1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 Free Software Foundation, Inc.
5 Copyright (C) 2019-2020 Advanced Micro Devices, Inc. All rights reserved.
7 This file is part of GDB.
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>. */
28 #include "breakpoint.h"
32 #include "gdbthread.h"
39 #include "observable.h"
44 #include "mi/mi-common.h"
45 #include "event-top.h"
47 #include "record-full.h"
48 #include "inline-frame.h"
50 #include "tracepoint.h"
54 #include "completer.h"
55 #include "target-descriptions.h"
56 #include "target-dcache.h"
59 #include "event-loop.h"
60 #include "thread-fsm.h"
61 #include "gdbsupport/enum-flags.h"
62 #include "progspace-and-thread.h"
63 #include "gdbsupport/gdb_optional.h"
64 #include "arch-utils.h"
65 #include "gdbsupport/scope-exit.h"
66 #include "gdbsupport/forward-scope-exit.h"
68 /* Prototypes for local functions */
70 static void sig_print_info (enum gdb_signal
);
72 static void sig_print_header (void);
74 static int follow_fork (void);
76 static int follow_fork_inferior (int follow_child
, int detach_fork
);
78 static void follow_inferior_reset_breakpoints (void);
80 static int currently_stepping (struct thread_info
*tp
);
82 void nullify_last_target_wait_ptid (void);
84 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
86 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
88 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
90 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
92 static void resume (gdb_signal sig
);
94 /* Asynchronous signal handler registered as event loop source for
95 when we have pending events ready to be passed to the core. */
96 static struct async_event_handler
*infrun_async_inferior_event_token
;
98 /* Stores whether infrun_async was previously enabled or disabled.
99 Starts off as -1, indicating "never enabled/disabled". */
100 static int infrun_is_async
= -1;
105 infrun_async (int enable
)
107 if (infrun_is_async
!= enable
)
109 infrun_is_async
= enable
;
112 fprintf_unfiltered (gdb_stdlog
,
113 "infrun: infrun_async(%d)\n",
117 mark_async_event_handler (infrun_async_inferior_event_token
);
119 clear_async_event_handler (infrun_async_inferior_event_token
);
126 mark_infrun_async_event_handler (void)
128 mark_async_event_handler (infrun_async_inferior_event_token
);
131 /* When set, stop the 'step' command if we enter a function which has
132 no line number information. The normal behavior is that we step
133 over such function. */
134 bool step_stop_if_no_debug
= false;
136 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
137 struct cmd_list_element
*c
, const char *value
)
139 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
142 /* proceed and normal_stop use this to notify the user when the
143 inferior stopped in a different thread than it had been running
146 static ptid_t previous_inferior_ptid
;
148 /* If set (default for legacy reasons), when following a fork, GDB
149 will detach from one of the fork branches, child or parent.
150 Exactly which branch is detached depends on 'set follow-fork-mode'
153 static bool detach_fork
= true;
155 bool debug_displaced
= false;
157 show_debug_displaced (struct ui_file
*file
, int from_tty
,
158 struct cmd_list_element
*c
, const char *value
)
160 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
163 unsigned int debug_infrun
= 0;
165 show_debug_infrun (struct ui_file
*file
, int from_tty
,
166 struct cmd_list_element
*c
, const char *value
)
168 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
172 /* Support for disabling address space randomization. */
174 bool disable_randomization
= true;
177 show_disable_randomization (struct ui_file
*file
, int from_tty
,
178 struct cmd_list_element
*c
, const char *value
)
180 if (target_supports_disable_randomization ())
181 fprintf_filtered (file
,
182 _("Disabling randomization of debuggee's "
183 "virtual address space is %s.\n"),
186 fputs_filtered (_("Disabling randomization of debuggee's "
187 "virtual address space is unsupported on\n"
188 "this platform.\n"), file
);
192 set_disable_randomization (const char *args
, int from_tty
,
193 struct cmd_list_element
*c
)
195 if (!target_supports_disable_randomization ())
196 error (_("Disabling randomization of debuggee's "
197 "virtual address space is unsupported on\n"
201 /* User interface for non-stop mode. */
203 bool non_stop
= false;
204 static bool non_stop_1
= false;
207 set_non_stop (const char *args
, int from_tty
,
208 struct cmd_list_element
*c
)
210 if (target_has_execution
)
212 non_stop_1
= non_stop
;
213 error (_("Cannot change this setting while the inferior is running."));
216 non_stop
= non_stop_1
;
220 show_non_stop (struct ui_file
*file
, int from_tty
,
221 struct cmd_list_element
*c
, const char *value
)
223 fprintf_filtered (file
,
224 _("Controlling the inferior in non-stop mode is %s.\n"),
228 /* "Observer mode" is somewhat like a more extreme version of
229 non-stop, in which all GDB operations that might affect the
230 target's execution have been disabled. */
232 bool observer_mode
= false;
233 static bool observer_mode_1
= false;
236 set_observer_mode (const char *args
, int from_tty
,
237 struct cmd_list_element
*c
)
239 if (target_has_execution
)
241 observer_mode_1
= observer_mode
;
242 error (_("Cannot change this setting while the inferior is running."));
245 observer_mode
= observer_mode_1
;
247 may_write_registers
= !observer_mode
;
248 may_write_memory
= !observer_mode
;
249 may_insert_breakpoints
= !observer_mode
;
250 may_insert_tracepoints
= !observer_mode
;
251 /* We can insert fast tracepoints in or out of observer mode,
252 but enable them if we're going into this mode. */
254 may_insert_fast_tracepoints
= true;
255 may_stop
= !observer_mode
;
256 update_target_permissions ();
258 /* Going *into* observer mode we must force non-stop, then
259 going out we leave it that way. */
262 pagination_enabled
= 0;
263 non_stop
= non_stop_1
= true;
267 printf_filtered (_("Observer mode is now %s.\n"),
268 (observer_mode
? "on" : "off"));
272 show_observer_mode (struct ui_file
*file
, int from_tty
,
273 struct cmd_list_element
*c
, const char *value
)
275 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
278 /* This updates the value of observer mode based on changes in
279 permissions. Note that we are deliberately ignoring the values of
280 may-write-registers and may-write-memory, since the user may have
281 reason to enable these during a session, for instance to turn on a
282 debugging-related global. */
285 update_observer_mode (void)
287 bool newval
= (!may_insert_breakpoints
288 && !may_insert_tracepoints
289 && may_insert_fast_tracepoints
293 /* Let the user know if things change. */
294 if (newval
!= observer_mode
)
295 printf_filtered (_("Observer mode is now %s.\n"),
296 (newval
? "on" : "off"));
298 observer_mode
= observer_mode_1
= newval
;
301 /* Tables of how to react to signals; the user sets them. */
303 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
304 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
305 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
307 /* Table of signals that are registered with "catch signal". A
308 non-zero entry indicates that the signal is caught by some "catch
310 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
312 /* Table of signals that the target may silently handle.
313 This is automatically determined from the flags above,
314 and simply cached here. */
315 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
317 #define SET_SIGS(nsigs,sigs,flags) \
319 int signum = (nsigs); \
320 while (signum-- > 0) \
321 if ((sigs)[signum]) \
322 (flags)[signum] = 1; \
325 #define UNSET_SIGS(nsigs,sigs,flags) \
327 int signum = (nsigs); \
328 while (signum-- > 0) \
329 if ((sigs)[signum]) \
330 (flags)[signum] = 0; \
333 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
334 this function is to avoid exporting `signal_program'. */
337 update_signals_program_target (void)
339 target_program_signals (signal_program
);
342 /* Value to pass to target_resume() to cause all threads to resume. */
344 #define RESUME_ALL minus_one_ptid
346 /* Command list pointer for the "stop" placeholder. */
348 static struct cmd_list_element
*stop_command
;
350 /* Nonzero if we want to give control to the user when we're notified
351 of shared library events by the dynamic linker. */
352 int stop_on_solib_events
;
354 /* Enable or disable optional shared library event breakpoints
355 as appropriate when the above flag is changed. */
358 set_stop_on_solib_events (const char *args
,
359 int from_tty
, struct cmd_list_element
*c
)
361 update_solib_breakpoints ();
365 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
366 struct cmd_list_element
*c
, const char *value
)
368 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
372 /* Nonzero after stop if current stack frame should be printed. */
374 static int stop_print_frame
;
376 /* This is a cached copy of the pid/waitstatus of the last event
377 returned by target_wait()/deprecated_target_wait_hook(). This
378 information is returned by get_last_target_status(). */
379 static ptid_t target_last_wait_ptid
;
380 static struct target_waitstatus target_last_waitstatus
;
382 void init_thread_stepping_state (struct thread_info
*tss
);
384 static const char follow_fork_mode_child
[] = "child";
385 static const char follow_fork_mode_parent
[] = "parent";
387 static const char *const follow_fork_mode_kind_names
[] = {
388 follow_fork_mode_child
,
389 follow_fork_mode_parent
,
393 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
395 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
396 struct cmd_list_element
*c
, const char *value
)
398 fprintf_filtered (file
,
399 _("Debugger response to a program "
400 "call of fork or vfork is \"%s\".\n"),
405 /* Handle changes to the inferior list based on the type of fork,
406 which process is being followed, and whether the other process
407 should be detached. On entry inferior_ptid must be the ptid of
408 the fork parent. At return inferior_ptid is the ptid of the
409 followed inferior. */
412 follow_fork_inferior (int follow_child
, int detach_fork
)
415 ptid_t parent_ptid
, child_ptid
;
417 has_vforked
= (inferior_thread ()->pending_follow
.kind
418 == TARGET_WAITKIND_VFORKED
);
419 parent_ptid
= inferior_ptid
;
420 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
423 && !non_stop
/* Non-stop always resumes both branches. */
424 && current_ui
->prompt_state
== PROMPT_BLOCKED
425 && !(follow_child
|| detach_fork
|| sched_multi
))
427 /* The parent stays blocked inside the vfork syscall until the
428 child execs or exits. If we don't let the child run, then
429 the parent stays blocked. If we're telling the parent to run
430 in the foreground, the user will not be able to ctrl-c to get
431 back the terminal, effectively hanging the debug session. */
432 fprintf_filtered (gdb_stderr
, _("\
433 Can not resume the parent process over vfork in the foreground while\n\
434 holding the child stopped. Try \"set detach-on-fork\" or \
435 \"set schedule-multiple\".\n"));
441 /* Detach new forked process? */
444 /* Before detaching from the child, remove all breakpoints
445 from it. If we forked, then this has already been taken
446 care of by infrun.c. If we vforked however, any
447 breakpoint inserted in the parent is visible in the
448 child, even those added while stopped in a vfork
449 catchpoint. This will remove the breakpoints from the
450 parent also, but they'll be reinserted below. */
453 /* Keep breakpoints list in sync. */
454 remove_breakpoints_inf (current_inferior ());
457 if (print_inferior_events
)
459 /* Ensure that we have a process ptid. */
460 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
462 target_terminal::ours_for_output ();
463 fprintf_filtered (gdb_stdlog
,
464 _("[Detaching after %s from child %s]\n"),
465 has_vforked
? "vfork" : "fork",
466 target_pid_to_str (process_ptid
).c_str ());
471 struct inferior
*parent_inf
, *child_inf
;
473 /* Add process to GDB's tables. */
474 child_inf
= add_inferior (child_ptid
.pid ());
476 parent_inf
= current_inferior ();
477 child_inf
->attach_flag
= parent_inf
->attach_flag
;
478 copy_terminal_info (child_inf
, parent_inf
);
479 child_inf
->gdbarch
= parent_inf
->gdbarch
;
480 copy_inferior_target_desc_info (child_inf
, parent_inf
);
482 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
484 inferior_ptid
= child_ptid
;
485 add_thread_silent (inferior_ptid
);
486 set_current_inferior (child_inf
);
487 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
489 /* If this is a vfork child, then the address-space is
490 shared with the parent. */
493 child_inf
->pspace
= parent_inf
->pspace
;
494 child_inf
->aspace
= parent_inf
->aspace
;
496 /* The parent will be frozen until the child is done
497 with the shared region. Keep track of the
499 child_inf
->vfork_parent
= parent_inf
;
500 child_inf
->pending_detach
= 0;
501 parent_inf
->vfork_child
= child_inf
;
502 parent_inf
->pending_detach
= 0;
506 child_inf
->aspace
= new_address_space ();
507 child_inf
->pspace
= new program_space (child_inf
->aspace
);
508 child_inf
->removable
= 1;
509 set_current_program_space (child_inf
->pspace
);
510 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
512 /* Let the shared library layer (e.g., solib-svr4) learn
513 about this new process, relocate the cloned exec, pull
514 in shared libraries, and install the solib event
515 breakpoint. If a "cloned-VM" event was propagated
516 better throughout the core, this wouldn't be
518 solib_create_inferior_hook (0);
524 struct inferior
*parent_inf
;
526 parent_inf
= current_inferior ();
528 /* If we detached from the child, then we have to be careful
529 to not insert breakpoints in the parent until the child
530 is done with the shared memory region. However, if we're
531 staying attached to the child, then we can and should
532 insert breakpoints, so that we can debug it. A
533 subsequent child exec or exit is enough to know when does
534 the child stops using the parent's address space. */
535 parent_inf
->waiting_for_vfork_done
= detach_fork
;
536 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
541 /* Follow the child. */
542 struct inferior
*parent_inf
, *child_inf
;
543 struct program_space
*parent_pspace
;
545 if (print_inferior_events
)
547 std::string parent_pid
= target_pid_to_str (parent_ptid
);
548 std::string child_pid
= target_pid_to_str (child_ptid
);
550 target_terminal::ours_for_output ();
551 fprintf_filtered (gdb_stdlog
,
552 _("[Attaching after %s %s to child %s]\n"),
554 has_vforked
? "vfork" : "fork",
558 /* Add the new inferior first, so that the target_detach below
559 doesn't unpush the target. */
561 child_inf
= add_inferior (child_ptid
.pid ());
563 parent_inf
= current_inferior ();
564 child_inf
->attach_flag
= parent_inf
->attach_flag
;
565 copy_terminal_info (child_inf
, parent_inf
);
566 child_inf
->gdbarch
= parent_inf
->gdbarch
;
567 copy_inferior_target_desc_info (child_inf
, parent_inf
);
569 parent_pspace
= parent_inf
->pspace
;
571 /* If we're vforking, we want to hold on to the parent until the
572 child exits or execs. At child exec or exit time we can
573 remove the old breakpoints from the parent and detach or
574 resume debugging it. Otherwise, detach the parent now; we'll
575 want to reuse it's program/address spaces, but we can't set
576 them to the child before removing breakpoints from the
577 parent, otherwise, the breakpoints module could decide to
578 remove breakpoints from the wrong process (since they'd be
579 assigned to the same address space). */
583 gdb_assert (child_inf
->vfork_parent
== NULL
);
584 gdb_assert (parent_inf
->vfork_child
== NULL
);
585 child_inf
->vfork_parent
= parent_inf
;
586 child_inf
->pending_detach
= 0;
587 parent_inf
->vfork_child
= child_inf
;
588 parent_inf
->pending_detach
= detach_fork
;
589 parent_inf
->waiting_for_vfork_done
= 0;
591 else if (detach_fork
)
593 if (print_inferior_events
)
595 /* Ensure that we have a process ptid. */
596 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
598 target_terminal::ours_for_output ();
599 fprintf_filtered (gdb_stdlog
,
600 _("[Detaching after fork from "
602 target_pid_to_str (process_ptid
).c_str ());
605 target_detach (parent_inf
, 0);
608 /* Note that the detach above makes PARENT_INF dangling. */
610 /* Add the child thread to the appropriate lists, and switch to
611 this new thread, before cloning the program space, and
612 informing the solib layer about this new process. */
614 inferior_ptid
= child_ptid
;
615 add_thread_silent (inferior_ptid
);
616 set_current_inferior (child_inf
);
618 /* If this is a vfork child, then the address-space is shared
619 with the parent. If we detached from the parent, then we can
620 reuse the parent's program/address spaces. */
621 if (has_vforked
|| detach_fork
)
623 child_inf
->pspace
= parent_pspace
;
624 child_inf
->aspace
= child_inf
->pspace
->aspace
;
628 child_inf
->aspace
= new_address_space ();
629 child_inf
->pspace
= new program_space (child_inf
->aspace
);
630 child_inf
->removable
= 1;
631 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
632 set_current_program_space (child_inf
->pspace
);
633 clone_program_space (child_inf
->pspace
, parent_pspace
);
635 /* Let the shared library layer (e.g., solib-svr4) learn
636 about this new process, relocate the cloned exec, pull in
637 shared libraries, and install the solib event breakpoint.
638 If a "cloned-VM" event was propagated better throughout
639 the core, this wouldn't be required. */
640 solib_create_inferior_hook (0);
644 return target_follow_fork (follow_child
, detach_fork
);
647 /* Tell the target to follow the fork we're stopped at. Returns true
648 if the inferior should be resumed; false, if the target for some
649 reason decided it's best not to resume. */
654 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
655 int should_resume
= 1;
656 struct thread_info
*tp
;
658 /* Copy user stepping state to the new inferior thread. FIXME: the
659 followed fork child thread should have a copy of most of the
660 parent thread structure's run control related fields, not just these.
661 Initialized to avoid "may be used uninitialized" warnings from gcc. */
662 struct breakpoint
*step_resume_breakpoint
= NULL
;
663 struct breakpoint
*exception_resume_breakpoint
= NULL
;
664 CORE_ADDR step_range_start
= 0;
665 CORE_ADDR step_range_end
= 0;
666 struct frame_id step_frame_id
= { 0 };
667 struct thread_fsm
*thread_fsm
= NULL
;
672 struct target_waitstatus wait_status
;
674 /* Get the last target status returned by target_wait(). */
675 get_last_target_status (&wait_ptid
, &wait_status
);
677 /* If not stopped at a fork event, then there's nothing else to
679 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
680 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
683 /* Check if we switched over from WAIT_PTID, since the event was
685 if (wait_ptid
!= minus_one_ptid
686 && inferior_ptid
!= wait_ptid
)
688 /* We did. Switch back to WAIT_PTID thread, to tell the
689 target to follow it (in either direction). We'll
690 afterwards refuse to resume, and inform the user what
692 thread_info
*wait_thread
693 = find_thread_ptid (wait_ptid
);
694 switch_to_thread (wait_thread
);
699 tp
= inferior_thread ();
701 /* If there were any forks/vforks that were caught and are now to be
702 followed, then do so now. */
703 switch (tp
->pending_follow
.kind
)
705 case TARGET_WAITKIND_FORKED
:
706 case TARGET_WAITKIND_VFORKED
:
708 ptid_t parent
, child
;
710 /* If the user did a next/step, etc, over a fork call,
711 preserve the stepping state in the fork child. */
712 if (follow_child
&& should_resume
)
714 step_resume_breakpoint
= clone_momentary_breakpoint
715 (tp
->control
.step_resume_breakpoint
);
716 step_range_start
= tp
->control
.step_range_start
;
717 step_range_end
= tp
->control
.step_range_end
;
718 step_frame_id
= tp
->control
.step_frame_id
;
719 exception_resume_breakpoint
720 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
721 thread_fsm
= tp
->thread_fsm
;
723 /* For now, delete the parent's sr breakpoint, otherwise,
724 parent/child sr breakpoints are considered duplicates,
725 and the child version will not be installed. Remove
726 this when the breakpoints module becomes aware of
727 inferiors and address spaces. */
728 delete_step_resume_breakpoint (tp
);
729 tp
->control
.step_range_start
= 0;
730 tp
->control
.step_range_end
= 0;
731 tp
->control
.step_frame_id
= null_frame_id
;
732 delete_exception_resume_breakpoint (tp
);
733 tp
->thread_fsm
= NULL
;
736 parent
= inferior_ptid
;
737 child
= tp
->pending_follow
.value
.related_pid
;
739 /* Set up inferior(s) as specified by the caller, and tell the
740 target to do whatever is necessary to follow either parent
742 if (follow_fork_inferior (follow_child
, detach_fork
))
744 /* Target refused to follow, or there's some other reason
745 we shouldn't resume. */
750 /* This pending follow fork event is now handled, one way
751 or another. The previous selected thread may be gone
752 from the lists by now, but if it is still around, need
753 to clear the pending follow request. */
754 tp
= find_thread_ptid (parent
);
756 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
758 /* This makes sure we don't try to apply the "Switched
759 over from WAIT_PID" logic above. */
760 nullify_last_target_wait_ptid ();
762 /* If we followed the child, switch to it... */
765 thread_info
*child_thr
= find_thread_ptid (child
);
766 switch_to_thread (child_thr
);
768 /* ... and preserve the stepping state, in case the
769 user was stepping over the fork call. */
772 tp
= inferior_thread ();
773 tp
->control
.step_resume_breakpoint
774 = step_resume_breakpoint
;
775 tp
->control
.step_range_start
= step_range_start
;
776 tp
->control
.step_range_end
= step_range_end
;
777 tp
->control
.step_frame_id
= step_frame_id
;
778 tp
->control
.exception_resume_breakpoint
779 = exception_resume_breakpoint
;
780 tp
->thread_fsm
= thread_fsm
;
784 /* If we get here, it was because we're trying to
785 resume from a fork catchpoint, but, the user
786 has switched threads away from the thread that
787 forked. In that case, the resume command
788 issued is most likely not applicable to the
789 child, so just warn, and refuse to resume. */
790 warning (_("Not resuming: switched threads "
791 "before following fork child."));
794 /* Reset breakpoints in the child as appropriate. */
795 follow_inferior_reset_breakpoints ();
800 case TARGET_WAITKIND_SPURIOUS
:
801 /* Nothing to follow. */
804 internal_error (__FILE__
, __LINE__
,
805 "Unexpected pending_follow.kind %d\n",
806 tp
->pending_follow
.kind
);
810 return should_resume
;
814 follow_inferior_reset_breakpoints (void)
816 struct thread_info
*tp
= inferior_thread ();
818 /* Was there a step_resume breakpoint? (There was if the user
819 did a "next" at the fork() call.) If so, explicitly reset its
820 thread number. Cloned step_resume breakpoints are disabled on
821 creation, so enable it here now that it is associated with the
824 step_resumes are a form of bp that are made to be per-thread.
825 Since we created the step_resume bp when the parent process
826 was being debugged, and now are switching to the child process,
827 from the breakpoint package's viewpoint, that's a switch of
828 "threads". We must update the bp's notion of which thread
829 it is for, or it'll be ignored when it triggers. */
831 if (tp
->control
.step_resume_breakpoint
)
833 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
834 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
837 /* Treat exception_resume breakpoints like step_resume breakpoints. */
838 if (tp
->control
.exception_resume_breakpoint
)
840 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
841 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
844 /* Reinsert all breakpoints in the child. The user may have set
845 breakpoints after catching the fork, in which case those
846 were never set in the child, but only in the parent. This makes
847 sure the inserted breakpoints match the breakpoint list. */
849 breakpoint_re_set ();
850 insert_breakpoints ();
853 /* The child has exited or execed: resume threads of the parent the
854 user wanted to be executing. */
857 proceed_after_vfork_done (struct thread_info
*thread
,
860 int pid
= * (int *) arg
;
862 if (thread
->ptid
.pid () == pid
863 && thread
->state
== THREAD_RUNNING
864 && !thread
->executing
865 && !thread
->stop_requested
866 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
869 fprintf_unfiltered (gdb_stdlog
,
870 "infrun: resuming vfork parent thread %s\n",
871 target_pid_to_str (thread
->ptid
).c_str ());
873 switch_to_thread (thread
);
874 clear_proceed_status (0);
875 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
881 /* Save/restore inferior_ptid, current program space and current
882 inferior. Only use this if the current context points at an exited
883 inferior (and therefore there's no current thread to save). */
884 class scoped_restore_exited_inferior
887 scoped_restore_exited_inferior ()
888 : m_saved_ptid (&inferior_ptid
)
892 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
893 scoped_restore_current_program_space m_pspace
;
894 scoped_restore_current_inferior m_inferior
;
897 /* Called whenever we notice an exec or exit event, to handle
898 detaching or resuming a vfork parent. */
901 handle_vfork_child_exec_or_exit (int exec
)
903 struct inferior
*inf
= current_inferior ();
905 if (inf
->vfork_parent
)
907 int resume_parent
= -1;
909 /* This exec or exit marks the end of the shared memory region
910 between the parent and the child. Break the bonds. */
911 inferior
*vfork_parent
= inf
->vfork_parent
;
912 inf
->vfork_parent
->vfork_child
= NULL
;
913 inf
->vfork_parent
= NULL
;
915 /* If the user wanted to detach from the parent, now is the
917 if (vfork_parent
->pending_detach
)
919 struct thread_info
*tp
;
920 struct program_space
*pspace
;
921 struct address_space
*aspace
;
923 /* follow-fork child, detach-on-fork on. */
925 vfork_parent
->pending_detach
= 0;
927 gdb::optional
<scoped_restore_exited_inferior
>
928 maybe_restore_inferior
;
929 gdb::optional
<scoped_restore_current_pspace_and_thread
>
930 maybe_restore_thread
;
932 /* If we're handling a child exit, then inferior_ptid points
933 at the inferior's pid, not to a thread. */
935 maybe_restore_inferior
.emplace ();
937 maybe_restore_thread
.emplace ();
939 /* We're letting loose of the parent. */
940 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 struct program_space
*pspace
;
1002 /* If this is a vfork child exiting, then the pspace and
1003 aspaces were shared with the parent. Since we're
1004 reporting the process exit, we'll be mourning all that is
1005 found in the address space, and switching to null_ptid,
1006 preparing to start a new inferior. But, since we don't
1007 want to clobber the parent's address/program spaces, we
1008 go ahead and create a new one for this exiting
1011 /* Switch to null_ptid while running clone_program_space, so
1012 that clone_program_space doesn't want to read the
1013 selected frame of a dead process. */
1014 scoped_restore restore_ptid
1015 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1017 /* This inferior is dead, so avoid giving the breakpoints
1018 module the option to write through to it (cloning a
1019 program space resets breakpoints). */
1022 pspace
= new program_space (maybe_new_address_space ());
1023 set_current_program_space (pspace
);
1025 inf
->symfile_flags
= SYMFILE_NO_READ
;
1026 clone_program_space (pspace
, vfork_parent
->pspace
);
1027 inf
->pspace
= pspace
;
1028 inf
->aspace
= pspace
->aspace
;
1030 resume_parent
= vfork_parent
->pid
;
1033 gdb_assert (current_program_space
== inf
->pspace
);
1035 if (non_stop
&& resume_parent
!= -1)
1037 /* If the user wanted the parent to be running, let it go
1039 scoped_restore_current_thread restore_thread
;
1042 fprintf_unfiltered (gdb_stdlog
,
1043 "infrun: resuming vfork parent process %d\n",
1046 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1051 /* Enum strings for "set|show follow-exec-mode". */
1053 static const char follow_exec_mode_new
[] = "new";
1054 static const char follow_exec_mode_same
[] = "same";
1055 static const char *const follow_exec_mode_names
[] =
1057 follow_exec_mode_new
,
1058 follow_exec_mode_same
,
1062 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1064 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1065 struct cmd_list_element
*c
, const char *value
)
1067 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1070 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1073 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1075 struct inferior
*inf
= current_inferior ();
1076 int pid
= ptid
.pid ();
1077 ptid_t process_ptid
;
1079 /* Switch terminal for any messages produced e.g. by
1080 breakpoint_re_set. */
1081 target_terminal::ours_for_output ();
1083 /* This is an exec event that we actually wish to pay attention to.
1084 Refresh our symbol table to the newly exec'd program, remove any
1085 momentary bp's, etc.
1087 If there are breakpoints, they aren't really inserted now,
1088 since the exec() transformed our inferior into a fresh set
1091 We want to preserve symbolic breakpoints on the list, since
1092 we have hopes that they can be reset after the new a.out's
1093 symbol table is read.
1095 However, any "raw" breakpoints must be removed from the list
1096 (e.g., the solib bp's), since their address is probably invalid
1099 And, we DON'T want to call delete_breakpoints() here, since
1100 that may write the bp's "shadow contents" (the instruction
1101 value that was overwritten with a TRAP instruction). Since
1102 we now have a new a.out, those shadow contents aren't valid. */
1104 mark_breakpoints_out ();
1106 /* The target reports the exec event to the main thread, even if
1107 some other thread does the exec, and even if the main thread was
1108 stopped or already gone. We may still have non-leader threads of
1109 the process on our list. E.g., on targets that don't have thread
1110 exit events (like remote); or on native Linux in non-stop mode if
1111 there were only two threads in the inferior and the non-leader
1112 one is the one that execs (and nothing forces an update of the
1113 thread list up to here). When debugging remotely, it's best to
1114 avoid extra traffic, when possible, so avoid syncing the thread
1115 list with the target, and instead go ahead and delete all threads
1116 of the process but one that reported the event. Note this must
1117 be done before calling update_breakpoints_after_exec, as
1118 otherwise clearing the threads' resources would reference stale
1119 thread breakpoints -- it may have been one of these threads that
1120 stepped across the exec. We could just clear their stepping
1121 states, but as long as we're iterating, might as well delete
1122 them. Deleting them now rather than at the next user-visible
1123 stop provides a nicer sequence of events for user and MI
1125 for (thread_info
*th
: all_threads_safe ())
1126 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1129 /* We also need to clear any left over stale state for the
1130 leader/event thread. E.g., if there was any step-resume
1131 breakpoint or similar, it's gone now. We cannot truly
1132 step-to-next statement through an exec(). */
1133 thread_info
*th
= inferior_thread ();
1134 th
->control
.step_resume_breakpoint
= NULL
;
1135 th
->control
.exception_resume_breakpoint
= NULL
;
1136 th
->control
.single_step_breakpoints
= NULL
;
1137 th
->control
.step_range_start
= 0;
1138 th
->control
.step_range_end
= 0;
1140 /* The user may have had the main thread held stopped in the
1141 previous image (e.g., schedlock on, or non-stop). Release
1143 th
->stop_requested
= 0;
1145 update_breakpoints_after_exec ();
1147 /* What is this a.out's name? */
1148 process_ptid
= ptid_t (pid
);
1149 printf_unfiltered (_("%s is executing new program: %s\n"),
1150 target_pid_to_str (process_ptid
).c_str (),
1153 /* We've followed the inferior through an exec. Therefore, the
1154 inferior has essentially been killed & reborn. */
1156 breakpoint_init_inferior (inf_execd
);
1158 gdb::unique_xmalloc_ptr
<char> exec_file_host
1159 = exec_file_find (exec_file_target
, NULL
);
1161 /* If we were unable to map the executable target pathname onto a host
1162 pathname, tell the user that. Otherwise GDB's subsequent behavior
1163 is confusing. Maybe it would even be better to stop at this point
1164 so that the user can specify a file manually before continuing. */
1165 if (exec_file_host
== NULL
)
1166 warning (_("Could not load symbols for executable %s.\n"
1167 "Do you need \"set sysroot\"?"),
1170 /* Reset the shared library package. This ensures that we get a
1171 shlib event when the child reaches "_start", at which point the
1172 dld will have had a chance to initialize the child. */
1173 /* Also, loading a symbol file below may trigger symbol lookups, and
1174 we don't want those to be satisfied by the libraries of the
1175 previous incarnation of this process. */
1176 no_shared_libraries (NULL
, 0);
1178 if (follow_exec_mode_string
== follow_exec_mode_new
)
1180 /* The user wants to keep the old inferior and program spaces
1181 around. Create a new fresh one, and switch to it. */
1183 /* Do exit processing for the original inferior before setting the new
1184 inferior's pid. Having two inferiors with the same pid would confuse
1185 find_inferior_p(t)id. Transfer the terminal state and info from the
1186 old to the new inferior. */
1187 inf
= add_inferior_with_spaces ();
1188 swap_terminal_info (inf
, current_inferior ());
1189 exit_inferior_silent (current_inferior ());
1192 target_follow_exec (inf
, exec_file_target
);
1194 set_current_inferior (inf
);
1195 set_current_program_space (inf
->pspace
);
1200 /* The old description may no longer be fit for the new image.
1201 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1202 old description; we'll read a new one below. No need to do
1203 this on "follow-exec-mode new", as the old inferior stays
1204 around (its description is later cleared/refetched on
1206 target_clear_description ();
1209 gdb_assert (current_program_space
== inf
->pspace
);
1211 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1212 because the proper displacement for a PIE (Position Independent
1213 Executable) main symbol file will only be computed by
1214 solib_create_inferior_hook below. breakpoint_re_set would fail
1215 to insert the breakpoints with the zero displacement. */
1216 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1218 /* If the target can specify a description, read it. Must do this
1219 after flipping to the new executable (because the target supplied
1220 description must be compatible with the executable's
1221 architecture, and the old executable may e.g., be 32-bit, while
1222 the new one 64-bit), and before anything involving memory or
1224 target_find_description ();
1226 solib_create_inferior_hook (0);
1228 jit_inferior_created_hook ();
1230 breakpoint_re_set ();
1232 /* Reinsert all breakpoints. (Those which were symbolic have
1233 been reset to the proper address in the new a.out, thanks
1234 to symbol_file_command...). */
1235 insert_breakpoints ();
1237 /* The next resume of this inferior should bring it to the shlib
1238 startup breakpoints. (If the user had also set bp's on
1239 "main" from the old (parent) process, then they'll auto-
1240 matically get reset there in the new process.). */
1243 /* The queue of threads that need to do a step-over operation to get
1244 past e.g., a breakpoint. What technique is used to step over the
1245 breakpoint/watchpoint does not matter -- all threads end up in the
1246 same queue, to maintain rough temporal order of execution, in order
1247 to avoid starvation, otherwise, we could e.g., find ourselves
1248 constantly stepping the same couple threads past their breakpoints
1249 over and over, if the single-step finish fast enough. */
1250 struct thread_info
*global_thread_step_over_chain_head
;
1252 /* Bit flags indicating what the thread needs to step over. */
1254 enum step_over_what_flag
1256 /* Step over a breakpoint. */
1257 STEP_OVER_BREAKPOINT
= 1,
1259 /* Step past a non-continuable watchpoint, in order to let the
1260 instruction execute so we can evaluate the watchpoint
1262 STEP_OVER_WATCHPOINT
= 2
1264 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1266 /* Info about an instruction that is being stepped over. */
1268 struct step_over_info
1270 /* If we're stepping past a breakpoint, this is the address space
1271 and address of the instruction the breakpoint is set at. We'll
1272 skip inserting all breakpoints here. Valid iff ASPACE is
1274 const address_space
*aspace
;
1277 /* The instruction being stepped over triggers a nonsteppable
1278 watchpoint. If true, we'll skip inserting watchpoints. */
1279 int nonsteppable_watchpoint_p
;
1281 /* The thread's global number. */
1285 /* The step-over info of the location that is being stepped over.
1287 Note that with async/breakpoint always-inserted mode, a user might
1288 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1289 being stepped over. As setting a new breakpoint inserts all
1290 breakpoints, we need to make sure the breakpoint being stepped over
1291 isn't inserted then. We do that by only clearing the step-over
1292 info when the step-over is actually finished (or aborted).
1294 Presently GDB can only step over one breakpoint at any given time.
1295 Given threads that can't run code in the same address space as the
1296 breakpoint's can't really miss the breakpoint, GDB could be taught
1297 to step-over at most one breakpoint per address space (so this info
1298 could move to the address space object if/when GDB is extended).
1299 The set of breakpoints being stepped over will normally be much
1300 smaller than the set of all breakpoints, so a flag in the
1301 breakpoint location structure would be wasteful. A separate list
1302 also saves complexity and run-time, as otherwise we'd have to go
1303 through all breakpoint locations clearing their flag whenever we
1304 start a new sequence. Similar considerations weigh against storing
1305 this info in the thread object. Plus, not all step overs actually
1306 have breakpoint locations -- e.g., stepping past a single-step
1307 breakpoint, or stepping to complete a non-continuable
1309 static struct step_over_info step_over_info
;
1311 /* Record the address of the breakpoint/instruction we're currently
1313 N.B. We record the aspace and address now, instead of say just the thread,
1314 because when we need the info later the thread may be running. */
1317 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1318 int nonsteppable_watchpoint_p
,
1321 step_over_info
.aspace
= aspace
;
1322 step_over_info
.address
= address
;
1323 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1324 step_over_info
.thread
= thread
;
1327 /* Called when we're not longer stepping over a breakpoint / an
1328 instruction, so all breakpoints are free to be (re)inserted. */
1331 clear_step_over_info (void)
1334 fprintf_unfiltered (gdb_stdlog
,
1335 "infrun: clear_step_over_info\n");
1336 step_over_info
.aspace
= NULL
;
1337 step_over_info
.address
= 0;
1338 step_over_info
.nonsteppable_watchpoint_p
= 0;
1339 step_over_info
.thread
= -1;
1345 stepping_past_instruction_at (struct address_space
*aspace
,
1348 return (step_over_info
.aspace
!= NULL
1349 && breakpoint_address_match (aspace
, address
,
1350 step_over_info
.aspace
,
1351 step_over_info
.address
));
1357 thread_is_stepping_over_breakpoint (int thread
)
1359 return (step_over_info
.thread
!= -1
1360 && thread
== step_over_info
.thread
);
1366 stepping_past_nonsteppable_watchpoint (void)
1368 return step_over_info
.nonsteppable_watchpoint_p
;
1371 /* Returns true if step-over info is valid. */
1374 step_over_info_valid_p (void)
1376 return (step_over_info
.aspace
!= NULL
1377 || stepping_past_nonsteppable_watchpoint ());
1381 /* Displaced stepping. */
1383 /* In non-stop debugging mode, we must take special care to manage
1384 breakpoints properly; in particular, the traditional strategy for
1385 stepping a thread past a breakpoint it has hit is unsuitable.
1386 'Displaced stepping' is a tactic for stepping one thread past a
1387 breakpoint it has hit while ensuring that other threads running
1388 concurrently will hit the breakpoint as they should.
1390 The traditional way to step a thread T off a breakpoint in a
1391 multi-threaded program in all-stop mode is as follows:
1393 a0) Initially, all threads are stopped, and breakpoints are not
1395 a1) We single-step T, leaving breakpoints uninserted.
1396 a2) We insert breakpoints, and resume all threads.
1398 In non-stop debugging, however, this strategy is unsuitable: we
1399 don't want to have to stop all threads in the system in order to
1400 continue or step T past a breakpoint. Instead, we use displaced
1403 n0) Initially, T is stopped, other threads are running, and
1404 breakpoints are inserted.
1405 n1) We copy the instruction "under" the breakpoint to a separate
1406 location, outside the main code stream, making any adjustments
1407 to the instruction, register, and memory state as directed by
1409 n2) We single-step T over the instruction at its new location.
1410 n3) We adjust the resulting register and memory state as directed
1411 by T's architecture. This includes resetting T's PC to point
1412 back into the main instruction stream.
1415 This approach depends on the following gdbarch methods:
1417 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1418 indicate where to copy the instruction, and how much space must
1419 be reserved there. We use these in step n1.
1421 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1422 address, and makes any necessary adjustments to the instruction,
1423 register contents, and memory. We use this in step n1.
1425 - gdbarch_displaced_step_fixup adjusts registers and memory after
1426 we have successfully single-stepped the instruction, to yield the
1427 same effect the instruction would have had if we had executed it
1428 at its original address. We use this in step n3.
1430 The gdbarch_displaced_step_copy_insn and
1431 gdbarch_displaced_step_fixup functions must be written so that
1432 copying an instruction with gdbarch_displaced_step_copy_insn,
1433 single-stepping across the copied instruction, and then applying
1434 gdbarch_displaced_insn_fixup should have the same effects on the
1435 thread's memory and registers as stepping the instruction in place
1436 would have. Exactly which responsibilities fall to the copy and
1437 which fall to the fixup is up to the author of those functions.
1439 See the comments in gdbarch.sh for details.
1441 Note that displaced stepping and software single-step cannot
1442 currently be used in combination, although with some care I think
1443 they could be made to. Software single-step works by placing
1444 breakpoints on all possible subsequent instructions; if the
1445 displaced instruction is a PC-relative jump, those breakpoints
1446 could fall in very strange places --- on pages that aren't
1447 executable, or at addresses that are not proper instruction
1448 boundaries. (We do generally let other threads run while we wait
1449 to hit the software single-step breakpoint, and they might
1450 encounter such a corrupted instruction.) One way to work around
1451 this would be to have gdbarch_displaced_step_copy_insn fully
1452 simulate the effect of PC-relative instructions (and return NULL)
1453 on architectures that use software single-stepping.
1455 In non-stop mode, we can have independent and simultaneous step
1456 requests, so more than one thread may need to simultaneously step
1457 over a breakpoint. The current implementation assumes there is
1458 only one scratch space per process. In this case, we have to
1459 serialize access to the scratch space. If thread A wants to step
1460 over a breakpoint, but we are currently waiting for some other
1461 thread to complete a displaced step, we leave thread A stopped and
1462 place it in the displaced_step_request_queue. Whenever a displaced
1463 step finishes, we pick the next thread in the queue and start a new
1464 displaced step operation on it. See displaced_step_prepare and
1465 displaced_step_fixup for details. */
1467 /* Default destructor for displaced_step_copy_insn_closure. */
1469 displaced_step_copy_insn_closure::~displaced_step_copy_insn_closure () = default;
1471 /* Get the displaced stepping state of process PID. */
1473 static displaced_step_inferior_state
*
1474 get_displaced_stepping_state (inferior
*inf
)
1476 return &inf
->displaced_step_state
;
1479 /* Returns true if any inferior has a thread doing a displaced
1483 displaced_step_in_progress_any_inferior ()
1485 for (inferior
*i
: all_inferiors ())
1487 if (i
->displaced_step_state
.step_thread
!= nullptr)
1494 /* Return true if thread represented by PTID is doing a displaced
1498 displaced_step_in_progress_thread (thread_info
*thread
)
1500 gdb_assert (thread
!= NULL
);
1502 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1505 /* Return true if process PID has a thread doing a displaced step. */
1508 displaced_step_in_progress (inferior
*inf
)
1510 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1513 /* If inferior is in displaced stepping, and ADDR equals to starting address
1514 of copy area, return corresponding displaced_step_copy_insn_closure. Otherwise,
1517 struct displaced_step_copy_insn_closure
*
1518 get_displaced_step_copy_insn_closure_by_addr (CORE_ADDR addr
)
1520 displaced_step_inferior_state
*displaced
1521 = get_displaced_stepping_state (current_inferior ());
1523 /* If checking the mode of displaced instruction in copy area. */
1524 if (displaced
->step_thread
!= nullptr
1525 && displaced
->step_copy
== addr
)
1526 return displaced
->step_closure
.get ();
1532 infrun_inferior_exit (struct inferior
*inf
)
1534 inf
->displaced_step_state
.reset ();
1537 /* If ON, and the architecture supports it, GDB will use displaced
1538 stepping to step over breakpoints. If OFF, or if the architecture
1539 doesn't support it, GDB will instead use the traditional
1540 hold-and-step approach. If AUTO (which is the default), GDB will
1541 decide which technique to use to step over breakpoints depending on
1542 whether the target works in a non-stop way (see use_displaced_stepping). */
1544 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1547 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1548 struct cmd_list_element
*c
,
1551 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1552 fprintf_filtered (file
,
1553 _("Debugger's willingness to use displaced stepping "
1554 "to step over breakpoints is %s (currently %s).\n"),
1555 value
, target_is_non_stop_p () ? "on" : "off");
1557 fprintf_filtered (file
,
1558 _("Debugger's willingness to use displaced stepping "
1559 "to step over breakpoints is %s.\n"), value
);
1562 /* Return true if the gdbarch implements the required methods to use
1563 displaced stepping. */
1566 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1568 /* Only check for the presence of step_copy_insn. Other required methods
1569 are checked by the gdbarch validation. */
1570 return gdbarch_displaced_step_copy_insn_p (arch
);
1573 /* Return non-zero if displaced stepping can/should be used to step
1574 over breakpoints of thread TP. */
1577 use_displaced_stepping (thread_info
*tp
)
1579 /* If the user disabled it explicitly, don't use displaced stepping. */
1580 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1583 /* If "auto", only use displaced stepping if the target operates in a non-stop
1585 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1586 && !target_is_non_stop_p ())
1589 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1591 /* If the architecture doesn't implement displaced stepping, don't use
1593 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1596 /* If recording, don't use displaced stepping. */
1597 if (find_record_target () != nullptr)
1600 displaced_step_inferior_state
*displaced_state
1601 = get_displaced_stepping_state (tp
->inf
);
1603 /* If displaced stepping failed before for this inferior, don't bother trying
1605 if (displaced_state
->failed_before
)
1611 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1614 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1616 displaced
->reset ();
1619 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1620 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1622 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1624 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1626 displaced_step_dump_bytes (struct ui_file
*file
,
1627 const gdb_byte
*buf
,
1632 for (i
= 0; i
< len
; i
++)
1633 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1634 fputs_unfiltered ("\n", file
);
1637 /* Prepare to single-step, using displaced stepping.
1639 Note that we cannot use displaced stepping when we have a signal to
1640 deliver. If we have a signal to deliver and an instruction to step
1641 over, then after the step, there will be no indication from the
1642 target whether the thread entered a signal handler or ignored the
1643 signal and stepped over the instruction successfully --- both cases
1644 result in a simple SIGTRAP. In the first case we mustn't do a
1645 fixup, and in the second case we must --- but we can't tell which.
1646 Comments in the code for 'random signals' in handle_inferior_event
1647 explain how we handle this case instead.
1649 Returns 1 if preparing was successful -- this thread is going to be
1650 stepped now; 0 if displaced stepping this thread got queued; or -1
1651 if this instruction can't be displaced stepped. */
1654 displaced_step_prepare_throw (thread_info
*tp
)
1656 regcache
*regcache
= get_thread_regcache (tp
);
1657 struct gdbarch
*gdbarch
= regcache
->arch ();
1658 const address_space
*aspace
= regcache
->aspace ();
1659 CORE_ADDR original
, copy
;
1663 /* We should never reach this function if the architecture does not
1664 support displaced stepping. */
1665 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1667 /* Nor if the thread isn't meant to step over a breakpoint. */
1668 gdb_assert (tp
->control
.trap_expected
);
1670 /* Disable range stepping while executing in the scratch pad. We
1671 want a single-step even if executing the displaced instruction in
1672 the scratch buffer lands within the stepping range (e.g., a
1674 tp
->control
.may_range_step
= 0;
1676 /* We have to displaced step one thread at a time, as we only have
1677 access to a single scratch space per inferior. */
1679 displaced_step_inferior_state
*displaced
1680 = get_displaced_stepping_state (tp
->inf
);
1682 if (displaced
->step_thread
!= nullptr)
1684 /* Already waiting for a displaced step to finish. Defer this
1685 request and place in queue. */
1687 if (debug_displaced
)
1688 fprintf_unfiltered (gdb_stdlog
,
1689 "displaced: deferring step of %s\n",
1690 target_pid_to_str (tp
->ptid
).c_str ());
1692 global_thread_step_over_chain_enqueue (tp
);
1697 if (debug_displaced
)
1698 fprintf_unfiltered (gdb_stdlog
,
1699 "displaced: stepping %s now\n",
1700 target_pid_to_str (tp
->ptid
).c_str ());
1703 displaced_step_reset (displaced
);
1705 scoped_restore_current_thread restore_thread
;
1707 switch_to_thread (tp
);
1709 original
= regcache_read_pc (regcache
);
1711 copy
= gdbarch_displaced_step_location (gdbarch
);
1712 len
= gdbarch_max_insn_length (gdbarch
);
1714 if (breakpoint_in_range_p (aspace
, copy
, len
))
1716 /* There's a breakpoint set in the scratch pad location range
1717 (which is usually around the entry point). We'd either
1718 install it before resuming, which would overwrite/corrupt the
1719 scratch pad, or if it was already inserted, this displaced
1720 step would overwrite it. The latter is OK in the sense that
1721 we already assume that no thread is going to execute the code
1722 in the scratch pad range (after initial startup) anyway, but
1723 the former is unacceptable. Simply punt and fallback to
1724 stepping over this breakpoint in-line. */
1725 if (debug_displaced
)
1727 fprintf_unfiltered (gdb_stdlog
,
1728 "displaced: breakpoint set in scratch pad. "
1729 "Stepping over breakpoint in-line instead.\n");
1735 /* Save the original contents of the copy area. */
1736 displaced
->step_saved_copy
.resize (len
);
1737 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1739 throw_error (MEMORY_ERROR
,
1740 _("Error accessing memory address %s (%s) for "
1741 "displaced-stepping scratch space."),
1742 paddress (gdbarch
, copy
), safe_strerror (status
));
1743 if (debug_displaced
)
1745 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1746 paddress (gdbarch
, copy
));
1747 displaced_step_dump_bytes (gdb_stdlog
,
1748 displaced
->step_saved_copy
.data (),
1752 displaced
->step_closure
1753 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1754 if (displaced
->step_closure
== NULL
)
1756 /* The architecture doesn't know how or want to displaced step
1757 this instruction or instruction sequence. Fallback to
1758 stepping over the breakpoint in-line. */
1762 /* Save the information we need to fix things up if the step
1764 displaced
->step_thread
= tp
;
1765 displaced
->step_gdbarch
= gdbarch
;
1766 displaced
->step_original
= original
;
1767 displaced
->step_copy
= copy
;
1770 displaced_step_reset_cleanup
cleanup (displaced
);
1772 /* Resume execution at the copy. */
1773 regcache_write_pc (regcache
, copy
);
1778 if (debug_displaced
)
1779 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1780 paddress (gdbarch
, copy
));
1785 /* Wrapper for displaced_step_prepare_throw that disabled further
1786 attempts at displaced stepping if we get a memory error. */
1789 displaced_step_prepare (thread_info
*thread
)
1795 prepared
= displaced_step_prepare_throw (thread
);
1797 catch (const gdb_exception_error
&ex
)
1799 struct displaced_step_inferior_state
*displaced_state
;
1801 if (ex
.error
!= MEMORY_ERROR
1802 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1807 fprintf_unfiltered (gdb_stdlog
,
1808 "infrun: disabling displaced stepping: %s\n",
1812 /* Be verbose if "set displaced-stepping" is "on", silent if
1814 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1816 warning (_("disabling displaced stepping: %s"),
1820 /* Disable further displaced stepping attempts. */
1822 = get_displaced_stepping_state (thread
->inf
);
1823 displaced_state
->failed_before
= 1;
1830 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1831 const gdb_byte
*myaddr
, int len
)
1833 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1835 inferior_ptid
= ptid
;
1836 write_memory (memaddr
, myaddr
, len
);
1839 /* Restore the contents of the copy area for thread PTID. */
1842 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1845 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1847 write_memory_ptid (ptid
, displaced
->step_copy
,
1848 displaced
->step_saved_copy
.data (), len
);
1849 if (debug_displaced
)
1850 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1851 target_pid_to_str (ptid
).c_str (),
1852 paddress (displaced
->step_gdbarch
,
1853 displaced
->step_copy
));
1856 /* If we displaced stepped an instruction successfully, adjust
1857 registers and memory to yield the same effect the instruction would
1858 have had if we had executed it at its original address, and return
1859 1. If the instruction didn't complete, relocate the PC and return
1860 -1. If the thread wasn't displaced stepping, return 0. */
1863 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1865 struct displaced_step_inferior_state
*displaced
1866 = get_displaced_stepping_state (event_thread
->inf
);
1869 /* Was this event for the thread we displaced? */
1870 if (displaced
->step_thread
!= event_thread
)
1873 displaced_step_reset_cleanup
cleanup (displaced
);
1875 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1877 /* Fixup may need to read memory/registers. Switch to the thread
1878 that we're fixing up. Also, target_stopped_by_watchpoint checks
1879 the current thread. */
1880 switch_to_thread (event_thread
);
1882 /* Did the instruction complete successfully? */
1883 if (signal
== GDB_SIGNAL_TRAP
1884 && !(target_stopped_by_watchpoint ()
1885 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1886 || target_have_steppable_watchpoint
)))
1888 /* Fix up the resulting state. */
1889 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1890 displaced
->step_closure
.get (),
1891 displaced
->step_original
,
1892 displaced
->step_copy
,
1893 get_thread_regcache (displaced
->step_thread
));
1898 /* Since the instruction didn't complete, all we can do is
1900 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1901 CORE_ADDR pc
= regcache_read_pc (regcache
);
1903 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1904 regcache_write_pc (regcache
, pc
);
1911 /* Data to be passed around while handling an event. This data is
1912 discarded between events. */
1913 struct execution_control_state
1916 /* The thread that got the event, if this was a thread event; NULL
1918 struct thread_info
*event_thread
;
1920 struct target_waitstatus ws
;
1921 int stop_func_filled_in
;
1922 CORE_ADDR stop_func_start
;
1923 CORE_ADDR stop_func_end
;
1924 const char *stop_func_name
;
1927 /* True if the event thread hit the single-step breakpoint of
1928 another thread. Thus the event doesn't cause a stop, the thread
1929 needs to be single-stepped past the single-step breakpoint before
1930 we can switch back to the original stepping thread. */
1931 int hit_singlestep_breakpoint
;
1934 /* Clear ECS and set it to point at TP. */
1937 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1939 memset (ecs
, 0, sizeof (*ecs
));
1940 ecs
->event_thread
= tp
;
1941 ecs
->ptid
= tp
->ptid
;
1944 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1945 static void prepare_to_wait (struct execution_control_state
*ecs
);
1946 static int keep_going_stepped_thread (struct thread_info
*tp
);
1947 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1949 /* Are there any pending step-over requests? If so, run all we can
1950 now and return true. Otherwise, return false. */
1953 start_step_over (void)
1955 struct thread_info
*tp
, *next
;
1957 /* Don't start a new step-over if we already have an in-line
1958 step-over operation ongoing. */
1959 if (step_over_info_valid_p ())
1962 for (tp
= global_thread_step_over_chain_head
; tp
!= NULL
; tp
= next
)
1964 struct execution_control_state ecss
;
1965 struct execution_control_state
*ecs
= &ecss
;
1966 step_over_what step_what
;
1967 int must_be_in_line
;
1969 gdb_assert (!tp
->stop_requested
);
1971 next
= global_thread_step_over_chain_next (tp
);
1973 /* If this inferior already has a displaced step in process,
1974 don't start a new one. */
1975 if (displaced_step_in_progress (tp
->inf
))
1978 step_what
= thread_still_needs_step_over (tp
);
1979 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1980 || ((step_what
& STEP_OVER_BREAKPOINT
)
1981 && !use_displaced_stepping (tp
)));
1983 /* We currently stop all threads of all processes to step-over
1984 in-line. If we need to start a new in-line step-over, let
1985 any pending displaced steps finish first. */
1986 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1989 global_thread_step_over_chain_remove (tp
);
1991 if (global_thread_step_over_chain_head
== NULL
)
1994 fprintf_unfiltered (gdb_stdlog
,
1995 "infrun: step-over queue now empty\n");
1998 if (tp
->control
.trap_expected
2002 internal_error (__FILE__
, __LINE__
,
2003 "[%s] has inconsistent state: "
2004 "trap_expected=%d, resumed=%d, executing=%d\n",
2005 target_pid_to_str (tp
->ptid
).c_str (),
2006 tp
->control
.trap_expected
,
2012 fprintf_unfiltered (gdb_stdlog
,
2013 "infrun: resuming [%s] for step-over\n",
2014 target_pid_to_str (tp
->ptid
).c_str ());
2016 /* keep_going_pass_signal skips the step-over if the breakpoint
2017 is no longer inserted. In all-stop, we want to keep looking
2018 for a thread that needs a step-over instead of resuming TP,
2019 because we wouldn't be able to resume anything else until the
2020 target stops again. In non-stop, the resume always resumes
2021 only TP, so it's OK to let the thread resume freely. */
2022 if (!target_is_non_stop_p () && !step_what
)
2025 switch_to_thread (tp
);
2026 reset_ecs (ecs
, tp
);
2027 keep_going_pass_signal (ecs
);
2029 if (!ecs
->wait_some_more
)
2030 error (_("Command aborted."));
2032 gdb_assert (tp
->resumed
);
2034 /* If we started a new in-line step-over, we're done. */
2035 if (step_over_info_valid_p ())
2037 gdb_assert (tp
->control
.trap_expected
);
2041 if (!target_is_non_stop_p ())
2043 /* On all-stop, shouldn't have resumed unless we needed a
2045 gdb_assert (tp
->control
.trap_expected
2046 || tp
->step_after_step_resume_breakpoint
);
2048 /* With remote targets (at least), in all-stop, we can't
2049 issue any further remote commands until the program stops
2054 /* Either the thread no longer needed a step-over, or a new
2055 displaced stepping sequence started. Even in the latter
2056 case, continue looking. Maybe we can also start another
2057 displaced step on a thread of other process. */
2063 /* Update global variables holding ptids to hold NEW_PTID if they were
2064 holding OLD_PTID. */
2066 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2068 if (inferior_ptid
== old_ptid
)
2069 inferior_ptid
= new_ptid
;
2074 static const char schedlock_off
[] = "off";
2075 static const char schedlock_on
[] = "on";
2076 static const char schedlock_step
[] = "step";
2077 static const char schedlock_replay
[] = "replay";
2078 static const char *const scheduler_enums
[] = {
2085 static const char *scheduler_mode
= schedlock_replay
;
2087 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2088 struct cmd_list_element
*c
, const char *value
)
2090 fprintf_filtered (file
,
2091 _("Mode for locking scheduler "
2092 "during execution is \"%s\".\n"),
2097 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2099 if (!target_can_lock_scheduler
)
2101 scheduler_mode
= schedlock_off
;
2102 error (_("Target '%s' cannot support this command."), target_shortname
);
2106 /* True if execution commands resume all threads of all processes by
2107 default; otherwise, resume only threads of the current inferior
2109 bool sched_multi
= false;
2111 /* Try to setup for software single stepping over the specified location.
2112 Return 1 if target_resume() should use hardware single step.
2114 GDBARCH the current gdbarch.
2115 PC the location to step over. */
2118 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2122 if (execution_direction
== EXEC_FORWARD
2123 && gdbarch_software_single_step_p (gdbarch
))
2124 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2132 user_visible_resume_ptid (int step
)
2138 /* With non-stop mode on, threads are always handled
2140 resume_ptid
= inferior_ptid
;
2142 else if ((scheduler_mode
== schedlock_on
)
2143 || (scheduler_mode
== schedlock_step
&& step
))
2145 /* User-settable 'scheduler' mode requires solo thread
2147 resume_ptid
= inferior_ptid
;
2149 else if ((scheduler_mode
== schedlock_replay
)
2150 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2152 /* User-settable 'scheduler' mode requires solo thread resume in replay
2154 resume_ptid
= inferior_ptid
;
2156 else if (!sched_multi
&& target_supports_multi_process ())
2158 /* Resume all threads of the current process (and none of other
2160 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2164 /* Resume all threads of all processes. */
2165 resume_ptid
= RESUME_ALL
;
2171 /* Return a ptid representing the set of threads that we will resume,
2172 in the perspective of the target, assuming run control handling
2173 does not require leaving some threads stopped (e.g., stepping past
2174 breakpoint). USER_STEP indicates whether we're about to start the
2175 target for a stepping command. */
2178 internal_resume_ptid (int user_step
)
2180 /* In non-stop, we always control threads individually. Note that
2181 the target may always work in non-stop mode even with "set
2182 non-stop off", in which case user_visible_resume_ptid could
2183 return a wildcard ptid. */
2184 if (target_is_non_stop_p ())
2185 return inferior_ptid
;
2187 return user_visible_resume_ptid (user_step
);
2190 /* Wrapper for target_resume, that handles infrun-specific
2194 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2196 struct thread_info
*tp
= inferior_thread ();
2198 gdb_assert (!tp
->stop_requested
);
2200 /* Install inferior's terminal modes. */
2201 target_terminal::inferior ();
2203 /* Avoid confusing the next resume, if the next stop/resume
2204 happens to apply to another thread. */
2205 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2207 /* Advise target which signals may be handled silently.
2209 If we have removed breakpoints because we are stepping over one
2210 in-line (in any thread), we need to receive all signals to avoid
2211 accidentally skipping a breakpoint during execution of a signal
2214 Likewise if we're displaced stepping, otherwise a trap for a
2215 breakpoint in a signal handler might be confused with the
2216 displaced step finishing. We don't make the displaced_step_fixup
2217 step distinguish the cases instead, because:
2219 - a backtrace while stopped in the signal handler would show the
2220 scratch pad as frame older than the signal handler, instead of
2221 the real mainline code.
2223 - when the thread is later resumed, the signal handler would
2224 return to the scratch pad area, which would no longer be
2226 if (step_over_info_valid_p ()
2227 || displaced_step_in_progress (tp
->inf
))
2228 target_pass_signals ({});
2230 target_pass_signals (signal_pass
);
2232 target_resume (resume_ptid
, step
, sig
);
2234 target_commit_resume ();
2237 /* Resume the inferior. SIG is the signal to give the inferior
2238 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2239 call 'resume', which handles exceptions. */
2242 resume_1 (enum gdb_signal sig
)
2244 struct regcache
*regcache
= get_current_regcache ();
2245 struct gdbarch
*gdbarch
= regcache
->arch ();
2246 struct thread_info
*tp
= inferior_thread ();
2247 CORE_ADDR pc
= regcache_read_pc (regcache
);
2248 const address_space
*aspace
= regcache
->aspace ();
2250 /* This represents the user's step vs continue request. When
2251 deciding whether "set scheduler-locking step" applies, it's the
2252 user's intention that counts. */
2253 const int user_step
= tp
->control
.stepping_command
;
2254 /* This represents what we'll actually request the target to do.
2255 This can decay from a step to a continue, if e.g., we need to
2256 implement single-stepping with breakpoints (software
2260 gdb_assert (!tp
->stop_requested
);
2261 gdb_assert (!thread_is_in_step_over_chain (tp
));
2263 if (tp
->suspend
.waitstatus_pending_p
)
2268 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2270 fprintf_unfiltered (gdb_stdlog
,
2271 "infrun: resume: thread %s has pending wait "
2272 "status %s (currently_stepping=%d).\n",
2273 target_pid_to_str (tp
->ptid
).c_str (),
2275 currently_stepping (tp
));
2280 /* FIXME: What should we do if we are supposed to resume this
2281 thread with a signal? Maybe we should maintain a queue of
2282 pending signals to deliver. */
2283 if (sig
!= GDB_SIGNAL_0
)
2285 warning (_("Couldn't deliver signal %s to %s."),
2286 gdb_signal_to_name (sig
),
2287 target_pid_to_str (tp
->ptid
).c_str ());
2290 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2292 if (target_can_async_p ())
2295 /* Tell the event loop we have an event to process. */
2296 mark_async_event_handler (infrun_async_inferior_event_token
);
2301 tp
->stepped_breakpoint
= 0;
2303 /* Depends on stepped_breakpoint. */
2304 step
= currently_stepping (tp
);
2306 if (current_inferior ()->waiting_for_vfork_done
)
2308 /* Don't try to single-step a vfork parent that is waiting for
2309 the child to get out of the shared memory region (by exec'ing
2310 or exiting). This is particularly important on software
2311 single-step archs, as the child process would trip on the
2312 software single step breakpoint inserted for the parent
2313 process. Since the parent will not actually execute any
2314 instruction until the child is out of the shared region (such
2315 are vfork's semantics), it is safe to simply continue it.
2316 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2317 the parent, and tell it to `keep_going', which automatically
2318 re-sets it stepping. */
2320 fprintf_unfiltered (gdb_stdlog
,
2321 "infrun: resume : clear step\n");
2326 fprintf_unfiltered (gdb_stdlog
,
2327 "infrun: resume (step=%d, signal=%s), "
2328 "trap_expected=%d, current thread [%s] at %s\n",
2329 step
, gdb_signal_to_symbol_string (sig
),
2330 tp
->control
.trap_expected
,
2331 target_pid_to_str (inferior_ptid
).c_str (),
2332 paddress (gdbarch
, pc
));
2334 /* Normally, by the time we reach `resume', the breakpoints are either
2335 removed or inserted, as appropriate. The exception is if we're sitting
2336 at a permanent breakpoint; we need to step over it, but permanent
2337 breakpoints can't be removed. So we have to test for it here. */
2338 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2340 if (sig
!= GDB_SIGNAL_0
)
2342 /* We have a signal to pass to the inferior. The resume
2343 may, or may not take us to the signal handler. If this
2344 is a step, we'll need to stop in the signal handler, if
2345 there's one, (if the target supports stepping into
2346 handlers), or in the next mainline instruction, if
2347 there's no handler. If this is a continue, we need to be
2348 sure to run the handler with all breakpoints inserted.
2349 In all cases, set a breakpoint at the current address
2350 (where the handler returns to), and once that breakpoint
2351 is hit, resume skipping the permanent breakpoint. If
2352 that breakpoint isn't hit, then we've stepped into the
2353 signal handler (or hit some other event). We'll delete
2354 the step-resume breakpoint then. */
2357 fprintf_unfiltered (gdb_stdlog
,
2358 "infrun: resume: skipping permanent breakpoint, "
2359 "deliver signal first\n");
2361 clear_step_over_info ();
2362 tp
->control
.trap_expected
= 0;
2364 if (tp
->control
.step_resume_breakpoint
== NULL
)
2366 /* Set a "high-priority" step-resume, as we don't want
2367 user breakpoints at PC to trigger (again) when this
2369 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2370 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2372 tp
->step_after_step_resume_breakpoint
= step
;
2375 insert_breakpoints ();
2379 /* There's no signal to pass, we can go ahead and skip the
2380 permanent breakpoint manually. */
2382 fprintf_unfiltered (gdb_stdlog
,
2383 "infrun: resume: skipping permanent breakpoint\n");
2384 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2385 /* Update pc to reflect the new address from which we will
2386 execute instructions. */
2387 pc
= regcache_read_pc (regcache
);
2391 /* We've already advanced the PC, so the stepping part
2392 is done. Now we need to arrange for a trap to be
2393 reported to handle_inferior_event. Set a breakpoint
2394 at the current PC, and run to it. Don't update
2395 prev_pc, because if we end in
2396 switch_back_to_stepped_thread, we want the "expected
2397 thread advanced also" branch to be taken. IOW, we
2398 don't want this thread to step further from PC
2400 gdb_assert (!step_over_info_valid_p ());
2401 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2402 insert_breakpoints ();
2404 resume_ptid
= internal_resume_ptid (user_step
);
2405 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2412 /* If we have a breakpoint to step over, make sure to do a single
2413 step only. Same if we have software watchpoints. */
2414 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2415 tp
->control
.may_range_step
= 0;
2417 /* If enabled, step over breakpoints by executing a copy of the
2418 instruction at a different address.
2420 We can't use displaced stepping when we have a signal to deliver;
2421 the comments for displaced_step_prepare explain why. The
2422 comments in the handle_inferior event for dealing with 'random
2423 signals' explain what we do instead.
2425 We can't use displaced stepping when we are waiting for vfork_done
2426 event, displaced stepping breaks the vfork child similarly as single
2427 step software breakpoint. */
2428 if (tp
->control
.trap_expected
2429 && use_displaced_stepping (tp
)
2430 && !step_over_info_valid_p ()
2431 && sig
== GDB_SIGNAL_0
2432 && !current_inferior ()->waiting_for_vfork_done
)
2434 int prepared
= displaced_step_prepare (tp
);
2439 fprintf_unfiltered (gdb_stdlog
,
2440 "Got placed in step-over queue\n");
2442 tp
->control
.trap_expected
= 0;
2445 else if (prepared
< 0)
2447 /* Fallback to stepping over the breakpoint in-line. */
2449 if (target_is_non_stop_p ())
2450 stop_all_threads ();
2452 set_step_over_info (regcache
->aspace (),
2453 regcache_read_pc (regcache
), 0, tp
->global_num
);
2455 step
= maybe_software_singlestep (gdbarch
, pc
);
2457 insert_breakpoints ();
2459 else if (prepared
> 0)
2461 struct displaced_step_inferior_state
*displaced
;
2463 /* Update pc to reflect the new address from which we will
2464 execute instructions due to displaced stepping. */
2465 pc
= regcache_read_pc (get_thread_regcache (tp
));
2467 displaced
= get_displaced_stepping_state (tp
->inf
);
2468 step
= gdbarch_displaced_step_hw_singlestep
2469 (gdbarch
, displaced
->step_closure
.get ());
2473 /* Do we need to do it the hard way, w/temp breakpoints? */
2475 step
= maybe_software_singlestep (gdbarch
, pc
);
2477 /* Currently, our software single-step implementation leads to different
2478 results than hardware single-stepping in one situation: when stepping
2479 into delivering a signal which has an associated signal handler,
2480 hardware single-step will stop at the first instruction of the handler,
2481 while software single-step will simply skip execution of the handler.
2483 For now, this difference in behavior is accepted since there is no
2484 easy way to actually implement single-stepping into a signal handler
2485 without kernel support.
2487 However, there is one scenario where this difference leads to follow-on
2488 problems: if we're stepping off a breakpoint by removing all breakpoints
2489 and then single-stepping. In this case, the software single-step
2490 behavior means that even if there is a *breakpoint* in the signal
2491 handler, GDB still would not stop.
2493 Fortunately, we can at least fix this particular issue. We detect
2494 here the case where we are about to deliver a signal while software
2495 single-stepping with breakpoints removed. In this situation, we
2496 revert the decisions to remove all breakpoints and insert single-
2497 step breakpoints, and instead we install a step-resume breakpoint
2498 at the current address, deliver the signal without stepping, and
2499 once we arrive back at the step-resume breakpoint, actually step
2500 over the breakpoint we originally wanted to step over. */
2501 if (thread_has_single_step_breakpoints_set (tp
)
2502 && sig
!= GDB_SIGNAL_0
2503 && step_over_info_valid_p ())
2505 /* If we have nested signals or a pending signal is delivered
2506 immediately after a handler returns, might might already have
2507 a step-resume breakpoint set on the earlier handler. We cannot
2508 set another step-resume breakpoint; just continue on until the
2509 original breakpoint is hit. */
2510 if (tp
->control
.step_resume_breakpoint
== NULL
)
2512 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2513 tp
->step_after_step_resume_breakpoint
= 1;
2516 delete_single_step_breakpoints (tp
);
2518 clear_step_over_info ();
2519 tp
->control
.trap_expected
= 0;
2521 insert_breakpoints ();
2524 /* If STEP is set, it's a request to use hardware stepping
2525 facilities. But in that case, we should never
2526 use singlestep breakpoint. */
2527 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2529 /* Decide the set of threads to ask the target to resume. */
2530 if (tp
->control
.trap_expected
)
2532 /* We're allowing a thread to run past a breakpoint it has
2533 hit, either by single-stepping the thread with the breakpoint
2534 removed, or by displaced stepping, with the breakpoint inserted.
2535 In the former case, we need to single-step only this thread,
2536 and keep others stopped, as they can miss this breakpoint if
2537 allowed to run. That's not really a problem for displaced
2538 stepping, but, we still keep other threads stopped, in case
2539 another thread is also stopped for a breakpoint waiting for
2540 its turn in the displaced stepping queue. */
2541 resume_ptid
= inferior_ptid
;
2544 resume_ptid
= internal_resume_ptid (user_step
);
2546 if (execution_direction
!= EXEC_REVERSE
2547 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2549 /* There are two cases where we currently need to step a
2550 breakpoint instruction when we have a signal to deliver:
2552 - See handle_signal_stop where we handle random signals that
2553 could take out us out of the stepping range. Normally, in
2554 that case we end up continuing (instead of stepping) over the
2555 signal handler with a breakpoint at PC, but there are cases
2556 where we should _always_ single-step, even if we have a
2557 step-resume breakpoint, like when a software watchpoint is
2558 set. Assuming single-stepping and delivering a signal at the
2559 same time would takes us to the signal handler, then we could
2560 have removed the breakpoint at PC to step over it. However,
2561 some hardware step targets (like e.g., Mac OS) can't step
2562 into signal handlers, and for those, we need to leave the
2563 breakpoint at PC inserted, as otherwise if the handler
2564 recurses and executes PC again, it'll miss the breakpoint.
2565 So we leave the breakpoint inserted anyway, but we need to
2566 record that we tried to step a breakpoint instruction, so
2567 that adjust_pc_after_break doesn't end up confused.
2569 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2570 in one thread after another thread that was stepping had been
2571 momentarily paused for a step-over. When we re-resume the
2572 stepping thread, it may be resumed from that address with a
2573 breakpoint that hasn't trapped yet. Seen with
2574 gdb.threads/non-stop-fair-events.exp, on targets that don't
2575 do displaced stepping. */
2578 fprintf_unfiltered (gdb_stdlog
,
2579 "infrun: resume: [%s] stepped breakpoint\n",
2580 target_pid_to_str (tp
->ptid
).c_str ());
2582 tp
->stepped_breakpoint
= 1;
2584 /* Most targets can step a breakpoint instruction, thus
2585 executing it normally. But if this one cannot, just
2586 continue and we will hit it anyway. */
2587 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2592 && tp
->control
.trap_expected
2593 && use_displaced_stepping (tp
)
2594 && !step_over_info_valid_p ())
2596 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2597 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2598 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2601 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2602 paddress (resume_gdbarch
, actual_pc
));
2603 read_memory (actual_pc
, buf
, sizeof (buf
));
2604 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2607 if (tp
->control
.may_range_step
)
2609 /* If we're resuming a thread with the PC out of the step
2610 range, then we're doing some nested/finer run control
2611 operation, like stepping the thread out of the dynamic
2612 linker or the displaced stepping scratch pad. We
2613 shouldn't have allowed a range step then. */
2614 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2617 do_target_resume (resume_ptid
, step
, sig
);
2621 /* Resume the inferior. SIG is the signal to give the inferior
2622 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2623 rolls back state on error. */
2626 resume (gdb_signal sig
)
2632 catch (const gdb_exception
&ex
)
2634 /* If resuming is being aborted for any reason, delete any
2635 single-step breakpoint resume_1 may have created, to avoid
2636 confusing the following resumption, and to avoid leaving
2637 single-step breakpoints perturbing other threads, in case
2638 we're running in non-stop mode. */
2639 if (inferior_ptid
!= null_ptid
)
2640 delete_single_step_breakpoints (inferior_thread ());
2650 /* Counter that tracks number of user visible stops. This can be used
2651 to tell whether a command has proceeded the inferior past the
2652 current location. This allows e.g., inferior function calls in
2653 breakpoint commands to not interrupt the command list. When the
2654 call finishes successfully, the inferior is standing at the same
2655 breakpoint as if nothing happened (and so we don't call
2657 static ULONGEST current_stop_id
;
2664 return current_stop_id
;
2667 /* Called when we report a user visible stop. */
2675 /* Clear out all variables saying what to do when inferior is continued.
2676 First do this, then set the ones you want, then call `proceed'. */
2679 clear_proceed_status_thread (struct thread_info
*tp
)
2682 fprintf_unfiltered (gdb_stdlog
,
2683 "infrun: clear_proceed_status_thread (%s)\n",
2684 target_pid_to_str (tp
->ptid
).c_str ());
2686 /* If we're starting a new sequence, then the previous finished
2687 single-step is no longer relevant. */
2688 if (tp
->suspend
.waitstatus_pending_p
)
2690 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2693 fprintf_unfiltered (gdb_stdlog
,
2694 "infrun: clear_proceed_status: pending "
2695 "event of %s was a finished step. "
2697 target_pid_to_str (tp
->ptid
).c_str ());
2699 tp
->suspend
.waitstatus_pending_p
= 0;
2700 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2702 else if (debug_infrun
)
2705 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2707 fprintf_unfiltered (gdb_stdlog
,
2708 "infrun: clear_proceed_status_thread: thread %s "
2709 "has pending wait status %s "
2710 "(currently_stepping=%d).\n",
2711 target_pid_to_str (tp
->ptid
).c_str (),
2713 currently_stepping (tp
));
2717 /* If this signal should not be seen by program, give it zero.
2718 Used for debugging signals. */
2719 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2720 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2722 delete tp
->thread_fsm
;
2723 tp
->thread_fsm
= NULL
;
2725 tp
->control
.trap_expected
= 0;
2726 tp
->control
.step_range_start
= 0;
2727 tp
->control
.step_range_end
= 0;
2728 tp
->control
.may_range_step
= 0;
2729 tp
->control
.step_frame_id
= null_frame_id
;
2730 tp
->control
.step_stack_frame_id
= null_frame_id
;
2731 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2732 tp
->control
.step_start_function
= NULL
;
2733 tp
->stop_requested
= 0;
2735 tp
->control
.stop_step
= 0;
2737 tp
->control
.proceed_to_finish
= 0;
2739 tp
->control
.stepping_command
= 0;
2741 /* Discard any remaining commands or status from previous stop. */
2742 bpstat_clear (&tp
->control
.stop_bpstat
);
2746 clear_proceed_status (int step
)
2748 /* With scheduler-locking replay, stop replaying other threads if we're
2749 not replaying the user-visible resume ptid.
2751 This is a convenience feature to not require the user to explicitly
2752 stop replaying the other threads. We're assuming that the user's
2753 intent is to resume tracing the recorded process. */
2754 if (!non_stop
&& scheduler_mode
== schedlock_replay
2755 && target_record_is_replaying (minus_one_ptid
)
2756 && !target_record_will_replay (user_visible_resume_ptid (step
),
2757 execution_direction
))
2758 target_record_stop_replaying ();
2760 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2762 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2764 /* In all-stop mode, delete the per-thread status of all threads
2765 we're about to resume, implicitly and explicitly. */
2766 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
2767 clear_proceed_status_thread (tp
);
2770 if (inferior_ptid
!= null_ptid
)
2772 struct inferior
*inferior
;
2776 /* If in non-stop mode, only delete the per-thread status of
2777 the current thread. */
2778 clear_proceed_status_thread (inferior_thread ());
2781 inferior
= current_inferior ();
2782 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2785 gdb::observers::about_to_proceed
.notify ();
2788 /* Returns true if TP is still stopped at a breakpoint that needs
2789 stepping-over in order to make progress. If the breakpoint is gone
2790 meanwhile, we can skip the whole step-over dance. */
2793 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2795 if (tp
->stepping_over_breakpoint
)
2797 struct regcache
*regcache
= get_thread_regcache (tp
);
2799 if (breakpoint_here_p (regcache
->aspace (),
2800 regcache_read_pc (regcache
))
2801 == ordinary_breakpoint_here
)
2804 tp
->stepping_over_breakpoint
= 0;
2810 /* Check whether thread TP still needs to start a step-over in order
2811 to make progress when resumed. Returns an bitwise or of enum
2812 step_over_what bits, indicating what needs to be stepped over. */
2814 static step_over_what
2815 thread_still_needs_step_over (struct thread_info
*tp
)
2817 step_over_what what
= 0;
2819 if (thread_still_needs_step_over_bp (tp
))
2820 what
|= STEP_OVER_BREAKPOINT
;
2822 if (tp
->stepping_over_watchpoint
2823 && !target_have_steppable_watchpoint
)
2824 what
|= STEP_OVER_WATCHPOINT
;
2829 /* Returns true if scheduler locking applies. STEP indicates whether
2830 we're about to do a step/next-like command to a thread. */
2833 schedlock_applies (struct thread_info
*tp
)
2835 return (scheduler_mode
== schedlock_on
2836 || (scheduler_mode
== schedlock_step
2837 && tp
->control
.stepping_command
)
2838 || (scheduler_mode
== schedlock_replay
2839 && target_record_will_replay (minus_one_ptid
,
2840 execution_direction
)));
2843 /* Basic routine for continuing the program in various fashions.
2845 ADDR is the address to resume at, or -1 for resume where stopped.
2846 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2847 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2849 You should call clear_proceed_status before calling proceed. */
2852 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2854 struct regcache
*regcache
;
2855 struct gdbarch
*gdbarch
;
2858 struct execution_control_state ecss
;
2859 struct execution_control_state
*ecs
= &ecss
;
2862 /* If we're stopped at a fork/vfork, follow the branch set by the
2863 "set follow-fork-mode" command; otherwise, we'll just proceed
2864 resuming the current thread. */
2865 if (!follow_fork ())
2867 /* The target for some reason decided not to resume. */
2869 if (target_can_async_p ())
2870 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2874 /* We'll update this if & when we switch to a new thread. */
2875 previous_inferior_ptid
= inferior_ptid
;
2877 regcache
= get_current_regcache ();
2878 gdbarch
= regcache
->arch ();
2879 const address_space
*aspace
= regcache
->aspace ();
2881 pc
= regcache_read_pc (regcache
);
2882 thread_info
*cur_thr
= inferior_thread ();
2884 /* Fill in with reasonable starting values. */
2885 init_thread_stepping_state (cur_thr
);
2887 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2889 if (addr
== (CORE_ADDR
) -1)
2891 if (pc
== cur_thr
->suspend
.stop_pc
2892 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2893 && execution_direction
!= EXEC_REVERSE
)
2894 /* There is a breakpoint at the address we will resume at,
2895 step one instruction before inserting breakpoints so that
2896 we do not stop right away (and report a second hit at this
2899 Note, we don't do this in reverse, because we won't
2900 actually be executing the breakpoint insn anyway.
2901 We'll be (un-)executing the previous instruction. */
2902 cur_thr
->stepping_over_breakpoint
= 1;
2903 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2904 && gdbarch_single_step_through_delay (gdbarch
,
2905 get_current_frame ()))
2906 /* We stepped onto an instruction that needs to be stepped
2907 again before re-inserting the breakpoint, do so. */
2908 cur_thr
->stepping_over_breakpoint
= 1;
2912 regcache_write_pc (regcache
, addr
);
2915 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2916 cur_thr
->suspend
.stop_signal
= siggnal
;
2918 resume_ptid
= user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2920 /* If an exception is thrown from this point on, make sure to
2921 propagate GDB's knowledge of the executing state to the
2922 frontend/user running state. */
2923 scoped_finish_thread_state
finish_state (resume_ptid
);
2925 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2926 threads (e.g., we might need to set threads stepping over
2927 breakpoints first), from the user/frontend's point of view, all
2928 threads in RESUME_PTID are now running. Unless we're calling an
2929 inferior function, as in that case we pretend the inferior
2930 doesn't run at all. */
2931 if (!cur_thr
->control
.in_infcall
)
2932 set_running (resume_ptid
, 1);
2935 fprintf_unfiltered (gdb_stdlog
,
2936 "infrun: proceed (addr=%s, signal=%s)\n",
2937 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_ptid
))
2969 /* Ignore the current thread here. It's handled
2974 if (!thread_still_needs_step_over (tp
))
2977 gdb_assert (!thread_is_in_step_over_chain (tp
));
2980 fprintf_unfiltered (gdb_stdlog
,
2981 "infrun: need to step-over [%s] first\n",
2982 target_pid_to_str (tp
->ptid
).c_str ());
2984 global_thread_step_over_chain_enqueue (tp
);
2988 /* Enqueue the current thread last, so that we move all other
2989 threads over their breakpoints first. */
2990 if (cur_thr
->stepping_over_breakpoint
)
2991 global_thread_step_over_chain_enqueue (cur_thr
);
2993 /* If the thread isn't started, we'll still need to set its prev_pc,
2994 so that switch_back_to_stepped_thread knows the thread hasn't
2995 advanced. Must do this before resuming any thread, as in
2996 all-stop/remote, once we resume we can't send any other packet
2997 until the target stops again. */
2998 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
3001 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3003 started
= start_step_over ();
3005 if (step_over_info_valid_p ())
3007 /* Either this thread started a new in-line step over, or some
3008 other thread was already doing one. In either case, don't
3009 resume anything else until the step-over is finished. */
3011 else if (started
&& !target_is_non_stop_p ())
3013 /* A new displaced stepping sequence was started. In all-stop,
3014 we can't talk to the target anymore until it next stops. */
3016 else if (!non_stop
&& target_is_non_stop_p ())
3018 /* In all-stop, but the target is always in non-stop mode.
3019 Start all other threads that are implicitly resumed too. */
3020 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
3025 fprintf_unfiltered (gdb_stdlog
,
3026 "infrun: proceed: [%s] resumed\n",
3027 target_pid_to_str (tp
->ptid
).c_str ());
3028 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3032 if (thread_is_in_step_over_chain (tp
))
3035 fprintf_unfiltered (gdb_stdlog
,
3036 "infrun: proceed: [%s] needs step-over\n",
3037 target_pid_to_str (tp
->ptid
).c_str ());
3042 fprintf_unfiltered (gdb_stdlog
,
3043 "infrun: proceed: resuming %s\n",
3044 target_pid_to_str (tp
->ptid
).c_str ());
3046 reset_ecs (ecs
, tp
);
3047 switch_to_thread (tp
);
3048 keep_going_pass_signal (ecs
);
3049 if (!ecs
->wait_some_more
)
3050 error (_("Command aborted."));
3053 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3055 /* The thread wasn't started, and isn't queued, run it now. */
3056 reset_ecs (ecs
, cur_thr
);
3057 switch_to_thread (cur_thr
);
3058 keep_going_pass_signal (ecs
);
3059 if (!ecs
->wait_some_more
)
3060 error (_("Command aborted."));
3064 target_commit_resume ();
3066 finish_state
.release ();
3068 /* Tell the event loop to wait for it to stop. If the target
3069 supports asynchronous execution, it'll do this from within
3071 if (!target_can_async_p ())
3072 mark_async_event_handler (infrun_async_inferior_event_token
);
3076 /* Start remote-debugging of a machine over a serial link. */
3079 start_remote (int from_tty
)
3081 struct inferior
*inferior
;
3083 inferior
= current_inferior ();
3084 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3086 /* Always go on waiting for the target, regardless of the mode. */
3087 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3088 indicate to wait_for_inferior that a target should timeout if
3089 nothing is returned (instead of just blocking). Because of this,
3090 targets expecting an immediate response need to, internally, set
3091 things up so that the target_wait() is forced to eventually
3093 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3094 differentiate to its caller what the state of the target is after
3095 the initial open has been performed. Here we're assuming that
3096 the target has stopped. It should be possible to eventually have
3097 target_open() return to the caller an indication that the target
3098 is currently running and GDB state should be set to the same as
3099 for an async run. */
3100 wait_for_inferior ();
3102 /* Now that the inferior has stopped, do any bookkeeping like
3103 loading shared libraries. We want to do this before normal_stop,
3104 so that the displayed frame is up to date. */
3105 post_create_inferior (current_top_target (), from_tty
);
3110 /* Initialize static vars when a new inferior begins. */
3113 init_wait_for_inferior (void)
3115 /* These are meaningless until the first time through wait_for_inferior. */
3117 breakpoint_init_inferior (inf_starting
);
3119 clear_proceed_status (0);
3121 target_last_wait_ptid
= minus_one_ptid
;
3123 previous_inferior_ptid
= inferior_ptid
;
3128 static void handle_inferior_event (struct execution_control_state
*ecs
);
3130 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3131 struct execution_control_state
*ecs
);
3132 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3133 struct execution_control_state
*ecs
);
3134 static void handle_signal_stop (struct execution_control_state
*ecs
);
3135 static void check_exception_resume (struct execution_control_state
*,
3136 struct frame_info
*);
3138 static void end_stepping_range (struct execution_control_state
*ecs
);
3139 static void stop_waiting (struct execution_control_state
*ecs
);
3140 static void keep_going (struct execution_control_state
*ecs
);
3141 static void process_event_stop_test (struct execution_control_state
*ecs
);
3142 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3144 /* This function is attached as a "thread_stop_requested" observer.
3145 Cleanup local state that assumed the PTID was to be resumed, and
3146 report the stop to the frontend. */
3149 infrun_thread_stop_requested (ptid_t ptid
)
3151 /* PTID was requested to stop. If the thread was already stopped,
3152 but the user/frontend doesn't know about that yet (e.g., the
3153 thread had been temporarily paused for some step-over), set up
3154 for reporting the stop now. */
3155 for (thread_info
*tp
: all_threads (ptid
))
3157 if (tp
->state
!= THREAD_RUNNING
)
3162 /* Remove matching threads from the step-over queue, so
3163 start_step_over doesn't try to resume them
3165 if (thread_is_in_step_over_chain (tp
))
3166 global_thread_step_over_chain_remove (tp
);
3168 /* If the thread is stopped, but the user/frontend doesn't
3169 know about that yet, queue a pending event, as if the
3170 thread had just stopped now. Unless the thread already had
3172 if (!tp
->suspend
.waitstatus_pending_p
)
3174 tp
->suspend
.waitstatus_pending_p
= 1;
3175 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3176 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3179 /* Clear the inline-frame state, since we're re-processing the
3181 clear_inline_frame_state (tp
->ptid
);
3183 /* If this thread was paused because some other thread was
3184 doing an inline-step over, let that finish first. Once
3185 that happens, we'll restart all threads and consume pending
3186 stop events then. */
3187 if (step_over_info_valid_p ())
3190 /* Otherwise we can process the (new) pending event now. Set
3191 it so this pending event is considered by
3198 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3200 if (target_last_wait_ptid
== tp
->ptid
)
3201 nullify_last_target_wait_ptid ();
3204 /* Delete the step resume, single-step and longjmp/exception resume
3205 breakpoints of TP. */
3208 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3210 delete_step_resume_breakpoint (tp
);
3211 delete_exception_resume_breakpoint (tp
);
3212 delete_single_step_breakpoints (tp
);
3215 /* If the target still has execution, call FUNC for each thread that
3216 just stopped. In all-stop, that's all the non-exited threads; in
3217 non-stop, that's the current thread, only. */
3219 typedef void (*for_each_just_stopped_thread_callback_func
)
3220 (struct thread_info
*tp
);
3223 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3225 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3228 if (target_is_non_stop_p ())
3230 /* If in non-stop mode, only the current thread stopped. */
3231 func (inferior_thread ());
3235 /* In all-stop mode, all threads have stopped. */
3236 for (thread_info
*tp
: all_non_exited_threads ())
3241 /* Delete the step resume and longjmp/exception resume breakpoints of
3242 the threads that just stopped. */
3245 delete_just_stopped_threads_infrun_breakpoints (void)
3247 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3250 /* Delete the single-step breakpoints of the threads that just
3254 delete_just_stopped_threads_single_step_breakpoints (void)
3256 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3262 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3263 const struct target_waitstatus
*ws
)
3265 std::string status_string
= target_waitstatus_to_string (ws
);
3268 /* The text is split over several lines because it was getting too long.
3269 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3270 output as a unit; we want only one timestamp printed if debug_timestamp
3273 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3276 waiton_ptid
.tid ());
3277 if (waiton_ptid
.pid () != -1)
3278 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3279 stb
.printf (", status) =\n");
3280 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3284 target_pid_to_str (result_ptid
).c_str ());
3285 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3287 /* This uses %s in part to handle %'s in the text, but also to avoid
3288 a gcc error: the format attribute requires a string literal. */
3289 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3292 /* Select a thread at random, out of those which are resumed and have
3295 static struct thread_info
*
3296 random_pending_event_thread (ptid_t waiton_ptid
)
3300 auto has_event
= [] (thread_info
*tp
)
3303 && tp
->suspend
.waitstatus_pending_p
);
3306 /* First see how many events we have. Count only resumed threads
3307 that have an event pending. */
3308 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3312 if (num_events
== 0)
3315 /* Now randomly pick a thread out of those that have had events. */
3316 int random_selector
= (int) ((num_events
* (double) rand ())
3317 / (RAND_MAX
+ 1.0));
3319 if (debug_infrun
&& num_events
> 1)
3320 fprintf_unfiltered (gdb_stdlog
,
3321 "infrun: Found %d events, selecting #%d\n",
3322 num_events
, random_selector
);
3324 /* Select the Nth thread that has had an event. */
3325 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3327 if (random_selector
-- == 0)
3330 gdb_assert_not_reached ("event thread not found");
3333 /* Wrapper for target_wait that first checks whether threads have
3334 pending statuses to report before actually asking the target for
3338 do_target_wait (ptid_t ptid
, struct target_waitstatus
*status
, int options
)
3341 struct thread_info
*tp
;
3343 /* First check if there is a resumed thread with a wait status
3345 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3347 tp
= random_pending_event_thread (ptid
);
3352 fprintf_unfiltered (gdb_stdlog
,
3353 "infrun: Waiting for specific thread %s.\n",
3354 target_pid_to_str (ptid
).c_str ());
3356 /* We have a specific thread to check. */
3357 tp
= find_thread_ptid (ptid
);
3358 gdb_assert (tp
!= NULL
);
3359 if (!tp
->suspend
.waitstatus_pending_p
)
3364 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3365 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3367 struct regcache
*regcache
= get_thread_regcache (tp
);
3368 struct gdbarch
*gdbarch
= regcache
->arch ();
3372 pc
= regcache_read_pc (regcache
);
3374 if (pc
!= tp
->suspend
.stop_pc
)
3377 fprintf_unfiltered (gdb_stdlog
,
3378 "infrun: PC of %s changed. was=%s, now=%s\n",
3379 target_pid_to_str (tp
->ptid
).c_str (),
3380 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3381 paddress (gdbarch
, pc
));
3384 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3387 fprintf_unfiltered (gdb_stdlog
,
3388 "infrun: previous breakpoint of %s, at %s gone\n",
3389 target_pid_to_str (tp
->ptid
).c_str (),
3390 paddress (gdbarch
, pc
));
3398 fprintf_unfiltered (gdb_stdlog
,
3399 "infrun: pending event of %s cancelled.\n",
3400 target_pid_to_str (tp
->ptid
).c_str ());
3402 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3403 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3412 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3414 fprintf_unfiltered (gdb_stdlog
,
3415 "infrun: Using pending wait status %s for %s.\n",
3417 target_pid_to_str (tp
->ptid
).c_str ());
3420 /* Now that we've selected our final event LWP, un-adjust its PC
3421 if it was a software breakpoint (and the target doesn't
3422 always adjust the PC itself). */
3423 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3424 && !target_supports_stopped_by_sw_breakpoint ())
3426 struct regcache
*regcache
;
3427 struct gdbarch
*gdbarch
;
3430 regcache
= get_thread_regcache (tp
);
3431 gdbarch
= regcache
->arch ();
3433 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3438 pc
= regcache_read_pc (regcache
);
3439 regcache_write_pc (regcache
, pc
+ decr_pc
);
3443 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3444 *status
= tp
->suspend
.waitstatus
;
3445 tp
->suspend
.waitstatus_pending_p
= 0;
3447 /* Wake up the event loop again, until all pending events are
3449 if (target_is_async_p ())
3450 mark_async_event_handler (infrun_async_inferior_event_token
);
3454 /* But if we don't find one, we'll have to wait. */
3456 if (deprecated_target_wait_hook
)
3457 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3459 event_ptid
= target_wait (ptid
, status
, options
);
3464 /* Prepare and stabilize the inferior for detaching it. E.g.,
3465 detaching while a thread is displaced stepping is a recipe for
3466 crashing it, as nothing would readjust the PC out of the scratch
3470 prepare_for_detach (void)
3472 struct inferior
*inf
= current_inferior ();
3473 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3475 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3477 /* Is any thread of this process displaced stepping? If not,
3478 there's nothing else to do. */
3479 if (displaced
->step_thread
== nullptr)
3483 fprintf_unfiltered (gdb_stdlog
,
3484 "displaced-stepping in-process while detaching");
3486 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3488 while (displaced
->step_thread
!= nullptr)
3490 struct execution_control_state ecss
;
3491 struct execution_control_state
*ecs
;
3494 memset (ecs
, 0, sizeof (*ecs
));
3496 overlay_cache_invalid
= 1;
3497 /* Flush target cache before starting to handle each event.
3498 Target was running and cache could be stale. This is just a
3499 heuristic. Running threads may modify target memory, but we
3500 don't get any event. */
3501 target_dcache_invalidate ();
3503 ecs
->ptid
= do_target_wait (pid_ptid
, &ecs
->ws
, 0);
3506 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3508 /* If an error happens while handling the event, propagate GDB's
3509 knowledge of the executing state to the frontend/user running
3511 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3513 /* Now figure out what to do with the result of the result. */
3514 handle_inferior_event (ecs
);
3516 /* No error, don't finish the state yet. */
3517 finish_state
.release ();
3519 /* Breakpoints and watchpoints are not installed on the target
3520 at this point, and signals are passed directly to the
3521 inferior, so this must mean the process is gone. */
3522 if (!ecs
->wait_some_more
)
3524 restore_detaching
.release ();
3525 error (_("Program exited while detaching"));
3529 restore_detaching
.release ();
3532 /* Wait for control to return from inferior to debugger.
3534 If inferior gets a signal, we may decide to start it up again
3535 instead of returning. That is why there is a loop in this function.
3536 When this function actually returns it means the inferior
3537 should be left stopped and GDB should read more commands. */
3540 wait_for_inferior (void)
3544 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3546 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3548 /* If an error happens while handling the event, propagate GDB's
3549 knowledge of the executing state to the frontend/user running
3551 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3555 struct execution_control_state ecss
;
3556 struct execution_control_state
*ecs
= &ecss
;
3557 ptid_t waiton_ptid
= minus_one_ptid
;
3559 memset (ecs
, 0, sizeof (*ecs
));
3561 overlay_cache_invalid
= 1;
3563 /* Flush target cache before starting to handle each event.
3564 Target was running and cache could be stale. This is just a
3565 heuristic. Running threads may modify target memory, but we
3566 don't get any event. */
3567 target_dcache_invalidate ();
3569 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
, 0);
3572 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3574 /* Now figure out what to do with the result of the result. */
3575 handle_inferior_event (ecs
);
3577 if (!ecs
->wait_some_more
)
3581 /* No error, don't finish the state yet. */
3582 finish_state
.release ();
3585 /* Cleanup that reinstalls the readline callback handler, if the
3586 target is running in the background. If while handling the target
3587 event something triggered a secondary prompt, like e.g., a
3588 pagination prompt, we'll have removed the callback handler (see
3589 gdb_readline_wrapper_line). Need to do this as we go back to the
3590 event loop, ready to process further input. Note this has no
3591 effect if the handler hasn't actually been removed, because calling
3592 rl_callback_handler_install resets the line buffer, thus losing
3596 reinstall_readline_callback_handler_cleanup ()
3598 struct ui
*ui
= current_ui
;
3602 /* We're not going back to the top level event loop yet. Don't
3603 install the readline callback, as it'd prep the terminal,
3604 readline-style (raw, noecho) (e.g., --batch). We'll install
3605 it the next time the prompt is displayed, when we're ready
3610 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3611 gdb_rl_callback_handler_reinstall ();
3614 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3615 that's just the event thread. In all-stop, that's all threads. */
3618 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3620 if (ecs
->event_thread
!= NULL
3621 && ecs
->event_thread
->thread_fsm
!= NULL
)
3622 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3626 for (thread_info
*thr
: all_non_exited_threads ())
3628 if (thr
->thread_fsm
== NULL
)
3630 if (thr
== ecs
->event_thread
)
3633 switch_to_thread (thr
);
3634 thr
->thread_fsm
->clean_up (thr
);
3637 if (ecs
->event_thread
!= NULL
)
3638 switch_to_thread (ecs
->event_thread
);
3642 /* Helper for all_uis_check_sync_execution_done that works on the
3646 check_curr_ui_sync_execution_done (void)
3648 struct ui
*ui
= current_ui
;
3650 if (ui
->prompt_state
== PROMPT_NEEDED
3652 && !gdb_in_secondary_prompt_p (ui
))
3654 target_terminal::ours ();
3655 gdb::observers::sync_execution_done
.notify ();
3656 ui_register_input_event_handler (ui
);
3663 all_uis_check_sync_execution_done (void)
3665 SWITCH_THRU_ALL_UIS ()
3667 check_curr_ui_sync_execution_done ();
3674 all_uis_on_sync_execution_starting (void)
3676 SWITCH_THRU_ALL_UIS ()
3678 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3679 async_disable_stdin ();
3683 /* Asynchronous version of wait_for_inferior. It is called by the
3684 event loop whenever a change of state is detected on the file
3685 descriptor corresponding to the target. It can be called more than
3686 once to complete a single execution command. In such cases we need
3687 to keep the state in a global variable ECSS. If it is the last time
3688 that this function is called for a single execution command, then
3689 report to the user that the inferior has stopped, and do the
3690 necessary cleanups. */
3693 fetch_inferior_event (void *client_data
)
3695 struct execution_control_state ecss
;
3696 struct execution_control_state
*ecs
= &ecss
;
3698 ptid_t waiton_ptid
= minus_one_ptid
;
3700 memset (ecs
, 0, sizeof (*ecs
));
3702 /* Events are always processed with the main UI as current UI. This
3703 way, warnings, debug output, etc. are always consistently sent to
3704 the main console. */
3705 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3707 /* End up with readline processing input, if necessary. */
3709 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3711 /* We're handling a live event, so make sure we're doing live
3712 debugging. If we're looking at traceframes while the target is
3713 running, we're going to need to get back to that mode after
3714 handling the event. */
3715 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3718 maybe_restore_traceframe
.emplace ();
3719 set_current_traceframe (-1);
3722 gdb::optional
<scoped_restore_current_thread
> maybe_restore_thread
;
3725 /* In non-stop mode, the user/frontend should not notice a thread
3726 switch due to internal events. Make sure we reverse to the
3727 user selected thread and frame after handling the event and
3728 running any breakpoint commands. */
3729 maybe_restore_thread
.emplace ();
3731 overlay_cache_invalid
= 1;
3732 /* Flush target cache before starting to handle each event. Target
3733 was running and cache could be stale. This is just a heuristic.
3734 Running threads may modify target memory, but we don't get any
3736 target_dcache_invalidate ();
3738 scoped_restore save_exec_dir
3739 = make_scoped_restore (&execution_direction
,
3740 target_execution_direction ());
3742 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
,
3743 target_can_async_p () ? TARGET_WNOHANG
: 0);
3746 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3748 /* If an error happens while handling the event, propagate GDB's
3749 knowledge of the executing state to the frontend/user running
3751 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3752 scoped_finish_thread_state
finish_state (finish_ptid
);
3754 /* Get executed before scoped_restore_current_thread above to apply
3755 still for the thread which has thrown the exception. */
3756 auto defer_bpstat_clear
3757 = make_scope_exit (bpstat_clear_actions
);
3758 auto defer_delete_threads
3759 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3761 /* Now figure out what to do with the result of the result. */
3762 handle_inferior_event (ecs
);
3764 if (!ecs
->wait_some_more
)
3766 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3767 int should_stop
= 1;
3768 struct thread_info
*thr
= ecs
->event_thread
;
3770 delete_just_stopped_threads_infrun_breakpoints ();
3774 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3776 if (thread_fsm
!= NULL
)
3777 should_stop
= thread_fsm
->should_stop (thr
);
3786 bool should_notify_stop
= true;
3789 clean_up_just_stopped_threads_fsms (ecs
);
3791 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3792 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3794 if (should_notify_stop
)
3796 /* We may not find an inferior if this was a process exit. */
3797 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3798 proceeded
= normal_stop ();
3803 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3809 defer_delete_threads
.release ();
3810 defer_bpstat_clear
.release ();
3812 /* No error, don't finish the thread states yet. */
3813 finish_state
.release ();
3815 /* This scope is used to ensure that readline callbacks are
3816 reinstalled here. */
3819 /* If a UI was in sync execution mode, and now isn't, restore its
3820 prompt (a synchronous execution command has finished, and we're
3821 ready for input). */
3822 all_uis_check_sync_execution_done ();
3825 && exec_done_display_p
3826 && (inferior_ptid
== null_ptid
3827 || inferior_thread ()->state
!= THREAD_RUNNING
))
3828 printf_unfiltered (_("completed.\n"));
3831 /* Record the frame and location we're currently stepping through. */
3833 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
3835 struct thread_info
*tp
= inferior_thread ();
3837 tp
->control
.step_frame_id
= get_frame_id (frame
);
3838 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3840 tp
->current_symtab
= sal
.symtab
;
3841 tp
->current_line
= sal
.line
;
3844 /* Clear context switchable stepping state. */
3847 init_thread_stepping_state (struct thread_info
*tss
)
3849 tss
->stepped_breakpoint
= 0;
3850 tss
->stepping_over_breakpoint
= 0;
3851 tss
->stepping_over_watchpoint
= 0;
3852 tss
->step_after_step_resume_breakpoint
= 0;
3855 /* Set the cached copy of the last ptid/waitstatus. */
3858 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
3860 target_last_wait_ptid
= ptid
;
3861 target_last_waitstatus
= status
;
3864 /* Return the cached copy of the last pid/waitstatus returned by
3865 target_wait()/deprecated_target_wait_hook(). The data is actually
3866 cached by handle_inferior_event(), which gets called immediately
3867 after target_wait()/deprecated_target_wait_hook(). */
3870 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
3872 *ptidp
= target_last_wait_ptid
;
3873 *status
= target_last_waitstatus
;
3877 nullify_last_target_wait_ptid (void)
3879 target_last_wait_ptid
= minus_one_ptid
;
3882 /* Switch thread contexts. */
3885 context_switch (execution_control_state
*ecs
)
3888 && ecs
->ptid
!= inferior_ptid
3889 && ecs
->event_thread
!= inferior_thread ())
3891 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
3892 target_pid_to_str (inferior_ptid
).c_str ());
3893 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
3894 target_pid_to_str (ecs
->ptid
).c_str ());
3897 switch_to_thread (ecs
->event_thread
);
3900 /* If the target can't tell whether we've hit breakpoints
3901 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3902 check whether that could have been caused by a breakpoint. If so,
3903 adjust the PC, per gdbarch_decr_pc_after_break. */
3906 adjust_pc_after_break (struct thread_info
*thread
,
3907 struct target_waitstatus
*ws
)
3909 struct regcache
*regcache
;
3910 struct gdbarch
*gdbarch
;
3911 CORE_ADDR breakpoint_pc
, decr_pc
;
3913 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3914 we aren't, just return.
3916 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3917 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3918 implemented by software breakpoints should be handled through the normal
3921 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3922 different signals (SIGILL or SIGEMT for instance), but it is less
3923 clear where the PC is pointing afterwards. It may not match
3924 gdbarch_decr_pc_after_break. I don't know any specific target that
3925 generates these signals at breakpoints (the code has been in GDB since at
3926 least 1992) so I can not guess how to handle them here.
3928 In earlier versions of GDB, a target with
3929 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3930 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3931 target with both of these set in GDB history, and it seems unlikely to be
3932 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3934 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
3937 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
3940 /* In reverse execution, when a breakpoint is hit, the instruction
3941 under it has already been de-executed. The reported PC always
3942 points at the breakpoint address, so adjusting it further would
3943 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3946 B1 0x08000000 : INSN1
3947 B2 0x08000001 : INSN2
3949 PC -> 0x08000003 : INSN4
3951 Say you're stopped at 0x08000003 as above. Reverse continuing
3952 from that point should hit B2 as below. Reading the PC when the
3953 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3954 been de-executed already.
3956 B1 0x08000000 : INSN1
3957 B2 PC -> 0x08000001 : INSN2
3961 We can't apply the same logic as for forward execution, because
3962 we would wrongly adjust the PC to 0x08000000, since there's a
3963 breakpoint at PC - 1. We'd then report a hit on B1, although
3964 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3966 if (execution_direction
== EXEC_REVERSE
)
3969 /* If the target can tell whether the thread hit a SW breakpoint,
3970 trust it. Targets that can tell also adjust the PC
3972 if (target_supports_stopped_by_sw_breakpoint ())
3975 /* Note that relying on whether a breakpoint is planted in memory to
3976 determine this can fail. E.g,. the breakpoint could have been
3977 removed since. Or the thread could have been told to step an
3978 instruction the size of a breakpoint instruction, and only
3979 _after_ was a breakpoint inserted at its address. */
3981 /* If this target does not decrement the PC after breakpoints, then
3982 we have nothing to do. */
3983 regcache
= get_thread_regcache (thread
);
3984 gdbarch
= regcache
->arch ();
3986 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3990 const address_space
*aspace
= regcache
->aspace ();
3992 /* Find the location where (if we've hit a breakpoint) the
3993 breakpoint would be. */
3994 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
3996 /* If the target can't tell whether a software breakpoint triggered,
3997 fallback to figuring it out based on breakpoints we think were
3998 inserted in the target, and on whether the thread was stepped or
4001 /* Check whether there actually is a software breakpoint inserted at
4004 If in non-stop mode, a race condition is possible where we've
4005 removed a breakpoint, but stop events for that breakpoint were
4006 already queued and arrive later. To suppress those spurious
4007 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4008 and retire them after a number of stop events are reported. Note
4009 this is an heuristic and can thus get confused. The real fix is
4010 to get the "stopped by SW BP and needs adjustment" info out of
4011 the target/kernel (and thus never reach here; see above). */
4012 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4013 || (target_is_non_stop_p ()
4014 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4016 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4018 if (record_full_is_used ())
4019 restore_operation_disable
.emplace
4020 (record_full_gdb_operation_disable_set ());
4022 /* When using hardware single-step, a SIGTRAP is reported for both
4023 a completed single-step and a software breakpoint. Need to
4024 differentiate between the two, as the latter needs adjusting
4025 but the former does not.
4027 The SIGTRAP can be due to a completed hardware single-step only if
4028 - we didn't insert software single-step breakpoints
4029 - this thread is currently being stepped
4031 If any of these events did not occur, we must have stopped due
4032 to hitting a software breakpoint, and have to back up to the
4035 As a special case, we could have hardware single-stepped a
4036 software breakpoint. In this case (prev_pc == breakpoint_pc),
4037 we also need to back up to the breakpoint address. */
4039 if (thread_has_single_step_breakpoints_set (thread
)
4040 || !currently_stepping (thread
)
4041 || (thread
->stepped_breakpoint
4042 && thread
->prev_pc
== breakpoint_pc
))
4043 regcache_write_pc (regcache
, breakpoint_pc
);
4048 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4050 for (frame
= get_prev_frame (frame
);
4052 frame
= get_prev_frame (frame
))
4054 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4056 if (get_frame_type (frame
) != INLINE_FRAME
)
4063 /* If the event thread has the stop requested flag set, pretend it
4064 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4068 handle_stop_requested (struct execution_control_state
*ecs
)
4070 if (ecs
->event_thread
->stop_requested
)
4072 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4073 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4074 handle_signal_stop (ecs
);
4080 /* Auxiliary function that handles syscall entry/return events.
4081 It returns 1 if the inferior should keep going (and GDB
4082 should ignore the event), or 0 if the event deserves to be
4086 handle_syscall_event (struct execution_control_state
*ecs
)
4088 struct regcache
*regcache
;
4091 context_switch (ecs
);
4093 regcache
= get_thread_regcache (ecs
->event_thread
);
4094 syscall_number
= ecs
->ws
.value
.syscall_number
;
4095 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4097 if (catch_syscall_enabled () > 0
4098 && catching_syscall_number (syscall_number
) > 0)
4101 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4104 ecs
->event_thread
->control
.stop_bpstat
4105 = bpstat_stop_status (regcache
->aspace (),
4106 ecs
->event_thread
->suspend
.stop_pc
,
4107 ecs
->event_thread
, &ecs
->ws
);
4109 if (handle_stop_requested (ecs
))
4112 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4114 /* Catchpoint hit. */
4119 if (handle_stop_requested (ecs
))
4122 /* If no catchpoint triggered for this, then keep going. */
4127 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4130 fill_in_stop_func (struct gdbarch
*gdbarch
,
4131 struct execution_control_state
*ecs
)
4133 if (!ecs
->stop_func_filled_in
)
4137 /* Don't care about return value; stop_func_start and stop_func_name
4138 will both be 0 if it doesn't work. */
4139 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4140 &ecs
->stop_func_name
,
4141 &ecs
->stop_func_start
,
4142 &ecs
->stop_func_end
,
4145 /* The call to find_pc_partial_function, above, will set
4146 stop_func_start and stop_func_end to the start and end
4147 of the range containing the stop pc. If this range
4148 contains the entry pc for the block (which is always the
4149 case for contiguous blocks), advance stop_func_start past
4150 the function's start offset and entrypoint. Note that
4151 stop_func_start is NOT advanced when in a range of a
4152 non-contiguous block that does not contain the entry pc. */
4153 if (block
!= nullptr
4154 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4155 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4157 ecs
->stop_func_start
4158 += gdbarch_deprecated_function_start_offset (gdbarch
);
4160 if (gdbarch_skip_entrypoint_p (gdbarch
))
4161 ecs
->stop_func_start
4162 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4165 ecs
->stop_func_filled_in
= 1;
4170 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4172 static enum stop_kind
4173 get_inferior_stop_soon (execution_control_state
*ecs
)
4175 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
4177 gdb_assert (inf
!= NULL
);
4178 return inf
->control
.stop_soon
;
4181 /* Wait for one event. Store the resulting waitstatus in WS, and
4182 return the event ptid. */
4185 wait_one (struct target_waitstatus
*ws
)
4188 ptid_t wait_ptid
= minus_one_ptid
;
4190 overlay_cache_invalid
= 1;
4192 /* Flush target cache before starting to handle each event.
4193 Target was running and cache could be stale. This is just a
4194 heuristic. Running threads may modify target memory, but we
4195 don't get any event. */
4196 target_dcache_invalidate ();
4198 if (deprecated_target_wait_hook
)
4199 event_ptid
= deprecated_target_wait_hook (wait_ptid
, ws
, 0);
4201 event_ptid
= target_wait (wait_ptid
, ws
, 0);
4204 print_target_wait_results (wait_ptid
, event_ptid
, ws
);
4209 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4210 instead of the current thread. */
4211 #define THREAD_STOPPED_BY(REASON) \
4213 thread_stopped_by_ ## REASON (ptid_t ptid) \
4215 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4216 inferior_ptid = ptid; \
4218 return target_stopped_by_ ## REASON (); \
4221 /* Generate thread_stopped_by_watchpoint. */
4222 THREAD_STOPPED_BY (watchpoint
)
4223 /* Generate thread_stopped_by_sw_breakpoint. */
4224 THREAD_STOPPED_BY (sw_breakpoint
)
4225 /* Generate thread_stopped_by_hw_breakpoint. */
4226 THREAD_STOPPED_BY (hw_breakpoint
)
4228 /* Save the thread's event and stop reason to process it later. */
4231 save_waitstatus (struct thread_info
*tp
, struct target_waitstatus
*ws
)
4235 std::string statstr
= target_waitstatus_to_string (ws
);
4237 fprintf_unfiltered (gdb_stdlog
,
4238 "infrun: saving status %s for %d.%ld.%ld\n",
4245 /* Record for later. */
4246 tp
->suspend
.waitstatus
= *ws
;
4247 tp
->suspend
.waitstatus_pending_p
= 1;
4249 struct regcache
*regcache
= get_thread_regcache (tp
);
4250 const address_space
*aspace
= regcache
->aspace ();
4252 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4253 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4255 CORE_ADDR pc
= regcache_read_pc (regcache
);
4257 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4259 if (thread_stopped_by_watchpoint (tp
->ptid
))
4261 tp
->suspend
.stop_reason
4262 = TARGET_STOPPED_BY_WATCHPOINT
;
4264 else if (target_supports_stopped_by_sw_breakpoint ()
4265 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4267 tp
->suspend
.stop_reason
4268 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4270 else if (target_supports_stopped_by_hw_breakpoint ()
4271 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4273 tp
->suspend
.stop_reason
4274 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4276 else if (!target_supports_stopped_by_hw_breakpoint ()
4277 && hardware_breakpoint_inserted_here_p (aspace
,
4280 tp
->suspend
.stop_reason
4281 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4283 else if (!target_supports_stopped_by_sw_breakpoint ()
4284 && software_breakpoint_inserted_here_p (aspace
,
4287 tp
->suspend
.stop_reason
4288 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4290 else if (!thread_has_single_step_breakpoints_set (tp
)
4291 && currently_stepping (tp
))
4293 tp
->suspend
.stop_reason
4294 = TARGET_STOPPED_BY_SINGLE_STEP
;
4302 stop_all_threads (void)
4304 /* We may need multiple passes to discover all threads. */
4308 gdb_assert (target_is_non_stop_p ());
4311 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4313 scoped_restore_current_thread restore_thread
;
4315 target_thread_events (1);
4316 SCOPE_EXIT
{ target_thread_events (0); };
4318 /* Request threads to stop, and then wait for the stops. Because
4319 threads we already know about can spawn more threads while we're
4320 trying to stop them, and we only learn about new threads when we
4321 update the thread list, do this in a loop, and keep iterating
4322 until two passes find no threads that need to be stopped. */
4323 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4326 fprintf_unfiltered (gdb_stdlog
,
4327 "infrun: stop_all_threads, pass=%d, "
4328 "iterations=%d\n", pass
, iterations
);
4332 struct target_waitstatus ws
;
4335 update_thread_list ();
4337 /* Go through all threads looking for threads that we need
4338 to tell the target to stop. */
4339 for (thread_info
*t
: all_non_exited_threads ())
4343 /* If already stopping, don't request a stop again.
4344 We just haven't seen the notification yet. */
4345 if (!t
->stop_requested
)
4348 fprintf_unfiltered (gdb_stdlog
,
4349 "infrun: %s executing, "
4351 target_pid_to_str (t
->ptid
).c_str ());
4352 target_stop (t
->ptid
);
4353 t
->stop_requested
= 1;
4358 fprintf_unfiltered (gdb_stdlog
,
4359 "infrun: %s executing, "
4360 "already stopping\n",
4361 target_pid_to_str (t
->ptid
).c_str ());
4364 if (t
->stop_requested
)
4370 fprintf_unfiltered (gdb_stdlog
,
4371 "infrun: %s not executing\n",
4372 target_pid_to_str (t
->ptid
).c_str ());
4374 /* The thread may be not executing, but still be
4375 resumed with a pending status to process. */
4383 /* If we find new threads on the second iteration, restart
4384 over. We want to see two iterations in a row with all
4389 event_ptid
= wait_one (&ws
);
4392 fprintf_unfiltered (gdb_stdlog
,
4393 "infrun: stop_all_threads %s %s\n",
4394 target_waitstatus_to_string (&ws
).c_str (),
4395 target_pid_to_str (event_ptid
).c_str ());
4398 if (ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4399 || ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4400 || ws
.kind
== TARGET_WAITKIND_EXITED
4401 || ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4403 /* All resumed threads exited
4404 or one thread/process exited/signalled. */
4408 thread_info
*t
= find_thread_ptid (event_ptid
);
4410 t
= add_thread (event_ptid
);
4412 t
->stop_requested
= 0;
4415 t
->control
.may_range_step
= 0;
4417 /* This may be the first time we see the inferior report
4419 inferior
*inf
= find_inferior_ptid (event_ptid
);
4420 if (inf
->needs_setup
)
4422 switch_to_thread_no_regs (t
);
4426 if (ws
.kind
== TARGET_WAITKIND_STOPPED
4427 && ws
.value
.sig
== GDB_SIGNAL_0
)
4429 /* We caught the event that we intended to catch, so
4430 there's no event pending. */
4431 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4432 t
->suspend
.waitstatus_pending_p
= 0;
4434 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4436 /* Add it back to the step-over queue. */
4439 fprintf_unfiltered (gdb_stdlog
,
4440 "infrun: displaced-step of %s "
4441 "canceled: adding back to the "
4442 "step-over queue\n",
4443 target_pid_to_str (t
->ptid
).c_str ());
4445 t
->control
.trap_expected
= 0;
4446 global_thread_step_over_chain_enqueue (t
);
4451 enum gdb_signal sig
;
4452 struct regcache
*regcache
;
4456 std::string statstr
= target_waitstatus_to_string (&ws
);
4458 fprintf_unfiltered (gdb_stdlog
,
4459 "infrun: target_wait %s, saving "
4460 "status for %d.%ld.%ld\n",
4467 /* Record for later. */
4468 save_waitstatus (t
, &ws
);
4470 sig
= (ws
.kind
== TARGET_WAITKIND_STOPPED
4471 ? ws
.value
.sig
: GDB_SIGNAL_0
);
4473 if (displaced_step_fixup (t
, sig
) < 0)
4475 /* Add it back to the step-over queue. */
4476 t
->control
.trap_expected
= 0;
4477 global_thread_step_over_chain_enqueue (t
);
4480 regcache
= get_thread_regcache (t
);
4481 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4485 fprintf_unfiltered (gdb_stdlog
,
4486 "infrun: saved stop_pc=%s for %s "
4487 "(currently_stepping=%d)\n",
4488 paddress (target_gdbarch (),
4489 t
->suspend
.stop_pc
),
4490 target_pid_to_str (t
->ptid
).c_str (),
4491 currently_stepping (t
));
4499 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4502 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4505 handle_no_resumed (struct execution_control_state
*ecs
)
4507 if (target_can_async_p ())
4514 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4522 /* There were no unwaited-for children left in the target, but,
4523 we're not synchronously waiting for events either. Just
4527 fprintf_unfiltered (gdb_stdlog
,
4528 "infrun: TARGET_WAITKIND_NO_RESUMED "
4529 "(ignoring: bg)\n");
4530 prepare_to_wait (ecs
);
4535 /* Otherwise, if we were running a synchronous execution command, we
4536 may need to cancel it and give the user back the terminal.
4538 In non-stop mode, the target can't tell whether we've already
4539 consumed previous stop events, so it can end up sending us a
4540 no-resumed event like so:
4542 #0 - thread 1 is left stopped
4544 #1 - thread 2 is resumed and hits breakpoint
4545 -> TARGET_WAITKIND_STOPPED
4547 #2 - thread 3 is resumed and exits
4548 this is the last resumed thread, so
4549 -> TARGET_WAITKIND_NO_RESUMED
4551 #3 - gdb processes stop for thread 2 and decides to re-resume
4554 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4555 thread 2 is now resumed, so the event should be ignored.
4557 IOW, if the stop for thread 2 doesn't end a foreground command,
4558 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4559 event. But it could be that the event meant that thread 2 itself
4560 (or whatever other thread was the last resumed thread) exited.
4562 To address this we refresh the thread list and check whether we
4563 have resumed threads _now_. In the example above, this removes
4564 thread 3 from the thread list. If thread 2 was re-resumed, we
4565 ignore this event. If we find no thread resumed, then we cancel
4566 the synchronous command show "no unwaited-for " to the user. */
4567 update_thread_list ();
4569 for (thread_info
*thread
: all_non_exited_threads ())
4571 if (thread
->executing
4572 || thread
->suspend
.waitstatus_pending_p
)
4574 /* There were no unwaited-for children left in the target at
4575 some point, but there are now. Just ignore. */
4577 fprintf_unfiltered (gdb_stdlog
,
4578 "infrun: TARGET_WAITKIND_NO_RESUMED "
4579 "(ignoring: found resumed)\n");
4580 prepare_to_wait (ecs
);
4585 /* Note however that we may find no resumed thread because the whole
4586 process exited meanwhile (thus updating the thread list results
4587 in an empty thread list). In this case we know we'll be getting
4588 a process exit event shortly. */
4589 for (inferior
*inf
: all_inferiors ())
4594 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4598 fprintf_unfiltered (gdb_stdlog
,
4599 "infrun: TARGET_WAITKIND_NO_RESUMED "
4600 "(expect process exit)\n");
4601 prepare_to_wait (ecs
);
4606 /* Go ahead and report the event. */
4610 /* Given an execution control state that has been freshly filled in by
4611 an event from the inferior, figure out what it means and take
4614 The alternatives are:
4616 1) stop_waiting and return; to really stop and return to the
4619 2) keep_going and return; to wait for the next event (set
4620 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4624 handle_inferior_event (struct execution_control_state
*ecs
)
4626 /* Make sure that all temporary struct value objects that were
4627 created during the handling of the event get deleted at the
4629 scoped_value_mark free_values
;
4631 enum stop_kind stop_soon
;
4634 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
4635 target_waitstatus_to_string (&ecs
->ws
).c_str ());
4637 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4639 /* We had an event in the inferior, but we are not interested in
4640 handling it at this level. The lower layers have already
4641 done what needs to be done, if anything.
4643 One of the possible circumstances for this is when the
4644 inferior produces output for the console. The inferior has
4645 not stopped, and we are ignoring the event. Another possible
4646 circumstance is any event which the lower level knows will be
4647 reported multiple times without an intervening resume. */
4648 prepare_to_wait (ecs
);
4652 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4654 prepare_to_wait (ecs
);
4658 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4659 && handle_no_resumed (ecs
))
4662 /* Cache the last pid/waitstatus. */
4663 set_last_target_status (ecs
->ptid
, ecs
->ws
);
4665 /* Always clear state belonging to the previous time we stopped. */
4666 stop_stack_dummy
= STOP_NONE
;
4668 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4670 /* No unwaited-for children left. IOW, all resumed children
4672 stop_print_frame
= 0;
4677 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
4678 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
4680 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
4681 /* If it's a new thread, add it to the thread database. */
4682 if (ecs
->event_thread
== NULL
)
4683 ecs
->event_thread
= add_thread (ecs
->ptid
);
4685 /* Disable range stepping. If the next step request could use a
4686 range, this will be end up re-enabled then. */
4687 ecs
->event_thread
->control
.may_range_step
= 0;
4690 /* Dependent on valid ECS->EVENT_THREAD. */
4691 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
4693 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4694 reinit_frame_cache ();
4696 breakpoint_retire_moribund ();
4698 /* First, distinguish signals caused by the debugger from signals
4699 that have to do with the program's own actions. Note that
4700 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4701 on the operating system version. Here we detect when a SIGILL or
4702 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4703 something similar for SIGSEGV, since a SIGSEGV will be generated
4704 when we're trying to execute a breakpoint instruction on a
4705 non-executable stack. This happens for call dummy breakpoints
4706 for architectures like SPARC that place call dummies on the
4708 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
4709 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
4710 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
4711 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
4713 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4715 if (breakpoint_inserted_here_p (regcache
->aspace (),
4716 regcache_read_pc (regcache
)))
4719 fprintf_unfiltered (gdb_stdlog
,
4720 "infrun: Treating signal as SIGTRAP\n");
4721 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
4725 /* Mark the non-executing threads accordingly. In all-stop, all
4726 threads of all processes are stopped when we get any event
4727 reported. In non-stop mode, only the event thread stops. */
4731 if (!target_is_non_stop_p ())
4732 mark_ptid
= minus_one_ptid
;
4733 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
4734 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4736 /* If we're handling a process exit in non-stop mode, even
4737 though threads haven't been deleted yet, one would think
4738 that there is nothing to do, as threads of the dead process
4739 will be soon deleted, and threads of any other process were
4740 left running. However, on some targets, threads survive a
4741 process exit event. E.g., for the "checkpoint" command,
4742 when the current checkpoint/fork exits, linux-fork.c
4743 automatically switches to another fork from within
4744 target_mourn_inferior, by associating the same
4745 inferior/thread to another fork. We haven't mourned yet at
4746 this point, but we must mark any threads left in the
4747 process as not-executing so that finish_thread_state marks
4748 them stopped (in the user's perspective) if/when we present
4749 the stop to the user. */
4750 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
4753 mark_ptid
= ecs
->ptid
;
4755 set_executing (mark_ptid
, 0);
4757 /* Likewise the resumed flag. */
4758 set_resumed (mark_ptid
, 0);
4761 switch (ecs
->ws
.kind
)
4763 case TARGET_WAITKIND_LOADED
:
4764 context_switch (ecs
);
4765 /* Ignore gracefully during startup of the inferior, as it might
4766 be the shell which has just loaded some objects, otherwise
4767 add the symbols for the newly loaded objects. Also ignore at
4768 the beginning of an attach or remote session; we will query
4769 the full list of libraries once the connection is
4772 stop_soon
= get_inferior_stop_soon (ecs
);
4773 if (stop_soon
== NO_STOP_QUIETLY
)
4775 struct regcache
*regcache
;
4777 regcache
= get_thread_regcache (ecs
->event_thread
);
4779 handle_solib_event ();
4781 ecs
->event_thread
->control
.stop_bpstat
4782 = bpstat_stop_status (regcache
->aspace (),
4783 ecs
->event_thread
->suspend
.stop_pc
,
4784 ecs
->event_thread
, &ecs
->ws
);
4786 if (handle_stop_requested (ecs
))
4789 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4791 /* A catchpoint triggered. */
4792 process_event_stop_test (ecs
);
4796 /* If requested, stop when the dynamic linker notifies
4797 gdb of events. This allows the user to get control
4798 and place breakpoints in initializer routines for
4799 dynamically loaded objects (among other things). */
4800 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4801 if (stop_on_solib_events
)
4803 /* Make sure we print "Stopped due to solib-event" in
4805 stop_print_frame
= 1;
4812 /* If we are skipping through a shell, or through shared library
4813 loading that we aren't interested in, resume the program. If
4814 we're running the program normally, also resume. */
4815 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
4817 /* Loading of shared libraries might have changed breakpoint
4818 addresses. Make sure new breakpoints are inserted. */
4819 if (stop_soon
== NO_STOP_QUIETLY
)
4820 insert_breakpoints ();
4821 resume (GDB_SIGNAL_0
);
4822 prepare_to_wait (ecs
);
4826 /* But stop if we're attaching or setting up a remote
4828 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4829 || stop_soon
== STOP_QUIETLY_REMOTE
)
4832 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4837 internal_error (__FILE__
, __LINE__
,
4838 _("unhandled stop_soon: %d"), (int) stop_soon
);
4840 case TARGET_WAITKIND_SPURIOUS
:
4841 if (handle_stop_requested (ecs
))
4843 context_switch (ecs
);
4844 resume (GDB_SIGNAL_0
);
4845 prepare_to_wait (ecs
);
4848 case TARGET_WAITKIND_THREAD_CREATED
:
4849 if (handle_stop_requested (ecs
))
4851 context_switch (ecs
);
4852 if (!switch_back_to_stepped_thread (ecs
))
4856 case TARGET_WAITKIND_EXITED
:
4857 case TARGET_WAITKIND_SIGNALLED
:
4858 inferior_ptid
= ecs
->ptid
;
4859 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
4860 set_current_program_space (current_inferior ()->pspace
);
4861 handle_vfork_child_exec_or_exit (0);
4862 target_terminal::ours (); /* Must do this before mourn anyway. */
4864 /* Clearing any previous state of convenience variables. */
4865 clear_exit_convenience_vars ();
4867 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4869 /* Record the exit code in the convenience variable $_exitcode, so
4870 that the user can inspect this again later. */
4871 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4872 (LONGEST
) ecs
->ws
.value
.integer
);
4874 /* Also record this in the inferior itself. */
4875 current_inferior ()->has_exit_code
= 1;
4876 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
4878 /* Support the --return-child-result option. */
4879 return_child_result_value
= ecs
->ws
.value
.integer
;
4881 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
4885 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
4887 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
4889 /* Set the value of the internal variable $_exitsignal,
4890 which holds the signal uncaught by the inferior. */
4891 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4892 gdbarch_gdb_signal_to_target (gdbarch
,
4893 ecs
->ws
.value
.sig
));
4897 /* We don't have access to the target's method used for
4898 converting between signal numbers (GDB's internal
4899 representation <-> target's representation).
4900 Therefore, we cannot do a good job at displaying this
4901 information to the user. It's better to just warn
4902 her about it (if infrun debugging is enabled), and
4905 fprintf_filtered (gdb_stdlog
, _("\
4906 Cannot fill $_exitsignal with the correct signal number.\n"));
4909 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
4912 gdb_flush (gdb_stdout
);
4913 target_mourn_inferior (inferior_ptid
);
4914 stop_print_frame
= 0;
4918 /* The following are the only cases in which we keep going;
4919 the above cases end in a continue or goto. */
4920 case TARGET_WAITKIND_FORKED
:
4921 case TARGET_WAITKIND_VFORKED
:
4922 /* Check whether the inferior is displaced stepping. */
4924 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4925 struct gdbarch
*gdbarch
= regcache
->arch ();
4927 /* If checking displaced stepping is supported, and thread
4928 ecs->ptid is displaced stepping. */
4929 if (displaced_step_in_progress_thread (ecs
->event_thread
))
4931 struct inferior
*parent_inf
4932 = find_inferior_ptid (ecs
->ptid
);
4933 struct regcache
*child_regcache
;
4934 CORE_ADDR parent_pc
;
4936 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
4938 struct displaced_step_inferior_state
*displaced
4939 = get_displaced_stepping_state (parent_inf
);
4941 /* Restore scratch pad for child process. */
4942 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
4945 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4946 indicating that the displaced stepping of syscall instruction
4947 has been done. Perform cleanup for parent process here. Note
4948 that this operation also cleans up the child process for vfork,
4949 because their pages are shared. */
4950 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
4951 /* Start a new step-over in another thread if there's one
4955 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4956 the child's PC is also within the scratchpad. Set the child's PC
4957 to the parent's PC value, which has already been fixed up.
4958 FIXME: we use the parent's aspace here, although we're touching
4959 the child, because the child hasn't been added to the inferior
4960 list yet at this point. */
4963 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
4965 parent_inf
->aspace
);
4966 /* Read PC value of parent process. */
4967 parent_pc
= regcache_read_pc (regcache
);
4969 if (debug_displaced
)
4970 fprintf_unfiltered (gdb_stdlog
,
4971 "displaced: write child pc from %s to %s\n",
4973 regcache_read_pc (child_regcache
)),
4974 paddress (gdbarch
, parent_pc
));
4976 regcache_write_pc (child_regcache
, parent_pc
);
4980 context_switch (ecs
);
4982 /* Immediately detach breakpoints from the child before there's
4983 any chance of letting the user delete breakpoints from the
4984 breakpoint lists. If we don't do this early, it's easy to
4985 leave left over traps in the child, vis: "break foo; catch
4986 fork; c; <fork>; del; c; <child calls foo>". We only follow
4987 the fork on the last `continue', and by that time the
4988 breakpoint at "foo" is long gone from the breakpoint table.
4989 If we vforked, then we don't need to unpatch here, since both
4990 parent and child are sharing the same memory pages; we'll
4991 need to unpatch at follow/detach time instead to be certain
4992 that new breakpoints added between catchpoint hit time and
4993 vfork follow are detached. */
4994 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
4996 /* This won't actually modify the breakpoint list, but will
4997 physically remove the breakpoints from the child. */
4998 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5001 delete_just_stopped_threads_single_step_breakpoints ();
5003 /* In case the event is caught by a catchpoint, remember that
5004 the event is to be followed at the next resume of the thread,
5005 and not immediately. */
5006 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5008 ecs
->event_thread
->suspend
.stop_pc
5009 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5011 ecs
->event_thread
->control
.stop_bpstat
5012 = bpstat_stop_status (get_current_regcache ()->aspace (),
5013 ecs
->event_thread
->suspend
.stop_pc
,
5014 ecs
->event_thread
, &ecs
->ws
);
5016 if (handle_stop_requested (ecs
))
5019 /* If no catchpoint triggered for this, then keep going. Note
5020 that we're interested in knowing the bpstat actually causes a
5021 stop, not just if it may explain the signal. Software
5022 watchpoints, for example, always appear in the bpstat. */
5023 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5027 = (follow_fork_mode_string
== follow_fork_mode_child
);
5029 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5031 should_resume
= follow_fork ();
5033 thread_info
*parent
= ecs
->event_thread
;
5034 thread_info
*child
= find_thread_ptid (ecs
->ws
.value
.related_pid
);
5036 /* At this point, the parent is marked running, and the
5037 child is marked stopped. */
5039 /* If not resuming the parent, mark it stopped. */
5040 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5041 parent
->set_running (false);
5043 /* If resuming the child, mark it running. */
5044 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5045 child
->set_running (true);
5047 /* In non-stop mode, also resume the other branch. */
5048 if (!detach_fork
&& (non_stop
5049 || (sched_multi
&& target_is_non_stop_p ())))
5052 switch_to_thread (parent
);
5054 switch_to_thread (child
);
5056 ecs
->event_thread
= inferior_thread ();
5057 ecs
->ptid
= inferior_ptid
;
5062 switch_to_thread (child
);
5064 switch_to_thread (parent
);
5066 ecs
->event_thread
= inferior_thread ();
5067 ecs
->ptid
= inferior_ptid
;
5075 process_event_stop_test (ecs
);
5078 case TARGET_WAITKIND_VFORK_DONE
:
5079 /* Done with the shared memory region. Re-insert breakpoints in
5080 the parent, and keep going. */
5082 context_switch (ecs
);
5084 current_inferior ()->waiting_for_vfork_done
= 0;
5085 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5087 if (handle_stop_requested (ecs
))
5090 /* This also takes care of reinserting breakpoints in the
5091 previously locked inferior. */
5095 case TARGET_WAITKIND_EXECD
:
5097 /* Note we can't read registers yet (the stop_pc), because we
5098 don't yet know the inferior's post-exec architecture.
5099 'stop_pc' is explicitly read below instead. */
5100 switch_to_thread_no_regs (ecs
->event_thread
);
5102 /* Do whatever is necessary to the parent branch of the vfork. */
5103 handle_vfork_child_exec_or_exit (1);
5105 /* This causes the eventpoints and symbol table to be reset.
5106 Must do this now, before trying to determine whether to
5108 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5110 /* In follow_exec we may have deleted the original thread and
5111 created a new one. Make sure that the event thread is the
5112 execd thread for that case (this is a nop otherwise). */
5113 ecs
->event_thread
= inferior_thread ();
5115 ecs
->event_thread
->suspend
.stop_pc
5116 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5118 ecs
->event_thread
->control
.stop_bpstat
5119 = bpstat_stop_status (get_current_regcache ()->aspace (),
5120 ecs
->event_thread
->suspend
.stop_pc
,
5121 ecs
->event_thread
, &ecs
->ws
);
5123 /* Note that this may be referenced from inside
5124 bpstat_stop_status above, through inferior_has_execd. */
5125 xfree (ecs
->ws
.value
.execd_pathname
);
5126 ecs
->ws
.value
.execd_pathname
= NULL
;
5128 if (handle_stop_requested (ecs
))
5131 /* If no catchpoint triggered for this, then keep going. */
5132 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5134 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5138 process_event_stop_test (ecs
);
5141 /* Be careful not to try to gather much state about a thread
5142 that's in a syscall. It's frequently a losing proposition. */
5143 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5144 /* Getting the current syscall number. */
5145 if (handle_syscall_event (ecs
) == 0)
5146 process_event_stop_test (ecs
);
5149 /* Before examining the threads further, step this thread to
5150 get it entirely out of the syscall. (We get notice of the
5151 event when the thread is just on the verge of exiting a
5152 syscall. Stepping one instruction seems to get it back
5154 case TARGET_WAITKIND_SYSCALL_RETURN
:
5155 if (handle_syscall_event (ecs
) == 0)
5156 process_event_stop_test (ecs
);
5159 case TARGET_WAITKIND_STOPPED
:
5160 handle_signal_stop (ecs
);
5163 case TARGET_WAITKIND_NO_HISTORY
:
5164 /* Reverse execution: target ran out of history info. */
5166 /* Switch to the stopped thread. */
5167 context_switch (ecs
);
5169 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5171 delete_just_stopped_threads_single_step_breakpoints ();
5172 ecs
->event_thread
->suspend
.stop_pc
5173 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5175 if (handle_stop_requested (ecs
))
5178 gdb::observers::no_history
.notify ();
5184 /* Restart threads back to what they were trying to do back when we
5185 paused them for an in-line step-over. The EVENT_THREAD thread is
5189 restart_threads (struct thread_info
*event_thread
)
5191 /* In case the instruction just stepped spawned a new thread. */
5192 update_thread_list ();
5194 for (thread_info
*tp
: all_non_exited_threads ())
5196 if (tp
== event_thread
)
5199 fprintf_unfiltered (gdb_stdlog
,
5200 "infrun: restart threads: "
5201 "[%s] is event thread\n",
5202 target_pid_to_str (tp
->ptid
).c_str ());
5206 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5209 fprintf_unfiltered (gdb_stdlog
,
5210 "infrun: restart threads: "
5211 "[%s] not meant to be running\n",
5212 target_pid_to_str (tp
->ptid
).c_str ());
5219 fprintf_unfiltered (gdb_stdlog
,
5220 "infrun: restart threads: [%s] resumed\n",
5221 target_pid_to_str (tp
->ptid
).c_str ());
5222 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5226 if (thread_is_in_step_over_chain (tp
))
5229 fprintf_unfiltered (gdb_stdlog
,
5230 "infrun: restart threads: "
5231 "[%s] needs step-over\n",
5232 target_pid_to_str (tp
->ptid
).c_str ());
5233 gdb_assert (!tp
->resumed
);
5238 if (tp
->suspend
.waitstatus_pending_p
)
5241 fprintf_unfiltered (gdb_stdlog
,
5242 "infrun: restart threads: "
5243 "[%s] has pending status\n",
5244 target_pid_to_str (tp
->ptid
).c_str ());
5249 gdb_assert (!tp
->stop_requested
);
5251 /* If some thread needs to start a step-over at this point, it
5252 should still be in the step-over queue, and thus skipped
5254 if (thread_still_needs_step_over (tp
))
5256 internal_error (__FILE__
, __LINE__
,
5257 "thread [%s] needs a step-over, but not in "
5258 "step-over queue\n",
5259 target_pid_to_str (tp
->ptid
).c_str ());
5262 if (currently_stepping (tp
))
5265 fprintf_unfiltered (gdb_stdlog
,
5266 "infrun: restart threads: [%s] was stepping\n",
5267 target_pid_to_str (tp
->ptid
).c_str ());
5268 keep_going_stepped_thread (tp
);
5272 struct execution_control_state ecss
;
5273 struct execution_control_state
*ecs
= &ecss
;
5276 fprintf_unfiltered (gdb_stdlog
,
5277 "infrun: restart threads: [%s] continuing\n",
5278 target_pid_to_str (tp
->ptid
).c_str ());
5279 reset_ecs (ecs
, tp
);
5280 switch_to_thread (tp
);
5281 keep_going_pass_signal (ecs
);
5286 /* Callback for iterate_over_threads. Find a resumed thread that has
5287 a pending waitstatus. */
5290 resumed_thread_with_pending_status (struct thread_info
*tp
,
5294 && tp
->suspend
.waitstatus_pending_p
);
5297 /* Called when we get an event that may finish an in-line or
5298 out-of-line (displaced stepping) step-over started previously.
5299 Return true if the event is processed and we should go back to the
5300 event loop; false if the caller should continue processing the
5304 finish_step_over (struct execution_control_state
*ecs
)
5306 int had_step_over_info
;
5308 displaced_step_fixup (ecs
->event_thread
,
5309 ecs
->event_thread
->suspend
.stop_signal
);
5311 had_step_over_info
= step_over_info_valid_p ();
5313 if (had_step_over_info
)
5315 /* If we're stepping over a breakpoint with all threads locked,
5316 then only the thread that was stepped should be reporting
5318 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5320 clear_step_over_info ();
5323 if (!target_is_non_stop_p ())
5326 /* Start a new step-over in another thread if there's one that
5330 /* If we were stepping over a breakpoint before, and haven't started
5331 a new in-line step-over sequence, then restart all other threads
5332 (except the event thread). We can't do this in all-stop, as then
5333 e.g., we wouldn't be able to issue any other remote packet until
5334 these other threads stop. */
5335 if (had_step_over_info
&& !step_over_info_valid_p ())
5337 struct thread_info
*pending
;
5339 /* If we only have threads with pending statuses, the restart
5340 below won't restart any thread and so nothing re-inserts the
5341 breakpoint we just stepped over. But we need it inserted
5342 when we later process the pending events, otherwise if
5343 another thread has a pending event for this breakpoint too,
5344 we'd discard its event (because the breakpoint that
5345 originally caused the event was no longer inserted). */
5346 context_switch (ecs
);
5347 insert_breakpoints ();
5350 scoped_restore save_defer_tc
5351 = make_scoped_defer_target_commit_resume ();
5352 restart_threads (ecs
->event_thread
);
5354 target_commit_resume ();
5356 /* If we have events pending, go through handle_inferior_event
5357 again, picking up a pending event at random. This avoids
5358 thread starvation. */
5360 /* But not if we just stepped over a watchpoint in order to let
5361 the instruction execute so we can evaluate its expression.
5362 The set of watchpoints that triggered is recorded in the
5363 breakpoint objects themselves (see bp->watchpoint_triggered).
5364 If we processed another event first, that other event could
5365 clobber this info. */
5366 if (ecs
->event_thread
->stepping_over_watchpoint
)
5369 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5371 if (pending
!= NULL
)
5373 struct thread_info
*tp
= ecs
->event_thread
;
5374 struct regcache
*regcache
;
5378 fprintf_unfiltered (gdb_stdlog
,
5379 "infrun: found resumed threads with "
5380 "pending events, saving status\n");
5383 gdb_assert (pending
!= tp
);
5385 /* Record the event thread's event for later. */
5386 save_waitstatus (tp
, &ecs
->ws
);
5387 /* This was cleared early, by handle_inferior_event. Set it
5388 so this pending event is considered by
5392 gdb_assert (!tp
->executing
);
5394 regcache
= get_thread_regcache (tp
);
5395 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5399 fprintf_unfiltered (gdb_stdlog
,
5400 "infrun: saved stop_pc=%s for %s "
5401 "(currently_stepping=%d)\n",
5402 paddress (target_gdbarch (),
5403 tp
->suspend
.stop_pc
),
5404 target_pid_to_str (tp
->ptid
).c_str (),
5405 currently_stepping (tp
));
5408 /* This in-line step-over finished; clear this so we won't
5409 start a new one. This is what handle_signal_stop would
5410 do, if we returned false. */
5411 tp
->stepping_over_breakpoint
= 0;
5413 /* Wake up the event loop again. */
5414 mark_async_event_handler (infrun_async_inferior_event_token
);
5416 prepare_to_wait (ecs
);
5424 /* Come here when the program has stopped with a signal. */
5427 handle_signal_stop (struct execution_control_state
*ecs
)
5429 struct frame_info
*frame
;
5430 struct gdbarch
*gdbarch
;
5431 int stopped_by_watchpoint
;
5432 enum stop_kind stop_soon
;
5435 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5437 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5439 /* Do we need to clean up the state of a thread that has
5440 completed a displaced single-step? (Doing so usually affects
5441 the PC, so do it here, before we set stop_pc.) */
5442 if (finish_step_over (ecs
))
5445 /* If we either finished a single-step or hit a breakpoint, but
5446 the user wanted this thread to be stopped, pretend we got a
5447 SIG0 (generic unsignaled stop). */
5448 if (ecs
->event_thread
->stop_requested
5449 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5450 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5452 ecs
->event_thread
->suspend
.stop_pc
5453 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5457 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5458 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5459 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
5461 inferior_ptid
= ecs
->ptid
;
5463 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5464 paddress (reg_gdbarch
,
5465 ecs
->event_thread
->suspend
.stop_pc
));
5466 if (target_stopped_by_watchpoint ())
5470 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5472 if (target_stopped_data_address (current_top_target (), &addr
))
5473 fprintf_unfiltered (gdb_stdlog
,
5474 "infrun: stopped data address = %s\n",
5475 paddress (reg_gdbarch
, addr
));
5477 fprintf_unfiltered (gdb_stdlog
,
5478 "infrun: (no data address available)\n");
5482 /* This is originated from start_remote(), start_inferior() and
5483 shared libraries hook functions. */
5484 stop_soon
= get_inferior_stop_soon (ecs
);
5485 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5487 context_switch (ecs
);
5489 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5490 stop_print_frame
= 1;
5495 /* This originates from attach_command(). We need to overwrite
5496 the stop_signal here, because some kernels don't ignore a
5497 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5498 See more comments in inferior.h. On the other hand, if we
5499 get a non-SIGSTOP, report it to the user - assume the backend
5500 will handle the SIGSTOP if it should show up later.
5502 Also consider that the attach is complete when we see a
5503 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5504 target extended-remote report it instead of a SIGSTOP
5505 (e.g. gdbserver). We already rely on SIGTRAP being our
5506 signal, so this is no exception.
5508 Also consider that the attach is complete when we see a
5509 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5510 the target to stop all threads of the inferior, in case the
5511 low level attach operation doesn't stop them implicitly. If
5512 they weren't stopped implicitly, then the stub will report a
5513 GDB_SIGNAL_0, meaning: stopped for no particular reason
5514 other than GDB's request. */
5515 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5516 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5517 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5518 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5520 stop_print_frame
= 1;
5522 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5526 /* See if something interesting happened to the non-current thread. If
5527 so, then switch to that thread. */
5528 if (ecs
->ptid
!= inferior_ptid
)
5531 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5533 context_switch (ecs
);
5535 if (deprecated_context_hook
)
5536 deprecated_context_hook (ecs
->event_thread
->global_num
);
5539 /* At this point, get hold of the now-current thread's frame. */
5540 frame
= get_current_frame ();
5541 gdbarch
= get_frame_arch (frame
);
5543 /* Pull the single step breakpoints out of the target. */
5544 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5546 struct regcache
*regcache
;
5549 regcache
= get_thread_regcache (ecs
->event_thread
);
5550 const address_space
*aspace
= regcache
->aspace ();
5552 pc
= regcache_read_pc (regcache
);
5554 /* However, before doing so, if this single-step breakpoint was
5555 actually for another thread, set this thread up for moving
5557 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5560 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5564 fprintf_unfiltered (gdb_stdlog
,
5565 "infrun: [%s] hit another thread's "
5566 "single-step breakpoint\n",
5567 target_pid_to_str (ecs
->ptid
).c_str ());
5569 ecs
->hit_singlestep_breakpoint
= 1;
5576 fprintf_unfiltered (gdb_stdlog
,
5577 "infrun: [%s] hit its "
5578 "single-step breakpoint\n",
5579 target_pid_to_str (ecs
->ptid
).c_str ());
5583 delete_just_stopped_threads_single_step_breakpoints ();
5585 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5586 && ecs
->event_thread
->control
.trap_expected
5587 && ecs
->event_thread
->stepping_over_watchpoint
)
5588 stopped_by_watchpoint
= 0;
5590 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5592 /* If necessary, step over this watchpoint. We'll be back to display
5594 if (stopped_by_watchpoint
5595 && (target_have_steppable_watchpoint
5596 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5598 /* At this point, we are stopped at an instruction which has
5599 attempted to write to a piece of memory under control of
5600 a watchpoint. The instruction hasn't actually executed
5601 yet. If we were to evaluate the watchpoint expression
5602 now, we would get the old value, and therefore no change
5603 would seem to have occurred.
5605 In order to make watchpoints work `right', we really need
5606 to complete the memory write, and then evaluate the
5607 watchpoint expression. We do this by single-stepping the
5610 It may not be necessary to disable the watchpoint to step over
5611 it. For example, the PA can (with some kernel cooperation)
5612 single step over a watchpoint without disabling the watchpoint.
5614 It is far more common to need to disable a watchpoint to step
5615 the inferior over it. If we have non-steppable watchpoints,
5616 we must disable the current watchpoint; it's simplest to
5617 disable all watchpoints.
5619 Any breakpoint at PC must also be stepped over -- if there's
5620 one, it will have already triggered before the watchpoint
5621 triggered, and we either already reported it to the user, or
5622 it didn't cause a stop and we called keep_going. In either
5623 case, if there was a breakpoint at PC, we must be trying to
5625 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5630 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5631 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5632 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5633 ecs
->event_thread
->control
.stop_step
= 0;
5634 stop_print_frame
= 1;
5635 stopped_by_random_signal
= 0;
5636 bpstat stop_chain
= NULL
;
5638 /* Hide inlined functions starting here, unless we just performed stepi or
5639 nexti. After stepi and nexti, always show the innermost frame (not any
5640 inline function call sites). */
5641 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5643 const address_space
*aspace
5644 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5646 /* skip_inline_frames is expensive, so we avoid it if we can
5647 determine that the address is one where functions cannot have
5648 been inlined. This improves performance with inferiors that
5649 load a lot of shared libraries, because the solib event
5650 breakpoint is defined as the address of a function (i.e. not
5651 inline). Note that we have to check the previous PC as well
5652 as the current one to catch cases when we have just
5653 single-stepped off a breakpoint prior to reinstating it.
5654 Note that we're assuming that the code we single-step to is
5655 not inline, but that's not definitive: there's nothing
5656 preventing the event breakpoint function from containing
5657 inlined code, and the single-step ending up there. If the
5658 user had set a breakpoint on that inlined code, the missing
5659 skip_inline_frames call would break things. Fortunately
5660 that's an extremely unlikely scenario. */
5661 if (!pc_at_non_inline_function (aspace
,
5662 ecs
->event_thread
->suspend
.stop_pc
,
5664 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5665 && ecs
->event_thread
->control
.trap_expected
5666 && pc_at_non_inline_function (aspace
,
5667 ecs
->event_thread
->prev_pc
,
5670 stop_chain
= build_bpstat_chain (aspace
,
5671 ecs
->event_thread
->suspend
.stop_pc
,
5673 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5675 /* Re-fetch current thread's frame in case that invalidated
5677 frame
= get_current_frame ();
5678 gdbarch
= get_frame_arch (frame
);
5682 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5683 && ecs
->event_thread
->control
.trap_expected
5684 && gdbarch_single_step_through_delay_p (gdbarch
)
5685 && currently_stepping (ecs
->event_thread
))
5687 /* We're trying to step off a breakpoint. Turns out that we're
5688 also on an instruction that needs to be stepped multiple
5689 times before it's been fully executing. E.g., architectures
5690 with a delay slot. It needs to be stepped twice, once for
5691 the instruction and once for the delay slot. */
5692 int step_through_delay
5693 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5695 if (debug_infrun
&& step_through_delay
)
5696 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
5697 if (ecs
->event_thread
->control
.step_range_end
== 0
5698 && step_through_delay
)
5700 /* The user issued a continue when stopped at a breakpoint.
5701 Set up for another trap and get out of here. */
5702 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5706 else if (step_through_delay
)
5708 /* The user issued a step when stopped at a breakpoint.
5709 Maybe we should stop, maybe we should not - the delay
5710 slot *might* correspond to a line of source. In any
5711 case, don't decide that here, just set
5712 ecs->stepping_over_breakpoint, making sure we
5713 single-step again before breakpoints are re-inserted. */
5714 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5718 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5719 handles this event. */
5720 ecs
->event_thread
->control
.stop_bpstat
5721 = bpstat_stop_status (get_current_regcache ()->aspace (),
5722 ecs
->event_thread
->suspend
.stop_pc
,
5723 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
5725 /* Following in case break condition called a
5727 stop_print_frame
= 1;
5729 /* This is where we handle "moribund" watchpoints. Unlike
5730 software breakpoints traps, hardware watchpoint traps are
5731 always distinguishable from random traps. If no high-level
5732 watchpoint is associated with the reported stop data address
5733 anymore, then the bpstat does not explain the signal ---
5734 simply make sure to ignore it if `stopped_by_watchpoint' is
5738 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5739 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5741 && stopped_by_watchpoint
)
5742 fprintf_unfiltered (gdb_stdlog
,
5743 "infrun: no user watchpoint explains "
5744 "watchpoint SIGTRAP, ignoring\n");
5746 /* NOTE: cagney/2003-03-29: These checks for a random signal
5747 at one stage in the past included checks for an inferior
5748 function call's call dummy's return breakpoint. The original
5749 comment, that went with the test, read:
5751 ``End of a stack dummy. Some systems (e.g. Sony news) give
5752 another signal besides SIGTRAP, so check here as well as
5755 If someone ever tries to get call dummys on a
5756 non-executable stack to work (where the target would stop
5757 with something like a SIGSEGV), then those tests might need
5758 to be re-instated. Given, however, that the tests were only
5759 enabled when momentary breakpoints were not being used, I
5760 suspect that it won't be the case.
5762 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5763 be necessary for call dummies on a non-executable stack on
5766 /* See if the breakpoints module can explain the signal. */
5768 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5769 ecs
->event_thread
->suspend
.stop_signal
);
5771 /* Maybe this was a trap for a software breakpoint that has since
5773 if (random_signal
&& target_stopped_by_sw_breakpoint ())
5775 if (program_breakpoint_here_p (gdbarch
,
5776 ecs
->event_thread
->suspend
.stop_pc
))
5778 struct regcache
*regcache
;
5781 /* Re-adjust PC to what the program would see if GDB was not
5783 regcache
= get_thread_regcache (ecs
->event_thread
);
5784 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
5787 gdb::optional
<scoped_restore_tmpl
<int>>
5788 restore_operation_disable
;
5790 if (record_full_is_used ())
5791 restore_operation_disable
.emplace
5792 (record_full_gdb_operation_disable_set ());
5794 regcache_write_pc (regcache
,
5795 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
5800 /* A delayed software breakpoint event. Ignore the trap. */
5802 fprintf_unfiltered (gdb_stdlog
,
5803 "infrun: delayed software breakpoint "
5804 "trap, ignoring\n");
5809 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5810 has since been removed. */
5811 if (random_signal
&& target_stopped_by_hw_breakpoint ())
5813 /* A delayed hardware breakpoint event. Ignore the trap. */
5815 fprintf_unfiltered (gdb_stdlog
,
5816 "infrun: delayed hardware breakpoint/watchpoint "
5817 "trap, ignoring\n");
5821 /* If not, perhaps stepping/nexting can. */
5823 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5824 && currently_stepping (ecs
->event_thread
));
5826 /* Perhaps the thread hit a single-step breakpoint of _another_
5827 thread. Single-step breakpoints are transparent to the
5828 breakpoints module. */
5830 random_signal
= !ecs
->hit_singlestep_breakpoint
;
5832 /* No? Perhaps we got a moribund watchpoint. */
5834 random_signal
= !stopped_by_watchpoint
;
5836 /* Always stop if the user explicitly requested this thread to
5838 if (ecs
->event_thread
->stop_requested
)
5842 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
5845 /* For the program's own signals, act according to
5846 the signal handling tables. */
5850 /* Signal not for debugging purposes. */
5851 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
5852 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
5855 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
5856 gdb_signal_to_symbol_string (stop_signal
));
5858 stopped_by_random_signal
= 1;
5860 /* Always stop on signals if we're either just gaining control
5861 of the program, or the user explicitly requested this thread
5862 to remain stopped. */
5863 if (stop_soon
!= NO_STOP_QUIETLY
5864 || ecs
->event_thread
->stop_requested
5866 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
5872 /* Notify observers the signal has "handle print" set. Note we
5873 returned early above if stopping; normal_stop handles the
5874 printing in that case. */
5875 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
5877 /* The signal table tells us to print about this signal. */
5878 target_terminal::ours_for_output ();
5879 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
5880 target_terminal::inferior ();
5883 /* Clear the signal if it should not be passed. */
5884 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
5885 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5887 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
5888 && ecs
->event_thread
->control
.trap_expected
5889 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5891 /* We were just starting a new sequence, attempting to
5892 single-step off of a breakpoint and expecting a SIGTRAP.
5893 Instead this signal arrives. This signal will take us out
5894 of the stepping range so GDB needs to remember to, when
5895 the signal handler returns, resume stepping off that
5897 /* To simplify things, "continue" is forced to use the same
5898 code paths as single-step - set a breakpoint at the
5899 signal return address and then, once hit, step off that
5902 fprintf_unfiltered (gdb_stdlog
,
5903 "infrun: signal arrived while stepping over "
5906 insert_hp_step_resume_breakpoint_at_frame (frame
);
5907 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5908 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5909 ecs
->event_thread
->control
.trap_expected
= 0;
5911 /* If we were nexting/stepping some other thread, switch to
5912 it, so that we don't continue it, losing control. */
5913 if (!switch_back_to_stepped_thread (ecs
))
5918 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
5919 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
5921 || ecs
->event_thread
->control
.step_range_end
== 1)
5922 && frame_id_eq (get_stack_frame_id (frame
),
5923 ecs
->event_thread
->control
.step_stack_frame_id
)
5924 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5926 /* The inferior is about to take a signal that will take it
5927 out of the single step range. Set a breakpoint at the
5928 current PC (which is presumably where the signal handler
5929 will eventually return) and then allow the inferior to
5932 Note that this is only needed for a signal delivered
5933 while in the single-step range. Nested signals aren't a
5934 problem as they eventually all return. */
5936 fprintf_unfiltered (gdb_stdlog
,
5937 "infrun: signal may take us out of "
5938 "single-step range\n");
5940 clear_step_over_info ();
5941 insert_hp_step_resume_breakpoint_at_frame (frame
);
5942 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5943 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5944 ecs
->event_thread
->control
.trap_expected
= 0;
5949 /* Note: step_resume_breakpoint may be non-NULL. This occurs
5950 when either there's a nested signal, or when there's a
5951 pending signal enabled just as the signal handler returns
5952 (leaving the inferior at the step-resume-breakpoint without
5953 actually executing it). Either way continue until the
5954 breakpoint is really hit. */
5956 if (!switch_back_to_stepped_thread (ecs
))
5959 fprintf_unfiltered (gdb_stdlog
,
5960 "infrun: random signal, keep going\n");
5967 process_event_stop_test (ecs
);
5970 /* Come here when we've got some debug event / signal we can explain
5971 (IOW, not a random signal), and test whether it should cause a
5972 stop, or whether we should resume the inferior (transparently).
5973 E.g., could be a breakpoint whose condition evaluates false; we
5974 could be still stepping within the line; etc. */
5977 process_event_stop_test (struct execution_control_state
*ecs
)
5979 struct symtab_and_line stop_pc_sal
;
5980 struct frame_info
*frame
;
5981 struct gdbarch
*gdbarch
;
5982 CORE_ADDR jmp_buf_pc
;
5983 struct bpstat_what what
;
5985 /* Handle cases caused by hitting a breakpoint. */
5987 frame
= get_current_frame ();
5988 gdbarch
= get_frame_arch (frame
);
5990 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
5992 if (what
.call_dummy
)
5994 stop_stack_dummy
= what
.call_dummy
;
5997 /* A few breakpoint types have callbacks associated (e.g.,
5998 bp_jit_event). Run them now. */
5999 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6001 /* If we hit an internal event that triggers symbol changes, the
6002 current frame will be invalidated within bpstat_what (e.g., if we
6003 hit an internal solib event). Re-fetch it. */
6004 frame
= get_current_frame ();
6005 gdbarch
= get_frame_arch (frame
);
6007 switch (what
.main_action
)
6009 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6010 /* If we hit the breakpoint at longjmp while stepping, we
6011 install a momentary breakpoint at the target of the
6015 fprintf_unfiltered (gdb_stdlog
,
6016 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6018 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6020 if (what
.is_longjmp
)
6022 struct value
*arg_value
;
6024 /* If we set the longjmp breakpoint via a SystemTap probe,
6025 then use it to extract the arguments. The destination PC
6026 is the third argument to the probe. */
6027 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6030 jmp_buf_pc
= value_as_address (arg_value
);
6031 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6033 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6034 || !gdbarch_get_longjmp_target (gdbarch
,
6035 frame
, &jmp_buf_pc
))
6038 fprintf_unfiltered (gdb_stdlog
,
6039 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6040 "(!gdbarch_get_longjmp_target)\n");
6045 /* Insert a breakpoint at resume address. */
6046 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6049 check_exception_resume (ecs
, frame
);
6053 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6055 struct frame_info
*init_frame
;
6057 /* There are several cases to consider.
6059 1. The initiating frame no longer exists. In this case we
6060 must stop, because the exception or longjmp has gone too
6063 2. The initiating frame exists, and is the same as the
6064 current frame. We stop, because the exception or longjmp
6067 3. The initiating frame exists and is different from the
6068 current frame. This means the exception or longjmp has
6069 been caught beneath the initiating frame, so keep going.
6071 4. longjmp breakpoint has been placed just to protect
6072 against stale dummy frames and user is not interested in
6073 stopping around longjmps. */
6076 fprintf_unfiltered (gdb_stdlog
,
6077 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6079 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6081 delete_exception_resume_breakpoint (ecs
->event_thread
);
6083 if (what
.is_longjmp
)
6085 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6087 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6095 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6099 struct frame_id current_id
6100 = get_frame_id (get_current_frame ());
6101 if (frame_id_eq (current_id
,
6102 ecs
->event_thread
->initiating_frame
))
6104 /* Case 2. Fall through. */
6114 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6116 delete_step_resume_breakpoint (ecs
->event_thread
);
6118 end_stepping_range (ecs
);
6122 case BPSTAT_WHAT_SINGLE
:
6124 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6125 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6126 /* Still need to check other stuff, at least the case where we
6127 are stepping and step out of the right range. */
6130 case BPSTAT_WHAT_STEP_RESUME
:
6132 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6134 delete_step_resume_breakpoint (ecs
->event_thread
);
6135 if (ecs
->event_thread
->control
.proceed_to_finish
6136 && execution_direction
== EXEC_REVERSE
)
6138 struct thread_info
*tp
= ecs
->event_thread
;
6140 /* We are finishing a function in reverse, and just hit the
6141 step-resume breakpoint at the start address of the
6142 function, and we're almost there -- just need to back up
6143 by one more single-step, which should take us back to the
6145 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6149 fill_in_stop_func (gdbarch
, ecs
);
6150 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6151 && execution_direction
== EXEC_REVERSE
)
6153 /* We are stepping over a function call in reverse, and just
6154 hit the step-resume breakpoint at the start address of
6155 the function. Go back to single-stepping, which should
6156 take us back to the function call. */
6157 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6163 case BPSTAT_WHAT_STOP_NOISY
:
6165 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6166 stop_print_frame
= 1;
6168 /* Assume the thread stopped for a breapoint. We'll still check
6169 whether a/the breakpoint is there when the thread is next
6171 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6176 case BPSTAT_WHAT_STOP_SILENT
:
6178 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6179 stop_print_frame
= 0;
6181 /* Assume the thread stopped for a breapoint. We'll still check
6182 whether a/the breakpoint is there when the thread is next
6184 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6188 case BPSTAT_WHAT_HP_STEP_RESUME
:
6190 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6192 delete_step_resume_breakpoint (ecs
->event_thread
);
6193 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6195 /* Back when the step-resume breakpoint was inserted, we
6196 were trying to single-step off a breakpoint. Go back to
6198 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6199 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6205 case BPSTAT_WHAT_KEEP_CHECKING
:
6209 /* If we stepped a permanent breakpoint and we had a high priority
6210 step-resume breakpoint for the address we stepped, but we didn't
6211 hit it, then we must have stepped into the signal handler. The
6212 step-resume was only necessary to catch the case of _not_
6213 stepping into the handler, so delete it, and fall through to
6214 checking whether the step finished. */
6215 if (ecs
->event_thread
->stepped_breakpoint
)
6217 struct breakpoint
*sr_bp
6218 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6221 && sr_bp
->loc
->permanent
6222 && sr_bp
->type
== bp_hp_step_resume
6223 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6226 fprintf_unfiltered (gdb_stdlog
,
6227 "infrun: stepped permanent breakpoint, stopped in "
6229 delete_step_resume_breakpoint (ecs
->event_thread
);
6230 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6234 /* We come here if we hit a breakpoint but should not stop for it.
6235 Possibly we also were stepping and should stop for that. So fall
6236 through and test for stepping. But, if not stepping, do not
6239 /* In all-stop mode, if we're currently stepping but have stopped in
6240 some other thread, we need to switch back to the stepped thread. */
6241 if (switch_back_to_stepped_thread (ecs
))
6244 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6247 fprintf_unfiltered (gdb_stdlog
,
6248 "infrun: step-resume breakpoint is inserted\n");
6250 /* Having a step-resume breakpoint overrides anything
6251 else having to do with stepping commands until
6252 that breakpoint is reached. */
6257 if (ecs
->event_thread
->control
.step_range_end
== 0)
6260 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6261 /* Likewise if we aren't even stepping. */
6266 /* Re-fetch current thread's frame in case the code above caused
6267 the frame cache to be re-initialized, making our FRAME variable
6268 a dangling pointer. */
6269 frame
= get_current_frame ();
6270 gdbarch
= get_frame_arch (frame
);
6271 fill_in_stop_func (gdbarch
, ecs
);
6273 /* If stepping through a line, keep going if still within it.
6275 Note that step_range_end is the address of the first instruction
6276 beyond the step range, and NOT the address of the last instruction
6279 Note also that during reverse execution, we may be stepping
6280 through a function epilogue and therefore must detect when
6281 the current-frame changes in the middle of a line. */
6283 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6285 && (execution_direction
!= EXEC_REVERSE
6286 || frame_id_eq (get_frame_id (frame
),
6287 ecs
->event_thread
->control
.step_frame_id
)))
6291 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6292 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6293 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6295 /* Tentatively re-enable range stepping; `resume' disables it if
6296 necessary (e.g., if we're stepping over a breakpoint or we
6297 have software watchpoints). */
6298 ecs
->event_thread
->control
.may_range_step
= 1;
6300 /* When stepping backward, stop at beginning of line range
6301 (unless it's the function entry point, in which case
6302 keep going back to the call point). */
6303 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6304 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6305 && stop_pc
!= ecs
->stop_func_start
6306 && execution_direction
== EXEC_REVERSE
)
6307 end_stepping_range (ecs
);
6314 /* We stepped out of the stepping range. */
6316 /* If we are stepping at the source level and entered the runtime
6317 loader dynamic symbol resolution code...
6319 EXEC_FORWARD: we keep on single stepping until we exit the run
6320 time loader code and reach the callee's address.
6322 EXEC_REVERSE: we've already executed the callee (backward), and
6323 the runtime loader code is handled just like any other
6324 undebuggable function call. Now we need only keep stepping
6325 backward through the trampoline code, and that's handled further
6326 down, so there is nothing for us to do here. */
6328 if (execution_direction
!= EXEC_REVERSE
6329 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6330 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6332 CORE_ADDR pc_after_resolver
=
6333 gdbarch_skip_solib_resolver (gdbarch
,
6334 ecs
->event_thread
->suspend
.stop_pc
);
6337 fprintf_unfiltered (gdb_stdlog
,
6338 "infrun: stepped into dynsym resolve code\n");
6340 if (pc_after_resolver
)
6342 /* Set up a step-resume breakpoint at the address
6343 indicated by SKIP_SOLIB_RESOLVER. */
6344 symtab_and_line sr_sal
;
6345 sr_sal
.pc
= pc_after_resolver
;
6346 sr_sal
.pspace
= get_frame_program_space (frame
);
6348 insert_step_resume_breakpoint_at_sal (gdbarch
,
6349 sr_sal
, null_frame_id
);
6356 /* Step through an indirect branch thunk. */
6357 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6358 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6359 ecs
->event_thread
->suspend
.stop_pc
))
6362 fprintf_unfiltered (gdb_stdlog
,
6363 "infrun: stepped into indirect branch thunk\n");
6368 if (ecs
->event_thread
->control
.step_range_end
!= 1
6369 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6370 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6371 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6374 fprintf_unfiltered (gdb_stdlog
,
6375 "infrun: stepped into signal trampoline\n");
6376 /* The inferior, while doing a "step" or "next", has ended up in
6377 a signal trampoline (either by a signal being delivered or by
6378 the signal handler returning). Just single-step until the
6379 inferior leaves the trampoline (either by calling the handler
6385 /* If we're in the return path from a shared library trampoline,
6386 we want to proceed through the trampoline when stepping. */
6387 /* macro/2012-04-25: This needs to come before the subroutine
6388 call check below as on some targets return trampolines look
6389 like subroutine calls (MIPS16 return thunks). */
6390 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6391 ecs
->event_thread
->suspend
.stop_pc
,
6392 ecs
->stop_func_name
)
6393 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6395 /* Determine where this trampoline returns. */
6396 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6397 CORE_ADDR real_stop_pc
6398 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6401 fprintf_unfiltered (gdb_stdlog
,
6402 "infrun: stepped into solib return tramp\n");
6404 /* Only proceed through if we know where it's going. */
6407 /* And put the step-breakpoint there and go until there. */
6408 symtab_and_line sr_sal
;
6409 sr_sal
.pc
= real_stop_pc
;
6410 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6411 sr_sal
.pspace
= get_frame_program_space (frame
);
6413 /* Do not specify what the fp should be when we stop since
6414 on some machines the prologue is where the new fp value
6416 insert_step_resume_breakpoint_at_sal (gdbarch
,
6417 sr_sal
, null_frame_id
);
6419 /* Restart without fiddling with the step ranges or
6426 /* Check for subroutine calls. The check for the current frame
6427 equalling the step ID is not necessary - the check of the
6428 previous frame's ID is sufficient - but it is a common case and
6429 cheaper than checking the previous frame's ID.
6431 NOTE: frame_id_eq will never report two invalid frame IDs as
6432 being equal, so to get into this block, both the current and
6433 previous frame must have valid frame IDs. */
6434 /* The outer_frame_id check is a heuristic to detect stepping
6435 through startup code. If we step over an instruction which
6436 sets the stack pointer from an invalid value to a valid value,
6437 we may detect that as a subroutine call from the mythical
6438 "outermost" function. This could be fixed by marking
6439 outermost frames as !stack_p,code_p,special_p. Then the
6440 initial outermost frame, before sp was valid, would
6441 have code_addr == &_start. See the comment in frame_id_eq
6443 if (!frame_id_eq (get_stack_frame_id (frame
),
6444 ecs
->event_thread
->control
.step_stack_frame_id
)
6445 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6446 ecs
->event_thread
->control
.step_stack_frame_id
)
6447 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6449 || (ecs
->event_thread
->control
.step_start_function
6450 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6452 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6453 CORE_ADDR real_stop_pc
;
6456 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6458 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6460 /* I presume that step_over_calls is only 0 when we're
6461 supposed to be stepping at the assembly language level
6462 ("stepi"). Just stop. */
6463 /* And this works the same backward as frontward. MVS */
6464 end_stepping_range (ecs
);
6468 /* Reverse stepping through solib trampolines. */
6470 if (execution_direction
== EXEC_REVERSE
6471 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6472 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6473 || (ecs
->stop_func_start
== 0
6474 && in_solib_dynsym_resolve_code (stop_pc
))))
6476 /* Any solib trampoline code can be handled in reverse
6477 by simply continuing to single-step. We have already
6478 executed the solib function (backwards), and a few
6479 steps will take us back through the trampoline to the
6485 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6487 /* We're doing a "next".
6489 Normal (forward) execution: set a breakpoint at the
6490 callee's return address (the address at which the caller
6493 Reverse (backward) execution. set the step-resume
6494 breakpoint at the start of the function that we just
6495 stepped into (backwards), and continue to there. When we
6496 get there, we'll need to single-step back to the caller. */
6498 if (execution_direction
== EXEC_REVERSE
)
6500 /* If we're already at the start of the function, we've either
6501 just stepped backward into a single instruction function,
6502 or stepped back out of a signal handler to the first instruction
6503 of the function. Just keep going, which will single-step back
6505 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6507 /* Normal function call return (static or dynamic). */
6508 symtab_and_line sr_sal
;
6509 sr_sal
.pc
= ecs
->stop_func_start
;
6510 sr_sal
.pspace
= get_frame_program_space (frame
);
6511 insert_step_resume_breakpoint_at_sal (gdbarch
,
6512 sr_sal
, null_frame_id
);
6516 insert_step_resume_breakpoint_at_caller (frame
);
6522 /* If we are in a function call trampoline (a stub between the
6523 calling routine and the real function), locate the real
6524 function. That's what tells us (a) whether we want to step
6525 into it at all, and (b) what prologue we want to run to the
6526 end of, if we do step into it. */
6527 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6528 if (real_stop_pc
== 0)
6529 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6530 if (real_stop_pc
!= 0)
6531 ecs
->stop_func_start
= real_stop_pc
;
6533 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6535 symtab_and_line sr_sal
;
6536 sr_sal
.pc
= ecs
->stop_func_start
;
6537 sr_sal
.pspace
= get_frame_program_space (frame
);
6539 insert_step_resume_breakpoint_at_sal (gdbarch
,
6540 sr_sal
, null_frame_id
);
6545 /* If we have line number information for the function we are
6546 thinking of stepping into and the function isn't on the skip
6549 If there are several symtabs at that PC (e.g. with include
6550 files), just want to know whether *any* of them have line
6551 numbers. find_pc_line handles this. */
6553 struct symtab_and_line tmp_sal
;
6555 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6556 if (tmp_sal
.line
!= 0
6557 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6560 if (execution_direction
== EXEC_REVERSE
)
6561 handle_step_into_function_backward (gdbarch
, ecs
);
6563 handle_step_into_function (gdbarch
, ecs
);
6568 /* If we have no line number and the step-stop-if-no-debug is
6569 set, we stop the step so that the user has a chance to switch
6570 in assembly mode. */
6571 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6572 && step_stop_if_no_debug
)
6574 end_stepping_range (ecs
);
6578 if (execution_direction
== EXEC_REVERSE
)
6580 /* If we're already at the start of the function, we've either just
6581 stepped backward into a single instruction function without line
6582 number info, or stepped back out of a signal handler to the first
6583 instruction of the function without line number info. Just keep
6584 going, which will single-step back to the caller. */
6585 if (ecs
->stop_func_start
!= stop_pc
)
6587 /* Set a breakpoint at callee's start address.
6588 From there we can step once and be back in the caller. */
6589 symtab_and_line sr_sal
;
6590 sr_sal
.pc
= ecs
->stop_func_start
;
6591 sr_sal
.pspace
= get_frame_program_space (frame
);
6592 insert_step_resume_breakpoint_at_sal (gdbarch
,
6593 sr_sal
, null_frame_id
);
6597 /* Set a breakpoint at callee's return address (the address
6598 at which the caller will resume). */
6599 insert_step_resume_breakpoint_at_caller (frame
);
6605 /* Reverse stepping through solib trampolines. */
6607 if (execution_direction
== EXEC_REVERSE
6608 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6610 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6612 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6613 || (ecs
->stop_func_start
== 0
6614 && in_solib_dynsym_resolve_code (stop_pc
)))
6616 /* Any solib trampoline code can be handled in reverse
6617 by simply continuing to single-step. We have already
6618 executed the solib function (backwards), and a few
6619 steps will take us back through the trampoline to the
6624 else if (in_solib_dynsym_resolve_code (stop_pc
))
6626 /* Stepped backward into the solib dynsym resolver.
6627 Set a breakpoint at its start and continue, then
6628 one more step will take us out. */
6629 symtab_and_line sr_sal
;
6630 sr_sal
.pc
= ecs
->stop_func_start
;
6631 sr_sal
.pspace
= get_frame_program_space (frame
);
6632 insert_step_resume_breakpoint_at_sal (gdbarch
,
6633 sr_sal
, null_frame_id
);
6639 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6641 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6642 the trampoline processing logic, however, there are some trampolines
6643 that have no names, so we should do trampoline handling first. */
6644 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6645 && ecs
->stop_func_name
== NULL
6646 && stop_pc_sal
.line
== 0)
6649 fprintf_unfiltered (gdb_stdlog
,
6650 "infrun: stepped into undebuggable function\n");
6652 /* The inferior just stepped into, or returned to, an
6653 undebuggable function (where there is no debugging information
6654 and no line number corresponding to the address where the
6655 inferior stopped). Since we want to skip this kind of code,
6656 we keep going until the inferior returns from this
6657 function - unless the user has asked us not to (via
6658 set step-mode) or we no longer know how to get back
6659 to the call site. */
6660 if (step_stop_if_no_debug
6661 || !frame_id_p (frame_unwind_caller_id (frame
)))
6663 /* If we have no line number and the step-stop-if-no-debug
6664 is set, we stop the step so that the user has a chance to
6665 switch in assembly mode. */
6666 end_stepping_range (ecs
);
6671 /* Set a breakpoint at callee's return address (the address
6672 at which the caller will resume). */
6673 insert_step_resume_breakpoint_at_caller (frame
);
6679 if (ecs
->event_thread
->control
.step_range_end
== 1)
6681 /* It is stepi or nexti. We always want to stop stepping after
6684 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
6685 end_stepping_range (ecs
);
6689 if (stop_pc_sal
.line
== 0)
6691 /* We have no line number information. That means to stop
6692 stepping (does this always happen right after one instruction,
6693 when we do "s" in a function with no line numbers,
6694 or can this happen as a result of a return or longjmp?). */
6696 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
6697 end_stepping_range (ecs
);
6701 /* Look for "calls" to inlined functions, part one. If the inline
6702 frame machinery detected some skipped call sites, we have entered
6703 a new inline function. */
6705 if (frame_id_eq (get_frame_id (get_current_frame ()),
6706 ecs
->event_thread
->control
.step_frame_id
)
6707 && inline_skipped_frames (ecs
->event_thread
))
6710 fprintf_unfiltered (gdb_stdlog
,
6711 "infrun: stepped into inlined function\n");
6713 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6715 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6717 /* For "step", we're going to stop. But if the call site
6718 for this inlined function is on the same source line as
6719 we were previously stepping, go down into the function
6720 first. Otherwise stop at the call site. */
6722 if (call_sal
.line
== ecs
->event_thread
->current_line
6723 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6724 step_into_inline_frame (ecs
->event_thread
);
6726 end_stepping_range (ecs
);
6731 /* For "next", we should stop at the call site if it is on a
6732 different source line. Otherwise continue through the
6733 inlined function. */
6734 if (call_sal
.line
== ecs
->event_thread
->current_line
6735 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6738 end_stepping_range (ecs
);
6743 /* Look for "calls" to inlined functions, part two. If we are still
6744 in the same real function we were stepping through, but we have
6745 to go further up to find the exact frame ID, we are stepping
6746 through a more inlined call beyond its call site. */
6748 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6749 && !frame_id_eq (get_frame_id (get_current_frame ()),
6750 ecs
->event_thread
->control
.step_frame_id
)
6751 && stepped_in_from (get_current_frame (),
6752 ecs
->event_thread
->control
.step_frame_id
))
6755 fprintf_unfiltered (gdb_stdlog
,
6756 "infrun: stepping through inlined function\n");
6758 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6761 end_stepping_range (ecs
);
6765 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
6766 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
6767 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
6769 /* We are at the start of a different line. So stop. Note that
6770 we don't stop if we step into the middle of a different line.
6771 That is said to make things like for (;;) statements work
6774 fprintf_unfiltered (gdb_stdlog
,
6775 "infrun: stepped to a different line\n");
6776 end_stepping_range (ecs
);
6780 /* We aren't done stepping.
6782 Optimize by setting the stepping range to the line.
6783 (We might not be in the original line, but if we entered a
6784 new line in mid-statement, we continue stepping. This makes
6785 things like for(;;) statements work better.) */
6787 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
6788 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
6789 ecs
->event_thread
->control
.may_range_step
= 1;
6790 set_step_info (frame
, stop_pc_sal
);
6793 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
6797 /* In all-stop mode, if we're currently stepping but have stopped in
6798 some other thread, we may need to switch back to the stepped
6799 thread. Returns true we set the inferior running, false if we left
6800 it stopped (and the event needs further processing). */
6803 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
6805 if (!target_is_non_stop_p ())
6807 struct thread_info
*stepping_thread
;
6809 /* If any thread is blocked on some internal breakpoint, and we
6810 simply need to step over that breakpoint to get it going
6811 again, do that first. */
6813 /* However, if we see an event for the stepping thread, then we
6814 know all other threads have been moved past their breakpoints
6815 already. Let the caller check whether the step is finished,
6816 etc., before deciding to move it past a breakpoint. */
6817 if (ecs
->event_thread
->control
.step_range_end
!= 0)
6820 /* Check if the current thread is blocked on an incomplete
6821 step-over, interrupted by a random signal. */
6822 if (ecs
->event_thread
->control
.trap_expected
6823 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
6827 fprintf_unfiltered (gdb_stdlog
,
6828 "infrun: need to finish step-over of [%s]\n",
6829 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
6835 /* Check if the current thread is blocked by a single-step
6836 breakpoint of another thread. */
6837 if (ecs
->hit_singlestep_breakpoint
)
6841 fprintf_unfiltered (gdb_stdlog
,
6842 "infrun: need to step [%s] over single-step "
6844 target_pid_to_str (ecs
->ptid
).c_str ());
6850 /* If this thread needs yet another step-over (e.g., stepping
6851 through a delay slot), do it first before moving on to
6853 if (thread_still_needs_step_over (ecs
->event_thread
))
6857 fprintf_unfiltered (gdb_stdlog
,
6858 "infrun: thread [%s] still needs step-over\n",
6859 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
6865 /* If scheduler locking applies even if not stepping, there's no
6866 need to walk over threads. Above we've checked whether the
6867 current thread is stepping. If some other thread not the
6868 event thread is stepping, then it must be that scheduler
6869 locking is not in effect. */
6870 if (schedlock_applies (ecs
->event_thread
))
6873 /* Otherwise, we no longer expect a trap in the current thread.
6874 Clear the trap_expected flag before switching back -- this is
6875 what keep_going does as well, if we call it. */
6876 ecs
->event_thread
->control
.trap_expected
= 0;
6878 /* Likewise, clear the signal if it should not be passed. */
6879 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
6880 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6882 /* Do all pending step-overs before actually proceeding with
6884 if (start_step_over ())
6886 prepare_to_wait (ecs
);
6890 /* Look for the stepping/nexting thread. */
6891 stepping_thread
= NULL
;
6893 for (thread_info
*tp
: all_non_exited_threads ())
6895 /* Ignore threads of processes the caller is not
6898 && tp
->ptid
.pid () != ecs
->ptid
.pid ())
6901 /* When stepping over a breakpoint, we lock all threads
6902 except the one that needs to move past the breakpoint.
6903 If a non-event thread has this set, the "incomplete
6904 step-over" check above should have caught it earlier. */
6905 if (tp
->control
.trap_expected
)
6907 internal_error (__FILE__
, __LINE__
,
6908 "[%s] has inconsistent state: "
6909 "trap_expected=%d\n",
6910 target_pid_to_str (tp
->ptid
).c_str (),
6911 tp
->control
.trap_expected
);
6914 /* Did we find the stepping thread? */
6915 if (tp
->control
.step_range_end
)
6917 /* Yep. There should only one though. */
6918 gdb_assert (stepping_thread
== NULL
);
6920 /* The event thread is handled at the top, before we
6922 gdb_assert (tp
!= ecs
->event_thread
);
6924 /* If some thread other than the event thread is
6925 stepping, then scheduler locking can't be in effect,
6926 otherwise we wouldn't have resumed the current event
6927 thread in the first place. */
6928 gdb_assert (!schedlock_applies (tp
));
6930 stepping_thread
= tp
;
6934 if (stepping_thread
!= NULL
)
6937 fprintf_unfiltered (gdb_stdlog
,
6938 "infrun: switching back to stepped thread\n");
6940 if (keep_going_stepped_thread (stepping_thread
))
6942 prepare_to_wait (ecs
);
6951 /* Set a previously stepped thread back to stepping. Returns true on
6952 success, false if the resume is not possible (e.g., the thread
6956 keep_going_stepped_thread (struct thread_info
*tp
)
6958 struct frame_info
*frame
;
6959 struct execution_control_state ecss
;
6960 struct execution_control_state
*ecs
= &ecss
;
6962 /* If the stepping thread exited, then don't try to switch back and
6963 resume it, which could fail in several different ways depending
6964 on the target. Instead, just keep going.
6966 We can find a stepping dead thread in the thread list in two
6969 - The target supports thread exit events, and when the target
6970 tries to delete the thread from the thread list, inferior_ptid
6971 pointed at the exiting thread. In such case, calling
6972 delete_thread does not really remove the thread from the list;
6973 instead, the thread is left listed, with 'exited' state.
6975 - The target's debug interface does not support thread exit
6976 events, and so we have no idea whatsoever if the previously
6977 stepping thread is still alive. For that reason, we need to
6978 synchronously query the target now. */
6980 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
6983 fprintf_unfiltered (gdb_stdlog
,
6984 "infrun: not resuming previously "
6985 "stepped thread, it has vanished\n");
6992 fprintf_unfiltered (gdb_stdlog
,
6993 "infrun: resuming previously stepped thread\n");
6995 reset_ecs (ecs
, tp
);
6996 switch_to_thread (tp
);
6998 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
6999 frame
= get_current_frame ();
7001 /* If the PC of the thread we were trying to single-step has
7002 changed, then that thread has trapped or been signaled, but the
7003 event has not been reported to GDB yet. Re-poll the target
7004 looking for this particular thread's event (i.e. temporarily
7005 enable schedlock) by:
7007 - setting a break at the current PC
7008 - resuming that particular thread, only (by setting trap
7011 This prevents us continuously moving the single-step breakpoint
7012 forward, one instruction at a time, overstepping. */
7014 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7019 fprintf_unfiltered (gdb_stdlog
,
7020 "infrun: expected thread advanced also (%s -> %s)\n",
7021 paddress (target_gdbarch (), tp
->prev_pc
),
7022 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7024 /* Clear the info of the previous step-over, as it's no longer
7025 valid (if the thread was trying to step over a breakpoint, it
7026 has already succeeded). It's what keep_going would do too,
7027 if we called it. Do this before trying to insert the sss
7028 breakpoint, otherwise if we were previously trying to step
7029 over this exact address in another thread, the breakpoint is
7031 clear_step_over_info ();
7032 tp
->control
.trap_expected
= 0;
7034 insert_single_step_breakpoint (get_frame_arch (frame
),
7035 get_frame_address_space (frame
),
7036 tp
->suspend
.stop_pc
);
7039 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7040 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7045 fprintf_unfiltered (gdb_stdlog
,
7046 "infrun: expected thread still hasn't advanced\n");
7048 keep_going_pass_signal (ecs
);
7053 /* Is thread TP in the middle of (software or hardware)
7054 single-stepping? (Note the result of this function must never be
7055 passed directly as target_resume's STEP parameter.) */
7058 currently_stepping (struct thread_info
*tp
)
7060 return ((tp
->control
.step_range_end
7061 && tp
->control
.step_resume_breakpoint
== NULL
)
7062 || tp
->control
.trap_expected
7063 || tp
->stepped_breakpoint
7064 || bpstat_should_step ());
7067 /* Inferior has stepped into a subroutine call with source code that
7068 we should not step over. Do step to the first line of code in
7072 handle_step_into_function (struct gdbarch
*gdbarch
,
7073 struct execution_control_state
*ecs
)
7075 fill_in_stop_func (gdbarch
, ecs
);
7077 compunit_symtab
*cust
7078 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7079 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7080 ecs
->stop_func_start
7081 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7083 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7084 /* Use the step_resume_break to step until the end of the prologue,
7085 even if that involves jumps (as it seems to on the vax under
7087 /* If the prologue ends in the middle of a source line, continue to
7088 the end of that source line (if it is still within the function).
7089 Otherwise, just go to end of prologue. */
7090 if (stop_func_sal
.end
7091 && stop_func_sal
.pc
!= ecs
->stop_func_start
7092 && stop_func_sal
.end
< ecs
->stop_func_end
)
7093 ecs
->stop_func_start
= stop_func_sal
.end
;
7095 /* Architectures which require breakpoint adjustment might not be able
7096 to place a breakpoint at the computed address. If so, the test
7097 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7098 ecs->stop_func_start to an address at which a breakpoint may be
7099 legitimately placed.
7101 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7102 made, GDB will enter an infinite loop when stepping through
7103 optimized code consisting of VLIW instructions which contain
7104 subinstructions corresponding to different source lines. On
7105 FR-V, it's not permitted to place a breakpoint on any but the
7106 first subinstruction of a VLIW instruction. When a breakpoint is
7107 set, GDB will adjust the breakpoint address to the beginning of
7108 the VLIW instruction. Thus, we need to make the corresponding
7109 adjustment here when computing the stop address. */
7111 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7113 ecs
->stop_func_start
7114 = gdbarch_adjust_breakpoint_address (gdbarch
,
7115 ecs
->stop_func_start
);
7118 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7120 /* We are already there: stop now. */
7121 end_stepping_range (ecs
);
7126 /* Put the step-breakpoint there and go until there. */
7127 symtab_and_line sr_sal
;
7128 sr_sal
.pc
= ecs
->stop_func_start
;
7129 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7130 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7132 /* Do not specify what the fp should be when we stop since on
7133 some machines the prologue is where the new fp value is
7135 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7137 /* And make sure stepping stops right away then. */
7138 ecs
->event_thread
->control
.step_range_end
7139 = ecs
->event_thread
->control
.step_range_start
;
7144 /* Inferior has stepped backward into a subroutine call with source
7145 code that we should not step over. Do step to the beginning of the
7146 last line of code in it. */
7149 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7150 struct execution_control_state
*ecs
)
7152 struct compunit_symtab
*cust
;
7153 struct symtab_and_line stop_func_sal
;
7155 fill_in_stop_func (gdbarch
, ecs
);
7157 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7158 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7159 ecs
->stop_func_start
7160 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7162 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7164 /* OK, we're just going to keep stepping here. */
7165 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7167 /* We're there already. Just stop stepping now. */
7168 end_stepping_range (ecs
);
7172 /* Else just reset the step range and keep going.
7173 No step-resume breakpoint, they don't work for
7174 epilogues, which can have multiple entry paths. */
7175 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7176 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7182 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7183 This is used to both functions and to skip over code. */
7186 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7187 struct symtab_and_line sr_sal
,
7188 struct frame_id sr_id
,
7189 enum bptype sr_type
)
7191 /* There should never be more than one step-resume or longjmp-resume
7192 breakpoint per thread, so we should never be setting a new
7193 step_resume_breakpoint when one is already active. */
7194 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7195 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7198 fprintf_unfiltered (gdb_stdlog
,
7199 "infrun: inserting step-resume breakpoint at %s\n",
7200 paddress (gdbarch
, sr_sal
.pc
));
7202 inferior_thread ()->control
.step_resume_breakpoint
7203 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7207 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7208 struct symtab_and_line sr_sal
,
7209 struct frame_id sr_id
)
7211 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7216 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7217 This is used to skip a potential signal handler.
7219 This is called with the interrupted function's frame. The signal
7220 handler, when it returns, will resume the interrupted function at
7224 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7226 gdb_assert (return_frame
!= NULL
);
7228 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7230 symtab_and_line sr_sal
;
7231 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7232 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7233 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7235 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7236 get_stack_frame_id (return_frame
),
7240 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7241 is used to skip a function after stepping into it (for "next" or if
7242 the called function has no debugging information).
7244 The current function has almost always been reached by single
7245 stepping a call or return instruction. NEXT_FRAME belongs to the
7246 current function, and the breakpoint will be set at the caller's
7249 This is a separate function rather than reusing
7250 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7251 get_prev_frame, which may stop prematurely (see the implementation
7252 of frame_unwind_caller_id for an example). */
7255 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7257 /* We shouldn't have gotten here if we don't know where the call site
7259 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7261 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7263 symtab_and_line sr_sal
;
7264 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7265 frame_unwind_caller_pc (next_frame
));
7266 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7267 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7269 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7270 frame_unwind_caller_id (next_frame
));
7273 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7274 new breakpoint at the target of a jmp_buf. The handling of
7275 longjmp-resume uses the same mechanisms used for handling
7276 "step-resume" breakpoints. */
7279 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7281 /* There should never be more than one longjmp-resume breakpoint per
7282 thread, so we should never be setting a new
7283 longjmp_resume_breakpoint when one is already active. */
7284 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7287 fprintf_unfiltered (gdb_stdlog
,
7288 "infrun: inserting longjmp-resume breakpoint at %s\n",
7289 paddress (gdbarch
, pc
));
7291 inferior_thread ()->control
.exception_resume_breakpoint
=
7292 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7295 /* Insert an exception resume breakpoint. TP is the thread throwing
7296 the exception. The block B is the block of the unwinder debug hook
7297 function. FRAME is the frame corresponding to the call to this
7298 function. SYM is the symbol of the function argument holding the
7299 target PC of the exception. */
7302 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7303 const struct block
*b
,
7304 struct frame_info
*frame
,
7309 struct block_symbol vsym
;
7310 struct value
*value
;
7312 struct breakpoint
*bp
;
7314 vsym
= lookup_symbol_search_name (sym
->search_name (),
7316 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7317 /* If the value was optimized out, revert to the old behavior. */
7318 if (! value_optimized_out (value
))
7320 handler
= value_as_address (value
);
7323 fprintf_unfiltered (gdb_stdlog
,
7324 "infrun: exception resume at %lx\n",
7325 (unsigned long) handler
);
7327 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7329 bp_exception_resume
).release ();
7331 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7334 bp
->thread
= tp
->global_num
;
7335 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7338 catch (const gdb_exception_error
&e
)
7340 /* We want to ignore errors here. */
7344 /* A helper for check_exception_resume that sets an
7345 exception-breakpoint based on a SystemTap probe. */
7348 insert_exception_resume_from_probe (struct thread_info
*tp
,
7349 const struct bound_probe
*probe
,
7350 struct frame_info
*frame
)
7352 struct value
*arg_value
;
7354 struct breakpoint
*bp
;
7356 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7360 handler
= value_as_address (arg_value
);
7363 fprintf_unfiltered (gdb_stdlog
,
7364 "infrun: exception resume at %s\n",
7365 paddress (get_objfile_arch (probe
->objfile
),
7368 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7369 handler
, bp_exception_resume
).release ();
7370 bp
->thread
= tp
->global_num
;
7371 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7374 /* This is called when an exception has been intercepted. Check to
7375 see whether the exception's destination is of interest, and if so,
7376 set an exception resume breakpoint there. */
7379 check_exception_resume (struct execution_control_state
*ecs
,
7380 struct frame_info
*frame
)
7382 struct bound_probe probe
;
7383 struct symbol
*func
;
7385 /* First see if this exception unwinding breakpoint was set via a
7386 SystemTap probe point. If so, the probe has two arguments: the
7387 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7388 set a breakpoint there. */
7389 probe
= find_probe_by_pc (get_frame_pc (frame
));
7392 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7396 func
= get_frame_function (frame
);
7402 const struct block
*b
;
7403 struct block_iterator iter
;
7407 /* The exception breakpoint is a thread-specific breakpoint on
7408 the unwinder's debug hook, declared as:
7410 void _Unwind_DebugHook (void *cfa, void *handler);
7412 The CFA argument indicates the frame to which control is
7413 about to be transferred. HANDLER is the destination PC.
7415 We ignore the CFA and set a temporary breakpoint at HANDLER.
7416 This is not extremely efficient but it avoids issues in gdb
7417 with computing the DWARF CFA, and it also works even in weird
7418 cases such as throwing an exception from inside a signal
7421 b
= SYMBOL_BLOCK_VALUE (func
);
7422 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7424 if (!SYMBOL_IS_ARGUMENT (sym
))
7431 insert_exception_resume_breakpoint (ecs
->event_thread
,
7437 catch (const gdb_exception_error
&e
)
7443 stop_waiting (struct execution_control_state
*ecs
)
7446 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7448 /* Let callers know we don't want to wait for the inferior anymore. */
7449 ecs
->wait_some_more
= 0;
7451 /* If all-stop, but the target is always in non-stop mode, stop all
7452 threads now that we're presenting the stop to the user. */
7453 if (!non_stop
&& target_is_non_stop_p ())
7454 stop_all_threads ();
7457 /* Like keep_going, but passes the signal to the inferior, even if the
7458 signal is set to nopass. */
7461 keep_going_pass_signal (struct execution_control_state
*ecs
)
7463 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7464 gdb_assert (!ecs
->event_thread
->resumed
);
7466 /* Save the pc before execution, to compare with pc after stop. */
7467 ecs
->event_thread
->prev_pc
7468 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7470 if (ecs
->event_thread
->control
.trap_expected
)
7472 struct thread_info
*tp
= ecs
->event_thread
;
7475 fprintf_unfiltered (gdb_stdlog
,
7476 "infrun: %s has trap_expected set, "
7477 "resuming to collect trap\n",
7478 target_pid_to_str (tp
->ptid
).c_str ());
7480 /* We haven't yet gotten our trap, and either: intercepted a
7481 non-signal event (e.g., a fork); or took a signal which we
7482 are supposed to pass through to the inferior. Simply
7484 resume (ecs
->event_thread
->suspend
.stop_signal
);
7486 else if (step_over_info_valid_p ())
7488 /* Another thread is stepping over a breakpoint in-line. If
7489 this thread needs a step-over too, queue the request. In
7490 either case, this resume must be deferred for later. */
7491 struct thread_info
*tp
= ecs
->event_thread
;
7493 if (ecs
->hit_singlestep_breakpoint
7494 || thread_still_needs_step_over (tp
))
7497 fprintf_unfiltered (gdb_stdlog
,
7498 "infrun: step-over already in progress: "
7499 "step-over for %s deferred\n",
7500 target_pid_to_str (tp
->ptid
).c_str ());
7501 global_thread_step_over_chain_enqueue (tp
);
7506 fprintf_unfiltered (gdb_stdlog
,
7507 "infrun: step-over in progress: "
7508 "resume of %s deferred\n",
7509 target_pid_to_str (tp
->ptid
).c_str ());
7514 struct regcache
*regcache
= get_current_regcache ();
7517 step_over_what step_what
;
7519 /* Either the trap was not expected, but we are continuing
7520 anyway (if we got a signal, the user asked it be passed to
7523 We got our expected trap, but decided we should resume from
7526 We're going to run this baby now!
7528 Note that insert_breakpoints won't try to re-insert
7529 already inserted breakpoints. Therefore, we don't
7530 care if breakpoints were already inserted, or not. */
7532 /* If we need to step over a breakpoint, and we're not using
7533 displaced stepping to do so, insert all breakpoints
7534 (watchpoints, etc.) but the one we're stepping over, step one
7535 instruction, and then re-insert the breakpoint when that step
7538 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7540 remove_bp
= (ecs
->hit_singlestep_breakpoint
7541 || (step_what
& STEP_OVER_BREAKPOINT
));
7542 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7544 /* We can't use displaced stepping if we need to step past a
7545 watchpoint. The instruction copied to the scratch pad would
7546 still trigger the watchpoint. */
7548 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7550 set_step_over_info (regcache
->aspace (),
7551 regcache_read_pc (regcache
), remove_wps
,
7552 ecs
->event_thread
->global_num
);
7554 else if (remove_wps
)
7555 set_step_over_info (NULL
, 0, remove_wps
, -1);
7557 /* If we now need to do an in-line step-over, we need to stop
7558 all other threads. Note this must be done before
7559 insert_breakpoints below, because that removes the breakpoint
7560 we're about to step over, otherwise other threads could miss
7562 if (step_over_info_valid_p () && target_is_non_stop_p ())
7563 stop_all_threads ();
7565 /* Stop stepping if inserting breakpoints fails. */
7568 insert_breakpoints ();
7570 catch (const gdb_exception_error
&e
)
7572 exception_print (gdb_stderr
, e
);
7574 clear_step_over_info ();
7578 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7580 resume (ecs
->event_thread
->suspend
.stop_signal
);
7583 prepare_to_wait (ecs
);
7586 /* Called when we should continue running the inferior, because the
7587 current event doesn't cause a user visible stop. This does the
7588 resuming part; waiting for the next event is done elsewhere. */
7591 keep_going (struct execution_control_state
*ecs
)
7593 if (ecs
->event_thread
->control
.trap_expected
7594 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7595 ecs
->event_thread
->control
.trap_expected
= 0;
7597 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7598 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7599 keep_going_pass_signal (ecs
);
7602 /* This function normally comes after a resume, before
7603 handle_inferior_event exits. It takes care of any last bits of
7604 housekeeping, and sets the all-important wait_some_more flag. */
7607 prepare_to_wait (struct execution_control_state
*ecs
)
7610 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7612 ecs
->wait_some_more
= 1;
7614 if (!target_is_async_p ())
7615 mark_infrun_async_event_handler ();
7618 /* We are done with the step range of a step/next/si/ni command.
7619 Called once for each n of a "step n" operation. */
7622 end_stepping_range (struct execution_control_state
*ecs
)
7624 ecs
->event_thread
->control
.stop_step
= 1;
7628 /* Several print_*_reason functions to print why the inferior has stopped.
7629 We always print something when the inferior exits, or receives a signal.
7630 The rest of the cases are dealt with later on in normal_stop and
7631 print_it_typical. Ideally there should be a call to one of these
7632 print_*_reason functions functions from handle_inferior_event each time
7633 stop_waiting is called.
7635 Note that we don't call these directly, instead we delegate that to
7636 the interpreters, through observers. Interpreters then call these
7637 with whatever uiout is right. */
7640 print_end_stepping_range_reason (struct ui_out
*uiout
)
7642 /* For CLI-like interpreters, print nothing. */
7644 if (uiout
->is_mi_like_p ())
7646 uiout
->field_string ("reason",
7647 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7652 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7654 annotate_signalled ();
7655 if (uiout
->is_mi_like_p ())
7657 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7658 uiout
->text ("\nProgram terminated with signal ");
7659 annotate_signal_name ();
7660 uiout
->field_string ("signal-name",
7661 gdb_signal_to_name (siggnal
));
7662 annotate_signal_name_end ();
7664 annotate_signal_string ();
7665 uiout
->field_string ("signal-meaning",
7666 gdb_signal_to_string (siggnal
));
7667 annotate_signal_string_end ();
7668 uiout
->text (".\n");
7669 uiout
->text ("The program no longer exists.\n");
7673 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7675 struct inferior
*inf
= current_inferior ();
7676 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7678 annotate_exited (exitstatus
);
7681 if (uiout
->is_mi_like_p ())
7682 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7683 std::string exit_code_str
7684 = string_printf ("0%o", (unsigned int) exitstatus
);
7685 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7686 plongest (inf
->num
), pidstr
.c_str (),
7687 string_field ("exit-code", exit_code_str
.c_str ()));
7691 if (uiout
->is_mi_like_p ())
7693 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7694 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7695 plongest (inf
->num
), pidstr
.c_str ());
7699 /* Some targets/architectures can do extra processing/display of
7700 segmentation faults. E.g., Intel MPX boundary faults.
7701 Call the architecture dependent function to handle the fault. */
7704 handle_segmentation_fault (struct ui_out
*uiout
)
7706 struct regcache
*regcache
= get_current_regcache ();
7707 struct gdbarch
*gdbarch
= regcache
->arch ();
7709 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7710 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7714 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7716 struct thread_info
*thr
= inferior_thread ();
7720 if (uiout
->is_mi_like_p ())
7722 else if (show_thread_that_caused_stop ())
7726 uiout
->text ("\nThread ");
7727 uiout
->field_string ("thread-id", print_thread_id (thr
));
7729 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7732 uiout
->text (" \"");
7733 uiout
->field_string ("name", name
);
7738 uiout
->text ("\nProgram");
7740 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
7741 uiout
->text (" stopped");
7744 uiout
->text (" received signal ");
7745 annotate_signal_name ();
7746 if (uiout
->is_mi_like_p ())
7748 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7749 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
7750 annotate_signal_name_end ();
7752 annotate_signal_string ();
7753 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
7755 if (siggnal
== GDB_SIGNAL_SEGV
)
7756 handle_segmentation_fault (uiout
);
7758 annotate_signal_string_end ();
7760 uiout
->text (".\n");
7764 print_no_history_reason (struct ui_out
*uiout
)
7766 uiout
->text ("\nNo more reverse-execution history.\n");
7769 /* Print current location without a level number, if we have changed
7770 functions or hit a breakpoint. Print source line if we have one.
7771 bpstat_print contains the logic deciding in detail what to print,
7772 based on the event(s) that just occurred. */
7775 print_stop_location (struct target_waitstatus
*ws
)
7778 enum print_what source_flag
;
7779 int do_frame_printing
= 1;
7780 struct thread_info
*tp
= inferior_thread ();
7782 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
7786 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7787 should) carry around the function and does (or should) use
7788 that when doing a frame comparison. */
7789 if (tp
->control
.stop_step
7790 && frame_id_eq (tp
->control
.step_frame_id
,
7791 get_frame_id (get_current_frame ()))
7792 && (tp
->control
.step_start_function
7793 == find_pc_function (tp
->suspend
.stop_pc
)))
7795 /* Finished step, just print source line. */
7796 source_flag
= SRC_LINE
;
7800 /* Print location and source line. */
7801 source_flag
= SRC_AND_LOC
;
7804 case PRINT_SRC_AND_LOC
:
7805 /* Print location and source line. */
7806 source_flag
= SRC_AND_LOC
;
7808 case PRINT_SRC_ONLY
:
7809 source_flag
= SRC_LINE
;
7812 /* Something bogus. */
7813 source_flag
= SRC_LINE
;
7814 do_frame_printing
= 0;
7817 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
7820 /* The behavior of this routine with respect to the source
7822 SRC_LINE: Print only source line
7823 LOCATION: Print only location
7824 SRC_AND_LOC: Print location and source line. */
7825 if (do_frame_printing
)
7826 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
7832 print_stop_event (struct ui_out
*uiout
, bool displays
)
7834 struct target_waitstatus last
;
7836 struct thread_info
*tp
;
7838 get_last_target_status (&last_ptid
, &last
);
7841 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
7843 print_stop_location (&last
);
7845 /* Display the auto-display expressions. */
7850 tp
= inferior_thread ();
7851 if (tp
->thread_fsm
!= NULL
7852 && tp
->thread_fsm
->finished_p ())
7854 struct return_value_info
*rv
;
7856 rv
= tp
->thread_fsm
->return_value ();
7858 print_return_value (uiout
, rv
);
7865 maybe_remove_breakpoints (void)
7867 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
7869 if (remove_breakpoints ())
7871 target_terminal::ours_for_output ();
7872 printf_filtered (_("Cannot remove breakpoints because "
7873 "program is no longer writable.\nFurther "
7874 "execution is probably impossible.\n"));
7879 /* The execution context that just caused a normal stop. */
7886 DISABLE_COPY_AND_ASSIGN (stop_context
);
7888 bool changed () const;
7893 /* The event PTID. */
7897 /* If stopp for a thread event, this is the thread that caused the
7899 struct thread_info
*thread
;
7901 /* The inferior that caused the stop. */
7905 /* Initializes a new stop context. If stopped for a thread event, this
7906 takes a strong reference to the thread. */
7908 stop_context::stop_context ()
7910 stop_id
= get_stop_id ();
7911 ptid
= inferior_ptid
;
7912 inf_num
= current_inferior ()->num
;
7914 if (inferior_ptid
!= null_ptid
)
7916 /* Take a strong reference so that the thread can't be deleted
7918 thread
= inferior_thread ();
7925 /* Release a stop context previously created with save_stop_context.
7926 Releases the strong reference to the thread as well. */
7928 stop_context::~stop_context ()
7934 /* Return true if the current context no longer matches the saved stop
7938 stop_context::changed () const
7940 if (ptid
!= inferior_ptid
)
7942 if (inf_num
!= current_inferior ()->num
)
7944 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
7946 if (get_stop_id () != stop_id
)
7956 struct target_waitstatus last
;
7959 get_last_target_status (&last_ptid
, &last
);
7963 /* If an exception is thrown from this point on, make sure to
7964 propagate GDB's knowledge of the executing state to the
7965 frontend/user running state. A QUIT is an easy exception to see
7966 here, so do this before any filtered output. */
7968 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
7971 maybe_finish_thread_state
.emplace (minus_one_ptid
);
7972 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
7973 || last
.kind
== TARGET_WAITKIND_EXITED
)
7975 /* On some targets, we may still have live threads in the
7976 inferior when we get a process exit event. E.g., for
7977 "checkpoint", when the current checkpoint/fork exits,
7978 linux-fork.c automatically switches to another fork from
7979 within target_mourn_inferior. */
7980 if (inferior_ptid
!= null_ptid
)
7981 maybe_finish_thread_state
.emplace (ptid_t (inferior_ptid
.pid ()));
7983 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
7984 maybe_finish_thread_state
.emplace (inferior_ptid
);
7986 /* As we're presenting a stop, and potentially removing breakpoints,
7987 update the thread list so we can tell whether there are threads
7988 running on the target. With target remote, for example, we can
7989 only learn about new threads when we explicitly update the thread
7990 list. Do this before notifying the interpreters about signal
7991 stops, end of stepping ranges, etc., so that the "new thread"
7992 output is emitted before e.g., "Program received signal FOO",
7993 instead of after. */
7994 update_thread_list ();
7996 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
7997 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
7999 /* As with the notification of thread events, we want to delay
8000 notifying the user that we've switched thread context until
8001 the inferior actually stops.
8003 There's no point in saying anything if the inferior has exited.
8004 Note that SIGNALLED here means "exited with a signal", not
8005 "received a signal".
8007 Also skip saying anything in non-stop mode. In that mode, as we
8008 don't want GDB to switch threads behind the user's back, to avoid
8009 races where the user is typing a command to apply to thread x,
8010 but GDB switches to thread y before the user finishes entering
8011 the command, fetch_inferior_event installs a cleanup to restore
8012 the current thread back to the thread the user had selected right
8013 after this event is handled, so we're not really switching, only
8014 informing of a stop. */
8016 && previous_inferior_ptid
!= inferior_ptid
8017 && target_has_execution
8018 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8019 && last
.kind
!= TARGET_WAITKIND_EXITED
8020 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8022 SWITCH_THRU_ALL_UIS ()
8024 target_terminal::ours_for_output ();
8025 printf_filtered (_("[Switching to %s]\n"),
8026 target_pid_to_str (inferior_ptid
).c_str ());
8027 annotate_thread_changed ();
8029 previous_inferior_ptid
= inferior_ptid
;
8032 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8034 SWITCH_THRU_ALL_UIS ()
8035 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8037 target_terminal::ours_for_output ();
8038 printf_filtered (_("No unwaited-for children left.\n"));
8042 /* Note: this depends on the update_thread_list call above. */
8043 maybe_remove_breakpoints ();
8045 /* If an auto-display called a function and that got a signal,
8046 delete that auto-display to avoid an infinite recursion. */
8048 if (stopped_by_random_signal
)
8049 disable_current_display ();
8051 SWITCH_THRU_ALL_UIS ()
8053 async_enable_stdin ();
8056 /* Let the user/frontend see the threads as stopped. */
8057 maybe_finish_thread_state
.reset ();
8059 /* Select innermost stack frame - i.e., current frame is frame 0,
8060 and current location is based on that. Handle the case where the
8061 dummy call is returning after being stopped. E.g. the dummy call
8062 previously hit a breakpoint. (If the dummy call returns
8063 normally, we won't reach here.) Do this before the stop hook is
8064 run, so that it doesn't get to see the temporary dummy frame,
8065 which is not where we'll present the stop. */
8066 if (has_stack_frames ())
8068 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8070 /* Pop the empty frame that contains the stack dummy. This
8071 also restores inferior state prior to the call (struct
8072 infcall_suspend_state). */
8073 struct frame_info
*frame
= get_current_frame ();
8075 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8077 /* frame_pop calls reinit_frame_cache as the last thing it
8078 does which means there's now no selected frame. */
8081 select_frame (get_current_frame ());
8083 /* Set the current source location. */
8084 set_current_sal_from_frame (get_current_frame ());
8087 /* Look up the hook_stop and run it (CLI internally handles problem
8088 of stop_command's pre-hook not existing). */
8089 if (stop_command
!= NULL
)
8091 stop_context saved_context
;
8095 execute_cmd_pre_hook (stop_command
);
8097 catch (const gdb_exception
&ex
)
8099 exception_fprintf (gdb_stderr
, ex
,
8100 "Error while running hook_stop:\n");
8103 /* If the stop hook resumes the target, then there's no point in
8104 trying to notify about the previous stop; its context is
8105 gone. Likewise if the command switches thread or inferior --
8106 the observers would print a stop for the wrong
8108 if (saved_context
.changed ())
8112 /* Notify observers about the stop. This is where the interpreters
8113 print the stop event. */
8114 if (inferior_ptid
!= null_ptid
)
8115 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8118 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8120 annotate_stopped ();
8122 if (target_has_execution
)
8124 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8125 && last
.kind
!= TARGET_WAITKIND_EXITED
8126 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8127 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8128 Delete any breakpoint that is to be deleted at the next stop. */
8129 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8132 /* Try to get rid of automatically added inferiors that are no
8133 longer needed. Keeping those around slows down things linearly.
8134 Note that this never removes the current inferior. */
8141 signal_stop_state (int signo
)
8143 return signal_stop
[signo
];
8147 signal_print_state (int signo
)
8149 return signal_print
[signo
];
8153 signal_pass_state (int signo
)
8155 return signal_program
[signo
];
8159 signal_cache_update (int signo
)
8163 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8164 signal_cache_update (signo
);
8169 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8170 && signal_print
[signo
] == 0
8171 && signal_program
[signo
] == 1
8172 && signal_catch
[signo
] == 0);
8176 signal_stop_update (int signo
, int state
)
8178 int ret
= signal_stop
[signo
];
8180 signal_stop
[signo
] = state
;
8181 signal_cache_update (signo
);
8186 signal_print_update (int signo
, int state
)
8188 int ret
= signal_print
[signo
];
8190 signal_print
[signo
] = state
;
8191 signal_cache_update (signo
);
8196 signal_pass_update (int signo
, int state
)
8198 int ret
= signal_program
[signo
];
8200 signal_program
[signo
] = state
;
8201 signal_cache_update (signo
);
8205 /* Update the global 'signal_catch' from INFO and notify the
8209 signal_catch_update (const unsigned int *info
)
8213 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8214 signal_catch
[i
] = info
[i
] > 0;
8215 signal_cache_update (-1);
8216 target_pass_signals (signal_pass
);
8220 sig_print_header (void)
8222 printf_filtered (_("Signal Stop\tPrint\tPass "
8223 "to program\tDescription\n"));
8227 sig_print_info (enum gdb_signal oursig
)
8229 const char *name
= gdb_signal_to_name (oursig
);
8230 int name_padding
= 13 - strlen (name
);
8232 if (name_padding
<= 0)
8235 printf_filtered ("%s", name
);
8236 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8237 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8238 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8239 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8240 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8243 /* Specify how various signals in the inferior should be handled. */
8246 handle_command (const char *args
, int from_tty
)
8248 int digits
, wordlen
;
8249 int sigfirst
, siglast
;
8250 enum gdb_signal oursig
;
8255 error_no_arg (_("signal to handle"));
8258 /* Allocate and zero an array of flags for which signals to handle. */
8260 const size_t nsigs
= GDB_SIGNAL_LAST
;
8261 unsigned char sigs
[nsigs
] {};
8263 /* Break the command line up into args. */
8265 gdb_argv
built_argv (args
);
8267 /* Walk through the args, looking for signal oursigs, signal names, and
8268 actions. Signal numbers and signal names may be interspersed with
8269 actions, with the actions being performed for all signals cumulatively
8270 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8272 for (char *arg
: built_argv
)
8274 wordlen
= strlen (arg
);
8275 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8279 sigfirst
= siglast
= -1;
8281 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8283 /* Apply action to all signals except those used by the
8284 debugger. Silently skip those. */
8287 siglast
= nsigs
- 1;
8289 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8291 SET_SIGS (nsigs
, sigs
, signal_stop
);
8292 SET_SIGS (nsigs
, sigs
, signal_print
);
8294 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8296 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8298 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8300 SET_SIGS (nsigs
, sigs
, signal_print
);
8302 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8304 SET_SIGS (nsigs
, sigs
, signal_program
);
8306 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8308 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8310 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8312 SET_SIGS (nsigs
, sigs
, signal_program
);
8314 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8316 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8317 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8319 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8321 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8323 else if (digits
> 0)
8325 /* It is numeric. The numeric signal refers to our own
8326 internal signal numbering from target.h, not to host/target
8327 signal number. This is a feature; users really should be
8328 using symbolic names anyway, and the common ones like
8329 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8331 sigfirst
= siglast
= (int)
8332 gdb_signal_from_command (atoi (arg
));
8333 if (arg
[digits
] == '-')
8336 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8338 if (sigfirst
> siglast
)
8340 /* Bet he didn't figure we'd think of this case... */
8341 std::swap (sigfirst
, siglast
);
8346 oursig
= gdb_signal_from_name (arg
);
8347 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8349 sigfirst
= siglast
= (int) oursig
;
8353 /* Not a number and not a recognized flag word => complain. */
8354 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8358 /* If any signal numbers or symbol names were found, set flags for
8359 which signals to apply actions to. */
8361 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8363 switch ((enum gdb_signal
) signum
)
8365 case GDB_SIGNAL_TRAP
:
8366 case GDB_SIGNAL_INT
:
8367 if (!allsigs
&& !sigs
[signum
])
8369 if (query (_("%s is used by the debugger.\n\
8370 Are you sure you want to change it? "),
8371 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8376 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8380 case GDB_SIGNAL_DEFAULT
:
8381 case GDB_SIGNAL_UNKNOWN
:
8382 /* Make sure that "all" doesn't print these. */
8391 for (int signum
= 0; signum
< nsigs
; signum
++)
8394 signal_cache_update (-1);
8395 target_pass_signals (signal_pass
);
8396 target_program_signals (signal_program
);
8400 /* Show the results. */
8401 sig_print_header ();
8402 for (; signum
< nsigs
; signum
++)
8404 sig_print_info ((enum gdb_signal
) signum
);
8411 /* Complete the "handle" command. */
8414 handle_completer (struct cmd_list_element
*ignore
,
8415 completion_tracker
&tracker
,
8416 const char *text
, const char *word
)
8418 static const char * const keywords
[] =
8432 signal_completer (ignore
, tracker
, text
, word
);
8433 complete_on_enum (tracker
, keywords
, word
, word
);
8437 gdb_signal_from_command (int num
)
8439 if (num
>= 1 && num
<= 15)
8440 return (enum gdb_signal
) num
;
8441 error (_("Only signals 1-15 are valid as numeric signals.\n\
8442 Use \"info signals\" for a list of symbolic signals."));
8445 /* Print current contents of the tables set by the handle command.
8446 It is possible we should just be printing signals actually used
8447 by the current target (but for things to work right when switching
8448 targets, all signals should be in the signal tables). */
8451 info_signals_command (const char *signum_exp
, int from_tty
)
8453 enum gdb_signal oursig
;
8455 sig_print_header ();
8459 /* First see if this is a symbol name. */
8460 oursig
= gdb_signal_from_name (signum_exp
);
8461 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8463 /* No, try numeric. */
8465 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8467 sig_print_info (oursig
);
8471 printf_filtered ("\n");
8472 /* These ugly casts brought to you by the native VAX compiler. */
8473 for (oursig
= GDB_SIGNAL_FIRST
;
8474 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8475 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8479 if (oursig
!= GDB_SIGNAL_UNKNOWN
8480 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8481 sig_print_info (oursig
);
8484 printf_filtered (_("\nUse the \"handle\" command "
8485 "to change these tables.\n"));
8488 /* The $_siginfo convenience variable is a bit special. We don't know
8489 for sure the type of the value until we actually have a chance to
8490 fetch the data. The type can change depending on gdbarch, so it is
8491 also dependent on which thread you have selected.
8493 1. making $_siginfo be an internalvar that creates a new value on
8496 2. making the value of $_siginfo be an lval_computed value. */
8498 /* This function implements the lval_computed support for reading a
8502 siginfo_value_read (struct value
*v
)
8504 LONGEST transferred
;
8506 /* If we can access registers, so can we access $_siginfo. Likewise
8508 validate_registers_access ();
8511 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8513 value_contents_all_raw (v
),
8515 TYPE_LENGTH (value_type (v
)));
8517 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8518 error (_("Unable to read siginfo"));
8521 /* This function implements the lval_computed support for writing a
8525 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8527 LONGEST transferred
;
8529 /* If we can access registers, so can we access $_siginfo. Likewise
8531 validate_registers_access ();
8533 transferred
= target_write (current_top_target (),
8534 TARGET_OBJECT_SIGNAL_INFO
,
8536 value_contents_all_raw (fromval
),
8538 TYPE_LENGTH (value_type (fromval
)));
8540 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8541 error (_("Unable to write siginfo"));
8544 static const struct lval_funcs siginfo_value_funcs
=
8550 /* Return a new value with the correct type for the siginfo object of
8551 the current thread using architecture GDBARCH. Return a void value
8552 if there's no object available. */
8554 static struct value
*
8555 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8558 if (target_has_stack
8559 && inferior_ptid
!= null_ptid
8560 && gdbarch_get_siginfo_type_p (gdbarch
))
8562 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8564 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8567 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8571 /* infcall_suspend_state contains state about the program itself like its
8572 registers and any signal it received when it last stopped.
8573 This state must be restored regardless of how the inferior function call
8574 ends (either successfully, or after it hits a breakpoint or signal)
8575 if the program is to properly continue where it left off. */
8577 class infcall_suspend_state
8580 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8581 once the inferior function call has finished. */
8582 infcall_suspend_state (struct gdbarch
*gdbarch
,
8583 const struct thread_info
*tp
,
8584 struct regcache
*regcache
)
8585 : m_thread_suspend (tp
->suspend
),
8586 m_registers (new readonly_detached_regcache (*regcache
))
8588 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8590 if (gdbarch_get_siginfo_type_p (gdbarch
))
8592 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8593 size_t len
= TYPE_LENGTH (type
);
8595 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8597 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8598 siginfo_data
.get (), 0, len
) != len
)
8600 /* Errors ignored. */
8601 siginfo_data
.reset (nullptr);
8607 m_siginfo_gdbarch
= gdbarch
;
8608 m_siginfo_data
= std::move (siginfo_data
);
8612 /* Return a pointer to the stored register state. */
8614 readonly_detached_regcache
*registers () const
8616 return m_registers
.get ();
8619 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8621 void restore (struct gdbarch
*gdbarch
,
8622 struct thread_info
*tp
,
8623 struct regcache
*regcache
) const
8625 tp
->suspend
= m_thread_suspend
;
8627 if (m_siginfo_gdbarch
== gdbarch
)
8629 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8631 /* Errors ignored. */
8632 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8633 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8636 /* The inferior can be gone if the user types "print exit(0)"
8637 (and perhaps other times). */
8638 if (target_has_execution
)
8639 /* NB: The register write goes through to the target. */
8640 regcache
->restore (registers ());
8644 /* How the current thread stopped before the inferior function call was
8646 struct thread_suspend_state m_thread_suspend
;
8648 /* The registers before the inferior function call was executed. */
8649 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8651 /* Format of SIGINFO_DATA or NULL if it is not present. */
8652 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8654 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8655 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8656 content would be invalid. */
8657 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8660 infcall_suspend_state_up
8661 save_infcall_suspend_state ()
8663 struct thread_info
*tp
= inferior_thread ();
8664 struct regcache
*regcache
= get_current_regcache ();
8665 struct gdbarch
*gdbarch
= regcache
->arch ();
8667 infcall_suspend_state_up inf_state
8668 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8670 /* Having saved the current state, adjust the thread state, discarding
8671 any stop signal information. The stop signal is not useful when
8672 starting an inferior function call, and run_inferior_call will not use
8673 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8674 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8679 /* Restore inferior session state to INF_STATE. */
8682 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8684 struct thread_info
*tp
= inferior_thread ();
8685 struct regcache
*regcache
= get_current_regcache ();
8686 struct gdbarch
*gdbarch
= regcache
->arch ();
8688 inf_state
->restore (gdbarch
, tp
, regcache
);
8689 discard_infcall_suspend_state (inf_state
);
8693 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8698 readonly_detached_regcache
*
8699 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8701 return inf_state
->registers ();
8704 /* infcall_control_state contains state regarding gdb's control of the
8705 inferior itself like stepping control. It also contains session state like
8706 the user's currently selected frame. */
8708 struct infcall_control_state
8710 struct thread_control_state thread_control
;
8711 struct inferior_control_state inferior_control
;
8714 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8715 int stopped_by_random_signal
= 0;
8717 /* ID if the selected frame when the inferior function call was made. */
8718 struct frame_id selected_frame_id
{};
8721 /* Save all of the information associated with the inferior<==>gdb
8724 infcall_control_state_up
8725 save_infcall_control_state ()
8727 infcall_control_state_up
inf_status (new struct infcall_control_state
);
8728 struct thread_info
*tp
= inferior_thread ();
8729 struct inferior
*inf
= current_inferior ();
8731 inf_status
->thread_control
= tp
->control
;
8732 inf_status
->inferior_control
= inf
->control
;
8734 tp
->control
.step_resume_breakpoint
= NULL
;
8735 tp
->control
.exception_resume_breakpoint
= NULL
;
8737 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8738 chain. If caller's caller is walking the chain, they'll be happier if we
8739 hand them back the original chain when restore_infcall_control_state is
8741 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
8744 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
8745 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
8747 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
8753 restore_selected_frame (const frame_id
&fid
)
8755 frame_info
*frame
= frame_find_by_id (fid
);
8757 /* If inf_status->selected_frame_id is NULL, there was no previously
8761 warning (_("Unable to restore previously selected frame."));
8765 select_frame (frame
);
8768 /* Restore inferior session state to INF_STATUS. */
8771 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
8773 struct thread_info
*tp
= inferior_thread ();
8774 struct inferior
*inf
= current_inferior ();
8776 if (tp
->control
.step_resume_breakpoint
)
8777 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
8779 if (tp
->control
.exception_resume_breakpoint
)
8780 tp
->control
.exception_resume_breakpoint
->disposition
8781 = disp_del_at_next_stop
;
8783 /* Handle the bpstat_copy of the chain. */
8784 bpstat_clear (&tp
->control
.stop_bpstat
);
8786 tp
->control
= inf_status
->thread_control
;
8787 inf
->control
= inf_status
->inferior_control
;
8790 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
8791 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
8793 if (target_has_stack
)
8795 /* The point of the try/catch is that if the stack is clobbered,
8796 walking the stack might encounter a garbage pointer and
8797 error() trying to dereference it. */
8800 restore_selected_frame (inf_status
->selected_frame_id
);
8802 catch (const gdb_exception_error
&ex
)
8804 exception_fprintf (gdb_stderr
, ex
,
8805 "Unable to restore previously selected frame:\n");
8806 /* Error in restoring the selected frame. Select the
8808 select_frame (get_current_frame ());
8816 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
8818 if (inf_status
->thread_control
.step_resume_breakpoint
)
8819 inf_status
->thread_control
.step_resume_breakpoint
->disposition
8820 = disp_del_at_next_stop
;
8822 if (inf_status
->thread_control
.exception_resume_breakpoint
)
8823 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
8824 = disp_del_at_next_stop
;
8826 /* See save_infcall_control_state for info on stop_bpstat. */
8827 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
8835 clear_exit_convenience_vars (void)
8837 clear_internalvar (lookup_internalvar ("_exitsignal"));
8838 clear_internalvar (lookup_internalvar ("_exitcode"));
8842 /* User interface for reverse debugging:
8843 Set exec-direction / show exec-direction commands
8844 (returns error unless target implements to_set_exec_direction method). */
8846 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
8847 static const char exec_forward
[] = "forward";
8848 static const char exec_reverse
[] = "reverse";
8849 static const char *exec_direction
= exec_forward
;
8850 static const char *const exec_direction_names
[] = {
8857 set_exec_direction_func (const char *args
, int from_tty
,
8858 struct cmd_list_element
*cmd
)
8860 if (target_can_execute_reverse
)
8862 if (!strcmp (exec_direction
, exec_forward
))
8863 execution_direction
= EXEC_FORWARD
;
8864 else if (!strcmp (exec_direction
, exec_reverse
))
8865 execution_direction
= EXEC_REVERSE
;
8869 exec_direction
= exec_forward
;
8870 error (_("Target does not support this operation."));
8875 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
8876 struct cmd_list_element
*cmd
, const char *value
)
8878 switch (execution_direction
) {
8880 fprintf_filtered (out
, _("Forward.\n"));
8883 fprintf_filtered (out
, _("Reverse.\n"));
8886 internal_error (__FILE__
, __LINE__
,
8887 _("bogus execution_direction value: %d"),
8888 (int) execution_direction
);
8893 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
8894 struct cmd_list_element
*c
, const char *value
)
8896 fprintf_filtered (file
, _("Resuming the execution of threads "
8897 "of all processes is %s.\n"), value
);
8900 /* Implementation of `siginfo' variable. */
8902 static const struct internalvar_funcs siginfo_funcs
=
8909 /* Callback for infrun's target events source. This is marked when a
8910 thread has a pending status to process. */
8913 infrun_async_inferior_event_handler (gdb_client_data data
)
8915 inferior_event_handler (INF_REG_EVENT
, NULL
);
8919 _initialize_infrun (void)
8921 struct cmd_list_element
*c
;
8923 /* Register extra event sources in the event loop. */
8924 infrun_async_inferior_event_token
8925 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
8927 add_info ("signals", info_signals_command
, _("\
8928 What debugger does when program gets various signals.\n\
8929 Specify a signal as argument to print info on that signal only."));
8930 add_info_alias ("handle", "signals", 0);
8932 c
= add_com ("handle", class_run
, handle_command
, _("\
8933 Specify how to handle signals.\n\
8934 Usage: handle SIGNAL [ACTIONS]\n\
8935 Args are signals and actions to apply to those signals.\n\
8936 If no actions are specified, the current settings for the specified signals\n\
8937 will be displayed instead.\n\
8939 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8940 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8941 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8942 The special arg \"all\" is recognized to mean all signals except those\n\
8943 used by the debugger, typically SIGTRAP and SIGINT.\n\
8945 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8946 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8947 Stop means reenter debugger if this signal happens (implies print).\n\
8948 Print means print a message if this signal happens.\n\
8949 Pass means let program see this signal; otherwise program doesn't know.\n\
8950 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8951 Pass and Stop may be combined.\n\
8953 Multiple signals may be specified. Signal numbers and signal names\n\
8954 may be interspersed with actions, with the actions being performed for\n\
8955 all signals cumulatively specified."));
8956 set_cmd_completer (c
, handle_completer
);
8959 stop_command
= add_cmd ("stop", class_obscure
,
8960 not_just_help_class_command
, _("\
8961 There is no `stop' command, but you can set a hook on `stop'.\n\
8962 This allows you to set a list of commands to be run each time execution\n\
8963 of the program stops."), &cmdlist
);
8965 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
8966 Set inferior debugging."), _("\
8967 Show inferior debugging."), _("\
8968 When non-zero, inferior specific debugging is enabled."),
8971 &setdebuglist
, &showdebuglist
);
8973 add_setshow_boolean_cmd ("displaced", class_maintenance
,
8974 &debug_displaced
, _("\
8975 Set displaced stepping debugging."), _("\
8976 Show displaced stepping debugging."), _("\
8977 When non-zero, displaced stepping specific debugging is enabled."),
8979 show_debug_displaced
,
8980 &setdebuglist
, &showdebuglist
);
8982 add_setshow_boolean_cmd ("non-stop", no_class
,
8984 Set whether gdb controls the inferior in non-stop mode."), _("\
8985 Show whether gdb controls the inferior in non-stop mode."), _("\
8986 When debugging a multi-threaded program and this setting is\n\
8987 off (the default, also called all-stop mode), when one thread stops\n\
8988 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
8989 all other threads in the program while you interact with the thread of\n\
8990 interest. When you continue or step a thread, you can allow the other\n\
8991 threads to run, or have them remain stopped, but while you inspect any\n\
8992 thread's state, all threads stop.\n\
8994 In non-stop mode, when one thread stops, other threads can continue\n\
8995 to run freely. You'll be able to step each thread independently,\n\
8996 leave it stopped or free to run as needed."),
9002 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9005 signal_print
[i
] = 1;
9006 signal_program
[i
] = 1;
9007 signal_catch
[i
] = 0;
9010 /* Signals caused by debugger's own actions should not be given to
9011 the program afterwards.
9013 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9014 explicitly specifies that it should be delivered to the target
9015 program. Typically, that would occur when a user is debugging a
9016 target monitor on a simulator: the target monitor sets a
9017 breakpoint; the simulator encounters this breakpoint and halts
9018 the simulation handing control to GDB; GDB, noting that the stop
9019 address doesn't map to any known breakpoint, returns control back
9020 to the simulator; the simulator then delivers the hardware
9021 equivalent of a GDB_SIGNAL_TRAP to the program being
9023 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9024 signal_program
[GDB_SIGNAL_INT
] = 0;
9026 /* Signals that are not errors should not normally enter the debugger. */
9027 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9028 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9029 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9030 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9031 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9032 signal_print
[GDB_SIGNAL_PROF
] = 0;
9033 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9034 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9035 signal_stop
[GDB_SIGNAL_IO
] = 0;
9036 signal_print
[GDB_SIGNAL_IO
] = 0;
9037 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9038 signal_print
[GDB_SIGNAL_POLL
] = 0;
9039 signal_stop
[GDB_SIGNAL_URG
] = 0;
9040 signal_print
[GDB_SIGNAL_URG
] = 0;
9041 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9042 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9043 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9044 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9046 /* These signals are used internally by user-level thread
9047 implementations. (See signal(5) on Solaris.) Like the above
9048 signals, a healthy program receives and handles them as part of
9049 its normal operation. */
9050 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9051 signal_print
[GDB_SIGNAL_LWP
] = 0;
9052 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9053 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9054 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9055 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9056 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9057 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9059 /* Update cached state. */
9060 signal_cache_update (-1);
9062 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9063 &stop_on_solib_events
, _("\
9064 Set stopping for shared library events."), _("\
9065 Show stopping for shared library events."), _("\
9066 If nonzero, gdb will give control to the user when the dynamic linker\n\
9067 notifies gdb of shared library events. The most common event of interest\n\
9068 to the user would be loading/unloading of a new library."),
9069 set_stop_on_solib_events
,
9070 show_stop_on_solib_events
,
9071 &setlist
, &showlist
);
9073 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9074 follow_fork_mode_kind_names
,
9075 &follow_fork_mode_string
, _("\
9076 Set debugger response to a program call of fork or vfork."), _("\
9077 Show debugger response to a program call of fork or vfork."), _("\
9078 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9079 parent - the original process is debugged after a fork\n\
9080 child - the new process is debugged after a fork\n\
9081 The unfollowed process will continue to run.\n\
9082 By default, the debugger will follow the parent process."),
9084 show_follow_fork_mode_string
,
9085 &setlist
, &showlist
);
9087 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9088 follow_exec_mode_names
,
9089 &follow_exec_mode_string
, _("\
9090 Set debugger response to a program call of exec."), _("\
9091 Show debugger response to a program call of exec."), _("\
9092 An exec call replaces the program image of a process.\n\
9094 follow-exec-mode can be:\n\
9096 new - the debugger creates a new inferior and rebinds the process\n\
9097 to this new inferior. The program the process was running before\n\
9098 the exec call can be restarted afterwards by restarting the original\n\
9101 same - the debugger keeps the process bound to the same inferior.\n\
9102 The new executable image replaces the previous executable loaded in\n\
9103 the inferior. Restarting the inferior after the exec call restarts\n\
9104 the executable the process was running after the exec call.\n\
9106 By default, the debugger will use the same inferior."),
9108 show_follow_exec_mode_string
,
9109 &setlist
, &showlist
);
9111 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9112 scheduler_enums
, &scheduler_mode
, _("\
9113 Set mode for locking scheduler during execution."), _("\
9114 Show mode for locking scheduler during execution."), _("\
9115 off == no locking (threads may preempt at any time)\n\
9116 on == full locking (no thread except the current thread may run)\n\
9117 This applies to both normal execution and replay mode.\n\
9118 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9119 In this mode, other threads may run during other commands.\n\
9120 This applies to both normal execution and replay mode.\n\
9121 replay == scheduler locked in replay mode and unlocked during normal execution."),
9122 set_schedlock_func
, /* traps on target vector */
9123 show_scheduler_mode
,
9124 &setlist
, &showlist
);
9126 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9127 Set mode for resuming threads of all processes."), _("\
9128 Show mode for resuming threads of all processes."), _("\
9129 When on, execution commands (such as 'continue' or 'next') resume all\n\
9130 threads of all processes. When off (which is the default), execution\n\
9131 commands only resume the threads of the current process. The set of\n\
9132 threads that are resumed is further refined by the scheduler-locking\n\
9133 mode (see help set scheduler-locking)."),
9135 show_schedule_multiple
,
9136 &setlist
, &showlist
);
9138 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9139 Set mode of the step operation."), _("\
9140 Show mode of the step operation."), _("\
9141 When set, doing a step over a function without debug line information\n\
9142 will stop at the first instruction of that function. Otherwise, the\n\
9143 function is skipped and the step command stops at a different source line."),
9145 show_step_stop_if_no_debug
,
9146 &setlist
, &showlist
);
9148 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9149 &can_use_displaced_stepping
, _("\
9150 Set debugger's willingness to use displaced stepping."), _("\
9151 Show debugger's willingness to use displaced stepping."), _("\
9152 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9153 supported by the target architecture. If off, gdb will not use displaced\n\
9154 stepping to step over breakpoints, even if such is supported by the target\n\
9155 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9156 if the target architecture supports it and non-stop mode is active, but will not\n\
9157 use it in all-stop mode (see help set non-stop)."),
9159 show_can_use_displaced_stepping
,
9160 &setlist
, &showlist
);
9162 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9163 &exec_direction
, _("Set direction of execution.\n\
9164 Options are 'forward' or 'reverse'."),
9165 _("Show direction of execution (forward/reverse)."),
9166 _("Tells gdb whether to execute forward or backward."),
9167 set_exec_direction_func
, show_exec_direction_func
,
9168 &setlist
, &showlist
);
9170 /* Set/show detach-on-fork: user-settable mode. */
9172 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9173 Set whether gdb will detach the child of a fork."), _("\
9174 Show whether gdb will detach the child of a fork."), _("\
9175 Tells gdb whether to detach the child of a fork."),
9176 NULL
, NULL
, &setlist
, &showlist
);
9178 /* Set/show disable address space randomization mode. */
9180 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9181 &disable_randomization
, _("\
9182 Set disabling of debuggee's virtual address space randomization."), _("\
9183 Show disabling of debuggee's virtual address space randomization."), _("\
9184 When this mode is on (which is the default), randomization of the virtual\n\
9185 address space is disabled. Standalone programs run with the randomization\n\
9186 enabled by default on some platforms."),
9187 &set_disable_randomization
,
9188 &show_disable_randomization
,
9189 &setlist
, &showlist
);
9191 /* ptid initializations */
9192 inferior_ptid
= null_ptid
;
9193 target_last_wait_ptid
= minus_one_ptid
;
9195 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9196 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9197 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9198 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9200 /* Explicitly create without lookup, since that tries to create a
9201 value with a void typed value, and when we get here, gdbarch
9202 isn't initialized yet. At this point, we're quite sure there
9203 isn't another convenience variable of the same name. */
9204 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9206 add_setshow_boolean_cmd ("observer", no_class
,
9207 &observer_mode_1
, _("\
9208 Set whether gdb controls the inferior in observer mode."), _("\
9209 Show whether gdb controls the inferior in observer mode."), _("\
9210 In observer mode, GDB can get data from the inferior, but not\n\
9211 affect its execution. Registers and memory may not be changed,\n\
9212 breakpoints may not be set, and the program cannot be interrupted\n\