1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2019 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "cli/cli-script.h"
33 #include "gdbthread.h"
41 #include "observable.h"
45 #include "dictionary.h"
47 #include "mi/mi-common.h"
48 #include "event-top.h"
50 #include "record-full.h"
51 #include "inline-frame.h"
53 #include "tracepoint.h"
54 #include "continuations.h"
59 #include "completer.h"
60 #include "target-descriptions.h"
61 #include "target-dcache.h"
64 #include "event-loop.h"
65 #include "thread-fsm.h"
66 #include "common/enum-flags.h"
67 #include "progspace-and-thread.h"
68 #include "common/gdb_optional.h"
69 #include "arch-utils.h"
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal
);
75 static void sig_print_header (void);
77 static int follow_fork (void);
79 static int follow_fork_inferior (int follow_child
, int detach_fork
);
81 static void follow_inferior_reset_breakpoints (void);
83 static int currently_stepping (struct thread_info
*tp
);
85 void nullify_last_target_wait_ptid (void);
87 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
89 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
91 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
93 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
95 static void resume (gdb_signal sig
);
97 /* Asynchronous signal handler registered as event loop source for
98 when we have pending events ready to be passed to the core. */
99 static struct async_event_handler
*infrun_async_inferior_event_token
;
101 /* Stores whether infrun_async was previously enabled or disabled.
102 Starts off as -1, indicating "never enabled/disabled". */
103 static int infrun_is_async
= -1;
108 infrun_async (int enable
)
110 if (infrun_is_async
!= enable
)
112 infrun_is_async
= enable
;
115 fprintf_unfiltered (gdb_stdlog
,
116 "infrun: infrun_async(%d)\n",
120 mark_async_event_handler (infrun_async_inferior_event_token
);
122 clear_async_event_handler (infrun_async_inferior_event_token
);
129 mark_infrun_async_event_handler (void)
131 mark_async_event_handler (infrun_async_inferior_event_token
);
134 /* When set, stop the 'step' command if we enter a function which has
135 no line number information. The normal behavior is that we step
136 over such function. */
137 int step_stop_if_no_debug
= 0;
139 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
140 struct cmd_list_element
*c
, const char *value
)
142 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
145 /* proceed and normal_stop use this to notify the user when the
146 inferior stopped in a different thread than it had been running
149 static ptid_t previous_inferior_ptid
;
151 /* If set (default for legacy reasons), when following a fork, GDB
152 will detach from one of the fork branches, child or parent.
153 Exactly which branch is detached depends on 'set follow-fork-mode'
156 static int detach_fork
= 1;
158 int debug_displaced
= 0;
160 show_debug_displaced (struct ui_file
*file
, int from_tty
,
161 struct cmd_list_element
*c
, const char *value
)
163 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
166 unsigned int debug_infrun
= 0;
168 show_debug_infrun (struct ui_file
*file
, int from_tty
,
169 struct cmd_list_element
*c
, const char *value
)
171 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
175 /* Support for disabling address space randomization. */
177 int disable_randomization
= 1;
180 show_disable_randomization (struct ui_file
*file
, int from_tty
,
181 struct cmd_list_element
*c
, const char *value
)
183 if (target_supports_disable_randomization ())
184 fprintf_filtered (file
,
185 _("Disabling randomization of debuggee's "
186 "virtual address space is %s.\n"),
189 fputs_filtered (_("Disabling randomization of debuggee's "
190 "virtual address space is unsupported on\n"
191 "this platform.\n"), file
);
195 set_disable_randomization (const char *args
, int from_tty
,
196 struct cmd_list_element
*c
)
198 if (!target_supports_disable_randomization ())
199 error (_("Disabling randomization of debuggee's "
200 "virtual address space is unsupported on\n"
204 /* User interface for non-stop mode. */
207 static int non_stop_1
= 0;
210 set_non_stop (const char *args
, int from_tty
,
211 struct cmd_list_element
*c
)
213 if (target_has_execution
)
215 non_stop_1
= non_stop
;
216 error (_("Cannot change this setting while the inferior is running."));
219 non_stop
= non_stop_1
;
223 show_non_stop (struct ui_file
*file
, int from_tty
,
224 struct cmd_list_element
*c
, const char *value
)
226 fprintf_filtered (file
,
227 _("Controlling the inferior in non-stop mode is %s.\n"),
231 /* "Observer mode" is somewhat like a more extreme version of
232 non-stop, in which all GDB operations that might affect the
233 target's execution have been disabled. */
235 int observer_mode
= 0;
236 static int observer_mode_1
= 0;
239 set_observer_mode (const char *args
, int from_tty
,
240 struct cmd_list_element
*c
)
242 if (target_has_execution
)
244 observer_mode_1
= observer_mode
;
245 error (_("Cannot change this setting while the inferior is running."));
248 observer_mode
= observer_mode_1
;
250 may_write_registers
= !observer_mode
;
251 may_write_memory
= !observer_mode
;
252 may_insert_breakpoints
= !observer_mode
;
253 may_insert_tracepoints
= !observer_mode
;
254 /* We can insert fast tracepoints in or out of observer mode,
255 but enable them if we're going into this mode. */
257 may_insert_fast_tracepoints
= 1;
258 may_stop
= !observer_mode
;
259 update_target_permissions ();
261 /* Going *into* observer mode we must force non-stop, then
262 going out we leave it that way. */
265 pagination_enabled
= 0;
266 non_stop
= non_stop_1
= 1;
270 printf_filtered (_("Observer mode is now %s.\n"),
271 (observer_mode
? "on" : "off"));
275 show_observer_mode (struct ui_file
*file
, int from_tty
,
276 struct cmd_list_element
*c
, const char *value
)
278 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
281 /* This updates the value of observer mode based on changes in
282 permissions. Note that we are deliberately ignoring the values of
283 may-write-registers and may-write-memory, since the user may have
284 reason to enable these during a session, for instance to turn on a
285 debugging-related global. */
288 update_observer_mode (void)
292 newval
= (!may_insert_breakpoints
293 && !may_insert_tracepoints
294 && may_insert_fast_tracepoints
298 /* Let the user know if things change. */
299 if (newval
!= observer_mode
)
300 printf_filtered (_("Observer mode is now %s.\n"),
301 (newval
? "on" : "off"));
303 observer_mode
= observer_mode_1
= newval
;
306 /* Tables of how to react to signals; the user sets them. */
308 static unsigned char *signal_stop
;
309 static unsigned char *signal_print
;
310 static unsigned char *signal_program
;
312 /* Table of signals that are registered with "catch signal". A
313 non-zero entry indicates that the signal is caught by some "catch
314 signal" command. This has size GDB_SIGNAL_LAST, to accommodate all
316 static unsigned char *signal_catch
;
318 /* Table of signals that the target may silently handle.
319 This is automatically determined from the flags above,
320 and simply cached here. */
321 static unsigned char *signal_pass
;
323 #define SET_SIGS(nsigs,sigs,flags) \
325 int signum = (nsigs); \
326 while (signum-- > 0) \
327 if ((sigs)[signum]) \
328 (flags)[signum] = 1; \
331 #define UNSET_SIGS(nsigs,sigs,flags) \
333 int signum = (nsigs); \
334 while (signum-- > 0) \
335 if ((sigs)[signum]) \
336 (flags)[signum] = 0; \
339 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
340 this function is to avoid exporting `signal_program'. */
343 update_signals_program_target (void)
345 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
348 /* Value to pass to target_resume() to cause all threads to resume. */
350 #define RESUME_ALL minus_one_ptid
352 /* Command list pointer for the "stop" placeholder. */
354 static struct cmd_list_element
*stop_command
;
356 /* Nonzero if we want to give control to the user when we're notified
357 of shared library events by the dynamic linker. */
358 int stop_on_solib_events
;
360 /* Enable or disable optional shared library event breakpoints
361 as appropriate when the above flag is changed. */
364 set_stop_on_solib_events (const char *args
,
365 int from_tty
, struct cmd_list_element
*c
)
367 update_solib_breakpoints ();
371 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
372 struct cmd_list_element
*c
, const char *value
)
374 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
378 /* Nonzero after stop if current stack frame should be printed. */
380 static int stop_print_frame
;
382 /* This is a cached copy of the pid/waitstatus of the last event
383 returned by target_wait()/deprecated_target_wait_hook(). This
384 information is returned by get_last_target_status(). */
385 static ptid_t target_last_wait_ptid
;
386 static struct target_waitstatus target_last_waitstatus
;
388 void init_thread_stepping_state (struct thread_info
*tss
);
390 static const char follow_fork_mode_child
[] = "child";
391 static const char follow_fork_mode_parent
[] = "parent";
393 static const char *const follow_fork_mode_kind_names
[] = {
394 follow_fork_mode_child
,
395 follow_fork_mode_parent
,
399 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
401 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
402 struct cmd_list_element
*c
, const char *value
)
404 fprintf_filtered (file
,
405 _("Debugger response to a program "
406 "call of fork or vfork is \"%s\".\n"),
411 /* Handle changes to the inferior list based on the type of fork,
412 which process is being followed, and whether the other process
413 should be detached. On entry inferior_ptid must be the ptid of
414 the fork parent. At return inferior_ptid is the ptid of the
415 followed inferior. */
418 follow_fork_inferior (int follow_child
, int detach_fork
)
421 ptid_t parent_ptid
, child_ptid
;
423 has_vforked
= (inferior_thread ()->pending_follow
.kind
424 == TARGET_WAITKIND_VFORKED
);
425 parent_ptid
= inferior_ptid
;
426 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
429 && !non_stop
/* Non-stop always resumes both branches. */
430 && current_ui
->prompt_state
== PROMPT_BLOCKED
431 && !(follow_child
|| detach_fork
|| sched_multi
))
433 /* The parent stays blocked inside the vfork syscall until the
434 child execs or exits. If we don't let the child run, then
435 the parent stays blocked. If we're telling the parent to run
436 in the foreground, the user will not be able to ctrl-c to get
437 back the terminal, effectively hanging the debug session. */
438 fprintf_filtered (gdb_stderr
, _("\
439 Can not resume the parent process over vfork in the foreground while\n\
440 holding the child stopped. Try \"set detach-on-fork\" or \
441 \"set schedule-multiple\".\n"));
442 /* FIXME output string > 80 columns. */
448 /* Detach new forked process? */
451 /* Before detaching from the child, remove all breakpoints
452 from it. If we forked, then this has already been taken
453 care of by infrun.c. If we vforked however, any
454 breakpoint inserted in the parent is visible in the
455 child, even those added while stopped in a vfork
456 catchpoint. This will remove the breakpoints from the
457 parent also, but they'll be reinserted below. */
460 /* Keep breakpoints list in sync. */
461 remove_breakpoints_inf (current_inferior ());
464 if (print_inferior_events
)
466 /* Ensure that we have a process ptid. */
467 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
469 target_terminal::ours_for_output ();
470 fprintf_filtered (gdb_stdlog
,
471 _("[Detaching after %s from child %s]\n"),
472 has_vforked
? "vfork" : "fork",
473 target_pid_to_str (process_ptid
));
478 struct inferior
*parent_inf
, *child_inf
;
480 /* Add process to GDB's tables. */
481 child_inf
= add_inferior (child_ptid
.pid ());
483 parent_inf
= current_inferior ();
484 child_inf
->attach_flag
= parent_inf
->attach_flag
;
485 copy_terminal_info (child_inf
, parent_inf
);
486 child_inf
->gdbarch
= parent_inf
->gdbarch
;
487 copy_inferior_target_desc_info (child_inf
, parent_inf
);
489 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
491 inferior_ptid
= child_ptid
;
492 add_thread_silent (inferior_ptid
);
493 set_current_inferior (child_inf
);
494 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
496 /* If this is a vfork child, then the address-space is
497 shared with the parent. */
500 child_inf
->pspace
= parent_inf
->pspace
;
501 child_inf
->aspace
= parent_inf
->aspace
;
503 /* The parent will be frozen until the child is done
504 with the shared region. Keep track of the
506 child_inf
->vfork_parent
= parent_inf
;
507 child_inf
->pending_detach
= 0;
508 parent_inf
->vfork_child
= child_inf
;
509 parent_inf
->pending_detach
= 0;
513 child_inf
->aspace
= new_address_space ();
514 child_inf
->pspace
= new program_space (child_inf
->aspace
);
515 child_inf
->removable
= 1;
516 set_current_program_space (child_inf
->pspace
);
517 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
519 /* Let the shared library layer (e.g., solib-svr4) learn
520 about this new process, relocate the cloned exec, pull
521 in shared libraries, and install the solib event
522 breakpoint. If a "cloned-VM" event was propagated
523 better throughout the core, this wouldn't be
525 solib_create_inferior_hook (0);
531 struct inferior
*parent_inf
;
533 parent_inf
= current_inferior ();
535 /* If we detached from the child, then we have to be careful
536 to not insert breakpoints in the parent until the child
537 is done with the shared memory region. However, if we're
538 staying attached to the child, then we can and should
539 insert breakpoints, so that we can debug it. A
540 subsequent child exec or exit is enough to know when does
541 the child stops using the parent's address space. */
542 parent_inf
->waiting_for_vfork_done
= detach_fork
;
543 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
548 /* Follow the child. */
549 struct inferior
*parent_inf
, *child_inf
;
550 struct program_space
*parent_pspace
;
552 if (print_inferior_events
)
554 std::string parent_pid
= target_pid_to_str (parent_ptid
);
555 std::string child_pid
= target_pid_to_str (child_ptid
);
557 target_terminal::ours_for_output ();
558 fprintf_filtered (gdb_stdlog
,
559 _("[Attaching after %s %s to child %s]\n"),
561 has_vforked
? "vfork" : "fork",
565 /* Add the new inferior first, so that the target_detach below
566 doesn't unpush the target. */
568 child_inf
= add_inferior (child_ptid
.pid ());
570 parent_inf
= current_inferior ();
571 child_inf
->attach_flag
= parent_inf
->attach_flag
;
572 copy_terminal_info (child_inf
, parent_inf
);
573 child_inf
->gdbarch
= parent_inf
->gdbarch
;
574 copy_inferior_target_desc_info (child_inf
, parent_inf
);
576 parent_pspace
= parent_inf
->pspace
;
578 /* If we're vforking, we want to hold on to the parent until the
579 child exits or execs. At child exec or exit time we can
580 remove the old breakpoints from the parent and detach or
581 resume debugging it. Otherwise, detach the parent now; we'll
582 want to reuse it's program/address spaces, but we can't set
583 them to the child before removing breakpoints from the
584 parent, otherwise, the breakpoints module could decide to
585 remove breakpoints from the wrong process (since they'd be
586 assigned to the same address space). */
590 gdb_assert (child_inf
->vfork_parent
== NULL
);
591 gdb_assert (parent_inf
->vfork_child
== NULL
);
592 child_inf
->vfork_parent
= parent_inf
;
593 child_inf
->pending_detach
= 0;
594 parent_inf
->vfork_child
= child_inf
;
595 parent_inf
->pending_detach
= detach_fork
;
596 parent_inf
->waiting_for_vfork_done
= 0;
598 else if (detach_fork
)
600 if (print_inferior_events
)
602 /* Ensure that we have a process ptid. */
603 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
605 target_terminal::ours_for_output ();
606 fprintf_filtered (gdb_stdlog
,
607 _("[Detaching after fork from "
609 target_pid_to_str (process_ptid
));
612 target_detach (parent_inf
, 0);
615 /* Note that the detach above makes PARENT_INF dangling. */
617 /* Add the child thread to the appropriate lists, and switch to
618 this new thread, before cloning the program space, and
619 informing the solib layer about this new process. */
621 inferior_ptid
= child_ptid
;
622 add_thread_silent (inferior_ptid
);
623 set_current_inferior (child_inf
);
625 /* If this is a vfork child, then the address-space is shared
626 with the parent. If we detached from the parent, then we can
627 reuse the parent's program/address spaces. */
628 if (has_vforked
|| detach_fork
)
630 child_inf
->pspace
= parent_pspace
;
631 child_inf
->aspace
= child_inf
->pspace
->aspace
;
635 child_inf
->aspace
= new_address_space ();
636 child_inf
->pspace
= new program_space (child_inf
->aspace
);
637 child_inf
->removable
= 1;
638 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
639 set_current_program_space (child_inf
->pspace
);
640 clone_program_space (child_inf
->pspace
, parent_pspace
);
642 /* Let the shared library layer (e.g., solib-svr4) learn
643 about this new process, relocate the cloned exec, pull in
644 shared libraries, and install the solib event breakpoint.
645 If a "cloned-VM" event was propagated better throughout
646 the core, this wouldn't be required. */
647 solib_create_inferior_hook (0);
651 return target_follow_fork (follow_child
, detach_fork
);
654 /* Tell the target to follow the fork we're stopped at. Returns true
655 if the inferior should be resumed; false, if the target for some
656 reason decided it's best not to resume. */
661 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
662 int should_resume
= 1;
663 struct thread_info
*tp
;
665 /* Copy user stepping state to the new inferior thread. FIXME: the
666 followed fork child thread should have a copy of most of the
667 parent thread structure's run control related fields, not just these.
668 Initialized to avoid "may be used uninitialized" warnings from gcc. */
669 struct breakpoint
*step_resume_breakpoint
= NULL
;
670 struct breakpoint
*exception_resume_breakpoint
= NULL
;
671 CORE_ADDR step_range_start
= 0;
672 CORE_ADDR step_range_end
= 0;
673 struct frame_id step_frame_id
= { 0 };
674 struct thread_fsm
*thread_fsm
= NULL
;
679 struct target_waitstatus wait_status
;
681 /* Get the last target status returned by target_wait(). */
682 get_last_target_status (&wait_ptid
, &wait_status
);
684 /* If not stopped at a fork event, then there's nothing else to
686 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
687 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
690 /* Check if we switched over from WAIT_PTID, since the event was
692 if (wait_ptid
!= minus_one_ptid
693 && inferior_ptid
!= wait_ptid
)
695 /* We did. Switch back to WAIT_PTID thread, to tell the
696 target to follow it (in either direction). We'll
697 afterwards refuse to resume, and inform the user what
699 thread_info
*wait_thread
700 = find_thread_ptid (wait_ptid
);
701 switch_to_thread (wait_thread
);
706 tp
= inferior_thread ();
708 /* If there were any forks/vforks that were caught and are now to be
709 followed, then do so now. */
710 switch (tp
->pending_follow
.kind
)
712 case TARGET_WAITKIND_FORKED
:
713 case TARGET_WAITKIND_VFORKED
:
715 ptid_t parent
, child
;
717 /* If the user did a next/step, etc, over a fork call,
718 preserve the stepping state in the fork child. */
719 if (follow_child
&& should_resume
)
721 step_resume_breakpoint
= clone_momentary_breakpoint
722 (tp
->control
.step_resume_breakpoint
);
723 step_range_start
= tp
->control
.step_range_start
;
724 step_range_end
= tp
->control
.step_range_end
;
725 step_frame_id
= tp
->control
.step_frame_id
;
726 exception_resume_breakpoint
727 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
728 thread_fsm
= tp
->thread_fsm
;
730 /* For now, delete the parent's sr breakpoint, otherwise,
731 parent/child sr breakpoints are considered duplicates,
732 and the child version will not be installed. Remove
733 this when the breakpoints module becomes aware of
734 inferiors and address spaces. */
735 delete_step_resume_breakpoint (tp
);
736 tp
->control
.step_range_start
= 0;
737 tp
->control
.step_range_end
= 0;
738 tp
->control
.step_frame_id
= null_frame_id
;
739 delete_exception_resume_breakpoint (tp
);
740 tp
->thread_fsm
= NULL
;
743 parent
= inferior_ptid
;
744 child
= tp
->pending_follow
.value
.related_pid
;
746 /* Set up inferior(s) as specified by the caller, and tell the
747 target to do whatever is necessary to follow either parent
749 if (follow_fork_inferior (follow_child
, detach_fork
))
751 /* Target refused to follow, or there's some other reason
752 we shouldn't resume. */
757 /* This pending follow fork event is now handled, one way
758 or another. The previous selected thread may be gone
759 from the lists by now, but if it is still around, need
760 to clear the pending follow request. */
761 tp
= find_thread_ptid (parent
);
763 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
765 /* This makes sure we don't try to apply the "Switched
766 over from WAIT_PID" logic above. */
767 nullify_last_target_wait_ptid ();
769 /* If we followed the child, switch to it... */
772 thread_info
*child_thr
= find_thread_ptid (child
);
773 switch_to_thread (child_thr
);
775 /* ... and preserve the stepping state, in case the
776 user was stepping over the fork call. */
779 tp
= inferior_thread ();
780 tp
->control
.step_resume_breakpoint
781 = step_resume_breakpoint
;
782 tp
->control
.step_range_start
= step_range_start
;
783 tp
->control
.step_range_end
= step_range_end
;
784 tp
->control
.step_frame_id
= step_frame_id
;
785 tp
->control
.exception_resume_breakpoint
786 = exception_resume_breakpoint
;
787 tp
->thread_fsm
= thread_fsm
;
791 /* If we get here, it was because we're trying to
792 resume from a fork catchpoint, but, the user
793 has switched threads away from the thread that
794 forked. In that case, the resume command
795 issued is most likely not applicable to the
796 child, so just warn, and refuse to resume. */
797 warning (_("Not resuming: switched threads "
798 "before following fork child."));
801 /* Reset breakpoints in the child as appropriate. */
802 follow_inferior_reset_breakpoints ();
807 case TARGET_WAITKIND_SPURIOUS
:
808 /* Nothing to follow. */
811 internal_error (__FILE__
, __LINE__
,
812 "Unexpected pending_follow.kind %d\n",
813 tp
->pending_follow
.kind
);
817 return should_resume
;
821 follow_inferior_reset_breakpoints (void)
823 struct thread_info
*tp
= inferior_thread ();
825 /* Was there a step_resume breakpoint? (There was if the user
826 did a "next" at the fork() call.) If so, explicitly reset its
827 thread number. Cloned step_resume breakpoints are disabled on
828 creation, so enable it here now that it is associated with the
831 step_resumes are a form of bp that are made to be per-thread.
832 Since we created the step_resume bp when the parent process
833 was being debugged, and now are switching to the child process,
834 from the breakpoint package's viewpoint, that's a switch of
835 "threads". We must update the bp's notion of which thread
836 it is for, or it'll be ignored when it triggers. */
838 if (tp
->control
.step_resume_breakpoint
)
840 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
841 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
844 /* Treat exception_resume breakpoints like step_resume breakpoints. */
845 if (tp
->control
.exception_resume_breakpoint
)
847 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
848 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
851 /* Reinsert all breakpoints in the child. The user may have set
852 breakpoints after catching the fork, in which case those
853 were never set in the child, but only in the parent. This makes
854 sure the inserted breakpoints match the breakpoint list. */
856 breakpoint_re_set ();
857 insert_breakpoints ();
860 /* The child has exited or execed: resume threads of the parent the
861 user wanted to be executing. */
864 proceed_after_vfork_done (struct thread_info
*thread
,
867 int pid
= * (int *) arg
;
869 if (thread
->ptid
.pid () == pid
870 && thread
->state
== THREAD_RUNNING
871 && !thread
->executing
872 && !thread
->stop_requested
873 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
876 fprintf_unfiltered (gdb_stdlog
,
877 "infrun: resuming vfork parent thread %s\n",
878 target_pid_to_str (thread
->ptid
));
880 switch_to_thread (thread
);
881 clear_proceed_status (0);
882 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
888 /* Save/restore inferior_ptid, current program space and current
889 inferior. Only use this if the current context points at an exited
890 inferior (and therefore there's no current thread to save). */
891 class scoped_restore_exited_inferior
894 scoped_restore_exited_inferior ()
895 : m_saved_ptid (&inferior_ptid
)
899 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
900 scoped_restore_current_program_space m_pspace
;
901 scoped_restore_current_inferior m_inferior
;
904 /* Called whenever we notice an exec or exit event, to handle
905 detaching or resuming a vfork parent. */
908 handle_vfork_child_exec_or_exit (int exec
)
910 struct inferior
*inf
= current_inferior ();
912 if (inf
->vfork_parent
)
914 int resume_parent
= -1;
916 /* This exec or exit marks the end of the shared memory region
917 between the parent and the child. If the user wanted to
918 detach from the parent, now is the time. */
920 if (inf
->vfork_parent
->pending_detach
)
922 struct thread_info
*tp
;
923 struct program_space
*pspace
;
924 struct address_space
*aspace
;
926 /* follow-fork child, detach-on-fork on. */
928 inf
->vfork_parent
->pending_detach
= 0;
930 gdb::optional
<scoped_restore_exited_inferior
>
931 maybe_restore_inferior
;
932 gdb::optional
<scoped_restore_current_pspace_and_thread
>
933 maybe_restore_thread
;
935 /* If we're handling a child exit, then inferior_ptid points
936 at the inferior's pid, not to a thread. */
938 maybe_restore_inferior
.emplace ();
940 maybe_restore_thread
.emplace ();
942 /* We're letting loose of the parent. */
943 tp
= any_live_thread_of_inferior (inf
->vfork_parent
);
944 switch_to_thread (tp
);
946 /* We're about to detach from the parent, which implicitly
947 removes breakpoints from its address space. There's a
948 catch here: we want to reuse the spaces for the child,
949 but, parent/child are still sharing the pspace at this
950 point, although the exec in reality makes the kernel give
951 the child a fresh set of new pages. The problem here is
952 that the breakpoints module being unaware of this, would
953 likely chose the child process to write to the parent
954 address space. Swapping the child temporarily away from
955 the spaces has the desired effect. Yes, this is "sort
958 pspace
= inf
->pspace
;
959 aspace
= inf
->aspace
;
963 if (print_inferior_events
)
966 = target_pid_to_str (ptid_t (inf
->vfork_parent
->pid
));
968 target_terminal::ours_for_output ();
972 fprintf_filtered (gdb_stdlog
,
973 _("[Detaching vfork parent %s "
974 "after child exec]\n"), pidstr
);
978 fprintf_filtered (gdb_stdlog
,
979 _("[Detaching vfork parent %s "
980 "after child exit]\n"), pidstr
);
984 target_detach (inf
->vfork_parent
, 0);
987 inf
->pspace
= pspace
;
988 inf
->aspace
= aspace
;
992 /* We're staying attached to the parent, so, really give the
993 child a new address space. */
994 inf
->pspace
= new program_space (maybe_new_address_space ());
995 inf
->aspace
= inf
->pspace
->aspace
;
997 set_current_program_space (inf
->pspace
);
999 resume_parent
= inf
->vfork_parent
->pid
;
1001 /* Break the bonds. */
1002 inf
->vfork_parent
->vfork_child
= NULL
;
1006 struct program_space
*pspace
;
1008 /* If this is a vfork child exiting, then the pspace and
1009 aspaces were shared with the parent. Since we're
1010 reporting the process exit, we'll be mourning all that is
1011 found in the address space, and switching to null_ptid,
1012 preparing to start a new inferior. But, since we don't
1013 want to clobber the parent's address/program spaces, we
1014 go ahead and create a new one for this exiting
1017 /* Switch to null_ptid while running clone_program_space, so
1018 that clone_program_space doesn't want to read the
1019 selected frame of a dead process. */
1020 scoped_restore restore_ptid
1021 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1023 /* This inferior is dead, so avoid giving the breakpoints
1024 module the option to write through to it (cloning a
1025 program space resets breakpoints). */
1028 pspace
= new program_space (maybe_new_address_space ());
1029 set_current_program_space (pspace
);
1031 inf
->symfile_flags
= SYMFILE_NO_READ
;
1032 clone_program_space (pspace
, inf
->vfork_parent
->pspace
);
1033 inf
->pspace
= pspace
;
1034 inf
->aspace
= pspace
->aspace
;
1036 resume_parent
= inf
->vfork_parent
->pid
;
1037 /* Break the bonds. */
1038 inf
->vfork_parent
->vfork_child
= NULL
;
1041 inf
->vfork_parent
= NULL
;
1043 gdb_assert (current_program_space
== inf
->pspace
);
1045 if (non_stop
&& resume_parent
!= -1)
1047 /* If the user wanted the parent to be running, let it go
1049 scoped_restore_current_thread restore_thread
;
1052 fprintf_unfiltered (gdb_stdlog
,
1053 "infrun: resuming vfork parent process %d\n",
1056 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1061 /* Enum strings for "set|show follow-exec-mode". */
1063 static const char follow_exec_mode_new
[] = "new";
1064 static const char follow_exec_mode_same
[] = "same";
1065 static const char *const follow_exec_mode_names
[] =
1067 follow_exec_mode_new
,
1068 follow_exec_mode_same
,
1072 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1074 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1075 struct cmd_list_element
*c
, const char *value
)
1077 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1080 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1083 follow_exec (ptid_t ptid
, char *exec_file_target
)
1085 struct inferior
*inf
= current_inferior ();
1086 int pid
= ptid
.pid ();
1087 ptid_t process_ptid
;
1089 /* This is an exec event that we actually wish to pay attention to.
1090 Refresh our symbol table to the newly exec'd program, remove any
1091 momentary bp's, etc.
1093 If there are breakpoints, they aren't really inserted now,
1094 since the exec() transformed our inferior into a fresh set
1097 We want to preserve symbolic breakpoints on the list, since
1098 we have hopes that they can be reset after the new a.out's
1099 symbol table is read.
1101 However, any "raw" breakpoints must be removed from the list
1102 (e.g., the solib bp's), since their address is probably invalid
1105 And, we DON'T want to call delete_breakpoints() here, since
1106 that may write the bp's "shadow contents" (the instruction
1107 value that was overwritten witha TRAP instruction). Since
1108 we now have a new a.out, those shadow contents aren't valid. */
1110 mark_breakpoints_out ();
1112 /* The target reports the exec event to the main thread, even if
1113 some other thread does the exec, and even if the main thread was
1114 stopped or already gone. We may still have non-leader threads of
1115 the process on our list. E.g., on targets that don't have thread
1116 exit events (like remote); or on native Linux in non-stop mode if
1117 there were only two threads in the inferior and the non-leader
1118 one is the one that execs (and nothing forces an update of the
1119 thread list up to here). When debugging remotely, it's best to
1120 avoid extra traffic, when possible, so avoid syncing the thread
1121 list with the target, and instead go ahead and delete all threads
1122 of the process but one that reported the event. Note this must
1123 be done before calling update_breakpoints_after_exec, as
1124 otherwise clearing the threads' resources would reference stale
1125 thread breakpoints -- it may have been one of these threads that
1126 stepped across the exec. We could just clear their stepping
1127 states, but as long as we're iterating, might as well delete
1128 them. Deleting them now rather than at the next user-visible
1129 stop provides a nicer sequence of events for user and MI
1131 for (thread_info
*th
: all_threads_safe ())
1132 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1135 /* We also need to clear any left over stale state for the
1136 leader/event thread. E.g., if there was any step-resume
1137 breakpoint or similar, it's gone now. We cannot truly
1138 step-to-next statement through an exec(). */
1139 thread_info
*th
= inferior_thread ();
1140 th
->control
.step_resume_breakpoint
= NULL
;
1141 th
->control
.exception_resume_breakpoint
= NULL
;
1142 th
->control
.single_step_breakpoints
= NULL
;
1143 th
->control
.step_range_start
= 0;
1144 th
->control
.step_range_end
= 0;
1146 /* The user may have had the main thread held stopped in the
1147 previous image (e.g., schedlock on, or non-stop). Release
1149 th
->stop_requested
= 0;
1151 update_breakpoints_after_exec ();
1153 /* What is this a.out's name? */
1154 process_ptid
= ptid_t (pid
);
1155 printf_unfiltered (_("%s is executing new program: %s\n"),
1156 target_pid_to_str (process_ptid
),
1159 /* We've followed the inferior through an exec. Therefore, the
1160 inferior has essentially been killed & reborn. */
1162 gdb_flush (gdb_stdout
);
1164 breakpoint_init_inferior (inf_execd
);
1166 gdb::unique_xmalloc_ptr
<char> exec_file_host
1167 = exec_file_find (exec_file_target
, NULL
);
1169 /* If we were unable to map the executable target pathname onto a host
1170 pathname, tell the user that. Otherwise GDB's subsequent behavior
1171 is confusing. Maybe it would even be better to stop at this point
1172 so that the user can specify a file manually before continuing. */
1173 if (exec_file_host
== NULL
)
1174 warning (_("Could not load symbols for executable %s.\n"
1175 "Do you need \"set sysroot\"?"),
1178 /* Reset the shared library package. This ensures that we get a
1179 shlib event when the child reaches "_start", at which point the
1180 dld will have had a chance to initialize the child. */
1181 /* Also, loading a symbol file below may trigger symbol lookups, and
1182 we don't want those to be satisfied by the libraries of the
1183 previous incarnation of this process. */
1184 no_shared_libraries (NULL
, 0);
1186 if (follow_exec_mode_string
== follow_exec_mode_new
)
1188 /* The user wants to keep the old inferior and program spaces
1189 around. Create a new fresh one, and switch to it. */
1191 /* Do exit processing for the original inferior before setting the new
1192 inferior's pid. Having two inferiors with the same pid would confuse
1193 find_inferior_p(t)id. Transfer the terminal state and info from the
1194 old to the new inferior. */
1195 inf
= add_inferior_with_spaces ();
1196 swap_terminal_info (inf
, current_inferior ());
1197 exit_inferior_silent (current_inferior ());
1200 target_follow_exec (inf
, exec_file_target
);
1202 set_current_inferior (inf
);
1203 set_current_program_space (inf
->pspace
);
1208 /* The old description may no longer be fit for the new image.
1209 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1210 old description; we'll read a new one below. No need to do
1211 this on "follow-exec-mode new", as the old inferior stays
1212 around (its description is later cleared/refetched on
1214 target_clear_description ();
1217 gdb_assert (current_program_space
== inf
->pspace
);
1219 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1220 because the proper displacement for a PIE (Position Independent
1221 Executable) main symbol file will only be computed by
1222 solib_create_inferior_hook below. breakpoint_re_set would fail
1223 to insert the breakpoints with the zero displacement. */
1224 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1226 /* If the target can specify a description, read it. Must do this
1227 after flipping to the new executable (because the target supplied
1228 description must be compatible with the executable's
1229 architecture, and the old executable may e.g., be 32-bit, while
1230 the new one 64-bit), and before anything involving memory or
1232 target_find_description ();
1234 solib_create_inferior_hook (0);
1236 jit_inferior_created_hook ();
1238 breakpoint_re_set ();
1240 /* Reinsert all breakpoints. (Those which were symbolic have
1241 been reset to the proper address in the new a.out, thanks
1242 to symbol_file_command...). */
1243 insert_breakpoints ();
1245 /* The next resume of this inferior should bring it to the shlib
1246 startup breakpoints. (If the user had also set bp's on
1247 "main" from the old (parent) process, then they'll auto-
1248 matically get reset there in the new process.). */
1251 /* The queue of threads that need to do a step-over operation to get
1252 past e.g., a breakpoint. What technique is used to step over the
1253 breakpoint/watchpoint does not matter -- all threads end up in the
1254 same queue, to maintain rough temporal order of execution, in order
1255 to avoid starvation, otherwise, we could e.g., find ourselves
1256 constantly stepping the same couple threads past their breakpoints
1257 over and over, if the single-step finish fast enough. */
1258 struct thread_info
*step_over_queue_head
;
1260 /* Bit flags indicating what the thread needs to step over. */
1262 enum step_over_what_flag
1264 /* Step over a breakpoint. */
1265 STEP_OVER_BREAKPOINT
= 1,
1267 /* Step past a non-continuable watchpoint, in order to let the
1268 instruction execute so we can evaluate the watchpoint
1270 STEP_OVER_WATCHPOINT
= 2
1272 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1274 /* Info about an instruction that is being stepped over. */
1276 struct step_over_info
1278 /* If we're stepping past a breakpoint, this is the address space
1279 and address of the instruction the breakpoint is set at. We'll
1280 skip inserting all breakpoints here. Valid iff ASPACE is
1282 const address_space
*aspace
;
1285 /* The instruction being stepped over triggers a nonsteppable
1286 watchpoint. If true, we'll skip inserting watchpoints. */
1287 int nonsteppable_watchpoint_p
;
1289 /* The thread's global number. */
1293 /* The step-over info of the location that is being stepped over.
1295 Note that with async/breakpoint always-inserted mode, a user might
1296 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1297 being stepped over. As setting a new breakpoint inserts all
1298 breakpoints, we need to make sure the breakpoint being stepped over
1299 isn't inserted then. We do that by only clearing the step-over
1300 info when the step-over is actually finished (or aborted).
1302 Presently GDB can only step over one breakpoint at any given time.
1303 Given threads that can't run code in the same address space as the
1304 breakpoint's can't really miss the breakpoint, GDB could be taught
1305 to step-over at most one breakpoint per address space (so this info
1306 could move to the address space object if/when GDB is extended).
1307 The set of breakpoints being stepped over will normally be much
1308 smaller than the set of all breakpoints, so a flag in the
1309 breakpoint location structure would be wasteful. A separate list
1310 also saves complexity and run-time, as otherwise we'd have to go
1311 through all breakpoint locations clearing their flag whenever we
1312 start a new sequence. Similar considerations weigh against storing
1313 this info in the thread object. Plus, not all step overs actually
1314 have breakpoint locations -- e.g., stepping past a single-step
1315 breakpoint, or stepping to complete a non-continuable
1317 static struct step_over_info step_over_info
;
1319 /* Record the address of the breakpoint/instruction we're currently
1321 N.B. We record the aspace and address now, instead of say just the thread,
1322 because when we need the info later the thread may be running. */
1325 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1326 int nonsteppable_watchpoint_p
,
1329 step_over_info
.aspace
= aspace
;
1330 step_over_info
.address
= address
;
1331 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1332 step_over_info
.thread
= thread
;
1335 /* Called when we're not longer stepping over a breakpoint / an
1336 instruction, so all breakpoints are free to be (re)inserted. */
1339 clear_step_over_info (void)
1342 fprintf_unfiltered (gdb_stdlog
,
1343 "infrun: clear_step_over_info\n");
1344 step_over_info
.aspace
= NULL
;
1345 step_over_info
.address
= 0;
1346 step_over_info
.nonsteppable_watchpoint_p
= 0;
1347 step_over_info
.thread
= -1;
1353 stepping_past_instruction_at (struct address_space
*aspace
,
1356 return (step_over_info
.aspace
!= NULL
1357 && breakpoint_address_match (aspace
, address
,
1358 step_over_info
.aspace
,
1359 step_over_info
.address
));
1365 thread_is_stepping_over_breakpoint (int thread
)
1367 return (step_over_info
.thread
!= -1
1368 && thread
== step_over_info
.thread
);
1374 stepping_past_nonsteppable_watchpoint (void)
1376 return step_over_info
.nonsteppable_watchpoint_p
;
1379 /* Returns true if step-over info is valid. */
1382 step_over_info_valid_p (void)
1384 return (step_over_info
.aspace
!= NULL
1385 || stepping_past_nonsteppable_watchpoint ());
1389 /* Displaced stepping. */
1391 /* In non-stop debugging mode, we must take special care to manage
1392 breakpoints properly; in particular, the traditional strategy for
1393 stepping a thread past a breakpoint it has hit is unsuitable.
1394 'Displaced stepping' is a tactic for stepping one thread past a
1395 breakpoint it has hit while ensuring that other threads running
1396 concurrently will hit the breakpoint as they should.
1398 The traditional way to step a thread T off a breakpoint in a
1399 multi-threaded program in all-stop mode is as follows:
1401 a0) Initially, all threads are stopped, and breakpoints are not
1403 a1) We single-step T, leaving breakpoints uninserted.
1404 a2) We insert breakpoints, and resume all threads.
1406 In non-stop debugging, however, this strategy is unsuitable: we
1407 don't want to have to stop all threads in the system in order to
1408 continue or step T past a breakpoint. Instead, we use displaced
1411 n0) Initially, T is stopped, other threads are running, and
1412 breakpoints are inserted.
1413 n1) We copy the instruction "under" the breakpoint to a separate
1414 location, outside the main code stream, making any adjustments
1415 to the instruction, register, and memory state as directed by
1417 n2) We single-step T over the instruction at its new location.
1418 n3) We adjust the resulting register and memory state as directed
1419 by T's architecture. This includes resetting T's PC to point
1420 back into the main instruction stream.
1423 This approach depends on the following gdbarch methods:
1425 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1426 indicate where to copy the instruction, and how much space must
1427 be reserved there. We use these in step n1.
1429 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1430 address, and makes any necessary adjustments to the instruction,
1431 register contents, and memory. We use this in step n1.
1433 - gdbarch_displaced_step_fixup adjusts registers and memory after
1434 we have successfuly single-stepped the instruction, to yield the
1435 same effect the instruction would have had if we had executed it
1436 at its original address. We use this in step n3.
1438 The gdbarch_displaced_step_copy_insn and
1439 gdbarch_displaced_step_fixup functions must be written so that
1440 copying an instruction with gdbarch_displaced_step_copy_insn,
1441 single-stepping across the copied instruction, and then applying
1442 gdbarch_displaced_insn_fixup should have the same effects on the
1443 thread's memory and registers as stepping the instruction in place
1444 would have. Exactly which responsibilities fall to the copy and
1445 which fall to the fixup is up to the author of those functions.
1447 See the comments in gdbarch.sh for details.
1449 Note that displaced stepping and software single-step cannot
1450 currently be used in combination, although with some care I think
1451 they could be made to. Software single-step works by placing
1452 breakpoints on all possible subsequent instructions; if the
1453 displaced instruction is a PC-relative jump, those breakpoints
1454 could fall in very strange places --- on pages that aren't
1455 executable, or at addresses that are not proper instruction
1456 boundaries. (We do generally let other threads run while we wait
1457 to hit the software single-step breakpoint, and they might
1458 encounter such a corrupted instruction.) One way to work around
1459 this would be to have gdbarch_displaced_step_copy_insn fully
1460 simulate the effect of PC-relative instructions (and return NULL)
1461 on architectures that use software single-stepping.
1463 In non-stop mode, we can have independent and simultaneous step
1464 requests, so more than one thread may need to simultaneously step
1465 over a breakpoint. The current implementation assumes there is
1466 only one scratch space per process. In this case, we have to
1467 serialize access to the scratch space. If thread A wants to step
1468 over a breakpoint, but we are currently waiting for some other
1469 thread to complete a displaced step, we leave thread A stopped and
1470 place it in the displaced_step_request_queue. Whenever a displaced
1471 step finishes, we pick the next thread in the queue and start a new
1472 displaced step operation on it. See displaced_step_prepare and
1473 displaced_step_fixup for details. */
1475 /* Default destructor for displaced_step_closure. */
1477 displaced_step_closure::~displaced_step_closure () = default;
1479 /* Get the displaced stepping state of process PID. */
1481 static displaced_step_inferior_state
*
1482 get_displaced_stepping_state (inferior
*inf
)
1484 return &inf
->displaced_step_state
;
1487 /* Returns true if any inferior has a thread doing a displaced
1491 displaced_step_in_progress_any_inferior ()
1493 for (inferior
*i
: all_inferiors ())
1495 if (i
->displaced_step_state
.step_thread
!= nullptr)
1502 /* Return true if thread represented by PTID is doing a displaced
1506 displaced_step_in_progress_thread (thread_info
*thread
)
1508 gdb_assert (thread
!= NULL
);
1510 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1513 /* Return true if process PID has a thread doing a displaced step. */
1516 displaced_step_in_progress (inferior
*inf
)
1518 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1521 /* If inferior is in displaced stepping, and ADDR equals to starting address
1522 of copy area, return corresponding displaced_step_closure. Otherwise,
1525 struct displaced_step_closure
*
1526 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1528 displaced_step_inferior_state
*displaced
1529 = get_displaced_stepping_state (current_inferior ());
1531 /* If checking the mode of displaced instruction in copy area. */
1532 if (displaced
->step_thread
!= nullptr
1533 && displaced
->step_copy
== addr
)
1534 return displaced
->step_closure
;
1540 infrun_inferior_exit (struct inferior
*inf
)
1542 inf
->displaced_step_state
.reset ();
1545 /* If ON, and the architecture supports it, GDB will use displaced
1546 stepping to step over breakpoints. If OFF, or if the architecture
1547 doesn't support it, GDB will instead use the traditional
1548 hold-and-step approach. If AUTO (which is the default), GDB will
1549 decide which technique to use to step over breakpoints depending on
1550 which of all-stop or non-stop mode is active --- displaced stepping
1551 in non-stop mode; hold-and-step in all-stop mode. */
1553 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1556 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1557 struct cmd_list_element
*c
,
1560 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1561 fprintf_filtered (file
,
1562 _("Debugger's willingness to use displaced stepping "
1563 "to step over breakpoints is %s (currently %s).\n"),
1564 value
, target_is_non_stop_p () ? "on" : "off");
1566 fprintf_filtered (file
,
1567 _("Debugger's willingness to use displaced stepping "
1568 "to step over breakpoints is %s.\n"), value
);
1571 /* Return non-zero if displaced stepping can/should be used to step
1572 over breakpoints of thread TP. */
1575 use_displaced_stepping (struct thread_info
*tp
)
1577 struct regcache
*regcache
= get_thread_regcache (tp
);
1578 struct gdbarch
*gdbarch
= regcache
->arch ();
1579 displaced_step_inferior_state
*displaced_state
1580 = get_displaced_stepping_state (tp
->inf
);
1582 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1583 && target_is_non_stop_p ())
1584 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1585 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1586 && find_record_target () == NULL
1587 && !displaced_state
->failed_before
);
1590 /* Clean out any stray displaced stepping state. */
1592 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1594 /* Indicate that there is no cleanup pending. */
1595 displaced
->step_thread
= nullptr;
1597 delete displaced
->step_closure
;
1598 displaced
->step_closure
= NULL
;
1602 displaced_step_clear_cleanup (void *arg
)
1604 struct displaced_step_inferior_state
*state
1605 = (struct displaced_step_inferior_state
*) arg
;
1607 displaced_step_clear (state
);
1610 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1612 displaced_step_dump_bytes (struct ui_file
*file
,
1613 const gdb_byte
*buf
,
1618 for (i
= 0; i
< len
; i
++)
1619 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1620 fputs_unfiltered ("\n", file
);
1623 /* Prepare to single-step, using displaced stepping.
1625 Note that we cannot use displaced stepping when we have a signal to
1626 deliver. If we have a signal to deliver and an instruction to step
1627 over, then after the step, there will be no indication from the
1628 target whether the thread entered a signal handler or ignored the
1629 signal and stepped over the instruction successfully --- both cases
1630 result in a simple SIGTRAP. In the first case we mustn't do a
1631 fixup, and in the second case we must --- but we can't tell which.
1632 Comments in the code for 'random signals' in handle_inferior_event
1633 explain how we handle this case instead.
1635 Returns 1 if preparing was successful -- this thread is going to be
1636 stepped now; 0 if displaced stepping this thread got queued; or -1
1637 if this instruction can't be displaced stepped. */
1640 displaced_step_prepare_throw (thread_info
*tp
)
1642 regcache
*regcache
= get_thread_regcache (tp
);
1643 struct gdbarch
*gdbarch
= regcache
->arch ();
1644 const address_space
*aspace
= regcache
->aspace ();
1645 CORE_ADDR original
, copy
;
1647 struct displaced_step_closure
*closure
;
1650 /* We should never reach this function if the architecture does not
1651 support displaced stepping. */
1652 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1654 /* Nor if the thread isn't meant to step over a breakpoint. */
1655 gdb_assert (tp
->control
.trap_expected
);
1657 /* Disable range stepping while executing in the scratch pad. We
1658 want a single-step even if executing the displaced instruction in
1659 the scratch buffer lands within the stepping range (e.g., a
1661 tp
->control
.may_range_step
= 0;
1663 /* We have to displaced step one thread at a time, as we only have
1664 access to a single scratch space per inferior. */
1666 displaced_step_inferior_state
*displaced
1667 = get_displaced_stepping_state (tp
->inf
);
1669 if (displaced
->step_thread
!= nullptr)
1671 /* Already waiting for a displaced step to finish. Defer this
1672 request and place in queue. */
1674 if (debug_displaced
)
1675 fprintf_unfiltered (gdb_stdlog
,
1676 "displaced: deferring step of %s\n",
1677 target_pid_to_str (tp
->ptid
));
1679 thread_step_over_chain_enqueue (tp
);
1684 if (debug_displaced
)
1685 fprintf_unfiltered (gdb_stdlog
,
1686 "displaced: stepping %s now\n",
1687 target_pid_to_str (tp
->ptid
));
1690 displaced_step_clear (displaced
);
1692 scoped_restore_current_thread restore_thread
;
1694 switch_to_thread (tp
);
1696 original
= regcache_read_pc (regcache
);
1698 copy
= gdbarch_displaced_step_location (gdbarch
);
1699 len
= gdbarch_max_insn_length (gdbarch
);
1701 if (breakpoint_in_range_p (aspace
, copy
, len
))
1703 /* There's a breakpoint set in the scratch pad location range
1704 (which is usually around the entry point). We'd either
1705 install it before resuming, which would overwrite/corrupt the
1706 scratch pad, or if it was already inserted, this displaced
1707 step would overwrite it. The latter is OK in the sense that
1708 we already assume that no thread is going to execute the code
1709 in the scratch pad range (after initial startup) anyway, but
1710 the former is unacceptable. Simply punt and fallback to
1711 stepping over this breakpoint in-line. */
1712 if (debug_displaced
)
1714 fprintf_unfiltered (gdb_stdlog
,
1715 "displaced: breakpoint set in scratch pad. "
1716 "Stepping over breakpoint in-line instead.\n");
1722 /* Save the original contents of the copy area. */
1723 displaced
->step_saved_copy
.resize (len
);
1724 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1726 throw_error (MEMORY_ERROR
,
1727 _("Error accessing memory address %s (%s) for "
1728 "displaced-stepping scratch space."),
1729 paddress (gdbarch
, copy
), safe_strerror (status
));
1730 if (debug_displaced
)
1732 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1733 paddress (gdbarch
, copy
));
1734 displaced_step_dump_bytes (gdb_stdlog
,
1735 displaced
->step_saved_copy
.data (),
1739 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1740 original
, copy
, regcache
);
1741 if (closure
== NULL
)
1743 /* The architecture doesn't know how or want to displaced step
1744 this instruction or instruction sequence. Fallback to
1745 stepping over the breakpoint in-line. */
1749 /* Save the information we need to fix things up if the step
1751 displaced
->step_thread
= tp
;
1752 displaced
->step_gdbarch
= gdbarch
;
1753 displaced
->step_closure
= closure
;
1754 displaced
->step_original
= original
;
1755 displaced
->step_copy
= copy
;
1757 cleanup
*ignore_cleanups
1758 = make_cleanup (displaced_step_clear_cleanup
, displaced
);
1760 /* Resume execution at the copy. */
1761 regcache_write_pc (regcache
, copy
);
1763 discard_cleanups (ignore_cleanups
);
1765 if (debug_displaced
)
1766 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1767 paddress (gdbarch
, copy
));
1772 /* Wrapper for displaced_step_prepare_throw that disabled further
1773 attempts at displaced stepping if we get a memory error. */
1776 displaced_step_prepare (thread_info
*thread
)
1782 prepared
= displaced_step_prepare_throw (thread
);
1784 CATCH (ex
, RETURN_MASK_ERROR
)
1786 struct displaced_step_inferior_state
*displaced_state
;
1788 if (ex
.error
!= MEMORY_ERROR
1789 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1790 throw_exception (ex
);
1794 fprintf_unfiltered (gdb_stdlog
,
1795 "infrun: disabling displaced stepping: %s\n",
1799 /* Be verbose if "set displaced-stepping" is "on", silent if
1801 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1803 warning (_("disabling displaced stepping: %s"),
1807 /* Disable further displaced stepping attempts. */
1809 = get_displaced_stepping_state (thread
->inf
);
1810 displaced_state
->failed_before
= 1;
1818 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1819 const gdb_byte
*myaddr
, int len
)
1821 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1823 inferior_ptid
= ptid
;
1824 write_memory (memaddr
, myaddr
, len
);
1827 /* Restore the contents of the copy area for thread PTID. */
1830 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1833 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1835 write_memory_ptid (ptid
, displaced
->step_copy
,
1836 displaced
->step_saved_copy
.data (), len
);
1837 if (debug_displaced
)
1838 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1839 target_pid_to_str (ptid
),
1840 paddress (displaced
->step_gdbarch
,
1841 displaced
->step_copy
));
1844 /* If we displaced stepped an instruction successfully, adjust
1845 registers and memory to yield the same effect the instruction would
1846 have had if we had executed it at its original address, and return
1847 1. If the instruction didn't complete, relocate the PC and return
1848 -1. If the thread wasn't displaced stepping, return 0. */
1851 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1853 struct cleanup
*old_cleanups
;
1854 struct displaced_step_inferior_state
*displaced
1855 = get_displaced_stepping_state (event_thread
->inf
);
1858 /* Was this event for the thread we displaced? */
1859 if (displaced
->step_thread
!= event_thread
)
1862 old_cleanups
= make_cleanup (displaced_step_clear_cleanup
, displaced
);
1864 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1866 /* Fixup may need to read memory/registers. Switch to the thread
1867 that we're fixing up. Also, target_stopped_by_watchpoint checks
1868 the current thread. */
1869 switch_to_thread (event_thread
);
1871 /* Did the instruction complete successfully? */
1872 if (signal
== GDB_SIGNAL_TRAP
1873 && !(target_stopped_by_watchpoint ()
1874 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1875 || target_have_steppable_watchpoint
)))
1877 /* Fix up the resulting state. */
1878 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1879 displaced
->step_closure
,
1880 displaced
->step_original
,
1881 displaced
->step_copy
,
1882 get_thread_regcache (displaced
->step_thread
));
1887 /* Since the instruction didn't complete, all we can do is
1889 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1890 CORE_ADDR pc
= regcache_read_pc (regcache
);
1892 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1893 regcache_write_pc (regcache
, pc
);
1897 do_cleanups (old_cleanups
);
1899 displaced
->step_thread
= nullptr;
1904 /* Data to be passed around while handling an event. This data is
1905 discarded between events. */
1906 struct execution_control_state
1909 /* The thread that got the event, if this was a thread event; NULL
1911 struct thread_info
*event_thread
;
1913 struct target_waitstatus ws
;
1914 int stop_func_filled_in
;
1915 CORE_ADDR stop_func_start
;
1916 CORE_ADDR stop_func_end
;
1917 const char *stop_func_name
;
1920 /* True if the event thread hit the single-step breakpoint of
1921 another thread. Thus the event doesn't cause a stop, the thread
1922 needs to be single-stepped past the single-step breakpoint before
1923 we can switch back to the original stepping thread. */
1924 int hit_singlestep_breakpoint
;
1927 /* Clear ECS and set it to point at TP. */
1930 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1932 memset (ecs
, 0, sizeof (*ecs
));
1933 ecs
->event_thread
= tp
;
1934 ecs
->ptid
= tp
->ptid
;
1937 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1938 static void prepare_to_wait (struct execution_control_state
*ecs
);
1939 static int keep_going_stepped_thread (struct thread_info
*tp
);
1940 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1942 /* Are there any pending step-over requests? If so, run all we can
1943 now and return true. Otherwise, return false. */
1946 start_step_over (void)
1948 struct thread_info
*tp
, *next
;
1950 /* Don't start a new step-over if we already have an in-line
1951 step-over operation ongoing. */
1952 if (step_over_info_valid_p ())
1955 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1957 struct execution_control_state ecss
;
1958 struct execution_control_state
*ecs
= &ecss
;
1959 step_over_what step_what
;
1960 int must_be_in_line
;
1962 gdb_assert (!tp
->stop_requested
);
1964 next
= thread_step_over_chain_next (tp
);
1966 /* If this inferior already has a displaced step in process,
1967 don't start a new one. */
1968 if (displaced_step_in_progress (tp
->inf
))
1971 step_what
= thread_still_needs_step_over (tp
);
1972 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1973 || ((step_what
& STEP_OVER_BREAKPOINT
)
1974 && !use_displaced_stepping (tp
)));
1976 /* We currently stop all threads of all processes to step-over
1977 in-line. If we need to start a new in-line step-over, let
1978 any pending displaced steps finish first. */
1979 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1982 thread_step_over_chain_remove (tp
);
1984 if (step_over_queue_head
== NULL
)
1987 fprintf_unfiltered (gdb_stdlog
,
1988 "infrun: step-over queue now empty\n");
1991 if (tp
->control
.trap_expected
1995 internal_error (__FILE__
, __LINE__
,
1996 "[%s] has inconsistent state: "
1997 "trap_expected=%d, resumed=%d, executing=%d\n",
1998 target_pid_to_str (tp
->ptid
),
1999 tp
->control
.trap_expected
,
2005 fprintf_unfiltered (gdb_stdlog
,
2006 "infrun: resuming [%s] for step-over\n",
2007 target_pid_to_str (tp
->ptid
));
2009 /* keep_going_pass_signal skips the step-over if the breakpoint
2010 is no longer inserted. In all-stop, we want to keep looking
2011 for a thread that needs a step-over instead of resuming TP,
2012 because we wouldn't be able to resume anything else until the
2013 target stops again. In non-stop, the resume always resumes
2014 only TP, so it's OK to let the thread resume freely. */
2015 if (!target_is_non_stop_p () && !step_what
)
2018 switch_to_thread (tp
);
2019 reset_ecs (ecs
, tp
);
2020 keep_going_pass_signal (ecs
);
2022 if (!ecs
->wait_some_more
)
2023 error (_("Command aborted."));
2025 gdb_assert (tp
->resumed
);
2027 /* If we started a new in-line step-over, we're done. */
2028 if (step_over_info_valid_p ())
2030 gdb_assert (tp
->control
.trap_expected
);
2034 if (!target_is_non_stop_p ())
2036 /* On all-stop, shouldn't have resumed unless we needed a
2038 gdb_assert (tp
->control
.trap_expected
2039 || tp
->step_after_step_resume_breakpoint
);
2041 /* With remote targets (at least), in all-stop, we can't
2042 issue any further remote commands until the program stops
2047 /* Either the thread no longer needed a step-over, or a new
2048 displaced stepping sequence started. Even in the latter
2049 case, continue looking. Maybe we can also start another
2050 displaced step on a thread of other process. */
2056 /* Update global variables holding ptids to hold NEW_PTID if they were
2057 holding OLD_PTID. */
2059 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2061 if (inferior_ptid
== old_ptid
)
2062 inferior_ptid
= new_ptid
;
2067 static const char schedlock_off
[] = "off";
2068 static const char schedlock_on
[] = "on";
2069 static const char schedlock_step
[] = "step";
2070 static const char schedlock_replay
[] = "replay";
2071 static const char *const scheduler_enums
[] = {
2078 static const char *scheduler_mode
= schedlock_replay
;
2080 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2081 struct cmd_list_element
*c
, const char *value
)
2083 fprintf_filtered (file
,
2084 _("Mode for locking scheduler "
2085 "during execution is \"%s\".\n"),
2090 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2092 if (!target_can_lock_scheduler
)
2094 scheduler_mode
= schedlock_off
;
2095 error (_("Target '%s' cannot support this command."), target_shortname
);
2099 /* True if execution commands resume all threads of all processes by
2100 default; otherwise, resume only threads of the current inferior
2102 int sched_multi
= 0;
2104 /* Try to setup for software single stepping over the specified location.
2105 Return 1 if target_resume() should use hardware single step.
2107 GDBARCH the current gdbarch.
2108 PC the location to step over. */
2111 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2115 if (execution_direction
== EXEC_FORWARD
2116 && gdbarch_software_single_step_p (gdbarch
))
2117 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2125 user_visible_resume_ptid (int step
)
2131 /* With non-stop mode on, threads are always handled
2133 resume_ptid
= inferior_ptid
;
2135 else if ((scheduler_mode
== schedlock_on
)
2136 || (scheduler_mode
== schedlock_step
&& step
))
2138 /* User-settable 'scheduler' mode requires solo thread
2140 resume_ptid
= inferior_ptid
;
2142 else if ((scheduler_mode
== schedlock_replay
)
2143 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2145 /* User-settable 'scheduler' mode requires solo thread resume in replay
2147 resume_ptid
= inferior_ptid
;
2149 else if (!sched_multi
&& target_supports_multi_process ())
2151 /* Resume all threads of the current process (and none of other
2153 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2157 /* Resume all threads of all processes. */
2158 resume_ptid
= RESUME_ALL
;
2164 /* Return a ptid representing the set of threads that we will resume,
2165 in the perspective of the target, assuming run control handling
2166 does not require leaving some threads stopped (e.g., stepping past
2167 breakpoint). USER_STEP indicates whether we're about to start the
2168 target for a stepping command. */
2171 internal_resume_ptid (int user_step
)
2173 /* In non-stop, we always control threads individually. Note that
2174 the target may always work in non-stop mode even with "set
2175 non-stop off", in which case user_visible_resume_ptid could
2176 return a wildcard ptid. */
2177 if (target_is_non_stop_p ())
2178 return inferior_ptid
;
2180 return user_visible_resume_ptid (user_step
);
2183 /* Wrapper for target_resume, that handles infrun-specific
2187 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2189 struct thread_info
*tp
= inferior_thread ();
2191 gdb_assert (!tp
->stop_requested
);
2193 /* Install inferior's terminal modes. */
2194 target_terminal::inferior ();
2196 /* Avoid confusing the next resume, if the next stop/resume
2197 happens to apply to another thread. */
2198 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2200 /* Advise target which signals may be handled silently.
2202 If we have removed breakpoints because we are stepping over one
2203 in-line (in any thread), we need to receive all signals to avoid
2204 accidentally skipping a breakpoint during execution of a signal
2207 Likewise if we're displaced stepping, otherwise a trap for a
2208 breakpoint in a signal handler might be confused with the
2209 displaced step finishing. We don't make the displaced_step_fixup
2210 step distinguish the cases instead, because:
2212 - a backtrace while stopped in the signal handler would show the
2213 scratch pad as frame older than the signal handler, instead of
2214 the real mainline code.
2216 - when the thread is later resumed, the signal handler would
2217 return to the scratch pad area, which would no longer be
2219 if (step_over_info_valid_p ()
2220 || displaced_step_in_progress (tp
->inf
))
2221 target_pass_signals (0, NULL
);
2223 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
2225 target_resume (resume_ptid
, step
, sig
);
2227 target_commit_resume ();
2230 /* Resume the inferior. SIG is the signal to give the inferior
2231 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2232 call 'resume', which handles exceptions. */
2235 resume_1 (enum gdb_signal sig
)
2237 struct regcache
*regcache
= get_current_regcache ();
2238 struct gdbarch
*gdbarch
= regcache
->arch ();
2239 struct thread_info
*tp
= inferior_thread ();
2240 CORE_ADDR pc
= regcache_read_pc (regcache
);
2241 const address_space
*aspace
= regcache
->aspace ();
2243 /* This represents the user's step vs continue request. When
2244 deciding whether "set scheduler-locking step" applies, it's the
2245 user's intention that counts. */
2246 const int user_step
= tp
->control
.stepping_command
;
2247 /* This represents what we'll actually request the target to do.
2248 This can decay from a step to a continue, if e.g., we need to
2249 implement single-stepping with breakpoints (software
2253 gdb_assert (!tp
->stop_requested
);
2254 gdb_assert (!thread_is_in_step_over_chain (tp
));
2256 if (tp
->suspend
.waitstatus_pending_p
)
2261 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2263 fprintf_unfiltered (gdb_stdlog
,
2264 "infrun: resume: thread %s has pending wait "
2265 "status %s (currently_stepping=%d).\n",
2266 target_pid_to_str (tp
->ptid
), statstr
.c_str (),
2267 currently_stepping (tp
));
2272 /* FIXME: What should we do if we are supposed to resume this
2273 thread with a signal? Maybe we should maintain a queue of
2274 pending signals to deliver. */
2275 if (sig
!= GDB_SIGNAL_0
)
2277 warning (_("Couldn't deliver signal %s to %s."),
2278 gdb_signal_to_name (sig
), target_pid_to_str (tp
->ptid
));
2281 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2283 if (target_can_async_p ())
2286 /* Tell the event loop we have an event to process. */
2287 mark_async_event_handler (infrun_async_inferior_event_token
);
2292 tp
->stepped_breakpoint
= 0;
2294 /* Depends on stepped_breakpoint. */
2295 step
= currently_stepping (tp
);
2297 if (current_inferior ()->waiting_for_vfork_done
)
2299 /* Don't try to single-step a vfork parent that is waiting for
2300 the child to get out of the shared memory region (by exec'ing
2301 or exiting). This is particularly important on software
2302 single-step archs, as the child process would trip on the
2303 software single step breakpoint inserted for the parent
2304 process. Since the parent will not actually execute any
2305 instruction until the child is out of the shared region (such
2306 are vfork's semantics), it is safe to simply continue it.
2307 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2308 the parent, and tell it to `keep_going', which automatically
2309 re-sets it stepping. */
2311 fprintf_unfiltered (gdb_stdlog
,
2312 "infrun: resume : clear step\n");
2317 fprintf_unfiltered (gdb_stdlog
,
2318 "infrun: resume (step=%d, signal=%s), "
2319 "trap_expected=%d, current thread [%s] at %s\n",
2320 step
, gdb_signal_to_symbol_string (sig
),
2321 tp
->control
.trap_expected
,
2322 target_pid_to_str (inferior_ptid
),
2323 paddress (gdbarch
, pc
));
2325 /* Normally, by the time we reach `resume', the breakpoints are either
2326 removed or inserted, as appropriate. The exception is if we're sitting
2327 at a permanent breakpoint; we need to step over it, but permanent
2328 breakpoints can't be removed. So we have to test for it here. */
2329 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2331 if (sig
!= GDB_SIGNAL_0
)
2333 /* We have a signal to pass to the inferior. The resume
2334 may, or may not take us to the signal handler. If this
2335 is a step, we'll need to stop in the signal handler, if
2336 there's one, (if the target supports stepping into
2337 handlers), or in the next mainline instruction, if
2338 there's no handler. If this is a continue, we need to be
2339 sure to run the handler with all breakpoints inserted.
2340 In all cases, set a breakpoint at the current address
2341 (where the handler returns to), and once that breakpoint
2342 is hit, resume skipping the permanent breakpoint. If
2343 that breakpoint isn't hit, then we've stepped into the
2344 signal handler (or hit some other event). We'll delete
2345 the step-resume breakpoint then. */
2348 fprintf_unfiltered (gdb_stdlog
,
2349 "infrun: resume: skipping permanent breakpoint, "
2350 "deliver signal first\n");
2352 clear_step_over_info ();
2353 tp
->control
.trap_expected
= 0;
2355 if (tp
->control
.step_resume_breakpoint
== NULL
)
2357 /* Set a "high-priority" step-resume, as we don't want
2358 user breakpoints at PC to trigger (again) when this
2360 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2361 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2363 tp
->step_after_step_resume_breakpoint
= step
;
2366 insert_breakpoints ();
2370 /* There's no signal to pass, we can go ahead and skip the
2371 permanent breakpoint manually. */
2373 fprintf_unfiltered (gdb_stdlog
,
2374 "infrun: resume: skipping permanent breakpoint\n");
2375 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2376 /* Update pc to reflect the new address from which we will
2377 execute instructions. */
2378 pc
= regcache_read_pc (regcache
);
2382 /* We've already advanced the PC, so the stepping part
2383 is done. Now we need to arrange for a trap to be
2384 reported to handle_inferior_event. Set a breakpoint
2385 at the current PC, and run to it. Don't update
2386 prev_pc, because if we end in
2387 switch_back_to_stepped_thread, we want the "expected
2388 thread advanced also" branch to be taken. IOW, we
2389 don't want this thread to step further from PC
2391 gdb_assert (!step_over_info_valid_p ());
2392 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2393 insert_breakpoints ();
2395 resume_ptid
= internal_resume_ptid (user_step
);
2396 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2403 /* If we have a breakpoint to step over, make sure to do a single
2404 step only. Same if we have software watchpoints. */
2405 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2406 tp
->control
.may_range_step
= 0;
2408 /* If enabled, step over breakpoints by executing a copy of the
2409 instruction at a different address.
2411 We can't use displaced stepping when we have a signal to deliver;
2412 the comments for displaced_step_prepare explain why. The
2413 comments in the handle_inferior event for dealing with 'random
2414 signals' explain what we do instead.
2416 We can't use displaced stepping when we are waiting for vfork_done
2417 event, displaced stepping breaks the vfork child similarly as single
2418 step software breakpoint. */
2419 if (tp
->control
.trap_expected
2420 && use_displaced_stepping (tp
)
2421 && !step_over_info_valid_p ()
2422 && sig
== GDB_SIGNAL_0
2423 && !current_inferior ()->waiting_for_vfork_done
)
2425 int prepared
= displaced_step_prepare (tp
);
2430 fprintf_unfiltered (gdb_stdlog
,
2431 "Got placed in step-over queue\n");
2433 tp
->control
.trap_expected
= 0;
2436 else if (prepared
< 0)
2438 /* Fallback to stepping over the breakpoint in-line. */
2440 if (target_is_non_stop_p ())
2441 stop_all_threads ();
2443 set_step_over_info (regcache
->aspace (),
2444 regcache_read_pc (regcache
), 0, tp
->global_num
);
2446 step
= maybe_software_singlestep (gdbarch
, pc
);
2448 insert_breakpoints ();
2450 else if (prepared
> 0)
2452 struct displaced_step_inferior_state
*displaced
;
2454 /* Update pc to reflect the new address from which we will
2455 execute instructions due to displaced stepping. */
2456 pc
= regcache_read_pc (get_thread_regcache (tp
));
2458 displaced
= get_displaced_stepping_state (tp
->inf
);
2459 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2460 displaced
->step_closure
);
2464 /* Do we need to do it the hard way, w/temp breakpoints? */
2466 step
= maybe_software_singlestep (gdbarch
, pc
);
2468 /* Currently, our software single-step implementation leads to different
2469 results than hardware single-stepping in one situation: when stepping
2470 into delivering a signal which has an associated signal handler,
2471 hardware single-step will stop at the first instruction of the handler,
2472 while software single-step will simply skip execution of the handler.
2474 For now, this difference in behavior is accepted since there is no
2475 easy way to actually implement single-stepping into a signal handler
2476 without kernel support.
2478 However, there is one scenario where this difference leads to follow-on
2479 problems: if we're stepping off a breakpoint by removing all breakpoints
2480 and then single-stepping. In this case, the software single-step
2481 behavior means that even if there is a *breakpoint* in the signal
2482 handler, GDB still would not stop.
2484 Fortunately, we can at least fix this particular issue. We detect
2485 here the case where we are about to deliver a signal while software
2486 single-stepping with breakpoints removed. In this situation, we
2487 revert the decisions to remove all breakpoints and insert single-
2488 step breakpoints, and instead we install a step-resume breakpoint
2489 at the current address, deliver the signal without stepping, and
2490 once we arrive back at the step-resume breakpoint, actually step
2491 over the breakpoint we originally wanted to step over. */
2492 if (thread_has_single_step_breakpoints_set (tp
)
2493 && sig
!= GDB_SIGNAL_0
2494 && step_over_info_valid_p ())
2496 /* If we have nested signals or a pending signal is delivered
2497 immediately after a handler returns, might might already have
2498 a step-resume breakpoint set on the earlier handler. We cannot
2499 set another step-resume breakpoint; just continue on until the
2500 original breakpoint is hit. */
2501 if (tp
->control
.step_resume_breakpoint
== NULL
)
2503 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2504 tp
->step_after_step_resume_breakpoint
= 1;
2507 delete_single_step_breakpoints (tp
);
2509 clear_step_over_info ();
2510 tp
->control
.trap_expected
= 0;
2512 insert_breakpoints ();
2515 /* If STEP is set, it's a request to use hardware stepping
2516 facilities. But in that case, we should never
2517 use singlestep breakpoint. */
2518 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2520 /* Decide the set of threads to ask the target to resume. */
2521 if (tp
->control
.trap_expected
)
2523 /* We're allowing a thread to run past a breakpoint it has
2524 hit, either by single-stepping the thread with the breakpoint
2525 removed, or by displaced stepping, with the breakpoint inserted.
2526 In the former case, we need to single-step only this thread,
2527 and keep others stopped, as they can miss this breakpoint if
2528 allowed to run. That's not really a problem for displaced
2529 stepping, but, we still keep other threads stopped, in case
2530 another thread is also stopped for a breakpoint waiting for
2531 its turn in the displaced stepping queue. */
2532 resume_ptid
= inferior_ptid
;
2535 resume_ptid
= internal_resume_ptid (user_step
);
2537 if (execution_direction
!= EXEC_REVERSE
2538 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2540 /* There are two cases where we currently need to step a
2541 breakpoint instruction when we have a signal to deliver:
2543 - See handle_signal_stop where we handle random signals that
2544 could take out us out of the stepping range. Normally, in
2545 that case we end up continuing (instead of stepping) over the
2546 signal handler with a breakpoint at PC, but there are cases
2547 where we should _always_ single-step, even if we have a
2548 step-resume breakpoint, like when a software watchpoint is
2549 set. Assuming single-stepping and delivering a signal at the
2550 same time would takes us to the signal handler, then we could
2551 have removed the breakpoint at PC to step over it. However,
2552 some hardware step targets (like e.g., Mac OS) can't step
2553 into signal handlers, and for those, we need to leave the
2554 breakpoint at PC inserted, as otherwise if the handler
2555 recurses and executes PC again, it'll miss the breakpoint.
2556 So we leave the breakpoint inserted anyway, but we need to
2557 record that we tried to step a breakpoint instruction, so
2558 that adjust_pc_after_break doesn't end up confused.
2560 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2561 in one thread after another thread that was stepping had been
2562 momentarily paused for a step-over. When we re-resume the
2563 stepping thread, it may be resumed from that address with a
2564 breakpoint that hasn't trapped yet. Seen with
2565 gdb.threads/non-stop-fair-events.exp, on targets that don't
2566 do displaced stepping. */
2569 fprintf_unfiltered (gdb_stdlog
,
2570 "infrun: resume: [%s] stepped breakpoint\n",
2571 target_pid_to_str (tp
->ptid
));
2573 tp
->stepped_breakpoint
= 1;
2575 /* Most targets can step a breakpoint instruction, thus
2576 executing it normally. But if this one cannot, just
2577 continue and we will hit it anyway. */
2578 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2583 && tp
->control
.trap_expected
2584 && use_displaced_stepping (tp
)
2585 && !step_over_info_valid_p ())
2587 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2588 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2589 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2592 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2593 paddress (resume_gdbarch
, actual_pc
));
2594 read_memory (actual_pc
, buf
, sizeof (buf
));
2595 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2598 if (tp
->control
.may_range_step
)
2600 /* If we're resuming a thread with the PC out of the step
2601 range, then we're doing some nested/finer run control
2602 operation, like stepping the thread out of the dynamic
2603 linker or the displaced stepping scratch pad. We
2604 shouldn't have allowed a range step then. */
2605 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2608 do_target_resume (resume_ptid
, step
, sig
);
2612 /* Resume the inferior. SIG is the signal to give the inferior
2613 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2614 rolls back state on error. */
2617 resume (gdb_signal sig
)
2623 CATCH (ex
, RETURN_MASK_ALL
)
2625 /* If resuming is being aborted for any reason, delete any
2626 single-step breakpoint resume_1 may have created, to avoid
2627 confusing the following resumption, and to avoid leaving
2628 single-step breakpoints perturbing other threads, in case
2629 we're running in non-stop mode. */
2630 if (inferior_ptid
!= null_ptid
)
2631 delete_single_step_breakpoints (inferior_thread ());
2632 throw_exception (ex
);
2642 /* Counter that tracks number of user visible stops. This can be used
2643 to tell whether a command has proceeded the inferior past the
2644 current location. This allows e.g., inferior function calls in
2645 breakpoint commands to not interrupt the command list. When the
2646 call finishes successfully, the inferior is standing at the same
2647 breakpoint as if nothing happened (and so we don't call
2649 static ULONGEST current_stop_id
;
2656 return current_stop_id
;
2659 /* Called when we report a user visible stop. */
2667 /* Clear out all variables saying what to do when inferior is continued.
2668 First do this, then set the ones you want, then call `proceed'. */
2671 clear_proceed_status_thread (struct thread_info
*tp
)
2674 fprintf_unfiltered (gdb_stdlog
,
2675 "infrun: clear_proceed_status_thread (%s)\n",
2676 target_pid_to_str (tp
->ptid
));
2678 /* If we're starting a new sequence, then the previous finished
2679 single-step is no longer relevant. */
2680 if (tp
->suspend
.waitstatus_pending_p
)
2682 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2685 fprintf_unfiltered (gdb_stdlog
,
2686 "infrun: clear_proceed_status: pending "
2687 "event of %s was a finished step. "
2689 target_pid_to_str (tp
->ptid
));
2691 tp
->suspend
.waitstatus_pending_p
= 0;
2692 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2694 else if (debug_infrun
)
2697 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2699 fprintf_unfiltered (gdb_stdlog
,
2700 "infrun: clear_proceed_status_thread: thread %s "
2701 "has pending wait status %s "
2702 "(currently_stepping=%d).\n",
2703 target_pid_to_str (tp
->ptid
), statstr
.c_str (),
2704 currently_stepping (tp
));
2708 /* If this signal should not be seen by program, give it zero.
2709 Used for debugging signals. */
2710 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2711 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2713 thread_fsm_delete (tp
->thread_fsm
);
2714 tp
->thread_fsm
= NULL
;
2716 tp
->control
.trap_expected
= 0;
2717 tp
->control
.step_range_start
= 0;
2718 tp
->control
.step_range_end
= 0;
2719 tp
->control
.may_range_step
= 0;
2720 tp
->control
.step_frame_id
= null_frame_id
;
2721 tp
->control
.step_stack_frame_id
= null_frame_id
;
2722 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2723 tp
->control
.step_start_function
= NULL
;
2724 tp
->stop_requested
= 0;
2726 tp
->control
.stop_step
= 0;
2728 tp
->control
.proceed_to_finish
= 0;
2730 tp
->control
.stepping_command
= 0;
2732 /* Discard any remaining commands or status from previous stop. */
2733 bpstat_clear (&tp
->control
.stop_bpstat
);
2737 clear_proceed_status (int step
)
2739 /* With scheduler-locking replay, stop replaying other threads if we're
2740 not replaying the user-visible resume ptid.
2742 This is a convenience feature to not require the user to explicitly
2743 stop replaying the other threads. We're assuming that the user's
2744 intent is to resume tracing the recorded process. */
2745 if (!non_stop
&& scheduler_mode
== schedlock_replay
2746 && target_record_is_replaying (minus_one_ptid
)
2747 && !target_record_will_replay (user_visible_resume_ptid (step
),
2748 execution_direction
))
2749 target_record_stop_replaying ();
2751 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2753 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2755 /* In all-stop mode, delete the per-thread status of all threads
2756 we're about to resume, implicitly and explicitly. */
2757 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
2758 clear_proceed_status_thread (tp
);
2761 if (inferior_ptid
!= null_ptid
)
2763 struct inferior
*inferior
;
2767 /* If in non-stop mode, only delete the per-thread status of
2768 the current thread. */
2769 clear_proceed_status_thread (inferior_thread ());
2772 inferior
= current_inferior ();
2773 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2776 gdb::observers::about_to_proceed
.notify ();
2779 /* Returns true if TP is still stopped at a breakpoint that needs
2780 stepping-over in order to make progress. If the breakpoint is gone
2781 meanwhile, we can skip the whole step-over dance. */
2784 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2786 if (tp
->stepping_over_breakpoint
)
2788 struct regcache
*regcache
= get_thread_regcache (tp
);
2790 if (breakpoint_here_p (regcache
->aspace (),
2791 regcache_read_pc (regcache
))
2792 == ordinary_breakpoint_here
)
2795 tp
->stepping_over_breakpoint
= 0;
2801 /* Check whether thread TP still needs to start a step-over in order
2802 to make progress when resumed. Returns an bitwise or of enum
2803 step_over_what bits, indicating what needs to be stepped over. */
2805 static step_over_what
2806 thread_still_needs_step_over (struct thread_info
*tp
)
2808 step_over_what what
= 0;
2810 if (thread_still_needs_step_over_bp (tp
))
2811 what
|= STEP_OVER_BREAKPOINT
;
2813 if (tp
->stepping_over_watchpoint
2814 && !target_have_steppable_watchpoint
)
2815 what
|= STEP_OVER_WATCHPOINT
;
2820 /* Returns true if scheduler locking applies. STEP indicates whether
2821 we're about to do a step/next-like command to a thread. */
2824 schedlock_applies (struct thread_info
*tp
)
2826 return (scheduler_mode
== schedlock_on
2827 || (scheduler_mode
== schedlock_step
2828 && tp
->control
.stepping_command
)
2829 || (scheduler_mode
== schedlock_replay
2830 && target_record_will_replay (minus_one_ptid
,
2831 execution_direction
)));
2834 /* Basic routine for continuing the program in various fashions.
2836 ADDR is the address to resume at, or -1 for resume where stopped.
2837 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2838 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2840 You should call clear_proceed_status before calling proceed. */
2843 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2845 struct regcache
*regcache
;
2846 struct gdbarch
*gdbarch
;
2849 struct execution_control_state ecss
;
2850 struct execution_control_state
*ecs
= &ecss
;
2853 /* If we're stopped at a fork/vfork, follow the branch set by the
2854 "set follow-fork-mode" command; otherwise, we'll just proceed
2855 resuming the current thread. */
2856 if (!follow_fork ())
2858 /* The target for some reason decided not to resume. */
2860 if (target_can_async_p ())
2861 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2865 /* We'll update this if & when we switch to a new thread. */
2866 previous_inferior_ptid
= inferior_ptid
;
2868 regcache
= get_current_regcache ();
2869 gdbarch
= regcache
->arch ();
2870 const address_space
*aspace
= regcache
->aspace ();
2872 pc
= regcache_read_pc (regcache
);
2873 thread_info
*cur_thr
= inferior_thread ();
2875 /* Fill in with reasonable starting values. */
2876 init_thread_stepping_state (cur_thr
);
2878 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2880 if (addr
== (CORE_ADDR
) -1)
2882 if (pc
== cur_thr
->suspend
.stop_pc
2883 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2884 && execution_direction
!= EXEC_REVERSE
)
2885 /* There is a breakpoint at the address we will resume at,
2886 step one instruction before inserting breakpoints so that
2887 we do not stop right away (and report a second hit at this
2890 Note, we don't do this in reverse, because we won't
2891 actually be executing the breakpoint insn anyway.
2892 We'll be (un-)executing the previous instruction. */
2893 cur_thr
->stepping_over_breakpoint
= 1;
2894 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2895 && gdbarch_single_step_through_delay (gdbarch
,
2896 get_current_frame ()))
2897 /* We stepped onto an instruction that needs to be stepped
2898 again before re-inserting the breakpoint, do so. */
2899 cur_thr
->stepping_over_breakpoint
= 1;
2903 regcache_write_pc (regcache
, addr
);
2906 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2907 cur_thr
->suspend
.stop_signal
= siggnal
;
2909 resume_ptid
= user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2911 /* If an exception is thrown from this point on, make sure to
2912 propagate GDB's knowledge of the executing state to the
2913 frontend/user running state. */
2914 scoped_finish_thread_state
finish_state (resume_ptid
);
2916 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2917 threads (e.g., we might need to set threads stepping over
2918 breakpoints first), from the user/frontend's point of view, all
2919 threads in RESUME_PTID are now running. Unless we're calling an
2920 inferior function, as in that case we pretend the inferior
2921 doesn't run at all. */
2922 if (!cur_thr
->control
.in_infcall
)
2923 set_running (resume_ptid
, 1);
2926 fprintf_unfiltered (gdb_stdlog
,
2927 "infrun: proceed (addr=%s, signal=%s)\n",
2928 paddress (gdbarch
, addr
),
2929 gdb_signal_to_symbol_string (siggnal
));
2931 annotate_starting ();
2933 /* Make sure that output from GDB appears before output from the
2935 gdb_flush (gdb_stdout
);
2937 /* Since we've marked the inferior running, give it the terminal. A
2938 QUIT/Ctrl-C from here on is forwarded to the target (which can
2939 still detect attempts to unblock a stuck connection with repeated
2940 Ctrl-C from within target_pass_ctrlc). */
2941 target_terminal::inferior ();
2943 /* In a multi-threaded task we may select another thread and
2944 then continue or step.
2946 But if a thread that we're resuming had stopped at a breakpoint,
2947 it will immediately cause another breakpoint stop without any
2948 execution (i.e. it will report a breakpoint hit incorrectly). So
2949 we must step over it first.
2951 Look for threads other than the current (TP) that reported a
2952 breakpoint hit and haven't been resumed yet since. */
2954 /* If scheduler locking applies, we can avoid iterating over all
2956 if (!non_stop
&& !schedlock_applies (cur_thr
))
2958 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
2960 /* Ignore the current thread here. It's handled
2965 if (!thread_still_needs_step_over (tp
))
2968 gdb_assert (!thread_is_in_step_over_chain (tp
));
2971 fprintf_unfiltered (gdb_stdlog
,
2972 "infrun: need to step-over [%s] first\n",
2973 target_pid_to_str (tp
->ptid
));
2975 thread_step_over_chain_enqueue (tp
);
2979 /* Enqueue the current thread last, so that we move all other
2980 threads over their breakpoints first. */
2981 if (cur_thr
->stepping_over_breakpoint
)
2982 thread_step_over_chain_enqueue (cur_thr
);
2984 /* If the thread isn't started, we'll still need to set its prev_pc,
2985 so that switch_back_to_stepped_thread knows the thread hasn't
2986 advanced. Must do this before resuming any thread, as in
2987 all-stop/remote, once we resume we can't send any other packet
2988 until the target stops again. */
2989 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
2992 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
2994 started
= start_step_over ();
2996 if (step_over_info_valid_p ())
2998 /* Either this thread started a new in-line step over, or some
2999 other thread was already doing one. In either case, don't
3000 resume anything else until the step-over is finished. */
3002 else if (started
&& !target_is_non_stop_p ())
3004 /* A new displaced stepping sequence was started. In all-stop,
3005 we can't talk to the target anymore until it next stops. */
3007 else if (!non_stop
&& target_is_non_stop_p ())
3009 /* In all-stop, but the target is always in non-stop mode.
3010 Start all other threads that are implicitly resumed too. */
3011 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
3016 fprintf_unfiltered (gdb_stdlog
,
3017 "infrun: proceed: [%s] resumed\n",
3018 target_pid_to_str (tp
->ptid
));
3019 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3023 if (thread_is_in_step_over_chain (tp
))
3026 fprintf_unfiltered (gdb_stdlog
,
3027 "infrun: proceed: [%s] needs step-over\n",
3028 target_pid_to_str (tp
->ptid
));
3033 fprintf_unfiltered (gdb_stdlog
,
3034 "infrun: proceed: resuming %s\n",
3035 target_pid_to_str (tp
->ptid
));
3037 reset_ecs (ecs
, tp
);
3038 switch_to_thread (tp
);
3039 keep_going_pass_signal (ecs
);
3040 if (!ecs
->wait_some_more
)
3041 error (_("Command aborted."));
3044 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3046 /* The thread wasn't started, and isn't queued, run it now. */
3047 reset_ecs (ecs
, cur_thr
);
3048 switch_to_thread (cur_thr
);
3049 keep_going_pass_signal (ecs
);
3050 if (!ecs
->wait_some_more
)
3051 error (_("Command aborted."));
3055 target_commit_resume ();
3057 finish_state
.release ();
3059 /* Tell the event loop to wait for it to stop. If the target
3060 supports asynchronous execution, it'll do this from within
3062 if (!target_can_async_p ())
3063 mark_async_event_handler (infrun_async_inferior_event_token
);
3067 /* Start remote-debugging of a machine over a serial link. */
3070 start_remote (int from_tty
)
3072 struct inferior
*inferior
;
3074 inferior
= current_inferior ();
3075 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3077 /* Always go on waiting for the target, regardless of the mode. */
3078 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3079 indicate to wait_for_inferior that a target should timeout if
3080 nothing is returned (instead of just blocking). Because of this,
3081 targets expecting an immediate response need to, internally, set
3082 things up so that the target_wait() is forced to eventually
3084 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3085 differentiate to its caller what the state of the target is after
3086 the initial open has been performed. Here we're assuming that
3087 the target has stopped. It should be possible to eventually have
3088 target_open() return to the caller an indication that the target
3089 is currently running and GDB state should be set to the same as
3090 for an async run. */
3091 wait_for_inferior ();
3093 /* Now that the inferior has stopped, do any bookkeeping like
3094 loading shared libraries. We want to do this before normal_stop,
3095 so that the displayed frame is up to date. */
3096 post_create_inferior (current_top_target (), from_tty
);
3101 /* Initialize static vars when a new inferior begins. */
3104 init_wait_for_inferior (void)
3106 /* These are meaningless until the first time through wait_for_inferior. */
3108 breakpoint_init_inferior (inf_starting
);
3110 clear_proceed_status (0);
3112 target_last_wait_ptid
= minus_one_ptid
;
3114 previous_inferior_ptid
= inferior_ptid
;
3119 static void handle_inferior_event (struct execution_control_state
*ecs
);
3121 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3122 struct execution_control_state
*ecs
);
3123 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3124 struct execution_control_state
*ecs
);
3125 static void handle_signal_stop (struct execution_control_state
*ecs
);
3126 static void check_exception_resume (struct execution_control_state
*,
3127 struct frame_info
*);
3129 static void end_stepping_range (struct execution_control_state
*ecs
);
3130 static void stop_waiting (struct execution_control_state
*ecs
);
3131 static void keep_going (struct execution_control_state
*ecs
);
3132 static void process_event_stop_test (struct execution_control_state
*ecs
);
3133 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3135 /* This function is attached as a "thread_stop_requested" observer.
3136 Cleanup local state that assumed the PTID was to be resumed, and
3137 report the stop to the frontend. */
3140 infrun_thread_stop_requested (ptid_t ptid
)
3142 /* PTID was requested to stop. If the thread was already stopped,
3143 but the user/frontend doesn't know about that yet (e.g., the
3144 thread had been temporarily paused for some step-over), set up
3145 for reporting the stop now. */
3146 for (thread_info
*tp
: all_threads (ptid
))
3148 if (tp
->state
!= THREAD_RUNNING
)
3153 /* Remove matching threads from the step-over queue, so
3154 start_step_over doesn't try to resume them
3156 if (thread_is_in_step_over_chain (tp
))
3157 thread_step_over_chain_remove (tp
);
3159 /* If the thread is stopped, but the user/frontend doesn't
3160 know about that yet, queue a pending event, as if the
3161 thread had just stopped now. Unless the thread already had
3163 if (!tp
->suspend
.waitstatus_pending_p
)
3165 tp
->suspend
.waitstatus_pending_p
= 1;
3166 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3167 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3170 /* Clear the inline-frame state, since we're re-processing the
3172 clear_inline_frame_state (tp
->ptid
);
3174 /* If this thread was paused because some other thread was
3175 doing an inline-step over, let that finish first. Once
3176 that happens, we'll restart all threads and consume pending
3177 stop events then. */
3178 if (step_over_info_valid_p ())
3181 /* Otherwise we can process the (new) pending event now. Set
3182 it so this pending event is considered by
3189 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3191 if (target_last_wait_ptid
== tp
->ptid
)
3192 nullify_last_target_wait_ptid ();
3195 /* Delete the step resume, single-step and longjmp/exception resume
3196 breakpoints of TP. */
3199 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3201 delete_step_resume_breakpoint (tp
);
3202 delete_exception_resume_breakpoint (tp
);
3203 delete_single_step_breakpoints (tp
);
3206 /* If the target still has execution, call FUNC for each thread that
3207 just stopped. In all-stop, that's all the non-exited threads; in
3208 non-stop, that's the current thread, only. */
3210 typedef void (*for_each_just_stopped_thread_callback_func
)
3211 (struct thread_info
*tp
);
3214 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3216 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3219 if (target_is_non_stop_p ())
3221 /* If in non-stop mode, only the current thread stopped. */
3222 func (inferior_thread ());
3226 /* In all-stop mode, all threads have stopped. */
3227 for (thread_info
*tp
: all_non_exited_threads ())
3232 /* Delete the step resume and longjmp/exception resume breakpoints of
3233 the threads that just stopped. */
3236 delete_just_stopped_threads_infrun_breakpoints (void)
3238 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3241 /* Delete the single-step breakpoints of the threads that just
3245 delete_just_stopped_threads_single_step_breakpoints (void)
3247 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3250 /* A cleanup wrapper. */
3253 delete_just_stopped_threads_infrun_breakpoints_cleanup (void *arg
)
3255 delete_just_stopped_threads_infrun_breakpoints ();
3261 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3262 const struct target_waitstatus
*ws
)
3264 std::string status_string
= target_waitstatus_to_string (ws
);
3267 /* The text is split over several lines because it was getting too long.
3268 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3269 output as a unit; we want only one timestamp printed if debug_timestamp
3272 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3275 waiton_ptid
.tid ());
3276 if (waiton_ptid
.pid () != -1)
3277 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
));
3278 stb
.printf (", status) =\n");
3279 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3283 target_pid_to_str (result_ptid
));
3284 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3286 /* This uses %s in part to handle %'s in the text, but also to avoid
3287 a gcc error: the format attribute requires a string literal. */
3288 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3291 /* Select a thread at random, out of those which are resumed and have
3294 static struct thread_info
*
3295 random_pending_event_thread (ptid_t waiton_ptid
)
3299 auto has_event
= [] (thread_info
*tp
)
3302 && tp
->suspend
.waitstatus_pending_p
);
3305 /* First see how many events we have. Count only resumed threads
3306 that have an event pending. */
3307 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3311 if (num_events
== 0)
3314 /* Now randomly pick a thread out of those that have had events. */
3315 int random_selector
= (int) ((num_events
* (double) rand ())
3316 / (RAND_MAX
+ 1.0));
3318 if (debug_infrun
&& num_events
> 1)
3319 fprintf_unfiltered (gdb_stdlog
,
3320 "infrun: Found %d events, selecting #%d\n",
3321 num_events
, random_selector
);
3323 /* Select the Nth thread that has had an event. */
3324 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3326 if (random_selector
-- == 0)
3329 gdb_assert_not_reached ("event thread not found");
3332 /* Wrapper for target_wait that first checks whether threads have
3333 pending statuses to report before actually asking the target for
3337 do_target_wait (ptid_t ptid
, struct target_waitstatus
*status
, int options
)
3340 struct thread_info
*tp
;
3342 /* First check if there is a resumed thread with a wait status
3344 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3346 tp
= random_pending_event_thread (ptid
);
3351 fprintf_unfiltered (gdb_stdlog
,
3352 "infrun: Waiting for specific thread %s.\n",
3353 target_pid_to_str (ptid
));
3355 /* We have a specific thread to check. */
3356 tp
= find_thread_ptid (ptid
);
3357 gdb_assert (tp
!= NULL
);
3358 if (!tp
->suspend
.waitstatus_pending_p
)
3363 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3364 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3366 struct regcache
*regcache
= get_thread_regcache (tp
);
3367 struct gdbarch
*gdbarch
= regcache
->arch ();
3371 pc
= regcache_read_pc (regcache
);
3373 if (pc
!= tp
->suspend
.stop_pc
)
3376 fprintf_unfiltered (gdb_stdlog
,
3377 "infrun: PC of %s changed. was=%s, now=%s\n",
3378 target_pid_to_str (tp
->ptid
),
3379 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3380 paddress (gdbarch
, pc
));
3383 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3386 fprintf_unfiltered (gdb_stdlog
,
3387 "infrun: previous breakpoint of %s, at %s gone\n",
3388 target_pid_to_str (tp
->ptid
),
3389 paddress (gdbarch
, pc
));
3397 fprintf_unfiltered (gdb_stdlog
,
3398 "infrun: pending event of %s cancelled.\n",
3399 target_pid_to_str (tp
->ptid
));
3401 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3402 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3411 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3413 fprintf_unfiltered (gdb_stdlog
,
3414 "infrun: Using pending wait status %s for %s.\n",
3416 target_pid_to_str (tp
->ptid
));
3419 /* Now that we've selected our final event LWP, un-adjust its PC
3420 if it was a software breakpoint (and the target doesn't
3421 always adjust the PC itself). */
3422 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3423 && !target_supports_stopped_by_sw_breakpoint ())
3425 struct regcache
*regcache
;
3426 struct gdbarch
*gdbarch
;
3429 regcache
= get_thread_regcache (tp
);
3430 gdbarch
= regcache
->arch ();
3432 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3437 pc
= regcache_read_pc (regcache
);
3438 regcache_write_pc (regcache
, pc
+ decr_pc
);
3442 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3443 *status
= tp
->suspend
.waitstatus
;
3444 tp
->suspend
.waitstatus_pending_p
= 0;
3446 /* Wake up the event loop again, until all pending events are
3448 if (target_is_async_p ())
3449 mark_async_event_handler (infrun_async_inferior_event_token
);
3453 /* But if we don't find one, we'll have to wait. */
3455 if (deprecated_target_wait_hook
)
3456 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3458 event_ptid
= target_wait (ptid
, status
, options
);
3463 /* Prepare and stabilize the inferior for detaching it. E.g.,
3464 detaching while a thread is displaced stepping is a recipe for
3465 crashing it, as nothing would readjust the PC out of the scratch
3469 prepare_for_detach (void)
3471 struct inferior
*inf
= current_inferior ();
3472 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3474 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3476 /* Is any thread of this process displaced stepping? If not,
3477 there's nothing else to do. */
3478 if (displaced
->step_thread
== nullptr)
3482 fprintf_unfiltered (gdb_stdlog
,
3483 "displaced-stepping in-process while detaching");
3485 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3487 while (displaced
->step_thread
!= nullptr)
3489 struct execution_control_state ecss
;
3490 struct execution_control_state
*ecs
;
3493 memset (ecs
, 0, sizeof (*ecs
));
3495 overlay_cache_invalid
= 1;
3496 /* Flush target cache before starting to handle each event.
3497 Target was running and cache could be stale. This is just a
3498 heuristic. Running threads may modify target memory, but we
3499 don't get any event. */
3500 target_dcache_invalidate ();
3502 ecs
->ptid
= do_target_wait (pid_ptid
, &ecs
->ws
, 0);
3505 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3507 /* If an error happens while handling the event, propagate GDB's
3508 knowledge of the executing state to the frontend/user running
3510 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3512 /* Now figure out what to do with the result of the result. */
3513 handle_inferior_event (ecs
);
3515 /* No error, don't finish the state yet. */
3516 finish_state
.release ();
3518 /* Breakpoints and watchpoints are not installed on the target
3519 at this point, and signals are passed directly to the
3520 inferior, so this must mean the process is gone. */
3521 if (!ecs
->wait_some_more
)
3523 restore_detaching
.release ();
3524 error (_("Program exited while detaching"));
3528 restore_detaching
.release ();
3531 /* Wait for control to return from inferior to debugger.
3533 If inferior gets a signal, we may decide to start it up again
3534 instead of returning. That is why there is a loop in this function.
3535 When this function actually returns it means the inferior
3536 should be left stopped and GDB should read more commands. */
3539 wait_for_inferior (void)
3541 struct cleanup
*old_cleanups
;
3545 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3548 = make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
,
3551 /* If an error happens while handling the event, propagate GDB's
3552 knowledge of the executing state to the frontend/user running
3554 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3558 struct execution_control_state ecss
;
3559 struct execution_control_state
*ecs
= &ecss
;
3560 ptid_t waiton_ptid
= minus_one_ptid
;
3562 memset (ecs
, 0, sizeof (*ecs
));
3564 overlay_cache_invalid
= 1;
3566 /* Flush target cache before starting to handle each event.
3567 Target was running and cache could be stale. This is just a
3568 heuristic. Running threads may modify target memory, but we
3569 don't get any event. */
3570 target_dcache_invalidate ();
3572 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
, 0);
3575 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3577 /* Now figure out what to do with the result of the result. */
3578 handle_inferior_event (ecs
);
3580 if (!ecs
->wait_some_more
)
3584 /* No error, don't finish the state yet. */
3585 finish_state
.release ();
3587 do_cleanups (old_cleanups
);
3590 /* Cleanup that reinstalls the readline callback handler, if the
3591 target is running in the background. If while handling the target
3592 event something triggered a secondary prompt, like e.g., a
3593 pagination prompt, we'll have removed the callback handler (see
3594 gdb_readline_wrapper_line). Need to do this as we go back to the
3595 event loop, ready to process further input. Note this has no
3596 effect if the handler hasn't actually been removed, because calling
3597 rl_callback_handler_install resets the line buffer, thus losing
3601 reinstall_readline_callback_handler_cleanup (void *arg
)
3603 struct ui
*ui
= current_ui
;
3607 /* We're not going back to the top level event loop yet. Don't
3608 install the readline callback, as it'd prep the terminal,
3609 readline-style (raw, noecho) (e.g., --batch). We'll install
3610 it the next time the prompt is displayed, when we're ready
3615 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3616 gdb_rl_callback_handler_reinstall ();
3619 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3620 that's just the event thread. In all-stop, that's all threads. */
3623 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3625 if (ecs
->event_thread
!= NULL
3626 && ecs
->event_thread
->thread_fsm
!= NULL
)
3627 thread_fsm_clean_up (ecs
->event_thread
->thread_fsm
,
3632 for (thread_info
*thr
: all_non_exited_threads ())
3634 if (thr
->thread_fsm
== NULL
)
3636 if (thr
== ecs
->event_thread
)
3639 switch_to_thread (thr
);
3640 thread_fsm_clean_up (thr
->thread_fsm
, thr
);
3643 if (ecs
->event_thread
!= NULL
)
3644 switch_to_thread (ecs
->event_thread
);
3648 /* Helper for all_uis_check_sync_execution_done that works on the
3652 check_curr_ui_sync_execution_done (void)
3654 struct ui
*ui
= current_ui
;
3656 if (ui
->prompt_state
== PROMPT_NEEDED
3658 && !gdb_in_secondary_prompt_p (ui
))
3660 target_terminal::ours ();
3661 gdb::observers::sync_execution_done
.notify ();
3662 ui_register_input_event_handler (ui
);
3669 all_uis_check_sync_execution_done (void)
3671 SWITCH_THRU_ALL_UIS ()
3673 check_curr_ui_sync_execution_done ();
3680 all_uis_on_sync_execution_starting (void)
3682 SWITCH_THRU_ALL_UIS ()
3684 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3685 async_disable_stdin ();
3689 /* Asynchronous version of wait_for_inferior. It is called by the
3690 event loop whenever a change of state is detected on the file
3691 descriptor corresponding to the target. It can be called more than
3692 once to complete a single execution command. In such cases we need
3693 to keep the state in a global variable ECSS. If it is the last time
3694 that this function is called for a single execution command, then
3695 report to the user that the inferior has stopped, and do the
3696 necessary cleanups. */
3699 fetch_inferior_event (void *client_data
)
3701 struct execution_control_state ecss
;
3702 struct execution_control_state
*ecs
= &ecss
;
3703 struct cleanup
*old_chain
= make_cleanup (null_cleanup
, NULL
);
3705 ptid_t waiton_ptid
= minus_one_ptid
;
3707 memset (ecs
, 0, sizeof (*ecs
));
3709 /* Events are always processed with the main UI as current UI. This
3710 way, warnings, debug output, etc. are always consistently sent to
3711 the main console. */
3712 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3714 /* End up with readline processing input, if necessary. */
3715 make_cleanup (reinstall_readline_callback_handler_cleanup
, NULL
);
3717 /* We're handling a live event, so make sure we're doing live
3718 debugging. If we're looking at traceframes while the target is
3719 running, we're going to need to get back to that mode after
3720 handling the event. */
3721 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3724 maybe_restore_traceframe
.emplace ();
3725 set_current_traceframe (-1);
3728 gdb::optional
<scoped_restore_current_thread
> maybe_restore_thread
;
3731 /* In non-stop mode, the user/frontend should not notice a thread
3732 switch due to internal events. Make sure we reverse to the
3733 user selected thread and frame after handling the event and
3734 running any breakpoint commands. */
3735 maybe_restore_thread
.emplace ();
3737 overlay_cache_invalid
= 1;
3738 /* Flush target cache before starting to handle each event. Target
3739 was running and cache could be stale. This is just a heuristic.
3740 Running threads may modify target memory, but we don't get any
3742 target_dcache_invalidate ();
3744 scoped_restore save_exec_dir
3745 = make_scoped_restore (&execution_direction
, target_execution_direction ());
3747 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
,
3748 target_can_async_p () ? TARGET_WNOHANG
: 0);
3751 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3753 /* If an error happens while handling the event, propagate GDB's
3754 knowledge of the executing state to the frontend/user running
3756 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3757 scoped_finish_thread_state
finish_state (finish_ptid
);
3759 /* Get executed before make_cleanup_restore_current_thread above to apply
3760 still for the thread which has thrown the exception. */
3761 struct cleanup
*ts_old_chain
= make_bpstat_clear_actions_cleanup ();
3763 make_cleanup (delete_just_stopped_threads_infrun_breakpoints_cleanup
, NULL
);
3765 /* Now figure out what to do with the result of the result. */
3766 handle_inferior_event (ecs
);
3768 if (!ecs
->wait_some_more
)
3770 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3771 int should_stop
= 1;
3772 struct thread_info
*thr
= ecs
->event_thread
;
3774 delete_just_stopped_threads_infrun_breakpoints ();
3778 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3780 if (thread_fsm
!= NULL
)
3781 should_stop
= thread_fsm_should_stop (thread_fsm
, thr
);
3790 int should_notify_stop
= 1;
3793 clean_up_just_stopped_threads_fsms (ecs
);
3795 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3798 = thread_fsm_should_notify_stop (thr
->thread_fsm
);
3801 if (should_notify_stop
)
3803 /* We may not find an inferior if this was a process exit. */
3804 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3805 proceeded
= normal_stop ();
3810 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3816 discard_cleanups (ts_old_chain
);
3818 /* No error, don't finish the thread states yet. */
3819 finish_state
.release ();
3821 /* Revert thread and frame. */
3822 do_cleanups (old_chain
);
3824 /* If a UI was in sync execution mode, and now isn't, restore its
3825 prompt (a synchronous execution command has finished, and we're
3826 ready for input). */
3827 all_uis_check_sync_execution_done ();
3830 && exec_done_display_p
3831 && (inferior_ptid
== null_ptid
3832 || inferior_thread ()->state
!= THREAD_RUNNING
))
3833 printf_unfiltered (_("completed.\n"));
3836 /* Record the frame and location we're currently stepping through. */
3838 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
3840 struct thread_info
*tp
= inferior_thread ();
3842 tp
->control
.step_frame_id
= get_frame_id (frame
);
3843 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3845 tp
->current_symtab
= sal
.symtab
;
3846 tp
->current_line
= sal
.line
;
3849 /* Clear context switchable stepping state. */
3852 init_thread_stepping_state (struct thread_info
*tss
)
3854 tss
->stepped_breakpoint
= 0;
3855 tss
->stepping_over_breakpoint
= 0;
3856 tss
->stepping_over_watchpoint
= 0;
3857 tss
->step_after_step_resume_breakpoint
= 0;
3860 /* Set the cached copy of the last ptid/waitstatus. */
3863 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
3865 target_last_wait_ptid
= ptid
;
3866 target_last_waitstatus
= status
;
3869 /* Return the cached copy of the last pid/waitstatus returned by
3870 target_wait()/deprecated_target_wait_hook(). The data is actually
3871 cached by handle_inferior_event(), which gets called immediately
3872 after target_wait()/deprecated_target_wait_hook(). */
3875 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
3877 *ptidp
= target_last_wait_ptid
;
3878 *status
= target_last_waitstatus
;
3882 nullify_last_target_wait_ptid (void)
3884 target_last_wait_ptid
= minus_one_ptid
;
3887 /* Switch thread contexts. */
3890 context_switch (execution_control_state
*ecs
)
3893 && ecs
->ptid
!= inferior_ptid
3894 && ecs
->event_thread
!= inferior_thread ())
3896 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
3897 target_pid_to_str (inferior_ptid
));
3898 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
3899 target_pid_to_str (ecs
->ptid
));
3902 switch_to_thread (ecs
->event_thread
);
3905 /* If the target can't tell whether we've hit breakpoints
3906 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3907 check whether that could have been caused by a breakpoint. If so,
3908 adjust the PC, per gdbarch_decr_pc_after_break. */
3911 adjust_pc_after_break (struct thread_info
*thread
,
3912 struct target_waitstatus
*ws
)
3914 struct regcache
*regcache
;
3915 struct gdbarch
*gdbarch
;
3916 CORE_ADDR breakpoint_pc
, decr_pc
;
3918 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3919 we aren't, just return.
3921 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3922 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3923 implemented by software breakpoints should be handled through the normal
3926 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3927 different signals (SIGILL or SIGEMT for instance), but it is less
3928 clear where the PC is pointing afterwards. It may not match
3929 gdbarch_decr_pc_after_break. I don't know any specific target that
3930 generates these signals at breakpoints (the code has been in GDB since at
3931 least 1992) so I can not guess how to handle them here.
3933 In earlier versions of GDB, a target with
3934 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3935 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3936 target with both of these set in GDB history, and it seems unlikely to be
3937 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3939 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
3942 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
3945 /* In reverse execution, when a breakpoint is hit, the instruction
3946 under it has already been de-executed. The reported PC always
3947 points at the breakpoint address, so adjusting it further would
3948 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3951 B1 0x08000000 : INSN1
3952 B2 0x08000001 : INSN2
3954 PC -> 0x08000003 : INSN4
3956 Say you're stopped at 0x08000003 as above. Reverse continuing
3957 from that point should hit B2 as below. Reading the PC when the
3958 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3959 been de-executed already.
3961 B1 0x08000000 : INSN1
3962 B2 PC -> 0x08000001 : INSN2
3966 We can't apply the same logic as for forward execution, because
3967 we would wrongly adjust the PC to 0x08000000, since there's a
3968 breakpoint at PC - 1. We'd then report a hit on B1, although
3969 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3971 if (execution_direction
== EXEC_REVERSE
)
3974 /* If the target can tell whether the thread hit a SW breakpoint,
3975 trust it. Targets that can tell also adjust the PC
3977 if (target_supports_stopped_by_sw_breakpoint ())
3980 /* Note that relying on whether a breakpoint is planted in memory to
3981 determine this can fail. E.g,. the breakpoint could have been
3982 removed since. Or the thread could have been told to step an
3983 instruction the size of a breakpoint instruction, and only
3984 _after_ was a breakpoint inserted at its address. */
3986 /* If this target does not decrement the PC after breakpoints, then
3987 we have nothing to do. */
3988 regcache
= get_thread_regcache (thread
);
3989 gdbarch
= regcache
->arch ();
3991 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3995 const address_space
*aspace
= regcache
->aspace ();
3997 /* Find the location where (if we've hit a breakpoint) the
3998 breakpoint would be. */
3999 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4001 /* If the target can't tell whether a software breakpoint triggered,
4002 fallback to figuring it out based on breakpoints we think were
4003 inserted in the target, and on whether the thread was stepped or
4006 /* Check whether there actually is a software breakpoint inserted at
4009 If in non-stop mode, a race condition is possible where we've
4010 removed a breakpoint, but stop events for that breakpoint were
4011 already queued and arrive later. To suppress those spurious
4012 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4013 and retire them after a number of stop events are reported. Note
4014 this is an heuristic and can thus get confused. The real fix is
4015 to get the "stopped by SW BP and needs adjustment" info out of
4016 the target/kernel (and thus never reach here; see above). */
4017 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4018 || (target_is_non_stop_p ()
4019 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4021 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4023 if (record_full_is_used ())
4024 restore_operation_disable
.emplace
4025 (record_full_gdb_operation_disable_set ());
4027 /* When using hardware single-step, a SIGTRAP is reported for both
4028 a completed single-step and a software breakpoint. Need to
4029 differentiate between the two, as the latter needs adjusting
4030 but the former does not.
4032 The SIGTRAP can be due to a completed hardware single-step only if
4033 - we didn't insert software single-step breakpoints
4034 - this thread is currently being stepped
4036 If any of these events did not occur, we must have stopped due
4037 to hitting a software breakpoint, and have to back up to the
4040 As a special case, we could have hardware single-stepped a
4041 software breakpoint. In this case (prev_pc == breakpoint_pc),
4042 we also need to back up to the breakpoint address. */
4044 if (thread_has_single_step_breakpoints_set (thread
)
4045 || !currently_stepping (thread
)
4046 || (thread
->stepped_breakpoint
4047 && thread
->prev_pc
== breakpoint_pc
))
4048 regcache_write_pc (regcache
, breakpoint_pc
);
4053 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4055 for (frame
= get_prev_frame (frame
);
4057 frame
= get_prev_frame (frame
))
4059 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4061 if (get_frame_type (frame
) != INLINE_FRAME
)
4068 /* If the event thread has the stop requested flag set, pretend it
4069 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4073 handle_stop_requested (struct execution_control_state
*ecs
)
4075 if (ecs
->event_thread
->stop_requested
)
4077 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4078 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4079 handle_signal_stop (ecs
);
4085 /* Auxiliary function that handles syscall entry/return events.
4086 It returns 1 if the inferior should keep going (and GDB
4087 should ignore the event), or 0 if the event deserves to be
4091 handle_syscall_event (struct execution_control_state
*ecs
)
4093 struct regcache
*regcache
;
4096 context_switch (ecs
);
4098 regcache
= get_thread_regcache (ecs
->event_thread
);
4099 syscall_number
= ecs
->ws
.value
.syscall_number
;
4100 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4102 if (catch_syscall_enabled () > 0
4103 && catching_syscall_number (syscall_number
) > 0)
4106 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4109 ecs
->event_thread
->control
.stop_bpstat
4110 = bpstat_stop_status (regcache
->aspace (),
4111 ecs
->event_thread
->suspend
.stop_pc
,
4112 ecs
->event_thread
, &ecs
->ws
);
4114 if (handle_stop_requested (ecs
))
4117 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4119 /* Catchpoint hit. */
4124 if (handle_stop_requested (ecs
))
4127 /* If no catchpoint triggered for this, then keep going. */
4132 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4135 fill_in_stop_func (struct gdbarch
*gdbarch
,
4136 struct execution_control_state
*ecs
)
4138 if (!ecs
->stop_func_filled_in
)
4140 /* Don't care about return value; stop_func_start and stop_func_name
4141 will both be 0 if it doesn't work. */
4142 find_function_entry_range_from_pc (ecs
->event_thread
->suspend
.stop_pc
,
4143 &ecs
->stop_func_name
,
4144 &ecs
->stop_func_start
,
4145 &ecs
->stop_func_end
);
4146 ecs
->stop_func_start
4147 += gdbarch_deprecated_function_start_offset (gdbarch
);
4149 if (gdbarch_skip_entrypoint_p (gdbarch
))
4150 ecs
->stop_func_start
= gdbarch_skip_entrypoint (gdbarch
,
4151 ecs
->stop_func_start
);
4153 ecs
->stop_func_filled_in
= 1;
4158 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4160 static enum stop_kind
4161 get_inferior_stop_soon (execution_control_state
*ecs
)
4163 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
4165 gdb_assert (inf
!= NULL
);
4166 return inf
->control
.stop_soon
;
4169 /* Wait for one event. Store the resulting waitstatus in WS, and
4170 return the event ptid. */
4173 wait_one (struct target_waitstatus
*ws
)
4176 ptid_t wait_ptid
= minus_one_ptid
;
4178 overlay_cache_invalid
= 1;
4180 /* Flush target cache before starting to handle each event.
4181 Target was running and cache could be stale. This is just a
4182 heuristic. Running threads may modify target memory, but we
4183 don't get any event. */
4184 target_dcache_invalidate ();
4186 if (deprecated_target_wait_hook
)
4187 event_ptid
= deprecated_target_wait_hook (wait_ptid
, ws
, 0);
4189 event_ptid
= target_wait (wait_ptid
, ws
, 0);
4192 print_target_wait_results (wait_ptid
, event_ptid
, ws
);
4197 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4198 instead of the current thread. */
4199 #define THREAD_STOPPED_BY(REASON) \
4201 thread_stopped_by_ ## REASON (ptid_t ptid) \
4203 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4204 inferior_ptid = ptid; \
4206 return target_stopped_by_ ## REASON (); \
4209 /* Generate thread_stopped_by_watchpoint. */
4210 THREAD_STOPPED_BY (watchpoint
)
4211 /* Generate thread_stopped_by_sw_breakpoint. */
4212 THREAD_STOPPED_BY (sw_breakpoint
)
4213 /* Generate thread_stopped_by_hw_breakpoint. */
4214 THREAD_STOPPED_BY (hw_breakpoint
)
4216 /* Save the thread's event and stop reason to process it later. */
4219 save_waitstatus (struct thread_info
*tp
, struct target_waitstatus
*ws
)
4223 std::string statstr
= target_waitstatus_to_string (ws
);
4225 fprintf_unfiltered (gdb_stdlog
,
4226 "infrun: saving status %s for %d.%ld.%ld\n",
4233 /* Record for later. */
4234 tp
->suspend
.waitstatus
= *ws
;
4235 tp
->suspend
.waitstatus_pending_p
= 1;
4237 struct regcache
*regcache
= get_thread_regcache (tp
);
4238 const address_space
*aspace
= regcache
->aspace ();
4240 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4241 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4243 CORE_ADDR pc
= regcache_read_pc (regcache
);
4245 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4247 if (thread_stopped_by_watchpoint (tp
->ptid
))
4249 tp
->suspend
.stop_reason
4250 = TARGET_STOPPED_BY_WATCHPOINT
;
4252 else if (target_supports_stopped_by_sw_breakpoint ()
4253 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4255 tp
->suspend
.stop_reason
4256 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4258 else if (target_supports_stopped_by_hw_breakpoint ()
4259 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4261 tp
->suspend
.stop_reason
4262 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4264 else if (!target_supports_stopped_by_hw_breakpoint ()
4265 && hardware_breakpoint_inserted_here_p (aspace
,
4268 tp
->suspend
.stop_reason
4269 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4271 else if (!target_supports_stopped_by_sw_breakpoint ()
4272 && software_breakpoint_inserted_here_p (aspace
,
4275 tp
->suspend
.stop_reason
4276 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4278 else if (!thread_has_single_step_breakpoints_set (tp
)
4279 && currently_stepping (tp
))
4281 tp
->suspend
.stop_reason
4282 = TARGET_STOPPED_BY_SINGLE_STEP
;
4287 /* A cleanup that disables thread create/exit events. */
4290 disable_thread_events (void *arg
)
4292 target_thread_events (0);
4298 stop_all_threads (void)
4300 /* We may need multiple passes to discover all threads. */
4303 struct cleanup
*old_chain
;
4305 gdb_assert (target_is_non_stop_p ());
4308 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4310 scoped_restore_current_thread restore_thread
;
4312 target_thread_events (1);
4313 old_chain
= make_cleanup (disable_thread_events
, NULL
);
4315 /* Request threads to stop, and then wait for the stops. Because
4316 threads we already know about can spawn more threads while we're
4317 trying to stop them, and we only learn about new threads when we
4318 update the thread list, do this in a loop, and keep iterating
4319 until two passes find no threads that need to be stopped. */
4320 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4323 fprintf_unfiltered (gdb_stdlog
,
4324 "infrun: stop_all_threads, pass=%d, "
4325 "iterations=%d\n", pass
, iterations
);
4329 struct target_waitstatus ws
;
4332 update_thread_list ();
4334 /* Go through all threads looking for threads that we need
4335 to tell the target to stop. */
4336 for (thread_info
*t
: all_non_exited_threads ())
4340 /* If already stopping, don't request a stop again.
4341 We just haven't seen the notification yet. */
4342 if (!t
->stop_requested
)
4345 fprintf_unfiltered (gdb_stdlog
,
4346 "infrun: %s executing, "
4348 target_pid_to_str (t
->ptid
));
4349 target_stop (t
->ptid
);
4350 t
->stop_requested
= 1;
4355 fprintf_unfiltered (gdb_stdlog
,
4356 "infrun: %s executing, "
4357 "already stopping\n",
4358 target_pid_to_str (t
->ptid
));
4361 if (t
->stop_requested
)
4367 fprintf_unfiltered (gdb_stdlog
,
4368 "infrun: %s not executing\n",
4369 target_pid_to_str (t
->ptid
));
4371 /* The thread may be not executing, but still be
4372 resumed with a pending status to process. */
4380 /* If we find new threads on the second iteration, restart
4381 over. We want to see two iterations in a row with all
4386 event_ptid
= wait_one (&ws
);
4388 if (ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4390 /* All resumed threads exited. */
4392 else if (ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4393 || ws
.kind
== TARGET_WAITKIND_EXITED
4394 || ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4398 ptid_t ptid
= ptid_t (ws
.value
.integer
);
4400 fprintf_unfiltered (gdb_stdlog
,
4401 "infrun: %s exited while "
4402 "stopping threads\n",
4403 target_pid_to_str (ptid
));
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
));
4445 t
->control
.trap_expected
= 0;
4446 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 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
),
4491 currently_stepping (t
));
4498 do_cleanups (old_chain
);
4501 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4504 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4507 handle_no_resumed (struct execution_control_state
*ecs
)
4509 if (target_can_async_p ())
4516 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4524 /* There were no unwaited-for children left in the target, but,
4525 we're not synchronously waiting for events either. Just
4529 fprintf_unfiltered (gdb_stdlog
,
4530 "infrun: TARGET_WAITKIND_NO_RESUMED "
4531 "(ignoring: bg)\n");
4532 prepare_to_wait (ecs
);
4537 /* Otherwise, if we were running a synchronous execution command, we
4538 may need to cancel it and give the user back the terminal.
4540 In non-stop mode, the target can't tell whether we've already
4541 consumed previous stop events, so it can end up sending us a
4542 no-resumed event like so:
4544 #0 - thread 1 is left stopped
4546 #1 - thread 2 is resumed and hits breakpoint
4547 -> TARGET_WAITKIND_STOPPED
4549 #2 - thread 3 is resumed and exits
4550 this is the last resumed thread, so
4551 -> TARGET_WAITKIND_NO_RESUMED
4553 #3 - gdb processes stop for thread 2 and decides to re-resume
4556 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4557 thread 2 is now resumed, so the event should be ignored.
4559 IOW, if the stop for thread 2 doesn't end a foreground command,
4560 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4561 event. But it could be that the event meant that thread 2 itself
4562 (or whatever other thread was the last resumed thread) exited.
4564 To address this we refresh the thread list and check whether we
4565 have resumed threads _now_. In the example above, this removes
4566 thread 3 from the thread list. If thread 2 was re-resumed, we
4567 ignore this event. If we find no thread resumed, then we cancel
4568 the synchronous command show "no unwaited-for " to the user. */
4569 update_thread_list ();
4571 for (thread_info
*thread
: all_non_exited_threads ())
4573 if (thread
->executing
4574 || thread
->suspend
.waitstatus_pending_p
)
4576 /* There were no unwaited-for children left in the target at
4577 some point, but there are now. Just ignore. */
4579 fprintf_unfiltered (gdb_stdlog
,
4580 "infrun: TARGET_WAITKIND_NO_RESUMED "
4581 "(ignoring: found resumed)\n");
4582 prepare_to_wait (ecs
);
4587 /* Note however that we may find no resumed thread because the whole
4588 process exited meanwhile (thus updating the thread list results
4589 in an empty thread list). In this case we know we'll be getting
4590 a process exit event shortly. */
4591 for (inferior
*inf
: all_inferiors ())
4596 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4600 fprintf_unfiltered (gdb_stdlog
,
4601 "infrun: TARGET_WAITKIND_NO_RESUMED "
4602 "(expect process exit)\n");
4603 prepare_to_wait (ecs
);
4608 /* Go ahead and report the event. */
4612 /* Given an execution control state that has been freshly filled in by
4613 an event from the inferior, figure out what it means and take
4616 The alternatives are:
4618 1) stop_waiting and return; to really stop and return to the
4621 2) keep_going and return; to wait for the next event (set
4622 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4626 handle_inferior_event_1 (struct execution_control_state
*ecs
)
4628 enum stop_kind stop_soon
;
4630 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4632 /* We had an event in the inferior, but we are not interested in
4633 handling it at this level. The lower layers have already
4634 done what needs to be done, if anything.
4636 One of the possible circumstances for this is when the
4637 inferior produces output for the console. The inferior has
4638 not stopped, and we are ignoring the event. Another possible
4639 circumstance is any event which the lower level knows will be
4640 reported multiple times without an intervening resume. */
4642 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_IGNORE\n");
4643 prepare_to_wait (ecs
);
4647 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4650 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_THREAD_EXITED\n");
4651 prepare_to_wait (ecs
);
4655 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4656 && handle_no_resumed (ecs
))
4659 /* Cache the last pid/waitstatus. */
4660 set_last_target_status (ecs
->ptid
, ecs
->ws
);
4662 /* Always clear state belonging to the previous time we stopped. */
4663 stop_stack_dummy
= STOP_NONE
;
4665 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4667 /* No unwaited-for children left. IOW, all resumed children
4670 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_RESUMED\n");
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
:
4765 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_LOADED\n");
4766 context_switch (ecs
);
4767 /* Ignore gracefully during startup of the inferior, as it might
4768 be the shell which has just loaded some objects, otherwise
4769 add the symbols for the newly loaded objects. Also ignore at
4770 the beginning of an attach or remote session; we will query
4771 the full list of libraries once the connection is
4774 stop_soon
= get_inferior_stop_soon (ecs
);
4775 if (stop_soon
== NO_STOP_QUIETLY
)
4777 struct regcache
*regcache
;
4779 regcache
= get_thread_regcache (ecs
->event_thread
);
4781 handle_solib_event ();
4783 ecs
->event_thread
->control
.stop_bpstat
4784 = bpstat_stop_status (regcache
->aspace (),
4785 ecs
->event_thread
->suspend
.stop_pc
,
4786 ecs
->event_thread
, &ecs
->ws
);
4788 if (handle_stop_requested (ecs
))
4791 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4793 /* A catchpoint triggered. */
4794 process_event_stop_test (ecs
);
4798 /* If requested, stop when the dynamic linker notifies
4799 gdb of events. This allows the user to get control
4800 and place breakpoints in initializer routines for
4801 dynamically loaded objects (among other things). */
4802 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4803 if (stop_on_solib_events
)
4805 /* Make sure we print "Stopped due to solib-event" in
4807 stop_print_frame
= 1;
4814 /* If we are skipping through a shell, or through shared library
4815 loading that we aren't interested in, resume the program. If
4816 we're running the program normally, also resume. */
4817 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
4819 /* Loading of shared libraries might have changed breakpoint
4820 addresses. Make sure new breakpoints are inserted. */
4821 if (stop_soon
== NO_STOP_QUIETLY
)
4822 insert_breakpoints ();
4823 resume (GDB_SIGNAL_0
);
4824 prepare_to_wait (ecs
);
4828 /* But stop if we're attaching or setting up a remote
4830 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4831 || stop_soon
== STOP_QUIETLY_REMOTE
)
4834 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4839 internal_error (__FILE__
, __LINE__
,
4840 _("unhandled stop_soon: %d"), (int) stop_soon
);
4842 case TARGET_WAITKIND_SPURIOUS
:
4844 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_SPURIOUS\n");
4845 if (handle_stop_requested (ecs
))
4847 context_switch (ecs
);
4848 resume (GDB_SIGNAL_0
);
4849 prepare_to_wait (ecs
);
4852 case TARGET_WAITKIND_THREAD_CREATED
:
4854 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_THREAD_CREATED\n");
4855 if (handle_stop_requested (ecs
))
4857 context_switch (ecs
);
4858 if (!switch_back_to_stepped_thread (ecs
))
4862 case TARGET_WAITKIND_EXITED
:
4863 case TARGET_WAITKIND_SIGNALLED
:
4866 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4867 fprintf_unfiltered (gdb_stdlog
,
4868 "infrun: TARGET_WAITKIND_EXITED\n");
4870 fprintf_unfiltered (gdb_stdlog
,
4871 "infrun: TARGET_WAITKIND_SIGNALLED\n");
4874 inferior_ptid
= ecs
->ptid
;
4875 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
4876 set_current_program_space (current_inferior ()->pspace
);
4877 handle_vfork_child_exec_or_exit (0);
4878 target_terminal::ours (); /* Must do this before mourn anyway. */
4880 /* Clearing any previous state of convenience variables. */
4881 clear_exit_convenience_vars ();
4883 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4885 /* Record the exit code in the convenience variable $_exitcode, so
4886 that the user can inspect this again later. */
4887 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4888 (LONGEST
) ecs
->ws
.value
.integer
);
4890 /* Also record this in the inferior itself. */
4891 current_inferior ()->has_exit_code
= 1;
4892 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
4894 /* Support the --return-child-result option. */
4895 return_child_result_value
= ecs
->ws
.value
.integer
;
4897 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
4901 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
4903 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
4905 /* Set the value of the internal variable $_exitsignal,
4906 which holds the signal uncaught by the inferior. */
4907 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4908 gdbarch_gdb_signal_to_target (gdbarch
,
4909 ecs
->ws
.value
.sig
));
4913 /* We don't have access to the target's method used for
4914 converting between signal numbers (GDB's internal
4915 representation <-> target's representation).
4916 Therefore, we cannot do a good job at displaying this
4917 information to the user. It's better to just warn
4918 her about it (if infrun debugging is enabled), and
4921 fprintf_filtered (gdb_stdlog
, _("\
4922 Cannot fill $_exitsignal with the correct signal number.\n"));
4925 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
4928 gdb_flush (gdb_stdout
);
4929 target_mourn_inferior (inferior_ptid
);
4930 stop_print_frame
= 0;
4934 /* The following are the only cases in which we keep going;
4935 the above cases end in a continue or goto. */
4936 case TARGET_WAITKIND_FORKED
:
4937 case TARGET_WAITKIND_VFORKED
:
4940 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
4941 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_FORKED\n");
4943 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_VFORKED\n");
4946 /* Check whether the inferior is displaced stepping. */
4948 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4949 struct gdbarch
*gdbarch
= regcache
->arch ();
4951 /* If checking displaced stepping is supported, and thread
4952 ecs->ptid is displaced stepping. */
4953 if (displaced_step_in_progress_thread (ecs
->event_thread
))
4955 struct inferior
*parent_inf
4956 = find_inferior_ptid (ecs
->ptid
);
4957 struct regcache
*child_regcache
;
4958 CORE_ADDR parent_pc
;
4960 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4961 indicating that the displaced stepping of syscall instruction
4962 has been done. Perform cleanup for parent process here. Note
4963 that this operation also cleans up the child process for vfork,
4964 because their pages are shared. */
4965 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
4966 /* Start a new step-over in another thread if there's one
4970 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
4972 struct displaced_step_inferior_state
*displaced
4973 = get_displaced_stepping_state (parent_inf
);
4975 /* Restore scratch pad for child process. */
4976 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
4979 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4980 the child's PC is also within the scratchpad. Set the child's PC
4981 to the parent's PC value, which has already been fixed up.
4982 FIXME: we use the parent's aspace here, although we're touching
4983 the child, because the child hasn't been added to the inferior
4984 list yet at this point. */
4987 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
4989 parent_inf
->aspace
);
4990 /* Read PC value of parent process. */
4991 parent_pc
= regcache_read_pc (regcache
);
4993 if (debug_displaced
)
4994 fprintf_unfiltered (gdb_stdlog
,
4995 "displaced: write child pc from %s to %s\n",
4997 regcache_read_pc (child_regcache
)),
4998 paddress (gdbarch
, parent_pc
));
5000 regcache_write_pc (child_regcache
, parent_pc
);
5004 context_switch (ecs
);
5006 /* Immediately detach breakpoints from the child before there's
5007 any chance of letting the user delete breakpoints from the
5008 breakpoint lists. If we don't do this early, it's easy to
5009 leave left over traps in the child, vis: "break foo; catch
5010 fork; c; <fork>; del; c; <child calls foo>". We only follow
5011 the fork on the last `continue', and by that time the
5012 breakpoint at "foo" is long gone from the breakpoint table.
5013 If we vforked, then we don't need to unpatch here, since both
5014 parent and child are sharing the same memory pages; we'll
5015 need to unpatch at follow/detach time instead to be certain
5016 that new breakpoints added between catchpoint hit time and
5017 vfork follow are detached. */
5018 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5020 /* This won't actually modify the breakpoint list, but will
5021 physically remove the breakpoints from the child. */
5022 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5025 delete_just_stopped_threads_single_step_breakpoints ();
5027 /* In case the event is caught by a catchpoint, remember that
5028 the event is to be followed at the next resume of the thread,
5029 and not immediately. */
5030 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5032 ecs
->event_thread
->suspend
.stop_pc
5033 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5035 ecs
->event_thread
->control
.stop_bpstat
5036 = bpstat_stop_status (get_current_regcache ()->aspace (),
5037 ecs
->event_thread
->suspend
.stop_pc
,
5038 ecs
->event_thread
, &ecs
->ws
);
5040 if (handle_stop_requested (ecs
))
5043 /* If no catchpoint triggered for this, then keep going. Note
5044 that we're interested in knowing the bpstat actually causes a
5045 stop, not just if it may explain the signal. Software
5046 watchpoints, for example, always appear in the bpstat. */
5047 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5051 = (follow_fork_mode_string
== follow_fork_mode_child
);
5053 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5055 should_resume
= follow_fork ();
5057 thread_info
*parent
= ecs
->event_thread
;
5058 thread_info
*child
= find_thread_ptid (ecs
->ws
.value
.related_pid
);
5060 /* At this point, the parent is marked running, and the
5061 child is marked stopped. */
5063 /* If not resuming the parent, mark it stopped. */
5064 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5065 parent
->set_running (false);
5067 /* If resuming the child, mark it running. */
5068 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5069 child
->set_running (true);
5071 /* In non-stop mode, also resume the other branch. */
5072 if (!detach_fork
&& (non_stop
5073 || (sched_multi
&& target_is_non_stop_p ())))
5076 switch_to_thread (parent
);
5078 switch_to_thread (child
);
5080 ecs
->event_thread
= inferior_thread ();
5081 ecs
->ptid
= inferior_ptid
;
5086 switch_to_thread (child
);
5088 switch_to_thread (parent
);
5090 ecs
->event_thread
= inferior_thread ();
5091 ecs
->ptid
= inferior_ptid
;
5099 process_event_stop_test (ecs
);
5102 case TARGET_WAITKIND_VFORK_DONE
:
5103 /* Done with the shared memory region. Re-insert breakpoints in
5104 the parent, and keep going. */
5107 fprintf_unfiltered (gdb_stdlog
,
5108 "infrun: TARGET_WAITKIND_VFORK_DONE\n");
5110 context_switch (ecs
);
5112 current_inferior ()->waiting_for_vfork_done
= 0;
5113 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5115 if (handle_stop_requested (ecs
))
5118 /* This also takes care of reinserting breakpoints in the
5119 previously locked inferior. */
5123 case TARGET_WAITKIND_EXECD
:
5125 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_EXECD\n");
5127 /* Note we can't read registers yet (the stop_pc), because we
5128 don't yet know the inferior's post-exec architecture.
5129 'stop_pc' is explicitly read below instead. */
5130 switch_to_thread_no_regs (ecs
->event_thread
);
5132 /* Do whatever is necessary to the parent branch of the vfork. */
5133 handle_vfork_child_exec_or_exit (1);
5135 /* This causes the eventpoints and symbol table to be reset.
5136 Must do this now, before trying to determine whether to
5138 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5140 /* In follow_exec we may have deleted the original thread and
5141 created a new one. Make sure that the event thread is the
5142 execd thread for that case (this is a nop otherwise). */
5143 ecs
->event_thread
= inferior_thread ();
5145 ecs
->event_thread
->suspend
.stop_pc
5146 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5148 ecs
->event_thread
->control
.stop_bpstat
5149 = bpstat_stop_status (get_current_regcache ()->aspace (),
5150 ecs
->event_thread
->suspend
.stop_pc
,
5151 ecs
->event_thread
, &ecs
->ws
);
5153 /* Note that this may be referenced from inside
5154 bpstat_stop_status above, through inferior_has_execd. */
5155 xfree (ecs
->ws
.value
.execd_pathname
);
5156 ecs
->ws
.value
.execd_pathname
= NULL
;
5158 if (handle_stop_requested (ecs
))
5161 /* If no catchpoint triggered for this, then keep going. */
5162 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5164 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5168 process_event_stop_test (ecs
);
5171 /* Be careful not to try to gather much state about a thread
5172 that's in a syscall. It's frequently a losing proposition. */
5173 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5175 fprintf_unfiltered (gdb_stdlog
,
5176 "infrun: TARGET_WAITKIND_SYSCALL_ENTRY\n");
5177 /* Getting the current syscall number. */
5178 if (handle_syscall_event (ecs
) == 0)
5179 process_event_stop_test (ecs
);
5182 /* Before examining the threads further, step this thread to
5183 get it entirely out of the syscall. (We get notice of the
5184 event when the thread is just on the verge of exiting a
5185 syscall. Stepping one instruction seems to get it back
5187 case TARGET_WAITKIND_SYSCALL_RETURN
:
5189 fprintf_unfiltered (gdb_stdlog
,
5190 "infrun: TARGET_WAITKIND_SYSCALL_RETURN\n");
5191 if (handle_syscall_event (ecs
) == 0)
5192 process_event_stop_test (ecs
);
5195 case TARGET_WAITKIND_STOPPED
:
5197 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_STOPPED\n");
5198 handle_signal_stop (ecs
);
5201 case TARGET_WAITKIND_NO_HISTORY
:
5203 fprintf_unfiltered (gdb_stdlog
, "infrun: TARGET_WAITKIND_NO_HISTORY\n");
5204 /* Reverse execution: target ran out of history info. */
5206 /* Switch to the stopped thread. */
5207 context_switch (ecs
);
5209 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5211 delete_just_stopped_threads_single_step_breakpoints ();
5212 ecs
->event_thread
->suspend
.stop_pc
5213 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5215 if (handle_stop_requested (ecs
))
5218 gdb::observers::no_history
.notify ();
5224 /* A wrapper around handle_inferior_event_1, which also makes sure
5225 that all temporary struct value objects that were created during
5226 the handling of the event get deleted at the end. */
5229 handle_inferior_event (struct execution_control_state
*ecs
)
5231 struct value
*mark
= value_mark ();
5233 handle_inferior_event_1 (ecs
);
5234 /* Purge all temporary values created during the event handling,
5235 as it could be a long time before we return to the command level
5236 where such values would otherwise be purged. */
5237 value_free_to_mark (mark
);
5240 /* Restart threads back to what they were trying to do back when we
5241 paused them for an in-line step-over. The EVENT_THREAD thread is
5245 restart_threads (struct thread_info
*event_thread
)
5247 /* In case the instruction just stepped spawned a new thread. */
5248 update_thread_list ();
5250 for (thread_info
*tp
: all_non_exited_threads ())
5252 if (tp
== event_thread
)
5255 fprintf_unfiltered (gdb_stdlog
,
5256 "infrun: restart threads: "
5257 "[%s] is event thread\n",
5258 target_pid_to_str (tp
->ptid
));
5262 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5265 fprintf_unfiltered (gdb_stdlog
,
5266 "infrun: restart threads: "
5267 "[%s] not meant to be running\n",
5268 target_pid_to_str (tp
->ptid
));
5275 fprintf_unfiltered (gdb_stdlog
,
5276 "infrun: restart threads: [%s] resumed\n",
5277 target_pid_to_str (tp
->ptid
));
5278 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5282 if (thread_is_in_step_over_chain (tp
))
5285 fprintf_unfiltered (gdb_stdlog
,
5286 "infrun: restart threads: "
5287 "[%s] needs step-over\n",
5288 target_pid_to_str (tp
->ptid
));
5289 gdb_assert (!tp
->resumed
);
5294 if (tp
->suspend
.waitstatus_pending_p
)
5297 fprintf_unfiltered (gdb_stdlog
,
5298 "infrun: restart threads: "
5299 "[%s] has pending status\n",
5300 target_pid_to_str (tp
->ptid
));
5305 gdb_assert (!tp
->stop_requested
);
5307 /* If some thread needs to start a step-over at this point, it
5308 should still be in the step-over queue, and thus skipped
5310 if (thread_still_needs_step_over (tp
))
5312 internal_error (__FILE__
, __LINE__
,
5313 "thread [%s] needs a step-over, but not in "
5314 "step-over queue\n",
5315 target_pid_to_str (tp
->ptid
));
5318 if (currently_stepping (tp
))
5321 fprintf_unfiltered (gdb_stdlog
,
5322 "infrun: restart threads: [%s] was stepping\n",
5323 target_pid_to_str (tp
->ptid
));
5324 keep_going_stepped_thread (tp
);
5328 struct execution_control_state ecss
;
5329 struct execution_control_state
*ecs
= &ecss
;
5332 fprintf_unfiltered (gdb_stdlog
,
5333 "infrun: restart threads: [%s] continuing\n",
5334 target_pid_to_str (tp
->ptid
));
5335 reset_ecs (ecs
, tp
);
5336 switch_to_thread (tp
);
5337 keep_going_pass_signal (ecs
);
5342 /* Callback for iterate_over_threads. Find a resumed thread that has
5343 a pending waitstatus. */
5346 resumed_thread_with_pending_status (struct thread_info
*tp
,
5350 && tp
->suspend
.waitstatus_pending_p
);
5353 /* Called when we get an event that may finish an in-line or
5354 out-of-line (displaced stepping) step-over started previously.
5355 Return true if the event is processed and we should go back to the
5356 event loop; false if the caller should continue processing the
5360 finish_step_over (struct execution_control_state
*ecs
)
5362 int had_step_over_info
;
5364 displaced_step_fixup (ecs
->event_thread
,
5365 ecs
->event_thread
->suspend
.stop_signal
);
5367 had_step_over_info
= step_over_info_valid_p ();
5369 if (had_step_over_info
)
5371 /* If we're stepping over a breakpoint with all threads locked,
5372 then only the thread that was stepped should be reporting
5374 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5376 clear_step_over_info ();
5379 if (!target_is_non_stop_p ())
5382 /* Start a new step-over in another thread if there's one that
5386 /* If we were stepping over a breakpoint before, and haven't started
5387 a new in-line step-over sequence, then restart all other threads
5388 (except the event thread). We can't do this in all-stop, as then
5389 e.g., we wouldn't be able to issue any other remote packet until
5390 these other threads stop. */
5391 if (had_step_over_info
&& !step_over_info_valid_p ())
5393 struct thread_info
*pending
;
5395 /* If we only have threads with pending statuses, the restart
5396 below won't restart any thread and so nothing re-inserts the
5397 breakpoint we just stepped over. But we need it inserted
5398 when we later process the pending events, otherwise if
5399 another thread has a pending event for this breakpoint too,
5400 we'd discard its event (because the breakpoint that
5401 originally caused the event was no longer inserted). */
5402 context_switch (ecs
);
5403 insert_breakpoints ();
5405 restart_threads (ecs
->event_thread
);
5407 /* If we have events pending, go through handle_inferior_event
5408 again, picking up a pending event at random. This avoids
5409 thread starvation. */
5411 /* But not if we just stepped over a watchpoint in order to let
5412 the instruction execute so we can evaluate its expression.
5413 The set of watchpoints that triggered is recorded in the
5414 breakpoint objects themselves (see bp->watchpoint_triggered).
5415 If we processed another event first, that other event could
5416 clobber this info. */
5417 if (ecs
->event_thread
->stepping_over_watchpoint
)
5420 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5422 if (pending
!= NULL
)
5424 struct thread_info
*tp
= ecs
->event_thread
;
5425 struct regcache
*regcache
;
5429 fprintf_unfiltered (gdb_stdlog
,
5430 "infrun: found resumed threads with "
5431 "pending events, saving status\n");
5434 gdb_assert (pending
!= tp
);
5436 /* Record the event thread's event for later. */
5437 save_waitstatus (tp
, &ecs
->ws
);
5438 /* This was cleared early, by handle_inferior_event. Set it
5439 so this pending event is considered by
5443 gdb_assert (!tp
->executing
);
5445 regcache
= get_thread_regcache (tp
);
5446 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5450 fprintf_unfiltered (gdb_stdlog
,
5451 "infrun: saved stop_pc=%s for %s "
5452 "(currently_stepping=%d)\n",
5453 paddress (target_gdbarch (),
5454 tp
->suspend
.stop_pc
),
5455 target_pid_to_str (tp
->ptid
),
5456 currently_stepping (tp
));
5459 /* This in-line step-over finished; clear this so we won't
5460 start a new one. This is what handle_signal_stop would
5461 do, if we returned false. */
5462 tp
->stepping_over_breakpoint
= 0;
5464 /* Wake up the event loop again. */
5465 mark_async_event_handler (infrun_async_inferior_event_token
);
5467 prepare_to_wait (ecs
);
5475 /* Come here when the program has stopped with a signal. */
5478 handle_signal_stop (struct execution_control_state
*ecs
)
5480 struct frame_info
*frame
;
5481 struct gdbarch
*gdbarch
;
5482 int stopped_by_watchpoint
;
5483 enum stop_kind stop_soon
;
5486 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5488 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5490 /* Do we need to clean up the state of a thread that has
5491 completed a displaced single-step? (Doing so usually affects
5492 the PC, so do it here, before we set stop_pc.) */
5493 if (finish_step_over (ecs
))
5496 /* If we either finished a single-step or hit a breakpoint, but
5497 the user wanted this thread to be stopped, pretend we got a
5498 SIG0 (generic unsignaled stop). */
5499 if (ecs
->event_thread
->stop_requested
5500 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5501 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5503 ecs
->event_thread
->suspend
.stop_pc
5504 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5508 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5509 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5510 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
5512 inferior_ptid
= ecs
->ptid
;
5514 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5515 paddress (reg_gdbarch
,
5516 ecs
->event_thread
->suspend
.stop_pc
));
5517 if (target_stopped_by_watchpoint ())
5521 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5523 if (target_stopped_data_address (current_top_target (), &addr
))
5524 fprintf_unfiltered (gdb_stdlog
,
5525 "infrun: stopped data address = %s\n",
5526 paddress (reg_gdbarch
, addr
));
5528 fprintf_unfiltered (gdb_stdlog
,
5529 "infrun: (no data address available)\n");
5533 /* This is originated from start_remote(), start_inferior() and
5534 shared libraries hook functions. */
5535 stop_soon
= get_inferior_stop_soon (ecs
);
5536 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5538 context_switch (ecs
);
5540 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5541 stop_print_frame
= 1;
5546 /* This originates from attach_command(). We need to overwrite
5547 the stop_signal here, because some kernels don't ignore a
5548 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5549 See more comments in inferior.h. On the other hand, if we
5550 get a non-SIGSTOP, report it to the user - assume the backend
5551 will handle the SIGSTOP if it should show up later.
5553 Also consider that the attach is complete when we see a
5554 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5555 target extended-remote report it instead of a SIGSTOP
5556 (e.g. gdbserver). We already rely on SIGTRAP being our
5557 signal, so this is no exception.
5559 Also consider that the attach is complete when we see a
5560 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5561 the target to stop all threads of the inferior, in case the
5562 low level attach operation doesn't stop them implicitly. If
5563 they weren't stopped implicitly, then the stub will report a
5564 GDB_SIGNAL_0, meaning: stopped for no particular reason
5565 other than GDB's request. */
5566 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5567 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5568 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5569 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5571 stop_print_frame
= 1;
5573 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5577 /* See if something interesting happened to the non-current thread. If
5578 so, then switch to that thread. */
5579 if (ecs
->ptid
!= inferior_ptid
)
5582 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5584 context_switch (ecs
);
5586 if (deprecated_context_hook
)
5587 deprecated_context_hook (ecs
->event_thread
->global_num
);
5590 /* At this point, get hold of the now-current thread's frame. */
5591 frame
= get_current_frame ();
5592 gdbarch
= get_frame_arch (frame
);
5594 /* Pull the single step breakpoints out of the target. */
5595 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5597 struct regcache
*regcache
;
5600 regcache
= get_thread_regcache (ecs
->event_thread
);
5601 const address_space
*aspace
= regcache
->aspace ();
5603 pc
= regcache_read_pc (regcache
);
5605 /* However, before doing so, if this single-step breakpoint was
5606 actually for another thread, set this thread up for moving
5608 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5611 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5615 fprintf_unfiltered (gdb_stdlog
,
5616 "infrun: [%s] hit another thread's "
5617 "single-step breakpoint\n",
5618 target_pid_to_str (ecs
->ptid
));
5620 ecs
->hit_singlestep_breakpoint
= 1;
5627 fprintf_unfiltered (gdb_stdlog
,
5628 "infrun: [%s] hit its "
5629 "single-step breakpoint\n",
5630 target_pid_to_str (ecs
->ptid
));
5634 delete_just_stopped_threads_single_step_breakpoints ();
5636 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5637 && ecs
->event_thread
->control
.trap_expected
5638 && ecs
->event_thread
->stepping_over_watchpoint
)
5639 stopped_by_watchpoint
= 0;
5641 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5643 /* If necessary, step over this watchpoint. We'll be back to display
5645 if (stopped_by_watchpoint
5646 && (target_have_steppable_watchpoint
5647 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5649 /* At this point, we are stopped at an instruction which has
5650 attempted to write to a piece of memory under control of
5651 a watchpoint. The instruction hasn't actually executed
5652 yet. If we were to evaluate the watchpoint expression
5653 now, we would get the old value, and therefore no change
5654 would seem to have occurred.
5656 In order to make watchpoints work `right', we really need
5657 to complete the memory write, and then evaluate the
5658 watchpoint expression. We do this by single-stepping the
5661 It may not be necessary to disable the watchpoint to step over
5662 it. For example, the PA can (with some kernel cooperation)
5663 single step over a watchpoint without disabling the watchpoint.
5665 It is far more common to need to disable a watchpoint to step
5666 the inferior over it. If we have non-steppable watchpoints,
5667 we must disable the current watchpoint; it's simplest to
5668 disable all watchpoints.
5670 Any breakpoint at PC must also be stepped over -- if there's
5671 one, it will have already triggered before the watchpoint
5672 triggered, and we either already reported it to the user, or
5673 it didn't cause a stop and we called keep_going. In either
5674 case, if there was a breakpoint at PC, we must be trying to
5676 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5681 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5682 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5683 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5684 ecs
->event_thread
->control
.stop_step
= 0;
5685 stop_print_frame
= 1;
5686 stopped_by_random_signal
= 0;
5687 bpstat stop_chain
= NULL
;
5689 /* Hide inlined functions starting here, unless we just performed stepi or
5690 nexti. After stepi and nexti, always show the innermost frame (not any
5691 inline function call sites). */
5692 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5694 const address_space
*aspace
5695 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5697 /* skip_inline_frames is expensive, so we avoid it if we can
5698 determine that the address is one where functions cannot have
5699 been inlined. This improves performance with inferiors that
5700 load a lot of shared libraries, because the solib event
5701 breakpoint is defined as the address of a function (i.e. not
5702 inline). Note that we have to check the previous PC as well
5703 as the current one to catch cases when we have just
5704 single-stepped off a breakpoint prior to reinstating it.
5705 Note that we're assuming that the code we single-step to is
5706 not inline, but that's not definitive: there's nothing
5707 preventing the event breakpoint function from containing
5708 inlined code, and the single-step ending up there. If the
5709 user had set a breakpoint on that inlined code, the missing
5710 skip_inline_frames call would break things. Fortunately
5711 that's an extremely unlikely scenario. */
5712 if (!pc_at_non_inline_function (aspace
,
5713 ecs
->event_thread
->suspend
.stop_pc
,
5715 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5716 && ecs
->event_thread
->control
.trap_expected
5717 && pc_at_non_inline_function (aspace
,
5718 ecs
->event_thread
->prev_pc
,
5721 stop_chain
= build_bpstat_chain (aspace
,
5722 ecs
->event_thread
->suspend
.stop_pc
,
5724 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5726 /* Re-fetch current thread's frame in case that invalidated
5728 frame
= get_current_frame ();
5729 gdbarch
= get_frame_arch (frame
);
5733 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5734 && ecs
->event_thread
->control
.trap_expected
5735 && gdbarch_single_step_through_delay_p (gdbarch
)
5736 && currently_stepping (ecs
->event_thread
))
5738 /* We're trying to step off a breakpoint. Turns out that we're
5739 also on an instruction that needs to be stepped multiple
5740 times before it's been fully executing. E.g., architectures
5741 with a delay slot. It needs to be stepped twice, once for
5742 the instruction and once for the delay slot. */
5743 int step_through_delay
5744 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5746 if (debug_infrun
&& step_through_delay
)
5747 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
5748 if (ecs
->event_thread
->control
.step_range_end
== 0
5749 && step_through_delay
)
5751 /* The user issued a continue when stopped at a breakpoint.
5752 Set up for another trap and get out of here. */
5753 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5757 else if (step_through_delay
)
5759 /* The user issued a step when stopped at a breakpoint.
5760 Maybe we should stop, maybe we should not - the delay
5761 slot *might* correspond to a line of source. In any
5762 case, don't decide that here, just set
5763 ecs->stepping_over_breakpoint, making sure we
5764 single-step again before breakpoints are re-inserted. */
5765 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5769 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5770 handles this event. */
5771 ecs
->event_thread
->control
.stop_bpstat
5772 = bpstat_stop_status (get_current_regcache ()->aspace (),
5773 ecs
->event_thread
->suspend
.stop_pc
,
5774 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
5776 /* Following in case break condition called a
5778 stop_print_frame
= 1;
5780 /* This is where we handle "moribund" watchpoints. Unlike
5781 software breakpoints traps, hardware watchpoint traps are
5782 always distinguishable from random traps. If no high-level
5783 watchpoint is associated with the reported stop data address
5784 anymore, then the bpstat does not explain the signal ---
5785 simply make sure to ignore it if `stopped_by_watchpoint' is
5789 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5790 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5792 && stopped_by_watchpoint
)
5793 fprintf_unfiltered (gdb_stdlog
,
5794 "infrun: no user watchpoint explains "
5795 "watchpoint SIGTRAP, ignoring\n");
5797 /* NOTE: cagney/2003-03-29: These checks for a random signal
5798 at one stage in the past included checks for an inferior
5799 function call's call dummy's return breakpoint. The original
5800 comment, that went with the test, read:
5802 ``End of a stack dummy. Some systems (e.g. Sony news) give
5803 another signal besides SIGTRAP, so check here as well as
5806 If someone ever tries to get call dummys on a
5807 non-executable stack to work (where the target would stop
5808 with something like a SIGSEGV), then those tests might need
5809 to be re-instated. Given, however, that the tests were only
5810 enabled when momentary breakpoints were not being used, I
5811 suspect that it won't be the case.
5813 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5814 be necessary for call dummies on a non-executable stack on
5817 /* See if the breakpoints module can explain the signal. */
5819 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5820 ecs
->event_thread
->suspend
.stop_signal
);
5822 /* Maybe this was a trap for a software breakpoint that has since
5824 if (random_signal
&& target_stopped_by_sw_breakpoint ())
5826 if (program_breakpoint_here_p (gdbarch
,
5827 ecs
->event_thread
->suspend
.stop_pc
))
5829 struct regcache
*regcache
;
5832 /* Re-adjust PC to what the program would see if GDB was not
5834 regcache
= get_thread_regcache (ecs
->event_thread
);
5835 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
5838 gdb::optional
<scoped_restore_tmpl
<int>>
5839 restore_operation_disable
;
5841 if (record_full_is_used ())
5842 restore_operation_disable
.emplace
5843 (record_full_gdb_operation_disable_set ());
5845 regcache_write_pc (regcache
,
5846 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
5851 /* A delayed software breakpoint event. Ignore the trap. */
5853 fprintf_unfiltered (gdb_stdlog
,
5854 "infrun: delayed software breakpoint "
5855 "trap, ignoring\n");
5860 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5861 has since been removed. */
5862 if (random_signal
&& target_stopped_by_hw_breakpoint ())
5864 /* A delayed hardware breakpoint event. Ignore the trap. */
5866 fprintf_unfiltered (gdb_stdlog
,
5867 "infrun: delayed hardware breakpoint/watchpoint "
5868 "trap, ignoring\n");
5872 /* If not, perhaps stepping/nexting can. */
5874 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5875 && currently_stepping (ecs
->event_thread
));
5877 /* Perhaps the thread hit a single-step breakpoint of _another_
5878 thread. Single-step breakpoints are transparent to the
5879 breakpoints module. */
5881 random_signal
= !ecs
->hit_singlestep_breakpoint
;
5883 /* No? Perhaps we got a moribund watchpoint. */
5885 random_signal
= !stopped_by_watchpoint
;
5887 /* Always stop if the user explicitly requested this thread to
5889 if (ecs
->event_thread
->stop_requested
)
5893 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
5896 /* For the program's own signals, act according to
5897 the signal handling tables. */
5901 /* Signal not for debugging purposes. */
5902 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
5903 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
5906 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
5907 gdb_signal_to_symbol_string (stop_signal
));
5909 stopped_by_random_signal
= 1;
5911 /* Always stop on signals if we're either just gaining control
5912 of the program, or the user explicitly requested this thread
5913 to remain stopped. */
5914 if (stop_soon
!= NO_STOP_QUIETLY
5915 || ecs
->event_thread
->stop_requested
5917 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
5923 /* Notify observers the signal has "handle print" set. Note we
5924 returned early above if stopping; normal_stop handles the
5925 printing in that case. */
5926 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
5928 /* The signal table tells us to print about this signal. */
5929 target_terminal::ours_for_output ();
5930 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
5931 target_terminal::inferior ();
5934 /* Clear the signal if it should not be passed. */
5935 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
5936 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5938 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
5939 && ecs
->event_thread
->control
.trap_expected
5940 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5942 /* We were just starting a new sequence, attempting to
5943 single-step off of a breakpoint and expecting a SIGTRAP.
5944 Instead this signal arrives. This signal will take us out
5945 of the stepping range so GDB needs to remember to, when
5946 the signal handler returns, resume stepping off that
5948 /* To simplify things, "continue" is forced to use the same
5949 code paths as single-step - set a breakpoint at the
5950 signal return address and then, once hit, step off that
5953 fprintf_unfiltered (gdb_stdlog
,
5954 "infrun: signal arrived while stepping over "
5957 insert_hp_step_resume_breakpoint_at_frame (frame
);
5958 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5959 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5960 ecs
->event_thread
->control
.trap_expected
= 0;
5962 /* If we were nexting/stepping some other thread, switch to
5963 it, so that we don't continue it, losing control. */
5964 if (!switch_back_to_stepped_thread (ecs
))
5969 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
5970 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
5972 || ecs
->event_thread
->control
.step_range_end
== 1)
5973 && frame_id_eq (get_stack_frame_id (frame
),
5974 ecs
->event_thread
->control
.step_stack_frame_id
)
5975 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5977 /* The inferior is about to take a signal that will take it
5978 out of the single step range. Set a breakpoint at the
5979 current PC (which is presumably where the signal handler
5980 will eventually return) and then allow the inferior to
5983 Note that this is only needed for a signal delivered
5984 while in the single-step range. Nested signals aren't a
5985 problem as they eventually all return. */
5987 fprintf_unfiltered (gdb_stdlog
,
5988 "infrun: signal may take us out of "
5989 "single-step range\n");
5991 clear_step_over_info ();
5992 insert_hp_step_resume_breakpoint_at_frame (frame
);
5993 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5994 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5995 ecs
->event_thread
->control
.trap_expected
= 0;
6000 /* Note: step_resume_breakpoint may be non-NULL. This occures
6001 when either there's a nested signal, or when there's a
6002 pending signal enabled just as the signal handler returns
6003 (leaving the inferior at the step-resume-breakpoint without
6004 actually executing it). Either way continue until the
6005 breakpoint is really hit. */
6007 if (!switch_back_to_stepped_thread (ecs
))
6010 fprintf_unfiltered (gdb_stdlog
,
6011 "infrun: random signal, keep going\n");
6018 process_event_stop_test (ecs
);
6021 /* Come here when we've got some debug event / signal we can explain
6022 (IOW, not a random signal), and test whether it should cause a
6023 stop, or whether we should resume the inferior (transparently).
6024 E.g., could be a breakpoint whose condition evaluates false; we
6025 could be still stepping within the line; etc. */
6028 process_event_stop_test (struct execution_control_state
*ecs
)
6030 struct symtab_and_line stop_pc_sal
;
6031 struct frame_info
*frame
;
6032 struct gdbarch
*gdbarch
;
6033 CORE_ADDR jmp_buf_pc
;
6034 struct bpstat_what what
;
6036 /* Handle cases caused by hitting a breakpoint. */
6038 frame
= get_current_frame ();
6039 gdbarch
= get_frame_arch (frame
);
6041 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6043 if (what
.call_dummy
)
6045 stop_stack_dummy
= what
.call_dummy
;
6048 /* A few breakpoint types have callbacks associated (e.g.,
6049 bp_jit_event). Run them now. */
6050 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6052 /* If we hit an internal event that triggers symbol changes, the
6053 current frame will be invalidated within bpstat_what (e.g., if we
6054 hit an internal solib event). Re-fetch it. */
6055 frame
= get_current_frame ();
6056 gdbarch
= get_frame_arch (frame
);
6058 switch (what
.main_action
)
6060 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6061 /* If we hit the breakpoint at longjmp while stepping, we
6062 install a momentary breakpoint at the target of the
6066 fprintf_unfiltered (gdb_stdlog
,
6067 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6069 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6071 if (what
.is_longjmp
)
6073 struct value
*arg_value
;
6075 /* If we set the longjmp breakpoint via a SystemTap probe,
6076 then use it to extract the arguments. The destination PC
6077 is the third argument to the probe. */
6078 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6081 jmp_buf_pc
= value_as_address (arg_value
);
6082 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6084 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6085 || !gdbarch_get_longjmp_target (gdbarch
,
6086 frame
, &jmp_buf_pc
))
6089 fprintf_unfiltered (gdb_stdlog
,
6090 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6091 "(!gdbarch_get_longjmp_target)\n");
6096 /* Insert a breakpoint at resume address. */
6097 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6100 check_exception_resume (ecs
, frame
);
6104 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6106 struct frame_info
*init_frame
;
6108 /* There are several cases to consider.
6110 1. The initiating frame no longer exists. In this case we
6111 must stop, because the exception or longjmp has gone too
6114 2. The initiating frame exists, and is the same as the
6115 current frame. We stop, because the exception or longjmp
6118 3. The initiating frame exists and is different from the
6119 current frame. This means the exception or longjmp has
6120 been caught beneath the initiating frame, so keep going.
6122 4. longjmp breakpoint has been placed just to protect
6123 against stale dummy frames and user is not interested in
6124 stopping around longjmps. */
6127 fprintf_unfiltered (gdb_stdlog
,
6128 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6130 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6132 delete_exception_resume_breakpoint (ecs
->event_thread
);
6134 if (what
.is_longjmp
)
6136 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6138 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6146 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6150 struct frame_id current_id
6151 = get_frame_id (get_current_frame ());
6152 if (frame_id_eq (current_id
,
6153 ecs
->event_thread
->initiating_frame
))
6155 /* Case 2. Fall through. */
6165 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6167 delete_step_resume_breakpoint (ecs
->event_thread
);
6169 end_stepping_range (ecs
);
6173 case BPSTAT_WHAT_SINGLE
:
6175 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6176 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6177 /* Still need to check other stuff, at least the case where we
6178 are stepping and step out of the right range. */
6181 case BPSTAT_WHAT_STEP_RESUME
:
6183 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6185 delete_step_resume_breakpoint (ecs
->event_thread
);
6186 if (ecs
->event_thread
->control
.proceed_to_finish
6187 && execution_direction
== EXEC_REVERSE
)
6189 struct thread_info
*tp
= ecs
->event_thread
;
6191 /* We are finishing a function in reverse, and just hit the
6192 step-resume breakpoint at the start address of the
6193 function, and we're almost there -- just need to back up
6194 by one more single-step, which should take us back to the
6196 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6200 fill_in_stop_func (gdbarch
, ecs
);
6201 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6202 && execution_direction
== EXEC_REVERSE
)
6204 /* We are stepping over a function call in reverse, and just
6205 hit the step-resume breakpoint at the start address of
6206 the function. Go back to single-stepping, which should
6207 take us back to the function call. */
6208 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6214 case BPSTAT_WHAT_STOP_NOISY
:
6216 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6217 stop_print_frame
= 1;
6219 /* Assume the thread stopped for a breapoint. We'll still check
6220 whether a/the breakpoint is there when the thread is next
6222 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6227 case BPSTAT_WHAT_STOP_SILENT
:
6229 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6230 stop_print_frame
= 0;
6232 /* Assume the thread stopped for a breapoint. We'll still check
6233 whether a/the breakpoint is there when the thread is next
6235 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6239 case BPSTAT_WHAT_HP_STEP_RESUME
:
6241 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6243 delete_step_resume_breakpoint (ecs
->event_thread
);
6244 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6246 /* Back when the step-resume breakpoint was inserted, we
6247 were trying to single-step off a breakpoint. Go back to
6249 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6250 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6256 case BPSTAT_WHAT_KEEP_CHECKING
:
6260 /* If we stepped a permanent breakpoint and we had a high priority
6261 step-resume breakpoint for the address we stepped, but we didn't
6262 hit it, then we must have stepped into the signal handler. The
6263 step-resume was only necessary to catch the case of _not_
6264 stepping into the handler, so delete it, and fall through to
6265 checking whether the step finished. */
6266 if (ecs
->event_thread
->stepped_breakpoint
)
6268 struct breakpoint
*sr_bp
6269 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6272 && sr_bp
->loc
->permanent
6273 && sr_bp
->type
== bp_hp_step_resume
6274 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6277 fprintf_unfiltered (gdb_stdlog
,
6278 "infrun: stepped permanent breakpoint, stopped in "
6280 delete_step_resume_breakpoint (ecs
->event_thread
);
6281 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6285 /* We come here if we hit a breakpoint but should not stop for it.
6286 Possibly we also were stepping and should stop for that. So fall
6287 through and test for stepping. But, if not stepping, do not
6290 /* In all-stop mode, if we're currently stepping but have stopped in
6291 some other thread, we need to switch back to the stepped thread. */
6292 if (switch_back_to_stepped_thread (ecs
))
6295 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6298 fprintf_unfiltered (gdb_stdlog
,
6299 "infrun: step-resume breakpoint is inserted\n");
6301 /* Having a step-resume breakpoint overrides anything
6302 else having to do with stepping commands until
6303 that breakpoint is reached. */
6308 if (ecs
->event_thread
->control
.step_range_end
== 0)
6311 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6312 /* Likewise if we aren't even stepping. */
6317 /* Re-fetch current thread's frame in case the code above caused
6318 the frame cache to be re-initialized, making our FRAME variable
6319 a dangling pointer. */
6320 frame
= get_current_frame ();
6321 gdbarch
= get_frame_arch (frame
);
6322 fill_in_stop_func (gdbarch
, ecs
);
6324 /* If stepping through a line, keep going if still within it.
6326 Note that step_range_end is the address of the first instruction
6327 beyond the step range, and NOT the address of the last instruction
6330 Note also that during reverse execution, we may be stepping
6331 through a function epilogue and therefore must detect when
6332 the current-frame changes in the middle of a line. */
6334 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6336 && (execution_direction
!= EXEC_REVERSE
6337 || frame_id_eq (get_frame_id (frame
),
6338 ecs
->event_thread
->control
.step_frame_id
)))
6342 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6343 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6344 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6346 /* Tentatively re-enable range stepping; `resume' disables it if
6347 necessary (e.g., if we're stepping over a breakpoint or we
6348 have software watchpoints). */
6349 ecs
->event_thread
->control
.may_range_step
= 1;
6351 /* When stepping backward, stop at beginning of line range
6352 (unless it's the function entry point, in which case
6353 keep going back to the call point). */
6354 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6355 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6356 && stop_pc
!= ecs
->stop_func_start
6357 && execution_direction
== EXEC_REVERSE
)
6358 end_stepping_range (ecs
);
6365 /* We stepped out of the stepping range. */
6367 /* If we are stepping at the source level and entered the runtime
6368 loader dynamic symbol resolution code...
6370 EXEC_FORWARD: we keep on single stepping until we exit the run
6371 time loader code and reach the callee's address.
6373 EXEC_REVERSE: we've already executed the callee (backward), and
6374 the runtime loader code is handled just like any other
6375 undebuggable function call. Now we need only keep stepping
6376 backward through the trampoline code, and that's handled further
6377 down, so there is nothing for us to do here. */
6379 if (execution_direction
!= EXEC_REVERSE
6380 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6381 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6383 CORE_ADDR pc_after_resolver
=
6384 gdbarch_skip_solib_resolver (gdbarch
,
6385 ecs
->event_thread
->suspend
.stop_pc
);
6388 fprintf_unfiltered (gdb_stdlog
,
6389 "infrun: stepped into dynsym resolve code\n");
6391 if (pc_after_resolver
)
6393 /* Set up a step-resume breakpoint at the address
6394 indicated by SKIP_SOLIB_RESOLVER. */
6395 symtab_and_line sr_sal
;
6396 sr_sal
.pc
= pc_after_resolver
;
6397 sr_sal
.pspace
= get_frame_program_space (frame
);
6399 insert_step_resume_breakpoint_at_sal (gdbarch
,
6400 sr_sal
, null_frame_id
);
6407 /* Step through an indirect branch thunk. */
6408 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6409 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6410 ecs
->event_thread
->suspend
.stop_pc
))
6413 fprintf_unfiltered (gdb_stdlog
,
6414 "infrun: stepped into indirect branch thunk\n");
6419 if (ecs
->event_thread
->control
.step_range_end
!= 1
6420 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6421 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6422 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6425 fprintf_unfiltered (gdb_stdlog
,
6426 "infrun: stepped into signal trampoline\n");
6427 /* The inferior, while doing a "step" or "next", has ended up in
6428 a signal trampoline (either by a signal being delivered or by
6429 the signal handler returning). Just single-step until the
6430 inferior leaves the trampoline (either by calling the handler
6436 /* If we're in the return path from a shared library trampoline,
6437 we want to proceed through the trampoline when stepping. */
6438 /* macro/2012-04-25: This needs to come before the subroutine
6439 call check below as on some targets return trampolines look
6440 like subroutine calls (MIPS16 return thunks). */
6441 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6442 ecs
->event_thread
->suspend
.stop_pc
,
6443 ecs
->stop_func_name
)
6444 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6446 /* Determine where this trampoline returns. */
6447 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6448 CORE_ADDR real_stop_pc
6449 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6452 fprintf_unfiltered (gdb_stdlog
,
6453 "infrun: stepped into solib return tramp\n");
6455 /* Only proceed through if we know where it's going. */
6458 /* And put the step-breakpoint there and go until there. */
6459 symtab_and_line sr_sal
;
6460 sr_sal
.pc
= real_stop_pc
;
6461 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6462 sr_sal
.pspace
= get_frame_program_space (frame
);
6464 /* Do not specify what the fp should be when we stop since
6465 on some machines the prologue is where the new fp value
6467 insert_step_resume_breakpoint_at_sal (gdbarch
,
6468 sr_sal
, null_frame_id
);
6470 /* Restart without fiddling with the step ranges or
6477 /* Check for subroutine calls. The check for the current frame
6478 equalling the step ID is not necessary - the check of the
6479 previous frame's ID is sufficient - but it is a common case and
6480 cheaper than checking the previous frame's ID.
6482 NOTE: frame_id_eq will never report two invalid frame IDs as
6483 being equal, so to get into this block, both the current and
6484 previous frame must have valid frame IDs. */
6485 /* The outer_frame_id check is a heuristic to detect stepping
6486 through startup code. If we step over an instruction which
6487 sets the stack pointer from an invalid value to a valid value,
6488 we may detect that as a subroutine call from the mythical
6489 "outermost" function. This could be fixed by marking
6490 outermost frames as !stack_p,code_p,special_p. Then the
6491 initial outermost frame, before sp was valid, would
6492 have code_addr == &_start. See the comment in frame_id_eq
6494 if (!frame_id_eq (get_stack_frame_id (frame
),
6495 ecs
->event_thread
->control
.step_stack_frame_id
)
6496 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6497 ecs
->event_thread
->control
.step_stack_frame_id
)
6498 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6500 || (ecs
->event_thread
->control
.step_start_function
6501 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6503 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6504 CORE_ADDR real_stop_pc
;
6507 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6509 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6511 /* I presume that step_over_calls is only 0 when we're
6512 supposed to be stepping at the assembly language level
6513 ("stepi"). Just stop. */
6514 /* And this works the same backward as frontward. MVS */
6515 end_stepping_range (ecs
);
6519 /* Reverse stepping through solib trampolines. */
6521 if (execution_direction
== EXEC_REVERSE
6522 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6523 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6524 || (ecs
->stop_func_start
== 0
6525 && in_solib_dynsym_resolve_code (stop_pc
))))
6527 /* Any solib trampoline code can be handled in reverse
6528 by simply continuing to single-step. We have already
6529 executed the solib function (backwards), and a few
6530 steps will take us back through the trampoline to the
6536 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6538 /* We're doing a "next".
6540 Normal (forward) execution: set a breakpoint at the
6541 callee's return address (the address at which the caller
6544 Reverse (backward) execution. set the step-resume
6545 breakpoint at the start of the function that we just
6546 stepped into (backwards), and continue to there. When we
6547 get there, we'll need to single-step back to the caller. */
6549 if (execution_direction
== EXEC_REVERSE
)
6551 /* If we're already at the start of the function, we've either
6552 just stepped backward into a single instruction function,
6553 or stepped back out of a signal handler to the first instruction
6554 of the function. Just keep going, which will single-step back
6556 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6558 /* Normal function call return (static or dynamic). */
6559 symtab_and_line sr_sal
;
6560 sr_sal
.pc
= ecs
->stop_func_start
;
6561 sr_sal
.pspace
= get_frame_program_space (frame
);
6562 insert_step_resume_breakpoint_at_sal (gdbarch
,
6563 sr_sal
, null_frame_id
);
6567 insert_step_resume_breakpoint_at_caller (frame
);
6573 /* If we are in a function call trampoline (a stub between the
6574 calling routine and the real function), locate the real
6575 function. That's what tells us (a) whether we want to step
6576 into it at all, and (b) what prologue we want to run to the
6577 end of, if we do step into it. */
6578 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6579 if (real_stop_pc
== 0)
6580 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6581 if (real_stop_pc
!= 0)
6582 ecs
->stop_func_start
= real_stop_pc
;
6584 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6586 symtab_and_line sr_sal
;
6587 sr_sal
.pc
= ecs
->stop_func_start
;
6588 sr_sal
.pspace
= get_frame_program_space (frame
);
6590 insert_step_resume_breakpoint_at_sal (gdbarch
,
6591 sr_sal
, null_frame_id
);
6596 /* If we have line number information for the function we are
6597 thinking of stepping into and the function isn't on the skip
6600 If there are several symtabs at that PC (e.g. with include
6601 files), just want to know whether *any* of them have line
6602 numbers. find_pc_line handles this. */
6604 struct symtab_and_line tmp_sal
;
6606 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6607 if (tmp_sal
.line
!= 0
6608 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6611 if (execution_direction
== EXEC_REVERSE
)
6612 handle_step_into_function_backward (gdbarch
, ecs
);
6614 handle_step_into_function (gdbarch
, ecs
);
6619 /* If we have no line number and the step-stop-if-no-debug is
6620 set, we stop the step so that the user has a chance to switch
6621 in assembly mode. */
6622 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6623 && step_stop_if_no_debug
)
6625 end_stepping_range (ecs
);
6629 if (execution_direction
== EXEC_REVERSE
)
6631 /* If we're already at the start of the function, we've either just
6632 stepped backward into a single instruction function without line
6633 number info, or stepped back out of a signal handler to the first
6634 instruction of the function without line number info. Just keep
6635 going, which will single-step back to the caller. */
6636 if (ecs
->stop_func_start
!= stop_pc
)
6638 /* Set a breakpoint at callee's start address.
6639 From there we can step once and be back in the caller. */
6640 symtab_and_line sr_sal
;
6641 sr_sal
.pc
= ecs
->stop_func_start
;
6642 sr_sal
.pspace
= get_frame_program_space (frame
);
6643 insert_step_resume_breakpoint_at_sal (gdbarch
,
6644 sr_sal
, null_frame_id
);
6648 /* Set a breakpoint at callee's return address (the address
6649 at which the caller will resume). */
6650 insert_step_resume_breakpoint_at_caller (frame
);
6656 /* Reverse stepping through solib trampolines. */
6658 if (execution_direction
== EXEC_REVERSE
6659 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6661 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6663 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6664 || (ecs
->stop_func_start
== 0
6665 && in_solib_dynsym_resolve_code (stop_pc
)))
6667 /* Any solib trampoline code can be handled in reverse
6668 by simply continuing to single-step. We have already
6669 executed the solib function (backwards), and a few
6670 steps will take us back through the trampoline to the
6675 else if (in_solib_dynsym_resolve_code (stop_pc
))
6677 /* Stepped backward into the solib dynsym resolver.
6678 Set a breakpoint at its start and continue, then
6679 one more step will take us out. */
6680 symtab_and_line sr_sal
;
6681 sr_sal
.pc
= ecs
->stop_func_start
;
6682 sr_sal
.pspace
= get_frame_program_space (frame
);
6683 insert_step_resume_breakpoint_at_sal (gdbarch
,
6684 sr_sal
, null_frame_id
);
6690 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6692 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6693 the trampoline processing logic, however, there are some trampolines
6694 that have no names, so we should do trampoline handling first. */
6695 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6696 && ecs
->stop_func_name
== NULL
6697 && stop_pc_sal
.line
== 0)
6700 fprintf_unfiltered (gdb_stdlog
,
6701 "infrun: stepped into undebuggable function\n");
6703 /* The inferior just stepped into, or returned to, an
6704 undebuggable function (where there is no debugging information
6705 and no line number corresponding to the address where the
6706 inferior stopped). Since we want to skip this kind of code,
6707 we keep going until the inferior returns from this
6708 function - unless the user has asked us not to (via
6709 set step-mode) or we no longer know how to get back
6710 to the call site. */
6711 if (step_stop_if_no_debug
6712 || !frame_id_p (frame_unwind_caller_id (frame
)))
6714 /* If we have no line number and the step-stop-if-no-debug
6715 is set, we stop the step so that the user has a chance to
6716 switch in assembly mode. */
6717 end_stepping_range (ecs
);
6722 /* Set a breakpoint at callee's return address (the address
6723 at which the caller will resume). */
6724 insert_step_resume_breakpoint_at_caller (frame
);
6730 if (ecs
->event_thread
->control
.step_range_end
== 1)
6732 /* It is stepi or nexti. We always want to stop stepping after
6735 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
6736 end_stepping_range (ecs
);
6740 if (stop_pc_sal
.line
== 0)
6742 /* We have no line number information. That means to stop
6743 stepping (does this always happen right after one instruction,
6744 when we do "s" in a function with no line numbers,
6745 or can this happen as a result of a return or longjmp?). */
6747 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
6748 end_stepping_range (ecs
);
6752 /* Look for "calls" to inlined functions, part one. If the inline
6753 frame machinery detected some skipped call sites, we have entered
6754 a new inline function. */
6756 if (frame_id_eq (get_frame_id (get_current_frame ()),
6757 ecs
->event_thread
->control
.step_frame_id
)
6758 && inline_skipped_frames (ecs
->event_thread
))
6761 fprintf_unfiltered (gdb_stdlog
,
6762 "infrun: stepped into inlined function\n");
6764 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6766 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6768 /* For "step", we're going to stop. But if the call site
6769 for this inlined function is on the same source line as
6770 we were previously stepping, go down into the function
6771 first. Otherwise stop at the call site. */
6773 if (call_sal
.line
== ecs
->event_thread
->current_line
6774 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6775 step_into_inline_frame (ecs
->event_thread
);
6777 end_stepping_range (ecs
);
6782 /* For "next", we should stop at the call site if it is on a
6783 different source line. Otherwise continue through the
6784 inlined function. */
6785 if (call_sal
.line
== ecs
->event_thread
->current_line
6786 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6789 end_stepping_range (ecs
);
6794 /* Look for "calls" to inlined functions, part two. If we are still
6795 in the same real function we were stepping through, but we have
6796 to go further up to find the exact frame ID, we are stepping
6797 through a more inlined call beyond its call site. */
6799 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6800 && !frame_id_eq (get_frame_id (get_current_frame ()),
6801 ecs
->event_thread
->control
.step_frame_id
)
6802 && stepped_in_from (get_current_frame (),
6803 ecs
->event_thread
->control
.step_frame_id
))
6806 fprintf_unfiltered (gdb_stdlog
,
6807 "infrun: stepping through inlined function\n");
6809 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6812 end_stepping_range (ecs
);
6816 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
6817 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
6818 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
6820 /* We are at the start of a different line. So stop. Note that
6821 we don't stop if we step into the middle of a different line.
6822 That is said to make things like for (;;) statements work
6825 fprintf_unfiltered (gdb_stdlog
,
6826 "infrun: stepped to a different line\n");
6827 end_stepping_range (ecs
);
6831 /* We aren't done stepping.
6833 Optimize by setting the stepping range to the line.
6834 (We might not be in the original line, but if we entered a
6835 new line in mid-statement, we continue stepping. This makes
6836 things like for(;;) statements work better.) */
6838 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
6839 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
6840 ecs
->event_thread
->control
.may_range_step
= 1;
6841 set_step_info (frame
, stop_pc_sal
);
6844 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
6848 /* In all-stop mode, if we're currently stepping but have stopped in
6849 some other thread, we may need to switch back to the stepped
6850 thread. Returns true we set the inferior running, false if we left
6851 it stopped (and the event needs further processing). */
6854 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
6856 if (!target_is_non_stop_p ())
6858 struct thread_info
*stepping_thread
;
6860 /* If any thread is blocked on some internal breakpoint, and we
6861 simply need to step over that breakpoint to get it going
6862 again, do that first. */
6864 /* However, if we see an event for the stepping thread, then we
6865 know all other threads have been moved past their breakpoints
6866 already. Let the caller check whether the step is finished,
6867 etc., before deciding to move it past a breakpoint. */
6868 if (ecs
->event_thread
->control
.step_range_end
!= 0)
6871 /* Check if the current thread is blocked on an incomplete
6872 step-over, interrupted by a random signal. */
6873 if (ecs
->event_thread
->control
.trap_expected
6874 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
6878 fprintf_unfiltered (gdb_stdlog
,
6879 "infrun: need to finish step-over of [%s]\n",
6880 target_pid_to_str (ecs
->event_thread
->ptid
));
6886 /* Check if the current thread is blocked by a single-step
6887 breakpoint of another thread. */
6888 if (ecs
->hit_singlestep_breakpoint
)
6892 fprintf_unfiltered (gdb_stdlog
,
6893 "infrun: need to step [%s] over single-step "
6895 target_pid_to_str (ecs
->ptid
));
6901 /* If this thread needs yet another step-over (e.g., stepping
6902 through a delay slot), do it first before moving on to
6904 if (thread_still_needs_step_over (ecs
->event_thread
))
6908 fprintf_unfiltered (gdb_stdlog
,
6909 "infrun: thread [%s] still needs step-over\n",
6910 target_pid_to_str (ecs
->event_thread
->ptid
));
6916 /* If scheduler locking applies even if not stepping, there's no
6917 need to walk over threads. Above we've checked whether the
6918 current thread is stepping. If some other thread not the
6919 event thread is stepping, then it must be that scheduler
6920 locking is not in effect. */
6921 if (schedlock_applies (ecs
->event_thread
))
6924 /* Otherwise, we no longer expect a trap in the current thread.
6925 Clear the trap_expected flag before switching back -- this is
6926 what keep_going does as well, if we call it. */
6927 ecs
->event_thread
->control
.trap_expected
= 0;
6929 /* Likewise, clear the signal if it should not be passed. */
6930 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
6931 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6933 /* Do all pending step-overs before actually proceeding with
6935 if (start_step_over ())
6937 prepare_to_wait (ecs
);
6941 /* Look for the stepping/nexting thread. */
6942 stepping_thread
= NULL
;
6944 for (thread_info
*tp
: all_non_exited_threads ())
6946 /* Ignore threads of processes the caller is not
6949 && tp
->ptid
.pid () != ecs
->ptid
.pid ())
6952 /* When stepping over a breakpoint, we lock all threads
6953 except the one that needs to move past the breakpoint.
6954 If a non-event thread has this set, the "incomplete
6955 step-over" check above should have caught it earlier. */
6956 if (tp
->control
.trap_expected
)
6958 internal_error (__FILE__
, __LINE__
,
6959 "[%s] has inconsistent state: "
6960 "trap_expected=%d\n",
6961 target_pid_to_str (tp
->ptid
),
6962 tp
->control
.trap_expected
);
6965 /* Did we find the stepping thread? */
6966 if (tp
->control
.step_range_end
)
6968 /* Yep. There should only one though. */
6969 gdb_assert (stepping_thread
== NULL
);
6971 /* The event thread is handled at the top, before we
6973 gdb_assert (tp
!= ecs
->event_thread
);
6975 /* If some thread other than the event thread is
6976 stepping, then scheduler locking can't be in effect,
6977 otherwise we wouldn't have resumed the current event
6978 thread in the first place. */
6979 gdb_assert (!schedlock_applies (tp
));
6981 stepping_thread
= tp
;
6985 if (stepping_thread
!= NULL
)
6988 fprintf_unfiltered (gdb_stdlog
,
6989 "infrun: switching back to stepped thread\n");
6991 if (keep_going_stepped_thread (stepping_thread
))
6993 prepare_to_wait (ecs
);
7002 /* Set a previously stepped thread back to stepping. Returns true on
7003 success, false if the resume is not possible (e.g., the thread
7007 keep_going_stepped_thread (struct thread_info
*tp
)
7009 struct frame_info
*frame
;
7010 struct execution_control_state ecss
;
7011 struct execution_control_state
*ecs
= &ecss
;
7013 /* If the stepping thread exited, then don't try to switch back and
7014 resume it, which could fail in several different ways depending
7015 on the target. Instead, just keep going.
7017 We can find a stepping dead thread in the thread list in two
7020 - The target supports thread exit events, and when the target
7021 tries to delete the thread from the thread list, inferior_ptid
7022 pointed at the exiting thread. In such case, calling
7023 delete_thread does not really remove the thread from the list;
7024 instead, the thread is left listed, with 'exited' state.
7026 - The target's debug interface does not support thread exit
7027 events, and so we have no idea whatsoever if the previously
7028 stepping thread is still alive. For that reason, we need to
7029 synchronously query the target now. */
7031 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7034 fprintf_unfiltered (gdb_stdlog
,
7035 "infrun: not resuming previously "
7036 "stepped thread, it has vanished\n");
7043 fprintf_unfiltered (gdb_stdlog
,
7044 "infrun: resuming previously stepped thread\n");
7046 reset_ecs (ecs
, tp
);
7047 switch_to_thread (tp
);
7049 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7050 frame
= get_current_frame ();
7052 /* If the PC of the thread we were trying to single-step has
7053 changed, then that thread has trapped or been signaled, but the
7054 event has not been reported to GDB yet. Re-poll the target
7055 looking for this particular thread's event (i.e. temporarily
7056 enable schedlock) by:
7058 - setting a break at the current PC
7059 - resuming that particular thread, only (by setting trap
7062 This prevents us continuously moving the single-step breakpoint
7063 forward, one instruction at a time, overstepping. */
7065 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7070 fprintf_unfiltered (gdb_stdlog
,
7071 "infrun: expected thread advanced also (%s -> %s)\n",
7072 paddress (target_gdbarch (), tp
->prev_pc
),
7073 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7075 /* Clear the info of the previous step-over, as it's no longer
7076 valid (if the thread was trying to step over a breakpoint, it
7077 has already succeeded). It's what keep_going would do too,
7078 if we called it. Do this before trying to insert the sss
7079 breakpoint, otherwise if we were previously trying to step
7080 over this exact address in another thread, the breakpoint is
7082 clear_step_over_info ();
7083 tp
->control
.trap_expected
= 0;
7085 insert_single_step_breakpoint (get_frame_arch (frame
),
7086 get_frame_address_space (frame
),
7087 tp
->suspend
.stop_pc
);
7090 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7091 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7096 fprintf_unfiltered (gdb_stdlog
,
7097 "infrun: expected thread still hasn't advanced\n");
7099 keep_going_pass_signal (ecs
);
7104 /* Is thread TP in the middle of (software or hardware)
7105 single-stepping? (Note the result of this function must never be
7106 passed directly as target_resume's STEP parameter.) */
7109 currently_stepping (struct thread_info
*tp
)
7111 return ((tp
->control
.step_range_end
7112 && tp
->control
.step_resume_breakpoint
== NULL
)
7113 || tp
->control
.trap_expected
7114 || tp
->stepped_breakpoint
7115 || bpstat_should_step ());
7118 /* Inferior has stepped into a subroutine call with source code that
7119 we should not step over. Do step to the first line of code in
7123 handle_step_into_function (struct gdbarch
*gdbarch
,
7124 struct execution_control_state
*ecs
)
7126 fill_in_stop_func (gdbarch
, ecs
);
7128 compunit_symtab
*cust
7129 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7130 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7131 ecs
->stop_func_start
7132 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7134 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7135 /* Use the step_resume_break to step until the end of the prologue,
7136 even if that involves jumps (as it seems to on the vax under
7138 /* If the prologue ends in the middle of a source line, continue to
7139 the end of that source line (if it is still within the function).
7140 Otherwise, just go to end of prologue. */
7141 if (stop_func_sal
.end
7142 && stop_func_sal
.pc
!= ecs
->stop_func_start
7143 && stop_func_sal
.end
< ecs
->stop_func_end
)
7144 ecs
->stop_func_start
= stop_func_sal
.end
;
7146 /* Architectures which require breakpoint adjustment might not be able
7147 to place a breakpoint at the computed address. If so, the test
7148 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7149 ecs->stop_func_start to an address at which a breakpoint may be
7150 legitimately placed.
7152 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7153 made, GDB will enter an infinite loop when stepping through
7154 optimized code consisting of VLIW instructions which contain
7155 subinstructions corresponding to different source lines. On
7156 FR-V, it's not permitted to place a breakpoint on any but the
7157 first subinstruction of a VLIW instruction. When a breakpoint is
7158 set, GDB will adjust the breakpoint address to the beginning of
7159 the VLIW instruction. Thus, we need to make the corresponding
7160 adjustment here when computing the stop address. */
7162 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7164 ecs
->stop_func_start
7165 = gdbarch_adjust_breakpoint_address (gdbarch
,
7166 ecs
->stop_func_start
);
7169 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7171 /* We are already there: stop now. */
7172 end_stepping_range (ecs
);
7177 /* Put the step-breakpoint there and go until there. */
7178 symtab_and_line sr_sal
;
7179 sr_sal
.pc
= ecs
->stop_func_start
;
7180 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7181 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7183 /* Do not specify what the fp should be when we stop since on
7184 some machines the prologue is where the new fp value is
7186 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7188 /* And make sure stepping stops right away then. */
7189 ecs
->event_thread
->control
.step_range_end
7190 = ecs
->event_thread
->control
.step_range_start
;
7195 /* Inferior has stepped backward into a subroutine call with source
7196 code that we should not step over. Do step to the beginning of the
7197 last line of code in it. */
7200 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7201 struct execution_control_state
*ecs
)
7203 struct compunit_symtab
*cust
;
7204 struct symtab_and_line stop_func_sal
;
7206 fill_in_stop_func (gdbarch
, ecs
);
7208 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7209 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7210 ecs
->stop_func_start
7211 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7213 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7215 /* OK, we're just going to keep stepping here. */
7216 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7218 /* We're there already. Just stop stepping now. */
7219 end_stepping_range (ecs
);
7223 /* Else just reset the step range and keep going.
7224 No step-resume breakpoint, they don't work for
7225 epilogues, which can have multiple entry paths. */
7226 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7227 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7233 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7234 This is used to both functions and to skip over code. */
7237 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7238 struct symtab_and_line sr_sal
,
7239 struct frame_id sr_id
,
7240 enum bptype sr_type
)
7242 /* There should never be more than one step-resume or longjmp-resume
7243 breakpoint per thread, so we should never be setting a new
7244 step_resume_breakpoint when one is already active. */
7245 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7246 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7249 fprintf_unfiltered (gdb_stdlog
,
7250 "infrun: inserting step-resume breakpoint at %s\n",
7251 paddress (gdbarch
, sr_sal
.pc
));
7253 inferior_thread ()->control
.step_resume_breakpoint
7254 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7258 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7259 struct symtab_and_line sr_sal
,
7260 struct frame_id sr_id
)
7262 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7267 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7268 This is used to skip a potential signal handler.
7270 This is called with the interrupted function's frame. The signal
7271 handler, when it returns, will resume the interrupted function at
7275 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7277 gdb_assert (return_frame
!= NULL
);
7279 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7281 symtab_and_line sr_sal
;
7282 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7283 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7284 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7286 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7287 get_stack_frame_id (return_frame
),
7291 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7292 is used to skip a function after stepping into it (for "next" or if
7293 the called function has no debugging information).
7295 The current function has almost always been reached by single
7296 stepping a call or return instruction. NEXT_FRAME belongs to the
7297 current function, and the breakpoint will be set at the caller's
7300 This is a separate function rather than reusing
7301 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7302 get_prev_frame, which may stop prematurely (see the implementation
7303 of frame_unwind_caller_id for an example). */
7306 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7308 /* We shouldn't have gotten here if we don't know where the call site
7310 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7312 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7314 symtab_and_line sr_sal
;
7315 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7316 frame_unwind_caller_pc (next_frame
));
7317 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7318 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7320 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7321 frame_unwind_caller_id (next_frame
));
7324 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7325 new breakpoint at the target of a jmp_buf. The handling of
7326 longjmp-resume uses the same mechanisms used for handling
7327 "step-resume" breakpoints. */
7330 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7332 /* There should never be more than one longjmp-resume breakpoint per
7333 thread, so we should never be setting a new
7334 longjmp_resume_breakpoint when one is already active. */
7335 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7338 fprintf_unfiltered (gdb_stdlog
,
7339 "infrun: inserting longjmp-resume breakpoint at %s\n",
7340 paddress (gdbarch
, pc
));
7342 inferior_thread ()->control
.exception_resume_breakpoint
=
7343 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7346 /* Insert an exception resume breakpoint. TP is the thread throwing
7347 the exception. The block B is the block of the unwinder debug hook
7348 function. FRAME is the frame corresponding to the call to this
7349 function. SYM is the symbol of the function argument holding the
7350 target PC of the exception. */
7353 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7354 const struct block
*b
,
7355 struct frame_info
*frame
,
7360 struct block_symbol vsym
;
7361 struct value
*value
;
7363 struct breakpoint
*bp
;
7365 vsym
= lookup_symbol_search_name (SYMBOL_SEARCH_NAME (sym
),
7367 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7368 /* If the value was optimized out, revert to the old behavior. */
7369 if (! value_optimized_out (value
))
7371 handler
= value_as_address (value
);
7374 fprintf_unfiltered (gdb_stdlog
,
7375 "infrun: exception resume at %lx\n",
7376 (unsigned long) handler
);
7378 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7380 bp_exception_resume
).release ();
7382 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7385 bp
->thread
= tp
->global_num
;
7386 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7389 CATCH (e
, RETURN_MASK_ERROR
)
7391 /* We want to ignore errors here. */
7396 /* A helper for check_exception_resume that sets an
7397 exception-breakpoint based on a SystemTap probe. */
7400 insert_exception_resume_from_probe (struct thread_info
*tp
,
7401 const struct bound_probe
*probe
,
7402 struct frame_info
*frame
)
7404 struct value
*arg_value
;
7406 struct breakpoint
*bp
;
7408 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7412 handler
= value_as_address (arg_value
);
7415 fprintf_unfiltered (gdb_stdlog
,
7416 "infrun: exception resume at %s\n",
7417 paddress (get_objfile_arch (probe
->objfile
),
7420 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7421 handler
, bp_exception_resume
).release ();
7422 bp
->thread
= tp
->global_num
;
7423 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7426 /* This is called when an exception has been intercepted. Check to
7427 see whether the exception's destination is of interest, and if so,
7428 set an exception resume breakpoint there. */
7431 check_exception_resume (struct execution_control_state
*ecs
,
7432 struct frame_info
*frame
)
7434 struct bound_probe probe
;
7435 struct symbol
*func
;
7437 /* First see if this exception unwinding breakpoint was set via a
7438 SystemTap probe point. If so, the probe has two arguments: the
7439 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7440 set a breakpoint there. */
7441 probe
= find_probe_by_pc (get_frame_pc (frame
));
7444 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7448 func
= get_frame_function (frame
);
7454 const struct block
*b
;
7455 struct block_iterator iter
;
7459 /* The exception breakpoint is a thread-specific breakpoint on
7460 the unwinder's debug hook, declared as:
7462 void _Unwind_DebugHook (void *cfa, void *handler);
7464 The CFA argument indicates the frame to which control is
7465 about to be transferred. HANDLER is the destination PC.
7467 We ignore the CFA and set a temporary breakpoint at HANDLER.
7468 This is not extremely efficient but it avoids issues in gdb
7469 with computing the DWARF CFA, and it also works even in weird
7470 cases such as throwing an exception from inside a signal
7473 b
= SYMBOL_BLOCK_VALUE (func
);
7474 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7476 if (!SYMBOL_IS_ARGUMENT (sym
))
7483 insert_exception_resume_breakpoint (ecs
->event_thread
,
7489 CATCH (e
, RETURN_MASK_ERROR
)
7496 stop_waiting (struct execution_control_state
*ecs
)
7499 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7501 /* Let callers know we don't want to wait for the inferior anymore. */
7502 ecs
->wait_some_more
= 0;
7504 /* If all-stop, but the target is always in non-stop mode, stop all
7505 threads now that we're presenting the stop to the user. */
7506 if (!non_stop
&& target_is_non_stop_p ())
7507 stop_all_threads ();
7510 /* Like keep_going, but passes the signal to the inferior, even if the
7511 signal is set to nopass. */
7514 keep_going_pass_signal (struct execution_control_state
*ecs
)
7516 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7517 gdb_assert (!ecs
->event_thread
->resumed
);
7519 /* Save the pc before execution, to compare with pc after stop. */
7520 ecs
->event_thread
->prev_pc
7521 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7523 if (ecs
->event_thread
->control
.trap_expected
)
7525 struct thread_info
*tp
= ecs
->event_thread
;
7528 fprintf_unfiltered (gdb_stdlog
,
7529 "infrun: %s has trap_expected set, "
7530 "resuming to collect trap\n",
7531 target_pid_to_str (tp
->ptid
));
7533 /* We haven't yet gotten our trap, and either: intercepted a
7534 non-signal event (e.g., a fork); or took a signal which we
7535 are supposed to pass through to the inferior. Simply
7537 resume (ecs
->event_thread
->suspend
.stop_signal
);
7539 else if (step_over_info_valid_p ())
7541 /* Another thread is stepping over a breakpoint in-line. If
7542 this thread needs a step-over too, queue the request. In
7543 either case, this resume must be deferred for later. */
7544 struct thread_info
*tp
= ecs
->event_thread
;
7546 if (ecs
->hit_singlestep_breakpoint
7547 || thread_still_needs_step_over (tp
))
7550 fprintf_unfiltered (gdb_stdlog
,
7551 "infrun: step-over already in progress: "
7552 "step-over for %s deferred\n",
7553 target_pid_to_str (tp
->ptid
));
7554 thread_step_over_chain_enqueue (tp
);
7559 fprintf_unfiltered (gdb_stdlog
,
7560 "infrun: step-over in progress: "
7561 "resume of %s deferred\n",
7562 target_pid_to_str (tp
->ptid
));
7567 struct regcache
*regcache
= get_current_regcache ();
7570 step_over_what step_what
;
7572 /* Either the trap was not expected, but we are continuing
7573 anyway (if we got a signal, the user asked it be passed to
7576 We got our expected trap, but decided we should resume from
7579 We're going to run this baby now!
7581 Note that insert_breakpoints won't try to re-insert
7582 already inserted breakpoints. Therefore, we don't
7583 care if breakpoints were already inserted, or not. */
7585 /* If we need to step over a breakpoint, and we're not using
7586 displaced stepping to do so, insert all breakpoints
7587 (watchpoints, etc.) but the one we're stepping over, step one
7588 instruction, and then re-insert the breakpoint when that step
7591 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7593 remove_bp
= (ecs
->hit_singlestep_breakpoint
7594 || (step_what
& STEP_OVER_BREAKPOINT
));
7595 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7597 /* We can't use displaced stepping if we need to step past a
7598 watchpoint. The instruction copied to the scratch pad would
7599 still trigger the watchpoint. */
7601 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7603 set_step_over_info (regcache
->aspace (),
7604 regcache_read_pc (regcache
), remove_wps
,
7605 ecs
->event_thread
->global_num
);
7607 else if (remove_wps
)
7608 set_step_over_info (NULL
, 0, remove_wps
, -1);
7610 /* If we now need to do an in-line step-over, we need to stop
7611 all other threads. Note this must be done before
7612 insert_breakpoints below, because that removes the breakpoint
7613 we're about to step over, otherwise other threads could miss
7615 if (step_over_info_valid_p () && target_is_non_stop_p ())
7616 stop_all_threads ();
7618 /* Stop stepping if inserting breakpoints fails. */
7621 insert_breakpoints ();
7623 CATCH (e
, RETURN_MASK_ERROR
)
7625 exception_print (gdb_stderr
, e
);
7627 clear_step_over_info ();
7632 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7634 resume (ecs
->event_thread
->suspend
.stop_signal
);
7637 prepare_to_wait (ecs
);
7640 /* Called when we should continue running the inferior, because the
7641 current event doesn't cause a user visible stop. This does the
7642 resuming part; waiting for the next event is done elsewhere. */
7645 keep_going (struct execution_control_state
*ecs
)
7647 if (ecs
->event_thread
->control
.trap_expected
7648 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7649 ecs
->event_thread
->control
.trap_expected
= 0;
7651 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7652 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7653 keep_going_pass_signal (ecs
);
7656 /* This function normally comes after a resume, before
7657 handle_inferior_event exits. It takes care of any last bits of
7658 housekeeping, and sets the all-important wait_some_more flag. */
7661 prepare_to_wait (struct execution_control_state
*ecs
)
7664 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7666 ecs
->wait_some_more
= 1;
7668 if (!target_is_async_p ())
7669 mark_infrun_async_event_handler ();
7672 /* We are done with the step range of a step/next/si/ni command.
7673 Called once for each n of a "step n" operation. */
7676 end_stepping_range (struct execution_control_state
*ecs
)
7678 ecs
->event_thread
->control
.stop_step
= 1;
7682 /* Several print_*_reason functions to print why the inferior has stopped.
7683 We always print something when the inferior exits, or receives a signal.
7684 The rest of the cases are dealt with later on in normal_stop and
7685 print_it_typical. Ideally there should be a call to one of these
7686 print_*_reason functions functions from handle_inferior_event each time
7687 stop_waiting is called.
7689 Note that we don't call these directly, instead we delegate that to
7690 the interpreters, through observers. Interpreters then call these
7691 with whatever uiout is right. */
7694 print_end_stepping_range_reason (struct ui_out
*uiout
)
7696 /* For CLI-like interpreters, print nothing. */
7698 if (uiout
->is_mi_like_p ())
7700 uiout
->field_string ("reason",
7701 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7706 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7708 annotate_signalled ();
7709 if (uiout
->is_mi_like_p ())
7711 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7712 uiout
->text ("\nProgram terminated with signal ");
7713 annotate_signal_name ();
7714 uiout
->field_string ("signal-name",
7715 gdb_signal_to_name (siggnal
));
7716 annotate_signal_name_end ();
7718 annotate_signal_string ();
7719 uiout
->field_string ("signal-meaning",
7720 gdb_signal_to_string (siggnal
));
7721 annotate_signal_string_end ();
7722 uiout
->text (".\n");
7723 uiout
->text ("The program no longer exists.\n");
7727 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7729 struct inferior
*inf
= current_inferior ();
7730 const char *pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7732 annotate_exited (exitstatus
);
7735 if (uiout
->is_mi_like_p ())
7736 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7737 uiout
->text ("[Inferior ");
7738 uiout
->text (plongest (inf
->num
));
7740 uiout
->text (pidstr
);
7741 uiout
->text (") exited with code ");
7742 uiout
->field_fmt ("exit-code", "0%o", (unsigned int) exitstatus
);
7743 uiout
->text ("]\n");
7747 if (uiout
->is_mi_like_p ())
7749 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7750 uiout
->text ("[Inferior ");
7751 uiout
->text (plongest (inf
->num
));
7753 uiout
->text (pidstr
);
7754 uiout
->text (") exited normally]\n");
7758 /* Some targets/architectures can do extra processing/display of
7759 segmentation faults. E.g., Intel MPX boundary faults.
7760 Call the architecture dependent function to handle the fault. */
7763 handle_segmentation_fault (struct ui_out
*uiout
)
7765 struct regcache
*regcache
= get_current_regcache ();
7766 struct gdbarch
*gdbarch
= regcache
->arch ();
7768 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7769 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7773 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7775 struct thread_info
*thr
= inferior_thread ();
7779 if (uiout
->is_mi_like_p ())
7781 else if (show_thread_that_caused_stop ())
7785 uiout
->text ("\nThread ");
7786 uiout
->field_fmt ("thread-id", "%s", print_thread_id (thr
));
7788 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7791 uiout
->text (" \"");
7792 uiout
->field_fmt ("name", "%s", name
);
7797 uiout
->text ("\nProgram");
7799 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
7800 uiout
->text (" stopped");
7803 uiout
->text (" received signal ");
7804 annotate_signal_name ();
7805 if (uiout
->is_mi_like_p ())
7807 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7808 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
7809 annotate_signal_name_end ();
7811 annotate_signal_string ();
7812 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
7814 if (siggnal
== GDB_SIGNAL_SEGV
)
7815 handle_segmentation_fault (uiout
);
7817 annotate_signal_string_end ();
7819 uiout
->text (".\n");
7823 print_no_history_reason (struct ui_out
*uiout
)
7825 uiout
->text ("\nNo more reverse-execution history.\n");
7828 /* Print current location without a level number, if we have changed
7829 functions or hit a breakpoint. Print source line if we have one.
7830 bpstat_print contains the logic deciding in detail what to print,
7831 based on the event(s) that just occurred. */
7834 print_stop_location (struct target_waitstatus
*ws
)
7837 enum print_what source_flag
;
7838 int do_frame_printing
= 1;
7839 struct thread_info
*tp
= inferior_thread ();
7841 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
7845 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7846 should) carry around the function and does (or should) use
7847 that when doing a frame comparison. */
7848 if (tp
->control
.stop_step
7849 && frame_id_eq (tp
->control
.step_frame_id
,
7850 get_frame_id (get_current_frame ()))
7851 && (tp
->control
.step_start_function
7852 == find_pc_function (tp
->suspend
.stop_pc
)))
7854 /* Finished step, just print source line. */
7855 source_flag
= SRC_LINE
;
7859 /* Print location and source line. */
7860 source_flag
= SRC_AND_LOC
;
7863 case PRINT_SRC_AND_LOC
:
7864 /* Print location and source line. */
7865 source_flag
= SRC_AND_LOC
;
7867 case PRINT_SRC_ONLY
:
7868 source_flag
= SRC_LINE
;
7871 /* Something bogus. */
7872 source_flag
= SRC_LINE
;
7873 do_frame_printing
= 0;
7876 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
7879 /* The behavior of this routine with respect to the source
7881 SRC_LINE: Print only source line
7882 LOCATION: Print only location
7883 SRC_AND_LOC: Print location and source line. */
7884 if (do_frame_printing
)
7885 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
7891 print_stop_event (struct ui_out
*uiout
)
7893 struct target_waitstatus last
;
7895 struct thread_info
*tp
;
7897 get_last_target_status (&last_ptid
, &last
);
7900 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
7902 print_stop_location (&last
);
7904 /* Display the auto-display expressions. */
7908 tp
= inferior_thread ();
7909 if (tp
->thread_fsm
!= NULL
7910 && thread_fsm_finished_p (tp
->thread_fsm
))
7912 struct return_value_info
*rv
;
7914 rv
= thread_fsm_return_value (tp
->thread_fsm
);
7916 print_return_value (uiout
, rv
);
7923 maybe_remove_breakpoints (void)
7925 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
7927 if (remove_breakpoints ())
7929 target_terminal::ours_for_output ();
7930 printf_filtered (_("Cannot remove breakpoints because "
7931 "program is no longer writable.\nFurther "
7932 "execution is probably impossible.\n"));
7937 /* The execution context that just caused a normal stop. */
7944 DISABLE_COPY_AND_ASSIGN (stop_context
);
7946 bool changed () const;
7951 /* The event PTID. */
7955 /* If stopp for a thread event, this is the thread that caused the
7957 struct thread_info
*thread
;
7959 /* The inferior that caused the stop. */
7963 /* Initializes a new stop context. If stopped for a thread event, this
7964 takes a strong reference to the thread. */
7966 stop_context::stop_context ()
7968 stop_id
= get_stop_id ();
7969 ptid
= inferior_ptid
;
7970 inf_num
= current_inferior ()->num
;
7972 if (inferior_ptid
!= null_ptid
)
7974 /* Take a strong reference so that the thread can't be deleted
7976 thread
= inferior_thread ();
7983 /* Release a stop context previously created with save_stop_context.
7984 Releases the strong reference to the thread as well. */
7986 stop_context::~stop_context ()
7992 /* Return true if the current context no longer matches the saved stop
7996 stop_context::changed () const
7998 if (ptid
!= inferior_ptid
)
8000 if (inf_num
!= current_inferior ()->num
)
8002 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8004 if (get_stop_id () != stop_id
)
8014 struct target_waitstatus last
;
8017 get_last_target_status (&last_ptid
, &last
);
8021 /* If an exception is thrown from this point on, make sure to
8022 propagate GDB's knowledge of the executing state to the
8023 frontend/user running state. A QUIT is an easy exception to see
8024 here, so do this before any filtered output. */
8026 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8029 maybe_finish_thread_state
.emplace (minus_one_ptid
);
8030 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8031 || last
.kind
== TARGET_WAITKIND_EXITED
)
8033 /* On some targets, we may still have live threads in the
8034 inferior when we get a process exit event. E.g., for
8035 "checkpoint", when the current checkpoint/fork exits,
8036 linux-fork.c automatically switches to another fork from
8037 within target_mourn_inferior. */
8038 if (inferior_ptid
!= null_ptid
)
8039 maybe_finish_thread_state
.emplace (ptid_t (inferior_ptid
.pid ()));
8041 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8042 maybe_finish_thread_state
.emplace (inferior_ptid
);
8044 /* As we're presenting a stop, and potentially removing breakpoints,
8045 update the thread list so we can tell whether there are threads
8046 running on the target. With target remote, for example, we can
8047 only learn about new threads when we explicitly update the thread
8048 list. Do this before notifying the interpreters about signal
8049 stops, end of stepping ranges, etc., so that the "new thread"
8050 output is emitted before e.g., "Program received signal FOO",
8051 instead of after. */
8052 update_thread_list ();
8054 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8055 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8057 /* As with the notification of thread events, we want to delay
8058 notifying the user that we've switched thread context until
8059 the inferior actually stops.
8061 There's no point in saying anything if the inferior has exited.
8062 Note that SIGNALLED here means "exited with a signal", not
8063 "received a signal".
8065 Also skip saying anything in non-stop mode. In that mode, as we
8066 don't want GDB to switch threads behind the user's back, to avoid
8067 races where the user is typing a command to apply to thread x,
8068 but GDB switches to thread y before the user finishes entering
8069 the command, fetch_inferior_event installs a cleanup to restore
8070 the current thread back to the thread the user had selected right
8071 after this event is handled, so we're not really switching, only
8072 informing of a stop. */
8074 && previous_inferior_ptid
!= inferior_ptid
8075 && target_has_execution
8076 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8077 && last
.kind
!= TARGET_WAITKIND_EXITED
8078 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8080 SWITCH_THRU_ALL_UIS ()
8082 target_terminal::ours_for_output ();
8083 printf_filtered (_("[Switching to %s]\n"),
8084 target_pid_to_str (inferior_ptid
));
8085 annotate_thread_changed ();
8087 previous_inferior_ptid
= inferior_ptid
;
8090 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8092 SWITCH_THRU_ALL_UIS ()
8093 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8095 target_terminal::ours_for_output ();
8096 printf_filtered (_("No unwaited-for children left.\n"));
8100 /* Note: this depends on the update_thread_list call above. */
8101 maybe_remove_breakpoints ();
8103 /* If an auto-display called a function and that got a signal,
8104 delete that auto-display to avoid an infinite recursion. */
8106 if (stopped_by_random_signal
)
8107 disable_current_display ();
8109 SWITCH_THRU_ALL_UIS ()
8111 async_enable_stdin ();
8114 /* Let the user/frontend see the threads as stopped. */
8115 maybe_finish_thread_state
.reset ();
8117 /* Select innermost stack frame - i.e., current frame is frame 0,
8118 and current location is based on that. Handle the case where the
8119 dummy call is returning after being stopped. E.g. the dummy call
8120 previously hit a breakpoint. (If the dummy call returns
8121 normally, we won't reach here.) Do this before the stop hook is
8122 run, so that it doesn't get to see the temporary dummy frame,
8123 which is not where we'll present the stop. */
8124 if (has_stack_frames ())
8126 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8128 /* Pop the empty frame that contains the stack dummy. This
8129 also restores inferior state prior to the call (struct
8130 infcall_suspend_state). */
8131 struct frame_info
*frame
= get_current_frame ();
8133 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8135 /* frame_pop calls reinit_frame_cache as the last thing it
8136 does which means there's now no selected frame. */
8139 select_frame (get_current_frame ());
8141 /* Set the current source location. */
8142 set_current_sal_from_frame (get_current_frame ());
8145 /* Look up the hook_stop and run it (CLI internally handles problem
8146 of stop_command's pre-hook not existing). */
8147 if (stop_command
!= NULL
)
8149 stop_context saved_context
;
8153 execute_cmd_pre_hook (stop_command
);
8155 CATCH (ex
, RETURN_MASK_ALL
)
8157 exception_fprintf (gdb_stderr
, ex
,
8158 "Error while running hook_stop:\n");
8162 /* If the stop hook resumes the target, then there's no point in
8163 trying to notify about the previous stop; its context is
8164 gone. Likewise if the command switches thread or inferior --
8165 the observers would print a stop for the wrong
8167 if (saved_context
.changed ())
8171 /* Notify observers about the stop. This is where the interpreters
8172 print the stop event. */
8173 if (inferior_ptid
!= null_ptid
)
8174 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8177 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8179 annotate_stopped ();
8181 if (target_has_execution
)
8183 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8184 && last
.kind
!= TARGET_WAITKIND_EXITED
)
8185 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8186 Delete any breakpoint that is to be deleted at the next stop. */
8187 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8190 /* Try to get rid of automatically added inferiors that are no
8191 longer needed. Keeping those around slows down things linearly.
8192 Note that this never removes the current inferior. */
8199 signal_stop_state (int signo
)
8201 return signal_stop
[signo
];
8205 signal_print_state (int signo
)
8207 return signal_print
[signo
];
8211 signal_pass_state (int signo
)
8213 return signal_program
[signo
];
8217 signal_cache_update (int signo
)
8221 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8222 signal_cache_update (signo
);
8227 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8228 && signal_print
[signo
] == 0
8229 && signal_program
[signo
] == 1
8230 && signal_catch
[signo
] == 0);
8234 signal_stop_update (int signo
, int state
)
8236 int ret
= signal_stop
[signo
];
8238 signal_stop
[signo
] = state
;
8239 signal_cache_update (signo
);
8244 signal_print_update (int signo
, int state
)
8246 int ret
= signal_print
[signo
];
8248 signal_print
[signo
] = state
;
8249 signal_cache_update (signo
);
8254 signal_pass_update (int signo
, int state
)
8256 int ret
= signal_program
[signo
];
8258 signal_program
[signo
] = state
;
8259 signal_cache_update (signo
);
8263 /* Update the global 'signal_catch' from INFO and notify the
8267 signal_catch_update (const unsigned int *info
)
8271 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8272 signal_catch
[i
] = info
[i
] > 0;
8273 signal_cache_update (-1);
8274 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
8278 sig_print_header (void)
8280 printf_filtered (_("Signal Stop\tPrint\tPass "
8281 "to program\tDescription\n"));
8285 sig_print_info (enum gdb_signal oursig
)
8287 const char *name
= gdb_signal_to_name (oursig
);
8288 int name_padding
= 13 - strlen (name
);
8290 if (name_padding
<= 0)
8293 printf_filtered ("%s", name
);
8294 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8295 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8296 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8297 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8298 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8301 /* Specify how various signals in the inferior should be handled. */
8304 handle_command (const char *args
, int from_tty
)
8306 int digits
, wordlen
;
8307 int sigfirst
, siglast
;
8308 enum gdb_signal oursig
;
8311 unsigned char *sigs
;
8315 error_no_arg (_("signal to handle"));
8318 /* Allocate and zero an array of flags for which signals to handle. */
8320 nsigs
= (int) GDB_SIGNAL_LAST
;
8321 sigs
= (unsigned char *) alloca (nsigs
);
8322 memset (sigs
, 0, nsigs
);
8324 /* Break the command line up into args. */
8326 gdb_argv
built_argv (args
);
8328 /* Walk through the args, looking for signal oursigs, signal names, and
8329 actions. Signal numbers and signal names may be interspersed with
8330 actions, with the actions being performed for all signals cumulatively
8331 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8333 for (char *arg
: built_argv
)
8335 wordlen
= strlen (arg
);
8336 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8340 sigfirst
= siglast
= -1;
8342 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8344 /* Apply action to all signals except those used by the
8345 debugger. Silently skip those. */
8348 siglast
= nsigs
- 1;
8350 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8352 SET_SIGS (nsigs
, sigs
, signal_stop
);
8353 SET_SIGS (nsigs
, sigs
, signal_print
);
8355 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8357 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8359 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8361 SET_SIGS (nsigs
, sigs
, signal_print
);
8363 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8365 SET_SIGS (nsigs
, sigs
, signal_program
);
8367 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8369 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8371 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8373 SET_SIGS (nsigs
, sigs
, signal_program
);
8375 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8377 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8378 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8380 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8382 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8384 else if (digits
> 0)
8386 /* It is numeric. The numeric signal refers to our own
8387 internal signal numbering from target.h, not to host/target
8388 signal number. This is a feature; users really should be
8389 using symbolic names anyway, and the common ones like
8390 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8392 sigfirst
= siglast
= (int)
8393 gdb_signal_from_command (atoi (arg
));
8394 if (arg
[digits
] == '-')
8397 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8399 if (sigfirst
> siglast
)
8401 /* Bet he didn't figure we'd think of this case... */
8402 std::swap (sigfirst
, siglast
);
8407 oursig
= gdb_signal_from_name (arg
);
8408 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8410 sigfirst
= siglast
= (int) oursig
;
8414 /* Not a number and not a recognized flag word => complain. */
8415 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8419 /* If any signal numbers or symbol names were found, set flags for
8420 which signals to apply actions to. */
8422 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8424 switch ((enum gdb_signal
) signum
)
8426 case GDB_SIGNAL_TRAP
:
8427 case GDB_SIGNAL_INT
:
8428 if (!allsigs
&& !sigs
[signum
])
8430 if (query (_("%s is used by the debugger.\n\
8431 Are you sure you want to change it? "),
8432 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8438 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8439 gdb_flush (gdb_stdout
);
8444 case GDB_SIGNAL_DEFAULT
:
8445 case GDB_SIGNAL_UNKNOWN
:
8446 /* Make sure that "all" doesn't print these. */
8455 for (int signum
= 0; signum
< nsigs
; signum
++)
8458 signal_cache_update (-1);
8459 target_pass_signals ((int) GDB_SIGNAL_LAST
, signal_pass
);
8460 target_program_signals ((int) GDB_SIGNAL_LAST
, signal_program
);
8464 /* Show the results. */
8465 sig_print_header ();
8466 for (; signum
< nsigs
; signum
++)
8468 sig_print_info ((enum gdb_signal
) signum
);
8475 /* Complete the "handle" command. */
8478 handle_completer (struct cmd_list_element
*ignore
,
8479 completion_tracker
&tracker
,
8480 const char *text
, const char *word
)
8482 static const char * const keywords
[] =
8496 signal_completer (ignore
, tracker
, text
, word
);
8497 complete_on_enum (tracker
, keywords
, word
, word
);
8501 gdb_signal_from_command (int num
)
8503 if (num
>= 1 && num
<= 15)
8504 return (enum gdb_signal
) num
;
8505 error (_("Only signals 1-15 are valid as numeric signals.\n\
8506 Use \"info signals\" for a list of symbolic signals."));
8509 /* Print current contents of the tables set by the handle command.
8510 It is possible we should just be printing signals actually used
8511 by the current target (but for things to work right when switching
8512 targets, all signals should be in the signal tables). */
8515 info_signals_command (const char *signum_exp
, int from_tty
)
8517 enum gdb_signal oursig
;
8519 sig_print_header ();
8523 /* First see if this is a symbol name. */
8524 oursig
= gdb_signal_from_name (signum_exp
);
8525 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8527 /* No, try numeric. */
8529 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8531 sig_print_info (oursig
);
8535 printf_filtered ("\n");
8536 /* These ugly casts brought to you by the native VAX compiler. */
8537 for (oursig
= GDB_SIGNAL_FIRST
;
8538 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8539 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8543 if (oursig
!= GDB_SIGNAL_UNKNOWN
8544 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8545 sig_print_info (oursig
);
8548 printf_filtered (_("\nUse the \"handle\" command "
8549 "to change these tables.\n"));
8552 /* The $_siginfo convenience variable is a bit special. We don't know
8553 for sure the type of the value until we actually have a chance to
8554 fetch the data. The type can change depending on gdbarch, so it is
8555 also dependent on which thread you have selected.
8557 1. making $_siginfo be an internalvar that creates a new value on
8560 2. making the value of $_siginfo be an lval_computed value. */
8562 /* This function implements the lval_computed support for reading a
8566 siginfo_value_read (struct value
*v
)
8568 LONGEST transferred
;
8570 /* If we can access registers, so can we access $_siginfo. Likewise
8572 validate_registers_access ();
8575 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8577 value_contents_all_raw (v
),
8579 TYPE_LENGTH (value_type (v
)));
8581 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8582 error (_("Unable to read siginfo"));
8585 /* This function implements the lval_computed support for writing a
8589 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8591 LONGEST transferred
;
8593 /* If we can access registers, so can we access $_siginfo. Likewise
8595 validate_registers_access ();
8597 transferred
= target_write (current_top_target (),
8598 TARGET_OBJECT_SIGNAL_INFO
,
8600 value_contents_all_raw (fromval
),
8602 TYPE_LENGTH (value_type (fromval
)));
8604 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8605 error (_("Unable to write siginfo"));
8608 static const struct lval_funcs siginfo_value_funcs
=
8614 /* Return a new value with the correct type for the siginfo object of
8615 the current thread using architecture GDBARCH. Return a void value
8616 if there's no object available. */
8618 static struct value
*
8619 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8622 if (target_has_stack
8623 && inferior_ptid
!= null_ptid
8624 && gdbarch_get_siginfo_type_p (gdbarch
))
8626 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8628 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8631 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8635 /* infcall_suspend_state contains state about the program itself like its
8636 registers and any signal it received when it last stopped.
8637 This state must be restored regardless of how the inferior function call
8638 ends (either successfully, or after it hits a breakpoint or signal)
8639 if the program is to properly continue where it left off. */
8641 class infcall_suspend_state
8644 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8645 once the inferior function call has finished. */
8646 infcall_suspend_state (struct gdbarch
*gdbarch
,
8647 const struct thread_info
*tp
,
8648 struct regcache
*regcache
)
8649 : m_thread_suspend (tp
->suspend
),
8650 m_registers (new readonly_detached_regcache (*regcache
))
8652 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8654 if (gdbarch_get_siginfo_type_p (gdbarch
))
8656 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8657 size_t len
= TYPE_LENGTH (type
);
8659 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8661 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8662 siginfo_data
.get (), 0, len
) != len
)
8664 /* Errors ignored. */
8665 siginfo_data
.reset (nullptr);
8671 m_siginfo_gdbarch
= gdbarch
;
8672 m_siginfo_data
= std::move (siginfo_data
);
8676 /* Return a pointer to the stored register state. */
8678 readonly_detached_regcache
*registers () const
8680 return m_registers
.get ();
8683 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8685 void restore (struct gdbarch
*gdbarch
,
8686 struct thread_info
*tp
,
8687 struct regcache
*regcache
) const
8689 tp
->suspend
= m_thread_suspend
;
8691 if (m_siginfo_gdbarch
== gdbarch
)
8693 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8695 /* Errors ignored. */
8696 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8697 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8700 /* The inferior can be gone if the user types "print exit(0)"
8701 (and perhaps other times). */
8702 if (target_has_execution
)
8703 /* NB: The register write goes through to the target. */
8704 regcache
->restore (registers ());
8708 /* How the current thread stopped before the inferior function call was
8710 struct thread_suspend_state m_thread_suspend
;
8712 /* The registers before the inferior function call was executed. */
8713 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8715 /* Format of SIGINFO_DATA or NULL if it is not present. */
8716 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8718 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8719 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8720 content would be invalid. */
8721 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8724 infcall_suspend_state_up
8725 save_infcall_suspend_state ()
8727 struct thread_info
*tp
= inferior_thread ();
8728 struct regcache
*regcache
= get_current_regcache ();
8729 struct gdbarch
*gdbarch
= regcache
->arch ();
8731 infcall_suspend_state_up inf_state
8732 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8734 /* Having saved the current state, adjust the thread state, discarding
8735 any stop signal information. The stop signal is not useful when
8736 starting an inferior function call, and run_inferior_call will not use
8737 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8738 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8743 /* Restore inferior session state to INF_STATE. */
8746 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8748 struct thread_info
*tp
= inferior_thread ();
8749 struct regcache
*regcache
= get_current_regcache ();
8750 struct gdbarch
*gdbarch
= regcache
->arch ();
8752 inf_state
->restore (gdbarch
, tp
, regcache
);
8753 discard_infcall_suspend_state (inf_state
);
8757 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8762 readonly_detached_regcache
*
8763 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8765 return inf_state
->registers ();
8768 /* infcall_control_state contains state regarding gdb's control of the
8769 inferior itself like stepping control. It also contains session state like
8770 the user's currently selected frame. */
8772 struct infcall_control_state
8774 struct thread_control_state thread_control
;
8775 struct inferior_control_state inferior_control
;
8778 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8779 int stopped_by_random_signal
= 0;
8781 /* ID if the selected frame when the inferior function call was made. */
8782 struct frame_id selected_frame_id
{};
8785 /* Save all of the information associated with the inferior<==>gdb
8788 infcall_control_state_up
8789 save_infcall_control_state ()
8791 infcall_control_state_up
inf_status (new struct infcall_control_state
);
8792 struct thread_info
*tp
= inferior_thread ();
8793 struct inferior
*inf
= current_inferior ();
8795 inf_status
->thread_control
= tp
->control
;
8796 inf_status
->inferior_control
= inf
->control
;
8798 tp
->control
.step_resume_breakpoint
= NULL
;
8799 tp
->control
.exception_resume_breakpoint
= NULL
;
8801 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8802 chain. If caller's caller is walking the chain, they'll be happier if we
8803 hand them back the original chain when restore_infcall_control_state is
8805 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
8808 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
8809 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
8811 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
8817 restore_selected_frame (const frame_id
&fid
)
8819 frame_info
*frame
= frame_find_by_id (fid
);
8821 /* If inf_status->selected_frame_id is NULL, there was no previously
8825 warning (_("Unable to restore previously selected frame."));
8829 select_frame (frame
);
8832 /* Restore inferior session state to INF_STATUS. */
8835 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
8837 struct thread_info
*tp
= inferior_thread ();
8838 struct inferior
*inf
= current_inferior ();
8840 if (tp
->control
.step_resume_breakpoint
)
8841 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
8843 if (tp
->control
.exception_resume_breakpoint
)
8844 tp
->control
.exception_resume_breakpoint
->disposition
8845 = disp_del_at_next_stop
;
8847 /* Handle the bpstat_copy of the chain. */
8848 bpstat_clear (&tp
->control
.stop_bpstat
);
8850 tp
->control
= inf_status
->thread_control
;
8851 inf
->control
= inf_status
->inferior_control
;
8854 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
8855 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
8857 if (target_has_stack
)
8859 /* The point of the try/catch is that if the stack is clobbered,
8860 walking the stack might encounter a garbage pointer and
8861 error() trying to dereference it. */
8864 restore_selected_frame (inf_status
->selected_frame_id
);
8866 CATCH (ex
, RETURN_MASK_ERROR
)
8868 exception_fprintf (gdb_stderr
, ex
,
8869 "Unable to restore previously selected frame:\n");
8870 /* Error in restoring the selected frame. Select the
8872 select_frame (get_current_frame ());
8881 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
8883 if (inf_status
->thread_control
.step_resume_breakpoint
)
8884 inf_status
->thread_control
.step_resume_breakpoint
->disposition
8885 = disp_del_at_next_stop
;
8887 if (inf_status
->thread_control
.exception_resume_breakpoint
)
8888 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
8889 = disp_del_at_next_stop
;
8891 /* See save_infcall_control_state for info on stop_bpstat. */
8892 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
8900 clear_exit_convenience_vars (void)
8902 clear_internalvar (lookup_internalvar ("_exitsignal"));
8903 clear_internalvar (lookup_internalvar ("_exitcode"));
8907 /* User interface for reverse debugging:
8908 Set exec-direction / show exec-direction commands
8909 (returns error unless target implements to_set_exec_direction method). */
8911 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
8912 static const char exec_forward
[] = "forward";
8913 static const char exec_reverse
[] = "reverse";
8914 static const char *exec_direction
= exec_forward
;
8915 static const char *const exec_direction_names
[] = {
8922 set_exec_direction_func (const char *args
, int from_tty
,
8923 struct cmd_list_element
*cmd
)
8925 if (target_can_execute_reverse
)
8927 if (!strcmp (exec_direction
, exec_forward
))
8928 execution_direction
= EXEC_FORWARD
;
8929 else if (!strcmp (exec_direction
, exec_reverse
))
8930 execution_direction
= EXEC_REVERSE
;
8934 exec_direction
= exec_forward
;
8935 error (_("Target does not support this operation."));
8940 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
8941 struct cmd_list_element
*cmd
, const char *value
)
8943 switch (execution_direction
) {
8945 fprintf_filtered (out
, _("Forward.\n"));
8948 fprintf_filtered (out
, _("Reverse.\n"));
8951 internal_error (__FILE__
, __LINE__
,
8952 _("bogus execution_direction value: %d"),
8953 (int) execution_direction
);
8958 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
8959 struct cmd_list_element
*c
, const char *value
)
8961 fprintf_filtered (file
, _("Resuming the execution of threads "
8962 "of all processes is %s.\n"), value
);
8965 /* Implementation of `siginfo' variable. */
8967 static const struct internalvar_funcs siginfo_funcs
=
8974 /* Callback for infrun's target events source. This is marked when a
8975 thread has a pending status to process. */
8978 infrun_async_inferior_event_handler (gdb_client_data data
)
8980 inferior_event_handler (INF_REG_EVENT
, NULL
);
8984 _initialize_infrun (void)
8988 struct cmd_list_element
*c
;
8990 /* Register extra event sources in the event loop. */
8991 infrun_async_inferior_event_token
8992 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
8994 add_info ("signals", info_signals_command
, _("\
8995 What debugger does when program gets various signals.\n\
8996 Specify a signal as argument to print info on that signal only."));
8997 add_info_alias ("handle", "signals", 0);
8999 c
= add_com ("handle", class_run
, handle_command
, _("\
9000 Specify how to handle signals.\n\
9001 Usage: handle SIGNAL [ACTIONS]\n\
9002 Args are signals and actions to apply to those signals.\n\
9003 If no actions are specified, the current settings for the specified signals\n\
9004 will be displayed instead.\n\
9006 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9007 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9008 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9009 The special arg \"all\" is recognized to mean all signals except those\n\
9010 used by the debugger, typically SIGTRAP and SIGINT.\n\
9012 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9013 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9014 Stop means reenter debugger if this signal happens (implies print).\n\
9015 Print means print a message if this signal happens.\n\
9016 Pass means let program see this signal; otherwise program doesn't know.\n\
9017 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9018 Pass and Stop may be combined.\n\
9020 Multiple signals may be specified. Signal numbers and signal names\n\
9021 may be interspersed with actions, with the actions being performed for\n\
9022 all signals cumulatively specified."));
9023 set_cmd_completer (c
, handle_completer
);
9026 stop_command
= add_cmd ("stop", class_obscure
,
9027 not_just_help_class_command
, _("\
9028 There is no `stop' command, but you can set a hook on `stop'.\n\
9029 This allows you to set a list of commands to be run each time execution\n\
9030 of the program stops."), &cmdlist
);
9032 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9033 Set inferior debugging."), _("\
9034 Show inferior debugging."), _("\
9035 When non-zero, inferior specific debugging is enabled."),
9038 &setdebuglist
, &showdebuglist
);
9040 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9041 &debug_displaced
, _("\
9042 Set displaced stepping debugging."), _("\
9043 Show displaced stepping debugging."), _("\
9044 When non-zero, displaced stepping specific debugging is enabled."),
9046 show_debug_displaced
,
9047 &setdebuglist
, &showdebuglist
);
9049 add_setshow_boolean_cmd ("non-stop", no_class
,
9051 Set whether gdb controls the inferior in non-stop mode."), _("\
9052 Show whether gdb controls the inferior in non-stop mode."), _("\
9053 When debugging a multi-threaded program and this setting is\n\
9054 off (the default, also called all-stop mode), when one thread stops\n\
9055 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9056 all other threads in the program while you interact with the thread of\n\
9057 interest. When you continue or step a thread, you can allow the other\n\
9058 threads to run, or have them remain stopped, but while you inspect any\n\
9059 thread's state, all threads stop.\n\
9061 In non-stop mode, when one thread stops, other threads can continue\n\
9062 to run freely. You'll be able to step each thread independently,\n\
9063 leave it stopped or free to run as needed."),
9069 numsigs
= (int) GDB_SIGNAL_LAST
;
9070 signal_stop
= XNEWVEC (unsigned char, numsigs
);
9071 signal_print
= XNEWVEC (unsigned char, numsigs
);
9072 signal_program
= XNEWVEC (unsigned char, numsigs
);
9073 signal_catch
= XNEWVEC (unsigned char, numsigs
);
9074 signal_pass
= XNEWVEC (unsigned char, numsigs
);
9075 for (i
= 0; i
< numsigs
; i
++)
9078 signal_print
[i
] = 1;
9079 signal_program
[i
] = 1;
9080 signal_catch
[i
] = 0;
9083 /* Signals caused by debugger's own actions should not be given to
9084 the program afterwards.
9086 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9087 explicitly specifies that it should be delivered to the target
9088 program. Typically, that would occur when a user is debugging a
9089 target monitor on a simulator: the target monitor sets a
9090 breakpoint; the simulator encounters this breakpoint and halts
9091 the simulation handing control to GDB; GDB, noting that the stop
9092 address doesn't map to any known breakpoint, returns control back
9093 to the simulator; the simulator then delivers the hardware
9094 equivalent of a GDB_SIGNAL_TRAP to the program being
9096 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9097 signal_program
[GDB_SIGNAL_INT
] = 0;
9099 /* Signals that are not errors should not normally enter the debugger. */
9100 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9101 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9102 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9103 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9104 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9105 signal_print
[GDB_SIGNAL_PROF
] = 0;
9106 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9107 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9108 signal_stop
[GDB_SIGNAL_IO
] = 0;
9109 signal_print
[GDB_SIGNAL_IO
] = 0;
9110 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9111 signal_print
[GDB_SIGNAL_POLL
] = 0;
9112 signal_stop
[GDB_SIGNAL_URG
] = 0;
9113 signal_print
[GDB_SIGNAL_URG
] = 0;
9114 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9115 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9116 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9117 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9119 /* These signals are used internally by user-level thread
9120 implementations. (See signal(5) on Solaris.) Like the above
9121 signals, a healthy program receives and handles them as part of
9122 its normal operation. */
9123 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9124 signal_print
[GDB_SIGNAL_LWP
] = 0;
9125 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9126 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9127 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9128 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9129 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9130 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9132 /* Update cached state. */
9133 signal_cache_update (-1);
9135 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9136 &stop_on_solib_events
, _("\
9137 Set stopping for shared library events."), _("\
9138 Show stopping for shared library events."), _("\
9139 If nonzero, gdb will give control to the user when the dynamic linker\n\
9140 notifies gdb of shared library events. The most common event of interest\n\
9141 to the user would be loading/unloading of a new library."),
9142 set_stop_on_solib_events
,
9143 show_stop_on_solib_events
,
9144 &setlist
, &showlist
);
9146 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9147 follow_fork_mode_kind_names
,
9148 &follow_fork_mode_string
, _("\
9149 Set debugger response to a program call of fork or vfork."), _("\
9150 Show debugger response to a program call of fork or vfork."), _("\
9151 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9152 parent - the original process is debugged after a fork\n\
9153 child - the new process is debugged after a fork\n\
9154 The unfollowed process will continue to run.\n\
9155 By default, the debugger will follow the parent process."),
9157 show_follow_fork_mode_string
,
9158 &setlist
, &showlist
);
9160 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9161 follow_exec_mode_names
,
9162 &follow_exec_mode_string
, _("\
9163 Set debugger response to a program call of exec."), _("\
9164 Show debugger response to a program call of exec."), _("\
9165 An exec call replaces the program image of a process.\n\
9167 follow-exec-mode can be:\n\
9169 new - the debugger creates a new inferior and rebinds the process\n\
9170 to this new inferior. The program the process was running before\n\
9171 the exec call can be restarted afterwards by restarting the original\n\
9174 same - the debugger keeps the process bound to the same inferior.\n\
9175 The new executable image replaces the previous executable loaded in\n\
9176 the inferior. Restarting the inferior after the exec call restarts\n\
9177 the executable the process was running after the exec call.\n\
9179 By default, the debugger will use the same inferior."),
9181 show_follow_exec_mode_string
,
9182 &setlist
, &showlist
);
9184 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9185 scheduler_enums
, &scheduler_mode
, _("\
9186 Set mode for locking scheduler during execution."), _("\
9187 Show mode for locking scheduler during execution."), _("\
9188 off == no locking (threads may preempt at any time)\n\
9189 on == full locking (no thread except the current thread may run)\n\
9190 This applies to both normal execution and replay mode.\n\
9191 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9192 In this mode, other threads may run during other commands.\n\
9193 This applies to both normal execution and replay mode.\n\
9194 replay == scheduler locked in replay mode and unlocked during normal execution."),
9195 set_schedlock_func
, /* traps on target vector */
9196 show_scheduler_mode
,
9197 &setlist
, &showlist
);
9199 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9200 Set mode for resuming threads of all processes."), _("\
9201 Show mode for resuming threads of all processes."), _("\
9202 When on, execution commands (such as 'continue' or 'next') resume all\n\
9203 threads of all processes. When off (which is the default), execution\n\
9204 commands only resume the threads of the current process. The set of\n\
9205 threads that are resumed is further refined by the scheduler-locking\n\
9206 mode (see help set scheduler-locking)."),
9208 show_schedule_multiple
,
9209 &setlist
, &showlist
);
9211 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9212 Set mode of the step operation."), _("\
9213 Show mode of the step operation."), _("\
9214 When set, doing a step over a function without debug line information\n\
9215 will stop at the first instruction of that function. Otherwise, the\n\
9216 function is skipped and the step command stops at a different source line."),
9218 show_step_stop_if_no_debug
,
9219 &setlist
, &showlist
);
9221 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9222 &can_use_displaced_stepping
, _("\
9223 Set debugger's willingness to use displaced stepping."), _("\
9224 Show debugger's willingness to use displaced stepping."), _("\
9225 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9226 supported by the target architecture. If off, gdb will not use displaced\n\
9227 stepping to step over breakpoints, even if such is supported by the target\n\
9228 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9229 if the target architecture supports it and non-stop mode is active, but will not\n\
9230 use it in all-stop mode (see help set non-stop)."),
9232 show_can_use_displaced_stepping
,
9233 &setlist
, &showlist
);
9235 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9236 &exec_direction
, _("Set direction of execution.\n\
9237 Options are 'forward' or 'reverse'."),
9238 _("Show direction of execution (forward/reverse)."),
9239 _("Tells gdb whether to execute forward or backward."),
9240 set_exec_direction_func
, show_exec_direction_func
,
9241 &setlist
, &showlist
);
9243 /* Set/show detach-on-fork: user-settable mode. */
9245 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9246 Set whether gdb will detach the child of a fork."), _("\
9247 Show whether gdb will detach the child of a fork."), _("\
9248 Tells gdb whether to detach the child of a fork."),
9249 NULL
, NULL
, &setlist
, &showlist
);
9251 /* Set/show disable address space randomization mode. */
9253 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9254 &disable_randomization
, _("\
9255 Set disabling of debuggee's virtual address space randomization."), _("\
9256 Show disabling of debuggee's virtual address space randomization."), _("\
9257 When this mode is on (which is the default), randomization of the virtual\n\
9258 address space is disabled. Standalone programs run with the randomization\n\
9259 enabled by default on some platforms."),
9260 &set_disable_randomization
,
9261 &show_disable_randomization
,
9262 &setlist
, &showlist
);
9264 /* ptid initializations */
9265 inferior_ptid
= null_ptid
;
9266 target_last_wait_ptid
= minus_one_ptid
;
9268 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9269 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9270 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9271 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9273 /* Explicitly create without lookup, since that tries to create a
9274 value with a void typed value, and when we get here, gdbarch
9275 isn't initialized yet. At this point, we're quite sure there
9276 isn't another convenience variable of the same name. */
9277 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9279 add_setshow_boolean_cmd ("observer", no_class
,
9280 &observer_mode_1
, _("\
9281 Set whether gdb controls the inferior in observer mode."), _("\
9282 Show whether gdb controls the inferior in observer mode."), _("\
9283 In observer mode, GDB can get data from the inferior, but not\n\
9284 affect its execution. Registers and memory may not be changed,\n\
9285 breakpoints may not be set, and the program cannot be interrupted\n\