1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "target-connection.h"
32 #include "gdbthread.h"
39 #include "observable.h"
44 #include "mi/mi-common.h"
45 #include "event-top.h"
47 #include "record-full.h"
48 #include "inline-frame.h"
50 #include "tracepoint.h"
54 #include "completer.h"
55 #include "target-descriptions.h"
56 #include "target-dcache.h"
59 #include "event-loop.h"
60 #include "thread-fsm.h"
61 #include "gdbsupport/enum-flags.h"
62 #include "progspace-and-thread.h"
63 #include "gdbsupport/gdb_optional.h"
64 #include "arch-utils.h"
65 #include "gdbsupport/scope-exit.h"
66 #include "gdbsupport/forward-scope-exit.h"
67 #include "gdb_select.h"
68 #include <unordered_map>
70 /* Prototypes for local functions */
72 static void sig_print_info (enum gdb_signal
);
74 static void sig_print_header (void);
76 static int follow_fork (void);
78 static int follow_fork_inferior (int follow_child
, int detach_fork
);
80 static void follow_inferior_reset_breakpoints (void);
82 static int currently_stepping (struct thread_info
*tp
);
84 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
86 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
88 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
90 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
92 static void resume (gdb_signal sig
);
94 static void wait_for_inferior (inferior
*inf
);
96 /* Asynchronous signal handler registered as event loop source for
97 when we have pending events ready to be passed to the core. */
98 static struct async_event_handler
*infrun_async_inferior_event_token
;
100 /* Stores whether infrun_async was previously enabled or disabled.
101 Starts off as -1, indicating "never enabled/disabled". */
102 static int infrun_is_async
= -1;
107 infrun_async (int enable
)
109 if (infrun_is_async
!= enable
)
111 infrun_is_async
= enable
;
114 fprintf_unfiltered (gdb_stdlog
,
115 "infrun: infrun_async(%d)\n",
119 mark_async_event_handler (infrun_async_inferior_event_token
);
121 clear_async_event_handler (infrun_async_inferior_event_token
);
128 mark_infrun_async_event_handler (void)
130 mark_async_event_handler (infrun_async_inferior_event_token
);
133 /* When set, stop the 'step' command if we enter a function which has
134 no line number information. The normal behavior is that we step
135 over such function. */
136 bool step_stop_if_no_debug
= false;
138 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
139 struct cmd_list_element
*c
, const char *value
)
141 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
144 /* proceed and normal_stop use this to notify the user when the
145 inferior stopped in a different thread than it had been running
148 static ptid_t previous_inferior_ptid
;
150 /* If set (default for legacy reasons), when following a fork, GDB
151 will detach from one of the fork branches, child or parent.
152 Exactly which branch is detached depends on 'set follow-fork-mode'
155 static bool detach_fork
= true;
157 bool debug_displaced
= false;
159 show_debug_displaced (struct ui_file
*file
, int from_tty
,
160 struct cmd_list_element
*c
, const char *value
)
162 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
165 unsigned int debug_infrun
= 0;
167 show_debug_infrun (struct ui_file
*file
, int from_tty
,
168 struct cmd_list_element
*c
, const char *value
)
170 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
174 /* Support for disabling address space randomization. */
176 bool disable_randomization
= true;
179 show_disable_randomization (struct ui_file
*file
, int from_tty
,
180 struct cmd_list_element
*c
, const char *value
)
182 if (target_supports_disable_randomization ())
183 fprintf_filtered (file
,
184 _("Disabling randomization of debuggee's "
185 "virtual address space is %s.\n"),
188 fputs_filtered (_("Disabling randomization of debuggee's "
189 "virtual address space is unsupported on\n"
190 "this platform.\n"), file
);
194 set_disable_randomization (const char *args
, int from_tty
,
195 struct cmd_list_element
*c
)
197 if (!target_supports_disable_randomization ())
198 error (_("Disabling randomization of debuggee's "
199 "virtual address space is unsupported on\n"
203 /* User interface for non-stop mode. */
205 bool non_stop
= false;
206 static bool non_stop_1
= false;
209 set_non_stop (const char *args
, int from_tty
,
210 struct cmd_list_element
*c
)
212 if (target_has_execution
)
214 non_stop_1
= non_stop
;
215 error (_("Cannot change this setting while the inferior is running."));
218 non_stop
= non_stop_1
;
222 show_non_stop (struct ui_file
*file
, int from_tty
,
223 struct cmd_list_element
*c
, const char *value
)
225 fprintf_filtered (file
,
226 _("Controlling the inferior in non-stop mode is %s.\n"),
230 /* "Observer mode" is somewhat like a more extreme version of
231 non-stop, in which all GDB operations that might affect the
232 target's execution have been disabled. */
234 bool observer_mode
= false;
235 static bool observer_mode_1
= false;
238 set_observer_mode (const char *args
, int from_tty
,
239 struct cmd_list_element
*c
)
241 if (target_has_execution
)
243 observer_mode_1
= observer_mode
;
244 error (_("Cannot change this setting while the inferior is running."));
247 observer_mode
= observer_mode_1
;
249 may_write_registers
= !observer_mode
;
250 may_write_memory
= !observer_mode
;
251 may_insert_breakpoints
= !observer_mode
;
252 may_insert_tracepoints
= !observer_mode
;
253 /* We can insert fast tracepoints in or out of observer mode,
254 but enable them if we're going into this mode. */
256 may_insert_fast_tracepoints
= true;
257 may_stop
= !observer_mode
;
258 update_target_permissions ();
260 /* Going *into* observer mode we must force non-stop, then
261 going out we leave it that way. */
264 pagination_enabled
= 0;
265 non_stop
= non_stop_1
= true;
269 printf_filtered (_("Observer mode is now %s.\n"),
270 (observer_mode
? "on" : "off"));
274 show_observer_mode (struct ui_file
*file
, int from_tty
,
275 struct cmd_list_element
*c
, const char *value
)
277 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
280 /* This updates the value of observer mode based on changes in
281 permissions. Note that we are deliberately ignoring the values of
282 may-write-registers and may-write-memory, since the user may have
283 reason to enable these during a session, for instance to turn on a
284 debugging-related global. */
287 update_observer_mode (void)
289 bool newval
= (!may_insert_breakpoints
290 && !may_insert_tracepoints
291 && may_insert_fast_tracepoints
295 /* Let the user know if things change. */
296 if (newval
!= observer_mode
)
297 printf_filtered (_("Observer mode is now %s.\n"),
298 (newval
? "on" : "off"));
300 observer_mode
= observer_mode_1
= newval
;
303 /* Tables of how to react to signals; the user sets them. */
305 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
306 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
307 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
309 /* Table of signals that are registered with "catch signal". A
310 non-zero entry indicates that the signal is caught by some "catch
312 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
314 /* Table of signals that the target may silently handle.
315 This is automatically determined from the flags above,
316 and simply cached here. */
317 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
319 #define SET_SIGS(nsigs,sigs,flags) \
321 int signum = (nsigs); \
322 while (signum-- > 0) \
323 if ((sigs)[signum]) \
324 (flags)[signum] = 1; \
327 #define UNSET_SIGS(nsigs,sigs,flags) \
329 int signum = (nsigs); \
330 while (signum-- > 0) \
331 if ((sigs)[signum]) \
332 (flags)[signum] = 0; \
335 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
336 this function is to avoid exporting `signal_program'. */
339 update_signals_program_target (void)
341 target_program_signals (signal_program
);
344 /* Value to pass to target_resume() to cause all threads to resume. */
346 #define RESUME_ALL minus_one_ptid
348 /* Command list pointer for the "stop" placeholder. */
350 static struct cmd_list_element
*stop_command
;
352 /* Nonzero if we want to give control to the user when we're notified
353 of shared library events by the dynamic linker. */
354 int stop_on_solib_events
;
356 /* Enable or disable optional shared library event breakpoints
357 as appropriate when the above flag is changed. */
360 set_stop_on_solib_events (const char *args
,
361 int from_tty
, struct cmd_list_element
*c
)
363 update_solib_breakpoints ();
367 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
368 struct cmd_list_element
*c
, const char *value
)
370 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
374 /* Nonzero after stop if current stack frame should be printed. */
376 static int stop_print_frame
;
378 /* This is a cached copy of the target/ptid/waitstatus of the last
379 event returned by target_wait()/deprecated_target_wait_hook().
380 This information is returned by get_last_target_status(). */
381 static process_stratum_target
*target_last_proc_target
;
382 static ptid_t target_last_wait_ptid
;
383 static struct target_waitstatus target_last_waitstatus
;
385 void init_thread_stepping_state (struct thread_info
*tss
);
387 static const char follow_fork_mode_child
[] = "child";
388 static const char follow_fork_mode_parent
[] = "parent";
390 static const char *const follow_fork_mode_kind_names
[] = {
391 follow_fork_mode_child
,
392 follow_fork_mode_parent
,
396 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
398 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
399 struct cmd_list_element
*c
, const char *value
)
401 fprintf_filtered (file
,
402 _("Debugger response to a program "
403 "call of fork or vfork is \"%s\".\n"),
408 /* Handle changes to the inferior list based on the type of fork,
409 which process is being followed, and whether the other process
410 should be detached. On entry inferior_ptid must be the ptid of
411 the fork parent. At return inferior_ptid is the ptid of the
412 followed inferior. */
415 follow_fork_inferior (int follow_child
, int detach_fork
)
418 ptid_t parent_ptid
, child_ptid
;
420 has_vforked
= (inferior_thread ()->pending_follow
.kind
421 == TARGET_WAITKIND_VFORKED
);
422 parent_ptid
= inferior_ptid
;
423 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
426 && !non_stop
/* Non-stop always resumes both branches. */
427 && current_ui
->prompt_state
== PROMPT_BLOCKED
428 && !(follow_child
|| detach_fork
|| sched_multi
))
430 /* The parent stays blocked inside the vfork syscall until the
431 child execs or exits. If we don't let the child run, then
432 the parent stays blocked. If we're telling the parent to run
433 in the foreground, the user will not be able to ctrl-c to get
434 back the terminal, effectively hanging the debug session. */
435 fprintf_filtered (gdb_stderr
, _("\
436 Can not resume the parent process over vfork in the foreground while\n\
437 holding the child stopped. Try \"set detach-on-fork\" or \
438 \"set schedule-multiple\".\n"));
444 /* Detach new forked process? */
447 /* Before detaching from the child, remove all breakpoints
448 from it. If we forked, then this has already been taken
449 care of by infrun.c. If we vforked however, any
450 breakpoint inserted in the parent is visible in the
451 child, even those added while stopped in a vfork
452 catchpoint. This will remove the breakpoints from the
453 parent also, but they'll be reinserted below. */
456 /* Keep breakpoints list in sync. */
457 remove_breakpoints_inf (current_inferior ());
460 if (print_inferior_events
)
462 /* Ensure that we have a process ptid. */
463 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
465 target_terminal::ours_for_output ();
466 fprintf_filtered (gdb_stdlog
,
467 _("[Detaching after %s from child %s]\n"),
468 has_vforked
? "vfork" : "fork",
469 target_pid_to_str (process_ptid
).c_str ());
474 struct inferior
*parent_inf
, *child_inf
;
476 /* Add process to GDB's tables. */
477 child_inf
= add_inferior (child_ptid
.pid ());
479 parent_inf
= current_inferior ();
480 child_inf
->attach_flag
= parent_inf
->attach_flag
;
481 copy_terminal_info (child_inf
, parent_inf
);
482 child_inf
->gdbarch
= parent_inf
->gdbarch
;
483 copy_inferior_target_desc_info (child_inf
, parent_inf
);
485 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
487 set_current_inferior (child_inf
);
488 switch_to_no_thread ();
489 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
490 push_target (parent_inf
->process_target ());
491 add_thread_silent (child_inf
->process_target (), child_ptid
);
492 inferior_ptid
= child_ptid
;
494 /* If this is a vfork child, then the address-space is
495 shared with the parent. */
498 child_inf
->pspace
= parent_inf
->pspace
;
499 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 process_stratum_target
*target
= parent_inf
->process_target ();
581 /* Hold a strong reference to the target while (maybe)
582 detaching the parent. Otherwise detaching could close the
584 auto target_ref
= target_ops_ref::new_reference (target
);
586 /* If we're vforking, we want to hold on to the parent until
587 the child exits or execs. At child exec or exit time we
588 can remove the old breakpoints from the parent and detach
589 or resume debugging it. Otherwise, detach the parent now;
590 we'll want to reuse it's program/address spaces, but we
591 can't set them to the child before removing breakpoints
592 from the parent, otherwise, the breakpoints module could
593 decide to remove breakpoints from the wrong process (since
594 they'd be assigned to the same address space). */
598 gdb_assert (child_inf
->vfork_parent
== NULL
);
599 gdb_assert (parent_inf
->vfork_child
== NULL
);
600 child_inf
->vfork_parent
= parent_inf
;
601 child_inf
->pending_detach
= 0;
602 parent_inf
->vfork_child
= child_inf
;
603 parent_inf
->pending_detach
= detach_fork
;
604 parent_inf
->waiting_for_vfork_done
= 0;
606 else if (detach_fork
)
608 if (print_inferior_events
)
610 /* Ensure that we have a process ptid. */
611 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
613 target_terminal::ours_for_output ();
614 fprintf_filtered (gdb_stdlog
,
615 _("[Detaching after fork from "
617 target_pid_to_str (process_ptid
).c_str ());
620 target_detach (parent_inf
, 0);
624 /* Note that the detach above makes PARENT_INF dangling. */
626 /* Add the child thread to the appropriate lists, and switch
627 to this new thread, before cloning the program space, and
628 informing the solib layer about this new process. */
630 set_current_inferior (child_inf
);
631 push_target (target
);
634 add_thread_silent (target
, child_ptid
);
635 inferior_ptid
= child_ptid
;
637 /* If this is a vfork child, then the address-space is shared
638 with the parent. If we detached from the parent, then we can
639 reuse the parent's program/address spaces. */
640 if (has_vforked
|| detach_fork
)
642 child_inf
->pspace
= parent_pspace
;
643 child_inf
->aspace
= child_inf
->pspace
->aspace
;
649 child_inf
->aspace
= new_address_space ();
650 child_inf
->pspace
= new program_space (child_inf
->aspace
);
651 child_inf
->removable
= 1;
652 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
653 set_current_program_space (child_inf
->pspace
);
654 clone_program_space (child_inf
->pspace
, parent_pspace
);
656 /* Let the shared library layer (e.g., solib-svr4) learn
657 about this new process, relocate the cloned exec, pull in
658 shared libraries, and install the solib event breakpoint.
659 If a "cloned-VM" event was propagated better throughout
660 the core, this wouldn't be required. */
661 solib_create_inferior_hook (0);
665 return target_follow_fork (follow_child
, detach_fork
);
668 /* Tell the target to follow the fork we're stopped at. Returns true
669 if the inferior should be resumed; false, if the target for some
670 reason decided it's best not to resume. */
675 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
676 int should_resume
= 1;
677 struct thread_info
*tp
;
679 /* Copy user stepping state to the new inferior thread. FIXME: the
680 followed fork child thread should have a copy of most of the
681 parent thread structure's run control related fields, not just these.
682 Initialized to avoid "may be used uninitialized" warnings from gcc. */
683 struct breakpoint
*step_resume_breakpoint
= NULL
;
684 struct breakpoint
*exception_resume_breakpoint
= NULL
;
685 CORE_ADDR step_range_start
= 0;
686 CORE_ADDR step_range_end
= 0;
687 struct frame_id step_frame_id
= { 0 };
688 struct thread_fsm
*thread_fsm
= NULL
;
692 process_stratum_target
*wait_target
;
694 struct target_waitstatus wait_status
;
696 /* Get the last target status returned by target_wait(). */
697 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
699 /* If not stopped at a fork event, then there's nothing else to
701 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
702 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
705 /* Check if we switched over from WAIT_PTID, since the event was
707 if (wait_ptid
!= minus_one_ptid
708 && (current_inferior ()->process_target () != wait_target
709 || inferior_ptid
!= wait_ptid
))
711 /* We did. Switch back to WAIT_PTID thread, to tell the
712 target to follow it (in either direction). We'll
713 afterwards refuse to resume, and inform the user what
715 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
716 switch_to_thread (wait_thread
);
721 tp
= inferior_thread ();
723 /* If there were any forks/vforks that were caught and are now to be
724 followed, then do so now. */
725 switch (tp
->pending_follow
.kind
)
727 case TARGET_WAITKIND_FORKED
:
728 case TARGET_WAITKIND_VFORKED
:
730 ptid_t parent
, child
;
732 /* If the user did a next/step, etc, over a fork call,
733 preserve the stepping state in the fork child. */
734 if (follow_child
&& should_resume
)
736 step_resume_breakpoint
= clone_momentary_breakpoint
737 (tp
->control
.step_resume_breakpoint
);
738 step_range_start
= tp
->control
.step_range_start
;
739 step_range_end
= tp
->control
.step_range_end
;
740 step_frame_id
= tp
->control
.step_frame_id
;
741 exception_resume_breakpoint
742 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
743 thread_fsm
= tp
->thread_fsm
;
745 /* For now, delete the parent's sr breakpoint, otherwise,
746 parent/child sr breakpoints are considered duplicates,
747 and the child version will not be installed. Remove
748 this when the breakpoints module becomes aware of
749 inferiors and address spaces. */
750 delete_step_resume_breakpoint (tp
);
751 tp
->control
.step_range_start
= 0;
752 tp
->control
.step_range_end
= 0;
753 tp
->control
.step_frame_id
= null_frame_id
;
754 delete_exception_resume_breakpoint (tp
);
755 tp
->thread_fsm
= NULL
;
758 parent
= inferior_ptid
;
759 child
= tp
->pending_follow
.value
.related_pid
;
761 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
762 /* Set up inferior(s) as specified by the caller, and tell the
763 target to do whatever is necessary to follow either parent
765 if (follow_fork_inferior (follow_child
, detach_fork
))
767 /* Target refused to follow, or there's some other reason
768 we shouldn't resume. */
773 /* This pending follow fork event is now handled, one way
774 or another. The previous selected thread may be gone
775 from the lists by now, but if it is still around, need
776 to clear the pending follow request. */
777 tp
= find_thread_ptid (parent_targ
, parent
);
779 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
781 /* This makes sure we don't try to apply the "Switched
782 over from WAIT_PID" logic above. */
783 nullify_last_target_wait_ptid ();
785 /* If we followed the child, switch to it... */
788 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
789 switch_to_thread (child_thr
);
791 /* ... and preserve the stepping state, in case the
792 user was stepping over the fork call. */
795 tp
= inferior_thread ();
796 tp
->control
.step_resume_breakpoint
797 = step_resume_breakpoint
;
798 tp
->control
.step_range_start
= step_range_start
;
799 tp
->control
.step_range_end
= step_range_end
;
800 tp
->control
.step_frame_id
= step_frame_id
;
801 tp
->control
.exception_resume_breakpoint
802 = exception_resume_breakpoint
;
803 tp
->thread_fsm
= thread_fsm
;
807 /* If we get here, it was because we're trying to
808 resume from a fork catchpoint, but, the user
809 has switched threads away from the thread that
810 forked. In that case, the resume command
811 issued is most likely not applicable to the
812 child, so just warn, and refuse to resume. */
813 warning (_("Not resuming: switched threads "
814 "before following fork child."));
817 /* Reset breakpoints in the child as appropriate. */
818 follow_inferior_reset_breakpoints ();
823 case TARGET_WAITKIND_SPURIOUS
:
824 /* Nothing to follow. */
827 internal_error (__FILE__
, __LINE__
,
828 "Unexpected pending_follow.kind %d\n",
829 tp
->pending_follow
.kind
);
833 return should_resume
;
837 follow_inferior_reset_breakpoints (void)
839 struct thread_info
*tp
= inferior_thread ();
841 /* Was there a step_resume breakpoint? (There was if the user
842 did a "next" at the fork() call.) If so, explicitly reset its
843 thread number. Cloned step_resume breakpoints are disabled on
844 creation, so enable it here now that it is associated with the
847 step_resumes are a form of bp that are made to be per-thread.
848 Since we created the step_resume bp when the parent process
849 was being debugged, and now are switching to the child process,
850 from the breakpoint package's viewpoint, that's a switch of
851 "threads". We must update the bp's notion of which thread
852 it is for, or it'll be ignored when it triggers. */
854 if (tp
->control
.step_resume_breakpoint
)
856 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
857 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
860 /* Treat exception_resume breakpoints like step_resume breakpoints. */
861 if (tp
->control
.exception_resume_breakpoint
)
863 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
864 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
867 /* Reinsert all breakpoints in the child. The user may have set
868 breakpoints after catching the fork, in which case those
869 were never set in the child, but only in the parent. This makes
870 sure the inserted breakpoints match the breakpoint list. */
872 breakpoint_re_set ();
873 insert_breakpoints ();
876 /* The child has exited or execed: resume threads of the parent the
877 user wanted to be executing. */
880 proceed_after_vfork_done (struct thread_info
*thread
,
883 int pid
= * (int *) arg
;
885 if (thread
->ptid
.pid () == pid
886 && thread
->state
== THREAD_RUNNING
887 && !thread
->executing
888 && !thread
->stop_requested
889 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
892 fprintf_unfiltered (gdb_stdlog
,
893 "infrun: resuming vfork parent thread %s\n",
894 target_pid_to_str (thread
->ptid
).c_str ());
896 switch_to_thread (thread
);
897 clear_proceed_status (0);
898 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
904 /* Save/restore inferior_ptid, current program space and current
905 inferior. Only use this if the current context points at an exited
906 inferior (and therefore there's no current thread to save). */
907 class scoped_restore_exited_inferior
910 scoped_restore_exited_inferior ()
911 : m_saved_ptid (&inferior_ptid
)
915 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
916 scoped_restore_current_program_space m_pspace
;
917 scoped_restore_current_inferior m_inferior
;
920 /* Called whenever we notice an exec or exit event, to handle
921 detaching or resuming a vfork parent. */
924 handle_vfork_child_exec_or_exit (int exec
)
926 struct inferior
*inf
= current_inferior ();
928 if (inf
->vfork_parent
)
930 int resume_parent
= -1;
932 /* This exec or exit marks the end of the shared memory region
933 between the parent and the child. Break the bonds. */
934 inferior
*vfork_parent
= inf
->vfork_parent
;
935 inf
->vfork_parent
->vfork_child
= NULL
;
936 inf
->vfork_parent
= NULL
;
938 /* If the user wanted to detach from the parent, now is the
940 if (vfork_parent
->pending_detach
)
942 struct thread_info
*tp
;
943 struct program_space
*pspace
;
944 struct address_space
*aspace
;
946 /* follow-fork child, detach-on-fork on. */
948 vfork_parent
->pending_detach
= 0;
950 gdb::optional
<scoped_restore_exited_inferior
>
951 maybe_restore_inferior
;
952 gdb::optional
<scoped_restore_current_pspace_and_thread
>
953 maybe_restore_thread
;
955 /* If we're handling a child exit, then inferior_ptid points
956 at the inferior's pid, not to a thread. */
958 maybe_restore_inferior
.emplace ();
960 maybe_restore_thread
.emplace ();
962 /* We're letting loose of the parent. */
963 tp
= any_live_thread_of_inferior (vfork_parent
);
964 switch_to_thread (tp
);
966 /* We're about to detach from the parent, which implicitly
967 removes breakpoints from its address space. There's a
968 catch here: we want to reuse the spaces for the child,
969 but, parent/child are still sharing the pspace at this
970 point, although the exec in reality makes the kernel give
971 the child a fresh set of new pages. The problem here is
972 that the breakpoints module being unaware of this, would
973 likely chose the child process to write to the parent
974 address space. Swapping the child temporarily away from
975 the spaces has the desired effect. Yes, this is "sort
978 pspace
= inf
->pspace
;
979 aspace
= inf
->aspace
;
983 if (print_inferior_events
)
986 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
988 target_terminal::ours_for_output ();
992 fprintf_filtered (gdb_stdlog
,
993 _("[Detaching vfork parent %s "
994 "after child exec]\n"), pidstr
.c_str ());
998 fprintf_filtered (gdb_stdlog
,
999 _("[Detaching vfork parent %s "
1000 "after child exit]\n"), pidstr
.c_str ());
1004 target_detach (vfork_parent
, 0);
1007 inf
->pspace
= pspace
;
1008 inf
->aspace
= aspace
;
1012 /* We're staying attached to the parent, so, really give the
1013 child a new address space. */
1014 inf
->pspace
= new program_space (maybe_new_address_space ());
1015 inf
->aspace
= inf
->pspace
->aspace
;
1017 set_current_program_space (inf
->pspace
);
1019 resume_parent
= vfork_parent
->pid
;
1023 /* If this is a vfork child exiting, then the pspace and
1024 aspaces were shared with the parent. Since we're
1025 reporting the process exit, we'll be mourning all that is
1026 found in the address space, and switching to null_ptid,
1027 preparing to start a new inferior. But, since we don't
1028 want to clobber the parent's address/program spaces, we
1029 go ahead and create a new one for this exiting
1032 /* Switch to null_ptid while running clone_program_space, so
1033 that clone_program_space doesn't want to read the
1034 selected frame of a dead process. */
1035 scoped_restore restore_ptid
1036 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1038 inf
->pspace
= new program_space (maybe_new_address_space ());
1039 inf
->aspace
= inf
->pspace
->aspace
;
1040 set_current_program_space (inf
->pspace
);
1042 inf
->symfile_flags
= SYMFILE_NO_READ
;
1043 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1045 resume_parent
= vfork_parent
->pid
;
1048 gdb_assert (current_program_space
== inf
->pspace
);
1050 if (non_stop
&& resume_parent
!= -1)
1052 /* If the user wanted the parent to be running, let it go
1054 scoped_restore_current_thread restore_thread
;
1057 fprintf_unfiltered (gdb_stdlog
,
1058 "infrun: resuming vfork parent process %d\n",
1061 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1066 /* Enum strings for "set|show follow-exec-mode". */
1068 static const char follow_exec_mode_new
[] = "new";
1069 static const char follow_exec_mode_same
[] = "same";
1070 static const char *const follow_exec_mode_names
[] =
1072 follow_exec_mode_new
,
1073 follow_exec_mode_same
,
1077 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1079 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1080 struct cmd_list_element
*c
, const char *value
)
1082 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1085 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1088 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1090 struct inferior
*inf
= current_inferior ();
1091 int pid
= ptid
.pid ();
1092 ptid_t process_ptid
;
1094 /* Switch terminal for any messages produced e.g. by
1095 breakpoint_re_set. */
1096 target_terminal::ours_for_output ();
1098 /* This is an exec event that we actually wish to pay attention to.
1099 Refresh our symbol table to the newly exec'd program, remove any
1100 momentary bp's, etc.
1102 If there are breakpoints, they aren't really inserted now,
1103 since the exec() transformed our inferior into a fresh set
1106 We want to preserve symbolic breakpoints on the list, since
1107 we have hopes that they can be reset after the new a.out's
1108 symbol table is read.
1110 However, any "raw" breakpoints must be removed from the list
1111 (e.g., the solib bp's), since their address is probably invalid
1114 And, we DON'T want to call delete_breakpoints() here, since
1115 that may write the bp's "shadow contents" (the instruction
1116 value that was overwritten with a TRAP instruction). Since
1117 we now have a new a.out, those shadow contents aren't valid. */
1119 mark_breakpoints_out ();
1121 /* The target reports the exec event to the main thread, even if
1122 some other thread does the exec, and even if the main thread was
1123 stopped or already gone. We may still have non-leader threads of
1124 the process on our list. E.g., on targets that don't have thread
1125 exit events (like remote); or on native Linux in non-stop mode if
1126 there were only two threads in the inferior and the non-leader
1127 one is the one that execs (and nothing forces an update of the
1128 thread list up to here). When debugging remotely, it's best to
1129 avoid extra traffic, when possible, so avoid syncing the thread
1130 list with the target, and instead go ahead and delete all threads
1131 of the process but one that reported the event. Note this must
1132 be done before calling update_breakpoints_after_exec, as
1133 otherwise clearing the threads' resources would reference stale
1134 thread breakpoints -- it may have been one of these threads that
1135 stepped across the exec. We could just clear their stepping
1136 states, but as long as we're iterating, might as well delete
1137 them. Deleting them now rather than at the next user-visible
1138 stop provides a nicer sequence of events for user and MI
1140 for (thread_info
*th
: all_threads_safe ())
1141 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1144 /* We also need to clear any left over stale state for the
1145 leader/event thread. E.g., if there was any step-resume
1146 breakpoint or similar, it's gone now. We cannot truly
1147 step-to-next statement through an exec(). */
1148 thread_info
*th
= inferior_thread ();
1149 th
->control
.step_resume_breakpoint
= NULL
;
1150 th
->control
.exception_resume_breakpoint
= NULL
;
1151 th
->control
.single_step_breakpoints
= NULL
;
1152 th
->control
.step_range_start
= 0;
1153 th
->control
.step_range_end
= 0;
1155 /* The user may have had the main thread held stopped in the
1156 previous image (e.g., schedlock on, or non-stop). Release
1158 th
->stop_requested
= 0;
1160 update_breakpoints_after_exec ();
1162 /* What is this a.out's name? */
1163 process_ptid
= ptid_t (pid
);
1164 printf_unfiltered (_("%s is executing new program: %s\n"),
1165 target_pid_to_str (process_ptid
).c_str (),
1168 /* We've followed the inferior through an exec. Therefore, the
1169 inferior has essentially been killed & reborn. */
1171 breakpoint_init_inferior (inf_execd
);
1173 gdb::unique_xmalloc_ptr
<char> exec_file_host
1174 = exec_file_find (exec_file_target
, NULL
);
1176 /* If we were unable to map the executable target pathname onto a host
1177 pathname, tell the user that. Otherwise GDB's subsequent behavior
1178 is confusing. Maybe it would even be better to stop at this point
1179 so that the user can specify a file manually before continuing. */
1180 if (exec_file_host
== NULL
)
1181 warning (_("Could not load symbols for executable %s.\n"
1182 "Do you need \"set sysroot\"?"),
1185 /* Reset the shared library package. This ensures that we get a
1186 shlib event when the child reaches "_start", at which point the
1187 dld will have had a chance to initialize the child. */
1188 /* Also, loading a symbol file below may trigger symbol lookups, and
1189 we don't want those to be satisfied by the libraries of the
1190 previous incarnation of this process. */
1191 no_shared_libraries (NULL
, 0);
1193 if (follow_exec_mode_string
== follow_exec_mode_new
)
1195 /* The user wants to keep the old inferior and program spaces
1196 around. Create a new fresh one, and switch to it. */
1198 /* Do exit processing for the original inferior before setting the new
1199 inferior's pid. Having two inferiors with the same pid would confuse
1200 find_inferior_p(t)id. Transfer the terminal state and info from the
1201 old to the new inferior. */
1202 inf
= add_inferior_with_spaces ();
1203 swap_terminal_info (inf
, current_inferior ());
1204 exit_inferior_silent (current_inferior ());
1207 target_follow_exec (inf
, exec_file_target
);
1209 inferior
*org_inferior
= current_inferior ();
1210 switch_to_inferior_no_thread (inf
);
1211 push_target (org_inferior
->process_target ());
1212 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1213 switch_to_thread (thr
);
1217 /* The old description may no longer be fit for the new image.
1218 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1219 old description; we'll read a new one below. No need to do
1220 this on "follow-exec-mode new", as the old inferior stays
1221 around (its description is later cleared/refetched on
1223 target_clear_description ();
1226 gdb_assert (current_program_space
== inf
->pspace
);
1228 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1229 because the proper displacement for a PIE (Position Independent
1230 Executable) main symbol file will only be computed by
1231 solib_create_inferior_hook below. breakpoint_re_set would fail
1232 to insert the breakpoints with the zero displacement. */
1233 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1235 /* If the target can specify a description, read it. Must do this
1236 after flipping to the new executable (because the target supplied
1237 description must be compatible with the executable's
1238 architecture, and the old executable may e.g., be 32-bit, while
1239 the new one 64-bit), and before anything involving memory or
1241 target_find_description ();
1243 solib_create_inferior_hook (0);
1245 jit_inferior_created_hook ();
1247 breakpoint_re_set ();
1249 /* Reinsert all breakpoints. (Those which were symbolic have
1250 been reset to the proper address in the new a.out, thanks
1251 to symbol_file_command...). */
1252 insert_breakpoints ();
1254 /* The next resume of this inferior should bring it to the shlib
1255 startup breakpoints. (If the user had also set bp's on
1256 "main" from the old (parent) process, then they'll auto-
1257 matically get reset there in the new process.). */
1260 /* The queue of threads that need to do a step-over operation to get
1261 past e.g., a breakpoint. What technique is used to step over the
1262 breakpoint/watchpoint does not matter -- all threads end up in the
1263 same queue, to maintain rough temporal order of execution, in order
1264 to avoid starvation, otherwise, we could e.g., find ourselves
1265 constantly stepping the same couple threads past their breakpoints
1266 over and over, if the single-step finish fast enough. */
1267 struct thread_info
*step_over_queue_head
;
1269 /* Bit flags indicating what the thread needs to step over. */
1271 enum step_over_what_flag
1273 /* Step over a breakpoint. */
1274 STEP_OVER_BREAKPOINT
= 1,
1276 /* Step past a non-continuable watchpoint, in order to let the
1277 instruction execute so we can evaluate the watchpoint
1279 STEP_OVER_WATCHPOINT
= 2
1281 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1283 /* Info about an instruction that is being stepped over. */
1285 struct step_over_info
1287 /* If we're stepping past a breakpoint, this is the address space
1288 and address of the instruction the breakpoint is set at. We'll
1289 skip inserting all breakpoints here. Valid iff ASPACE is
1291 const address_space
*aspace
;
1294 /* The instruction being stepped over triggers a nonsteppable
1295 watchpoint. If true, we'll skip inserting watchpoints. */
1296 int nonsteppable_watchpoint_p
;
1298 /* The thread's global number. */
1302 /* The step-over info of the location that is being stepped over.
1304 Note that with async/breakpoint always-inserted mode, a user might
1305 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1306 being stepped over. As setting a new breakpoint inserts all
1307 breakpoints, we need to make sure the breakpoint being stepped over
1308 isn't inserted then. We do that by only clearing the step-over
1309 info when the step-over is actually finished (or aborted).
1311 Presently GDB can only step over one breakpoint at any given time.
1312 Given threads that can't run code in the same address space as the
1313 breakpoint's can't really miss the breakpoint, GDB could be taught
1314 to step-over at most one breakpoint per address space (so this info
1315 could move to the address space object if/when GDB is extended).
1316 The set of breakpoints being stepped over will normally be much
1317 smaller than the set of all breakpoints, so a flag in the
1318 breakpoint location structure would be wasteful. A separate list
1319 also saves complexity and run-time, as otherwise we'd have to go
1320 through all breakpoint locations clearing their flag whenever we
1321 start a new sequence. Similar considerations weigh against storing
1322 this info in the thread object. Plus, not all step overs actually
1323 have breakpoint locations -- e.g., stepping past a single-step
1324 breakpoint, or stepping to complete a non-continuable
1326 static struct step_over_info step_over_info
;
1328 /* Record the address of the breakpoint/instruction we're currently
1330 N.B. We record the aspace and address now, instead of say just the thread,
1331 because when we need the info later the thread may be running. */
1334 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1335 int nonsteppable_watchpoint_p
,
1338 step_over_info
.aspace
= aspace
;
1339 step_over_info
.address
= address
;
1340 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1341 step_over_info
.thread
= thread
;
1344 /* Called when we're not longer stepping over a breakpoint / an
1345 instruction, so all breakpoints are free to be (re)inserted. */
1348 clear_step_over_info (void)
1351 fprintf_unfiltered (gdb_stdlog
,
1352 "infrun: clear_step_over_info\n");
1353 step_over_info
.aspace
= NULL
;
1354 step_over_info
.address
= 0;
1355 step_over_info
.nonsteppable_watchpoint_p
= 0;
1356 step_over_info
.thread
= -1;
1362 stepping_past_instruction_at (struct address_space
*aspace
,
1365 return (step_over_info
.aspace
!= NULL
1366 && breakpoint_address_match (aspace
, address
,
1367 step_over_info
.aspace
,
1368 step_over_info
.address
));
1374 thread_is_stepping_over_breakpoint (int thread
)
1376 return (step_over_info
.thread
!= -1
1377 && thread
== step_over_info
.thread
);
1383 stepping_past_nonsteppable_watchpoint (void)
1385 return step_over_info
.nonsteppable_watchpoint_p
;
1388 /* Returns true if step-over info is valid. */
1391 step_over_info_valid_p (void)
1393 return (step_over_info
.aspace
!= NULL
1394 || stepping_past_nonsteppable_watchpoint ());
1398 /* Displaced stepping. */
1400 /* In non-stop debugging mode, we must take special care to manage
1401 breakpoints properly; in particular, the traditional strategy for
1402 stepping a thread past a breakpoint it has hit is unsuitable.
1403 'Displaced stepping' is a tactic for stepping one thread past a
1404 breakpoint it has hit while ensuring that other threads running
1405 concurrently will hit the breakpoint as they should.
1407 The traditional way to step a thread T off a breakpoint in a
1408 multi-threaded program in all-stop mode is as follows:
1410 a0) Initially, all threads are stopped, and breakpoints are not
1412 a1) We single-step T, leaving breakpoints uninserted.
1413 a2) We insert breakpoints, and resume all threads.
1415 In non-stop debugging, however, this strategy is unsuitable: we
1416 don't want to have to stop all threads in the system in order to
1417 continue or step T past a breakpoint. Instead, we use displaced
1420 n0) Initially, T is stopped, other threads are running, and
1421 breakpoints are inserted.
1422 n1) We copy the instruction "under" the breakpoint to a separate
1423 location, outside the main code stream, making any adjustments
1424 to the instruction, register, and memory state as directed by
1426 n2) We single-step T over the instruction at its new location.
1427 n3) We adjust the resulting register and memory state as directed
1428 by T's architecture. This includes resetting T's PC to point
1429 back into the main instruction stream.
1432 This approach depends on the following gdbarch methods:
1434 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1435 indicate where to copy the instruction, and how much space must
1436 be reserved there. We use these in step n1.
1438 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1439 address, and makes any necessary adjustments to the instruction,
1440 register contents, and memory. We use this in step n1.
1442 - gdbarch_displaced_step_fixup adjusts registers and memory after
1443 we have successfully single-stepped the instruction, to yield the
1444 same effect the instruction would have had if we had executed it
1445 at its original address. We use this in step n3.
1447 The gdbarch_displaced_step_copy_insn and
1448 gdbarch_displaced_step_fixup functions must be written so that
1449 copying an instruction with gdbarch_displaced_step_copy_insn,
1450 single-stepping across the copied instruction, and then applying
1451 gdbarch_displaced_insn_fixup should have the same effects on the
1452 thread's memory and registers as stepping the instruction in place
1453 would have. Exactly which responsibilities fall to the copy and
1454 which fall to the fixup is up to the author of those functions.
1456 See the comments in gdbarch.sh for details.
1458 Note that displaced stepping and software single-step cannot
1459 currently be used in combination, although with some care I think
1460 they could be made to. Software single-step works by placing
1461 breakpoints on all possible subsequent instructions; if the
1462 displaced instruction is a PC-relative jump, those breakpoints
1463 could fall in very strange places --- on pages that aren't
1464 executable, or at addresses that are not proper instruction
1465 boundaries. (We do generally let other threads run while we wait
1466 to hit the software single-step breakpoint, and they might
1467 encounter such a corrupted instruction.) One way to work around
1468 this would be to have gdbarch_displaced_step_copy_insn fully
1469 simulate the effect of PC-relative instructions (and return NULL)
1470 on architectures that use software single-stepping.
1472 In non-stop mode, we can have independent and simultaneous step
1473 requests, so more than one thread may need to simultaneously step
1474 over a breakpoint. The current implementation assumes there is
1475 only one scratch space per process. In this case, we have to
1476 serialize access to the scratch space. If thread A wants to step
1477 over a breakpoint, but we are currently waiting for some other
1478 thread to complete a displaced step, we leave thread A stopped and
1479 place it in the displaced_step_request_queue. Whenever a displaced
1480 step finishes, we pick the next thread in the queue and start a new
1481 displaced step operation on it. See displaced_step_prepare and
1482 displaced_step_fixup for details. */
1484 /* Default destructor for displaced_step_closure. */
1486 displaced_step_closure::~displaced_step_closure () = default;
1488 /* Get the displaced stepping state of process PID. */
1490 static displaced_step_inferior_state
*
1491 get_displaced_stepping_state (inferior
*inf
)
1493 return &inf
->displaced_step_state
;
1496 /* Returns true if any inferior has a thread doing a displaced
1500 displaced_step_in_progress_any_inferior ()
1502 for (inferior
*i
: all_inferiors ())
1504 if (i
->displaced_step_state
.step_thread
!= nullptr)
1511 /* Return true if thread represented by PTID is doing a displaced
1515 displaced_step_in_progress_thread (thread_info
*thread
)
1517 gdb_assert (thread
!= NULL
);
1519 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1522 /* Return true if process PID has a thread doing a displaced step. */
1525 displaced_step_in_progress (inferior
*inf
)
1527 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1530 /* If inferior is in displaced stepping, and ADDR equals to starting address
1531 of copy area, return corresponding displaced_step_closure. Otherwise,
1534 struct displaced_step_closure
*
1535 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1537 displaced_step_inferior_state
*displaced
1538 = get_displaced_stepping_state (current_inferior ());
1540 /* If checking the mode of displaced instruction in copy area. */
1541 if (displaced
->step_thread
!= nullptr
1542 && displaced
->step_copy
== addr
)
1543 return displaced
->step_closure
.get ();
1549 infrun_inferior_exit (struct inferior
*inf
)
1551 inf
->displaced_step_state
.reset ();
1554 /* If ON, and the architecture supports it, GDB will use displaced
1555 stepping to step over breakpoints. If OFF, or if the architecture
1556 doesn't support it, GDB will instead use the traditional
1557 hold-and-step approach. If AUTO (which is the default), GDB will
1558 decide which technique to use to step over breakpoints depending on
1559 which of all-stop or non-stop mode is active --- displaced stepping
1560 in non-stop mode; hold-and-step in all-stop mode. */
1562 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1565 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1566 struct cmd_list_element
*c
,
1569 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1570 fprintf_filtered (file
,
1571 _("Debugger's willingness to use displaced stepping "
1572 "to step over breakpoints is %s (currently %s).\n"),
1573 value
, target_is_non_stop_p () ? "on" : "off");
1575 fprintf_filtered (file
,
1576 _("Debugger's willingness to use displaced stepping "
1577 "to step over breakpoints is %s.\n"), value
);
1580 /* Return non-zero if displaced stepping can/should be used to step
1581 over breakpoints of thread TP. */
1584 use_displaced_stepping (struct thread_info
*tp
)
1586 struct regcache
*regcache
= get_thread_regcache (tp
);
1587 struct gdbarch
*gdbarch
= regcache
->arch ();
1588 displaced_step_inferior_state
*displaced_state
1589 = get_displaced_stepping_state (tp
->inf
);
1591 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1592 && target_is_non_stop_p ())
1593 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1594 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1595 && find_record_target () == NULL
1596 && !displaced_state
->failed_before
);
1599 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1602 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1604 displaced
->reset ();
1607 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1608 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1610 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1612 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1614 displaced_step_dump_bytes (struct ui_file
*file
,
1615 const gdb_byte
*buf
,
1620 for (i
= 0; i
< len
; i
++)
1621 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1622 fputs_unfiltered ("\n", file
);
1625 /* Prepare to single-step, using displaced stepping.
1627 Note that we cannot use displaced stepping when we have a signal to
1628 deliver. If we have a signal to deliver and an instruction to step
1629 over, then after the step, there will be no indication from the
1630 target whether the thread entered a signal handler or ignored the
1631 signal and stepped over the instruction successfully --- both cases
1632 result in a simple SIGTRAP. In the first case we mustn't do a
1633 fixup, and in the second case we must --- but we can't tell which.
1634 Comments in the code for 'random signals' in handle_inferior_event
1635 explain how we handle this case instead.
1637 Returns 1 if preparing was successful -- this thread is going to be
1638 stepped now; 0 if displaced stepping this thread got queued; or -1
1639 if this instruction can't be displaced stepped. */
1642 displaced_step_prepare_throw (thread_info
*tp
)
1644 regcache
*regcache
= get_thread_regcache (tp
);
1645 struct gdbarch
*gdbarch
= regcache
->arch ();
1646 const address_space
*aspace
= regcache
->aspace ();
1647 CORE_ADDR original
, copy
;
1651 /* We should never reach this function if the architecture does not
1652 support displaced stepping. */
1653 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1655 /* Nor if the thread isn't meant to step over a breakpoint. */
1656 gdb_assert (tp
->control
.trap_expected
);
1658 /* Disable range stepping while executing in the scratch pad. We
1659 want a single-step even if executing the displaced instruction in
1660 the scratch buffer lands within the stepping range (e.g., a
1662 tp
->control
.may_range_step
= 0;
1664 /* We have to displaced step one thread at a time, as we only have
1665 access to a single scratch space per inferior. */
1667 displaced_step_inferior_state
*displaced
1668 = get_displaced_stepping_state (tp
->inf
);
1670 if (displaced
->step_thread
!= nullptr)
1672 /* Already waiting for a displaced step to finish. Defer this
1673 request and place in queue. */
1675 if (debug_displaced
)
1676 fprintf_unfiltered (gdb_stdlog
,
1677 "displaced: deferring step of %s\n",
1678 target_pid_to_str (tp
->ptid
).c_str ());
1680 thread_step_over_chain_enqueue (tp
);
1685 if (debug_displaced
)
1686 fprintf_unfiltered (gdb_stdlog
,
1687 "displaced: stepping %s now\n",
1688 target_pid_to_str (tp
->ptid
).c_str ());
1691 displaced_step_reset (displaced
);
1693 scoped_restore_current_thread restore_thread
;
1695 switch_to_thread (tp
);
1697 original
= regcache_read_pc (regcache
);
1699 copy
= gdbarch_displaced_step_location (gdbarch
);
1700 len
= gdbarch_max_insn_length (gdbarch
);
1702 if (breakpoint_in_range_p (aspace
, copy
, len
))
1704 /* There's a breakpoint set in the scratch pad location range
1705 (which is usually around the entry point). We'd either
1706 install it before resuming, which would overwrite/corrupt the
1707 scratch pad, or if it was already inserted, this displaced
1708 step would overwrite it. The latter is OK in the sense that
1709 we already assume that no thread is going to execute the code
1710 in the scratch pad range (after initial startup) anyway, but
1711 the former is unacceptable. Simply punt and fallback to
1712 stepping over this breakpoint in-line. */
1713 if (debug_displaced
)
1715 fprintf_unfiltered (gdb_stdlog
,
1716 "displaced: breakpoint set in scratch pad. "
1717 "Stepping over breakpoint in-line instead.\n");
1723 /* Save the original contents of the copy area. */
1724 displaced
->step_saved_copy
.resize (len
);
1725 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1727 throw_error (MEMORY_ERROR
,
1728 _("Error accessing memory address %s (%s) for "
1729 "displaced-stepping scratch space."),
1730 paddress (gdbarch
, copy
), safe_strerror (status
));
1731 if (debug_displaced
)
1733 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1734 paddress (gdbarch
, copy
));
1735 displaced_step_dump_bytes (gdb_stdlog
,
1736 displaced
->step_saved_copy
.data (),
1740 displaced
->step_closure
1741 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1742 if (displaced
->step_closure
== NULL
)
1744 /* The architecture doesn't know how or want to displaced step
1745 this instruction or instruction sequence. Fallback to
1746 stepping over the breakpoint in-line. */
1750 /* Save the information we need to fix things up if the step
1752 displaced
->step_thread
= tp
;
1753 displaced
->step_gdbarch
= gdbarch
;
1754 displaced
->step_original
= original
;
1755 displaced
->step_copy
= copy
;
1758 displaced_step_reset_cleanup
cleanup (displaced
);
1760 /* Resume execution at the copy. */
1761 regcache_write_pc (regcache
, copy
);
1766 if (debug_displaced
)
1767 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1768 paddress (gdbarch
, copy
));
1773 /* Wrapper for displaced_step_prepare_throw that disabled further
1774 attempts at displaced stepping if we get a memory error. */
1777 displaced_step_prepare (thread_info
*thread
)
1783 prepared
= displaced_step_prepare_throw (thread
);
1785 catch (const gdb_exception_error
&ex
)
1787 struct displaced_step_inferior_state
*displaced_state
;
1789 if (ex
.error
!= MEMORY_ERROR
1790 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1795 fprintf_unfiltered (gdb_stdlog
,
1796 "infrun: disabling displaced stepping: %s\n",
1800 /* Be verbose if "set displaced-stepping" is "on", silent if
1802 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1804 warning (_("disabling displaced stepping: %s"),
1808 /* Disable further displaced stepping attempts. */
1810 = get_displaced_stepping_state (thread
->inf
);
1811 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
).c_str (),
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 displaced_step_inferior_state
*displaced
1854 = get_displaced_stepping_state (event_thread
->inf
);
1857 /* Was this event for the thread we displaced? */
1858 if (displaced
->step_thread
!= event_thread
)
1861 displaced_step_reset_cleanup
cleanup (displaced
);
1863 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1865 /* Fixup may need to read memory/registers. Switch to the thread
1866 that we're fixing up. Also, target_stopped_by_watchpoint checks
1867 the current thread. */
1868 switch_to_thread (event_thread
);
1870 /* Did the instruction complete successfully? */
1871 if (signal
== GDB_SIGNAL_TRAP
1872 && !(target_stopped_by_watchpoint ()
1873 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1874 || target_have_steppable_watchpoint
)))
1876 /* Fix up the resulting state. */
1877 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1878 displaced
->step_closure
.get (),
1879 displaced
->step_original
,
1880 displaced
->step_copy
,
1881 get_thread_regcache (displaced
->step_thread
));
1886 /* Since the instruction didn't complete, all we can do is
1888 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1889 CORE_ADDR pc
= regcache_read_pc (regcache
);
1891 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1892 regcache_write_pc (regcache
, pc
);
1899 /* Data to be passed around while handling an event. This data is
1900 discarded between events. */
1901 struct execution_control_state
1903 process_stratum_target
*target
;
1905 /* The thread that got the event, if this was a thread event; NULL
1907 struct thread_info
*event_thread
;
1909 struct target_waitstatus ws
;
1910 int stop_func_filled_in
;
1911 CORE_ADDR stop_func_start
;
1912 CORE_ADDR stop_func_end
;
1913 const char *stop_func_name
;
1916 /* True if the event thread hit the single-step breakpoint of
1917 another thread. Thus the event doesn't cause a stop, the thread
1918 needs to be single-stepped past the single-step breakpoint before
1919 we can switch back to the original stepping thread. */
1920 int hit_singlestep_breakpoint
;
1923 /* Clear ECS and set it to point at TP. */
1926 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1928 memset (ecs
, 0, sizeof (*ecs
));
1929 ecs
->event_thread
= tp
;
1930 ecs
->ptid
= tp
->ptid
;
1933 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1934 static void prepare_to_wait (struct execution_control_state
*ecs
);
1935 static int keep_going_stepped_thread (struct thread_info
*tp
);
1936 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1938 /* Are there any pending step-over requests? If so, run all we can
1939 now and return true. Otherwise, return false. */
1942 start_step_over (void)
1944 struct thread_info
*tp
, *next
;
1946 /* Don't start a new step-over if we already have an in-line
1947 step-over operation ongoing. */
1948 if (step_over_info_valid_p ())
1951 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1953 struct execution_control_state ecss
;
1954 struct execution_control_state
*ecs
= &ecss
;
1955 step_over_what step_what
;
1956 int must_be_in_line
;
1958 gdb_assert (!tp
->stop_requested
);
1960 next
= thread_step_over_chain_next (tp
);
1962 /* If this inferior already has a displaced step in process,
1963 don't start a new one. */
1964 if (displaced_step_in_progress (tp
->inf
))
1967 step_what
= thread_still_needs_step_over (tp
);
1968 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1969 || ((step_what
& STEP_OVER_BREAKPOINT
)
1970 && !use_displaced_stepping (tp
)));
1972 /* We currently stop all threads of all processes to step-over
1973 in-line. If we need to start a new in-line step-over, let
1974 any pending displaced steps finish first. */
1975 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1978 thread_step_over_chain_remove (tp
);
1980 if (step_over_queue_head
== NULL
)
1983 fprintf_unfiltered (gdb_stdlog
,
1984 "infrun: step-over queue now empty\n");
1987 if (tp
->control
.trap_expected
1991 internal_error (__FILE__
, __LINE__
,
1992 "[%s] has inconsistent state: "
1993 "trap_expected=%d, resumed=%d, executing=%d\n",
1994 target_pid_to_str (tp
->ptid
).c_str (),
1995 tp
->control
.trap_expected
,
2001 fprintf_unfiltered (gdb_stdlog
,
2002 "infrun: resuming [%s] for step-over\n",
2003 target_pid_to_str (tp
->ptid
).c_str ());
2005 /* keep_going_pass_signal skips the step-over if the breakpoint
2006 is no longer inserted. In all-stop, we want to keep looking
2007 for a thread that needs a step-over instead of resuming TP,
2008 because we wouldn't be able to resume anything else until the
2009 target stops again. In non-stop, the resume always resumes
2010 only TP, so it's OK to let the thread resume freely. */
2011 if (!target_is_non_stop_p () && !step_what
)
2014 switch_to_thread (tp
);
2015 reset_ecs (ecs
, tp
);
2016 keep_going_pass_signal (ecs
);
2018 if (!ecs
->wait_some_more
)
2019 error (_("Command aborted."));
2021 gdb_assert (tp
->resumed
);
2023 /* If we started a new in-line step-over, we're done. */
2024 if (step_over_info_valid_p ())
2026 gdb_assert (tp
->control
.trap_expected
);
2030 if (!target_is_non_stop_p ())
2032 /* On all-stop, shouldn't have resumed unless we needed a
2034 gdb_assert (tp
->control
.trap_expected
2035 || tp
->step_after_step_resume_breakpoint
);
2037 /* With remote targets (at least), in all-stop, we can't
2038 issue any further remote commands until the program stops
2043 /* Either the thread no longer needed a step-over, or a new
2044 displaced stepping sequence started. Even in the latter
2045 case, continue looking. Maybe we can also start another
2046 displaced step on a thread of other process. */
2052 /* Update global variables holding ptids to hold NEW_PTID if they were
2053 holding OLD_PTID. */
2055 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2057 if (inferior_ptid
== old_ptid
)
2058 inferior_ptid
= new_ptid
;
2063 static const char schedlock_off
[] = "off";
2064 static const char schedlock_on
[] = "on";
2065 static const char schedlock_step
[] = "step";
2066 static const char schedlock_replay
[] = "replay";
2067 static const char *const scheduler_enums
[] = {
2074 static const char *scheduler_mode
= schedlock_replay
;
2076 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2077 struct cmd_list_element
*c
, const char *value
)
2079 fprintf_filtered (file
,
2080 _("Mode for locking scheduler "
2081 "during execution is \"%s\".\n"),
2086 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2088 if (!target_can_lock_scheduler
)
2090 scheduler_mode
= schedlock_off
;
2091 error (_("Target '%s' cannot support this command."), target_shortname
);
2095 /* True if execution commands resume all threads of all processes by
2096 default; otherwise, resume only threads of the current inferior
2098 bool sched_multi
= false;
2100 /* Try to setup for software single stepping over the specified location.
2101 Return 1 if target_resume() should use hardware single step.
2103 GDBARCH the current gdbarch.
2104 PC the location to step over. */
2107 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2111 if (execution_direction
== EXEC_FORWARD
2112 && gdbarch_software_single_step_p (gdbarch
))
2113 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2121 user_visible_resume_ptid (int step
)
2127 /* With non-stop mode on, threads are always handled
2129 resume_ptid
= inferior_ptid
;
2131 else if ((scheduler_mode
== schedlock_on
)
2132 || (scheduler_mode
== schedlock_step
&& step
))
2134 /* User-settable 'scheduler' mode requires solo thread
2136 resume_ptid
= inferior_ptid
;
2138 else if ((scheduler_mode
== schedlock_replay
)
2139 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2141 /* User-settable 'scheduler' mode requires solo thread resume in replay
2143 resume_ptid
= inferior_ptid
;
2145 else if (!sched_multi
&& target_supports_multi_process ())
2147 /* Resume all threads of the current process (and none of other
2149 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2153 /* Resume all threads of all processes. */
2154 resume_ptid
= RESUME_ALL
;
2162 process_stratum_target
*
2163 user_visible_resume_target (ptid_t resume_ptid
)
2165 return (resume_ptid
== minus_one_ptid
&& sched_multi
2167 : current_inferior ()->process_target ());
2170 /* Return a ptid representing the set of threads that we will resume,
2171 in the perspective of the target, assuming run control handling
2172 does not require leaving some threads stopped (e.g., stepping past
2173 breakpoint). USER_STEP indicates whether we're about to start the
2174 target for a stepping command. */
2177 internal_resume_ptid (int user_step
)
2179 /* In non-stop, we always control threads individually. Note that
2180 the target may always work in non-stop mode even with "set
2181 non-stop off", in which case user_visible_resume_ptid could
2182 return a wildcard ptid. */
2183 if (target_is_non_stop_p ())
2184 return inferior_ptid
;
2186 return user_visible_resume_ptid (user_step
);
2189 /* Wrapper for target_resume, that handles infrun-specific
2193 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2195 struct thread_info
*tp
= inferior_thread ();
2197 gdb_assert (!tp
->stop_requested
);
2199 /* Install inferior's terminal modes. */
2200 target_terminal::inferior ();
2202 /* Avoid confusing the next resume, if the next stop/resume
2203 happens to apply to another thread. */
2204 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2206 /* Advise target which signals may be handled silently.
2208 If we have removed breakpoints because we are stepping over one
2209 in-line (in any thread), we need to receive all signals to avoid
2210 accidentally skipping a breakpoint during execution of a signal
2213 Likewise if we're displaced stepping, otherwise a trap for a
2214 breakpoint in a signal handler might be confused with the
2215 displaced step finishing. We don't make the displaced_step_fixup
2216 step distinguish the cases instead, because:
2218 - a backtrace while stopped in the signal handler would show the
2219 scratch pad as frame older than the signal handler, instead of
2220 the real mainline code.
2222 - when the thread is later resumed, the signal handler would
2223 return to the scratch pad area, which would no longer be
2225 if (step_over_info_valid_p ()
2226 || displaced_step_in_progress (tp
->inf
))
2227 target_pass_signals ({});
2229 target_pass_signals (signal_pass
);
2231 target_resume (resume_ptid
, step
, sig
);
2233 target_commit_resume ();
2235 if (target_can_async_p ())
2239 /* Resume the inferior. SIG is the signal to give the inferior
2240 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2241 call 'resume', which handles exceptions. */
2244 resume_1 (enum gdb_signal sig
)
2246 struct regcache
*regcache
= get_current_regcache ();
2247 struct gdbarch
*gdbarch
= regcache
->arch ();
2248 struct thread_info
*tp
= inferior_thread ();
2249 CORE_ADDR pc
= regcache_read_pc (regcache
);
2250 const address_space
*aspace
= regcache
->aspace ();
2252 /* This represents the user's step vs continue request. When
2253 deciding whether "set scheduler-locking step" applies, it's the
2254 user's intention that counts. */
2255 const int user_step
= tp
->control
.stepping_command
;
2256 /* This represents what we'll actually request the target to do.
2257 This can decay from a step to a continue, if e.g., we need to
2258 implement single-stepping with breakpoints (software
2262 gdb_assert (!tp
->stop_requested
);
2263 gdb_assert (!thread_is_in_step_over_chain (tp
));
2265 if (tp
->suspend
.waitstatus_pending_p
)
2270 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2272 fprintf_unfiltered (gdb_stdlog
,
2273 "infrun: resume: thread %s has pending wait "
2274 "status %s (currently_stepping=%d).\n",
2275 target_pid_to_str (tp
->ptid
).c_str (),
2277 currently_stepping (tp
));
2280 tp
->inf
->process_target ()->threads_executing
= true;
2283 /* FIXME: What should we do if we are supposed to resume this
2284 thread with a signal? Maybe we should maintain a queue of
2285 pending signals to deliver. */
2286 if (sig
!= GDB_SIGNAL_0
)
2288 warning (_("Couldn't deliver signal %s to %s."),
2289 gdb_signal_to_name (sig
),
2290 target_pid_to_str (tp
->ptid
).c_str ());
2293 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2295 if (target_can_async_p ())
2298 /* Tell the event loop we have an event to process. */
2299 mark_async_event_handler (infrun_async_inferior_event_token
);
2304 tp
->stepped_breakpoint
= 0;
2306 /* Depends on stepped_breakpoint. */
2307 step
= currently_stepping (tp
);
2309 if (current_inferior ()->waiting_for_vfork_done
)
2311 /* Don't try to single-step a vfork parent that is waiting for
2312 the child to get out of the shared memory region (by exec'ing
2313 or exiting). This is particularly important on software
2314 single-step archs, as the child process would trip on the
2315 software single step breakpoint inserted for the parent
2316 process. Since the parent will not actually execute any
2317 instruction until the child is out of the shared region (such
2318 are vfork's semantics), it is safe to simply continue it.
2319 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2320 the parent, and tell it to `keep_going', which automatically
2321 re-sets it stepping. */
2323 fprintf_unfiltered (gdb_stdlog
,
2324 "infrun: resume : clear step\n");
2329 fprintf_unfiltered (gdb_stdlog
,
2330 "infrun: resume (step=%d, signal=%s), "
2331 "trap_expected=%d, current thread [%s] at %s\n",
2332 step
, gdb_signal_to_symbol_string (sig
),
2333 tp
->control
.trap_expected
,
2334 target_pid_to_str (inferior_ptid
).c_str (),
2335 paddress (gdbarch
, pc
));
2337 /* Normally, by the time we reach `resume', the breakpoints are either
2338 removed or inserted, as appropriate. The exception is if we're sitting
2339 at a permanent breakpoint; we need to step over it, but permanent
2340 breakpoints can't be removed. So we have to test for it here. */
2341 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2343 if (sig
!= GDB_SIGNAL_0
)
2345 /* We have a signal to pass to the inferior. The resume
2346 may, or may not take us to the signal handler. If this
2347 is a step, we'll need to stop in the signal handler, if
2348 there's one, (if the target supports stepping into
2349 handlers), or in the next mainline instruction, if
2350 there's no handler. If this is a continue, we need to be
2351 sure to run the handler with all breakpoints inserted.
2352 In all cases, set a breakpoint at the current address
2353 (where the handler returns to), and once that breakpoint
2354 is hit, resume skipping the permanent breakpoint. If
2355 that breakpoint isn't hit, then we've stepped into the
2356 signal handler (or hit some other event). We'll delete
2357 the step-resume breakpoint then. */
2360 fprintf_unfiltered (gdb_stdlog
,
2361 "infrun: resume: skipping permanent breakpoint, "
2362 "deliver signal first\n");
2364 clear_step_over_info ();
2365 tp
->control
.trap_expected
= 0;
2367 if (tp
->control
.step_resume_breakpoint
== NULL
)
2369 /* Set a "high-priority" step-resume, as we don't want
2370 user breakpoints at PC to trigger (again) when this
2372 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2373 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2375 tp
->step_after_step_resume_breakpoint
= step
;
2378 insert_breakpoints ();
2382 /* There's no signal to pass, we can go ahead and skip the
2383 permanent breakpoint manually. */
2385 fprintf_unfiltered (gdb_stdlog
,
2386 "infrun: resume: skipping permanent breakpoint\n");
2387 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2388 /* Update pc to reflect the new address from which we will
2389 execute instructions. */
2390 pc
= regcache_read_pc (regcache
);
2394 /* We've already advanced the PC, so the stepping part
2395 is done. Now we need to arrange for a trap to be
2396 reported to handle_inferior_event. Set a breakpoint
2397 at the current PC, and run to it. Don't update
2398 prev_pc, because if we end in
2399 switch_back_to_stepped_thread, we want the "expected
2400 thread advanced also" branch to be taken. IOW, we
2401 don't want this thread to step further from PC
2403 gdb_assert (!step_over_info_valid_p ());
2404 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2405 insert_breakpoints ();
2407 resume_ptid
= internal_resume_ptid (user_step
);
2408 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2415 /* If we have a breakpoint to step over, make sure to do a single
2416 step only. Same if we have software watchpoints. */
2417 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2418 tp
->control
.may_range_step
= 0;
2420 /* If displaced stepping is enabled, step over breakpoints by executing a
2421 copy of the instruction at a different address.
2423 We can't use displaced stepping when we have a signal to deliver;
2424 the comments for displaced_step_prepare explain why. The
2425 comments in the handle_inferior event for dealing with 'random
2426 signals' explain what we do instead.
2428 We can't use displaced stepping when we are waiting for vfork_done
2429 event, displaced stepping breaks the vfork child similarly as single
2430 step software breakpoint. */
2431 if (tp
->control
.trap_expected
2432 && use_displaced_stepping (tp
)
2433 && !step_over_info_valid_p ()
2434 && sig
== GDB_SIGNAL_0
2435 && !current_inferior ()->waiting_for_vfork_done
)
2437 int prepared
= displaced_step_prepare (tp
);
2442 fprintf_unfiltered (gdb_stdlog
,
2443 "Got placed in step-over queue\n");
2445 tp
->control
.trap_expected
= 0;
2448 else if (prepared
< 0)
2450 /* Fallback to stepping over the breakpoint in-line. */
2452 if (target_is_non_stop_p ())
2453 stop_all_threads ();
2455 set_step_over_info (regcache
->aspace (),
2456 regcache_read_pc (regcache
), 0, tp
->global_num
);
2458 step
= maybe_software_singlestep (gdbarch
, pc
);
2460 insert_breakpoints ();
2462 else if (prepared
> 0)
2464 struct displaced_step_inferior_state
*displaced
;
2466 /* Update pc to reflect the new address from which we will
2467 execute instructions due to displaced stepping. */
2468 pc
= regcache_read_pc (get_thread_regcache (tp
));
2470 displaced
= get_displaced_stepping_state (tp
->inf
);
2471 step
= gdbarch_displaced_step_hw_singlestep
2472 (gdbarch
, displaced
->step_closure
.get ());
2476 /* Do we need to do it the hard way, w/temp breakpoints? */
2478 step
= maybe_software_singlestep (gdbarch
, pc
);
2480 /* Currently, our software single-step implementation leads to different
2481 results than hardware single-stepping in one situation: when stepping
2482 into delivering a signal which has an associated signal handler,
2483 hardware single-step will stop at the first instruction of the handler,
2484 while software single-step will simply skip execution of the handler.
2486 For now, this difference in behavior is accepted since there is no
2487 easy way to actually implement single-stepping into a signal handler
2488 without kernel support.
2490 However, there is one scenario where this difference leads to follow-on
2491 problems: if we're stepping off a breakpoint by removing all breakpoints
2492 and then single-stepping. In this case, the software single-step
2493 behavior means that even if there is a *breakpoint* in the signal
2494 handler, GDB still would not stop.
2496 Fortunately, we can at least fix this particular issue. We detect
2497 here the case where we are about to deliver a signal while software
2498 single-stepping with breakpoints removed. In this situation, we
2499 revert the decisions to remove all breakpoints and insert single-
2500 step breakpoints, and instead we install a step-resume breakpoint
2501 at the current address, deliver the signal without stepping, and
2502 once we arrive back at the step-resume breakpoint, actually step
2503 over the breakpoint we originally wanted to step over. */
2504 if (thread_has_single_step_breakpoints_set (tp
)
2505 && sig
!= GDB_SIGNAL_0
2506 && step_over_info_valid_p ())
2508 /* If we have nested signals or a pending signal is delivered
2509 immediately after a handler returns, might already have
2510 a step-resume breakpoint set on the earlier handler. We cannot
2511 set another step-resume breakpoint; just continue on until the
2512 original breakpoint is hit. */
2513 if (tp
->control
.step_resume_breakpoint
== NULL
)
2515 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2516 tp
->step_after_step_resume_breakpoint
= 1;
2519 delete_single_step_breakpoints (tp
);
2521 clear_step_over_info ();
2522 tp
->control
.trap_expected
= 0;
2524 insert_breakpoints ();
2527 /* If STEP is set, it's a request to use hardware stepping
2528 facilities. But in that case, we should never
2529 use singlestep breakpoint. */
2530 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2532 /* Decide the set of threads to ask the target to resume. */
2533 if (tp
->control
.trap_expected
)
2535 /* We're allowing a thread to run past a breakpoint it has
2536 hit, either by single-stepping the thread with the breakpoint
2537 removed, or by displaced stepping, with the breakpoint inserted.
2538 In the former case, we need to single-step only this thread,
2539 and keep others stopped, as they can miss this breakpoint if
2540 allowed to run. That's not really a problem for displaced
2541 stepping, but, we still keep other threads stopped, in case
2542 another thread is also stopped for a breakpoint waiting for
2543 its turn in the displaced stepping queue. */
2544 resume_ptid
= inferior_ptid
;
2547 resume_ptid
= internal_resume_ptid (user_step
);
2549 if (execution_direction
!= EXEC_REVERSE
2550 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2552 /* There are two cases where we currently need to step a
2553 breakpoint instruction when we have a signal to deliver:
2555 - See handle_signal_stop where we handle random signals that
2556 could take out us out of the stepping range. Normally, in
2557 that case we end up continuing (instead of stepping) over the
2558 signal handler with a breakpoint at PC, but there are cases
2559 where we should _always_ single-step, even if we have a
2560 step-resume breakpoint, like when a software watchpoint is
2561 set. Assuming single-stepping and delivering a signal at the
2562 same time would takes us to the signal handler, then we could
2563 have removed the breakpoint at PC to step over it. However,
2564 some hardware step targets (like e.g., Mac OS) can't step
2565 into signal handlers, and for those, we need to leave the
2566 breakpoint at PC inserted, as otherwise if the handler
2567 recurses and executes PC again, it'll miss the breakpoint.
2568 So we leave the breakpoint inserted anyway, but we need to
2569 record that we tried to step a breakpoint instruction, so
2570 that adjust_pc_after_break doesn't end up confused.
2572 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2573 in one thread after another thread that was stepping had been
2574 momentarily paused for a step-over. When we re-resume the
2575 stepping thread, it may be resumed from that address with a
2576 breakpoint that hasn't trapped yet. Seen with
2577 gdb.threads/non-stop-fair-events.exp, on targets that don't
2578 do displaced stepping. */
2581 fprintf_unfiltered (gdb_stdlog
,
2582 "infrun: resume: [%s] stepped breakpoint\n",
2583 target_pid_to_str (tp
->ptid
).c_str ());
2585 tp
->stepped_breakpoint
= 1;
2587 /* Most targets can step a breakpoint instruction, thus
2588 executing it normally. But if this one cannot, just
2589 continue and we will hit it anyway. */
2590 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2595 && tp
->control
.trap_expected
2596 && use_displaced_stepping (tp
)
2597 && !step_over_info_valid_p ())
2599 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2600 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2601 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2604 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2605 paddress (resume_gdbarch
, actual_pc
));
2606 read_memory (actual_pc
, buf
, sizeof (buf
));
2607 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2610 if (tp
->control
.may_range_step
)
2612 /* If we're resuming a thread with the PC out of the step
2613 range, then we're doing some nested/finer run control
2614 operation, like stepping the thread out of the dynamic
2615 linker or the displaced stepping scratch pad. We
2616 shouldn't have allowed a range step then. */
2617 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2620 do_target_resume (resume_ptid
, step
, sig
);
2624 /* Resume the inferior. SIG is the signal to give the inferior
2625 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2626 rolls back state on error. */
2629 resume (gdb_signal sig
)
2635 catch (const gdb_exception
&ex
)
2637 /* If resuming is being aborted for any reason, delete any
2638 single-step breakpoint resume_1 may have created, to avoid
2639 confusing the following resumption, and to avoid leaving
2640 single-step breakpoints perturbing other threads, in case
2641 we're running in non-stop mode. */
2642 if (inferior_ptid
!= null_ptid
)
2643 delete_single_step_breakpoints (inferior_thread ());
2653 /* Counter that tracks number of user visible stops. This can be used
2654 to tell whether a command has proceeded the inferior past the
2655 current location. This allows e.g., inferior function calls in
2656 breakpoint commands to not interrupt the command list. When the
2657 call finishes successfully, the inferior is standing at the same
2658 breakpoint as if nothing happened (and so we don't call
2660 static ULONGEST current_stop_id
;
2667 return current_stop_id
;
2670 /* Called when we report a user visible stop. */
2678 /* Clear out all variables saying what to do when inferior is continued.
2679 First do this, then set the ones you want, then call `proceed'. */
2682 clear_proceed_status_thread (struct thread_info
*tp
)
2685 fprintf_unfiltered (gdb_stdlog
,
2686 "infrun: clear_proceed_status_thread (%s)\n",
2687 target_pid_to_str (tp
->ptid
).c_str ());
2689 /* If we're starting a new sequence, then the previous finished
2690 single-step is no longer relevant. */
2691 if (tp
->suspend
.waitstatus_pending_p
)
2693 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2696 fprintf_unfiltered (gdb_stdlog
,
2697 "infrun: clear_proceed_status: pending "
2698 "event of %s was a finished step. "
2700 target_pid_to_str (tp
->ptid
).c_str ());
2702 tp
->suspend
.waitstatus_pending_p
= 0;
2703 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2705 else if (debug_infrun
)
2708 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2710 fprintf_unfiltered (gdb_stdlog
,
2711 "infrun: clear_proceed_status_thread: thread %s "
2712 "has pending wait status %s "
2713 "(currently_stepping=%d).\n",
2714 target_pid_to_str (tp
->ptid
).c_str (),
2716 currently_stepping (tp
));
2720 /* If this signal should not be seen by program, give it zero.
2721 Used for debugging signals. */
2722 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2723 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2725 delete tp
->thread_fsm
;
2726 tp
->thread_fsm
= NULL
;
2728 tp
->control
.trap_expected
= 0;
2729 tp
->control
.step_range_start
= 0;
2730 tp
->control
.step_range_end
= 0;
2731 tp
->control
.may_range_step
= 0;
2732 tp
->control
.step_frame_id
= null_frame_id
;
2733 tp
->control
.step_stack_frame_id
= null_frame_id
;
2734 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2735 tp
->control
.step_start_function
= NULL
;
2736 tp
->stop_requested
= 0;
2738 tp
->control
.stop_step
= 0;
2740 tp
->control
.proceed_to_finish
= 0;
2742 tp
->control
.stepping_command
= 0;
2744 /* Discard any remaining commands or status from previous stop. */
2745 bpstat_clear (&tp
->control
.stop_bpstat
);
2749 clear_proceed_status (int step
)
2751 /* With scheduler-locking replay, stop replaying other threads if we're
2752 not replaying the user-visible resume ptid.
2754 This is a convenience feature to not require the user to explicitly
2755 stop replaying the other threads. We're assuming that the user's
2756 intent is to resume tracing the recorded process. */
2757 if (!non_stop
&& scheduler_mode
== schedlock_replay
2758 && target_record_is_replaying (minus_one_ptid
)
2759 && !target_record_will_replay (user_visible_resume_ptid (step
),
2760 execution_direction
))
2761 target_record_stop_replaying ();
2763 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2765 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2766 process_stratum_target
*resume_target
2767 = user_visible_resume_target (resume_ptid
);
2769 /* In all-stop mode, delete the per-thread status of all threads
2770 we're about to resume, implicitly and explicitly. */
2771 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2772 clear_proceed_status_thread (tp
);
2775 if (inferior_ptid
!= null_ptid
)
2777 struct inferior
*inferior
;
2781 /* If in non-stop mode, only delete the per-thread status of
2782 the current thread. */
2783 clear_proceed_status_thread (inferior_thread ());
2786 inferior
= current_inferior ();
2787 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2790 gdb::observers::about_to_proceed
.notify ();
2793 /* Returns true if TP is still stopped at a breakpoint that needs
2794 stepping-over in order to make progress. If the breakpoint is gone
2795 meanwhile, we can skip the whole step-over dance. */
2798 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2800 if (tp
->stepping_over_breakpoint
)
2802 struct regcache
*regcache
= get_thread_regcache (tp
);
2804 if (breakpoint_here_p (regcache
->aspace (),
2805 regcache_read_pc (regcache
))
2806 == ordinary_breakpoint_here
)
2809 tp
->stepping_over_breakpoint
= 0;
2815 /* Check whether thread TP still needs to start a step-over in order
2816 to make progress when resumed. Returns an bitwise or of enum
2817 step_over_what bits, indicating what needs to be stepped over. */
2819 static step_over_what
2820 thread_still_needs_step_over (struct thread_info
*tp
)
2822 step_over_what what
= 0;
2824 if (thread_still_needs_step_over_bp (tp
))
2825 what
|= STEP_OVER_BREAKPOINT
;
2827 if (tp
->stepping_over_watchpoint
2828 && !target_have_steppable_watchpoint
)
2829 what
|= STEP_OVER_WATCHPOINT
;
2834 /* Returns true if scheduler locking applies. STEP indicates whether
2835 we're about to do a step/next-like command to a thread. */
2838 schedlock_applies (struct thread_info
*tp
)
2840 return (scheduler_mode
== schedlock_on
2841 || (scheduler_mode
== schedlock_step
2842 && tp
->control
.stepping_command
)
2843 || (scheduler_mode
== schedlock_replay
2844 && target_record_will_replay (minus_one_ptid
,
2845 execution_direction
)));
2848 /* Calls target_commit_resume on all targets. */
2851 commit_resume_all_targets ()
2853 scoped_restore_current_thread restore_thread
;
2855 /* Map between process_target and a representative inferior. This
2856 is to avoid committing a resume in the same target more than
2857 once. Resumptions must be idempotent, so this is an
2859 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2861 for (inferior
*inf
: all_non_exited_inferiors ())
2862 if (inf
->has_execution ())
2863 conn_inf
[inf
->process_target ()] = inf
;
2865 for (const auto &ci
: conn_inf
)
2867 inferior
*inf
= ci
.second
;
2868 switch_to_inferior_no_thread (inf
);
2869 target_commit_resume ();
2873 /* Check that all the targets we're about to resume are in non-stop
2874 mode. Ideally, we'd only care whether all targets support
2875 target-async, but we're not there yet. E.g., stop_all_threads
2876 doesn't know how to handle all-stop targets. Also, the remote
2877 protocol in all-stop mode is synchronous, irrespective of
2878 target-async, which means that things like a breakpoint re-set
2879 triggered by one target would try to read memory from all targets
2883 check_multi_target_resumption (process_stratum_target
*resume_target
)
2885 if (!non_stop
&& resume_target
== nullptr)
2887 scoped_restore_current_thread restore_thread
;
2889 /* This is used to track whether we're resuming more than one
2891 process_stratum_target
*first_connection
= nullptr;
2893 /* The first inferior we see with a target that does not work in
2894 always-non-stop mode. */
2895 inferior
*first_not_non_stop
= nullptr;
2897 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2899 switch_to_inferior_no_thread (inf
);
2901 if (!target_has_execution
)
2904 process_stratum_target
*proc_target
2905 = current_inferior ()->process_target();
2907 if (!target_is_non_stop_p ())
2908 first_not_non_stop
= inf
;
2910 if (first_connection
== nullptr)
2911 first_connection
= proc_target
;
2912 else if (first_connection
!= proc_target
2913 && first_not_non_stop
!= nullptr)
2915 switch_to_inferior_no_thread (first_not_non_stop
);
2917 proc_target
= current_inferior ()->process_target();
2919 error (_("Connection %d (%s) does not support "
2920 "multi-target resumption."),
2921 proc_target
->connection_number
,
2922 make_target_connection_string (proc_target
).c_str ());
2928 /* Basic routine for continuing the program in various fashions.
2930 ADDR is the address to resume at, or -1 for resume where stopped.
2931 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2932 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2934 You should call clear_proceed_status before calling proceed. */
2937 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2939 struct regcache
*regcache
;
2940 struct gdbarch
*gdbarch
;
2942 struct execution_control_state ecss
;
2943 struct execution_control_state
*ecs
= &ecss
;
2946 /* If we're stopped at a fork/vfork, follow the branch set by the
2947 "set follow-fork-mode" command; otherwise, we'll just proceed
2948 resuming the current thread. */
2949 if (!follow_fork ())
2951 /* The target for some reason decided not to resume. */
2953 if (target_can_async_p ())
2954 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2958 /* We'll update this if & when we switch to a new thread. */
2959 previous_inferior_ptid
= inferior_ptid
;
2961 regcache
= get_current_regcache ();
2962 gdbarch
= regcache
->arch ();
2963 const address_space
*aspace
= regcache
->aspace ();
2965 pc
= regcache_read_pc (regcache
);
2966 thread_info
*cur_thr
= inferior_thread ();
2968 /* Fill in with reasonable starting values. */
2969 init_thread_stepping_state (cur_thr
);
2971 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2974 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2975 process_stratum_target
*resume_target
2976 = user_visible_resume_target (resume_ptid
);
2978 check_multi_target_resumption (resume_target
);
2980 if (addr
== (CORE_ADDR
) -1)
2982 if (pc
== cur_thr
->suspend
.stop_pc
2983 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2984 && execution_direction
!= EXEC_REVERSE
)
2985 /* There is a breakpoint at the address we will resume at,
2986 step one instruction before inserting breakpoints so that
2987 we do not stop right away (and report a second hit at this
2990 Note, we don't do this in reverse, because we won't
2991 actually be executing the breakpoint insn anyway.
2992 We'll be (un-)executing the previous instruction. */
2993 cur_thr
->stepping_over_breakpoint
= 1;
2994 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2995 && gdbarch_single_step_through_delay (gdbarch
,
2996 get_current_frame ()))
2997 /* We stepped onto an instruction that needs to be stepped
2998 again before re-inserting the breakpoint, do so. */
2999 cur_thr
->stepping_over_breakpoint
= 1;
3003 regcache_write_pc (regcache
, addr
);
3006 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3007 cur_thr
->suspend
.stop_signal
= siggnal
;
3009 /* If an exception is thrown from this point on, make sure to
3010 propagate GDB's knowledge of the executing state to the
3011 frontend/user running state. */
3012 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3014 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3015 threads (e.g., we might need to set threads stepping over
3016 breakpoints first), from the user/frontend's point of view, all
3017 threads in RESUME_PTID are now running. Unless we're calling an
3018 inferior function, as in that case we pretend the inferior
3019 doesn't run at all. */
3020 if (!cur_thr
->control
.in_infcall
)
3021 set_running (resume_target
, resume_ptid
, true);
3024 fprintf_unfiltered (gdb_stdlog
,
3025 "infrun: proceed (addr=%s, signal=%s)\n",
3026 paddress (gdbarch
, addr
),
3027 gdb_signal_to_symbol_string (siggnal
));
3029 annotate_starting ();
3031 /* Make sure that output from GDB appears before output from the
3033 gdb_flush (gdb_stdout
);
3035 /* Since we've marked the inferior running, give it the terminal. A
3036 QUIT/Ctrl-C from here on is forwarded to the target (which can
3037 still detect attempts to unblock a stuck connection with repeated
3038 Ctrl-C from within target_pass_ctrlc). */
3039 target_terminal::inferior ();
3041 /* In a multi-threaded task we may select another thread and
3042 then continue or step.
3044 But if a thread that we're resuming had stopped at a breakpoint,
3045 it will immediately cause another breakpoint stop without any
3046 execution (i.e. it will report a breakpoint hit incorrectly). So
3047 we must step over it first.
3049 Look for threads other than the current (TP) that reported a
3050 breakpoint hit and haven't been resumed yet since. */
3052 /* If scheduler locking applies, we can avoid iterating over all
3054 if (!non_stop
&& !schedlock_applies (cur_thr
))
3056 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3059 switch_to_thread_no_regs (tp
);
3061 /* Ignore the current thread here. It's handled
3066 if (!thread_still_needs_step_over (tp
))
3069 gdb_assert (!thread_is_in_step_over_chain (tp
));
3072 fprintf_unfiltered (gdb_stdlog
,
3073 "infrun: need to step-over [%s] first\n",
3074 target_pid_to_str (tp
->ptid
).c_str ());
3076 thread_step_over_chain_enqueue (tp
);
3079 switch_to_thread (cur_thr
);
3082 /* Enqueue the current thread last, so that we move all other
3083 threads over their breakpoints first. */
3084 if (cur_thr
->stepping_over_breakpoint
)
3085 thread_step_over_chain_enqueue (cur_thr
);
3087 /* If the thread isn't started, we'll still need to set its prev_pc,
3088 so that switch_back_to_stepped_thread knows the thread hasn't
3089 advanced. Must do this before resuming any thread, as in
3090 all-stop/remote, once we resume we can't send any other packet
3091 until the target stops again. */
3092 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
3095 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3097 started
= start_step_over ();
3099 if (step_over_info_valid_p ())
3101 /* Either this thread started a new in-line step over, or some
3102 other thread was already doing one. In either case, don't
3103 resume anything else until the step-over is finished. */
3105 else if (started
&& !target_is_non_stop_p ())
3107 /* A new displaced stepping sequence was started. In all-stop,
3108 we can't talk to the target anymore until it next stops. */
3110 else if (!non_stop
&& target_is_non_stop_p ())
3112 /* In all-stop, but the target is always in non-stop mode.
3113 Start all other threads that are implicitly resumed too. */
3114 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3117 switch_to_thread_no_regs (tp
);
3119 if (!tp
->inf
->has_execution ())
3122 fprintf_unfiltered (gdb_stdlog
,
3123 "infrun: proceed: [%s] target has "
3125 target_pid_to_str (tp
->ptid
).c_str ());
3132 fprintf_unfiltered (gdb_stdlog
,
3133 "infrun: proceed: [%s] resumed\n",
3134 target_pid_to_str (tp
->ptid
).c_str ());
3135 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3139 if (thread_is_in_step_over_chain (tp
))
3142 fprintf_unfiltered (gdb_stdlog
,
3143 "infrun: proceed: [%s] needs step-over\n",
3144 target_pid_to_str (tp
->ptid
).c_str ());
3149 fprintf_unfiltered (gdb_stdlog
,
3150 "infrun: proceed: resuming %s\n",
3151 target_pid_to_str (tp
->ptid
).c_str ());
3153 reset_ecs (ecs
, tp
);
3154 switch_to_thread (tp
);
3155 keep_going_pass_signal (ecs
);
3156 if (!ecs
->wait_some_more
)
3157 error (_("Command aborted."));
3160 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3162 /* The thread wasn't started, and isn't queued, run it now. */
3163 reset_ecs (ecs
, cur_thr
);
3164 switch_to_thread (cur_thr
);
3165 keep_going_pass_signal (ecs
);
3166 if (!ecs
->wait_some_more
)
3167 error (_("Command aborted."));
3171 commit_resume_all_targets ();
3173 finish_state
.release ();
3175 /* If we've switched threads above, switch back to the previously
3176 current thread. We don't want the user to see a different
3178 switch_to_thread (cur_thr
);
3180 /* Tell the event loop to wait for it to stop. If the target
3181 supports asynchronous execution, it'll do this from within
3183 if (!target_can_async_p ())
3184 mark_async_event_handler (infrun_async_inferior_event_token
);
3188 /* Start remote-debugging of a machine over a serial link. */
3191 start_remote (int from_tty
)
3193 inferior
*inf
= current_inferior ();
3194 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3196 /* Always go on waiting for the target, regardless of the mode. */
3197 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3198 indicate to wait_for_inferior that a target should timeout if
3199 nothing is returned (instead of just blocking). Because of this,
3200 targets expecting an immediate response need to, internally, set
3201 things up so that the target_wait() is forced to eventually
3203 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3204 differentiate to its caller what the state of the target is after
3205 the initial open has been performed. Here we're assuming that
3206 the target has stopped. It should be possible to eventually have
3207 target_open() return to the caller an indication that the target
3208 is currently running and GDB state should be set to the same as
3209 for an async run. */
3210 wait_for_inferior (inf
);
3212 /* Now that the inferior has stopped, do any bookkeeping like
3213 loading shared libraries. We want to do this before normal_stop,
3214 so that the displayed frame is up to date. */
3215 post_create_inferior (current_top_target (), from_tty
);
3220 /* Initialize static vars when a new inferior begins. */
3223 init_wait_for_inferior (void)
3225 /* These are meaningless until the first time through wait_for_inferior. */
3227 breakpoint_init_inferior (inf_starting
);
3229 clear_proceed_status (0);
3231 nullify_last_target_wait_ptid ();
3233 previous_inferior_ptid
= inferior_ptid
;
3238 static void handle_inferior_event (struct execution_control_state
*ecs
);
3240 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3241 struct execution_control_state
*ecs
);
3242 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3243 struct execution_control_state
*ecs
);
3244 static void handle_signal_stop (struct execution_control_state
*ecs
);
3245 static void check_exception_resume (struct execution_control_state
*,
3246 struct frame_info
*);
3248 static void end_stepping_range (struct execution_control_state
*ecs
);
3249 static void stop_waiting (struct execution_control_state
*ecs
);
3250 static void keep_going (struct execution_control_state
*ecs
);
3251 static void process_event_stop_test (struct execution_control_state
*ecs
);
3252 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3254 /* This function is attached as a "thread_stop_requested" observer.
3255 Cleanup local state that assumed the PTID was to be resumed, and
3256 report the stop to the frontend. */
3259 infrun_thread_stop_requested (ptid_t ptid
)
3261 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3263 /* PTID was requested to stop. If the thread was already stopped,
3264 but the user/frontend doesn't know about that yet (e.g., the
3265 thread had been temporarily paused for some step-over), set up
3266 for reporting the stop now. */
3267 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3269 if (tp
->state
!= THREAD_RUNNING
)
3274 /* Remove matching threads from the step-over queue, so
3275 start_step_over doesn't try to resume them
3277 if (thread_is_in_step_over_chain (tp
))
3278 thread_step_over_chain_remove (tp
);
3280 /* If the thread is stopped, but the user/frontend doesn't
3281 know about that yet, queue a pending event, as if the
3282 thread had just stopped now. Unless the thread already had
3284 if (!tp
->suspend
.waitstatus_pending_p
)
3286 tp
->suspend
.waitstatus_pending_p
= 1;
3287 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3288 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3291 /* Clear the inline-frame state, since we're re-processing the
3293 clear_inline_frame_state (tp
);
3295 /* If this thread was paused because some other thread was
3296 doing an inline-step over, let that finish first. Once
3297 that happens, we'll restart all threads and consume pending
3298 stop events then. */
3299 if (step_over_info_valid_p ())
3302 /* Otherwise we can process the (new) pending event now. Set
3303 it so this pending event is considered by
3310 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3312 if (target_last_proc_target
== tp
->inf
->process_target ()
3313 && target_last_wait_ptid
== tp
->ptid
)
3314 nullify_last_target_wait_ptid ();
3317 /* Delete the step resume, single-step and longjmp/exception resume
3318 breakpoints of TP. */
3321 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3323 delete_step_resume_breakpoint (tp
);
3324 delete_exception_resume_breakpoint (tp
);
3325 delete_single_step_breakpoints (tp
);
3328 /* If the target still has execution, call FUNC for each thread that
3329 just stopped. In all-stop, that's all the non-exited threads; in
3330 non-stop, that's the current thread, only. */
3332 typedef void (*for_each_just_stopped_thread_callback_func
)
3333 (struct thread_info
*tp
);
3336 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3338 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3341 if (target_is_non_stop_p ())
3343 /* If in non-stop mode, only the current thread stopped. */
3344 func (inferior_thread ());
3348 /* In all-stop mode, all threads have stopped. */
3349 for (thread_info
*tp
: all_non_exited_threads ())
3354 /* Delete the step resume and longjmp/exception resume breakpoints of
3355 the threads that just stopped. */
3358 delete_just_stopped_threads_infrun_breakpoints (void)
3360 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3363 /* Delete the single-step breakpoints of the threads that just
3367 delete_just_stopped_threads_single_step_breakpoints (void)
3369 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3375 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3376 const struct target_waitstatus
*ws
)
3378 std::string status_string
= target_waitstatus_to_string (ws
);
3381 /* The text is split over several lines because it was getting too long.
3382 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3383 output as a unit; we want only one timestamp printed if debug_timestamp
3386 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3389 waiton_ptid
.tid ());
3390 if (waiton_ptid
.pid () != -1)
3391 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3392 stb
.printf (", status) =\n");
3393 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3397 target_pid_to_str (result_ptid
).c_str ());
3398 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3400 /* This uses %s in part to handle %'s in the text, but also to avoid
3401 a gcc error: the format attribute requires a string literal. */
3402 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3405 /* Select a thread at random, out of those which are resumed and have
3408 static struct thread_info
*
3409 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3413 auto has_event
= [&] (thread_info
*tp
)
3415 return (tp
->ptid
.matches (waiton_ptid
)
3417 && tp
->suspend
.waitstatus_pending_p
);
3420 /* First see how many events we have. Count only resumed threads
3421 that have an event pending. */
3422 for (thread_info
*tp
: inf
->non_exited_threads ())
3426 if (num_events
== 0)
3429 /* Now randomly pick a thread out of those that have had events. */
3430 int random_selector
= (int) ((num_events
* (double) rand ())
3431 / (RAND_MAX
+ 1.0));
3433 if (debug_infrun
&& num_events
> 1)
3434 fprintf_unfiltered (gdb_stdlog
,
3435 "infrun: Found %d events, selecting #%d\n",
3436 num_events
, random_selector
);
3438 /* Select the Nth thread that has had an event. */
3439 for (thread_info
*tp
: inf
->non_exited_threads ())
3441 if (random_selector
-- == 0)
3444 gdb_assert_not_reached ("event thread not found");
3447 /* Wrapper for target_wait that first checks whether threads have
3448 pending statuses to report before actually asking the target for
3449 more events. INF is the inferior we're using to call target_wait
3453 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3454 target_waitstatus
*status
, int options
)
3457 struct thread_info
*tp
;
3459 /* First check if there is a resumed thread with a wait status
3461 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3463 tp
= random_pending_event_thread (inf
, ptid
);
3468 fprintf_unfiltered (gdb_stdlog
,
3469 "infrun: Waiting for specific thread %s.\n",
3470 target_pid_to_str (ptid
).c_str ());
3472 /* We have a specific thread to check. */
3473 tp
= find_thread_ptid (inf
, ptid
);
3474 gdb_assert (tp
!= NULL
);
3475 if (!tp
->suspend
.waitstatus_pending_p
)
3480 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3481 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3483 struct regcache
*regcache
= get_thread_regcache (tp
);
3484 struct gdbarch
*gdbarch
= regcache
->arch ();
3488 pc
= regcache_read_pc (regcache
);
3490 if (pc
!= tp
->suspend
.stop_pc
)
3493 fprintf_unfiltered (gdb_stdlog
,
3494 "infrun: PC of %s changed. was=%s, now=%s\n",
3495 target_pid_to_str (tp
->ptid
).c_str (),
3496 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3497 paddress (gdbarch
, pc
));
3500 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3503 fprintf_unfiltered (gdb_stdlog
,
3504 "infrun: previous breakpoint of %s, at %s gone\n",
3505 target_pid_to_str (tp
->ptid
).c_str (),
3506 paddress (gdbarch
, pc
));
3514 fprintf_unfiltered (gdb_stdlog
,
3515 "infrun: pending event of %s cancelled.\n",
3516 target_pid_to_str (tp
->ptid
).c_str ());
3518 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3519 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3528 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3530 fprintf_unfiltered (gdb_stdlog
,
3531 "infrun: Using pending wait status %s for %s.\n",
3533 target_pid_to_str (tp
->ptid
).c_str ());
3536 /* Now that we've selected our final event LWP, un-adjust its PC
3537 if it was a software breakpoint (and the target doesn't
3538 always adjust the PC itself). */
3539 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3540 && !target_supports_stopped_by_sw_breakpoint ())
3542 struct regcache
*regcache
;
3543 struct gdbarch
*gdbarch
;
3546 regcache
= get_thread_regcache (tp
);
3547 gdbarch
= regcache
->arch ();
3549 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3554 pc
= regcache_read_pc (regcache
);
3555 regcache_write_pc (regcache
, pc
+ decr_pc
);
3559 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3560 *status
= tp
->suspend
.waitstatus
;
3561 tp
->suspend
.waitstatus_pending_p
= 0;
3563 /* Wake up the event loop again, until all pending events are
3565 if (target_is_async_p ())
3566 mark_async_event_handler (infrun_async_inferior_event_token
);
3570 /* But if we don't find one, we'll have to wait. */
3572 if (deprecated_target_wait_hook
)
3573 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3575 event_ptid
= target_wait (ptid
, status
, options
);
3580 /* Returns true if INF has any resumed thread with a status
3584 threads_are_resumed_pending_p (inferior
*inf
)
3586 for (thread_info
*tp
: inf
->non_exited_threads ())
3588 && tp
->suspend
.waitstatus_pending_p
)
3594 /* Wrapper for target_wait that first checks whether threads have
3595 pending statuses to report before actually asking the target for
3596 more events. Polls for events from all inferiors/targets. */
3599 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3601 int num_inferiors
= 0;
3602 int random_selector
;
3604 /* For fairness, we pick the first inferior/target to poll at
3605 random, and then continue polling the rest of the inferior list
3606 starting from that one in a circular fashion until the whole list
3609 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3611 return (inf
->process_target () != NULL
3612 && (threads_are_executing (inf
->process_target ())
3613 || threads_are_resumed_pending_p (inf
))
3614 && ptid_t (inf
->pid
).matches (wait_ptid
));
3617 /* First see how many resumed inferiors we have. */
3618 for (inferior
*inf
: all_inferiors ())
3619 if (inferior_matches (inf
))
3622 if (num_inferiors
== 0)
3624 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3628 /* Now randomly pick an inferior out of those that were resumed. */
3629 random_selector
= (int)
3630 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3632 if (debug_infrun
&& num_inferiors
> 1)
3633 fprintf_unfiltered (gdb_stdlog
,
3634 "infrun: Found %d inferiors, starting at #%d\n",
3635 num_inferiors
, random_selector
);
3637 /* Select the Nth inferior that was resumed. */
3639 inferior
*selected
= nullptr;
3641 for (inferior
*inf
: all_inferiors ())
3642 if (inferior_matches (inf
))
3643 if (random_selector
-- == 0)
3649 /* Now poll for events out of each of the resumed inferior's
3650 targets, starting from the selected one. */
3652 auto do_wait
= [&] (inferior
*inf
)
3654 switch_to_inferior_no_thread (inf
);
3656 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3657 ecs
->target
= inf
->process_target ();
3658 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3661 /* Needed in all-stop+target-non-stop mode, because we end up here
3662 spuriously after the target is all stopped and we've already
3663 reported the stop to the user, polling for events. */
3664 scoped_restore_current_thread restore_thread
;
3666 int inf_num
= selected
->num
;
3667 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3668 if (inferior_matches (inf
))
3672 for (inferior
*inf
= inferior_list
;
3673 inf
!= NULL
&& inf
->num
< inf_num
;
3675 if (inferior_matches (inf
))
3679 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3683 /* Prepare and stabilize the inferior for detaching it. E.g.,
3684 detaching while a thread is displaced stepping is a recipe for
3685 crashing it, as nothing would readjust the PC out of the scratch
3689 prepare_for_detach (void)
3691 struct inferior
*inf
= current_inferior ();
3692 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3694 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3696 /* Is any thread of this process displaced stepping? If not,
3697 there's nothing else to do. */
3698 if (displaced
->step_thread
== nullptr)
3702 fprintf_unfiltered (gdb_stdlog
,
3703 "displaced-stepping in-process while detaching");
3705 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3707 while (displaced
->step_thread
!= nullptr)
3709 struct execution_control_state ecss
;
3710 struct execution_control_state
*ecs
;
3713 memset (ecs
, 0, sizeof (*ecs
));
3715 overlay_cache_invalid
= 1;
3716 /* Flush target cache before starting to handle each event.
3717 Target was running and cache could be stale. This is just a
3718 heuristic. Running threads may modify target memory, but we
3719 don't get any event. */
3720 target_dcache_invalidate ();
3722 do_target_wait (pid_ptid
, ecs
, 0);
3725 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3727 /* If an error happens while handling the event, propagate GDB's
3728 knowledge of the executing state to the frontend/user running
3730 scoped_finish_thread_state
finish_state (inf
->process_target (),
3733 /* Now figure out what to do with the result of the result. */
3734 handle_inferior_event (ecs
);
3736 /* No error, don't finish the state yet. */
3737 finish_state
.release ();
3739 /* Breakpoints and watchpoints are not installed on the target
3740 at this point, and signals are passed directly to the
3741 inferior, so this must mean the process is gone. */
3742 if (!ecs
->wait_some_more
)
3744 restore_detaching
.release ();
3745 error (_("Program exited while detaching"));
3749 restore_detaching
.release ();
3752 /* Wait for control to return from inferior to debugger.
3754 If inferior gets a signal, we may decide to start it up again
3755 instead of returning. That is why there is a loop in this function.
3756 When this function actually returns it means the inferior
3757 should be left stopped and GDB should read more commands. */
3760 wait_for_inferior (inferior
*inf
)
3764 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3766 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3768 /* If an error happens while handling the event, propagate GDB's
3769 knowledge of the executing state to the frontend/user running
3771 scoped_finish_thread_state finish_state
3772 (inf
->process_target (), minus_one_ptid
);
3776 struct execution_control_state ecss
;
3777 struct execution_control_state
*ecs
= &ecss
;
3779 memset (ecs
, 0, sizeof (*ecs
));
3781 overlay_cache_invalid
= 1;
3783 /* Flush target cache before starting to handle each event.
3784 Target was running and cache could be stale. This is just a
3785 heuristic. Running threads may modify target memory, but we
3786 don't get any event. */
3787 target_dcache_invalidate ();
3789 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3790 ecs
->target
= inf
->process_target ();
3793 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3795 /* Now figure out what to do with the result of the result. */
3796 handle_inferior_event (ecs
);
3798 if (!ecs
->wait_some_more
)
3802 /* No error, don't finish the state yet. */
3803 finish_state
.release ();
3806 /* Cleanup that reinstalls the readline callback handler, if the
3807 target is running in the background. If while handling the target
3808 event something triggered a secondary prompt, like e.g., a
3809 pagination prompt, we'll have removed the callback handler (see
3810 gdb_readline_wrapper_line). Need to do this as we go back to the
3811 event loop, ready to process further input. Note this has no
3812 effect if the handler hasn't actually been removed, because calling
3813 rl_callback_handler_install resets the line buffer, thus losing
3817 reinstall_readline_callback_handler_cleanup ()
3819 struct ui
*ui
= current_ui
;
3823 /* We're not going back to the top level event loop yet. Don't
3824 install the readline callback, as it'd prep the terminal,
3825 readline-style (raw, noecho) (e.g., --batch). We'll install
3826 it the next time the prompt is displayed, when we're ready
3831 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3832 gdb_rl_callback_handler_reinstall ();
3835 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3836 that's just the event thread. In all-stop, that's all threads. */
3839 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3841 if (ecs
->event_thread
!= NULL
3842 && ecs
->event_thread
->thread_fsm
!= NULL
)
3843 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3847 for (thread_info
*thr
: all_non_exited_threads ())
3849 if (thr
->thread_fsm
== NULL
)
3851 if (thr
== ecs
->event_thread
)
3854 switch_to_thread (thr
);
3855 thr
->thread_fsm
->clean_up (thr
);
3858 if (ecs
->event_thread
!= NULL
)
3859 switch_to_thread (ecs
->event_thread
);
3863 /* Helper for all_uis_check_sync_execution_done that works on the
3867 check_curr_ui_sync_execution_done (void)
3869 struct ui
*ui
= current_ui
;
3871 if (ui
->prompt_state
== PROMPT_NEEDED
3873 && !gdb_in_secondary_prompt_p (ui
))
3875 target_terminal::ours ();
3876 gdb::observers::sync_execution_done
.notify ();
3877 ui_register_input_event_handler (ui
);
3884 all_uis_check_sync_execution_done (void)
3886 SWITCH_THRU_ALL_UIS ()
3888 check_curr_ui_sync_execution_done ();
3895 all_uis_on_sync_execution_starting (void)
3897 SWITCH_THRU_ALL_UIS ()
3899 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3900 async_disable_stdin ();
3904 /* Asynchronous version of wait_for_inferior. It is called by the
3905 event loop whenever a change of state is detected on the file
3906 descriptor corresponding to the target. It can be called more than
3907 once to complete a single execution command. In such cases we need
3908 to keep the state in a global variable ECSS. If it is the last time
3909 that this function is called for a single execution command, then
3910 report to the user that the inferior has stopped, and do the
3911 necessary cleanups. */
3914 fetch_inferior_event (void *client_data
)
3916 struct execution_control_state ecss
;
3917 struct execution_control_state
*ecs
= &ecss
;
3920 memset (ecs
, 0, sizeof (*ecs
));
3922 /* Events are always processed with the main UI as current UI. This
3923 way, warnings, debug output, etc. are always consistently sent to
3924 the main console. */
3925 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3927 /* End up with readline processing input, if necessary. */
3929 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3931 /* We're handling a live event, so make sure we're doing live
3932 debugging. If we're looking at traceframes while the target is
3933 running, we're going to need to get back to that mode after
3934 handling the event. */
3935 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3938 maybe_restore_traceframe
.emplace ();
3939 set_current_traceframe (-1);
3942 /* The user/frontend should not notice a thread switch due to
3943 internal events. Make sure we revert to the user selected
3944 thread and frame after handling the event and running any
3945 breakpoint commands. */
3946 scoped_restore_current_thread restore_thread
;
3948 overlay_cache_invalid
= 1;
3949 /* Flush target cache before starting to handle each event. Target
3950 was running and cache could be stale. This is just a heuristic.
3951 Running threads may modify target memory, but we don't get any
3953 target_dcache_invalidate ();
3955 scoped_restore save_exec_dir
3956 = make_scoped_restore (&execution_direction
,
3957 target_execution_direction ());
3959 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3962 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3964 /* Switch to the target that generated the event, so we can do
3965 target calls. Any inferior bound to the target will do, so we
3966 just switch to the first we find. */
3967 for (inferior
*inf
: all_inferiors (ecs
->target
))
3969 switch_to_inferior_no_thread (inf
);
3974 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3976 /* If an error happens while handling the event, propagate GDB's
3977 knowledge of the executing state to the frontend/user running
3979 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3980 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3982 /* Get executed before scoped_restore_current_thread above to apply
3983 still for the thread which has thrown the exception. */
3984 auto defer_bpstat_clear
3985 = make_scope_exit (bpstat_clear_actions
);
3986 auto defer_delete_threads
3987 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3989 /* Now figure out what to do with the result of the result. */
3990 handle_inferior_event (ecs
);
3992 if (!ecs
->wait_some_more
)
3994 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3995 int should_stop
= 1;
3996 struct thread_info
*thr
= ecs
->event_thread
;
3998 delete_just_stopped_threads_infrun_breakpoints ();
4002 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4004 if (thread_fsm
!= NULL
)
4005 should_stop
= thread_fsm
->should_stop (thr
);
4014 bool should_notify_stop
= true;
4017 clean_up_just_stopped_threads_fsms (ecs
);
4019 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4020 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4022 if (should_notify_stop
)
4024 /* We may not find an inferior if this was a process exit. */
4025 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4026 proceeded
= normal_stop ();
4031 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4035 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4036 previously selected thread is gone. We have two
4037 choices - switch to no thread selected, or restore the
4038 previously selected thread (now exited). We chose the
4039 later, just because that's what GDB used to do. After
4040 this, "info threads" says "The current thread <Thread
4041 ID 2> has terminated." instead of "No thread
4045 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4046 restore_thread
.dont_restore ();
4050 defer_delete_threads
.release ();
4051 defer_bpstat_clear
.release ();
4053 /* No error, don't finish the thread states yet. */
4054 finish_state
.release ();
4056 /* This scope is used to ensure that readline callbacks are
4057 reinstalled here. */
4060 /* If a UI was in sync execution mode, and now isn't, restore its
4061 prompt (a synchronous execution command has finished, and we're
4062 ready for input). */
4063 all_uis_check_sync_execution_done ();
4066 && exec_done_display_p
4067 && (inferior_ptid
== null_ptid
4068 || inferior_thread ()->state
!= THREAD_RUNNING
))
4069 printf_unfiltered (_("completed.\n"));
4072 /* Record the frame and location we're currently stepping through. */
4074 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
4076 struct thread_info
*tp
= inferior_thread ();
4078 tp
->control
.step_frame_id
= get_frame_id (frame
);
4079 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4081 tp
->current_symtab
= sal
.symtab
;
4082 tp
->current_line
= sal
.line
;
4085 /* Clear context switchable stepping state. */
4088 init_thread_stepping_state (struct thread_info
*tss
)
4090 tss
->stepped_breakpoint
= 0;
4091 tss
->stepping_over_breakpoint
= 0;
4092 tss
->stepping_over_watchpoint
= 0;
4093 tss
->step_after_step_resume_breakpoint
= 0;
4099 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4100 target_waitstatus status
)
4102 target_last_proc_target
= target
;
4103 target_last_wait_ptid
= ptid
;
4104 target_last_waitstatus
= status
;
4110 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4111 target_waitstatus
*status
)
4113 if (target
!= nullptr)
4114 *target
= target_last_proc_target
;
4115 if (ptid
!= nullptr)
4116 *ptid
= target_last_wait_ptid
;
4117 if (status
!= nullptr)
4118 *status
= target_last_waitstatus
;
4124 nullify_last_target_wait_ptid (void)
4126 target_last_proc_target
= nullptr;
4127 target_last_wait_ptid
= minus_one_ptid
;
4128 target_last_waitstatus
= {};
4131 /* Switch thread contexts. */
4134 context_switch (execution_control_state
*ecs
)
4137 && ecs
->ptid
!= inferior_ptid
4138 && (inferior_ptid
== null_ptid
4139 || ecs
->event_thread
!= inferior_thread ()))
4141 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4142 target_pid_to_str (inferior_ptid
).c_str ());
4143 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4144 target_pid_to_str (ecs
->ptid
).c_str ());
4147 switch_to_thread (ecs
->event_thread
);
4150 /* If the target can't tell whether we've hit breakpoints
4151 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4152 check whether that could have been caused by a breakpoint. If so,
4153 adjust the PC, per gdbarch_decr_pc_after_break. */
4156 adjust_pc_after_break (struct thread_info
*thread
,
4157 struct target_waitstatus
*ws
)
4159 struct regcache
*regcache
;
4160 struct gdbarch
*gdbarch
;
4161 CORE_ADDR breakpoint_pc
, decr_pc
;
4163 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4164 we aren't, just return.
4166 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4167 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4168 implemented by software breakpoints should be handled through the normal
4171 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4172 different signals (SIGILL or SIGEMT for instance), but it is less
4173 clear where the PC is pointing afterwards. It may not match
4174 gdbarch_decr_pc_after_break. I don't know any specific target that
4175 generates these signals at breakpoints (the code has been in GDB since at
4176 least 1992) so I can not guess how to handle them here.
4178 In earlier versions of GDB, a target with
4179 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4180 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4181 target with both of these set in GDB history, and it seems unlikely to be
4182 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4184 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4187 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4190 /* In reverse execution, when a breakpoint is hit, the instruction
4191 under it has already been de-executed. The reported PC always
4192 points at the breakpoint address, so adjusting it further would
4193 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4196 B1 0x08000000 : INSN1
4197 B2 0x08000001 : INSN2
4199 PC -> 0x08000003 : INSN4
4201 Say you're stopped at 0x08000003 as above. Reverse continuing
4202 from that point should hit B2 as below. Reading the PC when the
4203 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4204 been de-executed already.
4206 B1 0x08000000 : INSN1
4207 B2 PC -> 0x08000001 : INSN2
4211 We can't apply the same logic as for forward execution, because
4212 we would wrongly adjust the PC to 0x08000000, since there's a
4213 breakpoint at PC - 1. We'd then report a hit on B1, although
4214 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4216 if (execution_direction
== EXEC_REVERSE
)
4219 /* If the target can tell whether the thread hit a SW breakpoint,
4220 trust it. Targets that can tell also adjust the PC
4222 if (target_supports_stopped_by_sw_breakpoint ())
4225 /* Note that relying on whether a breakpoint is planted in memory to
4226 determine this can fail. E.g,. the breakpoint could have been
4227 removed since. Or the thread could have been told to step an
4228 instruction the size of a breakpoint instruction, and only
4229 _after_ was a breakpoint inserted at its address. */
4231 /* If this target does not decrement the PC after breakpoints, then
4232 we have nothing to do. */
4233 regcache
= get_thread_regcache (thread
);
4234 gdbarch
= regcache
->arch ();
4236 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4240 const address_space
*aspace
= regcache
->aspace ();
4242 /* Find the location where (if we've hit a breakpoint) the
4243 breakpoint would be. */
4244 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4246 /* If the target can't tell whether a software breakpoint triggered,
4247 fallback to figuring it out based on breakpoints we think were
4248 inserted in the target, and on whether the thread was stepped or
4251 /* Check whether there actually is a software breakpoint inserted at
4254 If in non-stop mode, a race condition is possible where we've
4255 removed a breakpoint, but stop events for that breakpoint were
4256 already queued and arrive later. To suppress those spurious
4257 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4258 and retire them after a number of stop events are reported. Note
4259 this is an heuristic and can thus get confused. The real fix is
4260 to get the "stopped by SW BP and needs adjustment" info out of
4261 the target/kernel (and thus never reach here; see above). */
4262 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4263 || (target_is_non_stop_p ()
4264 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4266 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4268 if (record_full_is_used ())
4269 restore_operation_disable
.emplace
4270 (record_full_gdb_operation_disable_set ());
4272 /* When using hardware single-step, a SIGTRAP is reported for both
4273 a completed single-step and a software breakpoint. Need to
4274 differentiate between the two, as the latter needs adjusting
4275 but the former does not.
4277 The SIGTRAP can be due to a completed hardware single-step only if
4278 - we didn't insert software single-step breakpoints
4279 - this thread is currently being stepped
4281 If any of these events did not occur, we must have stopped due
4282 to hitting a software breakpoint, and have to back up to the
4285 As a special case, we could have hardware single-stepped a
4286 software breakpoint. In this case (prev_pc == breakpoint_pc),
4287 we also need to back up to the breakpoint address. */
4289 if (thread_has_single_step_breakpoints_set (thread
)
4290 || !currently_stepping (thread
)
4291 || (thread
->stepped_breakpoint
4292 && thread
->prev_pc
== breakpoint_pc
))
4293 regcache_write_pc (regcache
, breakpoint_pc
);
4298 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4300 for (frame
= get_prev_frame (frame
);
4302 frame
= get_prev_frame (frame
))
4304 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4306 if (get_frame_type (frame
) != INLINE_FRAME
)
4313 /* Look for an inline frame that is marked for skip.
4314 If PREV_FRAME is TRUE start at the previous frame,
4315 otherwise start at the current frame. Stop at the
4316 first non-inline frame, or at the frame where the
4320 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4322 struct frame_info
*frame
= get_current_frame ();
4325 frame
= get_prev_frame (frame
);
4327 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4329 const char *fn
= NULL
;
4330 symtab_and_line sal
;
4333 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4335 if (get_frame_type (frame
) != INLINE_FRAME
)
4338 sal
= find_frame_sal (frame
);
4339 sym
= get_frame_function (frame
);
4342 fn
= sym
->print_name ();
4345 && function_name_is_marked_for_skip (fn
, sal
))
4352 /* If the event thread has the stop requested flag set, pretend it
4353 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4357 handle_stop_requested (struct execution_control_state
*ecs
)
4359 if (ecs
->event_thread
->stop_requested
)
4361 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4362 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4363 handle_signal_stop (ecs
);
4369 /* Auxiliary function that handles syscall entry/return events.
4370 It returns 1 if the inferior should keep going (and GDB
4371 should ignore the event), or 0 if the event deserves to be
4375 handle_syscall_event (struct execution_control_state
*ecs
)
4377 struct regcache
*regcache
;
4380 context_switch (ecs
);
4382 regcache
= get_thread_regcache (ecs
->event_thread
);
4383 syscall_number
= ecs
->ws
.value
.syscall_number
;
4384 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4386 if (catch_syscall_enabled () > 0
4387 && catching_syscall_number (syscall_number
) > 0)
4390 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4393 ecs
->event_thread
->control
.stop_bpstat
4394 = bpstat_stop_status (regcache
->aspace (),
4395 ecs
->event_thread
->suspend
.stop_pc
,
4396 ecs
->event_thread
, &ecs
->ws
);
4398 if (handle_stop_requested (ecs
))
4401 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4403 /* Catchpoint hit. */
4408 if (handle_stop_requested (ecs
))
4411 /* If no catchpoint triggered for this, then keep going. */
4416 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4419 fill_in_stop_func (struct gdbarch
*gdbarch
,
4420 struct execution_control_state
*ecs
)
4422 if (!ecs
->stop_func_filled_in
)
4426 /* Don't care about return value; stop_func_start and stop_func_name
4427 will both be 0 if it doesn't work. */
4428 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4429 &ecs
->stop_func_name
,
4430 &ecs
->stop_func_start
,
4431 &ecs
->stop_func_end
,
4434 /* The call to find_pc_partial_function, above, will set
4435 stop_func_start and stop_func_end to the start and end
4436 of the range containing the stop pc. If this range
4437 contains the entry pc for the block (which is always the
4438 case for contiguous blocks), advance stop_func_start past
4439 the function's start offset and entrypoint. Note that
4440 stop_func_start is NOT advanced when in a range of a
4441 non-contiguous block that does not contain the entry pc. */
4442 if (block
!= nullptr
4443 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4444 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4446 ecs
->stop_func_start
4447 += gdbarch_deprecated_function_start_offset (gdbarch
);
4449 if (gdbarch_skip_entrypoint_p (gdbarch
))
4450 ecs
->stop_func_start
4451 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4454 ecs
->stop_func_filled_in
= 1;
4459 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4461 static enum stop_kind
4462 get_inferior_stop_soon (execution_control_state
*ecs
)
4464 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4466 gdb_assert (inf
!= NULL
);
4467 return inf
->control
.stop_soon
;
4470 /* Poll for one event out of the current target. Store the resulting
4471 waitstatus in WS, and return the event ptid. Does not block. */
4474 poll_one_curr_target (struct target_waitstatus
*ws
)
4478 overlay_cache_invalid
= 1;
4480 /* Flush target cache before starting to handle each event.
4481 Target was running and cache could be stale. This is just a
4482 heuristic. Running threads may modify target memory, but we
4483 don't get any event. */
4484 target_dcache_invalidate ();
4486 if (deprecated_target_wait_hook
)
4487 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4489 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4492 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4497 /* An event reported by wait_one. */
4499 struct wait_one_event
4501 /* The target the event came out of. */
4502 process_stratum_target
*target
;
4504 /* The PTID the event was for. */
4507 /* The waitstatus. */
4508 target_waitstatus ws
;
4511 /* Wait for one event out of any target. */
4513 static wait_one_event
4518 for (inferior
*inf
: all_inferiors ())
4520 process_stratum_target
*target
= inf
->process_target ();
4522 || !target
->is_async_p ()
4523 || !target
->threads_executing
)
4526 switch_to_inferior_no_thread (inf
);
4528 wait_one_event event
;
4529 event
.target
= target
;
4530 event
.ptid
= poll_one_curr_target (&event
.ws
);
4532 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4534 /* If nothing is resumed, remove the target from the
4538 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4542 /* Block waiting for some event. */
4549 for (inferior
*inf
: all_inferiors ())
4551 process_stratum_target
*target
= inf
->process_target ();
4553 || !target
->is_async_p ()
4554 || !target
->threads_executing
)
4557 int fd
= target
->async_wait_fd ();
4558 FD_SET (fd
, &readfds
);
4565 /* No waitable targets left. All must be stopped. */
4566 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4571 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4577 perror_with_name ("interruptible_select");
4582 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4583 instead of the current thread. */
4584 #define THREAD_STOPPED_BY(REASON) \
4586 thread_stopped_by_ ## REASON (ptid_t ptid) \
4588 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4589 inferior_ptid = ptid; \
4591 return target_stopped_by_ ## REASON (); \
4594 /* Generate thread_stopped_by_watchpoint. */
4595 THREAD_STOPPED_BY (watchpoint
)
4596 /* Generate thread_stopped_by_sw_breakpoint. */
4597 THREAD_STOPPED_BY (sw_breakpoint
)
4598 /* Generate thread_stopped_by_hw_breakpoint. */
4599 THREAD_STOPPED_BY (hw_breakpoint
)
4601 /* Save the thread's event and stop reason to process it later. */
4604 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4608 std::string statstr
= target_waitstatus_to_string (ws
);
4610 fprintf_unfiltered (gdb_stdlog
,
4611 "infrun: saving status %s for %d.%ld.%ld\n",
4618 /* Record for later. */
4619 tp
->suspend
.waitstatus
= *ws
;
4620 tp
->suspend
.waitstatus_pending_p
= 1;
4622 struct regcache
*regcache
= get_thread_regcache (tp
);
4623 const address_space
*aspace
= regcache
->aspace ();
4625 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4626 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4628 CORE_ADDR pc
= regcache_read_pc (regcache
);
4630 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4632 if (thread_stopped_by_watchpoint (tp
->ptid
))
4634 tp
->suspend
.stop_reason
4635 = TARGET_STOPPED_BY_WATCHPOINT
;
4637 else if (target_supports_stopped_by_sw_breakpoint ()
4638 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4640 tp
->suspend
.stop_reason
4641 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4643 else if (target_supports_stopped_by_hw_breakpoint ()
4644 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4646 tp
->suspend
.stop_reason
4647 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4649 else if (!target_supports_stopped_by_hw_breakpoint ()
4650 && hardware_breakpoint_inserted_here_p (aspace
,
4653 tp
->suspend
.stop_reason
4654 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4656 else if (!target_supports_stopped_by_sw_breakpoint ()
4657 && software_breakpoint_inserted_here_p (aspace
,
4660 tp
->suspend
.stop_reason
4661 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4663 else if (!thread_has_single_step_breakpoints_set (tp
)
4664 && currently_stepping (tp
))
4666 tp
->suspend
.stop_reason
4667 = TARGET_STOPPED_BY_SINGLE_STEP
;
4675 stop_all_threads (void)
4677 /* We may need multiple passes to discover all threads. */
4681 gdb_assert (target_is_non_stop_p ());
4684 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4686 scoped_restore_current_thread restore_thread
;
4688 target_thread_events (1);
4689 SCOPE_EXIT
{ target_thread_events (0); };
4691 /* Request threads to stop, and then wait for the stops. Because
4692 threads we already know about can spawn more threads while we're
4693 trying to stop them, and we only learn about new threads when we
4694 update the thread list, do this in a loop, and keep iterating
4695 until two passes find no threads that need to be stopped. */
4696 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4699 fprintf_unfiltered (gdb_stdlog
,
4700 "infrun: stop_all_threads, pass=%d, "
4701 "iterations=%d\n", pass
, iterations
);
4706 update_thread_list ();
4708 /* Go through all threads looking for threads that we need
4709 to tell the target to stop. */
4710 for (thread_info
*t
: all_non_exited_threads ())
4714 /* If already stopping, don't request a stop again.
4715 We just haven't seen the notification yet. */
4716 if (!t
->stop_requested
)
4719 fprintf_unfiltered (gdb_stdlog
,
4720 "infrun: %s executing, "
4722 target_pid_to_str (t
->ptid
).c_str ());
4723 switch_to_thread_no_regs (t
);
4724 target_stop (t
->ptid
);
4725 t
->stop_requested
= 1;
4730 fprintf_unfiltered (gdb_stdlog
,
4731 "infrun: %s executing, "
4732 "already stopping\n",
4733 target_pid_to_str (t
->ptid
).c_str ());
4736 if (t
->stop_requested
)
4742 fprintf_unfiltered (gdb_stdlog
,
4743 "infrun: %s not executing\n",
4744 target_pid_to_str (t
->ptid
).c_str ());
4746 /* The thread may be not executing, but still be
4747 resumed with a pending status to process. */
4755 /* If we find new threads on the second iteration, restart
4756 over. We want to see two iterations in a row with all
4761 wait_one_event event
= wait_one ();
4765 fprintf_unfiltered (gdb_stdlog
,
4766 "infrun: stop_all_threads %s %s\n",
4767 target_waitstatus_to_string (&event
.ws
).c_str (),
4768 target_pid_to_str (event
.ptid
).c_str ());
4771 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4772 || event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4773 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4774 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4776 /* All resumed threads exited
4777 or one thread/process exited/signalled. */
4781 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4783 t
= add_thread (event
.target
, event
.ptid
);
4785 t
->stop_requested
= 0;
4788 t
->control
.may_range_step
= 0;
4790 /* This may be the first time we see the inferior report
4792 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4793 if (inf
->needs_setup
)
4795 switch_to_thread_no_regs (t
);
4799 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4800 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4802 /* We caught the event that we intended to catch, so
4803 there's no event pending. */
4804 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4805 t
->suspend
.waitstatus_pending_p
= 0;
4807 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4809 /* Add it back to the step-over queue. */
4812 fprintf_unfiltered (gdb_stdlog
,
4813 "infrun: displaced-step of %s "
4814 "canceled: adding back to the "
4815 "step-over queue\n",
4816 target_pid_to_str (t
->ptid
).c_str ());
4818 t
->control
.trap_expected
= 0;
4819 thread_step_over_chain_enqueue (t
);
4824 enum gdb_signal sig
;
4825 struct regcache
*regcache
;
4829 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4831 fprintf_unfiltered (gdb_stdlog
,
4832 "infrun: target_wait %s, saving "
4833 "status for %d.%ld.%ld\n",
4840 /* Record for later. */
4841 save_waitstatus (t
, &event
.ws
);
4843 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4844 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4846 if (displaced_step_fixup (t
, sig
) < 0)
4848 /* Add it back to the step-over queue. */
4849 t
->control
.trap_expected
= 0;
4850 thread_step_over_chain_enqueue (t
);
4853 regcache
= get_thread_regcache (t
);
4854 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4858 fprintf_unfiltered (gdb_stdlog
,
4859 "infrun: saved stop_pc=%s for %s "
4860 "(currently_stepping=%d)\n",
4861 paddress (target_gdbarch (),
4862 t
->suspend
.stop_pc
),
4863 target_pid_to_str (t
->ptid
).c_str (),
4864 currently_stepping (t
));
4872 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4875 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4878 handle_no_resumed (struct execution_control_state
*ecs
)
4880 if (target_can_async_p ())
4887 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4895 /* There were no unwaited-for children left in the target, but,
4896 we're not synchronously waiting for events either. Just
4900 fprintf_unfiltered (gdb_stdlog
,
4901 "infrun: TARGET_WAITKIND_NO_RESUMED "
4902 "(ignoring: bg)\n");
4903 prepare_to_wait (ecs
);
4908 /* Otherwise, if we were running a synchronous execution command, we
4909 may need to cancel it and give the user back the terminal.
4911 In non-stop mode, the target can't tell whether we've already
4912 consumed previous stop events, so it can end up sending us a
4913 no-resumed event like so:
4915 #0 - thread 1 is left stopped
4917 #1 - thread 2 is resumed and hits breakpoint
4918 -> TARGET_WAITKIND_STOPPED
4920 #2 - thread 3 is resumed and exits
4921 this is the last resumed thread, so
4922 -> TARGET_WAITKIND_NO_RESUMED
4924 #3 - gdb processes stop for thread 2 and decides to re-resume
4927 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4928 thread 2 is now resumed, so the event should be ignored.
4930 IOW, if the stop for thread 2 doesn't end a foreground command,
4931 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4932 event. But it could be that the event meant that thread 2 itself
4933 (or whatever other thread was the last resumed thread) exited.
4935 To address this we refresh the thread list and check whether we
4936 have resumed threads _now_. In the example above, this removes
4937 thread 3 from the thread list. If thread 2 was re-resumed, we
4938 ignore this event. If we find no thread resumed, then we cancel
4939 the synchronous command show "no unwaited-for " to the user. */
4940 update_thread_list ();
4942 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4944 if (thread
->executing
4945 || thread
->suspend
.waitstatus_pending_p
)
4947 /* There were no unwaited-for children left in the target at
4948 some point, but there are now. Just ignore. */
4950 fprintf_unfiltered (gdb_stdlog
,
4951 "infrun: TARGET_WAITKIND_NO_RESUMED "
4952 "(ignoring: found resumed)\n");
4953 prepare_to_wait (ecs
);
4958 /* Note however that we may find no resumed thread because the whole
4959 process exited meanwhile (thus updating the thread list results
4960 in an empty thread list). In this case we know we'll be getting
4961 a process exit event shortly. */
4962 for (inferior
*inf
: all_non_exited_inferiors (ecs
->target
))
4964 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4968 fprintf_unfiltered (gdb_stdlog
,
4969 "infrun: TARGET_WAITKIND_NO_RESUMED "
4970 "(expect process exit)\n");
4971 prepare_to_wait (ecs
);
4976 /* Go ahead and report the event. */
4980 /* Given an execution control state that has been freshly filled in by
4981 an event from the inferior, figure out what it means and take
4984 The alternatives are:
4986 1) stop_waiting and return; to really stop and return to the
4989 2) keep_going and return; to wait for the next event (set
4990 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4994 handle_inferior_event (struct execution_control_state
*ecs
)
4996 /* Make sure that all temporary struct value objects that were
4997 created during the handling of the event get deleted at the
4999 scoped_value_mark free_values
;
5001 enum stop_kind stop_soon
;
5004 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5005 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5007 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5009 /* We had an event in the inferior, but we are not interested in
5010 handling it at this level. The lower layers have already
5011 done what needs to be done, if anything.
5013 One of the possible circumstances for this is when the
5014 inferior produces output for the console. The inferior has
5015 not stopped, and we are ignoring the event. Another possible
5016 circumstance is any event which the lower level knows will be
5017 reported multiple times without an intervening resume. */
5018 prepare_to_wait (ecs
);
5022 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5024 prepare_to_wait (ecs
);
5028 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5029 && handle_no_resumed (ecs
))
5032 /* Cache the last target/ptid/waitstatus. */
5033 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5035 /* Always clear state belonging to the previous time we stopped. */
5036 stop_stack_dummy
= STOP_NONE
;
5038 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5040 /* No unwaited-for children left. IOW, all resumed children
5042 stop_print_frame
= 0;
5047 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5048 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5050 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5051 /* If it's a new thread, add it to the thread database. */
5052 if (ecs
->event_thread
== NULL
)
5053 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5055 /* Disable range stepping. If the next step request could use a
5056 range, this will be end up re-enabled then. */
5057 ecs
->event_thread
->control
.may_range_step
= 0;
5060 /* Dependent on valid ECS->EVENT_THREAD. */
5061 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5063 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5064 reinit_frame_cache ();
5066 breakpoint_retire_moribund ();
5068 /* First, distinguish signals caused by the debugger from signals
5069 that have to do with the program's own actions. Note that
5070 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5071 on the operating system version. Here we detect when a SIGILL or
5072 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5073 something similar for SIGSEGV, since a SIGSEGV will be generated
5074 when we're trying to execute a breakpoint instruction on a
5075 non-executable stack. This happens for call dummy breakpoints
5076 for architectures like SPARC that place call dummies on the
5078 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5079 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5080 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5081 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5083 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5085 if (breakpoint_inserted_here_p (regcache
->aspace (),
5086 regcache_read_pc (regcache
)))
5089 fprintf_unfiltered (gdb_stdlog
,
5090 "infrun: Treating signal as SIGTRAP\n");
5091 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5095 /* Mark the non-executing threads accordingly. In all-stop, all
5096 threads of all processes are stopped when we get any event
5097 reported. In non-stop mode, only the event thread stops. */
5101 if (!target_is_non_stop_p ())
5102 mark_ptid
= minus_one_ptid
;
5103 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
5104 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5106 /* If we're handling a process exit in non-stop mode, even
5107 though threads haven't been deleted yet, one would think
5108 that there is nothing to do, as threads of the dead process
5109 will be soon deleted, and threads of any other process were
5110 left running. However, on some targets, threads survive a
5111 process exit event. E.g., for the "checkpoint" command,
5112 when the current checkpoint/fork exits, linux-fork.c
5113 automatically switches to another fork from within
5114 target_mourn_inferior, by associating the same
5115 inferior/thread to another fork. We haven't mourned yet at
5116 this point, but we must mark any threads left in the
5117 process as not-executing so that finish_thread_state marks
5118 them stopped (in the user's perspective) if/when we present
5119 the stop to the user. */
5120 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
5123 mark_ptid
= ecs
->ptid
;
5125 set_executing (ecs
->target
, mark_ptid
, false);
5127 /* Likewise the resumed flag. */
5128 set_resumed (ecs
->target
, mark_ptid
, false);
5131 switch (ecs
->ws
.kind
)
5133 case TARGET_WAITKIND_LOADED
:
5134 context_switch (ecs
);
5135 /* Ignore gracefully during startup of the inferior, as it might
5136 be the shell which has just loaded some objects, otherwise
5137 add the symbols for the newly loaded objects. Also ignore at
5138 the beginning of an attach or remote session; we will query
5139 the full list of libraries once the connection is
5142 stop_soon
= get_inferior_stop_soon (ecs
);
5143 if (stop_soon
== NO_STOP_QUIETLY
)
5145 struct regcache
*regcache
;
5147 regcache
= get_thread_regcache (ecs
->event_thread
);
5149 handle_solib_event ();
5151 ecs
->event_thread
->control
.stop_bpstat
5152 = bpstat_stop_status (regcache
->aspace (),
5153 ecs
->event_thread
->suspend
.stop_pc
,
5154 ecs
->event_thread
, &ecs
->ws
);
5156 if (handle_stop_requested (ecs
))
5159 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5161 /* A catchpoint triggered. */
5162 process_event_stop_test (ecs
);
5166 /* If requested, stop when the dynamic linker notifies
5167 gdb of events. This allows the user to get control
5168 and place breakpoints in initializer routines for
5169 dynamically loaded objects (among other things). */
5170 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5171 if (stop_on_solib_events
)
5173 /* Make sure we print "Stopped due to solib-event" in
5175 stop_print_frame
= 1;
5182 /* If we are skipping through a shell, or through shared library
5183 loading that we aren't interested in, resume the program. If
5184 we're running the program normally, also resume. */
5185 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5187 /* Loading of shared libraries might have changed breakpoint
5188 addresses. Make sure new breakpoints are inserted. */
5189 if (stop_soon
== NO_STOP_QUIETLY
)
5190 insert_breakpoints ();
5191 resume (GDB_SIGNAL_0
);
5192 prepare_to_wait (ecs
);
5196 /* But stop if we're attaching or setting up a remote
5198 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5199 || stop_soon
== STOP_QUIETLY_REMOTE
)
5202 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5207 internal_error (__FILE__
, __LINE__
,
5208 _("unhandled stop_soon: %d"), (int) stop_soon
);
5210 case TARGET_WAITKIND_SPURIOUS
:
5211 if (handle_stop_requested (ecs
))
5213 context_switch (ecs
);
5214 resume (GDB_SIGNAL_0
);
5215 prepare_to_wait (ecs
);
5218 case TARGET_WAITKIND_THREAD_CREATED
:
5219 if (handle_stop_requested (ecs
))
5221 context_switch (ecs
);
5222 if (!switch_back_to_stepped_thread (ecs
))
5226 case TARGET_WAITKIND_EXITED
:
5227 case TARGET_WAITKIND_SIGNALLED
:
5228 inferior_ptid
= ecs
->ptid
;
5229 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5230 set_current_program_space (current_inferior ()->pspace
);
5231 handle_vfork_child_exec_or_exit (0);
5232 target_terminal::ours (); /* Must do this before mourn anyway. */
5234 /* Clearing any previous state of convenience variables. */
5235 clear_exit_convenience_vars ();
5237 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5239 /* Record the exit code in the convenience variable $_exitcode, so
5240 that the user can inspect this again later. */
5241 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5242 (LONGEST
) ecs
->ws
.value
.integer
);
5244 /* Also record this in the inferior itself. */
5245 current_inferior ()->has_exit_code
= 1;
5246 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5248 /* Support the --return-child-result option. */
5249 return_child_result_value
= ecs
->ws
.value
.integer
;
5251 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5255 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5257 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5259 /* Set the value of the internal variable $_exitsignal,
5260 which holds the signal uncaught by the inferior. */
5261 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5262 gdbarch_gdb_signal_to_target (gdbarch
,
5263 ecs
->ws
.value
.sig
));
5267 /* We don't have access to the target's method used for
5268 converting between signal numbers (GDB's internal
5269 representation <-> target's representation).
5270 Therefore, we cannot do a good job at displaying this
5271 information to the user. It's better to just warn
5272 her about it (if infrun debugging is enabled), and
5275 fprintf_filtered (gdb_stdlog
, _("\
5276 Cannot fill $_exitsignal with the correct signal number.\n"));
5279 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5282 gdb_flush (gdb_stdout
);
5283 target_mourn_inferior (inferior_ptid
);
5284 stop_print_frame
= 0;
5288 case TARGET_WAITKIND_FORKED
:
5289 case TARGET_WAITKIND_VFORKED
:
5290 /* Check whether the inferior is displaced stepping. */
5292 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5293 struct gdbarch
*gdbarch
= regcache
->arch ();
5295 /* If checking displaced stepping is supported, and thread
5296 ecs->ptid is displaced stepping. */
5297 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5299 struct inferior
*parent_inf
5300 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5301 struct regcache
*child_regcache
;
5302 CORE_ADDR parent_pc
;
5304 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5306 struct displaced_step_inferior_state
*displaced
5307 = get_displaced_stepping_state (parent_inf
);
5309 /* Restore scratch pad for child process. */
5310 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5313 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5314 indicating that the displaced stepping of syscall instruction
5315 has been done. Perform cleanup for parent process here. Note
5316 that this operation also cleans up the child process for vfork,
5317 because their pages are shared. */
5318 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5319 /* Start a new step-over in another thread if there's one
5323 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5324 the child's PC is also within the scratchpad. Set the child's PC
5325 to the parent's PC value, which has already been fixed up.
5326 FIXME: we use the parent's aspace here, although we're touching
5327 the child, because the child hasn't been added to the inferior
5328 list yet at this point. */
5331 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5332 ecs
->ws
.value
.related_pid
,
5334 parent_inf
->aspace
);
5335 /* Read PC value of parent process. */
5336 parent_pc
= regcache_read_pc (regcache
);
5338 if (debug_displaced
)
5339 fprintf_unfiltered (gdb_stdlog
,
5340 "displaced: write child pc from %s to %s\n",
5342 regcache_read_pc (child_regcache
)),
5343 paddress (gdbarch
, parent_pc
));
5345 regcache_write_pc (child_regcache
, parent_pc
);
5349 context_switch (ecs
);
5351 /* Immediately detach breakpoints from the child before there's
5352 any chance of letting the user delete breakpoints from the
5353 breakpoint lists. If we don't do this early, it's easy to
5354 leave left over traps in the child, vis: "break foo; catch
5355 fork; c; <fork>; del; c; <child calls foo>". We only follow
5356 the fork on the last `continue', and by that time the
5357 breakpoint at "foo" is long gone from the breakpoint table.
5358 If we vforked, then we don't need to unpatch here, since both
5359 parent and child are sharing the same memory pages; we'll
5360 need to unpatch at follow/detach time instead to be certain
5361 that new breakpoints added between catchpoint hit time and
5362 vfork follow are detached. */
5363 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5365 /* This won't actually modify the breakpoint list, but will
5366 physically remove the breakpoints from the child. */
5367 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5370 delete_just_stopped_threads_single_step_breakpoints ();
5372 /* In case the event is caught by a catchpoint, remember that
5373 the event is to be followed at the next resume of the thread,
5374 and not immediately. */
5375 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5377 ecs
->event_thread
->suspend
.stop_pc
5378 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5380 ecs
->event_thread
->control
.stop_bpstat
5381 = bpstat_stop_status (get_current_regcache ()->aspace (),
5382 ecs
->event_thread
->suspend
.stop_pc
,
5383 ecs
->event_thread
, &ecs
->ws
);
5385 if (handle_stop_requested (ecs
))
5388 /* If no catchpoint triggered for this, then keep going. Note
5389 that we're interested in knowing the bpstat actually causes a
5390 stop, not just if it may explain the signal. Software
5391 watchpoints, for example, always appear in the bpstat. */
5392 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5396 = (follow_fork_mode_string
== follow_fork_mode_child
);
5398 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5400 process_stratum_target
*targ
5401 = ecs
->event_thread
->inf
->process_target ();
5403 should_resume
= follow_fork ();
5405 /* Note that one of these may be an invalid pointer,
5406 depending on detach_fork. */
5407 thread_info
*parent
= ecs
->event_thread
;
5409 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5411 /* At this point, the parent is marked running, and the
5412 child is marked stopped. */
5414 /* If not resuming the parent, mark it stopped. */
5415 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5416 parent
->set_running (false);
5418 /* If resuming the child, mark it running. */
5419 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5420 child
->set_running (true);
5422 /* In non-stop mode, also resume the other branch. */
5423 if (!detach_fork
&& (non_stop
5424 || (sched_multi
&& target_is_non_stop_p ())))
5427 switch_to_thread (parent
);
5429 switch_to_thread (child
);
5431 ecs
->event_thread
= inferior_thread ();
5432 ecs
->ptid
= inferior_ptid
;
5437 switch_to_thread (child
);
5439 switch_to_thread (parent
);
5441 ecs
->event_thread
= inferior_thread ();
5442 ecs
->ptid
= inferior_ptid
;
5450 process_event_stop_test (ecs
);
5453 case TARGET_WAITKIND_VFORK_DONE
:
5454 /* Done with the shared memory region. Re-insert breakpoints in
5455 the parent, and keep going. */
5457 context_switch (ecs
);
5459 current_inferior ()->waiting_for_vfork_done
= 0;
5460 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5462 if (handle_stop_requested (ecs
))
5465 /* This also takes care of reinserting breakpoints in the
5466 previously locked inferior. */
5470 case TARGET_WAITKIND_EXECD
:
5472 /* Note we can't read registers yet (the stop_pc), because we
5473 don't yet know the inferior's post-exec architecture.
5474 'stop_pc' is explicitly read below instead. */
5475 switch_to_thread_no_regs (ecs
->event_thread
);
5477 /* Do whatever is necessary to the parent branch of the vfork. */
5478 handle_vfork_child_exec_or_exit (1);
5480 /* This causes the eventpoints and symbol table to be reset.
5481 Must do this now, before trying to determine whether to
5483 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5485 /* In follow_exec we may have deleted the original thread and
5486 created a new one. Make sure that the event thread is the
5487 execd thread for that case (this is a nop otherwise). */
5488 ecs
->event_thread
= inferior_thread ();
5490 ecs
->event_thread
->suspend
.stop_pc
5491 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5493 ecs
->event_thread
->control
.stop_bpstat
5494 = bpstat_stop_status (get_current_regcache ()->aspace (),
5495 ecs
->event_thread
->suspend
.stop_pc
,
5496 ecs
->event_thread
, &ecs
->ws
);
5498 /* Note that this may be referenced from inside
5499 bpstat_stop_status above, through inferior_has_execd. */
5500 xfree (ecs
->ws
.value
.execd_pathname
);
5501 ecs
->ws
.value
.execd_pathname
= NULL
;
5503 if (handle_stop_requested (ecs
))
5506 /* If no catchpoint triggered for this, then keep going. */
5507 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5509 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5513 process_event_stop_test (ecs
);
5516 /* Be careful not to try to gather much state about a thread
5517 that's in a syscall. It's frequently a losing proposition. */
5518 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5519 /* Getting the current syscall number. */
5520 if (handle_syscall_event (ecs
) == 0)
5521 process_event_stop_test (ecs
);
5524 /* Before examining the threads further, step this thread to
5525 get it entirely out of the syscall. (We get notice of the
5526 event when the thread is just on the verge of exiting a
5527 syscall. Stepping one instruction seems to get it back
5529 case TARGET_WAITKIND_SYSCALL_RETURN
:
5530 if (handle_syscall_event (ecs
) == 0)
5531 process_event_stop_test (ecs
);
5534 case TARGET_WAITKIND_STOPPED
:
5535 handle_signal_stop (ecs
);
5538 case TARGET_WAITKIND_NO_HISTORY
:
5539 /* Reverse execution: target ran out of history info. */
5541 /* Switch to the stopped thread. */
5542 context_switch (ecs
);
5544 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5546 delete_just_stopped_threads_single_step_breakpoints ();
5547 ecs
->event_thread
->suspend
.stop_pc
5548 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5550 if (handle_stop_requested (ecs
))
5553 gdb::observers::no_history
.notify ();
5559 /* Restart threads back to what they were trying to do back when we
5560 paused them for an in-line step-over. The EVENT_THREAD thread is
5564 restart_threads (struct thread_info
*event_thread
)
5566 /* In case the instruction just stepped spawned a new thread. */
5567 update_thread_list ();
5569 for (thread_info
*tp
: all_non_exited_threads ())
5571 switch_to_thread_no_regs (tp
);
5573 if (tp
== event_thread
)
5576 fprintf_unfiltered (gdb_stdlog
,
5577 "infrun: restart threads: "
5578 "[%s] is event thread\n",
5579 target_pid_to_str (tp
->ptid
).c_str ());
5583 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5586 fprintf_unfiltered (gdb_stdlog
,
5587 "infrun: restart threads: "
5588 "[%s] not meant to be running\n",
5589 target_pid_to_str (tp
->ptid
).c_str ());
5596 fprintf_unfiltered (gdb_stdlog
,
5597 "infrun: restart threads: [%s] resumed\n",
5598 target_pid_to_str (tp
->ptid
).c_str ());
5599 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5603 if (thread_is_in_step_over_chain (tp
))
5606 fprintf_unfiltered (gdb_stdlog
,
5607 "infrun: restart threads: "
5608 "[%s] needs step-over\n",
5609 target_pid_to_str (tp
->ptid
).c_str ());
5610 gdb_assert (!tp
->resumed
);
5615 if (tp
->suspend
.waitstatus_pending_p
)
5618 fprintf_unfiltered (gdb_stdlog
,
5619 "infrun: restart threads: "
5620 "[%s] has pending status\n",
5621 target_pid_to_str (tp
->ptid
).c_str ());
5626 gdb_assert (!tp
->stop_requested
);
5628 /* If some thread needs to start a step-over at this point, it
5629 should still be in the step-over queue, and thus skipped
5631 if (thread_still_needs_step_over (tp
))
5633 internal_error (__FILE__
, __LINE__
,
5634 "thread [%s] needs a step-over, but not in "
5635 "step-over queue\n",
5636 target_pid_to_str (tp
->ptid
).c_str ());
5639 if (currently_stepping (tp
))
5642 fprintf_unfiltered (gdb_stdlog
,
5643 "infrun: restart threads: [%s] was stepping\n",
5644 target_pid_to_str (tp
->ptid
).c_str ());
5645 keep_going_stepped_thread (tp
);
5649 struct execution_control_state ecss
;
5650 struct execution_control_state
*ecs
= &ecss
;
5653 fprintf_unfiltered (gdb_stdlog
,
5654 "infrun: restart threads: [%s] continuing\n",
5655 target_pid_to_str (tp
->ptid
).c_str ());
5656 reset_ecs (ecs
, tp
);
5657 switch_to_thread (tp
);
5658 keep_going_pass_signal (ecs
);
5663 /* Callback for iterate_over_threads. Find a resumed thread that has
5664 a pending waitstatus. */
5667 resumed_thread_with_pending_status (struct thread_info
*tp
,
5671 && tp
->suspend
.waitstatus_pending_p
);
5674 /* Called when we get an event that may finish an in-line or
5675 out-of-line (displaced stepping) step-over started previously.
5676 Return true if the event is processed and we should go back to the
5677 event loop; false if the caller should continue processing the
5681 finish_step_over (struct execution_control_state
*ecs
)
5683 int had_step_over_info
;
5685 displaced_step_fixup (ecs
->event_thread
,
5686 ecs
->event_thread
->suspend
.stop_signal
);
5688 had_step_over_info
= step_over_info_valid_p ();
5690 if (had_step_over_info
)
5692 /* If we're stepping over a breakpoint with all threads locked,
5693 then only the thread that was stepped should be reporting
5695 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5697 clear_step_over_info ();
5700 if (!target_is_non_stop_p ())
5703 /* Start a new step-over in another thread if there's one that
5707 /* If we were stepping over a breakpoint before, and haven't started
5708 a new in-line step-over sequence, then restart all other threads
5709 (except the event thread). We can't do this in all-stop, as then
5710 e.g., we wouldn't be able to issue any other remote packet until
5711 these other threads stop. */
5712 if (had_step_over_info
&& !step_over_info_valid_p ())
5714 struct thread_info
*pending
;
5716 /* If we only have threads with pending statuses, the restart
5717 below won't restart any thread and so nothing re-inserts the
5718 breakpoint we just stepped over. But we need it inserted
5719 when we later process the pending events, otherwise if
5720 another thread has a pending event for this breakpoint too,
5721 we'd discard its event (because the breakpoint that
5722 originally caused the event was no longer inserted). */
5723 context_switch (ecs
);
5724 insert_breakpoints ();
5726 restart_threads (ecs
->event_thread
);
5728 /* If we have events pending, go through handle_inferior_event
5729 again, picking up a pending event at random. This avoids
5730 thread starvation. */
5732 /* But not if we just stepped over a watchpoint in order to let
5733 the instruction execute so we can evaluate its expression.
5734 The set of watchpoints that triggered is recorded in the
5735 breakpoint objects themselves (see bp->watchpoint_triggered).
5736 If we processed another event first, that other event could
5737 clobber this info. */
5738 if (ecs
->event_thread
->stepping_over_watchpoint
)
5741 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5743 if (pending
!= NULL
)
5745 struct thread_info
*tp
= ecs
->event_thread
;
5746 struct regcache
*regcache
;
5750 fprintf_unfiltered (gdb_stdlog
,
5751 "infrun: found resumed threads with "
5752 "pending events, saving status\n");
5755 gdb_assert (pending
!= tp
);
5757 /* Record the event thread's event for later. */
5758 save_waitstatus (tp
, &ecs
->ws
);
5759 /* This was cleared early, by handle_inferior_event. Set it
5760 so this pending event is considered by
5764 gdb_assert (!tp
->executing
);
5766 regcache
= get_thread_regcache (tp
);
5767 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5771 fprintf_unfiltered (gdb_stdlog
,
5772 "infrun: saved stop_pc=%s for %s "
5773 "(currently_stepping=%d)\n",
5774 paddress (target_gdbarch (),
5775 tp
->suspend
.stop_pc
),
5776 target_pid_to_str (tp
->ptid
).c_str (),
5777 currently_stepping (tp
));
5780 /* This in-line step-over finished; clear this so we won't
5781 start a new one. This is what handle_signal_stop would
5782 do, if we returned false. */
5783 tp
->stepping_over_breakpoint
= 0;
5785 /* Wake up the event loop again. */
5786 mark_async_event_handler (infrun_async_inferior_event_token
);
5788 prepare_to_wait (ecs
);
5796 /* Come here when the program has stopped with a signal. */
5799 handle_signal_stop (struct execution_control_state
*ecs
)
5801 struct frame_info
*frame
;
5802 struct gdbarch
*gdbarch
;
5803 int stopped_by_watchpoint
;
5804 enum stop_kind stop_soon
;
5807 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5809 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5811 /* Do we need to clean up the state of a thread that has
5812 completed a displaced single-step? (Doing so usually affects
5813 the PC, so do it here, before we set stop_pc.) */
5814 if (finish_step_over (ecs
))
5817 /* If we either finished a single-step or hit a breakpoint, but
5818 the user wanted this thread to be stopped, pretend we got a
5819 SIG0 (generic unsignaled stop). */
5820 if (ecs
->event_thread
->stop_requested
5821 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5822 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5824 ecs
->event_thread
->suspend
.stop_pc
5825 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5829 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5830 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5832 switch_to_thread (ecs
->event_thread
);
5834 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5835 paddress (reg_gdbarch
,
5836 ecs
->event_thread
->suspend
.stop_pc
));
5837 if (target_stopped_by_watchpoint ())
5841 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5843 if (target_stopped_data_address (current_top_target (), &addr
))
5844 fprintf_unfiltered (gdb_stdlog
,
5845 "infrun: stopped data address = %s\n",
5846 paddress (reg_gdbarch
, addr
));
5848 fprintf_unfiltered (gdb_stdlog
,
5849 "infrun: (no data address available)\n");
5853 /* This is originated from start_remote(), start_inferior() and
5854 shared libraries hook functions. */
5855 stop_soon
= get_inferior_stop_soon (ecs
);
5856 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5858 context_switch (ecs
);
5860 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5861 stop_print_frame
= 1;
5866 /* This originates from attach_command(). We need to overwrite
5867 the stop_signal here, because some kernels don't ignore a
5868 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5869 See more comments in inferior.h. On the other hand, if we
5870 get a non-SIGSTOP, report it to the user - assume the backend
5871 will handle the SIGSTOP if it should show up later.
5873 Also consider that the attach is complete when we see a
5874 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5875 target extended-remote report it instead of a SIGSTOP
5876 (e.g. gdbserver). We already rely on SIGTRAP being our
5877 signal, so this is no exception.
5879 Also consider that the attach is complete when we see a
5880 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5881 the target to stop all threads of the inferior, in case the
5882 low level attach operation doesn't stop them implicitly. If
5883 they weren't stopped implicitly, then the stub will report a
5884 GDB_SIGNAL_0, meaning: stopped for no particular reason
5885 other than GDB's request. */
5886 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5887 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5888 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5889 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5891 stop_print_frame
= 1;
5893 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5897 /* See if something interesting happened to the non-current thread. If
5898 so, then switch to that thread. */
5899 if (ecs
->ptid
!= inferior_ptid
)
5902 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5904 context_switch (ecs
);
5906 if (deprecated_context_hook
)
5907 deprecated_context_hook (ecs
->event_thread
->global_num
);
5910 /* At this point, get hold of the now-current thread's frame. */
5911 frame
= get_current_frame ();
5912 gdbarch
= get_frame_arch (frame
);
5914 /* Pull the single step breakpoints out of the target. */
5915 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5917 struct regcache
*regcache
;
5920 regcache
= get_thread_regcache (ecs
->event_thread
);
5921 const address_space
*aspace
= regcache
->aspace ();
5923 pc
= regcache_read_pc (regcache
);
5925 /* However, before doing so, if this single-step breakpoint was
5926 actually for another thread, set this thread up for moving
5928 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5931 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5935 fprintf_unfiltered (gdb_stdlog
,
5936 "infrun: [%s] hit another thread's "
5937 "single-step breakpoint\n",
5938 target_pid_to_str (ecs
->ptid
).c_str ());
5940 ecs
->hit_singlestep_breakpoint
= 1;
5947 fprintf_unfiltered (gdb_stdlog
,
5948 "infrun: [%s] hit its "
5949 "single-step breakpoint\n",
5950 target_pid_to_str (ecs
->ptid
).c_str ());
5954 delete_just_stopped_threads_single_step_breakpoints ();
5956 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5957 && ecs
->event_thread
->control
.trap_expected
5958 && ecs
->event_thread
->stepping_over_watchpoint
)
5959 stopped_by_watchpoint
= 0;
5961 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5963 /* If necessary, step over this watchpoint. We'll be back to display
5965 if (stopped_by_watchpoint
5966 && (target_have_steppable_watchpoint
5967 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5969 /* At this point, we are stopped at an instruction which has
5970 attempted to write to a piece of memory under control of
5971 a watchpoint. The instruction hasn't actually executed
5972 yet. If we were to evaluate the watchpoint expression
5973 now, we would get the old value, and therefore no change
5974 would seem to have occurred.
5976 In order to make watchpoints work `right', we really need
5977 to complete the memory write, and then evaluate the
5978 watchpoint expression. We do this by single-stepping the
5981 It may not be necessary to disable the watchpoint to step over
5982 it. For example, the PA can (with some kernel cooperation)
5983 single step over a watchpoint without disabling the watchpoint.
5985 It is far more common to need to disable a watchpoint to step
5986 the inferior over it. If we have non-steppable watchpoints,
5987 we must disable the current watchpoint; it's simplest to
5988 disable all watchpoints.
5990 Any breakpoint at PC must also be stepped over -- if there's
5991 one, it will have already triggered before the watchpoint
5992 triggered, and we either already reported it to the user, or
5993 it didn't cause a stop and we called keep_going. In either
5994 case, if there was a breakpoint at PC, we must be trying to
5996 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6001 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6002 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6003 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6004 ecs
->event_thread
->control
.stop_step
= 0;
6005 stop_print_frame
= 1;
6006 stopped_by_random_signal
= 0;
6007 bpstat stop_chain
= NULL
;
6009 /* Hide inlined functions starting here, unless we just performed stepi or
6010 nexti. After stepi and nexti, always show the innermost frame (not any
6011 inline function call sites). */
6012 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6014 const address_space
*aspace
6015 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6017 /* skip_inline_frames is expensive, so we avoid it if we can
6018 determine that the address is one where functions cannot have
6019 been inlined. This improves performance with inferiors that
6020 load a lot of shared libraries, because the solib event
6021 breakpoint is defined as the address of a function (i.e. not
6022 inline). Note that we have to check the previous PC as well
6023 as the current one to catch cases when we have just
6024 single-stepped off a breakpoint prior to reinstating it.
6025 Note that we're assuming that the code we single-step to is
6026 not inline, but that's not definitive: there's nothing
6027 preventing the event breakpoint function from containing
6028 inlined code, and the single-step ending up there. If the
6029 user had set a breakpoint on that inlined code, the missing
6030 skip_inline_frames call would break things. Fortunately
6031 that's an extremely unlikely scenario. */
6032 if (!pc_at_non_inline_function (aspace
,
6033 ecs
->event_thread
->suspend
.stop_pc
,
6035 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6036 && ecs
->event_thread
->control
.trap_expected
6037 && pc_at_non_inline_function (aspace
,
6038 ecs
->event_thread
->prev_pc
,
6041 stop_chain
= build_bpstat_chain (aspace
,
6042 ecs
->event_thread
->suspend
.stop_pc
,
6044 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6046 /* Re-fetch current thread's frame in case that invalidated
6048 frame
= get_current_frame ();
6049 gdbarch
= get_frame_arch (frame
);
6053 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6054 && ecs
->event_thread
->control
.trap_expected
6055 && gdbarch_single_step_through_delay_p (gdbarch
)
6056 && currently_stepping (ecs
->event_thread
))
6058 /* We're trying to step off a breakpoint. Turns out that we're
6059 also on an instruction that needs to be stepped multiple
6060 times before it's been fully executing. E.g., architectures
6061 with a delay slot. It needs to be stepped twice, once for
6062 the instruction and once for the delay slot. */
6063 int step_through_delay
6064 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6066 if (debug_infrun
&& step_through_delay
)
6067 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6068 if (ecs
->event_thread
->control
.step_range_end
== 0
6069 && step_through_delay
)
6071 /* The user issued a continue when stopped at a breakpoint.
6072 Set up for another trap and get out of here. */
6073 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6077 else if (step_through_delay
)
6079 /* The user issued a step when stopped at a breakpoint.
6080 Maybe we should stop, maybe we should not - the delay
6081 slot *might* correspond to a line of source. In any
6082 case, don't decide that here, just set
6083 ecs->stepping_over_breakpoint, making sure we
6084 single-step again before breakpoints are re-inserted. */
6085 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6089 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6090 handles this event. */
6091 ecs
->event_thread
->control
.stop_bpstat
6092 = bpstat_stop_status (get_current_regcache ()->aspace (),
6093 ecs
->event_thread
->suspend
.stop_pc
,
6094 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6096 /* Following in case break condition called a
6098 stop_print_frame
= 1;
6100 /* This is where we handle "moribund" watchpoints. Unlike
6101 software breakpoints traps, hardware watchpoint traps are
6102 always distinguishable from random traps. If no high-level
6103 watchpoint is associated with the reported stop data address
6104 anymore, then the bpstat does not explain the signal ---
6105 simply make sure to ignore it if `stopped_by_watchpoint' is
6109 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6110 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6112 && stopped_by_watchpoint
)
6113 fprintf_unfiltered (gdb_stdlog
,
6114 "infrun: no user watchpoint explains "
6115 "watchpoint SIGTRAP, ignoring\n");
6117 /* NOTE: cagney/2003-03-29: These checks for a random signal
6118 at one stage in the past included checks for an inferior
6119 function call's call dummy's return breakpoint. The original
6120 comment, that went with the test, read:
6122 ``End of a stack dummy. Some systems (e.g. Sony news) give
6123 another signal besides SIGTRAP, so check here as well as
6126 If someone ever tries to get call dummys on a
6127 non-executable stack to work (where the target would stop
6128 with something like a SIGSEGV), then those tests might need
6129 to be re-instated. Given, however, that the tests were only
6130 enabled when momentary breakpoints were not being used, I
6131 suspect that it won't be the case.
6133 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6134 be necessary for call dummies on a non-executable stack on
6137 /* See if the breakpoints module can explain the signal. */
6139 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6140 ecs
->event_thread
->suspend
.stop_signal
);
6142 /* Maybe this was a trap for a software breakpoint that has since
6144 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6146 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6147 ecs
->event_thread
->suspend
.stop_pc
))
6149 struct regcache
*regcache
;
6152 /* Re-adjust PC to what the program would see if GDB was not
6154 regcache
= get_thread_regcache (ecs
->event_thread
);
6155 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6158 gdb::optional
<scoped_restore_tmpl
<int>>
6159 restore_operation_disable
;
6161 if (record_full_is_used ())
6162 restore_operation_disable
.emplace
6163 (record_full_gdb_operation_disable_set ());
6165 regcache_write_pc (regcache
,
6166 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6171 /* A delayed software breakpoint event. Ignore the trap. */
6173 fprintf_unfiltered (gdb_stdlog
,
6174 "infrun: delayed software breakpoint "
6175 "trap, ignoring\n");
6180 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6181 has since been removed. */
6182 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6184 /* A delayed hardware breakpoint event. Ignore the trap. */
6186 fprintf_unfiltered (gdb_stdlog
,
6187 "infrun: delayed hardware breakpoint/watchpoint "
6188 "trap, ignoring\n");
6192 /* If not, perhaps stepping/nexting can. */
6194 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6195 && currently_stepping (ecs
->event_thread
));
6197 /* Perhaps the thread hit a single-step breakpoint of _another_
6198 thread. Single-step breakpoints are transparent to the
6199 breakpoints module. */
6201 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6203 /* No? Perhaps we got a moribund watchpoint. */
6205 random_signal
= !stopped_by_watchpoint
;
6207 /* Always stop if the user explicitly requested this thread to
6209 if (ecs
->event_thread
->stop_requested
)
6213 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6216 /* For the program's own signals, act according to
6217 the signal handling tables. */
6221 /* Signal not for debugging purposes. */
6222 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6223 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6226 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6227 gdb_signal_to_symbol_string (stop_signal
));
6229 stopped_by_random_signal
= 1;
6231 /* Always stop on signals if we're either just gaining control
6232 of the program, or the user explicitly requested this thread
6233 to remain stopped. */
6234 if (stop_soon
!= NO_STOP_QUIETLY
6235 || ecs
->event_thread
->stop_requested
6237 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6243 /* Notify observers the signal has "handle print" set. Note we
6244 returned early above if stopping; normal_stop handles the
6245 printing in that case. */
6246 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6248 /* The signal table tells us to print about this signal. */
6249 target_terminal::ours_for_output ();
6250 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6251 target_terminal::inferior ();
6254 /* Clear the signal if it should not be passed. */
6255 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6256 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6258 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6259 && ecs
->event_thread
->control
.trap_expected
6260 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6262 /* We were just starting a new sequence, attempting to
6263 single-step off of a breakpoint and expecting a SIGTRAP.
6264 Instead this signal arrives. This signal will take us out
6265 of the stepping range so GDB needs to remember to, when
6266 the signal handler returns, resume stepping off that
6268 /* To simplify things, "continue" is forced to use the same
6269 code paths as single-step - set a breakpoint at the
6270 signal return address and then, once hit, step off that
6273 fprintf_unfiltered (gdb_stdlog
,
6274 "infrun: signal arrived while stepping over "
6277 insert_hp_step_resume_breakpoint_at_frame (frame
);
6278 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6279 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6280 ecs
->event_thread
->control
.trap_expected
= 0;
6282 /* If we were nexting/stepping some other thread, switch to
6283 it, so that we don't continue it, losing control. */
6284 if (!switch_back_to_stepped_thread (ecs
))
6289 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6290 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6292 || ecs
->event_thread
->control
.step_range_end
== 1)
6293 && frame_id_eq (get_stack_frame_id (frame
),
6294 ecs
->event_thread
->control
.step_stack_frame_id
)
6295 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6297 /* The inferior is about to take a signal that will take it
6298 out of the single step range. Set a breakpoint at the
6299 current PC (which is presumably where the signal handler
6300 will eventually return) and then allow the inferior to
6303 Note that this is only needed for a signal delivered
6304 while in the single-step range. Nested signals aren't a
6305 problem as they eventually all return. */
6307 fprintf_unfiltered (gdb_stdlog
,
6308 "infrun: signal may take us out of "
6309 "single-step range\n");
6311 clear_step_over_info ();
6312 insert_hp_step_resume_breakpoint_at_frame (frame
);
6313 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6314 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6315 ecs
->event_thread
->control
.trap_expected
= 0;
6320 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6321 when either there's a nested signal, or when there's a
6322 pending signal enabled just as the signal handler returns
6323 (leaving the inferior at the step-resume-breakpoint without
6324 actually executing it). Either way continue until the
6325 breakpoint is really hit. */
6327 if (!switch_back_to_stepped_thread (ecs
))
6330 fprintf_unfiltered (gdb_stdlog
,
6331 "infrun: random signal, keep going\n");
6338 process_event_stop_test (ecs
);
6341 /* Come here when we've got some debug event / signal we can explain
6342 (IOW, not a random signal), and test whether it should cause a
6343 stop, or whether we should resume the inferior (transparently).
6344 E.g., could be a breakpoint whose condition evaluates false; we
6345 could be still stepping within the line; etc. */
6348 process_event_stop_test (struct execution_control_state
*ecs
)
6350 struct symtab_and_line stop_pc_sal
;
6351 struct frame_info
*frame
;
6352 struct gdbarch
*gdbarch
;
6353 CORE_ADDR jmp_buf_pc
;
6354 struct bpstat_what what
;
6356 /* Handle cases caused by hitting a breakpoint. */
6358 frame
= get_current_frame ();
6359 gdbarch
= get_frame_arch (frame
);
6361 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6363 if (what
.call_dummy
)
6365 stop_stack_dummy
= what
.call_dummy
;
6368 /* A few breakpoint types have callbacks associated (e.g.,
6369 bp_jit_event). Run them now. */
6370 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6372 /* If we hit an internal event that triggers symbol changes, the
6373 current frame will be invalidated within bpstat_what (e.g., if we
6374 hit an internal solib event). Re-fetch it. */
6375 frame
= get_current_frame ();
6376 gdbarch
= get_frame_arch (frame
);
6378 switch (what
.main_action
)
6380 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6381 /* If we hit the breakpoint at longjmp while stepping, we
6382 install a momentary breakpoint at the target of the
6386 fprintf_unfiltered (gdb_stdlog
,
6387 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6389 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6391 if (what
.is_longjmp
)
6393 struct value
*arg_value
;
6395 /* If we set the longjmp breakpoint via a SystemTap probe,
6396 then use it to extract the arguments. The destination PC
6397 is the third argument to the probe. */
6398 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6401 jmp_buf_pc
= value_as_address (arg_value
);
6402 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6404 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6405 || !gdbarch_get_longjmp_target (gdbarch
,
6406 frame
, &jmp_buf_pc
))
6409 fprintf_unfiltered (gdb_stdlog
,
6410 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6411 "(!gdbarch_get_longjmp_target)\n");
6416 /* Insert a breakpoint at resume address. */
6417 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6420 check_exception_resume (ecs
, frame
);
6424 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6426 struct frame_info
*init_frame
;
6428 /* There are several cases to consider.
6430 1. The initiating frame no longer exists. In this case we
6431 must stop, because the exception or longjmp has gone too
6434 2. The initiating frame exists, and is the same as the
6435 current frame. We stop, because the exception or longjmp
6438 3. The initiating frame exists and is different from the
6439 current frame. This means the exception or longjmp has
6440 been caught beneath the initiating frame, so keep going.
6442 4. longjmp breakpoint has been placed just to protect
6443 against stale dummy frames and user is not interested in
6444 stopping around longjmps. */
6447 fprintf_unfiltered (gdb_stdlog
,
6448 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6450 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6452 delete_exception_resume_breakpoint (ecs
->event_thread
);
6454 if (what
.is_longjmp
)
6456 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6458 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6466 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6470 struct frame_id current_id
6471 = get_frame_id (get_current_frame ());
6472 if (frame_id_eq (current_id
,
6473 ecs
->event_thread
->initiating_frame
))
6475 /* Case 2. Fall through. */
6485 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6487 delete_step_resume_breakpoint (ecs
->event_thread
);
6489 end_stepping_range (ecs
);
6493 case BPSTAT_WHAT_SINGLE
:
6495 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6496 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6497 /* Still need to check other stuff, at least the case where we
6498 are stepping and step out of the right range. */
6501 case BPSTAT_WHAT_STEP_RESUME
:
6503 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6505 delete_step_resume_breakpoint (ecs
->event_thread
);
6506 if (ecs
->event_thread
->control
.proceed_to_finish
6507 && execution_direction
== EXEC_REVERSE
)
6509 struct thread_info
*tp
= ecs
->event_thread
;
6511 /* We are finishing a function in reverse, and just hit the
6512 step-resume breakpoint at the start address of the
6513 function, and we're almost there -- just need to back up
6514 by one more single-step, which should take us back to the
6516 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6520 fill_in_stop_func (gdbarch
, ecs
);
6521 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6522 && execution_direction
== EXEC_REVERSE
)
6524 /* We are stepping over a function call in reverse, and just
6525 hit the step-resume breakpoint at the start address of
6526 the function. Go back to single-stepping, which should
6527 take us back to the function call. */
6528 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6534 case BPSTAT_WHAT_STOP_NOISY
:
6536 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6537 stop_print_frame
= 1;
6539 /* Assume the thread stopped for a breapoint. We'll still check
6540 whether a/the breakpoint is there when the thread is next
6542 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6547 case BPSTAT_WHAT_STOP_SILENT
:
6549 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6550 stop_print_frame
= 0;
6552 /* Assume the thread stopped for a breapoint. We'll still check
6553 whether a/the breakpoint is there when the thread is next
6555 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6559 case BPSTAT_WHAT_HP_STEP_RESUME
:
6561 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6563 delete_step_resume_breakpoint (ecs
->event_thread
);
6564 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6566 /* Back when the step-resume breakpoint was inserted, we
6567 were trying to single-step off a breakpoint. Go back to
6569 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6570 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6576 case BPSTAT_WHAT_KEEP_CHECKING
:
6580 /* If we stepped a permanent breakpoint and we had a high priority
6581 step-resume breakpoint for the address we stepped, but we didn't
6582 hit it, then we must have stepped into the signal handler. The
6583 step-resume was only necessary to catch the case of _not_
6584 stepping into the handler, so delete it, and fall through to
6585 checking whether the step finished. */
6586 if (ecs
->event_thread
->stepped_breakpoint
)
6588 struct breakpoint
*sr_bp
6589 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6592 && sr_bp
->loc
->permanent
6593 && sr_bp
->type
== bp_hp_step_resume
6594 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6597 fprintf_unfiltered (gdb_stdlog
,
6598 "infrun: stepped permanent breakpoint, stopped in "
6600 delete_step_resume_breakpoint (ecs
->event_thread
);
6601 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6605 /* We come here if we hit a breakpoint but should not stop for it.
6606 Possibly we also were stepping and should stop for that. So fall
6607 through and test for stepping. But, if not stepping, do not
6610 /* In all-stop mode, if we're currently stepping but have stopped in
6611 some other thread, we need to switch back to the stepped thread. */
6612 if (switch_back_to_stepped_thread (ecs
))
6615 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6618 fprintf_unfiltered (gdb_stdlog
,
6619 "infrun: step-resume breakpoint is inserted\n");
6621 /* Having a step-resume breakpoint overrides anything
6622 else having to do with stepping commands until
6623 that breakpoint is reached. */
6628 if (ecs
->event_thread
->control
.step_range_end
== 0)
6631 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6632 /* Likewise if we aren't even stepping. */
6637 /* Re-fetch current thread's frame in case the code above caused
6638 the frame cache to be re-initialized, making our FRAME variable
6639 a dangling pointer. */
6640 frame
= get_current_frame ();
6641 gdbarch
= get_frame_arch (frame
);
6642 fill_in_stop_func (gdbarch
, ecs
);
6644 /* If stepping through a line, keep going if still within it.
6646 Note that step_range_end is the address of the first instruction
6647 beyond the step range, and NOT the address of the last instruction
6650 Note also that during reverse execution, we may be stepping
6651 through a function epilogue and therefore must detect when
6652 the current-frame changes in the middle of a line. */
6654 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6656 && (execution_direction
!= EXEC_REVERSE
6657 || frame_id_eq (get_frame_id (frame
),
6658 ecs
->event_thread
->control
.step_frame_id
)))
6662 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6663 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6664 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6666 /* Tentatively re-enable range stepping; `resume' disables it if
6667 necessary (e.g., if we're stepping over a breakpoint or we
6668 have software watchpoints). */
6669 ecs
->event_thread
->control
.may_range_step
= 1;
6671 /* When stepping backward, stop at beginning of line range
6672 (unless it's the function entry point, in which case
6673 keep going back to the call point). */
6674 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6675 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6676 && stop_pc
!= ecs
->stop_func_start
6677 && execution_direction
== EXEC_REVERSE
)
6678 end_stepping_range (ecs
);
6685 /* We stepped out of the stepping range. */
6687 /* If we are stepping at the source level and entered the runtime
6688 loader dynamic symbol resolution code...
6690 EXEC_FORWARD: we keep on single stepping until we exit the run
6691 time loader code and reach the callee's address.
6693 EXEC_REVERSE: we've already executed the callee (backward), and
6694 the runtime loader code is handled just like any other
6695 undebuggable function call. Now we need only keep stepping
6696 backward through the trampoline code, and that's handled further
6697 down, so there is nothing for us to do here. */
6699 if (execution_direction
!= EXEC_REVERSE
6700 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6701 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6703 CORE_ADDR pc_after_resolver
=
6704 gdbarch_skip_solib_resolver (gdbarch
,
6705 ecs
->event_thread
->suspend
.stop_pc
);
6708 fprintf_unfiltered (gdb_stdlog
,
6709 "infrun: stepped into dynsym resolve code\n");
6711 if (pc_after_resolver
)
6713 /* Set up a step-resume breakpoint at the address
6714 indicated by SKIP_SOLIB_RESOLVER. */
6715 symtab_and_line sr_sal
;
6716 sr_sal
.pc
= pc_after_resolver
;
6717 sr_sal
.pspace
= get_frame_program_space (frame
);
6719 insert_step_resume_breakpoint_at_sal (gdbarch
,
6720 sr_sal
, null_frame_id
);
6727 /* Step through an indirect branch thunk. */
6728 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6729 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6730 ecs
->event_thread
->suspend
.stop_pc
))
6733 fprintf_unfiltered (gdb_stdlog
,
6734 "infrun: stepped into indirect branch thunk\n");
6739 if (ecs
->event_thread
->control
.step_range_end
!= 1
6740 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6741 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6742 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6745 fprintf_unfiltered (gdb_stdlog
,
6746 "infrun: stepped into signal trampoline\n");
6747 /* The inferior, while doing a "step" or "next", has ended up in
6748 a signal trampoline (either by a signal being delivered or by
6749 the signal handler returning). Just single-step until the
6750 inferior leaves the trampoline (either by calling the handler
6756 /* If we're in the return path from a shared library trampoline,
6757 we want to proceed through the trampoline when stepping. */
6758 /* macro/2012-04-25: This needs to come before the subroutine
6759 call check below as on some targets return trampolines look
6760 like subroutine calls (MIPS16 return thunks). */
6761 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6762 ecs
->event_thread
->suspend
.stop_pc
,
6763 ecs
->stop_func_name
)
6764 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6766 /* Determine where this trampoline returns. */
6767 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6768 CORE_ADDR real_stop_pc
6769 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6772 fprintf_unfiltered (gdb_stdlog
,
6773 "infrun: stepped into solib return tramp\n");
6775 /* Only proceed through if we know where it's going. */
6778 /* And put the step-breakpoint there and go until there. */
6779 symtab_and_line sr_sal
;
6780 sr_sal
.pc
= real_stop_pc
;
6781 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6782 sr_sal
.pspace
= get_frame_program_space (frame
);
6784 /* Do not specify what the fp should be when we stop since
6785 on some machines the prologue is where the new fp value
6787 insert_step_resume_breakpoint_at_sal (gdbarch
,
6788 sr_sal
, null_frame_id
);
6790 /* Restart without fiddling with the step ranges or
6797 /* Check for subroutine calls. The check for the current frame
6798 equalling the step ID is not necessary - the check of the
6799 previous frame's ID is sufficient - but it is a common case and
6800 cheaper than checking the previous frame's ID.
6802 NOTE: frame_id_eq will never report two invalid frame IDs as
6803 being equal, so to get into this block, both the current and
6804 previous frame must have valid frame IDs. */
6805 /* The outer_frame_id check is a heuristic to detect stepping
6806 through startup code. If we step over an instruction which
6807 sets the stack pointer from an invalid value to a valid value,
6808 we may detect that as a subroutine call from the mythical
6809 "outermost" function. This could be fixed by marking
6810 outermost frames as !stack_p,code_p,special_p. Then the
6811 initial outermost frame, before sp was valid, would
6812 have code_addr == &_start. See the comment in frame_id_eq
6814 if (!frame_id_eq (get_stack_frame_id (frame
),
6815 ecs
->event_thread
->control
.step_stack_frame_id
)
6816 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6817 ecs
->event_thread
->control
.step_stack_frame_id
)
6818 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6820 || (ecs
->event_thread
->control
.step_start_function
6821 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6823 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6824 CORE_ADDR real_stop_pc
;
6827 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6829 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6831 /* I presume that step_over_calls is only 0 when we're
6832 supposed to be stepping at the assembly language level
6833 ("stepi"). Just stop. */
6834 /* And this works the same backward as frontward. MVS */
6835 end_stepping_range (ecs
);
6839 /* Reverse stepping through solib trampolines. */
6841 if (execution_direction
== EXEC_REVERSE
6842 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6843 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6844 || (ecs
->stop_func_start
== 0
6845 && in_solib_dynsym_resolve_code (stop_pc
))))
6847 /* Any solib trampoline code can be handled in reverse
6848 by simply continuing to single-step. We have already
6849 executed the solib function (backwards), and a few
6850 steps will take us back through the trampoline to the
6856 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6858 /* We're doing a "next".
6860 Normal (forward) execution: set a breakpoint at the
6861 callee's return address (the address at which the caller
6864 Reverse (backward) execution. set the step-resume
6865 breakpoint at the start of the function that we just
6866 stepped into (backwards), and continue to there. When we
6867 get there, we'll need to single-step back to the caller. */
6869 if (execution_direction
== EXEC_REVERSE
)
6871 /* If we're already at the start of the function, we've either
6872 just stepped backward into a single instruction function,
6873 or stepped back out of a signal handler to the first instruction
6874 of the function. Just keep going, which will single-step back
6876 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6878 /* Normal function call return (static or dynamic). */
6879 symtab_and_line sr_sal
;
6880 sr_sal
.pc
= ecs
->stop_func_start
;
6881 sr_sal
.pspace
= get_frame_program_space (frame
);
6882 insert_step_resume_breakpoint_at_sal (gdbarch
,
6883 sr_sal
, null_frame_id
);
6887 insert_step_resume_breakpoint_at_caller (frame
);
6893 /* If we are in a function call trampoline (a stub between the
6894 calling routine and the real function), locate the real
6895 function. That's what tells us (a) whether we want to step
6896 into it at all, and (b) what prologue we want to run to the
6897 end of, if we do step into it. */
6898 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6899 if (real_stop_pc
== 0)
6900 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6901 if (real_stop_pc
!= 0)
6902 ecs
->stop_func_start
= real_stop_pc
;
6904 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6906 symtab_and_line sr_sal
;
6907 sr_sal
.pc
= ecs
->stop_func_start
;
6908 sr_sal
.pspace
= get_frame_program_space (frame
);
6910 insert_step_resume_breakpoint_at_sal (gdbarch
,
6911 sr_sal
, null_frame_id
);
6916 /* If we have line number information for the function we are
6917 thinking of stepping into and the function isn't on the skip
6920 If there are several symtabs at that PC (e.g. with include
6921 files), just want to know whether *any* of them have line
6922 numbers. find_pc_line handles this. */
6924 struct symtab_and_line tmp_sal
;
6926 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6927 if (tmp_sal
.line
!= 0
6928 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6930 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6932 if (execution_direction
== EXEC_REVERSE
)
6933 handle_step_into_function_backward (gdbarch
, ecs
);
6935 handle_step_into_function (gdbarch
, ecs
);
6940 /* If we have no line number and the step-stop-if-no-debug is
6941 set, we stop the step so that the user has a chance to switch
6942 in assembly mode. */
6943 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6944 && step_stop_if_no_debug
)
6946 end_stepping_range (ecs
);
6950 if (execution_direction
== EXEC_REVERSE
)
6952 /* If we're already at the start of the function, we've either just
6953 stepped backward into a single instruction function without line
6954 number info, or stepped back out of a signal handler to the first
6955 instruction of the function without line number info. Just keep
6956 going, which will single-step back to the caller. */
6957 if (ecs
->stop_func_start
!= stop_pc
)
6959 /* Set a breakpoint at callee's start address.
6960 From there we can step once and be back in the caller. */
6961 symtab_and_line sr_sal
;
6962 sr_sal
.pc
= ecs
->stop_func_start
;
6963 sr_sal
.pspace
= get_frame_program_space (frame
);
6964 insert_step_resume_breakpoint_at_sal (gdbarch
,
6965 sr_sal
, null_frame_id
);
6969 /* Set a breakpoint at callee's return address (the address
6970 at which the caller will resume). */
6971 insert_step_resume_breakpoint_at_caller (frame
);
6977 /* Reverse stepping through solib trampolines. */
6979 if (execution_direction
== EXEC_REVERSE
6980 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6982 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6984 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6985 || (ecs
->stop_func_start
== 0
6986 && in_solib_dynsym_resolve_code (stop_pc
)))
6988 /* Any solib trampoline code can be handled in reverse
6989 by simply continuing to single-step. We have already
6990 executed the solib function (backwards), and a few
6991 steps will take us back through the trampoline to the
6996 else if (in_solib_dynsym_resolve_code (stop_pc
))
6998 /* Stepped backward into the solib dynsym resolver.
6999 Set a breakpoint at its start and continue, then
7000 one more step will take us out. */
7001 symtab_and_line sr_sal
;
7002 sr_sal
.pc
= ecs
->stop_func_start
;
7003 sr_sal
.pspace
= get_frame_program_space (frame
);
7004 insert_step_resume_breakpoint_at_sal (gdbarch
,
7005 sr_sal
, null_frame_id
);
7011 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7013 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7014 the trampoline processing logic, however, there are some trampolines
7015 that have no names, so we should do trampoline handling first. */
7016 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7017 && ecs
->stop_func_name
== NULL
7018 && stop_pc_sal
.line
== 0)
7021 fprintf_unfiltered (gdb_stdlog
,
7022 "infrun: stepped into undebuggable function\n");
7024 /* The inferior just stepped into, or returned to, an
7025 undebuggable function (where there is no debugging information
7026 and no line number corresponding to the address where the
7027 inferior stopped). Since we want to skip this kind of code,
7028 we keep going until the inferior returns from this
7029 function - unless the user has asked us not to (via
7030 set step-mode) or we no longer know how to get back
7031 to the call site. */
7032 if (step_stop_if_no_debug
7033 || !frame_id_p (frame_unwind_caller_id (frame
)))
7035 /* If we have no line number and the step-stop-if-no-debug
7036 is set, we stop the step so that the user has a chance to
7037 switch in assembly mode. */
7038 end_stepping_range (ecs
);
7043 /* Set a breakpoint at callee's return address (the address
7044 at which the caller will resume). */
7045 insert_step_resume_breakpoint_at_caller (frame
);
7051 if (ecs
->event_thread
->control
.step_range_end
== 1)
7053 /* It is stepi or nexti. We always want to stop stepping after
7056 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7057 end_stepping_range (ecs
);
7061 if (stop_pc_sal
.line
== 0)
7063 /* We have no line number information. That means to stop
7064 stepping (does this always happen right after one instruction,
7065 when we do "s" in a function with no line numbers,
7066 or can this happen as a result of a return or longjmp?). */
7068 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7069 end_stepping_range (ecs
);
7073 /* Look for "calls" to inlined functions, part one. If the inline
7074 frame machinery detected some skipped call sites, we have entered
7075 a new inline function. */
7077 if (frame_id_eq (get_frame_id (get_current_frame ()),
7078 ecs
->event_thread
->control
.step_frame_id
)
7079 && inline_skipped_frames (ecs
->event_thread
))
7082 fprintf_unfiltered (gdb_stdlog
,
7083 "infrun: stepped into inlined function\n");
7085 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7087 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7089 /* For "step", we're going to stop. But if the call site
7090 for this inlined function is on the same source line as
7091 we were previously stepping, go down into the function
7092 first. Otherwise stop at the call site. */
7094 if (call_sal
.line
== ecs
->event_thread
->current_line
7095 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7097 step_into_inline_frame (ecs
->event_thread
);
7098 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7105 end_stepping_range (ecs
);
7110 /* For "next", we should stop at the call site if it is on a
7111 different source line. Otherwise continue through the
7112 inlined function. */
7113 if (call_sal
.line
== ecs
->event_thread
->current_line
7114 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7117 end_stepping_range (ecs
);
7122 /* Look for "calls" to inlined functions, part two. If we are still
7123 in the same real function we were stepping through, but we have
7124 to go further up to find the exact frame ID, we are stepping
7125 through a more inlined call beyond its call site. */
7127 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7128 && !frame_id_eq (get_frame_id (get_current_frame ()),
7129 ecs
->event_thread
->control
.step_frame_id
)
7130 && stepped_in_from (get_current_frame (),
7131 ecs
->event_thread
->control
.step_frame_id
))
7134 fprintf_unfiltered (gdb_stdlog
,
7135 "infrun: stepping through inlined function\n");
7137 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7138 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7141 end_stepping_range (ecs
);
7145 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7146 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7147 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7149 /* We are at the start of a different line. So stop. Note that
7150 we don't stop if we step into the middle of a different line.
7151 That is said to make things like for (;;) statements work
7154 fprintf_unfiltered (gdb_stdlog
,
7155 "infrun: stepped to a different line\n");
7156 end_stepping_range (ecs
);
7160 /* We aren't done stepping.
7162 Optimize by setting the stepping range to the line.
7163 (We might not be in the original line, but if we entered a
7164 new line in mid-statement, we continue stepping. This makes
7165 things like for(;;) statements work better.) */
7167 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7168 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7169 ecs
->event_thread
->control
.may_range_step
= 1;
7170 set_step_info (frame
, stop_pc_sal
);
7173 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7177 /* In all-stop mode, if we're currently stepping but have stopped in
7178 some other thread, we may need to switch back to the stepped
7179 thread. Returns true we set the inferior running, false if we left
7180 it stopped (and the event needs further processing). */
7183 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7185 if (!target_is_non_stop_p ())
7187 struct thread_info
*stepping_thread
;
7189 /* If any thread is blocked on some internal breakpoint, and we
7190 simply need to step over that breakpoint to get it going
7191 again, do that first. */
7193 /* However, if we see an event for the stepping thread, then we
7194 know all other threads have been moved past their breakpoints
7195 already. Let the caller check whether the step is finished,
7196 etc., before deciding to move it past a breakpoint. */
7197 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7200 /* Check if the current thread is blocked on an incomplete
7201 step-over, interrupted by a random signal. */
7202 if (ecs
->event_thread
->control
.trap_expected
7203 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7207 fprintf_unfiltered (gdb_stdlog
,
7208 "infrun: need to finish step-over of [%s]\n",
7209 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7215 /* Check if the current thread is blocked by a single-step
7216 breakpoint of another thread. */
7217 if (ecs
->hit_singlestep_breakpoint
)
7221 fprintf_unfiltered (gdb_stdlog
,
7222 "infrun: need to step [%s] over single-step "
7224 target_pid_to_str (ecs
->ptid
).c_str ());
7230 /* If this thread needs yet another step-over (e.g., stepping
7231 through a delay slot), do it first before moving on to
7233 if (thread_still_needs_step_over (ecs
->event_thread
))
7237 fprintf_unfiltered (gdb_stdlog
,
7238 "infrun: thread [%s] still needs step-over\n",
7239 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7245 /* If scheduler locking applies even if not stepping, there's no
7246 need to walk over threads. Above we've checked whether the
7247 current thread is stepping. If some other thread not the
7248 event thread is stepping, then it must be that scheduler
7249 locking is not in effect. */
7250 if (schedlock_applies (ecs
->event_thread
))
7253 /* Otherwise, we no longer expect a trap in the current thread.
7254 Clear the trap_expected flag before switching back -- this is
7255 what keep_going does as well, if we call it. */
7256 ecs
->event_thread
->control
.trap_expected
= 0;
7258 /* Likewise, clear the signal if it should not be passed. */
7259 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7260 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7262 /* Do all pending step-overs before actually proceeding with
7264 if (start_step_over ())
7266 prepare_to_wait (ecs
);
7270 /* Look for the stepping/nexting thread. */
7271 stepping_thread
= NULL
;
7273 for (thread_info
*tp
: all_non_exited_threads ())
7275 switch_to_thread_no_regs (tp
);
7277 /* Ignore threads of processes the caller is not
7280 && (tp
->inf
->process_target () != ecs
->target
7281 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7284 /* When stepping over a breakpoint, we lock all threads
7285 except the one that needs to move past the breakpoint.
7286 If a non-event thread has this set, the "incomplete
7287 step-over" check above should have caught it earlier. */
7288 if (tp
->control
.trap_expected
)
7290 internal_error (__FILE__
, __LINE__
,
7291 "[%s] has inconsistent state: "
7292 "trap_expected=%d\n",
7293 target_pid_to_str (tp
->ptid
).c_str (),
7294 tp
->control
.trap_expected
);
7297 /* Did we find the stepping thread? */
7298 if (tp
->control
.step_range_end
)
7300 /* Yep. There should only one though. */
7301 gdb_assert (stepping_thread
== NULL
);
7303 /* The event thread is handled at the top, before we
7305 gdb_assert (tp
!= ecs
->event_thread
);
7307 /* If some thread other than the event thread is
7308 stepping, then scheduler locking can't be in effect,
7309 otherwise we wouldn't have resumed the current event
7310 thread in the first place. */
7311 gdb_assert (!schedlock_applies (tp
));
7313 stepping_thread
= tp
;
7317 if (stepping_thread
!= NULL
)
7320 fprintf_unfiltered (gdb_stdlog
,
7321 "infrun: switching back to stepped thread\n");
7323 if (keep_going_stepped_thread (stepping_thread
))
7325 prepare_to_wait (ecs
);
7330 switch_to_thread (ecs
->event_thread
);
7336 /* Set a previously stepped thread back to stepping. Returns true on
7337 success, false if the resume is not possible (e.g., the thread
7341 keep_going_stepped_thread (struct thread_info
*tp
)
7343 struct frame_info
*frame
;
7344 struct execution_control_state ecss
;
7345 struct execution_control_state
*ecs
= &ecss
;
7347 /* If the stepping thread exited, then don't try to switch back and
7348 resume it, which could fail in several different ways depending
7349 on the target. Instead, just keep going.
7351 We can find a stepping dead thread in the thread list in two
7354 - The target supports thread exit events, and when the target
7355 tries to delete the thread from the thread list, inferior_ptid
7356 pointed at the exiting thread. In such case, calling
7357 delete_thread does not really remove the thread from the list;
7358 instead, the thread is left listed, with 'exited' state.
7360 - The target's debug interface does not support thread exit
7361 events, and so we have no idea whatsoever if the previously
7362 stepping thread is still alive. For that reason, we need to
7363 synchronously query the target now. */
7365 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7368 fprintf_unfiltered (gdb_stdlog
,
7369 "infrun: not resuming previously "
7370 "stepped thread, it has vanished\n");
7377 fprintf_unfiltered (gdb_stdlog
,
7378 "infrun: resuming previously stepped thread\n");
7380 reset_ecs (ecs
, tp
);
7381 switch_to_thread (tp
);
7383 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7384 frame
= get_current_frame ();
7386 /* If the PC of the thread we were trying to single-step has
7387 changed, then that thread has trapped or been signaled, but the
7388 event has not been reported to GDB yet. Re-poll the target
7389 looking for this particular thread's event (i.e. temporarily
7390 enable schedlock) by:
7392 - setting a break at the current PC
7393 - resuming that particular thread, only (by setting trap
7396 This prevents us continuously moving the single-step breakpoint
7397 forward, one instruction at a time, overstepping. */
7399 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7404 fprintf_unfiltered (gdb_stdlog
,
7405 "infrun: expected thread advanced also (%s -> %s)\n",
7406 paddress (target_gdbarch (), tp
->prev_pc
),
7407 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7409 /* Clear the info of the previous step-over, as it's no longer
7410 valid (if the thread was trying to step over a breakpoint, it
7411 has already succeeded). It's what keep_going would do too,
7412 if we called it. Do this before trying to insert the sss
7413 breakpoint, otherwise if we were previously trying to step
7414 over this exact address in another thread, the breakpoint is
7416 clear_step_over_info ();
7417 tp
->control
.trap_expected
= 0;
7419 insert_single_step_breakpoint (get_frame_arch (frame
),
7420 get_frame_address_space (frame
),
7421 tp
->suspend
.stop_pc
);
7424 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7425 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7430 fprintf_unfiltered (gdb_stdlog
,
7431 "infrun: expected thread still hasn't advanced\n");
7433 keep_going_pass_signal (ecs
);
7438 /* Is thread TP in the middle of (software or hardware)
7439 single-stepping? (Note the result of this function must never be
7440 passed directly as target_resume's STEP parameter.) */
7443 currently_stepping (struct thread_info
*tp
)
7445 return ((tp
->control
.step_range_end
7446 && tp
->control
.step_resume_breakpoint
== NULL
)
7447 || tp
->control
.trap_expected
7448 || tp
->stepped_breakpoint
7449 || bpstat_should_step ());
7452 /* Inferior has stepped into a subroutine call with source code that
7453 we should not step over. Do step to the first line of code in
7457 handle_step_into_function (struct gdbarch
*gdbarch
,
7458 struct execution_control_state
*ecs
)
7460 fill_in_stop_func (gdbarch
, ecs
);
7462 compunit_symtab
*cust
7463 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7464 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7465 ecs
->stop_func_start
7466 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7468 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7469 /* Use the step_resume_break to step until the end of the prologue,
7470 even if that involves jumps (as it seems to on the vax under
7472 /* If the prologue ends in the middle of a source line, continue to
7473 the end of that source line (if it is still within the function).
7474 Otherwise, just go to end of prologue. */
7475 if (stop_func_sal
.end
7476 && stop_func_sal
.pc
!= ecs
->stop_func_start
7477 && stop_func_sal
.end
< ecs
->stop_func_end
)
7478 ecs
->stop_func_start
= stop_func_sal
.end
;
7480 /* Architectures which require breakpoint adjustment might not be able
7481 to place a breakpoint at the computed address. If so, the test
7482 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7483 ecs->stop_func_start to an address at which a breakpoint may be
7484 legitimately placed.
7486 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7487 made, GDB will enter an infinite loop when stepping through
7488 optimized code consisting of VLIW instructions which contain
7489 subinstructions corresponding to different source lines. On
7490 FR-V, it's not permitted to place a breakpoint on any but the
7491 first subinstruction of a VLIW instruction. When a breakpoint is
7492 set, GDB will adjust the breakpoint address to the beginning of
7493 the VLIW instruction. Thus, we need to make the corresponding
7494 adjustment here when computing the stop address. */
7496 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7498 ecs
->stop_func_start
7499 = gdbarch_adjust_breakpoint_address (gdbarch
,
7500 ecs
->stop_func_start
);
7503 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7505 /* We are already there: stop now. */
7506 end_stepping_range (ecs
);
7511 /* Put the step-breakpoint there and go until there. */
7512 symtab_and_line sr_sal
;
7513 sr_sal
.pc
= ecs
->stop_func_start
;
7514 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7515 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7517 /* Do not specify what the fp should be when we stop since on
7518 some machines the prologue is where the new fp value is
7520 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7522 /* And make sure stepping stops right away then. */
7523 ecs
->event_thread
->control
.step_range_end
7524 = ecs
->event_thread
->control
.step_range_start
;
7529 /* Inferior has stepped backward into a subroutine call with source
7530 code that we should not step over. Do step to the beginning of the
7531 last line of code in it. */
7534 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7535 struct execution_control_state
*ecs
)
7537 struct compunit_symtab
*cust
;
7538 struct symtab_and_line stop_func_sal
;
7540 fill_in_stop_func (gdbarch
, ecs
);
7542 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7543 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7544 ecs
->stop_func_start
7545 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7547 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7549 /* OK, we're just going to keep stepping here. */
7550 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7552 /* We're there already. Just stop stepping now. */
7553 end_stepping_range (ecs
);
7557 /* Else just reset the step range and keep going.
7558 No step-resume breakpoint, they don't work for
7559 epilogues, which can have multiple entry paths. */
7560 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7561 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7567 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7568 This is used to both functions and to skip over code. */
7571 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7572 struct symtab_and_line sr_sal
,
7573 struct frame_id sr_id
,
7574 enum bptype sr_type
)
7576 /* There should never be more than one step-resume or longjmp-resume
7577 breakpoint per thread, so we should never be setting a new
7578 step_resume_breakpoint when one is already active. */
7579 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7580 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7583 fprintf_unfiltered (gdb_stdlog
,
7584 "infrun: inserting step-resume breakpoint at %s\n",
7585 paddress (gdbarch
, sr_sal
.pc
));
7587 inferior_thread ()->control
.step_resume_breakpoint
7588 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7592 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7593 struct symtab_and_line sr_sal
,
7594 struct frame_id sr_id
)
7596 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7601 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7602 This is used to skip a potential signal handler.
7604 This is called with the interrupted function's frame. The signal
7605 handler, when it returns, will resume the interrupted function at
7609 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7611 gdb_assert (return_frame
!= NULL
);
7613 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7615 symtab_and_line sr_sal
;
7616 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7617 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7618 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7620 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7621 get_stack_frame_id (return_frame
),
7625 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7626 is used to skip a function after stepping into it (for "next" or if
7627 the called function has no debugging information).
7629 The current function has almost always been reached by single
7630 stepping a call or return instruction. NEXT_FRAME belongs to the
7631 current function, and the breakpoint will be set at the caller's
7634 This is a separate function rather than reusing
7635 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7636 get_prev_frame, which may stop prematurely (see the implementation
7637 of frame_unwind_caller_id for an example). */
7640 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7642 /* We shouldn't have gotten here if we don't know where the call site
7644 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7646 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7648 symtab_and_line sr_sal
;
7649 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7650 frame_unwind_caller_pc (next_frame
));
7651 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7652 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7654 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7655 frame_unwind_caller_id (next_frame
));
7658 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7659 new breakpoint at the target of a jmp_buf. The handling of
7660 longjmp-resume uses the same mechanisms used for handling
7661 "step-resume" breakpoints. */
7664 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7666 /* There should never be more than one longjmp-resume breakpoint per
7667 thread, so we should never be setting a new
7668 longjmp_resume_breakpoint when one is already active. */
7669 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7672 fprintf_unfiltered (gdb_stdlog
,
7673 "infrun: inserting longjmp-resume breakpoint at %s\n",
7674 paddress (gdbarch
, pc
));
7676 inferior_thread ()->control
.exception_resume_breakpoint
=
7677 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7680 /* Insert an exception resume breakpoint. TP is the thread throwing
7681 the exception. The block B is the block of the unwinder debug hook
7682 function. FRAME is the frame corresponding to the call to this
7683 function. SYM is the symbol of the function argument holding the
7684 target PC of the exception. */
7687 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7688 const struct block
*b
,
7689 struct frame_info
*frame
,
7694 struct block_symbol vsym
;
7695 struct value
*value
;
7697 struct breakpoint
*bp
;
7699 vsym
= lookup_symbol_search_name (sym
->search_name (),
7701 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7702 /* If the value was optimized out, revert to the old behavior. */
7703 if (! value_optimized_out (value
))
7705 handler
= value_as_address (value
);
7708 fprintf_unfiltered (gdb_stdlog
,
7709 "infrun: exception resume at %lx\n",
7710 (unsigned long) handler
);
7712 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7714 bp_exception_resume
).release ();
7716 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7719 bp
->thread
= tp
->global_num
;
7720 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7723 catch (const gdb_exception_error
&e
)
7725 /* We want to ignore errors here. */
7729 /* A helper for check_exception_resume that sets an
7730 exception-breakpoint based on a SystemTap probe. */
7733 insert_exception_resume_from_probe (struct thread_info
*tp
,
7734 const struct bound_probe
*probe
,
7735 struct frame_info
*frame
)
7737 struct value
*arg_value
;
7739 struct breakpoint
*bp
;
7741 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7745 handler
= value_as_address (arg_value
);
7748 fprintf_unfiltered (gdb_stdlog
,
7749 "infrun: exception resume at %s\n",
7750 paddress (get_objfile_arch (probe
->objfile
),
7753 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7754 handler
, bp_exception_resume
).release ();
7755 bp
->thread
= tp
->global_num
;
7756 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7759 /* This is called when an exception has been intercepted. Check to
7760 see whether the exception's destination is of interest, and if so,
7761 set an exception resume breakpoint there. */
7764 check_exception_resume (struct execution_control_state
*ecs
,
7765 struct frame_info
*frame
)
7767 struct bound_probe probe
;
7768 struct symbol
*func
;
7770 /* First see if this exception unwinding breakpoint was set via a
7771 SystemTap probe point. If so, the probe has two arguments: the
7772 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7773 set a breakpoint there. */
7774 probe
= find_probe_by_pc (get_frame_pc (frame
));
7777 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7781 func
= get_frame_function (frame
);
7787 const struct block
*b
;
7788 struct block_iterator iter
;
7792 /* The exception breakpoint is a thread-specific breakpoint on
7793 the unwinder's debug hook, declared as:
7795 void _Unwind_DebugHook (void *cfa, void *handler);
7797 The CFA argument indicates the frame to which control is
7798 about to be transferred. HANDLER is the destination PC.
7800 We ignore the CFA and set a temporary breakpoint at HANDLER.
7801 This is not extremely efficient but it avoids issues in gdb
7802 with computing the DWARF CFA, and it also works even in weird
7803 cases such as throwing an exception from inside a signal
7806 b
= SYMBOL_BLOCK_VALUE (func
);
7807 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7809 if (!SYMBOL_IS_ARGUMENT (sym
))
7816 insert_exception_resume_breakpoint (ecs
->event_thread
,
7822 catch (const gdb_exception_error
&e
)
7828 stop_waiting (struct execution_control_state
*ecs
)
7831 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7833 /* Let callers know we don't want to wait for the inferior anymore. */
7834 ecs
->wait_some_more
= 0;
7836 /* If all-stop, but the target is always in non-stop mode, stop all
7837 threads now that we're presenting the stop to the user. */
7838 if (!non_stop
&& target_is_non_stop_p ())
7839 stop_all_threads ();
7842 /* Like keep_going, but passes the signal to the inferior, even if the
7843 signal is set to nopass. */
7846 keep_going_pass_signal (struct execution_control_state
*ecs
)
7848 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7849 gdb_assert (!ecs
->event_thread
->resumed
);
7851 /* Save the pc before execution, to compare with pc after stop. */
7852 ecs
->event_thread
->prev_pc
7853 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7855 if (ecs
->event_thread
->control
.trap_expected
)
7857 struct thread_info
*tp
= ecs
->event_thread
;
7860 fprintf_unfiltered (gdb_stdlog
,
7861 "infrun: %s has trap_expected set, "
7862 "resuming to collect trap\n",
7863 target_pid_to_str (tp
->ptid
).c_str ());
7865 /* We haven't yet gotten our trap, and either: intercepted a
7866 non-signal event (e.g., a fork); or took a signal which we
7867 are supposed to pass through to the inferior. Simply
7869 resume (ecs
->event_thread
->suspend
.stop_signal
);
7871 else if (step_over_info_valid_p ())
7873 /* Another thread is stepping over a breakpoint in-line. If
7874 this thread needs a step-over too, queue the request. In
7875 either case, this resume must be deferred for later. */
7876 struct thread_info
*tp
= ecs
->event_thread
;
7878 if (ecs
->hit_singlestep_breakpoint
7879 || thread_still_needs_step_over (tp
))
7882 fprintf_unfiltered (gdb_stdlog
,
7883 "infrun: step-over already in progress: "
7884 "step-over for %s deferred\n",
7885 target_pid_to_str (tp
->ptid
).c_str ());
7886 thread_step_over_chain_enqueue (tp
);
7891 fprintf_unfiltered (gdb_stdlog
,
7892 "infrun: step-over in progress: "
7893 "resume of %s deferred\n",
7894 target_pid_to_str (tp
->ptid
).c_str ());
7899 struct regcache
*regcache
= get_current_regcache ();
7902 step_over_what step_what
;
7904 /* Either the trap was not expected, but we are continuing
7905 anyway (if we got a signal, the user asked it be passed to
7908 We got our expected trap, but decided we should resume from
7911 We're going to run this baby now!
7913 Note that insert_breakpoints won't try to re-insert
7914 already inserted breakpoints. Therefore, we don't
7915 care if breakpoints were already inserted, or not. */
7917 /* If we need to step over a breakpoint, and we're not using
7918 displaced stepping to do so, insert all breakpoints
7919 (watchpoints, etc.) but the one we're stepping over, step one
7920 instruction, and then re-insert the breakpoint when that step
7923 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7925 remove_bp
= (ecs
->hit_singlestep_breakpoint
7926 || (step_what
& STEP_OVER_BREAKPOINT
));
7927 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7929 /* We can't use displaced stepping if we need to step past a
7930 watchpoint. The instruction copied to the scratch pad would
7931 still trigger the watchpoint. */
7933 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7935 set_step_over_info (regcache
->aspace (),
7936 regcache_read_pc (regcache
), remove_wps
,
7937 ecs
->event_thread
->global_num
);
7939 else if (remove_wps
)
7940 set_step_over_info (NULL
, 0, remove_wps
, -1);
7942 /* If we now need to do an in-line step-over, we need to stop
7943 all other threads. Note this must be done before
7944 insert_breakpoints below, because that removes the breakpoint
7945 we're about to step over, otherwise other threads could miss
7947 if (step_over_info_valid_p () && target_is_non_stop_p ())
7948 stop_all_threads ();
7950 /* Stop stepping if inserting breakpoints fails. */
7953 insert_breakpoints ();
7955 catch (const gdb_exception_error
&e
)
7957 exception_print (gdb_stderr
, e
);
7959 clear_step_over_info ();
7963 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7965 resume (ecs
->event_thread
->suspend
.stop_signal
);
7968 prepare_to_wait (ecs
);
7971 /* Called when we should continue running the inferior, because the
7972 current event doesn't cause a user visible stop. This does the
7973 resuming part; waiting for the next event is done elsewhere. */
7976 keep_going (struct execution_control_state
*ecs
)
7978 if (ecs
->event_thread
->control
.trap_expected
7979 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7980 ecs
->event_thread
->control
.trap_expected
= 0;
7982 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7983 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7984 keep_going_pass_signal (ecs
);
7987 /* This function normally comes after a resume, before
7988 handle_inferior_event exits. It takes care of any last bits of
7989 housekeeping, and sets the all-important wait_some_more flag. */
7992 prepare_to_wait (struct execution_control_state
*ecs
)
7995 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7997 ecs
->wait_some_more
= 1;
7999 if (!target_is_async_p ())
8000 mark_infrun_async_event_handler ();
8003 /* We are done with the step range of a step/next/si/ni command.
8004 Called once for each n of a "step n" operation. */
8007 end_stepping_range (struct execution_control_state
*ecs
)
8009 ecs
->event_thread
->control
.stop_step
= 1;
8013 /* Several print_*_reason functions to print why the inferior has stopped.
8014 We always print something when the inferior exits, or receives a signal.
8015 The rest of the cases are dealt with later on in normal_stop and
8016 print_it_typical. Ideally there should be a call to one of these
8017 print_*_reason functions functions from handle_inferior_event each time
8018 stop_waiting is called.
8020 Note that we don't call these directly, instead we delegate that to
8021 the interpreters, through observers. Interpreters then call these
8022 with whatever uiout is right. */
8025 print_end_stepping_range_reason (struct ui_out
*uiout
)
8027 /* For CLI-like interpreters, print nothing. */
8029 if (uiout
->is_mi_like_p ())
8031 uiout
->field_string ("reason",
8032 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8037 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8039 annotate_signalled ();
8040 if (uiout
->is_mi_like_p ())
8042 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8043 uiout
->text ("\nProgram terminated with signal ");
8044 annotate_signal_name ();
8045 uiout
->field_string ("signal-name",
8046 gdb_signal_to_name (siggnal
));
8047 annotate_signal_name_end ();
8049 annotate_signal_string ();
8050 uiout
->field_string ("signal-meaning",
8051 gdb_signal_to_string (siggnal
));
8052 annotate_signal_string_end ();
8053 uiout
->text (".\n");
8054 uiout
->text ("The program no longer exists.\n");
8058 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8060 struct inferior
*inf
= current_inferior ();
8061 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8063 annotate_exited (exitstatus
);
8066 if (uiout
->is_mi_like_p ())
8067 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8068 std::string exit_code_str
8069 = string_printf ("0%o", (unsigned int) exitstatus
);
8070 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8071 plongest (inf
->num
), pidstr
.c_str (),
8072 string_field ("exit-code", exit_code_str
.c_str ()));
8076 if (uiout
->is_mi_like_p ())
8078 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8079 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8080 plongest (inf
->num
), pidstr
.c_str ());
8084 /* Some targets/architectures can do extra processing/display of
8085 segmentation faults. E.g., Intel MPX boundary faults.
8086 Call the architecture dependent function to handle the fault. */
8089 handle_segmentation_fault (struct ui_out
*uiout
)
8091 struct regcache
*regcache
= get_current_regcache ();
8092 struct gdbarch
*gdbarch
= regcache
->arch ();
8094 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8095 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8099 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8101 struct thread_info
*thr
= inferior_thread ();
8105 if (uiout
->is_mi_like_p ())
8107 else if (show_thread_that_caused_stop ())
8111 uiout
->text ("\nThread ");
8112 uiout
->field_string ("thread-id", print_thread_id (thr
));
8114 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8117 uiout
->text (" \"");
8118 uiout
->field_string ("name", name
);
8123 uiout
->text ("\nProgram");
8125 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8126 uiout
->text (" stopped");
8129 uiout
->text (" received signal ");
8130 annotate_signal_name ();
8131 if (uiout
->is_mi_like_p ())
8133 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8134 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8135 annotate_signal_name_end ();
8137 annotate_signal_string ();
8138 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8140 if (siggnal
== GDB_SIGNAL_SEGV
)
8141 handle_segmentation_fault (uiout
);
8143 annotate_signal_string_end ();
8145 uiout
->text (".\n");
8149 print_no_history_reason (struct ui_out
*uiout
)
8151 uiout
->text ("\nNo more reverse-execution history.\n");
8154 /* Print current location without a level number, if we have changed
8155 functions or hit a breakpoint. Print source line if we have one.
8156 bpstat_print contains the logic deciding in detail what to print,
8157 based on the event(s) that just occurred. */
8160 print_stop_location (struct target_waitstatus
*ws
)
8163 enum print_what source_flag
;
8164 int do_frame_printing
= 1;
8165 struct thread_info
*tp
= inferior_thread ();
8167 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8171 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8172 should) carry around the function and does (or should) use
8173 that when doing a frame comparison. */
8174 if (tp
->control
.stop_step
8175 && frame_id_eq (tp
->control
.step_frame_id
,
8176 get_frame_id (get_current_frame ()))
8177 && (tp
->control
.step_start_function
8178 == find_pc_function (tp
->suspend
.stop_pc
)))
8180 /* Finished step, just print source line. */
8181 source_flag
= SRC_LINE
;
8185 /* Print location and source line. */
8186 source_flag
= SRC_AND_LOC
;
8189 case PRINT_SRC_AND_LOC
:
8190 /* Print location and source line. */
8191 source_flag
= SRC_AND_LOC
;
8193 case PRINT_SRC_ONLY
:
8194 source_flag
= SRC_LINE
;
8197 /* Something bogus. */
8198 source_flag
= SRC_LINE
;
8199 do_frame_printing
= 0;
8202 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8205 /* The behavior of this routine with respect to the source
8207 SRC_LINE: Print only source line
8208 LOCATION: Print only location
8209 SRC_AND_LOC: Print location and source line. */
8210 if (do_frame_printing
)
8211 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8217 print_stop_event (struct ui_out
*uiout
, bool displays
)
8219 struct target_waitstatus last
;
8220 struct thread_info
*tp
;
8222 get_last_target_status (nullptr, nullptr, &last
);
8225 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8227 print_stop_location (&last
);
8229 /* Display the auto-display expressions. */
8234 tp
= inferior_thread ();
8235 if (tp
->thread_fsm
!= NULL
8236 && tp
->thread_fsm
->finished_p ())
8238 struct return_value_info
*rv
;
8240 rv
= tp
->thread_fsm
->return_value ();
8242 print_return_value (uiout
, rv
);
8249 maybe_remove_breakpoints (void)
8251 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8253 if (remove_breakpoints ())
8255 target_terminal::ours_for_output ();
8256 printf_filtered (_("Cannot remove breakpoints because "
8257 "program is no longer writable.\nFurther "
8258 "execution is probably impossible.\n"));
8263 /* The execution context that just caused a normal stop. */
8270 DISABLE_COPY_AND_ASSIGN (stop_context
);
8272 bool changed () const;
8277 /* The event PTID. */
8281 /* If stopp for a thread event, this is the thread that caused the
8283 struct thread_info
*thread
;
8285 /* The inferior that caused the stop. */
8289 /* Initializes a new stop context. If stopped for a thread event, this
8290 takes a strong reference to the thread. */
8292 stop_context::stop_context ()
8294 stop_id
= get_stop_id ();
8295 ptid
= inferior_ptid
;
8296 inf_num
= current_inferior ()->num
;
8298 if (inferior_ptid
!= null_ptid
)
8300 /* Take a strong reference so that the thread can't be deleted
8302 thread
= inferior_thread ();
8309 /* Release a stop context previously created with save_stop_context.
8310 Releases the strong reference to the thread as well. */
8312 stop_context::~stop_context ()
8318 /* Return true if the current context no longer matches the saved stop
8322 stop_context::changed () const
8324 if (ptid
!= inferior_ptid
)
8326 if (inf_num
!= current_inferior ()->num
)
8328 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8330 if (get_stop_id () != stop_id
)
8340 struct target_waitstatus last
;
8342 get_last_target_status (nullptr, nullptr, &last
);
8346 /* If an exception is thrown from this point on, make sure to
8347 propagate GDB's knowledge of the executing state to the
8348 frontend/user running state. A QUIT is an easy exception to see
8349 here, so do this before any filtered output. */
8351 ptid_t finish_ptid
= null_ptid
;
8354 finish_ptid
= minus_one_ptid
;
8355 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8356 || last
.kind
== TARGET_WAITKIND_EXITED
)
8358 /* On some targets, we may still have live threads in the
8359 inferior when we get a process exit event. E.g., for
8360 "checkpoint", when the current checkpoint/fork exits,
8361 linux-fork.c automatically switches to another fork from
8362 within target_mourn_inferior. */
8363 if (inferior_ptid
!= null_ptid
)
8364 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8366 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8367 finish_ptid
= inferior_ptid
;
8369 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8370 if (finish_ptid
!= null_ptid
)
8372 maybe_finish_thread_state
.emplace
8373 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8376 /* As we're presenting a stop, and potentially removing breakpoints,
8377 update the thread list so we can tell whether there are threads
8378 running on the target. With target remote, for example, we can
8379 only learn about new threads when we explicitly update the thread
8380 list. Do this before notifying the interpreters about signal
8381 stops, end of stepping ranges, etc., so that the "new thread"
8382 output is emitted before e.g., "Program received signal FOO",
8383 instead of after. */
8384 update_thread_list ();
8386 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8387 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8389 /* As with the notification of thread events, we want to delay
8390 notifying the user that we've switched thread context until
8391 the inferior actually stops.
8393 There's no point in saying anything if the inferior has exited.
8394 Note that SIGNALLED here means "exited with a signal", not
8395 "received a signal".
8397 Also skip saying anything in non-stop mode. In that mode, as we
8398 don't want GDB to switch threads behind the user's back, to avoid
8399 races where the user is typing a command to apply to thread x,
8400 but GDB switches to thread y before the user finishes entering
8401 the command, fetch_inferior_event installs a cleanup to restore
8402 the current thread back to the thread the user had selected right
8403 after this event is handled, so we're not really switching, only
8404 informing of a stop. */
8406 && previous_inferior_ptid
!= inferior_ptid
8407 && target_has_execution
8408 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8409 && last
.kind
!= TARGET_WAITKIND_EXITED
8410 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8412 SWITCH_THRU_ALL_UIS ()
8414 target_terminal::ours_for_output ();
8415 printf_filtered (_("[Switching to %s]\n"),
8416 target_pid_to_str (inferior_ptid
).c_str ());
8417 annotate_thread_changed ();
8419 previous_inferior_ptid
= inferior_ptid
;
8422 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8424 SWITCH_THRU_ALL_UIS ()
8425 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8427 target_terminal::ours_for_output ();
8428 printf_filtered (_("No unwaited-for children left.\n"));
8432 /* Note: this depends on the update_thread_list call above. */
8433 maybe_remove_breakpoints ();
8435 /* If an auto-display called a function and that got a signal,
8436 delete that auto-display to avoid an infinite recursion. */
8438 if (stopped_by_random_signal
)
8439 disable_current_display ();
8441 SWITCH_THRU_ALL_UIS ()
8443 async_enable_stdin ();
8446 /* Let the user/frontend see the threads as stopped. */
8447 maybe_finish_thread_state
.reset ();
8449 /* Select innermost stack frame - i.e., current frame is frame 0,
8450 and current location is based on that. Handle the case where the
8451 dummy call is returning after being stopped. E.g. the dummy call
8452 previously hit a breakpoint. (If the dummy call returns
8453 normally, we won't reach here.) Do this before the stop hook is
8454 run, so that it doesn't get to see the temporary dummy frame,
8455 which is not where we'll present the stop. */
8456 if (has_stack_frames ())
8458 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8460 /* Pop the empty frame that contains the stack dummy. This
8461 also restores inferior state prior to the call (struct
8462 infcall_suspend_state). */
8463 struct frame_info
*frame
= get_current_frame ();
8465 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8467 /* frame_pop calls reinit_frame_cache as the last thing it
8468 does which means there's now no selected frame. */
8471 select_frame (get_current_frame ());
8473 /* Set the current source location. */
8474 set_current_sal_from_frame (get_current_frame ());
8477 /* Look up the hook_stop and run it (CLI internally handles problem
8478 of stop_command's pre-hook not existing). */
8479 if (stop_command
!= NULL
)
8481 stop_context saved_context
;
8485 execute_cmd_pre_hook (stop_command
);
8487 catch (const gdb_exception
&ex
)
8489 exception_fprintf (gdb_stderr
, ex
,
8490 "Error while running hook_stop:\n");
8493 /* If the stop hook resumes the target, then there's no point in
8494 trying to notify about the previous stop; its context is
8495 gone. Likewise if the command switches thread or inferior --
8496 the observers would print a stop for the wrong
8498 if (saved_context
.changed ())
8502 /* Notify observers about the stop. This is where the interpreters
8503 print the stop event. */
8504 if (inferior_ptid
!= null_ptid
)
8505 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8508 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8510 annotate_stopped ();
8512 if (target_has_execution
)
8514 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8515 && last
.kind
!= TARGET_WAITKIND_EXITED
8516 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8517 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8518 Delete any breakpoint that is to be deleted at the next stop. */
8519 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8522 /* Try to get rid of automatically added inferiors that are no
8523 longer needed. Keeping those around slows down things linearly.
8524 Note that this never removes the current inferior. */
8531 signal_stop_state (int signo
)
8533 return signal_stop
[signo
];
8537 signal_print_state (int signo
)
8539 return signal_print
[signo
];
8543 signal_pass_state (int signo
)
8545 return signal_program
[signo
];
8549 signal_cache_update (int signo
)
8553 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8554 signal_cache_update (signo
);
8559 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8560 && signal_print
[signo
] == 0
8561 && signal_program
[signo
] == 1
8562 && signal_catch
[signo
] == 0);
8566 signal_stop_update (int signo
, int state
)
8568 int ret
= signal_stop
[signo
];
8570 signal_stop
[signo
] = state
;
8571 signal_cache_update (signo
);
8576 signal_print_update (int signo
, int state
)
8578 int ret
= signal_print
[signo
];
8580 signal_print
[signo
] = state
;
8581 signal_cache_update (signo
);
8586 signal_pass_update (int signo
, int state
)
8588 int ret
= signal_program
[signo
];
8590 signal_program
[signo
] = state
;
8591 signal_cache_update (signo
);
8595 /* Update the global 'signal_catch' from INFO and notify the
8599 signal_catch_update (const unsigned int *info
)
8603 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8604 signal_catch
[i
] = info
[i
] > 0;
8605 signal_cache_update (-1);
8606 target_pass_signals (signal_pass
);
8610 sig_print_header (void)
8612 printf_filtered (_("Signal Stop\tPrint\tPass "
8613 "to program\tDescription\n"));
8617 sig_print_info (enum gdb_signal oursig
)
8619 const char *name
= gdb_signal_to_name (oursig
);
8620 int name_padding
= 13 - strlen (name
);
8622 if (name_padding
<= 0)
8625 printf_filtered ("%s", name
);
8626 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8627 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8628 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8629 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8630 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8633 /* Specify how various signals in the inferior should be handled. */
8636 handle_command (const char *args
, int from_tty
)
8638 int digits
, wordlen
;
8639 int sigfirst
, siglast
;
8640 enum gdb_signal oursig
;
8645 error_no_arg (_("signal to handle"));
8648 /* Allocate and zero an array of flags for which signals to handle. */
8650 const size_t nsigs
= GDB_SIGNAL_LAST
;
8651 unsigned char sigs
[nsigs
] {};
8653 /* Break the command line up into args. */
8655 gdb_argv
built_argv (args
);
8657 /* Walk through the args, looking for signal oursigs, signal names, and
8658 actions. Signal numbers and signal names may be interspersed with
8659 actions, with the actions being performed for all signals cumulatively
8660 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8662 for (char *arg
: built_argv
)
8664 wordlen
= strlen (arg
);
8665 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8669 sigfirst
= siglast
= -1;
8671 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8673 /* Apply action to all signals except those used by the
8674 debugger. Silently skip those. */
8677 siglast
= nsigs
- 1;
8679 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8681 SET_SIGS (nsigs
, sigs
, signal_stop
);
8682 SET_SIGS (nsigs
, sigs
, signal_print
);
8684 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8686 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8688 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8690 SET_SIGS (nsigs
, sigs
, signal_print
);
8692 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8694 SET_SIGS (nsigs
, sigs
, signal_program
);
8696 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8698 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8700 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8702 SET_SIGS (nsigs
, sigs
, signal_program
);
8704 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8706 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8707 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8709 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8711 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8713 else if (digits
> 0)
8715 /* It is numeric. The numeric signal refers to our own
8716 internal signal numbering from target.h, not to host/target
8717 signal number. This is a feature; users really should be
8718 using symbolic names anyway, and the common ones like
8719 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8721 sigfirst
= siglast
= (int)
8722 gdb_signal_from_command (atoi (arg
));
8723 if (arg
[digits
] == '-')
8726 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8728 if (sigfirst
> siglast
)
8730 /* Bet he didn't figure we'd think of this case... */
8731 std::swap (sigfirst
, siglast
);
8736 oursig
= gdb_signal_from_name (arg
);
8737 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8739 sigfirst
= siglast
= (int) oursig
;
8743 /* Not a number and not a recognized flag word => complain. */
8744 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8748 /* If any signal numbers or symbol names were found, set flags for
8749 which signals to apply actions to. */
8751 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8753 switch ((enum gdb_signal
) signum
)
8755 case GDB_SIGNAL_TRAP
:
8756 case GDB_SIGNAL_INT
:
8757 if (!allsigs
&& !sigs
[signum
])
8759 if (query (_("%s is used by the debugger.\n\
8760 Are you sure you want to change it? "),
8761 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8766 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8770 case GDB_SIGNAL_DEFAULT
:
8771 case GDB_SIGNAL_UNKNOWN
:
8772 /* Make sure that "all" doesn't print these. */
8781 for (int signum
= 0; signum
< nsigs
; signum
++)
8784 signal_cache_update (-1);
8785 target_pass_signals (signal_pass
);
8786 target_program_signals (signal_program
);
8790 /* Show the results. */
8791 sig_print_header ();
8792 for (; signum
< nsigs
; signum
++)
8794 sig_print_info ((enum gdb_signal
) signum
);
8801 /* Complete the "handle" command. */
8804 handle_completer (struct cmd_list_element
*ignore
,
8805 completion_tracker
&tracker
,
8806 const char *text
, const char *word
)
8808 static const char * const keywords
[] =
8822 signal_completer (ignore
, tracker
, text
, word
);
8823 complete_on_enum (tracker
, keywords
, word
, word
);
8827 gdb_signal_from_command (int num
)
8829 if (num
>= 1 && num
<= 15)
8830 return (enum gdb_signal
) num
;
8831 error (_("Only signals 1-15 are valid as numeric signals.\n\
8832 Use \"info signals\" for a list of symbolic signals."));
8835 /* Print current contents of the tables set by the handle command.
8836 It is possible we should just be printing signals actually used
8837 by the current target (but for things to work right when switching
8838 targets, all signals should be in the signal tables). */
8841 info_signals_command (const char *signum_exp
, int from_tty
)
8843 enum gdb_signal oursig
;
8845 sig_print_header ();
8849 /* First see if this is a symbol name. */
8850 oursig
= gdb_signal_from_name (signum_exp
);
8851 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8853 /* No, try numeric. */
8855 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8857 sig_print_info (oursig
);
8861 printf_filtered ("\n");
8862 /* These ugly casts brought to you by the native VAX compiler. */
8863 for (oursig
= GDB_SIGNAL_FIRST
;
8864 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8865 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8869 if (oursig
!= GDB_SIGNAL_UNKNOWN
8870 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8871 sig_print_info (oursig
);
8874 printf_filtered (_("\nUse the \"handle\" command "
8875 "to change these tables.\n"));
8878 /* The $_siginfo convenience variable is a bit special. We don't know
8879 for sure the type of the value until we actually have a chance to
8880 fetch the data. The type can change depending on gdbarch, so it is
8881 also dependent on which thread you have selected.
8883 1. making $_siginfo be an internalvar that creates a new value on
8886 2. making the value of $_siginfo be an lval_computed value. */
8888 /* This function implements the lval_computed support for reading a
8892 siginfo_value_read (struct value
*v
)
8894 LONGEST transferred
;
8896 /* If we can access registers, so can we access $_siginfo. Likewise
8898 validate_registers_access ();
8901 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8903 value_contents_all_raw (v
),
8905 TYPE_LENGTH (value_type (v
)));
8907 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8908 error (_("Unable to read siginfo"));
8911 /* This function implements the lval_computed support for writing a
8915 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8917 LONGEST transferred
;
8919 /* If we can access registers, so can we access $_siginfo. Likewise
8921 validate_registers_access ();
8923 transferred
= target_write (current_top_target (),
8924 TARGET_OBJECT_SIGNAL_INFO
,
8926 value_contents_all_raw (fromval
),
8928 TYPE_LENGTH (value_type (fromval
)));
8930 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8931 error (_("Unable to write siginfo"));
8934 static const struct lval_funcs siginfo_value_funcs
=
8940 /* Return a new value with the correct type for the siginfo object of
8941 the current thread using architecture GDBARCH. Return a void value
8942 if there's no object available. */
8944 static struct value
*
8945 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8948 if (target_has_stack
8949 && inferior_ptid
!= null_ptid
8950 && gdbarch_get_siginfo_type_p (gdbarch
))
8952 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8954 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8957 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8961 /* infcall_suspend_state contains state about the program itself like its
8962 registers and any signal it received when it last stopped.
8963 This state must be restored regardless of how the inferior function call
8964 ends (either successfully, or after it hits a breakpoint or signal)
8965 if the program is to properly continue where it left off. */
8967 class infcall_suspend_state
8970 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8971 once the inferior function call has finished. */
8972 infcall_suspend_state (struct gdbarch
*gdbarch
,
8973 const struct thread_info
*tp
,
8974 struct regcache
*regcache
)
8975 : m_thread_suspend (tp
->suspend
),
8976 m_registers (new readonly_detached_regcache (*regcache
))
8978 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8980 if (gdbarch_get_siginfo_type_p (gdbarch
))
8982 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8983 size_t len
= TYPE_LENGTH (type
);
8985 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8987 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8988 siginfo_data
.get (), 0, len
) != len
)
8990 /* Errors ignored. */
8991 siginfo_data
.reset (nullptr);
8997 m_siginfo_gdbarch
= gdbarch
;
8998 m_siginfo_data
= std::move (siginfo_data
);
9002 /* Return a pointer to the stored register state. */
9004 readonly_detached_regcache
*registers () const
9006 return m_registers
.get ();
9009 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9011 void restore (struct gdbarch
*gdbarch
,
9012 struct thread_info
*tp
,
9013 struct regcache
*regcache
) const
9015 tp
->suspend
= m_thread_suspend
;
9017 if (m_siginfo_gdbarch
== gdbarch
)
9019 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9021 /* Errors ignored. */
9022 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9023 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9026 /* The inferior can be gone if the user types "print exit(0)"
9027 (and perhaps other times). */
9028 if (target_has_execution
)
9029 /* NB: The register write goes through to the target. */
9030 regcache
->restore (registers ());
9034 /* How the current thread stopped before the inferior function call was
9036 struct thread_suspend_state m_thread_suspend
;
9038 /* The registers before the inferior function call was executed. */
9039 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9041 /* Format of SIGINFO_DATA or NULL if it is not present. */
9042 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9044 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9045 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9046 content would be invalid. */
9047 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9050 infcall_suspend_state_up
9051 save_infcall_suspend_state ()
9053 struct thread_info
*tp
= inferior_thread ();
9054 struct regcache
*regcache
= get_current_regcache ();
9055 struct gdbarch
*gdbarch
= regcache
->arch ();
9057 infcall_suspend_state_up inf_state
9058 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9060 /* Having saved the current state, adjust the thread state, discarding
9061 any stop signal information. The stop signal is not useful when
9062 starting an inferior function call, and run_inferior_call will not use
9063 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9064 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9069 /* Restore inferior session state to INF_STATE. */
9072 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9074 struct thread_info
*tp
= inferior_thread ();
9075 struct regcache
*regcache
= get_current_regcache ();
9076 struct gdbarch
*gdbarch
= regcache
->arch ();
9078 inf_state
->restore (gdbarch
, tp
, regcache
);
9079 discard_infcall_suspend_state (inf_state
);
9083 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9088 readonly_detached_regcache
*
9089 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9091 return inf_state
->registers ();
9094 /* infcall_control_state contains state regarding gdb's control of the
9095 inferior itself like stepping control. It also contains session state like
9096 the user's currently selected frame. */
9098 struct infcall_control_state
9100 struct thread_control_state thread_control
;
9101 struct inferior_control_state inferior_control
;
9104 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9105 int stopped_by_random_signal
= 0;
9107 /* ID if the selected frame when the inferior function call was made. */
9108 struct frame_id selected_frame_id
{};
9111 /* Save all of the information associated with the inferior<==>gdb
9114 infcall_control_state_up
9115 save_infcall_control_state ()
9117 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9118 struct thread_info
*tp
= inferior_thread ();
9119 struct inferior
*inf
= current_inferior ();
9121 inf_status
->thread_control
= tp
->control
;
9122 inf_status
->inferior_control
= inf
->control
;
9124 tp
->control
.step_resume_breakpoint
= NULL
;
9125 tp
->control
.exception_resume_breakpoint
= NULL
;
9127 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9128 chain. If caller's caller is walking the chain, they'll be happier if we
9129 hand them back the original chain when restore_infcall_control_state is
9131 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9134 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9135 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9137 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9143 restore_selected_frame (const frame_id
&fid
)
9145 frame_info
*frame
= frame_find_by_id (fid
);
9147 /* If inf_status->selected_frame_id is NULL, there was no previously
9151 warning (_("Unable to restore previously selected frame."));
9155 select_frame (frame
);
9158 /* Restore inferior session state to INF_STATUS. */
9161 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9163 struct thread_info
*tp
= inferior_thread ();
9164 struct inferior
*inf
= current_inferior ();
9166 if (tp
->control
.step_resume_breakpoint
)
9167 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9169 if (tp
->control
.exception_resume_breakpoint
)
9170 tp
->control
.exception_resume_breakpoint
->disposition
9171 = disp_del_at_next_stop
;
9173 /* Handle the bpstat_copy of the chain. */
9174 bpstat_clear (&tp
->control
.stop_bpstat
);
9176 tp
->control
= inf_status
->thread_control
;
9177 inf
->control
= inf_status
->inferior_control
;
9180 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9181 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9183 if (target_has_stack
)
9185 /* The point of the try/catch is that if the stack is clobbered,
9186 walking the stack might encounter a garbage pointer and
9187 error() trying to dereference it. */
9190 restore_selected_frame (inf_status
->selected_frame_id
);
9192 catch (const gdb_exception_error
&ex
)
9194 exception_fprintf (gdb_stderr
, ex
,
9195 "Unable to restore previously selected frame:\n");
9196 /* Error in restoring the selected frame. Select the
9198 select_frame (get_current_frame ());
9206 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9208 if (inf_status
->thread_control
.step_resume_breakpoint
)
9209 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9210 = disp_del_at_next_stop
;
9212 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9213 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9214 = disp_del_at_next_stop
;
9216 /* See save_infcall_control_state for info on stop_bpstat. */
9217 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9225 clear_exit_convenience_vars (void)
9227 clear_internalvar (lookup_internalvar ("_exitsignal"));
9228 clear_internalvar (lookup_internalvar ("_exitcode"));
9232 /* User interface for reverse debugging:
9233 Set exec-direction / show exec-direction commands
9234 (returns error unless target implements to_set_exec_direction method). */
9236 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9237 static const char exec_forward
[] = "forward";
9238 static const char exec_reverse
[] = "reverse";
9239 static const char *exec_direction
= exec_forward
;
9240 static const char *const exec_direction_names
[] = {
9247 set_exec_direction_func (const char *args
, int from_tty
,
9248 struct cmd_list_element
*cmd
)
9250 if (target_can_execute_reverse
)
9252 if (!strcmp (exec_direction
, exec_forward
))
9253 execution_direction
= EXEC_FORWARD
;
9254 else if (!strcmp (exec_direction
, exec_reverse
))
9255 execution_direction
= EXEC_REVERSE
;
9259 exec_direction
= exec_forward
;
9260 error (_("Target does not support this operation."));
9265 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9266 struct cmd_list_element
*cmd
, const char *value
)
9268 switch (execution_direction
) {
9270 fprintf_filtered (out
, _("Forward.\n"));
9273 fprintf_filtered (out
, _("Reverse.\n"));
9276 internal_error (__FILE__
, __LINE__
,
9277 _("bogus execution_direction value: %d"),
9278 (int) execution_direction
);
9283 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9284 struct cmd_list_element
*c
, const char *value
)
9286 fprintf_filtered (file
, _("Resuming the execution of threads "
9287 "of all processes is %s.\n"), value
);
9290 /* Implementation of `siginfo' variable. */
9292 static const struct internalvar_funcs siginfo_funcs
=
9299 /* Callback for infrun's target events source. This is marked when a
9300 thread has a pending status to process. */
9303 infrun_async_inferior_event_handler (gdb_client_data data
)
9305 inferior_event_handler (INF_REG_EVENT
, NULL
);
9308 void _initialize_infrun ();
9310 _initialize_infrun ()
9312 struct cmd_list_element
*c
;
9314 /* Register extra event sources in the event loop. */
9315 infrun_async_inferior_event_token
9316 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9318 add_info ("signals", info_signals_command
, _("\
9319 What debugger does when program gets various signals.\n\
9320 Specify a signal as argument to print info on that signal only."));
9321 add_info_alias ("handle", "signals", 0);
9323 c
= add_com ("handle", class_run
, handle_command
, _("\
9324 Specify how to handle signals.\n\
9325 Usage: handle SIGNAL [ACTIONS]\n\
9326 Args are signals and actions to apply to those signals.\n\
9327 If no actions are specified, the current settings for the specified signals\n\
9328 will be displayed instead.\n\
9330 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9331 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9332 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9333 The special arg \"all\" is recognized to mean all signals except those\n\
9334 used by the debugger, typically SIGTRAP and SIGINT.\n\
9336 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9337 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9338 Stop means reenter debugger if this signal happens (implies print).\n\
9339 Print means print a message if this signal happens.\n\
9340 Pass means let program see this signal; otherwise program doesn't know.\n\
9341 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9342 Pass and Stop may be combined.\n\
9344 Multiple signals may be specified. Signal numbers and signal names\n\
9345 may be interspersed with actions, with the actions being performed for\n\
9346 all signals cumulatively specified."));
9347 set_cmd_completer (c
, handle_completer
);
9350 stop_command
= add_cmd ("stop", class_obscure
,
9351 not_just_help_class_command
, _("\
9352 There is no `stop' command, but you can set a hook on `stop'.\n\
9353 This allows you to set a list of commands to be run each time execution\n\
9354 of the program stops."), &cmdlist
);
9356 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9357 Set inferior debugging."), _("\
9358 Show inferior debugging."), _("\
9359 When non-zero, inferior specific debugging is enabled."),
9362 &setdebuglist
, &showdebuglist
);
9364 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9365 &debug_displaced
, _("\
9366 Set displaced stepping debugging."), _("\
9367 Show displaced stepping debugging."), _("\
9368 When non-zero, displaced stepping specific debugging is enabled."),
9370 show_debug_displaced
,
9371 &setdebuglist
, &showdebuglist
);
9373 add_setshow_boolean_cmd ("non-stop", no_class
,
9375 Set whether gdb controls the inferior in non-stop mode."), _("\
9376 Show whether gdb controls the inferior in non-stop mode."), _("\
9377 When debugging a multi-threaded program and this setting is\n\
9378 off (the default, also called all-stop mode), when one thread stops\n\
9379 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9380 all other threads in the program while you interact with the thread of\n\
9381 interest. When you continue or step a thread, you can allow the other\n\
9382 threads to run, or have them remain stopped, but while you inspect any\n\
9383 thread's state, all threads stop.\n\
9385 In non-stop mode, when one thread stops, other threads can continue\n\
9386 to run freely. You'll be able to step each thread independently,\n\
9387 leave it stopped or free to run as needed."),
9393 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9396 signal_print
[i
] = 1;
9397 signal_program
[i
] = 1;
9398 signal_catch
[i
] = 0;
9401 /* Signals caused by debugger's own actions should not be given to
9402 the program afterwards.
9404 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9405 explicitly specifies that it should be delivered to the target
9406 program. Typically, that would occur when a user is debugging a
9407 target monitor on a simulator: the target monitor sets a
9408 breakpoint; the simulator encounters this breakpoint and halts
9409 the simulation handing control to GDB; GDB, noting that the stop
9410 address doesn't map to any known breakpoint, returns control back
9411 to the simulator; the simulator then delivers the hardware
9412 equivalent of a GDB_SIGNAL_TRAP to the program being
9414 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9415 signal_program
[GDB_SIGNAL_INT
] = 0;
9417 /* Signals that are not errors should not normally enter the debugger. */
9418 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9419 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9420 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9421 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9422 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9423 signal_print
[GDB_SIGNAL_PROF
] = 0;
9424 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9425 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9426 signal_stop
[GDB_SIGNAL_IO
] = 0;
9427 signal_print
[GDB_SIGNAL_IO
] = 0;
9428 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9429 signal_print
[GDB_SIGNAL_POLL
] = 0;
9430 signal_stop
[GDB_SIGNAL_URG
] = 0;
9431 signal_print
[GDB_SIGNAL_URG
] = 0;
9432 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9433 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9434 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9435 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9437 /* These signals are used internally by user-level thread
9438 implementations. (See signal(5) on Solaris.) Like the above
9439 signals, a healthy program receives and handles them as part of
9440 its normal operation. */
9441 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9442 signal_print
[GDB_SIGNAL_LWP
] = 0;
9443 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9444 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9445 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9446 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9447 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9448 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9450 /* Update cached state. */
9451 signal_cache_update (-1);
9453 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9454 &stop_on_solib_events
, _("\
9455 Set stopping for shared library events."), _("\
9456 Show stopping for shared library events."), _("\
9457 If nonzero, gdb will give control to the user when the dynamic linker\n\
9458 notifies gdb of shared library events. The most common event of interest\n\
9459 to the user would be loading/unloading of a new library."),
9460 set_stop_on_solib_events
,
9461 show_stop_on_solib_events
,
9462 &setlist
, &showlist
);
9464 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9465 follow_fork_mode_kind_names
,
9466 &follow_fork_mode_string
, _("\
9467 Set debugger response to a program call of fork or vfork."), _("\
9468 Show debugger response to a program call of fork or vfork."), _("\
9469 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9470 parent - the original process is debugged after a fork\n\
9471 child - the new process is debugged after a fork\n\
9472 The unfollowed process will continue to run.\n\
9473 By default, the debugger will follow the parent process."),
9475 show_follow_fork_mode_string
,
9476 &setlist
, &showlist
);
9478 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9479 follow_exec_mode_names
,
9480 &follow_exec_mode_string
, _("\
9481 Set debugger response to a program call of exec."), _("\
9482 Show debugger response to a program call of exec."), _("\
9483 An exec call replaces the program image of a process.\n\
9485 follow-exec-mode can be:\n\
9487 new - the debugger creates a new inferior and rebinds the process\n\
9488 to this new inferior. The program the process was running before\n\
9489 the exec call can be restarted afterwards by restarting the original\n\
9492 same - the debugger keeps the process bound to the same inferior.\n\
9493 The new executable image replaces the previous executable loaded in\n\
9494 the inferior. Restarting the inferior after the exec call restarts\n\
9495 the executable the process was running after the exec call.\n\
9497 By default, the debugger will use the same inferior."),
9499 show_follow_exec_mode_string
,
9500 &setlist
, &showlist
);
9502 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9503 scheduler_enums
, &scheduler_mode
, _("\
9504 Set mode for locking scheduler during execution."), _("\
9505 Show mode for locking scheduler during execution."), _("\
9506 off == no locking (threads may preempt at any time)\n\
9507 on == full locking (no thread except the current thread may run)\n\
9508 This applies to both normal execution and replay mode.\n\
9509 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9510 In this mode, other threads may run during other commands.\n\
9511 This applies to both normal execution and replay mode.\n\
9512 replay == scheduler locked in replay mode and unlocked during normal execution."),
9513 set_schedlock_func
, /* traps on target vector */
9514 show_scheduler_mode
,
9515 &setlist
, &showlist
);
9517 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9518 Set mode for resuming threads of all processes."), _("\
9519 Show mode for resuming threads of all processes."), _("\
9520 When on, execution commands (such as 'continue' or 'next') resume all\n\
9521 threads of all processes. When off (which is the default), execution\n\
9522 commands only resume the threads of the current process. The set of\n\
9523 threads that are resumed is further refined by the scheduler-locking\n\
9524 mode (see help set scheduler-locking)."),
9526 show_schedule_multiple
,
9527 &setlist
, &showlist
);
9529 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9530 Set mode of the step operation."), _("\
9531 Show mode of the step operation."), _("\
9532 When set, doing a step over a function without debug line information\n\
9533 will stop at the first instruction of that function. Otherwise, the\n\
9534 function is skipped and the step command stops at a different source line."),
9536 show_step_stop_if_no_debug
,
9537 &setlist
, &showlist
);
9539 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9540 &can_use_displaced_stepping
, _("\
9541 Set debugger's willingness to use displaced stepping."), _("\
9542 Show debugger's willingness to use displaced stepping."), _("\
9543 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9544 supported by the target architecture. If off, gdb will not use displaced\n\
9545 stepping to step over breakpoints, even if such is supported by the target\n\
9546 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9547 if the target architecture supports it and non-stop mode is active, but will not\n\
9548 use it in all-stop mode (see help set non-stop)."),
9550 show_can_use_displaced_stepping
,
9551 &setlist
, &showlist
);
9553 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9554 &exec_direction
, _("Set direction of execution.\n\
9555 Options are 'forward' or 'reverse'."),
9556 _("Show direction of execution (forward/reverse)."),
9557 _("Tells gdb whether to execute forward or backward."),
9558 set_exec_direction_func
, show_exec_direction_func
,
9559 &setlist
, &showlist
);
9561 /* Set/show detach-on-fork: user-settable mode. */
9563 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9564 Set whether gdb will detach the child of a fork."), _("\
9565 Show whether gdb will detach the child of a fork."), _("\
9566 Tells gdb whether to detach the child of a fork."),
9567 NULL
, NULL
, &setlist
, &showlist
);
9569 /* Set/show disable address space randomization mode. */
9571 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9572 &disable_randomization
, _("\
9573 Set disabling of debuggee's virtual address space randomization."), _("\
9574 Show disabling of debuggee's virtual address space randomization."), _("\
9575 When this mode is on (which is the default), randomization of the virtual\n\
9576 address space is disabled. Standalone programs run with the randomization\n\
9577 enabled by default on some platforms."),
9578 &set_disable_randomization
,
9579 &show_disable_randomization
,
9580 &setlist
, &showlist
);
9582 /* ptid initializations */
9583 inferior_ptid
= null_ptid
;
9584 target_last_wait_ptid
= minus_one_ptid
;
9586 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9587 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9588 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9589 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9591 /* Explicitly create without lookup, since that tries to create a
9592 value with a void typed value, and when we get here, gdbarch
9593 isn't initialized yet. At this point, we're quite sure there
9594 isn't another convenience variable of the same name. */
9595 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9597 add_setshow_boolean_cmd ("observer", no_class
,
9598 &observer_mode_1
, _("\
9599 Set whether gdb controls the inferior in observer mode."), _("\
9600 Show whether gdb controls the inferior in observer mode."), _("\
9601 In observer mode, GDB can get data from the inferior, but not\n\
9602 affect its execution. Registers and memory may not be changed,\n\
9603 breakpoints may not be set, and the program cannot be interrupted\n\