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 "gdbthread.h"
38 #include "observable.h"
43 #include "mi/mi-common.h"
44 #include "event-top.h"
46 #include "record-full.h"
47 #include "inline-frame.h"
49 #include "tracepoint.h"
53 #include "completer.h"
54 #include "target-descriptions.h"
55 #include "target-dcache.h"
58 #include "event-loop.h"
59 #include "thread-fsm.h"
60 #include "gdbsupport/enum-flags.h"
61 #include "progspace-and-thread.h"
62 #include "gdbsupport/gdb_optional.h"
63 #include "arch-utils.h"
64 #include "gdbsupport/scope-exit.h"
65 #include "gdbsupport/forward-scope-exit.h"
66 #include "gdb_select.h"
67 #include <unordered_map>
69 /* Prototypes for local functions */
71 static void sig_print_info (enum gdb_signal
);
73 static void sig_print_header (void);
75 static int follow_fork (void);
77 static int follow_fork_inferior (int follow_child
, int detach_fork
);
79 static void follow_inferior_reset_breakpoints (void);
81 static int currently_stepping (struct thread_info
*tp
);
83 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
85 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
87 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
89 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
91 static void resume (gdb_signal sig
);
93 static void wait_for_inferior (inferior
*inf
);
95 /* Asynchronous signal handler registered as event loop source for
96 when we have pending events ready to be passed to the core. */
97 static struct async_event_handler
*infrun_async_inferior_event_token
;
99 /* Stores whether infrun_async was previously enabled or disabled.
100 Starts off as -1, indicating "never enabled/disabled". */
101 static int infrun_is_async
= -1;
106 infrun_async (int enable
)
108 if (infrun_is_async
!= enable
)
110 infrun_is_async
= enable
;
113 fprintf_unfiltered (gdb_stdlog
,
114 "infrun: infrun_async(%d)\n",
118 mark_async_event_handler (infrun_async_inferior_event_token
);
120 clear_async_event_handler (infrun_async_inferior_event_token
);
127 mark_infrun_async_event_handler (void)
129 mark_async_event_handler (infrun_async_inferior_event_token
);
132 /* When set, stop the 'step' command if we enter a function which has
133 no line number information. The normal behavior is that we step
134 over such function. */
135 bool step_stop_if_no_debug
= false;
137 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
138 struct cmd_list_element
*c
, const char *value
)
140 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
143 /* proceed and normal_stop use this to notify the user when the
144 inferior stopped in a different thread than it had been running
147 static ptid_t previous_inferior_ptid
;
149 /* If set (default for legacy reasons), when following a fork, GDB
150 will detach from one of the fork branches, child or parent.
151 Exactly which branch is detached depends on 'set follow-fork-mode'
154 static bool detach_fork
= true;
156 bool debug_displaced
= false;
158 show_debug_displaced (struct ui_file
*file
, int from_tty
,
159 struct cmd_list_element
*c
, const char *value
)
161 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
164 unsigned int debug_infrun
= 0;
166 show_debug_infrun (struct ui_file
*file
, int from_tty
,
167 struct cmd_list_element
*c
, const char *value
)
169 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
173 /* Support for disabling address space randomization. */
175 bool disable_randomization
= true;
178 show_disable_randomization (struct ui_file
*file
, int from_tty
,
179 struct cmd_list_element
*c
, const char *value
)
181 if (target_supports_disable_randomization ())
182 fprintf_filtered (file
,
183 _("Disabling randomization of debuggee's "
184 "virtual address space is %s.\n"),
187 fputs_filtered (_("Disabling randomization of debuggee's "
188 "virtual address space is unsupported on\n"
189 "this platform.\n"), file
);
193 set_disable_randomization (const char *args
, int from_tty
,
194 struct cmd_list_element
*c
)
196 if (!target_supports_disable_randomization ())
197 error (_("Disabling randomization of debuggee's "
198 "virtual address space is unsupported on\n"
202 /* User interface for non-stop mode. */
204 bool non_stop
= false;
205 static bool non_stop_1
= false;
208 set_non_stop (const char *args
, int from_tty
,
209 struct cmd_list_element
*c
)
211 if (target_has_execution
)
213 non_stop_1
= non_stop
;
214 error (_("Cannot change this setting while the inferior is running."));
217 non_stop
= non_stop_1
;
221 show_non_stop (struct ui_file
*file
, int from_tty
,
222 struct cmd_list_element
*c
, const char *value
)
224 fprintf_filtered (file
,
225 _("Controlling the inferior in non-stop mode is %s.\n"),
229 /* "Observer mode" is somewhat like a more extreme version of
230 non-stop, in which all GDB operations that might affect the
231 target's execution have been disabled. */
233 bool observer_mode
= false;
234 static bool observer_mode_1
= false;
237 set_observer_mode (const char *args
, int from_tty
,
238 struct cmd_list_element
*c
)
240 if (target_has_execution
)
242 observer_mode_1
= observer_mode
;
243 error (_("Cannot change this setting while the inferior is running."));
246 observer_mode
= observer_mode_1
;
248 may_write_registers
= !observer_mode
;
249 may_write_memory
= !observer_mode
;
250 may_insert_breakpoints
= !observer_mode
;
251 may_insert_tracepoints
= !observer_mode
;
252 /* We can insert fast tracepoints in or out of observer mode,
253 but enable them if we're going into this mode. */
255 may_insert_fast_tracepoints
= true;
256 may_stop
= !observer_mode
;
257 update_target_permissions ();
259 /* Going *into* observer mode we must force non-stop, then
260 going out we leave it that way. */
263 pagination_enabled
= 0;
264 non_stop
= non_stop_1
= true;
268 printf_filtered (_("Observer mode is now %s.\n"),
269 (observer_mode
? "on" : "off"));
273 show_observer_mode (struct ui_file
*file
, int from_tty
,
274 struct cmd_list_element
*c
, const char *value
)
276 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
279 /* This updates the value of observer mode based on changes in
280 permissions. Note that we are deliberately ignoring the values of
281 may-write-registers and may-write-memory, since the user may have
282 reason to enable these during a session, for instance to turn on a
283 debugging-related global. */
286 update_observer_mode (void)
288 bool newval
= (!may_insert_breakpoints
289 && !may_insert_tracepoints
290 && may_insert_fast_tracepoints
294 /* Let the user know if things change. */
295 if (newval
!= observer_mode
)
296 printf_filtered (_("Observer mode is now %s.\n"),
297 (newval
? "on" : "off"));
299 observer_mode
= observer_mode_1
= newval
;
302 /* Tables of how to react to signals; the user sets them. */
304 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
305 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
306 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
308 /* Table of signals that are registered with "catch signal". A
309 non-zero entry indicates that the signal is caught by some "catch
311 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
313 /* Table of signals that the target may silently handle.
314 This is automatically determined from the flags above,
315 and simply cached here. */
316 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
318 #define SET_SIGS(nsigs,sigs,flags) \
320 int signum = (nsigs); \
321 while (signum-- > 0) \
322 if ((sigs)[signum]) \
323 (flags)[signum] = 1; \
326 #define UNSET_SIGS(nsigs,sigs,flags) \
328 int signum = (nsigs); \
329 while (signum-- > 0) \
330 if ((sigs)[signum]) \
331 (flags)[signum] = 0; \
334 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
335 this function is to avoid exporting `signal_program'. */
338 update_signals_program_target (void)
340 target_program_signals (signal_program
);
343 /* Value to pass to target_resume() to cause all threads to resume. */
345 #define RESUME_ALL minus_one_ptid
347 /* Command list pointer for the "stop" placeholder. */
349 static struct cmd_list_element
*stop_command
;
351 /* Nonzero if we want to give control to the user when we're notified
352 of shared library events by the dynamic linker. */
353 int stop_on_solib_events
;
355 /* Enable or disable optional shared library event breakpoints
356 as appropriate when the above flag is changed. */
359 set_stop_on_solib_events (const char *args
,
360 int from_tty
, struct cmd_list_element
*c
)
362 update_solib_breakpoints ();
366 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
367 struct cmd_list_element
*c
, const char *value
)
369 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
373 /* Nonzero after stop if current stack frame should be printed. */
375 static int stop_print_frame
;
377 /* This is a cached copy of the target/ptid/waitstatus of the last
378 event returned by target_wait()/deprecated_target_wait_hook().
379 This information is returned by get_last_target_status(). */
380 static process_stratum_target
*target_last_proc_target
;
381 static ptid_t target_last_wait_ptid
;
382 static struct target_waitstatus target_last_waitstatus
;
384 void init_thread_stepping_state (struct thread_info
*tss
);
386 static const char follow_fork_mode_child
[] = "child";
387 static const char follow_fork_mode_parent
[] = "parent";
389 static const char *const follow_fork_mode_kind_names
[] = {
390 follow_fork_mode_child
,
391 follow_fork_mode_parent
,
395 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
397 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
398 struct cmd_list_element
*c
, const char *value
)
400 fprintf_filtered (file
,
401 _("Debugger response to a program "
402 "call of fork or vfork is \"%s\".\n"),
407 /* Handle changes to the inferior list based on the type of fork,
408 which process is being followed, and whether the other process
409 should be detached. On entry inferior_ptid must be the ptid of
410 the fork parent. At return inferior_ptid is the ptid of the
411 followed inferior. */
414 follow_fork_inferior (int follow_child
, int detach_fork
)
417 ptid_t parent_ptid
, child_ptid
;
419 has_vforked
= (inferior_thread ()->pending_follow
.kind
420 == TARGET_WAITKIND_VFORKED
);
421 parent_ptid
= inferior_ptid
;
422 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
425 && !non_stop
/* Non-stop always resumes both branches. */
426 && current_ui
->prompt_state
== PROMPT_BLOCKED
427 && !(follow_child
|| detach_fork
|| sched_multi
))
429 /* The parent stays blocked inside the vfork syscall until the
430 child execs or exits. If we don't let the child run, then
431 the parent stays blocked. If we're telling the parent to run
432 in the foreground, the user will not be able to ctrl-c to get
433 back the terminal, effectively hanging the debug session. */
434 fprintf_filtered (gdb_stderr
, _("\
435 Can not resume the parent process over vfork in the foreground while\n\
436 holding the child stopped. Try \"set detach-on-fork\" or \
437 \"set schedule-multiple\".\n"));
443 /* Detach new forked process? */
446 /* Before detaching from the child, remove all breakpoints
447 from it. If we forked, then this has already been taken
448 care of by infrun.c. If we vforked however, any
449 breakpoint inserted in the parent is visible in the
450 child, even those added while stopped in a vfork
451 catchpoint. This will remove the breakpoints from the
452 parent also, but they'll be reinserted below. */
455 /* Keep breakpoints list in sync. */
456 remove_breakpoints_inf (current_inferior ());
459 if (print_inferior_events
)
461 /* Ensure that we have a process ptid. */
462 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
464 target_terminal::ours_for_output ();
465 fprintf_filtered (gdb_stdlog
,
466 _("[Detaching after %s from child %s]\n"),
467 has_vforked
? "vfork" : "fork",
468 target_pid_to_str (process_ptid
).c_str ());
473 struct inferior
*parent_inf
, *child_inf
;
475 /* Add process to GDB's tables. */
476 child_inf
= add_inferior (child_ptid
.pid ());
478 parent_inf
= current_inferior ();
479 child_inf
->attach_flag
= parent_inf
->attach_flag
;
480 copy_terminal_info (child_inf
, parent_inf
);
481 child_inf
->gdbarch
= parent_inf
->gdbarch
;
482 copy_inferior_target_desc_info (child_inf
, parent_inf
);
484 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
486 set_current_inferior (child_inf
);
487 switch_to_no_thread ();
488 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
489 push_target (parent_inf
->process_target ());
490 add_thread_silent (child_inf
->process_target (), child_ptid
);
491 inferior_ptid
= child_ptid
;
493 /* If this is a vfork child, then the address-space is
494 shared with the parent. */
497 child_inf
->pspace
= parent_inf
->pspace
;
498 child_inf
->aspace
= parent_inf
->aspace
;
502 /* The parent will be frozen until the child is done
503 with the shared region. Keep track of the
505 child_inf
->vfork_parent
= parent_inf
;
506 child_inf
->pending_detach
= 0;
507 parent_inf
->vfork_child
= child_inf
;
508 parent_inf
->pending_detach
= 0;
512 child_inf
->aspace
= new_address_space ();
513 child_inf
->pspace
= new program_space (child_inf
->aspace
);
514 child_inf
->removable
= 1;
515 set_current_program_space (child_inf
->pspace
);
516 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
518 /* Let the shared library layer (e.g., solib-svr4) learn
519 about this new process, relocate the cloned exec, pull
520 in shared libraries, and install the solib event
521 breakpoint. If a "cloned-VM" event was propagated
522 better throughout the core, this wouldn't be
524 solib_create_inferior_hook (0);
530 struct inferior
*parent_inf
;
532 parent_inf
= current_inferior ();
534 /* If we detached from the child, then we have to be careful
535 to not insert breakpoints in the parent until the child
536 is done with the shared memory region. However, if we're
537 staying attached to the child, then we can and should
538 insert breakpoints, so that we can debug it. A
539 subsequent child exec or exit is enough to know when does
540 the child stops using the parent's address space. */
541 parent_inf
->waiting_for_vfork_done
= detach_fork
;
542 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
547 /* Follow the child. */
548 struct inferior
*parent_inf
, *child_inf
;
549 struct program_space
*parent_pspace
;
551 if (print_inferior_events
)
553 std::string parent_pid
= target_pid_to_str (parent_ptid
);
554 std::string child_pid
= target_pid_to_str (child_ptid
);
556 target_terminal::ours_for_output ();
557 fprintf_filtered (gdb_stdlog
,
558 _("[Attaching after %s %s to child %s]\n"),
560 has_vforked
? "vfork" : "fork",
564 /* Add the new inferior first, so that the target_detach below
565 doesn't unpush the target. */
567 child_inf
= add_inferior (child_ptid
.pid ());
569 parent_inf
= current_inferior ();
570 child_inf
->attach_flag
= parent_inf
->attach_flag
;
571 copy_terminal_info (child_inf
, parent_inf
);
572 child_inf
->gdbarch
= parent_inf
->gdbarch
;
573 copy_inferior_target_desc_info (child_inf
, parent_inf
);
575 parent_pspace
= parent_inf
->pspace
;
577 process_stratum_target
*target
= parent_inf
->process_target ();
580 /* Hold a strong reference to the target while (maybe)
581 detaching the parent. Otherwise detaching could close the
583 auto target_ref
= target_ops_ref::new_reference (target
);
585 /* If we're vforking, we want to hold on to the parent until
586 the child exits or execs. At child exec or exit time we
587 can remove the old breakpoints from the parent and detach
588 or resume debugging it. Otherwise, detach the parent now;
589 we'll want to reuse it's program/address spaces, but we
590 can't set them to the child before removing breakpoints
591 from the parent, otherwise, the breakpoints module could
592 decide to remove breakpoints from the wrong process (since
593 they'd be assigned to the same address space). */
597 gdb_assert (child_inf
->vfork_parent
== NULL
);
598 gdb_assert (parent_inf
->vfork_child
== NULL
);
599 child_inf
->vfork_parent
= parent_inf
;
600 child_inf
->pending_detach
= 0;
601 parent_inf
->vfork_child
= child_inf
;
602 parent_inf
->pending_detach
= detach_fork
;
603 parent_inf
->waiting_for_vfork_done
= 0;
605 else if (detach_fork
)
607 if (print_inferior_events
)
609 /* Ensure that we have a process ptid. */
610 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
612 target_terminal::ours_for_output ();
613 fprintf_filtered (gdb_stdlog
,
614 _("[Detaching after fork from "
616 target_pid_to_str (process_ptid
).c_str ());
619 target_detach (parent_inf
, 0);
623 /* Note that the detach above makes PARENT_INF dangling. */
625 /* Add the child thread to the appropriate lists, and switch
626 to this new thread, before cloning the program space, and
627 informing the solib layer about this new process. */
629 set_current_inferior (child_inf
);
630 push_target (target
);
633 add_thread_silent (target
, child_ptid
);
634 inferior_ptid
= child_ptid
;
636 /* If this is a vfork child, then the address-space is shared
637 with the parent. If we detached from the parent, then we can
638 reuse the parent's program/address spaces. */
639 if (has_vforked
|| detach_fork
)
641 child_inf
->pspace
= parent_pspace
;
642 child_inf
->aspace
= child_inf
->pspace
->aspace
;
648 child_inf
->aspace
= new_address_space ();
649 child_inf
->pspace
= new program_space (child_inf
->aspace
);
650 child_inf
->removable
= 1;
651 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
652 set_current_program_space (child_inf
->pspace
);
653 clone_program_space (child_inf
->pspace
, parent_pspace
);
655 /* Let the shared library layer (e.g., solib-svr4) learn
656 about this new process, relocate the cloned exec, pull in
657 shared libraries, and install the solib event breakpoint.
658 If a "cloned-VM" event was propagated better throughout
659 the core, this wouldn't be required. */
660 solib_create_inferior_hook (0);
664 return target_follow_fork (follow_child
, detach_fork
);
667 /* Tell the target to follow the fork we're stopped at. Returns true
668 if the inferior should be resumed; false, if the target for some
669 reason decided it's best not to resume. */
674 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
675 int should_resume
= 1;
676 struct thread_info
*tp
;
678 /* Copy user stepping state to the new inferior thread. FIXME: the
679 followed fork child thread should have a copy of most of the
680 parent thread structure's run control related fields, not just these.
681 Initialized to avoid "may be used uninitialized" warnings from gcc. */
682 struct breakpoint
*step_resume_breakpoint
= NULL
;
683 struct breakpoint
*exception_resume_breakpoint
= NULL
;
684 CORE_ADDR step_range_start
= 0;
685 CORE_ADDR step_range_end
= 0;
686 struct frame_id step_frame_id
= { 0 };
687 struct thread_fsm
*thread_fsm
= NULL
;
691 process_stratum_target
*wait_target
;
693 struct target_waitstatus wait_status
;
695 /* Get the last target status returned by target_wait(). */
696 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
698 /* If not stopped at a fork event, then there's nothing else to
700 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
701 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
704 /* Check if we switched over from WAIT_PTID, since the event was
706 if (wait_ptid
!= minus_one_ptid
707 && (current_inferior ()->process_target () != wait_target
708 || inferior_ptid
!= wait_ptid
))
710 /* We did. Switch back to WAIT_PTID thread, to tell the
711 target to follow it (in either direction). We'll
712 afterwards refuse to resume, and inform the user what
714 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
715 switch_to_thread (wait_thread
);
720 tp
= inferior_thread ();
722 /* If there were any forks/vforks that were caught and are now to be
723 followed, then do so now. */
724 switch (tp
->pending_follow
.kind
)
726 case TARGET_WAITKIND_FORKED
:
727 case TARGET_WAITKIND_VFORKED
:
729 ptid_t parent
, child
;
731 /* If the user did a next/step, etc, over a fork call,
732 preserve the stepping state in the fork child. */
733 if (follow_child
&& should_resume
)
735 step_resume_breakpoint
= clone_momentary_breakpoint
736 (tp
->control
.step_resume_breakpoint
);
737 step_range_start
= tp
->control
.step_range_start
;
738 step_range_end
= tp
->control
.step_range_end
;
739 step_frame_id
= tp
->control
.step_frame_id
;
740 exception_resume_breakpoint
741 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
742 thread_fsm
= tp
->thread_fsm
;
744 /* For now, delete the parent's sr breakpoint, otherwise,
745 parent/child sr breakpoints are considered duplicates,
746 and the child version will not be installed. Remove
747 this when the breakpoints module becomes aware of
748 inferiors and address spaces. */
749 delete_step_resume_breakpoint (tp
);
750 tp
->control
.step_range_start
= 0;
751 tp
->control
.step_range_end
= 0;
752 tp
->control
.step_frame_id
= null_frame_id
;
753 delete_exception_resume_breakpoint (tp
);
754 tp
->thread_fsm
= NULL
;
757 parent
= inferior_ptid
;
758 child
= tp
->pending_follow
.value
.related_pid
;
760 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
761 /* Set up inferior(s) as specified by the caller, and tell the
762 target to do whatever is necessary to follow either parent
764 if (follow_fork_inferior (follow_child
, detach_fork
))
766 /* Target refused to follow, or there's some other reason
767 we shouldn't resume. */
772 /* This pending follow fork event is now handled, one way
773 or another. The previous selected thread may be gone
774 from the lists by now, but if it is still around, need
775 to clear the pending follow request. */
776 tp
= find_thread_ptid (parent_targ
, parent
);
778 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
780 /* This makes sure we don't try to apply the "Switched
781 over from WAIT_PID" logic above. */
782 nullify_last_target_wait_ptid ();
784 /* If we followed the child, switch to it... */
787 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
788 switch_to_thread (child_thr
);
790 /* ... and preserve the stepping state, in case the
791 user was stepping over the fork call. */
794 tp
= inferior_thread ();
795 tp
->control
.step_resume_breakpoint
796 = step_resume_breakpoint
;
797 tp
->control
.step_range_start
= step_range_start
;
798 tp
->control
.step_range_end
= step_range_end
;
799 tp
->control
.step_frame_id
= step_frame_id
;
800 tp
->control
.exception_resume_breakpoint
801 = exception_resume_breakpoint
;
802 tp
->thread_fsm
= thread_fsm
;
806 /* If we get here, it was because we're trying to
807 resume from a fork catchpoint, but, the user
808 has switched threads away from the thread that
809 forked. In that case, the resume command
810 issued is most likely not applicable to the
811 child, so just warn, and refuse to resume. */
812 warning (_("Not resuming: switched threads "
813 "before following fork child."));
816 /* Reset breakpoints in the child as appropriate. */
817 follow_inferior_reset_breakpoints ();
822 case TARGET_WAITKIND_SPURIOUS
:
823 /* Nothing to follow. */
826 internal_error (__FILE__
, __LINE__
,
827 "Unexpected pending_follow.kind %d\n",
828 tp
->pending_follow
.kind
);
832 return should_resume
;
836 follow_inferior_reset_breakpoints (void)
838 struct thread_info
*tp
= inferior_thread ();
840 /* Was there a step_resume breakpoint? (There was if the user
841 did a "next" at the fork() call.) If so, explicitly reset its
842 thread number. Cloned step_resume breakpoints are disabled on
843 creation, so enable it here now that it is associated with the
846 step_resumes are a form of bp that are made to be per-thread.
847 Since we created the step_resume bp when the parent process
848 was being debugged, and now are switching to the child process,
849 from the breakpoint package's viewpoint, that's a switch of
850 "threads". We must update the bp's notion of which thread
851 it is for, or it'll be ignored when it triggers. */
853 if (tp
->control
.step_resume_breakpoint
)
855 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
856 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
859 /* Treat exception_resume breakpoints like step_resume breakpoints. */
860 if (tp
->control
.exception_resume_breakpoint
)
862 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
863 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
866 /* Reinsert all breakpoints in the child. The user may have set
867 breakpoints after catching the fork, in which case those
868 were never set in the child, but only in the parent. This makes
869 sure the inserted breakpoints match the breakpoint list. */
871 breakpoint_re_set ();
872 insert_breakpoints ();
875 /* The child has exited or execed: resume threads of the parent the
876 user wanted to be executing. */
879 proceed_after_vfork_done (struct thread_info
*thread
,
882 int pid
= * (int *) arg
;
884 if (thread
->ptid
.pid () == pid
885 && thread
->state
== THREAD_RUNNING
886 && !thread
->executing
887 && !thread
->stop_requested
888 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
891 fprintf_unfiltered (gdb_stdlog
,
892 "infrun: resuming vfork parent thread %s\n",
893 target_pid_to_str (thread
->ptid
).c_str ());
895 switch_to_thread (thread
);
896 clear_proceed_status (0);
897 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
903 /* Save/restore inferior_ptid, current program space and current
904 inferior. Only use this if the current context points at an exited
905 inferior (and therefore there's no current thread to save). */
906 class scoped_restore_exited_inferior
909 scoped_restore_exited_inferior ()
910 : m_saved_ptid (&inferior_ptid
)
914 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
915 scoped_restore_current_program_space m_pspace
;
916 scoped_restore_current_inferior m_inferior
;
919 /* Called whenever we notice an exec or exit event, to handle
920 detaching or resuming a vfork parent. */
923 handle_vfork_child_exec_or_exit (int exec
)
925 struct inferior
*inf
= current_inferior ();
927 if (inf
->vfork_parent
)
929 int resume_parent
= -1;
931 /* This exec or exit marks the end of the shared memory region
932 between the parent and the child. Break the bonds. */
933 inferior
*vfork_parent
= inf
->vfork_parent
;
934 inf
->vfork_parent
->vfork_child
= NULL
;
935 inf
->vfork_parent
= NULL
;
937 /* If the user wanted to detach from the parent, now is the
939 if (vfork_parent
->pending_detach
)
941 struct thread_info
*tp
;
942 struct program_space
*pspace
;
943 struct address_space
*aspace
;
945 /* follow-fork child, detach-on-fork on. */
947 vfork_parent
->pending_detach
= 0;
949 gdb::optional
<scoped_restore_exited_inferior
>
950 maybe_restore_inferior
;
951 gdb::optional
<scoped_restore_current_pspace_and_thread
>
952 maybe_restore_thread
;
954 /* If we're handling a child exit, then inferior_ptid points
955 at the inferior's pid, not to a thread. */
957 maybe_restore_inferior
.emplace ();
959 maybe_restore_thread
.emplace ();
961 /* We're letting loose of the parent. */
962 tp
= any_live_thread_of_inferior (vfork_parent
);
963 switch_to_thread (tp
);
965 /* We're about to detach from the parent, which implicitly
966 removes breakpoints from its address space. There's a
967 catch here: we want to reuse the spaces for the child,
968 but, parent/child are still sharing the pspace at this
969 point, although the exec in reality makes the kernel give
970 the child a fresh set of new pages. The problem here is
971 that the breakpoints module being unaware of this, would
972 likely chose the child process to write to the parent
973 address space. Swapping the child temporarily away from
974 the spaces has the desired effect. Yes, this is "sort
977 pspace
= inf
->pspace
;
978 aspace
= inf
->aspace
;
982 if (print_inferior_events
)
985 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
987 target_terminal::ours_for_output ();
991 fprintf_filtered (gdb_stdlog
,
992 _("[Detaching vfork parent %s "
993 "after child exec]\n"), pidstr
.c_str ());
997 fprintf_filtered (gdb_stdlog
,
998 _("[Detaching vfork parent %s "
999 "after child exit]\n"), pidstr
.c_str ());
1003 target_detach (vfork_parent
, 0);
1006 inf
->pspace
= pspace
;
1007 inf
->aspace
= aspace
;
1011 /* We're staying attached to the parent, so, really give the
1012 child a new address space. */
1013 inf
->pspace
= new program_space (maybe_new_address_space ());
1014 inf
->aspace
= inf
->pspace
->aspace
;
1016 set_current_program_space (inf
->pspace
);
1018 resume_parent
= vfork_parent
->pid
;
1022 struct program_space
*pspace
;
1024 /* If this is a vfork child exiting, then the pspace and
1025 aspaces were shared with the parent. Since we're
1026 reporting the process exit, we'll be mourning all that is
1027 found in the address space, and switching to null_ptid,
1028 preparing to start a new inferior. But, since we don't
1029 want to clobber the parent's address/program spaces, we
1030 go ahead and create a new one for this exiting
1033 /* Switch to null_ptid while running clone_program_space, so
1034 that clone_program_space doesn't want to read the
1035 selected frame of a dead process. */
1036 scoped_restore restore_ptid
1037 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1039 /* This inferior is dead, so avoid giving the breakpoints
1040 module the option to write through to it (cloning a
1041 program space resets breakpoints). */
1044 pspace
= new program_space (maybe_new_address_space ());
1045 set_current_program_space (pspace
);
1047 inf
->symfile_flags
= SYMFILE_NO_READ
;
1048 clone_program_space (pspace
, vfork_parent
->pspace
);
1049 inf
->pspace
= pspace
;
1050 inf
->aspace
= pspace
->aspace
;
1052 resume_parent
= vfork_parent
->pid
;
1055 gdb_assert (current_program_space
== inf
->pspace
);
1057 if (non_stop
&& resume_parent
!= -1)
1059 /* If the user wanted the parent to be running, let it go
1061 scoped_restore_current_thread restore_thread
;
1064 fprintf_unfiltered (gdb_stdlog
,
1065 "infrun: resuming vfork parent process %d\n",
1068 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1073 /* Enum strings for "set|show follow-exec-mode". */
1075 static const char follow_exec_mode_new
[] = "new";
1076 static const char follow_exec_mode_same
[] = "same";
1077 static const char *const follow_exec_mode_names
[] =
1079 follow_exec_mode_new
,
1080 follow_exec_mode_same
,
1084 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1086 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1087 struct cmd_list_element
*c
, const char *value
)
1089 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1092 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1095 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1097 struct inferior
*inf
= current_inferior ();
1098 int pid
= ptid
.pid ();
1099 ptid_t process_ptid
;
1101 /* Switch terminal for any messages produced e.g. by
1102 breakpoint_re_set. */
1103 target_terminal::ours_for_output ();
1105 /* This is an exec event that we actually wish to pay attention to.
1106 Refresh our symbol table to the newly exec'd program, remove any
1107 momentary bp's, etc.
1109 If there are breakpoints, they aren't really inserted now,
1110 since the exec() transformed our inferior into a fresh set
1113 We want to preserve symbolic breakpoints on the list, since
1114 we have hopes that they can be reset after the new a.out's
1115 symbol table is read.
1117 However, any "raw" breakpoints must be removed from the list
1118 (e.g., the solib bp's), since their address is probably invalid
1121 And, we DON'T want to call delete_breakpoints() here, since
1122 that may write the bp's "shadow contents" (the instruction
1123 value that was overwritten with a TRAP instruction). Since
1124 we now have a new a.out, those shadow contents aren't valid. */
1126 mark_breakpoints_out ();
1128 /* The target reports the exec event to the main thread, even if
1129 some other thread does the exec, and even if the main thread was
1130 stopped or already gone. We may still have non-leader threads of
1131 the process on our list. E.g., on targets that don't have thread
1132 exit events (like remote); or on native Linux in non-stop mode if
1133 there were only two threads in the inferior and the non-leader
1134 one is the one that execs (and nothing forces an update of the
1135 thread list up to here). When debugging remotely, it's best to
1136 avoid extra traffic, when possible, so avoid syncing the thread
1137 list with the target, and instead go ahead and delete all threads
1138 of the process but one that reported the event. Note this must
1139 be done before calling update_breakpoints_after_exec, as
1140 otherwise clearing the threads' resources would reference stale
1141 thread breakpoints -- it may have been one of these threads that
1142 stepped across the exec. We could just clear their stepping
1143 states, but as long as we're iterating, might as well delete
1144 them. Deleting them now rather than at the next user-visible
1145 stop provides a nicer sequence of events for user and MI
1147 for (thread_info
*th
: all_threads_safe ())
1148 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1151 /* We also need to clear any left over stale state for the
1152 leader/event thread. E.g., if there was any step-resume
1153 breakpoint or similar, it's gone now. We cannot truly
1154 step-to-next statement through an exec(). */
1155 thread_info
*th
= inferior_thread ();
1156 th
->control
.step_resume_breakpoint
= NULL
;
1157 th
->control
.exception_resume_breakpoint
= NULL
;
1158 th
->control
.single_step_breakpoints
= NULL
;
1159 th
->control
.step_range_start
= 0;
1160 th
->control
.step_range_end
= 0;
1162 /* The user may have had the main thread held stopped in the
1163 previous image (e.g., schedlock on, or non-stop). Release
1165 th
->stop_requested
= 0;
1167 update_breakpoints_after_exec ();
1169 /* What is this a.out's name? */
1170 process_ptid
= ptid_t (pid
);
1171 printf_unfiltered (_("%s is executing new program: %s\n"),
1172 target_pid_to_str (process_ptid
).c_str (),
1175 /* We've followed the inferior through an exec. Therefore, the
1176 inferior has essentially been killed & reborn. */
1178 breakpoint_init_inferior (inf_execd
);
1180 gdb::unique_xmalloc_ptr
<char> exec_file_host
1181 = exec_file_find (exec_file_target
, NULL
);
1183 /* If we were unable to map the executable target pathname onto a host
1184 pathname, tell the user that. Otherwise GDB's subsequent behavior
1185 is confusing. Maybe it would even be better to stop at this point
1186 so that the user can specify a file manually before continuing. */
1187 if (exec_file_host
== NULL
)
1188 warning (_("Could not load symbols for executable %s.\n"
1189 "Do you need \"set sysroot\"?"),
1192 /* Reset the shared library package. This ensures that we get a
1193 shlib event when the child reaches "_start", at which point the
1194 dld will have had a chance to initialize the child. */
1195 /* Also, loading a symbol file below may trigger symbol lookups, and
1196 we don't want those to be satisfied by the libraries of the
1197 previous incarnation of this process. */
1198 no_shared_libraries (NULL
, 0);
1200 if (follow_exec_mode_string
== follow_exec_mode_new
)
1202 /* The user wants to keep the old inferior and program spaces
1203 around. Create a new fresh one, and switch to it. */
1205 /* Do exit processing for the original inferior before setting the new
1206 inferior's pid. Having two inferiors with the same pid would confuse
1207 find_inferior_p(t)id. Transfer the terminal state and info from the
1208 old to the new inferior. */
1209 inf
= add_inferior_with_spaces ();
1210 swap_terminal_info (inf
, current_inferior ());
1211 exit_inferior_silent (current_inferior ());
1214 target_follow_exec (inf
, exec_file_target
);
1216 inferior
*org_inferior
= current_inferior ();
1217 switch_to_inferior_no_thread (inf
);
1218 push_target (org_inferior
->process_target ());
1219 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1220 switch_to_thread (thr
);
1224 /* The old description may no longer be fit for the new image.
1225 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1226 old description; we'll read a new one below. No need to do
1227 this on "follow-exec-mode new", as the old inferior stays
1228 around (its description is later cleared/refetched on
1230 target_clear_description ();
1233 gdb_assert (current_program_space
== inf
->pspace
);
1235 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1236 because the proper displacement for a PIE (Position Independent
1237 Executable) main symbol file will only be computed by
1238 solib_create_inferior_hook below. breakpoint_re_set would fail
1239 to insert the breakpoints with the zero displacement. */
1240 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1242 /* If the target can specify a description, read it. Must do this
1243 after flipping to the new executable (because the target supplied
1244 description must be compatible with the executable's
1245 architecture, and the old executable may e.g., be 32-bit, while
1246 the new one 64-bit), and before anything involving memory or
1248 target_find_description ();
1250 solib_create_inferior_hook (0);
1252 jit_inferior_created_hook ();
1254 breakpoint_re_set ();
1256 /* Reinsert all breakpoints. (Those which were symbolic have
1257 been reset to the proper address in the new a.out, thanks
1258 to symbol_file_command...). */
1259 insert_breakpoints ();
1261 /* The next resume of this inferior should bring it to the shlib
1262 startup breakpoints. (If the user had also set bp's on
1263 "main" from the old (parent) process, then they'll auto-
1264 matically get reset there in the new process.). */
1267 /* The queue of threads that need to do a step-over operation to get
1268 past e.g., a breakpoint. What technique is used to step over the
1269 breakpoint/watchpoint does not matter -- all threads end up in the
1270 same queue, to maintain rough temporal order of execution, in order
1271 to avoid starvation, otherwise, we could e.g., find ourselves
1272 constantly stepping the same couple threads past their breakpoints
1273 over and over, if the single-step finish fast enough. */
1274 struct thread_info
*step_over_queue_head
;
1276 /* Bit flags indicating what the thread needs to step over. */
1278 enum step_over_what_flag
1280 /* Step over a breakpoint. */
1281 STEP_OVER_BREAKPOINT
= 1,
1283 /* Step past a non-continuable watchpoint, in order to let the
1284 instruction execute so we can evaluate the watchpoint
1286 STEP_OVER_WATCHPOINT
= 2
1288 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1290 /* Info about an instruction that is being stepped over. */
1292 struct step_over_info
1294 /* If we're stepping past a breakpoint, this is the address space
1295 and address of the instruction the breakpoint is set at. We'll
1296 skip inserting all breakpoints here. Valid iff ASPACE is
1298 const address_space
*aspace
;
1301 /* The instruction being stepped over triggers a nonsteppable
1302 watchpoint. If true, we'll skip inserting watchpoints. */
1303 int nonsteppable_watchpoint_p
;
1305 /* The thread's global number. */
1309 /* The step-over info of the location that is being stepped over.
1311 Note that with async/breakpoint always-inserted mode, a user might
1312 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1313 being stepped over. As setting a new breakpoint inserts all
1314 breakpoints, we need to make sure the breakpoint being stepped over
1315 isn't inserted then. We do that by only clearing the step-over
1316 info when the step-over is actually finished (or aborted).
1318 Presently GDB can only step over one breakpoint at any given time.
1319 Given threads that can't run code in the same address space as the
1320 breakpoint's can't really miss the breakpoint, GDB could be taught
1321 to step-over at most one breakpoint per address space (so this info
1322 could move to the address space object if/when GDB is extended).
1323 The set of breakpoints being stepped over will normally be much
1324 smaller than the set of all breakpoints, so a flag in the
1325 breakpoint location structure would be wasteful. A separate list
1326 also saves complexity and run-time, as otherwise we'd have to go
1327 through all breakpoint locations clearing their flag whenever we
1328 start a new sequence. Similar considerations weigh against storing
1329 this info in the thread object. Plus, not all step overs actually
1330 have breakpoint locations -- e.g., stepping past a single-step
1331 breakpoint, or stepping to complete a non-continuable
1333 static struct step_over_info step_over_info
;
1335 /* Record the address of the breakpoint/instruction we're currently
1337 N.B. We record the aspace and address now, instead of say just the thread,
1338 because when we need the info later the thread may be running. */
1341 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1342 int nonsteppable_watchpoint_p
,
1345 step_over_info
.aspace
= aspace
;
1346 step_over_info
.address
= address
;
1347 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1348 step_over_info
.thread
= thread
;
1351 /* Called when we're not longer stepping over a breakpoint / an
1352 instruction, so all breakpoints are free to be (re)inserted. */
1355 clear_step_over_info (void)
1358 fprintf_unfiltered (gdb_stdlog
,
1359 "infrun: clear_step_over_info\n");
1360 step_over_info
.aspace
= NULL
;
1361 step_over_info
.address
= 0;
1362 step_over_info
.nonsteppable_watchpoint_p
= 0;
1363 step_over_info
.thread
= -1;
1369 stepping_past_instruction_at (struct address_space
*aspace
,
1372 return (step_over_info
.aspace
!= NULL
1373 && breakpoint_address_match (aspace
, address
,
1374 step_over_info
.aspace
,
1375 step_over_info
.address
));
1381 thread_is_stepping_over_breakpoint (int thread
)
1383 return (step_over_info
.thread
!= -1
1384 && thread
== step_over_info
.thread
);
1390 stepping_past_nonsteppable_watchpoint (void)
1392 return step_over_info
.nonsteppable_watchpoint_p
;
1395 /* Returns true if step-over info is valid. */
1398 step_over_info_valid_p (void)
1400 return (step_over_info
.aspace
!= NULL
1401 || stepping_past_nonsteppable_watchpoint ());
1405 /* Displaced stepping. */
1407 /* In non-stop debugging mode, we must take special care to manage
1408 breakpoints properly; in particular, the traditional strategy for
1409 stepping a thread past a breakpoint it has hit is unsuitable.
1410 'Displaced stepping' is a tactic for stepping one thread past a
1411 breakpoint it has hit while ensuring that other threads running
1412 concurrently will hit the breakpoint as they should.
1414 The traditional way to step a thread T off a breakpoint in a
1415 multi-threaded program in all-stop mode is as follows:
1417 a0) Initially, all threads are stopped, and breakpoints are not
1419 a1) We single-step T, leaving breakpoints uninserted.
1420 a2) We insert breakpoints, and resume all threads.
1422 In non-stop debugging, however, this strategy is unsuitable: we
1423 don't want to have to stop all threads in the system in order to
1424 continue or step T past a breakpoint. Instead, we use displaced
1427 n0) Initially, T is stopped, other threads are running, and
1428 breakpoints are inserted.
1429 n1) We copy the instruction "under" the breakpoint to a separate
1430 location, outside the main code stream, making any adjustments
1431 to the instruction, register, and memory state as directed by
1433 n2) We single-step T over the instruction at its new location.
1434 n3) We adjust the resulting register and memory state as directed
1435 by T's architecture. This includes resetting T's PC to point
1436 back into the main instruction stream.
1439 This approach depends on the following gdbarch methods:
1441 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1442 indicate where to copy the instruction, and how much space must
1443 be reserved there. We use these in step n1.
1445 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1446 address, and makes any necessary adjustments to the instruction,
1447 register contents, and memory. We use this in step n1.
1449 - gdbarch_displaced_step_fixup adjusts registers and memory after
1450 we have successfully single-stepped the instruction, to yield the
1451 same effect the instruction would have had if we had executed it
1452 at its original address. We use this in step n3.
1454 The gdbarch_displaced_step_copy_insn and
1455 gdbarch_displaced_step_fixup functions must be written so that
1456 copying an instruction with gdbarch_displaced_step_copy_insn,
1457 single-stepping across the copied instruction, and then applying
1458 gdbarch_displaced_insn_fixup should have the same effects on the
1459 thread's memory and registers as stepping the instruction in place
1460 would have. Exactly which responsibilities fall to the copy and
1461 which fall to the fixup is up to the author of those functions.
1463 See the comments in gdbarch.sh for details.
1465 Note that displaced stepping and software single-step cannot
1466 currently be used in combination, although with some care I think
1467 they could be made to. Software single-step works by placing
1468 breakpoints on all possible subsequent instructions; if the
1469 displaced instruction is a PC-relative jump, those breakpoints
1470 could fall in very strange places --- on pages that aren't
1471 executable, or at addresses that are not proper instruction
1472 boundaries. (We do generally let other threads run while we wait
1473 to hit the software single-step breakpoint, and they might
1474 encounter such a corrupted instruction.) One way to work around
1475 this would be to have gdbarch_displaced_step_copy_insn fully
1476 simulate the effect of PC-relative instructions (and return NULL)
1477 on architectures that use software single-stepping.
1479 In non-stop mode, we can have independent and simultaneous step
1480 requests, so more than one thread may need to simultaneously step
1481 over a breakpoint. The current implementation assumes there is
1482 only one scratch space per process. In this case, we have to
1483 serialize access to the scratch space. If thread A wants to step
1484 over a breakpoint, but we are currently waiting for some other
1485 thread to complete a displaced step, we leave thread A stopped and
1486 place it in the displaced_step_request_queue. Whenever a displaced
1487 step finishes, we pick the next thread in the queue and start a new
1488 displaced step operation on it. See displaced_step_prepare and
1489 displaced_step_fixup for details. */
1491 /* Default destructor for displaced_step_closure. */
1493 displaced_step_closure::~displaced_step_closure () = default;
1495 /* Get the displaced stepping state of process PID. */
1497 static displaced_step_inferior_state
*
1498 get_displaced_stepping_state (inferior
*inf
)
1500 return &inf
->displaced_step_state
;
1503 /* Returns true if any inferior has a thread doing a displaced
1507 displaced_step_in_progress_any_inferior ()
1509 for (inferior
*i
: all_inferiors ())
1511 if (i
->displaced_step_state
.step_thread
!= nullptr)
1518 /* Return true if thread represented by PTID is doing a displaced
1522 displaced_step_in_progress_thread (thread_info
*thread
)
1524 gdb_assert (thread
!= NULL
);
1526 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1529 /* Return true if process PID has a thread doing a displaced step. */
1532 displaced_step_in_progress (inferior
*inf
)
1534 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1537 /* If inferior is in displaced stepping, and ADDR equals to starting address
1538 of copy area, return corresponding displaced_step_closure. Otherwise,
1541 struct displaced_step_closure
*
1542 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1544 displaced_step_inferior_state
*displaced
1545 = get_displaced_stepping_state (current_inferior ());
1547 /* If checking the mode of displaced instruction in copy area. */
1548 if (displaced
->step_thread
!= nullptr
1549 && displaced
->step_copy
== addr
)
1550 return displaced
->step_closure
;
1556 infrun_inferior_exit (struct inferior
*inf
)
1558 inf
->displaced_step_state
.reset ();
1561 /* If ON, and the architecture supports it, GDB will use displaced
1562 stepping to step over breakpoints. If OFF, or if the architecture
1563 doesn't support it, GDB will instead use the traditional
1564 hold-and-step approach. If AUTO (which is the default), GDB will
1565 decide which technique to use to step over breakpoints depending on
1566 which of all-stop or non-stop mode is active --- displaced stepping
1567 in non-stop mode; hold-and-step in all-stop mode. */
1569 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1572 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1573 struct cmd_list_element
*c
,
1576 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1577 fprintf_filtered (file
,
1578 _("Debugger's willingness to use displaced stepping "
1579 "to step over breakpoints is %s (currently %s).\n"),
1580 value
, target_is_non_stop_p () ? "on" : "off");
1582 fprintf_filtered (file
,
1583 _("Debugger's willingness to use displaced stepping "
1584 "to step over breakpoints is %s.\n"), value
);
1587 /* Return non-zero if displaced stepping can/should be used to step
1588 over breakpoints of thread TP. */
1591 use_displaced_stepping (struct thread_info
*tp
)
1593 struct regcache
*regcache
= get_thread_regcache (tp
);
1594 struct gdbarch
*gdbarch
= regcache
->arch ();
1595 displaced_step_inferior_state
*displaced_state
1596 = get_displaced_stepping_state (tp
->inf
);
1598 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1599 && target_is_non_stop_p ())
1600 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1601 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1602 && find_record_target () == NULL
1603 && !displaced_state
->failed_before
);
1606 /* Clean out any stray displaced stepping state. */
1608 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1610 /* Indicate that there is no cleanup pending. */
1611 displaced
->step_thread
= nullptr;
1613 delete displaced
->step_closure
;
1614 displaced
->step_closure
= NULL
;
1617 /* A cleanup that wraps displaced_step_clear. */
1618 using displaced_step_clear_cleanup
1619 = FORWARD_SCOPE_EXIT (displaced_step_clear
);
1621 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1623 displaced_step_dump_bytes (struct ui_file
*file
,
1624 const gdb_byte
*buf
,
1629 for (i
= 0; i
< len
; i
++)
1630 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1631 fputs_unfiltered ("\n", file
);
1634 /* Prepare to single-step, using displaced stepping.
1636 Note that we cannot use displaced stepping when we have a signal to
1637 deliver. If we have a signal to deliver and an instruction to step
1638 over, then after the step, there will be no indication from the
1639 target whether the thread entered a signal handler or ignored the
1640 signal and stepped over the instruction successfully --- both cases
1641 result in a simple SIGTRAP. In the first case we mustn't do a
1642 fixup, and in the second case we must --- but we can't tell which.
1643 Comments in the code for 'random signals' in handle_inferior_event
1644 explain how we handle this case instead.
1646 Returns 1 if preparing was successful -- this thread is going to be
1647 stepped now; 0 if displaced stepping this thread got queued; or -1
1648 if this instruction can't be displaced stepped. */
1651 displaced_step_prepare_throw (thread_info
*tp
)
1653 regcache
*regcache
= get_thread_regcache (tp
);
1654 struct gdbarch
*gdbarch
= regcache
->arch ();
1655 const address_space
*aspace
= regcache
->aspace ();
1656 CORE_ADDR original
, copy
;
1658 struct displaced_step_closure
*closure
;
1661 /* We should never reach this function if the architecture does not
1662 support displaced stepping. */
1663 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1665 /* Nor if the thread isn't meant to step over a breakpoint. */
1666 gdb_assert (tp
->control
.trap_expected
);
1668 /* Disable range stepping while executing in the scratch pad. We
1669 want a single-step even if executing the displaced instruction in
1670 the scratch buffer lands within the stepping range (e.g., a
1672 tp
->control
.may_range_step
= 0;
1674 /* We have to displaced step one thread at a time, as we only have
1675 access to a single scratch space per inferior. */
1677 displaced_step_inferior_state
*displaced
1678 = get_displaced_stepping_state (tp
->inf
);
1680 if (displaced
->step_thread
!= nullptr)
1682 /* Already waiting for a displaced step to finish. Defer this
1683 request and place in queue. */
1685 if (debug_displaced
)
1686 fprintf_unfiltered (gdb_stdlog
,
1687 "displaced: deferring step of %s\n",
1688 target_pid_to_str (tp
->ptid
).c_str ());
1690 thread_step_over_chain_enqueue (tp
);
1695 if (debug_displaced
)
1696 fprintf_unfiltered (gdb_stdlog
,
1697 "displaced: stepping %s now\n",
1698 target_pid_to_str (tp
->ptid
).c_str ());
1701 displaced_step_clear (displaced
);
1703 scoped_restore_current_thread restore_thread
;
1705 switch_to_thread (tp
);
1707 original
= regcache_read_pc (regcache
);
1709 copy
= gdbarch_displaced_step_location (gdbarch
);
1710 len
= gdbarch_max_insn_length (gdbarch
);
1712 if (breakpoint_in_range_p (aspace
, copy
, len
))
1714 /* There's a breakpoint set in the scratch pad location range
1715 (which is usually around the entry point). We'd either
1716 install it before resuming, which would overwrite/corrupt the
1717 scratch pad, or if it was already inserted, this displaced
1718 step would overwrite it. The latter is OK in the sense that
1719 we already assume that no thread is going to execute the code
1720 in the scratch pad range (after initial startup) anyway, but
1721 the former is unacceptable. Simply punt and fallback to
1722 stepping over this breakpoint in-line. */
1723 if (debug_displaced
)
1725 fprintf_unfiltered (gdb_stdlog
,
1726 "displaced: breakpoint set in scratch pad. "
1727 "Stepping over breakpoint in-line instead.\n");
1733 /* Save the original contents of the copy area. */
1734 displaced
->step_saved_copy
.resize (len
);
1735 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1737 throw_error (MEMORY_ERROR
,
1738 _("Error accessing memory address %s (%s) for "
1739 "displaced-stepping scratch space."),
1740 paddress (gdbarch
, copy
), safe_strerror (status
));
1741 if (debug_displaced
)
1743 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1744 paddress (gdbarch
, copy
));
1745 displaced_step_dump_bytes (gdb_stdlog
,
1746 displaced
->step_saved_copy
.data (),
1750 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1751 original
, copy
, regcache
);
1752 if (closure
== NULL
)
1754 /* The architecture doesn't know how or want to displaced step
1755 this instruction or instruction sequence. Fallback to
1756 stepping over the breakpoint in-line. */
1760 /* Save the information we need to fix things up if the step
1762 displaced
->step_thread
= tp
;
1763 displaced
->step_gdbarch
= gdbarch
;
1764 displaced
->step_closure
= closure
;
1765 displaced
->step_original
= original
;
1766 displaced
->step_copy
= copy
;
1769 displaced_step_clear_cleanup
cleanup (displaced
);
1771 /* Resume execution at the copy. */
1772 regcache_write_pc (regcache
, copy
);
1777 if (debug_displaced
)
1778 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1779 paddress (gdbarch
, copy
));
1784 /* Wrapper for displaced_step_prepare_throw that disabled further
1785 attempts at displaced stepping if we get a memory error. */
1788 displaced_step_prepare (thread_info
*thread
)
1794 prepared
= displaced_step_prepare_throw (thread
);
1796 catch (const gdb_exception_error
&ex
)
1798 struct displaced_step_inferior_state
*displaced_state
;
1800 if (ex
.error
!= MEMORY_ERROR
1801 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1806 fprintf_unfiltered (gdb_stdlog
,
1807 "infrun: disabling displaced stepping: %s\n",
1811 /* Be verbose if "set displaced-stepping" is "on", silent if
1813 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1815 warning (_("disabling displaced stepping: %s"),
1819 /* Disable further displaced stepping attempts. */
1821 = get_displaced_stepping_state (thread
->inf
);
1822 displaced_state
->failed_before
= 1;
1829 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1830 const gdb_byte
*myaddr
, int len
)
1832 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1834 inferior_ptid
= ptid
;
1835 write_memory (memaddr
, myaddr
, len
);
1838 /* Restore the contents of the copy area for thread PTID. */
1841 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1844 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1846 write_memory_ptid (ptid
, displaced
->step_copy
,
1847 displaced
->step_saved_copy
.data (), len
);
1848 if (debug_displaced
)
1849 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1850 target_pid_to_str (ptid
).c_str (),
1851 paddress (displaced
->step_gdbarch
,
1852 displaced
->step_copy
));
1855 /* If we displaced stepped an instruction successfully, adjust
1856 registers and memory to yield the same effect the instruction would
1857 have had if we had executed it at its original address, and return
1858 1. If the instruction didn't complete, relocate the PC and return
1859 -1. If the thread wasn't displaced stepping, return 0. */
1862 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1864 struct displaced_step_inferior_state
*displaced
1865 = get_displaced_stepping_state (event_thread
->inf
);
1868 /* Was this event for the thread we displaced? */
1869 if (displaced
->step_thread
!= event_thread
)
1872 displaced_step_clear_cleanup
cleanup (displaced
);
1874 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1876 /* Fixup may need to read memory/registers. Switch to the thread
1877 that we're fixing up. Also, target_stopped_by_watchpoint checks
1878 the current thread. */
1879 switch_to_thread (event_thread
);
1881 /* Did the instruction complete successfully? */
1882 if (signal
== GDB_SIGNAL_TRAP
1883 && !(target_stopped_by_watchpoint ()
1884 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1885 || target_have_steppable_watchpoint
)))
1887 /* Fix up the resulting state. */
1888 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1889 displaced
->step_closure
,
1890 displaced
->step_original
,
1891 displaced
->step_copy
,
1892 get_thread_regcache (displaced
->step_thread
));
1897 /* Since the instruction didn't complete, all we can do is
1899 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1900 CORE_ADDR pc
= regcache_read_pc (regcache
);
1902 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1903 regcache_write_pc (regcache
, pc
);
1910 /* Data to be passed around while handling an event. This data is
1911 discarded between events. */
1912 struct execution_control_state
1914 process_stratum_target
*target
;
1916 /* The thread that got the event, if this was a thread event; NULL
1918 struct thread_info
*event_thread
;
1920 struct target_waitstatus ws
;
1921 int stop_func_filled_in
;
1922 CORE_ADDR stop_func_start
;
1923 CORE_ADDR stop_func_end
;
1924 const char *stop_func_name
;
1927 /* True if the event thread hit the single-step breakpoint of
1928 another thread. Thus the event doesn't cause a stop, the thread
1929 needs to be single-stepped past the single-step breakpoint before
1930 we can switch back to the original stepping thread. */
1931 int hit_singlestep_breakpoint
;
1934 /* Clear ECS and set it to point at TP. */
1937 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1939 memset (ecs
, 0, sizeof (*ecs
));
1940 ecs
->event_thread
= tp
;
1941 ecs
->ptid
= tp
->ptid
;
1944 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1945 static void prepare_to_wait (struct execution_control_state
*ecs
);
1946 static int keep_going_stepped_thread (struct thread_info
*tp
);
1947 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1949 /* Are there any pending step-over requests? If so, run all we can
1950 now and return true. Otherwise, return false. */
1953 start_step_over (void)
1955 struct thread_info
*tp
, *next
;
1957 /* Don't start a new step-over if we already have an in-line
1958 step-over operation ongoing. */
1959 if (step_over_info_valid_p ())
1962 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1964 struct execution_control_state ecss
;
1965 struct execution_control_state
*ecs
= &ecss
;
1966 step_over_what step_what
;
1967 int must_be_in_line
;
1969 gdb_assert (!tp
->stop_requested
);
1971 next
= thread_step_over_chain_next (tp
);
1973 /* If this inferior already has a displaced step in process,
1974 don't start a new one. */
1975 if (displaced_step_in_progress (tp
->inf
))
1978 step_what
= thread_still_needs_step_over (tp
);
1979 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1980 || ((step_what
& STEP_OVER_BREAKPOINT
)
1981 && !use_displaced_stepping (tp
)));
1983 /* We currently stop all threads of all processes to step-over
1984 in-line. If we need to start a new in-line step-over, let
1985 any pending displaced steps finish first. */
1986 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1989 thread_step_over_chain_remove (tp
);
1991 if (step_over_queue_head
== NULL
)
1994 fprintf_unfiltered (gdb_stdlog
,
1995 "infrun: step-over queue now empty\n");
1998 if (tp
->control
.trap_expected
2002 internal_error (__FILE__
, __LINE__
,
2003 "[%s] has inconsistent state: "
2004 "trap_expected=%d, resumed=%d, executing=%d\n",
2005 target_pid_to_str (tp
->ptid
).c_str (),
2006 tp
->control
.trap_expected
,
2012 fprintf_unfiltered (gdb_stdlog
,
2013 "infrun: resuming [%s] for step-over\n",
2014 target_pid_to_str (tp
->ptid
).c_str ());
2016 /* keep_going_pass_signal skips the step-over if the breakpoint
2017 is no longer inserted. In all-stop, we want to keep looking
2018 for a thread that needs a step-over instead of resuming TP,
2019 because we wouldn't be able to resume anything else until the
2020 target stops again. In non-stop, the resume always resumes
2021 only TP, so it's OK to let the thread resume freely. */
2022 if (!target_is_non_stop_p () && !step_what
)
2025 switch_to_thread (tp
);
2026 reset_ecs (ecs
, tp
);
2027 keep_going_pass_signal (ecs
);
2029 if (!ecs
->wait_some_more
)
2030 error (_("Command aborted."));
2032 gdb_assert (tp
->resumed
);
2034 /* If we started a new in-line step-over, we're done. */
2035 if (step_over_info_valid_p ())
2037 gdb_assert (tp
->control
.trap_expected
);
2041 if (!target_is_non_stop_p ())
2043 /* On all-stop, shouldn't have resumed unless we needed a
2045 gdb_assert (tp
->control
.trap_expected
2046 || tp
->step_after_step_resume_breakpoint
);
2048 /* With remote targets (at least), in all-stop, we can't
2049 issue any further remote commands until the program stops
2054 /* Either the thread no longer needed a step-over, or a new
2055 displaced stepping sequence started. Even in the latter
2056 case, continue looking. Maybe we can also start another
2057 displaced step on a thread of other process. */
2063 /* Update global variables holding ptids to hold NEW_PTID if they were
2064 holding OLD_PTID. */
2066 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2068 if (inferior_ptid
== old_ptid
)
2069 inferior_ptid
= new_ptid
;
2074 static const char schedlock_off
[] = "off";
2075 static const char schedlock_on
[] = "on";
2076 static const char schedlock_step
[] = "step";
2077 static const char schedlock_replay
[] = "replay";
2078 static const char *const scheduler_enums
[] = {
2085 static const char *scheduler_mode
= schedlock_replay
;
2087 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2088 struct cmd_list_element
*c
, const char *value
)
2090 fprintf_filtered (file
,
2091 _("Mode for locking scheduler "
2092 "during execution is \"%s\".\n"),
2097 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2099 if (!target_can_lock_scheduler
)
2101 scheduler_mode
= schedlock_off
;
2102 error (_("Target '%s' cannot support this command."), target_shortname
);
2106 /* True if execution commands resume all threads of all processes by
2107 default; otherwise, resume only threads of the current inferior
2109 bool sched_multi
= false;
2111 /* Try to setup for software single stepping over the specified location.
2112 Return 1 if target_resume() should use hardware single step.
2114 GDBARCH the current gdbarch.
2115 PC the location to step over. */
2118 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2122 if (execution_direction
== EXEC_FORWARD
2123 && gdbarch_software_single_step_p (gdbarch
))
2124 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2132 user_visible_resume_ptid (int step
)
2138 /* With non-stop mode on, threads are always handled
2140 resume_ptid
= inferior_ptid
;
2142 else if ((scheduler_mode
== schedlock_on
)
2143 || (scheduler_mode
== schedlock_step
&& step
))
2145 /* User-settable 'scheduler' mode requires solo thread
2147 resume_ptid
= inferior_ptid
;
2149 else if ((scheduler_mode
== schedlock_replay
)
2150 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2152 /* User-settable 'scheduler' mode requires solo thread resume in replay
2154 resume_ptid
= inferior_ptid
;
2156 else if (!sched_multi
&& target_supports_multi_process ())
2158 /* Resume all threads of the current process (and none of other
2160 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2164 /* Resume all threads of all processes. */
2165 resume_ptid
= RESUME_ALL
;
2173 process_stratum_target
*
2174 user_visible_resume_target (ptid_t resume_ptid
)
2176 return (resume_ptid
== minus_one_ptid
&& sched_multi
2178 : current_inferior ()->process_target ());
2181 /* Return a ptid representing the set of threads that we will resume,
2182 in the perspective of the target, assuming run control handling
2183 does not require leaving some threads stopped (e.g., stepping past
2184 breakpoint). USER_STEP indicates whether we're about to start the
2185 target for a stepping command. */
2188 internal_resume_ptid (int user_step
)
2190 /* In non-stop, we always control threads individually. Note that
2191 the target may always work in non-stop mode even with "set
2192 non-stop off", in which case user_visible_resume_ptid could
2193 return a wildcard ptid. */
2194 if (target_is_non_stop_p ())
2195 return inferior_ptid
;
2197 return user_visible_resume_ptid (user_step
);
2200 /* Wrapper for target_resume, that handles infrun-specific
2204 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2206 struct thread_info
*tp
= inferior_thread ();
2208 gdb_assert (!tp
->stop_requested
);
2210 /* Install inferior's terminal modes. */
2211 target_terminal::inferior ();
2213 /* Avoid confusing the next resume, if the next stop/resume
2214 happens to apply to another thread. */
2215 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2217 /* Advise target which signals may be handled silently.
2219 If we have removed breakpoints because we are stepping over one
2220 in-line (in any thread), we need to receive all signals to avoid
2221 accidentally skipping a breakpoint during execution of a signal
2224 Likewise if we're displaced stepping, otherwise a trap for a
2225 breakpoint in a signal handler might be confused with the
2226 displaced step finishing. We don't make the displaced_step_fixup
2227 step distinguish the cases instead, because:
2229 - a backtrace while stopped in the signal handler would show the
2230 scratch pad as frame older than the signal handler, instead of
2231 the real mainline code.
2233 - when the thread is later resumed, the signal handler would
2234 return to the scratch pad area, which would no longer be
2236 if (step_over_info_valid_p ()
2237 || displaced_step_in_progress (tp
->inf
))
2238 target_pass_signals ({});
2240 target_pass_signals (signal_pass
);
2242 target_resume (resume_ptid
, step
, sig
);
2244 target_commit_resume ();
2246 if (target_can_async_p ())
2250 /* Resume the inferior. SIG is the signal to give the inferior
2251 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2252 call 'resume', which handles exceptions. */
2255 resume_1 (enum gdb_signal sig
)
2257 struct regcache
*regcache
= get_current_regcache ();
2258 struct gdbarch
*gdbarch
= regcache
->arch ();
2259 struct thread_info
*tp
= inferior_thread ();
2260 CORE_ADDR pc
= regcache_read_pc (regcache
);
2261 const address_space
*aspace
= regcache
->aspace ();
2263 /* This represents the user's step vs continue request. When
2264 deciding whether "set scheduler-locking step" applies, it's the
2265 user's intention that counts. */
2266 const int user_step
= tp
->control
.stepping_command
;
2267 /* This represents what we'll actually request the target to do.
2268 This can decay from a step to a continue, if e.g., we need to
2269 implement single-stepping with breakpoints (software
2273 gdb_assert (!tp
->stop_requested
);
2274 gdb_assert (!thread_is_in_step_over_chain (tp
));
2276 if (tp
->suspend
.waitstatus_pending_p
)
2281 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2283 fprintf_unfiltered (gdb_stdlog
,
2284 "infrun: resume: thread %s has pending wait "
2285 "status %s (currently_stepping=%d).\n",
2286 target_pid_to_str (tp
->ptid
).c_str (),
2288 currently_stepping (tp
));
2291 tp
->inf
->process_target ()->threads_executing
= true;
2294 /* FIXME: What should we do if we are supposed to resume this
2295 thread with a signal? Maybe we should maintain a queue of
2296 pending signals to deliver. */
2297 if (sig
!= GDB_SIGNAL_0
)
2299 warning (_("Couldn't deliver signal %s to %s."),
2300 gdb_signal_to_name (sig
),
2301 target_pid_to_str (tp
->ptid
).c_str ());
2304 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2306 if (target_can_async_p ())
2309 /* Tell the event loop we have an event to process. */
2310 mark_async_event_handler (infrun_async_inferior_event_token
);
2315 tp
->stepped_breakpoint
= 0;
2317 /* Depends on stepped_breakpoint. */
2318 step
= currently_stepping (tp
);
2320 if (current_inferior ()->waiting_for_vfork_done
)
2322 /* Don't try to single-step a vfork parent that is waiting for
2323 the child to get out of the shared memory region (by exec'ing
2324 or exiting). This is particularly important on software
2325 single-step archs, as the child process would trip on the
2326 software single step breakpoint inserted for the parent
2327 process. Since the parent will not actually execute any
2328 instruction until the child is out of the shared region (such
2329 are vfork's semantics), it is safe to simply continue it.
2330 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2331 the parent, and tell it to `keep_going', which automatically
2332 re-sets it stepping. */
2334 fprintf_unfiltered (gdb_stdlog
,
2335 "infrun: resume : clear step\n");
2340 fprintf_unfiltered (gdb_stdlog
,
2341 "infrun: resume (step=%d, signal=%s), "
2342 "trap_expected=%d, current thread [%s] at %s\n",
2343 step
, gdb_signal_to_symbol_string (sig
),
2344 tp
->control
.trap_expected
,
2345 target_pid_to_str (inferior_ptid
).c_str (),
2346 paddress (gdbarch
, pc
));
2348 /* Normally, by the time we reach `resume', the breakpoints are either
2349 removed or inserted, as appropriate. The exception is if we're sitting
2350 at a permanent breakpoint; we need to step over it, but permanent
2351 breakpoints can't be removed. So we have to test for it here. */
2352 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2354 if (sig
!= GDB_SIGNAL_0
)
2356 /* We have a signal to pass to the inferior. The resume
2357 may, or may not take us to the signal handler. If this
2358 is a step, we'll need to stop in the signal handler, if
2359 there's one, (if the target supports stepping into
2360 handlers), or in the next mainline instruction, if
2361 there's no handler. If this is a continue, we need to be
2362 sure to run the handler with all breakpoints inserted.
2363 In all cases, set a breakpoint at the current address
2364 (where the handler returns to), and once that breakpoint
2365 is hit, resume skipping the permanent breakpoint. If
2366 that breakpoint isn't hit, then we've stepped into the
2367 signal handler (or hit some other event). We'll delete
2368 the step-resume breakpoint then. */
2371 fprintf_unfiltered (gdb_stdlog
,
2372 "infrun: resume: skipping permanent breakpoint, "
2373 "deliver signal first\n");
2375 clear_step_over_info ();
2376 tp
->control
.trap_expected
= 0;
2378 if (tp
->control
.step_resume_breakpoint
== NULL
)
2380 /* Set a "high-priority" step-resume, as we don't want
2381 user breakpoints at PC to trigger (again) when this
2383 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2384 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2386 tp
->step_after_step_resume_breakpoint
= step
;
2389 insert_breakpoints ();
2393 /* There's no signal to pass, we can go ahead and skip the
2394 permanent breakpoint manually. */
2396 fprintf_unfiltered (gdb_stdlog
,
2397 "infrun: resume: skipping permanent breakpoint\n");
2398 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2399 /* Update pc to reflect the new address from which we will
2400 execute instructions. */
2401 pc
= regcache_read_pc (regcache
);
2405 /* We've already advanced the PC, so the stepping part
2406 is done. Now we need to arrange for a trap to be
2407 reported to handle_inferior_event. Set a breakpoint
2408 at the current PC, and run to it. Don't update
2409 prev_pc, because if we end in
2410 switch_back_to_stepped_thread, we want the "expected
2411 thread advanced also" branch to be taken. IOW, we
2412 don't want this thread to step further from PC
2414 gdb_assert (!step_over_info_valid_p ());
2415 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2416 insert_breakpoints ();
2418 resume_ptid
= internal_resume_ptid (user_step
);
2419 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2426 /* If we have a breakpoint to step over, make sure to do a single
2427 step only. Same if we have software watchpoints. */
2428 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2429 tp
->control
.may_range_step
= 0;
2431 /* If enabled, step over breakpoints by executing a copy of the
2432 instruction at a different address.
2434 We can't use displaced stepping when we have a signal to deliver;
2435 the comments for displaced_step_prepare explain why. The
2436 comments in the handle_inferior event for dealing with 'random
2437 signals' explain what we do instead.
2439 We can't use displaced stepping when we are waiting for vfork_done
2440 event, displaced stepping breaks the vfork child similarly as single
2441 step software breakpoint. */
2442 if (tp
->control
.trap_expected
2443 && use_displaced_stepping (tp
)
2444 && !step_over_info_valid_p ()
2445 && sig
== GDB_SIGNAL_0
2446 && !current_inferior ()->waiting_for_vfork_done
)
2448 int prepared
= displaced_step_prepare (tp
);
2453 fprintf_unfiltered (gdb_stdlog
,
2454 "Got placed in step-over queue\n");
2456 tp
->control
.trap_expected
= 0;
2459 else if (prepared
< 0)
2461 /* Fallback to stepping over the breakpoint in-line. */
2463 if (target_is_non_stop_p ())
2464 stop_all_threads ();
2466 set_step_over_info (regcache
->aspace (),
2467 regcache_read_pc (regcache
), 0, tp
->global_num
);
2469 step
= maybe_software_singlestep (gdbarch
, pc
);
2471 insert_breakpoints ();
2473 else if (prepared
> 0)
2475 struct displaced_step_inferior_state
*displaced
;
2477 /* Update pc to reflect the new address from which we will
2478 execute instructions due to displaced stepping. */
2479 pc
= regcache_read_pc (get_thread_regcache (tp
));
2481 displaced
= get_displaced_stepping_state (tp
->inf
);
2482 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2483 displaced
->step_closure
);
2487 /* Do we need to do it the hard way, w/temp breakpoints? */
2489 step
= maybe_software_singlestep (gdbarch
, pc
);
2491 /* Currently, our software single-step implementation leads to different
2492 results than hardware single-stepping in one situation: when stepping
2493 into delivering a signal which has an associated signal handler,
2494 hardware single-step will stop at the first instruction of the handler,
2495 while software single-step will simply skip execution of the handler.
2497 For now, this difference in behavior is accepted since there is no
2498 easy way to actually implement single-stepping into a signal handler
2499 without kernel support.
2501 However, there is one scenario where this difference leads to follow-on
2502 problems: if we're stepping off a breakpoint by removing all breakpoints
2503 and then single-stepping. In this case, the software single-step
2504 behavior means that even if there is a *breakpoint* in the signal
2505 handler, GDB still would not stop.
2507 Fortunately, we can at least fix this particular issue. We detect
2508 here the case where we are about to deliver a signal while software
2509 single-stepping with breakpoints removed. In this situation, we
2510 revert the decisions to remove all breakpoints and insert single-
2511 step breakpoints, and instead we install a step-resume breakpoint
2512 at the current address, deliver the signal without stepping, and
2513 once we arrive back at the step-resume breakpoint, actually step
2514 over the breakpoint we originally wanted to step over. */
2515 if (thread_has_single_step_breakpoints_set (tp
)
2516 && sig
!= GDB_SIGNAL_0
2517 && step_over_info_valid_p ())
2519 /* If we have nested signals or a pending signal is delivered
2520 immediately after a handler returns, might might already have
2521 a step-resume breakpoint set on the earlier handler. We cannot
2522 set another step-resume breakpoint; just continue on until the
2523 original breakpoint is hit. */
2524 if (tp
->control
.step_resume_breakpoint
== NULL
)
2526 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2527 tp
->step_after_step_resume_breakpoint
= 1;
2530 delete_single_step_breakpoints (tp
);
2532 clear_step_over_info ();
2533 tp
->control
.trap_expected
= 0;
2535 insert_breakpoints ();
2538 /* If STEP is set, it's a request to use hardware stepping
2539 facilities. But in that case, we should never
2540 use singlestep breakpoint. */
2541 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2543 /* Decide the set of threads to ask the target to resume. */
2544 if (tp
->control
.trap_expected
)
2546 /* We're allowing a thread to run past a breakpoint it has
2547 hit, either by single-stepping the thread with the breakpoint
2548 removed, or by displaced stepping, with the breakpoint inserted.
2549 In the former case, we need to single-step only this thread,
2550 and keep others stopped, as they can miss this breakpoint if
2551 allowed to run. That's not really a problem for displaced
2552 stepping, but, we still keep other threads stopped, in case
2553 another thread is also stopped for a breakpoint waiting for
2554 its turn in the displaced stepping queue. */
2555 resume_ptid
= inferior_ptid
;
2558 resume_ptid
= internal_resume_ptid (user_step
);
2560 if (execution_direction
!= EXEC_REVERSE
2561 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2563 /* There are two cases where we currently need to step a
2564 breakpoint instruction when we have a signal to deliver:
2566 - See handle_signal_stop where we handle random signals that
2567 could take out us out of the stepping range. Normally, in
2568 that case we end up continuing (instead of stepping) over the
2569 signal handler with a breakpoint at PC, but there are cases
2570 where we should _always_ single-step, even if we have a
2571 step-resume breakpoint, like when a software watchpoint is
2572 set. Assuming single-stepping and delivering a signal at the
2573 same time would takes us to the signal handler, then we could
2574 have removed the breakpoint at PC to step over it. However,
2575 some hardware step targets (like e.g., Mac OS) can't step
2576 into signal handlers, and for those, we need to leave the
2577 breakpoint at PC inserted, as otherwise if the handler
2578 recurses and executes PC again, it'll miss the breakpoint.
2579 So we leave the breakpoint inserted anyway, but we need to
2580 record that we tried to step a breakpoint instruction, so
2581 that adjust_pc_after_break doesn't end up confused.
2583 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2584 in one thread after another thread that was stepping had been
2585 momentarily paused for a step-over. When we re-resume the
2586 stepping thread, it may be resumed from that address with a
2587 breakpoint that hasn't trapped yet. Seen with
2588 gdb.threads/non-stop-fair-events.exp, on targets that don't
2589 do displaced stepping. */
2592 fprintf_unfiltered (gdb_stdlog
,
2593 "infrun: resume: [%s] stepped breakpoint\n",
2594 target_pid_to_str (tp
->ptid
).c_str ());
2596 tp
->stepped_breakpoint
= 1;
2598 /* Most targets can step a breakpoint instruction, thus
2599 executing it normally. But if this one cannot, just
2600 continue and we will hit it anyway. */
2601 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2606 && tp
->control
.trap_expected
2607 && use_displaced_stepping (tp
)
2608 && !step_over_info_valid_p ())
2610 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2611 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2612 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2615 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2616 paddress (resume_gdbarch
, actual_pc
));
2617 read_memory (actual_pc
, buf
, sizeof (buf
));
2618 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2621 if (tp
->control
.may_range_step
)
2623 /* If we're resuming a thread with the PC out of the step
2624 range, then we're doing some nested/finer run control
2625 operation, like stepping the thread out of the dynamic
2626 linker or the displaced stepping scratch pad. We
2627 shouldn't have allowed a range step then. */
2628 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2631 do_target_resume (resume_ptid
, step
, sig
);
2635 /* Resume the inferior. SIG is the signal to give the inferior
2636 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2637 rolls back state on error. */
2640 resume (gdb_signal sig
)
2646 catch (const gdb_exception
&ex
)
2648 /* If resuming is being aborted for any reason, delete any
2649 single-step breakpoint resume_1 may have created, to avoid
2650 confusing the following resumption, and to avoid leaving
2651 single-step breakpoints perturbing other threads, in case
2652 we're running in non-stop mode. */
2653 if (inferior_ptid
!= null_ptid
)
2654 delete_single_step_breakpoints (inferior_thread ());
2664 /* Counter that tracks number of user visible stops. This can be used
2665 to tell whether a command has proceeded the inferior past the
2666 current location. This allows e.g., inferior function calls in
2667 breakpoint commands to not interrupt the command list. When the
2668 call finishes successfully, the inferior is standing at the same
2669 breakpoint as if nothing happened (and so we don't call
2671 static ULONGEST current_stop_id
;
2678 return current_stop_id
;
2681 /* Called when we report a user visible stop. */
2689 /* Clear out all variables saying what to do when inferior is continued.
2690 First do this, then set the ones you want, then call `proceed'. */
2693 clear_proceed_status_thread (struct thread_info
*tp
)
2696 fprintf_unfiltered (gdb_stdlog
,
2697 "infrun: clear_proceed_status_thread (%s)\n",
2698 target_pid_to_str (tp
->ptid
).c_str ());
2700 /* If we're starting a new sequence, then the previous finished
2701 single-step is no longer relevant. */
2702 if (tp
->suspend
.waitstatus_pending_p
)
2704 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2707 fprintf_unfiltered (gdb_stdlog
,
2708 "infrun: clear_proceed_status: pending "
2709 "event of %s was a finished step. "
2711 target_pid_to_str (tp
->ptid
).c_str ());
2713 tp
->suspend
.waitstatus_pending_p
= 0;
2714 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2716 else if (debug_infrun
)
2719 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2721 fprintf_unfiltered (gdb_stdlog
,
2722 "infrun: clear_proceed_status_thread: thread %s "
2723 "has pending wait status %s "
2724 "(currently_stepping=%d).\n",
2725 target_pid_to_str (tp
->ptid
).c_str (),
2727 currently_stepping (tp
));
2731 /* If this signal should not be seen by program, give it zero.
2732 Used for debugging signals. */
2733 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2734 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2736 delete tp
->thread_fsm
;
2737 tp
->thread_fsm
= NULL
;
2739 tp
->control
.trap_expected
= 0;
2740 tp
->control
.step_range_start
= 0;
2741 tp
->control
.step_range_end
= 0;
2742 tp
->control
.may_range_step
= 0;
2743 tp
->control
.step_frame_id
= null_frame_id
;
2744 tp
->control
.step_stack_frame_id
= null_frame_id
;
2745 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2746 tp
->control
.step_start_function
= NULL
;
2747 tp
->stop_requested
= 0;
2749 tp
->control
.stop_step
= 0;
2751 tp
->control
.proceed_to_finish
= 0;
2753 tp
->control
.stepping_command
= 0;
2755 /* Discard any remaining commands or status from previous stop. */
2756 bpstat_clear (&tp
->control
.stop_bpstat
);
2760 clear_proceed_status (int step
)
2762 /* With scheduler-locking replay, stop replaying other threads if we're
2763 not replaying the user-visible resume ptid.
2765 This is a convenience feature to not require the user to explicitly
2766 stop replaying the other threads. We're assuming that the user's
2767 intent is to resume tracing the recorded process. */
2768 if (!non_stop
&& scheduler_mode
== schedlock_replay
2769 && target_record_is_replaying (minus_one_ptid
)
2770 && !target_record_will_replay (user_visible_resume_ptid (step
),
2771 execution_direction
))
2772 target_record_stop_replaying ();
2774 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2776 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2777 process_stratum_target
*resume_target
2778 = user_visible_resume_target (resume_ptid
);
2780 /* In all-stop mode, delete the per-thread status of all threads
2781 we're about to resume, implicitly and explicitly. */
2782 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2783 clear_proceed_status_thread (tp
);
2786 if (inferior_ptid
!= null_ptid
)
2788 struct inferior
*inferior
;
2792 /* If in non-stop mode, only delete the per-thread status of
2793 the current thread. */
2794 clear_proceed_status_thread (inferior_thread ());
2797 inferior
= current_inferior ();
2798 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2801 gdb::observers::about_to_proceed
.notify ();
2804 /* Returns true if TP is still stopped at a breakpoint that needs
2805 stepping-over in order to make progress. If the breakpoint is gone
2806 meanwhile, we can skip the whole step-over dance. */
2809 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2811 if (tp
->stepping_over_breakpoint
)
2813 struct regcache
*regcache
= get_thread_regcache (tp
);
2815 if (breakpoint_here_p (regcache
->aspace (),
2816 regcache_read_pc (regcache
))
2817 == ordinary_breakpoint_here
)
2820 tp
->stepping_over_breakpoint
= 0;
2826 /* Check whether thread TP still needs to start a step-over in order
2827 to make progress when resumed. Returns an bitwise or of enum
2828 step_over_what bits, indicating what needs to be stepped over. */
2830 static step_over_what
2831 thread_still_needs_step_over (struct thread_info
*tp
)
2833 step_over_what what
= 0;
2835 if (thread_still_needs_step_over_bp (tp
))
2836 what
|= STEP_OVER_BREAKPOINT
;
2838 if (tp
->stepping_over_watchpoint
2839 && !target_have_steppable_watchpoint
)
2840 what
|= STEP_OVER_WATCHPOINT
;
2845 /* Returns true if scheduler locking applies. STEP indicates whether
2846 we're about to do a step/next-like command to a thread. */
2849 schedlock_applies (struct thread_info
*tp
)
2851 return (scheduler_mode
== schedlock_on
2852 || (scheduler_mode
== schedlock_step
2853 && tp
->control
.stepping_command
)
2854 || (scheduler_mode
== schedlock_replay
2855 && target_record_will_replay (minus_one_ptid
,
2856 execution_direction
)));
2859 /* Calls target_commit_resume on all targets. */
2862 commit_resume_all_targets ()
2864 scoped_restore_current_thread restore_thread
;
2866 /* Map between process_target and a representative inferior. This
2867 is to avoid committing a resume in the same target more than
2868 once. Resumptions must be idempotent, so this is an
2870 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2872 for (inferior
*inf
: all_non_exited_inferiors ())
2873 if (inf
->has_execution ())
2874 conn_inf
[inf
->process_target ()] = inf
;
2876 for (const auto &ci
: conn_inf
)
2878 inferior
*inf
= ci
.second
;
2879 switch_to_inferior_no_thread (inf
);
2880 target_commit_resume ();
2884 /* Basic routine for continuing the program in various fashions.
2886 ADDR is the address to resume at, or -1 for resume where stopped.
2887 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2888 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2890 You should call clear_proceed_status before calling proceed. */
2893 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2895 struct regcache
*regcache
;
2896 struct gdbarch
*gdbarch
;
2898 struct execution_control_state ecss
;
2899 struct execution_control_state
*ecs
= &ecss
;
2902 /* If we're stopped at a fork/vfork, follow the branch set by the
2903 "set follow-fork-mode" command; otherwise, we'll just proceed
2904 resuming the current thread. */
2905 if (!follow_fork ())
2907 /* The target for some reason decided not to resume. */
2909 if (target_can_async_p ())
2910 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2914 /* We'll update this if & when we switch to a new thread. */
2915 previous_inferior_ptid
= inferior_ptid
;
2917 regcache
= get_current_regcache ();
2918 gdbarch
= regcache
->arch ();
2919 const address_space
*aspace
= regcache
->aspace ();
2921 pc
= regcache_read_pc (regcache
);
2922 thread_info
*cur_thr
= inferior_thread ();
2924 /* Fill in with reasonable starting values. */
2925 init_thread_stepping_state (cur_thr
);
2927 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2930 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2931 process_stratum_target
*resume_target
2932 = user_visible_resume_target (resume_ptid
);
2934 if (addr
== (CORE_ADDR
) -1)
2936 if (pc
== cur_thr
->suspend
.stop_pc
2937 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2938 && execution_direction
!= EXEC_REVERSE
)
2939 /* There is a breakpoint at the address we will resume at,
2940 step one instruction before inserting breakpoints so that
2941 we do not stop right away (and report a second hit at this
2944 Note, we don't do this in reverse, because we won't
2945 actually be executing the breakpoint insn anyway.
2946 We'll be (un-)executing the previous instruction. */
2947 cur_thr
->stepping_over_breakpoint
= 1;
2948 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2949 && gdbarch_single_step_through_delay (gdbarch
,
2950 get_current_frame ()))
2951 /* We stepped onto an instruction that needs to be stepped
2952 again before re-inserting the breakpoint, do so. */
2953 cur_thr
->stepping_over_breakpoint
= 1;
2957 regcache_write_pc (regcache
, addr
);
2960 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2961 cur_thr
->suspend
.stop_signal
= siggnal
;
2963 /* If an exception is thrown from this point on, make sure to
2964 propagate GDB's knowledge of the executing state to the
2965 frontend/user running state. */
2966 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2968 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2969 threads (e.g., we might need to set threads stepping over
2970 breakpoints first), from the user/frontend's point of view, all
2971 threads in RESUME_PTID are now running. Unless we're calling an
2972 inferior function, as in that case we pretend the inferior
2973 doesn't run at all. */
2974 if (!cur_thr
->control
.in_infcall
)
2975 set_running (resume_target
, resume_ptid
, 1);
2978 fprintf_unfiltered (gdb_stdlog
,
2979 "infrun: proceed (addr=%s, signal=%s)\n",
2980 paddress (gdbarch
, addr
),
2981 gdb_signal_to_symbol_string (siggnal
));
2983 annotate_starting ();
2985 /* Make sure that output from GDB appears before output from the
2987 gdb_flush (gdb_stdout
);
2989 /* Since we've marked the inferior running, give it the terminal. A
2990 QUIT/Ctrl-C from here on is forwarded to the target (which can
2991 still detect attempts to unblock a stuck connection with repeated
2992 Ctrl-C from within target_pass_ctrlc). */
2993 target_terminal::inferior ();
2995 /* In a multi-threaded task we may select another thread and
2996 then continue or step.
2998 But if a thread that we're resuming had stopped at a breakpoint,
2999 it will immediately cause another breakpoint stop without any
3000 execution (i.e. it will report a breakpoint hit incorrectly). So
3001 we must step over it first.
3003 Look for threads other than the current (TP) that reported a
3004 breakpoint hit and haven't been resumed yet since. */
3006 /* If scheduler locking applies, we can avoid iterating over all
3008 if (!non_stop
&& !schedlock_applies (cur_thr
))
3010 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3013 switch_to_thread_no_regs (tp
);
3015 /* Ignore the current thread here. It's handled
3020 if (!thread_still_needs_step_over (tp
))
3023 gdb_assert (!thread_is_in_step_over_chain (tp
));
3026 fprintf_unfiltered (gdb_stdlog
,
3027 "infrun: need to step-over [%s] first\n",
3028 target_pid_to_str (tp
->ptid
).c_str ());
3030 thread_step_over_chain_enqueue (tp
);
3033 switch_to_thread (cur_thr
);
3036 /* Enqueue the current thread last, so that we move all other
3037 threads over their breakpoints first. */
3038 if (cur_thr
->stepping_over_breakpoint
)
3039 thread_step_over_chain_enqueue (cur_thr
);
3041 /* If the thread isn't started, we'll still need to set its prev_pc,
3042 so that switch_back_to_stepped_thread knows the thread hasn't
3043 advanced. Must do this before resuming any thread, as in
3044 all-stop/remote, once we resume we can't send any other packet
3045 until the target stops again. */
3046 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
3049 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3051 started
= start_step_over ();
3053 if (step_over_info_valid_p ())
3055 /* Either this thread started a new in-line step over, or some
3056 other thread was already doing one. In either case, don't
3057 resume anything else until the step-over is finished. */
3059 else if (started
&& !target_is_non_stop_p ())
3061 /* A new displaced stepping sequence was started. In all-stop,
3062 we can't talk to the target anymore until it next stops. */
3064 else if (!non_stop
&& target_is_non_stop_p ())
3066 /* In all-stop, but the target is always in non-stop mode.
3067 Start all other threads that are implicitly resumed too. */
3068 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3071 switch_to_thread_no_regs (tp
);
3073 if (!tp
->inf
->has_execution ())
3076 fprintf_unfiltered (gdb_stdlog
,
3077 "infrun: proceed: [%s] target has "
3079 target_pid_to_str (tp
->ptid
).c_str ());
3086 fprintf_unfiltered (gdb_stdlog
,
3087 "infrun: proceed: [%s] resumed\n",
3088 target_pid_to_str (tp
->ptid
).c_str ());
3089 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3093 if (thread_is_in_step_over_chain (tp
))
3096 fprintf_unfiltered (gdb_stdlog
,
3097 "infrun: proceed: [%s] needs step-over\n",
3098 target_pid_to_str (tp
->ptid
).c_str ());
3103 fprintf_unfiltered (gdb_stdlog
,
3104 "infrun: proceed: resuming %s\n",
3105 target_pid_to_str (tp
->ptid
).c_str ());
3107 reset_ecs (ecs
, tp
);
3108 switch_to_thread (tp
);
3109 keep_going_pass_signal (ecs
);
3110 if (!ecs
->wait_some_more
)
3111 error (_("Command aborted."));
3114 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3116 /* The thread wasn't started, and isn't queued, run it now. */
3117 reset_ecs (ecs
, cur_thr
);
3118 switch_to_thread (cur_thr
);
3119 keep_going_pass_signal (ecs
);
3120 if (!ecs
->wait_some_more
)
3121 error (_("Command aborted."));
3125 commit_resume_all_targets ();
3127 finish_state
.release ();
3129 /* If we've switched threads above, switch back to the previously
3130 current thread. We don't want the user to see a different
3132 switch_to_thread (cur_thr
);
3134 /* Tell the event loop to wait for it to stop. If the target
3135 supports asynchronous execution, it'll do this from within
3137 if (!target_can_async_p ())
3138 mark_async_event_handler (infrun_async_inferior_event_token
);
3142 /* Start remote-debugging of a machine over a serial link. */
3145 start_remote (int from_tty
)
3147 inferior
*inf
= current_inferior ();
3148 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3150 /* Always go on waiting for the target, regardless of the mode. */
3151 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3152 indicate to wait_for_inferior that a target should timeout if
3153 nothing is returned (instead of just blocking). Because of this,
3154 targets expecting an immediate response need to, internally, set
3155 things up so that the target_wait() is forced to eventually
3157 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3158 differentiate to its caller what the state of the target is after
3159 the initial open has been performed. Here we're assuming that
3160 the target has stopped. It should be possible to eventually have
3161 target_open() return to the caller an indication that the target
3162 is currently running and GDB state should be set to the same as
3163 for an async run. */
3164 wait_for_inferior (inf
);
3166 /* Now that the inferior has stopped, do any bookkeeping like
3167 loading shared libraries. We want to do this before normal_stop,
3168 so that the displayed frame is up to date. */
3169 post_create_inferior (current_top_target (), from_tty
);
3174 /* Initialize static vars when a new inferior begins. */
3177 init_wait_for_inferior (void)
3179 /* These are meaningless until the first time through wait_for_inferior. */
3181 breakpoint_init_inferior (inf_starting
);
3183 clear_proceed_status (0);
3185 nullify_last_target_wait_ptid ();
3187 previous_inferior_ptid
= inferior_ptid
;
3192 static void handle_inferior_event (struct execution_control_state
*ecs
);
3194 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3195 struct execution_control_state
*ecs
);
3196 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3197 struct execution_control_state
*ecs
);
3198 static void handle_signal_stop (struct execution_control_state
*ecs
);
3199 static void check_exception_resume (struct execution_control_state
*,
3200 struct frame_info
*);
3202 static void end_stepping_range (struct execution_control_state
*ecs
);
3203 static void stop_waiting (struct execution_control_state
*ecs
);
3204 static void keep_going (struct execution_control_state
*ecs
);
3205 static void process_event_stop_test (struct execution_control_state
*ecs
);
3206 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3208 /* This function is attached as a "thread_stop_requested" observer.
3209 Cleanup local state that assumed the PTID was to be resumed, and
3210 report the stop to the frontend. */
3213 infrun_thread_stop_requested (ptid_t ptid
)
3215 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3217 /* PTID was requested to stop. If the thread was already stopped,
3218 but the user/frontend doesn't know about that yet (e.g., the
3219 thread had been temporarily paused for some step-over), set up
3220 for reporting the stop now. */
3221 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3223 if (tp
->state
!= THREAD_RUNNING
)
3228 /* Remove matching threads from the step-over queue, so
3229 start_step_over doesn't try to resume them
3231 if (thread_is_in_step_over_chain (tp
))
3232 thread_step_over_chain_remove (tp
);
3234 /* If the thread is stopped, but the user/frontend doesn't
3235 know about that yet, queue a pending event, as if the
3236 thread had just stopped now. Unless the thread already had
3238 if (!tp
->suspend
.waitstatus_pending_p
)
3240 tp
->suspend
.waitstatus_pending_p
= 1;
3241 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3242 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3245 /* Clear the inline-frame state, since we're re-processing the
3247 clear_inline_frame_state (tp
);
3249 /* If this thread was paused because some other thread was
3250 doing an inline-step over, let that finish first. Once
3251 that happens, we'll restart all threads and consume pending
3252 stop events then. */
3253 if (step_over_info_valid_p ())
3256 /* Otherwise we can process the (new) pending event now. Set
3257 it so this pending event is considered by
3264 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3266 if (target_last_proc_target
== tp
->inf
->process_target ()
3267 && target_last_wait_ptid
== tp
->ptid
)
3268 nullify_last_target_wait_ptid ();
3271 /* Delete the step resume, single-step and longjmp/exception resume
3272 breakpoints of TP. */
3275 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3277 delete_step_resume_breakpoint (tp
);
3278 delete_exception_resume_breakpoint (tp
);
3279 delete_single_step_breakpoints (tp
);
3282 /* If the target still has execution, call FUNC for each thread that
3283 just stopped. In all-stop, that's all the non-exited threads; in
3284 non-stop, that's the current thread, only. */
3286 typedef void (*for_each_just_stopped_thread_callback_func
)
3287 (struct thread_info
*tp
);
3290 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3292 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3295 if (target_is_non_stop_p ())
3297 /* If in non-stop mode, only the current thread stopped. */
3298 func (inferior_thread ());
3302 /* In all-stop mode, all threads have stopped. */
3303 for (thread_info
*tp
: all_non_exited_threads ())
3308 /* Delete the step resume and longjmp/exception resume breakpoints of
3309 the threads that just stopped. */
3312 delete_just_stopped_threads_infrun_breakpoints (void)
3314 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3317 /* Delete the single-step breakpoints of the threads that just
3321 delete_just_stopped_threads_single_step_breakpoints (void)
3323 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3329 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3330 const struct target_waitstatus
*ws
)
3332 std::string status_string
= target_waitstatus_to_string (ws
);
3335 /* The text is split over several lines because it was getting too long.
3336 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3337 output as a unit; we want only one timestamp printed if debug_timestamp
3340 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3343 waiton_ptid
.tid ());
3344 if (waiton_ptid
.pid () != -1)
3345 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3346 stb
.printf (", status) =\n");
3347 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3351 target_pid_to_str (result_ptid
).c_str ());
3352 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3354 /* This uses %s in part to handle %'s in the text, but also to avoid
3355 a gcc error: the format attribute requires a string literal. */
3356 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3359 /* Select a thread at random, out of those which are resumed and have
3362 static struct thread_info
*
3363 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3367 auto has_event
= [&] (thread_info
*tp
)
3369 return (tp
->ptid
.matches (waiton_ptid
)
3371 && tp
->suspend
.waitstatus_pending_p
);
3374 /* First see how many events we have. Count only resumed threads
3375 that have an event pending. */
3376 for (thread_info
*tp
: inf
->non_exited_threads ())
3380 if (num_events
== 0)
3383 /* Now randomly pick a thread out of those that have had events. */
3384 int random_selector
= (int) ((num_events
* (double) rand ())
3385 / (RAND_MAX
+ 1.0));
3387 if (debug_infrun
&& num_events
> 1)
3388 fprintf_unfiltered (gdb_stdlog
,
3389 "infrun: Found %d events, selecting #%d\n",
3390 num_events
, random_selector
);
3392 /* Select the Nth thread that has had an event. */
3393 for (thread_info
*tp
: inf
->non_exited_threads ())
3395 if (random_selector
-- == 0)
3398 gdb_assert_not_reached ("event thread not found");
3401 /* Wrapper for target_wait that first checks whether threads have
3402 pending statuses to report before actually asking the target for
3403 more events. INF is the inferior we're using to call target_wait
3407 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3408 target_waitstatus
*status
, int options
)
3411 struct thread_info
*tp
;
3413 /* First check if there is a resumed thread with a wait status
3415 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3417 tp
= random_pending_event_thread (inf
, ptid
);
3422 fprintf_unfiltered (gdb_stdlog
,
3423 "infrun: Waiting for specific thread %s.\n",
3424 target_pid_to_str (ptid
).c_str ());
3426 /* We have a specific thread to check. */
3427 tp
= find_thread_ptid (inf
, ptid
);
3428 gdb_assert (tp
!= NULL
);
3429 if (!tp
->suspend
.waitstatus_pending_p
)
3434 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3435 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3437 struct regcache
*regcache
= get_thread_regcache (tp
);
3438 struct gdbarch
*gdbarch
= regcache
->arch ();
3442 pc
= regcache_read_pc (regcache
);
3444 if (pc
!= tp
->suspend
.stop_pc
)
3447 fprintf_unfiltered (gdb_stdlog
,
3448 "infrun: PC of %s changed. was=%s, now=%s\n",
3449 target_pid_to_str (tp
->ptid
).c_str (),
3450 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3451 paddress (gdbarch
, pc
));
3454 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3457 fprintf_unfiltered (gdb_stdlog
,
3458 "infrun: previous breakpoint of %s, at %s gone\n",
3459 target_pid_to_str (tp
->ptid
).c_str (),
3460 paddress (gdbarch
, pc
));
3468 fprintf_unfiltered (gdb_stdlog
,
3469 "infrun: pending event of %s cancelled.\n",
3470 target_pid_to_str (tp
->ptid
).c_str ());
3472 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3473 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3482 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3484 fprintf_unfiltered (gdb_stdlog
,
3485 "infrun: Using pending wait status %s for %s.\n",
3487 target_pid_to_str (tp
->ptid
).c_str ());
3490 /* Now that we've selected our final event LWP, un-adjust its PC
3491 if it was a software breakpoint (and the target doesn't
3492 always adjust the PC itself). */
3493 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3494 && !target_supports_stopped_by_sw_breakpoint ())
3496 struct regcache
*regcache
;
3497 struct gdbarch
*gdbarch
;
3500 regcache
= get_thread_regcache (tp
);
3501 gdbarch
= regcache
->arch ();
3503 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3508 pc
= regcache_read_pc (regcache
);
3509 regcache_write_pc (regcache
, pc
+ decr_pc
);
3513 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3514 *status
= tp
->suspend
.waitstatus
;
3515 tp
->suspend
.waitstatus_pending_p
= 0;
3517 /* Wake up the event loop again, until all pending events are
3519 if (target_is_async_p ())
3520 mark_async_event_handler (infrun_async_inferior_event_token
);
3524 /* But if we don't find one, we'll have to wait. */
3526 if (deprecated_target_wait_hook
)
3527 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3529 event_ptid
= target_wait (ptid
, status
, options
);
3534 /* Returns true if INF has any resumed thread with a status
3538 threads_are_resumed_pending_p (inferior
*inf
)
3540 for (thread_info
*tp
: inf
->non_exited_threads ())
3542 && tp
->suspend
.waitstatus_pending_p
)
3548 /* Wrapper for target_wait that first checks whether threads have
3549 pending statuses to report before actually asking the target for
3550 more events. Polls for events from all inferiors/targets. */
3553 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3555 int num_inferiors
= 0;
3556 int random_selector
;
3558 /* For fairness, we pick the first inferior/target to poll at
3559 random, and then continue polling the rest of the inferior list
3560 starting from that one in a circular fashion until the whole list
3563 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3565 return (inf
->process_target () != NULL
3566 && (threads_are_executing (inf
->process_target ())
3567 || threads_are_resumed_pending_p (inf
))
3568 && ptid_t (inf
->pid
).matches (wait_ptid
));
3571 /* First see how many resumed inferiors we have. */
3572 for (inferior
*inf
: all_inferiors ())
3573 if (inferior_matches (inf
))
3576 if (num_inferiors
== 0)
3578 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3582 /* Now randomly pick an inferior out of those that were resumed. */
3583 random_selector
= (int)
3584 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3586 if (debug_infrun
&& num_inferiors
> 1)
3587 fprintf_unfiltered (gdb_stdlog
,
3588 "infrun: Found %d inferiors, starting at #%d\n",
3589 num_inferiors
, random_selector
);
3591 /* Select the Nth inferior that was resumed. */
3593 inferior
*selected
= nullptr;
3595 for (inferior
*inf
: all_inferiors ())
3596 if (inferior_matches (inf
))
3597 if (random_selector
-- == 0)
3603 /* Now poll for events out of each of the resumed inferior's
3604 targets, starting from the selected one. */
3606 auto do_wait
= [&] (inferior
*inf
)
3608 switch_to_inferior_no_thread (inf
);
3610 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3611 ecs
->target
= inf
->process_target ();
3612 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3615 /* Needed in all-stop+target-non-stop mode, because we end up here
3616 spuriously after the target is all stopped and we've already
3617 reported the stop to the user, polling for events. */
3618 scoped_restore_current_thread restore_thread
;
3620 int inf_num
= selected
->num
;
3621 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3622 if (inferior_matches (inf
))
3626 for (inferior
*inf
= inferior_list
;
3627 inf
!= NULL
&& inf
->num
< inf_num
;
3629 if (inferior_matches (inf
))
3633 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3637 /* Prepare and stabilize the inferior for detaching it. E.g.,
3638 detaching while a thread is displaced stepping is a recipe for
3639 crashing it, as nothing would readjust the PC out of the scratch
3643 prepare_for_detach (void)
3645 struct inferior
*inf
= current_inferior ();
3646 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3648 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3650 /* Is any thread of this process displaced stepping? If not,
3651 there's nothing else to do. */
3652 if (displaced
->step_thread
== nullptr)
3656 fprintf_unfiltered (gdb_stdlog
,
3657 "displaced-stepping in-process while detaching");
3659 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3661 while (displaced
->step_thread
!= nullptr)
3663 struct execution_control_state ecss
;
3664 struct execution_control_state
*ecs
;
3667 memset (ecs
, 0, sizeof (*ecs
));
3669 overlay_cache_invalid
= 1;
3670 /* Flush target cache before starting to handle each event.
3671 Target was running and cache could be stale. This is just a
3672 heuristic. Running threads may modify target memory, but we
3673 don't get any event. */
3674 target_dcache_invalidate ();
3676 do_target_wait (pid_ptid
, ecs
, 0);
3679 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3681 /* If an error happens while handling the event, propagate GDB's
3682 knowledge of the executing state to the frontend/user running
3684 scoped_finish_thread_state
finish_state (inf
->process_target (),
3687 /* Now figure out what to do with the result of the result. */
3688 handle_inferior_event (ecs
);
3690 /* No error, don't finish the state yet. */
3691 finish_state
.release ();
3693 /* Breakpoints and watchpoints are not installed on the target
3694 at this point, and signals are passed directly to the
3695 inferior, so this must mean the process is gone. */
3696 if (!ecs
->wait_some_more
)
3698 restore_detaching
.release ();
3699 error (_("Program exited while detaching"));
3703 restore_detaching
.release ();
3706 /* Wait for control to return from inferior to debugger.
3708 If inferior gets a signal, we may decide to start it up again
3709 instead of returning. That is why there is a loop in this function.
3710 When this function actually returns it means the inferior
3711 should be left stopped and GDB should read more commands. */
3714 wait_for_inferior (inferior
*inf
)
3718 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3720 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3722 /* If an error happens while handling the event, propagate GDB's
3723 knowledge of the executing state to the frontend/user running
3725 scoped_finish_thread_state finish_state
3726 (inf
->process_target (), minus_one_ptid
);
3730 struct execution_control_state ecss
;
3731 struct execution_control_state
*ecs
= &ecss
;
3733 memset (ecs
, 0, sizeof (*ecs
));
3735 overlay_cache_invalid
= 1;
3737 /* Flush target cache before starting to handle each event.
3738 Target was running and cache could be stale. This is just a
3739 heuristic. Running threads may modify target memory, but we
3740 don't get any event. */
3741 target_dcache_invalidate ();
3743 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3744 ecs
->target
= inf
->process_target ();
3747 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3749 /* Now figure out what to do with the result of the result. */
3750 handle_inferior_event (ecs
);
3752 if (!ecs
->wait_some_more
)
3756 /* No error, don't finish the state yet. */
3757 finish_state
.release ();
3760 /* Cleanup that reinstalls the readline callback handler, if the
3761 target is running in the background. If while handling the target
3762 event something triggered a secondary prompt, like e.g., a
3763 pagination prompt, we'll have removed the callback handler (see
3764 gdb_readline_wrapper_line). Need to do this as we go back to the
3765 event loop, ready to process further input. Note this has no
3766 effect if the handler hasn't actually been removed, because calling
3767 rl_callback_handler_install resets the line buffer, thus losing
3771 reinstall_readline_callback_handler_cleanup ()
3773 struct ui
*ui
= current_ui
;
3777 /* We're not going back to the top level event loop yet. Don't
3778 install the readline callback, as it'd prep the terminal,
3779 readline-style (raw, noecho) (e.g., --batch). We'll install
3780 it the next time the prompt is displayed, when we're ready
3785 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3786 gdb_rl_callback_handler_reinstall ();
3789 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3790 that's just the event thread. In all-stop, that's all threads. */
3793 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3795 if (ecs
->event_thread
!= NULL
3796 && ecs
->event_thread
->thread_fsm
!= NULL
)
3797 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3801 for (thread_info
*thr
: all_non_exited_threads ())
3803 if (thr
->thread_fsm
== NULL
)
3805 if (thr
== ecs
->event_thread
)
3808 switch_to_thread (thr
);
3809 thr
->thread_fsm
->clean_up (thr
);
3812 if (ecs
->event_thread
!= NULL
)
3813 switch_to_thread (ecs
->event_thread
);
3817 /* Helper for all_uis_check_sync_execution_done that works on the
3821 check_curr_ui_sync_execution_done (void)
3823 struct ui
*ui
= current_ui
;
3825 if (ui
->prompt_state
== PROMPT_NEEDED
3827 && !gdb_in_secondary_prompt_p (ui
))
3829 target_terminal::ours ();
3830 gdb::observers::sync_execution_done
.notify ();
3831 ui_register_input_event_handler (ui
);
3838 all_uis_check_sync_execution_done (void)
3840 SWITCH_THRU_ALL_UIS ()
3842 check_curr_ui_sync_execution_done ();
3849 all_uis_on_sync_execution_starting (void)
3851 SWITCH_THRU_ALL_UIS ()
3853 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3854 async_disable_stdin ();
3858 /* Asynchronous version of wait_for_inferior. It is called by the
3859 event loop whenever a change of state is detected on the file
3860 descriptor corresponding to the target. It can be called more than
3861 once to complete a single execution command. In such cases we need
3862 to keep the state in a global variable ECSS. If it is the last time
3863 that this function is called for a single execution command, then
3864 report to the user that the inferior has stopped, and do the
3865 necessary cleanups. */
3868 fetch_inferior_event (void *client_data
)
3870 struct execution_control_state ecss
;
3871 struct execution_control_state
*ecs
= &ecss
;
3874 memset (ecs
, 0, sizeof (*ecs
));
3876 /* Events are always processed with the main UI as current UI. This
3877 way, warnings, debug output, etc. are always consistently sent to
3878 the main console. */
3879 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3881 /* End up with readline processing input, if necessary. */
3883 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3885 /* We're handling a live event, so make sure we're doing live
3886 debugging. If we're looking at traceframes while the target is
3887 running, we're going to need to get back to that mode after
3888 handling the event. */
3889 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3892 maybe_restore_traceframe
.emplace ();
3893 set_current_traceframe (-1);
3896 /* The user/frontend should not notice a thread switch due to
3897 internal events. Make sure we revert to the user selected
3898 thread and frame after handling the event and running any
3899 breakpoint commands. */
3900 scoped_restore_current_thread restore_thread
;
3902 overlay_cache_invalid
= 1;
3903 /* Flush target cache before starting to handle each event. Target
3904 was running and cache could be stale. This is just a heuristic.
3905 Running threads may modify target memory, but we don't get any
3907 target_dcache_invalidate ();
3909 scoped_restore save_exec_dir
3910 = make_scoped_restore (&execution_direction
,
3911 target_execution_direction ());
3913 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3916 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3918 /* Switch to the target that generated the event, so we can do
3919 target calls. Any inferior bound to the target will do, so we
3920 just switch to the first we find. */
3921 for (inferior
*inf
: all_inferiors (ecs
->target
))
3923 switch_to_inferior_no_thread (inf
);
3928 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3930 /* If an error happens while handling the event, propagate GDB's
3931 knowledge of the executing state to the frontend/user running
3933 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3934 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3936 /* Get executed before scoped_restore_current_thread above to apply
3937 still for the thread which has thrown the exception. */
3938 auto defer_bpstat_clear
3939 = make_scope_exit (bpstat_clear_actions
);
3940 auto defer_delete_threads
3941 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3943 /* Now figure out what to do with the result of the result. */
3944 handle_inferior_event (ecs
);
3946 if (!ecs
->wait_some_more
)
3948 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3949 int should_stop
= 1;
3950 struct thread_info
*thr
= ecs
->event_thread
;
3952 delete_just_stopped_threads_infrun_breakpoints ();
3956 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3958 if (thread_fsm
!= NULL
)
3959 should_stop
= thread_fsm
->should_stop (thr
);
3968 bool should_notify_stop
= true;
3971 clean_up_just_stopped_threads_fsms (ecs
);
3973 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3974 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3976 if (should_notify_stop
)
3978 /* We may not find an inferior if this was a process exit. */
3979 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3980 proceeded
= normal_stop ();
3985 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3989 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3990 previously selected thread is gone. We have two
3991 choices - switch to no thread selected, or restore the
3992 previously selected thread (now exited). We chose the
3993 later, just because that's what GDB used to do. After
3994 this, "info threads" says "The current thread <Thread
3995 ID 2> has terminated." instead of "No thread
3999 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4000 restore_thread
.dont_restore ();
4004 defer_delete_threads
.release ();
4005 defer_bpstat_clear
.release ();
4007 /* No error, don't finish the thread states yet. */
4008 finish_state
.release ();
4010 /* This scope is used to ensure that readline callbacks are
4011 reinstalled here. */
4014 /* If a UI was in sync execution mode, and now isn't, restore its
4015 prompt (a synchronous execution command has finished, and we're
4016 ready for input). */
4017 all_uis_check_sync_execution_done ();
4020 && exec_done_display_p
4021 && (inferior_ptid
== null_ptid
4022 || inferior_thread ()->state
!= THREAD_RUNNING
))
4023 printf_unfiltered (_("completed.\n"));
4026 /* Record the frame and location we're currently stepping through. */
4028 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
4030 struct thread_info
*tp
= inferior_thread ();
4032 tp
->control
.step_frame_id
= get_frame_id (frame
);
4033 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4035 tp
->current_symtab
= sal
.symtab
;
4036 tp
->current_line
= sal
.line
;
4039 /* Clear context switchable stepping state. */
4042 init_thread_stepping_state (struct thread_info
*tss
)
4044 tss
->stepped_breakpoint
= 0;
4045 tss
->stepping_over_breakpoint
= 0;
4046 tss
->stepping_over_watchpoint
= 0;
4047 tss
->step_after_step_resume_breakpoint
= 0;
4053 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4054 target_waitstatus status
)
4056 target_last_proc_target
= target
;
4057 target_last_wait_ptid
= ptid
;
4058 target_last_waitstatus
= status
;
4064 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4065 target_waitstatus
*status
)
4067 if (target
!= nullptr)
4068 *target
= target_last_proc_target
;
4069 if (ptid
!= nullptr)
4070 *ptid
= target_last_wait_ptid
;
4071 if (status
!= nullptr)
4072 *status
= target_last_waitstatus
;
4078 nullify_last_target_wait_ptid (void)
4080 target_last_proc_target
= nullptr;
4081 target_last_wait_ptid
= minus_one_ptid
;
4082 target_last_waitstatus
= {};
4085 /* Switch thread contexts. */
4088 context_switch (execution_control_state
*ecs
)
4091 && ecs
->ptid
!= inferior_ptid
4092 && (inferior_ptid
== null_ptid
4093 || ecs
->event_thread
!= inferior_thread ()))
4095 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4096 target_pid_to_str (inferior_ptid
).c_str ());
4097 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4098 target_pid_to_str (ecs
->ptid
).c_str ());
4101 switch_to_thread (ecs
->event_thread
);
4104 /* If the target can't tell whether we've hit breakpoints
4105 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4106 check whether that could have been caused by a breakpoint. If so,
4107 adjust the PC, per gdbarch_decr_pc_after_break. */
4110 adjust_pc_after_break (struct thread_info
*thread
,
4111 struct target_waitstatus
*ws
)
4113 struct regcache
*regcache
;
4114 struct gdbarch
*gdbarch
;
4115 CORE_ADDR breakpoint_pc
, decr_pc
;
4117 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4118 we aren't, just return.
4120 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4121 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4122 implemented by software breakpoints should be handled through the normal
4125 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4126 different signals (SIGILL or SIGEMT for instance), but it is less
4127 clear where the PC is pointing afterwards. It may not match
4128 gdbarch_decr_pc_after_break. I don't know any specific target that
4129 generates these signals at breakpoints (the code has been in GDB since at
4130 least 1992) so I can not guess how to handle them here.
4132 In earlier versions of GDB, a target with
4133 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4134 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4135 target with both of these set in GDB history, and it seems unlikely to be
4136 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4138 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4141 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4144 /* In reverse execution, when a breakpoint is hit, the instruction
4145 under it has already been de-executed. The reported PC always
4146 points at the breakpoint address, so adjusting it further would
4147 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4150 B1 0x08000000 : INSN1
4151 B2 0x08000001 : INSN2
4153 PC -> 0x08000003 : INSN4
4155 Say you're stopped at 0x08000003 as above. Reverse continuing
4156 from that point should hit B2 as below. Reading the PC when the
4157 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4158 been de-executed already.
4160 B1 0x08000000 : INSN1
4161 B2 PC -> 0x08000001 : INSN2
4165 We can't apply the same logic as for forward execution, because
4166 we would wrongly adjust the PC to 0x08000000, since there's a
4167 breakpoint at PC - 1. We'd then report a hit on B1, although
4168 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4170 if (execution_direction
== EXEC_REVERSE
)
4173 /* If the target can tell whether the thread hit a SW breakpoint,
4174 trust it. Targets that can tell also adjust the PC
4176 if (target_supports_stopped_by_sw_breakpoint ())
4179 /* Note that relying on whether a breakpoint is planted in memory to
4180 determine this can fail. E.g,. the breakpoint could have been
4181 removed since. Or the thread could have been told to step an
4182 instruction the size of a breakpoint instruction, and only
4183 _after_ was a breakpoint inserted at its address. */
4185 /* If this target does not decrement the PC after breakpoints, then
4186 we have nothing to do. */
4187 regcache
= get_thread_regcache (thread
);
4188 gdbarch
= regcache
->arch ();
4190 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4194 const address_space
*aspace
= regcache
->aspace ();
4196 /* Find the location where (if we've hit a breakpoint) the
4197 breakpoint would be. */
4198 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4200 /* If the target can't tell whether a software breakpoint triggered,
4201 fallback to figuring it out based on breakpoints we think were
4202 inserted in the target, and on whether the thread was stepped or
4205 /* Check whether there actually is a software breakpoint inserted at
4208 If in non-stop mode, a race condition is possible where we've
4209 removed a breakpoint, but stop events for that breakpoint were
4210 already queued and arrive later. To suppress those spurious
4211 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4212 and retire them after a number of stop events are reported. Note
4213 this is an heuristic and can thus get confused. The real fix is
4214 to get the "stopped by SW BP and needs adjustment" info out of
4215 the target/kernel (and thus never reach here; see above). */
4216 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4217 || (target_is_non_stop_p ()
4218 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4220 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4222 if (record_full_is_used ())
4223 restore_operation_disable
.emplace
4224 (record_full_gdb_operation_disable_set ());
4226 /* When using hardware single-step, a SIGTRAP is reported for both
4227 a completed single-step and a software breakpoint. Need to
4228 differentiate between the two, as the latter needs adjusting
4229 but the former does not.
4231 The SIGTRAP can be due to a completed hardware single-step only if
4232 - we didn't insert software single-step breakpoints
4233 - this thread is currently being stepped
4235 If any of these events did not occur, we must have stopped due
4236 to hitting a software breakpoint, and have to back up to the
4239 As a special case, we could have hardware single-stepped a
4240 software breakpoint. In this case (prev_pc == breakpoint_pc),
4241 we also need to back up to the breakpoint address. */
4243 if (thread_has_single_step_breakpoints_set (thread
)
4244 || !currently_stepping (thread
)
4245 || (thread
->stepped_breakpoint
4246 && thread
->prev_pc
== breakpoint_pc
))
4247 regcache_write_pc (regcache
, breakpoint_pc
);
4252 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4254 for (frame
= get_prev_frame (frame
);
4256 frame
= get_prev_frame (frame
))
4258 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4260 if (get_frame_type (frame
) != INLINE_FRAME
)
4267 /* Look for an inline frame that is marked for skip.
4268 If PREV_FRAME is TRUE start at the previous frame,
4269 otherwise start at the current frame. Stop at the
4270 first non-inline frame, or at the frame where the
4274 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4276 struct frame_info
*frame
= get_current_frame ();
4279 frame
= get_prev_frame (frame
);
4281 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4283 const char *fn
= NULL
;
4284 symtab_and_line sal
;
4287 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4289 if (get_frame_type (frame
) != INLINE_FRAME
)
4292 sal
= find_frame_sal (frame
);
4293 sym
= get_frame_function (frame
);
4296 fn
= sym
->print_name ();
4299 && function_name_is_marked_for_skip (fn
, sal
))
4306 /* If the event thread has the stop requested flag set, pretend it
4307 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4311 handle_stop_requested (struct execution_control_state
*ecs
)
4313 if (ecs
->event_thread
->stop_requested
)
4315 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4316 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4317 handle_signal_stop (ecs
);
4323 /* Auxiliary function that handles syscall entry/return events.
4324 It returns 1 if the inferior should keep going (and GDB
4325 should ignore the event), or 0 if the event deserves to be
4329 handle_syscall_event (struct execution_control_state
*ecs
)
4331 struct regcache
*regcache
;
4334 context_switch (ecs
);
4336 regcache
= get_thread_regcache (ecs
->event_thread
);
4337 syscall_number
= ecs
->ws
.value
.syscall_number
;
4338 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4340 if (catch_syscall_enabled () > 0
4341 && catching_syscall_number (syscall_number
) > 0)
4344 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4347 ecs
->event_thread
->control
.stop_bpstat
4348 = bpstat_stop_status (regcache
->aspace (),
4349 ecs
->event_thread
->suspend
.stop_pc
,
4350 ecs
->event_thread
, &ecs
->ws
);
4352 if (handle_stop_requested (ecs
))
4355 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4357 /* Catchpoint hit. */
4362 if (handle_stop_requested (ecs
))
4365 /* If no catchpoint triggered for this, then keep going. */
4370 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4373 fill_in_stop_func (struct gdbarch
*gdbarch
,
4374 struct execution_control_state
*ecs
)
4376 if (!ecs
->stop_func_filled_in
)
4380 /* Don't care about return value; stop_func_start and stop_func_name
4381 will both be 0 if it doesn't work. */
4382 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4383 &ecs
->stop_func_name
,
4384 &ecs
->stop_func_start
,
4385 &ecs
->stop_func_end
,
4388 /* The call to find_pc_partial_function, above, will set
4389 stop_func_start and stop_func_end to the start and end
4390 of the range containing the stop pc. If this range
4391 contains the entry pc for the block (which is always the
4392 case for contiguous blocks), advance stop_func_start past
4393 the function's start offset and entrypoint. Note that
4394 stop_func_start is NOT advanced when in a range of a
4395 non-contiguous block that does not contain the entry pc. */
4396 if (block
!= nullptr
4397 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4398 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4400 ecs
->stop_func_start
4401 += gdbarch_deprecated_function_start_offset (gdbarch
);
4403 if (gdbarch_skip_entrypoint_p (gdbarch
))
4404 ecs
->stop_func_start
4405 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4408 ecs
->stop_func_filled_in
= 1;
4413 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4415 static enum stop_kind
4416 get_inferior_stop_soon (execution_control_state
*ecs
)
4418 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4420 gdb_assert (inf
!= NULL
);
4421 return inf
->control
.stop_soon
;
4424 /* Poll for one event out of the current target. Store the resulting
4425 waitstatus in WS, and return the event ptid. Does not block. */
4428 poll_one_curr_target (struct target_waitstatus
*ws
)
4432 overlay_cache_invalid
= 1;
4434 /* Flush target cache before starting to handle each event.
4435 Target was running and cache could be stale. This is just a
4436 heuristic. Running threads may modify target memory, but we
4437 don't get any event. */
4438 target_dcache_invalidate ();
4440 if (deprecated_target_wait_hook
)
4441 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4443 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4446 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4451 /* An event reported by wait_one. */
4453 struct wait_one_event
4455 /* The target the event came out of. */
4456 process_stratum_target
*target
;
4458 /* The PTID the event was for. */
4461 /* The waitstatus. */
4462 target_waitstatus ws
;
4465 /* Wait for one event out of any target. */
4467 static wait_one_event
4472 for (inferior
*inf
: all_inferiors ())
4474 process_stratum_target
*target
= inf
->process_target ();
4476 || !target
->is_async_p ()
4477 || !target
->threads_executing
)
4480 switch_to_inferior_no_thread (inf
);
4482 wait_one_event event
;
4483 event
.target
= target
;
4484 event
.ptid
= poll_one_curr_target (&event
.ws
);
4486 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4488 /* If nothing is resumed, remove the target from the
4492 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4496 /* Block waiting for some event. */
4503 for (inferior
*inf
: all_inferiors ())
4505 process_stratum_target
*target
= inf
->process_target ();
4507 || !target
->is_async_p ()
4508 || !target
->threads_executing
)
4511 int fd
= target
->async_wait_fd ();
4512 FD_SET (fd
, &readfds
);
4519 /* No waitable targets left. All must be stopped. */
4520 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4525 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4531 perror_with_name ("interruptible_select");
4536 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4537 instead of the current thread. */
4538 #define THREAD_STOPPED_BY(REASON) \
4540 thread_stopped_by_ ## REASON (ptid_t ptid) \
4542 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4543 inferior_ptid = ptid; \
4545 return target_stopped_by_ ## REASON (); \
4548 /* Generate thread_stopped_by_watchpoint. */
4549 THREAD_STOPPED_BY (watchpoint
)
4550 /* Generate thread_stopped_by_sw_breakpoint. */
4551 THREAD_STOPPED_BY (sw_breakpoint
)
4552 /* Generate thread_stopped_by_hw_breakpoint. */
4553 THREAD_STOPPED_BY (hw_breakpoint
)
4555 /* Save the thread's event and stop reason to process it later. */
4558 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4562 std::string statstr
= target_waitstatus_to_string (ws
);
4564 fprintf_unfiltered (gdb_stdlog
,
4565 "infrun: saving status %s for %d.%ld.%ld\n",
4572 /* Record for later. */
4573 tp
->suspend
.waitstatus
= *ws
;
4574 tp
->suspend
.waitstatus_pending_p
= 1;
4576 struct regcache
*regcache
= get_thread_regcache (tp
);
4577 const address_space
*aspace
= regcache
->aspace ();
4579 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4580 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4582 CORE_ADDR pc
= regcache_read_pc (regcache
);
4584 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4586 if (thread_stopped_by_watchpoint (tp
->ptid
))
4588 tp
->suspend
.stop_reason
4589 = TARGET_STOPPED_BY_WATCHPOINT
;
4591 else if (target_supports_stopped_by_sw_breakpoint ()
4592 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4594 tp
->suspend
.stop_reason
4595 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4597 else if (target_supports_stopped_by_hw_breakpoint ()
4598 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4600 tp
->suspend
.stop_reason
4601 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4603 else if (!target_supports_stopped_by_hw_breakpoint ()
4604 && hardware_breakpoint_inserted_here_p (aspace
,
4607 tp
->suspend
.stop_reason
4608 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4610 else if (!target_supports_stopped_by_sw_breakpoint ()
4611 && software_breakpoint_inserted_here_p (aspace
,
4614 tp
->suspend
.stop_reason
4615 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4617 else if (!thread_has_single_step_breakpoints_set (tp
)
4618 && currently_stepping (tp
))
4620 tp
->suspend
.stop_reason
4621 = TARGET_STOPPED_BY_SINGLE_STEP
;
4629 stop_all_threads (void)
4631 /* We may need multiple passes to discover all threads. */
4635 gdb_assert (target_is_non_stop_p ());
4638 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4640 scoped_restore_current_thread restore_thread
;
4642 target_thread_events (1);
4643 SCOPE_EXIT
{ target_thread_events (0); };
4645 /* Request threads to stop, and then wait for the stops. Because
4646 threads we already know about can spawn more threads while we're
4647 trying to stop them, and we only learn about new threads when we
4648 update the thread list, do this in a loop, and keep iterating
4649 until two passes find no threads that need to be stopped. */
4650 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4653 fprintf_unfiltered (gdb_stdlog
,
4654 "infrun: stop_all_threads, pass=%d, "
4655 "iterations=%d\n", pass
, iterations
);
4660 update_thread_list ();
4662 /* Go through all threads looking for threads that we need
4663 to tell the target to stop. */
4664 for (thread_info
*t
: all_non_exited_threads ())
4668 /* If already stopping, don't request a stop again.
4669 We just haven't seen the notification yet. */
4670 if (!t
->stop_requested
)
4673 fprintf_unfiltered (gdb_stdlog
,
4674 "infrun: %s executing, "
4676 target_pid_to_str (t
->ptid
).c_str ());
4677 switch_to_thread_no_regs (t
);
4678 target_stop (t
->ptid
);
4679 t
->stop_requested
= 1;
4684 fprintf_unfiltered (gdb_stdlog
,
4685 "infrun: %s executing, "
4686 "already stopping\n",
4687 target_pid_to_str (t
->ptid
).c_str ());
4690 if (t
->stop_requested
)
4696 fprintf_unfiltered (gdb_stdlog
,
4697 "infrun: %s not executing\n",
4698 target_pid_to_str (t
->ptid
).c_str ());
4700 /* The thread may be not executing, but still be
4701 resumed with a pending status to process. */
4709 /* If we find new threads on the second iteration, restart
4710 over. We want to see two iterations in a row with all
4715 wait_one_event event
= wait_one ();
4719 fprintf_unfiltered (gdb_stdlog
,
4720 "infrun: stop_all_threads %s %s\n",
4721 target_waitstatus_to_string (&event
.ws
).c_str (),
4722 target_pid_to_str (event
.ptid
).c_str ());
4725 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4726 || event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4727 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4728 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4730 /* All resumed threads exited
4731 or one thread/process exited/signalled. */
4735 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4737 t
= add_thread (event
.target
, event
.ptid
);
4739 t
->stop_requested
= 0;
4742 t
->control
.may_range_step
= 0;
4744 /* This may be the first time we see the inferior report
4746 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4747 if (inf
->needs_setup
)
4749 switch_to_thread_no_regs (t
);
4753 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4754 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4756 /* We caught the event that we intended to catch, so
4757 there's no event pending. */
4758 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4759 t
->suspend
.waitstatus_pending_p
= 0;
4761 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4763 /* Add it back to the step-over queue. */
4766 fprintf_unfiltered (gdb_stdlog
,
4767 "infrun: displaced-step of %s "
4768 "canceled: adding back to the "
4769 "step-over queue\n",
4770 target_pid_to_str (t
->ptid
).c_str ());
4772 t
->control
.trap_expected
= 0;
4773 thread_step_over_chain_enqueue (t
);
4778 enum gdb_signal sig
;
4779 struct regcache
*regcache
;
4783 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4785 fprintf_unfiltered (gdb_stdlog
,
4786 "infrun: target_wait %s, saving "
4787 "status for %d.%ld.%ld\n",
4794 /* Record for later. */
4795 save_waitstatus (t
, &event
.ws
);
4797 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4798 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4800 if (displaced_step_fixup (t
, sig
) < 0)
4802 /* Add it back to the step-over queue. */
4803 t
->control
.trap_expected
= 0;
4804 thread_step_over_chain_enqueue (t
);
4807 regcache
= get_thread_regcache (t
);
4808 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4812 fprintf_unfiltered (gdb_stdlog
,
4813 "infrun: saved stop_pc=%s for %s "
4814 "(currently_stepping=%d)\n",
4815 paddress (target_gdbarch (),
4816 t
->suspend
.stop_pc
),
4817 target_pid_to_str (t
->ptid
).c_str (),
4818 currently_stepping (t
));
4826 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4829 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4832 handle_no_resumed (struct execution_control_state
*ecs
)
4834 if (target_can_async_p ())
4841 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4849 /* There were no unwaited-for children left in the target, but,
4850 we're not synchronously waiting for events either. Just
4854 fprintf_unfiltered (gdb_stdlog
,
4855 "infrun: TARGET_WAITKIND_NO_RESUMED "
4856 "(ignoring: bg)\n");
4857 prepare_to_wait (ecs
);
4862 /* Otherwise, if we were running a synchronous execution command, we
4863 may need to cancel it and give the user back the terminal.
4865 In non-stop mode, the target can't tell whether we've already
4866 consumed previous stop events, so it can end up sending us a
4867 no-resumed event like so:
4869 #0 - thread 1 is left stopped
4871 #1 - thread 2 is resumed and hits breakpoint
4872 -> TARGET_WAITKIND_STOPPED
4874 #2 - thread 3 is resumed and exits
4875 this is the last resumed thread, so
4876 -> TARGET_WAITKIND_NO_RESUMED
4878 #3 - gdb processes stop for thread 2 and decides to re-resume
4881 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4882 thread 2 is now resumed, so the event should be ignored.
4884 IOW, if the stop for thread 2 doesn't end a foreground command,
4885 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4886 event. But it could be that the event meant that thread 2 itself
4887 (or whatever other thread was the last resumed thread) exited.
4889 To address this we refresh the thread list and check whether we
4890 have resumed threads _now_. In the example above, this removes
4891 thread 3 from the thread list. If thread 2 was re-resumed, we
4892 ignore this event. If we find no thread resumed, then we cancel
4893 the synchronous command show "no unwaited-for " to the user. */
4894 update_thread_list ();
4896 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4898 if (thread
->executing
4899 || thread
->suspend
.waitstatus_pending_p
)
4901 /* There were no unwaited-for children left in the target at
4902 some point, but there are now. Just ignore. */
4904 fprintf_unfiltered (gdb_stdlog
,
4905 "infrun: TARGET_WAITKIND_NO_RESUMED "
4906 "(ignoring: found resumed)\n");
4907 prepare_to_wait (ecs
);
4912 /* Note however that we may find no resumed thread because the whole
4913 process exited meanwhile (thus updating the thread list results
4914 in an empty thread list). In this case we know we'll be getting
4915 a process exit event shortly. */
4916 for (inferior
*inf
: all_non_exited_inferiors (ecs
->target
))
4918 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4922 fprintf_unfiltered (gdb_stdlog
,
4923 "infrun: TARGET_WAITKIND_NO_RESUMED "
4924 "(expect process exit)\n");
4925 prepare_to_wait (ecs
);
4930 /* Go ahead and report the event. */
4934 /* Given an execution control state that has been freshly filled in by
4935 an event from the inferior, figure out what it means and take
4938 The alternatives are:
4940 1) stop_waiting and return; to really stop and return to the
4943 2) keep_going and return; to wait for the next event (set
4944 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4948 handle_inferior_event (struct execution_control_state
*ecs
)
4950 /* Make sure that all temporary struct value objects that were
4951 created during the handling of the event get deleted at the
4953 scoped_value_mark free_values
;
4955 enum stop_kind stop_soon
;
4958 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
4959 target_waitstatus_to_string (&ecs
->ws
).c_str ());
4961 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4963 /* We had an event in the inferior, but we are not interested in
4964 handling it at this level. The lower layers have already
4965 done what needs to be done, if anything.
4967 One of the possible circumstances for this is when the
4968 inferior produces output for the console. The inferior has
4969 not stopped, and we are ignoring the event. Another possible
4970 circumstance is any event which the lower level knows will be
4971 reported multiple times without an intervening resume. */
4972 prepare_to_wait (ecs
);
4976 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4978 prepare_to_wait (ecs
);
4982 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4983 && handle_no_resumed (ecs
))
4986 /* Cache the last target/ptid/waitstatus. */
4987 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
4989 /* Always clear state belonging to the previous time we stopped. */
4990 stop_stack_dummy
= STOP_NONE
;
4992 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4994 /* No unwaited-for children left. IOW, all resumed children
4996 stop_print_frame
= 0;
5001 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5002 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5004 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5005 /* If it's a new thread, add it to the thread database. */
5006 if (ecs
->event_thread
== NULL
)
5007 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5009 /* Disable range stepping. If the next step request could use a
5010 range, this will be end up re-enabled then. */
5011 ecs
->event_thread
->control
.may_range_step
= 0;
5014 /* Dependent on valid ECS->EVENT_THREAD. */
5015 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5017 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5018 reinit_frame_cache ();
5020 breakpoint_retire_moribund ();
5022 /* First, distinguish signals caused by the debugger from signals
5023 that have to do with the program's own actions. Note that
5024 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5025 on the operating system version. Here we detect when a SIGILL or
5026 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5027 something similar for SIGSEGV, since a SIGSEGV will be generated
5028 when we're trying to execute a breakpoint instruction on a
5029 non-executable stack. This happens for call dummy breakpoints
5030 for architectures like SPARC that place call dummies on the
5032 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5033 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5034 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5035 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5037 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5039 if (breakpoint_inserted_here_p (regcache
->aspace (),
5040 regcache_read_pc (regcache
)))
5043 fprintf_unfiltered (gdb_stdlog
,
5044 "infrun: Treating signal as SIGTRAP\n");
5045 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5049 /* Mark the non-executing threads accordingly. In all-stop, all
5050 threads of all processes are stopped when we get any event
5051 reported. In non-stop mode, only the event thread stops. */
5055 if (!target_is_non_stop_p ())
5056 mark_ptid
= minus_one_ptid
;
5057 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
5058 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5060 /* If we're handling a process exit in non-stop mode, even
5061 though threads haven't been deleted yet, one would think
5062 that there is nothing to do, as threads of the dead process
5063 will be soon deleted, and threads of any other process were
5064 left running. However, on some targets, threads survive a
5065 process exit event. E.g., for the "checkpoint" command,
5066 when the current checkpoint/fork exits, linux-fork.c
5067 automatically switches to another fork from within
5068 target_mourn_inferior, by associating the same
5069 inferior/thread to another fork. We haven't mourned yet at
5070 this point, but we must mark any threads left in the
5071 process as not-executing so that finish_thread_state marks
5072 them stopped (in the user's perspective) if/when we present
5073 the stop to the user. */
5074 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
5077 mark_ptid
= ecs
->ptid
;
5079 set_executing (ecs
->target
, mark_ptid
, 0);
5081 /* Likewise the resumed flag. */
5082 set_resumed (ecs
->target
, mark_ptid
, 0);
5085 switch (ecs
->ws
.kind
)
5087 case TARGET_WAITKIND_LOADED
:
5088 context_switch (ecs
);
5089 /* Ignore gracefully during startup of the inferior, as it might
5090 be the shell which has just loaded some objects, otherwise
5091 add the symbols for the newly loaded objects. Also ignore at
5092 the beginning of an attach or remote session; we will query
5093 the full list of libraries once the connection is
5096 stop_soon
= get_inferior_stop_soon (ecs
);
5097 if (stop_soon
== NO_STOP_QUIETLY
)
5099 struct regcache
*regcache
;
5101 regcache
= get_thread_regcache (ecs
->event_thread
);
5103 handle_solib_event ();
5105 ecs
->event_thread
->control
.stop_bpstat
5106 = bpstat_stop_status (regcache
->aspace (),
5107 ecs
->event_thread
->suspend
.stop_pc
,
5108 ecs
->event_thread
, &ecs
->ws
);
5110 if (handle_stop_requested (ecs
))
5113 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5115 /* A catchpoint triggered. */
5116 process_event_stop_test (ecs
);
5120 /* If requested, stop when the dynamic linker notifies
5121 gdb of events. This allows the user to get control
5122 and place breakpoints in initializer routines for
5123 dynamically loaded objects (among other things). */
5124 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5125 if (stop_on_solib_events
)
5127 /* Make sure we print "Stopped due to solib-event" in
5129 stop_print_frame
= 1;
5136 /* If we are skipping through a shell, or through shared library
5137 loading that we aren't interested in, resume the program. If
5138 we're running the program normally, also resume. */
5139 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5141 /* Loading of shared libraries might have changed breakpoint
5142 addresses. Make sure new breakpoints are inserted. */
5143 if (stop_soon
== NO_STOP_QUIETLY
)
5144 insert_breakpoints ();
5145 resume (GDB_SIGNAL_0
);
5146 prepare_to_wait (ecs
);
5150 /* But stop if we're attaching or setting up a remote
5152 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5153 || stop_soon
== STOP_QUIETLY_REMOTE
)
5156 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5161 internal_error (__FILE__
, __LINE__
,
5162 _("unhandled stop_soon: %d"), (int) stop_soon
);
5164 case TARGET_WAITKIND_SPURIOUS
:
5165 if (handle_stop_requested (ecs
))
5167 context_switch (ecs
);
5168 resume (GDB_SIGNAL_0
);
5169 prepare_to_wait (ecs
);
5172 case TARGET_WAITKIND_THREAD_CREATED
:
5173 if (handle_stop_requested (ecs
))
5175 context_switch (ecs
);
5176 if (!switch_back_to_stepped_thread (ecs
))
5180 case TARGET_WAITKIND_EXITED
:
5181 case TARGET_WAITKIND_SIGNALLED
:
5182 inferior_ptid
= ecs
->ptid
;
5183 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5184 set_current_program_space (current_inferior ()->pspace
);
5185 handle_vfork_child_exec_or_exit (0);
5186 target_terminal::ours (); /* Must do this before mourn anyway. */
5188 /* Clearing any previous state of convenience variables. */
5189 clear_exit_convenience_vars ();
5191 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5193 /* Record the exit code in the convenience variable $_exitcode, so
5194 that the user can inspect this again later. */
5195 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5196 (LONGEST
) ecs
->ws
.value
.integer
);
5198 /* Also record this in the inferior itself. */
5199 current_inferior ()->has_exit_code
= 1;
5200 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5202 /* Support the --return-child-result option. */
5203 return_child_result_value
= ecs
->ws
.value
.integer
;
5205 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5209 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5211 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5213 /* Set the value of the internal variable $_exitsignal,
5214 which holds the signal uncaught by the inferior. */
5215 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5216 gdbarch_gdb_signal_to_target (gdbarch
,
5217 ecs
->ws
.value
.sig
));
5221 /* We don't have access to the target's method used for
5222 converting between signal numbers (GDB's internal
5223 representation <-> target's representation).
5224 Therefore, we cannot do a good job at displaying this
5225 information to the user. It's better to just warn
5226 her about it (if infrun debugging is enabled), and
5229 fprintf_filtered (gdb_stdlog
, _("\
5230 Cannot fill $_exitsignal with the correct signal number.\n"));
5233 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5236 gdb_flush (gdb_stdout
);
5237 target_mourn_inferior (inferior_ptid
);
5238 stop_print_frame
= 0;
5242 /* The following are the only cases in which we keep going;
5243 the above cases end in a continue or goto. */
5244 case TARGET_WAITKIND_FORKED
:
5245 case TARGET_WAITKIND_VFORKED
:
5246 /* Check whether the inferior is displaced stepping. */
5248 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5249 struct gdbarch
*gdbarch
= regcache
->arch ();
5251 /* If checking displaced stepping is supported, and thread
5252 ecs->ptid is displaced stepping. */
5253 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5255 struct inferior
*parent_inf
5256 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5257 struct regcache
*child_regcache
;
5258 CORE_ADDR parent_pc
;
5260 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5261 indicating that the displaced stepping of syscall instruction
5262 has been done. Perform cleanup for parent process here. Note
5263 that this operation also cleans up the child process for vfork,
5264 because their pages are shared. */
5265 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5266 /* Start a new step-over in another thread if there's one
5270 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5272 struct displaced_step_inferior_state
*displaced
5273 = get_displaced_stepping_state (parent_inf
);
5275 /* Restore scratch pad for child process. */
5276 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5279 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5280 the child's PC is also within the scratchpad. Set the child's PC
5281 to the parent's PC value, which has already been fixed up.
5282 FIXME: we use the parent's aspace here, although we're touching
5283 the child, because the child hasn't been added to the inferior
5284 list yet at this point. */
5287 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5288 ecs
->ws
.value
.related_pid
,
5290 parent_inf
->aspace
);
5291 /* Read PC value of parent process. */
5292 parent_pc
= regcache_read_pc (regcache
);
5294 if (debug_displaced
)
5295 fprintf_unfiltered (gdb_stdlog
,
5296 "displaced: write child pc from %s to %s\n",
5298 regcache_read_pc (child_regcache
)),
5299 paddress (gdbarch
, parent_pc
));
5301 regcache_write_pc (child_regcache
, parent_pc
);
5305 context_switch (ecs
);
5307 /* Immediately detach breakpoints from the child before there's
5308 any chance of letting the user delete breakpoints from the
5309 breakpoint lists. If we don't do this early, it's easy to
5310 leave left over traps in the child, vis: "break foo; catch
5311 fork; c; <fork>; del; c; <child calls foo>". We only follow
5312 the fork on the last `continue', and by that time the
5313 breakpoint at "foo" is long gone from the breakpoint table.
5314 If we vforked, then we don't need to unpatch here, since both
5315 parent and child are sharing the same memory pages; we'll
5316 need to unpatch at follow/detach time instead to be certain
5317 that new breakpoints added between catchpoint hit time and
5318 vfork follow are detached. */
5319 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5321 /* This won't actually modify the breakpoint list, but will
5322 physically remove the breakpoints from the child. */
5323 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5326 delete_just_stopped_threads_single_step_breakpoints ();
5328 /* In case the event is caught by a catchpoint, remember that
5329 the event is to be followed at the next resume of the thread,
5330 and not immediately. */
5331 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5333 ecs
->event_thread
->suspend
.stop_pc
5334 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5336 ecs
->event_thread
->control
.stop_bpstat
5337 = bpstat_stop_status (get_current_regcache ()->aspace (),
5338 ecs
->event_thread
->suspend
.stop_pc
,
5339 ecs
->event_thread
, &ecs
->ws
);
5341 if (handle_stop_requested (ecs
))
5344 /* If no catchpoint triggered for this, then keep going. Note
5345 that we're interested in knowing the bpstat actually causes a
5346 stop, not just if it may explain the signal. Software
5347 watchpoints, for example, always appear in the bpstat. */
5348 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5352 = (follow_fork_mode_string
== follow_fork_mode_child
);
5354 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5356 process_stratum_target
*targ
5357 = ecs
->event_thread
->inf
->process_target ();
5359 should_resume
= follow_fork ();
5361 /* Note that one of these may be an invalid pointer,
5362 depending on detach_fork. */
5363 thread_info
*parent
= ecs
->event_thread
;
5365 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5367 /* At this point, the parent is marked running, and the
5368 child is marked stopped. */
5370 /* If not resuming the parent, mark it stopped. */
5371 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5372 parent
->set_running (false);
5374 /* If resuming the child, mark it running. */
5375 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5376 child
->set_running (true);
5378 /* In non-stop mode, also resume the other branch. */
5379 if (!detach_fork
&& (non_stop
5380 || (sched_multi
&& target_is_non_stop_p ())))
5383 switch_to_thread (parent
);
5385 switch_to_thread (child
);
5387 ecs
->event_thread
= inferior_thread ();
5388 ecs
->ptid
= inferior_ptid
;
5393 switch_to_thread (child
);
5395 switch_to_thread (parent
);
5397 ecs
->event_thread
= inferior_thread ();
5398 ecs
->ptid
= inferior_ptid
;
5406 process_event_stop_test (ecs
);
5409 case TARGET_WAITKIND_VFORK_DONE
:
5410 /* Done with the shared memory region. Re-insert breakpoints in
5411 the parent, and keep going. */
5413 context_switch (ecs
);
5415 current_inferior ()->waiting_for_vfork_done
= 0;
5416 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5418 if (handle_stop_requested (ecs
))
5421 /* This also takes care of reinserting breakpoints in the
5422 previously locked inferior. */
5426 case TARGET_WAITKIND_EXECD
:
5428 /* Note we can't read registers yet (the stop_pc), because we
5429 don't yet know the inferior's post-exec architecture.
5430 'stop_pc' is explicitly read below instead. */
5431 switch_to_thread_no_regs (ecs
->event_thread
);
5433 /* Do whatever is necessary to the parent branch of the vfork. */
5434 handle_vfork_child_exec_or_exit (1);
5436 /* This causes the eventpoints and symbol table to be reset.
5437 Must do this now, before trying to determine whether to
5439 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5441 /* In follow_exec we may have deleted the original thread and
5442 created a new one. Make sure that the event thread is the
5443 execd thread for that case (this is a nop otherwise). */
5444 ecs
->event_thread
= inferior_thread ();
5446 ecs
->event_thread
->suspend
.stop_pc
5447 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5449 ecs
->event_thread
->control
.stop_bpstat
5450 = bpstat_stop_status (get_current_regcache ()->aspace (),
5451 ecs
->event_thread
->suspend
.stop_pc
,
5452 ecs
->event_thread
, &ecs
->ws
);
5454 /* Note that this may be referenced from inside
5455 bpstat_stop_status above, through inferior_has_execd. */
5456 xfree (ecs
->ws
.value
.execd_pathname
);
5457 ecs
->ws
.value
.execd_pathname
= NULL
;
5459 if (handle_stop_requested (ecs
))
5462 /* If no catchpoint triggered for this, then keep going. */
5463 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5465 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5469 process_event_stop_test (ecs
);
5472 /* Be careful not to try to gather much state about a thread
5473 that's in a syscall. It's frequently a losing proposition. */
5474 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5475 /* Getting the current syscall number. */
5476 if (handle_syscall_event (ecs
) == 0)
5477 process_event_stop_test (ecs
);
5480 /* Before examining the threads further, step this thread to
5481 get it entirely out of the syscall. (We get notice of the
5482 event when the thread is just on the verge of exiting a
5483 syscall. Stepping one instruction seems to get it back
5485 case TARGET_WAITKIND_SYSCALL_RETURN
:
5486 if (handle_syscall_event (ecs
) == 0)
5487 process_event_stop_test (ecs
);
5490 case TARGET_WAITKIND_STOPPED
:
5491 handle_signal_stop (ecs
);
5494 case TARGET_WAITKIND_NO_HISTORY
:
5495 /* Reverse execution: target ran out of history info. */
5497 /* Switch to the stopped thread. */
5498 context_switch (ecs
);
5500 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5502 delete_just_stopped_threads_single_step_breakpoints ();
5503 ecs
->event_thread
->suspend
.stop_pc
5504 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5506 if (handle_stop_requested (ecs
))
5509 gdb::observers::no_history
.notify ();
5515 /* Restart threads back to what they were trying to do back when we
5516 paused them for an in-line step-over. The EVENT_THREAD thread is
5520 restart_threads (struct thread_info
*event_thread
)
5522 /* In case the instruction just stepped spawned a new thread. */
5523 update_thread_list ();
5525 for (thread_info
*tp
: all_non_exited_threads ())
5527 switch_to_thread_no_regs (tp
);
5529 if (tp
== event_thread
)
5532 fprintf_unfiltered (gdb_stdlog
,
5533 "infrun: restart threads: "
5534 "[%s] is event thread\n",
5535 target_pid_to_str (tp
->ptid
).c_str ());
5539 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5542 fprintf_unfiltered (gdb_stdlog
,
5543 "infrun: restart threads: "
5544 "[%s] not meant to be running\n",
5545 target_pid_to_str (tp
->ptid
).c_str ());
5552 fprintf_unfiltered (gdb_stdlog
,
5553 "infrun: restart threads: [%s] resumed\n",
5554 target_pid_to_str (tp
->ptid
).c_str ());
5555 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5559 if (thread_is_in_step_over_chain (tp
))
5562 fprintf_unfiltered (gdb_stdlog
,
5563 "infrun: restart threads: "
5564 "[%s] needs step-over\n",
5565 target_pid_to_str (tp
->ptid
).c_str ());
5566 gdb_assert (!tp
->resumed
);
5571 if (tp
->suspend
.waitstatus_pending_p
)
5574 fprintf_unfiltered (gdb_stdlog
,
5575 "infrun: restart threads: "
5576 "[%s] has pending status\n",
5577 target_pid_to_str (tp
->ptid
).c_str ());
5582 gdb_assert (!tp
->stop_requested
);
5584 /* If some thread needs to start a step-over at this point, it
5585 should still be in the step-over queue, and thus skipped
5587 if (thread_still_needs_step_over (tp
))
5589 internal_error (__FILE__
, __LINE__
,
5590 "thread [%s] needs a step-over, but not in "
5591 "step-over queue\n",
5592 target_pid_to_str (tp
->ptid
).c_str ());
5595 if (currently_stepping (tp
))
5598 fprintf_unfiltered (gdb_stdlog
,
5599 "infrun: restart threads: [%s] was stepping\n",
5600 target_pid_to_str (tp
->ptid
).c_str ());
5601 keep_going_stepped_thread (tp
);
5605 struct execution_control_state ecss
;
5606 struct execution_control_state
*ecs
= &ecss
;
5609 fprintf_unfiltered (gdb_stdlog
,
5610 "infrun: restart threads: [%s] continuing\n",
5611 target_pid_to_str (tp
->ptid
).c_str ());
5612 reset_ecs (ecs
, tp
);
5613 switch_to_thread (tp
);
5614 keep_going_pass_signal (ecs
);
5619 /* Callback for iterate_over_threads. Find a resumed thread that has
5620 a pending waitstatus. */
5623 resumed_thread_with_pending_status (struct thread_info
*tp
,
5627 && tp
->suspend
.waitstatus_pending_p
);
5630 /* Called when we get an event that may finish an in-line or
5631 out-of-line (displaced stepping) step-over started previously.
5632 Return true if the event is processed and we should go back to the
5633 event loop; false if the caller should continue processing the
5637 finish_step_over (struct execution_control_state
*ecs
)
5639 int had_step_over_info
;
5641 displaced_step_fixup (ecs
->event_thread
,
5642 ecs
->event_thread
->suspend
.stop_signal
);
5644 had_step_over_info
= step_over_info_valid_p ();
5646 if (had_step_over_info
)
5648 /* If we're stepping over a breakpoint with all threads locked,
5649 then only the thread that was stepped should be reporting
5651 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5653 clear_step_over_info ();
5656 if (!target_is_non_stop_p ())
5659 /* Start a new step-over in another thread if there's one that
5663 /* If we were stepping over a breakpoint before, and haven't started
5664 a new in-line step-over sequence, then restart all other threads
5665 (except the event thread). We can't do this in all-stop, as then
5666 e.g., we wouldn't be able to issue any other remote packet until
5667 these other threads stop. */
5668 if (had_step_over_info
&& !step_over_info_valid_p ())
5670 struct thread_info
*pending
;
5672 /* If we only have threads with pending statuses, the restart
5673 below won't restart any thread and so nothing re-inserts the
5674 breakpoint we just stepped over. But we need it inserted
5675 when we later process the pending events, otherwise if
5676 another thread has a pending event for this breakpoint too,
5677 we'd discard its event (because the breakpoint that
5678 originally caused the event was no longer inserted). */
5679 context_switch (ecs
);
5680 insert_breakpoints ();
5682 restart_threads (ecs
->event_thread
);
5684 /* If we have events pending, go through handle_inferior_event
5685 again, picking up a pending event at random. This avoids
5686 thread starvation. */
5688 /* But not if we just stepped over a watchpoint in order to let
5689 the instruction execute so we can evaluate its expression.
5690 The set of watchpoints that triggered is recorded in the
5691 breakpoint objects themselves (see bp->watchpoint_triggered).
5692 If we processed another event first, that other event could
5693 clobber this info. */
5694 if (ecs
->event_thread
->stepping_over_watchpoint
)
5697 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5699 if (pending
!= NULL
)
5701 struct thread_info
*tp
= ecs
->event_thread
;
5702 struct regcache
*regcache
;
5706 fprintf_unfiltered (gdb_stdlog
,
5707 "infrun: found resumed threads with "
5708 "pending events, saving status\n");
5711 gdb_assert (pending
!= tp
);
5713 /* Record the event thread's event for later. */
5714 save_waitstatus (tp
, &ecs
->ws
);
5715 /* This was cleared early, by handle_inferior_event. Set it
5716 so this pending event is considered by
5720 gdb_assert (!tp
->executing
);
5722 regcache
= get_thread_regcache (tp
);
5723 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5727 fprintf_unfiltered (gdb_stdlog
,
5728 "infrun: saved stop_pc=%s for %s "
5729 "(currently_stepping=%d)\n",
5730 paddress (target_gdbarch (),
5731 tp
->suspend
.stop_pc
),
5732 target_pid_to_str (tp
->ptid
).c_str (),
5733 currently_stepping (tp
));
5736 /* This in-line step-over finished; clear this so we won't
5737 start a new one. This is what handle_signal_stop would
5738 do, if we returned false. */
5739 tp
->stepping_over_breakpoint
= 0;
5741 /* Wake up the event loop again. */
5742 mark_async_event_handler (infrun_async_inferior_event_token
);
5744 prepare_to_wait (ecs
);
5752 /* Come here when the program has stopped with a signal. */
5755 handle_signal_stop (struct execution_control_state
*ecs
)
5757 struct frame_info
*frame
;
5758 struct gdbarch
*gdbarch
;
5759 int stopped_by_watchpoint
;
5760 enum stop_kind stop_soon
;
5763 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5765 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5767 /* Do we need to clean up the state of a thread that has
5768 completed a displaced single-step? (Doing so usually affects
5769 the PC, so do it here, before we set stop_pc.) */
5770 if (finish_step_over (ecs
))
5773 /* If we either finished a single-step or hit a breakpoint, but
5774 the user wanted this thread to be stopped, pretend we got a
5775 SIG0 (generic unsignaled stop). */
5776 if (ecs
->event_thread
->stop_requested
5777 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5778 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5780 ecs
->event_thread
->suspend
.stop_pc
5781 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5785 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5786 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5788 switch_to_thread (ecs
->event_thread
);
5790 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5791 paddress (reg_gdbarch
,
5792 ecs
->event_thread
->suspend
.stop_pc
));
5793 if (target_stopped_by_watchpoint ())
5797 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5799 if (target_stopped_data_address (current_top_target (), &addr
))
5800 fprintf_unfiltered (gdb_stdlog
,
5801 "infrun: stopped data address = %s\n",
5802 paddress (reg_gdbarch
, addr
));
5804 fprintf_unfiltered (gdb_stdlog
,
5805 "infrun: (no data address available)\n");
5809 /* This is originated from start_remote(), start_inferior() and
5810 shared libraries hook functions. */
5811 stop_soon
= get_inferior_stop_soon (ecs
);
5812 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5814 context_switch (ecs
);
5816 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5817 stop_print_frame
= 1;
5822 /* This originates from attach_command(). We need to overwrite
5823 the stop_signal here, because some kernels don't ignore a
5824 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5825 See more comments in inferior.h. On the other hand, if we
5826 get a non-SIGSTOP, report it to the user - assume the backend
5827 will handle the SIGSTOP if it should show up later.
5829 Also consider that the attach is complete when we see a
5830 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5831 target extended-remote report it instead of a SIGSTOP
5832 (e.g. gdbserver). We already rely on SIGTRAP being our
5833 signal, so this is no exception.
5835 Also consider that the attach is complete when we see a
5836 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5837 the target to stop all threads of the inferior, in case the
5838 low level attach operation doesn't stop them implicitly. If
5839 they weren't stopped implicitly, then the stub will report a
5840 GDB_SIGNAL_0, meaning: stopped for no particular reason
5841 other than GDB's request. */
5842 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5843 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5844 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5845 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5847 stop_print_frame
= 1;
5849 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5853 /* See if something interesting happened to the non-current thread. If
5854 so, then switch to that thread. */
5855 if (ecs
->ptid
!= inferior_ptid
)
5858 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5860 context_switch (ecs
);
5862 if (deprecated_context_hook
)
5863 deprecated_context_hook (ecs
->event_thread
->global_num
);
5866 /* At this point, get hold of the now-current thread's frame. */
5867 frame
= get_current_frame ();
5868 gdbarch
= get_frame_arch (frame
);
5870 /* Pull the single step breakpoints out of the target. */
5871 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5873 struct regcache
*regcache
;
5876 regcache
= get_thread_regcache (ecs
->event_thread
);
5877 const address_space
*aspace
= regcache
->aspace ();
5879 pc
= regcache_read_pc (regcache
);
5881 /* However, before doing so, if this single-step breakpoint was
5882 actually for another thread, set this thread up for moving
5884 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5887 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5891 fprintf_unfiltered (gdb_stdlog
,
5892 "infrun: [%s] hit another thread's "
5893 "single-step breakpoint\n",
5894 target_pid_to_str (ecs
->ptid
).c_str ());
5896 ecs
->hit_singlestep_breakpoint
= 1;
5903 fprintf_unfiltered (gdb_stdlog
,
5904 "infrun: [%s] hit its "
5905 "single-step breakpoint\n",
5906 target_pid_to_str (ecs
->ptid
).c_str ());
5910 delete_just_stopped_threads_single_step_breakpoints ();
5912 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5913 && ecs
->event_thread
->control
.trap_expected
5914 && ecs
->event_thread
->stepping_over_watchpoint
)
5915 stopped_by_watchpoint
= 0;
5917 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5919 /* If necessary, step over this watchpoint. We'll be back to display
5921 if (stopped_by_watchpoint
5922 && (target_have_steppable_watchpoint
5923 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5925 /* At this point, we are stopped at an instruction which has
5926 attempted to write to a piece of memory under control of
5927 a watchpoint. The instruction hasn't actually executed
5928 yet. If we were to evaluate the watchpoint expression
5929 now, we would get the old value, and therefore no change
5930 would seem to have occurred.
5932 In order to make watchpoints work `right', we really need
5933 to complete the memory write, and then evaluate the
5934 watchpoint expression. We do this by single-stepping the
5937 It may not be necessary to disable the watchpoint to step over
5938 it. For example, the PA can (with some kernel cooperation)
5939 single step over a watchpoint without disabling the watchpoint.
5941 It is far more common to need to disable a watchpoint to step
5942 the inferior over it. If we have non-steppable watchpoints,
5943 we must disable the current watchpoint; it's simplest to
5944 disable all watchpoints.
5946 Any breakpoint at PC must also be stepped over -- if there's
5947 one, it will have already triggered before the watchpoint
5948 triggered, and we either already reported it to the user, or
5949 it didn't cause a stop and we called keep_going. In either
5950 case, if there was a breakpoint at PC, we must be trying to
5952 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5957 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5958 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5959 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5960 ecs
->event_thread
->control
.stop_step
= 0;
5961 stop_print_frame
= 1;
5962 stopped_by_random_signal
= 0;
5963 bpstat stop_chain
= NULL
;
5965 /* Hide inlined functions starting here, unless we just performed stepi or
5966 nexti. After stepi and nexti, always show the innermost frame (not any
5967 inline function call sites). */
5968 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5970 const address_space
*aspace
5971 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5973 /* skip_inline_frames is expensive, so we avoid it if we can
5974 determine that the address is one where functions cannot have
5975 been inlined. This improves performance with inferiors that
5976 load a lot of shared libraries, because the solib event
5977 breakpoint is defined as the address of a function (i.e. not
5978 inline). Note that we have to check the previous PC as well
5979 as the current one to catch cases when we have just
5980 single-stepped off a breakpoint prior to reinstating it.
5981 Note that we're assuming that the code we single-step to is
5982 not inline, but that's not definitive: there's nothing
5983 preventing the event breakpoint function from containing
5984 inlined code, and the single-step ending up there. If the
5985 user had set a breakpoint on that inlined code, the missing
5986 skip_inline_frames call would break things. Fortunately
5987 that's an extremely unlikely scenario. */
5988 if (!pc_at_non_inline_function (aspace
,
5989 ecs
->event_thread
->suspend
.stop_pc
,
5991 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5992 && ecs
->event_thread
->control
.trap_expected
5993 && pc_at_non_inline_function (aspace
,
5994 ecs
->event_thread
->prev_pc
,
5997 stop_chain
= build_bpstat_chain (aspace
,
5998 ecs
->event_thread
->suspend
.stop_pc
,
6000 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6002 /* Re-fetch current thread's frame in case that invalidated
6004 frame
= get_current_frame ();
6005 gdbarch
= get_frame_arch (frame
);
6009 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6010 && ecs
->event_thread
->control
.trap_expected
6011 && gdbarch_single_step_through_delay_p (gdbarch
)
6012 && currently_stepping (ecs
->event_thread
))
6014 /* We're trying to step off a breakpoint. Turns out that we're
6015 also on an instruction that needs to be stepped multiple
6016 times before it's been fully executing. E.g., architectures
6017 with a delay slot. It needs to be stepped twice, once for
6018 the instruction and once for the delay slot. */
6019 int step_through_delay
6020 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6022 if (debug_infrun
&& step_through_delay
)
6023 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6024 if (ecs
->event_thread
->control
.step_range_end
== 0
6025 && step_through_delay
)
6027 /* The user issued a continue when stopped at a breakpoint.
6028 Set up for another trap and get out of here. */
6029 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6033 else if (step_through_delay
)
6035 /* The user issued a step when stopped at a breakpoint.
6036 Maybe we should stop, maybe we should not - the delay
6037 slot *might* correspond to a line of source. In any
6038 case, don't decide that here, just set
6039 ecs->stepping_over_breakpoint, making sure we
6040 single-step again before breakpoints are re-inserted. */
6041 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6045 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6046 handles this event. */
6047 ecs
->event_thread
->control
.stop_bpstat
6048 = bpstat_stop_status (get_current_regcache ()->aspace (),
6049 ecs
->event_thread
->suspend
.stop_pc
,
6050 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6052 /* Following in case break condition called a
6054 stop_print_frame
= 1;
6056 /* This is where we handle "moribund" watchpoints. Unlike
6057 software breakpoints traps, hardware watchpoint traps are
6058 always distinguishable from random traps. If no high-level
6059 watchpoint is associated with the reported stop data address
6060 anymore, then the bpstat does not explain the signal ---
6061 simply make sure to ignore it if `stopped_by_watchpoint' is
6065 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6066 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6068 && stopped_by_watchpoint
)
6069 fprintf_unfiltered (gdb_stdlog
,
6070 "infrun: no user watchpoint explains "
6071 "watchpoint SIGTRAP, ignoring\n");
6073 /* NOTE: cagney/2003-03-29: These checks for a random signal
6074 at one stage in the past included checks for an inferior
6075 function call's call dummy's return breakpoint. The original
6076 comment, that went with the test, read:
6078 ``End of a stack dummy. Some systems (e.g. Sony news) give
6079 another signal besides SIGTRAP, so check here as well as
6082 If someone ever tries to get call dummys on a
6083 non-executable stack to work (where the target would stop
6084 with something like a SIGSEGV), then those tests might need
6085 to be re-instated. Given, however, that the tests were only
6086 enabled when momentary breakpoints were not being used, I
6087 suspect that it won't be the case.
6089 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6090 be necessary for call dummies on a non-executable stack on
6093 /* See if the breakpoints module can explain the signal. */
6095 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6096 ecs
->event_thread
->suspend
.stop_signal
);
6098 /* Maybe this was a trap for a software breakpoint that has since
6100 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6102 if (program_breakpoint_here_p (gdbarch
,
6103 ecs
->event_thread
->suspend
.stop_pc
))
6105 struct regcache
*regcache
;
6108 /* Re-adjust PC to what the program would see if GDB was not
6110 regcache
= get_thread_regcache (ecs
->event_thread
);
6111 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6114 gdb::optional
<scoped_restore_tmpl
<int>>
6115 restore_operation_disable
;
6117 if (record_full_is_used ())
6118 restore_operation_disable
.emplace
6119 (record_full_gdb_operation_disable_set ());
6121 regcache_write_pc (regcache
,
6122 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6127 /* A delayed software breakpoint event. Ignore the trap. */
6129 fprintf_unfiltered (gdb_stdlog
,
6130 "infrun: delayed software breakpoint "
6131 "trap, ignoring\n");
6136 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6137 has since been removed. */
6138 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6140 /* A delayed hardware breakpoint event. Ignore the trap. */
6142 fprintf_unfiltered (gdb_stdlog
,
6143 "infrun: delayed hardware breakpoint/watchpoint "
6144 "trap, ignoring\n");
6148 /* If not, perhaps stepping/nexting can. */
6150 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6151 && currently_stepping (ecs
->event_thread
));
6153 /* Perhaps the thread hit a single-step breakpoint of _another_
6154 thread. Single-step breakpoints are transparent to the
6155 breakpoints module. */
6157 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6159 /* No? Perhaps we got a moribund watchpoint. */
6161 random_signal
= !stopped_by_watchpoint
;
6163 /* Always stop if the user explicitly requested this thread to
6165 if (ecs
->event_thread
->stop_requested
)
6169 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6172 /* For the program's own signals, act according to
6173 the signal handling tables. */
6177 /* Signal not for debugging purposes. */
6178 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6179 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6182 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6183 gdb_signal_to_symbol_string (stop_signal
));
6185 stopped_by_random_signal
= 1;
6187 /* Always stop on signals if we're either just gaining control
6188 of the program, or the user explicitly requested this thread
6189 to remain stopped. */
6190 if (stop_soon
!= NO_STOP_QUIETLY
6191 || ecs
->event_thread
->stop_requested
6193 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6199 /* Notify observers the signal has "handle print" set. Note we
6200 returned early above if stopping; normal_stop handles the
6201 printing in that case. */
6202 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6204 /* The signal table tells us to print about this signal. */
6205 target_terminal::ours_for_output ();
6206 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6207 target_terminal::inferior ();
6210 /* Clear the signal if it should not be passed. */
6211 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6212 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6214 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6215 && ecs
->event_thread
->control
.trap_expected
6216 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6218 /* We were just starting a new sequence, attempting to
6219 single-step off of a breakpoint and expecting a SIGTRAP.
6220 Instead this signal arrives. This signal will take us out
6221 of the stepping range so GDB needs to remember to, when
6222 the signal handler returns, resume stepping off that
6224 /* To simplify things, "continue" is forced to use the same
6225 code paths as single-step - set a breakpoint at the
6226 signal return address and then, once hit, step off that
6229 fprintf_unfiltered (gdb_stdlog
,
6230 "infrun: signal arrived while stepping over "
6233 insert_hp_step_resume_breakpoint_at_frame (frame
);
6234 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6235 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6236 ecs
->event_thread
->control
.trap_expected
= 0;
6238 /* If we were nexting/stepping some other thread, switch to
6239 it, so that we don't continue it, losing control. */
6240 if (!switch_back_to_stepped_thread (ecs
))
6245 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6246 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6248 || ecs
->event_thread
->control
.step_range_end
== 1)
6249 && frame_id_eq (get_stack_frame_id (frame
),
6250 ecs
->event_thread
->control
.step_stack_frame_id
)
6251 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6253 /* The inferior is about to take a signal that will take it
6254 out of the single step range. Set a breakpoint at the
6255 current PC (which is presumably where the signal handler
6256 will eventually return) and then allow the inferior to
6259 Note that this is only needed for a signal delivered
6260 while in the single-step range. Nested signals aren't a
6261 problem as they eventually all return. */
6263 fprintf_unfiltered (gdb_stdlog
,
6264 "infrun: signal may take us out of "
6265 "single-step range\n");
6267 clear_step_over_info ();
6268 insert_hp_step_resume_breakpoint_at_frame (frame
);
6269 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6270 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6271 ecs
->event_thread
->control
.trap_expected
= 0;
6276 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6277 when either there's a nested signal, or when there's a
6278 pending signal enabled just as the signal handler returns
6279 (leaving the inferior at the step-resume-breakpoint without
6280 actually executing it). Either way continue until the
6281 breakpoint is really hit. */
6283 if (!switch_back_to_stepped_thread (ecs
))
6286 fprintf_unfiltered (gdb_stdlog
,
6287 "infrun: random signal, keep going\n");
6294 process_event_stop_test (ecs
);
6297 /* Come here when we've got some debug event / signal we can explain
6298 (IOW, not a random signal), and test whether it should cause a
6299 stop, or whether we should resume the inferior (transparently).
6300 E.g., could be a breakpoint whose condition evaluates false; we
6301 could be still stepping within the line; etc. */
6304 process_event_stop_test (struct execution_control_state
*ecs
)
6306 struct symtab_and_line stop_pc_sal
;
6307 struct frame_info
*frame
;
6308 struct gdbarch
*gdbarch
;
6309 CORE_ADDR jmp_buf_pc
;
6310 struct bpstat_what what
;
6312 /* Handle cases caused by hitting a breakpoint. */
6314 frame
= get_current_frame ();
6315 gdbarch
= get_frame_arch (frame
);
6317 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6319 if (what
.call_dummy
)
6321 stop_stack_dummy
= what
.call_dummy
;
6324 /* A few breakpoint types have callbacks associated (e.g.,
6325 bp_jit_event). Run them now. */
6326 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6328 /* If we hit an internal event that triggers symbol changes, the
6329 current frame will be invalidated within bpstat_what (e.g., if we
6330 hit an internal solib event). Re-fetch it. */
6331 frame
= get_current_frame ();
6332 gdbarch
= get_frame_arch (frame
);
6334 switch (what
.main_action
)
6336 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6337 /* If we hit the breakpoint at longjmp while stepping, we
6338 install a momentary breakpoint at the target of the
6342 fprintf_unfiltered (gdb_stdlog
,
6343 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6345 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6347 if (what
.is_longjmp
)
6349 struct value
*arg_value
;
6351 /* If we set the longjmp breakpoint via a SystemTap probe,
6352 then use it to extract the arguments. The destination PC
6353 is the third argument to the probe. */
6354 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6357 jmp_buf_pc
= value_as_address (arg_value
);
6358 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6360 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6361 || !gdbarch_get_longjmp_target (gdbarch
,
6362 frame
, &jmp_buf_pc
))
6365 fprintf_unfiltered (gdb_stdlog
,
6366 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6367 "(!gdbarch_get_longjmp_target)\n");
6372 /* Insert a breakpoint at resume address. */
6373 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6376 check_exception_resume (ecs
, frame
);
6380 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6382 struct frame_info
*init_frame
;
6384 /* There are several cases to consider.
6386 1. The initiating frame no longer exists. In this case we
6387 must stop, because the exception or longjmp has gone too
6390 2. The initiating frame exists, and is the same as the
6391 current frame. We stop, because the exception or longjmp
6394 3. The initiating frame exists and is different from the
6395 current frame. This means the exception or longjmp has
6396 been caught beneath the initiating frame, so keep going.
6398 4. longjmp breakpoint has been placed just to protect
6399 against stale dummy frames and user is not interested in
6400 stopping around longjmps. */
6403 fprintf_unfiltered (gdb_stdlog
,
6404 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6406 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6408 delete_exception_resume_breakpoint (ecs
->event_thread
);
6410 if (what
.is_longjmp
)
6412 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6414 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6422 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6426 struct frame_id current_id
6427 = get_frame_id (get_current_frame ());
6428 if (frame_id_eq (current_id
,
6429 ecs
->event_thread
->initiating_frame
))
6431 /* Case 2. Fall through. */
6441 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6443 delete_step_resume_breakpoint (ecs
->event_thread
);
6445 end_stepping_range (ecs
);
6449 case BPSTAT_WHAT_SINGLE
:
6451 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6452 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6453 /* Still need to check other stuff, at least the case where we
6454 are stepping and step out of the right range. */
6457 case BPSTAT_WHAT_STEP_RESUME
:
6459 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6461 delete_step_resume_breakpoint (ecs
->event_thread
);
6462 if (ecs
->event_thread
->control
.proceed_to_finish
6463 && execution_direction
== EXEC_REVERSE
)
6465 struct thread_info
*tp
= ecs
->event_thread
;
6467 /* We are finishing a function in reverse, and just hit the
6468 step-resume breakpoint at the start address of the
6469 function, and we're almost there -- just need to back up
6470 by one more single-step, which should take us back to the
6472 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6476 fill_in_stop_func (gdbarch
, ecs
);
6477 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6478 && execution_direction
== EXEC_REVERSE
)
6480 /* We are stepping over a function call in reverse, and just
6481 hit the step-resume breakpoint at the start address of
6482 the function. Go back to single-stepping, which should
6483 take us back to the function call. */
6484 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6490 case BPSTAT_WHAT_STOP_NOISY
:
6492 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6493 stop_print_frame
= 1;
6495 /* Assume the thread stopped for a breapoint. We'll still check
6496 whether a/the breakpoint is there when the thread is next
6498 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6503 case BPSTAT_WHAT_STOP_SILENT
:
6505 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6506 stop_print_frame
= 0;
6508 /* Assume the thread stopped for a breapoint. We'll still check
6509 whether a/the breakpoint is there when the thread is next
6511 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6515 case BPSTAT_WHAT_HP_STEP_RESUME
:
6517 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6519 delete_step_resume_breakpoint (ecs
->event_thread
);
6520 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6522 /* Back when the step-resume breakpoint was inserted, we
6523 were trying to single-step off a breakpoint. Go back to
6525 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6526 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6532 case BPSTAT_WHAT_KEEP_CHECKING
:
6536 /* If we stepped a permanent breakpoint and we had a high priority
6537 step-resume breakpoint for the address we stepped, but we didn't
6538 hit it, then we must have stepped into the signal handler. The
6539 step-resume was only necessary to catch the case of _not_
6540 stepping into the handler, so delete it, and fall through to
6541 checking whether the step finished. */
6542 if (ecs
->event_thread
->stepped_breakpoint
)
6544 struct breakpoint
*sr_bp
6545 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6548 && sr_bp
->loc
->permanent
6549 && sr_bp
->type
== bp_hp_step_resume
6550 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6553 fprintf_unfiltered (gdb_stdlog
,
6554 "infrun: stepped permanent breakpoint, stopped in "
6556 delete_step_resume_breakpoint (ecs
->event_thread
);
6557 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6561 /* We come here if we hit a breakpoint but should not stop for it.
6562 Possibly we also were stepping and should stop for that. So fall
6563 through and test for stepping. But, if not stepping, do not
6566 /* In all-stop mode, if we're currently stepping but have stopped in
6567 some other thread, we need to switch back to the stepped thread. */
6568 if (switch_back_to_stepped_thread (ecs
))
6571 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6574 fprintf_unfiltered (gdb_stdlog
,
6575 "infrun: step-resume breakpoint is inserted\n");
6577 /* Having a step-resume breakpoint overrides anything
6578 else having to do with stepping commands until
6579 that breakpoint is reached. */
6584 if (ecs
->event_thread
->control
.step_range_end
== 0)
6587 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6588 /* Likewise if we aren't even stepping. */
6593 /* Re-fetch current thread's frame in case the code above caused
6594 the frame cache to be re-initialized, making our FRAME variable
6595 a dangling pointer. */
6596 frame
= get_current_frame ();
6597 gdbarch
= get_frame_arch (frame
);
6598 fill_in_stop_func (gdbarch
, ecs
);
6600 /* If stepping through a line, keep going if still within it.
6602 Note that step_range_end is the address of the first instruction
6603 beyond the step range, and NOT the address of the last instruction
6606 Note also that during reverse execution, we may be stepping
6607 through a function epilogue and therefore must detect when
6608 the current-frame changes in the middle of a line. */
6610 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6612 && (execution_direction
!= EXEC_REVERSE
6613 || frame_id_eq (get_frame_id (frame
),
6614 ecs
->event_thread
->control
.step_frame_id
)))
6618 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6619 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6620 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6622 /* Tentatively re-enable range stepping; `resume' disables it if
6623 necessary (e.g., if we're stepping over a breakpoint or we
6624 have software watchpoints). */
6625 ecs
->event_thread
->control
.may_range_step
= 1;
6627 /* When stepping backward, stop at beginning of line range
6628 (unless it's the function entry point, in which case
6629 keep going back to the call point). */
6630 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6631 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6632 && stop_pc
!= ecs
->stop_func_start
6633 && execution_direction
== EXEC_REVERSE
)
6634 end_stepping_range (ecs
);
6641 /* We stepped out of the stepping range. */
6643 /* If we are stepping at the source level and entered the runtime
6644 loader dynamic symbol resolution code...
6646 EXEC_FORWARD: we keep on single stepping until we exit the run
6647 time loader code and reach the callee's address.
6649 EXEC_REVERSE: we've already executed the callee (backward), and
6650 the runtime loader code is handled just like any other
6651 undebuggable function call. Now we need only keep stepping
6652 backward through the trampoline code, and that's handled further
6653 down, so there is nothing for us to do here. */
6655 if (execution_direction
!= EXEC_REVERSE
6656 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6657 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6659 CORE_ADDR pc_after_resolver
=
6660 gdbarch_skip_solib_resolver (gdbarch
,
6661 ecs
->event_thread
->suspend
.stop_pc
);
6664 fprintf_unfiltered (gdb_stdlog
,
6665 "infrun: stepped into dynsym resolve code\n");
6667 if (pc_after_resolver
)
6669 /* Set up a step-resume breakpoint at the address
6670 indicated by SKIP_SOLIB_RESOLVER. */
6671 symtab_and_line sr_sal
;
6672 sr_sal
.pc
= pc_after_resolver
;
6673 sr_sal
.pspace
= get_frame_program_space (frame
);
6675 insert_step_resume_breakpoint_at_sal (gdbarch
,
6676 sr_sal
, null_frame_id
);
6683 /* Step through an indirect branch thunk. */
6684 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6685 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6686 ecs
->event_thread
->suspend
.stop_pc
))
6689 fprintf_unfiltered (gdb_stdlog
,
6690 "infrun: stepped into indirect branch thunk\n");
6695 if (ecs
->event_thread
->control
.step_range_end
!= 1
6696 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6697 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6698 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6701 fprintf_unfiltered (gdb_stdlog
,
6702 "infrun: stepped into signal trampoline\n");
6703 /* The inferior, while doing a "step" or "next", has ended up in
6704 a signal trampoline (either by a signal being delivered or by
6705 the signal handler returning). Just single-step until the
6706 inferior leaves the trampoline (either by calling the handler
6712 /* If we're in the return path from a shared library trampoline,
6713 we want to proceed through the trampoline when stepping. */
6714 /* macro/2012-04-25: This needs to come before the subroutine
6715 call check below as on some targets return trampolines look
6716 like subroutine calls (MIPS16 return thunks). */
6717 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6718 ecs
->event_thread
->suspend
.stop_pc
,
6719 ecs
->stop_func_name
)
6720 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6722 /* Determine where this trampoline returns. */
6723 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6724 CORE_ADDR real_stop_pc
6725 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6728 fprintf_unfiltered (gdb_stdlog
,
6729 "infrun: stepped into solib return tramp\n");
6731 /* Only proceed through if we know where it's going. */
6734 /* And put the step-breakpoint there and go until there. */
6735 symtab_and_line sr_sal
;
6736 sr_sal
.pc
= real_stop_pc
;
6737 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6738 sr_sal
.pspace
= get_frame_program_space (frame
);
6740 /* Do not specify what the fp should be when we stop since
6741 on some machines the prologue is where the new fp value
6743 insert_step_resume_breakpoint_at_sal (gdbarch
,
6744 sr_sal
, null_frame_id
);
6746 /* Restart without fiddling with the step ranges or
6753 /* Check for subroutine calls. The check for the current frame
6754 equalling the step ID is not necessary - the check of the
6755 previous frame's ID is sufficient - but it is a common case and
6756 cheaper than checking the previous frame's ID.
6758 NOTE: frame_id_eq will never report two invalid frame IDs as
6759 being equal, so to get into this block, both the current and
6760 previous frame must have valid frame IDs. */
6761 /* The outer_frame_id check is a heuristic to detect stepping
6762 through startup code. If we step over an instruction which
6763 sets the stack pointer from an invalid value to a valid value,
6764 we may detect that as a subroutine call from the mythical
6765 "outermost" function. This could be fixed by marking
6766 outermost frames as !stack_p,code_p,special_p. Then the
6767 initial outermost frame, before sp was valid, would
6768 have code_addr == &_start. See the comment in frame_id_eq
6770 if (!frame_id_eq (get_stack_frame_id (frame
),
6771 ecs
->event_thread
->control
.step_stack_frame_id
)
6772 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6773 ecs
->event_thread
->control
.step_stack_frame_id
)
6774 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6776 || (ecs
->event_thread
->control
.step_start_function
6777 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6779 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6780 CORE_ADDR real_stop_pc
;
6783 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6785 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6787 /* I presume that step_over_calls is only 0 when we're
6788 supposed to be stepping at the assembly language level
6789 ("stepi"). Just stop. */
6790 /* And this works the same backward as frontward. MVS */
6791 end_stepping_range (ecs
);
6795 /* Reverse stepping through solib trampolines. */
6797 if (execution_direction
== EXEC_REVERSE
6798 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6799 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6800 || (ecs
->stop_func_start
== 0
6801 && in_solib_dynsym_resolve_code (stop_pc
))))
6803 /* Any solib trampoline code can be handled in reverse
6804 by simply continuing to single-step. We have already
6805 executed the solib function (backwards), and a few
6806 steps will take us back through the trampoline to the
6812 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6814 /* We're doing a "next".
6816 Normal (forward) execution: set a breakpoint at the
6817 callee's return address (the address at which the caller
6820 Reverse (backward) execution. set the step-resume
6821 breakpoint at the start of the function that we just
6822 stepped into (backwards), and continue to there. When we
6823 get there, we'll need to single-step back to the caller. */
6825 if (execution_direction
== EXEC_REVERSE
)
6827 /* If we're already at the start of the function, we've either
6828 just stepped backward into a single instruction function,
6829 or stepped back out of a signal handler to the first instruction
6830 of the function. Just keep going, which will single-step back
6832 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6834 /* Normal function call return (static or dynamic). */
6835 symtab_and_line sr_sal
;
6836 sr_sal
.pc
= ecs
->stop_func_start
;
6837 sr_sal
.pspace
= get_frame_program_space (frame
);
6838 insert_step_resume_breakpoint_at_sal (gdbarch
,
6839 sr_sal
, null_frame_id
);
6843 insert_step_resume_breakpoint_at_caller (frame
);
6849 /* If we are in a function call trampoline (a stub between the
6850 calling routine and the real function), locate the real
6851 function. That's what tells us (a) whether we want to step
6852 into it at all, and (b) what prologue we want to run to the
6853 end of, if we do step into it. */
6854 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6855 if (real_stop_pc
== 0)
6856 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6857 if (real_stop_pc
!= 0)
6858 ecs
->stop_func_start
= real_stop_pc
;
6860 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6862 symtab_and_line sr_sal
;
6863 sr_sal
.pc
= ecs
->stop_func_start
;
6864 sr_sal
.pspace
= get_frame_program_space (frame
);
6866 insert_step_resume_breakpoint_at_sal (gdbarch
,
6867 sr_sal
, null_frame_id
);
6872 /* If we have line number information for the function we are
6873 thinking of stepping into and the function isn't on the skip
6876 If there are several symtabs at that PC (e.g. with include
6877 files), just want to know whether *any* of them have line
6878 numbers. find_pc_line handles this. */
6880 struct symtab_and_line tmp_sal
;
6882 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6883 if (tmp_sal
.line
!= 0
6884 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6886 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6888 if (execution_direction
== EXEC_REVERSE
)
6889 handle_step_into_function_backward (gdbarch
, ecs
);
6891 handle_step_into_function (gdbarch
, ecs
);
6896 /* If we have no line number and the step-stop-if-no-debug is
6897 set, we stop the step so that the user has a chance to switch
6898 in assembly mode. */
6899 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6900 && step_stop_if_no_debug
)
6902 end_stepping_range (ecs
);
6906 if (execution_direction
== EXEC_REVERSE
)
6908 /* If we're already at the start of the function, we've either just
6909 stepped backward into a single instruction function without line
6910 number info, or stepped back out of a signal handler to the first
6911 instruction of the function without line number info. Just keep
6912 going, which will single-step back to the caller. */
6913 if (ecs
->stop_func_start
!= stop_pc
)
6915 /* Set a breakpoint at callee's start address.
6916 From there we can step once and be back in the caller. */
6917 symtab_and_line sr_sal
;
6918 sr_sal
.pc
= ecs
->stop_func_start
;
6919 sr_sal
.pspace
= get_frame_program_space (frame
);
6920 insert_step_resume_breakpoint_at_sal (gdbarch
,
6921 sr_sal
, null_frame_id
);
6925 /* Set a breakpoint at callee's return address (the address
6926 at which the caller will resume). */
6927 insert_step_resume_breakpoint_at_caller (frame
);
6933 /* Reverse stepping through solib trampolines. */
6935 if (execution_direction
== EXEC_REVERSE
6936 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6938 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6940 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6941 || (ecs
->stop_func_start
== 0
6942 && in_solib_dynsym_resolve_code (stop_pc
)))
6944 /* Any solib trampoline code can be handled in reverse
6945 by simply continuing to single-step. We have already
6946 executed the solib function (backwards), and a few
6947 steps will take us back through the trampoline to the
6952 else if (in_solib_dynsym_resolve_code (stop_pc
))
6954 /* Stepped backward into the solib dynsym resolver.
6955 Set a breakpoint at its start and continue, then
6956 one more step will take us out. */
6957 symtab_and_line sr_sal
;
6958 sr_sal
.pc
= ecs
->stop_func_start
;
6959 sr_sal
.pspace
= get_frame_program_space (frame
);
6960 insert_step_resume_breakpoint_at_sal (gdbarch
,
6961 sr_sal
, null_frame_id
);
6967 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6969 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6970 the trampoline processing logic, however, there are some trampolines
6971 that have no names, so we should do trampoline handling first. */
6972 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6973 && ecs
->stop_func_name
== NULL
6974 && stop_pc_sal
.line
== 0)
6977 fprintf_unfiltered (gdb_stdlog
,
6978 "infrun: stepped into undebuggable function\n");
6980 /* The inferior just stepped into, or returned to, an
6981 undebuggable function (where there is no debugging information
6982 and no line number corresponding to the address where the
6983 inferior stopped). Since we want to skip this kind of code,
6984 we keep going until the inferior returns from this
6985 function - unless the user has asked us not to (via
6986 set step-mode) or we no longer know how to get back
6987 to the call site. */
6988 if (step_stop_if_no_debug
6989 || !frame_id_p (frame_unwind_caller_id (frame
)))
6991 /* If we have no line number and the step-stop-if-no-debug
6992 is set, we stop the step so that the user has a chance to
6993 switch in assembly mode. */
6994 end_stepping_range (ecs
);
6999 /* Set a breakpoint at callee's return address (the address
7000 at which the caller will resume). */
7001 insert_step_resume_breakpoint_at_caller (frame
);
7007 if (ecs
->event_thread
->control
.step_range_end
== 1)
7009 /* It is stepi or nexti. We always want to stop stepping after
7012 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7013 end_stepping_range (ecs
);
7017 if (stop_pc_sal
.line
== 0)
7019 /* We have no line number information. That means to stop
7020 stepping (does this always happen right after one instruction,
7021 when we do "s" in a function with no line numbers,
7022 or can this happen as a result of a return or longjmp?). */
7024 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7025 end_stepping_range (ecs
);
7029 /* Look for "calls" to inlined functions, part one. If the inline
7030 frame machinery detected some skipped call sites, we have entered
7031 a new inline function. */
7033 if (frame_id_eq (get_frame_id (get_current_frame ()),
7034 ecs
->event_thread
->control
.step_frame_id
)
7035 && inline_skipped_frames (ecs
->event_thread
))
7038 fprintf_unfiltered (gdb_stdlog
,
7039 "infrun: stepped into inlined function\n");
7041 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7043 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7045 /* For "step", we're going to stop. But if the call site
7046 for this inlined function is on the same source line as
7047 we were previously stepping, go down into the function
7048 first. Otherwise stop at the call site. */
7050 if (call_sal
.line
== ecs
->event_thread
->current_line
7051 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7053 step_into_inline_frame (ecs
->event_thread
);
7054 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7061 end_stepping_range (ecs
);
7066 /* For "next", we should stop at the call site if it is on a
7067 different source line. Otherwise continue through the
7068 inlined function. */
7069 if (call_sal
.line
== ecs
->event_thread
->current_line
7070 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7073 end_stepping_range (ecs
);
7078 /* Look for "calls" to inlined functions, part two. If we are still
7079 in the same real function we were stepping through, but we have
7080 to go further up to find the exact frame ID, we are stepping
7081 through a more inlined call beyond its call site. */
7083 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7084 && !frame_id_eq (get_frame_id (get_current_frame ()),
7085 ecs
->event_thread
->control
.step_frame_id
)
7086 && stepped_in_from (get_current_frame (),
7087 ecs
->event_thread
->control
.step_frame_id
))
7090 fprintf_unfiltered (gdb_stdlog
,
7091 "infrun: stepping through inlined function\n");
7093 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7094 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7097 end_stepping_range (ecs
);
7101 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7102 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7103 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7105 /* We are at the start of a different line. So stop. Note that
7106 we don't stop if we step into the middle of a different line.
7107 That is said to make things like for (;;) statements work
7110 fprintf_unfiltered (gdb_stdlog
,
7111 "infrun: stepped to a different line\n");
7112 end_stepping_range (ecs
);
7116 /* We aren't done stepping.
7118 Optimize by setting the stepping range to the line.
7119 (We might not be in the original line, but if we entered a
7120 new line in mid-statement, we continue stepping. This makes
7121 things like for(;;) statements work better.) */
7123 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7124 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7125 ecs
->event_thread
->control
.may_range_step
= 1;
7126 set_step_info (frame
, stop_pc_sal
);
7129 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7133 /* In all-stop mode, if we're currently stepping but have stopped in
7134 some other thread, we may need to switch back to the stepped
7135 thread. Returns true we set the inferior running, false if we left
7136 it stopped (and the event needs further processing). */
7139 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7141 if (!target_is_non_stop_p ())
7143 struct thread_info
*stepping_thread
;
7145 /* If any thread is blocked on some internal breakpoint, and we
7146 simply need to step over that breakpoint to get it going
7147 again, do that first. */
7149 /* However, if we see an event for the stepping thread, then we
7150 know all other threads have been moved past their breakpoints
7151 already. Let the caller check whether the step is finished,
7152 etc., before deciding to move it past a breakpoint. */
7153 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7156 /* Check if the current thread is blocked on an incomplete
7157 step-over, interrupted by a random signal. */
7158 if (ecs
->event_thread
->control
.trap_expected
7159 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7163 fprintf_unfiltered (gdb_stdlog
,
7164 "infrun: need to finish step-over of [%s]\n",
7165 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7171 /* Check if the current thread is blocked by a single-step
7172 breakpoint of another thread. */
7173 if (ecs
->hit_singlestep_breakpoint
)
7177 fprintf_unfiltered (gdb_stdlog
,
7178 "infrun: need to step [%s] over single-step "
7180 target_pid_to_str (ecs
->ptid
).c_str ());
7186 /* If this thread needs yet another step-over (e.g., stepping
7187 through a delay slot), do it first before moving on to
7189 if (thread_still_needs_step_over (ecs
->event_thread
))
7193 fprintf_unfiltered (gdb_stdlog
,
7194 "infrun: thread [%s] still needs step-over\n",
7195 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7201 /* If scheduler locking applies even if not stepping, there's no
7202 need to walk over threads. Above we've checked whether the
7203 current thread is stepping. If some other thread not the
7204 event thread is stepping, then it must be that scheduler
7205 locking is not in effect. */
7206 if (schedlock_applies (ecs
->event_thread
))
7209 /* Otherwise, we no longer expect a trap in the current thread.
7210 Clear the trap_expected flag before switching back -- this is
7211 what keep_going does as well, if we call it. */
7212 ecs
->event_thread
->control
.trap_expected
= 0;
7214 /* Likewise, clear the signal if it should not be passed. */
7215 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7216 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7218 /* Do all pending step-overs before actually proceeding with
7220 if (start_step_over ())
7222 prepare_to_wait (ecs
);
7226 /* Look for the stepping/nexting thread. */
7227 stepping_thread
= NULL
;
7229 for (thread_info
*tp
: all_non_exited_threads ())
7231 switch_to_thread_no_regs (tp
);
7233 /* Ignore threads of processes the caller is not
7236 && (tp
->inf
->process_target () != ecs
->target
7237 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7240 /* When stepping over a breakpoint, we lock all threads
7241 except the one that needs to move past the breakpoint.
7242 If a non-event thread has this set, the "incomplete
7243 step-over" check above should have caught it earlier. */
7244 if (tp
->control
.trap_expected
)
7246 internal_error (__FILE__
, __LINE__
,
7247 "[%s] has inconsistent state: "
7248 "trap_expected=%d\n",
7249 target_pid_to_str (tp
->ptid
).c_str (),
7250 tp
->control
.trap_expected
);
7253 /* Did we find the stepping thread? */
7254 if (tp
->control
.step_range_end
)
7256 /* Yep. There should only one though. */
7257 gdb_assert (stepping_thread
== NULL
);
7259 /* The event thread is handled at the top, before we
7261 gdb_assert (tp
!= ecs
->event_thread
);
7263 /* If some thread other than the event thread is
7264 stepping, then scheduler locking can't be in effect,
7265 otherwise we wouldn't have resumed the current event
7266 thread in the first place. */
7267 gdb_assert (!schedlock_applies (tp
));
7269 stepping_thread
= tp
;
7273 if (stepping_thread
!= NULL
)
7276 fprintf_unfiltered (gdb_stdlog
,
7277 "infrun: switching back to stepped thread\n");
7279 if (keep_going_stepped_thread (stepping_thread
))
7281 prepare_to_wait (ecs
);
7286 switch_to_thread (ecs
->event_thread
);
7292 /* Set a previously stepped thread back to stepping. Returns true on
7293 success, false if the resume is not possible (e.g., the thread
7297 keep_going_stepped_thread (struct thread_info
*tp
)
7299 struct frame_info
*frame
;
7300 struct execution_control_state ecss
;
7301 struct execution_control_state
*ecs
= &ecss
;
7303 /* If the stepping thread exited, then don't try to switch back and
7304 resume it, which could fail in several different ways depending
7305 on the target. Instead, just keep going.
7307 We can find a stepping dead thread in the thread list in two
7310 - The target supports thread exit events, and when the target
7311 tries to delete the thread from the thread list, inferior_ptid
7312 pointed at the exiting thread. In such case, calling
7313 delete_thread does not really remove the thread from the list;
7314 instead, the thread is left listed, with 'exited' state.
7316 - The target's debug interface does not support thread exit
7317 events, and so we have no idea whatsoever if the previously
7318 stepping thread is still alive. For that reason, we need to
7319 synchronously query the target now. */
7321 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7324 fprintf_unfiltered (gdb_stdlog
,
7325 "infrun: not resuming previously "
7326 "stepped thread, it has vanished\n");
7333 fprintf_unfiltered (gdb_stdlog
,
7334 "infrun: resuming previously stepped thread\n");
7336 reset_ecs (ecs
, tp
);
7337 switch_to_thread (tp
);
7339 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7340 frame
= get_current_frame ();
7342 /* If the PC of the thread we were trying to single-step has
7343 changed, then that thread has trapped or been signaled, but the
7344 event has not been reported to GDB yet. Re-poll the target
7345 looking for this particular thread's event (i.e. temporarily
7346 enable schedlock) by:
7348 - setting a break at the current PC
7349 - resuming that particular thread, only (by setting trap
7352 This prevents us continuously moving the single-step breakpoint
7353 forward, one instruction at a time, overstepping. */
7355 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7360 fprintf_unfiltered (gdb_stdlog
,
7361 "infrun: expected thread advanced also (%s -> %s)\n",
7362 paddress (target_gdbarch (), tp
->prev_pc
),
7363 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7365 /* Clear the info of the previous step-over, as it's no longer
7366 valid (if the thread was trying to step over a breakpoint, it
7367 has already succeeded). It's what keep_going would do too,
7368 if we called it. Do this before trying to insert the sss
7369 breakpoint, otherwise if we were previously trying to step
7370 over this exact address in another thread, the breakpoint is
7372 clear_step_over_info ();
7373 tp
->control
.trap_expected
= 0;
7375 insert_single_step_breakpoint (get_frame_arch (frame
),
7376 get_frame_address_space (frame
),
7377 tp
->suspend
.stop_pc
);
7380 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7381 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7386 fprintf_unfiltered (gdb_stdlog
,
7387 "infrun: expected thread still hasn't advanced\n");
7389 keep_going_pass_signal (ecs
);
7394 /* Is thread TP in the middle of (software or hardware)
7395 single-stepping? (Note the result of this function must never be
7396 passed directly as target_resume's STEP parameter.) */
7399 currently_stepping (struct thread_info
*tp
)
7401 return ((tp
->control
.step_range_end
7402 && tp
->control
.step_resume_breakpoint
== NULL
)
7403 || tp
->control
.trap_expected
7404 || tp
->stepped_breakpoint
7405 || bpstat_should_step ());
7408 /* Inferior has stepped into a subroutine call with source code that
7409 we should not step over. Do step to the first line of code in
7413 handle_step_into_function (struct gdbarch
*gdbarch
,
7414 struct execution_control_state
*ecs
)
7416 fill_in_stop_func (gdbarch
, ecs
);
7418 compunit_symtab
*cust
7419 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7420 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7421 ecs
->stop_func_start
7422 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7424 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7425 /* Use the step_resume_break to step until the end of the prologue,
7426 even if that involves jumps (as it seems to on the vax under
7428 /* If the prologue ends in the middle of a source line, continue to
7429 the end of that source line (if it is still within the function).
7430 Otherwise, just go to end of prologue. */
7431 if (stop_func_sal
.end
7432 && stop_func_sal
.pc
!= ecs
->stop_func_start
7433 && stop_func_sal
.end
< ecs
->stop_func_end
)
7434 ecs
->stop_func_start
= stop_func_sal
.end
;
7436 /* Architectures which require breakpoint adjustment might not be able
7437 to place a breakpoint at the computed address. If so, the test
7438 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7439 ecs->stop_func_start to an address at which a breakpoint may be
7440 legitimately placed.
7442 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7443 made, GDB will enter an infinite loop when stepping through
7444 optimized code consisting of VLIW instructions which contain
7445 subinstructions corresponding to different source lines. On
7446 FR-V, it's not permitted to place a breakpoint on any but the
7447 first subinstruction of a VLIW instruction. When a breakpoint is
7448 set, GDB will adjust the breakpoint address to the beginning of
7449 the VLIW instruction. Thus, we need to make the corresponding
7450 adjustment here when computing the stop address. */
7452 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7454 ecs
->stop_func_start
7455 = gdbarch_adjust_breakpoint_address (gdbarch
,
7456 ecs
->stop_func_start
);
7459 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7461 /* We are already there: stop now. */
7462 end_stepping_range (ecs
);
7467 /* Put the step-breakpoint there and go until there. */
7468 symtab_and_line sr_sal
;
7469 sr_sal
.pc
= ecs
->stop_func_start
;
7470 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7471 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7473 /* Do not specify what the fp should be when we stop since on
7474 some machines the prologue is where the new fp value is
7476 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7478 /* And make sure stepping stops right away then. */
7479 ecs
->event_thread
->control
.step_range_end
7480 = ecs
->event_thread
->control
.step_range_start
;
7485 /* Inferior has stepped backward into a subroutine call with source
7486 code that we should not step over. Do step to the beginning of the
7487 last line of code in it. */
7490 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7491 struct execution_control_state
*ecs
)
7493 struct compunit_symtab
*cust
;
7494 struct symtab_and_line stop_func_sal
;
7496 fill_in_stop_func (gdbarch
, ecs
);
7498 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7499 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7500 ecs
->stop_func_start
7501 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7503 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7505 /* OK, we're just going to keep stepping here. */
7506 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7508 /* We're there already. Just stop stepping now. */
7509 end_stepping_range (ecs
);
7513 /* Else just reset the step range and keep going.
7514 No step-resume breakpoint, they don't work for
7515 epilogues, which can have multiple entry paths. */
7516 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7517 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7523 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7524 This is used to both functions and to skip over code. */
7527 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7528 struct symtab_and_line sr_sal
,
7529 struct frame_id sr_id
,
7530 enum bptype sr_type
)
7532 /* There should never be more than one step-resume or longjmp-resume
7533 breakpoint per thread, so we should never be setting a new
7534 step_resume_breakpoint when one is already active. */
7535 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7536 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7539 fprintf_unfiltered (gdb_stdlog
,
7540 "infrun: inserting step-resume breakpoint at %s\n",
7541 paddress (gdbarch
, sr_sal
.pc
));
7543 inferior_thread ()->control
.step_resume_breakpoint
7544 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7548 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7549 struct symtab_and_line sr_sal
,
7550 struct frame_id sr_id
)
7552 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7557 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7558 This is used to skip a potential signal handler.
7560 This is called with the interrupted function's frame. The signal
7561 handler, when it returns, will resume the interrupted function at
7565 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7567 gdb_assert (return_frame
!= NULL
);
7569 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7571 symtab_and_line sr_sal
;
7572 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7573 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7574 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7576 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7577 get_stack_frame_id (return_frame
),
7581 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7582 is used to skip a function after stepping into it (for "next" or if
7583 the called function has no debugging information).
7585 The current function has almost always been reached by single
7586 stepping a call or return instruction. NEXT_FRAME belongs to the
7587 current function, and the breakpoint will be set at the caller's
7590 This is a separate function rather than reusing
7591 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7592 get_prev_frame, which may stop prematurely (see the implementation
7593 of frame_unwind_caller_id for an example). */
7596 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7598 /* We shouldn't have gotten here if we don't know where the call site
7600 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7602 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7604 symtab_and_line sr_sal
;
7605 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7606 frame_unwind_caller_pc (next_frame
));
7607 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7608 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7610 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7611 frame_unwind_caller_id (next_frame
));
7614 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7615 new breakpoint at the target of a jmp_buf. The handling of
7616 longjmp-resume uses the same mechanisms used for handling
7617 "step-resume" breakpoints. */
7620 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7622 /* There should never be more than one longjmp-resume breakpoint per
7623 thread, so we should never be setting a new
7624 longjmp_resume_breakpoint when one is already active. */
7625 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7628 fprintf_unfiltered (gdb_stdlog
,
7629 "infrun: inserting longjmp-resume breakpoint at %s\n",
7630 paddress (gdbarch
, pc
));
7632 inferior_thread ()->control
.exception_resume_breakpoint
=
7633 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7636 /* Insert an exception resume breakpoint. TP is the thread throwing
7637 the exception. The block B is the block of the unwinder debug hook
7638 function. FRAME is the frame corresponding to the call to this
7639 function. SYM is the symbol of the function argument holding the
7640 target PC of the exception. */
7643 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7644 const struct block
*b
,
7645 struct frame_info
*frame
,
7650 struct block_symbol vsym
;
7651 struct value
*value
;
7653 struct breakpoint
*bp
;
7655 vsym
= lookup_symbol_search_name (sym
->search_name (),
7657 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7658 /* If the value was optimized out, revert to the old behavior. */
7659 if (! value_optimized_out (value
))
7661 handler
= value_as_address (value
);
7664 fprintf_unfiltered (gdb_stdlog
,
7665 "infrun: exception resume at %lx\n",
7666 (unsigned long) handler
);
7668 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7670 bp_exception_resume
).release ();
7672 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7675 bp
->thread
= tp
->global_num
;
7676 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7679 catch (const gdb_exception_error
&e
)
7681 /* We want to ignore errors here. */
7685 /* A helper for check_exception_resume that sets an
7686 exception-breakpoint based on a SystemTap probe. */
7689 insert_exception_resume_from_probe (struct thread_info
*tp
,
7690 const struct bound_probe
*probe
,
7691 struct frame_info
*frame
)
7693 struct value
*arg_value
;
7695 struct breakpoint
*bp
;
7697 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7701 handler
= value_as_address (arg_value
);
7704 fprintf_unfiltered (gdb_stdlog
,
7705 "infrun: exception resume at %s\n",
7706 paddress (get_objfile_arch (probe
->objfile
),
7709 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7710 handler
, bp_exception_resume
).release ();
7711 bp
->thread
= tp
->global_num
;
7712 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7715 /* This is called when an exception has been intercepted. Check to
7716 see whether the exception's destination is of interest, and if so,
7717 set an exception resume breakpoint there. */
7720 check_exception_resume (struct execution_control_state
*ecs
,
7721 struct frame_info
*frame
)
7723 struct bound_probe probe
;
7724 struct symbol
*func
;
7726 /* First see if this exception unwinding breakpoint was set via a
7727 SystemTap probe point. If so, the probe has two arguments: the
7728 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7729 set a breakpoint there. */
7730 probe
= find_probe_by_pc (get_frame_pc (frame
));
7733 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7737 func
= get_frame_function (frame
);
7743 const struct block
*b
;
7744 struct block_iterator iter
;
7748 /* The exception breakpoint is a thread-specific breakpoint on
7749 the unwinder's debug hook, declared as:
7751 void _Unwind_DebugHook (void *cfa, void *handler);
7753 The CFA argument indicates the frame to which control is
7754 about to be transferred. HANDLER is the destination PC.
7756 We ignore the CFA and set a temporary breakpoint at HANDLER.
7757 This is not extremely efficient but it avoids issues in gdb
7758 with computing the DWARF CFA, and it also works even in weird
7759 cases such as throwing an exception from inside a signal
7762 b
= SYMBOL_BLOCK_VALUE (func
);
7763 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7765 if (!SYMBOL_IS_ARGUMENT (sym
))
7772 insert_exception_resume_breakpoint (ecs
->event_thread
,
7778 catch (const gdb_exception_error
&e
)
7784 stop_waiting (struct execution_control_state
*ecs
)
7787 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7789 /* Let callers know we don't want to wait for the inferior anymore. */
7790 ecs
->wait_some_more
= 0;
7792 /* If all-stop, but the target is always in non-stop mode, stop all
7793 threads now that we're presenting the stop to the user. */
7794 if (!non_stop
&& target_is_non_stop_p ())
7795 stop_all_threads ();
7798 /* Like keep_going, but passes the signal to the inferior, even if the
7799 signal is set to nopass. */
7802 keep_going_pass_signal (struct execution_control_state
*ecs
)
7804 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7805 gdb_assert (!ecs
->event_thread
->resumed
);
7807 /* Save the pc before execution, to compare with pc after stop. */
7808 ecs
->event_thread
->prev_pc
7809 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7811 if (ecs
->event_thread
->control
.trap_expected
)
7813 struct thread_info
*tp
= ecs
->event_thread
;
7816 fprintf_unfiltered (gdb_stdlog
,
7817 "infrun: %s has trap_expected set, "
7818 "resuming to collect trap\n",
7819 target_pid_to_str (tp
->ptid
).c_str ());
7821 /* We haven't yet gotten our trap, and either: intercepted a
7822 non-signal event (e.g., a fork); or took a signal which we
7823 are supposed to pass through to the inferior. Simply
7825 resume (ecs
->event_thread
->suspend
.stop_signal
);
7827 else if (step_over_info_valid_p ())
7829 /* Another thread is stepping over a breakpoint in-line. If
7830 this thread needs a step-over too, queue the request. In
7831 either case, this resume must be deferred for later. */
7832 struct thread_info
*tp
= ecs
->event_thread
;
7834 if (ecs
->hit_singlestep_breakpoint
7835 || thread_still_needs_step_over (tp
))
7838 fprintf_unfiltered (gdb_stdlog
,
7839 "infrun: step-over already in progress: "
7840 "step-over for %s deferred\n",
7841 target_pid_to_str (tp
->ptid
).c_str ());
7842 thread_step_over_chain_enqueue (tp
);
7847 fprintf_unfiltered (gdb_stdlog
,
7848 "infrun: step-over in progress: "
7849 "resume of %s deferred\n",
7850 target_pid_to_str (tp
->ptid
).c_str ());
7855 struct regcache
*regcache
= get_current_regcache ();
7858 step_over_what step_what
;
7860 /* Either the trap was not expected, but we are continuing
7861 anyway (if we got a signal, the user asked it be passed to
7864 We got our expected trap, but decided we should resume from
7867 We're going to run this baby now!
7869 Note that insert_breakpoints won't try to re-insert
7870 already inserted breakpoints. Therefore, we don't
7871 care if breakpoints were already inserted, or not. */
7873 /* If we need to step over a breakpoint, and we're not using
7874 displaced stepping to do so, insert all breakpoints
7875 (watchpoints, etc.) but the one we're stepping over, step one
7876 instruction, and then re-insert the breakpoint when that step
7879 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7881 remove_bp
= (ecs
->hit_singlestep_breakpoint
7882 || (step_what
& STEP_OVER_BREAKPOINT
));
7883 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7885 /* We can't use displaced stepping if we need to step past a
7886 watchpoint. The instruction copied to the scratch pad would
7887 still trigger the watchpoint. */
7889 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7891 set_step_over_info (regcache
->aspace (),
7892 regcache_read_pc (regcache
), remove_wps
,
7893 ecs
->event_thread
->global_num
);
7895 else if (remove_wps
)
7896 set_step_over_info (NULL
, 0, remove_wps
, -1);
7898 /* If we now need to do an in-line step-over, we need to stop
7899 all other threads. Note this must be done before
7900 insert_breakpoints below, because that removes the breakpoint
7901 we're about to step over, otherwise other threads could miss
7903 if (step_over_info_valid_p () && target_is_non_stop_p ())
7904 stop_all_threads ();
7906 /* Stop stepping if inserting breakpoints fails. */
7909 insert_breakpoints ();
7911 catch (const gdb_exception_error
&e
)
7913 exception_print (gdb_stderr
, e
);
7915 clear_step_over_info ();
7919 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7921 resume (ecs
->event_thread
->suspend
.stop_signal
);
7924 prepare_to_wait (ecs
);
7927 /* Called when we should continue running the inferior, because the
7928 current event doesn't cause a user visible stop. This does the
7929 resuming part; waiting for the next event is done elsewhere. */
7932 keep_going (struct execution_control_state
*ecs
)
7934 if (ecs
->event_thread
->control
.trap_expected
7935 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7936 ecs
->event_thread
->control
.trap_expected
= 0;
7938 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7939 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7940 keep_going_pass_signal (ecs
);
7943 /* This function normally comes after a resume, before
7944 handle_inferior_event exits. It takes care of any last bits of
7945 housekeeping, and sets the all-important wait_some_more flag. */
7948 prepare_to_wait (struct execution_control_state
*ecs
)
7951 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7953 ecs
->wait_some_more
= 1;
7955 if (!target_is_async_p ())
7956 mark_infrun_async_event_handler ();
7959 /* We are done with the step range of a step/next/si/ni command.
7960 Called once for each n of a "step n" operation. */
7963 end_stepping_range (struct execution_control_state
*ecs
)
7965 ecs
->event_thread
->control
.stop_step
= 1;
7969 /* Several print_*_reason functions to print why the inferior has stopped.
7970 We always print something when the inferior exits, or receives a signal.
7971 The rest of the cases are dealt with later on in normal_stop and
7972 print_it_typical. Ideally there should be a call to one of these
7973 print_*_reason functions functions from handle_inferior_event each time
7974 stop_waiting is called.
7976 Note that we don't call these directly, instead we delegate that to
7977 the interpreters, through observers. Interpreters then call these
7978 with whatever uiout is right. */
7981 print_end_stepping_range_reason (struct ui_out
*uiout
)
7983 /* For CLI-like interpreters, print nothing. */
7985 if (uiout
->is_mi_like_p ())
7987 uiout
->field_string ("reason",
7988 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7993 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7995 annotate_signalled ();
7996 if (uiout
->is_mi_like_p ())
7998 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7999 uiout
->text ("\nProgram terminated with signal ");
8000 annotate_signal_name ();
8001 uiout
->field_string ("signal-name",
8002 gdb_signal_to_name (siggnal
));
8003 annotate_signal_name_end ();
8005 annotate_signal_string ();
8006 uiout
->field_string ("signal-meaning",
8007 gdb_signal_to_string (siggnal
));
8008 annotate_signal_string_end ();
8009 uiout
->text (".\n");
8010 uiout
->text ("The program no longer exists.\n");
8014 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8016 struct inferior
*inf
= current_inferior ();
8017 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8019 annotate_exited (exitstatus
);
8022 if (uiout
->is_mi_like_p ())
8023 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8024 std::string exit_code_str
8025 = string_printf ("0%o", (unsigned int) exitstatus
);
8026 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8027 plongest (inf
->num
), pidstr
.c_str (),
8028 string_field ("exit-code", exit_code_str
.c_str ()));
8032 if (uiout
->is_mi_like_p ())
8034 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8035 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8036 plongest (inf
->num
), pidstr
.c_str ());
8040 /* Some targets/architectures can do extra processing/display of
8041 segmentation faults. E.g., Intel MPX boundary faults.
8042 Call the architecture dependent function to handle the fault. */
8045 handle_segmentation_fault (struct ui_out
*uiout
)
8047 struct regcache
*regcache
= get_current_regcache ();
8048 struct gdbarch
*gdbarch
= regcache
->arch ();
8050 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8051 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8055 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8057 struct thread_info
*thr
= inferior_thread ();
8061 if (uiout
->is_mi_like_p ())
8063 else if (show_thread_that_caused_stop ())
8067 uiout
->text ("\nThread ");
8068 uiout
->field_string ("thread-id", print_thread_id (thr
));
8070 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8073 uiout
->text (" \"");
8074 uiout
->field_string ("name", name
);
8079 uiout
->text ("\nProgram");
8081 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8082 uiout
->text (" stopped");
8085 uiout
->text (" received signal ");
8086 annotate_signal_name ();
8087 if (uiout
->is_mi_like_p ())
8089 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8090 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8091 annotate_signal_name_end ();
8093 annotate_signal_string ();
8094 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8096 if (siggnal
== GDB_SIGNAL_SEGV
)
8097 handle_segmentation_fault (uiout
);
8099 annotate_signal_string_end ();
8101 uiout
->text (".\n");
8105 print_no_history_reason (struct ui_out
*uiout
)
8107 uiout
->text ("\nNo more reverse-execution history.\n");
8110 /* Print current location without a level number, if we have changed
8111 functions or hit a breakpoint. Print source line if we have one.
8112 bpstat_print contains the logic deciding in detail what to print,
8113 based on the event(s) that just occurred. */
8116 print_stop_location (struct target_waitstatus
*ws
)
8119 enum print_what source_flag
;
8120 int do_frame_printing
= 1;
8121 struct thread_info
*tp
= inferior_thread ();
8123 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8127 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8128 should) carry around the function and does (or should) use
8129 that when doing a frame comparison. */
8130 if (tp
->control
.stop_step
8131 && frame_id_eq (tp
->control
.step_frame_id
,
8132 get_frame_id (get_current_frame ()))
8133 && (tp
->control
.step_start_function
8134 == find_pc_function (tp
->suspend
.stop_pc
)))
8136 /* Finished step, just print source line. */
8137 source_flag
= SRC_LINE
;
8141 /* Print location and source line. */
8142 source_flag
= SRC_AND_LOC
;
8145 case PRINT_SRC_AND_LOC
:
8146 /* Print location and source line. */
8147 source_flag
= SRC_AND_LOC
;
8149 case PRINT_SRC_ONLY
:
8150 source_flag
= SRC_LINE
;
8153 /* Something bogus. */
8154 source_flag
= SRC_LINE
;
8155 do_frame_printing
= 0;
8158 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8161 /* The behavior of this routine with respect to the source
8163 SRC_LINE: Print only source line
8164 LOCATION: Print only location
8165 SRC_AND_LOC: Print location and source line. */
8166 if (do_frame_printing
)
8167 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8173 print_stop_event (struct ui_out
*uiout
, bool displays
)
8175 struct target_waitstatus last
;
8176 struct thread_info
*tp
;
8178 get_last_target_status (nullptr, nullptr, &last
);
8181 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8183 print_stop_location (&last
);
8185 /* Display the auto-display expressions. */
8190 tp
= inferior_thread ();
8191 if (tp
->thread_fsm
!= NULL
8192 && tp
->thread_fsm
->finished_p ())
8194 struct return_value_info
*rv
;
8196 rv
= tp
->thread_fsm
->return_value ();
8198 print_return_value (uiout
, rv
);
8205 maybe_remove_breakpoints (void)
8207 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8209 if (remove_breakpoints ())
8211 target_terminal::ours_for_output ();
8212 printf_filtered (_("Cannot remove breakpoints because "
8213 "program is no longer writable.\nFurther "
8214 "execution is probably impossible.\n"));
8219 /* The execution context that just caused a normal stop. */
8226 DISABLE_COPY_AND_ASSIGN (stop_context
);
8228 bool changed () const;
8233 /* The event PTID. */
8237 /* If stopp for a thread event, this is the thread that caused the
8239 struct thread_info
*thread
;
8241 /* The inferior that caused the stop. */
8245 /* Initializes a new stop context. If stopped for a thread event, this
8246 takes a strong reference to the thread. */
8248 stop_context::stop_context ()
8250 stop_id
= get_stop_id ();
8251 ptid
= inferior_ptid
;
8252 inf_num
= current_inferior ()->num
;
8254 if (inferior_ptid
!= null_ptid
)
8256 /* Take a strong reference so that the thread can't be deleted
8258 thread
= inferior_thread ();
8265 /* Release a stop context previously created with save_stop_context.
8266 Releases the strong reference to the thread as well. */
8268 stop_context::~stop_context ()
8274 /* Return true if the current context no longer matches the saved stop
8278 stop_context::changed () const
8280 if (ptid
!= inferior_ptid
)
8282 if (inf_num
!= current_inferior ()->num
)
8284 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8286 if (get_stop_id () != stop_id
)
8296 struct target_waitstatus last
;
8298 get_last_target_status (nullptr, nullptr, &last
);
8302 /* If an exception is thrown from this point on, make sure to
8303 propagate GDB's knowledge of the executing state to the
8304 frontend/user running state. A QUIT is an easy exception to see
8305 here, so do this before any filtered output. */
8307 ptid_t finish_ptid
= null_ptid
;
8310 finish_ptid
= minus_one_ptid
;
8311 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8312 || last
.kind
== TARGET_WAITKIND_EXITED
)
8314 /* On some targets, we may still have live threads in the
8315 inferior when we get a process exit event. E.g., for
8316 "checkpoint", when the current checkpoint/fork exits,
8317 linux-fork.c automatically switches to another fork from
8318 within target_mourn_inferior. */
8319 if (inferior_ptid
!= null_ptid
)
8320 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8322 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8323 finish_ptid
= inferior_ptid
;
8325 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8326 if (finish_ptid
!= null_ptid
)
8328 maybe_finish_thread_state
.emplace
8329 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8332 /* As we're presenting a stop, and potentially removing breakpoints,
8333 update the thread list so we can tell whether there are threads
8334 running on the target. With target remote, for example, we can
8335 only learn about new threads when we explicitly update the thread
8336 list. Do this before notifying the interpreters about signal
8337 stops, end of stepping ranges, etc., so that the "new thread"
8338 output is emitted before e.g., "Program received signal FOO",
8339 instead of after. */
8340 update_thread_list ();
8342 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8343 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8345 /* As with the notification of thread events, we want to delay
8346 notifying the user that we've switched thread context until
8347 the inferior actually stops.
8349 There's no point in saying anything if the inferior has exited.
8350 Note that SIGNALLED here means "exited with a signal", not
8351 "received a signal".
8353 Also skip saying anything in non-stop mode. In that mode, as we
8354 don't want GDB to switch threads behind the user's back, to avoid
8355 races where the user is typing a command to apply to thread x,
8356 but GDB switches to thread y before the user finishes entering
8357 the command, fetch_inferior_event installs a cleanup to restore
8358 the current thread back to the thread the user had selected right
8359 after this event is handled, so we're not really switching, only
8360 informing of a stop. */
8362 && previous_inferior_ptid
!= inferior_ptid
8363 && target_has_execution
8364 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8365 && last
.kind
!= TARGET_WAITKIND_EXITED
8366 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8368 SWITCH_THRU_ALL_UIS ()
8370 target_terminal::ours_for_output ();
8371 printf_filtered (_("[Switching to %s]\n"),
8372 target_pid_to_str (inferior_ptid
).c_str ());
8373 annotate_thread_changed ();
8375 previous_inferior_ptid
= inferior_ptid
;
8378 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8380 SWITCH_THRU_ALL_UIS ()
8381 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8383 target_terminal::ours_for_output ();
8384 printf_filtered (_("No unwaited-for children left.\n"));
8388 /* Note: this depends on the update_thread_list call above. */
8389 maybe_remove_breakpoints ();
8391 /* If an auto-display called a function and that got a signal,
8392 delete that auto-display to avoid an infinite recursion. */
8394 if (stopped_by_random_signal
)
8395 disable_current_display ();
8397 SWITCH_THRU_ALL_UIS ()
8399 async_enable_stdin ();
8402 /* Let the user/frontend see the threads as stopped. */
8403 maybe_finish_thread_state
.reset ();
8405 /* Select innermost stack frame - i.e., current frame is frame 0,
8406 and current location is based on that. Handle the case where the
8407 dummy call is returning after being stopped. E.g. the dummy call
8408 previously hit a breakpoint. (If the dummy call returns
8409 normally, we won't reach here.) Do this before the stop hook is
8410 run, so that it doesn't get to see the temporary dummy frame,
8411 which is not where we'll present the stop. */
8412 if (has_stack_frames ())
8414 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8416 /* Pop the empty frame that contains the stack dummy. This
8417 also restores inferior state prior to the call (struct
8418 infcall_suspend_state). */
8419 struct frame_info
*frame
= get_current_frame ();
8421 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8423 /* frame_pop calls reinit_frame_cache as the last thing it
8424 does which means there's now no selected frame. */
8427 select_frame (get_current_frame ());
8429 /* Set the current source location. */
8430 set_current_sal_from_frame (get_current_frame ());
8433 /* Look up the hook_stop and run it (CLI internally handles problem
8434 of stop_command's pre-hook not existing). */
8435 if (stop_command
!= NULL
)
8437 stop_context saved_context
;
8441 execute_cmd_pre_hook (stop_command
);
8443 catch (const gdb_exception
&ex
)
8445 exception_fprintf (gdb_stderr
, ex
,
8446 "Error while running hook_stop:\n");
8449 /* If the stop hook resumes the target, then there's no point in
8450 trying to notify about the previous stop; its context is
8451 gone. Likewise if the command switches thread or inferior --
8452 the observers would print a stop for the wrong
8454 if (saved_context
.changed ())
8458 /* Notify observers about the stop. This is where the interpreters
8459 print the stop event. */
8460 if (inferior_ptid
!= null_ptid
)
8461 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8464 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8466 annotate_stopped ();
8468 if (target_has_execution
)
8470 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8471 && last
.kind
!= TARGET_WAITKIND_EXITED
8472 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8473 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8474 Delete any breakpoint that is to be deleted at the next stop. */
8475 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8478 /* Try to get rid of automatically added inferiors that are no
8479 longer needed. Keeping those around slows down things linearly.
8480 Note that this never removes the current inferior. */
8487 signal_stop_state (int signo
)
8489 return signal_stop
[signo
];
8493 signal_print_state (int signo
)
8495 return signal_print
[signo
];
8499 signal_pass_state (int signo
)
8501 return signal_program
[signo
];
8505 signal_cache_update (int signo
)
8509 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8510 signal_cache_update (signo
);
8515 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8516 && signal_print
[signo
] == 0
8517 && signal_program
[signo
] == 1
8518 && signal_catch
[signo
] == 0);
8522 signal_stop_update (int signo
, int state
)
8524 int ret
= signal_stop
[signo
];
8526 signal_stop
[signo
] = state
;
8527 signal_cache_update (signo
);
8532 signal_print_update (int signo
, int state
)
8534 int ret
= signal_print
[signo
];
8536 signal_print
[signo
] = state
;
8537 signal_cache_update (signo
);
8542 signal_pass_update (int signo
, int state
)
8544 int ret
= signal_program
[signo
];
8546 signal_program
[signo
] = state
;
8547 signal_cache_update (signo
);
8551 /* Update the global 'signal_catch' from INFO and notify the
8555 signal_catch_update (const unsigned int *info
)
8559 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8560 signal_catch
[i
] = info
[i
] > 0;
8561 signal_cache_update (-1);
8562 target_pass_signals (signal_pass
);
8566 sig_print_header (void)
8568 printf_filtered (_("Signal Stop\tPrint\tPass "
8569 "to program\tDescription\n"));
8573 sig_print_info (enum gdb_signal oursig
)
8575 const char *name
= gdb_signal_to_name (oursig
);
8576 int name_padding
= 13 - strlen (name
);
8578 if (name_padding
<= 0)
8581 printf_filtered ("%s", name
);
8582 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8583 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8584 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8585 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8586 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8589 /* Specify how various signals in the inferior should be handled. */
8592 handle_command (const char *args
, int from_tty
)
8594 int digits
, wordlen
;
8595 int sigfirst
, siglast
;
8596 enum gdb_signal oursig
;
8601 error_no_arg (_("signal to handle"));
8604 /* Allocate and zero an array of flags for which signals to handle. */
8606 const size_t nsigs
= GDB_SIGNAL_LAST
;
8607 unsigned char sigs
[nsigs
] {};
8609 /* Break the command line up into args. */
8611 gdb_argv
built_argv (args
);
8613 /* Walk through the args, looking for signal oursigs, signal names, and
8614 actions. Signal numbers and signal names may be interspersed with
8615 actions, with the actions being performed for all signals cumulatively
8616 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8618 for (char *arg
: built_argv
)
8620 wordlen
= strlen (arg
);
8621 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8625 sigfirst
= siglast
= -1;
8627 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8629 /* Apply action to all signals except those used by the
8630 debugger. Silently skip those. */
8633 siglast
= nsigs
- 1;
8635 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8637 SET_SIGS (nsigs
, sigs
, signal_stop
);
8638 SET_SIGS (nsigs
, sigs
, signal_print
);
8640 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8642 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8644 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8646 SET_SIGS (nsigs
, sigs
, signal_print
);
8648 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8650 SET_SIGS (nsigs
, sigs
, signal_program
);
8652 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8654 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8656 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8658 SET_SIGS (nsigs
, sigs
, signal_program
);
8660 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8662 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8663 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8665 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8667 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8669 else if (digits
> 0)
8671 /* It is numeric. The numeric signal refers to our own
8672 internal signal numbering from target.h, not to host/target
8673 signal number. This is a feature; users really should be
8674 using symbolic names anyway, and the common ones like
8675 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8677 sigfirst
= siglast
= (int)
8678 gdb_signal_from_command (atoi (arg
));
8679 if (arg
[digits
] == '-')
8682 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8684 if (sigfirst
> siglast
)
8686 /* Bet he didn't figure we'd think of this case... */
8687 std::swap (sigfirst
, siglast
);
8692 oursig
= gdb_signal_from_name (arg
);
8693 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8695 sigfirst
= siglast
= (int) oursig
;
8699 /* Not a number and not a recognized flag word => complain. */
8700 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8704 /* If any signal numbers or symbol names were found, set flags for
8705 which signals to apply actions to. */
8707 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8709 switch ((enum gdb_signal
) signum
)
8711 case GDB_SIGNAL_TRAP
:
8712 case GDB_SIGNAL_INT
:
8713 if (!allsigs
&& !sigs
[signum
])
8715 if (query (_("%s is used by the debugger.\n\
8716 Are you sure you want to change it? "),
8717 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8722 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8726 case GDB_SIGNAL_DEFAULT
:
8727 case GDB_SIGNAL_UNKNOWN
:
8728 /* Make sure that "all" doesn't print these. */
8737 for (int signum
= 0; signum
< nsigs
; signum
++)
8740 signal_cache_update (-1);
8741 target_pass_signals (signal_pass
);
8742 target_program_signals (signal_program
);
8746 /* Show the results. */
8747 sig_print_header ();
8748 for (; signum
< nsigs
; signum
++)
8750 sig_print_info ((enum gdb_signal
) signum
);
8757 /* Complete the "handle" command. */
8760 handle_completer (struct cmd_list_element
*ignore
,
8761 completion_tracker
&tracker
,
8762 const char *text
, const char *word
)
8764 static const char * const keywords
[] =
8778 signal_completer (ignore
, tracker
, text
, word
);
8779 complete_on_enum (tracker
, keywords
, word
, word
);
8783 gdb_signal_from_command (int num
)
8785 if (num
>= 1 && num
<= 15)
8786 return (enum gdb_signal
) num
;
8787 error (_("Only signals 1-15 are valid as numeric signals.\n\
8788 Use \"info signals\" for a list of symbolic signals."));
8791 /* Print current contents of the tables set by the handle command.
8792 It is possible we should just be printing signals actually used
8793 by the current target (but for things to work right when switching
8794 targets, all signals should be in the signal tables). */
8797 info_signals_command (const char *signum_exp
, int from_tty
)
8799 enum gdb_signal oursig
;
8801 sig_print_header ();
8805 /* First see if this is a symbol name. */
8806 oursig
= gdb_signal_from_name (signum_exp
);
8807 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8809 /* No, try numeric. */
8811 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8813 sig_print_info (oursig
);
8817 printf_filtered ("\n");
8818 /* These ugly casts brought to you by the native VAX compiler. */
8819 for (oursig
= GDB_SIGNAL_FIRST
;
8820 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8821 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8825 if (oursig
!= GDB_SIGNAL_UNKNOWN
8826 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8827 sig_print_info (oursig
);
8830 printf_filtered (_("\nUse the \"handle\" command "
8831 "to change these tables.\n"));
8834 /* The $_siginfo convenience variable is a bit special. We don't know
8835 for sure the type of the value until we actually have a chance to
8836 fetch the data. The type can change depending on gdbarch, so it is
8837 also dependent on which thread you have selected.
8839 1. making $_siginfo be an internalvar that creates a new value on
8842 2. making the value of $_siginfo be an lval_computed value. */
8844 /* This function implements the lval_computed support for reading a
8848 siginfo_value_read (struct value
*v
)
8850 LONGEST transferred
;
8852 /* If we can access registers, so can we access $_siginfo. Likewise
8854 validate_registers_access ();
8857 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8859 value_contents_all_raw (v
),
8861 TYPE_LENGTH (value_type (v
)));
8863 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8864 error (_("Unable to read siginfo"));
8867 /* This function implements the lval_computed support for writing a
8871 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8873 LONGEST transferred
;
8875 /* If we can access registers, so can we access $_siginfo. Likewise
8877 validate_registers_access ();
8879 transferred
= target_write (current_top_target (),
8880 TARGET_OBJECT_SIGNAL_INFO
,
8882 value_contents_all_raw (fromval
),
8884 TYPE_LENGTH (value_type (fromval
)));
8886 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8887 error (_("Unable to write siginfo"));
8890 static const struct lval_funcs siginfo_value_funcs
=
8896 /* Return a new value with the correct type for the siginfo object of
8897 the current thread using architecture GDBARCH. Return a void value
8898 if there's no object available. */
8900 static struct value
*
8901 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8904 if (target_has_stack
8905 && inferior_ptid
!= null_ptid
8906 && gdbarch_get_siginfo_type_p (gdbarch
))
8908 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8910 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8913 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8917 /* infcall_suspend_state contains state about the program itself like its
8918 registers and any signal it received when it last stopped.
8919 This state must be restored regardless of how the inferior function call
8920 ends (either successfully, or after it hits a breakpoint or signal)
8921 if the program is to properly continue where it left off. */
8923 class infcall_suspend_state
8926 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8927 once the inferior function call has finished. */
8928 infcall_suspend_state (struct gdbarch
*gdbarch
,
8929 const struct thread_info
*tp
,
8930 struct regcache
*regcache
)
8931 : m_thread_suspend (tp
->suspend
),
8932 m_registers (new readonly_detached_regcache (*regcache
))
8934 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8936 if (gdbarch_get_siginfo_type_p (gdbarch
))
8938 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8939 size_t len
= TYPE_LENGTH (type
);
8941 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8943 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8944 siginfo_data
.get (), 0, len
) != len
)
8946 /* Errors ignored. */
8947 siginfo_data
.reset (nullptr);
8953 m_siginfo_gdbarch
= gdbarch
;
8954 m_siginfo_data
= std::move (siginfo_data
);
8958 /* Return a pointer to the stored register state. */
8960 readonly_detached_regcache
*registers () const
8962 return m_registers
.get ();
8965 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8967 void restore (struct gdbarch
*gdbarch
,
8968 struct thread_info
*tp
,
8969 struct regcache
*regcache
) const
8971 tp
->suspend
= m_thread_suspend
;
8973 if (m_siginfo_gdbarch
== gdbarch
)
8975 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8977 /* Errors ignored. */
8978 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8979 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8982 /* The inferior can be gone if the user types "print exit(0)"
8983 (and perhaps other times). */
8984 if (target_has_execution
)
8985 /* NB: The register write goes through to the target. */
8986 regcache
->restore (registers ());
8990 /* How the current thread stopped before the inferior function call was
8992 struct thread_suspend_state m_thread_suspend
;
8994 /* The registers before the inferior function call was executed. */
8995 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8997 /* Format of SIGINFO_DATA or NULL if it is not present. */
8998 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9000 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9001 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9002 content would be invalid. */
9003 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9006 infcall_suspend_state_up
9007 save_infcall_suspend_state ()
9009 struct thread_info
*tp
= inferior_thread ();
9010 struct regcache
*regcache
= get_current_regcache ();
9011 struct gdbarch
*gdbarch
= regcache
->arch ();
9013 infcall_suspend_state_up inf_state
9014 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9016 /* Having saved the current state, adjust the thread state, discarding
9017 any stop signal information. The stop signal is not useful when
9018 starting an inferior function call, and run_inferior_call will not use
9019 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9020 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9025 /* Restore inferior session state to INF_STATE. */
9028 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9030 struct thread_info
*tp
= inferior_thread ();
9031 struct regcache
*regcache
= get_current_regcache ();
9032 struct gdbarch
*gdbarch
= regcache
->arch ();
9034 inf_state
->restore (gdbarch
, tp
, regcache
);
9035 discard_infcall_suspend_state (inf_state
);
9039 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9044 readonly_detached_regcache
*
9045 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9047 return inf_state
->registers ();
9050 /* infcall_control_state contains state regarding gdb's control of the
9051 inferior itself like stepping control. It also contains session state like
9052 the user's currently selected frame. */
9054 struct infcall_control_state
9056 struct thread_control_state thread_control
;
9057 struct inferior_control_state inferior_control
;
9060 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9061 int stopped_by_random_signal
= 0;
9063 /* ID if the selected frame when the inferior function call was made. */
9064 struct frame_id selected_frame_id
{};
9067 /* Save all of the information associated with the inferior<==>gdb
9070 infcall_control_state_up
9071 save_infcall_control_state ()
9073 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9074 struct thread_info
*tp
= inferior_thread ();
9075 struct inferior
*inf
= current_inferior ();
9077 inf_status
->thread_control
= tp
->control
;
9078 inf_status
->inferior_control
= inf
->control
;
9080 tp
->control
.step_resume_breakpoint
= NULL
;
9081 tp
->control
.exception_resume_breakpoint
= NULL
;
9083 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9084 chain. If caller's caller is walking the chain, they'll be happier if we
9085 hand them back the original chain when restore_infcall_control_state is
9087 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9090 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9091 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9093 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9099 restore_selected_frame (const frame_id
&fid
)
9101 frame_info
*frame
= frame_find_by_id (fid
);
9103 /* If inf_status->selected_frame_id is NULL, there was no previously
9107 warning (_("Unable to restore previously selected frame."));
9111 select_frame (frame
);
9114 /* Restore inferior session state to INF_STATUS. */
9117 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9119 struct thread_info
*tp
= inferior_thread ();
9120 struct inferior
*inf
= current_inferior ();
9122 if (tp
->control
.step_resume_breakpoint
)
9123 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9125 if (tp
->control
.exception_resume_breakpoint
)
9126 tp
->control
.exception_resume_breakpoint
->disposition
9127 = disp_del_at_next_stop
;
9129 /* Handle the bpstat_copy of the chain. */
9130 bpstat_clear (&tp
->control
.stop_bpstat
);
9132 tp
->control
= inf_status
->thread_control
;
9133 inf
->control
= inf_status
->inferior_control
;
9136 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9137 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9139 if (target_has_stack
)
9141 /* The point of the try/catch is that if the stack is clobbered,
9142 walking the stack might encounter a garbage pointer and
9143 error() trying to dereference it. */
9146 restore_selected_frame (inf_status
->selected_frame_id
);
9148 catch (const gdb_exception_error
&ex
)
9150 exception_fprintf (gdb_stderr
, ex
,
9151 "Unable to restore previously selected frame:\n");
9152 /* Error in restoring the selected frame. Select the
9154 select_frame (get_current_frame ());
9162 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9164 if (inf_status
->thread_control
.step_resume_breakpoint
)
9165 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9166 = disp_del_at_next_stop
;
9168 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9169 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9170 = disp_del_at_next_stop
;
9172 /* See save_infcall_control_state for info on stop_bpstat. */
9173 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9181 clear_exit_convenience_vars (void)
9183 clear_internalvar (lookup_internalvar ("_exitsignal"));
9184 clear_internalvar (lookup_internalvar ("_exitcode"));
9188 /* User interface for reverse debugging:
9189 Set exec-direction / show exec-direction commands
9190 (returns error unless target implements to_set_exec_direction method). */
9192 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9193 static const char exec_forward
[] = "forward";
9194 static const char exec_reverse
[] = "reverse";
9195 static const char *exec_direction
= exec_forward
;
9196 static const char *const exec_direction_names
[] = {
9203 set_exec_direction_func (const char *args
, int from_tty
,
9204 struct cmd_list_element
*cmd
)
9206 if (target_can_execute_reverse
)
9208 if (!strcmp (exec_direction
, exec_forward
))
9209 execution_direction
= EXEC_FORWARD
;
9210 else if (!strcmp (exec_direction
, exec_reverse
))
9211 execution_direction
= EXEC_REVERSE
;
9215 exec_direction
= exec_forward
;
9216 error (_("Target does not support this operation."));
9221 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9222 struct cmd_list_element
*cmd
, const char *value
)
9224 switch (execution_direction
) {
9226 fprintf_filtered (out
, _("Forward.\n"));
9229 fprintf_filtered (out
, _("Reverse.\n"));
9232 internal_error (__FILE__
, __LINE__
,
9233 _("bogus execution_direction value: %d"),
9234 (int) execution_direction
);
9239 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9240 struct cmd_list_element
*c
, const char *value
)
9242 fprintf_filtered (file
, _("Resuming the execution of threads "
9243 "of all processes is %s.\n"), value
);
9246 /* Implementation of `siginfo' variable. */
9248 static const struct internalvar_funcs siginfo_funcs
=
9255 /* Callback for infrun's target events source. This is marked when a
9256 thread has a pending status to process. */
9259 infrun_async_inferior_event_handler (gdb_client_data data
)
9261 inferior_event_handler (INF_REG_EVENT
, NULL
);
9265 _initialize_infrun (void)
9267 struct cmd_list_element
*c
;
9269 /* Register extra event sources in the event loop. */
9270 infrun_async_inferior_event_token
9271 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9273 add_info ("signals", info_signals_command
, _("\
9274 What debugger does when program gets various signals.\n\
9275 Specify a signal as argument to print info on that signal only."));
9276 add_info_alias ("handle", "signals", 0);
9278 c
= add_com ("handle", class_run
, handle_command
, _("\
9279 Specify how to handle signals.\n\
9280 Usage: handle SIGNAL [ACTIONS]\n\
9281 Args are signals and actions to apply to those signals.\n\
9282 If no actions are specified, the current settings for the specified signals\n\
9283 will be displayed instead.\n\
9285 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9286 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9287 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9288 The special arg \"all\" is recognized to mean all signals except those\n\
9289 used by the debugger, typically SIGTRAP and SIGINT.\n\
9291 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9292 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9293 Stop means reenter debugger if this signal happens (implies print).\n\
9294 Print means print a message if this signal happens.\n\
9295 Pass means let program see this signal; otherwise program doesn't know.\n\
9296 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9297 Pass and Stop may be combined.\n\
9299 Multiple signals may be specified. Signal numbers and signal names\n\
9300 may be interspersed with actions, with the actions being performed for\n\
9301 all signals cumulatively specified."));
9302 set_cmd_completer (c
, handle_completer
);
9305 stop_command
= add_cmd ("stop", class_obscure
,
9306 not_just_help_class_command
, _("\
9307 There is no `stop' command, but you can set a hook on `stop'.\n\
9308 This allows you to set a list of commands to be run each time execution\n\
9309 of the program stops."), &cmdlist
);
9311 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9312 Set inferior debugging."), _("\
9313 Show inferior debugging."), _("\
9314 When non-zero, inferior specific debugging is enabled."),
9317 &setdebuglist
, &showdebuglist
);
9319 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9320 &debug_displaced
, _("\
9321 Set displaced stepping debugging."), _("\
9322 Show displaced stepping debugging."), _("\
9323 When non-zero, displaced stepping specific debugging is enabled."),
9325 show_debug_displaced
,
9326 &setdebuglist
, &showdebuglist
);
9328 add_setshow_boolean_cmd ("non-stop", no_class
,
9330 Set whether gdb controls the inferior in non-stop mode."), _("\
9331 Show whether gdb controls the inferior in non-stop mode."), _("\
9332 When debugging a multi-threaded program and this setting is\n\
9333 off (the default, also called all-stop mode), when one thread stops\n\
9334 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9335 all other threads in the program while you interact with the thread of\n\
9336 interest. When you continue or step a thread, you can allow the other\n\
9337 threads to run, or have them remain stopped, but while you inspect any\n\
9338 thread's state, all threads stop.\n\
9340 In non-stop mode, when one thread stops, other threads can continue\n\
9341 to run freely. You'll be able to step each thread independently,\n\
9342 leave it stopped or free to run as needed."),
9348 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9351 signal_print
[i
] = 1;
9352 signal_program
[i
] = 1;
9353 signal_catch
[i
] = 0;
9356 /* Signals caused by debugger's own actions should not be given to
9357 the program afterwards.
9359 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9360 explicitly specifies that it should be delivered to the target
9361 program. Typically, that would occur when a user is debugging a
9362 target monitor on a simulator: the target monitor sets a
9363 breakpoint; the simulator encounters this breakpoint and halts
9364 the simulation handing control to GDB; GDB, noting that the stop
9365 address doesn't map to any known breakpoint, returns control back
9366 to the simulator; the simulator then delivers the hardware
9367 equivalent of a GDB_SIGNAL_TRAP to the program being
9369 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9370 signal_program
[GDB_SIGNAL_INT
] = 0;
9372 /* Signals that are not errors should not normally enter the debugger. */
9373 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9374 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9375 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9376 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9377 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9378 signal_print
[GDB_SIGNAL_PROF
] = 0;
9379 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9380 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9381 signal_stop
[GDB_SIGNAL_IO
] = 0;
9382 signal_print
[GDB_SIGNAL_IO
] = 0;
9383 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9384 signal_print
[GDB_SIGNAL_POLL
] = 0;
9385 signal_stop
[GDB_SIGNAL_URG
] = 0;
9386 signal_print
[GDB_SIGNAL_URG
] = 0;
9387 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9388 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9389 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9390 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9392 /* These signals are used internally by user-level thread
9393 implementations. (See signal(5) on Solaris.) Like the above
9394 signals, a healthy program receives and handles them as part of
9395 its normal operation. */
9396 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9397 signal_print
[GDB_SIGNAL_LWP
] = 0;
9398 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9399 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9400 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9401 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9402 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9403 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9405 /* Update cached state. */
9406 signal_cache_update (-1);
9408 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9409 &stop_on_solib_events
, _("\
9410 Set stopping for shared library events."), _("\
9411 Show stopping for shared library events."), _("\
9412 If nonzero, gdb will give control to the user when the dynamic linker\n\
9413 notifies gdb of shared library events. The most common event of interest\n\
9414 to the user would be loading/unloading of a new library."),
9415 set_stop_on_solib_events
,
9416 show_stop_on_solib_events
,
9417 &setlist
, &showlist
);
9419 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9420 follow_fork_mode_kind_names
,
9421 &follow_fork_mode_string
, _("\
9422 Set debugger response to a program call of fork or vfork."), _("\
9423 Show debugger response to a program call of fork or vfork."), _("\
9424 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9425 parent - the original process is debugged after a fork\n\
9426 child - the new process is debugged after a fork\n\
9427 The unfollowed process will continue to run.\n\
9428 By default, the debugger will follow the parent process."),
9430 show_follow_fork_mode_string
,
9431 &setlist
, &showlist
);
9433 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9434 follow_exec_mode_names
,
9435 &follow_exec_mode_string
, _("\
9436 Set debugger response to a program call of exec."), _("\
9437 Show debugger response to a program call of exec."), _("\
9438 An exec call replaces the program image of a process.\n\
9440 follow-exec-mode can be:\n\
9442 new - the debugger creates a new inferior and rebinds the process\n\
9443 to this new inferior. The program the process was running before\n\
9444 the exec call can be restarted afterwards by restarting the original\n\
9447 same - the debugger keeps the process bound to the same inferior.\n\
9448 The new executable image replaces the previous executable loaded in\n\
9449 the inferior. Restarting the inferior after the exec call restarts\n\
9450 the executable the process was running after the exec call.\n\
9452 By default, the debugger will use the same inferior."),
9454 show_follow_exec_mode_string
,
9455 &setlist
, &showlist
);
9457 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9458 scheduler_enums
, &scheduler_mode
, _("\
9459 Set mode for locking scheduler during execution."), _("\
9460 Show mode for locking scheduler during execution."), _("\
9461 off == no locking (threads may preempt at any time)\n\
9462 on == full locking (no thread except the current thread may run)\n\
9463 This applies to both normal execution and replay mode.\n\
9464 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9465 In this mode, other threads may run during other commands.\n\
9466 This applies to both normal execution and replay mode.\n\
9467 replay == scheduler locked in replay mode and unlocked during normal execution."),
9468 set_schedlock_func
, /* traps on target vector */
9469 show_scheduler_mode
,
9470 &setlist
, &showlist
);
9472 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9473 Set mode for resuming threads of all processes."), _("\
9474 Show mode for resuming threads of all processes."), _("\
9475 When on, execution commands (such as 'continue' or 'next') resume all\n\
9476 threads of all processes. When off (which is the default), execution\n\
9477 commands only resume the threads of the current process. The set of\n\
9478 threads that are resumed is further refined by the scheduler-locking\n\
9479 mode (see help set scheduler-locking)."),
9481 show_schedule_multiple
,
9482 &setlist
, &showlist
);
9484 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9485 Set mode of the step operation."), _("\
9486 Show mode of the step operation."), _("\
9487 When set, doing a step over a function without debug line information\n\
9488 will stop at the first instruction of that function. Otherwise, the\n\
9489 function is skipped and the step command stops at a different source line."),
9491 show_step_stop_if_no_debug
,
9492 &setlist
, &showlist
);
9494 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9495 &can_use_displaced_stepping
, _("\
9496 Set debugger's willingness to use displaced stepping."), _("\
9497 Show debugger's willingness to use displaced stepping."), _("\
9498 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9499 supported by the target architecture. If off, gdb will not use displaced\n\
9500 stepping to step over breakpoints, even if such is supported by the target\n\
9501 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9502 if the target architecture supports it and non-stop mode is active, but will not\n\
9503 use it in all-stop mode (see help set non-stop)."),
9505 show_can_use_displaced_stepping
,
9506 &setlist
, &showlist
);
9508 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9509 &exec_direction
, _("Set direction of execution.\n\
9510 Options are 'forward' or 'reverse'."),
9511 _("Show direction of execution (forward/reverse)."),
9512 _("Tells gdb whether to execute forward or backward."),
9513 set_exec_direction_func
, show_exec_direction_func
,
9514 &setlist
, &showlist
);
9516 /* Set/show detach-on-fork: user-settable mode. */
9518 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9519 Set whether gdb will detach the child of a fork."), _("\
9520 Show whether gdb will detach the child of a fork."), _("\
9521 Tells gdb whether to detach the child of a fork."),
9522 NULL
, NULL
, &setlist
, &showlist
);
9524 /* Set/show disable address space randomization mode. */
9526 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9527 &disable_randomization
, _("\
9528 Set disabling of debuggee's virtual address space randomization."), _("\
9529 Show disabling of debuggee's virtual address space randomization."), _("\
9530 When this mode is on (which is the default), randomization of the virtual\n\
9531 address space is disabled. Standalone programs run with the randomization\n\
9532 enabled by default on some platforms."),
9533 &set_disable_randomization
,
9534 &show_disable_randomization
,
9535 &setlist
, &showlist
);
9537 /* ptid initializations */
9538 inferior_ptid
= null_ptid
;
9539 target_last_wait_ptid
= minus_one_ptid
;
9541 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9542 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9543 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9544 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9546 /* Explicitly create without lookup, since that tries to create a
9547 value with a void typed value, and when we get here, gdbarch
9548 isn't initialized yet. At this point, we're quite sure there
9549 isn't another convenience variable of the same name. */
9550 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9552 add_setshow_boolean_cmd ("observer", no_class
,
9553 &observer_mode_1
, _("\
9554 Set whether gdb controls the inferior in observer mode."), _("\
9555 Show whether gdb controls the inferior in observer mode."), _("\
9556 In observer mode, GDB can get data from the inferior, but not\n\
9557 affect its execution. Registers and memory may not be changed,\n\
9558 breakpoints may not be set, and the program cannot be interrupted\n\