1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "target-connection.h"
32 #include "gdbthread.h"
39 #include "observable.h"
44 #include "mi/mi-common.h"
45 #include "event-top.h"
47 #include "record-full.h"
48 #include "inline-frame.h"
50 #include "tracepoint.h"
54 #include "completer.h"
55 #include "target-descriptions.h"
56 #include "target-dcache.h"
59 #include "gdbsupport/event-loop.h"
60 #include "thread-fsm.h"
61 #include "gdbsupport/enum-flags.h"
62 #include "progspace-and-thread.h"
63 #include "gdbsupport/gdb_optional.h"
64 #include "arch-utils.h"
65 #include "gdbsupport/scope-exit.h"
66 #include "gdbsupport/forward-scope-exit.h"
67 #include "gdbsupport/gdb_select.h"
68 #include <unordered_map>
69 #include "async-event.h"
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal
);
75 static void sig_print_header (void);
77 static void follow_inferior_reset_breakpoints (void);
79 static int currently_stepping (struct thread_info
*tp
);
81 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
83 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
85 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
87 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
89 static void resume (gdb_signal sig
);
91 static void wait_for_inferior (inferior
*inf
);
93 /* Asynchronous signal handler registered as event loop source for
94 when we have pending events ready to be passed to the core. */
95 static struct async_event_handler
*infrun_async_inferior_event_token
;
97 /* Stores whether infrun_async was previously enabled or disabled.
98 Starts off as -1, indicating "never enabled/disabled". */
99 static int infrun_is_async
= -1;
104 infrun_async (int enable
)
106 if (infrun_is_async
!= enable
)
108 infrun_is_async
= enable
;
111 fprintf_unfiltered (gdb_stdlog
,
112 "infrun: infrun_async(%d)\n",
116 mark_async_event_handler (infrun_async_inferior_event_token
);
118 clear_async_event_handler (infrun_async_inferior_event_token
);
125 mark_infrun_async_event_handler (void)
127 mark_async_event_handler (infrun_async_inferior_event_token
);
130 /* When set, stop the 'step' command if we enter a function which has
131 no line number information. The normal behavior is that we step
132 over such function. */
133 bool step_stop_if_no_debug
= false;
135 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
136 struct cmd_list_element
*c
, const char *value
)
138 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
141 /* proceed and normal_stop use this to notify the user when the
142 inferior stopped in a different thread than it had been running
145 static ptid_t previous_inferior_ptid
;
147 /* If set (default for legacy reasons), when following a fork, GDB
148 will detach from one of the fork branches, child or parent.
149 Exactly which branch is detached depends on 'set follow-fork-mode'
152 static bool detach_fork
= true;
154 bool debug_displaced
= false;
156 show_debug_displaced (struct ui_file
*file
, int from_tty
,
157 struct cmd_list_element
*c
, const char *value
)
159 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
162 unsigned int debug_infrun
= 0;
164 show_debug_infrun (struct ui_file
*file
, int from_tty
,
165 struct cmd_list_element
*c
, const char *value
)
167 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
171 /* Support for disabling address space randomization. */
173 bool disable_randomization
= true;
176 show_disable_randomization (struct ui_file
*file
, int from_tty
,
177 struct cmd_list_element
*c
, const char *value
)
179 if (target_supports_disable_randomization ())
180 fprintf_filtered (file
,
181 _("Disabling randomization of debuggee's "
182 "virtual address space is %s.\n"),
185 fputs_filtered (_("Disabling randomization of debuggee's "
186 "virtual address space is unsupported on\n"
187 "this platform.\n"), file
);
191 set_disable_randomization (const char *args
, int from_tty
,
192 struct cmd_list_element
*c
)
194 if (!target_supports_disable_randomization ())
195 error (_("Disabling randomization of debuggee's "
196 "virtual address space is unsupported on\n"
200 /* User interface for non-stop mode. */
202 bool non_stop
= false;
203 static bool non_stop_1
= false;
206 set_non_stop (const char *args
, int from_tty
,
207 struct cmd_list_element
*c
)
209 if (target_has_execution
)
211 non_stop_1
= non_stop
;
212 error (_("Cannot change this setting while the inferior is running."));
215 non_stop
= non_stop_1
;
219 show_non_stop (struct ui_file
*file
, int from_tty
,
220 struct cmd_list_element
*c
, const char *value
)
222 fprintf_filtered (file
,
223 _("Controlling the inferior in non-stop mode is %s.\n"),
227 /* "Observer mode" is somewhat like a more extreme version of
228 non-stop, in which all GDB operations that might affect the
229 target's execution have been disabled. */
231 bool observer_mode
= false;
232 static bool observer_mode_1
= false;
235 set_observer_mode (const char *args
, int from_tty
,
236 struct cmd_list_element
*c
)
238 if (target_has_execution
)
240 observer_mode_1
= observer_mode
;
241 error (_("Cannot change this setting while the inferior is running."));
244 observer_mode
= observer_mode_1
;
246 may_write_registers
= !observer_mode
;
247 may_write_memory
= !observer_mode
;
248 may_insert_breakpoints
= !observer_mode
;
249 may_insert_tracepoints
= !observer_mode
;
250 /* We can insert fast tracepoints in or out of observer mode,
251 but enable them if we're going into this mode. */
253 may_insert_fast_tracepoints
= true;
254 may_stop
= !observer_mode
;
255 update_target_permissions ();
257 /* Going *into* observer mode we must force non-stop, then
258 going out we leave it that way. */
261 pagination_enabled
= 0;
262 non_stop
= non_stop_1
= true;
266 printf_filtered (_("Observer mode is now %s.\n"),
267 (observer_mode
? "on" : "off"));
271 show_observer_mode (struct ui_file
*file
, int from_tty
,
272 struct cmd_list_element
*c
, const char *value
)
274 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
277 /* This updates the value of observer mode based on changes in
278 permissions. Note that we are deliberately ignoring the values of
279 may-write-registers and may-write-memory, since the user may have
280 reason to enable these during a session, for instance to turn on a
281 debugging-related global. */
284 update_observer_mode (void)
286 bool newval
= (!may_insert_breakpoints
287 && !may_insert_tracepoints
288 && may_insert_fast_tracepoints
292 /* Let the user know if things change. */
293 if (newval
!= observer_mode
)
294 printf_filtered (_("Observer mode is now %s.\n"),
295 (newval
? "on" : "off"));
297 observer_mode
= observer_mode_1
= newval
;
300 /* Tables of how to react to signals; the user sets them. */
302 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
303 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
304 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
306 /* Table of signals that are registered with "catch signal". A
307 non-zero entry indicates that the signal is caught by some "catch
309 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
311 /* Table of signals that the target may silently handle.
312 This is automatically determined from the flags above,
313 and simply cached here. */
314 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
316 #define SET_SIGS(nsigs,sigs,flags) \
318 int signum = (nsigs); \
319 while (signum-- > 0) \
320 if ((sigs)[signum]) \
321 (flags)[signum] = 1; \
324 #define UNSET_SIGS(nsigs,sigs,flags) \
326 int signum = (nsigs); \
327 while (signum-- > 0) \
328 if ((sigs)[signum]) \
329 (flags)[signum] = 0; \
332 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
333 this function is to avoid exporting `signal_program'. */
336 update_signals_program_target (void)
338 target_program_signals (signal_program
);
341 /* Value to pass to target_resume() to cause all threads to resume. */
343 #define RESUME_ALL minus_one_ptid
345 /* Command list pointer for the "stop" placeholder. */
347 static struct cmd_list_element
*stop_command
;
349 /* Nonzero if we want to give control to the user when we're notified
350 of shared library events by the dynamic linker. */
351 int stop_on_solib_events
;
353 /* Enable or disable optional shared library event breakpoints
354 as appropriate when the above flag is changed. */
357 set_stop_on_solib_events (const char *args
,
358 int from_tty
, struct cmd_list_element
*c
)
360 update_solib_breakpoints ();
364 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
365 struct cmd_list_element
*c
, const char *value
)
367 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
371 /* Nonzero after stop if current stack frame should be printed. */
373 static int stop_print_frame
;
375 /* This is a cached copy of the target/ptid/waitstatus of the last
376 event returned by target_wait()/deprecated_target_wait_hook().
377 This information is returned by get_last_target_status(). */
378 static process_stratum_target
*target_last_proc_target
;
379 static ptid_t target_last_wait_ptid
;
380 static struct target_waitstatus target_last_waitstatus
;
382 void init_thread_stepping_state (struct thread_info
*tss
);
384 static const char follow_fork_mode_child
[] = "child";
385 static const char follow_fork_mode_parent
[] = "parent";
387 static const char *const follow_fork_mode_kind_names
[] = {
388 follow_fork_mode_child
,
389 follow_fork_mode_parent
,
393 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
395 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
396 struct cmd_list_element
*c
, const char *value
)
398 fprintf_filtered (file
,
399 _("Debugger response to a program "
400 "call of fork or vfork is \"%s\".\n"),
405 /* Handle changes to the inferior list based on the type of fork,
406 which process is being followed, and whether the other process
407 should be detached. On entry inferior_ptid must be the ptid of
408 the fork parent. At return inferior_ptid is the ptid of the
409 followed inferior. */
412 follow_fork_inferior (bool follow_child
, bool detach_fork
)
415 ptid_t parent_ptid
, child_ptid
;
417 has_vforked
= (inferior_thread ()->pending_follow
.kind
418 == TARGET_WAITKIND_VFORKED
);
419 parent_ptid
= inferior_ptid
;
420 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
423 && !non_stop
/* Non-stop always resumes both branches. */
424 && current_ui
->prompt_state
== PROMPT_BLOCKED
425 && !(follow_child
|| detach_fork
|| sched_multi
))
427 /* The parent stays blocked inside the vfork syscall until the
428 child execs or exits. If we don't let the child run, then
429 the parent stays blocked. If we're telling the parent to run
430 in the foreground, the user will not be able to ctrl-c to get
431 back the terminal, effectively hanging the debug session. */
432 fprintf_filtered (gdb_stderr
, _("\
433 Can not resume the parent process over vfork in the foreground while\n\
434 holding the child stopped. Try \"set detach-on-fork\" or \
435 \"set schedule-multiple\".\n"));
441 /* Detach new forked process? */
444 /* Before detaching from the child, remove all breakpoints
445 from it. If we forked, then this has already been taken
446 care of by infrun.c. If we vforked however, any
447 breakpoint inserted in the parent is visible in the
448 child, even those added while stopped in a vfork
449 catchpoint. This will remove the breakpoints from the
450 parent also, but they'll be reinserted below. */
453 /* Keep breakpoints list in sync. */
454 remove_breakpoints_inf (current_inferior ());
457 if (print_inferior_events
)
459 /* Ensure that we have a process ptid. */
460 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
462 target_terminal::ours_for_output ();
463 fprintf_filtered (gdb_stdlog
,
464 _("[Detaching after %s from child %s]\n"),
465 has_vforked
? "vfork" : "fork",
466 target_pid_to_str (process_ptid
).c_str ());
471 struct inferior
*parent_inf
, *child_inf
;
473 /* Add process to GDB's tables. */
474 child_inf
= add_inferior (child_ptid
.pid ());
476 parent_inf
= current_inferior ();
477 child_inf
->attach_flag
= parent_inf
->attach_flag
;
478 copy_terminal_info (child_inf
, parent_inf
);
479 child_inf
->gdbarch
= parent_inf
->gdbarch
;
480 copy_inferior_target_desc_info (child_inf
, parent_inf
);
482 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
484 set_current_inferior (child_inf
);
485 switch_to_no_thread ();
486 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
487 push_target (parent_inf
->process_target ());
488 add_thread_silent (child_inf
->process_target (), child_ptid
);
489 inferior_ptid
= child_ptid
;
491 /* If this is a vfork child, then the address-space is
492 shared with the parent. */
495 child_inf
->pspace
= parent_inf
->pspace
;
496 child_inf
->aspace
= parent_inf
->aspace
;
500 /* The parent will be frozen until the child is done
501 with the shared region. Keep track of the
503 child_inf
->vfork_parent
= parent_inf
;
504 child_inf
->pending_detach
= 0;
505 parent_inf
->vfork_child
= child_inf
;
506 parent_inf
->pending_detach
= 0;
510 child_inf
->aspace
= new_address_space ();
511 child_inf
->pspace
= new program_space (child_inf
->aspace
);
512 child_inf
->removable
= 1;
513 set_current_program_space (child_inf
->pspace
);
514 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
516 /* Let the shared library layer (e.g., solib-svr4) learn
517 about this new process, relocate the cloned exec, pull
518 in shared libraries, and install the solib event
519 breakpoint. If a "cloned-VM" event was propagated
520 better throughout the core, this wouldn't be
522 solib_create_inferior_hook (0);
528 struct inferior
*parent_inf
;
530 parent_inf
= current_inferior ();
532 /* If we detached from the child, then we have to be careful
533 to not insert breakpoints in the parent until the child
534 is done with the shared memory region. However, if we're
535 staying attached to the child, then we can and should
536 insert breakpoints, so that we can debug it. A
537 subsequent child exec or exit is enough to know when does
538 the child stops using the parent's address space. */
539 parent_inf
->waiting_for_vfork_done
= detach_fork
;
540 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
545 /* Follow the child. */
546 struct inferior
*parent_inf
, *child_inf
;
547 struct program_space
*parent_pspace
;
549 if (print_inferior_events
)
551 std::string parent_pid
= target_pid_to_str (parent_ptid
);
552 std::string child_pid
= target_pid_to_str (child_ptid
);
554 target_terminal::ours_for_output ();
555 fprintf_filtered (gdb_stdlog
,
556 _("[Attaching after %s %s to child %s]\n"),
558 has_vforked
? "vfork" : "fork",
562 /* Add the new inferior first, so that the target_detach below
563 doesn't unpush the target. */
565 child_inf
= add_inferior (child_ptid
.pid ());
567 parent_inf
= current_inferior ();
568 child_inf
->attach_flag
= parent_inf
->attach_flag
;
569 copy_terminal_info (child_inf
, parent_inf
);
570 child_inf
->gdbarch
= parent_inf
->gdbarch
;
571 copy_inferior_target_desc_info (child_inf
, parent_inf
);
573 parent_pspace
= parent_inf
->pspace
;
575 process_stratum_target
*target
= parent_inf
->process_target ();
578 /* Hold a strong reference to the target while (maybe)
579 detaching the parent. Otherwise detaching could close the
581 auto target_ref
= target_ops_ref::new_reference (target
);
583 /* If we're vforking, we want to hold on to the parent until
584 the child exits or execs. At child exec or exit time we
585 can remove the old breakpoints from the parent and detach
586 or resume debugging it. Otherwise, detach the parent now;
587 we'll want to reuse it's program/address spaces, but we
588 can't set them to the child before removing breakpoints
589 from the parent, otherwise, the breakpoints module could
590 decide to remove breakpoints from the wrong process (since
591 they'd be assigned to the same address space). */
595 gdb_assert (child_inf
->vfork_parent
== NULL
);
596 gdb_assert (parent_inf
->vfork_child
== NULL
);
597 child_inf
->vfork_parent
= parent_inf
;
598 child_inf
->pending_detach
= 0;
599 parent_inf
->vfork_child
= child_inf
;
600 parent_inf
->pending_detach
= detach_fork
;
601 parent_inf
->waiting_for_vfork_done
= 0;
603 else if (detach_fork
)
605 if (print_inferior_events
)
607 /* Ensure that we have a process ptid. */
608 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
610 target_terminal::ours_for_output ();
611 fprintf_filtered (gdb_stdlog
,
612 _("[Detaching after fork from "
614 target_pid_to_str (process_ptid
).c_str ());
617 target_detach (parent_inf
, 0);
621 /* Note that the detach above makes PARENT_INF dangling. */
623 /* Add the child thread to the appropriate lists, and switch
624 to this new thread, before cloning the program space, and
625 informing the solib layer about this new process. */
627 set_current_inferior (child_inf
);
628 push_target (target
);
631 add_thread_silent (target
, child_ptid
);
632 inferior_ptid
= child_ptid
;
634 /* If this is a vfork child, then the address-space is shared
635 with the parent. If we detached from the parent, then we can
636 reuse the parent's program/address spaces. */
637 if (has_vforked
|| detach_fork
)
639 child_inf
->pspace
= parent_pspace
;
640 child_inf
->aspace
= child_inf
->pspace
->aspace
;
646 child_inf
->aspace
= new_address_space ();
647 child_inf
->pspace
= new program_space (child_inf
->aspace
);
648 child_inf
->removable
= 1;
649 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
650 set_current_program_space (child_inf
->pspace
);
651 clone_program_space (child_inf
->pspace
, parent_pspace
);
653 /* Let the shared library layer (e.g., solib-svr4) learn
654 about this new process, relocate the cloned exec, pull in
655 shared libraries, and install the solib event breakpoint.
656 If a "cloned-VM" event was propagated better throughout
657 the core, this wouldn't be required. */
658 solib_create_inferior_hook (0);
662 return target_follow_fork (follow_child
, detach_fork
);
665 /* Tell the target to follow the fork we're stopped at. Returns true
666 if the inferior should be resumed; false, if the target for some
667 reason decided it's best not to resume. */
672 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
673 bool should_resume
= true;
674 struct thread_info
*tp
;
676 /* Copy user stepping state to the new inferior thread. FIXME: the
677 followed fork child thread should have a copy of most of the
678 parent thread structure's run control related fields, not just these.
679 Initialized to avoid "may be used uninitialized" warnings from gcc. */
680 struct breakpoint
*step_resume_breakpoint
= NULL
;
681 struct breakpoint
*exception_resume_breakpoint
= NULL
;
682 CORE_ADDR step_range_start
= 0;
683 CORE_ADDR step_range_end
= 0;
684 struct frame_id step_frame_id
= { 0 };
685 struct thread_fsm
*thread_fsm
= NULL
;
689 process_stratum_target
*wait_target
;
691 struct target_waitstatus wait_status
;
693 /* Get the last target status returned by target_wait(). */
694 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
696 /* If not stopped at a fork event, then there's nothing else to
698 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
699 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
702 /* Check if we switched over from WAIT_PTID, since the event was
704 if (wait_ptid
!= minus_one_ptid
705 && (current_inferior ()->process_target () != wait_target
706 || inferior_ptid
!= wait_ptid
))
708 /* We did. Switch back to WAIT_PTID thread, to tell the
709 target to follow it (in either direction). We'll
710 afterwards refuse to resume, and inform the user what
712 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
713 switch_to_thread (wait_thread
);
714 should_resume
= false;
718 tp
= inferior_thread ();
720 /* If there were any forks/vforks that were caught and are now to be
721 followed, then do so now. */
722 switch (tp
->pending_follow
.kind
)
724 case TARGET_WAITKIND_FORKED
:
725 case TARGET_WAITKIND_VFORKED
:
727 ptid_t parent
, child
;
729 /* If the user did a next/step, etc, over a fork call,
730 preserve the stepping state in the fork child. */
731 if (follow_child
&& should_resume
)
733 step_resume_breakpoint
= clone_momentary_breakpoint
734 (tp
->control
.step_resume_breakpoint
);
735 step_range_start
= tp
->control
.step_range_start
;
736 step_range_end
= tp
->control
.step_range_end
;
737 step_frame_id
= tp
->control
.step_frame_id
;
738 exception_resume_breakpoint
739 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
740 thread_fsm
= tp
->thread_fsm
;
742 /* For now, delete the parent's sr breakpoint, otherwise,
743 parent/child sr breakpoints are considered duplicates,
744 and the child version will not be installed. Remove
745 this when the breakpoints module becomes aware of
746 inferiors and address spaces. */
747 delete_step_resume_breakpoint (tp
);
748 tp
->control
.step_range_start
= 0;
749 tp
->control
.step_range_end
= 0;
750 tp
->control
.step_frame_id
= null_frame_id
;
751 delete_exception_resume_breakpoint (tp
);
752 tp
->thread_fsm
= NULL
;
755 parent
= inferior_ptid
;
756 child
= tp
->pending_follow
.value
.related_pid
;
758 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
759 /* Set up inferior(s) as specified by the caller, and tell the
760 target to do whatever is necessary to follow either parent
762 if (follow_fork_inferior (follow_child
, detach_fork
))
764 /* Target refused to follow, or there's some other reason
765 we shouldn't resume. */
770 /* This pending follow fork event is now handled, one way
771 or another. The previous selected thread may be gone
772 from the lists by now, but if it is still around, need
773 to clear the pending follow request. */
774 tp
= find_thread_ptid (parent_targ
, parent
);
776 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
778 /* This makes sure we don't try to apply the "Switched
779 over from WAIT_PID" logic above. */
780 nullify_last_target_wait_ptid ();
782 /* If we followed the child, switch to it... */
785 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
786 switch_to_thread (child_thr
);
788 /* ... and preserve the stepping state, in case the
789 user was stepping over the fork call. */
792 tp
= inferior_thread ();
793 tp
->control
.step_resume_breakpoint
794 = step_resume_breakpoint
;
795 tp
->control
.step_range_start
= step_range_start
;
796 tp
->control
.step_range_end
= step_range_end
;
797 tp
->control
.step_frame_id
= step_frame_id
;
798 tp
->control
.exception_resume_breakpoint
799 = exception_resume_breakpoint
;
800 tp
->thread_fsm
= thread_fsm
;
804 /* If we get here, it was because we're trying to
805 resume from a fork catchpoint, but, the user
806 has switched threads away from the thread that
807 forked. In that case, the resume command
808 issued is most likely not applicable to the
809 child, so just warn, and refuse to resume. */
810 warning (_("Not resuming: switched threads "
811 "before following fork child."));
814 /* Reset breakpoints in the child as appropriate. */
815 follow_inferior_reset_breakpoints ();
820 case TARGET_WAITKIND_SPURIOUS
:
821 /* Nothing to follow. */
824 internal_error (__FILE__
, __LINE__
,
825 "Unexpected pending_follow.kind %d\n",
826 tp
->pending_follow
.kind
);
830 return should_resume
;
834 follow_inferior_reset_breakpoints (void)
836 struct thread_info
*tp
= inferior_thread ();
838 /* Was there a step_resume breakpoint? (There was if the user
839 did a "next" at the fork() call.) If so, explicitly reset its
840 thread number. Cloned step_resume breakpoints are disabled on
841 creation, so enable it here now that it is associated with the
844 step_resumes are a form of bp that are made to be per-thread.
845 Since we created the step_resume bp when the parent process
846 was being debugged, and now are switching to the child process,
847 from the breakpoint package's viewpoint, that's a switch of
848 "threads". We must update the bp's notion of which thread
849 it is for, or it'll be ignored when it triggers. */
851 if (tp
->control
.step_resume_breakpoint
)
853 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
854 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
857 /* Treat exception_resume breakpoints like step_resume breakpoints. */
858 if (tp
->control
.exception_resume_breakpoint
)
860 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
861 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
864 /* Reinsert all breakpoints in the child. The user may have set
865 breakpoints after catching the fork, in which case those
866 were never set in the child, but only in the parent. This makes
867 sure the inserted breakpoints match the breakpoint list. */
869 breakpoint_re_set ();
870 insert_breakpoints ();
873 /* The child has exited or execed: resume threads of the parent the
874 user wanted to be executing. */
877 proceed_after_vfork_done (struct thread_info
*thread
,
880 int pid
= * (int *) arg
;
882 if (thread
->ptid
.pid () == pid
883 && thread
->state
== THREAD_RUNNING
884 && !thread
->executing
885 && !thread
->stop_requested
886 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
889 fprintf_unfiltered (gdb_stdlog
,
890 "infrun: resuming vfork parent thread %s\n",
891 target_pid_to_str (thread
->ptid
).c_str ());
893 switch_to_thread (thread
);
894 clear_proceed_status (0);
895 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
901 /* Save/restore inferior_ptid, current program space and current
902 inferior. Only use this if the current context points at an exited
903 inferior (and therefore there's no current thread to save). */
904 class scoped_restore_exited_inferior
907 scoped_restore_exited_inferior ()
908 : m_saved_ptid (&inferior_ptid
)
912 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
913 scoped_restore_current_program_space m_pspace
;
914 scoped_restore_current_inferior m_inferior
;
917 /* Called whenever we notice an exec or exit event, to handle
918 detaching or resuming a vfork parent. */
921 handle_vfork_child_exec_or_exit (int exec
)
923 struct inferior
*inf
= current_inferior ();
925 if (inf
->vfork_parent
)
927 int resume_parent
= -1;
929 /* This exec or exit marks the end of the shared memory region
930 between the parent and the child. Break the bonds. */
931 inferior
*vfork_parent
= inf
->vfork_parent
;
932 inf
->vfork_parent
->vfork_child
= NULL
;
933 inf
->vfork_parent
= NULL
;
935 /* If the user wanted to detach from the parent, now is the
937 if (vfork_parent
->pending_detach
)
939 struct thread_info
*tp
;
940 struct program_space
*pspace
;
941 struct address_space
*aspace
;
943 /* follow-fork child, detach-on-fork on. */
945 vfork_parent
->pending_detach
= 0;
947 gdb::optional
<scoped_restore_exited_inferior
>
948 maybe_restore_inferior
;
949 gdb::optional
<scoped_restore_current_pspace_and_thread
>
950 maybe_restore_thread
;
952 /* If we're handling a child exit, then inferior_ptid points
953 at the inferior's pid, not to a thread. */
955 maybe_restore_inferior
.emplace ();
957 maybe_restore_thread
.emplace ();
959 /* We're letting loose of the parent. */
960 tp
= any_live_thread_of_inferior (vfork_parent
);
961 switch_to_thread (tp
);
963 /* We're about to detach from the parent, which implicitly
964 removes breakpoints from its address space. There's a
965 catch here: we want to reuse the spaces for the child,
966 but, parent/child are still sharing the pspace at this
967 point, although the exec in reality makes the kernel give
968 the child a fresh set of new pages. The problem here is
969 that the breakpoints module being unaware of this, would
970 likely chose the child process to write to the parent
971 address space. Swapping the child temporarily away from
972 the spaces has the desired effect. Yes, this is "sort
975 pspace
= inf
->pspace
;
976 aspace
= inf
->aspace
;
980 if (print_inferior_events
)
983 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
985 target_terminal::ours_for_output ();
989 fprintf_filtered (gdb_stdlog
,
990 _("[Detaching vfork parent %s "
991 "after child exec]\n"), pidstr
.c_str ());
995 fprintf_filtered (gdb_stdlog
,
996 _("[Detaching vfork parent %s "
997 "after child exit]\n"), pidstr
.c_str ());
1001 target_detach (vfork_parent
, 0);
1004 inf
->pspace
= pspace
;
1005 inf
->aspace
= aspace
;
1009 /* We're staying attached to the parent, so, really give the
1010 child a new address space. */
1011 inf
->pspace
= new program_space (maybe_new_address_space ());
1012 inf
->aspace
= inf
->pspace
->aspace
;
1014 set_current_program_space (inf
->pspace
);
1016 resume_parent
= vfork_parent
->pid
;
1020 /* If this is a vfork child exiting, then the pspace and
1021 aspaces were shared with the parent. Since we're
1022 reporting the process exit, we'll be mourning all that is
1023 found in the address space, and switching to null_ptid,
1024 preparing to start a new inferior. But, since we don't
1025 want to clobber the parent's address/program spaces, we
1026 go ahead and create a new one for this exiting
1029 /* Switch to null_ptid while running clone_program_space, so
1030 that clone_program_space doesn't want to read the
1031 selected frame of a dead process. */
1032 scoped_restore restore_ptid
1033 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1035 inf
->pspace
= new program_space (maybe_new_address_space ());
1036 inf
->aspace
= inf
->pspace
->aspace
;
1037 set_current_program_space (inf
->pspace
);
1039 inf
->symfile_flags
= SYMFILE_NO_READ
;
1040 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1042 resume_parent
= vfork_parent
->pid
;
1045 gdb_assert (current_program_space
== inf
->pspace
);
1047 if (non_stop
&& resume_parent
!= -1)
1049 /* If the user wanted the parent to be running, let it go
1051 scoped_restore_current_thread restore_thread
;
1054 fprintf_unfiltered (gdb_stdlog
,
1055 "infrun: resuming vfork parent process %d\n",
1058 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1063 /* Enum strings for "set|show follow-exec-mode". */
1065 static const char follow_exec_mode_new
[] = "new";
1066 static const char follow_exec_mode_same
[] = "same";
1067 static const char *const follow_exec_mode_names
[] =
1069 follow_exec_mode_new
,
1070 follow_exec_mode_same
,
1074 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1076 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1077 struct cmd_list_element
*c
, const char *value
)
1079 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1082 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1085 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1087 struct inferior
*inf
= current_inferior ();
1088 int pid
= ptid
.pid ();
1089 ptid_t process_ptid
;
1091 /* Switch terminal for any messages produced e.g. by
1092 breakpoint_re_set. */
1093 target_terminal::ours_for_output ();
1095 /* This is an exec event that we actually wish to pay attention to.
1096 Refresh our symbol table to the newly exec'd program, remove any
1097 momentary bp's, etc.
1099 If there are breakpoints, they aren't really inserted now,
1100 since the exec() transformed our inferior into a fresh set
1103 We want to preserve symbolic breakpoints on the list, since
1104 we have hopes that they can be reset after the new a.out's
1105 symbol table is read.
1107 However, any "raw" breakpoints must be removed from the list
1108 (e.g., the solib bp's), since their address is probably invalid
1111 And, we DON'T want to call delete_breakpoints() here, since
1112 that may write the bp's "shadow contents" (the instruction
1113 value that was overwritten with a TRAP instruction). Since
1114 we now have a new a.out, those shadow contents aren't valid. */
1116 mark_breakpoints_out ();
1118 /* The target reports the exec event to the main thread, even if
1119 some other thread does the exec, and even if the main thread was
1120 stopped or already gone. We may still have non-leader threads of
1121 the process on our list. E.g., on targets that don't have thread
1122 exit events (like remote); or on native Linux in non-stop mode if
1123 there were only two threads in the inferior and the non-leader
1124 one is the one that execs (and nothing forces an update of the
1125 thread list up to here). When debugging remotely, it's best to
1126 avoid extra traffic, when possible, so avoid syncing the thread
1127 list with the target, and instead go ahead and delete all threads
1128 of the process but one that reported the event. Note this must
1129 be done before calling update_breakpoints_after_exec, as
1130 otherwise clearing the threads' resources would reference stale
1131 thread breakpoints -- it may have been one of these threads that
1132 stepped across the exec. We could just clear their stepping
1133 states, but as long as we're iterating, might as well delete
1134 them. Deleting them now rather than at the next user-visible
1135 stop provides a nicer sequence of events for user and MI
1137 for (thread_info
*th
: all_threads_safe ())
1138 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1141 /* We also need to clear any left over stale state for the
1142 leader/event thread. E.g., if there was any step-resume
1143 breakpoint or similar, it's gone now. We cannot truly
1144 step-to-next statement through an exec(). */
1145 thread_info
*th
= inferior_thread ();
1146 th
->control
.step_resume_breakpoint
= NULL
;
1147 th
->control
.exception_resume_breakpoint
= NULL
;
1148 th
->control
.single_step_breakpoints
= NULL
;
1149 th
->control
.step_range_start
= 0;
1150 th
->control
.step_range_end
= 0;
1152 /* The user may have had the main thread held stopped in the
1153 previous image (e.g., schedlock on, or non-stop). Release
1155 th
->stop_requested
= 0;
1157 update_breakpoints_after_exec ();
1159 /* What is this a.out's name? */
1160 process_ptid
= ptid_t (pid
);
1161 printf_unfiltered (_("%s is executing new program: %s\n"),
1162 target_pid_to_str (process_ptid
).c_str (),
1165 /* We've followed the inferior through an exec. Therefore, the
1166 inferior has essentially been killed & reborn. */
1168 breakpoint_init_inferior (inf_execd
);
1170 gdb::unique_xmalloc_ptr
<char> exec_file_host
1171 = exec_file_find (exec_file_target
, NULL
);
1173 /* If we were unable to map the executable target pathname onto a host
1174 pathname, tell the user that. Otherwise GDB's subsequent behavior
1175 is confusing. Maybe it would even be better to stop at this point
1176 so that the user can specify a file manually before continuing. */
1177 if (exec_file_host
== NULL
)
1178 warning (_("Could not load symbols for executable %s.\n"
1179 "Do you need \"set sysroot\"?"),
1182 /* Reset the shared library package. This ensures that we get a
1183 shlib event when the child reaches "_start", at which point the
1184 dld will have had a chance to initialize the child. */
1185 /* Also, loading a symbol file below may trigger symbol lookups, and
1186 we don't want those to be satisfied by the libraries of the
1187 previous incarnation of this process. */
1188 no_shared_libraries (NULL
, 0);
1190 if (follow_exec_mode_string
== follow_exec_mode_new
)
1192 /* The user wants to keep the old inferior and program spaces
1193 around. Create a new fresh one, and switch to it. */
1195 /* Do exit processing for the original inferior before setting the new
1196 inferior's pid. Having two inferiors with the same pid would confuse
1197 find_inferior_p(t)id. Transfer the terminal state and info from the
1198 old to the new inferior. */
1199 inf
= add_inferior_with_spaces ();
1200 swap_terminal_info (inf
, current_inferior ());
1201 exit_inferior_silent (current_inferior ());
1204 target_follow_exec (inf
, exec_file_target
);
1206 inferior
*org_inferior
= current_inferior ();
1207 switch_to_inferior_no_thread (inf
);
1208 push_target (org_inferior
->process_target ());
1209 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1210 switch_to_thread (thr
);
1214 /* The old description may no longer be fit for the new image.
1215 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1216 old description; we'll read a new one below. No need to do
1217 this on "follow-exec-mode new", as the old inferior stays
1218 around (its description is later cleared/refetched on
1220 target_clear_description ();
1223 gdb_assert (current_program_space
== inf
->pspace
);
1225 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1226 because the proper displacement for a PIE (Position Independent
1227 Executable) main symbol file will only be computed by
1228 solib_create_inferior_hook below. breakpoint_re_set would fail
1229 to insert the breakpoints with the zero displacement. */
1230 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1232 /* If the target can specify a description, read it. Must do this
1233 after flipping to the new executable (because the target supplied
1234 description must be compatible with the executable's
1235 architecture, and the old executable may e.g., be 32-bit, while
1236 the new one 64-bit), and before anything involving memory or
1238 target_find_description ();
1240 solib_create_inferior_hook (0);
1242 jit_inferior_created_hook ();
1244 breakpoint_re_set ();
1246 /* Reinsert all breakpoints. (Those which were symbolic have
1247 been reset to the proper address in the new a.out, thanks
1248 to symbol_file_command...). */
1249 insert_breakpoints ();
1251 /* The next resume of this inferior should bring it to the shlib
1252 startup breakpoints. (If the user had also set bp's on
1253 "main" from the old (parent) process, then they'll auto-
1254 matically get reset there in the new process.). */
1257 /* The queue of threads that need to do a step-over operation to get
1258 past e.g., a breakpoint. What technique is used to step over the
1259 breakpoint/watchpoint does not matter -- all threads end up in the
1260 same queue, to maintain rough temporal order of execution, in order
1261 to avoid starvation, otherwise, we could e.g., find ourselves
1262 constantly stepping the same couple threads past their breakpoints
1263 over and over, if the single-step finish fast enough. */
1264 struct thread_info
*step_over_queue_head
;
1266 /* Bit flags indicating what the thread needs to step over. */
1268 enum step_over_what_flag
1270 /* Step over a breakpoint. */
1271 STEP_OVER_BREAKPOINT
= 1,
1273 /* Step past a non-continuable watchpoint, in order to let the
1274 instruction execute so we can evaluate the watchpoint
1276 STEP_OVER_WATCHPOINT
= 2
1278 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1280 /* Info about an instruction that is being stepped over. */
1282 struct step_over_info
1284 /* If we're stepping past a breakpoint, this is the address space
1285 and address of the instruction the breakpoint is set at. We'll
1286 skip inserting all breakpoints here. Valid iff ASPACE is
1288 const address_space
*aspace
;
1291 /* The instruction being stepped over triggers a nonsteppable
1292 watchpoint. If true, we'll skip inserting watchpoints. */
1293 int nonsteppable_watchpoint_p
;
1295 /* The thread's global number. */
1299 /* The step-over info of the location that is being stepped over.
1301 Note that with async/breakpoint always-inserted mode, a user might
1302 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1303 being stepped over. As setting a new breakpoint inserts all
1304 breakpoints, we need to make sure the breakpoint being stepped over
1305 isn't inserted then. We do that by only clearing the step-over
1306 info when the step-over is actually finished (or aborted).
1308 Presently GDB can only step over one breakpoint at any given time.
1309 Given threads that can't run code in the same address space as the
1310 breakpoint's can't really miss the breakpoint, GDB could be taught
1311 to step-over at most one breakpoint per address space (so this info
1312 could move to the address space object if/when GDB is extended).
1313 The set of breakpoints being stepped over will normally be much
1314 smaller than the set of all breakpoints, so a flag in the
1315 breakpoint location structure would be wasteful. A separate list
1316 also saves complexity and run-time, as otherwise we'd have to go
1317 through all breakpoint locations clearing their flag whenever we
1318 start a new sequence. Similar considerations weigh against storing
1319 this info in the thread object. Plus, not all step overs actually
1320 have breakpoint locations -- e.g., stepping past a single-step
1321 breakpoint, or stepping to complete a non-continuable
1323 static struct step_over_info step_over_info
;
1325 /* Record the address of the breakpoint/instruction we're currently
1327 N.B. We record the aspace and address now, instead of say just the thread,
1328 because when we need the info later the thread may be running. */
1331 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1332 int nonsteppable_watchpoint_p
,
1335 step_over_info
.aspace
= aspace
;
1336 step_over_info
.address
= address
;
1337 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1338 step_over_info
.thread
= thread
;
1341 /* Called when we're not longer stepping over a breakpoint / an
1342 instruction, so all breakpoints are free to be (re)inserted. */
1345 clear_step_over_info (void)
1348 fprintf_unfiltered (gdb_stdlog
,
1349 "infrun: clear_step_over_info\n");
1350 step_over_info
.aspace
= NULL
;
1351 step_over_info
.address
= 0;
1352 step_over_info
.nonsteppable_watchpoint_p
= 0;
1353 step_over_info
.thread
= -1;
1359 stepping_past_instruction_at (struct address_space
*aspace
,
1362 return (step_over_info
.aspace
!= NULL
1363 && breakpoint_address_match (aspace
, address
,
1364 step_over_info
.aspace
,
1365 step_over_info
.address
));
1371 thread_is_stepping_over_breakpoint (int thread
)
1373 return (step_over_info
.thread
!= -1
1374 && thread
== step_over_info
.thread
);
1380 stepping_past_nonsteppable_watchpoint (void)
1382 return step_over_info
.nonsteppable_watchpoint_p
;
1385 /* Returns true if step-over info is valid. */
1388 step_over_info_valid_p (void)
1390 return (step_over_info
.aspace
!= NULL
1391 || stepping_past_nonsteppable_watchpoint ());
1395 /* Displaced stepping. */
1397 /* In non-stop debugging mode, we must take special care to manage
1398 breakpoints properly; in particular, the traditional strategy for
1399 stepping a thread past a breakpoint it has hit is unsuitable.
1400 'Displaced stepping' is a tactic for stepping one thread past a
1401 breakpoint it has hit while ensuring that other threads running
1402 concurrently will hit the breakpoint as they should.
1404 The traditional way to step a thread T off a breakpoint in a
1405 multi-threaded program in all-stop mode is as follows:
1407 a0) Initially, all threads are stopped, and breakpoints are not
1409 a1) We single-step T, leaving breakpoints uninserted.
1410 a2) We insert breakpoints, and resume all threads.
1412 In non-stop debugging, however, this strategy is unsuitable: we
1413 don't want to have to stop all threads in the system in order to
1414 continue or step T past a breakpoint. Instead, we use displaced
1417 n0) Initially, T is stopped, other threads are running, and
1418 breakpoints are inserted.
1419 n1) We copy the instruction "under" the breakpoint to a separate
1420 location, outside the main code stream, making any adjustments
1421 to the instruction, register, and memory state as directed by
1423 n2) We single-step T over the instruction at its new location.
1424 n3) We adjust the resulting register and memory state as directed
1425 by T's architecture. This includes resetting T's PC to point
1426 back into the main instruction stream.
1429 This approach depends on the following gdbarch methods:
1431 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1432 indicate where to copy the instruction, and how much space must
1433 be reserved there. We use these in step n1.
1435 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1436 address, and makes any necessary adjustments to the instruction,
1437 register contents, and memory. We use this in step n1.
1439 - gdbarch_displaced_step_fixup adjusts registers and memory after
1440 we have successfully single-stepped the instruction, to yield the
1441 same effect the instruction would have had if we had executed it
1442 at its original address. We use this in step n3.
1444 The gdbarch_displaced_step_copy_insn and
1445 gdbarch_displaced_step_fixup functions must be written so that
1446 copying an instruction with gdbarch_displaced_step_copy_insn,
1447 single-stepping across the copied instruction, and then applying
1448 gdbarch_displaced_insn_fixup should have the same effects on the
1449 thread's memory and registers as stepping the instruction in place
1450 would have. Exactly which responsibilities fall to the copy and
1451 which fall to the fixup is up to the author of those functions.
1453 See the comments in gdbarch.sh for details.
1455 Note that displaced stepping and software single-step cannot
1456 currently be used in combination, although with some care I think
1457 they could be made to. Software single-step works by placing
1458 breakpoints on all possible subsequent instructions; if the
1459 displaced instruction is a PC-relative jump, those breakpoints
1460 could fall in very strange places --- on pages that aren't
1461 executable, or at addresses that are not proper instruction
1462 boundaries. (We do generally let other threads run while we wait
1463 to hit the software single-step breakpoint, and they might
1464 encounter such a corrupted instruction.) One way to work around
1465 this would be to have gdbarch_displaced_step_copy_insn fully
1466 simulate the effect of PC-relative instructions (and return NULL)
1467 on architectures that use software single-stepping.
1469 In non-stop mode, we can have independent and simultaneous step
1470 requests, so more than one thread may need to simultaneously step
1471 over a breakpoint. The current implementation assumes there is
1472 only one scratch space per process. In this case, we have to
1473 serialize access to the scratch space. If thread A wants to step
1474 over a breakpoint, but we are currently waiting for some other
1475 thread to complete a displaced step, we leave thread A stopped and
1476 place it in the displaced_step_request_queue. Whenever a displaced
1477 step finishes, we pick the next thread in the queue and start a new
1478 displaced step operation on it. See displaced_step_prepare and
1479 displaced_step_fixup for details. */
1481 /* Default destructor for displaced_step_closure. */
1483 displaced_step_closure::~displaced_step_closure () = default;
1485 /* Get the displaced stepping state of process PID. */
1487 static displaced_step_inferior_state
*
1488 get_displaced_stepping_state (inferior
*inf
)
1490 return &inf
->displaced_step_state
;
1493 /* Returns true if any inferior has a thread doing a displaced
1497 displaced_step_in_progress_any_inferior ()
1499 for (inferior
*i
: all_inferiors ())
1501 if (i
->displaced_step_state
.step_thread
!= nullptr)
1508 /* Return true if thread represented by PTID is doing a displaced
1512 displaced_step_in_progress_thread (thread_info
*thread
)
1514 gdb_assert (thread
!= NULL
);
1516 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1519 /* Return true if process PID has a thread doing a displaced step. */
1522 displaced_step_in_progress (inferior
*inf
)
1524 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1527 /* If inferior is in displaced stepping, and ADDR equals to starting address
1528 of copy area, return corresponding displaced_step_closure. Otherwise,
1531 struct displaced_step_closure
*
1532 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1534 displaced_step_inferior_state
*displaced
1535 = get_displaced_stepping_state (current_inferior ());
1537 /* If checking the mode of displaced instruction in copy area. */
1538 if (displaced
->step_thread
!= nullptr
1539 && displaced
->step_copy
== addr
)
1540 return displaced
->step_closure
.get ();
1546 infrun_inferior_exit (struct inferior
*inf
)
1548 inf
->displaced_step_state
.reset ();
1551 /* If ON, and the architecture supports it, GDB will use displaced
1552 stepping to step over breakpoints. If OFF, or if the architecture
1553 doesn't support it, GDB will instead use the traditional
1554 hold-and-step approach. If AUTO (which is the default), GDB will
1555 decide which technique to use to step over breakpoints depending on
1556 whether the target works in a non-stop way (see use_displaced_stepping). */
1558 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1561 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1562 struct cmd_list_element
*c
,
1565 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1566 fprintf_filtered (file
,
1567 _("Debugger's willingness to use displaced stepping "
1568 "to step over breakpoints is %s (currently %s).\n"),
1569 value
, target_is_non_stop_p () ? "on" : "off");
1571 fprintf_filtered (file
,
1572 _("Debugger's willingness to use displaced stepping "
1573 "to step over breakpoints is %s.\n"), value
);
1576 /* Return true if the gdbarch implements the required methods to use
1577 displaced stepping. */
1580 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1582 /* Only check for the presence of step_copy_insn. Other required methods
1583 are checked by the gdbarch validation. */
1584 return gdbarch_displaced_step_copy_insn_p (arch
);
1587 /* Return non-zero if displaced stepping can/should be used to step
1588 over breakpoints of thread TP. */
1591 use_displaced_stepping (thread_info
*tp
)
1593 /* If the user disabled it explicitly, don't use displaced stepping. */
1594 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1597 /* If "auto", only use displaced stepping if the target operates in a non-stop
1599 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1600 && !target_is_non_stop_p ())
1603 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1605 /* If the architecture doesn't implement displaced stepping, don't use
1607 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1610 /* If recording, don't use displaced stepping. */
1611 if (find_record_target () != nullptr)
1614 displaced_step_inferior_state
*displaced_state
1615 = get_displaced_stepping_state (tp
->inf
);
1617 /* If displaced stepping failed before for this inferior, don't bother trying
1619 if (displaced_state
->failed_before
)
1625 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1628 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1630 displaced
->reset ();
1633 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1634 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1636 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1638 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1640 displaced_step_dump_bytes (struct ui_file
*file
,
1641 const gdb_byte
*buf
,
1646 for (i
= 0; i
< len
; i
++)
1647 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1648 fputs_unfiltered ("\n", file
);
1651 /* Prepare to single-step, using displaced stepping.
1653 Note that we cannot use displaced stepping when we have a signal to
1654 deliver. If we have a signal to deliver and an instruction to step
1655 over, then after the step, there will be no indication from the
1656 target whether the thread entered a signal handler or ignored the
1657 signal and stepped over the instruction successfully --- both cases
1658 result in a simple SIGTRAP. In the first case we mustn't do a
1659 fixup, and in the second case we must --- but we can't tell which.
1660 Comments in the code for 'random signals' in handle_inferior_event
1661 explain how we handle this case instead.
1663 Returns 1 if preparing was successful -- this thread is going to be
1664 stepped now; 0 if displaced stepping this thread got queued; or -1
1665 if this instruction can't be displaced stepped. */
1668 displaced_step_prepare_throw (thread_info
*tp
)
1670 regcache
*regcache
= get_thread_regcache (tp
);
1671 struct gdbarch
*gdbarch
= regcache
->arch ();
1672 const address_space
*aspace
= regcache
->aspace ();
1673 CORE_ADDR original
, copy
;
1677 /* We should never reach this function if the architecture does not
1678 support displaced stepping. */
1679 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1681 /* Nor if the thread isn't meant to step over a breakpoint. */
1682 gdb_assert (tp
->control
.trap_expected
);
1684 /* Disable range stepping while executing in the scratch pad. We
1685 want a single-step even if executing the displaced instruction in
1686 the scratch buffer lands within the stepping range (e.g., a
1688 tp
->control
.may_range_step
= 0;
1690 /* We have to displaced step one thread at a time, as we only have
1691 access to a single scratch space per inferior. */
1693 displaced_step_inferior_state
*displaced
1694 = get_displaced_stepping_state (tp
->inf
);
1696 if (displaced
->step_thread
!= nullptr)
1698 /* Already waiting for a displaced step to finish. Defer this
1699 request and place in queue. */
1701 if (debug_displaced
)
1702 fprintf_unfiltered (gdb_stdlog
,
1703 "displaced: deferring step of %s\n",
1704 target_pid_to_str (tp
->ptid
).c_str ());
1706 thread_step_over_chain_enqueue (tp
);
1711 if (debug_displaced
)
1712 fprintf_unfiltered (gdb_stdlog
,
1713 "displaced: stepping %s now\n",
1714 target_pid_to_str (tp
->ptid
).c_str ());
1717 displaced_step_reset (displaced
);
1719 scoped_restore_current_thread restore_thread
;
1721 switch_to_thread (tp
);
1723 original
= regcache_read_pc (regcache
);
1725 copy
= gdbarch_displaced_step_location (gdbarch
);
1726 len
= gdbarch_max_insn_length (gdbarch
);
1728 if (breakpoint_in_range_p (aspace
, copy
, len
))
1730 /* There's a breakpoint set in the scratch pad location range
1731 (which is usually around the entry point). We'd either
1732 install it before resuming, which would overwrite/corrupt the
1733 scratch pad, or if it was already inserted, this displaced
1734 step would overwrite it. The latter is OK in the sense that
1735 we already assume that no thread is going to execute the code
1736 in the scratch pad range (after initial startup) anyway, but
1737 the former is unacceptable. Simply punt and fallback to
1738 stepping over this breakpoint in-line. */
1739 if (debug_displaced
)
1741 fprintf_unfiltered (gdb_stdlog
,
1742 "displaced: breakpoint set in scratch pad. "
1743 "Stepping over breakpoint in-line instead.\n");
1749 /* Save the original contents of the copy area. */
1750 displaced
->step_saved_copy
.resize (len
);
1751 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1753 throw_error (MEMORY_ERROR
,
1754 _("Error accessing memory address %s (%s) for "
1755 "displaced-stepping scratch space."),
1756 paddress (gdbarch
, copy
), safe_strerror (status
));
1757 if (debug_displaced
)
1759 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1760 paddress (gdbarch
, copy
));
1761 displaced_step_dump_bytes (gdb_stdlog
,
1762 displaced
->step_saved_copy
.data (),
1766 displaced
->step_closure
1767 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1768 if (displaced
->step_closure
== NULL
)
1770 /* The architecture doesn't know how or want to displaced step
1771 this instruction or instruction sequence. Fallback to
1772 stepping over the breakpoint in-line. */
1776 /* Save the information we need to fix things up if the step
1778 displaced
->step_thread
= tp
;
1779 displaced
->step_gdbarch
= gdbarch
;
1780 displaced
->step_original
= original
;
1781 displaced
->step_copy
= copy
;
1784 displaced_step_reset_cleanup
cleanup (displaced
);
1786 /* Resume execution at the copy. */
1787 regcache_write_pc (regcache
, copy
);
1792 if (debug_displaced
)
1793 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1794 paddress (gdbarch
, copy
));
1799 /* Wrapper for displaced_step_prepare_throw that disabled further
1800 attempts at displaced stepping if we get a memory error. */
1803 displaced_step_prepare (thread_info
*thread
)
1809 prepared
= displaced_step_prepare_throw (thread
);
1811 catch (const gdb_exception_error
&ex
)
1813 struct displaced_step_inferior_state
*displaced_state
;
1815 if (ex
.error
!= MEMORY_ERROR
1816 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1821 fprintf_unfiltered (gdb_stdlog
,
1822 "infrun: disabling displaced stepping: %s\n",
1826 /* Be verbose if "set displaced-stepping" is "on", silent if
1828 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1830 warning (_("disabling displaced stepping: %s"),
1834 /* Disable further displaced stepping attempts. */
1836 = get_displaced_stepping_state (thread
->inf
);
1837 displaced_state
->failed_before
= 1;
1844 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1845 const gdb_byte
*myaddr
, int len
)
1847 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1849 inferior_ptid
= ptid
;
1850 write_memory (memaddr
, myaddr
, len
);
1853 /* Restore the contents of the copy area for thread PTID. */
1856 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1859 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1861 write_memory_ptid (ptid
, displaced
->step_copy
,
1862 displaced
->step_saved_copy
.data (), len
);
1863 if (debug_displaced
)
1864 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1865 target_pid_to_str (ptid
).c_str (),
1866 paddress (displaced
->step_gdbarch
,
1867 displaced
->step_copy
));
1870 /* If we displaced stepped an instruction successfully, adjust
1871 registers and memory to yield the same effect the instruction would
1872 have had if we had executed it at its original address, and return
1873 1. If the instruction didn't complete, relocate the PC and return
1874 -1. If the thread wasn't displaced stepping, return 0. */
1877 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1879 struct displaced_step_inferior_state
*displaced
1880 = get_displaced_stepping_state (event_thread
->inf
);
1883 /* Was this event for the thread we displaced? */
1884 if (displaced
->step_thread
!= event_thread
)
1887 displaced_step_reset_cleanup
cleanup (displaced
);
1889 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1891 /* Fixup may need to read memory/registers. Switch to the thread
1892 that we're fixing up. Also, target_stopped_by_watchpoint checks
1893 the current thread. */
1894 switch_to_thread (event_thread
);
1896 /* Did the instruction complete successfully? */
1897 if (signal
== GDB_SIGNAL_TRAP
1898 && !(target_stopped_by_watchpoint ()
1899 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1900 || target_have_steppable_watchpoint
)))
1902 /* Fix up the resulting state. */
1903 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1904 displaced
->step_closure
.get (),
1905 displaced
->step_original
,
1906 displaced
->step_copy
,
1907 get_thread_regcache (displaced
->step_thread
));
1912 /* Since the instruction didn't complete, all we can do is
1914 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1915 CORE_ADDR pc
= regcache_read_pc (regcache
);
1917 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1918 regcache_write_pc (regcache
, pc
);
1925 /* Data to be passed around while handling an event. This data is
1926 discarded between events. */
1927 struct execution_control_state
1929 process_stratum_target
*target
;
1931 /* The thread that got the event, if this was a thread event; NULL
1933 struct thread_info
*event_thread
;
1935 struct target_waitstatus ws
;
1936 int stop_func_filled_in
;
1937 CORE_ADDR stop_func_start
;
1938 CORE_ADDR stop_func_end
;
1939 const char *stop_func_name
;
1942 /* True if the event thread hit the single-step breakpoint of
1943 another thread. Thus the event doesn't cause a stop, the thread
1944 needs to be single-stepped past the single-step breakpoint before
1945 we can switch back to the original stepping thread. */
1946 int hit_singlestep_breakpoint
;
1949 /* Clear ECS and set it to point at TP. */
1952 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1954 memset (ecs
, 0, sizeof (*ecs
));
1955 ecs
->event_thread
= tp
;
1956 ecs
->ptid
= tp
->ptid
;
1959 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1960 static void prepare_to_wait (struct execution_control_state
*ecs
);
1961 static int keep_going_stepped_thread (struct thread_info
*tp
);
1962 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1964 /* Are there any pending step-over requests? If so, run all we can
1965 now and return true. Otherwise, return false. */
1968 start_step_over (void)
1970 struct thread_info
*tp
, *next
;
1972 /* Don't start a new step-over if we already have an in-line
1973 step-over operation ongoing. */
1974 if (step_over_info_valid_p ())
1977 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1979 struct execution_control_state ecss
;
1980 struct execution_control_state
*ecs
= &ecss
;
1981 step_over_what step_what
;
1982 int must_be_in_line
;
1984 gdb_assert (!tp
->stop_requested
);
1986 next
= thread_step_over_chain_next (tp
);
1988 /* If this inferior already has a displaced step in process,
1989 don't start a new one. */
1990 if (displaced_step_in_progress (tp
->inf
))
1993 step_what
= thread_still_needs_step_over (tp
);
1994 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1995 || ((step_what
& STEP_OVER_BREAKPOINT
)
1996 && !use_displaced_stepping (tp
)));
1998 /* We currently stop all threads of all processes to step-over
1999 in-line. If we need to start a new in-line step-over, let
2000 any pending displaced steps finish first. */
2001 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
2004 thread_step_over_chain_remove (tp
);
2006 if (step_over_queue_head
== NULL
)
2009 fprintf_unfiltered (gdb_stdlog
,
2010 "infrun: step-over queue now empty\n");
2013 if (tp
->control
.trap_expected
2017 internal_error (__FILE__
, __LINE__
,
2018 "[%s] has inconsistent state: "
2019 "trap_expected=%d, resumed=%d, executing=%d\n",
2020 target_pid_to_str (tp
->ptid
).c_str (),
2021 tp
->control
.trap_expected
,
2027 fprintf_unfiltered (gdb_stdlog
,
2028 "infrun: resuming [%s] for step-over\n",
2029 target_pid_to_str (tp
->ptid
).c_str ());
2031 /* keep_going_pass_signal skips the step-over if the breakpoint
2032 is no longer inserted. In all-stop, we want to keep looking
2033 for a thread that needs a step-over instead of resuming TP,
2034 because we wouldn't be able to resume anything else until the
2035 target stops again. In non-stop, the resume always resumes
2036 only TP, so it's OK to let the thread resume freely. */
2037 if (!target_is_non_stop_p () && !step_what
)
2040 switch_to_thread (tp
);
2041 reset_ecs (ecs
, tp
);
2042 keep_going_pass_signal (ecs
);
2044 if (!ecs
->wait_some_more
)
2045 error (_("Command aborted."));
2047 gdb_assert (tp
->resumed
);
2049 /* If we started a new in-line step-over, we're done. */
2050 if (step_over_info_valid_p ())
2052 gdb_assert (tp
->control
.trap_expected
);
2056 if (!target_is_non_stop_p ())
2058 /* On all-stop, shouldn't have resumed unless we needed a
2060 gdb_assert (tp
->control
.trap_expected
2061 || tp
->step_after_step_resume_breakpoint
);
2063 /* With remote targets (at least), in all-stop, we can't
2064 issue any further remote commands until the program stops
2069 /* Either the thread no longer needed a step-over, or a new
2070 displaced stepping sequence started. Even in the latter
2071 case, continue looking. Maybe we can also start another
2072 displaced step on a thread of other process. */
2078 /* Update global variables holding ptids to hold NEW_PTID if they were
2079 holding OLD_PTID. */
2081 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2083 if (inferior_ptid
== old_ptid
)
2084 inferior_ptid
= new_ptid
;
2089 static const char schedlock_off
[] = "off";
2090 static const char schedlock_on
[] = "on";
2091 static const char schedlock_step
[] = "step";
2092 static const char schedlock_replay
[] = "replay";
2093 static const char *const scheduler_enums
[] = {
2100 static const char *scheduler_mode
= schedlock_replay
;
2102 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2103 struct cmd_list_element
*c
, const char *value
)
2105 fprintf_filtered (file
,
2106 _("Mode for locking scheduler "
2107 "during execution is \"%s\".\n"),
2112 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2114 if (!target_can_lock_scheduler
)
2116 scheduler_mode
= schedlock_off
;
2117 error (_("Target '%s' cannot support this command."), target_shortname
);
2121 /* True if execution commands resume all threads of all processes by
2122 default; otherwise, resume only threads of the current inferior
2124 bool sched_multi
= false;
2126 /* Try to setup for software single stepping over the specified location.
2127 Return 1 if target_resume() should use hardware single step.
2129 GDBARCH the current gdbarch.
2130 PC the location to step over. */
2133 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2137 if (execution_direction
== EXEC_FORWARD
2138 && gdbarch_software_single_step_p (gdbarch
))
2139 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2147 user_visible_resume_ptid (int step
)
2153 /* With non-stop mode on, threads are always handled
2155 resume_ptid
= inferior_ptid
;
2157 else if ((scheduler_mode
== schedlock_on
)
2158 || (scheduler_mode
== schedlock_step
&& step
))
2160 /* User-settable 'scheduler' mode requires solo thread
2162 resume_ptid
= inferior_ptid
;
2164 else if ((scheduler_mode
== schedlock_replay
)
2165 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2167 /* User-settable 'scheduler' mode requires solo thread resume in replay
2169 resume_ptid
= inferior_ptid
;
2171 else if (!sched_multi
&& target_supports_multi_process ())
2173 /* Resume all threads of the current process (and none of other
2175 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2179 /* Resume all threads of all processes. */
2180 resume_ptid
= RESUME_ALL
;
2188 process_stratum_target
*
2189 user_visible_resume_target (ptid_t resume_ptid
)
2191 return (resume_ptid
== minus_one_ptid
&& sched_multi
2193 : current_inferior ()->process_target ());
2196 /* Return a ptid representing the set of threads that we will resume,
2197 in the perspective of the target, assuming run control handling
2198 does not require leaving some threads stopped (e.g., stepping past
2199 breakpoint). USER_STEP indicates whether we're about to start the
2200 target for a stepping command. */
2203 internal_resume_ptid (int user_step
)
2205 /* In non-stop, we always control threads individually. Note that
2206 the target may always work in non-stop mode even with "set
2207 non-stop off", in which case user_visible_resume_ptid could
2208 return a wildcard ptid. */
2209 if (target_is_non_stop_p ())
2210 return inferior_ptid
;
2212 return user_visible_resume_ptid (user_step
);
2215 /* Wrapper for target_resume, that handles infrun-specific
2219 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2221 struct thread_info
*tp
= inferior_thread ();
2223 gdb_assert (!tp
->stop_requested
);
2225 /* Install inferior's terminal modes. */
2226 target_terminal::inferior ();
2228 /* Avoid confusing the next resume, if the next stop/resume
2229 happens to apply to another thread. */
2230 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2232 /* Advise target which signals may be handled silently.
2234 If we have removed breakpoints because we are stepping over one
2235 in-line (in any thread), we need to receive all signals to avoid
2236 accidentally skipping a breakpoint during execution of a signal
2239 Likewise if we're displaced stepping, otherwise a trap for a
2240 breakpoint in a signal handler might be confused with the
2241 displaced step finishing. We don't make the displaced_step_fixup
2242 step distinguish the cases instead, because:
2244 - a backtrace while stopped in the signal handler would show the
2245 scratch pad as frame older than the signal handler, instead of
2246 the real mainline code.
2248 - when the thread is later resumed, the signal handler would
2249 return to the scratch pad area, which would no longer be
2251 if (step_over_info_valid_p ()
2252 || displaced_step_in_progress (tp
->inf
))
2253 target_pass_signals ({});
2255 target_pass_signals (signal_pass
);
2257 target_resume (resume_ptid
, step
, sig
);
2259 target_commit_resume ();
2261 if (target_can_async_p ())
2265 /* Resume the inferior. SIG is the signal to give the inferior
2266 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2267 call 'resume', which handles exceptions. */
2270 resume_1 (enum gdb_signal sig
)
2272 struct regcache
*regcache
= get_current_regcache ();
2273 struct gdbarch
*gdbarch
= regcache
->arch ();
2274 struct thread_info
*tp
= inferior_thread ();
2275 CORE_ADDR pc
= regcache_read_pc (regcache
);
2276 const address_space
*aspace
= regcache
->aspace ();
2278 /* This represents the user's step vs continue request. When
2279 deciding whether "set scheduler-locking step" applies, it's the
2280 user's intention that counts. */
2281 const int user_step
= tp
->control
.stepping_command
;
2282 /* This represents what we'll actually request the target to do.
2283 This can decay from a step to a continue, if e.g., we need to
2284 implement single-stepping with breakpoints (software
2288 gdb_assert (!tp
->stop_requested
);
2289 gdb_assert (!thread_is_in_step_over_chain (tp
));
2291 if (tp
->suspend
.waitstatus_pending_p
)
2296 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2298 fprintf_unfiltered (gdb_stdlog
,
2299 "infrun: resume: thread %s has pending wait "
2300 "status %s (currently_stepping=%d).\n",
2301 target_pid_to_str (tp
->ptid
).c_str (),
2303 currently_stepping (tp
));
2306 tp
->inf
->process_target ()->threads_executing
= true;
2309 /* FIXME: What should we do if we are supposed to resume this
2310 thread with a signal? Maybe we should maintain a queue of
2311 pending signals to deliver. */
2312 if (sig
!= GDB_SIGNAL_0
)
2314 warning (_("Couldn't deliver signal %s to %s."),
2315 gdb_signal_to_name (sig
),
2316 target_pid_to_str (tp
->ptid
).c_str ());
2319 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2321 if (target_can_async_p ())
2324 /* Tell the event loop we have an event to process. */
2325 mark_async_event_handler (infrun_async_inferior_event_token
);
2330 tp
->stepped_breakpoint
= 0;
2332 /* Depends on stepped_breakpoint. */
2333 step
= currently_stepping (tp
);
2335 if (current_inferior ()->waiting_for_vfork_done
)
2337 /* Don't try to single-step a vfork parent that is waiting for
2338 the child to get out of the shared memory region (by exec'ing
2339 or exiting). This is particularly important on software
2340 single-step archs, as the child process would trip on the
2341 software single step breakpoint inserted for the parent
2342 process. Since the parent will not actually execute any
2343 instruction until the child is out of the shared region (such
2344 are vfork's semantics), it is safe to simply continue it.
2345 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2346 the parent, and tell it to `keep_going', which automatically
2347 re-sets it stepping. */
2349 fprintf_unfiltered (gdb_stdlog
,
2350 "infrun: resume : clear step\n");
2355 fprintf_unfiltered (gdb_stdlog
,
2356 "infrun: resume (step=%d, signal=%s), "
2357 "trap_expected=%d, current thread [%s] at %s\n",
2358 step
, gdb_signal_to_symbol_string (sig
),
2359 tp
->control
.trap_expected
,
2360 target_pid_to_str (inferior_ptid
).c_str (),
2361 paddress (gdbarch
, pc
));
2363 /* Normally, by the time we reach `resume', the breakpoints are either
2364 removed or inserted, as appropriate. The exception is if we're sitting
2365 at a permanent breakpoint; we need to step over it, but permanent
2366 breakpoints can't be removed. So we have to test for it here. */
2367 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2369 if (sig
!= GDB_SIGNAL_0
)
2371 /* We have a signal to pass to the inferior. The resume
2372 may, or may not take us to the signal handler. If this
2373 is a step, we'll need to stop in the signal handler, if
2374 there's one, (if the target supports stepping into
2375 handlers), or in the next mainline instruction, if
2376 there's no handler. If this is a continue, we need to be
2377 sure to run the handler with all breakpoints inserted.
2378 In all cases, set a breakpoint at the current address
2379 (where the handler returns to), and once that breakpoint
2380 is hit, resume skipping the permanent breakpoint. If
2381 that breakpoint isn't hit, then we've stepped into the
2382 signal handler (or hit some other event). We'll delete
2383 the step-resume breakpoint then. */
2386 fprintf_unfiltered (gdb_stdlog
,
2387 "infrun: resume: skipping permanent breakpoint, "
2388 "deliver signal first\n");
2390 clear_step_over_info ();
2391 tp
->control
.trap_expected
= 0;
2393 if (tp
->control
.step_resume_breakpoint
== NULL
)
2395 /* Set a "high-priority" step-resume, as we don't want
2396 user breakpoints at PC to trigger (again) when this
2398 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2399 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2401 tp
->step_after_step_resume_breakpoint
= step
;
2404 insert_breakpoints ();
2408 /* There's no signal to pass, we can go ahead and skip the
2409 permanent breakpoint manually. */
2411 fprintf_unfiltered (gdb_stdlog
,
2412 "infrun: resume: skipping permanent breakpoint\n");
2413 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2414 /* Update pc to reflect the new address from which we will
2415 execute instructions. */
2416 pc
= regcache_read_pc (regcache
);
2420 /* We've already advanced the PC, so the stepping part
2421 is done. Now we need to arrange for a trap to be
2422 reported to handle_inferior_event. Set a breakpoint
2423 at the current PC, and run to it. Don't update
2424 prev_pc, because if we end in
2425 switch_back_to_stepped_thread, we want the "expected
2426 thread advanced also" branch to be taken. IOW, we
2427 don't want this thread to step further from PC
2429 gdb_assert (!step_over_info_valid_p ());
2430 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2431 insert_breakpoints ();
2433 resume_ptid
= internal_resume_ptid (user_step
);
2434 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2441 /* If we have a breakpoint to step over, make sure to do a single
2442 step only. Same if we have software watchpoints. */
2443 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2444 tp
->control
.may_range_step
= 0;
2446 /* If displaced stepping is enabled, step over breakpoints by executing a
2447 copy of the instruction at a different address.
2449 We can't use displaced stepping when we have a signal to deliver;
2450 the comments for displaced_step_prepare explain why. The
2451 comments in the handle_inferior event for dealing with 'random
2452 signals' explain what we do instead.
2454 We can't use displaced stepping when we are waiting for vfork_done
2455 event, displaced stepping breaks the vfork child similarly as single
2456 step software breakpoint. */
2457 if (tp
->control
.trap_expected
2458 && use_displaced_stepping (tp
)
2459 && !step_over_info_valid_p ()
2460 && sig
== GDB_SIGNAL_0
2461 && !current_inferior ()->waiting_for_vfork_done
)
2463 int prepared
= displaced_step_prepare (tp
);
2468 fprintf_unfiltered (gdb_stdlog
,
2469 "Got placed in step-over queue\n");
2471 tp
->control
.trap_expected
= 0;
2474 else if (prepared
< 0)
2476 /* Fallback to stepping over the breakpoint in-line. */
2478 if (target_is_non_stop_p ())
2479 stop_all_threads ();
2481 set_step_over_info (regcache
->aspace (),
2482 regcache_read_pc (regcache
), 0, tp
->global_num
);
2484 step
= maybe_software_singlestep (gdbarch
, pc
);
2486 insert_breakpoints ();
2488 else if (prepared
> 0)
2490 struct displaced_step_inferior_state
*displaced
;
2492 /* Update pc to reflect the new address from which we will
2493 execute instructions due to displaced stepping. */
2494 pc
= regcache_read_pc (get_thread_regcache (tp
));
2496 displaced
= get_displaced_stepping_state (tp
->inf
);
2497 step
= gdbarch_displaced_step_hw_singlestep
2498 (gdbarch
, displaced
->step_closure
.get ());
2502 /* Do we need to do it the hard way, w/temp breakpoints? */
2504 step
= maybe_software_singlestep (gdbarch
, pc
);
2506 /* Currently, our software single-step implementation leads to different
2507 results than hardware single-stepping in one situation: when stepping
2508 into delivering a signal which has an associated signal handler,
2509 hardware single-step will stop at the first instruction of the handler,
2510 while software single-step will simply skip execution of the handler.
2512 For now, this difference in behavior is accepted since there is no
2513 easy way to actually implement single-stepping into a signal handler
2514 without kernel support.
2516 However, there is one scenario where this difference leads to follow-on
2517 problems: if we're stepping off a breakpoint by removing all breakpoints
2518 and then single-stepping. In this case, the software single-step
2519 behavior means that even if there is a *breakpoint* in the signal
2520 handler, GDB still would not stop.
2522 Fortunately, we can at least fix this particular issue. We detect
2523 here the case where we are about to deliver a signal while software
2524 single-stepping with breakpoints removed. In this situation, we
2525 revert the decisions to remove all breakpoints and insert single-
2526 step breakpoints, and instead we install a step-resume breakpoint
2527 at the current address, deliver the signal without stepping, and
2528 once we arrive back at the step-resume breakpoint, actually step
2529 over the breakpoint we originally wanted to step over. */
2530 if (thread_has_single_step_breakpoints_set (tp
)
2531 && sig
!= GDB_SIGNAL_0
2532 && step_over_info_valid_p ())
2534 /* If we have nested signals or a pending signal is delivered
2535 immediately after a handler returns, might already have
2536 a step-resume breakpoint set on the earlier handler. We cannot
2537 set another step-resume breakpoint; just continue on until the
2538 original breakpoint is hit. */
2539 if (tp
->control
.step_resume_breakpoint
== NULL
)
2541 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2542 tp
->step_after_step_resume_breakpoint
= 1;
2545 delete_single_step_breakpoints (tp
);
2547 clear_step_over_info ();
2548 tp
->control
.trap_expected
= 0;
2550 insert_breakpoints ();
2553 /* If STEP is set, it's a request to use hardware stepping
2554 facilities. But in that case, we should never
2555 use singlestep breakpoint. */
2556 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2558 /* Decide the set of threads to ask the target to resume. */
2559 if (tp
->control
.trap_expected
)
2561 /* We're allowing a thread to run past a breakpoint it has
2562 hit, either by single-stepping the thread with the breakpoint
2563 removed, or by displaced stepping, with the breakpoint inserted.
2564 In the former case, we need to single-step only this thread,
2565 and keep others stopped, as they can miss this breakpoint if
2566 allowed to run. That's not really a problem for displaced
2567 stepping, but, we still keep other threads stopped, in case
2568 another thread is also stopped for a breakpoint waiting for
2569 its turn in the displaced stepping queue. */
2570 resume_ptid
= inferior_ptid
;
2573 resume_ptid
= internal_resume_ptid (user_step
);
2575 if (execution_direction
!= EXEC_REVERSE
2576 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2578 /* There are two cases where we currently need to step a
2579 breakpoint instruction when we have a signal to deliver:
2581 - See handle_signal_stop where we handle random signals that
2582 could take out us out of the stepping range. Normally, in
2583 that case we end up continuing (instead of stepping) over the
2584 signal handler with a breakpoint at PC, but there are cases
2585 where we should _always_ single-step, even if we have a
2586 step-resume breakpoint, like when a software watchpoint is
2587 set. Assuming single-stepping and delivering a signal at the
2588 same time would takes us to the signal handler, then we could
2589 have removed the breakpoint at PC to step over it. However,
2590 some hardware step targets (like e.g., Mac OS) can't step
2591 into signal handlers, and for those, we need to leave the
2592 breakpoint at PC inserted, as otherwise if the handler
2593 recurses and executes PC again, it'll miss the breakpoint.
2594 So we leave the breakpoint inserted anyway, but we need to
2595 record that we tried to step a breakpoint instruction, so
2596 that adjust_pc_after_break doesn't end up confused.
2598 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2599 in one thread after another thread that was stepping had been
2600 momentarily paused for a step-over. When we re-resume the
2601 stepping thread, it may be resumed from that address with a
2602 breakpoint that hasn't trapped yet. Seen with
2603 gdb.threads/non-stop-fair-events.exp, on targets that don't
2604 do displaced stepping. */
2607 fprintf_unfiltered (gdb_stdlog
,
2608 "infrun: resume: [%s] stepped breakpoint\n",
2609 target_pid_to_str (tp
->ptid
).c_str ());
2611 tp
->stepped_breakpoint
= 1;
2613 /* Most targets can step a breakpoint instruction, thus
2614 executing it normally. But if this one cannot, just
2615 continue and we will hit it anyway. */
2616 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2621 && tp
->control
.trap_expected
2622 && use_displaced_stepping (tp
)
2623 && !step_over_info_valid_p ())
2625 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2626 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2627 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2630 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2631 paddress (resume_gdbarch
, actual_pc
));
2632 read_memory (actual_pc
, buf
, sizeof (buf
));
2633 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2636 if (tp
->control
.may_range_step
)
2638 /* If we're resuming a thread with the PC out of the step
2639 range, then we're doing some nested/finer run control
2640 operation, like stepping the thread out of the dynamic
2641 linker or the displaced stepping scratch pad. We
2642 shouldn't have allowed a range step then. */
2643 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2646 do_target_resume (resume_ptid
, step
, sig
);
2650 /* Resume the inferior. SIG is the signal to give the inferior
2651 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2652 rolls back state on error. */
2655 resume (gdb_signal sig
)
2661 catch (const gdb_exception
&ex
)
2663 /* If resuming is being aborted for any reason, delete any
2664 single-step breakpoint resume_1 may have created, to avoid
2665 confusing the following resumption, and to avoid leaving
2666 single-step breakpoints perturbing other threads, in case
2667 we're running in non-stop mode. */
2668 if (inferior_ptid
!= null_ptid
)
2669 delete_single_step_breakpoints (inferior_thread ());
2679 /* Counter that tracks number of user visible stops. This can be used
2680 to tell whether a command has proceeded the inferior past the
2681 current location. This allows e.g., inferior function calls in
2682 breakpoint commands to not interrupt the command list. When the
2683 call finishes successfully, the inferior is standing at the same
2684 breakpoint as if nothing happened (and so we don't call
2686 static ULONGEST current_stop_id
;
2693 return current_stop_id
;
2696 /* Called when we report a user visible stop. */
2704 /* Clear out all variables saying what to do when inferior is continued.
2705 First do this, then set the ones you want, then call `proceed'. */
2708 clear_proceed_status_thread (struct thread_info
*tp
)
2711 fprintf_unfiltered (gdb_stdlog
,
2712 "infrun: clear_proceed_status_thread (%s)\n",
2713 target_pid_to_str (tp
->ptid
).c_str ());
2715 /* If we're starting a new sequence, then the previous finished
2716 single-step is no longer relevant. */
2717 if (tp
->suspend
.waitstatus_pending_p
)
2719 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2722 fprintf_unfiltered (gdb_stdlog
,
2723 "infrun: clear_proceed_status: pending "
2724 "event of %s was a finished step. "
2726 target_pid_to_str (tp
->ptid
).c_str ());
2728 tp
->suspend
.waitstatus_pending_p
= 0;
2729 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2731 else if (debug_infrun
)
2734 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2736 fprintf_unfiltered (gdb_stdlog
,
2737 "infrun: clear_proceed_status_thread: thread %s "
2738 "has pending wait status %s "
2739 "(currently_stepping=%d).\n",
2740 target_pid_to_str (tp
->ptid
).c_str (),
2742 currently_stepping (tp
));
2746 /* If this signal should not be seen by program, give it zero.
2747 Used for debugging signals. */
2748 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2749 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2751 delete tp
->thread_fsm
;
2752 tp
->thread_fsm
= NULL
;
2754 tp
->control
.trap_expected
= 0;
2755 tp
->control
.step_range_start
= 0;
2756 tp
->control
.step_range_end
= 0;
2757 tp
->control
.may_range_step
= 0;
2758 tp
->control
.step_frame_id
= null_frame_id
;
2759 tp
->control
.step_stack_frame_id
= null_frame_id
;
2760 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2761 tp
->control
.step_start_function
= NULL
;
2762 tp
->stop_requested
= 0;
2764 tp
->control
.stop_step
= 0;
2766 tp
->control
.proceed_to_finish
= 0;
2768 tp
->control
.stepping_command
= 0;
2770 /* Discard any remaining commands or status from previous stop. */
2771 bpstat_clear (&tp
->control
.stop_bpstat
);
2775 clear_proceed_status (int step
)
2777 /* With scheduler-locking replay, stop replaying other threads if we're
2778 not replaying the user-visible resume ptid.
2780 This is a convenience feature to not require the user to explicitly
2781 stop replaying the other threads. We're assuming that the user's
2782 intent is to resume tracing the recorded process. */
2783 if (!non_stop
&& scheduler_mode
== schedlock_replay
2784 && target_record_is_replaying (minus_one_ptid
)
2785 && !target_record_will_replay (user_visible_resume_ptid (step
),
2786 execution_direction
))
2787 target_record_stop_replaying ();
2789 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2791 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2792 process_stratum_target
*resume_target
2793 = user_visible_resume_target (resume_ptid
);
2795 /* In all-stop mode, delete the per-thread status of all threads
2796 we're about to resume, implicitly and explicitly. */
2797 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2798 clear_proceed_status_thread (tp
);
2801 if (inferior_ptid
!= null_ptid
)
2803 struct inferior
*inferior
;
2807 /* If in non-stop mode, only delete the per-thread status of
2808 the current thread. */
2809 clear_proceed_status_thread (inferior_thread ());
2812 inferior
= current_inferior ();
2813 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2816 gdb::observers::about_to_proceed
.notify ();
2819 /* Returns true if TP is still stopped at a breakpoint that needs
2820 stepping-over in order to make progress. If the breakpoint is gone
2821 meanwhile, we can skip the whole step-over dance. */
2824 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2826 if (tp
->stepping_over_breakpoint
)
2828 struct regcache
*regcache
= get_thread_regcache (tp
);
2830 if (breakpoint_here_p (regcache
->aspace (),
2831 regcache_read_pc (regcache
))
2832 == ordinary_breakpoint_here
)
2835 tp
->stepping_over_breakpoint
= 0;
2841 /* Check whether thread TP still needs to start a step-over in order
2842 to make progress when resumed. Returns an bitwise or of enum
2843 step_over_what bits, indicating what needs to be stepped over. */
2845 static step_over_what
2846 thread_still_needs_step_over (struct thread_info
*tp
)
2848 step_over_what what
= 0;
2850 if (thread_still_needs_step_over_bp (tp
))
2851 what
|= STEP_OVER_BREAKPOINT
;
2853 if (tp
->stepping_over_watchpoint
2854 && !target_have_steppable_watchpoint
)
2855 what
|= STEP_OVER_WATCHPOINT
;
2860 /* Returns true if scheduler locking applies. STEP indicates whether
2861 we're about to do a step/next-like command to a thread. */
2864 schedlock_applies (struct thread_info
*tp
)
2866 return (scheduler_mode
== schedlock_on
2867 || (scheduler_mode
== schedlock_step
2868 && tp
->control
.stepping_command
)
2869 || (scheduler_mode
== schedlock_replay
2870 && target_record_will_replay (minus_one_ptid
,
2871 execution_direction
)));
2874 /* Calls target_commit_resume on all targets. */
2877 commit_resume_all_targets ()
2879 scoped_restore_current_thread restore_thread
;
2881 /* Map between process_target and a representative inferior. This
2882 is to avoid committing a resume in the same target more than
2883 once. Resumptions must be idempotent, so this is an
2885 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2887 for (inferior
*inf
: all_non_exited_inferiors ())
2888 if (inf
->has_execution ())
2889 conn_inf
[inf
->process_target ()] = inf
;
2891 for (const auto &ci
: conn_inf
)
2893 inferior
*inf
= ci
.second
;
2894 switch_to_inferior_no_thread (inf
);
2895 target_commit_resume ();
2899 /* Check that all the targets we're about to resume are in non-stop
2900 mode. Ideally, we'd only care whether all targets support
2901 target-async, but we're not there yet. E.g., stop_all_threads
2902 doesn't know how to handle all-stop targets. Also, the remote
2903 protocol in all-stop mode is synchronous, irrespective of
2904 target-async, which means that things like a breakpoint re-set
2905 triggered by one target would try to read memory from all targets
2909 check_multi_target_resumption (process_stratum_target
*resume_target
)
2911 if (!non_stop
&& resume_target
== nullptr)
2913 scoped_restore_current_thread restore_thread
;
2915 /* This is used to track whether we're resuming more than one
2917 process_stratum_target
*first_connection
= nullptr;
2919 /* The first inferior we see with a target that does not work in
2920 always-non-stop mode. */
2921 inferior
*first_not_non_stop
= nullptr;
2923 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2925 switch_to_inferior_no_thread (inf
);
2927 if (!target_has_execution
)
2930 process_stratum_target
*proc_target
2931 = current_inferior ()->process_target();
2933 if (!target_is_non_stop_p ())
2934 first_not_non_stop
= inf
;
2936 if (first_connection
== nullptr)
2937 first_connection
= proc_target
;
2938 else if (first_connection
!= proc_target
2939 && first_not_non_stop
!= nullptr)
2941 switch_to_inferior_no_thread (first_not_non_stop
);
2943 proc_target
= current_inferior ()->process_target();
2945 error (_("Connection %d (%s) does not support "
2946 "multi-target resumption."),
2947 proc_target
->connection_number
,
2948 make_target_connection_string (proc_target
).c_str ());
2954 /* Basic routine for continuing the program in various fashions.
2956 ADDR is the address to resume at, or -1 for resume where stopped.
2957 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2958 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2960 You should call clear_proceed_status before calling proceed. */
2963 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2965 struct regcache
*regcache
;
2966 struct gdbarch
*gdbarch
;
2968 struct execution_control_state ecss
;
2969 struct execution_control_state
*ecs
= &ecss
;
2972 /* If we're stopped at a fork/vfork, follow the branch set by the
2973 "set follow-fork-mode" command; otherwise, we'll just proceed
2974 resuming the current thread. */
2975 if (!follow_fork ())
2977 /* The target for some reason decided not to resume. */
2979 if (target_can_async_p ())
2980 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2984 /* We'll update this if & when we switch to a new thread. */
2985 previous_inferior_ptid
= inferior_ptid
;
2987 regcache
= get_current_regcache ();
2988 gdbarch
= regcache
->arch ();
2989 const address_space
*aspace
= regcache
->aspace ();
2991 pc
= regcache_read_pc (regcache
);
2992 thread_info
*cur_thr
= inferior_thread ();
2994 /* Fill in with reasonable starting values. */
2995 init_thread_stepping_state (cur_thr
);
2997 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
3000 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
3001 process_stratum_target
*resume_target
3002 = user_visible_resume_target (resume_ptid
);
3004 check_multi_target_resumption (resume_target
);
3006 if (addr
== (CORE_ADDR
) -1)
3008 if (pc
== cur_thr
->suspend
.stop_pc
3009 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3010 && execution_direction
!= EXEC_REVERSE
)
3011 /* There is a breakpoint at the address we will resume at,
3012 step one instruction before inserting breakpoints so that
3013 we do not stop right away (and report a second hit at this
3016 Note, we don't do this in reverse, because we won't
3017 actually be executing the breakpoint insn anyway.
3018 We'll be (un-)executing the previous instruction. */
3019 cur_thr
->stepping_over_breakpoint
= 1;
3020 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3021 && gdbarch_single_step_through_delay (gdbarch
,
3022 get_current_frame ()))
3023 /* We stepped onto an instruction that needs to be stepped
3024 again before re-inserting the breakpoint, do so. */
3025 cur_thr
->stepping_over_breakpoint
= 1;
3029 regcache_write_pc (regcache
, addr
);
3032 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3033 cur_thr
->suspend
.stop_signal
= siggnal
;
3035 /* If an exception is thrown from this point on, make sure to
3036 propagate GDB's knowledge of the executing state to the
3037 frontend/user running state. */
3038 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3040 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3041 threads (e.g., we might need to set threads stepping over
3042 breakpoints first), from the user/frontend's point of view, all
3043 threads in RESUME_PTID are now running. Unless we're calling an
3044 inferior function, as in that case we pretend the inferior
3045 doesn't run at all. */
3046 if (!cur_thr
->control
.in_infcall
)
3047 set_running (resume_target
, resume_ptid
, true);
3050 fprintf_unfiltered (gdb_stdlog
,
3051 "infrun: proceed (addr=%s, signal=%s)\n",
3052 paddress (gdbarch
, addr
),
3053 gdb_signal_to_symbol_string (siggnal
));
3055 annotate_starting ();
3057 /* Make sure that output from GDB appears before output from the
3059 gdb_flush (gdb_stdout
);
3061 /* Since we've marked the inferior running, give it the terminal. A
3062 QUIT/Ctrl-C from here on is forwarded to the target (which can
3063 still detect attempts to unblock a stuck connection with repeated
3064 Ctrl-C from within target_pass_ctrlc). */
3065 target_terminal::inferior ();
3067 /* In a multi-threaded task we may select another thread and
3068 then continue or step.
3070 But if a thread that we're resuming had stopped at a breakpoint,
3071 it will immediately cause another breakpoint stop without any
3072 execution (i.e. it will report a breakpoint hit incorrectly). So
3073 we must step over it first.
3075 Look for threads other than the current (TP) that reported a
3076 breakpoint hit and haven't been resumed yet since. */
3078 /* If scheduler locking applies, we can avoid iterating over all
3080 if (!non_stop
&& !schedlock_applies (cur_thr
))
3082 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3085 switch_to_thread_no_regs (tp
);
3087 /* Ignore the current thread here. It's handled
3092 if (!thread_still_needs_step_over (tp
))
3095 gdb_assert (!thread_is_in_step_over_chain (tp
));
3098 fprintf_unfiltered (gdb_stdlog
,
3099 "infrun: need to step-over [%s] first\n",
3100 target_pid_to_str (tp
->ptid
).c_str ());
3102 thread_step_over_chain_enqueue (tp
);
3105 switch_to_thread (cur_thr
);
3108 /* Enqueue the current thread last, so that we move all other
3109 threads over their breakpoints first. */
3110 if (cur_thr
->stepping_over_breakpoint
)
3111 thread_step_over_chain_enqueue (cur_thr
);
3113 /* If the thread isn't started, we'll still need to set its prev_pc,
3114 so that switch_back_to_stepped_thread knows the thread hasn't
3115 advanced. Must do this before resuming any thread, as in
3116 all-stop/remote, once we resume we can't send any other packet
3117 until the target stops again. */
3118 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
3121 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3123 started
= start_step_over ();
3125 if (step_over_info_valid_p ())
3127 /* Either this thread started a new in-line step over, or some
3128 other thread was already doing one. In either case, don't
3129 resume anything else until the step-over is finished. */
3131 else if (started
&& !target_is_non_stop_p ())
3133 /* A new displaced stepping sequence was started. In all-stop,
3134 we can't talk to the target anymore until it next stops. */
3136 else if (!non_stop
&& target_is_non_stop_p ())
3138 /* In all-stop, but the target is always in non-stop mode.
3139 Start all other threads that are implicitly resumed too. */
3140 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3143 switch_to_thread_no_regs (tp
);
3145 if (!tp
->inf
->has_execution ())
3148 fprintf_unfiltered (gdb_stdlog
,
3149 "infrun: proceed: [%s] target has "
3151 target_pid_to_str (tp
->ptid
).c_str ());
3158 fprintf_unfiltered (gdb_stdlog
,
3159 "infrun: proceed: [%s] resumed\n",
3160 target_pid_to_str (tp
->ptid
).c_str ());
3161 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3165 if (thread_is_in_step_over_chain (tp
))
3168 fprintf_unfiltered (gdb_stdlog
,
3169 "infrun: proceed: [%s] needs step-over\n",
3170 target_pid_to_str (tp
->ptid
).c_str ());
3175 fprintf_unfiltered (gdb_stdlog
,
3176 "infrun: proceed: resuming %s\n",
3177 target_pid_to_str (tp
->ptid
).c_str ());
3179 reset_ecs (ecs
, tp
);
3180 switch_to_thread (tp
);
3181 keep_going_pass_signal (ecs
);
3182 if (!ecs
->wait_some_more
)
3183 error (_("Command aborted."));
3186 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3188 /* The thread wasn't started, and isn't queued, run it now. */
3189 reset_ecs (ecs
, cur_thr
);
3190 switch_to_thread (cur_thr
);
3191 keep_going_pass_signal (ecs
);
3192 if (!ecs
->wait_some_more
)
3193 error (_("Command aborted."));
3197 commit_resume_all_targets ();
3199 finish_state
.release ();
3201 /* If we've switched threads above, switch back to the previously
3202 current thread. We don't want the user to see a different
3204 switch_to_thread (cur_thr
);
3206 /* Tell the event loop to wait for it to stop. If the target
3207 supports asynchronous execution, it'll do this from within
3209 if (!target_can_async_p ())
3210 mark_async_event_handler (infrun_async_inferior_event_token
);
3214 /* Start remote-debugging of a machine over a serial link. */
3217 start_remote (int from_tty
)
3219 inferior
*inf
= current_inferior ();
3220 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3222 /* Always go on waiting for the target, regardless of the mode. */
3223 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3224 indicate to wait_for_inferior that a target should timeout if
3225 nothing is returned (instead of just blocking). Because of this,
3226 targets expecting an immediate response need to, internally, set
3227 things up so that the target_wait() is forced to eventually
3229 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3230 differentiate to its caller what the state of the target is after
3231 the initial open has been performed. Here we're assuming that
3232 the target has stopped. It should be possible to eventually have
3233 target_open() return to the caller an indication that the target
3234 is currently running and GDB state should be set to the same as
3235 for an async run. */
3236 wait_for_inferior (inf
);
3238 /* Now that the inferior has stopped, do any bookkeeping like
3239 loading shared libraries. We want to do this before normal_stop,
3240 so that the displayed frame is up to date. */
3241 post_create_inferior (current_top_target (), from_tty
);
3246 /* Initialize static vars when a new inferior begins. */
3249 init_wait_for_inferior (void)
3251 /* These are meaningless until the first time through wait_for_inferior. */
3253 breakpoint_init_inferior (inf_starting
);
3255 clear_proceed_status (0);
3257 nullify_last_target_wait_ptid ();
3259 previous_inferior_ptid
= inferior_ptid
;
3264 static void handle_inferior_event (struct execution_control_state
*ecs
);
3266 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3267 struct execution_control_state
*ecs
);
3268 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3269 struct execution_control_state
*ecs
);
3270 static void handle_signal_stop (struct execution_control_state
*ecs
);
3271 static void check_exception_resume (struct execution_control_state
*,
3272 struct frame_info
*);
3274 static void end_stepping_range (struct execution_control_state
*ecs
);
3275 static void stop_waiting (struct execution_control_state
*ecs
);
3276 static void keep_going (struct execution_control_state
*ecs
);
3277 static void process_event_stop_test (struct execution_control_state
*ecs
);
3278 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3280 /* This function is attached as a "thread_stop_requested" observer.
3281 Cleanup local state that assumed the PTID was to be resumed, and
3282 report the stop to the frontend. */
3285 infrun_thread_stop_requested (ptid_t ptid
)
3287 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3289 /* PTID was requested to stop. If the thread was already stopped,
3290 but the user/frontend doesn't know about that yet (e.g., the
3291 thread had been temporarily paused for some step-over), set up
3292 for reporting the stop now. */
3293 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3295 if (tp
->state
!= THREAD_RUNNING
)
3300 /* Remove matching threads from the step-over queue, so
3301 start_step_over doesn't try to resume them
3303 if (thread_is_in_step_over_chain (tp
))
3304 thread_step_over_chain_remove (tp
);
3306 /* If the thread is stopped, but the user/frontend doesn't
3307 know about that yet, queue a pending event, as if the
3308 thread had just stopped now. Unless the thread already had
3310 if (!tp
->suspend
.waitstatus_pending_p
)
3312 tp
->suspend
.waitstatus_pending_p
= 1;
3313 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3314 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3317 /* Clear the inline-frame state, since we're re-processing the
3319 clear_inline_frame_state (tp
);
3321 /* If this thread was paused because some other thread was
3322 doing an inline-step over, let that finish first. Once
3323 that happens, we'll restart all threads and consume pending
3324 stop events then. */
3325 if (step_over_info_valid_p ())
3328 /* Otherwise we can process the (new) pending event now. Set
3329 it so this pending event is considered by
3336 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3338 if (target_last_proc_target
== tp
->inf
->process_target ()
3339 && target_last_wait_ptid
== tp
->ptid
)
3340 nullify_last_target_wait_ptid ();
3343 /* Delete the step resume, single-step and longjmp/exception resume
3344 breakpoints of TP. */
3347 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3349 delete_step_resume_breakpoint (tp
);
3350 delete_exception_resume_breakpoint (tp
);
3351 delete_single_step_breakpoints (tp
);
3354 /* If the target still has execution, call FUNC for each thread that
3355 just stopped. In all-stop, that's all the non-exited threads; in
3356 non-stop, that's the current thread, only. */
3358 typedef void (*for_each_just_stopped_thread_callback_func
)
3359 (struct thread_info
*tp
);
3362 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3364 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3367 if (target_is_non_stop_p ())
3369 /* If in non-stop mode, only the current thread stopped. */
3370 func (inferior_thread ());
3374 /* In all-stop mode, all threads have stopped. */
3375 for (thread_info
*tp
: all_non_exited_threads ())
3380 /* Delete the step resume and longjmp/exception resume breakpoints of
3381 the threads that just stopped. */
3384 delete_just_stopped_threads_infrun_breakpoints (void)
3386 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3389 /* Delete the single-step breakpoints of the threads that just
3393 delete_just_stopped_threads_single_step_breakpoints (void)
3395 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3401 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3402 const struct target_waitstatus
*ws
)
3404 std::string status_string
= target_waitstatus_to_string (ws
);
3407 /* The text is split over several lines because it was getting too long.
3408 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3409 output as a unit; we want only one timestamp printed if debug_timestamp
3412 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3415 waiton_ptid
.tid ());
3416 if (waiton_ptid
.pid () != -1)
3417 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3418 stb
.printf (", status) =\n");
3419 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3423 target_pid_to_str (result_ptid
).c_str ());
3424 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3426 /* This uses %s in part to handle %'s in the text, but also to avoid
3427 a gcc error: the format attribute requires a string literal. */
3428 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3431 /* Select a thread at random, out of those which are resumed and have
3434 static struct thread_info
*
3435 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3439 auto has_event
= [&] (thread_info
*tp
)
3441 return (tp
->ptid
.matches (waiton_ptid
)
3443 && tp
->suspend
.waitstatus_pending_p
);
3446 /* First see how many events we have. Count only resumed threads
3447 that have an event pending. */
3448 for (thread_info
*tp
: inf
->non_exited_threads ())
3452 if (num_events
== 0)
3455 /* Now randomly pick a thread out of those that have had events. */
3456 int random_selector
= (int) ((num_events
* (double) rand ())
3457 / (RAND_MAX
+ 1.0));
3459 if (debug_infrun
&& num_events
> 1)
3460 fprintf_unfiltered (gdb_stdlog
,
3461 "infrun: Found %d events, selecting #%d\n",
3462 num_events
, random_selector
);
3464 /* Select the Nth thread that has had an event. */
3465 for (thread_info
*tp
: inf
->non_exited_threads ())
3467 if (random_selector
-- == 0)
3470 gdb_assert_not_reached ("event thread not found");
3473 /* Wrapper for target_wait that first checks whether threads have
3474 pending statuses to report before actually asking the target for
3475 more events. INF is the inferior we're using to call target_wait
3479 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3480 target_waitstatus
*status
, int options
)
3483 struct thread_info
*tp
;
3485 /* We know that we are looking for an event in the target of inferior
3486 INF, but we don't know which thread the event might come from. As
3487 such we want to make sure that INFERIOR_PTID is reset so that none of
3488 the wait code relies on it - doing so is always a mistake. */
3489 switch_to_inferior_no_thread (inf
);
3491 /* First check if there is a resumed thread with a wait status
3493 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3495 tp
= random_pending_event_thread (inf
, ptid
);
3500 fprintf_unfiltered (gdb_stdlog
,
3501 "infrun: Waiting for specific thread %s.\n",
3502 target_pid_to_str (ptid
).c_str ());
3504 /* We have a specific thread to check. */
3505 tp
= find_thread_ptid (inf
, ptid
);
3506 gdb_assert (tp
!= NULL
);
3507 if (!tp
->suspend
.waitstatus_pending_p
)
3512 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3513 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3515 struct regcache
*regcache
= get_thread_regcache (tp
);
3516 struct gdbarch
*gdbarch
= regcache
->arch ();
3520 pc
= regcache_read_pc (regcache
);
3522 if (pc
!= tp
->suspend
.stop_pc
)
3525 fprintf_unfiltered (gdb_stdlog
,
3526 "infrun: PC of %s changed. was=%s, now=%s\n",
3527 target_pid_to_str (tp
->ptid
).c_str (),
3528 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3529 paddress (gdbarch
, pc
));
3532 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3535 fprintf_unfiltered (gdb_stdlog
,
3536 "infrun: previous breakpoint of %s, at %s gone\n",
3537 target_pid_to_str (tp
->ptid
).c_str (),
3538 paddress (gdbarch
, pc
));
3546 fprintf_unfiltered (gdb_stdlog
,
3547 "infrun: pending event of %s cancelled.\n",
3548 target_pid_to_str (tp
->ptid
).c_str ());
3550 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3551 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3560 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3562 fprintf_unfiltered (gdb_stdlog
,
3563 "infrun: Using pending wait status %s for %s.\n",
3565 target_pid_to_str (tp
->ptid
).c_str ());
3568 /* Now that we've selected our final event LWP, un-adjust its PC
3569 if it was a software breakpoint (and the target doesn't
3570 always adjust the PC itself). */
3571 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3572 && !target_supports_stopped_by_sw_breakpoint ())
3574 struct regcache
*regcache
;
3575 struct gdbarch
*gdbarch
;
3578 regcache
= get_thread_regcache (tp
);
3579 gdbarch
= regcache
->arch ();
3581 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3586 pc
= regcache_read_pc (regcache
);
3587 regcache_write_pc (regcache
, pc
+ decr_pc
);
3591 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3592 *status
= tp
->suspend
.waitstatus
;
3593 tp
->suspend
.waitstatus_pending_p
= 0;
3595 /* Wake up the event loop again, until all pending events are
3597 if (target_is_async_p ())
3598 mark_async_event_handler (infrun_async_inferior_event_token
);
3602 /* But if we don't find one, we'll have to wait. */
3604 if (deprecated_target_wait_hook
)
3605 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3607 event_ptid
= target_wait (ptid
, status
, options
);
3612 /* Returns true if INF has any resumed thread with a status
3616 threads_are_resumed_pending_p (inferior
*inf
)
3618 for (thread_info
*tp
: inf
->non_exited_threads ())
3620 && tp
->suspend
.waitstatus_pending_p
)
3626 /* Wrapper for target_wait that first checks whether threads have
3627 pending statuses to report before actually asking the target for
3628 more events. Polls for events from all inferiors/targets. */
3631 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3633 int num_inferiors
= 0;
3634 int random_selector
;
3636 /* For fairness, we pick the first inferior/target to poll at
3637 random, and then continue polling the rest of the inferior list
3638 starting from that one in a circular fashion until the whole list
3641 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3643 return (inf
->process_target () != NULL
3644 && (threads_are_executing (inf
->process_target ())
3645 || threads_are_resumed_pending_p (inf
))
3646 && ptid_t (inf
->pid
).matches (wait_ptid
));
3649 /* First see how many resumed inferiors we have. */
3650 for (inferior
*inf
: all_inferiors ())
3651 if (inferior_matches (inf
))
3654 if (num_inferiors
== 0)
3656 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3660 /* Now randomly pick an inferior out of those that were resumed. */
3661 random_selector
= (int)
3662 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3664 if (debug_infrun
&& num_inferiors
> 1)
3665 fprintf_unfiltered (gdb_stdlog
,
3666 "infrun: Found %d inferiors, starting at #%d\n",
3667 num_inferiors
, random_selector
);
3669 /* Select the Nth inferior that was resumed. */
3671 inferior
*selected
= nullptr;
3673 for (inferior
*inf
: all_inferiors ())
3674 if (inferior_matches (inf
))
3675 if (random_selector
-- == 0)
3681 /* Now poll for events out of each of the resumed inferior's
3682 targets, starting from the selected one. */
3684 auto do_wait
= [&] (inferior
*inf
)
3686 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3687 ecs
->target
= inf
->process_target ();
3688 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3691 /* Needed in all-stop+target-non-stop mode, because we end up here
3692 spuriously after the target is all stopped and we've already
3693 reported the stop to the user, polling for events. */
3694 scoped_restore_current_thread restore_thread
;
3696 int inf_num
= selected
->num
;
3697 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3698 if (inferior_matches (inf
))
3702 for (inferior
*inf
= inferior_list
;
3703 inf
!= NULL
&& inf
->num
< inf_num
;
3705 if (inferior_matches (inf
))
3709 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3713 /* Prepare and stabilize the inferior for detaching it. E.g.,
3714 detaching while a thread is displaced stepping is a recipe for
3715 crashing it, as nothing would readjust the PC out of the scratch
3719 prepare_for_detach (void)
3721 struct inferior
*inf
= current_inferior ();
3722 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3724 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3726 /* Is any thread of this process displaced stepping? If not,
3727 there's nothing else to do. */
3728 if (displaced
->step_thread
== nullptr)
3732 fprintf_unfiltered (gdb_stdlog
,
3733 "displaced-stepping in-process while detaching");
3735 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3737 while (displaced
->step_thread
!= nullptr)
3739 struct execution_control_state ecss
;
3740 struct execution_control_state
*ecs
;
3743 memset (ecs
, 0, sizeof (*ecs
));
3745 overlay_cache_invalid
= 1;
3746 /* Flush target cache before starting to handle each event.
3747 Target was running and cache could be stale. This is just a
3748 heuristic. Running threads may modify target memory, but we
3749 don't get any event. */
3750 target_dcache_invalidate ();
3752 do_target_wait (pid_ptid
, ecs
, 0);
3755 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3757 /* If an error happens while handling the event, propagate GDB's
3758 knowledge of the executing state to the frontend/user running
3760 scoped_finish_thread_state
finish_state (inf
->process_target (),
3763 /* Now figure out what to do with the result of the result. */
3764 handle_inferior_event (ecs
);
3766 /* No error, don't finish the state yet. */
3767 finish_state
.release ();
3769 /* Breakpoints and watchpoints are not installed on the target
3770 at this point, and signals are passed directly to the
3771 inferior, so this must mean the process is gone. */
3772 if (!ecs
->wait_some_more
)
3774 restore_detaching
.release ();
3775 error (_("Program exited while detaching"));
3779 restore_detaching
.release ();
3782 /* Wait for control to return from inferior to debugger.
3784 If inferior gets a signal, we may decide to start it up again
3785 instead of returning. That is why there is a loop in this function.
3786 When this function actually returns it means the inferior
3787 should be left stopped and GDB should read more commands. */
3790 wait_for_inferior (inferior
*inf
)
3794 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3796 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3798 /* If an error happens while handling the event, propagate GDB's
3799 knowledge of the executing state to the frontend/user running
3801 scoped_finish_thread_state finish_state
3802 (inf
->process_target (), minus_one_ptid
);
3806 struct execution_control_state ecss
;
3807 struct execution_control_state
*ecs
= &ecss
;
3809 memset (ecs
, 0, sizeof (*ecs
));
3811 overlay_cache_invalid
= 1;
3813 /* Flush target cache before starting to handle each event.
3814 Target was running and cache could be stale. This is just a
3815 heuristic. Running threads may modify target memory, but we
3816 don't get any event. */
3817 target_dcache_invalidate ();
3819 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3820 ecs
->target
= inf
->process_target ();
3823 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3825 /* Now figure out what to do with the result of the result. */
3826 handle_inferior_event (ecs
);
3828 if (!ecs
->wait_some_more
)
3832 /* No error, don't finish the state yet. */
3833 finish_state
.release ();
3836 /* Cleanup that reinstalls the readline callback handler, if the
3837 target is running in the background. If while handling the target
3838 event something triggered a secondary prompt, like e.g., a
3839 pagination prompt, we'll have removed the callback handler (see
3840 gdb_readline_wrapper_line). Need to do this as we go back to the
3841 event loop, ready to process further input. Note this has no
3842 effect if the handler hasn't actually been removed, because calling
3843 rl_callback_handler_install resets the line buffer, thus losing
3847 reinstall_readline_callback_handler_cleanup ()
3849 struct ui
*ui
= current_ui
;
3853 /* We're not going back to the top level event loop yet. Don't
3854 install the readline callback, as it'd prep the terminal,
3855 readline-style (raw, noecho) (e.g., --batch). We'll install
3856 it the next time the prompt is displayed, when we're ready
3861 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3862 gdb_rl_callback_handler_reinstall ();
3865 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3866 that's just the event thread. In all-stop, that's all threads. */
3869 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3871 if (ecs
->event_thread
!= NULL
3872 && ecs
->event_thread
->thread_fsm
!= NULL
)
3873 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3877 for (thread_info
*thr
: all_non_exited_threads ())
3879 if (thr
->thread_fsm
== NULL
)
3881 if (thr
== ecs
->event_thread
)
3884 switch_to_thread (thr
);
3885 thr
->thread_fsm
->clean_up (thr
);
3888 if (ecs
->event_thread
!= NULL
)
3889 switch_to_thread (ecs
->event_thread
);
3893 /* Helper for all_uis_check_sync_execution_done that works on the
3897 check_curr_ui_sync_execution_done (void)
3899 struct ui
*ui
= current_ui
;
3901 if (ui
->prompt_state
== PROMPT_NEEDED
3903 && !gdb_in_secondary_prompt_p (ui
))
3905 target_terminal::ours ();
3906 gdb::observers::sync_execution_done
.notify ();
3907 ui_register_input_event_handler (ui
);
3914 all_uis_check_sync_execution_done (void)
3916 SWITCH_THRU_ALL_UIS ()
3918 check_curr_ui_sync_execution_done ();
3925 all_uis_on_sync_execution_starting (void)
3927 SWITCH_THRU_ALL_UIS ()
3929 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3930 async_disable_stdin ();
3934 /* Asynchronous version of wait_for_inferior. It is called by the
3935 event loop whenever a change of state is detected on the file
3936 descriptor corresponding to the target. It can be called more than
3937 once to complete a single execution command. In such cases we need
3938 to keep the state in a global variable ECSS. If it is the last time
3939 that this function is called for a single execution command, then
3940 report to the user that the inferior has stopped, and do the
3941 necessary cleanups. */
3944 fetch_inferior_event (void *client_data
)
3946 struct execution_control_state ecss
;
3947 struct execution_control_state
*ecs
= &ecss
;
3950 memset (ecs
, 0, sizeof (*ecs
));
3952 /* Events are always processed with the main UI as current UI. This
3953 way, warnings, debug output, etc. are always consistently sent to
3954 the main console. */
3955 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3957 /* End up with readline processing input, if necessary. */
3959 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3961 /* We're handling a live event, so make sure we're doing live
3962 debugging. If we're looking at traceframes while the target is
3963 running, we're going to need to get back to that mode after
3964 handling the event. */
3965 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3968 maybe_restore_traceframe
.emplace ();
3969 set_current_traceframe (-1);
3972 /* The user/frontend should not notice a thread switch due to
3973 internal events. Make sure we revert to the user selected
3974 thread and frame after handling the event and running any
3975 breakpoint commands. */
3976 scoped_restore_current_thread restore_thread
;
3978 overlay_cache_invalid
= 1;
3979 /* Flush target cache before starting to handle each event. Target
3980 was running and cache could be stale. This is just a heuristic.
3981 Running threads may modify target memory, but we don't get any
3983 target_dcache_invalidate ();
3985 scoped_restore save_exec_dir
3986 = make_scoped_restore (&execution_direction
,
3987 target_execution_direction ());
3989 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3992 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3994 /* Switch to the target that generated the event, so we can do
3995 target calls. Any inferior bound to the target will do, so we
3996 just switch to the first we find. */
3997 for (inferior
*inf
: all_inferiors (ecs
->target
))
3999 switch_to_inferior_no_thread (inf
);
4004 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
4006 /* If an error happens while handling the event, propagate GDB's
4007 knowledge of the executing state to the frontend/user running
4009 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
4010 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
4012 /* Get executed before scoped_restore_current_thread above to apply
4013 still for the thread which has thrown the exception. */
4014 auto defer_bpstat_clear
4015 = make_scope_exit (bpstat_clear_actions
);
4016 auto defer_delete_threads
4017 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
4019 /* Now figure out what to do with the result of the result. */
4020 handle_inferior_event (ecs
);
4022 if (!ecs
->wait_some_more
)
4024 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4025 int should_stop
= 1;
4026 struct thread_info
*thr
= ecs
->event_thread
;
4028 delete_just_stopped_threads_infrun_breakpoints ();
4032 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4034 if (thread_fsm
!= NULL
)
4035 should_stop
= thread_fsm
->should_stop (thr
);
4044 bool should_notify_stop
= true;
4047 clean_up_just_stopped_threads_fsms (ecs
);
4049 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4050 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4052 if (should_notify_stop
)
4054 /* We may not find an inferior if this was a process exit. */
4055 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4056 proceeded
= normal_stop ();
4061 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4065 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4066 previously selected thread is gone. We have two
4067 choices - switch to no thread selected, or restore the
4068 previously selected thread (now exited). We chose the
4069 later, just because that's what GDB used to do. After
4070 this, "info threads" says "The current thread <Thread
4071 ID 2> has terminated." instead of "No thread
4075 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4076 restore_thread
.dont_restore ();
4080 defer_delete_threads
.release ();
4081 defer_bpstat_clear
.release ();
4083 /* No error, don't finish the thread states yet. */
4084 finish_state
.release ();
4086 /* This scope is used to ensure that readline callbacks are
4087 reinstalled here. */
4090 /* If a UI was in sync execution mode, and now isn't, restore its
4091 prompt (a synchronous execution command has finished, and we're
4092 ready for input). */
4093 all_uis_check_sync_execution_done ();
4096 && exec_done_display_p
4097 && (inferior_ptid
== null_ptid
4098 || inferior_thread ()->state
!= THREAD_RUNNING
))
4099 printf_unfiltered (_("completed.\n"));
4105 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4106 struct symtab_and_line sal
)
4108 /* This can be removed once this function no longer implicitly relies on the
4109 inferior_ptid value. */
4110 gdb_assert (inferior_ptid
== tp
->ptid
);
4112 tp
->control
.step_frame_id
= get_frame_id (frame
);
4113 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4115 tp
->current_symtab
= sal
.symtab
;
4116 tp
->current_line
= sal
.line
;
4119 /* Clear context switchable stepping state. */
4122 init_thread_stepping_state (struct thread_info
*tss
)
4124 tss
->stepped_breakpoint
= 0;
4125 tss
->stepping_over_breakpoint
= 0;
4126 tss
->stepping_over_watchpoint
= 0;
4127 tss
->step_after_step_resume_breakpoint
= 0;
4133 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4134 target_waitstatus status
)
4136 target_last_proc_target
= target
;
4137 target_last_wait_ptid
= ptid
;
4138 target_last_waitstatus
= status
;
4144 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4145 target_waitstatus
*status
)
4147 if (target
!= nullptr)
4148 *target
= target_last_proc_target
;
4149 if (ptid
!= nullptr)
4150 *ptid
= target_last_wait_ptid
;
4151 if (status
!= nullptr)
4152 *status
= target_last_waitstatus
;
4158 nullify_last_target_wait_ptid (void)
4160 target_last_proc_target
= nullptr;
4161 target_last_wait_ptid
= minus_one_ptid
;
4162 target_last_waitstatus
= {};
4165 /* Switch thread contexts. */
4168 context_switch (execution_control_state
*ecs
)
4171 && ecs
->ptid
!= inferior_ptid
4172 && (inferior_ptid
== null_ptid
4173 || ecs
->event_thread
!= inferior_thread ()))
4175 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4176 target_pid_to_str (inferior_ptid
).c_str ());
4177 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4178 target_pid_to_str (ecs
->ptid
).c_str ());
4181 switch_to_thread (ecs
->event_thread
);
4184 /* If the target can't tell whether we've hit breakpoints
4185 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4186 check whether that could have been caused by a breakpoint. If so,
4187 adjust the PC, per gdbarch_decr_pc_after_break. */
4190 adjust_pc_after_break (struct thread_info
*thread
,
4191 struct target_waitstatus
*ws
)
4193 struct regcache
*regcache
;
4194 struct gdbarch
*gdbarch
;
4195 CORE_ADDR breakpoint_pc
, decr_pc
;
4197 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4198 we aren't, just return.
4200 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4201 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4202 implemented by software breakpoints should be handled through the normal
4205 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4206 different signals (SIGILL or SIGEMT for instance), but it is less
4207 clear where the PC is pointing afterwards. It may not match
4208 gdbarch_decr_pc_after_break. I don't know any specific target that
4209 generates these signals at breakpoints (the code has been in GDB since at
4210 least 1992) so I can not guess how to handle them here.
4212 In earlier versions of GDB, a target with
4213 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4214 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4215 target with both of these set in GDB history, and it seems unlikely to be
4216 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4218 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4221 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4224 /* In reverse execution, when a breakpoint is hit, the instruction
4225 under it has already been de-executed. The reported PC always
4226 points at the breakpoint address, so adjusting it further would
4227 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4230 B1 0x08000000 : INSN1
4231 B2 0x08000001 : INSN2
4233 PC -> 0x08000003 : INSN4
4235 Say you're stopped at 0x08000003 as above. Reverse continuing
4236 from that point should hit B2 as below. Reading the PC when the
4237 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4238 been de-executed already.
4240 B1 0x08000000 : INSN1
4241 B2 PC -> 0x08000001 : INSN2
4245 We can't apply the same logic as for forward execution, because
4246 we would wrongly adjust the PC to 0x08000000, since there's a
4247 breakpoint at PC - 1. We'd then report a hit on B1, although
4248 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4250 if (execution_direction
== EXEC_REVERSE
)
4253 /* If the target can tell whether the thread hit a SW breakpoint,
4254 trust it. Targets that can tell also adjust the PC
4256 if (target_supports_stopped_by_sw_breakpoint ())
4259 /* Note that relying on whether a breakpoint is planted in memory to
4260 determine this can fail. E.g,. the breakpoint could have been
4261 removed since. Or the thread could have been told to step an
4262 instruction the size of a breakpoint instruction, and only
4263 _after_ was a breakpoint inserted at its address. */
4265 /* If this target does not decrement the PC after breakpoints, then
4266 we have nothing to do. */
4267 regcache
= get_thread_regcache (thread
);
4268 gdbarch
= regcache
->arch ();
4270 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4274 const address_space
*aspace
= regcache
->aspace ();
4276 /* Find the location where (if we've hit a breakpoint) the
4277 breakpoint would be. */
4278 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4280 /* If the target can't tell whether a software breakpoint triggered,
4281 fallback to figuring it out based on breakpoints we think were
4282 inserted in the target, and on whether the thread was stepped or
4285 /* Check whether there actually is a software breakpoint inserted at
4288 If in non-stop mode, a race condition is possible where we've
4289 removed a breakpoint, but stop events for that breakpoint were
4290 already queued and arrive later. To suppress those spurious
4291 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4292 and retire them after a number of stop events are reported. Note
4293 this is an heuristic and can thus get confused. The real fix is
4294 to get the "stopped by SW BP and needs adjustment" info out of
4295 the target/kernel (and thus never reach here; see above). */
4296 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4297 || (target_is_non_stop_p ()
4298 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4300 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4302 if (record_full_is_used ())
4303 restore_operation_disable
.emplace
4304 (record_full_gdb_operation_disable_set ());
4306 /* When using hardware single-step, a SIGTRAP is reported for both
4307 a completed single-step and a software breakpoint. Need to
4308 differentiate between the two, as the latter needs adjusting
4309 but the former does not.
4311 The SIGTRAP can be due to a completed hardware single-step only if
4312 - we didn't insert software single-step breakpoints
4313 - this thread is currently being stepped
4315 If any of these events did not occur, we must have stopped due
4316 to hitting a software breakpoint, and have to back up to the
4319 As a special case, we could have hardware single-stepped a
4320 software breakpoint. In this case (prev_pc == breakpoint_pc),
4321 we also need to back up to the breakpoint address. */
4323 if (thread_has_single_step_breakpoints_set (thread
)
4324 || !currently_stepping (thread
)
4325 || (thread
->stepped_breakpoint
4326 && thread
->prev_pc
== breakpoint_pc
))
4327 regcache_write_pc (regcache
, breakpoint_pc
);
4332 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4334 for (frame
= get_prev_frame (frame
);
4336 frame
= get_prev_frame (frame
))
4338 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4340 if (get_frame_type (frame
) != INLINE_FRAME
)
4347 /* Look for an inline frame that is marked for skip.
4348 If PREV_FRAME is TRUE start at the previous frame,
4349 otherwise start at the current frame. Stop at the
4350 first non-inline frame, or at the frame where the
4354 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4356 struct frame_info
*frame
= get_current_frame ();
4359 frame
= get_prev_frame (frame
);
4361 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4363 const char *fn
= NULL
;
4364 symtab_and_line sal
;
4367 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4369 if (get_frame_type (frame
) != INLINE_FRAME
)
4372 sal
= find_frame_sal (frame
);
4373 sym
= get_frame_function (frame
);
4376 fn
= sym
->print_name ();
4379 && function_name_is_marked_for_skip (fn
, sal
))
4386 /* If the event thread has the stop requested flag set, pretend it
4387 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4391 handle_stop_requested (struct execution_control_state
*ecs
)
4393 if (ecs
->event_thread
->stop_requested
)
4395 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4396 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4397 handle_signal_stop (ecs
);
4403 /* Auxiliary function that handles syscall entry/return events.
4404 It returns 1 if the inferior should keep going (and GDB
4405 should ignore the event), or 0 if the event deserves to be
4409 handle_syscall_event (struct execution_control_state
*ecs
)
4411 struct regcache
*regcache
;
4414 context_switch (ecs
);
4416 regcache
= get_thread_regcache (ecs
->event_thread
);
4417 syscall_number
= ecs
->ws
.value
.syscall_number
;
4418 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4420 if (catch_syscall_enabled () > 0
4421 && catching_syscall_number (syscall_number
) > 0)
4424 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4427 ecs
->event_thread
->control
.stop_bpstat
4428 = bpstat_stop_status (regcache
->aspace (),
4429 ecs
->event_thread
->suspend
.stop_pc
,
4430 ecs
->event_thread
, &ecs
->ws
);
4432 if (handle_stop_requested (ecs
))
4435 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4437 /* Catchpoint hit. */
4442 if (handle_stop_requested (ecs
))
4445 /* If no catchpoint triggered for this, then keep going. */
4450 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4453 fill_in_stop_func (struct gdbarch
*gdbarch
,
4454 struct execution_control_state
*ecs
)
4456 if (!ecs
->stop_func_filled_in
)
4460 /* Don't care about return value; stop_func_start and stop_func_name
4461 will both be 0 if it doesn't work. */
4462 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4463 &ecs
->stop_func_name
,
4464 &ecs
->stop_func_start
,
4465 &ecs
->stop_func_end
,
4468 /* The call to find_pc_partial_function, above, will set
4469 stop_func_start and stop_func_end to the start and end
4470 of the range containing the stop pc. If this range
4471 contains the entry pc for the block (which is always the
4472 case for contiguous blocks), advance stop_func_start past
4473 the function's start offset and entrypoint. Note that
4474 stop_func_start is NOT advanced when in a range of a
4475 non-contiguous block that does not contain the entry pc. */
4476 if (block
!= nullptr
4477 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4478 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4480 ecs
->stop_func_start
4481 += gdbarch_deprecated_function_start_offset (gdbarch
);
4483 if (gdbarch_skip_entrypoint_p (gdbarch
))
4484 ecs
->stop_func_start
4485 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4488 ecs
->stop_func_filled_in
= 1;
4493 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4495 static enum stop_kind
4496 get_inferior_stop_soon (execution_control_state
*ecs
)
4498 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4500 gdb_assert (inf
!= NULL
);
4501 return inf
->control
.stop_soon
;
4504 /* Poll for one event out of the current target. Store the resulting
4505 waitstatus in WS, and return the event ptid. Does not block. */
4508 poll_one_curr_target (struct target_waitstatus
*ws
)
4512 overlay_cache_invalid
= 1;
4514 /* Flush target cache before starting to handle each event.
4515 Target was running and cache could be stale. This is just a
4516 heuristic. Running threads may modify target memory, but we
4517 don't get any event. */
4518 target_dcache_invalidate ();
4520 if (deprecated_target_wait_hook
)
4521 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4523 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4526 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4531 /* An event reported by wait_one. */
4533 struct wait_one_event
4535 /* The target the event came out of. */
4536 process_stratum_target
*target
;
4538 /* The PTID the event was for. */
4541 /* The waitstatus. */
4542 target_waitstatus ws
;
4545 /* Wait for one event out of any target. */
4547 static wait_one_event
4552 for (inferior
*inf
: all_inferiors ())
4554 process_stratum_target
*target
= inf
->process_target ();
4556 || !target
->is_async_p ()
4557 || !target
->threads_executing
)
4560 switch_to_inferior_no_thread (inf
);
4562 wait_one_event event
;
4563 event
.target
= target
;
4564 event
.ptid
= poll_one_curr_target (&event
.ws
);
4566 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4568 /* If nothing is resumed, remove the target from the
4572 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4576 /* Block waiting for some event. */
4583 for (inferior
*inf
: all_inferiors ())
4585 process_stratum_target
*target
= inf
->process_target ();
4587 || !target
->is_async_p ()
4588 || !target
->threads_executing
)
4591 int fd
= target
->async_wait_fd ();
4592 FD_SET (fd
, &readfds
);
4599 /* No waitable targets left. All must be stopped. */
4600 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4605 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4611 perror_with_name ("interruptible_select");
4616 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4617 instead of the current thread. */
4618 #define THREAD_STOPPED_BY(REASON) \
4620 thread_stopped_by_ ## REASON (ptid_t ptid) \
4622 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4623 inferior_ptid = ptid; \
4625 return target_stopped_by_ ## REASON (); \
4628 /* Generate thread_stopped_by_watchpoint. */
4629 THREAD_STOPPED_BY (watchpoint
)
4630 /* Generate thread_stopped_by_sw_breakpoint. */
4631 THREAD_STOPPED_BY (sw_breakpoint
)
4632 /* Generate thread_stopped_by_hw_breakpoint. */
4633 THREAD_STOPPED_BY (hw_breakpoint
)
4635 /* Save the thread's event and stop reason to process it later. */
4638 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4642 std::string statstr
= target_waitstatus_to_string (ws
);
4644 fprintf_unfiltered (gdb_stdlog
,
4645 "infrun: saving status %s for %d.%ld.%ld\n",
4652 /* Record for later. */
4653 tp
->suspend
.waitstatus
= *ws
;
4654 tp
->suspend
.waitstatus_pending_p
= 1;
4656 struct regcache
*regcache
= get_thread_regcache (tp
);
4657 const address_space
*aspace
= regcache
->aspace ();
4659 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4660 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4662 CORE_ADDR pc
= regcache_read_pc (regcache
);
4664 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4666 if (thread_stopped_by_watchpoint (tp
->ptid
))
4668 tp
->suspend
.stop_reason
4669 = TARGET_STOPPED_BY_WATCHPOINT
;
4671 else if (target_supports_stopped_by_sw_breakpoint ()
4672 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4674 tp
->suspend
.stop_reason
4675 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4677 else if (target_supports_stopped_by_hw_breakpoint ()
4678 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4680 tp
->suspend
.stop_reason
4681 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4683 else if (!target_supports_stopped_by_hw_breakpoint ()
4684 && hardware_breakpoint_inserted_here_p (aspace
,
4687 tp
->suspend
.stop_reason
4688 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4690 else if (!target_supports_stopped_by_sw_breakpoint ()
4691 && software_breakpoint_inserted_here_p (aspace
,
4694 tp
->suspend
.stop_reason
4695 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4697 else if (!thread_has_single_step_breakpoints_set (tp
)
4698 && currently_stepping (tp
))
4700 tp
->suspend
.stop_reason
4701 = TARGET_STOPPED_BY_SINGLE_STEP
;
4709 stop_all_threads (void)
4711 /* We may need multiple passes to discover all threads. */
4715 gdb_assert (exists_non_stop_target ());
4718 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4720 scoped_restore_current_thread restore_thread
;
4722 target_thread_events (1);
4723 SCOPE_EXIT
{ target_thread_events (0); };
4725 /* Request threads to stop, and then wait for the stops. Because
4726 threads we already know about can spawn more threads while we're
4727 trying to stop them, and we only learn about new threads when we
4728 update the thread list, do this in a loop, and keep iterating
4729 until two passes find no threads that need to be stopped. */
4730 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4733 fprintf_unfiltered (gdb_stdlog
,
4734 "infrun: stop_all_threads, pass=%d, "
4735 "iterations=%d\n", pass
, iterations
);
4740 update_thread_list ();
4742 /* Go through all threads looking for threads that we need
4743 to tell the target to stop. */
4744 for (thread_info
*t
: all_non_exited_threads ())
4746 /* For a single-target setting with an all-stop target,
4747 we would not even arrive here. For a multi-target
4748 setting, until GDB is able to handle a mixture of
4749 all-stop and non-stop targets, simply skip all-stop
4750 targets' threads. This should be fine due to the
4751 protection of 'check_multi_target_resumption'. */
4753 switch_to_thread_no_regs (t
);
4754 if (!target_is_non_stop_p ())
4759 /* If already stopping, don't request a stop again.
4760 We just haven't seen the notification yet. */
4761 if (!t
->stop_requested
)
4764 fprintf_unfiltered (gdb_stdlog
,
4765 "infrun: %s executing, "
4767 target_pid_to_str (t
->ptid
).c_str ());
4768 target_stop (t
->ptid
);
4769 t
->stop_requested
= 1;
4774 fprintf_unfiltered (gdb_stdlog
,
4775 "infrun: %s executing, "
4776 "already stopping\n",
4777 target_pid_to_str (t
->ptid
).c_str ());
4780 if (t
->stop_requested
)
4786 fprintf_unfiltered (gdb_stdlog
,
4787 "infrun: %s not executing\n",
4788 target_pid_to_str (t
->ptid
).c_str ());
4790 /* The thread may be not executing, but still be
4791 resumed with a pending status to process. */
4799 /* If we find new threads on the second iteration, restart
4800 over. We want to see two iterations in a row with all
4805 wait_one_event event
= wait_one ();
4809 fprintf_unfiltered (gdb_stdlog
,
4810 "infrun: stop_all_threads %s %s\n",
4811 target_waitstatus_to_string (&event
.ws
).c_str (),
4812 target_pid_to_str (event
.ptid
).c_str ());
4815 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4816 || event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4817 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4818 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4820 /* All resumed threads exited
4821 or one thread/process exited/signalled. */
4825 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4827 t
= add_thread (event
.target
, event
.ptid
);
4829 t
->stop_requested
= 0;
4832 t
->control
.may_range_step
= 0;
4834 /* This may be the first time we see the inferior report
4836 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4837 if (inf
->needs_setup
)
4839 switch_to_thread_no_regs (t
);
4843 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4844 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4846 /* We caught the event that we intended to catch, so
4847 there's no event pending. */
4848 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4849 t
->suspend
.waitstatus_pending_p
= 0;
4851 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4853 /* Add it back to the step-over queue. */
4856 fprintf_unfiltered (gdb_stdlog
,
4857 "infrun: displaced-step of %s "
4858 "canceled: adding back to the "
4859 "step-over queue\n",
4860 target_pid_to_str (t
->ptid
).c_str ());
4862 t
->control
.trap_expected
= 0;
4863 thread_step_over_chain_enqueue (t
);
4868 enum gdb_signal sig
;
4869 struct regcache
*regcache
;
4873 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4875 fprintf_unfiltered (gdb_stdlog
,
4876 "infrun: target_wait %s, saving "
4877 "status for %d.%ld.%ld\n",
4884 /* Record for later. */
4885 save_waitstatus (t
, &event
.ws
);
4887 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4888 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4890 if (displaced_step_fixup (t
, sig
) < 0)
4892 /* Add it back to the step-over queue. */
4893 t
->control
.trap_expected
= 0;
4894 thread_step_over_chain_enqueue (t
);
4897 regcache
= get_thread_regcache (t
);
4898 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4902 fprintf_unfiltered (gdb_stdlog
,
4903 "infrun: saved stop_pc=%s for %s "
4904 "(currently_stepping=%d)\n",
4905 paddress (target_gdbarch (),
4906 t
->suspend
.stop_pc
),
4907 target_pid_to_str (t
->ptid
).c_str (),
4908 currently_stepping (t
));
4916 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4919 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4922 handle_no_resumed (struct execution_control_state
*ecs
)
4924 if (target_can_async_p ())
4931 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4939 /* There were no unwaited-for children left in the target, but,
4940 we're not synchronously waiting for events either. Just
4944 fprintf_unfiltered (gdb_stdlog
,
4945 "infrun: TARGET_WAITKIND_NO_RESUMED "
4946 "(ignoring: bg)\n");
4947 prepare_to_wait (ecs
);
4952 /* Otherwise, if we were running a synchronous execution command, we
4953 may need to cancel it and give the user back the terminal.
4955 In non-stop mode, the target can't tell whether we've already
4956 consumed previous stop events, so it can end up sending us a
4957 no-resumed event like so:
4959 #0 - thread 1 is left stopped
4961 #1 - thread 2 is resumed and hits breakpoint
4962 -> TARGET_WAITKIND_STOPPED
4964 #2 - thread 3 is resumed and exits
4965 this is the last resumed thread, so
4966 -> TARGET_WAITKIND_NO_RESUMED
4968 #3 - gdb processes stop for thread 2 and decides to re-resume
4971 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4972 thread 2 is now resumed, so the event should be ignored.
4974 IOW, if the stop for thread 2 doesn't end a foreground command,
4975 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4976 event. But it could be that the event meant that thread 2 itself
4977 (or whatever other thread was the last resumed thread) exited.
4979 To address this we refresh the thread list and check whether we
4980 have resumed threads _now_. In the example above, this removes
4981 thread 3 from the thread list. If thread 2 was re-resumed, we
4982 ignore this event. If we find no thread resumed, then we cancel
4983 the synchronous command show "no unwaited-for " to the user. */
4984 update_thread_list ();
4986 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4988 if (thread
->executing
4989 || thread
->suspend
.waitstatus_pending_p
)
4991 /* There were no unwaited-for children left in the target at
4992 some point, but there are now. Just ignore. */
4994 fprintf_unfiltered (gdb_stdlog
,
4995 "infrun: TARGET_WAITKIND_NO_RESUMED "
4996 "(ignoring: found resumed)\n");
4997 prepare_to_wait (ecs
);
5002 /* Note however that we may find no resumed thread because the whole
5003 process exited meanwhile (thus updating the thread list results
5004 in an empty thread list). In this case we know we'll be getting
5005 a process exit event shortly. */
5006 for (inferior
*inf
: all_non_exited_inferiors (ecs
->target
))
5008 thread_info
*thread
= any_live_thread_of_inferior (inf
);
5012 fprintf_unfiltered (gdb_stdlog
,
5013 "infrun: TARGET_WAITKIND_NO_RESUMED "
5014 "(expect process exit)\n");
5015 prepare_to_wait (ecs
);
5020 /* Go ahead and report the event. */
5024 /* Given an execution control state that has been freshly filled in by
5025 an event from the inferior, figure out what it means and take
5028 The alternatives are:
5030 1) stop_waiting and return; to really stop and return to the
5033 2) keep_going and return; to wait for the next event (set
5034 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5038 handle_inferior_event (struct execution_control_state
*ecs
)
5040 /* Make sure that all temporary struct value objects that were
5041 created during the handling of the event get deleted at the
5043 scoped_value_mark free_values
;
5045 enum stop_kind stop_soon
;
5048 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5049 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5051 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5053 /* We had an event in the inferior, but we are not interested in
5054 handling it at this level. The lower layers have already
5055 done what needs to be done, if anything.
5057 One of the possible circumstances for this is when the
5058 inferior produces output for the console. The inferior has
5059 not stopped, and we are ignoring the event. Another possible
5060 circumstance is any event which the lower level knows will be
5061 reported multiple times without an intervening resume. */
5062 prepare_to_wait (ecs
);
5066 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5068 prepare_to_wait (ecs
);
5072 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5073 && handle_no_resumed (ecs
))
5076 /* Cache the last target/ptid/waitstatus. */
5077 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5079 /* Always clear state belonging to the previous time we stopped. */
5080 stop_stack_dummy
= STOP_NONE
;
5082 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5084 /* No unwaited-for children left. IOW, all resumed children
5086 stop_print_frame
= 0;
5091 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5092 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5094 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5095 /* If it's a new thread, add it to the thread database. */
5096 if (ecs
->event_thread
== NULL
)
5097 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5099 /* Disable range stepping. If the next step request could use a
5100 range, this will be end up re-enabled then. */
5101 ecs
->event_thread
->control
.may_range_step
= 0;
5104 /* Dependent on valid ECS->EVENT_THREAD. */
5105 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5107 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5108 reinit_frame_cache ();
5110 breakpoint_retire_moribund ();
5112 /* First, distinguish signals caused by the debugger from signals
5113 that have to do with the program's own actions. Note that
5114 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5115 on the operating system version. Here we detect when a SIGILL or
5116 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5117 something similar for SIGSEGV, since a SIGSEGV will be generated
5118 when we're trying to execute a breakpoint instruction on a
5119 non-executable stack. This happens for call dummy breakpoints
5120 for architectures like SPARC that place call dummies on the
5122 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5123 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5124 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5125 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5127 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5129 if (breakpoint_inserted_here_p (regcache
->aspace (),
5130 regcache_read_pc (regcache
)))
5133 fprintf_unfiltered (gdb_stdlog
,
5134 "infrun: Treating signal as SIGTRAP\n");
5135 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5139 /* Mark the non-executing threads accordingly. In all-stop, all
5140 threads of all processes are stopped when we get any event
5141 reported. In non-stop mode, only the event thread stops. */
5145 if (!target_is_non_stop_p ())
5146 mark_ptid
= minus_one_ptid
;
5147 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
5148 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5150 /* If we're handling a process exit in non-stop mode, even
5151 though threads haven't been deleted yet, one would think
5152 that there is nothing to do, as threads of the dead process
5153 will be soon deleted, and threads of any other process were
5154 left running. However, on some targets, threads survive a
5155 process exit event. E.g., for the "checkpoint" command,
5156 when the current checkpoint/fork exits, linux-fork.c
5157 automatically switches to another fork from within
5158 target_mourn_inferior, by associating the same
5159 inferior/thread to another fork. We haven't mourned yet at
5160 this point, but we must mark any threads left in the
5161 process as not-executing so that finish_thread_state marks
5162 them stopped (in the user's perspective) if/when we present
5163 the stop to the user. */
5164 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
5167 mark_ptid
= ecs
->ptid
;
5169 set_executing (ecs
->target
, mark_ptid
, false);
5171 /* Likewise the resumed flag. */
5172 set_resumed (ecs
->target
, mark_ptid
, false);
5175 switch (ecs
->ws
.kind
)
5177 case TARGET_WAITKIND_LOADED
:
5178 context_switch (ecs
);
5179 /* Ignore gracefully during startup of the inferior, as it might
5180 be the shell which has just loaded some objects, otherwise
5181 add the symbols for the newly loaded objects. Also ignore at
5182 the beginning of an attach or remote session; we will query
5183 the full list of libraries once the connection is
5186 stop_soon
= get_inferior_stop_soon (ecs
);
5187 if (stop_soon
== NO_STOP_QUIETLY
)
5189 struct regcache
*regcache
;
5191 regcache
= get_thread_regcache (ecs
->event_thread
);
5193 handle_solib_event ();
5195 ecs
->event_thread
->control
.stop_bpstat
5196 = bpstat_stop_status (regcache
->aspace (),
5197 ecs
->event_thread
->suspend
.stop_pc
,
5198 ecs
->event_thread
, &ecs
->ws
);
5200 if (handle_stop_requested (ecs
))
5203 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5205 /* A catchpoint triggered. */
5206 process_event_stop_test (ecs
);
5210 /* If requested, stop when the dynamic linker notifies
5211 gdb of events. This allows the user to get control
5212 and place breakpoints in initializer routines for
5213 dynamically loaded objects (among other things). */
5214 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5215 if (stop_on_solib_events
)
5217 /* Make sure we print "Stopped due to solib-event" in
5219 stop_print_frame
= 1;
5226 /* If we are skipping through a shell, or through shared library
5227 loading that we aren't interested in, resume the program. If
5228 we're running the program normally, also resume. */
5229 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5231 /* Loading of shared libraries might have changed breakpoint
5232 addresses. Make sure new breakpoints are inserted. */
5233 if (stop_soon
== NO_STOP_QUIETLY
)
5234 insert_breakpoints ();
5235 resume (GDB_SIGNAL_0
);
5236 prepare_to_wait (ecs
);
5240 /* But stop if we're attaching or setting up a remote
5242 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5243 || stop_soon
== STOP_QUIETLY_REMOTE
)
5246 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5251 internal_error (__FILE__
, __LINE__
,
5252 _("unhandled stop_soon: %d"), (int) stop_soon
);
5254 case TARGET_WAITKIND_SPURIOUS
:
5255 if (handle_stop_requested (ecs
))
5257 context_switch (ecs
);
5258 resume (GDB_SIGNAL_0
);
5259 prepare_to_wait (ecs
);
5262 case TARGET_WAITKIND_THREAD_CREATED
:
5263 if (handle_stop_requested (ecs
))
5265 context_switch (ecs
);
5266 if (!switch_back_to_stepped_thread (ecs
))
5270 case TARGET_WAITKIND_EXITED
:
5271 case TARGET_WAITKIND_SIGNALLED
:
5272 inferior_ptid
= ecs
->ptid
;
5273 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5274 set_current_program_space (current_inferior ()->pspace
);
5275 handle_vfork_child_exec_or_exit (0);
5276 target_terminal::ours (); /* Must do this before mourn anyway. */
5278 /* Clearing any previous state of convenience variables. */
5279 clear_exit_convenience_vars ();
5281 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5283 /* Record the exit code in the convenience variable $_exitcode, so
5284 that the user can inspect this again later. */
5285 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5286 (LONGEST
) ecs
->ws
.value
.integer
);
5288 /* Also record this in the inferior itself. */
5289 current_inferior ()->has_exit_code
= 1;
5290 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5292 /* Support the --return-child-result option. */
5293 return_child_result_value
= ecs
->ws
.value
.integer
;
5295 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5299 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5301 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5303 /* Set the value of the internal variable $_exitsignal,
5304 which holds the signal uncaught by the inferior. */
5305 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5306 gdbarch_gdb_signal_to_target (gdbarch
,
5307 ecs
->ws
.value
.sig
));
5311 /* We don't have access to the target's method used for
5312 converting between signal numbers (GDB's internal
5313 representation <-> target's representation).
5314 Therefore, we cannot do a good job at displaying this
5315 information to the user. It's better to just warn
5316 her about it (if infrun debugging is enabled), and
5319 fprintf_filtered (gdb_stdlog
, _("\
5320 Cannot fill $_exitsignal with the correct signal number.\n"));
5323 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5326 gdb_flush (gdb_stdout
);
5327 target_mourn_inferior (inferior_ptid
);
5328 stop_print_frame
= 0;
5332 case TARGET_WAITKIND_FORKED
:
5333 case TARGET_WAITKIND_VFORKED
:
5334 /* Check whether the inferior is displaced stepping. */
5336 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5337 struct gdbarch
*gdbarch
= regcache
->arch ();
5339 /* If checking displaced stepping is supported, and thread
5340 ecs->ptid is displaced stepping. */
5341 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5343 struct inferior
*parent_inf
5344 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5345 struct regcache
*child_regcache
;
5346 CORE_ADDR parent_pc
;
5348 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5350 struct displaced_step_inferior_state
*displaced
5351 = get_displaced_stepping_state (parent_inf
);
5353 /* Restore scratch pad for child process. */
5354 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5357 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5358 indicating that the displaced stepping of syscall instruction
5359 has been done. Perform cleanup for parent process here. Note
5360 that this operation also cleans up the child process for vfork,
5361 because their pages are shared. */
5362 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5363 /* Start a new step-over in another thread if there's one
5367 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5368 the child's PC is also within the scratchpad. Set the child's PC
5369 to the parent's PC value, which has already been fixed up.
5370 FIXME: we use the parent's aspace here, although we're touching
5371 the child, because the child hasn't been added to the inferior
5372 list yet at this point. */
5375 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5376 ecs
->ws
.value
.related_pid
,
5378 parent_inf
->aspace
);
5379 /* Read PC value of parent process. */
5380 parent_pc
= regcache_read_pc (regcache
);
5382 if (debug_displaced
)
5383 fprintf_unfiltered (gdb_stdlog
,
5384 "displaced: write child pc from %s to %s\n",
5386 regcache_read_pc (child_regcache
)),
5387 paddress (gdbarch
, parent_pc
));
5389 regcache_write_pc (child_regcache
, parent_pc
);
5393 context_switch (ecs
);
5395 /* Immediately detach breakpoints from the child before there's
5396 any chance of letting the user delete breakpoints from the
5397 breakpoint lists. If we don't do this early, it's easy to
5398 leave left over traps in the child, vis: "break foo; catch
5399 fork; c; <fork>; del; c; <child calls foo>". We only follow
5400 the fork on the last `continue', and by that time the
5401 breakpoint at "foo" is long gone from the breakpoint table.
5402 If we vforked, then we don't need to unpatch here, since both
5403 parent and child are sharing the same memory pages; we'll
5404 need to unpatch at follow/detach time instead to be certain
5405 that new breakpoints added between catchpoint hit time and
5406 vfork follow are detached. */
5407 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5409 /* This won't actually modify the breakpoint list, but will
5410 physically remove the breakpoints from the child. */
5411 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5414 delete_just_stopped_threads_single_step_breakpoints ();
5416 /* In case the event is caught by a catchpoint, remember that
5417 the event is to be followed at the next resume of the thread,
5418 and not immediately. */
5419 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5421 ecs
->event_thread
->suspend
.stop_pc
5422 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5424 ecs
->event_thread
->control
.stop_bpstat
5425 = bpstat_stop_status (get_current_regcache ()->aspace (),
5426 ecs
->event_thread
->suspend
.stop_pc
,
5427 ecs
->event_thread
, &ecs
->ws
);
5429 if (handle_stop_requested (ecs
))
5432 /* If no catchpoint triggered for this, then keep going. Note
5433 that we're interested in knowing the bpstat actually causes a
5434 stop, not just if it may explain the signal. Software
5435 watchpoints, for example, always appear in the bpstat. */
5436 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5439 = (follow_fork_mode_string
== follow_fork_mode_child
);
5441 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5443 process_stratum_target
*targ
5444 = ecs
->event_thread
->inf
->process_target ();
5446 bool should_resume
= follow_fork ();
5448 /* Note that one of these may be an invalid pointer,
5449 depending on detach_fork. */
5450 thread_info
*parent
= ecs
->event_thread
;
5452 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5454 /* At this point, the parent is marked running, and the
5455 child is marked stopped. */
5457 /* If not resuming the parent, mark it stopped. */
5458 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5459 parent
->set_running (false);
5461 /* If resuming the child, mark it running. */
5462 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5463 child
->set_running (true);
5465 /* In non-stop mode, also resume the other branch. */
5466 if (!detach_fork
&& (non_stop
5467 || (sched_multi
&& target_is_non_stop_p ())))
5470 switch_to_thread (parent
);
5472 switch_to_thread (child
);
5474 ecs
->event_thread
= inferior_thread ();
5475 ecs
->ptid
= inferior_ptid
;
5480 switch_to_thread (child
);
5482 switch_to_thread (parent
);
5484 ecs
->event_thread
= inferior_thread ();
5485 ecs
->ptid
= inferior_ptid
;
5493 process_event_stop_test (ecs
);
5496 case TARGET_WAITKIND_VFORK_DONE
:
5497 /* Done with the shared memory region. Re-insert breakpoints in
5498 the parent, and keep going. */
5500 context_switch (ecs
);
5502 current_inferior ()->waiting_for_vfork_done
= 0;
5503 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5505 if (handle_stop_requested (ecs
))
5508 /* This also takes care of reinserting breakpoints in the
5509 previously locked inferior. */
5513 case TARGET_WAITKIND_EXECD
:
5515 /* Note we can't read registers yet (the stop_pc), because we
5516 don't yet know the inferior's post-exec architecture.
5517 'stop_pc' is explicitly read below instead. */
5518 switch_to_thread_no_regs (ecs
->event_thread
);
5520 /* Do whatever is necessary to the parent branch of the vfork. */
5521 handle_vfork_child_exec_or_exit (1);
5523 /* This causes the eventpoints and symbol table to be reset.
5524 Must do this now, before trying to determine whether to
5526 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5528 /* In follow_exec we may have deleted the original thread and
5529 created a new one. Make sure that the event thread is the
5530 execd thread for that case (this is a nop otherwise). */
5531 ecs
->event_thread
= inferior_thread ();
5533 ecs
->event_thread
->suspend
.stop_pc
5534 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5536 ecs
->event_thread
->control
.stop_bpstat
5537 = bpstat_stop_status (get_current_regcache ()->aspace (),
5538 ecs
->event_thread
->suspend
.stop_pc
,
5539 ecs
->event_thread
, &ecs
->ws
);
5541 /* Note that this may be referenced from inside
5542 bpstat_stop_status above, through inferior_has_execd. */
5543 xfree (ecs
->ws
.value
.execd_pathname
);
5544 ecs
->ws
.value
.execd_pathname
= NULL
;
5546 if (handle_stop_requested (ecs
))
5549 /* If no catchpoint triggered for this, then keep going. */
5550 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5552 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5556 process_event_stop_test (ecs
);
5559 /* Be careful not to try to gather much state about a thread
5560 that's in a syscall. It's frequently a losing proposition. */
5561 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5562 /* Getting the current syscall number. */
5563 if (handle_syscall_event (ecs
) == 0)
5564 process_event_stop_test (ecs
);
5567 /* Before examining the threads further, step this thread to
5568 get it entirely out of the syscall. (We get notice of the
5569 event when the thread is just on the verge of exiting a
5570 syscall. Stepping one instruction seems to get it back
5572 case TARGET_WAITKIND_SYSCALL_RETURN
:
5573 if (handle_syscall_event (ecs
) == 0)
5574 process_event_stop_test (ecs
);
5577 case TARGET_WAITKIND_STOPPED
:
5578 handle_signal_stop (ecs
);
5581 case TARGET_WAITKIND_NO_HISTORY
:
5582 /* Reverse execution: target ran out of history info. */
5584 /* Switch to the stopped thread. */
5585 context_switch (ecs
);
5587 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5589 delete_just_stopped_threads_single_step_breakpoints ();
5590 ecs
->event_thread
->suspend
.stop_pc
5591 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5593 if (handle_stop_requested (ecs
))
5596 gdb::observers::no_history
.notify ();
5602 /* Restart threads back to what they were trying to do back when we
5603 paused them for an in-line step-over. The EVENT_THREAD thread is
5607 restart_threads (struct thread_info
*event_thread
)
5609 /* In case the instruction just stepped spawned a new thread. */
5610 update_thread_list ();
5612 for (thread_info
*tp
: all_non_exited_threads ())
5614 switch_to_thread_no_regs (tp
);
5616 if (tp
== event_thread
)
5619 fprintf_unfiltered (gdb_stdlog
,
5620 "infrun: restart threads: "
5621 "[%s] is event thread\n",
5622 target_pid_to_str (tp
->ptid
).c_str ());
5626 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5629 fprintf_unfiltered (gdb_stdlog
,
5630 "infrun: restart threads: "
5631 "[%s] not meant to be running\n",
5632 target_pid_to_str (tp
->ptid
).c_str ());
5639 fprintf_unfiltered (gdb_stdlog
,
5640 "infrun: restart threads: [%s] resumed\n",
5641 target_pid_to_str (tp
->ptid
).c_str ());
5642 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5646 if (thread_is_in_step_over_chain (tp
))
5649 fprintf_unfiltered (gdb_stdlog
,
5650 "infrun: restart threads: "
5651 "[%s] needs step-over\n",
5652 target_pid_to_str (tp
->ptid
).c_str ());
5653 gdb_assert (!tp
->resumed
);
5658 if (tp
->suspend
.waitstatus_pending_p
)
5661 fprintf_unfiltered (gdb_stdlog
,
5662 "infrun: restart threads: "
5663 "[%s] has pending status\n",
5664 target_pid_to_str (tp
->ptid
).c_str ());
5669 gdb_assert (!tp
->stop_requested
);
5671 /* If some thread needs to start a step-over at this point, it
5672 should still be in the step-over queue, and thus skipped
5674 if (thread_still_needs_step_over (tp
))
5676 internal_error (__FILE__
, __LINE__
,
5677 "thread [%s] needs a step-over, but not in "
5678 "step-over queue\n",
5679 target_pid_to_str (tp
->ptid
).c_str ());
5682 if (currently_stepping (tp
))
5685 fprintf_unfiltered (gdb_stdlog
,
5686 "infrun: restart threads: [%s] was stepping\n",
5687 target_pid_to_str (tp
->ptid
).c_str ());
5688 keep_going_stepped_thread (tp
);
5692 struct execution_control_state ecss
;
5693 struct execution_control_state
*ecs
= &ecss
;
5696 fprintf_unfiltered (gdb_stdlog
,
5697 "infrun: restart threads: [%s] continuing\n",
5698 target_pid_to_str (tp
->ptid
).c_str ());
5699 reset_ecs (ecs
, tp
);
5700 switch_to_thread (tp
);
5701 keep_going_pass_signal (ecs
);
5706 /* Callback for iterate_over_threads. Find a resumed thread that has
5707 a pending waitstatus. */
5710 resumed_thread_with_pending_status (struct thread_info
*tp
,
5714 && tp
->suspend
.waitstatus_pending_p
);
5717 /* Called when we get an event that may finish an in-line or
5718 out-of-line (displaced stepping) step-over started previously.
5719 Return true if the event is processed and we should go back to the
5720 event loop; false if the caller should continue processing the
5724 finish_step_over (struct execution_control_state
*ecs
)
5726 int had_step_over_info
;
5728 displaced_step_fixup (ecs
->event_thread
,
5729 ecs
->event_thread
->suspend
.stop_signal
);
5731 had_step_over_info
= step_over_info_valid_p ();
5733 if (had_step_over_info
)
5735 /* If we're stepping over a breakpoint with all threads locked,
5736 then only the thread that was stepped should be reporting
5738 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5740 clear_step_over_info ();
5743 if (!target_is_non_stop_p ())
5746 /* Start a new step-over in another thread if there's one that
5750 /* If we were stepping over a breakpoint before, and haven't started
5751 a new in-line step-over sequence, then restart all other threads
5752 (except the event thread). We can't do this in all-stop, as then
5753 e.g., we wouldn't be able to issue any other remote packet until
5754 these other threads stop. */
5755 if (had_step_over_info
&& !step_over_info_valid_p ())
5757 struct thread_info
*pending
;
5759 /* If we only have threads with pending statuses, the restart
5760 below won't restart any thread and so nothing re-inserts the
5761 breakpoint we just stepped over. But we need it inserted
5762 when we later process the pending events, otherwise if
5763 another thread has a pending event for this breakpoint too,
5764 we'd discard its event (because the breakpoint that
5765 originally caused the event was no longer inserted). */
5766 context_switch (ecs
);
5767 insert_breakpoints ();
5769 restart_threads (ecs
->event_thread
);
5771 /* If we have events pending, go through handle_inferior_event
5772 again, picking up a pending event at random. This avoids
5773 thread starvation. */
5775 /* But not if we just stepped over a watchpoint in order to let
5776 the instruction execute so we can evaluate its expression.
5777 The set of watchpoints that triggered is recorded in the
5778 breakpoint objects themselves (see bp->watchpoint_triggered).
5779 If we processed another event first, that other event could
5780 clobber this info. */
5781 if (ecs
->event_thread
->stepping_over_watchpoint
)
5784 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5786 if (pending
!= NULL
)
5788 struct thread_info
*tp
= ecs
->event_thread
;
5789 struct regcache
*regcache
;
5793 fprintf_unfiltered (gdb_stdlog
,
5794 "infrun: found resumed threads with "
5795 "pending events, saving status\n");
5798 gdb_assert (pending
!= tp
);
5800 /* Record the event thread's event for later. */
5801 save_waitstatus (tp
, &ecs
->ws
);
5802 /* This was cleared early, by handle_inferior_event. Set it
5803 so this pending event is considered by
5807 gdb_assert (!tp
->executing
);
5809 regcache
= get_thread_regcache (tp
);
5810 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5814 fprintf_unfiltered (gdb_stdlog
,
5815 "infrun: saved stop_pc=%s for %s "
5816 "(currently_stepping=%d)\n",
5817 paddress (target_gdbarch (),
5818 tp
->suspend
.stop_pc
),
5819 target_pid_to_str (tp
->ptid
).c_str (),
5820 currently_stepping (tp
));
5823 /* This in-line step-over finished; clear this so we won't
5824 start a new one. This is what handle_signal_stop would
5825 do, if we returned false. */
5826 tp
->stepping_over_breakpoint
= 0;
5828 /* Wake up the event loop again. */
5829 mark_async_event_handler (infrun_async_inferior_event_token
);
5831 prepare_to_wait (ecs
);
5839 /* Come here when the program has stopped with a signal. */
5842 handle_signal_stop (struct execution_control_state
*ecs
)
5844 struct frame_info
*frame
;
5845 struct gdbarch
*gdbarch
;
5846 int stopped_by_watchpoint
;
5847 enum stop_kind stop_soon
;
5850 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5852 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5854 /* Do we need to clean up the state of a thread that has
5855 completed a displaced single-step? (Doing so usually affects
5856 the PC, so do it here, before we set stop_pc.) */
5857 if (finish_step_over (ecs
))
5860 /* If we either finished a single-step or hit a breakpoint, but
5861 the user wanted this thread to be stopped, pretend we got a
5862 SIG0 (generic unsignaled stop). */
5863 if (ecs
->event_thread
->stop_requested
5864 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5865 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5867 ecs
->event_thread
->suspend
.stop_pc
5868 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5872 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5873 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5875 switch_to_thread (ecs
->event_thread
);
5877 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5878 paddress (reg_gdbarch
,
5879 ecs
->event_thread
->suspend
.stop_pc
));
5880 if (target_stopped_by_watchpoint ())
5884 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5886 if (target_stopped_data_address (current_top_target (), &addr
))
5887 fprintf_unfiltered (gdb_stdlog
,
5888 "infrun: stopped data address = %s\n",
5889 paddress (reg_gdbarch
, addr
));
5891 fprintf_unfiltered (gdb_stdlog
,
5892 "infrun: (no data address available)\n");
5896 /* This is originated from start_remote(), start_inferior() and
5897 shared libraries hook functions. */
5898 stop_soon
= get_inferior_stop_soon (ecs
);
5899 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5901 context_switch (ecs
);
5903 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5904 stop_print_frame
= 1;
5909 /* This originates from attach_command(). We need to overwrite
5910 the stop_signal here, because some kernels don't ignore a
5911 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5912 See more comments in inferior.h. On the other hand, if we
5913 get a non-SIGSTOP, report it to the user - assume the backend
5914 will handle the SIGSTOP if it should show up later.
5916 Also consider that the attach is complete when we see a
5917 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5918 target extended-remote report it instead of a SIGSTOP
5919 (e.g. gdbserver). We already rely on SIGTRAP being our
5920 signal, so this is no exception.
5922 Also consider that the attach is complete when we see a
5923 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5924 the target to stop all threads of the inferior, in case the
5925 low level attach operation doesn't stop them implicitly. If
5926 they weren't stopped implicitly, then the stub will report a
5927 GDB_SIGNAL_0, meaning: stopped for no particular reason
5928 other than GDB's request. */
5929 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5930 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5931 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5932 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5934 stop_print_frame
= 1;
5936 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5940 /* See if something interesting happened to the non-current thread. If
5941 so, then switch to that thread. */
5942 if (ecs
->ptid
!= inferior_ptid
)
5945 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5947 context_switch (ecs
);
5949 if (deprecated_context_hook
)
5950 deprecated_context_hook (ecs
->event_thread
->global_num
);
5953 /* At this point, get hold of the now-current thread's frame. */
5954 frame
= get_current_frame ();
5955 gdbarch
= get_frame_arch (frame
);
5957 /* Pull the single step breakpoints out of the target. */
5958 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5960 struct regcache
*regcache
;
5963 regcache
= get_thread_regcache (ecs
->event_thread
);
5964 const address_space
*aspace
= regcache
->aspace ();
5966 pc
= regcache_read_pc (regcache
);
5968 /* However, before doing so, if this single-step breakpoint was
5969 actually for another thread, set this thread up for moving
5971 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5974 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5978 fprintf_unfiltered (gdb_stdlog
,
5979 "infrun: [%s] hit another thread's "
5980 "single-step breakpoint\n",
5981 target_pid_to_str (ecs
->ptid
).c_str ());
5983 ecs
->hit_singlestep_breakpoint
= 1;
5990 fprintf_unfiltered (gdb_stdlog
,
5991 "infrun: [%s] hit its "
5992 "single-step breakpoint\n",
5993 target_pid_to_str (ecs
->ptid
).c_str ());
5997 delete_just_stopped_threads_single_step_breakpoints ();
5999 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6000 && ecs
->event_thread
->control
.trap_expected
6001 && ecs
->event_thread
->stepping_over_watchpoint
)
6002 stopped_by_watchpoint
= 0;
6004 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
6006 /* If necessary, step over this watchpoint. We'll be back to display
6008 if (stopped_by_watchpoint
6009 && (target_have_steppable_watchpoint
6010 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6012 /* At this point, we are stopped at an instruction which has
6013 attempted to write to a piece of memory under control of
6014 a watchpoint. The instruction hasn't actually executed
6015 yet. If we were to evaluate the watchpoint expression
6016 now, we would get the old value, and therefore no change
6017 would seem to have occurred.
6019 In order to make watchpoints work `right', we really need
6020 to complete the memory write, and then evaluate the
6021 watchpoint expression. We do this by single-stepping the
6024 It may not be necessary to disable the watchpoint to step over
6025 it. For example, the PA can (with some kernel cooperation)
6026 single step over a watchpoint without disabling the watchpoint.
6028 It is far more common to need to disable a watchpoint to step
6029 the inferior over it. If we have non-steppable watchpoints,
6030 we must disable the current watchpoint; it's simplest to
6031 disable all watchpoints.
6033 Any breakpoint at PC must also be stepped over -- if there's
6034 one, it will have already triggered before the watchpoint
6035 triggered, and we either already reported it to the user, or
6036 it didn't cause a stop and we called keep_going. In either
6037 case, if there was a breakpoint at PC, we must be trying to
6039 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6044 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6045 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6046 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6047 ecs
->event_thread
->control
.stop_step
= 0;
6048 stop_print_frame
= 1;
6049 stopped_by_random_signal
= 0;
6050 bpstat stop_chain
= NULL
;
6052 /* Hide inlined functions starting here, unless we just performed stepi or
6053 nexti. After stepi and nexti, always show the innermost frame (not any
6054 inline function call sites). */
6055 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6057 const address_space
*aspace
6058 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6060 /* skip_inline_frames is expensive, so we avoid it if we can
6061 determine that the address is one where functions cannot have
6062 been inlined. This improves performance with inferiors that
6063 load a lot of shared libraries, because the solib event
6064 breakpoint is defined as the address of a function (i.e. not
6065 inline). Note that we have to check the previous PC as well
6066 as the current one to catch cases when we have just
6067 single-stepped off a breakpoint prior to reinstating it.
6068 Note that we're assuming that the code we single-step to is
6069 not inline, but that's not definitive: there's nothing
6070 preventing the event breakpoint function from containing
6071 inlined code, and the single-step ending up there. If the
6072 user had set a breakpoint on that inlined code, the missing
6073 skip_inline_frames call would break things. Fortunately
6074 that's an extremely unlikely scenario. */
6075 if (!pc_at_non_inline_function (aspace
,
6076 ecs
->event_thread
->suspend
.stop_pc
,
6078 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6079 && ecs
->event_thread
->control
.trap_expected
6080 && pc_at_non_inline_function (aspace
,
6081 ecs
->event_thread
->prev_pc
,
6084 stop_chain
= build_bpstat_chain (aspace
,
6085 ecs
->event_thread
->suspend
.stop_pc
,
6087 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6089 /* Re-fetch current thread's frame in case that invalidated
6091 frame
= get_current_frame ();
6092 gdbarch
= get_frame_arch (frame
);
6096 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6097 && ecs
->event_thread
->control
.trap_expected
6098 && gdbarch_single_step_through_delay_p (gdbarch
)
6099 && currently_stepping (ecs
->event_thread
))
6101 /* We're trying to step off a breakpoint. Turns out that we're
6102 also on an instruction that needs to be stepped multiple
6103 times before it's been fully executing. E.g., architectures
6104 with a delay slot. It needs to be stepped twice, once for
6105 the instruction and once for the delay slot. */
6106 int step_through_delay
6107 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6109 if (debug_infrun
&& step_through_delay
)
6110 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6111 if (ecs
->event_thread
->control
.step_range_end
== 0
6112 && step_through_delay
)
6114 /* The user issued a continue when stopped at a breakpoint.
6115 Set up for another trap and get out of here. */
6116 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6120 else if (step_through_delay
)
6122 /* The user issued a step when stopped at a breakpoint.
6123 Maybe we should stop, maybe we should not - the delay
6124 slot *might* correspond to a line of source. In any
6125 case, don't decide that here, just set
6126 ecs->stepping_over_breakpoint, making sure we
6127 single-step again before breakpoints are re-inserted. */
6128 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6132 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6133 handles this event. */
6134 ecs
->event_thread
->control
.stop_bpstat
6135 = bpstat_stop_status (get_current_regcache ()->aspace (),
6136 ecs
->event_thread
->suspend
.stop_pc
,
6137 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6139 /* Following in case break condition called a
6141 stop_print_frame
= 1;
6143 /* This is where we handle "moribund" watchpoints. Unlike
6144 software breakpoints traps, hardware watchpoint traps are
6145 always distinguishable from random traps. If no high-level
6146 watchpoint is associated with the reported stop data address
6147 anymore, then the bpstat does not explain the signal ---
6148 simply make sure to ignore it if `stopped_by_watchpoint' is
6152 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6153 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6155 && stopped_by_watchpoint
)
6156 fprintf_unfiltered (gdb_stdlog
,
6157 "infrun: no user watchpoint explains "
6158 "watchpoint SIGTRAP, ignoring\n");
6160 /* NOTE: cagney/2003-03-29: These checks for a random signal
6161 at one stage in the past included checks for an inferior
6162 function call's call dummy's return breakpoint. The original
6163 comment, that went with the test, read:
6165 ``End of a stack dummy. Some systems (e.g. Sony news) give
6166 another signal besides SIGTRAP, so check here as well as
6169 If someone ever tries to get call dummys on a
6170 non-executable stack to work (where the target would stop
6171 with something like a SIGSEGV), then those tests might need
6172 to be re-instated. Given, however, that the tests were only
6173 enabled when momentary breakpoints were not being used, I
6174 suspect that it won't be the case.
6176 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6177 be necessary for call dummies on a non-executable stack on
6180 /* See if the breakpoints module can explain the signal. */
6182 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6183 ecs
->event_thread
->suspend
.stop_signal
);
6185 /* Maybe this was a trap for a software breakpoint that has since
6187 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6189 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6190 ecs
->event_thread
->suspend
.stop_pc
))
6192 struct regcache
*regcache
;
6195 /* Re-adjust PC to what the program would see if GDB was not
6197 regcache
= get_thread_regcache (ecs
->event_thread
);
6198 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6201 gdb::optional
<scoped_restore_tmpl
<int>>
6202 restore_operation_disable
;
6204 if (record_full_is_used ())
6205 restore_operation_disable
.emplace
6206 (record_full_gdb_operation_disable_set ());
6208 regcache_write_pc (regcache
,
6209 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6214 /* A delayed software breakpoint event. Ignore the trap. */
6216 fprintf_unfiltered (gdb_stdlog
,
6217 "infrun: delayed software breakpoint "
6218 "trap, ignoring\n");
6223 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6224 has since been removed. */
6225 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6227 /* A delayed hardware breakpoint event. Ignore the trap. */
6229 fprintf_unfiltered (gdb_stdlog
,
6230 "infrun: delayed hardware breakpoint/watchpoint "
6231 "trap, ignoring\n");
6235 /* If not, perhaps stepping/nexting can. */
6237 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6238 && currently_stepping (ecs
->event_thread
));
6240 /* Perhaps the thread hit a single-step breakpoint of _another_
6241 thread. Single-step breakpoints are transparent to the
6242 breakpoints module. */
6244 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6246 /* No? Perhaps we got a moribund watchpoint. */
6248 random_signal
= !stopped_by_watchpoint
;
6250 /* Always stop if the user explicitly requested this thread to
6252 if (ecs
->event_thread
->stop_requested
)
6256 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6259 /* For the program's own signals, act according to
6260 the signal handling tables. */
6264 /* Signal not for debugging purposes. */
6265 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6266 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6269 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6270 gdb_signal_to_symbol_string (stop_signal
));
6272 stopped_by_random_signal
= 1;
6274 /* Always stop on signals if we're either just gaining control
6275 of the program, or the user explicitly requested this thread
6276 to remain stopped. */
6277 if (stop_soon
!= NO_STOP_QUIETLY
6278 || ecs
->event_thread
->stop_requested
6280 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6286 /* Notify observers the signal has "handle print" set. Note we
6287 returned early above if stopping; normal_stop handles the
6288 printing in that case. */
6289 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6291 /* The signal table tells us to print about this signal. */
6292 target_terminal::ours_for_output ();
6293 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6294 target_terminal::inferior ();
6297 /* Clear the signal if it should not be passed. */
6298 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6299 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6301 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6302 && ecs
->event_thread
->control
.trap_expected
6303 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6305 /* We were just starting a new sequence, attempting to
6306 single-step off of a breakpoint and expecting a SIGTRAP.
6307 Instead this signal arrives. This signal will take us out
6308 of the stepping range so GDB needs to remember to, when
6309 the signal handler returns, resume stepping off that
6311 /* To simplify things, "continue" is forced to use the same
6312 code paths as single-step - set a breakpoint at the
6313 signal return address and then, once hit, step off that
6316 fprintf_unfiltered (gdb_stdlog
,
6317 "infrun: signal arrived while stepping over "
6320 insert_hp_step_resume_breakpoint_at_frame (frame
);
6321 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6322 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6323 ecs
->event_thread
->control
.trap_expected
= 0;
6325 /* If we were nexting/stepping some other thread, switch to
6326 it, so that we don't continue it, losing control. */
6327 if (!switch_back_to_stepped_thread (ecs
))
6332 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6333 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6335 || ecs
->event_thread
->control
.step_range_end
== 1)
6336 && frame_id_eq (get_stack_frame_id (frame
),
6337 ecs
->event_thread
->control
.step_stack_frame_id
)
6338 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6340 /* The inferior is about to take a signal that will take it
6341 out of the single step range. Set a breakpoint at the
6342 current PC (which is presumably where the signal handler
6343 will eventually return) and then allow the inferior to
6346 Note that this is only needed for a signal delivered
6347 while in the single-step range. Nested signals aren't a
6348 problem as they eventually all return. */
6350 fprintf_unfiltered (gdb_stdlog
,
6351 "infrun: signal may take us out of "
6352 "single-step range\n");
6354 clear_step_over_info ();
6355 insert_hp_step_resume_breakpoint_at_frame (frame
);
6356 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6357 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6358 ecs
->event_thread
->control
.trap_expected
= 0;
6363 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6364 when either there's a nested signal, or when there's a
6365 pending signal enabled just as the signal handler returns
6366 (leaving the inferior at the step-resume-breakpoint without
6367 actually executing it). Either way continue until the
6368 breakpoint is really hit. */
6370 if (!switch_back_to_stepped_thread (ecs
))
6373 fprintf_unfiltered (gdb_stdlog
,
6374 "infrun: random signal, keep going\n");
6381 process_event_stop_test (ecs
);
6384 /* Come here when we've got some debug event / signal we can explain
6385 (IOW, not a random signal), and test whether it should cause a
6386 stop, or whether we should resume the inferior (transparently).
6387 E.g., could be a breakpoint whose condition evaluates false; we
6388 could be still stepping within the line; etc. */
6391 process_event_stop_test (struct execution_control_state
*ecs
)
6393 struct symtab_and_line stop_pc_sal
;
6394 struct frame_info
*frame
;
6395 struct gdbarch
*gdbarch
;
6396 CORE_ADDR jmp_buf_pc
;
6397 struct bpstat_what what
;
6399 /* Handle cases caused by hitting a breakpoint. */
6401 frame
= get_current_frame ();
6402 gdbarch
= get_frame_arch (frame
);
6404 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6406 if (what
.call_dummy
)
6408 stop_stack_dummy
= what
.call_dummy
;
6411 /* A few breakpoint types have callbacks associated (e.g.,
6412 bp_jit_event). Run them now. */
6413 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6415 /* If we hit an internal event that triggers symbol changes, the
6416 current frame will be invalidated within bpstat_what (e.g., if we
6417 hit an internal solib event). Re-fetch it. */
6418 frame
= get_current_frame ();
6419 gdbarch
= get_frame_arch (frame
);
6421 switch (what
.main_action
)
6423 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6424 /* If we hit the breakpoint at longjmp while stepping, we
6425 install a momentary breakpoint at the target of the
6429 fprintf_unfiltered (gdb_stdlog
,
6430 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6432 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6434 if (what
.is_longjmp
)
6436 struct value
*arg_value
;
6438 /* If we set the longjmp breakpoint via a SystemTap probe,
6439 then use it to extract the arguments. The destination PC
6440 is the third argument to the probe. */
6441 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6444 jmp_buf_pc
= value_as_address (arg_value
);
6445 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6447 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6448 || !gdbarch_get_longjmp_target (gdbarch
,
6449 frame
, &jmp_buf_pc
))
6452 fprintf_unfiltered (gdb_stdlog
,
6453 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6454 "(!gdbarch_get_longjmp_target)\n");
6459 /* Insert a breakpoint at resume address. */
6460 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6463 check_exception_resume (ecs
, frame
);
6467 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6469 struct frame_info
*init_frame
;
6471 /* There are several cases to consider.
6473 1. The initiating frame no longer exists. In this case we
6474 must stop, because the exception or longjmp has gone too
6477 2. The initiating frame exists, and is the same as the
6478 current frame. We stop, because the exception or longjmp
6481 3. The initiating frame exists and is different from the
6482 current frame. This means the exception or longjmp has
6483 been caught beneath the initiating frame, so keep going.
6485 4. longjmp breakpoint has been placed just to protect
6486 against stale dummy frames and user is not interested in
6487 stopping around longjmps. */
6490 fprintf_unfiltered (gdb_stdlog
,
6491 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6493 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6495 delete_exception_resume_breakpoint (ecs
->event_thread
);
6497 if (what
.is_longjmp
)
6499 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6501 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6509 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6513 struct frame_id current_id
6514 = get_frame_id (get_current_frame ());
6515 if (frame_id_eq (current_id
,
6516 ecs
->event_thread
->initiating_frame
))
6518 /* Case 2. Fall through. */
6528 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6530 delete_step_resume_breakpoint (ecs
->event_thread
);
6532 end_stepping_range (ecs
);
6536 case BPSTAT_WHAT_SINGLE
:
6538 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6539 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6540 /* Still need to check other stuff, at least the case where we
6541 are stepping and step out of the right range. */
6544 case BPSTAT_WHAT_STEP_RESUME
:
6546 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6548 delete_step_resume_breakpoint (ecs
->event_thread
);
6549 if (ecs
->event_thread
->control
.proceed_to_finish
6550 && execution_direction
== EXEC_REVERSE
)
6552 struct thread_info
*tp
= ecs
->event_thread
;
6554 /* We are finishing a function in reverse, and just hit the
6555 step-resume breakpoint at the start address of the
6556 function, and we're almost there -- just need to back up
6557 by one more single-step, which should take us back to the
6559 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6563 fill_in_stop_func (gdbarch
, ecs
);
6564 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6565 && execution_direction
== EXEC_REVERSE
)
6567 /* We are stepping over a function call in reverse, and just
6568 hit the step-resume breakpoint at the start address of
6569 the function. Go back to single-stepping, which should
6570 take us back to the function call. */
6571 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6577 case BPSTAT_WHAT_STOP_NOISY
:
6579 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6580 stop_print_frame
= 1;
6582 /* Assume the thread stopped for a breapoint. We'll still check
6583 whether a/the breakpoint is there when the thread is next
6585 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6590 case BPSTAT_WHAT_STOP_SILENT
:
6592 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6593 stop_print_frame
= 0;
6595 /* Assume the thread stopped for a breapoint. We'll still check
6596 whether a/the breakpoint is there when the thread is next
6598 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6602 case BPSTAT_WHAT_HP_STEP_RESUME
:
6604 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6606 delete_step_resume_breakpoint (ecs
->event_thread
);
6607 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6609 /* Back when the step-resume breakpoint was inserted, we
6610 were trying to single-step off a breakpoint. Go back to
6612 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6613 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6619 case BPSTAT_WHAT_KEEP_CHECKING
:
6623 /* If we stepped a permanent breakpoint and we had a high priority
6624 step-resume breakpoint for the address we stepped, but we didn't
6625 hit it, then we must have stepped into the signal handler. The
6626 step-resume was only necessary to catch the case of _not_
6627 stepping into the handler, so delete it, and fall through to
6628 checking whether the step finished. */
6629 if (ecs
->event_thread
->stepped_breakpoint
)
6631 struct breakpoint
*sr_bp
6632 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6635 && sr_bp
->loc
->permanent
6636 && sr_bp
->type
== bp_hp_step_resume
6637 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6640 fprintf_unfiltered (gdb_stdlog
,
6641 "infrun: stepped permanent breakpoint, stopped in "
6643 delete_step_resume_breakpoint (ecs
->event_thread
);
6644 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6648 /* We come here if we hit a breakpoint but should not stop for it.
6649 Possibly we also were stepping and should stop for that. So fall
6650 through and test for stepping. But, if not stepping, do not
6653 /* In all-stop mode, if we're currently stepping but have stopped in
6654 some other thread, we need to switch back to the stepped thread. */
6655 if (switch_back_to_stepped_thread (ecs
))
6658 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6661 fprintf_unfiltered (gdb_stdlog
,
6662 "infrun: step-resume breakpoint is inserted\n");
6664 /* Having a step-resume breakpoint overrides anything
6665 else having to do with stepping commands until
6666 that breakpoint is reached. */
6671 if (ecs
->event_thread
->control
.step_range_end
== 0)
6674 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6675 /* Likewise if we aren't even stepping. */
6680 /* Re-fetch current thread's frame in case the code above caused
6681 the frame cache to be re-initialized, making our FRAME variable
6682 a dangling pointer. */
6683 frame
= get_current_frame ();
6684 gdbarch
= get_frame_arch (frame
);
6685 fill_in_stop_func (gdbarch
, ecs
);
6687 /* If stepping through a line, keep going if still within it.
6689 Note that step_range_end is the address of the first instruction
6690 beyond the step range, and NOT the address of the last instruction
6693 Note also that during reverse execution, we may be stepping
6694 through a function epilogue and therefore must detect when
6695 the current-frame changes in the middle of a line. */
6697 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6699 && (execution_direction
!= EXEC_REVERSE
6700 || frame_id_eq (get_frame_id (frame
),
6701 ecs
->event_thread
->control
.step_frame_id
)))
6705 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6706 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6707 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6709 /* Tentatively re-enable range stepping; `resume' disables it if
6710 necessary (e.g., if we're stepping over a breakpoint or we
6711 have software watchpoints). */
6712 ecs
->event_thread
->control
.may_range_step
= 1;
6714 /* When stepping backward, stop at beginning of line range
6715 (unless it's the function entry point, in which case
6716 keep going back to the call point). */
6717 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6718 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6719 && stop_pc
!= ecs
->stop_func_start
6720 && execution_direction
== EXEC_REVERSE
)
6721 end_stepping_range (ecs
);
6728 /* We stepped out of the stepping range. */
6730 /* If we are stepping at the source level and entered the runtime
6731 loader dynamic symbol resolution code...
6733 EXEC_FORWARD: we keep on single stepping until we exit the run
6734 time loader code and reach the callee's address.
6736 EXEC_REVERSE: we've already executed the callee (backward), and
6737 the runtime loader code is handled just like any other
6738 undebuggable function call. Now we need only keep stepping
6739 backward through the trampoline code, and that's handled further
6740 down, so there is nothing for us to do here. */
6742 if (execution_direction
!= EXEC_REVERSE
6743 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6744 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6746 CORE_ADDR pc_after_resolver
=
6747 gdbarch_skip_solib_resolver (gdbarch
,
6748 ecs
->event_thread
->suspend
.stop_pc
);
6751 fprintf_unfiltered (gdb_stdlog
,
6752 "infrun: stepped into dynsym resolve code\n");
6754 if (pc_after_resolver
)
6756 /* Set up a step-resume breakpoint at the address
6757 indicated by SKIP_SOLIB_RESOLVER. */
6758 symtab_and_line sr_sal
;
6759 sr_sal
.pc
= pc_after_resolver
;
6760 sr_sal
.pspace
= get_frame_program_space (frame
);
6762 insert_step_resume_breakpoint_at_sal (gdbarch
,
6763 sr_sal
, null_frame_id
);
6770 /* Step through an indirect branch thunk. */
6771 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6772 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6773 ecs
->event_thread
->suspend
.stop_pc
))
6776 fprintf_unfiltered (gdb_stdlog
,
6777 "infrun: stepped into indirect branch thunk\n");
6782 if (ecs
->event_thread
->control
.step_range_end
!= 1
6783 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6784 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6785 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6788 fprintf_unfiltered (gdb_stdlog
,
6789 "infrun: stepped into signal trampoline\n");
6790 /* The inferior, while doing a "step" or "next", has ended up in
6791 a signal trampoline (either by a signal being delivered or by
6792 the signal handler returning). Just single-step until the
6793 inferior leaves the trampoline (either by calling the handler
6799 /* If we're in the return path from a shared library trampoline,
6800 we want to proceed through the trampoline when stepping. */
6801 /* macro/2012-04-25: This needs to come before the subroutine
6802 call check below as on some targets return trampolines look
6803 like subroutine calls (MIPS16 return thunks). */
6804 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6805 ecs
->event_thread
->suspend
.stop_pc
,
6806 ecs
->stop_func_name
)
6807 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6809 /* Determine where this trampoline returns. */
6810 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6811 CORE_ADDR real_stop_pc
6812 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6815 fprintf_unfiltered (gdb_stdlog
,
6816 "infrun: stepped into solib return tramp\n");
6818 /* Only proceed through if we know where it's going. */
6821 /* And put the step-breakpoint there and go until there. */
6822 symtab_and_line sr_sal
;
6823 sr_sal
.pc
= real_stop_pc
;
6824 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6825 sr_sal
.pspace
= get_frame_program_space (frame
);
6827 /* Do not specify what the fp should be when we stop since
6828 on some machines the prologue is where the new fp value
6830 insert_step_resume_breakpoint_at_sal (gdbarch
,
6831 sr_sal
, null_frame_id
);
6833 /* Restart without fiddling with the step ranges or
6840 /* Check for subroutine calls. The check for the current frame
6841 equalling the step ID is not necessary - the check of the
6842 previous frame's ID is sufficient - but it is a common case and
6843 cheaper than checking the previous frame's ID.
6845 NOTE: frame_id_eq will never report two invalid frame IDs as
6846 being equal, so to get into this block, both the current and
6847 previous frame must have valid frame IDs. */
6848 /* The outer_frame_id check is a heuristic to detect stepping
6849 through startup code. If we step over an instruction which
6850 sets the stack pointer from an invalid value to a valid value,
6851 we may detect that as a subroutine call from the mythical
6852 "outermost" function. This could be fixed by marking
6853 outermost frames as !stack_p,code_p,special_p. Then the
6854 initial outermost frame, before sp was valid, would
6855 have code_addr == &_start. See the comment in frame_id_eq
6857 if (!frame_id_eq (get_stack_frame_id (frame
),
6858 ecs
->event_thread
->control
.step_stack_frame_id
)
6859 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6860 ecs
->event_thread
->control
.step_stack_frame_id
)
6861 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6863 || (ecs
->event_thread
->control
.step_start_function
6864 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6866 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6867 CORE_ADDR real_stop_pc
;
6870 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6872 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6874 /* I presume that step_over_calls is only 0 when we're
6875 supposed to be stepping at the assembly language level
6876 ("stepi"). Just stop. */
6877 /* And this works the same backward as frontward. MVS */
6878 end_stepping_range (ecs
);
6882 /* Reverse stepping through solib trampolines. */
6884 if (execution_direction
== EXEC_REVERSE
6885 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6886 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6887 || (ecs
->stop_func_start
== 0
6888 && in_solib_dynsym_resolve_code (stop_pc
))))
6890 /* Any solib trampoline code can be handled in reverse
6891 by simply continuing to single-step. We have already
6892 executed the solib function (backwards), and a few
6893 steps will take us back through the trampoline to the
6899 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6901 /* We're doing a "next".
6903 Normal (forward) execution: set a breakpoint at the
6904 callee's return address (the address at which the caller
6907 Reverse (backward) execution. set the step-resume
6908 breakpoint at the start of the function that we just
6909 stepped into (backwards), and continue to there. When we
6910 get there, we'll need to single-step back to the caller. */
6912 if (execution_direction
== EXEC_REVERSE
)
6914 /* If we're already at the start of the function, we've either
6915 just stepped backward into a single instruction function,
6916 or stepped back out of a signal handler to the first instruction
6917 of the function. Just keep going, which will single-step back
6919 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6921 /* Normal function call return (static or dynamic). */
6922 symtab_and_line sr_sal
;
6923 sr_sal
.pc
= ecs
->stop_func_start
;
6924 sr_sal
.pspace
= get_frame_program_space (frame
);
6925 insert_step_resume_breakpoint_at_sal (gdbarch
,
6926 sr_sal
, null_frame_id
);
6930 insert_step_resume_breakpoint_at_caller (frame
);
6936 /* If we are in a function call trampoline (a stub between the
6937 calling routine and the real function), locate the real
6938 function. That's what tells us (a) whether we want to step
6939 into it at all, and (b) what prologue we want to run to the
6940 end of, if we do step into it. */
6941 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6942 if (real_stop_pc
== 0)
6943 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6944 if (real_stop_pc
!= 0)
6945 ecs
->stop_func_start
= real_stop_pc
;
6947 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6949 symtab_and_line sr_sal
;
6950 sr_sal
.pc
= ecs
->stop_func_start
;
6951 sr_sal
.pspace
= get_frame_program_space (frame
);
6953 insert_step_resume_breakpoint_at_sal (gdbarch
,
6954 sr_sal
, null_frame_id
);
6959 /* If we have line number information for the function we are
6960 thinking of stepping into and the function isn't on the skip
6963 If there are several symtabs at that PC (e.g. with include
6964 files), just want to know whether *any* of them have line
6965 numbers. find_pc_line handles this. */
6967 struct symtab_and_line tmp_sal
;
6969 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6970 if (tmp_sal
.line
!= 0
6971 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6973 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6975 if (execution_direction
== EXEC_REVERSE
)
6976 handle_step_into_function_backward (gdbarch
, ecs
);
6978 handle_step_into_function (gdbarch
, ecs
);
6983 /* If we have no line number and the step-stop-if-no-debug is
6984 set, we stop the step so that the user has a chance to switch
6985 in assembly mode. */
6986 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6987 && step_stop_if_no_debug
)
6989 end_stepping_range (ecs
);
6993 if (execution_direction
== EXEC_REVERSE
)
6995 /* If we're already at the start of the function, we've either just
6996 stepped backward into a single instruction function without line
6997 number info, or stepped back out of a signal handler to the first
6998 instruction of the function without line number info. Just keep
6999 going, which will single-step back to the caller. */
7000 if (ecs
->stop_func_start
!= stop_pc
)
7002 /* Set a breakpoint at callee's start address.
7003 From there we can step once and be back in the caller. */
7004 symtab_and_line sr_sal
;
7005 sr_sal
.pc
= ecs
->stop_func_start
;
7006 sr_sal
.pspace
= get_frame_program_space (frame
);
7007 insert_step_resume_breakpoint_at_sal (gdbarch
,
7008 sr_sal
, null_frame_id
);
7012 /* Set a breakpoint at callee's return address (the address
7013 at which the caller will resume). */
7014 insert_step_resume_breakpoint_at_caller (frame
);
7020 /* Reverse stepping through solib trampolines. */
7022 if (execution_direction
== EXEC_REVERSE
7023 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7025 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
7027 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7028 || (ecs
->stop_func_start
== 0
7029 && in_solib_dynsym_resolve_code (stop_pc
)))
7031 /* Any solib trampoline code can be handled in reverse
7032 by simply continuing to single-step. We have already
7033 executed the solib function (backwards), and a few
7034 steps will take us back through the trampoline to the
7039 else if (in_solib_dynsym_resolve_code (stop_pc
))
7041 /* Stepped backward into the solib dynsym resolver.
7042 Set a breakpoint at its start and continue, then
7043 one more step will take us out. */
7044 symtab_and_line sr_sal
;
7045 sr_sal
.pc
= ecs
->stop_func_start
;
7046 sr_sal
.pspace
= get_frame_program_space (frame
);
7047 insert_step_resume_breakpoint_at_sal (gdbarch
,
7048 sr_sal
, null_frame_id
);
7054 /* This always returns the sal for the inner-most frame when we are in a
7055 stack of inlined frames, even if GDB actually believes that it is in a
7056 more outer frame. This is checked for below by calls to
7057 inline_skipped_frames. */
7058 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7060 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7061 the trampoline processing logic, however, there are some trampolines
7062 that have no names, so we should do trampoline handling first. */
7063 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7064 && ecs
->stop_func_name
== NULL
7065 && stop_pc_sal
.line
== 0)
7068 fprintf_unfiltered (gdb_stdlog
,
7069 "infrun: stepped into undebuggable function\n");
7071 /* The inferior just stepped into, or returned to, an
7072 undebuggable function (where there is no debugging information
7073 and no line number corresponding to the address where the
7074 inferior stopped). Since we want to skip this kind of code,
7075 we keep going until the inferior returns from this
7076 function - unless the user has asked us not to (via
7077 set step-mode) or we no longer know how to get back
7078 to the call site. */
7079 if (step_stop_if_no_debug
7080 || !frame_id_p (frame_unwind_caller_id (frame
)))
7082 /* If we have no line number and the step-stop-if-no-debug
7083 is set, we stop the step so that the user has a chance to
7084 switch in assembly mode. */
7085 end_stepping_range (ecs
);
7090 /* Set a breakpoint at callee's return address (the address
7091 at which the caller will resume). */
7092 insert_step_resume_breakpoint_at_caller (frame
);
7098 if (ecs
->event_thread
->control
.step_range_end
== 1)
7100 /* It is stepi or nexti. We always want to stop stepping after
7103 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7104 end_stepping_range (ecs
);
7108 if (stop_pc_sal
.line
== 0)
7110 /* We have no line number information. That means to stop
7111 stepping (does this always happen right after one instruction,
7112 when we do "s" in a function with no line numbers,
7113 or can this happen as a result of a return or longjmp?). */
7115 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7116 end_stepping_range (ecs
);
7120 /* Look for "calls" to inlined functions, part one. If the inline
7121 frame machinery detected some skipped call sites, we have entered
7122 a new inline function. */
7124 if (frame_id_eq (get_frame_id (get_current_frame ()),
7125 ecs
->event_thread
->control
.step_frame_id
)
7126 && inline_skipped_frames (ecs
->event_thread
))
7129 fprintf_unfiltered (gdb_stdlog
,
7130 "infrun: stepped into inlined function\n");
7132 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7134 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7136 /* For "step", we're going to stop. But if the call site
7137 for this inlined function is on the same source line as
7138 we were previously stepping, go down into the function
7139 first. Otherwise stop at the call site. */
7141 if (call_sal
.line
== ecs
->event_thread
->current_line
7142 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7144 step_into_inline_frame (ecs
->event_thread
);
7145 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7152 end_stepping_range (ecs
);
7157 /* For "next", we should stop at the call site if it is on a
7158 different source line. Otherwise continue through the
7159 inlined function. */
7160 if (call_sal
.line
== ecs
->event_thread
->current_line
7161 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7164 end_stepping_range (ecs
);
7169 /* Look for "calls" to inlined functions, part two. If we are still
7170 in the same real function we were stepping through, but we have
7171 to go further up to find the exact frame ID, we are stepping
7172 through a more inlined call beyond its call site. */
7174 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7175 && !frame_id_eq (get_frame_id (get_current_frame ()),
7176 ecs
->event_thread
->control
.step_frame_id
)
7177 && stepped_in_from (get_current_frame (),
7178 ecs
->event_thread
->control
.step_frame_id
))
7181 fprintf_unfiltered (gdb_stdlog
,
7182 "infrun: stepping through inlined function\n");
7184 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7185 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7188 end_stepping_range (ecs
);
7192 bool refresh_step_info
= true;
7193 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7194 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7195 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7197 if (stop_pc_sal
.is_stmt
)
7199 /* We are at the start of a different line. So stop. Note that
7200 we don't stop if we step into the middle of a different line.
7201 That is said to make things like for (;;) statements work
7204 fprintf_unfiltered (gdb_stdlog
,
7205 "infrun: stepped to a different line\n");
7206 end_stepping_range (ecs
);
7209 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7210 ecs
->event_thread
->control
.step_frame_id
))
7212 /* We are at the start of a different line, however, this line is
7213 not marked as a statement, and we have not changed frame. We
7214 ignore this line table entry, and continue stepping forward,
7215 looking for a better place to stop. */
7216 refresh_step_info
= false;
7218 fprintf_unfiltered (gdb_stdlog
,
7219 "infrun: stepped to a different line, but "
7220 "it's not the start of a statement\n");
7224 /* We aren't done stepping.
7226 Optimize by setting the stepping range to the line.
7227 (We might not be in the original line, but if we entered a
7228 new line in mid-statement, we continue stepping. This makes
7229 things like for(;;) statements work better.)
7231 If we entered a SAL that indicates a non-statement line table entry,
7232 then we update the stepping range, but we don't update the step info,
7233 which includes things like the line number we are stepping away from.
7234 This means we will stop when we find a line table entry that is marked
7235 as is-statement, even if it matches the non-statement one we just
7238 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7239 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7240 ecs
->event_thread
->control
.may_range_step
= 1;
7241 if (refresh_step_info
)
7242 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7245 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7249 /* In all-stop mode, if we're currently stepping but have stopped in
7250 some other thread, we may need to switch back to the stepped
7251 thread. Returns true we set the inferior running, false if we left
7252 it stopped (and the event needs further processing). */
7255 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7257 if (!target_is_non_stop_p ())
7259 struct thread_info
*stepping_thread
;
7261 /* If any thread is blocked on some internal breakpoint, and we
7262 simply need to step over that breakpoint to get it going
7263 again, do that first. */
7265 /* However, if we see an event for the stepping thread, then we
7266 know all other threads have been moved past their breakpoints
7267 already. Let the caller check whether the step is finished,
7268 etc., before deciding to move it past a breakpoint. */
7269 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7272 /* Check if the current thread is blocked on an incomplete
7273 step-over, interrupted by a random signal. */
7274 if (ecs
->event_thread
->control
.trap_expected
7275 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7279 fprintf_unfiltered (gdb_stdlog
,
7280 "infrun: need to finish step-over of [%s]\n",
7281 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7287 /* Check if the current thread is blocked by a single-step
7288 breakpoint of another thread. */
7289 if (ecs
->hit_singlestep_breakpoint
)
7293 fprintf_unfiltered (gdb_stdlog
,
7294 "infrun: need to step [%s] over single-step "
7296 target_pid_to_str (ecs
->ptid
).c_str ());
7302 /* If this thread needs yet another step-over (e.g., stepping
7303 through a delay slot), do it first before moving on to
7305 if (thread_still_needs_step_over (ecs
->event_thread
))
7309 fprintf_unfiltered (gdb_stdlog
,
7310 "infrun: thread [%s] still needs step-over\n",
7311 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7317 /* If scheduler locking applies even if not stepping, there's no
7318 need to walk over threads. Above we've checked whether the
7319 current thread is stepping. If some other thread not the
7320 event thread is stepping, then it must be that scheduler
7321 locking is not in effect. */
7322 if (schedlock_applies (ecs
->event_thread
))
7325 /* Otherwise, we no longer expect a trap in the current thread.
7326 Clear the trap_expected flag before switching back -- this is
7327 what keep_going does as well, if we call it. */
7328 ecs
->event_thread
->control
.trap_expected
= 0;
7330 /* Likewise, clear the signal if it should not be passed. */
7331 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7332 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7334 /* Do all pending step-overs before actually proceeding with
7336 if (start_step_over ())
7338 prepare_to_wait (ecs
);
7342 /* Look for the stepping/nexting thread. */
7343 stepping_thread
= NULL
;
7345 for (thread_info
*tp
: all_non_exited_threads ())
7347 switch_to_thread_no_regs (tp
);
7349 /* Ignore threads of processes the caller is not
7352 && (tp
->inf
->process_target () != ecs
->target
7353 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7356 /* When stepping over a breakpoint, we lock all threads
7357 except the one that needs to move past the breakpoint.
7358 If a non-event thread has this set, the "incomplete
7359 step-over" check above should have caught it earlier. */
7360 if (tp
->control
.trap_expected
)
7362 internal_error (__FILE__
, __LINE__
,
7363 "[%s] has inconsistent state: "
7364 "trap_expected=%d\n",
7365 target_pid_to_str (tp
->ptid
).c_str (),
7366 tp
->control
.trap_expected
);
7369 /* Did we find the stepping thread? */
7370 if (tp
->control
.step_range_end
)
7372 /* Yep. There should only one though. */
7373 gdb_assert (stepping_thread
== NULL
);
7375 /* The event thread is handled at the top, before we
7377 gdb_assert (tp
!= ecs
->event_thread
);
7379 /* If some thread other than the event thread is
7380 stepping, then scheduler locking can't be in effect,
7381 otherwise we wouldn't have resumed the current event
7382 thread in the first place. */
7383 gdb_assert (!schedlock_applies (tp
));
7385 stepping_thread
= tp
;
7389 if (stepping_thread
!= NULL
)
7392 fprintf_unfiltered (gdb_stdlog
,
7393 "infrun: switching back to stepped thread\n");
7395 if (keep_going_stepped_thread (stepping_thread
))
7397 prepare_to_wait (ecs
);
7402 switch_to_thread (ecs
->event_thread
);
7408 /* Set a previously stepped thread back to stepping. Returns true on
7409 success, false if the resume is not possible (e.g., the thread
7413 keep_going_stepped_thread (struct thread_info
*tp
)
7415 struct frame_info
*frame
;
7416 struct execution_control_state ecss
;
7417 struct execution_control_state
*ecs
= &ecss
;
7419 /* If the stepping thread exited, then don't try to switch back and
7420 resume it, which could fail in several different ways depending
7421 on the target. Instead, just keep going.
7423 We can find a stepping dead thread in the thread list in two
7426 - The target supports thread exit events, and when the target
7427 tries to delete the thread from the thread list, inferior_ptid
7428 pointed at the exiting thread. In such case, calling
7429 delete_thread does not really remove the thread from the list;
7430 instead, the thread is left listed, with 'exited' state.
7432 - The target's debug interface does not support thread exit
7433 events, and so we have no idea whatsoever if the previously
7434 stepping thread is still alive. For that reason, we need to
7435 synchronously query the target now. */
7437 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7440 fprintf_unfiltered (gdb_stdlog
,
7441 "infrun: not resuming previously "
7442 "stepped thread, it has vanished\n");
7449 fprintf_unfiltered (gdb_stdlog
,
7450 "infrun: resuming previously stepped thread\n");
7452 reset_ecs (ecs
, tp
);
7453 switch_to_thread (tp
);
7455 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7456 frame
= get_current_frame ();
7458 /* If the PC of the thread we were trying to single-step has
7459 changed, then that thread has trapped or been signaled, but the
7460 event has not been reported to GDB yet. Re-poll the target
7461 looking for this particular thread's event (i.e. temporarily
7462 enable schedlock) by:
7464 - setting a break at the current PC
7465 - resuming that particular thread, only (by setting trap
7468 This prevents us continuously moving the single-step breakpoint
7469 forward, one instruction at a time, overstepping. */
7471 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7476 fprintf_unfiltered (gdb_stdlog
,
7477 "infrun: expected thread advanced also (%s -> %s)\n",
7478 paddress (target_gdbarch (), tp
->prev_pc
),
7479 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7481 /* Clear the info of the previous step-over, as it's no longer
7482 valid (if the thread was trying to step over a breakpoint, it
7483 has already succeeded). It's what keep_going would do too,
7484 if we called it. Do this before trying to insert the sss
7485 breakpoint, otherwise if we were previously trying to step
7486 over this exact address in another thread, the breakpoint is
7488 clear_step_over_info ();
7489 tp
->control
.trap_expected
= 0;
7491 insert_single_step_breakpoint (get_frame_arch (frame
),
7492 get_frame_address_space (frame
),
7493 tp
->suspend
.stop_pc
);
7496 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7497 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7502 fprintf_unfiltered (gdb_stdlog
,
7503 "infrun: expected thread still hasn't advanced\n");
7505 keep_going_pass_signal (ecs
);
7510 /* Is thread TP in the middle of (software or hardware)
7511 single-stepping? (Note the result of this function must never be
7512 passed directly as target_resume's STEP parameter.) */
7515 currently_stepping (struct thread_info
*tp
)
7517 return ((tp
->control
.step_range_end
7518 && tp
->control
.step_resume_breakpoint
== NULL
)
7519 || tp
->control
.trap_expected
7520 || tp
->stepped_breakpoint
7521 || bpstat_should_step ());
7524 /* Inferior has stepped into a subroutine call with source code that
7525 we should not step over. Do step to the first line of code in
7529 handle_step_into_function (struct gdbarch
*gdbarch
,
7530 struct execution_control_state
*ecs
)
7532 fill_in_stop_func (gdbarch
, ecs
);
7534 compunit_symtab
*cust
7535 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7536 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7537 ecs
->stop_func_start
7538 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7540 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7541 /* Use the step_resume_break to step until the end of the prologue,
7542 even if that involves jumps (as it seems to on the vax under
7544 /* If the prologue ends in the middle of a source line, continue to
7545 the end of that source line (if it is still within the function).
7546 Otherwise, just go to end of prologue. */
7547 if (stop_func_sal
.end
7548 && stop_func_sal
.pc
!= ecs
->stop_func_start
7549 && stop_func_sal
.end
< ecs
->stop_func_end
)
7550 ecs
->stop_func_start
= stop_func_sal
.end
;
7552 /* Architectures which require breakpoint adjustment might not be able
7553 to place a breakpoint at the computed address. If so, the test
7554 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7555 ecs->stop_func_start to an address at which a breakpoint may be
7556 legitimately placed.
7558 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7559 made, GDB will enter an infinite loop when stepping through
7560 optimized code consisting of VLIW instructions which contain
7561 subinstructions corresponding to different source lines. On
7562 FR-V, it's not permitted to place a breakpoint on any but the
7563 first subinstruction of a VLIW instruction. When a breakpoint is
7564 set, GDB will adjust the breakpoint address to the beginning of
7565 the VLIW instruction. Thus, we need to make the corresponding
7566 adjustment here when computing the stop address. */
7568 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7570 ecs
->stop_func_start
7571 = gdbarch_adjust_breakpoint_address (gdbarch
,
7572 ecs
->stop_func_start
);
7575 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7577 /* We are already there: stop now. */
7578 end_stepping_range (ecs
);
7583 /* Put the step-breakpoint there and go until there. */
7584 symtab_and_line sr_sal
;
7585 sr_sal
.pc
= ecs
->stop_func_start
;
7586 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7587 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7589 /* Do not specify what the fp should be when we stop since on
7590 some machines the prologue is where the new fp value is
7592 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7594 /* And make sure stepping stops right away then. */
7595 ecs
->event_thread
->control
.step_range_end
7596 = ecs
->event_thread
->control
.step_range_start
;
7601 /* Inferior has stepped backward into a subroutine call with source
7602 code that we should not step over. Do step to the beginning of the
7603 last line of code in it. */
7606 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7607 struct execution_control_state
*ecs
)
7609 struct compunit_symtab
*cust
;
7610 struct symtab_and_line stop_func_sal
;
7612 fill_in_stop_func (gdbarch
, ecs
);
7614 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7615 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7616 ecs
->stop_func_start
7617 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7619 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7621 /* OK, we're just going to keep stepping here. */
7622 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7624 /* We're there already. Just stop stepping now. */
7625 end_stepping_range (ecs
);
7629 /* Else just reset the step range and keep going.
7630 No step-resume breakpoint, they don't work for
7631 epilogues, which can have multiple entry paths. */
7632 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7633 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7639 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7640 This is used to both functions and to skip over code. */
7643 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7644 struct symtab_and_line sr_sal
,
7645 struct frame_id sr_id
,
7646 enum bptype sr_type
)
7648 /* There should never be more than one step-resume or longjmp-resume
7649 breakpoint per thread, so we should never be setting a new
7650 step_resume_breakpoint when one is already active. */
7651 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7652 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7655 fprintf_unfiltered (gdb_stdlog
,
7656 "infrun: inserting step-resume breakpoint at %s\n",
7657 paddress (gdbarch
, sr_sal
.pc
));
7659 inferior_thread ()->control
.step_resume_breakpoint
7660 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7664 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7665 struct symtab_and_line sr_sal
,
7666 struct frame_id sr_id
)
7668 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7673 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7674 This is used to skip a potential signal handler.
7676 This is called with the interrupted function's frame. The signal
7677 handler, when it returns, will resume the interrupted function at
7681 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7683 gdb_assert (return_frame
!= NULL
);
7685 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7687 symtab_and_line sr_sal
;
7688 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7689 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7690 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7692 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7693 get_stack_frame_id (return_frame
),
7697 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7698 is used to skip a function after stepping into it (for "next" or if
7699 the called function has no debugging information).
7701 The current function has almost always been reached by single
7702 stepping a call or return instruction. NEXT_FRAME belongs to the
7703 current function, and the breakpoint will be set at the caller's
7706 This is a separate function rather than reusing
7707 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7708 get_prev_frame, which may stop prematurely (see the implementation
7709 of frame_unwind_caller_id for an example). */
7712 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7714 /* We shouldn't have gotten here if we don't know where the call site
7716 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7718 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7720 symtab_and_line sr_sal
;
7721 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7722 frame_unwind_caller_pc (next_frame
));
7723 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7724 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7726 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7727 frame_unwind_caller_id (next_frame
));
7730 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7731 new breakpoint at the target of a jmp_buf. The handling of
7732 longjmp-resume uses the same mechanisms used for handling
7733 "step-resume" breakpoints. */
7736 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7738 /* There should never be more than one longjmp-resume breakpoint per
7739 thread, so we should never be setting a new
7740 longjmp_resume_breakpoint when one is already active. */
7741 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7744 fprintf_unfiltered (gdb_stdlog
,
7745 "infrun: inserting longjmp-resume breakpoint at %s\n",
7746 paddress (gdbarch
, pc
));
7748 inferior_thread ()->control
.exception_resume_breakpoint
=
7749 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7752 /* Insert an exception resume breakpoint. TP is the thread throwing
7753 the exception. The block B is the block of the unwinder debug hook
7754 function. FRAME is the frame corresponding to the call to this
7755 function. SYM is the symbol of the function argument holding the
7756 target PC of the exception. */
7759 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7760 const struct block
*b
,
7761 struct frame_info
*frame
,
7766 struct block_symbol vsym
;
7767 struct value
*value
;
7769 struct breakpoint
*bp
;
7771 vsym
= lookup_symbol_search_name (sym
->search_name (),
7773 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7774 /* If the value was optimized out, revert to the old behavior. */
7775 if (! value_optimized_out (value
))
7777 handler
= value_as_address (value
);
7780 fprintf_unfiltered (gdb_stdlog
,
7781 "infrun: exception resume at %lx\n",
7782 (unsigned long) handler
);
7784 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7786 bp_exception_resume
).release ();
7788 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7791 bp
->thread
= tp
->global_num
;
7792 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7795 catch (const gdb_exception_error
&e
)
7797 /* We want to ignore errors here. */
7801 /* A helper for check_exception_resume that sets an
7802 exception-breakpoint based on a SystemTap probe. */
7805 insert_exception_resume_from_probe (struct thread_info
*tp
,
7806 const struct bound_probe
*probe
,
7807 struct frame_info
*frame
)
7809 struct value
*arg_value
;
7811 struct breakpoint
*bp
;
7813 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7817 handler
= value_as_address (arg_value
);
7820 fprintf_unfiltered (gdb_stdlog
,
7821 "infrun: exception resume at %s\n",
7822 paddress (probe
->objfile
->arch (),
7825 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7826 handler
, bp_exception_resume
).release ();
7827 bp
->thread
= tp
->global_num
;
7828 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7831 /* This is called when an exception has been intercepted. Check to
7832 see whether the exception's destination is of interest, and if so,
7833 set an exception resume breakpoint there. */
7836 check_exception_resume (struct execution_control_state
*ecs
,
7837 struct frame_info
*frame
)
7839 struct bound_probe probe
;
7840 struct symbol
*func
;
7842 /* First see if this exception unwinding breakpoint was set via a
7843 SystemTap probe point. If so, the probe has two arguments: the
7844 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7845 set a breakpoint there. */
7846 probe
= find_probe_by_pc (get_frame_pc (frame
));
7849 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7853 func
= get_frame_function (frame
);
7859 const struct block
*b
;
7860 struct block_iterator iter
;
7864 /* The exception breakpoint is a thread-specific breakpoint on
7865 the unwinder's debug hook, declared as:
7867 void _Unwind_DebugHook (void *cfa, void *handler);
7869 The CFA argument indicates the frame to which control is
7870 about to be transferred. HANDLER is the destination PC.
7872 We ignore the CFA and set a temporary breakpoint at HANDLER.
7873 This is not extremely efficient but it avoids issues in gdb
7874 with computing the DWARF CFA, and it also works even in weird
7875 cases such as throwing an exception from inside a signal
7878 b
= SYMBOL_BLOCK_VALUE (func
);
7879 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7881 if (!SYMBOL_IS_ARGUMENT (sym
))
7888 insert_exception_resume_breakpoint (ecs
->event_thread
,
7894 catch (const gdb_exception_error
&e
)
7900 stop_waiting (struct execution_control_state
*ecs
)
7903 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7905 /* Let callers know we don't want to wait for the inferior anymore. */
7906 ecs
->wait_some_more
= 0;
7908 /* If all-stop, but there exists a non-stop target, stop all
7909 threads now that we're presenting the stop to the user. */
7910 if (!non_stop
&& exists_non_stop_target ())
7911 stop_all_threads ();
7914 /* Like keep_going, but passes the signal to the inferior, even if the
7915 signal is set to nopass. */
7918 keep_going_pass_signal (struct execution_control_state
*ecs
)
7920 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7921 gdb_assert (!ecs
->event_thread
->resumed
);
7923 /* Save the pc before execution, to compare with pc after stop. */
7924 ecs
->event_thread
->prev_pc
7925 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7927 if (ecs
->event_thread
->control
.trap_expected
)
7929 struct thread_info
*tp
= ecs
->event_thread
;
7932 fprintf_unfiltered (gdb_stdlog
,
7933 "infrun: %s has trap_expected set, "
7934 "resuming to collect trap\n",
7935 target_pid_to_str (tp
->ptid
).c_str ());
7937 /* We haven't yet gotten our trap, and either: intercepted a
7938 non-signal event (e.g., a fork); or took a signal which we
7939 are supposed to pass through to the inferior. Simply
7941 resume (ecs
->event_thread
->suspend
.stop_signal
);
7943 else if (step_over_info_valid_p ())
7945 /* Another thread is stepping over a breakpoint in-line. If
7946 this thread needs a step-over too, queue the request. In
7947 either case, this resume must be deferred for later. */
7948 struct thread_info
*tp
= ecs
->event_thread
;
7950 if (ecs
->hit_singlestep_breakpoint
7951 || thread_still_needs_step_over (tp
))
7954 fprintf_unfiltered (gdb_stdlog
,
7955 "infrun: step-over already in progress: "
7956 "step-over for %s deferred\n",
7957 target_pid_to_str (tp
->ptid
).c_str ());
7958 thread_step_over_chain_enqueue (tp
);
7963 fprintf_unfiltered (gdb_stdlog
,
7964 "infrun: step-over in progress: "
7965 "resume of %s deferred\n",
7966 target_pid_to_str (tp
->ptid
).c_str ());
7971 struct regcache
*regcache
= get_current_regcache ();
7974 step_over_what step_what
;
7976 /* Either the trap was not expected, but we are continuing
7977 anyway (if we got a signal, the user asked it be passed to
7980 We got our expected trap, but decided we should resume from
7983 We're going to run this baby now!
7985 Note that insert_breakpoints won't try to re-insert
7986 already inserted breakpoints. Therefore, we don't
7987 care if breakpoints were already inserted, or not. */
7989 /* If we need to step over a breakpoint, and we're not using
7990 displaced stepping to do so, insert all breakpoints
7991 (watchpoints, etc.) but the one we're stepping over, step one
7992 instruction, and then re-insert the breakpoint when that step
7995 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7997 remove_bp
= (ecs
->hit_singlestep_breakpoint
7998 || (step_what
& STEP_OVER_BREAKPOINT
));
7999 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
8001 /* We can't use displaced stepping if we need to step past a
8002 watchpoint. The instruction copied to the scratch pad would
8003 still trigger the watchpoint. */
8005 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
8007 set_step_over_info (regcache
->aspace (),
8008 regcache_read_pc (regcache
), remove_wps
,
8009 ecs
->event_thread
->global_num
);
8011 else if (remove_wps
)
8012 set_step_over_info (NULL
, 0, remove_wps
, -1);
8014 /* If we now need to do an in-line step-over, we need to stop
8015 all other threads. Note this must be done before
8016 insert_breakpoints below, because that removes the breakpoint
8017 we're about to step over, otherwise other threads could miss
8019 if (step_over_info_valid_p () && target_is_non_stop_p ())
8020 stop_all_threads ();
8022 /* Stop stepping if inserting breakpoints fails. */
8025 insert_breakpoints ();
8027 catch (const gdb_exception_error
&e
)
8029 exception_print (gdb_stderr
, e
);
8031 clear_step_over_info ();
8035 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8037 resume (ecs
->event_thread
->suspend
.stop_signal
);
8040 prepare_to_wait (ecs
);
8043 /* Called when we should continue running the inferior, because the
8044 current event doesn't cause a user visible stop. This does the
8045 resuming part; waiting for the next event is done elsewhere. */
8048 keep_going (struct execution_control_state
*ecs
)
8050 if (ecs
->event_thread
->control
.trap_expected
8051 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
8052 ecs
->event_thread
->control
.trap_expected
= 0;
8054 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
8055 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8056 keep_going_pass_signal (ecs
);
8059 /* This function normally comes after a resume, before
8060 handle_inferior_event exits. It takes care of any last bits of
8061 housekeeping, and sets the all-important wait_some_more flag. */
8064 prepare_to_wait (struct execution_control_state
*ecs
)
8067 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
8069 ecs
->wait_some_more
= 1;
8071 if (!target_is_async_p ())
8072 mark_infrun_async_event_handler ();
8075 /* We are done with the step range of a step/next/si/ni command.
8076 Called once for each n of a "step n" operation. */
8079 end_stepping_range (struct execution_control_state
*ecs
)
8081 ecs
->event_thread
->control
.stop_step
= 1;
8085 /* Several print_*_reason functions to print why the inferior has stopped.
8086 We always print something when the inferior exits, or receives a signal.
8087 The rest of the cases are dealt with later on in normal_stop and
8088 print_it_typical. Ideally there should be a call to one of these
8089 print_*_reason functions functions from handle_inferior_event each time
8090 stop_waiting is called.
8092 Note that we don't call these directly, instead we delegate that to
8093 the interpreters, through observers. Interpreters then call these
8094 with whatever uiout is right. */
8097 print_end_stepping_range_reason (struct ui_out
*uiout
)
8099 /* For CLI-like interpreters, print nothing. */
8101 if (uiout
->is_mi_like_p ())
8103 uiout
->field_string ("reason",
8104 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8109 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8111 annotate_signalled ();
8112 if (uiout
->is_mi_like_p ())
8114 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8115 uiout
->text ("\nProgram terminated with signal ");
8116 annotate_signal_name ();
8117 uiout
->field_string ("signal-name",
8118 gdb_signal_to_name (siggnal
));
8119 annotate_signal_name_end ();
8121 annotate_signal_string ();
8122 uiout
->field_string ("signal-meaning",
8123 gdb_signal_to_string (siggnal
));
8124 annotate_signal_string_end ();
8125 uiout
->text (".\n");
8126 uiout
->text ("The program no longer exists.\n");
8130 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8132 struct inferior
*inf
= current_inferior ();
8133 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8135 annotate_exited (exitstatus
);
8138 if (uiout
->is_mi_like_p ())
8139 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8140 std::string exit_code_str
8141 = string_printf ("0%o", (unsigned int) exitstatus
);
8142 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8143 plongest (inf
->num
), pidstr
.c_str (),
8144 string_field ("exit-code", exit_code_str
.c_str ()));
8148 if (uiout
->is_mi_like_p ())
8150 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8151 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8152 plongest (inf
->num
), pidstr
.c_str ());
8156 /* Some targets/architectures can do extra processing/display of
8157 segmentation faults. E.g., Intel MPX boundary faults.
8158 Call the architecture dependent function to handle the fault. */
8161 handle_segmentation_fault (struct ui_out
*uiout
)
8163 struct regcache
*regcache
= get_current_regcache ();
8164 struct gdbarch
*gdbarch
= regcache
->arch ();
8166 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8167 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8171 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8173 struct thread_info
*thr
= inferior_thread ();
8177 if (uiout
->is_mi_like_p ())
8179 else if (show_thread_that_caused_stop ())
8183 uiout
->text ("\nThread ");
8184 uiout
->field_string ("thread-id", print_thread_id (thr
));
8186 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8189 uiout
->text (" \"");
8190 uiout
->field_string ("name", name
);
8195 uiout
->text ("\nProgram");
8197 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8198 uiout
->text (" stopped");
8201 uiout
->text (" received signal ");
8202 annotate_signal_name ();
8203 if (uiout
->is_mi_like_p ())
8205 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8206 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8207 annotate_signal_name_end ();
8209 annotate_signal_string ();
8210 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8212 if (siggnal
== GDB_SIGNAL_SEGV
)
8213 handle_segmentation_fault (uiout
);
8215 annotate_signal_string_end ();
8217 uiout
->text (".\n");
8221 print_no_history_reason (struct ui_out
*uiout
)
8223 uiout
->text ("\nNo more reverse-execution history.\n");
8226 /* Print current location without a level number, if we have changed
8227 functions or hit a breakpoint. Print source line if we have one.
8228 bpstat_print contains the logic deciding in detail what to print,
8229 based on the event(s) that just occurred. */
8232 print_stop_location (struct target_waitstatus
*ws
)
8235 enum print_what source_flag
;
8236 int do_frame_printing
= 1;
8237 struct thread_info
*tp
= inferior_thread ();
8239 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8243 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8244 should) carry around the function and does (or should) use
8245 that when doing a frame comparison. */
8246 if (tp
->control
.stop_step
8247 && frame_id_eq (tp
->control
.step_frame_id
,
8248 get_frame_id (get_current_frame ()))
8249 && (tp
->control
.step_start_function
8250 == find_pc_function (tp
->suspend
.stop_pc
)))
8252 /* Finished step, just print source line. */
8253 source_flag
= SRC_LINE
;
8257 /* Print location and source line. */
8258 source_flag
= SRC_AND_LOC
;
8261 case PRINT_SRC_AND_LOC
:
8262 /* Print location and source line. */
8263 source_flag
= SRC_AND_LOC
;
8265 case PRINT_SRC_ONLY
:
8266 source_flag
= SRC_LINE
;
8269 /* Something bogus. */
8270 source_flag
= SRC_LINE
;
8271 do_frame_printing
= 0;
8274 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8277 /* The behavior of this routine with respect to the source
8279 SRC_LINE: Print only source line
8280 LOCATION: Print only location
8281 SRC_AND_LOC: Print location and source line. */
8282 if (do_frame_printing
)
8283 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8289 print_stop_event (struct ui_out
*uiout
, bool displays
)
8291 struct target_waitstatus last
;
8292 struct thread_info
*tp
;
8294 get_last_target_status (nullptr, nullptr, &last
);
8297 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8299 print_stop_location (&last
);
8301 /* Display the auto-display expressions. */
8306 tp
= inferior_thread ();
8307 if (tp
->thread_fsm
!= NULL
8308 && tp
->thread_fsm
->finished_p ())
8310 struct return_value_info
*rv
;
8312 rv
= tp
->thread_fsm
->return_value ();
8314 print_return_value (uiout
, rv
);
8321 maybe_remove_breakpoints (void)
8323 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8325 if (remove_breakpoints ())
8327 target_terminal::ours_for_output ();
8328 printf_filtered (_("Cannot remove breakpoints because "
8329 "program is no longer writable.\nFurther "
8330 "execution is probably impossible.\n"));
8335 /* The execution context that just caused a normal stop. */
8342 DISABLE_COPY_AND_ASSIGN (stop_context
);
8344 bool changed () const;
8349 /* The event PTID. */
8353 /* If stopp for a thread event, this is the thread that caused the
8355 struct thread_info
*thread
;
8357 /* The inferior that caused the stop. */
8361 /* Initializes a new stop context. If stopped for a thread event, this
8362 takes a strong reference to the thread. */
8364 stop_context::stop_context ()
8366 stop_id
= get_stop_id ();
8367 ptid
= inferior_ptid
;
8368 inf_num
= current_inferior ()->num
;
8370 if (inferior_ptid
!= null_ptid
)
8372 /* Take a strong reference so that the thread can't be deleted
8374 thread
= inferior_thread ();
8381 /* Release a stop context previously created with save_stop_context.
8382 Releases the strong reference to the thread as well. */
8384 stop_context::~stop_context ()
8390 /* Return true if the current context no longer matches the saved stop
8394 stop_context::changed () const
8396 if (ptid
!= inferior_ptid
)
8398 if (inf_num
!= current_inferior ()->num
)
8400 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8402 if (get_stop_id () != stop_id
)
8412 struct target_waitstatus last
;
8414 get_last_target_status (nullptr, nullptr, &last
);
8418 /* If an exception is thrown from this point on, make sure to
8419 propagate GDB's knowledge of the executing state to the
8420 frontend/user running state. A QUIT is an easy exception to see
8421 here, so do this before any filtered output. */
8423 ptid_t finish_ptid
= null_ptid
;
8426 finish_ptid
= minus_one_ptid
;
8427 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8428 || last
.kind
== TARGET_WAITKIND_EXITED
)
8430 /* On some targets, we may still have live threads in the
8431 inferior when we get a process exit event. E.g., for
8432 "checkpoint", when the current checkpoint/fork exits,
8433 linux-fork.c automatically switches to another fork from
8434 within target_mourn_inferior. */
8435 if (inferior_ptid
!= null_ptid
)
8436 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8438 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8439 finish_ptid
= inferior_ptid
;
8441 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8442 if (finish_ptid
!= null_ptid
)
8444 maybe_finish_thread_state
.emplace
8445 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8448 /* As we're presenting a stop, and potentially removing breakpoints,
8449 update the thread list so we can tell whether there are threads
8450 running on the target. With target remote, for example, we can
8451 only learn about new threads when we explicitly update the thread
8452 list. Do this before notifying the interpreters about signal
8453 stops, end of stepping ranges, etc., so that the "new thread"
8454 output is emitted before e.g., "Program received signal FOO",
8455 instead of after. */
8456 update_thread_list ();
8458 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8459 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8461 /* As with the notification of thread events, we want to delay
8462 notifying the user that we've switched thread context until
8463 the inferior actually stops.
8465 There's no point in saying anything if the inferior has exited.
8466 Note that SIGNALLED here means "exited with a signal", not
8467 "received a signal".
8469 Also skip saying anything in non-stop mode. In that mode, as we
8470 don't want GDB to switch threads behind the user's back, to avoid
8471 races where the user is typing a command to apply to thread x,
8472 but GDB switches to thread y before the user finishes entering
8473 the command, fetch_inferior_event installs a cleanup to restore
8474 the current thread back to the thread the user had selected right
8475 after this event is handled, so we're not really switching, only
8476 informing of a stop. */
8478 && previous_inferior_ptid
!= inferior_ptid
8479 && target_has_execution
8480 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8481 && last
.kind
!= TARGET_WAITKIND_EXITED
8482 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8484 SWITCH_THRU_ALL_UIS ()
8486 target_terminal::ours_for_output ();
8487 printf_filtered (_("[Switching to %s]\n"),
8488 target_pid_to_str (inferior_ptid
).c_str ());
8489 annotate_thread_changed ();
8491 previous_inferior_ptid
= inferior_ptid
;
8494 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8496 SWITCH_THRU_ALL_UIS ()
8497 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8499 target_terminal::ours_for_output ();
8500 printf_filtered (_("No unwaited-for children left.\n"));
8504 /* Note: this depends on the update_thread_list call above. */
8505 maybe_remove_breakpoints ();
8507 /* If an auto-display called a function and that got a signal,
8508 delete that auto-display to avoid an infinite recursion. */
8510 if (stopped_by_random_signal
)
8511 disable_current_display ();
8513 SWITCH_THRU_ALL_UIS ()
8515 async_enable_stdin ();
8518 /* Let the user/frontend see the threads as stopped. */
8519 maybe_finish_thread_state
.reset ();
8521 /* Select innermost stack frame - i.e., current frame is frame 0,
8522 and current location is based on that. Handle the case where the
8523 dummy call is returning after being stopped. E.g. the dummy call
8524 previously hit a breakpoint. (If the dummy call returns
8525 normally, we won't reach here.) Do this before the stop hook is
8526 run, so that it doesn't get to see the temporary dummy frame,
8527 which is not where we'll present the stop. */
8528 if (has_stack_frames ())
8530 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8532 /* Pop the empty frame that contains the stack dummy. This
8533 also restores inferior state prior to the call (struct
8534 infcall_suspend_state). */
8535 struct frame_info
*frame
= get_current_frame ();
8537 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8539 /* frame_pop calls reinit_frame_cache as the last thing it
8540 does which means there's now no selected frame. */
8543 select_frame (get_current_frame ());
8545 /* Set the current source location. */
8546 set_current_sal_from_frame (get_current_frame ());
8549 /* Look up the hook_stop and run it (CLI internally handles problem
8550 of stop_command's pre-hook not existing). */
8551 if (stop_command
!= NULL
)
8553 stop_context saved_context
;
8557 execute_cmd_pre_hook (stop_command
);
8559 catch (const gdb_exception
&ex
)
8561 exception_fprintf (gdb_stderr
, ex
,
8562 "Error while running hook_stop:\n");
8565 /* If the stop hook resumes the target, then there's no point in
8566 trying to notify about the previous stop; its context is
8567 gone. Likewise if the command switches thread or inferior --
8568 the observers would print a stop for the wrong
8570 if (saved_context
.changed ())
8574 /* Notify observers about the stop. This is where the interpreters
8575 print the stop event. */
8576 if (inferior_ptid
!= null_ptid
)
8577 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8580 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8582 annotate_stopped ();
8584 if (target_has_execution
)
8586 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8587 && last
.kind
!= TARGET_WAITKIND_EXITED
8588 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8589 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8590 Delete any breakpoint that is to be deleted at the next stop. */
8591 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8594 /* Try to get rid of automatically added inferiors that are no
8595 longer needed. Keeping those around slows down things linearly.
8596 Note that this never removes the current inferior. */
8603 signal_stop_state (int signo
)
8605 return signal_stop
[signo
];
8609 signal_print_state (int signo
)
8611 return signal_print
[signo
];
8615 signal_pass_state (int signo
)
8617 return signal_program
[signo
];
8621 signal_cache_update (int signo
)
8625 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8626 signal_cache_update (signo
);
8631 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8632 && signal_print
[signo
] == 0
8633 && signal_program
[signo
] == 1
8634 && signal_catch
[signo
] == 0);
8638 signal_stop_update (int signo
, int state
)
8640 int ret
= signal_stop
[signo
];
8642 signal_stop
[signo
] = state
;
8643 signal_cache_update (signo
);
8648 signal_print_update (int signo
, int state
)
8650 int ret
= signal_print
[signo
];
8652 signal_print
[signo
] = state
;
8653 signal_cache_update (signo
);
8658 signal_pass_update (int signo
, int state
)
8660 int ret
= signal_program
[signo
];
8662 signal_program
[signo
] = state
;
8663 signal_cache_update (signo
);
8667 /* Update the global 'signal_catch' from INFO and notify the
8671 signal_catch_update (const unsigned int *info
)
8675 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8676 signal_catch
[i
] = info
[i
] > 0;
8677 signal_cache_update (-1);
8678 target_pass_signals (signal_pass
);
8682 sig_print_header (void)
8684 printf_filtered (_("Signal Stop\tPrint\tPass "
8685 "to program\tDescription\n"));
8689 sig_print_info (enum gdb_signal oursig
)
8691 const char *name
= gdb_signal_to_name (oursig
);
8692 int name_padding
= 13 - strlen (name
);
8694 if (name_padding
<= 0)
8697 printf_filtered ("%s", name
);
8698 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8699 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8700 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8701 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8702 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8705 /* Specify how various signals in the inferior should be handled. */
8708 handle_command (const char *args
, int from_tty
)
8710 int digits
, wordlen
;
8711 int sigfirst
, siglast
;
8712 enum gdb_signal oursig
;
8717 error_no_arg (_("signal to handle"));
8720 /* Allocate and zero an array of flags for which signals to handle. */
8722 const size_t nsigs
= GDB_SIGNAL_LAST
;
8723 unsigned char sigs
[nsigs
] {};
8725 /* Break the command line up into args. */
8727 gdb_argv
built_argv (args
);
8729 /* Walk through the args, looking for signal oursigs, signal names, and
8730 actions. Signal numbers and signal names may be interspersed with
8731 actions, with the actions being performed for all signals cumulatively
8732 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8734 for (char *arg
: built_argv
)
8736 wordlen
= strlen (arg
);
8737 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8741 sigfirst
= siglast
= -1;
8743 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8745 /* Apply action to all signals except those used by the
8746 debugger. Silently skip those. */
8749 siglast
= nsigs
- 1;
8751 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8753 SET_SIGS (nsigs
, sigs
, signal_stop
);
8754 SET_SIGS (nsigs
, sigs
, signal_print
);
8756 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8758 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8760 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8762 SET_SIGS (nsigs
, sigs
, signal_print
);
8764 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8766 SET_SIGS (nsigs
, sigs
, signal_program
);
8768 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8770 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8772 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8774 SET_SIGS (nsigs
, sigs
, signal_program
);
8776 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8778 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8779 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8781 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8783 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8785 else if (digits
> 0)
8787 /* It is numeric. The numeric signal refers to our own
8788 internal signal numbering from target.h, not to host/target
8789 signal number. This is a feature; users really should be
8790 using symbolic names anyway, and the common ones like
8791 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8793 sigfirst
= siglast
= (int)
8794 gdb_signal_from_command (atoi (arg
));
8795 if (arg
[digits
] == '-')
8798 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8800 if (sigfirst
> siglast
)
8802 /* Bet he didn't figure we'd think of this case... */
8803 std::swap (sigfirst
, siglast
);
8808 oursig
= gdb_signal_from_name (arg
);
8809 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8811 sigfirst
= siglast
= (int) oursig
;
8815 /* Not a number and not a recognized flag word => complain. */
8816 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8820 /* If any signal numbers or symbol names were found, set flags for
8821 which signals to apply actions to. */
8823 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8825 switch ((enum gdb_signal
) signum
)
8827 case GDB_SIGNAL_TRAP
:
8828 case GDB_SIGNAL_INT
:
8829 if (!allsigs
&& !sigs
[signum
])
8831 if (query (_("%s is used by the debugger.\n\
8832 Are you sure you want to change it? "),
8833 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8838 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8842 case GDB_SIGNAL_DEFAULT
:
8843 case GDB_SIGNAL_UNKNOWN
:
8844 /* Make sure that "all" doesn't print these. */
8853 for (int signum
= 0; signum
< nsigs
; signum
++)
8856 signal_cache_update (-1);
8857 target_pass_signals (signal_pass
);
8858 target_program_signals (signal_program
);
8862 /* Show the results. */
8863 sig_print_header ();
8864 for (; signum
< nsigs
; signum
++)
8866 sig_print_info ((enum gdb_signal
) signum
);
8873 /* Complete the "handle" command. */
8876 handle_completer (struct cmd_list_element
*ignore
,
8877 completion_tracker
&tracker
,
8878 const char *text
, const char *word
)
8880 static const char * const keywords
[] =
8894 signal_completer (ignore
, tracker
, text
, word
);
8895 complete_on_enum (tracker
, keywords
, word
, word
);
8899 gdb_signal_from_command (int num
)
8901 if (num
>= 1 && num
<= 15)
8902 return (enum gdb_signal
) num
;
8903 error (_("Only signals 1-15 are valid as numeric signals.\n\
8904 Use \"info signals\" for a list of symbolic signals."));
8907 /* Print current contents of the tables set by the handle command.
8908 It is possible we should just be printing signals actually used
8909 by the current target (but for things to work right when switching
8910 targets, all signals should be in the signal tables). */
8913 info_signals_command (const char *signum_exp
, int from_tty
)
8915 enum gdb_signal oursig
;
8917 sig_print_header ();
8921 /* First see if this is a symbol name. */
8922 oursig
= gdb_signal_from_name (signum_exp
);
8923 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8925 /* No, try numeric. */
8927 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8929 sig_print_info (oursig
);
8933 printf_filtered ("\n");
8934 /* These ugly casts brought to you by the native VAX compiler. */
8935 for (oursig
= GDB_SIGNAL_FIRST
;
8936 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8937 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8941 if (oursig
!= GDB_SIGNAL_UNKNOWN
8942 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8943 sig_print_info (oursig
);
8946 printf_filtered (_("\nUse the \"handle\" command "
8947 "to change these tables.\n"));
8950 /* The $_siginfo convenience variable is a bit special. We don't know
8951 for sure the type of the value until we actually have a chance to
8952 fetch the data. The type can change depending on gdbarch, so it is
8953 also dependent on which thread you have selected.
8955 1. making $_siginfo be an internalvar that creates a new value on
8958 2. making the value of $_siginfo be an lval_computed value. */
8960 /* This function implements the lval_computed support for reading a
8964 siginfo_value_read (struct value
*v
)
8966 LONGEST transferred
;
8968 /* If we can access registers, so can we access $_siginfo. Likewise
8970 validate_registers_access ();
8973 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8975 value_contents_all_raw (v
),
8977 TYPE_LENGTH (value_type (v
)));
8979 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8980 error (_("Unable to read siginfo"));
8983 /* This function implements the lval_computed support for writing a
8987 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8989 LONGEST transferred
;
8991 /* If we can access registers, so can we access $_siginfo. Likewise
8993 validate_registers_access ();
8995 transferred
= target_write (current_top_target (),
8996 TARGET_OBJECT_SIGNAL_INFO
,
8998 value_contents_all_raw (fromval
),
9000 TYPE_LENGTH (value_type (fromval
)));
9002 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
9003 error (_("Unable to write siginfo"));
9006 static const struct lval_funcs siginfo_value_funcs
=
9012 /* Return a new value with the correct type for the siginfo object of
9013 the current thread using architecture GDBARCH. Return a void value
9014 if there's no object available. */
9016 static struct value
*
9017 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9020 if (target_has_stack
9021 && inferior_ptid
!= null_ptid
9022 && gdbarch_get_siginfo_type_p (gdbarch
))
9024 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9026 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
9029 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
9033 /* infcall_suspend_state contains state about the program itself like its
9034 registers and any signal it received when it last stopped.
9035 This state must be restored regardless of how the inferior function call
9036 ends (either successfully, or after it hits a breakpoint or signal)
9037 if the program is to properly continue where it left off. */
9039 class infcall_suspend_state
9042 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9043 once the inferior function call has finished. */
9044 infcall_suspend_state (struct gdbarch
*gdbarch
,
9045 const struct thread_info
*tp
,
9046 struct regcache
*regcache
)
9047 : m_thread_suspend (tp
->suspend
),
9048 m_registers (new readonly_detached_regcache (*regcache
))
9050 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9052 if (gdbarch_get_siginfo_type_p (gdbarch
))
9054 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9055 size_t len
= TYPE_LENGTH (type
);
9057 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9059 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9060 siginfo_data
.get (), 0, len
) != len
)
9062 /* Errors ignored. */
9063 siginfo_data
.reset (nullptr);
9069 m_siginfo_gdbarch
= gdbarch
;
9070 m_siginfo_data
= std::move (siginfo_data
);
9074 /* Return a pointer to the stored register state. */
9076 readonly_detached_regcache
*registers () const
9078 return m_registers
.get ();
9081 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9083 void restore (struct gdbarch
*gdbarch
,
9084 struct thread_info
*tp
,
9085 struct regcache
*regcache
) const
9087 tp
->suspend
= m_thread_suspend
;
9089 if (m_siginfo_gdbarch
== gdbarch
)
9091 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9093 /* Errors ignored. */
9094 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9095 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9098 /* The inferior can be gone if the user types "print exit(0)"
9099 (and perhaps other times). */
9100 if (target_has_execution
)
9101 /* NB: The register write goes through to the target. */
9102 regcache
->restore (registers ());
9106 /* How the current thread stopped before the inferior function call was
9108 struct thread_suspend_state m_thread_suspend
;
9110 /* The registers before the inferior function call was executed. */
9111 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9113 /* Format of SIGINFO_DATA or NULL if it is not present. */
9114 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9116 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9117 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9118 content would be invalid. */
9119 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9122 infcall_suspend_state_up
9123 save_infcall_suspend_state ()
9125 struct thread_info
*tp
= inferior_thread ();
9126 struct regcache
*regcache
= get_current_regcache ();
9127 struct gdbarch
*gdbarch
= regcache
->arch ();
9129 infcall_suspend_state_up inf_state
9130 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9132 /* Having saved the current state, adjust the thread state, discarding
9133 any stop signal information. The stop signal is not useful when
9134 starting an inferior function call, and run_inferior_call will not use
9135 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9136 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9141 /* Restore inferior session state to INF_STATE. */
9144 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9146 struct thread_info
*tp
= inferior_thread ();
9147 struct regcache
*regcache
= get_current_regcache ();
9148 struct gdbarch
*gdbarch
= regcache
->arch ();
9150 inf_state
->restore (gdbarch
, tp
, regcache
);
9151 discard_infcall_suspend_state (inf_state
);
9155 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9160 readonly_detached_regcache
*
9161 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9163 return inf_state
->registers ();
9166 /* infcall_control_state contains state regarding gdb's control of the
9167 inferior itself like stepping control. It also contains session state like
9168 the user's currently selected frame. */
9170 struct infcall_control_state
9172 struct thread_control_state thread_control
;
9173 struct inferior_control_state inferior_control
;
9176 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9177 int stopped_by_random_signal
= 0;
9179 /* ID if the selected frame when the inferior function call was made. */
9180 struct frame_id selected_frame_id
{};
9183 /* Save all of the information associated with the inferior<==>gdb
9186 infcall_control_state_up
9187 save_infcall_control_state ()
9189 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9190 struct thread_info
*tp
= inferior_thread ();
9191 struct inferior
*inf
= current_inferior ();
9193 inf_status
->thread_control
= tp
->control
;
9194 inf_status
->inferior_control
= inf
->control
;
9196 tp
->control
.step_resume_breakpoint
= NULL
;
9197 tp
->control
.exception_resume_breakpoint
= NULL
;
9199 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9200 chain. If caller's caller is walking the chain, they'll be happier if we
9201 hand them back the original chain when restore_infcall_control_state is
9203 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9206 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9207 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9209 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9215 restore_selected_frame (const frame_id
&fid
)
9217 frame_info
*frame
= frame_find_by_id (fid
);
9219 /* If inf_status->selected_frame_id is NULL, there was no previously
9223 warning (_("Unable to restore previously selected frame."));
9227 select_frame (frame
);
9230 /* Restore inferior session state to INF_STATUS. */
9233 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9235 struct thread_info
*tp
= inferior_thread ();
9236 struct inferior
*inf
= current_inferior ();
9238 if (tp
->control
.step_resume_breakpoint
)
9239 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9241 if (tp
->control
.exception_resume_breakpoint
)
9242 tp
->control
.exception_resume_breakpoint
->disposition
9243 = disp_del_at_next_stop
;
9245 /* Handle the bpstat_copy of the chain. */
9246 bpstat_clear (&tp
->control
.stop_bpstat
);
9248 tp
->control
= inf_status
->thread_control
;
9249 inf
->control
= inf_status
->inferior_control
;
9252 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9253 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9255 if (target_has_stack
)
9257 /* The point of the try/catch is that if the stack is clobbered,
9258 walking the stack might encounter a garbage pointer and
9259 error() trying to dereference it. */
9262 restore_selected_frame (inf_status
->selected_frame_id
);
9264 catch (const gdb_exception_error
&ex
)
9266 exception_fprintf (gdb_stderr
, ex
,
9267 "Unable to restore previously selected frame:\n");
9268 /* Error in restoring the selected frame. Select the
9270 select_frame (get_current_frame ());
9278 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9280 if (inf_status
->thread_control
.step_resume_breakpoint
)
9281 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9282 = disp_del_at_next_stop
;
9284 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9285 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9286 = disp_del_at_next_stop
;
9288 /* See save_infcall_control_state for info on stop_bpstat. */
9289 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9297 clear_exit_convenience_vars (void)
9299 clear_internalvar (lookup_internalvar ("_exitsignal"));
9300 clear_internalvar (lookup_internalvar ("_exitcode"));
9304 /* User interface for reverse debugging:
9305 Set exec-direction / show exec-direction commands
9306 (returns error unless target implements to_set_exec_direction method). */
9308 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9309 static const char exec_forward
[] = "forward";
9310 static const char exec_reverse
[] = "reverse";
9311 static const char *exec_direction
= exec_forward
;
9312 static const char *const exec_direction_names
[] = {
9319 set_exec_direction_func (const char *args
, int from_tty
,
9320 struct cmd_list_element
*cmd
)
9322 if (target_can_execute_reverse
)
9324 if (!strcmp (exec_direction
, exec_forward
))
9325 execution_direction
= EXEC_FORWARD
;
9326 else if (!strcmp (exec_direction
, exec_reverse
))
9327 execution_direction
= EXEC_REVERSE
;
9331 exec_direction
= exec_forward
;
9332 error (_("Target does not support this operation."));
9337 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9338 struct cmd_list_element
*cmd
, const char *value
)
9340 switch (execution_direction
) {
9342 fprintf_filtered (out
, _("Forward.\n"));
9345 fprintf_filtered (out
, _("Reverse.\n"));
9348 internal_error (__FILE__
, __LINE__
,
9349 _("bogus execution_direction value: %d"),
9350 (int) execution_direction
);
9355 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9356 struct cmd_list_element
*c
, const char *value
)
9358 fprintf_filtered (file
, _("Resuming the execution of threads "
9359 "of all processes is %s.\n"), value
);
9362 /* Implementation of `siginfo' variable. */
9364 static const struct internalvar_funcs siginfo_funcs
=
9371 /* Callback for infrun's target events source. This is marked when a
9372 thread has a pending status to process. */
9375 infrun_async_inferior_event_handler (gdb_client_data data
)
9377 inferior_event_handler (INF_REG_EVENT
, NULL
);
9380 void _initialize_infrun ();
9382 _initialize_infrun ()
9384 struct cmd_list_element
*c
;
9386 /* Register extra event sources in the event loop. */
9387 infrun_async_inferior_event_token
9388 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9390 add_info ("signals", info_signals_command
, _("\
9391 What debugger does when program gets various signals.\n\
9392 Specify a signal as argument to print info on that signal only."));
9393 add_info_alias ("handle", "signals", 0);
9395 c
= add_com ("handle", class_run
, handle_command
, _("\
9396 Specify how to handle signals.\n\
9397 Usage: handle SIGNAL [ACTIONS]\n\
9398 Args are signals and actions to apply to those signals.\n\
9399 If no actions are specified, the current settings for the specified signals\n\
9400 will be displayed instead.\n\
9402 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9403 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9404 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9405 The special arg \"all\" is recognized to mean all signals except those\n\
9406 used by the debugger, typically SIGTRAP and SIGINT.\n\
9408 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9409 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9410 Stop means reenter debugger if this signal happens (implies print).\n\
9411 Print means print a message if this signal happens.\n\
9412 Pass means let program see this signal; otherwise program doesn't know.\n\
9413 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9414 Pass and Stop may be combined.\n\
9416 Multiple signals may be specified. Signal numbers and signal names\n\
9417 may be interspersed with actions, with the actions being performed for\n\
9418 all signals cumulatively specified."));
9419 set_cmd_completer (c
, handle_completer
);
9422 stop_command
= add_cmd ("stop", class_obscure
,
9423 not_just_help_class_command
, _("\
9424 There is no `stop' command, but you can set a hook on `stop'.\n\
9425 This allows you to set a list of commands to be run each time execution\n\
9426 of the program stops."), &cmdlist
);
9428 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9429 Set inferior debugging."), _("\
9430 Show inferior debugging."), _("\
9431 When non-zero, inferior specific debugging is enabled."),
9434 &setdebuglist
, &showdebuglist
);
9436 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9437 &debug_displaced
, _("\
9438 Set displaced stepping debugging."), _("\
9439 Show displaced stepping debugging."), _("\
9440 When non-zero, displaced stepping specific debugging is enabled."),
9442 show_debug_displaced
,
9443 &setdebuglist
, &showdebuglist
);
9445 add_setshow_boolean_cmd ("non-stop", no_class
,
9447 Set whether gdb controls the inferior in non-stop mode."), _("\
9448 Show whether gdb controls the inferior in non-stop mode."), _("\
9449 When debugging a multi-threaded program and this setting is\n\
9450 off (the default, also called all-stop mode), when one thread stops\n\
9451 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9452 all other threads in the program while you interact with the thread of\n\
9453 interest. When you continue or step a thread, you can allow the other\n\
9454 threads to run, or have them remain stopped, but while you inspect any\n\
9455 thread's state, all threads stop.\n\
9457 In non-stop mode, when one thread stops, other threads can continue\n\
9458 to run freely. You'll be able to step each thread independently,\n\
9459 leave it stopped or free to run as needed."),
9465 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9468 signal_print
[i
] = 1;
9469 signal_program
[i
] = 1;
9470 signal_catch
[i
] = 0;
9473 /* Signals caused by debugger's own actions should not be given to
9474 the program afterwards.
9476 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9477 explicitly specifies that it should be delivered to the target
9478 program. Typically, that would occur when a user is debugging a
9479 target monitor on a simulator: the target monitor sets a
9480 breakpoint; the simulator encounters this breakpoint and halts
9481 the simulation handing control to GDB; GDB, noting that the stop
9482 address doesn't map to any known breakpoint, returns control back
9483 to the simulator; the simulator then delivers the hardware
9484 equivalent of a GDB_SIGNAL_TRAP to the program being
9486 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9487 signal_program
[GDB_SIGNAL_INT
] = 0;
9489 /* Signals that are not errors should not normally enter the debugger. */
9490 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9491 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9492 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9493 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9494 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9495 signal_print
[GDB_SIGNAL_PROF
] = 0;
9496 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9497 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9498 signal_stop
[GDB_SIGNAL_IO
] = 0;
9499 signal_print
[GDB_SIGNAL_IO
] = 0;
9500 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9501 signal_print
[GDB_SIGNAL_POLL
] = 0;
9502 signal_stop
[GDB_SIGNAL_URG
] = 0;
9503 signal_print
[GDB_SIGNAL_URG
] = 0;
9504 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9505 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9506 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9507 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9509 /* These signals are used internally by user-level thread
9510 implementations. (See signal(5) on Solaris.) Like the above
9511 signals, a healthy program receives and handles them as part of
9512 its normal operation. */
9513 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9514 signal_print
[GDB_SIGNAL_LWP
] = 0;
9515 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9516 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9517 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9518 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9519 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9520 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9522 /* Update cached state. */
9523 signal_cache_update (-1);
9525 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9526 &stop_on_solib_events
, _("\
9527 Set stopping for shared library events."), _("\
9528 Show stopping for shared library events."), _("\
9529 If nonzero, gdb will give control to the user when the dynamic linker\n\
9530 notifies gdb of shared library events. The most common event of interest\n\
9531 to the user would be loading/unloading of a new library."),
9532 set_stop_on_solib_events
,
9533 show_stop_on_solib_events
,
9534 &setlist
, &showlist
);
9536 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9537 follow_fork_mode_kind_names
,
9538 &follow_fork_mode_string
, _("\
9539 Set debugger response to a program call of fork or vfork."), _("\
9540 Show debugger response to a program call of fork or vfork."), _("\
9541 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9542 parent - the original process is debugged after a fork\n\
9543 child - the new process is debugged after a fork\n\
9544 The unfollowed process will continue to run.\n\
9545 By default, the debugger will follow the parent process."),
9547 show_follow_fork_mode_string
,
9548 &setlist
, &showlist
);
9550 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9551 follow_exec_mode_names
,
9552 &follow_exec_mode_string
, _("\
9553 Set debugger response to a program call of exec."), _("\
9554 Show debugger response to a program call of exec."), _("\
9555 An exec call replaces the program image of a process.\n\
9557 follow-exec-mode can be:\n\
9559 new - the debugger creates a new inferior and rebinds the process\n\
9560 to this new inferior. The program the process was running before\n\
9561 the exec call can be restarted afterwards by restarting the original\n\
9564 same - the debugger keeps the process bound to the same inferior.\n\
9565 The new executable image replaces the previous executable loaded in\n\
9566 the inferior. Restarting the inferior after the exec call restarts\n\
9567 the executable the process was running after the exec call.\n\
9569 By default, the debugger will use the same inferior."),
9571 show_follow_exec_mode_string
,
9572 &setlist
, &showlist
);
9574 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9575 scheduler_enums
, &scheduler_mode
, _("\
9576 Set mode for locking scheduler during execution."), _("\
9577 Show mode for locking scheduler during execution."), _("\
9578 off == no locking (threads may preempt at any time)\n\
9579 on == full locking (no thread except the current thread may run)\n\
9580 This applies to both normal execution and replay mode.\n\
9581 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9582 In this mode, other threads may run during other commands.\n\
9583 This applies to both normal execution and replay mode.\n\
9584 replay == scheduler locked in replay mode and unlocked during normal execution."),
9585 set_schedlock_func
, /* traps on target vector */
9586 show_scheduler_mode
,
9587 &setlist
, &showlist
);
9589 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9590 Set mode for resuming threads of all processes."), _("\
9591 Show mode for resuming threads of all processes."), _("\
9592 When on, execution commands (such as 'continue' or 'next') resume all\n\
9593 threads of all processes. When off (which is the default), execution\n\
9594 commands only resume the threads of the current process. The set of\n\
9595 threads that are resumed is further refined by the scheduler-locking\n\
9596 mode (see help set scheduler-locking)."),
9598 show_schedule_multiple
,
9599 &setlist
, &showlist
);
9601 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9602 Set mode of the step operation."), _("\
9603 Show mode of the step operation."), _("\
9604 When set, doing a step over a function without debug line information\n\
9605 will stop at the first instruction of that function. Otherwise, the\n\
9606 function is skipped and the step command stops at a different source line."),
9608 show_step_stop_if_no_debug
,
9609 &setlist
, &showlist
);
9611 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9612 &can_use_displaced_stepping
, _("\
9613 Set debugger's willingness to use displaced stepping."), _("\
9614 Show debugger's willingness to use displaced stepping."), _("\
9615 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9616 supported by the target architecture. If off, gdb will not use displaced\n\
9617 stepping to step over breakpoints, even if such is supported by the target\n\
9618 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9619 if the target architecture supports it and non-stop mode is active, but will not\n\
9620 use it in all-stop mode (see help set non-stop)."),
9622 show_can_use_displaced_stepping
,
9623 &setlist
, &showlist
);
9625 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9626 &exec_direction
, _("Set direction of execution.\n\
9627 Options are 'forward' or 'reverse'."),
9628 _("Show direction of execution (forward/reverse)."),
9629 _("Tells gdb whether to execute forward or backward."),
9630 set_exec_direction_func
, show_exec_direction_func
,
9631 &setlist
, &showlist
);
9633 /* Set/show detach-on-fork: user-settable mode. */
9635 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9636 Set whether gdb will detach the child of a fork."), _("\
9637 Show whether gdb will detach the child of a fork."), _("\
9638 Tells gdb whether to detach the child of a fork."),
9639 NULL
, NULL
, &setlist
, &showlist
);
9641 /* Set/show disable address space randomization mode. */
9643 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9644 &disable_randomization
, _("\
9645 Set disabling of debuggee's virtual address space randomization."), _("\
9646 Show disabling of debuggee's virtual address space randomization."), _("\
9647 When this mode is on (which is the default), randomization of the virtual\n\
9648 address space is disabled. Standalone programs run with the randomization\n\
9649 enabled by default on some platforms."),
9650 &set_disable_randomization
,
9651 &show_disable_randomization
,
9652 &setlist
, &showlist
);
9654 /* ptid initializations */
9655 inferior_ptid
= null_ptid
;
9656 target_last_wait_ptid
= minus_one_ptid
;
9658 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9659 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9660 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9661 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9663 /* Explicitly create without lookup, since that tries to create a
9664 value with a void typed value, and when we get here, gdbarch
9665 isn't initialized yet. At this point, we're quite sure there
9666 isn't another convenience variable of the same name. */
9667 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9669 add_setshow_boolean_cmd ("observer", no_class
,
9670 &observer_mode_1
, _("\
9671 Set whether gdb controls the inferior in observer mode."), _("\
9672 Show whether gdb controls the inferior in observer mode."), _("\
9673 In observer mode, GDB can get data from the inferior, but not\n\
9674 affect its execution. Registers and memory may not be changed,\n\
9675 breakpoints may not be set, and the program cannot be interrupted\n\