakpoint hit incorrectly). So
2958 we must step over it first.
2960 Look for threads other than the current (TP) that reported a
2961 breakpoint hit and haven't been resumed yet since. */
2963 /* If scheduler locking applies, we can avoid iterating over all
2965 if (!non_stop
&& !schedlock_applies (cur_thr
))
2967 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
2970 switch_to_thread_no_regs (tp
);
2972 /* Ignore the current thread here. It's handled
2977 if (!thread_still_needs_step_over (tp
))
2980 gdb_assert (!thread_is_in_step_over_chain (tp
));
2982 infrun_debug_printf ("need to step-over [%s] first",
2983 target_pid_to_str (tp
->ptid
).c_str ());
2985 global_thread_step_over_chain_enqueue (tp
);
2988 switch_to_thread (cur_thr
);
2991 /* Enqueue the current thread last, so that we move all other
2992 threads over their breakpoints first. */
2993 if (cur_thr
->stepping_over_breakpoint
)
2994 global_thread_step_over_chain_enqueue (cur_thr
);
2996 /* If the thread isn't started, we'll still need to set its prev_pc,
2997 so that switch_back_to_stepped_thread knows the thread hasn't
2998 advanced. Must do this before resuming any thread, as in
2999 all-stop/remote, once we resume we can't send any other packet
3000 until the target stops again. */
3001 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3004 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3006 started
= start_step_over ();
3008 if (step_over_info_valid_p ())
3010 /* Either this thread started a new in-line step over, or some
3011 other thread was already doing one. In either case, don't
3012 resume anything else until the step-over is finished. */
3014 else if (started
&& !target_is_non_stop_p ())
3016 /* A new displaced stepping sequence was started. In all-stop,
3017 we can't talk to the target anymore until it next stops. */
3019 else if (!non_stop
&& target_is_non_stop_p ())
3021 /* In all-stop, but the target is always in non-stop mode.
3022 Start all other threads that are implicitly resumed too. */
3023 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3026 switch_to_thread_no_regs (tp
);
3028 if (!tp
->inf
->has_execution ())
3030 infrun_debug_printf ("[%s] target has no execution",
3031 target_pid_to_str (tp
->ptid
).c_str ());
3037 infrun_debug_printf ("[%s] resumed",
3038 target_pid_to_str (tp
->ptid
).c_str ());
3039 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3043 if (thread_is_in_step_over_chain (tp
))
3045 infrun_debug_printf ("[%s] needs step-over",
3046 target_pid_to_str (tp
->ptid
).c_str ());
3050 infrun_debug_printf ("resuming %s",
3051 target_pid_to_str (tp
->ptid
).c_str ());
3053 reset_ecs (ecs
, tp
);
3054 switch_to_thread (tp
);
3055 keep_going_pass_signal (ecs
);
3056 if (!ecs
->wait_some_more
)
3057 error (_("Command aborted."));
3060 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3062 /* The thread wasn't started, and isn't queued, run it now. */
3063 reset_ecs (ecs
, cur_thr
);
3064 switch_to_thread (cur_thr
);
3065 keep_going_pass_signal (ecs
);
3066 if (!ecs
->wait_some_more
)
3067 error (_("Command aborted."));
3071 commit_resume_all_targets ();
3073 finish_state
.release ();
3075 /* If we've switched threads above, switch back to the previously
3076 current thread. We don't want the user to see a different
3078 switch_to_thread (cur_thr
);
3080 /* Tell the event loop to wait for it to stop. If the target
3081 supports asynchronous execution, it'll do this from within
3083 if (!target_can_async_p ())
3084 mark_async_event_handler (infrun_async_inferior_event_token
);
3088 /* Start remote-debugging of a machine over a serial link. */
3091 start_remote (int from_tty
)
3093 inferior
*inf
= current_inferior ();
3094 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3096 /* Always go on waiting for the target, regardless of the mode. */
3097 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3098 indicate to wait_for_inferior that a target should timeout if
3099 nothing is returned (instead of just blocking). Because of this,
3100 targets expecting an immediate response need to, internally, set
3101 things up so that the target_wait() is forced to eventually
3103 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3104 differentiate to its caller what the state of the target is after
3105 the initial open has been performed. Here we're assuming that
3106 the target has stopped. It should be possible to eventually have
3107 target_open() return to the caller an indication that the target
3108 is currently running and GDB state should be set to the same as
3109 for an async run. */
3110 wait_for_inferior (inf
);
3112 /* Now that the inferior has stopped, do any bookkeeping like
3113 loading shared libraries. We want to do this before normal_stop,
3114 so that the displayed frame is up to date. */
3115 post_create_inferior (from_tty
);
3120 /* Initialize static vars when a new inferior begins. */
3123 init_wait_for_inferior (void)
3125 /* These are meaningless until the first time through wait_for_inferior. */
3127 breakpoint_init_inferior (inf_starting
);
3129 clear_proceed_status (0);
3131 nullify_last_target_wait_ptid ();
3133 previous_inferior_ptid
= inferior_ptid
;
3138 static void handle_inferior_event (struct execution_control_state
*ecs
);
3140 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3141 struct execution_control_state
*ecs
);
3142 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3143 struct execution_control_state
*ecs
);
3144 static void handle_signal_stop (struct execution_control_state
*ecs
);
3145 static void check_exception_resume (struct execution_control_state
*,
3146 struct frame_info
*);
3148 static void end_stepping_range (struct execution_control_state
*ecs
);
3149 static void stop_waiting (struct execution_control_state
*ecs
);
3150 static void keep_going (struct execution_control_state
*ecs
);
3151 static void process_event_stop_test (struct execution_control_state
*ecs
);
3152 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3154 /* This function is attached as a "thread_stop_requested" observer.
3155 Cleanup local state that assumed the PTID was to be resumed, and
3156 report the stop to the frontend. */
3159 infrun_thread_stop_requested (ptid_t ptid
)
3161 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3163 /* PTID was requested to stop. If the thread was already stopped,
3164 but the user/frontend doesn't know about that yet (e.g., the
3165 thread had been temporarily paused for some step-over), set up
3166 for reporting the stop now. */
3167 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3169 if (tp
->state
!= THREAD_RUNNING
)
3174 /* Remove matching threads from the step-over queue, so
3175 start_step_over doesn't try to resume them
3177 if (thread_is_in_step_over_chain (tp
))
3178 global_thread_step_over_chain_remove (tp
);
3180 /* If the thread is stopped, but the user/frontend doesn't
3181 know about that yet, queue a pending event, as if the
3182 thread had just stopped now. Unless the thread already had
3184 if (!tp
->suspend
.waitstatus_pending_p
)
3186 tp
->suspend
.waitstatus_pending_p
= 1;
3187 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3188 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3191 /* Clear the inline-frame state, since we're re-processing the
3193 clear_inline_frame_state (tp
);
3195 /* If this thread was paused because some other thread was
3196 doing an inline-step over, let that finish first. Once
3197 that happens, we'll restart all threads and consume pending
3198 stop events then. */
3199 if (step_over_info_valid_p ())
3202 /* Otherwise we can process the (new) pending event now. Set
3203 it so this pending event is considered by
3210 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3212 if (target_last_proc_target
== tp
->inf
->process_target ()
3213 && target_last_wait_ptid
== tp
->ptid
)
3214 nullify_last_target_wait_ptid ();
3217 /* Delete the step resume, single-step and longjmp/exception resume
3218 breakpoints of TP. */
3221 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3223 delete_step_resume_breakpoint (tp
);
3224 delete_exception_resume_breakpoint (tp
);
3225 delete_single_step_breakpoints (tp
);
3228 /* If the target still has execution, call FUNC for each thread that
3229 just stopped. In all-stop, that's all the non-exited threads; in
3230 non-stop, that's the current thread, only. */
3232 typedef void (*for_each_just_stopped_thread_callback_func
)
3233 (struct thread_info
*tp
);
3236 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3238 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3241 if (target_is_non_stop_p ())
3243 /* If in non-stop mode, only the current thread stopped. */
3244 func (inferior_thread ());
3248 /* In all-stop mode, all threads have stopped. */
3249 for (thread_info
*tp
: all_non_exited_threads ())
3254 /* Delete the step resume and longjmp/exception resume breakpoints of
3255 the threads that just stopped. */
3258 delete_just_stopped_threads_infrun_breakpoints (void)
3260 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3263 /* Delete the single-step breakpoints of the threads that just
3267 delete_just_stopped_threads_single_step_breakpoints (void)
3269 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3275 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3276 const struct target_waitstatus
*ws
)
3278 std::string status_string
= target_waitstatus_to_string (ws
);
3281 /* The text is split over several lines because it was getting too long.
3282 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3283 output as a unit; we want only one timestamp printed if debug_timestamp
3286 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3289 waiton_ptid
.tid ());
3290 if (waiton_ptid
.pid () != -1)
3291 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3292 stb
.printf (", status) =\n");
3293 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3297 target_pid_to_str (result_ptid
).c_str ());
3298 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3300 /* This uses %s in part to handle %'s in the text, but also to avoid
3301 a gcc error: the format attribute requires a string literal. */
3302 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3305 /* Select a thread at random, out of those which are resumed and have
3308 static struct thread_info
*
3309 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3313 auto has_event
= [&] (thread_info
*tp
)
3315 return (tp
->ptid
.matches (waiton_ptid
)
3317 && tp
->suspend
.waitstatus_pending_p
);
3320 /* First see how many events we have. Count only resumed threads
3321 that have an event pending. */
3322 for (thread_info
*tp
: inf
->non_exited_threads ())
3326 if (num_events
== 0)
3329 /* Now randomly pick a thread out of those that have had events. */
3330 int random_selector
= (int) ((num_events
* (double) rand ())
3331 / (RAND_MAX
+ 1.0));
3334 infrun_debug_printf ("Found %d events, selecting #%d",
3335 num_events
, random_selector
);
3337 /* Select the Nth thread that has had an event. */
3338 for (thread_info
*tp
: inf
->non_exited_threads ())
3340 if (random_selector
-- == 0)
3343 gdb_assert_not_reached ("event thread not found");
3346 /* Wrapper for target_wait that first checks whether threads have
3347 pending statuses to report before actually asking the target for
3348 more events. INF is the inferior we're using to call target_wait
3352 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3353 target_waitstatus
*status
, target_wait_flags options
)
3356 struct thread_info
*tp
;
3358 /* We know that we are looking for an event in the target of inferior
3359 INF, but we don't know which thread the event might come from. As
3360 such we want to make sure that INFERIOR_PTID is reset so that none of
3361 the wait code relies on it - doing so is always a mistake. */
3362 switch_to_inferior_no_thread (inf
);
3364 /* First check if there is a resumed thread with a wait status
3366 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3368 tp
= random_pending_event_thread (inf
, ptid
);
3372 infrun_debug_printf ("Waiting for specific thread %s.",
3373 target_pid_to_str (ptid
).c_str ());
3375 /* We have a specific thread to check. */
3376 tp
= find_thread_ptid (inf
, ptid
);
3377 gdb_assert (tp
!= NULL
);
3378 if (!tp
->suspend
.waitstatus_pending_p
)
3383 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3384 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3386 struct regcache
*regcache
= get_thread_regcache (tp
);
3387 struct gdbarch
*gdbarch
= regcache
->arch ();
3391 pc
= regcache_read_pc (regcache
);
3393 if (pc
!= tp
->suspend
.stop_pc
)
3395 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3396 target_pid_to_str (tp
->ptid
).c_str (),
3397 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3398 paddress (gdbarch
, pc
));
3401 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3403 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3404 target_pid_to_str (tp
->ptid
).c_str (),
3405 paddress (gdbarch
, pc
));
3412 infrun_debug_printf ("pending event of %s cancelled.",
3413 target_pid_to_str (tp
->ptid
).c_str ());
3415 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3416 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3422 infrun_debug_printf ("Using pending wait status %s for %s.",
3423 target_waitstatus_to_string
3424 (&tp
->suspend
.waitstatus
).c_str (),
3425 target_pid_to_str (tp
->ptid
).c_str ());
3427 /* Now that we've selected our final event LWP, un-adjust its PC
3428 if it was a software breakpoint (and the target doesn't
3429 always adjust the PC itself). */
3430 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3431 && !target_supports_stopped_by_sw_breakpoint ())
3433 struct regcache
*regcache
;
3434 struct gdbarch
*gdbarch
;
3437 regcache
= get_thread_regcache (tp
);
3438 gdbarch
= regcache
->arch ();
3440 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3445 pc
= regcache_read_pc (regcache
);
3446 regcache_write_pc (regcache
, pc
+ decr_pc
);
3450 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3451 *status
= tp
->suspend
.waitstatus
;
3452 tp
->suspend
.waitstatus_pending_p
= 0;
3454 /* Wake up the event loop again, until all pending events are
3456 if (target_is_async_p ())
3457 mark_async_event_handler (infrun_async_inferior_event_token
);
3461 /* But if we don't find one, we'll have to wait. */
3463 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3465 if (!target_can_async_p ())
3466 options
&= ~TARGET_WNOHANG
;
3468 if (deprecated_target_wait_hook
)
3469 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3471 event_ptid
= target_wait (ptid
, status
, options
);
3476 /* Wrapper for target_wait that first checks whether threads have
3477 pending statuses to report before actually asking the target for
3478 more events. Polls for events from all inferiors/targets. */
3481 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3482 target_wait_flags options
)
3484 int num_inferiors
= 0;
3485 int random_selector
;
3487 /* For fairness, we pick the first inferior/target to poll at random
3488 out of all inferiors that may report events, and then continue
3489 polling the rest of the inferior list starting from that one in a
3490 circular fashion until the whole list is polled once. */
3492 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3494 return (inf
->process_target () != NULL
3495 && ptid_t (inf
->pid
).matches (wait_ptid
));
3498 /* First see how many matching inferiors we have. */
3499 for (inferior
*inf
: all_inferiors ())
3500 if (inferior_matches (inf
))
3503 if (num_inferiors
== 0)
3505 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3509 /* Now randomly pick an inferior out of those that matched. */
3510 random_selector
= (int)
3511 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3513 if (num_inferiors
> 1)
3514 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3515 num_inferiors
, random_selector
);
3517 /* Select the Nth inferior that matched. */
3519 inferior
*selected
= nullptr;
3521 for (inferior
*inf
: all_inferiors ())
3522 if (inferior_matches (inf
))
3523 if (random_selector
-- == 0)
3529 /* Now poll for events out of each of the matching inferior's
3530 targets, starting from the selected one. */
3532 auto do_wait
= [&] (inferior
*inf
)
3534 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3535 ecs
->target
= inf
->process_target ();
3536 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3539 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3540 here spuriously after the target is all stopped and we've already
3541 reported the stop to the user, polling for events. */
3542 scoped_restore_current_thread restore_thread
;
3544 int inf_num
= selected
->num
;
3545 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3546 if (inferior_matches (inf
))
3550 for (inferior
*inf
= inferior_list
;
3551 inf
!= NULL
&& inf
->num
< inf_num
;
3553 if (inferior_matches (inf
))
3557 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3561 /* Prepare and stabilize the inferior for detaching it. E.g.,
3562 detaching while a thread is displaced stepping is a recipe for
3563 crashing it, as nothing would readjust the PC out of the scratch
3567 prepare_for_detach (void)
3569 struct inferior
*inf
= current_inferior ();
3570 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3572 /* Is any thread of this process displaced stepping? If not,
3573 there's nothing else to do. */
3574 if (displaced_step_in_progress (inf
))
3577 infrun_debug_printf ("displaced-stepping in-process while detaching");
3579 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3581 while (displaced_step_in_progress (inf
))
3583 struct execution_control_state ecss
;
3584 struct execution_control_state
*ecs
;
3587 memset (ecs
, 0, sizeof (*ecs
));
3589 overlay_cache_invalid
= 1;
3590 /* Flush target cache before starting to handle each event.
3591 Target was running and cache could be stale. This is just a
3592 heuristic. Running threads may modify target memory, but we
3593 don't get any event. */
3594 target_dcache_invalidate ();
3596 do_target_wait (pid_ptid
, ecs
, 0);
3599 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3601 /* If an error happens while handling the event, propagate GDB's
3602 knowledge of the executing state to the frontend/user running
3604 scoped_finish_thread_state
finish_state (inf
->process_target (),
3607 /* Now figure out what to do with the result of the result. */
3608 handle_inferior_event (ecs
);
3610 /* No error, don't finish the state yet. */
3611 finish_state
.release ();
3613 /* Breakpoints and watchpoints are not installed on the target
3614 at this point, and signals are passed directly to the
3615 inferior, so this must mean the process is gone. */
3616 if (!ecs
->wait_some_more
)
3618 restore_detaching
.release ();
3619 error (_("Program exited while detaching"));
3623 restore_detaching
.release ();
3626 /* Wait for control to return from inferior to debugger.
3628 If inferior gets a signal, we may decide to start it up again
3629 instead of returning. That is why there is a loop in this function.
3630 When this function actually returns it means the inferior
3631 should be left stopped and GDB should read more commands. */
3634 wait_for_inferior (inferior
*inf
)
3636 infrun_debug_printf ("wait_for_inferior ()");
3638 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3640 /* If an error happens while handling the event, propagate GDB's
3641 knowledge of the executing state to the frontend/user running
3643 scoped_finish_thread_state finish_state
3644 (inf
->process_target (), minus_one_ptid
);
3648 struct execution_control_state ecss
;
3649 struct execution_control_state
*ecs
= &ecss
;
3651 memset (ecs
, 0, sizeof (*ecs
));
3653 overlay_cache_invalid
= 1;
3655 /* Flush target cache before starting to handle each event.
3656 Target was running and cache could be stale. This is just a
3657 heuristic. Running threads may modify target memory, but we
3658 don't get any event. */
3659 target_dcache_invalidate ();
3661 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3662 ecs
->target
= inf
->process_target ();
3665 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3667 /* Now figure out what to do with the result of the result. */
3668 handle_inferior_event (ecs
);
3670 if (!ecs
->wait_some_more
)
3674 /* No error, don't finish the state yet. */
3675 finish_state
.release ();
3678 /* Cleanup that reinstalls the readline callback handler, if the
3679 target is running in the background. If while handling the target
3680 event something triggered a secondary prompt, like e.g., a
3681 pagination prompt, we'll have removed the callback handler (see
3682 gdb_readline_wrapper_line). Need to do this as we go back to the
3683 event loop, ready to process further input. Note this has no
3684 effect if the handler hasn't actually been removed, because calling
3685 rl_callback_handler_install resets the line buffer, thus losing
3689 reinstall_readline_callback_handler_cleanup ()
3691 struct ui
*ui
= current_ui
;
3695 /* We're not going back to the top level event loop yet. Don't
3696 install the readline callback, as it'd prep the terminal,
3697 readline-style (raw, noecho) (e.g., --batch). We'll install
3698 it the next time the prompt is displayed, when we're ready
3703 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3704 gdb_rl_callback_handler_reinstall ();
3707 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3708 that's just the event thread. In all-stop, that's all threads. */
3711 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3713 if (ecs
->event_thread
!= NULL
3714 && ecs
->event_thread
->thread_fsm
!= NULL
)
3715 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3719 for (thread_info
*thr
: all_non_exited_threads ())
3721 if (thr
->thread_fsm
== NULL
)
3723 if (thr
== ecs
->event_thread
)
3726 switch_to_thread (thr
);
3727 thr
->thread_fsm
->clean_up (thr
);
3730 if (ecs
->event_thread
!= NULL
)
3731 switch_to_thread (ecs
->event_thread
);
3735 /* Helper for all_uis_check_sync_execution_done that works on the
3739 check_curr_ui_sync_execution_done (void)
3741 struct ui
*ui
= current_ui
;
3743 if (ui
->prompt_state
== PROMPT_NEEDED
3745 && !gdb_in_secondary_prompt_p (ui
))
3747 target_terminal::ours ();
3748 gdb::observers::sync_execution_done
.notify ();
3749 ui_register_input_event_handler (ui
);
3756 all_uis_check_sync_execution_done (void)
3758 SWITCH_THRU_ALL_UIS ()
3760 check_curr_ui_sync_execution_done ();
3767 all_uis_on_sync_execution_starting (void)
3769 SWITCH_THRU_ALL_UIS ()
3771 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3772 async_disable_stdin ();
3776 /* Asynchronous version of wait_for_inferior. It is called by the
3777 event loop whenever a change of state is detected on the file
3778 descriptor corresponding to the target. It can be called more than
3779 once to complete a single execution command. In such cases we need
3780 to keep the state in a global variable ECSS. If it is the last time
3781 that this function is called for a single execution command, then
3782 report to the user that the inferior has stopped, and do the
3783 necessary cleanups. */
3786 fetch_inferior_event ()
3788 struct execution_control_state ecss
;
3789 struct execution_control_state
*ecs
= &ecss
;
3792 memset (ecs
, 0, sizeof (*ecs
));
3794 /* Events are always processed with the main UI as current UI. This
3795 way, warnings, debug output, etc. are always consistently sent to
3796 the main console. */
3797 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3799 /* Temporarily disable pagination. Otherwise, the user would be
3800 given an option to press 'q' to quit, which would cause an early
3801 exit and could leave GDB in a half-baked state. */
3802 scoped_restore save_pagination
3803 = make_scoped_restore (&pagination_enabled
, false);
3805 /* End up with readline processing input, if necessary. */
3807 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3809 /* We're handling a live event, so make sure we're doing live
3810 debugging. If we're looking at traceframes while the target is
3811 running, we're going to need to get back to that mode after
3812 handling the event. */
3813 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3816 maybe_restore_traceframe
.emplace ();
3817 set_current_traceframe (-1);
3820 /* The user/frontend should not notice a thread switch due to
3821 internal events. Make sure we revert to the user selected
3822 thread and frame after handling the event and running any
3823 breakpoint commands. */
3824 scoped_restore_current_thread restore_thread
;
3826 overlay_cache_invalid
= 1;
3827 /* Flush target cache before starting to handle each event. Target
3828 was running and cache could be stale. This is just a heuristic.
3829 Running threads may modify target memory, but we don't get any
3831 target_dcache_invalidate ();
3833 scoped_restore save_exec_dir
3834 = make_scoped_restore (&execution_direction
,
3835 target_execution_direction ());
3837 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3840 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3842 /* Switch to the target that generated the event, so we can do
3844 switch_to_target_no_thread (ecs
->target
);
3847 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3849 /* If an error happens while handling the event, propagate GDB's
3850 knowledge of the executing state to the frontend/user running
3852 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3853 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3855 /* Get executed before scoped_restore_current_thread above to apply
3856 still for the thread which has thrown the exception. */
3857 auto defer_bpstat_clear
3858 = make_scope_exit (bpstat_clear_actions
);
3859 auto defer_delete_threads
3860 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3862 /* Now figure out what to do with the result of the result. */
3863 handle_inferior_event (ecs
);
3865 if (!ecs
->wait_some_more
)
3867 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3868 bool should_stop
= true;
3869 struct thread_info
*thr
= ecs
->event_thread
;
3871 delete_just_stopped_threads_infrun_breakpoints ();
3875 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3877 if (thread_fsm
!= NULL
)
3878 should_stop
= thread_fsm
->should_stop (thr
);
3887 bool should_notify_stop
= true;
3890 clean_up_just_stopped_threads_fsms (ecs
);
3892 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3893 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3895 if (should_notify_stop
)
3897 /* We may not find an inferior if this was a process exit. */
3898 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3899 proceeded
= normal_stop ();
3904 inferior_event_handler (INF_EXEC_COMPLETE
);
3908 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3909 previously selected thread is gone. We have two
3910 choices - switch to no thread selected, or restore the
3911 previously selected thread (now exited). We chose the
3912 later, just because that's what GDB used to do. After
3913 this, "info threads" says "The current thread <Thread
3914 ID 2> has terminated." instead of "No thread
3918 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3919 restore_thread
.dont_restore ();
3923 defer_delete_threads
.release ();
3924 defer_bpstat_clear
.release ();
3926 /* No error, don't finish the thread states yet. */
3927 finish_state
.release ();
3929 /* This scope is used to ensure that readline callbacks are
3930 reinstalled here. */
3933 /* If a UI was in sync execution mode, and now isn't, restore its
3934 prompt (a synchronous execution command has finished, and we're
3935 ready for input). */
3936 all_uis_check_sync_execution_done ();
3939 && exec_done_display_p
3940 && (inferior_ptid
== null_ptid
3941 || inferior_thread ()->state
!= THREAD_RUNNING
))
3942 printf_unfiltered (_("completed.\n"));
3948 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
3949 struct symtab_and_line sal
)
3951 /* This can be removed once this function no longer implicitly relies on the
3952 inferior_ptid value. */
3953 gdb_assert (inferior_ptid
== tp
->ptid
);
3955 tp
->control
.step_frame_id
= get_frame_id (frame
);
3956 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3958 tp
->current_symtab
= sal
.symtab
;
3959 tp
->current_line
= sal
.line
;
3962 /* Clear context switchable stepping state. */
3965 init_thread_stepping_state (struct thread_info
*tss
)
3967 tss
->stepped_breakpoint
= 0;
3968 tss
->stepping_over_breakpoint
= 0;
3969 tss
->stepping_over_watchpoint
= 0;
3970 tss
->step_after_step_resume_breakpoint
= 0;
3976 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
3977 target_waitstatus status
)
3979 target_last_proc_target
= target
;
3980 target_last_wait_ptid
= ptid
;
3981 target_last_waitstatus
= status
;
3987 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
3988 target_waitstatus
*status
)
3990 if (target
!= nullptr)
3991 *target
= target_last_proc_target
;
3992 if (ptid
!= nullptr)
3993 *ptid
= target_last_wait_ptid
;
3994 if (status
!= nullptr)
3995 *status
= target_last_waitstatus
;
4001 nullify_last_target_wait_ptid (void)
4003 target_last_proc_target
= nullptr;
4004 target_last_wait_ptid
= minus_one_ptid
;
4005 target_last_waitstatus
= {};
4008 /* Switch thread contexts. */
4011 context_switch (execution_control_state
*ecs
)
4013 if (ecs
->ptid
!= inferior_ptid
4014 && (inferior_ptid
== null_ptid
4015 || ecs
->event_thread
!= inferior_thread ()))
4017 infrun_debug_printf ("Switching context from %s to %s",
4018 target_pid_to_str (inferior_ptid
).c_str (),
4019 target_pid_to_str (ecs
->ptid
).c_str ());
4022 switch_to_thread (ecs
->event_thread
);
4025 /* If the target can't tell whether we've hit breakpoints
4026 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4027 check whether that could have been caused by a breakpoint. If so,
4028 adjust the PC, per gdbarch_decr_pc_after_break. */
4031 adjust_pc_after_break (struct thread_info
*thread
,
4032 struct target_waitstatus
*ws
)
4034 struct regcache
*regcache
;
4035 struct gdbarch
*gdbarch
;
4036 CORE_ADDR breakpoint_pc
, decr_pc
;
4038 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4039 we aren't, just return.
4041 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4042 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4043 implemented by software breakpoints should be handled through the normal
4046 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4047 different signals (SIGILL or SIGEMT for instance), but it is less
4048 clear where the PC is pointing afterwards. It may not match
4049 gdbarch_decr_pc_after_break. I don't know any specific target that
4050 generates these signals at breakpoints (the code has been in GDB since at
4051 least 1992) so I can not guess how to handle them here.
4053 In earlier versions of GDB, a target with
4054 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4055 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4056 target with both of these set in GDB history, and it seems unlikely to be
4057 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4059 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4062 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4065 /* In reverse execution, when a breakpoint is hit, the instruction
4066 under it has already been de-executed. The reported PC always
4067 points at the breakpoint address, so adjusting it further would
4068 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4071 B1 0x08000000 : INSN1
4072 B2 0x08000001 : INSN2
4074 PC -> 0x08000003 : INSN4
4076 Say you're stopped at 0x08000003 as above. Reverse continuing
4077 from that point should hit B2 as below. Reading the PC when the
4078 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4079 been de-executed already.
4081 B1 0x08000000 : INSN1
4082 B2 PC -> 0x08000001 : INSN2
4086 We can't apply the same logic as for forward execution, because
4087 we would wrongly adjust the PC to 0x08000000, since there's a
4088 breakpoint at PC - 1. We'd then report a hit on B1, although
4089 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4091 if (execution_direction
== EXEC_REVERSE
)
4094 /* If the target can tell whether the thread hit a SW breakpoint,
4095 trust it. Targets that can tell also adjust the PC
4097 if (target_supports_stopped_by_sw_breakpoint ())
4100 /* Note that relying on whether a breakpoint is planted in memory to
4101 determine this can fail. E.g,. the breakpoint could have been
4102 removed since. Or the thread could have been told to step an
4103 instruction the size of a breakpoint instruction, and only
4104 _after_ was a breakpoint inserted at its address. */
4106 /* If this target does not decrement the PC after breakpoints, then
4107 we have nothing to do. */
4108 regcache
= get_thread_regcache (thread
);
4109 gdbarch
= regcache
->arch ();
4111 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4115 const address_space
*aspace
= regcache
->aspace ();
4117 /* Find the location where (if we've hit a breakpoint) the
4118 breakpoint would be. */
4119 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4121 /* If the target can't tell whether a software breakpoint triggered,
4122 fallback to figuring it out based on breakpoints we think were
4123 inserted in the target, and on whether the thread was stepped or
4126 /* Check whether there actually is a software breakpoint inserted at
4129 If in non-stop mode, a race condition is possible where we've
4130 removed a breakpoint, but stop events for that breakpoint were
4131 already queued and arrive later. To suppress those spurious
4132 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4133 and retire them after a number of stop events are reported. Note
4134 this is an heuristic and can thus get confused. The real fix is
4135 to get the "stopped by SW BP and needs adjustment" info out of
4136 the target/kernel (and thus never reach here; see above). */
4137 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4138 || (target_is_non_stop_p ()
4139 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4141 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4143 if (record_full_is_used ())
4144 restore_operation_disable
.emplace
4145 (record_full_gdb_operation_disable_set ());
4147 /* When using hardware single-step, a SIGTRAP is reported for both
4148 a completed single-step and a software breakpoint. Need to
4149 differentiate between the two, as the latter needs adjusting
4150 but the former does not.
4152 The SIGTRAP can be due to a completed hardware single-step only if
4153 - we didn't insert software single-step breakpoints
4154 - this thread is currently being stepped
4156 If any of these events did not occur, we must have stopped due
4157 to hitting a software breakpoint, and have to back up to the
4160 As a special case, we could have hardware single-stepped a
4161 software breakpoint. In this case (prev_pc == breakpoint_pc),
4162 we also need to back up to the breakpoint address. */
4164 if (thread_has_single_step_breakpoints_set (thread
)
4165 || !currently_stepping (thread
)
4166 || (thread
->stepped_breakpoint
4167 && thread
->prev_pc
== breakpoint_pc
))
4168 regcache_write_pc (regcache
, breakpoint_pc
);
4173 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4175 for (frame
= get_prev_frame (frame
);
4177 frame
= get_prev_frame (frame
))
4179 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4182 if (get_frame_type (frame
) != INLINE_FRAME
)
4189 /* Look for an inline frame that is marked for skip.
4190 If PREV_FRAME is TRUE start at the previous frame,
4191 otherwise start at the current frame. Stop at the
4192 first non-inline frame, or at the frame where the
4196 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4198 struct frame_info
*frame
= get_current_frame ();
4201 frame
= get_prev_frame (frame
);
4203 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4205 const char *fn
= NULL
;
4206 symtab_and_line sal
;
4209 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4211 if (get_frame_type (frame
) != INLINE_FRAME
)
4214 sal
= find_frame_sal (frame
);
4215 sym
= get_frame_function (frame
);
4218 fn
= sym
->print_name ();
4221 && function_name_is_marked_for_skip (fn
, sal
))
4228 /* If the event thread has the stop requested flag set, pretend it
4229 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4233 handle_stop_requested (struct execution_control_state
*ecs
)
4235 if (ecs
->event_thread
->stop_requested
)
4237 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4238 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4239 handle_signal_stop (ecs
);
4245 /* Auxiliary function that handles syscall entry/return events.
4246 It returns true if the inferior should keep going (and GDB
4247 should ignore the event), or false if the event deserves to be
4251 handle_syscall_event (struct execution_control_state
*ecs
)
4253 struct regcache
*regcache
;
4256 context_switch (ecs
);
4258 regcache
= get_thread_regcache (ecs
->event_thread
);
4259 syscall_number
= ecs
->ws
.value
.syscall_number
;
4260 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4262 if (catch_syscall_enabled () > 0
4263 && catching_syscall_number (syscall_number
) > 0)
4265 infrun_debug_printf ("syscall number=%d", syscall_number
);
4267 ecs
->event_thread
->control
.stop_bpstat
4268 = bpstat_stop_status (regcache
->aspace (),
4269 ecs
->event_thread
->suspend
.stop_pc
,
4270 ecs
->event_thread
, &ecs
->ws
);
4272 if (handle_stop_requested (ecs
))
4275 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4277 /* Catchpoint hit. */
4282 if (handle_stop_requested (ecs
))
4285 /* If no catchpoint triggered for this, then keep going. */
4291 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4294 fill_in_stop_func (struct gdbarch
*gdbarch
,
4295 struct execution_control_state
*ecs
)
4297 if (!ecs
->stop_func_filled_in
)
4300 const general_symbol_info
*gsi
;
4302 /* Don't care about return value; stop_func_start and stop_func_name
4303 will both be 0 if it doesn't work. */
4304 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4306 &ecs
->stop_func_start
,
4307 &ecs
->stop_func_end
,
4309 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4311 /* The call to find_pc_partial_function, above, will set
4312 stop_func_start and stop_func_end to the start and end
4313 of the range containing the stop pc. If this range
4314 contains the entry pc for the block (which is always the
4315 case for contiguous blocks), advance stop_func_start past
4316 the function's start offset and entrypoint. Note that
4317 stop_func_start is NOT advanced when in a range of a
4318 non-contiguous block that does not contain the entry pc. */
4319 if (block
!= nullptr
4320 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4321 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4323 ecs
->stop_func_start
4324 += gdbarch_deprecated_function_start_offset (gdbarch
);
4326 if (gdbarch_skip_entrypoint_p (gdbarch
))
4327 ecs
->stop_func_start
4328 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4331 ecs
->stop_func_filled_in
= 1;
4336 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4338 static enum stop_kind
4339 get_inferior_stop_soon (execution_control_state
*ecs
)
4341 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4343 gdb_assert (inf
!= NULL
);
4344 return inf
->control
.stop_soon
;
4347 /* Poll for one event out of the current target. Store the resulting
4348 waitstatus in WS, and return the event ptid. Does not block. */
4351 poll_one_curr_target (struct target_waitstatus
*ws
)
4355 overlay_cache_invalid
= 1;
4357 /* Flush target cache before starting to handle each event.
4358 Target was running and cache could be stale. This is just a
4359 heuristic. Running threads may modify target memory, but we
4360 don't get any event. */
4361 target_dcache_invalidate ();
4363 if (deprecated_target_wait_hook
)
4364 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4366 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4369 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4374 /* An event reported by wait_one. */
4376 struct wait_one_event
4378 /* The target the event came out of. */
4379 process_stratum_target
*target
;
4381 /* The PTID the event was for. */
4384 /* The waitstatus. */
4385 target_waitstatus ws
;
4388 /* Wait for one event out of any target. */
4390 static wait_one_event
4395 for (inferior
*inf
: all_inferiors ())
4397 process_stratum_target
*target
= inf
->process_target ();
4399 || !target
->is_async_p ()
4400 || !target
->threads_executing
)
4403 switch_to_inferior_no_thread (inf
);
4405 wait_one_event event
;
4406 event
.target
= target
;
4407 event
.ptid
= poll_one_curr_target (&event
.ws
);
4409 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4411 /* If nothing is resumed, remove the target from the
4415 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4419 /* Block waiting for some event. */
4426 for (inferior
*inf
: all_inferiors ())
4428 process_stratum_target
*target
= inf
->process_target ();
4430 || !target
->is_async_p ()
4431 || !target
->threads_executing
)
4434 int fd
= target
->async_wait_fd ();
4435 FD_SET (fd
, &readfds
);
4442 /* No waitable targets left. All must be stopped. */
4443 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4448 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4454 perror_with_name ("interruptible_select");
4459 /* Save the thread's event and stop reason to process it later. */
4462 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4464 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4465 target_waitstatus_to_string (ws
).c_str (),
4470 /* Record for later. */
4471 tp
->suspend
.waitstatus
= *ws
;
4472 tp
->suspend
.waitstatus_pending_p
= 1;
4474 struct regcache
*regcache
= get_thread_regcache (tp
);
4475 const address_space
*aspace
= regcache
->aspace ();
4477 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4478 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4480 CORE_ADDR pc
= regcache_read_pc (regcache
);
4482 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4484 scoped_restore_current_thread restore_thread
;
4485 switch_to_thread (tp
);
4487 if (target_stopped_by_watchpoint ())
4489 tp
->suspend
.stop_reason
4490 = TARGET_STOPPED_BY_WATCHPOINT
;
4492 else if (target_supports_stopped_by_sw_breakpoint ()
4493 && target_stopped_by_sw_breakpoint ())
4495 tp
->suspend
.stop_reason
4496 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4498 else if (target_supports_stopped_by_hw_breakpoint ()
4499 && target_stopped_by_hw_breakpoint ())
4501 tp
->suspend
.stop_reason
4502 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4504 else if (!target_supports_stopped_by_hw_breakpoint ()
4505 && hardware_breakpoint_inserted_here_p (aspace
,
4508 tp
->suspend
.stop_reason
4509 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4511 else if (!target_supports_stopped_by_sw_breakpoint ()
4512 && software_breakpoint_inserted_here_p (aspace
,
4515 tp
->suspend
.stop_reason
4516 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4518 else if (!thread_has_single_step_breakpoints_set (tp
)
4519 && currently_stepping (tp
))
4521 tp
->suspend
.stop_reason
4522 = TARGET_STOPPED_BY_SINGLE_STEP
;
4527 /* Mark the non-executing threads accordingly. In all-stop, all
4528 threads of all processes are stopped when we get any event
4529 reported. In non-stop mode, only the event thread stops. */
4532 mark_non_executing_threads (process_stratum_target
*target
,
4534 struct target_waitstatus ws
)
4538 if (!target_is_non_stop_p ())
4539 mark_ptid
= minus_one_ptid
;
4540 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4541 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4543 /* If we're handling a process exit in non-stop mode, even
4544 though threads haven't been deleted yet, one would think
4545 that there is nothing to do, as threads of the dead process
4546 will be soon deleted, and threads of any other process were
4547 left running. However, on some targets, threads survive a
4548 process exit event. E.g., for the "checkpoint" command,
4549 when the current checkpoint/fork exits, linux-fork.c
4550 automatically switches to another fork from within
4551 target_mourn_inferior, by associating the same
4552 inferior/thread to another fork. We haven't mourned yet at
4553 this point, but we must mark any threads left in the
4554 process as not-executing so that finish_thread_state marks
4555 them stopped (in the user's perspective) if/when we present
4556 the stop to the user. */
4557 mark_ptid
= ptid_t (event_ptid
.pid ());
4560 mark_ptid
= event_ptid
;
4562 set_executing (target
, mark_ptid
, false);
4564 /* Likewise the resumed flag. */
4565 set_resumed (target
, mark_ptid
, false);
4571 stop_all_threads (void)
4573 /* We may need multiple passes to discover all threads. */
4577 gdb_assert (exists_non_stop_target ());
4579 infrun_debug_printf ("starting");
4581 scoped_restore_current_thread restore_thread
;
4583 /* Enable thread events of all targets. */
4584 for (auto *target
: all_non_exited_process_targets ())
4586 switch_to_target_no_thread (target
);
4587 target_thread_events (true);
4592 /* Disable thread events of all targets. */
4593 for (auto *target
: all_non_exited_process_targets ())
4595 switch_to_target_no_thread (target
);
4596 target_thread_events (false);
4599 /* Use debug_prefixed_printf directly to get a meaningful function
4602 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
4605 /* Request threads to stop, and then wait for the stops. Because
4606 threads we already know about can spawn more threads while we're
4607 trying to stop them, and we only learn about new threads when we
4608 update the thread list, do this in a loop, and keep iterating
4609 until two passes find no threads that need to be stopped. */
4610 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4612 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4615 int waits_needed
= 0;
4617 for (auto *target
: all_non_exited_process_targets ())
4619 switch_to_target_no_thread (target
);
4620 update_thread_list ();
4623 /* Go through all threads looking for threads that we need
4624 to tell the target to stop. */
4625 for (thread_info
*t
: all_non_exited_threads ())
4627 /* For a single-target setting with an all-stop target,
4628 we would not even arrive here. For a multi-target
4629 setting, until GDB is able to handle a mixture of
4630 all-stop and non-stop targets, simply skip all-stop
4631 targets' threads. This should be fine due to the
4632 protection of 'check_multi_target_resumption'. */
4634 switch_to_thread_no_regs (t
);
4635 if (!target_is_non_stop_p ())
4640 /* If already stopping, don't request a stop again.
4641 We just haven't seen the notification yet. */
4642 if (!t
->stop_requested
)
4644 infrun_debug_printf (" %s executing, need stop",
4645 target_pid_to_str (t
->ptid
).c_str ());
4646 target_stop (t
->ptid
);
4647 t
->stop_requested
= 1;
4651 infrun_debug_printf (" %s executing, already stopping",
4652 target_pid_to_str (t
->ptid
).c_str ());
4655 if (t
->stop_requested
)
4660 infrun_debug_printf (" %s not executing",
4661 target_pid_to_str (t
->ptid
).c_str ());
4663 /* The thread may be not executing, but still be
4664 resumed with a pending status to process. */
4669 if (waits_needed
== 0)
4672 /* If we find new threads on the second iteration, restart
4673 over. We want to see two iterations in a row with all
4678 for (int i
= 0; i
< waits_needed
; i
++)
4680 wait_one_event event
= wait_one ();
4683 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4684 target_pid_to_str (event
.ptid
).c_str ());
4686 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4688 /* All resumed threads exited. */
4691 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4692 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4693 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4695 /* One thread/process exited/signalled. */
4697 thread_info
*t
= nullptr;
4699 /* The target may have reported just a pid. If so, try
4700 the first non-exited thread. */
4701 if (event
.ptid
.is_pid ())
4703 int pid
= event
.ptid
.pid ();
4704 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4705 for (thread_info
*tp
: inf
->non_exited_threads ())
4711 /* If there is no available thread, the event would
4712 have to be appended to a per-inferior event list,
4713 which does not exist (and if it did, we'd have
4714 to adjust run control command to be able to
4715 resume such an inferior). We assert here instead
4716 of going into an infinite loop. */
4717 gdb_assert (t
!= nullptr);
4720 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4724 t
= find_thread_ptid (event
.target
, event
.ptid
);
4725 /* Check if this is the first time we see this thread.
4726 Don't bother adding if it individually exited. */
4728 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4729 t
= add_thread (event
.target
, event
.ptid
);
4734 /* Set the threads as non-executing to avoid
4735 another stop attempt on them. */
4736 switch_to_thread_no_regs (t
);
4737 mark_non_executing_threads (event
.target
, event
.ptid
,
4739 save_waitstatus (t
, &event
.ws
);
4740 t
->stop_requested
= false;
4745 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4747 t
= add_thread (event
.target
, event
.ptid
);
4749 t
->stop_requested
= 0;
4752 t
->control
.may_range_step
= 0;
4754 /* This may be the first time we see the inferior report
4756 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4757 if (inf
->needs_setup
)
4759 switch_to_thread_no_regs (t
);
4763 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4764 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4766 /* We caught the event that we intended to catch, so
4767 there's no event pending. */
4768 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4769 t
->suspend
.waitstatus_pending_p
= 0;
4771 if (displaced_step_finish (t
, GDB_SIGNAL_0
)
4772 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4774 /* Add it back to the step-over queue. */
4776 ("displaced-step of %s canceled: adding back to "
4777 "the step-over queue",
4778 target_pid_to_str (t
->ptid
).c_str ());
4780 t
->control
.trap_expected
= 0;
4781 global_thread_step_over_chain_enqueue (t
);
4786 enum gdb_signal sig
;
4787 struct regcache
*regcache
;
4790 ("target_wait %s, saving status for %d.%ld.%ld",
4791 target_waitstatus_to_string (&event
.ws
).c_str (),
4792 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4794 /* Record for later. */
4795 save_waitstatus (t
, &event
.ws
);
4797 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4798 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4800 if (displaced_step_finish (t
, sig
)
4801 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4803 /* Add it back to the step-over queue. */
4804 t
->control
.trap_expected
= 0;
4805 global_thread_step_over_chain_enqueue (t
);
4808 regcache
= get_thread_regcache (t
);
4809 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4811 infrun_debug_printf ("saved stop_pc=%s for %s "
4812 "(currently_stepping=%d)",
4813 paddress (target_gdbarch (),
4814 t
->suspend
.stop_pc
),
4815 target_pid_to_str (t
->ptid
).c_str (),
4816 currently_stepping (t
));
4824 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4827 handle_no_resumed (struct execution_control_state
*ecs
)
4829 if (target_can_async_p ())
4831 bool any_sync
= false;
4833 for (ui
*ui
: all_uis ())
4835 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4843 /* There were no unwaited-for children left in the target, but,
4844 we're not synchronously waiting for events either. Just
4847 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4848 prepare_to_wait (ecs
);
4853 /* Otherwise, if we were running a synchronous execution command, we
4854 may need to cancel it and give the user back the terminal.
4856 In non-stop mode, the target can't tell whether we've already
4857 consumed previous stop events, so it can end up sending us a
4858 no-resumed event like so:
4860 #0 - thread 1 is left stopped
4862 #1 - thread 2 is resumed and hits breakpoint
4863 -> TARGET_WAITKIND_STOPPED
4865 #2 - thread 3 is resumed and exits
4866 this is the last resumed thread, so
4867 -> TARGET_WAITKIND_NO_RESUMED
4869 #3 - gdb processes stop for thread 2 and decides to re-resume
4872 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4873 thread 2 is now resumed, so the event should be ignored.
4875 IOW, if the stop for thread 2 doesn't end a foreground command,
4876 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4877 event. But it could be that the event meant that thread 2 itself
4878 (or whatever other thread was the last resumed thread) exited.
4880 To address this we refresh the thread list and check whether we
4881 have resumed threads _now_. In the example above, this removes
4882 thread 3 from the thread list. If thread 2 was re-resumed, we
4883 ignore this event. If we find no thread resumed, then we cancel
4884 the synchronous command and show "no unwaited-for " to the
4887 inferior
*curr_inf
= current_inferior ();
4889 scoped_restore_current_thread restore_thread
;
4891 for (auto *target
: all_non_exited_process_targets ())
4893 switch_to_target_no_thread (target
);
4894 update_thread_list ();
4899 - the current target has no thread executing, and
4900 - the current inferior is native, and
4901 - the current inferior is the one which has the terminal, and
4904 then a Ctrl-C from this point on would remain stuck in the
4905 kernel, until a thread resumes and dequeues it. That would
4906 result in the GDB CLI not reacting to Ctrl-C, not able to
4907 interrupt the program. To address this, if the current inferior
4908 no longer has any thread executing, we give the terminal to some
4909 other inferior that has at least one thread executing. */
4910 bool swap_terminal
= true;
4912 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4913 whether to report it to the user. */
4914 bool ignore_event
= false;
4916 for (thread_info
*thread
: all_non_exited_threads ())
4918 if (swap_terminal
&& thread
->executing
)
4920 if (thread
->inf
!= curr_inf
)
4922 target_terminal::ours ();
4924 switch_to_thread (thread
);
4925 target_terminal::inferior ();
4927 swap_terminal
= false;
4931 && (thread
->executing
4932 || thread
->suspend
.waitstatus_pending_p
))
4934 /* Either there were no unwaited-for children left in the
4935 target at some point, but there are now, or some target
4936 other than the eventing one has unwaited-for children
4937 left. Just ignore. */
4938 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
4939 "(ignoring: found resumed)");
4941 ignore_event
= true;
4944 if (ignore_event
&& !swap_terminal
)
4950 switch_to_inferior_no_thread (curr_inf
);
4951 prepare_to_wait (ecs
);
4955 /* Go ahead and report the event. */
4959 /* Given an execution control state that has been freshly filled in by
4960 an event from the inferior, figure out what it means and take
4963 The alternatives are:
4965 1) stop_waiting and return; to really stop and return to the
4968 2) keep_going and return; to wait for the next event (set
4969 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4973 handle_inferior_event (struct execution_control_state
*ecs
)
4975 /* Make sure that all temporary struct value objects that were
4976 created during the handling of the event get deleted at the
4978 scoped_value_mark free_values
;
4980 enum stop_kind stop_soon
;
4982 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
4984 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4986 /* We had an event in the inferior, but we are not interested in
4987 handling it at this level. The lower layers have already
4988 done what needs to be done, if anything.
4990 One of the possible circumstances for this is when the
4991 inferior produces output for the console. The inferior has
4992 not stopped, and we are ignoring the event. Another possible
4993 circumstance is any event which the lower level knows will be
4994 reported multiple times without an intervening resume. */
4995 prepare_to_wait (ecs
);
4999 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5001 prepare_to_wait (ecs
);
5005 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5006 && handle_no_resumed (ecs
))
5009 /* Cache the last target/ptid/waitstatus. */
5010 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5012 /* Always clear state belonging to the previous time we stopped. */
5013 stop_stack_dummy
= STOP_NONE
;
5015 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5017 /* No unwaited-for children left. IOW, all resumed children
5019 stop_print_frame
= false;
5024 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5025 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5027 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5028 /* If it's a new thread, add it to the thread database. */
5029 if (ecs
->event_thread
== NULL
)
5030 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5032 /* Disable range stepping. If the next step request could use a
5033 range, this will be end up re-enabled then. */
5034 ecs
->event_thread
->control
.may_range_step
= 0;
5037 /* Dependent on valid ECS->EVENT_THREAD. */
5038 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5040 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5041 reinit_frame_cache ();
5043 breakpoint_retire_moribund ();
5045 /* First, distinguish signals caused by the debugger from signals
5046 that have to do with the program's own actions. Note that
5047 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5048 on the operating system version. Here we detect when a SIGILL or
5049 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5050 something similar for SIGSEGV, since a SIGSEGV will be generated
5051 when we're trying to execute a breakpoint instruction on a
5052 non-executable stack. This happens for call dummy breakpoints
5053 for architectures like SPARC that place call dummies on the
5055 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5056 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5057 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5058 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5060 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5062 if (breakpoint_inserted_here_p (regcache
->aspace (),
5063 regcache_read_pc (regcache
)))
5065 infrun_debug_printf ("Treating signal as SIGTRAP");
5066 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5070 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5072 switch (ecs
->ws
.kind
)
5074 case TARGET_WAITKIND_LOADED
:
5075 context_switch (ecs
);
5076 /* Ignore gracefully during startup of the inferior, as it might
5077 be the shell which has just loaded some objects, otherwise
5078 add the symbols for the newly loaded objects. Also ignore at
5079 the beginning of an attach or remote session; we will query
5080 the full list of libraries once the connection is
5083 stop_soon
= get_inferior_stop_soon (ecs
);
5084 if (stop_soon
== NO_STOP_QUIETLY
)
5086 struct regcache
*regcache
;
5088 regcache
= get_thread_regcache (ecs
->event_thread
);
5090 handle_solib_event ();
5092 ecs
->event_thread
->control
.stop_bpstat
5093 = bpstat_stop_status (regcache
->aspace (),
5094 ecs
->event_thread
->suspend
.stop_pc
,
5095 ecs
->event_thread
, &ecs
->ws
);
5097 if (handle_stop_requested (ecs
))
5100 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5102 /* A catchpoint triggered. */
5103 process_event_stop_test (ecs
);
5107 /* If requested, stop when the dynamic linker notifies
5108 gdb of events. This allows the user to get control
5109 and place breakpoints in initializer routines for
5110 dynamically loaded objects (among other things). */
5111 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5112 if (stop_on_solib_events
)
5114 /* Make sure we print "Stopped due to solib-event" in
5116 stop_print_frame
= true;
5123 /* If we are skipping through a shell, or through shared library
5124 loading that we aren't interested in, resume the program. If
5125 we're running the program normally, also resume. */
5126 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5128 /* Loading of shared libraries might have changed breakpoint
5129 addresses. Make sure new breakpoints are inserted. */
5130 if (stop_soon
== NO_STOP_QUIETLY
)
5131 insert_breakpoints ();
5132 resume (GDB_SIGNAL_0
);
5133 prepare_to_wait (ecs
);
5137 /* But stop if we're attaching or setting up a remote
5139 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5140 || stop_soon
== STOP_QUIETLY_REMOTE
)
5142 infrun_debug_printf ("quietly stopped");
5147 internal_error (__FILE__
, __LINE__
,
5148 _("unhandled stop_soon: %d"), (int) stop_soon
);
5150 case TARGET_WAITKIND_SPURIOUS
:
5151 if (handle_stop_requested (ecs
))
5153 context_switch (ecs
);
5154 resume (GDB_SIGNAL_0
);
5155 prepare_to_wait (ecs
);
5158 case TARGET_WAITKIND_THREAD_CREATED
:
5159 if (handle_stop_requested (ecs
))
5161 context_switch (ecs
);
5162 if (!switch_back_to_stepped_thread (ecs
))
5166 case TARGET_WAITKIND_EXITED
:
5167 case TARGET_WAITKIND_SIGNALLED
:
5169 /* Depending on the system, ecs->ptid may point to a thread or
5170 to a process. On some targets, target_mourn_inferior may
5171 need to have access to the just-exited thread. That is the
5172 case of GNU/Linux's "checkpoint" support, for example.
5173 Call the switch_to_xxx routine as appropriate. */
5174 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5176 switch_to_thread (thr
);
5179 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5180 switch_to_inferior_no_thread (inf
);
5183 handle_vfork_child_exec_or_exit (0);
5184 target_terminal::ours (); /* Must do this before mourn anyway. */
5186 /* Clearing any previous state of convenience variables. */
5187 clear_exit_convenience_vars ();
5189 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5191 /* Record the exit code in the convenience variable $_exitcode, so
5192 that the user can inspect this again later. */
5193 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5194 (LONGEST
) ecs
->ws
.value
.integer
);
5196 /* Also record this in the inferior itself. */
5197 current_inferior ()->has_exit_code
= 1;
5198 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5200 /* Support the --return-child-result option. */
5201 return_child_result_value
= ecs
->ws
.value
.integer
;
5203 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5207 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5209 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5211 /* Set the value of the internal variable $_exitsignal,
5212 which holds the signal uncaught by the inferior. */
5213 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5214 gdbarch_gdb_signal_to_target (gdbarch
,
5215 ecs
->ws
.value
.sig
));
5219 /* We don't have access to the target's method used for
5220 converting between signal numbers (GDB's internal
5221 representation <-> target's representation).
5222 Therefore, we cannot do a good job at displaying this
5223 information to the user. It's better to just warn
5224 her about it (if infrun debugging is enabled), and
5226 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5230 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5233 gdb_flush (gdb_stdout
);
5234 target_mourn_inferior (inferior_ptid
);
5235 stop_print_frame
= false;
5239 case TARGET_WAITKIND_FORKED
:
5240 case TARGET_WAITKIND_VFORKED
:
5241 /* Check whether the inferior is displaced stepping. */
5243 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5244 struct gdbarch
*gdbarch
= regcache
->arch ();
5245 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5247 /* If this is a fork (child gets its own address space copy) and some
5248 displaced step buffers were in use at the time of the fork, restore
5249 the displaced step buffer bytes in the child process. */
5250 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5251 gdbarch_displaced_step_restore_all_in_ptid
5252 (gdbarch
, parent_inf
, ecs
->ws
.value
.related_pid
);
5254 /* If displaced stepping is supported, and thread ecs->ptid is
5255 displaced stepping. */
5256 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5258 struct regcache
*child_regcache
;
5259 CORE_ADDR parent_pc
;
5261 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5262 indicating that the displaced stepping of syscall instruction
5263 has been done. Perform cleanup for parent process here. Note
5264 that this operation also cleans up the child process for vfork,
5265 because their pages are shared. */
5266 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5267 /* Start a new step-over in another thread if there's one
5271 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5272 the child's PC is also within the scratchpad. Set the child's PC
5273 to the parent's PC value, which has already been fixed up.
5274 FIXME: we use the parent's aspace here, although we're touching
5275 the child, because the child hasn't been added to the inferior
5276 list yet at this point. */
5279 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5280 ecs
->ws
.value
.related_pid
,
5282 parent_inf
->aspace
);
5283 /* Read PC value of parent process. */
5284 parent_pc
= regcache_read_pc (regcache
);
5286 displaced_debug_printf ("write child pc from %s to %s",
5288 regcache_read_pc (child_regcache
)),
5289 paddress (gdbarch
, parent_pc
));
5291 regcache_write_pc (child_regcache
, parent_pc
);
5295 context_switch (ecs
);
5297 /* Immediately detach breakpoints from the child before there's
5298 any chance of letting the user delete breakpoints from the
5299 breakpoint lists. If we don't do this early, it's easy to
5300 leave left over traps in the child, vis: "break foo; catch
5301 fork; c; <fork>; del; c; <child calls foo>". We only follow
5302 the fork on the last `continue', and by that time the
5303 breakpoint at "foo" is long gone from the breakpoint table.
5304 If we vforked, then we don't need to unpatch here, since both
5305 parent and child are sharing the same memory pages; we'll
5306 need to unpatch at follow/detach time instead to be certain
5307 that new breakpoints added between catchpoint hit time and
5308 vfork follow are detached. */
5309 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5311 /* This won't actually modify the breakpoint list, but will
5312 physically remove the breakpoints from the child. */
5313 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5316 delete_just_stopped_threads_single_step_breakpoints ();
5318 /* In case the event is caught by a catchpoint, remember that
5319 the event is to be followed at the next resume of the thread,
5320 and not immediately. */
5321 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5323 ecs
->event_thread
->suspend
.stop_pc
5324 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5326 ecs
->event_thread
->control
.stop_bpstat
5327 = bpstat_stop_status (get_current_regcache ()->aspace (),
5328 ecs
->event_thread
->suspend
.stop_pc
,
5329 ecs
->event_thread
, &ecs
->ws
);
5331 if (handle_stop_requested (ecs
))
5334 /* If no catchpoint triggered for this, then keep going. Note
5335 that we're interested in knowing the bpstat actually causes a
5336 stop, not just if it may explain the signal. Software
5337 watchpoints, for example, always appear in the bpstat. */
5338 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5341 = (follow_fork_mode_string
== follow_fork_mode_child
);
5343 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5345 process_stratum_target
*targ
5346 = ecs
->event_thread
->inf
->process_target ();
5348 bool should_resume
= follow_fork ();
5350 /* Note that one of these may be an invalid pointer,
5351 depending on detach_fork. */
5352 thread_info
*parent
= ecs
->event_thread
;
5354 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5356 /* At this point, the parent is marked running, and the
5357 child is marked stopped. */
5359 /* If not resuming the parent, mark it stopped. */
5360 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5361 parent
->set_running (false);
5363 /* If resuming the child, mark it running. */
5364 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5365 child
->set_running (true);
5367 /* In non-stop mode, also resume the other branch. */
5368 if (!detach_fork
&& (non_stop
5369 || (sched_multi
&& target_is_non_stop_p ())))
5372 switch_to_thread (parent
);
5374 switch_to_thread (child
);
5376 ecs
->event_thread
= inferior_thread ();
5377 ecs
->ptid
= inferior_ptid
;
5382 switch_to_thread (child
);
5384 switch_to_thread (parent
);
5386 ecs
->event_thread
= inferior_thread ();
5387 ecs
->ptid
= inferior_ptid
;
5395 process_event_stop_test (ecs
);
5398 case TARGET_WAITKIND_VFORK_DONE
:
5399 /* Done with the shared memory region. Re-insert breakpoints in
5400 the parent, and keep going. */
5402 context_switch (ecs
);
5404 current_inferior ()->waiting_for_vfork_done
= 0;
5405 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5407 if (handle_stop_requested (ecs
))
5410 /* This also takes care of reinserting breakpoints in the
5411 previously locked inferior. */
5415 case TARGET_WAITKIND_EXECD
:
5417 /* Note we can't read registers yet (the stop_pc), because we
5418 don't yet know the inferior's post-exec architecture.
5419 'stop_pc' is explicitly read below instead. */
5420 switch_to_thread_no_regs (ecs
->event_thread
);
5422 /* Do whatever is necessary to the parent branch of the vfork. */
5423 handle_vfork_child_exec_or_exit (1);
5425 /* This causes the eventpoints and symbol table to be reset.
5426 Must do this now, before trying to determine whether to
5428 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5430 /* In follow_exec we may have deleted the original thread and
5431 created a new one. Make sure that the event thread is the
5432 execd thread for that case (this is a nop otherwise). */
5433 ecs
->event_thread
= inferior_thread ();
5435 ecs
->event_thread
->suspend
.stop_pc
5436 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5438 ecs
->event_thread
->control
.stop_bpstat
5439 = bpstat_stop_status (get_current_regcache ()->aspace (),
5440 ecs
->event_thread
->suspend
.stop_pc
,
5441 ecs
->event_thread
, &ecs
->ws
);
5443 /* Note that this may be referenced from inside
5444 bpstat_stop_status above, through inferior_has_execd. */
5445 xfree (ecs
->ws
.value
.execd_pathname
);
5446 ecs
->ws
.value
.execd_pathname
= NULL
;
5448 if (handle_stop_requested (ecs
))
5451 /* If no catchpoint triggered for this, then keep going. */
5452 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5454 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5458 process_event_stop_test (ecs
);
5461 /* Be careful not to try to gather much state about a thread
5462 that's in a syscall. It's frequently a losing proposition. */
5463 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5464 /* Getting the current syscall number. */
5465 if (handle_syscall_event (ecs
) == 0)
5466 process_event_stop_test (ecs
);
5469 /* Before examining the threads further, step this thread to
5470 get it entirely out of the syscall. (We get notice of the
5471 event when the thread is just on the verge of exiting a
5472 syscall. Stepping one instruction seems to get it back
5474 case TARGET_WAITKIND_SYSCALL_RETURN
:
5475 if (handle_syscall_event (ecs
) == 0)
5476 process_event_stop_test (ecs
);
5479 case TARGET_WAITKIND_STOPPED
:
5480 handle_signal_stop (ecs
);
5483 case TARGET_WAITKIND_NO_HISTORY
:
5484 /* Reverse execution: target ran out of history info. */
5486 /* Switch to the stopped thread. */
5487 context_switch (ecs
);
5488 infrun_debug_printf ("stopped");
5490 delete_just_stopped_threads_single_step_breakpoints ();
5491 ecs
->event_thread
->suspend
.stop_pc
5492 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5494 if (handle_stop_requested (ecs
))
5497 gdb::observers::no_history
.notify ();
5503 /* Restart threads back to what they were trying to do back when we
5504 paused them for an in-line step-over. The EVENT_THREAD thread is
5508 restart_threads (struct thread_info
*event_thread
)
5510 /* In case the instruction just stepped spawned a new thread. */
5511 update_thread_list ();
5513 for (thread_info
*tp
: all_non_exited_threads ())
5515 switch_to_thread_no_regs (tp
);
5517 if (tp
== event_thread
)
5519 infrun_debug_printf ("restart threads: [%s] is event thread",
5520 target_pid_to_str (tp
->ptid
).c_str ());
5524 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5526 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5527 target_pid_to_str (tp
->ptid
).c_str ());
5533 infrun_debug_printf ("restart threads: [%s] resumed",
5534 target_pid_to_str (tp
->ptid
).c_str ());
5535 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5539 if (thread_is_in_step_over_chain (tp
))
5541 infrun_debug_printf ("restart threads: [%s] needs step-over",
5542 target_pid_to_str (tp
->ptid
).c_str ());
5543 gdb_assert (!tp
->resumed
);
5548 if (tp
->suspend
.waitstatus_pending_p
)
5550 infrun_debug_printf ("restart threads: [%s] has pending status",
5551 target_pid_to_str (tp
->ptid
).c_str ());
5556 gdb_assert (!tp
->stop_requested
);
5558 /* If some thread needs to start a step-over at this point, it
5559 should still be in the step-over queue, and thus skipped
5561 if (thread_still_needs_step_over (tp
))
5563 internal_error (__FILE__
, __LINE__
,
5564 "thread [%s] needs a step-over, but not in "
5565 "step-over queue\n",
5566 target_pid_to_str (tp
->ptid
).c_str ());
5569 if (currently_stepping (tp
))
5571 infrun_debug_printf ("restart threads: [%s] was stepping",
5572 target_pid_to_str (tp
->ptid
).c_str ());
5573 keep_going_stepped_thread (tp
);
5577 struct execution_control_state ecss
;
5578 struct execution_control_state
*ecs
= &ecss
;
5580 infrun_debug_printf ("restart threads: [%s] continuing",
5581 target_pid_to_str (tp
->ptid
).c_str ());
5582 reset_ecs (ecs
, tp
);
5583 switch_to_thread (tp
);
5584 keep_going_pass_signal (ecs
);
5589 /* Callback for iterate_over_threads. Find a resumed thread that has
5590 a pending waitstatus. */
5593 resumed_thread_with_pending_status (struct thread_info
*tp
,
5597 && tp
->suspend
.waitstatus_pending_p
);
5600 /* Called when we get an event that may finish an in-line or
5601 out-of-line (displaced stepping) step-over started previously.
5602 Return true if the event is processed and we should go back to the
5603 event loop; false if the caller should continue processing the
5607 finish_step_over (struct execution_control_state
*ecs
)
5609 displaced_step_finish (ecs
->event_thread
,
5610 ecs
->event_thread
->suspend
.stop_signal
);
5612 bool had_step_over_info
= step_over_info_valid_p ();
5614 if (had_step_over_info
)
5616 /* If we're stepping over a breakpoint with all threads locked,
5617 then only the thread that was stepped should be reporting
5619 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5621 clear_step_over_info ();
5624 if (!target_is_non_stop_p ())
5627 /* Start a new step-over in another thread if there's one that
5631 /* If we were stepping over a breakpoint before, and haven't started
5632 a new in-line step-over sequence, then restart all other threads
5633 (except the event thread). We can't do this in all-stop, as then
5634 e.g., we wouldn't be able to issue any other remote packet until
5635 these other threads stop. */
5636 if (had_step_over_info
&& !step_over_info_valid_p ())
5638 struct thread_info
*pending
;
5640 /* If we only have threads with pending statuses, the restart
5641 below won't restart any thread and so nothing re-inserts the
5642 breakpoint we just stepped over. But we need it inserted
5643 when we later process the pending events, otherwise if
5644 another thread has a pending event for this breakpoint too,
5645 we'd discard its event (because the breakpoint that
5646 originally caused the event was no longer inserted). */
5647 context_switch (ecs
);
5648 insert_breakpoints ();
5650 restart_threads (ecs
->event_thread
);
5652 /* If we have events pending, go through handle_inferior_event
5653 again, picking up a pending event at random. This avoids
5654 thread starvation. */
5656 /* But not if we just stepped over a watchpoint in order to let
5657 the instruction execute so we can evaluate its expression.
5658 The set of watchpoints that triggered is recorded in the
5659 breakpoint objects themselves (see bp->watchpoint_triggered).
5660 If we processed another event first, that other event could
5661 clobber this info. */
5662 if (ecs
->event_thread
->stepping_over_watchpoint
)
5665 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5667 if (pending
!= NULL
)
5669 struct thread_info
*tp
= ecs
->event_thread
;
5670 struct regcache
*regcache
;
5672 infrun_debug_printf ("found resumed threads with "
5673 "pending events, saving status");
5675 gdb_assert (pending
!= tp
);
5677 /* Record the event thread's event for later. */
5678 save_waitstatus (tp
, &ecs
->ws
);
5679 /* This was cleared early, by handle_inferior_event. Set it
5680 so this pending event is considered by
5684 gdb_assert (!tp
->executing
);
5686 regcache
= get_thread_regcache (tp
);
5687 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5689 infrun_debug_printf ("saved stop_pc=%s for %s "
5690 "(currently_stepping=%d)",
5691 paddress (target_gdbarch (),
5692 tp
->suspend
.stop_pc
),
5693 target_pid_to_str (tp
->ptid
).c_str (),
5694 currently_stepping (tp
));
5696 /* This in-line step-over finished; clear this so we won't
5697 start a new one. This is what handle_signal_stop would
5698 do, if we returned false. */
5699 tp
->stepping_over_breakpoint
= 0;
5701 /* Wake up the event loop again. */
5702 mark_async_event_handler (infrun_async_inferior_event_token
);
5704 prepare_to_wait (ecs
);
5712 /* Come here when the program has stopped with a signal. */
5715 handle_signal_stop (struct execution_control_state
*ecs
)
5717 struct frame_info
*frame
;
5718 struct gdbarch
*gdbarch
;
5719 int stopped_by_watchpoint
;
5720 enum stop_kind stop_soon
;
5723 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5725 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5727 /* Do we need to clean up the state of a thread that has
5728 completed a displaced single-step? (Doing so usually affects
5729 the PC, so do it here, before we set stop_pc.) */
5730 if (finish_step_over (ecs
))
5733 /* If we either finished a single-step or hit a breakpoint, but
5734 the user wanted this thread to be stopped, pretend we got a
5735 SIG0 (generic unsignaled stop). */
5736 if (ecs
->event_thread
->stop_requested
5737 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5738 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5740 ecs
->event_thread
->suspend
.stop_pc
5741 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5745 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5746 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5748 switch_to_thread (ecs
->event_thread
);
5750 infrun_debug_printf ("stop_pc=%s",
5751 paddress (reg_gdbarch
,
5752 ecs
->event_thread
->suspend
.stop_pc
));
5753 if (target_stopped_by_watchpoint ())
5757 infrun_debug_printf ("stopped by watchpoint");
5759 if (target_stopped_data_address (current_top_target (), &addr
))
5760 infrun_debug_printf ("stopped data address=%s",
5761 paddress (reg_gdbarch
, addr
));
5763 infrun_debug_printf ("(no data address available)");
5767 /* This is originated from start_remote(), start_inferior() and
5768 shared libraries hook functions. */
5769 stop_soon
= get_inferior_stop_soon (ecs
);
5770 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5772 context_switch (ecs
);
5773 infrun_debug_printf ("quietly stopped");
5774 stop_print_frame
= true;
5779 /* This originates from attach_command(). We need to overwrite
5780 the stop_signal here, because some kernels don't ignore a
5781 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5782 See more comments in inferior.h. On the other hand, if we
5783 get a non-SIGSTOP, report it to the user - assume the backend
5784 will handle the SIGSTOP if it should show up later.
5786 Also consider that the attach is complete when we see a
5787 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5788 target extended-remote report it instead of a SIGSTOP
5789 (e.g. gdbserver). We already rely on SIGTRAP being our
5790 signal, so this is no exception.
5792 Also consider that the attach is complete when we see a
5793 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5794 the target to stop all threads of the inferior, in case the
5795 low level attach operation doesn't stop them implicitly. If
5796 they weren't stopped implicitly, then the stub will report a
5797 GDB_SIGNAL_0, meaning: stopped for no particular reason
5798 other than GDB's request. */
5799 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5800 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5801 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5802 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5804 stop_print_frame
= true;
5806 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5810 /* See if something interesting happened to the non-current thread. If
5811 so, then switch to that thread. */
5812 if (ecs
->ptid
!= inferior_ptid
)
5814 infrun_debug_printf ("context switch");
5816 context_switch (ecs
);
5818 if (deprecated_context_hook
)
5819 deprecated_context_hook (ecs
->event_thread
->global_num
);
5822 /* At this point, get hold of the now-current thread's frame. */
5823 frame
= get_current_frame ();
5824 gdbarch
= get_frame_arch (frame
);
5826 /* Pull the single step breakpoints out of the target. */
5827 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5829 struct regcache
*regcache
;
5832 regcache
= get_thread_regcache (ecs
->event_thread
);
5833 const address_space
*aspace
= regcache
->aspace ();
5835 pc
= regcache_read_pc (regcache
);
5837 /* However, before doing so, if this single-step breakpoint was
5838 actually for another thread, set this thread up for moving
5840 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5843 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5845 infrun_debug_printf ("[%s] hit another thread's single-step "
5847 target_pid_to_str (ecs
->ptid
).c_str ());
5848 ecs
->hit_singlestep_breakpoint
= 1;
5853 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5854 target_pid_to_str (ecs
->ptid
).c_str ());
5857 delete_just_stopped_threads_single_step_breakpoints ();
5859 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5860 && ecs
->event_thread
->control
.trap_expected
5861 && ecs
->event_thread
->stepping_over_watchpoint
)
5862 stopped_by_watchpoint
= 0;
5864 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5866 /* If necessary, step over this watchpoint. We'll be back to display
5868 if (stopped_by_watchpoint
5869 && (target_have_steppable_watchpoint ()
5870 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5872 /* At this point, we are stopped at an instruction which has
5873 attempted to write to a piece of memory under control of
5874 a watchpoint. The instruction hasn't actually executed
5875 yet. If we were to evaluate the watchpoint expression
5876 now, we would get the old value, and therefore no change
5877 would seem to have occurred.
5879 In order to make watchpoints work `right', we really need
5880 to complete the memory write, and then evaluate the
5881 watchpoint expression. We do this by single-stepping the
5884 It may not be necessary to disable the watchpoint to step over
5885 it. For example, the PA can (with some kernel cooperation)
5886 single step over a watchpoint without disabling the watchpoint.
5888 It is far more common to need to disable a watchpoint to step
5889 the inferior over it. If we have non-steppable watchpoints,
5890 we must disable the current watchpoint; it's simplest to
5891 disable all watchpoints.
5893 Any breakpoint at PC must also be stepped over -- if there's
5894 one, it will have already triggered before the watchpoint
5895 triggered, and we either already reported it to the user, or
5896 it didn't cause a stop and we called keep_going. In either
5897 case, if there was a breakpoint at PC, we must be trying to
5899 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5904 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5905 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5906 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5907 ecs
->event_thread
->control
.stop_step
= 0;
5908 stop_print_frame
= true;
5909 stopped_by_random_signal
= 0;
5910 bpstat stop_chain
= NULL
;
5912 /* Hide inlined functions starting here, unless we just performed stepi or
5913 nexti. After stepi and nexti, always show the innermost frame (not any
5914 inline function call sites). */
5915 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5917 const address_space
*aspace
5918 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5920 /* skip_inline_frames is expensive, so we avoid it if we can
5921 determine that the address is one where functions cannot have
5922 been inlined. This improves performance with inferiors that
5923 load a lot of shared libraries, because the solib event
5924 breakpoint is defined as the address of a function (i.e. not
5925 inline). Note that we have to check the previous PC as well
5926 as the current one to catch cases when we have just
5927 single-stepped off a breakpoint prior to reinstating it.
5928 Note that we're assuming that the code we single-step to is
5929 not inline, but that's not definitive: there's nothing
5930 preventing the event breakpoint function from containing
5931 inlined code, and the single-step ending up there. If the
5932 user had set a breakpoint on that inlined code, the missing
5933 skip_inline_frames call would break things. Fortunately
5934 that's an extremely unlikely scenario. */
5935 if (!pc_at_non_inline_function (aspace
,
5936 ecs
->event_thread
->suspend
.stop_pc
,
5938 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5939 && ecs
->event_thread
->control
.trap_expected
5940 && pc_at_non_inline_function (aspace
,
5941 ecs
->event_thread
->prev_pc
,
5944 stop_chain
= build_bpstat_chain (aspace
,
5945 ecs
->event_thread
->suspend
.stop_pc
,
5947 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5949 /* Re-fetch current thread's frame in case that invalidated
5951 frame
= get_current_frame ();
5952 gdbarch
= get_frame_arch (frame
);
5956 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5957 && ecs
->event_thread
->control
.trap_expected
5958 && gdbarch_single_step_through_delay_p (gdbarch
)
5959 && currently_stepping (ecs
->event_thread
))
5961 /* We're trying to step off a breakpoint. Turns out that we're
5962 also on an instruction that needs to be stepped multiple
5963 times before it's been fully executing. E.g., architectures
5964 with a delay slot. It needs to be stepped twice, once for
5965 the instruction and once for the delay slot. */
5966 int step_through_delay
5967 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5969 if (step_through_delay
)
5970 infrun_debug_printf ("step through delay");
5972 if (ecs
->event_thread
->control
.step_range_end
== 0
5973 && step_through_delay
)
5975 /* The user issued a continue when stopped at a breakpoint.
5976 Set up for another trap and get out of here. */
5977 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5981 else if (step_through_delay
)
5983 /* The user issued a step when stopped at a breakpoint.
5984 Maybe we should stop, maybe we should not - the delay
5985 slot *might* correspond to a line of source. In any
5986 case, don't decide that here, just set
5987 ecs->stepping_over_breakpoint, making sure we
5988 single-step again before breakpoints are re-inserted. */
5989 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5993 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5994 handles this event. */
5995 ecs
->event_thread
->control
.stop_bpstat
5996 = bpstat_stop_status (get_current_regcache ()->aspace (),
5997 ecs
->event_thread
->suspend
.stop_pc
,
5998 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6000 /* Following in case break condition called a
6002 stop_print_frame
= true;
6004 /* This is where we handle "moribund" watchpoints. Unlike
6005 software breakpoints traps, hardware watchpoint traps are
6006 always distinguishable from random traps. If no high-level
6007 watchpoint is associated with the reported stop data address
6008 anymore, then the bpstat does not explain the signal ---
6009 simply make sure to ignore it if `stopped_by_watchpoint' is
6012 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6013 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6015 && stopped_by_watchpoint
)
6017 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6021 /* NOTE: cagney/2003-03-29: These checks for a random signal
6022 at one stage in the past included checks for an inferior
6023 function call's call dummy's return breakpoint. The original
6024 comment, that went with the test, read:
6026 ``End of a stack dummy. Some systems (e.g. Sony news) give
6027 another signal besides SIGTRAP, so check here as well as
6030 If someone ever tries to get call dummys on a
6031 non-executable stack to work (where the target would stop
6032 with something like a SIGSEGV), then those tests might need
6033 to be re-instated. Given, however, that the tests were only
6034 enabled when momentary breakpoints were not being used, I
6035 suspect that it won't be the case.
6037 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6038 be necessary for call dummies on a non-executable stack on
6041 /* See if the breakpoints module can explain the signal. */
6043 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6044 ecs
->event_thread
->suspend
.stop_signal
);
6046 /* Maybe this was a trap for a software breakpoint that has since
6048 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6050 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6051 ecs
->event_thread
->suspend
.stop_pc
))
6053 struct regcache
*regcache
;
6056 /* Re-adjust PC to what the program would see if GDB was not
6058 regcache
= get_thread_regcache (ecs
->event_thread
);
6059 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6062 gdb::optional
<scoped_restore_tmpl
<int>>
6063 restore_operation_disable
;
6065 if (record_full_is_used ())
6066 restore_operation_disable
.emplace
6067 (record_full_gdb_operation_disable_set ());
6069 regcache_write_pc (regcache
,
6070 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6075 /* A delayed software breakpoint event. Ignore the trap. */
6076 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6081 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6082 has since been removed. */
6083 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6085 /* A delayed hardware breakpoint event. Ignore the trap. */
6086 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6091 /* If not, perhaps stepping/nexting can. */
6093 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6094 && currently_stepping (ecs
->event_thread
));
6096 /* Perhaps the thread hit a single-step breakpoint of _another_
6097 thread. Single-step breakpoints are transparent to the
6098 breakpoints module. */
6100 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6102 /* No? Perhaps we got a moribund watchpoint. */
6104 random_signal
= !stopped_by_watchpoint
;
6106 /* Always stop if the user explicitly requested this thread to
6108 if (ecs
->event_thread
->stop_requested
)
6111 infrun_debug_printf ("user-requested stop");
6114 /* For the program's own signals, act according to
6115 the signal handling tables. */
6119 /* Signal not for debugging purposes. */
6120 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6121 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6123 infrun_debug_printf ("random signal (%s)",
6124 gdb_signal_to_symbol_string (stop_signal
));
6126 stopped_by_random_signal
= 1;
6128 /* Always stop on signals if we're either just gaining control
6129 of the program, or the user explicitly requested this thread
6130 to remain stopped. */
6131 if (stop_soon
!= NO_STOP_QUIETLY
6132 || ecs
->event_thread
->stop_requested
6134 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6140 /* Notify observers the signal has "handle print" set. Note we
6141 returned early above if stopping; normal_stop handles the
6142 printing in that case. */
6143 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6145 /* The signal table tells us to print about this signal. */
6146 target_terminal::ours_for_output ();
6147 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6148 target_terminal::inferior ();
6151 /* Clear the signal if it should not be passed. */
6152 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6153 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6155 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6156 && ecs
->event_thread
->control
.trap_expected
6157 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6159 /* We were just starting a new sequence, attempting to
6160 single-step off of a breakpoint and expecting a SIGTRAP.
6161 Instead this signal arrives. This signal will take us out
6162 of the stepping range so GDB needs to remember to, when
6163 the signal handler returns, resume stepping off that
6165 /* To simplify things, "continue" is forced to use the same
6166 code paths as single-step - set a breakpoint at the
6167 signal return address and then, once hit, step off that
6169 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6171 insert_hp_step_resume_breakpoint_at_frame (frame
);
6172 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6173 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6174 ecs
->event_thread
->control
.trap_expected
= 0;
6176 /* If we were nexting/stepping some other thread, switch to
6177 it, so that we don't continue it, losing control. */
6178 if (!switch_back_to_stepped_thread (ecs
))
6183 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6184 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6186 || ecs
->event_thread
->control
.step_range_end
== 1)
6187 && frame_id_eq (get_stack_frame_id (frame
),
6188 ecs
->event_thread
->control
.step_stack_frame_id
)
6189 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6191 /* The inferior is about to take a signal that will take it
6192 out of the single step range. Set a breakpoint at the
6193 current PC (which is presumably where the signal handler
6194 will eventually return) and then allow the inferior to
6197 Note that this is only needed for a signal delivered
6198 while in the single-step range. Nested signals aren't a
6199 problem as they eventually all return. */
6200 infrun_debug_printf ("signal may take us out of single-step range");
6202 clear_step_over_info ();
6203 insert_hp_step_resume_breakpoint_at_frame (frame
);
6204 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6205 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6206 ecs
->event_thread
->control
.trap_expected
= 0;
6211 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6212 when either there's a nested signal, or when there's a
6213 pending signal enabled just as the signal handler returns
6214 (leaving the inferior at the step-resume-breakpoint without
6215 actually executing it). Either way continue until the
6216 breakpoint is really hit. */
6218 if (!switch_back_to_stepped_thread (ecs
))
6220 infrun_debug_printf ("random signal, keep going");
6227 process_event_stop_test (ecs
);
6230 /* Come here when we've got some debug event / signal we can explain
6231 (IOW, not a random signal), and test whether it should cause a
6232 stop, or whether we should resume the inferior (transparently).
6233 E.g., could be a breakpoint whose condition evaluates false; we
6234 could be still stepping within the line; etc. */
6237 process_event_stop_test (struct execution_control_state
*ecs
)
6239 struct symtab_and_line stop_pc_sal
;
6240 struct frame_info
*frame
;
6241 struct gdbarch
*gdbarch
;
6242 CORE_ADDR jmp_buf_pc
;
6243 struct bpstat_what what
;
6245 /* Handle cases caused by hitting a breakpoint. */
6247 frame
= get_current_frame ();
6248 gdbarch
= get_frame_arch (frame
);
6250 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6252 if (what
.call_dummy
)
6254 stop_stack_dummy
= what
.call_dummy
;
6257 /* A few breakpoint types have callbacks associated (e.g.,
6258 bp_jit_event). Run them now. */
6259 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6261 /* If we hit an internal event that triggers symbol changes, the
6262 current frame will be invalidated within bpstat_what (e.g., if we
6263 hit an internal solib event). Re-fetch it. */
6264 frame
= get_current_frame ();
6265 gdbarch
= get_frame_arch (frame
);
6267 switch (what
.main_action
)
6269 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6270 /* If we hit the breakpoint at longjmp while stepping, we
6271 install a momentary breakpoint at the target of the
6274 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6276 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6278 if (what
.is_longjmp
)
6280 struct value
*arg_value
;
6282 /* If we set the longjmp breakpoint via a SystemTap probe,
6283 then use it to extract the arguments. The destination PC
6284 is the third argument to the probe. */
6285 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6288 jmp_buf_pc
= value_as_address (arg_value
);
6289 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6291 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6292 || !gdbarch_get_longjmp_target (gdbarch
,
6293 frame
, &jmp_buf_pc
))
6295 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6296 "(!gdbarch_get_longjmp_target)");
6301 /* Insert a breakpoint at resume address. */
6302 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6305 check_exception_resume (ecs
, frame
);
6309 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6311 struct frame_info
*init_frame
;
6313 /* There are several cases to consider.
6315 1. The initiating frame no longer exists. In this case we
6316 must stop, because the exception or longjmp has gone too
6319 2. The initiating frame exists, and is the same as the
6320 current frame. We stop, because the exception or longjmp
6323 3. The initiating frame exists and is different from the
6324 current frame. This means the exception or longjmp has
6325 been caught beneath the initiating frame, so keep going.
6327 4. longjmp breakpoint has been placed just to protect
6328 against stale dummy frames and user is not interested in
6329 stopping around longjmps. */
6331 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6333 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6335 delete_exception_resume_breakpoint (ecs
->event_thread
);
6337 if (what
.is_longjmp
)
6339 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6341 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6349 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6353 struct frame_id current_id
6354 = get_frame_id (get_current_frame ());
6355 if (frame_id_eq (current_id
,
6356 ecs
->event_thread
->initiating_frame
))
6358 /* Case 2. Fall through. */
6368 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6370 delete_step_resume_breakpoint (ecs
->event_thread
);
6372 end_stepping_range (ecs
);
6376 case BPSTAT_WHAT_SINGLE
:
6377 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6378 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6379 /* Still need to check other stuff, at least the case where we
6380 are stepping and step out of the right range. */
6383 case BPSTAT_WHAT_STEP_RESUME
:
6384 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6386 delete_step_resume_breakpoint (ecs
->event_thread
);
6387 if (ecs
->event_thread
->control
.proceed_to_finish
6388 && execution_direction
== EXEC_REVERSE
)
6390 struct thread_info
*tp
= ecs
->event_thread
;
6392 /* We are finishing a function in reverse, and just hit the
6393 step-resume breakpoint at the start address of the
6394 function, and we're almost there -- just need to back up
6395 by one more single-step, which should take us back to the
6397 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6401 fill_in_stop_func (gdbarch
, ecs
);
6402 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6403 && execution_direction
== EXEC_REVERSE
)
6405 /* We are stepping over a function call in reverse, and just
6406 hit the step-resume breakpoint at the start address of
6407 the function. Go back to single-stepping, which should
6408 take us back to the function call. */
6409 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6415 case BPSTAT_WHAT_STOP_NOISY
:
6416 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6417 stop_print_frame
= true;
6419 /* Assume the thread stopped for a breakpoint. We'll still check
6420 whether a/the breakpoint is there when the thread is next
6422 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6427 case BPSTAT_WHAT_STOP_SILENT
:
6428 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6429 stop_print_frame
= false;
6431 /* Assume the thread stopped for a breakpoint. We'll still check
6432 whether a/the breakpoint is there when the thread is next
6434 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6438 case BPSTAT_WHAT_HP_STEP_RESUME
:
6439 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6441 delete_step_resume_breakpoint (ecs
->event_thread
);
6442 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6444 /* Back when the step-resume breakpoint was inserted, we
6445 were trying to single-step off a breakpoint. Go back to
6447 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6448 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6454 case BPSTAT_WHAT_KEEP_CHECKING
:
6458 /* If we stepped a permanent breakpoint and we had a high priority
6459 step-resume breakpoint for the address we stepped, but we didn't
6460 hit it, then we must have stepped into the signal handler. The
6461 step-resume was only necessary to catch the case of _not_
6462 stepping into the handler, so delete it, and fall through to
6463 checking whether the step finished. */
6464 if (ecs
->event_thread
->stepped_breakpoint
)
6466 struct breakpoint
*sr_bp
6467 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6470 && sr_bp
->loc
->permanent
6471 && sr_bp
->type
== bp_hp_step_resume
6472 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6474 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6475 delete_step_resume_breakpoint (ecs
->event_thread
);
6476 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6480 /* We come here if we hit a breakpoint but should not stop for it.
6481 Possibly we also were stepping and should stop for that. So fall
6482 through and test for stepping. But, if not stepping, do not
6485 /* In all-stop mode, if we're currently stepping but have stopped in
6486 some other thread, we need to switch back to the stepped thread. */
6487 if (switch_back_to_stepped_thread (ecs
))
6490 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6492 infrun_debug_printf ("step-resume breakpoint is inserted");
6494 /* Having a step-resume breakpoint overrides anything
6495 else having to do with stepping commands until
6496 that breakpoint is reached. */
6501 if (ecs
->event_thread
->control
.step_range_end
== 0)
6503 infrun_debug_printf ("no stepping, continue");
6504 /* Likewise if we aren't even stepping. */
6509 /* Re-fetch current thread's frame in case the code above caused
6510 the frame cache to be re-initialized, making our FRAME variable
6511 a dangling pointer. */
6512 frame
= get_current_frame ();
6513 gdbarch
= get_frame_arch (frame
);
6514 fill_in_stop_func (gdbarch
, ecs
);
6516 /* If stepping through a line, keep going if still within it.
6518 Note that step_range_end is the address of the first instruction
6519 beyond the step range, and NOT the address of the last instruction
6522 Note also that during reverse execution, we may be stepping
6523 through a function epilogue and therefore must detect when
6524 the current-frame changes in the middle of a line. */
6526 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6528 && (execution_direction
!= EXEC_REVERSE
6529 || frame_id_eq (get_frame_id (frame
),
6530 ecs
->event_thread
->control
.step_frame_id
)))
6533 ("stepping inside range [%s-%s]",
6534 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6535 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6537 /* Tentatively re-enable range stepping; `resume' disables it if
6538 necessary (e.g., if we're stepping over a breakpoint or we
6539 have software watchpoints). */
6540 ecs
->event_thread
->control
.may_range_step
= 1;
6542 /* When stepping backward, stop at beginning of line range
6543 (unless it's the function entry point, in which case
6544 keep going back to the call point). */
6545 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6546 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6547 && stop_pc
!= ecs
->stop_func_start
6548 && execution_direction
== EXEC_REVERSE
)
6549 end_stepping_range (ecs
);
6556 /* We stepped out of the stepping range. */
6558 /* If we are stepping at the source level and entered the runtime
6559 loader dynamic symbol resolution code...
6561 EXEC_FORWARD: we keep on single stepping until we exit the run
6562 time loader code and reach the callee's address.
6564 EXEC_REVERSE: we've already executed the callee (backward), and
6565 the runtime loader code is handled just like any other
6566 undebuggable function call. Now we need only keep stepping
6567 backward through the trampoline code, and that's handled further
6568 down, so there is nothing for us to do here. */
6570 if (execution_direction
!= EXEC_REVERSE
6571 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6572 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6574 CORE_ADDR pc_after_resolver
=
6575 gdbarch_skip_solib_resolver (gdbarch
,
6576 ecs
->event_thread
->suspend
.stop_pc
);
6578 infrun_debug_printf ("stepped into dynsym resolve code");
6580 if (pc_after_resolver
)
6582 /* Set up a step-resume breakpoint at the address
6583 indicated by SKIP_SOLIB_RESOLVER. */
6584 symtab_and_line sr_sal
;
6585 sr_sal
.pc
= pc_after_resolver
;
6586 sr_sal
.pspace
= get_frame_program_space (frame
);
6588 insert_step_resume_breakpoint_at_sal (gdbarch
,
6589 sr_sal
, null_frame_id
);
6596 /* Step through an indirect branch thunk. */
6597 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6598 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6599 ecs
->event_thread
->suspend
.stop_pc
))
6601 infrun_debug_printf ("stepped into indirect branch thunk");
6606 if (ecs
->event_thread
->control
.step_range_end
!= 1
6607 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6608 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6609 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6611 infrun_debug_printf ("stepped into signal trampoline");
6612 /* The inferior, while doing a "step" or "next", has ended up in
6613 a signal trampoline (either by a signal being delivered or by
6614 the signal handler returning). Just single-step until the
6615 inferior leaves the trampoline (either by calling the handler
6621 /* If we're in the return path from a shared library trampoline,
6622 we want to proceed through the trampoline when stepping. */
6623 /* macro/2012-04-25: This needs to come before the subroutine
6624 call check below as on some targets return trampolines look
6625 like subroutine calls (MIPS16 return thunks). */
6626 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6627 ecs
->event_thread
->suspend
.stop_pc
,
6628 ecs
->stop_func_name
)
6629 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6631 /* Determine where this trampoline returns. */
6632 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6633 CORE_ADDR real_stop_pc
6634 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6636 infrun_debug_printf ("stepped into solib return tramp");
6638 /* Only proceed through if we know where it's going. */
6641 /* And put the step-breakpoint there and go until there. */
6642 symtab_and_line sr_sal
;
6643 sr_sal
.pc
= real_stop_pc
;
6644 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6645 sr_sal
.pspace
= get_frame_program_space (frame
);
6647 /* Do not specify what the fp should be when we stop since
6648 on some machines the prologue is where the new fp value
6650 insert_step_resume_breakpoint_at_sal (gdbarch
,
6651 sr_sal
, null_frame_id
);
6653 /* Restart without fiddling with the step ranges or
6660 /* Check for subroutine calls. The check for the current frame
6661 equalling the step ID is not necessary - the check of the
6662 previous frame's ID is sufficient - but it is a common case and
6663 cheaper than checking the previous frame's ID.
6665 NOTE: frame_id_eq will never report two invalid frame IDs as
6666 being equal, so to get into this block, both the current and
6667 previous frame must have valid frame IDs. */
6668 /* The outer_frame_id check is a heuristic to detect stepping
6669 through startup code. If we step over an instruction which
6670 sets the stack pointer from an invalid value to a valid value,
6671 we may detect that as a subroutine call from the mythical
6672 "outermost" function. This could be fixed by marking
6673 outermost frames as !stack_p,code_p,special_p. Then the
6674 initial outermost frame, before sp was valid, would
6675 have code_addr == &_start. See the comment in frame_id_eq
6677 if (!frame_id_eq (get_stack_frame_id (frame
),
6678 ecs
->event_thread
->control
.step_stack_frame_id
)
6679 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6680 ecs
->event_thread
->control
.step_stack_frame_id
)
6681 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6683 || (ecs
->event_thread
->control
.step_start_function
6684 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6686 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6687 CORE_ADDR real_stop_pc
;
6689 infrun_debug_printf ("stepped into subroutine");
6691 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6693 /* I presume that step_over_calls is only 0 when we're
6694 supposed to be stepping at the assembly language level
6695 ("stepi"). Just stop. */
6696 /* And this works the same backward as frontward. MVS */
6697 end_stepping_range (ecs
);
6701 /* Reverse stepping through solib trampolines. */
6703 if (execution_direction
== EXEC_REVERSE
6704 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6705 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6706 || (ecs
->stop_func_start
== 0
6707 && in_solib_dynsym_resolve_code (stop_pc
))))
6709 /* Any solib trampoline code can be handled in reverse
6710 by simply continuing to single-step. We have already
6711 executed the solib function (backwards), and a few
6712 steps will take us back through the trampoline to the
6718 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6720 /* We're doing a "next".
6722 Normal (forward) execution: set a breakpoint at the
6723 callee's return address (the address at which the caller
6726 Reverse (backward) execution. set the step-resume
6727 breakpoint at the start of the function that we just
6728 stepped into (backwards), and continue to there. When we
6729 get there, we'll need to single-step back to the caller. */
6731 if (execution_direction
== EXEC_REVERSE
)
6733 /* If we're already at the start of the function, we've either
6734 just stepped backward into a single instruction function,
6735 or stepped back out of a signal handler to the first instruction
6736 of the function. Just keep going, which will single-step back
6738 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6740 /* Normal function call return (static or dynamic). */
6741 symtab_and_line sr_sal
;
6742 sr_sal
.pc
= ecs
->stop_func_start
;
6743 sr_sal
.pspace
= get_frame_program_space (frame
);
6744 insert_step_resume_breakpoint_at_sal (gdbarch
,
6745 sr_sal
, null_frame_id
);
6749 insert_step_resume_breakpoint_at_caller (frame
);
6755 /* If we are in a function call trampoline (a stub between the
6756 calling routine and the real function), locate the real
6757 function. That's what tells us (a) whether we want to step
6758 into it at all, and (b) what prologue we want to run to the
6759 end of, if we do step into it. */
6760 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6761 if (real_stop_pc
== 0)
6762 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6763 if (real_stop_pc
!= 0)
6764 ecs
->stop_func_start
= real_stop_pc
;
6766 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6768 symtab_and_line sr_sal
;
6769 sr_sal
.pc
= ecs
->stop_func_start
;
6770 sr_sal
.pspace
= get_frame_program_space (frame
);
6772 insert_step_resume_breakpoint_at_sal (gdbarch
,
6773 sr_sal
, null_frame_id
);
6778 /* If we have line number information for the function we are
6779 thinking of stepping into and the function isn't on the skip
6782 If there are several symtabs at that PC (e.g. with include
6783 files), just want to know whether *any* of them have line
6784 numbers. find_pc_line handles this. */
6786 struct symtab_and_line tmp_sal
;
6788 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6789 if (tmp_sal
.line
!= 0
6790 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6792 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6794 if (execution_direction
== EXEC_REVERSE
)
6795 handle_step_into_function_backward (gdbarch
, ecs
);
6797 handle_step_into_function (gdbarch
, ecs
);
6802 /* If we have no line number and the step-stop-if-no-debug is
6803 set, we stop the step so that the user has a chance to switch
6804 in assembly mode. */
6805 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6806 && step_stop_if_no_debug
)
6808 end_stepping_range (ecs
);
6812 if (execution_direction
== EXEC_REVERSE
)
6814 /* If we're already at the start of the function, we've either just
6815 stepped backward into a single instruction function without line
6816 number info, or stepped back out of a signal handler to the first
6817 instruction of the function without line number info. Just keep
6818 going, which will single-step back to the caller. */
6819 if (ecs
->stop_func_start
!= stop_pc
)
6821 /* Set a breakpoint at callee's start address.
6822 From there we can step once and be back in the caller. */
6823 symtab_and_line sr_sal
;
6824 sr_sal
.pc
= ecs
->stop_func_start
;
6825 sr_sal
.pspace
= get_frame_program_space (frame
);
6826 insert_step_resume_breakpoint_at_sal (gdbarch
,
6827 sr_sal
, null_frame_id
);
6831 /* Set a breakpoint at callee's return address (the address
6832 at which the caller will resume). */
6833 insert_step_resume_breakpoint_at_caller (frame
);
6839 /* Reverse stepping through solib trampolines. */
6841 if (execution_direction
== EXEC_REVERSE
6842 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6844 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6846 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6847 || (ecs
->stop_func_start
== 0
6848 && in_solib_dynsym_resolve_code (stop_pc
)))
6850 /* Any solib trampoline code can be handled in reverse
6851 by simply continuing to single-step. We have already
6852 executed the solib function (backwards), and a few
6853 steps will take us back through the trampoline to the
6858 else if (in_solib_dynsym_resolve_code (stop_pc
))
6860 /* Stepped backward into the solib dynsym resolver.
6861 Set a breakpoint at its start and continue, then
6862 one more step will take us out. */
6863 symtab_and_line sr_sal
;
6864 sr_sal
.pc
= ecs
->stop_func_start
;
6865 sr_sal
.pspace
= get_frame_program_space (frame
);
6866 insert_step_resume_breakpoint_at_sal (gdbarch
,
6867 sr_sal
, null_frame_id
);
6873 /* This always returns the sal for the inner-most frame when we are in a
6874 stack of inlined frames, even if GDB actually believes that it is in a
6875 more outer frame. This is checked for below by calls to
6876 inline_skipped_frames. */
6877 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6879 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6880 the trampoline processing logic, however, there are some trampolines
6881 that have no names, so we should do trampoline handling first. */
6882 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6883 && ecs
->stop_func_name
== NULL
6884 && stop_pc_sal
.line
== 0)
6886 infrun_debug_printf ("stepped into undebuggable function");
6888 /* The inferior just stepped into, or returned to, an
6889 undebuggable function (where there is no debugging information
6890 and no line number corresponding to the address where the
6891 inferior stopped). Since we want to skip this kind of code,
6892 we keep going until the inferior returns from this
6893 function - unless the user has asked us not to (via
6894 set step-mode) or we no longer know how to get back
6895 to the call site. */
6896 if (step_stop_if_no_debug
6897 || !frame_id_p (frame_unwind_caller_id (frame
)))
6899 /* If we have no line number and the step-stop-if-no-debug
6900 is set, we stop the step so that the user has a chance to
6901 switch in assembly mode. */
6902 end_stepping_range (ecs
);
6907 /* Set a breakpoint at callee's return address (the address
6908 at which the caller will resume). */
6909 insert_step_resume_breakpoint_at_caller (frame
);
6915 if (ecs
->event_thread
->control
.step_range_end
== 1)
6917 /* It is stepi or nexti. We always want to stop stepping after
6919 infrun_debug_printf ("stepi/nexti");
6920 end_stepping_range (ecs
);
6924 if (stop_pc_sal
.line
== 0)
6926 /* We have no line number information. That means to stop
6927 stepping (does this always happen right after one instruction,
6928 when we do "s" in a function with no line numbers,
6929 or can this happen as a result of a return or longjmp?). */
6930 infrun_debug_printf ("line number info");
6931 end_stepping_range (ecs
);
6935 /* Look for "calls" to inlined functions, part one. If the inline
6936 frame machinery detected some skipped call sites, we have entered
6937 a new inline function. */
6939 if (frame_id_eq (get_frame_id (get_current_frame ()),
6940 ecs
->event_thread
->control
.step_frame_id
)
6941 && inline_skipped_frames (ecs
->event_thread
))
6943 infrun_debug_printf ("stepped into inlined function");
6945 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6947 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6949 /* For "step", we're going to stop. But if the call site
6950 for this inlined function is on the same source line as
6951 we were previously stepping, go down into the function
6952 first. Otherwise stop at the call site. */
6954 if (call_sal
.line
== ecs
->event_thread
->current_line
6955 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6957 step_into_inline_frame (ecs
->event_thread
);
6958 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6965 end_stepping_range (ecs
);
6970 /* For "next", we should stop at the call site if it is on a
6971 different source line. Otherwise continue through the
6972 inlined function. */
6973 if (call_sal
.line
== ecs
->event_thread
->current_line
6974 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6977 end_stepping_range (ecs
);
6982 /* Look for "calls" to inlined functions, part two. If we are still
6983 in the same real function we were stepping through, but we have
6984 to go further up to find the exact frame ID, we are stepping
6985 through a more inlined call beyond its call site. */
6987 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6988 && !frame_id_eq (get_frame_id (get_current_frame ()),
6989 ecs
->event_thread
->control
.step_frame_id
)
6990 && stepped_in_from (get_current_frame (),
6991 ecs
->event_thread
->control
.step_frame_id
))
6993 infrun_debug_printf ("stepping through inlined function");
6995 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
6996 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6999 end_stepping_range (ecs
);
7003 bool refresh_step_info
= true;
7004 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7005 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7006 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7008 if (stop_pc_sal
.is_stmt
)
7010 /* We are at the start of a different line. So stop. Note that
7011 we don't stop if we step into the middle of a different line.
7012 That is said to make things like for (;;) statements work
7014 infrun_debug_printf ("stepped to a different line");
7015 end_stepping_range (ecs
);
7018 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7019 ecs
->event_thread
->control
.step_frame_id
))
7021 /* We are at the start of a different line, however, this line is
7022 not marked as a statement, and we have not changed frame. We
7023 ignore this line table entry, and continue stepping forward,
7024 looking for a better place to stop. */
7025 refresh_step_info
= false;
7026 infrun_debug_printf ("stepped to a different line, but "
7027 "it's not the start of a statement");
7031 /* We aren't done stepping.
7033 Optimize by setting the stepping range to the line.
7034 (We might not be in the original line, but if we entered a
7035 new line in mid-statement, we continue stepping. This makes
7036 things like for(;;) statements work better.)
7038 If we entered a SAL that indicates a non-statement line table entry,
7039 then we update the stepping range, but we don't update the step info,
7040 which includes things like the line number we are stepping away from.
7041 This means we will stop when we find a line table entry that is marked
7042 as is-statement, even if it matches the non-statement one we just
7045 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7046 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7047 ecs
->event_thread
->control
.may_range_step
= 1;
7048 if (refresh_step_info
)
7049 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7051 infrun_debug_printf ("keep going");
7055 /* In all-stop mode, if we're currently stepping but have stopped in
7056 some other thread, we may need to switch back to the stepped
7057 thread. Returns true we set the inferior running, false if we left
7058 it stopped (and the event needs further processing). */
7061 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7063 if (!target_is_non_stop_p ())
7065 struct thread_info
*stepping_thread
;
7067 /* If any thread is blocked on some internal breakpoint, and we
7068 simply need to step over that breakpoint to get it going
7069 again, do that first. */
7071 /* However, if we see an event for the stepping thread, then we
7072 know all other threads have been moved past their breakpoints
7073 already. Let the caller check whether the step is finished,
7074 etc., before deciding to move it past a breakpoint. */
7075 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7078 /* Check if the current thread is blocked on an incomplete
7079 step-over, interrupted by a random signal. */
7080 if (ecs
->event_thread
->control
.trap_expected
7081 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7084 ("need to finish step-over of [%s]",
7085 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7090 /* Check if the current thread is blocked by a single-step
7091 breakpoint of another thread. */
7092 if (ecs
->hit_singlestep_breakpoint
)
7094 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7095 target_pid_to_str (ecs
->ptid
).c_str ());
7100 /* If this thread needs yet another step-over (e.g., stepping
7101 through a delay slot), do it first before moving on to
7103 if (thread_still_needs_step_over (ecs
->event_thread
))
7106 ("thread [%s] still needs step-over",
7107 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7112 /* If scheduler locking applies even if not stepping, there's no
7113 need to walk over threads. Above we've checked whether the
7114 current thread is stepping. If some other thread not the
7115 event thread is stepping, then it must be that scheduler
7116 locking is not in effect. */
7117 if (schedlock_applies (ecs
->event_thread
))
7120 /* Otherwise, we no longer expect a trap in the current thread.
7121 Clear the trap_expected flag before switching back -- this is
7122 what keep_going does as well, if we call it. */
7123 ecs
->event_thread
->control
.trap_expected
= 0;
7125 /* Likewise, clear the signal if it should not be passed. */
7126 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7127 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7129 /* Do all pending step-overs before actually proceeding with
7131 if (start_step_over ())
7133 prepare_to_wait (ecs
);
7137 /* Look for the stepping/nexting thread. */
7138 stepping_thread
= NULL
;
7140 for (thread_info
*tp
: all_non_exited_threads ())
7142 switch_to_thread_no_regs (tp
);
7144 /* Ignore threads of processes the caller is not
7147 && (tp
->inf
->process_target () != ecs
->target
7148 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7151 /* When stepping over a breakpoint, we lock all threads
7152 except the one that needs to move past the breakpoint.
7153 If a non-event thread has this set, the "incomplete
7154 step-over" check above should have caught it earlier. */
7155 if (tp
->control
.trap_expected
)
7157 internal_error (__FILE__
, __LINE__
,
7158 "[%s] has inconsistent state: "
7159 "trap_expected=%d\n",
7160 target_pid_to_str (tp
->ptid
).c_str (),
7161 tp
->control
.trap_expected
);
7164 /* Did we find the stepping thread? */
7165 if (tp
->control
.step_range_end
)
7167 /* Yep. There should only one though. */
7168 gdb_assert (stepping_thread
== NULL
);
7170 /* The event thread is handled at the top, before we
7172 gdb_assert (tp
!= ecs
->event_thread
);
7174 /* If some thread other than the event thread is
7175 stepping, then scheduler locking can't be in effect,
7176 otherwise we wouldn't have resumed the current event
7177 thread in the first place. */
7178 gdb_assert (!schedlock_applies (tp
));
7180 stepping_thread
= tp
;
7184 if (stepping_thread
!= NULL
)
7186 infrun_debug_printf ("switching back to stepped thread");
7188 if (keep_going_stepped_thread (stepping_thread
))
7190 prepare_to_wait (ecs
);
7195 switch_to_thread (ecs
->event_thread
);
7201 /* Set a previously stepped thread back to stepping. Returns true on
7202 success, false if the resume is not possible (e.g., the thread
7206 keep_going_stepped_thread (struct thread_info
*tp
)
7208 struct frame_info
*frame
;
7209 struct execution_control_state ecss
;
7210 struct execution_control_state
*ecs
= &ecss
;
7212 /* If the stepping thread exited, then don't try to switch back and
7213 resume it, which could fail in several different ways depending
7214 on the target. Instead, just keep going.
7216 We can find a stepping dead thread in the thread list in two
7219 - The target supports thread exit events, and when the target
7220 tries to delete the thread from the thread list, inferior_ptid
7221 pointed at the exiting thread. In such case, calling
7222 delete_thread does not really remove the thread from the list;
7223 instead, the thread is left listed, with 'exited' state.
7225 - The target's debug interface does not support thread exit
7226 events, and so we have no idea whatsoever if the previously
7227 stepping thread is still alive. For that reason, we need to
7228 synchronously query the target now. */
7230 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7232 infrun_debug_printf ("not resuming previously stepped thread, it has "
7239 infrun_debug_printf ("resuming previously stepped thread");
7241 reset_ecs (ecs
, tp
);
7242 switch_to_thread (tp
);
7244 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7245 frame
= get_current_frame ();
7247 /* If the PC of the thread we were trying to single-step has
7248 changed, then that thread has trapped or been signaled, but the
7249 event has not been reported to GDB yet. Re-poll the target
7250 looking for this particular thread's event (i.e. temporarily
7251 enable schedlock) by:
7253 - setting a break at the current PC
7254 - resuming that particular thread, only (by setting trap
7257 This prevents us continuously moving the single-step breakpoint
7258 forward, one instruction at a time, overstepping. */
7260 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7264 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7265 paddress (target_gdbarch (), tp
->prev_pc
),
7266 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7268 /* Clear the info of the previous step-over, as it's no longer
7269 valid (if the thread was trying to step over a breakpoint, it
7270 has already succeeded). It's what keep_going would do too,
7271 if we called it. Do this before trying to insert the sss
7272 breakpoint, otherwise if we were previously trying to step
7273 over this exact address in another thread, the breakpoint is
7275 clear_step_over_info ();
7276 tp
->control
.trap_expected
= 0;
7278 insert_single_step_breakpoint (get_frame_arch (frame
),
7279 get_frame_address_space (frame
),
7280 tp
->suspend
.stop_pc
);
7283 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7284 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7288 infrun_debug_printf ("expected thread still hasn't advanced");
7290 keep_going_pass_signal (ecs
);
7296 /* Is thread TP in the middle of (software or hardware)
7297 single-stepping? (Note the result of this function must never be
7298 passed directly as target_resume's STEP parameter.) */
7301 currently_stepping (struct thread_info
*tp
)
7303 return ((tp
->control
.step_range_end
7304 && tp
->control
.step_resume_breakpoint
== NULL
)
7305 || tp
->control
.trap_expected
7306 || tp
->stepped_breakpoint
7307 || bpstat_should_step ());
7310 /* Inferior has stepped into a subroutine call with source code that
7311 we should not step over. Do step to the first line of code in
7315 handle_step_into_function (struct gdbarch
*gdbarch
,
7316 struct execution_control_state
*ecs
)
7318 fill_in_stop_func (gdbarch
, ecs
);
7320 compunit_symtab
*cust
7321 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7322 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7323 ecs
->stop_func_start
7324 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7326 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7327 /* Use the step_resume_break to step until the end of the prologue,
7328 even if that involves jumps (as it seems to on the vax under
7330 /* If the prologue ends in the middle of a source line, continue to
7331 the end of that source line (if it is still within the function).
7332 Otherwise, just go to end of prologue. */
7333 if (stop_func_sal
.end
7334 && stop_func_sal
.pc
!= ecs
->stop_func_start
7335 && stop_func_sal
.end
< ecs
->stop_func_end
)
7336 ecs
->stop_func_start
= stop_func_sal
.end
;
7338 /* Architectures which require breakpoint adjustment might not be able
7339 to place a breakpoint at the computed address. If so, the test
7340 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7341 ecs->stop_func_start to an address at which a breakpoint may be
7342 legitimately placed.
7344 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7345 made, GDB will enter an infinite loop when stepping through
7346 optimized code consisting of VLIW instructions which contain
7347 subinstructions corresponding to different source lines. On
7348 FR-V, it's not permitted to place a breakpoint on any but the
7349 first subinstruction of a VLIW instruction. When a breakpoint is
7350 set, GDB will adjust the breakpoint address to the beginning of
7351 the VLIW instruction. Thus, we need to make the corresponding
7352 adjustment here when computing the stop address. */
7354 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7356 ecs
->stop_func_start
7357 = gdbarch_adjust_breakpoint_address (gdbarch
,
7358 ecs
->stop_func_start
);
7361 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7363 /* We are already there: stop now. */
7364 end_stepping_range (ecs
);
7369 /* Put the step-breakpoint there and go until there. */
7370 symtab_and_line sr_sal
;
7371 sr_sal
.pc
= ecs
->stop_func_start
;
7372 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7373 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7375 /* Do not specify what the fp should be when we stop since on
7376 some machines the prologue is where the new fp value is
7378 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7380 /* And make sure stepping stops right away then. */
7381 ecs
->event_thread
->control
.step_range_end
7382 = ecs
->event_thread
->control
.step_range_start
;
7387 /* Inferior has stepped backward into a subroutine call with source
7388 code that we should not step over. Do step to the beginning of the
7389 last line of code in it. */
7392 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7393 struct execution_control_state
*ecs
)
7395 struct compunit_symtab
*cust
;
7396 struct symtab_and_line stop_func_sal
;
7398 fill_in_stop_func (gdbarch
, ecs
);
7400 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7401 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7402 ecs
->stop_func_start
7403 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7405 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7407 /* OK, we're just going to keep stepping here. */
7408 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7410 /* We're there already. Just stop stepping now. */
7411 end_stepping_range (ecs
);
7415 /* Else just reset the step range and keep going.
7416 No step-resume breakpoint, they don't work for
7417 epilogues, which can have multiple entry paths. */
7418 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7419 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7425 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7426 This is used to both functions and to skip over code. */
7429 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7430 struct symtab_and_line sr_sal
,
7431 struct frame_id sr_id
,
7432 enum bptype sr_type
)
7434 /* There should never be more than one step-resume or longjmp-resume
7435 breakpoint per thread, so we should never be setting a new
7436 step_resume_breakpoint when one is already active. */
7437 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7438 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7440 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7441 paddress (gdbarch
, sr_sal
.pc
));
7443 inferior_thread ()->control
.step_resume_breakpoint
7444 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7448 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7449 struct symtab_and_line sr_sal
,
7450 struct frame_id sr_id
)
7452 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7457 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7458 This is used to skip a potential signal handler.
7460 This is called with the interrupted function's frame. The signal
7461 handler, when it returns, will resume the interrupted function at
7465 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7467 gdb_assert (return_frame
!= NULL
);
7469 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7471 symtab_and_line sr_sal
;
7472 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7473 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7474 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7476 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7477 get_stack_frame_id (return_frame
),
7481 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7482 is used to skip a function after stepping into it (for "next" or if
7483 the called function has no debugging information).
7485 The current function has almost always been reached by single
7486 stepping a call or return instruction. NEXT_FRAME belongs to the
7487 current function, and the breakpoint will be set at the caller's
7490 This is a separate function rather than reusing
7491 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7492 get_prev_frame, which may stop prematurely (see the implementation
7493 of frame_unwind_caller_id for an example). */
7496 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7498 /* We shouldn't have gotten here if we don't know where the call site
7500 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7502 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7504 symtab_and_line sr_sal
;
7505 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7506 frame_unwind_caller_pc (next_frame
));
7507 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7508 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7510 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7511 frame_unwind_caller_id (next_frame
));
7514 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7515 new breakpoint at the target of a jmp_buf. The handling of
7516 longjmp-resume uses the same mechanisms used for handling
7517 "step-resume" breakpoints. */
7520 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7522 /* There should never be more than one longjmp-resume breakpoint per
7523 thread, so we should never be setting a new
7524 longjmp_resume_breakpoint when one is already active. */
7525 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7527 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7528 paddress (gdbarch
, pc
));
7530 inferior_thread ()->control
.exception_resume_breakpoint
=
7531 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7534 /* Insert an exception resume breakpoint. TP is the thread throwing
7535 the exception. The block B is the block of the unwinder debug hook
7536 function. FRAME is the frame corresponding to the call to this
7537 function. SYM is the symbol of the function argument holding the
7538 target PC of the exception. */
7541 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7542 const struct block
*b
,
7543 struct frame_info
*frame
,
7548 struct block_symbol vsym
;
7549 struct value
*value
;
7551 struct breakpoint
*bp
;
7553 vsym
= lookup_symbol_search_name (sym
->search_name (),
7555 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7556 /* If the value was optimized out, revert to the old behavior. */
7557 if (! value_optimized_out (value
))
7559 handler
= value_as_address (value
);
7561 infrun_debug_printf ("exception resume at %lx",
7562 (unsigned long) handler
);
7564 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7566 bp_exception_resume
).release ();
7568 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7571 bp
->thread
= tp
->global_num
;
7572 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7575 catch (const gdb_exception_error
&e
)
7577 /* We want to ignore errors here. */
7581 /* A helper for check_exception_resume that sets an
7582 exception-breakpoint based on a SystemTap probe. */
7585 insert_exception_resume_from_probe (struct thread_info
*tp
,
7586 const struct bound_probe
*probe
,
7587 struct frame_info
*frame
)
7589 struct value
*arg_value
;
7591 struct breakpoint
*bp
;
7593 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7597 handler
= value_as_address (arg_value
);
7599 infrun_debug_printf ("exception resume at %s",
7600 paddress (probe
->objfile
->arch (), handler
));
7602 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7603 handler
, bp_exception_resume
).release ();
7604 bp
->thread
= tp
->global_num
;
7605 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7608 /* This is called when an exception has been intercepted. Check to
7609 see whether the exception's destination is of interest, and if so,
7610 set an exception resume breakpoint there. */
7613 check_exception_resume (struct execution_control_state
*ecs
,
7614 struct frame_info
*frame
)
7616 struct bound_probe probe
;
7617 struct symbol
*func
;
7619 /* First see if this exception unwinding breakpoint was set via a
7620 SystemTap probe point. If so, the probe has two arguments: the
7621 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7622 set a breakpoint there. */
7623 probe
= find_probe_by_pc (get_frame_pc (frame
));
7626 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7630 func
= get_frame_function (frame
);
7636 const struct block
*b
;
7637 struct block_iterator iter
;
7641 /* The exception breakpoint is a thread-specific breakpoint on
7642 the unwinder's debug hook, declared as:
7644 void _Unwind_DebugHook (void *cfa, void *handler);
7646 The CFA argument indicates the frame to which control is
7647 about to be transferred. HANDLER is the destination PC.
7649 We ignore the CFA and set a temporary breakpoint at HANDLER.
7650 This is not extremely efficient but it avoids issues in gdb
7651 with computing the DWARF CFA, and it also works even in weird
7652 cases such as throwing an exception from inside a signal
7655 b
= SYMBOL_BLOCK_VALUE (func
);
7656 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7658 if (!SYMBOL_IS_ARGUMENT (sym
))
7665 insert_exception_resume_breakpoint (ecs
->event_thread
,
7671 catch (const gdb_exception_error
&e
)
7677 stop_waiting (struct execution_control_state
*ecs
)
7679 infrun_debug_printf ("stop_waiting");
7681 /* Let callers know we don't want to wait for the inferior anymore. */
7682 ecs
->wait_some_more
= 0;
7684 /* If all-stop, but there exists a non-stop target, stop all
7685 threads now that we're presenting the stop to the user. */
7686 if (!non_stop
&& exists_non_stop_target ())
7687 stop_all_threads ();
7690 /* Like keep_going, but passes the signal to the inferior, even if the
7691 signal is set to nopass. */
7694 keep_going_pass_signal (struct execution_control_state
*ecs
)
7696 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7697 gdb_assert (!ecs
->event_thread
->resumed
);
7699 /* Save the pc before execution, to compare with pc after stop. */
7700 ecs
->event_thread
->prev_pc
7701 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7703 if (ecs
->event_thread
->control
.trap_expected
)
7705 struct thread_info
*tp
= ecs
->event_thread
;
7707 infrun_debug_printf ("%s has trap_expected set, "
7708 "resuming to collect trap",
7709 target_pid_to_str (tp
->ptid
).c_str ());
7711 /* We haven't yet gotten our trap, and either: intercepted a
7712 non-signal event (e.g., a fork); or took a signal which we
7713 are supposed to pass through to the inferior. Simply
7715 resume (ecs
->event_thread
->suspend
.stop_signal
);
7717 else if (step_over_info_valid_p ())
7719 /* Another thread is stepping over a breakpoint in-line. If
7720 this thread needs a step-over too, queue the request. In
7721 either case, this resume must be deferred for later. */
7722 struct thread_info
*tp
= ecs
->event_thread
;
7724 if (ecs
->hit_singlestep_breakpoint
7725 || thread_still_needs_step_over (tp
))
7727 infrun_debug_printf ("step-over already in progress: "
7728 "step-over for %s deferred",
7729 target_pid_to_str (tp
->ptid
).c_str ());
7730 global_thread_step_over_chain_enqueue (tp
);
7734 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7735 target_pid_to_str (tp
->ptid
).c_str ());
7740 struct regcache
*regcache
= get_current_regcache ();
7743 step_over_what step_what
;
7745 /* Either the trap was not expected, but we are continuing
7746 anyway (if we got a signal, the user asked it be passed to
7749 We got our expected trap, but decided we should resume from
7752 We're going to run this baby now!
7754 Note that insert_breakpoints won't try to re-insert
7755 already inserted breakpoints. Therefore, we don't
7756 care if breakpoints were already inserted, or not. */
7758 /* If we need to step over a breakpoint, and we're not using
7759 displaced stepping to do so, insert all breakpoints
7760 (watchpoints, etc.) but the one we're stepping over, step one
7761 instruction, and then re-insert the breakpoint when that step
7764 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7766 remove_bp
= (ecs
->hit_singlestep_breakpoint
7767 || (step_what
& STEP_OVER_BREAKPOINT
));
7768 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7770 /* We can't use displaced stepping if we need to step past a
7771 watchpoint. The instruction copied to the scratch pad would
7772 still trigger the watchpoint. */
7774 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7776 set_step_over_info (regcache
->aspace (),
7777 regcache_read_pc (regcache
), remove_wps
,
7778 ecs
->event_thread
->global_num
);
7780 else if (remove_wps
)
7781 set_step_over_info (NULL
, 0, remove_wps
, -1);
7783 /* If we now need to do an in-line step-over, we need to stop
7784 all other threads. Note this must be done before
7785 insert_breakpoints below, because that removes the breakpoint
7786 we're about to step over, otherwise other threads could miss
7788 if (step_over_info_valid_p () && target_is_non_stop_p ())
7789 stop_all_threads ();
7791 /* Stop stepping if inserting breakpoints fails. */
7794 insert_breakpoints ();
7796 catch (const gdb_exception_error
&e
)
7798 exception_print (gdb_stderr
, e
);
7800 clear_step_over_info ();
7804 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7806 resume (ecs
->event_thread
->suspend
.stop_signal
);
7809 prepare_to_wait (ecs
);
7812 /* Called when we should continue running the inferior, because the
7813 current event doesn't cause a user visible stop. This does the
7814 resuming part; waiting for the next event is done elsewhere. */
7817 keep_going (struct execution_control_state
*ecs
)
7819 if (ecs
->event_thread
->control
.trap_expected
7820 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7821 ecs
->event_thread
->control
.trap_expected
= 0;
7823 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7824 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7825 keep_going_pass_signal (ecs
);
7828 /* This function normally comes after a resume, before
7829 handle_inferior_event exits. It takes care of any last bits of
7830 housekeeping, and sets the all-important wait_some_more flag. */
7833 prepare_to_wait (struct execution_control_state
*ecs
)
7835 infrun_debug_printf ("prepare_to_wait");
7837 ecs
->wait_some_more
= 1;
7839 /* If the target can't async, emulate it by marking the infrun event
7840 handler such that as soon as we get back to the event-loop, we
7841 immediately end up in fetch_inferior_event again calling
7843 if (!target_can_async_p ())
7844 mark_infrun_async_event_handler ();
7847 /* We are done with the step range of a step/next/si/ni command.
7848 Called once for each n of a "step n" operation. */
7851 end_stepping_range (struct execution_control_state
*ecs
)
7853 ecs
->event_thread
->control
.stop_step
= 1;
7857 /* Several print_*_reason functions to print why the inferior has stopped.
7858 We always print something when the inferior exits, or receives a signal.
7859 The rest of the cases are dealt with later on in normal_stop and
7860 print_it_typical. Ideally there should be a call to one of these
7861 print_*_reason functions functions from handle_inferior_event each time
7862 stop_waiting is called.
7864 Note that we don't call these directly, instead we delegate that to
7865 the interpreters, through observers. Interpreters then call these
7866 with whatever uiout is right. */
7869 print_end_stepping_range_reason (struct ui_out
*uiout
)
7871 /* For CLI-like interpreters, print nothing. */
7873 if (uiout
->is_mi_like_p ())
7875 uiout
->field_string ("reason",
7876 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7881 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7883 annotate_signalled ();
7884 if (uiout
->is_mi_like_p ())
7886 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7887 uiout
->text ("\nProgram terminated with signal ");
7888 annotate_signal_name ();
7889 uiout
->field_string ("signal-name",
7890 gdb_signal_to_name (siggnal
));
7891 annotate_signal_name_end ();
7893 annotate_signal_string ();
7894 uiout
->field_string ("signal-meaning",
7895 gdb_signal_to_string (siggnal
));
7896 annotate_signal_string_end ();
7897 uiout
->text (".\n");
7898 uiout
->text ("The program no longer exists.\n");
7902 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7904 struct inferior
*inf
= current_inferior ();
7905 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7907 annotate_exited (exitstatus
);
7910 if (uiout
->is_mi_like_p ())
7911 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7912 std::string exit_code_str
7913 = string_printf ("0%o", (unsigned int) exitstatus
);
7914 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7915 plongest (inf
->num
), pidstr
.c_str (),
7916 string_field ("exit-code", exit_code_str
.c_str ()));
7920 if (uiout
->is_mi_like_p ())
7922 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7923 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7924 plongest (inf
->num
), pidstr
.c_str ());
7929 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7931 struct thread_info
*thr
= inferior_thread ();
7935 if (uiout
->is_mi_like_p ())
7937 else if (show_thread_that_caused_stop ())
7941 uiout
->text ("\nThread ");
7942 uiout
->field_string ("thread-id", print_thread_id (thr
));
7944 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7947 uiout
->text (" \"");
7948 uiout
->field_string ("name", name
);
7953 uiout
->text ("\nProgram");
7955 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
7956 uiout
->text (" stopped");
7959 uiout
->text (" received signal ");
7960 annotate_signal_name ();
7961 if (uiout
->is_mi_like_p ())
7963 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7964 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
7965 annotate_signal_name_end ();
7967 annotate_signal_string ();
7968 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
7970 struct regcache
*regcache
= get_current_regcache ();
7971 struct gdbarch
*gdbarch
= regcache
->arch ();
7972 if (gdbarch_report_signal_info_p (gdbarch
))
7973 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
7975 annotate_signal_string_end ();
7977 uiout
->text (".\n");
7981 print_no_history_reason (struct ui_out
*uiout
)
7983 uiout
->text ("\nNo more reverse-execution history.\n");
7986 /* Print current location without a level number, if we have changed
7987 functions or hit a breakpoint. Print source line if we have one.
7988 bpstat_print contains the logic deciding in detail what to print,
7989 based on the event(s) that just occurred. */
7992 print_stop_location (struct target_waitstatus
*ws
)
7995 enum print_what source_flag
;
7996 int do_frame_printing
= 1;
7997 struct thread_info
*tp
= inferior_thread ();
7999 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8003 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8004 should) carry around the function and does (or should) use
8005 that when doing a frame comparison. */
8006 if (tp
->control
.stop_step
8007 && frame_id_eq (tp
->control
.step_frame_id
,
8008 get_frame_id (get_current_frame ()))
8009 && (tp
->control
.step_start_function
8010 == find_pc_function (tp
->suspend
.stop_pc
)))
8012 /* Finished step, just print source line. */
8013 source_flag
= SRC_LINE
;
8017 /* Print location and source line. */
8018 source_flag
= SRC_AND_LOC
;
8021 case PRINT_SRC_AND_LOC
:
8022 /* Print location and source line. */
8023 source_flag
= SRC_AND_LOC
;
8025 case PRINT_SRC_ONLY
:
8026 source_flag
= SRC_LINE
;
8029 /* Something bogus. */
8030 source_flag
= SRC_LINE
;
8031 do_frame_printing
= 0;
8034 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8037 /* The behavior of this routine with respect to the source
8039 SRC_LINE: Print only source line
8040 LOCATION: Print only location
8041 SRC_AND_LOC: Print location and source line. */
8042 if (do_frame_printing
)
8043 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8049 print_stop_event (struct ui_out
*uiout
, bool displays
)
8051 struct target_waitstatus last
;
8052 struct thread_info
*tp
;
8054 get_last_target_status (nullptr, nullptr, &last
);
8057 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8059 print_stop_location (&last
);
8061 /* Display the auto-display expressions. */
8066 tp
= inferior_thread ();
8067 if (tp
->thread_fsm
!= NULL
8068 && tp
->thread_fsm
->finished_p ())
8070 struct return_value_info
*rv
;
8072 rv
= tp
->thread_fsm
->return_value ();
8074 print_return_value (uiout
, rv
);
8081 maybe_remove_breakpoints (void)
8083 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8085 if (remove_breakpoints ())
8087 target_terminal::ours_for_output ();
8088 printf_filtered (_("Cannot remove breakpoints because "
8089 "program is no longer writable.\nFurther "
8090 "execution is probably impossible.\n"));
8095 /* The execution context that just caused a normal stop. */
8102 DISABLE_COPY_AND_ASSIGN (stop_context
);
8104 bool changed () const;
8109 /* The event PTID. */
8113 /* If stopp for a thread event, this is the thread that caused the
8115 struct thread_info
*thread
;
8117 /* The inferior that caused the stop. */
8121 /* Initializes a new stop context. If stopped for a thread event, this
8122 takes a strong reference to the thread. */
8124 stop_context::stop_context ()
8126 stop_id
= get_stop_id ();
8127 ptid
= inferior_ptid
;
8128 inf_num
= current_inferior ()->num
;
8130 if (inferior_ptid
!= null_ptid
)
8132 /* Take a strong reference so that the thread can't be deleted
8134 thread
= inferior_thread ();
8141 /* Release a stop context previously created with save_stop_context.
8142 Releases the strong reference to the thread as well. */
8144 stop_context::~stop_context ()
8150 /* Return true if the current context no longer matches the saved stop
8154 stop_context::changed () const
8156 if (ptid
!= inferior_ptid
)
8158 if (inf_num
!= current_inferior ()->num
)
8160 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8162 if (get_stop_id () != stop_id
)
8172 struct target_waitstatus last
;
8174 get_last_target_status (nullptr, nullptr, &last
);
8178 /* If an exception is thrown from this point on, make sure to
8179 propagate GDB's knowledge of the executing state to the
8180 frontend/user running state. A QUIT is an easy exception to see
8181 here, so do this before any filtered output. */
8183 ptid_t finish_ptid
= null_ptid
;
8186 finish_ptid
= minus_one_ptid
;
8187 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8188 || last
.kind
== TARGET_WAITKIND_EXITED
)
8190 /* On some targets, we may still have live threads in the
8191 inferior when we get a process exit event. E.g., for
8192 "checkpoint", when the current checkpoint/fork exits,
8193 linux-fork.c automatically switches to another fork from
8194 within target_mourn_inferior. */
8195 if (inferior_ptid
!= null_ptid
)
8196 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8198 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8199 finish_ptid
= inferior_ptid
;
8201 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8202 if (finish_ptid
!= null_ptid
)
8204 maybe_finish_thread_state
.emplace
8205 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8208 /* As we're presenting a stop, and potentially removing breakpoints,
8209 update the thread list so we can tell whether there are threads
8210 running on the target. With target remote, for example, we can
8211 only learn about new threads when we explicitly update the thread
8212 list. Do this before notifying the interpreters about signal
8213 stops, end of stepping ranges, etc., so that the "new thread"
8214 output is emitted before e.g., "Program received signal FOO",
8215 instead of after. */
8216 update_thread_list ();
8218 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8219 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8221 /* As with the notification of thread events, we want to delay
8222 notifying the user that we've switched thread context until
8223 the inferior actually stops.
8225 There's no point in saying anything if the inferior has exited.
8226 Note that SIGNALLED here means "exited with a signal", not
8227 "received a signal".
8229 Also skip saying anything in non-stop mode. In that mode, as we
8230 don't want GDB to switch threads behind the user's back, to avoid
8231 races where the user is typing a command to apply to thread x,
8232 but GDB switches to thread y before the user finishes entering
8233 the command, fetch_inferior_event installs a cleanup to restore
8234 the current thread back to the thread the user had selected right
8235 after this event is handled, so we're not really switching, only
8236 informing of a stop. */
8238 && previous_inferior_ptid
!= inferior_ptid
8239 && target_has_execution ()
8240 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8241 && last
.kind
!= TARGET_WAITKIND_EXITED
8242 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8244 SWITCH_THRU_ALL_UIS ()
8246 target_terminal::ours_for_output ();
8247 printf_filtered (_("[Switching to %s]\n"),
8248 target_pid_to_str (inferior_ptid
).c_str ());
8249 annotate_thread_changed ();
8251 previous_inferior_ptid
= inferior_ptid
;
8254 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8256 SWITCH_THRU_ALL_UIS ()
8257 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8259 target_terminal::ours_for_output ();
8260 printf_filtered (_("No unwaited-for children left.\n"));
8264 /* Note: this depends on the update_thread_list call above. */
8265 maybe_remove_breakpoints ();
8267 /* If an auto-display called a function and that got a signal,
8268 delete that auto-display to avoid an infinite recursion. */
8270 if (stopped_by_random_signal
)
8271 disable_current_display ();
8273 SWITCH_THRU_ALL_UIS ()
8275 async_enable_stdin ();
8278 /* Let the user/frontend see the threads as stopped. */
8279 maybe_finish_thread_state
.reset ();
8281 /* Select innermost stack frame - i.e., current frame is frame 0,
8282 and current location is based on that. Handle the case where the
8283 dummy call is returning after being stopped. E.g. the dummy call
8284 previously hit a breakpoint. (If the dummy call returns
8285 normally, we won't reach here.) Do this before the stop hook is
8286 run, so that it doesn't get to see the temporary dummy frame,
8287 which is not where we'll present the stop. */
8288 if (has_stack_frames ())
8290 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8292 /* Pop the empty frame that contains the stack dummy. This
8293 also restores inferior state prior to the call (struct
8294 infcall_suspend_state). */
8295 struct frame_info
*frame
= get_current_frame ();
8297 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8299 /* frame_pop calls reinit_frame_cache as the last thing it
8300 does which means there's now no selected frame. */
8303 select_frame (get_current_frame ());
8305 /* Set the current source location. */
8306 set_current_sal_from_frame (get_current_frame ());
8309 /* Look up the hook_stop and run it (CLI internally handles problem
8310 of stop_command's pre-hook not existing). */
8311 if (stop_command
!= NULL
)
8313 stop_context saved_context
;
8317 execute_cmd_pre_hook (stop_command
);
8319 catch (const gdb_exception
&ex
)
8321 exception_fprintf (gdb_stderr
, ex
,
8322 "Error while running hook_stop:\n");
8325 /* If the stop hook resumes the target, then there's no point in
8326 trying to notify about the previous stop; its context is
8327 gone. Likewise if the command switches thread or inferior --
8328 the observers would print a stop for the wrong
8330 if (saved_context
.changed ())
8334 /* Notify observers about the stop. This is where the interpreters
8335 print the stop event. */
8336 if (inferior_ptid
!= null_ptid
)
8337 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8340 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8342 annotate_stopped ();
8344 if (target_has_execution ())
8346 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8347 && last
.kind
!= TARGET_WAITKIND_EXITED
8348 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8349 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8350 Delete any breakpoint that is to be deleted at the next stop. */
8351 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8354 /* Try to get rid of automatically added inferiors that are no
8355 longer needed. Keeping those around slows down things linearly.
8356 Note that this never removes the current inferior. */
8363 signal_stop_state (int signo
)
8365 return signal_stop
[signo
];
8369 signal_print_state (int signo
)
8371 return signal_print
[signo
];
8375 signal_pass_state (int signo
)
8377 return signal_program
[signo
];
8381 signal_cache_update (int signo
)
8385 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8386 signal_cache_update (signo
);
8391 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8392 && signal_print
[signo
] == 0
8393 && signal_program
[signo
] == 1
8394 && signal_catch
[signo
] == 0);
8398 signal_stop_update (int signo
, int state
)
8400 int ret
= signal_stop
[signo
];
8402 signal_stop
[signo
] = state
;
8403 signal_cache_update (signo
);
8408 signal_print_update (int signo
, int state
)
8410 int ret
= signal_print
[signo
];
8412 signal_print
[signo
] = state
;
8413 signal_cache_update (signo
);
8418 signal_pass_update (int signo
, int state
)
8420 int ret
= signal_program
[signo
];
8422 signal_program
[signo
] = state
;
8423 signal_cache_update (signo
);
8427 /* Update the global 'signal_catch' from INFO and notify the
8431 signal_catch_update (const unsigned int *info
)
8435 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8436 signal_catch
[i
] = info
[i
] > 0;
8437 signal_cache_update (-1);
8438 target_pass_signals (signal_pass
);
8442 sig_print_header (void)
8444 printf_filtered (_("Signal Stop\tPrint\tPass "
8445 "to program\tDescription\n"));
8449 sig_print_info (enum gdb_signal oursig
)
8451 const char *name
= gdb_signal_to_name (oursig
);
8452 int name_padding
= 13 - strlen (name
);
8454 if (name_padding
<= 0)
8457 printf_filtered ("%s", name
);
8458 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8459 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8460 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8461 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8462 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8465 /* Specify how various signals in the inferior should be handled. */
8468 handle_command (const char *args
, int from_tty
)
8470 int digits
, wordlen
;
8471 int sigfirst
, siglast
;
8472 enum gdb_signal oursig
;
8477 error_no_arg (_("signal to handle"));
8480 /* Allocate and zero an array of flags for which signals to handle. */
8482 const size_t nsigs
= GDB_SIGNAL_LAST
;
8483 unsigned char sigs
[nsigs
] {};
8485 /* Break the command line up into args. */
8487 gdb_argv
built_argv (args
);
8489 /* Walk through the args, looking for signal oursigs, signal names, and
8490 actions. Signal numbers and signal names may be interspersed with
8491 actions, with the actions being performed for all signals cumulatively
8492 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8494 for (char *arg
: built_argv
)
8496 wordlen
= strlen (arg
);
8497 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8501 sigfirst
= siglast
= -1;
8503 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8505 /* Apply action to all signals except those used by the
8506 debugger. Silently skip those. */
8509 siglast
= nsigs
- 1;
8511 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8513 SET_SIGS (nsigs
, sigs
, signal_stop
);
8514 SET_SIGS (nsigs
, sigs
, signal_print
);
8516 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8518 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8520 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8522 SET_SIGS (nsigs
, sigs
, signal_print
);
8524 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8526 SET_SIGS (nsigs
, sigs
, signal_program
);
8528 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8530 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8532 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8534 SET_SIGS (nsigs
, sigs
, signal_program
);
8536 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8538 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8539 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8541 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8543 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8545 else if (digits
> 0)
8547 /* It is numeric. The numeric signal refers to our own
8548 internal signal numbering from target.h, not to host/target
8549 signal number. This is a feature; users really should be
8550 using symbolic names anyway, and the common ones like
8551 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8553 sigfirst
= siglast
= (int)
8554 gdb_signal_from_command (atoi (arg
));
8555 if (arg
[digits
] == '-')
8558 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8560 if (sigfirst
> siglast
)
8562 /* Bet he didn't figure we'd think of this case... */
8563 std::swap (sigfirst
, siglast
);
8568 oursig
= gdb_signal_from_name (arg
);
8569 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8571 sigfirst
= siglast
= (int) oursig
;
8575 /* Not a number and not a recognized flag word => complain. */
8576 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8580 /* If any signal numbers or symbol names were found, set flags for
8581 which signals to apply actions to. */
8583 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8585 switch ((enum gdb_signal
) signum
)
8587 case GDB_SIGNAL_TRAP
:
8588 case GDB_SIGNAL_INT
:
8589 if (!allsigs
&& !sigs
[signum
])
8591 if (query (_("%s is used by the debugger.\n\
8592 Are you sure you want to change it? "),
8593 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8598 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8602 case GDB_SIGNAL_DEFAULT
:
8603 case GDB_SIGNAL_UNKNOWN
:
8604 /* Make sure that "all" doesn't print these. */
8613 for (int signum
= 0; signum
< nsigs
; signum
++)
8616 signal_cache_update (-1);
8617 target_pass_signals (signal_pass
);
8618 target_program_signals (signal_program
);
8622 /* Show the results. */
8623 sig_print_header ();
8624 for (; signum
< nsigs
; signum
++)
8626 sig_print_info ((enum gdb_signal
) signum
);
8633 /* Complete the "handle" command. */
8636 handle_completer (struct cmd_list_element
*ignore
,
8637 completion_tracker
&tracker
,
8638 const char *text
, const char *word
)
8640 static const char * const keywords
[] =
8654 signal_completer (ignore
, tracker
, text
, word
);
8655 complete_on_enum (tracker
, keywords
, word
, word
);
8659 gdb_signal_from_command (int num
)
8661 if (num
>= 1 && num
<= 15)
8662 return (enum gdb_signal
) num
;
8663 error (_("Only signals 1-15 are valid as numeric signals.\n\
8664 Use \"info signals\" for a list of symbolic signals."));
8667 /* Print current contents of the tables set by the handle command.
8668 It is possible we should just be printing signals actually used
8669 by the current target (but for things to work right when switching
8670 targets, all signals should be in the signal tables). */
8673 info_signals_command (const char *signum_exp
, int from_tty
)
8675 enum gdb_signal oursig
;
8677 sig_print_header ();
8681 /* First see if this is a symbol name. */
8682 oursig
= gdb_signal_from_name (signum_exp
);
8683 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8685 /* No, try numeric. */
8687 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8689 sig_print_info (oursig
);
8693 printf_filtered ("\n");
8694 /* These ugly casts brought to you by the native VAX compiler. */
8695 for (oursig
= GDB_SIGNAL_FIRST
;
8696 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8697 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8701 if (oursig
!= GDB_SIGNAL_UNKNOWN
8702 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8703 sig_print_info (oursig
);
8706 printf_filtered (_("\nUse the \"handle\" command "
8707 "to change these tables.\n"));
8710 /* The $_siginfo convenience variable is a bit special. We don't know
8711 for sure the type of the value until we actually have a chance to
8712 fetch the data. The type can change depending on gdbarch, so it is
8713 also dependent on which thread you have selected.
8715 1. making $_siginfo be an internalvar that creates a new value on
8718 2. making the value of $_siginfo be an lval_computed value. */
8720 /* This function implements the lval_computed support for reading a
8724 siginfo_value_read (struct value
*v
)
8726 LONGEST transferred
;
8728 /* If we can access registers, so can we access $_siginfo. Likewise
8730 validate_registers_access ();
8733 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8735 value_contents_all_raw (v
),
8737 TYPE_LENGTH (value_type (v
)));
8739 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8740 error (_("Unable to read siginfo"));
8743 /* This function implements the lval_computed support for writing a
8747 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8749 LONGEST transferred
;
8751 /* If we can access registers, so can we access $_siginfo. Likewise
8753 validate_registers_access ();
8755 transferred
= target_write (current_top_target (),
8756 TARGET_OBJECT_SIGNAL_INFO
,
8758 value_contents_all_raw (fromval
),
8760 TYPE_LENGTH (value_type (fromval
)));
8762 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8763 error (_("Unable to write siginfo"));
8766 static const struct lval_funcs siginfo_value_funcs
=
8772 /* Return a new value with the correct type for the siginfo object of
8773 the current thread using architecture GDBARCH. Return a void value
8774 if there's no object available. */
8776 static struct value
*
8777 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8780 if (target_has_stack ()
8781 && inferior_ptid
!= null_ptid
8782 && gdbarch_get_siginfo_type_p (gdbarch
))
8784 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8786 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8789 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8793 /* infcall_suspend_state contains state about the program itself like its
8794 registers and any signal it received when it last stopped.
8795 This state must be restored regardless of how the inferior function call
8796 ends (either successfully, or after it hits a breakpoint or signal)
8797 if the program is to properly continue where it left off. */
8799 class infcall_suspend_state
8802 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8803 once the inferior function call has finished. */
8804 infcall_suspend_state (struct gdbarch
*gdbarch
,
8805 const struct thread_info
*tp
,
8806 struct regcache
*regcache
)
8807 : m_thread_suspend (tp
->suspend
),
8808 m_registers (new readonly_detached_regcache (*regcache
))
8810 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8812 if (gdbarch_get_siginfo_type_p (gdbarch
))
8814 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8815 size_t len
= TYPE_LENGTH (type
);
8817 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8819 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8820 siginfo_data
.get (), 0, len
) != len
)
8822 /* Errors ignored. */
8823 siginfo_data
.reset (nullptr);
8829 m_siginfo_gdbarch
= gdbarch
;
8830 m_siginfo_data
= std::move (siginfo_data
);
8834 /* Return a pointer to the stored register state. */
8836 readonly_detached_regcache
*registers () const
8838 return m_registers
.get ();
8841 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8843 void restore (struct gdbarch
*gdbarch
,
8844 struct thread_info
*tp
,
8845 struct regcache
*regcache
) const
8847 tp
->suspend
= m_thread_suspend
;
8849 if (m_siginfo_gdbarch
== gdbarch
)
8851 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8853 /* Errors ignored. */
8854 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8855 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8858 /* The inferior can be gone if the user types "print exit(0)"
8859 (and perhaps other times). */
8860 if (target_has_execution ())
8861 /* NB: The register write goes through to the target. */
8862 regcache
->restore (registers ());
8866 /* How the current thread stopped before the inferior function call was
8868 struct thread_suspend_state m_thread_suspend
;
8870 /* The registers before the inferior function call was executed. */
8871 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8873 /* Format of SIGINFO_DATA or NULL if it is not present. */
8874 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8876 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8877 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8878 content would be invalid. */
8879 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8882 infcall_suspend_state_up
8883 save_infcall_suspend_state ()
8885 struct thread_info
*tp
= inferior_thread ();
8886 struct regcache
*regcache
= get_current_regcache ();
8887 struct gdbarch
*gdbarch
= regcache
->arch ();
8889 infcall_suspend_state_up inf_state
8890 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8892 /* Having saved the current state, adjust the thread state, discarding
8893 any stop signal information. The stop signal is not useful when
8894 starting an inferior function call, and run_inferior_call will not use
8895 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8896 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8901 /* Restore inferior session state to INF_STATE. */
8904 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8906 struct thread_info
*tp
= inferior_thread ();
8907 struct regcache
*regcache
= get_current_regcache ();
8908 struct gdbarch
*gdbarch
= regcache
->arch ();
8910 inf_state
->restore (gdbarch
, tp
, regcache
);
8911 discard_infcall_suspend_state (inf_state
);
8915 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8920 readonly_detached_regcache
*
8921 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8923 return inf_state
->registers ();
8926 /* infcall_control_state contains state regarding gdb's control of the
8927 inferior itself like stepping control. It also contains session state like
8928 the user's currently selected frame. */
8930 struct infcall_control_state
8932 struct thread_control_state thread_control
;
8933 struct inferior_control_state inferior_control
;
8936 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8937 int stopped_by_random_signal
= 0;
8939 /* ID and level of the selected frame when the inferior function
8941 struct frame_id selected_frame_id
{};
8942 int selected_frame_level
= -1;
8945 /* Save all of the information associated with the inferior<==>gdb
8948 infcall_control_state_up
8949 save_infcall_control_state ()
8951 infcall_control_state_up
inf_status (new struct infcall_control_state
);
8952 struct thread_info
*tp
= inferior_thread ();
8953 struct inferior
*inf
= current_inferior ();
8955 inf_status
->thread_control
= tp
->control
;
8956 inf_status
->inferior_control
= inf
->control
;
8958 tp
->control
.step_resume_breakpoint
= NULL
;
8959 tp
->control
.exception_resume_breakpoint
= NULL
;
8961 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8962 chain. If caller's caller is walking the chain, they'll be happier if we
8963 hand them back the original chain when restore_infcall_control_state is
8965 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
8968 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
8969 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
8971 save_selected_frame (&inf_status
->selected_frame_id
,
8972 &inf_status
->selected_frame_level
);
8977 /* Restore inferior session state to INF_STATUS. */
8980 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
8982 struct thread_info
*tp
= inferior_thread ();
8983 struct inferior
*inf
= current_inferior ();
8985 if (tp
->control
.step_resume_breakpoint
)
8986 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
8988 if (tp
->control
.exception_resume_breakpoint
)
8989 tp
->control
.exception_resume_breakpoint
->disposition
8990 = disp_del_at_next_stop
;
8992 /* Handle the bpstat_copy of the chain. */
8993 bpstat_clear (&tp
->control
.stop_bpstat
);
8995 tp
->control
= inf_status
->thread_control
;
8996 inf
->control
= inf_status
->inferior_control
;
8999 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9000 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9002 if (target_has_stack ())
9004 restore_selected_frame (inf_status
->selected_frame_id
,
9005 inf_status
->selected_frame_level
);
9012 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9014 if (inf_status
->thread_control
.step_resume_breakpoint
)
9015 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9016 = disp_del_at_next_stop
;
9018 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9019 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9020 = disp_del_at_next_stop
;
9022 /* See save_infcall_control_state for info on stop_bpstat. */
9023 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9031 clear_exit_convenience_vars (void)
9033 clear_internalvar (lookup_internalvar ("_exitsignal"));
9034 clear_internalvar (lookup_internalvar ("_exitcode"));
9038 /* User interface for reverse debugging:
9039 Set exec-direction / show exec-direction commands
9040 (returns error unless target implements to_set_exec_direction method). */
9042 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9043 static const char exec_forward
[] = "forward";
9044 static const char exec_reverse
[] = "reverse";
9045 static const char *exec_direction
= exec_forward
;
9046 static const char *const exec_direction_names
[] = {
9053 set_exec_direction_func (const char *args
, int from_tty
,
9054 struct cmd_list_element
*cmd
)
9056 if (target_can_execute_reverse ())
9058 if (!strcmp (exec_direction
, exec_forward
))
9059 execution_direction
= EXEC_FORWARD
;
9060 else if (!strcmp (exec_direction
, exec_reverse
))
9061 execution_direction
= EXEC_REVERSE
;
9065 exec_direction
= exec_forward
;
9066 error (_("Target does not support this operation."));
9071 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9072 struct cmd_list_element
*cmd
, const char *value
)
9074 switch (execution_direction
) {
9076 fprintf_filtered (out
, _("Forward.\n"));
9079 fprintf_filtered (out
, _("Reverse.\n"));
9082 internal_error (__FILE__
, __LINE__
,
9083 _("bogus execution_direction value: %d"),
9084 (int) execution_direction
);
9089 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9090 struct cmd_list_element
*c
, const char *value
)
9092 fprintf_filtered (file
, _("Resuming the execution of threads "
9093 "of all processes is %s.\n"), value
);
9096 /* Implementation of `siginfo' variable. */
9098 static const struct internalvar_funcs siginfo_funcs
=
9105 /* Callback for infrun's target events source. This is marked when a
9106 thread has a pending status to process. */
9109 infrun_async_inferior_event_handler (gdb_client_data data
)
9111 inferior_event_handler (INF_REG_EVENT
);
9118 /* Verify that when two threads with the same ptid exist (from two different
9119 targets) and one of them changes ptid, we only update inferior_ptid if
9120 it is appropriate. */
9123 infrun_thread_ptid_changed ()
9125 gdbarch
*arch
= current_inferior ()->gdbarch
;
9127 /* The thread which inferior_ptid represents changes ptid. */
9129 scoped_restore_current_pspace_and_thread restore
;
9131 scoped_mock_context
<test_target_ops
> target1 (arch
);
9132 scoped_mock_context
<test_target_ops
> target2 (arch
);
9133 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9135 ptid_t
old_ptid (111, 222);
9136 ptid_t
new_ptid (111, 333);
9138 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9139 target1
.mock_thread
.ptid
= old_ptid
;
9140 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9141 target2
.mock_thread
.ptid
= old_ptid
;
9143 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9144 set_current_inferior (&target1
.mock_inferior
);
9146 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9148 gdb_assert (inferior_ptid
== new_ptid
);
9151 /* A thread with the same ptid as inferior_ptid, but from another target,
9154 scoped_restore_current_pspace_and_thread restore
;
9156 scoped_mock_context
<test_target_ops
> target1 (arch
);
9157 scoped_mock_context
<test_target_ops
> target2 (arch
);
9158 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9160 ptid_t
old_ptid (111, 222);
9161 ptid_t
new_ptid (111, 333);
9163 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9164 target1
.mock_thread
.ptid
= old_ptid
;
9165 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9166 target2
.mock_thread
.ptid
= old_ptid
;
9168 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9169 set_current_inferior (&target2
.mock_inferior
);
9171 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9173 gdb_assert (inferior_ptid
== old_ptid
);
9177 } /* namespace selftests */
9179 #endif /* GDB_SELF_TEST */
9181 void _initialize_infrun ();
9183 _initialize_infrun ()
9185 struct cmd_list_element
*c
;
9187 /* Register extra event sources in the event loop. */
9188 infrun_async_inferior_event_token
9189 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9192 add_info ("signals", info_signals_command
, _("\
9193 What debugger does when program gets various signals.\n\
9194 Specify a signal as argument to print info on that signal only."));
9195 add_info_alias ("handle", "signals", 0);
9197 c
= add_com ("handle", class_run
, handle_command
, _("\
9198 Specify how to handle signals.\n\
9199 Usage: handle SIGNAL [ACTIONS]\n\
9200 Args are signals and actions to apply to those signals.\n\
9201 If no actions are specified, the current settings for the specified signals\n\
9202 will be displayed instead.\n\
9204 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9205 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9206 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9207 The special arg \"all\" is recognized to mean all signals except those\n\
9208 used by the debugger, typically SIGTRAP and SIGINT.\n\
9210 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9211 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9212 Stop means reenter debugger if this signal happens (implies print).\n\
9213 Print means print a message if this signal happens.\n\
9214 Pass means let program see this signal; otherwise program doesn't know.\n\
9215 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9216 Pass and Stop may be combined.\n\
9218 Multiple signals may be specified. Signal numbers and signal names\n\
9219 may be interspersed with actions, with the actions being performed for\n\
9220 all signals cumulatively specified."));
9221 set_cmd_completer (c
, handle_completer
);
9224 stop_command
= add_cmd ("stop", class_obscure
,
9225 not_just_help_class_command
, _("\
9226 There is no `stop' command, but you can set a hook on `stop'.\n\
9227 This allows you to set a list of commands to be run each time execution\n\
9228 of the program stops."), &cmdlist
);
9230 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9231 Set inferior debugging."), _("\
9232 Show inferior debugging."), _("\
9233 When non-zero, inferior specific debugging is enabled."),
9236 &setdebuglist
, &showdebuglist
);
9238 add_setshow_boolean_cmd ("non-stop", no_class
,
9240 Set whether gdb controls the inferior in non-stop mode."), _("\
9241 Show whether gdb controls the inferior in non-stop mode."), _("\
9242 When debugging a multi-threaded program and this setting is\n\
9243 off (the default, also called all-stop mode), when one thread stops\n\
9244 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9245 all other threads in the program while you interact with the thread of\n\
9246 interest. When you continue or step a thread, you can allow the other\n\
9247 threads to run, or have them remain stopped, but while you inspect any\n\
9248 thread's state, all threads stop.\n\
9250 In non-stop mode, when one thread stops, other threads can continue\n\
9251 to run freely. You'll be able to step each thread independently,\n\
9252 leave it stopped or free to run as needed."),
9258 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9261 signal_print
[i
] = 1;
9262 signal_program
[i
] = 1;
9263 signal_catch
[i
] = 0;
9266 /* Signals caused by debugger's own actions should not be given to
9267 the program afterwards.
9269 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9270 explicitly specifies that it should be delivered to the target
9271 program. Typically, that would occur when a user is debugging a
9272 target monitor on a simulator: the target monitor sets a
9273 breakpoint; the simulator encounters this breakpoint and halts
9274 the simulation handing control to GDB; GDB, noting that the stop
9275 address doesn't map to any known breakpoint, returns control back
9276 to the simulator; the simulator then delivers the hardware
9277 equivalent of a GDB_SIGNAL_TRAP to the program being
9279 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9280 signal_program
[GDB_SIGNAL_INT
] = 0;
9282 /* Signals that are not errors should not normally enter the debugger. */
9283 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9284 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9285 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9286 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9287 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9288 signal_print
[GDB_SIGNAL_PROF
] = 0;
9289 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9290 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9291 signal_stop
[GDB_SIGNAL_IO
] = 0;
9292 signal_print
[GDB_SIGNAL_IO
] = 0;
9293 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9294 signal_print
[GDB_SIGNAL_POLL
] = 0;
9295 signal_stop
[GDB_SIGNAL_URG
] = 0;
9296 signal_print
[GDB_SIGNAL_URG
] = 0;
9297 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9298 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9299 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9300 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9302 /* These signals are used internally by user-level thread
9303 implementations. (See signal(5) on Solaris.) Like the above
9304 signals, a healthy program receives and handles them as part of
9305 its normal operation. */
9306 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9307 signal_print
[GDB_SIGNAL_LWP
] = 0;
9308 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9309 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9310 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9311 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9312 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9313 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9315 /* Update cached state. */
9316 signal_cache_update (-1);
9318 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9319 &stop_on_solib_events
, _("\
9320 Set stopping for shared library events."), _("\
9321 Show stopping for shared library events."), _("\
9322 If nonzero, gdb will give control to the user when the dynamic linker\n\
9323 notifies gdb of shared library events. The most common event of interest\n\
9324 to the user would be loading/unloading of a new library."),
9325 set_stop_on_solib_events
,
9326 show_stop_on_solib_events
,
9327 &setlist
, &showlist
);
9329 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9330 follow_fork_mode_kind_names
,
9331 &follow_fork_mode_string
, _("\
9332 Set debugger response to a program call of fork or vfork."), _("\
9333 Show debugger response to a program call of fork or vfork."), _("\
9334 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9335 parent - the original process is debugged after a fork\n\
9336 child - the new process is debugged after a fork\n\
9337 The unfollowed process will continue to run.\n\
9338 By default, the debugger will follow the parent process."),
9340 show_follow_fork_mode_string
,
9341 &setlist
, &showlist
);
9343 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9344 follow_exec_mode_names
,
9345 &follow_exec_mode_string
, _("\
9346 Set debugger response to a program call of exec."), _("\
9347 Show debugger response to a program call of exec."), _("\
9348 An exec call replaces the program image of a process.\n\
9350 follow-exec-mode can be:\n\
9352 new - the debugger creates a new inferior and rebinds the process\n\
9353 to this new inferior. The program the process was running before\n\
9354 the exec call can be restarted afterwards by restarting the original\n\
9357 same - the debugger keeps the process bound to the same inferior.\n\
9358 The new executable image replaces the previous executable loaded in\n\
9359 the inferior. Restarting the inferior after the exec call restarts\n\
9360 the executable the process was running after the exec call.\n\
9362 By default, the debugger will use the same inferior."),
9364 show_follow_exec_mode_string
,
9365 &setlist
, &showlist
);
9367 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9368 scheduler_enums
, &scheduler_mode
, _("\
9369 Set mode for locking scheduler during execution."), _("\
9370 Show mode for locking scheduler during execution."), _("\
9371 off == no locking (threads may preempt at any time)\n\
9372 on == full locking (no thread except the current thread may run)\n\
9373 This applies to both normal execution and replay mode.\n\
9374 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9375 In this mode, other threads may run during other commands.\n\
9376 This applies to both normal execution and replay mode.\n\
9377 replay == scheduler locked in replay mode and unlocked during normal execution."),
9378 set_schedlock_func
, /* traps on target vector */
9379 show_scheduler_mode
,
9380 &setlist
, &showlist
);
9382 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9383 Set mode for resuming threads of all processes."), _("\
9384 Show mode for resuming threads of all processes."), _("\
9385 When on, execution commands (such as 'continue' or 'next') resume all\n\
9386 threads of all processes. When off (which is the default), execution\n\
9387 commands only resume the threads of the current process. The set of\n\
9388 threads that are resumed is further refined by the scheduler-locking\n\
9389 mode (see help set scheduler-locking)."),
9391 show_schedule_multiple
,
9392 &setlist
, &showlist
);
9394 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9395 Set mode of the step operation."), _("\
9396 Show mode of the step operation."), _("\
9397 When set, doing a step over a function without debug line information\n\
9398 will stop at the first instruction of that function. Otherwise, the\n\
9399 function is skipped and the step command stops at a different source line."),
9401 show_step_stop_if_no_debug
,
9402 &setlist
, &showlist
);
9404 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9405 &can_use_displaced_stepping
, _("\
9406 Set debugger's willingness to use displaced stepping."), _("\
9407 Show debugger's willingness to use displaced stepping."), _("\
9408 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9409 supported by the target architecture. If off, gdb will not use displaced\n\
9410 stepping to step over breakpoints, even if such is supported by the target\n\
9411 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9412 if the target architecture supports it and non-stop mode is active, but will not\n\
9413 use it in all-stop mode (see help set non-stop)."),
9415 show_can_use_displaced_stepping
,
9416 &setlist
, &showlist
);
9418 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9419 &exec_direction
, _("Set direction of execution.\n\
9420 Options are 'forward' or 'reverse'."),
9421 _("Show direction of execution (forward/reverse)."),
9422 _("Tells gdb whether to execute forward or backward."),
9423 set_exec_direction_func
, show_exec_direction_func
,
9424 &setlist
, &showlist
);
9426 /* Set/show detach-on-fork: user-settable mode. */
9428 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9429 Set whether gdb will detach the child of a fork."), _("\
9430 Show whether gdb will detach the child of a fork."), _("\
9431 Tells gdb whether to detach the child of a fork."),
9432 NULL
, NULL
, &setlist
, &showlist
);
9434 /* Set/show disable address space randomization mode. */
9436 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9437 &disable_randomization
, _("\
9438 Set disabling of debuggee's virtual address space randomization."), _("\
9439 Show disabling of debuggee's virtual address space randomization."), _("\
9440 When this mode is on (which is the default), randomization of the virtual\n\
9441 address space is disabled. Standalone programs run with the randomization\n\
9442 enabled by default on some platforms."),
9443 &set_disable_randomization
,
9444 &show_disable_randomization
,
9445 &setlist
, &showlist
);
9447 /* ptid initializations */
9448 inferior_ptid
= null_ptid
;
9449 target_last_wait_ptid
= minus_one_ptid
;
9451 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9452 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9453 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9454 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9455 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
);
9457 /* Explicitly create without lookup, since that tries to create a
9458 value with a void typed value, and when we get here, gdbarch
9459 isn't initialized yet. At this point, we're quite sure there
9460 isn't another convenience variable of the same name. */
9461 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9463 add_setshow_boolean_cmd ("observer", no_class
,
9464 &observer_mode_1
, _("\
9465 Set whether gdb controls the inferior in observer mode."), _("\
9466 Show whether gdb controls the inferior in observer mode."), _("\
9467 In observer mode, GDB can get data from the inferior, but not\n\
9468 affect its execution. Registers and memory may not be changed,\n\
9469 breakpoints may not be set, and the program cannot be interrupted\n\
9477 selftests::register_test ("infrun_thread_ptid_changed",
9478 selftests::infrun_thread_ptid_changed
);