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
;
1649 struct displaced_step_closure
*closure
;
1652 /* We should never reach this function if the architecture does not
1653 support displaced stepping. */
1654 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1656 /* Nor if the thread isn't meant to step over a breakpoint. */
1657 gdb_assert (tp
->control
.trap_expected
);
1659 /* Disable range stepping while executing in the scratch pad. We
1660 want a single-step even if executing the displaced instruction in
1661 the scratch buffer lands within the stepping range (e.g., a
1663 tp
->control
.may_range_step
= 0;
1665 /* We have to displaced step one thread at a time, as we only have
1666 access to a single scratch space per inferior. */
1668 displaced_step_inferior_state
*displaced
1669 = get_displaced_stepping_state (tp
->inf
);
1671 if (displaced
->step_thread
!= nullptr)
1673 /* Already waiting for a displaced step to finish. Defer this
1674 request and place in queue. */
1676 if (debug_displaced
)
1677 fprintf_unfiltered (gdb_stdlog
,
1678 "displaced: deferring step of %s\n",
1679 target_pid_to_str (tp
->ptid
).c_str ());
1681 thread_step_over_chain_enqueue (tp
);
1686 if (debug_displaced
)
1687 fprintf_unfiltered (gdb_stdlog
,
1688 "displaced: stepping %s now\n",
1689 target_pid_to_str (tp
->ptid
).c_str ());
1692 displaced_step_reset (displaced
);
1694 scoped_restore_current_thread restore_thread
;
1696 switch_to_thread (tp
);
1698 original
= regcache_read_pc (regcache
);
1700 copy
= gdbarch_displaced_step_location (gdbarch
);
1701 len
= gdbarch_max_insn_length (gdbarch
);
1703 if (breakpoint_in_range_p (aspace
, copy
, len
))
1705 /* There's a breakpoint set in the scratch pad location range
1706 (which is usually around the entry point). We'd either
1707 install it before resuming, which would overwrite/corrupt the
1708 scratch pad, or if it was already inserted, this displaced
1709 step would overwrite it. The latter is OK in the sense that
1710 we already assume that no thread is going to execute the code
1711 in the scratch pad range (after initial startup) anyway, but
1712 the former is unacceptable. Simply punt and fallback to
1713 stepping over this breakpoint in-line. */
1714 if (debug_displaced
)
1716 fprintf_unfiltered (gdb_stdlog
,
1717 "displaced: breakpoint set in scratch pad. "
1718 "Stepping over breakpoint in-line instead.\n");
1724 /* Save the original contents of the copy area. */
1725 displaced
->step_saved_copy
.resize (len
);
1726 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1728 throw_error (MEMORY_ERROR
,
1729 _("Error accessing memory address %s (%s) for "
1730 "displaced-stepping scratch space."),
1731 paddress (gdbarch
, copy
), safe_strerror (status
));
1732 if (debug_displaced
)
1734 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1735 paddress (gdbarch
, copy
));
1736 displaced_step_dump_bytes (gdb_stdlog
,
1737 displaced
->step_saved_copy
.data (),
1741 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1742 original
, copy
, regcache
);
1743 if (closure
== NULL
)
1745 /* The architecture doesn't know how or want to displaced step
1746 this instruction or instruction sequence. Fallback to
1747 stepping over the breakpoint in-line. */
1751 /* Save the information we need to fix things up if the step
1753 displaced
->step_thread
= tp
;
1754 displaced
->step_gdbarch
= gdbarch
;
1755 displaced
->step_closure
.reset (closure
);
1756 displaced
->step_original
= original
;
1757 displaced
->step_copy
= copy
;
1760 displaced_step_reset_cleanup
cleanup (displaced
);
1762 /* Resume execution at the copy. */
1763 regcache_write_pc (regcache
, copy
);
1768 if (debug_displaced
)
1769 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1770 paddress (gdbarch
, copy
));
1775 /* Wrapper for displaced_step_prepare_throw that disabled further
1776 attempts at displaced stepping if we get a memory error. */
1779 displaced_step_prepare (thread_info
*thread
)
1785 prepared
= displaced_step_prepare_throw (thread
);
1787 catch (const gdb_exception_error
&ex
)
1789 struct displaced_step_inferior_state
*displaced_state
;
1791 if (ex
.error
!= MEMORY_ERROR
1792 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1797 fprintf_unfiltered (gdb_stdlog
,
1798 "infrun: disabling displaced stepping: %s\n",
1802 /* Be verbose if "set displaced-stepping" is "on", silent if
1804 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1806 warning (_("disabling displaced stepping: %s"),
1810 /* Disable further displaced stepping attempts. */
1812 = get_displaced_stepping_state (thread
->inf
);
1813 displaced_state
->failed_before
= 1;
1820 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1821 const gdb_byte
*myaddr
, int len
)
1823 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1825 inferior_ptid
= ptid
;
1826 write_memory (memaddr
, myaddr
, len
);
1829 /* Restore the contents of the copy area for thread PTID. */
1832 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1835 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1837 write_memory_ptid (ptid
, displaced
->step_copy
,
1838 displaced
->step_saved_copy
.data (), len
);
1839 if (debug_displaced
)
1840 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1841 target_pid_to_str (ptid
).c_str (),
1842 paddress (displaced
->step_gdbarch
,
1843 displaced
->step_copy
));
1846 /* If we displaced stepped an instruction successfully, adjust
1847 registers and memory to yield the same effect the instruction would
1848 have had if we had executed it at its original address, and return
1849 1. If the instruction didn't complete, relocate the PC and return
1850 -1. If the thread wasn't displaced stepping, return 0. */
1853 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1855 struct displaced_step_inferior_state
*displaced
1856 = get_displaced_stepping_state (event_thread
->inf
);
1859 /* Was this event for the thread we displaced? */
1860 if (displaced
->step_thread
!= event_thread
)
1863 displaced_step_reset_cleanup
cleanup (displaced
);
1865 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1867 /* Fixup may need to read memory/registers. Switch to the thread
1868 that we're fixing up. Also, target_stopped_by_watchpoint checks
1869 the current thread. */
1870 switch_to_thread (event_thread
);
1872 /* Did the instruction complete successfully? */
1873 if (signal
== GDB_SIGNAL_TRAP
1874 && !(target_stopped_by_watchpoint ()
1875 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1876 || target_have_steppable_watchpoint
)))
1878 /* Fix up the resulting state. */
1879 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1880 displaced
->step_closure
.get (),
1881 displaced
->step_original
,
1882 displaced
->step_copy
,
1883 get_thread_regcache (displaced
->step_thread
));
1888 /* Since the instruction didn't complete, all we can do is
1890 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1891 CORE_ADDR pc
= regcache_read_pc (regcache
);
1893 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1894 regcache_write_pc (regcache
, pc
);
1901 /* Data to be passed around while handling an event. This data is
1902 discarded between events. */
1903 struct execution_control_state
1905 process_stratum_target
*target
;
1907 /* The thread that got the event, if this was a thread event; NULL
1909 struct thread_info
*event_thread
;
1911 struct target_waitstatus ws
;
1912 int stop_func_filled_in
;
1913 CORE_ADDR stop_func_start
;
1914 CORE_ADDR stop_func_end
;
1915 const char *stop_func_name
;
1918 /* True if the event thread hit the single-step breakpoint of
1919 another thread. Thus the event doesn't cause a stop, the thread
1920 needs to be single-stepped past the single-step breakpoint before
1921 we can switch back to the original stepping thread. */
1922 int hit_singlestep_breakpoint
;
1925 /* Clear ECS and set it to point at TP. */
1928 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1930 memset (ecs
, 0, sizeof (*ecs
));
1931 ecs
->event_thread
= tp
;
1932 ecs
->ptid
= tp
->ptid
;
1935 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1936 static void prepare_to_wait (struct execution_control_state
*ecs
);
1937 static int keep_going_stepped_thread (struct thread_info
*tp
);
1938 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1940 /* Are there any pending step-over requests? If so, run all we can
1941 now and return true. Otherwise, return false. */
1944 start_step_over (void)
1946 struct thread_info
*tp
, *next
;
1948 /* Don't start a new step-over if we already have an in-line
1949 step-over operation ongoing. */
1950 if (step_over_info_valid_p ())
1953 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1955 struct execution_control_state ecss
;
1956 struct execution_control_state
*ecs
= &ecss
;
1957 step_over_what step_what
;
1958 int must_be_in_line
;
1960 gdb_assert (!tp
->stop_requested
);
1962 next
= thread_step_over_chain_next (tp
);
1964 /* If this inferior already has a displaced step in process,
1965 don't start a new one. */
1966 if (displaced_step_in_progress (tp
->inf
))
1969 step_what
= thread_still_needs_step_over (tp
);
1970 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1971 || ((step_what
& STEP_OVER_BREAKPOINT
)
1972 && !use_displaced_stepping (tp
)));
1974 /* We currently stop all threads of all processes to step-over
1975 in-line. If we need to start a new in-line step-over, let
1976 any pending displaced steps finish first. */
1977 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1980 thread_step_over_chain_remove (tp
);
1982 if (step_over_queue_head
== NULL
)
1985 fprintf_unfiltered (gdb_stdlog
,
1986 "infrun: step-over queue now empty\n");
1989 if (tp
->control
.trap_expected
1993 internal_error (__FILE__
, __LINE__
,
1994 "[%s] has inconsistent state: "
1995 "trap_expected=%d, resumed=%d, executing=%d\n",
1996 target_pid_to_str (tp
->ptid
).c_str (),
1997 tp
->control
.trap_expected
,
2003 fprintf_unfiltered (gdb_stdlog
,
2004 "infrun: resuming [%s] for step-over\n",
2005 target_pid_to_str (tp
->ptid
).c_str ());
2007 /* keep_going_pass_signal skips the step-over if the breakpoint
2008 is no longer inserted. In all-stop, we want to keep looking
2009 for a thread that needs a step-over instead of resuming TP,
2010 because we wouldn't be able to resume anything else until the
2011 target stops again. In non-stop, the resume always resumes
2012 only TP, so it's OK to let the thread resume freely. */
2013 if (!target_is_non_stop_p () && !step_what
)
2016 switch_to_thread (tp
);
2017 reset_ecs (ecs
, tp
);
2018 keep_going_pass_signal (ecs
);
2020 if (!ecs
->wait_some_more
)
2021 error (_("Command aborted."));
2023 gdb_assert (tp
->resumed
);
2025 /* If we started a new in-line step-over, we're done. */
2026 if (step_over_info_valid_p ())
2028 gdb_assert (tp
->control
.trap_expected
);
2032 if (!target_is_non_stop_p ())
2034 /* On all-stop, shouldn't have resumed unless we needed a
2036 gdb_assert (tp
->control
.trap_expected
2037 || tp
->step_after_step_resume_breakpoint
);
2039 /* With remote targets (at least), in all-stop, we can't
2040 issue any further remote commands until the program stops
2045 /* Either the thread no longer needed a step-over, or a new
2046 displaced stepping sequence started. Even in the latter
2047 case, continue looking. Maybe we can also start another
2048 displaced step on a thread of other process. */
2054 /* Update global variables holding ptids to hold NEW_PTID if they were
2055 holding OLD_PTID. */
2057 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2059 if (inferior_ptid
== old_ptid
)
2060 inferior_ptid
= new_ptid
;
2065 static const char schedlock_off
[] = "off";
2066 static const char schedlock_on
[] = "on";
2067 static const char schedlock_step
[] = "step";
2068 static const char schedlock_replay
[] = "replay";
2069 static const char *const scheduler_enums
[] = {
2076 static const char *scheduler_mode
= schedlock_replay
;
2078 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2079 struct cmd_list_element
*c
, const char *value
)
2081 fprintf_filtered (file
,
2082 _("Mode for locking scheduler "
2083 "during execution is \"%s\".\n"),
2088 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2090 if (!target_can_lock_scheduler
)
2092 scheduler_mode
= schedlock_off
;
2093 error (_("Target '%s' cannot support this command."), target_shortname
);
2097 /* True if execution commands resume all threads of all processes by
2098 default; otherwise, resume only threads of the current inferior
2100 bool sched_multi
= false;
2102 /* Try to setup for software single stepping over the specified location.
2103 Return 1 if target_resume() should use hardware single step.
2105 GDBARCH the current gdbarch.
2106 PC the location to step over. */
2109 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2113 if (execution_direction
== EXEC_FORWARD
2114 && gdbarch_software_single_step_p (gdbarch
))
2115 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2123 user_visible_resume_ptid (int step
)
2129 /* With non-stop mode on, threads are always handled
2131 resume_ptid
= inferior_ptid
;
2133 else if ((scheduler_mode
== schedlock_on
)
2134 || (scheduler_mode
== schedlock_step
&& step
))
2136 /* User-settable 'scheduler' mode requires solo thread
2138 resume_ptid
= inferior_ptid
;
2140 else if ((scheduler_mode
== schedlock_replay
)
2141 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2143 /* User-settable 'scheduler' mode requires solo thread resume in replay
2145 resume_ptid
= inferior_ptid
;
2147 else if (!sched_multi
&& target_supports_multi_process ())
2149 /* Resume all threads of the current process (and none of other
2151 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2155 /* Resume all threads of all processes. */
2156 resume_ptid
= RESUME_ALL
;
2164 process_stratum_target
*
2165 user_visible_resume_target (ptid_t resume_ptid
)
2167 return (resume_ptid
== minus_one_ptid
&& sched_multi
2169 : current_inferior ()->process_target ());
2172 /* Return a ptid representing the set of threads that we will resume,
2173 in the perspective of the target, assuming run control handling
2174 does not require leaving some threads stopped (e.g., stepping past
2175 breakpoint). USER_STEP indicates whether we're about to start the
2176 target for a stepping command. */
2179 internal_resume_ptid (int user_step
)
2181 /* In non-stop, we always control threads individually. Note that
2182 the target may always work in non-stop mode even with "set
2183 non-stop off", in which case user_visible_resume_ptid could
2184 return a wildcard ptid. */
2185 if (target_is_non_stop_p ())
2186 return inferior_ptid
;
2188 return user_visible_resume_ptid (user_step
);
2191 /* Wrapper for target_resume, that handles infrun-specific
2195 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2197 struct thread_info
*tp
= inferior_thread ();
2199 gdb_assert (!tp
->stop_requested
);
2201 /* Install inferior's terminal modes. */
2202 target_terminal::inferior ();
2204 /* Avoid confusing the next resume, if the next stop/resume
2205 happens to apply to another thread. */
2206 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2208 /* Advise target which signals may be handled silently.
2210 If we have removed breakpoints because we are stepping over one
2211 in-line (in any thread), we need to receive all signals to avoid
2212 accidentally skipping a breakpoint during execution of a signal
2215 Likewise if we're displaced stepping, otherwise a trap for a
2216 breakpoint in a signal handler might be confused with the
2217 displaced step finishing. We don't make the displaced_step_fixup
2218 step distinguish the cases instead, because:
2220 - a backtrace while stopped in the signal handler would show the
2221 scratch pad as frame older than the signal handler, instead of
2222 the real mainline code.
2224 - when the thread is later resumed, the signal handler would
2225 return to the scratch pad area, which would no longer be
2227 if (step_over_info_valid_p ()
2228 || displaced_step_in_progress (tp
->inf
))
2229 target_pass_signals ({});
2231 target_pass_signals (signal_pass
);
2233 target_resume (resume_ptid
, step
, sig
);
2235 target_commit_resume ();
2237 if (target_can_async_p ())
2241 /* Resume the inferior. SIG is the signal to give the inferior
2242 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2243 call 'resume', which handles exceptions. */
2246 resume_1 (enum gdb_signal sig
)
2248 struct regcache
*regcache
= get_current_regcache ();
2249 struct gdbarch
*gdbarch
= regcache
->arch ();
2250 struct thread_info
*tp
= inferior_thread ();
2251 CORE_ADDR pc
= regcache_read_pc (regcache
);
2252 const address_space
*aspace
= regcache
->aspace ();
2254 /* This represents the user's step vs continue request. When
2255 deciding whether "set scheduler-locking step" applies, it's the
2256 user's intention that counts. */
2257 const int user_step
= tp
->control
.stepping_command
;
2258 /* This represents what we'll actually request the target to do.
2259 This can decay from a step to a continue, if e.g., we need to
2260 implement single-stepping with breakpoints (software
2264 gdb_assert (!tp
->stop_requested
);
2265 gdb_assert (!thread_is_in_step_over_chain (tp
));
2267 if (tp
->suspend
.waitstatus_pending_p
)
2272 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2274 fprintf_unfiltered (gdb_stdlog
,
2275 "infrun: resume: thread %s has pending wait "
2276 "status %s (currently_stepping=%d).\n",
2277 target_pid_to_str (tp
->ptid
).c_str (),
2279 currently_stepping (tp
));
2282 tp
->inf
->process_target ()->threads_executing
= true;
2285 /* FIXME: What should we do if we are supposed to resume this
2286 thread with a signal? Maybe we should maintain a queue of
2287 pending signals to deliver. */
2288 if (sig
!= GDB_SIGNAL_0
)
2290 warning (_("Couldn't deliver signal %s to %s."),
2291 gdb_signal_to_name (sig
),
2292 target_pid_to_str (tp
->ptid
).c_str ());
2295 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2297 if (target_can_async_p ())
2300 /* Tell the event loop we have an event to process. */
2301 mark_async_event_handler (infrun_async_inferior_event_token
);
2306 tp
->stepped_breakpoint
= 0;
2308 /* Depends on stepped_breakpoint. */
2309 step
= currently_stepping (tp
);
2311 if (current_inferior ()->waiting_for_vfork_done
)
2313 /* Don't try to single-step a vfork parent that is waiting for
2314 the child to get out of the shared memory region (by exec'ing
2315 or exiting). This is particularly important on software
2316 single-step archs, as the child process would trip on the
2317 software single step breakpoint inserted for the parent
2318 process. Since the parent will not actually execute any
2319 instruction until the child is out of the shared region (such
2320 are vfork's semantics), it is safe to simply continue it.
2321 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2322 the parent, and tell it to `keep_going', which automatically
2323 re-sets it stepping. */
2325 fprintf_unfiltered (gdb_stdlog
,
2326 "infrun: resume : clear step\n");
2331 fprintf_unfiltered (gdb_stdlog
,
2332 "infrun: resume (step=%d, signal=%s), "
2333 "trap_expected=%d, current thread [%s] at %s\n",
2334 step
, gdb_signal_to_symbol_string (sig
),
2335 tp
->control
.trap_expected
,
2336 target_pid_to_str (inferior_ptid
).c_str (),
2337 paddress (gdbarch
, pc
));
2339 /* Normally, by the time we reach `resume', the breakpoints are either
2340 removed or inserted, as appropriate. The exception is if we're sitting
2341 at a permanent breakpoint; we need to step over it, but permanent
2342 breakpoints can't be removed. So we have to test for it here. */
2343 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2345 if (sig
!= GDB_SIGNAL_0
)
2347 /* We have a signal to pass to the inferior. The resume
2348 may, or may not take us to the signal handler. If this
2349 is a step, we'll need to stop in the signal handler, if
2350 there's one, (if the target supports stepping into
2351 handlers), or in the next mainline instruction, if
2352 there's no handler. If this is a continue, we need to be
2353 sure to run the handler with all breakpoints inserted.
2354 In all cases, set a breakpoint at the current address
2355 (where the handler returns to), and once that breakpoint
2356 is hit, resume skipping the permanent breakpoint. If
2357 that breakpoint isn't hit, then we've stepped into the
2358 signal handler (or hit some other event). We'll delete
2359 the step-resume breakpoint then. */
2362 fprintf_unfiltered (gdb_stdlog
,
2363 "infrun: resume: skipping permanent breakpoint, "
2364 "deliver signal first\n");
2366 clear_step_over_info ();
2367 tp
->control
.trap_expected
= 0;
2369 if (tp
->control
.step_resume_breakpoint
== NULL
)
2371 /* Set a "high-priority" step-resume, as we don't want
2372 user breakpoints at PC to trigger (again) when this
2374 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2375 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2377 tp
->step_after_step_resume_breakpoint
= step
;
2380 insert_breakpoints ();
2384 /* There's no signal to pass, we can go ahead and skip the
2385 permanent breakpoint manually. */
2387 fprintf_unfiltered (gdb_stdlog
,
2388 "infrun: resume: skipping permanent breakpoint\n");
2389 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2390 /* Update pc to reflect the new address from which we will
2391 execute instructions. */
2392 pc
= regcache_read_pc (regcache
);
2396 /* We've already advanced the PC, so the stepping part
2397 is done. Now we need to arrange for a trap to be
2398 reported to handle_inferior_event. Set a breakpoint
2399 at the current PC, and run to it. Don't update
2400 prev_pc, because if we end in
2401 switch_back_to_stepped_thread, we want the "expected
2402 thread advanced also" branch to be taken. IOW, we
2403 don't want this thread to step further from PC
2405 gdb_assert (!step_over_info_valid_p ());
2406 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2407 insert_breakpoints ();
2409 resume_ptid
= internal_resume_ptid (user_step
);
2410 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2417 /* If we have a breakpoint to step over, make sure to do a single
2418 step only. Same if we have software watchpoints. */
2419 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2420 tp
->control
.may_range_step
= 0;
2422 /* If displaced stepping is enabled, step over breakpoints by executing a
2423 copy of the instruction at a different address.
2425 We can't use displaced stepping when we have a signal to deliver;
2426 the comments for displaced_step_prepare explain why. The
2427 comments in the handle_inferior event for dealing with 'random
2428 signals' explain what we do instead.
2430 We can't use displaced stepping when we are waiting for vfork_done
2431 event, displaced stepping breaks the vfork child similarly as single
2432 step software breakpoint. */
2433 if (tp
->control
.trap_expected
2434 && use_displaced_stepping (tp
)
2435 && !step_over_info_valid_p ()
2436 && sig
== GDB_SIGNAL_0
2437 && !current_inferior ()->waiting_for_vfork_done
)
2439 int prepared
= displaced_step_prepare (tp
);
2444 fprintf_unfiltered (gdb_stdlog
,
2445 "Got placed in step-over queue\n");
2447 tp
->control
.trap_expected
= 0;
2450 else if (prepared
< 0)
2452 /* Fallback to stepping over the breakpoint in-line. */
2454 if (target_is_non_stop_p ())
2455 stop_all_threads ();
2457 set_step_over_info (regcache
->aspace (),
2458 regcache_read_pc (regcache
), 0, tp
->global_num
);
2460 step
= maybe_software_singlestep (gdbarch
, pc
);
2462 insert_breakpoints ();
2464 else if (prepared
> 0)
2466 struct displaced_step_inferior_state
*displaced
;
2468 /* Update pc to reflect the new address from which we will
2469 execute instructions due to displaced stepping. */
2470 pc
= regcache_read_pc (get_thread_regcache (tp
));
2472 displaced
= get_displaced_stepping_state (tp
->inf
);
2473 step
= gdbarch_displaced_step_hw_singlestep
2474 (gdbarch
, displaced
->step_closure
.get ());
2478 /* Do we need to do it the hard way, w/temp breakpoints? */
2480 step
= maybe_software_singlestep (gdbarch
, pc
);
2482 /* Currently, our software single-step implementation leads to different
2483 results than hardware single-stepping in one situation: when stepping
2484 into delivering a signal which has an associated signal handler,
2485 hardware single-step will stop at the first instruction of the handler,
2486 while software single-step will simply skip execution of the handler.
2488 For now, this difference in behavior is accepted since there is no
2489 easy way to actually implement single-stepping into a signal handler
2490 without kernel support.
2492 However, there is one scenario where this difference leads to follow-on
2493 problems: if we're stepping off a breakpoint by removing all breakpoints
2494 and then single-stepping. In this case, the software single-step
2495 behavior means that even if there is a *breakpoint* in the signal
2496 handler, GDB still would not stop.
2498 Fortunately, we can at least fix this particular issue. We detect
2499 here the case where we are about to deliver a signal while software
2500 single-stepping with breakpoints removed. In this situation, we
2501 revert the decisions to remove all breakpoints and insert single-
2502 step breakpoints, and instead we install a step-resume breakpoint
2503 at the current address, deliver the signal without stepping, and
2504 once we arrive back at the step-resume breakpoint, actually step
2505 over the breakpoint we originally wanted to step over. */
2506 if (thread_has_single_step_breakpoints_set (tp
)
2507 && sig
!= GDB_SIGNAL_0
2508 && step_over_info_valid_p ())
2510 /* If we have nested signals or a pending signal is delivered
2511 immediately after a handler returns, might already have
2512 a step-resume breakpoint set on the earlier handler. We cannot
2513 set another step-resume breakpoint; just continue on until the
2514 original breakpoint is hit. */
2515 if (tp
->control
.step_resume_breakpoint
== NULL
)
2517 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2518 tp
->step_after_step_resume_breakpoint
= 1;
2521 delete_single_step_breakpoints (tp
);
2523 clear_step_over_info ();
2524 tp
->control
.trap_expected
= 0;
2526 insert_breakpoints ();
2529 /* If STEP is set, it's a request to use hardware stepping
2530 facilities. But in that case, we should never
2531 use singlestep breakpoint. */
2532 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2534 /* Decide the set of threads to ask the target to resume. */
2535 if (tp
->control
.trap_expected
)
2537 /* We're allowing a thread to run past a breakpoint it has
2538 hit, either by single-stepping the thread with the breakpoint
2539 removed, or by displaced stepping, with the breakpoint inserted.
2540 In the former case, we need to single-step only this thread,
2541 and keep others stopped, as they can miss this breakpoint if
2542 allowed to run. That's not really a problem for displaced
2543 stepping, but, we still keep other threads stopped, in case
2544 another thread is also stopped for a breakpoint waiting for
2545 its turn in the displaced stepping queue. */
2546 resume_ptid
= inferior_ptid
;
2549 resume_ptid
= internal_resume_ptid (user_step
);
2551 if (execution_direction
!= EXEC_REVERSE
2552 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2554 /* There are two cases where we currently need to step a
2555 breakpoint instruction when we have a signal to deliver:
2557 - See handle_signal_stop where we handle random signals that
2558 could take out us out of the stepping range. Normally, in
2559 that case we end up continuing (instead of stepping) over the
2560 signal handler with a breakpoint at PC, but there are cases
2561 where we should _always_ single-step, even if we have a
2562 step-resume breakpoint, like when a software watchpoint is
2563 set. Assuming single-stepping and delivering a signal at the
2564 same time would takes us to the signal handler, then we could
2565 have removed the breakpoint at PC to step over it. However,
2566 some hardware step targets (like e.g., Mac OS) can't step
2567 into signal handlers, and for those, we need to leave the
2568 breakpoint at PC inserted, as otherwise if the handler
2569 recurses and executes PC again, it'll miss the breakpoint.
2570 So we leave the breakpoint inserted anyway, but we need to
2571 record that we tried to step a breakpoint instruction, so
2572 that adjust_pc_after_break doesn't end up confused.
2574 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2575 in one thread after another thread that was stepping had been
2576 momentarily paused for a step-over. When we re-resume the
2577 stepping thread, it may be resumed from that address with a
2578 breakpoint that hasn't trapped yet. Seen with
2579 gdb.threads/non-stop-fair-events.exp, on targets that don't
2580 do displaced stepping. */
2583 fprintf_unfiltered (gdb_stdlog
,
2584 "infrun: resume: [%s] stepped breakpoint\n",
2585 target_pid_to_str (tp
->ptid
).c_str ());
2587 tp
->stepped_breakpoint
= 1;
2589 /* Most targets can step a breakpoint instruction, thus
2590 executing it normally. But if this one cannot, just
2591 continue and we will hit it anyway. */
2592 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2597 && tp
->control
.trap_expected
2598 && use_displaced_stepping (tp
)
2599 && !step_over_info_valid_p ())
2601 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2602 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2603 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2606 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2607 paddress (resume_gdbarch
, actual_pc
));
2608 read_memory (actual_pc
, buf
, sizeof (buf
));
2609 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2612 if (tp
->control
.may_range_step
)
2614 /* If we're resuming a thread with the PC out of the step
2615 range, then we're doing some nested/finer run control
2616 operation, like stepping the thread out of the dynamic
2617 linker or the displaced stepping scratch pad. We
2618 shouldn't have allowed a range step then. */
2619 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2622 do_target_resume (resume_ptid
, step
, sig
);
2626 /* Resume the inferior. SIG is the signal to give the inferior
2627 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2628 rolls back state on error. */
2631 resume (gdb_signal sig
)
2637 catch (const gdb_exception
&ex
)
2639 /* If resuming is being aborted for any reason, delete any
2640 single-step breakpoint resume_1 may have created, to avoid
2641 confusing the following resumption, and to avoid leaving
2642 single-step breakpoints perturbing other threads, in case
2643 we're running in non-stop mode. */
2644 if (inferior_ptid
!= null_ptid
)
2645 delete_single_step_breakpoints (inferior_thread ());
2655 /* Counter that tracks number of user visible stops. This can be used
2656 to tell whether a command has proceeded the inferior past the
2657 current location. This allows e.g., inferior function calls in
2658 breakpoint commands to not interrupt the command list. When the
2659 call finishes successfully, the inferior is standing at the same
2660 breakpoint as if nothing happened (and so we don't call
2662 static ULONGEST current_stop_id
;
2669 return current_stop_id
;
2672 /* Called when we report a user visible stop. */
2680 /* Clear out all variables saying what to do when inferior is continued.
2681 First do this, then set the ones you want, then call `proceed'. */
2684 clear_proceed_status_thread (struct thread_info
*tp
)
2687 fprintf_unfiltered (gdb_stdlog
,
2688 "infrun: clear_proceed_status_thread (%s)\n",
2689 target_pid_to_str (tp
->ptid
).c_str ());
2691 /* If we're starting a new sequence, then the previous finished
2692 single-step is no longer relevant. */
2693 if (tp
->suspend
.waitstatus_pending_p
)
2695 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2698 fprintf_unfiltered (gdb_stdlog
,
2699 "infrun: clear_proceed_status: pending "
2700 "event of %s was a finished step. "
2702 target_pid_to_str (tp
->ptid
).c_str ());
2704 tp
->suspend
.waitstatus_pending_p
= 0;
2705 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2707 else if (debug_infrun
)
2710 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2712 fprintf_unfiltered (gdb_stdlog
,
2713 "infrun: clear_proceed_status_thread: thread %s "
2714 "has pending wait status %s "
2715 "(currently_stepping=%d).\n",
2716 target_pid_to_str (tp
->ptid
).c_str (),
2718 currently_stepping (tp
));
2722 /* If this signal should not be seen by program, give it zero.
2723 Used for debugging signals. */
2724 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2725 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2727 delete tp
->thread_fsm
;
2728 tp
->thread_fsm
= NULL
;
2730 tp
->control
.trap_expected
= 0;
2731 tp
->control
.step_range_start
= 0;
2732 tp
->control
.step_range_end
= 0;
2733 tp
->control
.may_range_step
= 0;
2734 tp
->control
.step_frame_id
= null_frame_id
;
2735 tp
->control
.step_stack_frame_id
= null_frame_id
;
2736 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2737 tp
->control
.step_start_function
= NULL
;
2738 tp
->stop_requested
= 0;
2740 tp
->control
.stop_step
= 0;
2742 tp
->control
.proceed_to_finish
= 0;
2744 tp
->control
.stepping_command
= 0;
2746 /* Discard any remaining commands or status from previous stop. */
2747 bpstat_clear (&tp
->control
.stop_bpstat
);
2751 clear_proceed_status (int step
)
2753 /* With scheduler-locking replay, stop replaying other threads if we're
2754 not replaying the user-visible resume ptid.
2756 This is a convenience feature to not require the user to explicitly
2757 stop replaying the other threads. We're assuming that the user's
2758 intent is to resume tracing the recorded process. */
2759 if (!non_stop
&& scheduler_mode
== schedlock_replay
2760 && target_record_is_replaying (minus_one_ptid
)
2761 && !target_record_will_replay (user_visible_resume_ptid (step
),
2762 execution_direction
))
2763 target_record_stop_replaying ();
2765 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2767 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2768 process_stratum_target
*resume_target
2769 = user_visible_resume_target (resume_ptid
);
2771 /* In all-stop mode, delete the per-thread status of all threads
2772 we're about to resume, implicitly and explicitly. */
2773 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2774 clear_proceed_status_thread (tp
);
2777 if (inferior_ptid
!= null_ptid
)
2779 struct inferior
*inferior
;
2783 /* If in non-stop mode, only delete the per-thread status of
2784 the current thread. */
2785 clear_proceed_status_thread (inferior_thread ());
2788 inferior
= current_inferior ();
2789 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2792 gdb::observers::about_to_proceed
.notify ();
2795 /* Returns true if TP is still stopped at a breakpoint that needs
2796 stepping-over in order to make progress. If the breakpoint is gone
2797 meanwhile, we can skip the whole step-over dance. */
2800 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2802 if (tp
->stepping_over_breakpoint
)
2804 struct regcache
*regcache
= get_thread_regcache (tp
);
2806 if (breakpoint_here_p (regcache
->aspace (),
2807 regcache_read_pc (regcache
))
2808 == ordinary_breakpoint_here
)
2811 tp
->stepping_over_breakpoint
= 0;
2817 /* Check whether thread TP still needs to start a step-over in order
2818 to make progress when resumed. Returns an bitwise or of enum
2819 step_over_what bits, indicating what needs to be stepped over. */
2821 static step_over_what
2822 thread_still_needs_step_over (struct thread_info
*tp
)
2824 step_over_what what
= 0;
2826 if (thread_still_needs_step_over_bp (tp
))
2827 what
|= STEP_OVER_BREAKPOINT
;
2829 if (tp
->stepping_over_watchpoint
2830 && !target_have_steppable_watchpoint
)
2831 what
|= STEP_OVER_WATCHPOINT
;
2836 /* Returns true if scheduler locking applies. STEP indicates whether
2837 we're about to do a step/next-like command to a thread. */
2840 schedlock_applies (struct thread_info
*tp
)
2842 return (scheduler_mode
== schedlock_on
2843 || (scheduler_mode
== schedlock_step
2844 && tp
->control
.stepping_command
)
2845 || (scheduler_mode
== schedlock_replay
2846 && target_record_will_replay (minus_one_ptid
,
2847 execution_direction
)));
2850 /* Calls target_commit_resume on all targets. */
2853 commit_resume_all_targets ()
2855 scoped_restore_current_thread restore_thread
;
2857 /* Map between process_target and a representative inferior. This
2858 is to avoid committing a resume in the same target more than
2859 once. Resumptions must be idempotent, so this is an
2861 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2863 for (inferior
*inf
: all_non_exited_inferiors ())
2864 if (inf
->has_execution ())
2865 conn_inf
[inf
->process_target ()] = inf
;
2867 for (const auto &ci
: conn_inf
)
2869 inferior
*inf
= ci
.second
;
2870 switch_to_inferior_no_thread (inf
);
2871 target_commit_resume ();
2875 /* Check that all the targets we're about to resume are in non-stop
2876 mode. Ideally, we'd only care whether all targets support
2877 target-async, but we're not there yet. E.g., stop_all_threads
2878 doesn't know how to handle all-stop targets. Also, the remote
2879 protocol in all-stop mode is synchronous, irrespective of
2880 target-async, which means that things like a breakpoint re-set
2881 triggered by one target would try to read memory from all targets
2885 check_multi_target_resumption (process_stratum_target
*resume_target
)
2887 if (!non_stop
&& resume_target
== nullptr)
2889 scoped_restore_current_thread restore_thread
;
2891 /* This is used to track whether we're resuming more than one
2893 process_stratum_target
*first_connection
= nullptr;
2895 /* The first inferior we see with a target that does not work in
2896 always-non-stop mode. */
2897 inferior
*first_not_non_stop
= nullptr;
2899 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2901 switch_to_inferior_no_thread (inf
);
2903 if (!target_has_execution
)
2906 process_stratum_target
*proc_target
2907 = current_inferior ()->process_target();
2909 if (!target_is_non_stop_p ())
2910 first_not_non_stop
= inf
;
2912 if (first_connection
== nullptr)
2913 first_connection
= proc_target
;
2914 else if (first_connection
!= proc_target
2915 && first_not_non_stop
!= nullptr)
2917 switch_to_inferior_no_thread (first_not_non_stop
);
2919 proc_target
= current_inferior ()->process_target();
2921 error (_("Connection %d (%s) does not support "
2922 "multi-target resumption."),
2923 proc_target
->connection_number
,
2924 make_target_connection_string (proc_target
).c_str ());
2930 /* Basic routine for continuing the program in various fashions.
2932 ADDR is the address to resume at, or -1 for resume where stopped.
2933 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2934 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2936 You should call clear_proceed_status before calling proceed. */
2939 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2941 struct regcache
*regcache
;
2942 struct gdbarch
*gdbarch
;
2944 struct execution_control_state ecss
;
2945 struct execution_control_state
*ecs
= &ecss
;
2948 /* If we're stopped at a fork/vfork, follow the branch set by the
2949 "set follow-fork-mode" command; otherwise, we'll just proceed
2950 resuming the current thread. */
2951 if (!follow_fork ())
2953 /* The target for some reason decided not to resume. */
2955 if (target_can_async_p ())
2956 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2960 /* We'll update this if & when we switch to a new thread. */
2961 previous_inferior_ptid
= inferior_ptid
;
2963 regcache
= get_current_regcache ();
2964 gdbarch
= regcache
->arch ();
2965 const address_space
*aspace
= regcache
->aspace ();
2967 pc
= regcache_read_pc (regcache
);
2968 thread_info
*cur_thr
= inferior_thread ();
2970 /* Fill in with reasonable starting values. */
2971 init_thread_stepping_state (cur_thr
);
2973 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2976 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2977 process_stratum_target
*resume_target
2978 = user_visible_resume_target (resume_ptid
);
2980 check_multi_target_resumption (resume_target
);
2982 if (addr
== (CORE_ADDR
) -1)
2984 if (pc
== cur_thr
->suspend
.stop_pc
2985 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2986 && execution_direction
!= EXEC_REVERSE
)
2987 /* There is a breakpoint at the address we will resume at,
2988 step one instruction before inserting breakpoints so that
2989 we do not stop right away (and report a second hit at this
2992 Note, we don't do this in reverse, because we won't
2993 actually be executing the breakpoint insn anyway.
2994 We'll be (un-)executing the previous instruction. */
2995 cur_thr
->stepping_over_breakpoint
= 1;
2996 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2997 && gdbarch_single_step_through_delay (gdbarch
,
2998 get_current_frame ()))
2999 /* We stepped onto an instruction that needs to be stepped
3000 again before re-inserting the breakpoint, do so. */
3001 cur_thr
->stepping_over_breakpoint
= 1;
3005 regcache_write_pc (regcache
, addr
);
3008 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3009 cur_thr
->suspend
.stop_signal
= siggnal
;
3011 /* If an exception is thrown from this point on, make sure to
3012 propagate GDB's knowledge of the executing state to the
3013 frontend/user running state. */
3014 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3016 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3017 threads (e.g., we might need to set threads stepping over
3018 breakpoints first), from the user/frontend's point of view, all
3019 threads in RESUME_PTID are now running. Unless we're calling an
3020 inferior function, as in that case we pretend the inferior
3021 doesn't run at all. */
3022 if (!cur_thr
->control
.in_infcall
)
3023 set_running (resume_target
, resume_ptid
, true);
3026 fprintf_unfiltered (gdb_stdlog
,
3027 "infrun: proceed (addr=%s, signal=%s)\n",
3028 paddress (gdbarch
, addr
),
3029 gdb_signal_to_symbol_string (siggnal
));
3031 annotate_starting ();
3033 /* Make sure that output from GDB appears before output from the
3035 gdb_flush (gdb_stdout
);
3037 /* Since we've marked the inferior running, give it the terminal. A
3038 QUIT/Ctrl-C from here on is forwarded to the target (which can
3039 still detect attempts to unblock a stuck connection with repeated
3040 Ctrl-C from within target_pass_ctrlc). */
3041 target_terminal::inferior ();
3043 /* In a multi-threaded task we may select another thread and
3044 then continue or step.
3046 But if a thread that we're resuming had stopped at a breakpoint,
3047 it will immediately cause another breakpoint stop without any
3048 execution (i.e. it will report a breakpoint hit incorrectly). So
3049 we must step over it first.
3051 Look for threads other than the current (TP) that reported a
3052 breakpoint hit and haven't been resumed yet since. */
3054 /* If scheduler locking applies, we can avoid iterating over all
3056 if (!non_stop
&& !schedlock_applies (cur_thr
))
3058 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3061 switch_to_thread_no_regs (tp
);
3063 /* Ignore the current thread here. It's handled
3068 if (!thread_still_needs_step_over (tp
))
3071 gdb_assert (!thread_is_in_step_over_chain (tp
));
3074 fprintf_unfiltered (gdb_stdlog
,
3075 "infrun: need to step-over [%s] first\n",
3076 target_pid_to_str (tp
->ptid
).c_str ());
3078 thread_step_over_chain_enqueue (tp
);
3081 switch_to_thread (cur_thr
);
3084 /* Enqueue the current thread last, so that we move all other
3085 threads over their breakpoints first. */
3086 if (cur_thr
->stepping_over_breakpoint
)
3087 thread_step_over_chain_enqueue (cur_thr
);
3089 /* If the thread isn't started, we'll still need to set its prev_pc,
3090 so that switch_back_to_stepped_thread knows the thread hasn't
3091 advanced. Must do this before resuming any thread, as in
3092 all-stop/remote, once we resume we can't send any other packet
3093 until the target stops again. */
3094 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
3097 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3099 started
= start_step_over ();
3101 if (step_over_info_valid_p ())
3103 /* Either this thread started a new in-line step over, or some
3104 other thread was already doing one. In either case, don't
3105 resume anything else until the step-over is finished. */
3107 else if (started
&& !target_is_non_stop_p ())
3109 /* A new displaced stepping sequence was started. In all-stop,
3110 we can't talk to the target anymore until it next stops. */
3112 else if (!non_stop
&& target_is_non_stop_p ())
3114 /* In all-stop, but the target is always in non-stop mode.
3115 Start all other threads that are implicitly resumed too. */
3116 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3119 switch_to_thread_no_regs (tp
);
3121 if (!tp
->inf
->has_execution ())
3124 fprintf_unfiltered (gdb_stdlog
,
3125 "infrun: proceed: [%s] target has "
3127 target_pid_to_str (tp
->ptid
).c_str ());
3134 fprintf_unfiltered (gdb_stdlog
,
3135 "infrun: proceed: [%s] resumed\n",
3136 target_pid_to_str (tp
->ptid
).c_str ());
3137 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3141 if (thread_is_in_step_over_chain (tp
))
3144 fprintf_unfiltered (gdb_stdlog
,
3145 "infrun: proceed: [%s] needs step-over\n",
3146 target_pid_to_str (tp
->ptid
).c_str ());
3151 fprintf_unfiltered (gdb_stdlog
,
3152 "infrun: proceed: resuming %s\n",
3153 target_pid_to_str (tp
->ptid
).c_str ());
3155 reset_ecs (ecs
, tp
);
3156 switch_to_thread (tp
);
3157 keep_going_pass_signal (ecs
);
3158 if (!ecs
->wait_some_more
)
3159 error (_("Command aborted."));
3162 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3164 /* The thread wasn't started, and isn't queued, run it now. */
3165 reset_ecs (ecs
, cur_thr
);
3166 switch_to_thread (cur_thr
);
3167 keep_going_pass_signal (ecs
);
3168 if (!ecs
->wait_some_more
)
3169 error (_("Command aborted."));
3173 commit_resume_all_targets ();
3175 finish_state
.release ();
3177 /* If we've switched threads above, switch back to the previously
3178 current thread. We don't want the user to see a different
3180 switch_to_thread (cur_thr
);
3182 /* Tell the event loop to wait for it to stop. If the target
3183 supports asynchronous execution, it'll do this from within
3185 if (!target_can_async_p ())
3186 mark_async_event_handler (infrun_async_inferior_event_token
);
3190 /* Start remote-debugging of a machine over a serial link. */
3193 start_remote (int from_tty
)
3195 inferior
*inf
= current_inferior ();
3196 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3198 /* Always go on waiting for the target, regardless of the mode. */
3199 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3200 indicate to wait_for_inferior that a target should timeout if
3201 nothing is returned (instead of just blocking). Because of this,
3202 targets expecting an immediate response need to, internally, set
3203 things up so that the target_wait() is forced to eventually
3205 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3206 differentiate to its caller what the state of the target is after
3207 the initial open has been performed. Here we're assuming that
3208 the target has stopped. It should be possible to eventually have
3209 target_open() return to the caller an indication that the target
3210 is currently running and GDB state should be set to the same as
3211 for an async run. */
3212 wait_for_inferior (inf
);
3214 /* Now that the inferior has stopped, do any bookkeeping like
3215 loading shared libraries. We want to do this before normal_stop,
3216 so that the displayed frame is up to date. */
3217 post_create_inferior (current_top_target (), from_tty
);
3222 /* Initialize static vars when a new inferior begins. */
3225 init_wait_for_inferior (void)
3227 /* These are meaningless until the first time through wait_for_inferior. */
3229 breakpoint_init_inferior (inf_starting
);
3231 clear_proceed_status (0);
3233 nullify_last_target_wait_ptid ();
3235 previous_inferior_ptid
= inferior_ptid
;
3240 static void handle_inferior_event (struct execution_control_state
*ecs
);
3242 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3243 struct execution_control_state
*ecs
);
3244 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3245 struct execution_control_state
*ecs
);
3246 static void handle_signal_stop (struct execution_control_state
*ecs
);
3247 static void check_exception_resume (struct execution_control_state
*,
3248 struct frame_info
*);
3250 static void end_stepping_range (struct execution_control_state
*ecs
);
3251 static void stop_waiting (struct execution_control_state
*ecs
);
3252 static void keep_going (struct execution_control_state
*ecs
);
3253 static void process_event_stop_test (struct execution_control_state
*ecs
);
3254 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3256 /* This function is attached as a "thread_stop_requested" observer.
3257 Cleanup local state that assumed the PTID was to be resumed, and
3258 report the stop to the frontend. */
3261 infrun_thread_stop_requested (ptid_t ptid
)
3263 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3265 /* PTID was requested to stop. If the thread was already stopped,
3266 but the user/frontend doesn't know about that yet (e.g., the
3267 thread had been temporarily paused for some step-over), set up
3268 for reporting the stop now. */
3269 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3271 if (tp
->state
!= THREAD_RUNNING
)
3276 /* Remove matching threads from the step-over queue, so
3277 start_step_over doesn't try to resume them
3279 if (thread_is_in_step_over_chain (tp
))
3280 thread_step_over_chain_remove (tp
);
3282 /* If the thread is stopped, but the user/frontend doesn't
3283 know about that yet, queue a pending event, as if the
3284 thread had just stopped now. Unless the thread already had
3286 if (!tp
->suspend
.waitstatus_pending_p
)
3288 tp
->suspend
.waitstatus_pending_p
= 1;
3289 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3290 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3293 /* Clear the inline-frame state, since we're re-processing the
3295 clear_inline_frame_state (tp
);
3297 /* If this thread was paused because some other thread was
3298 doing an inline-step over, let that finish first. Once
3299 that happens, we'll restart all threads and consume pending
3300 stop events then. */
3301 if (step_over_info_valid_p ())
3304 /* Otherwise we can process the (new) pending event now. Set
3305 it so this pending event is considered by
3312 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3314 if (target_last_proc_target
== tp
->inf
->process_target ()
3315 && target_last_wait_ptid
== tp
->ptid
)
3316 nullify_last_target_wait_ptid ();
3319 /* Delete the step resume, single-step and longjmp/exception resume
3320 breakpoints of TP. */
3323 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3325 delete_step_resume_breakpoint (tp
);
3326 delete_exception_resume_breakpoint (tp
);
3327 delete_single_step_breakpoints (tp
);
3330 /* If the target still has execution, call FUNC for each thread that
3331 just stopped. In all-stop, that's all the non-exited threads; in
3332 non-stop, that's the current thread, only. */
3334 typedef void (*for_each_just_stopped_thread_callback_func
)
3335 (struct thread_info
*tp
);
3338 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3340 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3343 if (target_is_non_stop_p ())
3345 /* If in non-stop mode, only the current thread stopped. */
3346 func (inferior_thread ());
3350 /* In all-stop mode, all threads have stopped. */
3351 for (thread_info
*tp
: all_non_exited_threads ())
3356 /* Delete the step resume and longjmp/exception resume breakpoints of
3357 the threads that just stopped. */
3360 delete_just_stopped_threads_infrun_breakpoints (void)
3362 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3365 /* Delete the single-step breakpoints of the threads that just
3369 delete_just_stopped_threads_single_step_breakpoints (void)
3371 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3377 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3378 const struct target_waitstatus
*ws
)
3380 std::string status_string
= target_waitstatus_to_string (ws
);
3383 /* The text is split over several lines because it was getting too long.
3384 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3385 output as a unit; we want only one timestamp printed if debug_timestamp
3388 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3391 waiton_ptid
.tid ());
3392 if (waiton_ptid
.pid () != -1)
3393 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3394 stb
.printf (", status) =\n");
3395 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3399 target_pid_to_str (result_ptid
).c_str ());
3400 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3402 /* This uses %s in part to handle %'s in the text, but also to avoid
3403 a gcc error: the format attribute requires a string literal. */
3404 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3407 /* Select a thread at random, out of those which are resumed and have
3410 static struct thread_info
*
3411 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3415 auto has_event
= [&] (thread_info
*tp
)
3417 return (tp
->ptid
.matches (waiton_ptid
)
3419 && tp
->suspend
.waitstatus_pending_p
);
3422 /* First see how many events we have. Count only resumed threads
3423 that have an event pending. */
3424 for (thread_info
*tp
: inf
->non_exited_threads ())
3428 if (num_events
== 0)
3431 /* Now randomly pick a thread out of those that have had events. */
3432 int random_selector
= (int) ((num_events
* (double) rand ())
3433 / (RAND_MAX
+ 1.0));
3435 if (debug_infrun
&& num_events
> 1)
3436 fprintf_unfiltered (gdb_stdlog
,
3437 "infrun: Found %d events, selecting #%d\n",
3438 num_events
, random_selector
);
3440 /* Select the Nth thread that has had an event. */
3441 for (thread_info
*tp
: inf
->non_exited_threads ())
3443 if (random_selector
-- == 0)
3446 gdb_assert_not_reached ("event thread not found");
3449 /* Wrapper for target_wait that first checks whether threads have
3450 pending statuses to report before actually asking the target for
3451 more events. INF is the inferior we're using to call target_wait
3455 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3456 target_waitstatus
*status
, int options
)
3459 struct thread_info
*tp
;
3461 /* First check if there is a resumed thread with a wait status
3463 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3465 tp
= random_pending_event_thread (inf
, ptid
);
3470 fprintf_unfiltered (gdb_stdlog
,
3471 "infrun: Waiting for specific thread %s.\n",
3472 target_pid_to_str (ptid
).c_str ());
3474 /* We have a specific thread to check. */
3475 tp
= find_thread_ptid (inf
, ptid
);
3476 gdb_assert (tp
!= NULL
);
3477 if (!tp
->suspend
.waitstatus_pending_p
)
3482 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3483 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3485 struct regcache
*regcache
= get_thread_regcache (tp
);
3486 struct gdbarch
*gdbarch
= regcache
->arch ();
3490 pc
= regcache_read_pc (regcache
);
3492 if (pc
!= tp
->suspend
.stop_pc
)
3495 fprintf_unfiltered (gdb_stdlog
,
3496 "infrun: PC of %s changed. was=%s, now=%s\n",
3497 target_pid_to_str (tp
->ptid
).c_str (),
3498 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3499 paddress (gdbarch
, pc
));
3502 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3505 fprintf_unfiltered (gdb_stdlog
,
3506 "infrun: previous breakpoint of %s, at %s gone\n",
3507 target_pid_to_str (tp
->ptid
).c_str (),
3508 paddress (gdbarch
, pc
));
3516 fprintf_unfiltered (gdb_stdlog
,
3517 "infrun: pending event of %s cancelled.\n",
3518 target_pid_to_str (tp
->ptid
).c_str ());
3520 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3521 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3530 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3532 fprintf_unfiltered (gdb_stdlog
,
3533 "infrun: Using pending wait status %s for %s.\n",
3535 target_pid_to_str (tp
->ptid
).c_str ());
3538 /* Now that we've selected our final event LWP, un-adjust its PC
3539 if it was a software breakpoint (and the target doesn't
3540 always adjust the PC itself). */
3541 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3542 && !target_supports_stopped_by_sw_breakpoint ())
3544 struct regcache
*regcache
;
3545 struct gdbarch
*gdbarch
;
3548 regcache
= get_thread_regcache (tp
);
3549 gdbarch
= regcache
->arch ();
3551 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3556 pc
= regcache_read_pc (regcache
);
3557 regcache_write_pc (regcache
, pc
+ decr_pc
);
3561 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3562 *status
= tp
->suspend
.waitstatus
;
3563 tp
->suspend
.waitstatus_pending_p
= 0;
3565 /* Wake up the event loop again, until all pending events are
3567 if (target_is_async_p ())
3568 mark_async_event_handler (infrun_async_inferior_event_token
);
3572 /* But if we don't find one, we'll have to wait. */
3574 if (deprecated_target_wait_hook
)
3575 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3577 event_ptid
= target_wait (ptid
, status
, options
);
3582 /* Returns true if INF has any resumed thread with a status
3586 threads_are_resumed_pending_p (inferior
*inf
)
3588 for (thread_info
*tp
: inf
->non_exited_threads ())
3590 && tp
->suspend
.waitstatus_pending_p
)
3596 /* Wrapper for target_wait that first checks whether threads have
3597 pending statuses to report before actually asking the target for
3598 more events. Polls for events from all inferiors/targets. */
3601 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3603 int num_inferiors
= 0;
3604 int random_selector
;
3606 /* For fairness, we pick the first inferior/target to poll at
3607 random, and then continue polling the rest of the inferior list
3608 starting from that one in a circular fashion until the whole list
3611 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3613 return (inf
->process_target () != NULL
3614 && (threads_are_executing (inf
->process_target ())
3615 || threads_are_resumed_pending_p (inf
))
3616 && ptid_t (inf
->pid
).matches (wait_ptid
));
3619 /* First see how many resumed inferiors we have. */
3620 for (inferior
*inf
: all_inferiors ())
3621 if (inferior_matches (inf
))
3624 if (num_inferiors
== 0)
3626 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3630 /* Now randomly pick an inferior out of those that were resumed. */
3631 random_selector
= (int)
3632 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3634 if (debug_infrun
&& num_inferiors
> 1)
3635 fprintf_unfiltered (gdb_stdlog
,
3636 "infrun: Found %d inferiors, starting at #%d\n",
3637 num_inferiors
, random_selector
);
3639 /* Select the Nth inferior that was resumed. */
3641 inferior
*selected
= nullptr;
3643 for (inferior
*inf
: all_inferiors ())
3644 if (inferior_matches (inf
))
3645 if (random_selector
-- == 0)
3651 /* Now poll for events out of each of the resumed inferior's
3652 targets, starting from the selected one. */
3654 auto do_wait
= [&] (inferior
*inf
)
3656 switch_to_inferior_no_thread (inf
);
3658 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3659 ecs
->target
= inf
->process_target ();
3660 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3663 /* Needed in all-stop+target-non-stop mode, because we end up here
3664 spuriously after the target is all stopped and we've already
3665 reported the stop to the user, polling for events. */
3666 scoped_restore_current_thread restore_thread
;
3668 int inf_num
= selected
->num
;
3669 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3670 if (inferior_matches (inf
))
3674 for (inferior
*inf
= inferior_list
;
3675 inf
!= NULL
&& inf
->num
< inf_num
;
3677 if (inferior_matches (inf
))
3681 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3685 /* Prepare and stabilize the inferior for detaching it. E.g.,
3686 detaching while a thread is displaced stepping is a recipe for
3687 crashing it, as nothing would readjust the PC out of the scratch
3691 prepare_for_detach (void)
3693 struct inferior
*inf
= current_inferior ();
3694 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3696 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3698 /* Is any thread of this process displaced stepping? If not,
3699 there's nothing else to do. */
3700 if (displaced
->step_thread
== nullptr)
3704 fprintf_unfiltered (gdb_stdlog
,
3705 "displaced-stepping in-process while detaching");
3707 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3709 while (displaced
->step_thread
!= nullptr)
3711 struct execution_control_state ecss
;
3712 struct execution_control_state
*ecs
;
3715 memset (ecs
, 0, sizeof (*ecs
));
3717 overlay_cache_invalid
= 1;
3718 /* Flush target cache before starting to handle each event.
3719 Target was running and cache could be stale. This is just a
3720 heuristic. Running threads may modify target memory, but we
3721 don't get any event. */
3722 target_dcache_invalidate ();
3724 do_target_wait (pid_ptid
, ecs
, 0);
3727 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3729 /* If an error happens while handling the event, propagate GDB's
3730 knowledge of the executing state to the frontend/user running
3732 scoped_finish_thread_state
finish_state (inf
->process_target (),
3735 /* Now figure out what to do with the result of the result. */
3736 handle_inferior_event (ecs
);
3738 /* No error, don't finish the state yet. */
3739 finish_state
.release ();
3741 /* Breakpoints and watchpoints are not installed on the target
3742 at this point, and signals are passed directly to the
3743 inferior, so this must mean the process is gone. */
3744 if (!ecs
->wait_some_more
)
3746 restore_detaching
.release ();
3747 error (_("Program exited while detaching"));
3751 restore_detaching
.release ();
3754 /* Wait for control to return from inferior to debugger.
3756 If inferior gets a signal, we may decide to start it up again
3757 instead of returning. That is why there is a loop in this function.
3758 When this function actually returns it means the inferior
3759 should be left stopped and GDB should read more commands. */
3762 wait_for_inferior (inferior
*inf
)
3766 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3768 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3770 /* If an error happens while handling the event, propagate GDB's
3771 knowledge of the executing state to the frontend/user running
3773 scoped_finish_thread_state finish_state
3774 (inf
->process_target (), minus_one_ptid
);
3778 struct execution_control_state ecss
;
3779 struct execution_control_state
*ecs
= &ecss
;
3781 memset (ecs
, 0, sizeof (*ecs
));
3783 overlay_cache_invalid
= 1;
3785 /* Flush target cache before starting to handle each event.
3786 Target was running and cache could be stale. This is just a
3787 heuristic. Running threads may modify target memory, but we
3788 don't get any event. */
3789 target_dcache_invalidate ();
3791 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3792 ecs
->target
= inf
->process_target ();
3795 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3797 /* Now figure out what to do with the result of the result. */
3798 handle_inferior_event (ecs
);
3800 if (!ecs
->wait_some_more
)
3804 /* No error, don't finish the state yet. */
3805 finish_state
.release ();
3808 /* Cleanup that reinstalls the readline callback handler, if the
3809 target is running in the background. If while handling the target
3810 event something triggered a secondary prompt, like e.g., a
3811 pagination prompt, we'll have removed the callback handler (see
3812 gdb_readline_wrapper_line). Need to do this as we go back to the
3813 event loop, ready to process further input. Note this has no
3814 effect if the handler hasn't actually been removed, because calling
3815 rl_callback_handler_install resets the line buffer, thus losing
3819 reinstall_readline_callback_handler_cleanup ()
3821 struct ui
*ui
= current_ui
;
3825 /* We're not going back to the top level event loop yet. Don't
3826 install the readline callback, as it'd prep the terminal,
3827 readline-style (raw, noecho) (e.g., --batch). We'll install
3828 it the next time the prompt is displayed, when we're ready
3833 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3834 gdb_rl_callback_handler_reinstall ();
3837 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3838 that's just the event thread. In all-stop, that's all threads. */
3841 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3843 if (ecs
->event_thread
!= NULL
3844 && ecs
->event_thread
->thread_fsm
!= NULL
)
3845 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3849 for (thread_info
*thr
: all_non_exited_threads ())
3851 if (thr
->thread_fsm
== NULL
)
3853 if (thr
== ecs
->event_thread
)
3856 switch_to_thread (thr
);
3857 thr
->thread_fsm
->clean_up (thr
);
3860 if (ecs
->event_thread
!= NULL
)
3861 switch_to_thread (ecs
->event_thread
);
3865 /* Helper for all_uis_check_sync_execution_done that works on the
3869 check_curr_ui_sync_execution_done (void)
3871 struct ui
*ui
= current_ui
;
3873 if (ui
->prompt_state
== PROMPT_NEEDED
3875 && !gdb_in_secondary_prompt_p (ui
))
3877 target_terminal::ours ();
3878 gdb::observers::sync_execution_done
.notify ();
3879 ui_register_input_event_handler (ui
);
3886 all_uis_check_sync_execution_done (void)
3888 SWITCH_THRU_ALL_UIS ()
3890 check_curr_ui_sync_execution_done ();
3897 all_uis_on_sync_execution_starting (void)
3899 SWITCH_THRU_ALL_UIS ()
3901 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3902 async_disable_stdin ();
3906 /* Asynchronous version of wait_for_inferior. It is called by the
3907 event loop whenever a change of state is detected on the file
3908 descriptor corresponding to the target. It can be called more than
3909 once to complete a single execution command. In such cases we need
3910 to keep the state in a global variable ECSS. If it is the last time
3911 that this function is called for a single execution command, then
3912 report to the user that the inferior has stopped, and do the
3913 necessary cleanups. */
3916 fetch_inferior_event (void *client_data
)
3918 struct execution_control_state ecss
;
3919 struct execution_control_state
*ecs
= &ecss
;
3922 memset (ecs
, 0, sizeof (*ecs
));
3924 /* Events are always processed with the main UI as current UI. This
3925 way, warnings, debug output, etc. are always consistently sent to
3926 the main console. */
3927 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3929 /* End up with readline processing input, if necessary. */
3931 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3933 /* We're handling a live event, so make sure we're doing live
3934 debugging. If we're looking at traceframes while the target is
3935 running, we're going to need to get back to that mode after
3936 handling the event. */
3937 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3940 maybe_restore_traceframe
.emplace ();
3941 set_current_traceframe (-1);
3944 /* The user/frontend should not notice a thread switch due to
3945 internal events. Make sure we revert to the user selected
3946 thread and frame after handling the event and running any
3947 breakpoint commands. */
3948 scoped_restore_current_thread restore_thread
;
3950 overlay_cache_invalid
= 1;
3951 /* Flush target cache before starting to handle each event. Target
3952 was running and cache could be stale. This is just a heuristic.
3953 Running threads may modify target memory, but we don't get any
3955 target_dcache_invalidate ();
3957 scoped_restore save_exec_dir
3958 = make_scoped_restore (&execution_direction
,
3959 target_execution_direction ());
3961 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3964 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3966 /* Switch to the target that generated the event, so we can do
3967 target calls. Any inferior bound to the target will do, so we
3968 just switch to the first we find. */
3969 for (inferior
*inf
: all_inferiors (ecs
->target
))
3971 switch_to_inferior_no_thread (inf
);
3976 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3978 /* If an error happens while handling the event, propagate GDB's
3979 knowledge of the executing state to the frontend/user running
3981 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3982 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3984 /* Get executed before scoped_restore_current_thread above to apply
3985 still for the thread which has thrown the exception. */
3986 auto defer_bpstat_clear
3987 = make_scope_exit (bpstat_clear_actions
);
3988 auto defer_delete_threads
3989 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3991 /* Now figure out what to do with the result of the result. */
3992 handle_inferior_event (ecs
);
3994 if (!ecs
->wait_some_more
)
3996 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3997 int should_stop
= 1;
3998 struct thread_info
*thr
= ecs
->event_thread
;
4000 delete_just_stopped_threads_infrun_breakpoints ();
4004 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4006 if (thread_fsm
!= NULL
)
4007 should_stop
= thread_fsm
->should_stop (thr
);
4016 bool should_notify_stop
= true;
4019 clean_up_just_stopped_threads_fsms (ecs
);
4021 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4022 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4024 if (should_notify_stop
)
4026 /* We may not find an inferior if this was a process exit. */
4027 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4028 proceeded
= normal_stop ();
4033 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4037 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4038 previously selected thread is gone. We have two
4039 choices - switch to no thread selected, or restore the
4040 previously selected thread (now exited). We chose the
4041 later, just because that's what GDB used to do. After
4042 this, "info threads" says "The current thread <Thread
4043 ID 2> has terminated." instead of "No thread
4047 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4048 restore_thread
.dont_restore ();
4052 defer_delete_threads
.release ();
4053 defer_bpstat_clear
.release ();
4055 /* No error, don't finish the thread states yet. */
4056 finish_state
.release ();
4058 /* This scope is used to ensure that readline callbacks are
4059 reinstalled here. */
4062 /* If a UI was in sync execution mode, and now isn't, restore its
4063 prompt (a synchronous execution command has finished, and we're
4064 ready for input). */
4065 all_uis_check_sync_execution_done ();
4068 && exec_done_display_p
4069 && (inferior_ptid
== null_ptid
4070 || inferior_thread ()->state
!= THREAD_RUNNING
))
4071 printf_unfiltered (_("completed.\n"));
4074 /* Record the frame and location we're currently stepping through. */
4076 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
4078 struct thread_info
*tp
= inferior_thread ();
4080 tp
->control
.step_frame_id
= get_frame_id (frame
);
4081 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4083 tp
->current_symtab
= sal
.symtab
;
4084 tp
->current_line
= sal
.line
;
4087 /* Clear context switchable stepping state. */
4090 init_thread_stepping_state (struct thread_info
*tss
)
4092 tss
->stepped_breakpoint
= 0;
4093 tss
->stepping_over_breakpoint
= 0;
4094 tss
->stepping_over_watchpoint
= 0;
4095 tss
->step_after_step_resume_breakpoint
= 0;
4101 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4102 target_waitstatus status
)
4104 target_last_proc_target
= target
;
4105 target_last_wait_ptid
= ptid
;
4106 target_last_waitstatus
= status
;
4112 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4113 target_waitstatus
*status
)
4115 if (target
!= nullptr)
4116 *target
= target_last_proc_target
;
4117 if (ptid
!= nullptr)
4118 *ptid
= target_last_wait_ptid
;
4119 if (status
!= nullptr)
4120 *status
= target_last_waitstatus
;
4126 nullify_last_target_wait_ptid (void)
4128 target_last_proc_target
= nullptr;
4129 target_last_wait_ptid
= minus_one_ptid
;
4130 target_last_waitstatus
= {};
4133 /* Switch thread contexts. */
4136 context_switch (execution_control_state
*ecs
)
4139 && ecs
->ptid
!= inferior_ptid
4140 && (inferior_ptid
== null_ptid
4141 || ecs
->event_thread
!= inferior_thread ()))
4143 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4144 target_pid_to_str (inferior_ptid
).c_str ());
4145 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4146 target_pid_to_str (ecs
->ptid
).c_str ());
4149 switch_to_thread (ecs
->event_thread
);
4152 /* If the target can't tell whether we've hit breakpoints
4153 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4154 check whether that could have been caused by a breakpoint. If so,
4155 adjust the PC, per gdbarch_decr_pc_after_break. */
4158 adjust_pc_after_break (struct thread_info
*thread
,
4159 struct target_waitstatus
*ws
)
4161 struct regcache
*regcache
;
4162 struct gdbarch
*gdbarch
;
4163 CORE_ADDR breakpoint_pc
, decr_pc
;
4165 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4166 we aren't, just return.
4168 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4169 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4170 implemented by software breakpoints should be handled through the normal
4173 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4174 different signals (SIGILL or SIGEMT for instance), but it is less
4175 clear where the PC is pointing afterwards. It may not match
4176 gdbarch_decr_pc_after_break. I don't know any specific target that
4177 generates these signals at breakpoints (the code has been in GDB since at
4178 least 1992) so I can not guess how to handle them here.
4180 In earlier versions of GDB, a target with
4181 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4182 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4183 target with both of these set in GDB history, and it seems unlikely to be
4184 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4186 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4189 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4192 /* In reverse execution, when a breakpoint is hit, the instruction
4193 under it has already been de-executed. The reported PC always
4194 points at the breakpoint address, so adjusting it further would
4195 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4198 B1 0x08000000 : INSN1
4199 B2 0x08000001 : INSN2
4201 PC -> 0x08000003 : INSN4
4203 Say you're stopped at 0x08000003 as above. Reverse continuing
4204 from that point should hit B2 as below. Reading the PC when the
4205 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4206 been de-executed already.
4208 B1 0x08000000 : INSN1
4209 B2 PC -> 0x08000001 : INSN2
4213 We can't apply the same logic as for forward execution, because
4214 we would wrongly adjust the PC to 0x08000000, since there's a
4215 breakpoint at PC - 1. We'd then report a hit on B1, although
4216 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4218 if (execution_direction
== EXEC_REVERSE
)
4221 /* If the target can tell whether the thread hit a SW breakpoint,
4222 trust it. Targets that can tell also adjust the PC
4224 if (target_supports_stopped_by_sw_breakpoint ())
4227 /* Note that relying on whether a breakpoint is planted in memory to
4228 determine this can fail. E.g,. the breakpoint could have been
4229 removed since. Or the thread could have been told to step an
4230 instruction the size of a breakpoint instruction, and only
4231 _after_ was a breakpoint inserted at its address. */
4233 /* If this target does not decrement the PC after breakpoints, then
4234 we have nothing to do. */
4235 regcache
= get_thread_regcache (thread
);
4236 gdbarch
= regcache
->arch ();
4238 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4242 const address_space
*aspace
= regcache
->aspace ();
4244 /* Find the location where (if we've hit a breakpoint) the
4245 breakpoint would be. */
4246 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4248 /* If the target can't tell whether a software breakpoint triggered,
4249 fallback to figuring it out based on breakpoints we think were
4250 inserted in the target, and on whether the thread was stepped or
4253 /* Check whether there actually is a software breakpoint inserted at
4256 If in non-stop mode, a race condition is possible where we've
4257 removed a breakpoint, but stop events for that breakpoint were
4258 already queued and arrive later. To suppress those spurious
4259 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4260 and retire them after a number of stop events are reported. Note
4261 this is an heuristic and can thus get confused. The real fix is
4262 to get the "stopped by SW BP and needs adjustment" info out of
4263 the target/kernel (and thus never reach here; see above). */
4264 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4265 || (target_is_non_stop_p ()
4266 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4268 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4270 if (record_full_is_used ())
4271 restore_operation_disable
.emplace
4272 (record_full_gdb_operation_disable_set ());
4274 /* When using hardware single-step, a SIGTRAP is reported for both
4275 a completed single-step and a software breakpoint. Need to
4276 differentiate between the two, as the latter needs adjusting
4277 but the former does not.
4279 The SIGTRAP can be due to a completed hardware single-step only if
4280 - we didn't insert software single-step breakpoints
4281 - this thread is currently being stepped
4283 If any of these events did not occur, we must have stopped due
4284 to hitting a software breakpoint, and have to back up to the
4287 As a special case, we could have hardware single-stepped a
4288 software breakpoint. In this case (prev_pc == breakpoint_pc),
4289 we also need to back up to the breakpoint address. */
4291 if (thread_has_single_step_breakpoints_set (thread
)
4292 || !currently_stepping (thread
)
4293 || (thread
->stepped_breakpoint
4294 && thread
->prev_pc
== breakpoint_pc
))
4295 regcache_write_pc (regcache
, breakpoint_pc
);
4300 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4302 for (frame
= get_prev_frame (frame
);
4304 frame
= get_prev_frame (frame
))
4306 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4308 if (get_frame_type (frame
) != INLINE_FRAME
)
4315 /* Look for an inline frame that is marked for skip.
4316 If PREV_FRAME is TRUE start at the previous frame,
4317 otherwise start at the current frame. Stop at the
4318 first non-inline frame, or at the frame where the
4322 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4324 struct frame_info
*frame
= get_current_frame ();
4327 frame
= get_prev_frame (frame
);
4329 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4331 const char *fn
= NULL
;
4332 symtab_and_line sal
;
4335 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4337 if (get_frame_type (frame
) != INLINE_FRAME
)
4340 sal
= find_frame_sal (frame
);
4341 sym
= get_frame_function (frame
);
4344 fn
= sym
->print_name ();
4347 && function_name_is_marked_for_skip (fn
, sal
))
4354 /* If the event thread has the stop requested flag set, pretend it
4355 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4359 handle_stop_requested (struct execution_control_state
*ecs
)
4361 if (ecs
->event_thread
->stop_requested
)
4363 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4364 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4365 handle_signal_stop (ecs
);
4371 /* Auxiliary function that handles syscall entry/return events.
4372 It returns 1 if the inferior should keep going (and GDB
4373 should ignore the event), or 0 if the event deserves to be
4377 handle_syscall_event (struct execution_control_state
*ecs
)
4379 struct regcache
*regcache
;
4382 context_switch (ecs
);
4384 regcache
= get_thread_regcache (ecs
->event_thread
);
4385 syscall_number
= ecs
->ws
.value
.syscall_number
;
4386 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4388 if (catch_syscall_enabled () > 0
4389 && catching_syscall_number (syscall_number
) > 0)
4392 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4395 ecs
->event_thread
->control
.stop_bpstat
4396 = bpstat_stop_status (regcache
->aspace (),
4397 ecs
->event_thread
->suspend
.stop_pc
,
4398 ecs
->event_thread
, &ecs
->ws
);
4400 if (handle_stop_requested (ecs
))
4403 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4405 /* Catchpoint hit. */
4410 if (handle_stop_requested (ecs
))
4413 /* If no catchpoint triggered for this, then keep going. */
4418 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4421 fill_in_stop_func (struct gdbarch
*gdbarch
,
4422 struct execution_control_state
*ecs
)
4424 if (!ecs
->stop_func_filled_in
)
4428 /* Don't care about return value; stop_func_start and stop_func_name
4429 will both be 0 if it doesn't work. */
4430 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4431 &ecs
->stop_func_name
,
4432 &ecs
->stop_func_start
,
4433 &ecs
->stop_func_end
,
4436 /* The call to find_pc_partial_function, above, will set
4437 stop_func_start and stop_func_end to the start and end
4438 of the range containing the stop pc. If this range
4439 contains the entry pc for the block (which is always the
4440 case for contiguous blocks), advance stop_func_start past
4441 the function's start offset and entrypoint. Note that
4442 stop_func_start is NOT advanced when in a range of a
4443 non-contiguous block that does not contain the entry pc. */
4444 if (block
!= nullptr
4445 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4446 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4448 ecs
->stop_func_start
4449 += gdbarch_deprecated_function_start_offset (gdbarch
);
4451 if (gdbarch_skip_entrypoint_p (gdbarch
))
4452 ecs
->stop_func_start
4453 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4456 ecs
->stop_func_filled_in
= 1;
4461 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4463 static enum stop_kind
4464 get_inferior_stop_soon (execution_control_state
*ecs
)
4466 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4468 gdb_assert (inf
!= NULL
);
4469 return inf
->control
.stop_soon
;
4472 /* Poll for one event out of the current target. Store the resulting
4473 waitstatus in WS, and return the event ptid. Does not block. */
4476 poll_one_curr_target (struct target_waitstatus
*ws
)
4480 overlay_cache_invalid
= 1;
4482 /* Flush target cache before starting to handle each event.
4483 Target was running and cache could be stale. This is just a
4484 heuristic. Running threads may modify target memory, but we
4485 don't get any event. */
4486 target_dcache_invalidate ();
4488 if (deprecated_target_wait_hook
)
4489 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4491 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4494 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4499 /* An event reported by wait_one. */
4501 struct wait_one_event
4503 /* The target the event came out of. */
4504 process_stratum_target
*target
;
4506 /* The PTID the event was for. */
4509 /* The waitstatus. */
4510 target_waitstatus ws
;
4513 /* Wait for one event out of any target. */
4515 static wait_one_event
4520 for (inferior
*inf
: all_inferiors ())
4522 process_stratum_target
*target
= inf
->process_target ();
4524 || !target
->is_async_p ()
4525 || !target
->threads_executing
)
4528 switch_to_inferior_no_thread (inf
);
4530 wait_one_event event
;
4531 event
.target
= target
;
4532 event
.ptid
= poll_one_curr_target (&event
.ws
);
4534 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4536 /* If nothing is resumed, remove the target from the
4540 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4544 /* Block waiting for some event. */
4551 for (inferior
*inf
: all_inferiors ())
4553 process_stratum_target
*target
= inf
->process_target ();
4555 || !target
->is_async_p ()
4556 || !target
->threads_executing
)
4559 int fd
= target
->async_wait_fd ();
4560 FD_SET (fd
, &readfds
);
4567 /* No waitable targets left. All must be stopped. */
4568 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4573 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4579 perror_with_name ("interruptible_select");
4584 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4585 instead of the current thread. */
4586 #define THREAD_STOPPED_BY(REASON) \
4588 thread_stopped_by_ ## REASON (ptid_t ptid) \
4590 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4591 inferior_ptid = ptid; \
4593 return target_stopped_by_ ## REASON (); \
4596 /* Generate thread_stopped_by_watchpoint. */
4597 THREAD_STOPPED_BY (watchpoint
)
4598 /* Generate thread_stopped_by_sw_breakpoint. */
4599 THREAD_STOPPED_BY (sw_breakpoint
)
4600 /* Generate thread_stopped_by_hw_breakpoint. */
4601 THREAD_STOPPED_BY (hw_breakpoint
)
4603 /* Save the thread's event and stop reason to process it later. */
4606 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4610 std::string statstr
= target_waitstatus_to_string (ws
);
4612 fprintf_unfiltered (gdb_stdlog
,
4613 "infrun: saving status %s for %d.%ld.%ld\n",
4620 /* Record for later. */
4621 tp
->suspend
.waitstatus
= *ws
;
4622 tp
->suspend
.waitstatus_pending_p
= 1;
4624 struct regcache
*regcache
= get_thread_regcache (tp
);
4625 const address_space
*aspace
= regcache
->aspace ();
4627 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4628 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4630 CORE_ADDR pc
= regcache_read_pc (regcache
);
4632 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4634 if (thread_stopped_by_watchpoint (tp
->ptid
))
4636 tp
->suspend
.stop_reason
4637 = TARGET_STOPPED_BY_WATCHPOINT
;
4639 else if (target_supports_stopped_by_sw_breakpoint ()
4640 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4642 tp
->suspend
.stop_reason
4643 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4645 else if (target_supports_stopped_by_hw_breakpoint ()
4646 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4648 tp
->suspend
.stop_reason
4649 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4651 else if (!target_supports_stopped_by_hw_breakpoint ()
4652 && hardware_breakpoint_inserted_here_p (aspace
,
4655 tp
->suspend
.stop_reason
4656 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4658 else if (!target_supports_stopped_by_sw_breakpoint ()
4659 && software_breakpoint_inserted_here_p (aspace
,
4662 tp
->suspend
.stop_reason
4663 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4665 else if (!thread_has_single_step_breakpoints_set (tp
)
4666 && currently_stepping (tp
))
4668 tp
->suspend
.stop_reason
4669 = TARGET_STOPPED_BY_SINGLE_STEP
;
4677 stop_all_threads (void)
4679 /* We may need multiple passes to discover all threads. */
4683 gdb_assert (target_is_non_stop_p ());
4686 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4688 scoped_restore_current_thread restore_thread
;
4690 target_thread_events (1);
4691 SCOPE_EXIT
{ target_thread_events (0); };
4693 /* Request threads to stop, and then wait for the stops. Because
4694 threads we already know about can spawn more threads while we're
4695 trying to stop them, and we only learn about new threads when we
4696 update the thread list, do this in a loop, and keep iterating
4697 until two passes find no threads that need to be stopped. */
4698 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4701 fprintf_unfiltered (gdb_stdlog
,
4702 "infrun: stop_all_threads, pass=%d, "
4703 "iterations=%d\n", pass
, iterations
);
4708 update_thread_list ();
4710 /* Go through all threads looking for threads that we need
4711 to tell the target to stop. */
4712 for (thread_info
*t
: all_non_exited_threads ())
4716 /* If already stopping, don't request a stop again.
4717 We just haven't seen the notification yet. */
4718 if (!t
->stop_requested
)
4721 fprintf_unfiltered (gdb_stdlog
,
4722 "infrun: %s executing, "
4724 target_pid_to_str (t
->ptid
).c_str ());
4725 switch_to_thread_no_regs (t
);
4726 target_stop (t
->ptid
);
4727 t
->stop_requested
= 1;
4732 fprintf_unfiltered (gdb_stdlog
,
4733 "infrun: %s executing, "
4734 "already stopping\n",
4735 target_pid_to_str (t
->ptid
).c_str ());
4738 if (t
->stop_requested
)
4744 fprintf_unfiltered (gdb_stdlog
,
4745 "infrun: %s not executing\n",
4746 target_pid_to_str (t
->ptid
).c_str ());
4748 /* The thread may be not executing, but still be
4749 resumed with a pending status to process. */
4757 /* If we find new threads on the second iteration, restart
4758 over. We want to see two iterations in a row with all
4763 wait_one_event event
= wait_one ();
4767 fprintf_unfiltered (gdb_stdlog
,
4768 "infrun: stop_all_threads %s %s\n",
4769 target_waitstatus_to_string (&event
.ws
).c_str (),
4770 target_pid_to_str (event
.ptid
).c_str ());
4773 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4774 || event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4775 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4776 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4778 /* All resumed threads exited
4779 or one thread/process exited/signalled. */
4783 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4785 t
= add_thread (event
.target
, event
.ptid
);
4787 t
->stop_requested
= 0;
4790 t
->control
.may_range_step
= 0;
4792 /* This may be the first time we see the inferior report
4794 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4795 if (inf
->needs_setup
)
4797 switch_to_thread_no_regs (t
);
4801 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4802 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4804 /* We caught the event that we intended to catch, so
4805 there's no event pending. */
4806 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4807 t
->suspend
.waitstatus_pending_p
= 0;
4809 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4811 /* Add it back to the step-over queue. */
4814 fprintf_unfiltered (gdb_stdlog
,
4815 "infrun: displaced-step of %s "
4816 "canceled: adding back to the "
4817 "step-over queue\n",
4818 target_pid_to_str (t
->ptid
).c_str ());
4820 t
->control
.trap_expected
= 0;
4821 thread_step_over_chain_enqueue (t
);
4826 enum gdb_signal sig
;
4827 struct regcache
*regcache
;
4831 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4833 fprintf_unfiltered (gdb_stdlog
,
4834 "infrun: target_wait %s, saving "
4835 "status for %d.%ld.%ld\n",
4842 /* Record for later. */
4843 save_waitstatus (t
, &event
.ws
);
4845 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4846 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4848 if (displaced_step_fixup (t
, sig
) < 0)
4850 /* Add it back to the step-over queue. */
4851 t
->control
.trap_expected
= 0;
4852 thread_step_over_chain_enqueue (t
);
4855 regcache
= get_thread_regcache (t
);
4856 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4860 fprintf_unfiltered (gdb_stdlog
,
4861 "infrun: saved stop_pc=%s for %s "
4862 "(currently_stepping=%d)\n",
4863 paddress (target_gdbarch (),
4864 t
->suspend
.stop_pc
),
4865 target_pid_to_str (t
->ptid
).c_str (),
4866 currently_stepping (t
));
4874 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4877 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4880 handle_no_resumed (struct execution_control_state
*ecs
)
4882 if (target_can_async_p ())
4889 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4897 /* There were no unwaited-for children left in the target, but,
4898 we're not synchronously waiting for events either. Just
4902 fprintf_unfiltered (gdb_stdlog
,
4903 "infrun: TARGET_WAITKIND_NO_RESUMED "
4904 "(ignoring: bg)\n");
4905 prepare_to_wait (ecs
);
4910 /* Otherwise, if we were running a synchronous execution command, we
4911 may need to cancel it and give the user back the terminal.
4913 In non-stop mode, the target can't tell whether we've already
4914 consumed previous stop events, so it can end up sending us a
4915 no-resumed event like so:
4917 #0 - thread 1 is left stopped
4919 #1 - thread 2 is resumed and hits breakpoint
4920 -> TARGET_WAITKIND_STOPPED
4922 #2 - thread 3 is resumed and exits
4923 this is the last resumed thread, so
4924 -> TARGET_WAITKIND_NO_RESUMED
4926 #3 - gdb processes stop for thread 2 and decides to re-resume
4929 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4930 thread 2 is now resumed, so the event should be ignored.
4932 IOW, if the stop for thread 2 doesn't end a foreground command,
4933 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4934 event. But it could be that the event meant that thread 2 itself
4935 (or whatever other thread was the last resumed thread) exited.
4937 To address this we refresh the thread list and check whether we
4938 have resumed threads _now_. In the example above, this removes
4939 thread 3 from the thread list. If thread 2 was re-resumed, we
4940 ignore this event. If we find no thread resumed, then we cancel
4941 the synchronous command show "no unwaited-for " to the user. */
4942 update_thread_list ();
4944 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4946 if (thread
->executing
4947 || thread
->suspend
.waitstatus_pending_p
)
4949 /* There were no unwaited-for children left in the target at
4950 some point, but there are now. Just ignore. */
4952 fprintf_unfiltered (gdb_stdlog
,
4953 "infrun: TARGET_WAITKIND_NO_RESUMED "
4954 "(ignoring: found resumed)\n");
4955 prepare_to_wait (ecs
);
4960 /* Note however that we may find no resumed thread because the whole
4961 process exited meanwhile (thus updating the thread list results
4962 in an empty thread list). In this case we know we'll be getting
4963 a process exit event shortly. */
4964 for (inferior
*inf
: all_non_exited_inferiors (ecs
->target
))
4966 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4970 fprintf_unfiltered (gdb_stdlog
,
4971 "infrun: TARGET_WAITKIND_NO_RESUMED "
4972 "(expect process exit)\n");
4973 prepare_to_wait (ecs
);
4978 /* Go ahead and report the event. */
4982 /* Given an execution control state that has been freshly filled in by
4983 an event from the inferior, figure out what it means and take
4986 The alternatives are:
4988 1) stop_waiting and return; to really stop and return to the
4991 2) keep_going and return; to wait for the next event (set
4992 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4996 handle_inferior_event (struct execution_control_state
*ecs
)
4998 /* Make sure that all temporary struct value objects that were
4999 created during the handling of the event get deleted at the
5001 scoped_value_mark free_values
;
5003 enum stop_kind stop_soon
;
5006 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5007 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5009 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5011 /* We had an event in the inferior, but we are not interested in
5012 handling it at this level. The lower layers have already
5013 done what needs to be done, if anything.
5015 One of the possible circumstances for this is when the
5016 inferior produces output for the console. The inferior has
5017 not stopped, and we are ignoring the event. Another possible
5018 circumstance is any event which the lower level knows will be
5019 reported multiple times without an intervening resume. */
5020 prepare_to_wait (ecs
);
5024 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5026 prepare_to_wait (ecs
);
5030 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5031 && handle_no_resumed (ecs
))
5034 /* Cache the last target/ptid/waitstatus. */
5035 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5037 /* Always clear state belonging to the previous time we stopped. */
5038 stop_stack_dummy
= STOP_NONE
;
5040 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5042 /* No unwaited-for children left. IOW, all resumed children
5044 stop_print_frame
= 0;
5049 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5050 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5052 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5053 /* If it's a new thread, add it to the thread database. */
5054 if (ecs
->event_thread
== NULL
)
5055 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5057 /* Disable range stepping. If the next step request could use a
5058 range, this will be end up re-enabled then. */
5059 ecs
->event_thread
->control
.may_range_step
= 0;
5062 /* Dependent on valid ECS->EVENT_THREAD. */
5063 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5065 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5066 reinit_frame_cache ();
5068 breakpoint_retire_moribund ();
5070 /* First, distinguish signals caused by the debugger from signals
5071 that have to do with the program's own actions. Note that
5072 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5073 on the operating system version. Here we detect when a SIGILL or
5074 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5075 something similar for SIGSEGV, since a SIGSEGV will be generated
5076 when we're trying to execute a breakpoint instruction on a
5077 non-executable stack. This happens for call dummy breakpoints
5078 for architectures like SPARC that place call dummies on the
5080 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5081 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5082 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5083 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5085 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5087 if (breakpoint_inserted_here_p (regcache
->aspace (),
5088 regcache_read_pc (regcache
)))
5091 fprintf_unfiltered (gdb_stdlog
,
5092 "infrun: Treating signal as SIGTRAP\n");
5093 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5097 /* Mark the non-executing threads accordingly. In all-stop, all
5098 threads of all processes are stopped when we get any event
5099 reported. In non-stop mode, only the event thread stops. */
5103 if (!target_is_non_stop_p ())
5104 mark_ptid
= minus_one_ptid
;
5105 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
5106 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5108 /* If we're handling a process exit in non-stop mode, even
5109 though threads haven't been deleted yet, one would think
5110 that there is nothing to do, as threads of the dead process
5111 will be soon deleted, and threads of any other process were
5112 left running. However, on some targets, threads survive a
5113 process exit event. E.g., for the "checkpoint" command,
5114 when the current checkpoint/fork exits, linux-fork.c
5115 automatically switches to another fork from within
5116 target_mourn_inferior, by associating the same
5117 inferior/thread to another fork. We haven't mourned yet at
5118 this point, but we must mark any threads left in the
5119 process as not-executing so that finish_thread_state marks
5120 them stopped (in the user's perspective) if/when we present
5121 the stop to the user. */
5122 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
5125 mark_ptid
= ecs
->ptid
;
5127 set_executing (ecs
->target
, mark_ptid
, false);
5129 /* Likewise the resumed flag. */
5130 set_resumed (ecs
->target
, mark_ptid
, false);
5133 switch (ecs
->ws
.kind
)
5135 case TARGET_WAITKIND_LOADED
:
5136 context_switch (ecs
);
5137 /* Ignore gracefully during startup of the inferior, as it might
5138 be the shell which has just loaded some objects, otherwise
5139 add the symbols for the newly loaded objects. Also ignore at
5140 the beginning of an attach or remote session; we will query
5141 the full list of libraries once the connection is
5144 stop_soon
= get_inferior_stop_soon (ecs
);
5145 if (stop_soon
== NO_STOP_QUIETLY
)
5147 struct regcache
*regcache
;
5149 regcache
= get_thread_regcache (ecs
->event_thread
);
5151 handle_solib_event ();
5153 ecs
->event_thread
->control
.stop_bpstat
5154 = bpstat_stop_status (regcache
->aspace (),
5155 ecs
->event_thread
->suspend
.stop_pc
,
5156 ecs
->event_thread
, &ecs
->ws
);
5158 if (handle_stop_requested (ecs
))
5161 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5163 /* A catchpoint triggered. */
5164 process_event_stop_test (ecs
);
5168 /* If requested, stop when the dynamic linker notifies
5169 gdb of events. This allows the user to get control
5170 and place breakpoints in initializer routines for
5171 dynamically loaded objects (among other things). */
5172 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5173 if (stop_on_solib_events
)
5175 /* Make sure we print "Stopped due to solib-event" in
5177 stop_print_frame
= 1;
5184 /* If we are skipping through a shell, or through shared library
5185 loading that we aren't interested in, resume the program. If
5186 we're running the program normally, also resume. */
5187 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5189 /* Loading of shared libraries might have changed breakpoint
5190 addresses. Make sure new breakpoints are inserted. */
5191 if (stop_soon
== NO_STOP_QUIETLY
)
5192 insert_breakpoints ();
5193 resume (GDB_SIGNAL_0
);
5194 prepare_to_wait (ecs
);
5198 /* But stop if we're attaching or setting up a remote
5200 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5201 || stop_soon
== STOP_QUIETLY_REMOTE
)
5204 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5209 internal_error (__FILE__
, __LINE__
,
5210 _("unhandled stop_soon: %d"), (int) stop_soon
);
5212 case TARGET_WAITKIND_SPURIOUS
:
5213 if (handle_stop_requested (ecs
))
5215 context_switch (ecs
);
5216 resume (GDB_SIGNAL_0
);
5217 prepare_to_wait (ecs
);
5220 case TARGET_WAITKIND_THREAD_CREATED
:
5221 if (handle_stop_requested (ecs
))
5223 context_switch (ecs
);
5224 if (!switch_back_to_stepped_thread (ecs
))
5228 case TARGET_WAITKIND_EXITED
:
5229 case TARGET_WAITKIND_SIGNALLED
:
5230 inferior_ptid
= ecs
->ptid
;
5231 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5232 set_current_program_space (current_inferior ()->pspace
);
5233 handle_vfork_child_exec_or_exit (0);
5234 target_terminal::ours (); /* Must do this before mourn anyway. */
5236 /* Clearing any previous state of convenience variables. */
5237 clear_exit_convenience_vars ();
5239 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5241 /* Record the exit code in the convenience variable $_exitcode, so
5242 that the user can inspect this again later. */
5243 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5244 (LONGEST
) ecs
->ws
.value
.integer
);
5246 /* Also record this in the inferior itself. */
5247 current_inferior ()->has_exit_code
= 1;
5248 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5250 /* Support the --return-child-result option. */
5251 return_child_result_value
= ecs
->ws
.value
.integer
;
5253 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5257 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5259 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5261 /* Set the value of the internal variable $_exitsignal,
5262 which holds the signal uncaught by the inferior. */
5263 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5264 gdbarch_gdb_signal_to_target (gdbarch
,
5265 ecs
->ws
.value
.sig
));
5269 /* We don't have access to the target's method used for
5270 converting between signal numbers (GDB's internal
5271 representation <-> target's representation).
5272 Therefore, we cannot do a good job at displaying this
5273 information to the user. It's better to just warn
5274 her about it (if infrun debugging is enabled), and
5277 fprintf_filtered (gdb_stdlog
, _("\
5278 Cannot fill $_exitsignal with the correct signal number.\n"));
5281 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5284 gdb_flush (gdb_stdout
);
5285 target_mourn_inferior (inferior_ptid
);
5286 stop_print_frame
= 0;
5290 case TARGET_WAITKIND_FORKED
:
5291 case TARGET_WAITKIND_VFORKED
:
5292 /* Check whether the inferior is displaced stepping. */
5294 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5295 struct gdbarch
*gdbarch
= regcache
->arch ();
5297 /* If checking displaced stepping is supported, and thread
5298 ecs->ptid is displaced stepping. */
5299 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5301 struct inferior
*parent_inf
5302 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5303 struct regcache
*child_regcache
;
5304 CORE_ADDR parent_pc
;
5306 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5308 struct displaced_step_inferior_state
*displaced
5309 = get_displaced_stepping_state (parent_inf
);
5311 /* Restore scratch pad for child process. */
5312 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5315 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5316 indicating that the displaced stepping of syscall instruction
5317 has been done. Perform cleanup for parent process here. Note
5318 that this operation also cleans up the child process for vfork,
5319 because their pages are shared. */
5320 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5321 /* Start a new step-over in another thread if there's one
5325 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5326 the child's PC is also within the scratchpad. Set the child's PC
5327 to the parent's PC value, which has already been fixed up.
5328 FIXME: we use the parent's aspace here, although we're touching
5329 the child, because the child hasn't been added to the inferior
5330 list yet at this point. */
5333 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5334 ecs
->ws
.value
.related_pid
,
5336 parent_inf
->aspace
);
5337 /* Read PC value of parent process. */
5338 parent_pc
= regcache_read_pc (regcache
);
5340 if (debug_displaced
)
5341 fprintf_unfiltered (gdb_stdlog
,
5342 "displaced: write child pc from %s to %s\n",
5344 regcache_read_pc (child_regcache
)),
5345 paddress (gdbarch
, parent_pc
));
5347 regcache_write_pc (child_regcache
, parent_pc
);
5351 context_switch (ecs
);
5353 /* Immediately detach breakpoints from the child before there's
5354 any chance of letting the user delete breakpoints from the
5355 breakpoint lists. If we don't do this early, it's easy to
5356 leave left over traps in the child, vis: "break foo; catch
5357 fork; c; <fork>; del; c; <child calls foo>". We only follow
5358 the fork on the last `continue', and by that time the
5359 breakpoint at "foo" is long gone from the breakpoint table.
5360 If we vforked, then we don't need to unpatch here, since both
5361 parent and child are sharing the same memory pages; we'll
5362 need to unpatch at follow/detach time instead to be certain
5363 that new breakpoints added between catchpoint hit time and
5364 vfork follow are detached. */
5365 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5367 /* This won't actually modify the breakpoint list, but will
5368 physically remove the breakpoints from the child. */
5369 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5372 delete_just_stopped_threads_single_step_breakpoints ();
5374 /* In case the event is caught by a catchpoint, remember that
5375 the event is to be followed at the next resume of the thread,
5376 and not immediately. */
5377 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5379 ecs
->event_thread
->suspend
.stop_pc
5380 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5382 ecs
->event_thread
->control
.stop_bpstat
5383 = bpstat_stop_status (get_current_regcache ()->aspace (),
5384 ecs
->event_thread
->suspend
.stop_pc
,
5385 ecs
->event_thread
, &ecs
->ws
);
5387 if (handle_stop_requested (ecs
))
5390 /* If no catchpoint triggered for this, then keep going. Note
5391 that we're interested in knowing the bpstat actually causes a
5392 stop, not just if it may explain the signal. Software
5393 watchpoints, for example, always appear in the bpstat. */
5394 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5398 = (follow_fork_mode_string
== follow_fork_mode_child
);
5400 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5402 process_stratum_target
*targ
5403 = ecs
->event_thread
->inf
->process_target ();
5405 should_resume
= follow_fork ();
5407 /* Note that one of these may be an invalid pointer,
5408 depending on detach_fork. */
5409 thread_info
*parent
= ecs
->event_thread
;
5411 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5413 /* At this point, the parent is marked running, and the
5414 child is marked stopped. */
5416 /* If not resuming the parent, mark it stopped. */
5417 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5418 parent
->set_running (false);
5420 /* If resuming the child, mark it running. */
5421 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5422 child
->set_running (true);
5424 /* In non-stop mode, also resume the other branch. */
5425 if (!detach_fork
&& (non_stop
5426 || (sched_multi
&& target_is_non_stop_p ())))
5429 switch_to_thread (parent
);
5431 switch_to_thread (child
);
5433 ecs
->event_thread
= inferior_thread ();
5434 ecs
->ptid
= inferior_ptid
;
5439 switch_to_thread (child
);
5441 switch_to_thread (parent
);
5443 ecs
->event_thread
= inferior_thread ();
5444 ecs
->ptid
= inferior_ptid
;
5452 process_event_stop_test (ecs
);
5455 case TARGET_WAITKIND_VFORK_DONE
:
5456 /* Done with the shared memory region. Re-insert breakpoints in
5457 the parent, and keep going. */
5459 context_switch (ecs
);
5461 current_inferior ()->waiting_for_vfork_done
= 0;
5462 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5464 if (handle_stop_requested (ecs
))
5467 /* This also takes care of reinserting breakpoints in the
5468 previously locked inferior. */
5472 case TARGET_WAITKIND_EXECD
:
5474 /* Note we can't read registers yet (the stop_pc), because we
5475 don't yet know the inferior's post-exec architecture.
5476 'stop_pc' is explicitly read below instead. */
5477 switch_to_thread_no_regs (ecs
->event_thread
);
5479 /* Do whatever is necessary to the parent branch of the vfork. */
5480 handle_vfork_child_exec_or_exit (1);
5482 /* This causes the eventpoints and symbol table to be reset.
5483 Must do this now, before trying to determine whether to
5485 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5487 /* In follow_exec we may have deleted the original thread and
5488 created a new one. Make sure that the event thread is the
5489 execd thread for that case (this is a nop otherwise). */
5490 ecs
->event_thread
= inferior_thread ();
5492 ecs
->event_thread
->suspend
.stop_pc
5493 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5495 ecs
->event_thread
->control
.stop_bpstat
5496 = bpstat_stop_status (get_current_regcache ()->aspace (),
5497 ecs
->event_thread
->suspend
.stop_pc
,
5498 ecs
->event_thread
, &ecs
->ws
);
5500 /* Note that this may be referenced from inside
5501 bpstat_stop_status above, through inferior_has_execd. */
5502 xfree (ecs
->ws
.value
.execd_pathname
);
5503 ecs
->ws
.value
.execd_pathname
= NULL
;
5505 if (handle_stop_requested (ecs
))
5508 /* If no catchpoint triggered for this, then keep going. */
5509 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5511 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5515 process_event_stop_test (ecs
);
5518 /* Be careful not to try to gather much state about a thread
5519 that's in a syscall. It's frequently a losing proposition. */
5520 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5521 /* Getting the current syscall number. */
5522 if (handle_syscall_event (ecs
) == 0)
5523 process_event_stop_test (ecs
);
5526 /* Before examining the threads further, step this thread to
5527 get it entirely out of the syscall. (We get notice of the
5528 event when the thread is just on the verge of exiting a
5529 syscall. Stepping one instruction seems to get it back
5531 case TARGET_WAITKIND_SYSCALL_RETURN
:
5532 if (handle_syscall_event (ecs
) == 0)
5533 process_event_stop_test (ecs
);
5536 case TARGET_WAITKIND_STOPPED
:
5537 handle_signal_stop (ecs
);
5540 case TARGET_WAITKIND_NO_HISTORY
:
5541 /* Reverse execution: target ran out of history info. */
5543 /* Switch to the stopped thread. */
5544 context_switch (ecs
);
5546 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5548 delete_just_stopped_threads_single_step_breakpoints ();
5549 ecs
->event_thread
->suspend
.stop_pc
5550 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5552 if (handle_stop_requested (ecs
))
5555 gdb::observers::no_history
.notify ();
5561 /* Restart threads back to what they were trying to do back when we
5562 paused them for an in-line step-over. The EVENT_THREAD thread is
5566 restart_threads (struct thread_info
*event_thread
)
5568 /* In case the instruction just stepped spawned a new thread. */
5569 update_thread_list ();
5571 for (thread_info
*tp
: all_non_exited_threads ())
5573 switch_to_thread_no_regs (tp
);
5575 if (tp
== event_thread
)
5578 fprintf_unfiltered (gdb_stdlog
,
5579 "infrun: restart threads: "
5580 "[%s] is event thread\n",
5581 target_pid_to_str (tp
->ptid
).c_str ());
5585 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5588 fprintf_unfiltered (gdb_stdlog
,
5589 "infrun: restart threads: "
5590 "[%s] not meant to be running\n",
5591 target_pid_to_str (tp
->ptid
).c_str ());
5598 fprintf_unfiltered (gdb_stdlog
,
5599 "infrun: restart threads: [%s] resumed\n",
5600 target_pid_to_str (tp
->ptid
).c_str ());
5601 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5605 if (thread_is_in_step_over_chain (tp
))
5608 fprintf_unfiltered (gdb_stdlog
,
5609 "infrun: restart threads: "
5610 "[%s] needs step-over\n",
5611 target_pid_to_str (tp
->ptid
).c_str ());
5612 gdb_assert (!tp
->resumed
);
5617 if (tp
->suspend
.waitstatus_pending_p
)
5620 fprintf_unfiltered (gdb_stdlog
,
5621 "infrun: restart threads: "
5622 "[%s] has pending status\n",
5623 target_pid_to_str (tp
->ptid
).c_str ());
5628 gdb_assert (!tp
->stop_requested
);
5630 /* If some thread needs to start a step-over at this point, it
5631 should still be in the step-over queue, and thus skipped
5633 if (thread_still_needs_step_over (tp
))
5635 internal_error (__FILE__
, __LINE__
,
5636 "thread [%s] needs a step-over, but not in "
5637 "step-over queue\n",
5638 target_pid_to_str (tp
->ptid
).c_str ());
5641 if (currently_stepping (tp
))
5644 fprintf_unfiltered (gdb_stdlog
,
5645 "infrun: restart threads: [%s] was stepping\n",
5646 target_pid_to_str (tp
->ptid
).c_str ());
5647 keep_going_stepped_thread (tp
);
5651 struct execution_control_state ecss
;
5652 struct execution_control_state
*ecs
= &ecss
;
5655 fprintf_unfiltered (gdb_stdlog
,
5656 "infrun: restart threads: [%s] continuing\n",
5657 target_pid_to_str (tp
->ptid
).c_str ());
5658 reset_ecs (ecs
, tp
);
5659 switch_to_thread (tp
);
5660 keep_going_pass_signal (ecs
);
5665 /* Callback for iterate_over_threads. Find a resumed thread that has
5666 a pending waitstatus. */
5669 resumed_thread_with_pending_status (struct thread_info
*tp
,
5673 && tp
->suspend
.waitstatus_pending_p
);
5676 /* Called when we get an event that may finish an in-line or
5677 out-of-line (displaced stepping) step-over started previously.
5678 Return true if the event is processed and we should go back to the
5679 event loop; false if the caller should continue processing the
5683 finish_step_over (struct execution_control_state
*ecs
)
5685 int had_step_over_info
;
5687 displaced_step_fixup (ecs
->event_thread
,
5688 ecs
->event_thread
->suspend
.stop_signal
);
5690 had_step_over_info
= step_over_info_valid_p ();
5692 if (had_step_over_info
)
5694 /* If we're stepping over a breakpoint with all threads locked,
5695 then only the thread that was stepped should be reporting
5697 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5699 clear_step_over_info ();
5702 if (!target_is_non_stop_p ())
5705 /* Start a new step-over in another thread if there's one that
5709 /* If we were stepping over a breakpoint before, and haven't started
5710 a new in-line step-over sequence, then restart all other threads
5711 (except the event thread). We can't do this in all-stop, as then
5712 e.g., we wouldn't be able to issue any other remote packet until
5713 these other threads stop. */
5714 if (had_step_over_info
&& !step_over_info_valid_p ())
5716 struct thread_info
*pending
;
5718 /* If we only have threads with pending statuses, the restart
5719 below won't restart any thread and so nothing re-inserts the
5720 breakpoint we just stepped over. But we need it inserted
5721 when we later process the pending events, otherwise if
5722 another thread has a pending event for this breakpoint too,
5723 we'd discard its event (because the breakpoint that
5724 originally caused the event was no longer inserted). */
5725 context_switch (ecs
);
5726 insert_breakpoints ();
5728 restart_threads (ecs
->event_thread
);
5730 /* If we have events pending, go through handle_inferior_event
5731 again, picking up a pending event at random. This avoids
5732 thread starvation. */
5734 /* But not if we just stepped over a watchpoint in order to let
5735 the instruction execute so we can evaluate its expression.
5736 The set of watchpoints that triggered is recorded in the
5737 breakpoint objects themselves (see bp->watchpoint_triggered).
5738 If we processed another event first, that other event could
5739 clobber this info. */
5740 if (ecs
->event_thread
->stepping_over_watchpoint
)
5743 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5745 if (pending
!= NULL
)
5747 struct thread_info
*tp
= ecs
->event_thread
;
5748 struct regcache
*regcache
;
5752 fprintf_unfiltered (gdb_stdlog
,
5753 "infrun: found resumed threads with "
5754 "pending events, saving status\n");
5757 gdb_assert (pending
!= tp
);
5759 /* Record the event thread's event for later. */
5760 save_waitstatus (tp
, &ecs
->ws
);
5761 /* This was cleared early, by handle_inferior_event. Set it
5762 so this pending event is considered by
5766 gdb_assert (!tp
->executing
);
5768 regcache
= get_thread_regcache (tp
);
5769 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5773 fprintf_unfiltered (gdb_stdlog
,
5774 "infrun: saved stop_pc=%s for %s "
5775 "(currently_stepping=%d)\n",
5776 paddress (target_gdbarch (),
5777 tp
->suspend
.stop_pc
),
5778 target_pid_to_str (tp
->ptid
).c_str (),
5779 currently_stepping (tp
));
5782 /* This in-line step-over finished; clear this so we won't
5783 start a new one. This is what handle_signal_stop would
5784 do, if we returned false. */
5785 tp
->stepping_over_breakpoint
= 0;
5787 /* Wake up the event loop again. */
5788 mark_async_event_handler (infrun_async_inferior_event_token
);
5790 prepare_to_wait (ecs
);
5798 /* Come here when the program has stopped with a signal. */
5801 handle_signal_stop (struct execution_control_state
*ecs
)
5803 struct frame_info
*frame
;
5804 struct gdbarch
*gdbarch
;
5805 int stopped_by_watchpoint
;
5806 enum stop_kind stop_soon
;
5809 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5811 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5813 /* Do we need to clean up the state of a thread that has
5814 completed a displaced single-step? (Doing so usually affects
5815 the PC, so do it here, before we set stop_pc.) */
5816 if (finish_step_over (ecs
))
5819 /* If we either finished a single-step or hit a breakpoint, but
5820 the user wanted this thread to be stopped, pretend we got a
5821 SIG0 (generic unsignaled stop). */
5822 if (ecs
->event_thread
->stop_requested
5823 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5824 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5826 ecs
->event_thread
->suspend
.stop_pc
5827 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5831 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5832 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5834 switch_to_thread (ecs
->event_thread
);
5836 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5837 paddress (reg_gdbarch
,
5838 ecs
->event_thread
->suspend
.stop_pc
));
5839 if (target_stopped_by_watchpoint ())
5843 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5845 if (target_stopped_data_address (current_top_target (), &addr
))
5846 fprintf_unfiltered (gdb_stdlog
,
5847 "infrun: stopped data address = %s\n",
5848 paddress (reg_gdbarch
, addr
));
5850 fprintf_unfiltered (gdb_stdlog
,
5851 "infrun: (no data address available)\n");
5855 /* This is originated from start_remote(), start_inferior() and
5856 shared libraries hook functions. */
5857 stop_soon
= get_inferior_stop_soon (ecs
);
5858 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5860 context_switch (ecs
);
5862 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5863 stop_print_frame
= 1;
5868 /* This originates from attach_command(). We need to overwrite
5869 the stop_signal here, because some kernels don't ignore a
5870 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5871 See more comments in inferior.h. On the other hand, if we
5872 get a non-SIGSTOP, report it to the user - assume the backend
5873 will handle the SIGSTOP if it should show up later.
5875 Also consider that the attach is complete when we see a
5876 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5877 target extended-remote report it instead of a SIGSTOP
5878 (e.g. gdbserver). We already rely on SIGTRAP being our
5879 signal, so this is no exception.
5881 Also consider that the attach is complete when we see a
5882 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5883 the target to stop all threads of the inferior, in case the
5884 low level attach operation doesn't stop them implicitly. If
5885 they weren't stopped implicitly, then the stub will report a
5886 GDB_SIGNAL_0, meaning: stopped for no particular reason
5887 other than GDB's request. */
5888 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5889 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5890 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5891 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5893 stop_print_frame
= 1;
5895 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5899 /* See if something interesting happened to the non-current thread. If
5900 so, then switch to that thread. */
5901 if (ecs
->ptid
!= inferior_ptid
)
5904 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5906 context_switch (ecs
);
5908 if (deprecated_context_hook
)
5909 deprecated_context_hook (ecs
->event_thread
->global_num
);
5912 /* At this point, get hold of the now-current thread's frame. */
5913 frame
= get_current_frame ();
5914 gdbarch
= get_frame_arch (frame
);
5916 /* Pull the single step breakpoints out of the target. */
5917 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5919 struct regcache
*regcache
;
5922 regcache
= get_thread_regcache (ecs
->event_thread
);
5923 const address_space
*aspace
= regcache
->aspace ();
5925 pc
= regcache_read_pc (regcache
);
5927 /* However, before doing so, if this single-step breakpoint was
5928 actually for another thread, set this thread up for moving
5930 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5933 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5937 fprintf_unfiltered (gdb_stdlog
,
5938 "infrun: [%s] hit another thread's "
5939 "single-step breakpoint\n",
5940 target_pid_to_str (ecs
->ptid
).c_str ());
5942 ecs
->hit_singlestep_breakpoint
= 1;
5949 fprintf_unfiltered (gdb_stdlog
,
5950 "infrun: [%s] hit its "
5951 "single-step breakpoint\n",
5952 target_pid_to_str (ecs
->ptid
).c_str ());
5956 delete_just_stopped_threads_single_step_breakpoints ();
5958 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5959 && ecs
->event_thread
->control
.trap_expected
5960 && ecs
->event_thread
->stepping_over_watchpoint
)
5961 stopped_by_watchpoint
= 0;
5963 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5965 /* If necessary, step over this watchpoint. We'll be back to display
5967 if (stopped_by_watchpoint
5968 && (target_have_steppable_watchpoint
5969 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5971 /* At this point, we are stopped at an instruction which has
5972 attempted to write to a piece of memory under control of
5973 a watchpoint. The instruction hasn't actually executed
5974 yet. If we were to evaluate the watchpoint expression
5975 now, we would get the old value, and therefore no change
5976 would seem to have occurred.
5978 In order to make watchpoints work `right', we really need
5979 to complete the memory write, and then evaluate the
5980 watchpoint expression. We do this by single-stepping the
5983 It may not be necessary to disable the watchpoint to step over
5984 it. For example, the PA can (with some kernel cooperation)
5985 single step over a watchpoint without disabling the watchpoint.
5987 It is far more common to need to disable a watchpoint to step
5988 the inferior over it. If we have non-steppable watchpoints,
5989 we must disable the current watchpoint; it's simplest to
5990 disable all watchpoints.
5992 Any breakpoint at PC must also be stepped over -- if there's
5993 one, it will have already triggered before the watchpoint
5994 triggered, and we either already reported it to the user, or
5995 it didn't cause a stop and we called keep_going. In either
5996 case, if there was a breakpoint at PC, we must be trying to
5998 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6003 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6004 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6005 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6006 ecs
->event_thread
->control
.stop_step
= 0;
6007 stop_print_frame
= 1;
6008 stopped_by_random_signal
= 0;
6009 bpstat stop_chain
= NULL
;
6011 /* Hide inlined functions starting here, unless we just performed stepi or
6012 nexti. After stepi and nexti, always show the innermost frame (not any
6013 inline function call sites). */
6014 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6016 const address_space
*aspace
6017 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6019 /* skip_inline_frames is expensive, so we avoid it if we can
6020 determine that the address is one where functions cannot have
6021 been inlined. This improves performance with inferiors that
6022 load a lot of shared libraries, because the solib event
6023 breakpoint is defined as the address of a function (i.e. not
6024 inline). Note that we have to check the previous PC as well
6025 as the current one to catch cases when we have just
6026 single-stepped off a breakpoint prior to reinstating it.
6027 Note that we're assuming that the code we single-step to is
6028 not inline, but that's not definitive: there's nothing
6029 preventing the event breakpoint function from containing
6030 inlined code, and the single-step ending up there. If the
6031 user had set a breakpoint on that inlined code, the missing
6032 skip_inline_frames call would break things. Fortunately
6033 that's an extremely unlikely scenario. */
6034 if (!pc_at_non_inline_function (aspace
,
6035 ecs
->event_thread
->suspend
.stop_pc
,
6037 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6038 && ecs
->event_thread
->control
.trap_expected
6039 && pc_at_non_inline_function (aspace
,
6040 ecs
->event_thread
->prev_pc
,
6043 stop_chain
= build_bpstat_chain (aspace
,
6044 ecs
->event_thread
->suspend
.stop_pc
,
6046 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6048 /* Re-fetch current thread's frame in case that invalidated
6050 frame
= get_current_frame ();
6051 gdbarch
= get_frame_arch (frame
);
6055 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6056 && ecs
->event_thread
->control
.trap_expected
6057 && gdbarch_single_step_through_delay_p (gdbarch
)
6058 && currently_stepping (ecs
->event_thread
))
6060 /* We're trying to step off a breakpoint. Turns out that we're
6061 also on an instruction that needs to be stepped multiple
6062 times before it's been fully executing. E.g., architectures
6063 with a delay slot. It needs to be stepped twice, once for
6064 the instruction and once for the delay slot. */
6065 int step_through_delay
6066 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6068 if (debug_infrun
&& step_through_delay
)
6069 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6070 if (ecs
->event_thread
->control
.step_range_end
== 0
6071 && step_through_delay
)
6073 /* The user issued a continue when stopped at a breakpoint.
6074 Set up for another trap and get out of here. */
6075 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6079 else if (step_through_delay
)
6081 /* The user issued a step when stopped at a breakpoint.
6082 Maybe we should stop, maybe we should not - the delay
6083 slot *might* correspond to a line of source. In any
6084 case, don't decide that here, just set
6085 ecs->stepping_over_breakpoint, making sure we
6086 single-step again before breakpoints are re-inserted. */
6087 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6091 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6092 handles this event. */
6093 ecs
->event_thread
->control
.stop_bpstat
6094 = bpstat_stop_status (get_current_regcache ()->aspace (),
6095 ecs
->event_thread
->suspend
.stop_pc
,
6096 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6098 /* Following in case break condition called a
6100 stop_print_frame
= 1;
6102 /* This is where we handle "moribund" watchpoints. Unlike
6103 software breakpoints traps, hardware watchpoint traps are
6104 always distinguishable from random traps. If no high-level
6105 watchpoint is associated with the reported stop data address
6106 anymore, then the bpstat does not explain the signal ---
6107 simply make sure to ignore it if `stopped_by_watchpoint' is
6111 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6112 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6114 && stopped_by_watchpoint
)
6115 fprintf_unfiltered (gdb_stdlog
,
6116 "infrun: no user watchpoint explains "
6117 "watchpoint SIGTRAP, ignoring\n");
6119 /* NOTE: cagney/2003-03-29: These checks for a random signal
6120 at one stage in the past included checks for an inferior
6121 function call's call dummy's return breakpoint. The original
6122 comment, that went with the test, read:
6124 ``End of a stack dummy. Some systems (e.g. Sony news) give
6125 another signal besides SIGTRAP, so check here as well as
6128 If someone ever tries to get call dummys on a
6129 non-executable stack to work (where the target would stop
6130 with something like a SIGSEGV), then those tests might need
6131 to be re-instated. Given, however, that the tests were only
6132 enabled when momentary breakpoints were not being used, I
6133 suspect that it won't be the case.
6135 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6136 be necessary for call dummies on a non-executable stack on
6139 /* See if the breakpoints module can explain the signal. */
6141 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6142 ecs
->event_thread
->suspend
.stop_signal
);
6144 /* Maybe this was a trap for a software breakpoint that has since
6146 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6148 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6149 ecs
->event_thread
->suspend
.stop_pc
))
6151 struct regcache
*regcache
;
6154 /* Re-adjust PC to what the program would see if GDB was not
6156 regcache
= get_thread_regcache (ecs
->event_thread
);
6157 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6160 gdb::optional
<scoped_restore_tmpl
<int>>
6161 restore_operation_disable
;
6163 if (record_full_is_used ())
6164 restore_operation_disable
.emplace
6165 (record_full_gdb_operation_disable_set ());
6167 regcache_write_pc (regcache
,
6168 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6173 /* A delayed software breakpoint event. Ignore the trap. */
6175 fprintf_unfiltered (gdb_stdlog
,
6176 "infrun: delayed software breakpoint "
6177 "trap, ignoring\n");
6182 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6183 has since been removed. */
6184 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6186 /* A delayed hardware breakpoint event. Ignore the trap. */
6188 fprintf_unfiltered (gdb_stdlog
,
6189 "infrun: delayed hardware breakpoint/watchpoint "
6190 "trap, ignoring\n");
6194 /* If not, perhaps stepping/nexting can. */
6196 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6197 && currently_stepping (ecs
->event_thread
));
6199 /* Perhaps the thread hit a single-step breakpoint of _another_
6200 thread. Single-step breakpoints are transparent to the
6201 breakpoints module. */
6203 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6205 /* No? Perhaps we got a moribund watchpoint. */
6207 random_signal
= !stopped_by_watchpoint
;
6209 /* Always stop if the user explicitly requested this thread to
6211 if (ecs
->event_thread
->stop_requested
)
6215 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6218 /* For the program's own signals, act according to
6219 the signal handling tables. */
6223 /* Signal not for debugging purposes. */
6224 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6225 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6228 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6229 gdb_signal_to_symbol_string (stop_signal
));
6231 stopped_by_random_signal
= 1;
6233 /* Always stop on signals if we're either just gaining control
6234 of the program, or the user explicitly requested this thread
6235 to remain stopped. */
6236 if (stop_soon
!= NO_STOP_QUIETLY
6237 || ecs
->event_thread
->stop_requested
6239 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6245 /* Notify observers the signal has "handle print" set. Note we
6246 returned early above if stopping; normal_stop handles the
6247 printing in that case. */
6248 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6250 /* The signal table tells us to print about this signal. */
6251 target_terminal::ours_for_output ();
6252 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6253 target_terminal::inferior ();
6256 /* Clear the signal if it should not be passed. */
6257 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6258 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6260 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6261 && ecs
->event_thread
->control
.trap_expected
6262 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6264 /* We were just starting a new sequence, attempting to
6265 single-step off of a breakpoint and expecting a SIGTRAP.
6266 Instead this signal arrives. This signal will take us out
6267 of the stepping range so GDB needs to remember to, when
6268 the signal handler returns, resume stepping off that
6270 /* To simplify things, "continue" is forced to use the same
6271 code paths as single-step - set a breakpoint at the
6272 signal return address and then, once hit, step off that
6275 fprintf_unfiltered (gdb_stdlog
,
6276 "infrun: signal arrived while stepping over "
6279 insert_hp_step_resume_breakpoint_at_frame (frame
);
6280 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6281 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6282 ecs
->event_thread
->control
.trap_expected
= 0;
6284 /* If we were nexting/stepping some other thread, switch to
6285 it, so that we don't continue it, losing control. */
6286 if (!switch_back_to_stepped_thread (ecs
))
6291 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6292 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6294 || ecs
->event_thread
->control
.step_range_end
== 1)
6295 && frame_id_eq (get_stack_frame_id (frame
),
6296 ecs
->event_thread
->control
.step_stack_frame_id
)
6297 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6299 /* The inferior is about to take a signal that will take it
6300 out of the single step range. Set a breakpoint at the
6301 current PC (which is presumably where the signal handler
6302 will eventually return) and then allow the inferior to
6305 Note that this is only needed for a signal delivered
6306 while in the single-step range. Nested signals aren't a
6307 problem as they eventually all return. */
6309 fprintf_unfiltered (gdb_stdlog
,
6310 "infrun: signal may take us out of "
6311 "single-step range\n");
6313 clear_step_over_info ();
6314 insert_hp_step_resume_breakpoint_at_frame (frame
);
6315 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6316 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6317 ecs
->event_thread
->control
.trap_expected
= 0;
6322 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6323 when either there's a nested signal, or when there's a
6324 pending signal enabled just as the signal handler returns
6325 (leaving the inferior at the step-resume-breakpoint without
6326 actually executing it). Either way continue until the
6327 breakpoint is really hit. */
6329 if (!switch_back_to_stepped_thread (ecs
))
6332 fprintf_unfiltered (gdb_stdlog
,
6333 "infrun: random signal, keep going\n");
6340 process_event_stop_test (ecs
);
6343 /* Come here when we've got some debug event / signal we can explain
6344 (IOW, not a random signal), and test whether it should cause a
6345 stop, or whether we should resume the inferior (transparently).
6346 E.g., could be a breakpoint whose condition evaluates false; we
6347 could be still stepping within the line; etc. */
6350 process_event_stop_test (struct execution_control_state
*ecs
)
6352 struct symtab_and_line stop_pc_sal
;
6353 struct frame_info
*frame
;
6354 struct gdbarch
*gdbarch
;
6355 CORE_ADDR jmp_buf_pc
;
6356 struct bpstat_what what
;
6358 /* Handle cases caused by hitting a breakpoint. */
6360 frame
= get_current_frame ();
6361 gdbarch
= get_frame_arch (frame
);
6363 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6365 if (what
.call_dummy
)
6367 stop_stack_dummy
= what
.call_dummy
;
6370 /* A few breakpoint types have callbacks associated (e.g.,
6371 bp_jit_event). Run them now. */
6372 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6374 /* If we hit an internal event that triggers symbol changes, the
6375 current frame will be invalidated within bpstat_what (e.g., if we
6376 hit an internal solib event). Re-fetch it. */
6377 frame
= get_current_frame ();
6378 gdbarch
= get_frame_arch (frame
);
6380 switch (what
.main_action
)
6382 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6383 /* If we hit the breakpoint at longjmp while stepping, we
6384 install a momentary breakpoint at the target of the
6388 fprintf_unfiltered (gdb_stdlog
,
6389 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6391 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6393 if (what
.is_longjmp
)
6395 struct value
*arg_value
;
6397 /* If we set the longjmp breakpoint via a SystemTap probe,
6398 then use it to extract the arguments. The destination PC
6399 is the third argument to the probe. */
6400 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6403 jmp_buf_pc
= value_as_address (arg_value
);
6404 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6406 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6407 || !gdbarch_get_longjmp_target (gdbarch
,
6408 frame
, &jmp_buf_pc
))
6411 fprintf_unfiltered (gdb_stdlog
,
6412 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6413 "(!gdbarch_get_longjmp_target)\n");
6418 /* Insert a breakpoint at resume address. */
6419 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6422 check_exception_resume (ecs
, frame
);
6426 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6428 struct frame_info
*init_frame
;
6430 /* There are several cases to consider.
6432 1. The initiating frame no longer exists. In this case we
6433 must stop, because the exception or longjmp has gone too
6436 2. The initiating frame exists, and is the same as the
6437 current frame. We stop, because the exception or longjmp
6440 3. The initiating frame exists and is different from the
6441 current frame. This means the exception or longjmp has
6442 been caught beneath the initiating frame, so keep going.
6444 4. longjmp breakpoint has been placed just to protect
6445 against stale dummy frames and user is not interested in
6446 stopping around longjmps. */
6449 fprintf_unfiltered (gdb_stdlog
,
6450 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6452 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6454 delete_exception_resume_breakpoint (ecs
->event_thread
);
6456 if (what
.is_longjmp
)
6458 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6460 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6468 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6472 struct frame_id current_id
6473 = get_frame_id (get_current_frame ());
6474 if (frame_id_eq (current_id
,
6475 ecs
->event_thread
->initiating_frame
))
6477 /* Case 2. Fall through. */
6487 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6489 delete_step_resume_breakpoint (ecs
->event_thread
);
6491 end_stepping_range (ecs
);
6495 case BPSTAT_WHAT_SINGLE
:
6497 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6498 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6499 /* Still need to check other stuff, at least the case where we
6500 are stepping and step out of the right range. */
6503 case BPSTAT_WHAT_STEP_RESUME
:
6505 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6507 delete_step_resume_breakpoint (ecs
->event_thread
);
6508 if (ecs
->event_thread
->control
.proceed_to_finish
6509 && execution_direction
== EXEC_REVERSE
)
6511 struct thread_info
*tp
= ecs
->event_thread
;
6513 /* We are finishing a function in reverse, and just hit the
6514 step-resume breakpoint at the start address of the
6515 function, and we're almost there -- just need to back up
6516 by one more single-step, which should take us back to the
6518 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6522 fill_in_stop_func (gdbarch
, ecs
);
6523 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6524 && execution_direction
== EXEC_REVERSE
)
6526 /* We are stepping over a function call in reverse, and just
6527 hit the step-resume breakpoint at the start address of
6528 the function. Go back to single-stepping, which should
6529 take us back to the function call. */
6530 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6536 case BPSTAT_WHAT_STOP_NOISY
:
6538 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6539 stop_print_frame
= 1;
6541 /* Assume the thread stopped for a breapoint. We'll still check
6542 whether a/the breakpoint is there when the thread is next
6544 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6549 case BPSTAT_WHAT_STOP_SILENT
:
6551 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6552 stop_print_frame
= 0;
6554 /* Assume the thread stopped for a breapoint. We'll still check
6555 whether a/the breakpoint is there when the thread is next
6557 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6561 case BPSTAT_WHAT_HP_STEP_RESUME
:
6563 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6565 delete_step_resume_breakpoint (ecs
->event_thread
);
6566 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6568 /* Back when the step-resume breakpoint was inserted, we
6569 were trying to single-step off a breakpoint. Go back to
6571 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6572 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6578 case BPSTAT_WHAT_KEEP_CHECKING
:
6582 /* If we stepped a permanent breakpoint and we had a high priority
6583 step-resume breakpoint for the address we stepped, but we didn't
6584 hit it, then we must have stepped into the signal handler. The
6585 step-resume was only necessary to catch the case of _not_
6586 stepping into the handler, so delete it, and fall through to
6587 checking whether the step finished. */
6588 if (ecs
->event_thread
->stepped_breakpoint
)
6590 struct breakpoint
*sr_bp
6591 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6594 && sr_bp
->loc
->permanent
6595 && sr_bp
->type
== bp_hp_step_resume
6596 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6599 fprintf_unfiltered (gdb_stdlog
,
6600 "infrun: stepped permanent breakpoint, stopped in "
6602 delete_step_resume_breakpoint (ecs
->event_thread
);
6603 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6607 /* We come here if we hit a breakpoint but should not stop for it.
6608 Possibly we also were stepping and should stop for that. So fall
6609 through and test for stepping. But, if not stepping, do not
6612 /* In all-stop mode, if we're currently stepping but have stopped in
6613 some other thread, we need to switch back to the stepped thread. */
6614 if (switch_back_to_stepped_thread (ecs
))
6617 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6620 fprintf_unfiltered (gdb_stdlog
,
6621 "infrun: step-resume breakpoint is inserted\n");
6623 /* Having a step-resume breakpoint overrides anything
6624 else having to do with stepping commands until
6625 that breakpoint is reached. */
6630 if (ecs
->event_thread
->control
.step_range_end
== 0)
6633 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6634 /* Likewise if we aren't even stepping. */
6639 /* Re-fetch current thread's frame in case the code above caused
6640 the frame cache to be re-initialized, making our FRAME variable
6641 a dangling pointer. */
6642 frame
= get_current_frame ();
6643 gdbarch
= get_frame_arch (frame
);
6644 fill_in_stop_func (gdbarch
, ecs
);
6646 /* If stepping through a line, keep going if still within it.
6648 Note that step_range_end is the address of the first instruction
6649 beyond the step range, and NOT the address of the last instruction
6652 Note also that during reverse execution, we may be stepping
6653 through a function epilogue and therefore must detect when
6654 the current-frame changes in the middle of a line. */
6656 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6658 && (execution_direction
!= EXEC_REVERSE
6659 || frame_id_eq (get_frame_id (frame
),
6660 ecs
->event_thread
->control
.step_frame_id
)))
6664 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6665 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6666 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6668 /* Tentatively re-enable range stepping; `resume' disables it if
6669 necessary (e.g., if we're stepping over a breakpoint or we
6670 have software watchpoints). */
6671 ecs
->event_thread
->control
.may_range_step
= 1;
6673 /* When stepping backward, stop at beginning of line range
6674 (unless it's the function entry point, in which case
6675 keep going back to the call point). */
6676 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6677 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6678 && stop_pc
!= ecs
->stop_func_start
6679 && execution_direction
== EXEC_REVERSE
)
6680 end_stepping_range (ecs
);
6687 /* We stepped out of the stepping range. */
6689 /* If we are stepping at the source level and entered the runtime
6690 loader dynamic symbol resolution code...
6692 EXEC_FORWARD: we keep on single stepping until we exit the run
6693 time loader code and reach the callee's address.
6695 EXEC_REVERSE: we've already executed the callee (backward), and
6696 the runtime loader code is handled just like any other
6697 undebuggable function call. Now we need only keep stepping
6698 backward through the trampoline code, and that's handled further
6699 down, so there is nothing for us to do here. */
6701 if (execution_direction
!= EXEC_REVERSE
6702 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6703 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6705 CORE_ADDR pc_after_resolver
=
6706 gdbarch_skip_solib_resolver (gdbarch
,
6707 ecs
->event_thread
->suspend
.stop_pc
);
6710 fprintf_unfiltered (gdb_stdlog
,
6711 "infrun: stepped into dynsym resolve code\n");
6713 if (pc_after_resolver
)
6715 /* Set up a step-resume breakpoint at the address
6716 indicated by SKIP_SOLIB_RESOLVER. */
6717 symtab_and_line sr_sal
;
6718 sr_sal
.pc
= pc_after_resolver
;
6719 sr_sal
.pspace
= get_frame_program_space (frame
);
6721 insert_step_resume_breakpoint_at_sal (gdbarch
,
6722 sr_sal
, null_frame_id
);
6729 /* Step through an indirect branch thunk. */
6730 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6731 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6732 ecs
->event_thread
->suspend
.stop_pc
))
6735 fprintf_unfiltered (gdb_stdlog
,
6736 "infrun: stepped into indirect branch thunk\n");
6741 if (ecs
->event_thread
->control
.step_range_end
!= 1
6742 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6743 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6744 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6747 fprintf_unfiltered (gdb_stdlog
,
6748 "infrun: stepped into signal trampoline\n");
6749 /* The inferior, while doing a "step" or "next", has ended up in
6750 a signal trampoline (either by a signal being delivered or by
6751 the signal handler returning). Just single-step until the
6752 inferior leaves the trampoline (either by calling the handler
6758 /* If we're in the return path from a shared library trampoline,
6759 we want to proceed through the trampoline when stepping. */
6760 /* macro/2012-04-25: This needs to come before the subroutine
6761 call check below as on some targets return trampolines look
6762 like subroutine calls (MIPS16 return thunks). */
6763 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6764 ecs
->event_thread
->suspend
.stop_pc
,
6765 ecs
->stop_func_name
)
6766 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6768 /* Determine where this trampoline returns. */
6769 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6770 CORE_ADDR real_stop_pc
6771 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6774 fprintf_unfiltered (gdb_stdlog
,
6775 "infrun: stepped into solib return tramp\n");
6777 /* Only proceed through if we know where it's going. */
6780 /* And put the step-breakpoint there and go until there. */
6781 symtab_and_line sr_sal
;
6782 sr_sal
.pc
= real_stop_pc
;
6783 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6784 sr_sal
.pspace
= get_frame_program_space (frame
);
6786 /* Do not specify what the fp should be when we stop since
6787 on some machines the prologue is where the new fp value
6789 insert_step_resume_breakpoint_at_sal (gdbarch
,
6790 sr_sal
, null_frame_id
);
6792 /* Restart without fiddling with the step ranges or
6799 /* Check for subroutine calls. The check for the current frame
6800 equalling the step ID is not necessary - the check of the
6801 previous frame's ID is sufficient - but it is a common case and
6802 cheaper than checking the previous frame's ID.
6804 NOTE: frame_id_eq will never report two invalid frame IDs as
6805 being equal, so to get into this block, both the current and
6806 previous frame must have valid frame IDs. */
6807 /* The outer_frame_id check is a heuristic to detect stepping
6808 through startup code. If we step over an instruction which
6809 sets the stack pointer from an invalid value to a valid value,
6810 we may detect that as a subroutine call from the mythical
6811 "outermost" function. This could be fixed by marking
6812 outermost frames as !stack_p,code_p,special_p. Then the
6813 initial outermost frame, before sp was valid, would
6814 have code_addr == &_start. See the comment in frame_id_eq
6816 if (!frame_id_eq (get_stack_frame_id (frame
),
6817 ecs
->event_thread
->control
.step_stack_frame_id
)
6818 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6819 ecs
->event_thread
->control
.step_stack_frame_id
)
6820 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6822 || (ecs
->event_thread
->control
.step_start_function
6823 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6825 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6826 CORE_ADDR real_stop_pc
;
6829 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6831 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6833 /* I presume that step_over_calls is only 0 when we're
6834 supposed to be stepping at the assembly language level
6835 ("stepi"). Just stop. */
6836 /* And this works the same backward as frontward. MVS */
6837 end_stepping_range (ecs
);
6841 /* Reverse stepping through solib trampolines. */
6843 if (execution_direction
== EXEC_REVERSE
6844 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6845 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6846 || (ecs
->stop_func_start
== 0
6847 && in_solib_dynsym_resolve_code (stop_pc
))))
6849 /* Any solib trampoline code can be handled in reverse
6850 by simply continuing to single-step. We have already
6851 executed the solib function (backwards), and a few
6852 steps will take us back through the trampoline to the
6858 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6860 /* We're doing a "next".
6862 Normal (forward) execution: set a breakpoint at the
6863 callee's return address (the address at which the caller
6866 Reverse (backward) execution. set the step-resume
6867 breakpoint at the start of the function that we just
6868 stepped into (backwards), and continue to there. When we
6869 get there, we'll need to single-step back to the caller. */
6871 if (execution_direction
== EXEC_REVERSE
)
6873 /* If we're already at the start of the function, we've either
6874 just stepped backward into a single instruction function,
6875 or stepped back out of a signal handler to the first instruction
6876 of the function. Just keep going, which will single-step back
6878 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6880 /* Normal function call return (static or dynamic). */
6881 symtab_and_line sr_sal
;
6882 sr_sal
.pc
= ecs
->stop_func_start
;
6883 sr_sal
.pspace
= get_frame_program_space (frame
);
6884 insert_step_resume_breakpoint_at_sal (gdbarch
,
6885 sr_sal
, null_frame_id
);
6889 insert_step_resume_breakpoint_at_caller (frame
);
6895 /* If we are in a function call trampoline (a stub between the
6896 calling routine and the real function), locate the real
6897 function. That's what tells us (a) whether we want to step
6898 into it at all, and (b) what prologue we want to run to the
6899 end of, if we do step into it. */
6900 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6901 if (real_stop_pc
== 0)
6902 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6903 if (real_stop_pc
!= 0)
6904 ecs
->stop_func_start
= real_stop_pc
;
6906 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6908 symtab_and_line sr_sal
;
6909 sr_sal
.pc
= ecs
->stop_func_start
;
6910 sr_sal
.pspace
= get_frame_program_space (frame
);
6912 insert_step_resume_breakpoint_at_sal (gdbarch
,
6913 sr_sal
, null_frame_id
);
6918 /* If we have line number information for the function we are
6919 thinking of stepping into and the function isn't on the skip
6922 If there are several symtabs at that PC (e.g. with include
6923 files), just want to know whether *any* of them have line
6924 numbers. find_pc_line handles this. */
6926 struct symtab_and_line tmp_sal
;
6928 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6929 if (tmp_sal
.line
!= 0
6930 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6932 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6934 if (execution_direction
== EXEC_REVERSE
)
6935 handle_step_into_function_backward (gdbarch
, ecs
);
6937 handle_step_into_function (gdbarch
, ecs
);
6942 /* If we have no line number and the step-stop-if-no-debug is
6943 set, we stop the step so that the user has a chance to switch
6944 in assembly mode. */
6945 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6946 && step_stop_if_no_debug
)
6948 end_stepping_range (ecs
);
6952 if (execution_direction
== EXEC_REVERSE
)
6954 /* If we're already at the start of the function, we've either just
6955 stepped backward into a single instruction function without line
6956 number info, or stepped back out of a signal handler to the first
6957 instruction of the function without line number info. Just keep
6958 going, which will single-step back to the caller. */
6959 if (ecs
->stop_func_start
!= stop_pc
)
6961 /* Set a breakpoint at callee's start address.
6962 From there we can step once and be back in the caller. */
6963 symtab_and_line sr_sal
;
6964 sr_sal
.pc
= ecs
->stop_func_start
;
6965 sr_sal
.pspace
= get_frame_program_space (frame
);
6966 insert_step_resume_breakpoint_at_sal (gdbarch
,
6967 sr_sal
, null_frame_id
);
6971 /* Set a breakpoint at callee's return address (the address
6972 at which the caller will resume). */
6973 insert_step_resume_breakpoint_at_caller (frame
);
6979 /* Reverse stepping through solib trampolines. */
6981 if (execution_direction
== EXEC_REVERSE
6982 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6984 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6986 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6987 || (ecs
->stop_func_start
== 0
6988 && in_solib_dynsym_resolve_code (stop_pc
)))
6990 /* Any solib trampoline code can be handled in reverse
6991 by simply continuing to single-step. We have already
6992 executed the solib function (backwards), and a few
6993 steps will take us back through the trampoline to the
6998 else if (in_solib_dynsym_resolve_code (stop_pc
))
7000 /* Stepped backward into the solib dynsym resolver.
7001 Set a breakpoint at its start and continue, then
7002 one more step will take us out. */
7003 symtab_and_line sr_sal
;
7004 sr_sal
.pc
= ecs
->stop_func_start
;
7005 sr_sal
.pspace
= get_frame_program_space (frame
);
7006 insert_step_resume_breakpoint_at_sal (gdbarch
,
7007 sr_sal
, null_frame_id
);
7013 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7015 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7016 the trampoline processing logic, however, there are some trampolines
7017 that have no names, so we should do trampoline handling first. */
7018 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7019 && ecs
->stop_func_name
== NULL
7020 && stop_pc_sal
.line
== 0)
7023 fprintf_unfiltered (gdb_stdlog
,
7024 "infrun: stepped into undebuggable function\n");
7026 /* The inferior just stepped into, or returned to, an
7027 undebuggable function (where there is no debugging information
7028 and no line number corresponding to the address where the
7029 inferior stopped). Since we want to skip this kind of code,
7030 we keep going until the inferior returns from this
7031 function - unless the user has asked us not to (via
7032 set step-mode) or we no longer know how to get back
7033 to the call site. */
7034 if (step_stop_if_no_debug
7035 || !frame_id_p (frame_unwind_caller_id (frame
)))
7037 /* If we have no line number and the step-stop-if-no-debug
7038 is set, we stop the step so that the user has a chance to
7039 switch in assembly mode. */
7040 end_stepping_range (ecs
);
7045 /* Set a breakpoint at callee's return address (the address
7046 at which the caller will resume). */
7047 insert_step_resume_breakpoint_at_caller (frame
);
7053 if (ecs
->event_thread
->control
.step_range_end
== 1)
7055 /* It is stepi or nexti. We always want to stop stepping after
7058 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7059 end_stepping_range (ecs
);
7063 if (stop_pc_sal
.line
== 0)
7065 /* We have no line number information. That means to stop
7066 stepping (does this always happen right after one instruction,
7067 when we do "s" in a function with no line numbers,
7068 or can this happen as a result of a return or longjmp?). */
7070 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7071 end_stepping_range (ecs
);
7075 /* Look for "calls" to inlined functions, part one. If the inline
7076 frame machinery detected some skipped call sites, we have entered
7077 a new inline function. */
7079 if (frame_id_eq (get_frame_id (get_current_frame ()),
7080 ecs
->event_thread
->control
.step_frame_id
)
7081 && inline_skipped_frames (ecs
->event_thread
))
7084 fprintf_unfiltered (gdb_stdlog
,
7085 "infrun: stepped into inlined function\n");
7087 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7089 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7091 /* For "step", we're going to stop. But if the call site
7092 for this inlined function is on the same source line as
7093 we were previously stepping, go down into the function
7094 first. Otherwise stop at the call site. */
7096 if (call_sal
.line
== ecs
->event_thread
->current_line
7097 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7099 step_into_inline_frame (ecs
->event_thread
);
7100 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7107 end_stepping_range (ecs
);
7112 /* For "next", we should stop at the call site if it is on a
7113 different source line. Otherwise continue through the
7114 inlined function. */
7115 if (call_sal
.line
== ecs
->event_thread
->current_line
7116 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7119 end_stepping_range (ecs
);
7124 /* Look for "calls" to inlined functions, part two. If we are still
7125 in the same real function we were stepping through, but we have
7126 to go further up to find the exact frame ID, we are stepping
7127 through a more inlined call beyond its call site. */
7129 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7130 && !frame_id_eq (get_frame_id (get_current_frame ()),
7131 ecs
->event_thread
->control
.step_frame_id
)
7132 && stepped_in_from (get_current_frame (),
7133 ecs
->event_thread
->control
.step_frame_id
))
7136 fprintf_unfiltered (gdb_stdlog
,
7137 "infrun: stepping through inlined function\n");
7139 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7140 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7143 end_stepping_range (ecs
);
7147 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7148 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7149 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7151 /* We are at the start of a different line. So stop. Note that
7152 we don't stop if we step into the middle of a different line.
7153 That is said to make things like for (;;) statements work
7156 fprintf_unfiltered (gdb_stdlog
,
7157 "infrun: stepped to a different line\n");
7158 end_stepping_range (ecs
);
7162 /* We aren't done stepping.
7164 Optimize by setting the stepping range to the line.
7165 (We might not be in the original line, but if we entered a
7166 new line in mid-statement, we continue stepping. This makes
7167 things like for(;;) statements work better.) */
7169 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7170 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7171 ecs
->event_thread
->control
.may_range_step
= 1;
7172 set_step_info (frame
, stop_pc_sal
);
7175 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7179 /* In all-stop mode, if we're currently stepping but have stopped in
7180 some other thread, we may need to switch back to the stepped
7181 thread. Returns true we set the inferior running, false if we left
7182 it stopped (and the event needs further processing). */
7185 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7187 if (!target_is_non_stop_p ())
7189 struct thread_info
*stepping_thread
;
7191 /* If any thread is blocked on some internal breakpoint, and we
7192 simply need to step over that breakpoint to get it going
7193 again, do that first. */
7195 /* However, if we see an event for the stepping thread, then we
7196 know all other threads have been moved past their breakpoints
7197 already. Let the caller check whether the step is finished,
7198 etc., before deciding to move it past a breakpoint. */
7199 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7202 /* Check if the current thread is blocked on an incomplete
7203 step-over, interrupted by a random signal. */
7204 if (ecs
->event_thread
->control
.trap_expected
7205 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7209 fprintf_unfiltered (gdb_stdlog
,
7210 "infrun: need to finish step-over of [%s]\n",
7211 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7217 /* Check if the current thread is blocked by a single-step
7218 breakpoint of another thread. */
7219 if (ecs
->hit_singlestep_breakpoint
)
7223 fprintf_unfiltered (gdb_stdlog
,
7224 "infrun: need to step [%s] over single-step "
7226 target_pid_to_str (ecs
->ptid
).c_str ());
7232 /* If this thread needs yet another step-over (e.g., stepping
7233 through a delay slot), do it first before moving on to
7235 if (thread_still_needs_step_over (ecs
->event_thread
))
7239 fprintf_unfiltered (gdb_stdlog
,
7240 "infrun: thread [%s] still needs step-over\n",
7241 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7247 /* If scheduler locking applies even if not stepping, there's no
7248 need to walk over threads. Above we've checked whether the
7249 current thread is stepping. If some other thread not the
7250 event thread is stepping, then it must be that scheduler
7251 locking is not in effect. */
7252 if (schedlock_applies (ecs
->event_thread
))
7255 /* Otherwise, we no longer expect a trap in the current thread.
7256 Clear the trap_expected flag before switching back -- this is
7257 what keep_going does as well, if we call it. */
7258 ecs
->event_thread
->control
.trap_expected
= 0;
7260 /* Likewise, clear the signal if it should not be passed. */
7261 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7262 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7264 /* Do all pending step-overs before actually proceeding with
7266 if (start_step_over ())
7268 prepare_to_wait (ecs
);
7272 /* Look for the stepping/nexting thread. */
7273 stepping_thread
= NULL
;
7275 for (thread_info
*tp
: all_non_exited_threads ())
7277 switch_to_thread_no_regs (tp
);
7279 /* Ignore threads of processes the caller is not
7282 && (tp
->inf
->process_target () != ecs
->target
7283 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7286 /* When stepping over a breakpoint, we lock all threads
7287 except the one that needs to move past the breakpoint.
7288 If a non-event thread has this set, the "incomplete
7289 step-over" check above should have caught it earlier. */
7290 if (tp
->control
.trap_expected
)
7292 internal_error (__FILE__
, __LINE__
,
7293 "[%s] has inconsistent state: "
7294 "trap_expected=%d\n",
7295 target_pid_to_str (tp
->ptid
).c_str (),
7296 tp
->control
.trap_expected
);
7299 /* Did we find the stepping thread? */
7300 if (tp
->control
.step_range_end
)
7302 /* Yep. There should only one though. */
7303 gdb_assert (stepping_thread
== NULL
);
7305 /* The event thread is handled at the top, before we
7307 gdb_assert (tp
!= ecs
->event_thread
);
7309 /* If some thread other than the event thread is
7310 stepping, then scheduler locking can't be in effect,
7311 otherwise we wouldn't have resumed the current event
7312 thread in the first place. */
7313 gdb_assert (!schedlock_applies (tp
));
7315 stepping_thread
= tp
;
7319 if (stepping_thread
!= NULL
)
7322 fprintf_unfiltered (gdb_stdlog
,
7323 "infrun: switching back to stepped thread\n");
7325 if (keep_going_stepped_thread (stepping_thread
))
7327 prepare_to_wait (ecs
);
7332 switch_to_thread (ecs
->event_thread
);
7338 /* Set a previously stepped thread back to stepping. Returns true on
7339 success, false if the resume is not possible (e.g., the thread
7343 keep_going_stepped_thread (struct thread_info
*tp
)
7345 struct frame_info
*frame
;
7346 struct execution_control_state ecss
;
7347 struct execution_control_state
*ecs
= &ecss
;
7349 /* If the stepping thread exited, then don't try to switch back and
7350 resume it, which could fail in several different ways depending
7351 on the target. Instead, just keep going.
7353 We can find a stepping dead thread in the thread list in two
7356 - The target supports thread exit events, and when the target
7357 tries to delete the thread from the thread list, inferior_ptid
7358 pointed at the exiting thread. In such case, calling
7359 delete_thread does not really remove the thread from the list;
7360 instead, the thread is left listed, with 'exited' state.
7362 - The target's debug interface does not support thread exit
7363 events, and so we have no idea whatsoever if the previously
7364 stepping thread is still alive. For that reason, we need to
7365 synchronously query the target now. */
7367 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7370 fprintf_unfiltered (gdb_stdlog
,
7371 "infrun: not resuming previously "
7372 "stepped thread, it has vanished\n");
7379 fprintf_unfiltered (gdb_stdlog
,
7380 "infrun: resuming previously stepped thread\n");
7382 reset_ecs (ecs
, tp
);
7383 switch_to_thread (tp
);
7385 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7386 frame
= get_current_frame ();
7388 /* If the PC of the thread we were trying to single-step has
7389 changed, then that thread has trapped or been signaled, but the
7390 event has not been reported to GDB yet. Re-poll the target
7391 looking for this particular thread's event (i.e. temporarily
7392 enable schedlock) by:
7394 - setting a break at the current PC
7395 - resuming that particular thread, only (by setting trap
7398 This prevents us continuously moving the single-step breakpoint
7399 forward, one instruction at a time, overstepping. */
7401 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7406 fprintf_unfiltered (gdb_stdlog
,
7407 "infrun: expected thread advanced also (%s -> %s)\n",
7408 paddress (target_gdbarch (), tp
->prev_pc
),
7409 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7411 /* Clear the info of the previous step-over, as it's no longer
7412 valid (if the thread was trying to step over a breakpoint, it
7413 has already succeeded). It's what keep_going would do too,
7414 if we called it. Do this before trying to insert the sss
7415 breakpoint, otherwise if we were previously trying to step
7416 over this exact address in another thread, the breakpoint is
7418 clear_step_over_info ();
7419 tp
->control
.trap_expected
= 0;
7421 insert_single_step_breakpoint (get_frame_arch (frame
),
7422 get_frame_address_space (frame
),
7423 tp
->suspend
.stop_pc
);
7426 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7427 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7432 fprintf_unfiltered (gdb_stdlog
,
7433 "infrun: expected thread still hasn't advanced\n");
7435 keep_going_pass_signal (ecs
);
7440 /* Is thread TP in the middle of (software or hardware)
7441 single-stepping? (Note the result of this function must never be
7442 passed directly as target_resume's STEP parameter.) */
7445 currently_stepping (struct thread_info
*tp
)
7447 return ((tp
->control
.step_range_end
7448 && tp
->control
.step_resume_breakpoint
== NULL
)
7449 || tp
->control
.trap_expected
7450 || tp
->stepped_breakpoint
7451 || bpstat_should_step ());
7454 /* Inferior has stepped into a subroutine call with source code that
7455 we should not step over. Do step to the first line of code in
7459 handle_step_into_function (struct gdbarch
*gdbarch
,
7460 struct execution_control_state
*ecs
)
7462 fill_in_stop_func (gdbarch
, ecs
);
7464 compunit_symtab
*cust
7465 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7466 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7467 ecs
->stop_func_start
7468 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7470 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7471 /* Use the step_resume_break to step until the end of the prologue,
7472 even if that involves jumps (as it seems to on the vax under
7474 /* If the prologue ends in the middle of a source line, continue to
7475 the end of that source line (if it is still within the function).
7476 Otherwise, just go to end of prologue. */
7477 if (stop_func_sal
.end
7478 && stop_func_sal
.pc
!= ecs
->stop_func_start
7479 && stop_func_sal
.end
< ecs
->stop_func_end
)
7480 ecs
->stop_func_start
= stop_func_sal
.end
;
7482 /* Architectures which require breakpoint adjustment might not be able
7483 to place a breakpoint at the computed address. If so, the test
7484 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7485 ecs->stop_func_start to an address at which a breakpoint may be
7486 legitimately placed.
7488 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7489 made, GDB will enter an infinite loop when stepping through
7490 optimized code consisting of VLIW instructions which contain
7491 subinstructions corresponding to different source lines. On
7492 FR-V, it's not permitted to place a breakpoint on any but the
7493 first subinstruction of a VLIW instruction. When a breakpoint is
7494 set, GDB will adjust the breakpoint address to the beginning of
7495 the VLIW instruction. Thus, we need to make the corresponding
7496 adjustment here when computing the stop address. */
7498 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7500 ecs
->stop_func_start
7501 = gdbarch_adjust_breakpoint_address (gdbarch
,
7502 ecs
->stop_func_start
);
7505 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7507 /* We are already there: stop now. */
7508 end_stepping_range (ecs
);
7513 /* Put the step-breakpoint there and go until there. */
7514 symtab_and_line sr_sal
;
7515 sr_sal
.pc
= ecs
->stop_func_start
;
7516 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7517 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7519 /* Do not specify what the fp should be when we stop since on
7520 some machines the prologue is where the new fp value is
7522 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7524 /* And make sure stepping stops right away then. */
7525 ecs
->event_thread
->control
.step_range_end
7526 = ecs
->event_thread
->control
.step_range_start
;
7531 /* Inferior has stepped backward into a subroutine call with source
7532 code that we should not step over. Do step to the beginning of the
7533 last line of code in it. */
7536 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7537 struct execution_control_state
*ecs
)
7539 struct compunit_symtab
*cust
;
7540 struct symtab_and_line stop_func_sal
;
7542 fill_in_stop_func (gdbarch
, ecs
);
7544 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7545 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7546 ecs
->stop_func_start
7547 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7549 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7551 /* OK, we're just going to keep stepping here. */
7552 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7554 /* We're there already. Just stop stepping now. */
7555 end_stepping_range (ecs
);
7559 /* Else just reset the step range and keep going.
7560 No step-resume breakpoint, they don't work for
7561 epilogues, which can have multiple entry paths. */
7562 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7563 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7569 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7570 This is used to both functions and to skip over code. */
7573 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7574 struct symtab_and_line sr_sal
,
7575 struct frame_id sr_id
,
7576 enum bptype sr_type
)
7578 /* There should never be more than one step-resume or longjmp-resume
7579 breakpoint per thread, so we should never be setting a new
7580 step_resume_breakpoint when one is already active. */
7581 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7582 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7585 fprintf_unfiltered (gdb_stdlog
,
7586 "infrun: inserting step-resume breakpoint at %s\n",
7587 paddress (gdbarch
, sr_sal
.pc
));
7589 inferior_thread ()->control
.step_resume_breakpoint
7590 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7594 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7595 struct symtab_and_line sr_sal
,
7596 struct frame_id sr_id
)
7598 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7603 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7604 This is used to skip a potential signal handler.
7606 This is called with the interrupted function's frame. The signal
7607 handler, when it returns, will resume the interrupted function at
7611 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7613 gdb_assert (return_frame
!= NULL
);
7615 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7617 symtab_and_line sr_sal
;
7618 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7619 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7620 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7622 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7623 get_stack_frame_id (return_frame
),
7627 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7628 is used to skip a function after stepping into it (for "next" or if
7629 the called function has no debugging information).
7631 The current function has almost always been reached by single
7632 stepping a call or return instruction. NEXT_FRAME belongs to the
7633 current function, and the breakpoint will be set at the caller's
7636 This is a separate function rather than reusing
7637 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7638 get_prev_frame, which may stop prematurely (see the implementation
7639 of frame_unwind_caller_id for an example). */
7642 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7644 /* We shouldn't have gotten here if we don't know where the call site
7646 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7648 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7650 symtab_and_line sr_sal
;
7651 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7652 frame_unwind_caller_pc (next_frame
));
7653 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7654 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7656 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7657 frame_unwind_caller_id (next_frame
));
7660 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7661 new breakpoint at the target of a jmp_buf. The handling of
7662 longjmp-resume uses the same mechanisms used for handling
7663 "step-resume" breakpoints. */
7666 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7668 /* There should never be more than one longjmp-resume breakpoint per
7669 thread, so we should never be setting a new
7670 longjmp_resume_breakpoint when one is already active. */
7671 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7674 fprintf_unfiltered (gdb_stdlog
,
7675 "infrun: inserting longjmp-resume breakpoint at %s\n",
7676 paddress (gdbarch
, pc
));
7678 inferior_thread ()->control
.exception_resume_breakpoint
=
7679 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7682 /* Insert an exception resume breakpoint. TP is the thread throwing
7683 the exception. The block B is the block of the unwinder debug hook
7684 function. FRAME is the frame corresponding to the call to this
7685 function. SYM is the symbol of the function argument holding the
7686 target PC of the exception. */
7689 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7690 const struct block
*b
,
7691 struct frame_info
*frame
,
7696 struct block_symbol vsym
;
7697 struct value
*value
;
7699 struct breakpoint
*bp
;
7701 vsym
= lookup_symbol_search_name (sym
->search_name (),
7703 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7704 /* If the value was optimized out, revert to the old behavior. */
7705 if (! value_optimized_out (value
))
7707 handler
= value_as_address (value
);
7710 fprintf_unfiltered (gdb_stdlog
,
7711 "infrun: exception resume at %lx\n",
7712 (unsigned long) handler
);
7714 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7716 bp_exception_resume
).release ();
7718 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7721 bp
->thread
= tp
->global_num
;
7722 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7725 catch (const gdb_exception_error
&e
)
7727 /* We want to ignore errors here. */
7731 /* A helper for check_exception_resume that sets an
7732 exception-breakpoint based on a SystemTap probe. */
7735 insert_exception_resume_from_probe (struct thread_info
*tp
,
7736 const struct bound_probe
*probe
,
7737 struct frame_info
*frame
)
7739 struct value
*arg_value
;
7741 struct breakpoint
*bp
;
7743 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7747 handler
= value_as_address (arg_value
);
7750 fprintf_unfiltered (gdb_stdlog
,
7751 "infrun: exception resume at %s\n",
7752 paddress (get_objfile_arch (probe
->objfile
),
7755 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7756 handler
, bp_exception_resume
).release ();
7757 bp
->thread
= tp
->global_num
;
7758 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7761 /* This is called when an exception has been intercepted. Check to
7762 see whether the exception's destination is of interest, and if so,
7763 set an exception resume breakpoint there. */
7766 check_exception_resume (struct execution_control_state
*ecs
,
7767 struct frame_info
*frame
)
7769 struct bound_probe probe
;
7770 struct symbol
*func
;
7772 /* First see if this exception unwinding breakpoint was set via a
7773 SystemTap probe point. If so, the probe has two arguments: the
7774 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7775 set a breakpoint there. */
7776 probe
= find_probe_by_pc (get_frame_pc (frame
));
7779 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7783 func
= get_frame_function (frame
);
7789 const struct block
*b
;
7790 struct block_iterator iter
;
7794 /* The exception breakpoint is a thread-specific breakpoint on
7795 the unwinder's debug hook, declared as:
7797 void _Unwind_DebugHook (void *cfa, void *handler);
7799 The CFA argument indicates the frame to which control is
7800 about to be transferred. HANDLER is the destination PC.
7802 We ignore the CFA and set a temporary breakpoint at HANDLER.
7803 This is not extremely efficient but it avoids issues in gdb
7804 with computing the DWARF CFA, and it also works even in weird
7805 cases such as throwing an exception from inside a signal
7808 b
= SYMBOL_BLOCK_VALUE (func
);
7809 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7811 if (!SYMBOL_IS_ARGUMENT (sym
))
7818 insert_exception_resume_breakpoint (ecs
->event_thread
,
7824 catch (const gdb_exception_error
&e
)
7830 stop_waiting (struct execution_control_state
*ecs
)
7833 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7835 /* Let callers know we don't want to wait for the inferior anymore. */
7836 ecs
->wait_some_more
= 0;
7838 /* If all-stop, but the target is always in non-stop mode, stop all
7839 threads now that we're presenting the stop to the user. */
7840 if (!non_stop
&& target_is_non_stop_p ())
7841 stop_all_threads ();
7844 /* Like keep_going, but passes the signal to the inferior, even if the
7845 signal is set to nopass. */
7848 keep_going_pass_signal (struct execution_control_state
*ecs
)
7850 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7851 gdb_assert (!ecs
->event_thread
->resumed
);
7853 /* Save the pc before execution, to compare with pc after stop. */
7854 ecs
->event_thread
->prev_pc
7855 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7857 if (ecs
->event_thread
->control
.trap_expected
)
7859 struct thread_info
*tp
= ecs
->event_thread
;
7862 fprintf_unfiltered (gdb_stdlog
,
7863 "infrun: %s has trap_expected set, "
7864 "resuming to collect trap\n",
7865 target_pid_to_str (tp
->ptid
).c_str ());
7867 /* We haven't yet gotten our trap, and either: intercepted a
7868 non-signal event (e.g., a fork); or took a signal which we
7869 are supposed to pass through to the inferior. Simply
7871 resume (ecs
->event_thread
->suspend
.stop_signal
);
7873 else if (step_over_info_valid_p ())
7875 /* Another thread is stepping over a breakpoint in-line. If
7876 this thread needs a step-over too, queue the request. In
7877 either case, this resume must be deferred for later. */
7878 struct thread_info
*tp
= ecs
->event_thread
;
7880 if (ecs
->hit_singlestep_breakpoint
7881 || thread_still_needs_step_over (tp
))
7884 fprintf_unfiltered (gdb_stdlog
,
7885 "infrun: step-over already in progress: "
7886 "step-over for %s deferred\n",
7887 target_pid_to_str (tp
->ptid
).c_str ());
7888 thread_step_over_chain_enqueue (tp
);
7893 fprintf_unfiltered (gdb_stdlog
,
7894 "infrun: step-over in progress: "
7895 "resume of %s deferred\n",
7896 target_pid_to_str (tp
->ptid
).c_str ());
7901 struct regcache
*regcache
= get_current_regcache ();
7904 step_over_what step_what
;
7906 /* Either the trap was not expected, but we are continuing
7907 anyway (if we got a signal, the user asked it be passed to
7910 We got our expected trap, but decided we should resume from
7913 We're going to run this baby now!
7915 Note that insert_breakpoints won't try to re-insert
7916 already inserted breakpoints. Therefore, we don't
7917 care if breakpoints were already inserted, or not. */
7919 /* If we need to step over a breakpoint, and we're not using
7920 displaced stepping to do so, insert all breakpoints
7921 (watchpoints, etc.) but the one we're stepping over, step one
7922 instruction, and then re-insert the breakpoint when that step
7925 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7927 remove_bp
= (ecs
->hit_singlestep_breakpoint
7928 || (step_what
& STEP_OVER_BREAKPOINT
));
7929 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7931 /* We can't use displaced stepping if we need to step past a
7932 watchpoint. The instruction copied to the scratch pad would
7933 still trigger the watchpoint. */
7935 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7937 set_step_over_info (regcache
->aspace (),
7938 regcache_read_pc (regcache
), remove_wps
,
7939 ecs
->event_thread
->global_num
);
7941 else if (remove_wps
)
7942 set_step_over_info (NULL
, 0, remove_wps
, -1);
7944 /* If we now need to do an in-line step-over, we need to stop
7945 all other threads. Note this must be done before
7946 insert_breakpoints below, because that removes the breakpoint
7947 we're about to step over, otherwise other threads could miss
7949 if (step_over_info_valid_p () && target_is_non_stop_p ())
7950 stop_all_threads ();
7952 /* Stop stepping if inserting breakpoints fails. */
7955 insert_breakpoints ();
7957 catch (const gdb_exception_error
&e
)
7959 exception_print (gdb_stderr
, e
);
7961 clear_step_over_info ();
7965 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7967 resume (ecs
->event_thread
->suspend
.stop_signal
);
7970 prepare_to_wait (ecs
);
7973 /* Called when we should continue running the inferior, because the
7974 current event doesn't cause a user visible stop. This does the
7975 resuming part; waiting for the next event is done elsewhere. */
7978 keep_going (struct execution_control_state
*ecs
)
7980 if (ecs
->event_thread
->control
.trap_expected
7981 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7982 ecs
->event_thread
->control
.trap_expected
= 0;
7984 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7985 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7986 keep_going_pass_signal (ecs
);
7989 /* This function normally comes after a resume, before
7990 handle_inferior_event exits. It takes care of any last bits of
7991 housekeeping, and sets the all-important wait_some_more flag. */
7994 prepare_to_wait (struct execution_control_state
*ecs
)
7997 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7999 ecs
->wait_some_more
= 1;
8001 if (!target_is_async_p ())
8002 mark_infrun_async_event_handler ();
8005 /* We are done with the step range of a step/next/si/ni command.
8006 Called once for each n of a "step n" operation. */
8009 end_stepping_range (struct execution_control_state
*ecs
)
8011 ecs
->event_thread
->control
.stop_step
= 1;
8015 /* Several print_*_reason functions to print why the inferior has stopped.
8016 We always print something when the inferior exits, or receives a signal.
8017 The rest of the cases are dealt with later on in normal_stop and
8018 print_it_typical. Ideally there should be a call to one of these
8019 print_*_reason functions functions from handle_inferior_event each time
8020 stop_waiting is called.
8022 Note that we don't call these directly, instead we delegate that to
8023 the interpreters, through observers. Interpreters then call these
8024 with whatever uiout is right. */
8027 print_end_stepping_range_reason (struct ui_out
*uiout
)
8029 /* For CLI-like interpreters, print nothing. */
8031 if (uiout
->is_mi_like_p ())
8033 uiout
->field_string ("reason",
8034 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8039 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8041 annotate_signalled ();
8042 if (uiout
->is_mi_like_p ())
8044 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8045 uiout
->text ("\nProgram terminated with signal ");
8046 annotate_signal_name ();
8047 uiout
->field_string ("signal-name",
8048 gdb_signal_to_name (siggnal
));
8049 annotate_signal_name_end ();
8051 annotate_signal_string ();
8052 uiout
->field_string ("signal-meaning",
8053 gdb_signal_to_string (siggnal
));
8054 annotate_signal_string_end ();
8055 uiout
->text (".\n");
8056 uiout
->text ("The program no longer exists.\n");
8060 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8062 struct inferior
*inf
= current_inferior ();
8063 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8065 annotate_exited (exitstatus
);
8068 if (uiout
->is_mi_like_p ())
8069 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8070 std::string exit_code_str
8071 = string_printf ("0%o", (unsigned int) exitstatus
);
8072 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8073 plongest (inf
->num
), pidstr
.c_str (),
8074 string_field ("exit-code", exit_code_str
.c_str ()));
8078 if (uiout
->is_mi_like_p ())
8080 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8081 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8082 plongest (inf
->num
), pidstr
.c_str ());
8086 /* Some targets/architectures can do extra processing/display of
8087 segmentation faults. E.g., Intel MPX boundary faults.
8088 Call the architecture dependent function to handle the fault. */
8091 handle_segmentation_fault (struct ui_out
*uiout
)
8093 struct regcache
*regcache
= get_current_regcache ();
8094 struct gdbarch
*gdbarch
= regcache
->arch ();
8096 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8097 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8101 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8103 struct thread_info
*thr
= inferior_thread ();
8107 if (uiout
->is_mi_like_p ())
8109 else if (show_thread_that_caused_stop ())
8113 uiout
->text ("\nThread ");
8114 uiout
->field_string ("thread-id", print_thread_id (thr
));
8116 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8119 uiout
->text (" \"");
8120 uiout
->field_string ("name", name
);
8125 uiout
->text ("\nProgram");
8127 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8128 uiout
->text (" stopped");
8131 uiout
->text (" received signal ");
8132 annotate_signal_name ();
8133 if (uiout
->is_mi_like_p ())
8135 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8136 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8137 annotate_signal_name_end ();
8139 annotate_signal_string ();
8140 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8142 if (siggnal
== GDB_SIGNAL_SEGV
)
8143 handle_segmentation_fault (uiout
);
8145 annotate_signal_string_end ();
8147 uiout
->text (".\n");
8151 print_no_history_reason (struct ui_out
*uiout
)
8153 uiout
->text ("\nNo more reverse-execution history.\n");
8156 /* Print current location without a level number, if we have changed
8157 functions or hit a breakpoint. Print source line if we have one.
8158 bpstat_print contains the logic deciding in detail what to print,
8159 based on the event(s) that just occurred. */
8162 print_stop_location (struct target_waitstatus
*ws
)
8165 enum print_what source_flag
;
8166 int do_frame_printing
= 1;
8167 struct thread_info
*tp
= inferior_thread ();
8169 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8173 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8174 should) carry around the function and does (or should) use
8175 that when doing a frame comparison. */
8176 if (tp
->control
.stop_step
8177 && frame_id_eq (tp
->control
.step_frame_id
,
8178 get_frame_id (get_current_frame ()))
8179 && (tp
->control
.step_start_function
8180 == find_pc_function (tp
->suspend
.stop_pc
)))
8182 /* Finished step, just print source line. */
8183 source_flag
= SRC_LINE
;
8187 /* Print location and source line. */
8188 source_flag
= SRC_AND_LOC
;
8191 case PRINT_SRC_AND_LOC
:
8192 /* Print location and source line. */
8193 source_flag
= SRC_AND_LOC
;
8195 case PRINT_SRC_ONLY
:
8196 source_flag
= SRC_LINE
;
8199 /* Something bogus. */
8200 source_flag
= SRC_LINE
;
8201 do_frame_printing
= 0;
8204 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8207 /* The behavior of this routine with respect to the source
8209 SRC_LINE: Print only source line
8210 LOCATION: Print only location
8211 SRC_AND_LOC: Print location and source line. */
8212 if (do_frame_printing
)
8213 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8219 print_stop_event (struct ui_out
*uiout
, bool displays
)
8221 struct target_waitstatus last
;
8222 struct thread_info
*tp
;
8224 get_last_target_status (nullptr, nullptr, &last
);
8227 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8229 print_stop_location (&last
);
8231 /* Display the auto-display expressions. */
8236 tp
= inferior_thread ();
8237 if (tp
->thread_fsm
!= NULL
8238 && tp
->thread_fsm
->finished_p ())
8240 struct return_value_info
*rv
;
8242 rv
= tp
->thread_fsm
->return_value ();
8244 print_return_value (uiout
, rv
);
8251 maybe_remove_breakpoints (void)
8253 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8255 if (remove_breakpoints ())
8257 target_terminal::ours_for_output ();
8258 printf_filtered (_("Cannot remove breakpoints because "
8259 "program is no longer writable.\nFurther "
8260 "execution is probably impossible.\n"));
8265 /* The execution context that just caused a normal stop. */
8272 DISABLE_COPY_AND_ASSIGN (stop_context
);
8274 bool changed () const;
8279 /* The event PTID. */
8283 /* If stopp for a thread event, this is the thread that caused the
8285 struct thread_info
*thread
;
8287 /* The inferior that caused the stop. */
8291 /* Initializes a new stop context. If stopped for a thread event, this
8292 takes a strong reference to the thread. */
8294 stop_context::stop_context ()
8296 stop_id
= get_stop_id ();
8297 ptid
= inferior_ptid
;
8298 inf_num
= current_inferior ()->num
;
8300 if (inferior_ptid
!= null_ptid
)
8302 /* Take a strong reference so that the thread can't be deleted
8304 thread
= inferior_thread ();
8311 /* Release a stop context previously created with save_stop_context.
8312 Releases the strong reference to the thread as well. */
8314 stop_context::~stop_context ()
8320 /* Return true if the current context no longer matches the saved stop
8324 stop_context::changed () const
8326 if (ptid
!= inferior_ptid
)
8328 if (inf_num
!= current_inferior ()->num
)
8330 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8332 if (get_stop_id () != stop_id
)
8342 struct target_waitstatus last
;
8344 get_last_target_status (nullptr, nullptr, &last
);
8348 /* If an exception is thrown from this point on, make sure to
8349 propagate GDB's knowledge of the executing state to the
8350 frontend/user running state. A QUIT is an easy exception to see
8351 here, so do this before any filtered output. */
8353 ptid_t finish_ptid
= null_ptid
;
8356 finish_ptid
= minus_one_ptid
;
8357 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8358 || last
.kind
== TARGET_WAITKIND_EXITED
)
8360 /* On some targets, we may still have live threads in the
8361 inferior when we get a process exit event. E.g., for
8362 "checkpoint", when the current checkpoint/fork exits,
8363 linux-fork.c automatically switches to another fork from
8364 within target_mourn_inferior. */
8365 if (inferior_ptid
!= null_ptid
)
8366 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8368 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8369 finish_ptid
= inferior_ptid
;
8371 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8372 if (finish_ptid
!= null_ptid
)
8374 maybe_finish_thread_state
.emplace
8375 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8378 /* As we're presenting a stop, and potentially removing breakpoints,
8379 update the thread list so we can tell whether there are threads
8380 running on the target. With target remote, for example, we can
8381 only learn about new threads when we explicitly update the thread
8382 list. Do this before notifying the interpreters about signal
8383 stops, end of stepping ranges, etc., so that the "new thread"
8384 output is emitted before e.g., "Program received signal FOO",
8385 instead of after. */
8386 update_thread_list ();
8388 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8389 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8391 /* As with the notification of thread events, we want to delay
8392 notifying the user that we've switched thread context until
8393 the inferior actually stops.
8395 There's no point in saying anything if the inferior has exited.
8396 Note that SIGNALLED here means "exited with a signal", not
8397 "received a signal".
8399 Also skip saying anything in non-stop mode. In that mode, as we
8400 don't want GDB to switch threads behind the user's back, to avoid
8401 races where the user is typing a command to apply to thread x,
8402 but GDB switches to thread y before the user finishes entering
8403 the command, fetch_inferior_event installs a cleanup to restore
8404 the current thread back to the thread the user had selected right
8405 after this event is handled, so we're not really switching, only
8406 informing of a stop. */
8408 && previous_inferior_ptid
!= inferior_ptid
8409 && target_has_execution
8410 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8411 && last
.kind
!= TARGET_WAITKIND_EXITED
8412 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8414 SWITCH_THRU_ALL_UIS ()
8416 target_terminal::ours_for_output ();
8417 printf_filtered (_("[Switching to %s]\n"),
8418 target_pid_to_str (inferior_ptid
).c_str ());
8419 annotate_thread_changed ();
8421 previous_inferior_ptid
= inferior_ptid
;
8424 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8426 SWITCH_THRU_ALL_UIS ()
8427 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8429 target_terminal::ours_for_output ();
8430 printf_filtered (_("No unwaited-for children left.\n"));
8434 /* Note: this depends on the update_thread_list call above. */
8435 maybe_remove_breakpoints ();
8437 /* If an auto-display called a function and that got a signal,
8438 delete that auto-display to avoid an infinite recursion. */
8440 if (stopped_by_random_signal
)
8441 disable_current_display ();
8443 SWITCH_THRU_ALL_UIS ()
8445 async_enable_stdin ();
8448 /* Let the user/frontend see the threads as stopped. */
8449 maybe_finish_thread_state
.reset ();
8451 /* Select innermost stack frame - i.e., current frame is frame 0,
8452 and current location is based on that. Handle the case where the
8453 dummy call is returning after being stopped. E.g. the dummy call
8454 previously hit a breakpoint. (If the dummy call returns
8455 normally, we won't reach here.) Do this before the stop hook is
8456 run, so that it doesn't get to see the temporary dummy frame,
8457 which is not where we'll present the stop. */
8458 if (has_stack_frames ())
8460 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8462 /* Pop the empty frame that contains the stack dummy. This
8463 also restores inferior state prior to the call (struct
8464 infcall_suspend_state). */
8465 struct frame_info
*frame
= get_current_frame ();
8467 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8469 /* frame_pop calls reinit_frame_cache as the last thing it
8470 does which means there's now no selected frame. */
8473 select_frame (get_current_frame ());
8475 /* Set the current source location. */
8476 set_current_sal_from_frame (get_current_frame ());
8479 /* Look up the hook_stop and run it (CLI internally handles problem
8480 of stop_command's pre-hook not existing). */
8481 if (stop_command
!= NULL
)
8483 stop_context saved_context
;
8487 execute_cmd_pre_hook (stop_command
);
8489 catch (const gdb_exception
&ex
)
8491 exception_fprintf (gdb_stderr
, ex
,
8492 "Error while running hook_stop:\n");
8495 /* If the stop hook resumes the target, then there's no point in
8496 trying to notify about the previous stop; its context is
8497 gone. Likewise if the command switches thread or inferior --
8498 the observers would print a stop for the wrong
8500 if (saved_context
.changed ())
8504 /* Notify observers about the stop. This is where the interpreters
8505 print the stop event. */
8506 if (inferior_ptid
!= null_ptid
)
8507 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8510 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8512 annotate_stopped ();
8514 if (target_has_execution
)
8516 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8517 && last
.kind
!= TARGET_WAITKIND_EXITED
8518 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8519 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8520 Delete any breakpoint that is to be deleted at the next stop. */
8521 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8524 /* Try to get rid of automatically added inferiors that are no
8525 longer needed. Keeping those around slows down things linearly.
8526 Note that this never removes the current inferior. */
8533 signal_stop_state (int signo
)
8535 return signal_stop
[signo
];
8539 signal_print_state (int signo
)
8541 return signal_print
[signo
];
8545 signal_pass_state (int signo
)
8547 return signal_program
[signo
];
8551 signal_cache_update (int signo
)
8555 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8556 signal_cache_update (signo
);
8561 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8562 && signal_print
[signo
] == 0
8563 && signal_program
[signo
] == 1
8564 && signal_catch
[signo
] == 0);
8568 signal_stop_update (int signo
, int state
)
8570 int ret
= signal_stop
[signo
];
8572 signal_stop
[signo
] = state
;
8573 signal_cache_update (signo
);
8578 signal_print_update (int signo
, int state
)
8580 int ret
= signal_print
[signo
];
8582 signal_print
[signo
] = state
;
8583 signal_cache_update (signo
);
8588 signal_pass_update (int signo
, int state
)
8590 int ret
= signal_program
[signo
];
8592 signal_program
[signo
] = state
;
8593 signal_cache_update (signo
);
8597 /* Update the global 'signal_catch' from INFO and notify the
8601 signal_catch_update (const unsigned int *info
)
8605 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8606 signal_catch
[i
] = info
[i
] > 0;
8607 signal_cache_update (-1);
8608 target_pass_signals (signal_pass
);
8612 sig_print_header (void)
8614 printf_filtered (_("Signal Stop\tPrint\tPass "
8615 "to program\tDescription\n"));
8619 sig_print_info (enum gdb_signal oursig
)
8621 const char *name
= gdb_signal_to_name (oursig
);
8622 int name_padding
= 13 - strlen (name
);
8624 if (name_padding
<= 0)
8627 printf_filtered ("%s", name
);
8628 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8629 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8630 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8631 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8632 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8635 /* Specify how various signals in the inferior should be handled. */
8638 handle_command (const char *args
, int from_tty
)
8640 int digits
, wordlen
;
8641 int sigfirst
, siglast
;
8642 enum gdb_signal oursig
;
8647 error_no_arg (_("signal to handle"));
8650 /* Allocate and zero an array of flags for which signals to handle. */
8652 const size_t nsigs
= GDB_SIGNAL_LAST
;
8653 unsigned char sigs
[nsigs
] {};
8655 /* Break the command line up into args. */
8657 gdb_argv
built_argv (args
);
8659 /* Walk through the args, looking for signal oursigs, signal names, and
8660 actions. Signal numbers and signal names may be interspersed with
8661 actions, with the actions being performed for all signals cumulatively
8662 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8664 for (char *arg
: built_argv
)
8666 wordlen
= strlen (arg
);
8667 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8671 sigfirst
= siglast
= -1;
8673 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8675 /* Apply action to all signals except those used by the
8676 debugger. Silently skip those. */
8679 siglast
= nsigs
- 1;
8681 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8683 SET_SIGS (nsigs
, sigs
, signal_stop
);
8684 SET_SIGS (nsigs
, sigs
, signal_print
);
8686 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8688 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8690 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8692 SET_SIGS (nsigs
, sigs
, signal_print
);
8694 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8696 SET_SIGS (nsigs
, sigs
, signal_program
);
8698 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8700 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8702 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8704 SET_SIGS (nsigs
, sigs
, signal_program
);
8706 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8708 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8709 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8711 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8713 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8715 else if (digits
> 0)
8717 /* It is numeric. The numeric signal refers to our own
8718 internal signal numbering from target.h, not to host/target
8719 signal number. This is a feature; users really should be
8720 using symbolic names anyway, and the common ones like
8721 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8723 sigfirst
= siglast
= (int)
8724 gdb_signal_from_command (atoi (arg
));
8725 if (arg
[digits
] == '-')
8728 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8730 if (sigfirst
> siglast
)
8732 /* Bet he didn't figure we'd think of this case... */
8733 std::swap (sigfirst
, siglast
);
8738 oursig
= gdb_signal_from_name (arg
);
8739 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8741 sigfirst
= siglast
= (int) oursig
;
8745 /* Not a number and not a recognized flag word => complain. */
8746 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8750 /* If any signal numbers or symbol names were found, set flags for
8751 which signals to apply actions to. */
8753 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8755 switch ((enum gdb_signal
) signum
)
8757 case GDB_SIGNAL_TRAP
:
8758 case GDB_SIGNAL_INT
:
8759 if (!allsigs
&& !sigs
[signum
])
8761 if (query (_("%s is used by the debugger.\n\
8762 Are you sure you want to change it? "),
8763 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8768 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8772 case GDB_SIGNAL_DEFAULT
:
8773 case GDB_SIGNAL_UNKNOWN
:
8774 /* Make sure that "all" doesn't print these. */
8783 for (int signum
= 0; signum
< nsigs
; signum
++)
8786 signal_cache_update (-1);
8787 target_pass_signals (signal_pass
);
8788 target_program_signals (signal_program
);
8792 /* Show the results. */
8793 sig_print_header ();
8794 for (; signum
< nsigs
; signum
++)
8796 sig_print_info ((enum gdb_signal
) signum
);
8803 /* Complete the "handle" command. */
8806 handle_completer (struct cmd_list_element
*ignore
,
8807 completion_tracker
&tracker
,
8808 const char *text
, const char *word
)
8810 static const char * const keywords
[] =
8824 signal_completer (ignore
, tracker
, text
, word
);
8825 complete_on_enum (tracker
, keywords
, word
, word
);
8829 gdb_signal_from_command (int num
)
8831 if (num
>= 1 && num
<= 15)
8832 return (enum gdb_signal
) num
;
8833 error (_("Only signals 1-15 are valid as numeric signals.\n\
8834 Use \"info signals\" for a list of symbolic signals."));
8837 /* Print current contents of the tables set by the handle command.
8838 It is possible we should just be printing signals actually used
8839 by the current target (but for things to work right when switching
8840 targets, all signals should be in the signal tables). */
8843 info_signals_command (const char *signum_exp
, int from_tty
)
8845 enum gdb_signal oursig
;
8847 sig_print_header ();
8851 /* First see if this is a symbol name. */
8852 oursig
= gdb_signal_from_name (signum_exp
);
8853 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8855 /* No, try numeric. */
8857 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8859 sig_print_info (oursig
);
8863 printf_filtered ("\n");
8864 /* These ugly casts brought to you by the native VAX compiler. */
8865 for (oursig
= GDB_SIGNAL_FIRST
;
8866 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8867 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8871 if (oursig
!= GDB_SIGNAL_UNKNOWN
8872 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8873 sig_print_info (oursig
);
8876 printf_filtered (_("\nUse the \"handle\" command "
8877 "to change these tables.\n"));
8880 /* The $_siginfo convenience variable is a bit special. We don't know
8881 for sure the type of the value until we actually have a chance to
8882 fetch the data. The type can change depending on gdbarch, so it is
8883 also dependent on which thread you have selected.
8885 1. making $_siginfo be an internalvar that creates a new value on
8888 2. making the value of $_siginfo be an lval_computed value. */
8890 /* This function implements the lval_computed support for reading a
8894 siginfo_value_read (struct value
*v
)
8896 LONGEST transferred
;
8898 /* If we can access registers, so can we access $_siginfo. Likewise
8900 validate_registers_access ();
8903 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8905 value_contents_all_raw (v
),
8907 TYPE_LENGTH (value_type (v
)));
8909 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8910 error (_("Unable to read siginfo"));
8913 /* This function implements the lval_computed support for writing a
8917 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8919 LONGEST transferred
;
8921 /* If we can access registers, so can we access $_siginfo. Likewise
8923 validate_registers_access ();
8925 transferred
= target_write (current_top_target (),
8926 TARGET_OBJECT_SIGNAL_INFO
,
8928 value_contents_all_raw (fromval
),
8930 TYPE_LENGTH (value_type (fromval
)));
8932 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8933 error (_("Unable to write siginfo"));
8936 static const struct lval_funcs siginfo_value_funcs
=
8942 /* Return a new value with the correct type for the siginfo object of
8943 the current thread using architecture GDBARCH. Return a void value
8944 if there's no object available. */
8946 static struct value
*
8947 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8950 if (target_has_stack
8951 && inferior_ptid
!= null_ptid
8952 && gdbarch_get_siginfo_type_p (gdbarch
))
8954 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8956 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8959 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8963 /* infcall_suspend_state contains state about the program itself like its
8964 registers and any signal it received when it last stopped.
8965 This state must be restored regardless of how the inferior function call
8966 ends (either successfully, or after it hits a breakpoint or signal)
8967 if the program is to properly continue where it left off. */
8969 class infcall_suspend_state
8972 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8973 once the inferior function call has finished. */
8974 infcall_suspend_state (struct gdbarch
*gdbarch
,
8975 const struct thread_info
*tp
,
8976 struct regcache
*regcache
)
8977 : m_thread_suspend (tp
->suspend
),
8978 m_registers (new readonly_detached_regcache (*regcache
))
8980 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8982 if (gdbarch_get_siginfo_type_p (gdbarch
))
8984 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8985 size_t len
= TYPE_LENGTH (type
);
8987 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8989 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8990 siginfo_data
.get (), 0, len
) != len
)
8992 /* Errors ignored. */
8993 siginfo_data
.reset (nullptr);
8999 m_siginfo_gdbarch
= gdbarch
;
9000 m_siginfo_data
= std::move (siginfo_data
);
9004 /* Return a pointer to the stored register state. */
9006 readonly_detached_regcache
*registers () const
9008 return m_registers
.get ();
9011 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9013 void restore (struct gdbarch
*gdbarch
,
9014 struct thread_info
*tp
,
9015 struct regcache
*regcache
) const
9017 tp
->suspend
= m_thread_suspend
;
9019 if (m_siginfo_gdbarch
== gdbarch
)
9021 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9023 /* Errors ignored. */
9024 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9025 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9028 /* The inferior can be gone if the user types "print exit(0)"
9029 (and perhaps other times). */
9030 if (target_has_execution
)
9031 /* NB: The register write goes through to the target. */
9032 regcache
->restore (registers ());
9036 /* How the current thread stopped before the inferior function call was
9038 struct thread_suspend_state m_thread_suspend
;
9040 /* The registers before the inferior function call was executed. */
9041 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9043 /* Format of SIGINFO_DATA or NULL if it is not present. */
9044 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9046 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9047 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9048 content would be invalid. */
9049 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9052 infcall_suspend_state_up
9053 save_infcall_suspend_state ()
9055 struct thread_info
*tp
= inferior_thread ();
9056 struct regcache
*regcache
= get_current_regcache ();
9057 struct gdbarch
*gdbarch
= regcache
->arch ();
9059 infcall_suspend_state_up inf_state
9060 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9062 /* Having saved the current state, adjust the thread state, discarding
9063 any stop signal information. The stop signal is not useful when
9064 starting an inferior function call, and run_inferior_call will not use
9065 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9066 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9071 /* Restore inferior session state to INF_STATE. */
9074 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9076 struct thread_info
*tp
= inferior_thread ();
9077 struct regcache
*regcache
= get_current_regcache ();
9078 struct gdbarch
*gdbarch
= regcache
->arch ();
9080 inf_state
->restore (gdbarch
, tp
, regcache
);
9081 discard_infcall_suspend_state (inf_state
);
9085 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9090 readonly_detached_regcache
*
9091 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9093 return inf_state
->registers ();
9096 /* infcall_control_state contains state regarding gdb's control of the
9097 inferior itself like stepping control. It also contains session state like
9098 the user's currently selected frame. */
9100 struct infcall_control_state
9102 struct thread_control_state thread_control
;
9103 struct inferior_control_state inferior_control
;
9106 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9107 int stopped_by_random_signal
= 0;
9109 /* ID if the selected frame when the inferior function call was made. */
9110 struct frame_id selected_frame_id
{};
9113 /* Save all of the information associated with the inferior<==>gdb
9116 infcall_control_state_up
9117 save_infcall_control_state ()
9119 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9120 struct thread_info
*tp
= inferior_thread ();
9121 struct inferior
*inf
= current_inferior ();
9123 inf_status
->thread_control
= tp
->control
;
9124 inf_status
->inferior_control
= inf
->control
;
9126 tp
->control
.step_resume_breakpoint
= NULL
;
9127 tp
->control
.exception_resume_breakpoint
= NULL
;
9129 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9130 chain. If caller's caller is walking the chain, they'll be happier if we
9131 hand them back the original chain when restore_infcall_control_state is
9133 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9136 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9137 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9139 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9145 restore_selected_frame (const frame_id
&fid
)
9147 frame_info
*frame
= frame_find_by_id (fid
);
9149 /* If inf_status->selected_frame_id is NULL, there was no previously
9153 warning (_("Unable to restore previously selected frame."));
9157 select_frame (frame
);
9160 /* Restore inferior session state to INF_STATUS. */
9163 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9165 struct thread_info
*tp
= inferior_thread ();
9166 struct inferior
*inf
= current_inferior ();
9168 if (tp
->control
.step_resume_breakpoint
)
9169 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9171 if (tp
->control
.exception_resume_breakpoint
)
9172 tp
->control
.exception_resume_breakpoint
->disposition
9173 = disp_del_at_next_stop
;
9175 /* Handle the bpstat_copy of the chain. */
9176 bpstat_clear (&tp
->control
.stop_bpstat
);
9178 tp
->control
= inf_status
->thread_control
;
9179 inf
->control
= inf_status
->inferior_control
;
9182 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9183 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9185 if (target_has_stack
)
9187 /* The point of the try/catch is that if the stack is clobbered,
9188 walking the stack might encounter a garbage pointer and
9189 error() trying to dereference it. */
9192 restore_selected_frame (inf_status
->selected_frame_id
);
9194 catch (const gdb_exception_error
&ex
)
9196 exception_fprintf (gdb_stderr
, ex
,
9197 "Unable to restore previously selected frame:\n");
9198 /* Error in restoring the selected frame. Select the
9200 select_frame (get_current_frame ());
9208 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9210 if (inf_status
->thread_control
.step_resume_breakpoint
)
9211 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9212 = disp_del_at_next_stop
;
9214 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9215 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9216 = disp_del_at_next_stop
;
9218 /* See save_infcall_control_state for info on stop_bpstat. */
9219 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9227 clear_exit_convenience_vars (void)
9229 clear_internalvar (lookup_internalvar ("_exitsignal"));
9230 clear_internalvar (lookup_internalvar ("_exitcode"));
9234 /* User interface for reverse debugging:
9235 Set exec-direction / show exec-direction commands
9236 (returns error unless target implements to_set_exec_direction method). */
9238 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9239 static const char exec_forward
[] = "forward";
9240 static const char exec_reverse
[] = "reverse";
9241 static const char *exec_direction
= exec_forward
;
9242 static const char *const exec_direction_names
[] = {
9249 set_exec_direction_func (const char *args
, int from_tty
,
9250 struct cmd_list_element
*cmd
)
9252 if (target_can_execute_reverse
)
9254 if (!strcmp (exec_direction
, exec_forward
))
9255 execution_direction
= EXEC_FORWARD
;
9256 else if (!strcmp (exec_direction
, exec_reverse
))
9257 execution_direction
= EXEC_REVERSE
;
9261 exec_direction
= exec_forward
;
9262 error (_("Target does not support this operation."));
9267 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9268 struct cmd_list_element
*cmd
, const char *value
)
9270 switch (execution_direction
) {
9272 fprintf_filtered (out
, _("Forward.\n"));
9275 fprintf_filtered (out
, _("Reverse.\n"));
9278 internal_error (__FILE__
, __LINE__
,
9279 _("bogus execution_direction value: %d"),
9280 (int) execution_direction
);
9285 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9286 struct cmd_list_element
*c
, const char *value
)
9288 fprintf_filtered (file
, _("Resuming the execution of threads "
9289 "of all processes is %s.\n"), value
);
9292 /* Implementation of `siginfo' variable. */
9294 static const struct internalvar_funcs siginfo_funcs
=
9301 /* Callback for infrun's target events source. This is marked when a
9302 thread has a pending status to process. */
9305 infrun_async_inferior_event_handler (gdb_client_data data
)
9307 inferior_event_handler (INF_REG_EVENT
, NULL
);
9310 void _initialize_infrun ();
9312 _initialize_infrun ()
9314 struct cmd_list_element
*c
;
9316 /* Register extra event sources in the event loop. */
9317 infrun_async_inferior_event_token
9318 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9320 add_info ("signals", info_signals_command
, _("\
9321 What debugger does when program gets various signals.\n\
9322 Specify a signal as argument to print info on that signal only."));
9323 add_info_alias ("handle", "signals", 0);
9325 c
= add_com ("handle", class_run
, handle_command
, _("\
9326 Specify how to handle signals.\n\
9327 Usage: handle SIGNAL [ACTIONS]\n\
9328 Args are signals and actions to apply to those signals.\n\
9329 If no actions are specified, the current settings for the specified signals\n\
9330 will be displayed instead.\n\
9332 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9333 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9334 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9335 The special arg \"all\" is recognized to mean all signals except those\n\
9336 used by the debugger, typically SIGTRAP and SIGINT.\n\
9338 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9339 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9340 Stop means reenter debugger if this signal happens (implies print).\n\
9341 Print means print a message if this signal happens.\n\
9342 Pass means let program see this signal; otherwise program doesn't know.\n\
9343 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9344 Pass and Stop may be combined.\n\
9346 Multiple signals may be specified. Signal numbers and signal names\n\
9347 may be interspersed with actions, with the actions being performed for\n\
9348 all signals cumulatively specified."));
9349 set_cmd_completer (c
, handle_completer
);
9352 stop_command
= add_cmd ("stop", class_obscure
,
9353 not_just_help_class_command
, _("\
9354 There is no `stop' command, but you can set a hook on `stop'.\n\
9355 This allows you to set a list of commands to be run each time execution\n\
9356 of the program stops."), &cmdlist
);
9358 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9359 Set inferior debugging."), _("\
9360 Show inferior debugging."), _("\
9361 When non-zero, inferior specific debugging is enabled."),
9364 &setdebuglist
, &showdebuglist
);
9366 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9367 &debug_displaced
, _("\
9368 Set displaced stepping debugging."), _("\
9369 Show displaced stepping debugging."), _("\
9370 When non-zero, displaced stepping specific debugging is enabled."),
9372 show_debug_displaced
,
9373 &setdebuglist
, &showdebuglist
);
9375 add_setshow_boolean_cmd ("non-stop", no_class
,
9377 Set whether gdb controls the inferior in non-stop mode."), _("\
9378 Show whether gdb controls the inferior in non-stop mode."), _("\
9379 When debugging a multi-threaded program and this setting is\n\
9380 off (the default, also called all-stop mode), when one thread stops\n\
9381 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9382 all other threads in the program while you interact with the thread of\n\
9383 interest. When you continue or step a thread, you can allow the other\n\
9384 threads to run, or have them remain stopped, but while you inspect any\n\
9385 thread's state, all threads stop.\n\
9387 In non-stop mode, when one thread stops, other threads can continue\n\
9388 to run freely. You'll be able to step each thread independently,\n\
9389 leave it stopped or free to run as needed."),
9395 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9398 signal_print
[i
] = 1;
9399 signal_program
[i
] = 1;
9400 signal_catch
[i
] = 0;
9403 /* Signals caused by debugger's own actions should not be given to
9404 the program afterwards.
9406 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9407 explicitly specifies that it should be delivered to the target
9408 program. Typically, that would occur when a user is debugging a
9409 target monitor on a simulator: the target monitor sets a
9410 breakpoint; the simulator encounters this breakpoint and halts
9411 the simulation handing control to GDB; GDB, noting that the stop
9412 address doesn't map to any known breakpoint, returns control back
9413 to the simulator; the simulator then delivers the hardware
9414 equivalent of a GDB_SIGNAL_TRAP to the program being
9416 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9417 signal_program
[GDB_SIGNAL_INT
] = 0;
9419 /* Signals that are not errors should not normally enter the debugger. */
9420 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9421 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9422 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9423 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9424 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9425 signal_print
[GDB_SIGNAL_PROF
] = 0;
9426 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9427 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9428 signal_stop
[GDB_SIGNAL_IO
] = 0;
9429 signal_print
[GDB_SIGNAL_IO
] = 0;
9430 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9431 signal_print
[GDB_SIGNAL_POLL
] = 0;
9432 signal_stop
[GDB_SIGNAL_URG
] = 0;
9433 signal_print
[GDB_SIGNAL_URG
] = 0;
9434 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9435 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9436 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9437 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9439 /* These signals are used internally by user-level thread
9440 implementations. (See signal(5) on Solaris.) Like the above
9441 signals, a healthy program receives and handles them as part of
9442 its normal operation. */
9443 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9444 signal_print
[GDB_SIGNAL_LWP
] = 0;
9445 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9446 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9447 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9448 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9449 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9450 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9452 /* Update cached state. */
9453 signal_cache_update (-1);
9455 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9456 &stop_on_solib_events
, _("\
9457 Set stopping for shared library events."), _("\
9458 Show stopping for shared library events."), _("\
9459 If nonzero, gdb will give control to the user when the dynamic linker\n\
9460 notifies gdb of shared library events. The most common event of interest\n\
9461 to the user would be loading/unloading of a new library."),
9462 set_stop_on_solib_events
,
9463 show_stop_on_solib_events
,
9464 &setlist
, &showlist
);
9466 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9467 follow_fork_mode_kind_names
,
9468 &follow_fork_mode_string
, _("\
9469 Set debugger response to a program call of fork or vfork."), _("\
9470 Show debugger response to a program call of fork or vfork."), _("\
9471 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9472 parent - the original process is debugged after a fork\n\
9473 child - the new process is debugged after a fork\n\
9474 The unfollowed process will continue to run.\n\
9475 By default, the debugger will follow the parent process."),
9477 show_follow_fork_mode_string
,
9478 &setlist
, &showlist
);
9480 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9481 follow_exec_mode_names
,
9482 &follow_exec_mode_string
, _("\
9483 Set debugger response to a program call of exec."), _("\
9484 Show debugger response to a program call of exec."), _("\
9485 An exec call replaces the program image of a process.\n\
9487 follow-exec-mode can be:\n\
9489 new - the debugger creates a new inferior and rebinds the process\n\
9490 to this new inferior. The program the process was running before\n\
9491 the exec call can be restarted afterwards by restarting the original\n\
9494 same - the debugger keeps the process bound to the same inferior.\n\
9495 The new executable image replaces the previous executable loaded in\n\
9496 the inferior. Restarting the inferior after the exec call restarts\n\
9497 the executable the process was running after the exec call.\n\
9499 By default, the debugger will use the same inferior."),
9501 show_follow_exec_mode_string
,
9502 &setlist
, &showlist
);
9504 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9505 scheduler_enums
, &scheduler_mode
, _("\
9506 Set mode for locking scheduler during execution."), _("\
9507 Show mode for locking scheduler during execution."), _("\
9508 off == no locking (threads may preempt at any time)\n\
9509 on == full locking (no thread except the current thread may run)\n\
9510 This applies to both normal execution and replay mode.\n\
9511 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9512 In this mode, other threads may run during other commands.\n\
9513 This applies to both normal execution and replay mode.\n\
9514 replay == scheduler locked in replay mode and unlocked during normal execution."),
9515 set_schedlock_func
, /* traps on target vector */
9516 show_scheduler_mode
,
9517 &setlist
, &showlist
);
9519 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9520 Set mode for resuming threads of all processes."), _("\
9521 Show mode for resuming threads of all processes."), _("\
9522 When on, execution commands (such as 'continue' or 'next') resume all\n\
9523 threads of all processes. When off (which is the default), execution\n\
9524 commands only resume the threads of the current process. The set of\n\
9525 threads that are resumed is further refined by the scheduler-locking\n\
9526 mode (see help set scheduler-locking)."),
9528 show_schedule_multiple
,
9529 &setlist
, &showlist
);
9531 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9532 Set mode of the step operation."), _("\
9533 Show mode of the step operation."), _("\
9534 When set, doing a step over a function without debug line information\n\
9535 will stop at the first instruction of that function. Otherwise, the\n\
9536 function is skipped and the step command stops at a different source line."),
9538 show_step_stop_if_no_debug
,
9539 &setlist
, &showlist
);
9541 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9542 &can_use_displaced_stepping
, _("\
9543 Set debugger's willingness to use displaced stepping."), _("\
9544 Show debugger's willingness to use displaced stepping."), _("\
9545 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9546 supported by the target architecture. If off, gdb will not use displaced\n\
9547 stepping to step over breakpoints, even if such is supported by the target\n\
9548 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9549 if the target architecture supports it and non-stop mode is active, but will not\n\
9550 use it in all-stop mode (see help set non-stop)."),
9552 show_can_use_displaced_stepping
,
9553 &setlist
, &showlist
);
9555 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9556 &exec_direction
, _("Set direction of execution.\n\
9557 Options are 'forward' or 'reverse'."),
9558 _("Show direction of execution (forward/reverse)."),
9559 _("Tells gdb whether to execute forward or backward."),
9560 set_exec_direction_func
, show_exec_direction_func
,
9561 &setlist
, &showlist
);
9563 /* Set/show detach-on-fork: user-settable mode. */
9565 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9566 Set whether gdb will detach the child of a fork."), _("\
9567 Show whether gdb will detach the child of a fork."), _("\
9568 Tells gdb whether to detach the child of a fork."),
9569 NULL
, NULL
, &setlist
, &showlist
);
9571 /* Set/show disable address space randomization mode. */
9573 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9574 &disable_randomization
, _("\
9575 Set disabling of debuggee's virtual address space randomization."), _("\
9576 Show disabling of debuggee's virtual address space randomization."), _("\
9577 When this mode is on (which is the default), randomization of the virtual\n\
9578 address space is disabled. Standalone programs run with the randomization\n\
9579 enabled by default on some platforms."),
9580 &set_disable_randomization
,
9581 &show_disable_randomization
,
9582 &setlist
, &showlist
);
9584 /* ptid initializations */
9585 inferior_ptid
= null_ptid
;
9586 target_last_wait_ptid
= minus_one_ptid
;
9588 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9589 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9590 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9591 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9593 /* Explicitly create without lookup, since that tries to create a
9594 value with a void typed value, and when we get here, gdbarch
9595 isn't initialized yet. At this point, we're quite sure there
9596 isn't another convenience variable of the same name. */
9597 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9599 add_setshow_boolean_cmd ("observer", no_class
,
9600 &observer_mode_1
, _("\
9601 Set whether gdb controls the inferior in observer mode."), _("\
9602 Show whether gdb controls the inferior in observer mode."), _("\
9603 In observer mode, GDB can get data from the inferior, but not\n\
9604 affect its execution. Registers and memory may not be changed,\n\
9605 breakpoints may not be set, and the program cannot be interrupted\n\