1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2021 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/>. */
22 #include "displaced-stepping.h"
28 #include "breakpoint.h"
32 #include "target-connection.h"
33 #include "gdbthread.h"
40 #include "observable.h"
45 #include "mi/mi-common.h"
46 #include "event-top.h"
48 #include "record-full.h"
49 #include "inline-frame.h"
51 #include "tracepoint.h"
55 #include "completer.h"
56 #include "target-descriptions.h"
57 #include "target-dcache.h"
60 #include "gdbsupport/event-loop.h"
61 #include "thread-fsm.h"
62 #include "gdbsupport/enum-flags.h"
63 #include "progspace-and-thread.h"
64 #include "gdbsupport/gdb_optional.h"
65 #include "arch-utils.h"
66 #include "gdbsupport/scope-exit.h"
67 #include "gdbsupport/forward-scope-exit.h"
68 #include "gdbsupport/gdb_select.h"
69 #include <unordered_map>
70 #include "async-event.h"
71 #include "gdbsupport/selftest.h"
72 #include "scoped-mock-context.h"
73 #include "test-target.h"
74 #include "gdbsupport/common-debug.h"
76 /* Prototypes for local functions */
78 static void sig_print_info (enum gdb_signal
);
80 static void sig_print_header (void);
82 static void follow_inferior_reset_breakpoints (void);
84 static bool currently_stepping (struct thread_info
*tp
);
86 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
88 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
90 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
92 static bool maybe_software_singlestep (struct gdbarch
*gdbarch
);
94 static void resume (gdb_signal sig
);
96 static void wait_for_inferior (inferior
*inf
);
98 /* Asynchronous signal handler registered as event loop source for
99 when we have pending events ready to be passed to the core. */
100 static struct async_event_handler
*infrun_async_inferior_event_token
;
102 /* Stores whether infrun_async was previously enabled or disabled.
103 Starts off as -1, indicating "never enabled/disabled". */
104 static int infrun_is_async
= -1;
109 infrun_async (int enable
)
111 if (infrun_is_async
!= enable
)
113 infrun_is_async
= enable
;
115 infrun_debug_printf ("enable=%d", enable
);
118 mark_async_event_handler (infrun_async_inferior_event_token
);
120 clear_async_event_handler (infrun_async_inferior_event_token
);
127 mark_infrun_async_event_handler (void)
129 mark_async_event_handler (infrun_async_inferior_event_token
);
132 /* When set, stop the 'step' command if we enter a function which has
133 no line number information. The normal behavior is that we step
134 over such function. */
135 bool step_stop_if_no_debug
= false;
137 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
138 struct cmd_list_element
*c
, const char *value
)
140 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
143 /* proceed and normal_stop use this to notify the user when the
144 inferior stopped in a different thread than it had been running
147 static ptid_t previous_inferior_ptid
;
149 /* If set (default for legacy reasons), when following a fork, GDB
150 will detach from one of the fork branches, child or parent.
151 Exactly which branch is detached depends on 'set follow-fork-mode'
154 static bool detach_fork
= true;
156 bool debug_infrun
= false;
158 show_debug_infrun (struct ui_file
*file
, int from_tty
,
159 struct cmd_list_element
*c
, const char *value
)
161 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
164 /* Support for disabling address space randomization. */
166 bool disable_randomization
= true;
169 show_disable_randomization (struct ui_file
*file
, int from_tty
,
170 struct cmd_list_element
*c
, const char *value
)
172 if (target_supports_disable_randomization ())
173 fprintf_filtered (file
,
174 _("Disabling randomization of debuggee's "
175 "virtual address space is %s.\n"),
178 fputs_filtered (_("Disabling randomization of debuggee's "
179 "virtual address space is unsupported on\n"
180 "this platform.\n"), file
);
184 set_disable_randomization (const char *args
, int from_tty
,
185 struct cmd_list_element
*c
)
187 if (!target_supports_disable_randomization ())
188 error (_("Disabling randomization of debuggee's "
189 "virtual address space is unsupported on\n"
193 /* User interface for non-stop mode. */
195 bool non_stop
= false;
196 static bool non_stop_1
= false;
199 set_non_stop (const char *args
, int from_tty
,
200 struct cmd_list_element
*c
)
202 if (target_has_execution ())
204 non_stop_1
= non_stop
;
205 error (_("Cannot change this setting while the inferior is running."));
208 non_stop
= non_stop_1
;
212 show_non_stop (struct ui_file
*file
, int from_tty
,
213 struct cmd_list_element
*c
, const char *value
)
215 fprintf_filtered (file
,
216 _("Controlling the inferior in non-stop mode is %s.\n"),
220 /* "Observer mode" is somewhat like a more extreme version of
221 non-stop, in which all GDB operations that might affect the
222 target's execution have been disabled. */
224 static bool observer_mode
= false;
225 static bool observer_mode_1
= false;
228 set_observer_mode (const char *args
, int from_tty
,
229 struct cmd_list_element
*c
)
231 if (target_has_execution ())
233 observer_mode_1
= observer_mode
;
234 error (_("Cannot change this setting while the inferior is running."));
237 observer_mode
= observer_mode_1
;
239 may_write_registers
= !observer_mode
;
240 may_write_memory
= !observer_mode
;
241 may_insert_breakpoints
= !observer_mode
;
242 may_insert_tracepoints
= !observer_mode
;
243 /* We can insert fast tracepoints in or out of observer mode,
244 but enable them if we're going into this mode. */
246 may_insert_fast_tracepoints
= true;
247 may_stop
= !observer_mode
;
248 update_target_permissions ();
250 /* Going *into* observer mode we must force non-stop, then
251 going out we leave it that way. */
254 pagination_enabled
= 0;
255 non_stop
= non_stop_1
= true;
259 printf_filtered (_("Observer mode is now %s.\n"),
260 (observer_mode
? "on" : "off"));
264 show_observer_mode (struct ui_file
*file
, int from_tty
,
265 struct cmd_list_element
*c
, const char *value
)
267 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
270 /* This updates the value of observer mode based on changes in
271 permissions. Note that we are deliberately ignoring the values of
272 may-write-registers and may-write-memory, since the user may have
273 reason to enable these during a session, for instance to turn on a
274 debugging-related global. */
277 update_observer_mode (void)
279 bool newval
= (!may_insert_breakpoints
280 && !may_insert_tracepoints
281 && may_insert_fast_tracepoints
285 /* Let the user know if things change. */
286 if (newval
!= observer_mode
)
287 printf_filtered (_("Observer mode is now %s.\n"),
288 (newval
? "on" : "off"));
290 observer_mode
= observer_mode_1
= newval
;
293 /* Tables of how to react to signals; the user sets them. */
295 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
296 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
297 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
299 /* Table of signals that are registered with "catch signal". A
300 non-zero entry indicates that the signal is caught by some "catch
302 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
304 /* Table of signals that the target may silently handle.
305 This is automatically determined from the flags above,
306 and simply cached here. */
307 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
309 #define SET_SIGS(nsigs,sigs,flags) \
311 int signum = (nsigs); \
312 while (signum-- > 0) \
313 if ((sigs)[signum]) \
314 (flags)[signum] = 1; \
317 #define UNSET_SIGS(nsigs,sigs,flags) \
319 int signum = (nsigs); \
320 while (signum-- > 0) \
321 if ((sigs)[signum]) \
322 (flags)[signum] = 0; \
325 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
326 this function is to avoid exporting `signal_program'. */
329 update_signals_program_target (void)
331 target_program_signals (signal_program
);
334 /* Value to pass to target_resume() to cause all threads to resume. */
336 #define RESUME_ALL minus_one_ptid
338 /* Command list pointer for the "stop" placeholder. */
340 static struct cmd_list_element
*stop_command
;
342 /* Nonzero if we want to give control to the user when we're notified
343 of shared library events by the dynamic linker. */
344 int stop_on_solib_events
;
346 /* Enable or disable optional shared library event breakpoints
347 as appropriate when the above flag is changed. */
350 set_stop_on_solib_events (const char *args
,
351 int from_tty
, struct cmd_list_element
*c
)
353 update_solib_breakpoints ();
357 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
358 struct cmd_list_element
*c
, const char *value
)
360 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
364 /* True after stop if current stack frame should be printed. */
366 static bool stop_print_frame
;
368 /* This is a cached copy of the target/ptid/waitstatus of the last
369 event returned by target_wait()/deprecated_target_wait_hook().
370 This information is returned by get_last_target_status(). */
371 static process_stratum_target
*target_last_proc_target
;
372 static ptid_t target_last_wait_ptid
;
373 static struct target_waitstatus target_last_waitstatus
;
375 void init_thread_stepping_state (struct thread_info
*tss
);
377 static const char follow_fork_mode_child
[] = "child";
378 static const char follow_fork_mode_parent
[] = "parent";
380 static const char *const follow_fork_mode_kind_names
[] = {
381 follow_fork_mode_child
,
382 follow_fork_mode_parent
,
386 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
388 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
389 struct cmd_list_element
*c
, const char *value
)
391 fprintf_filtered (file
,
392 _("Debugger response to a program "
393 "call of fork or vfork is \"%s\".\n"),
398 /* Handle changes to the inferior list based on the type of fork,
399 which process is being followed, and whether the other process
400 should be detached. On entry inferior_ptid must be the ptid of
401 the fork parent. At return inferior_ptid is the ptid of the
402 followed inferior. */
405 follow_fork_inferior (bool follow_child
, bool detach_fork
)
407 target_waitkind fork_kind
= inferior_thread ()->pending_follow
.kind ();
408 gdb_assert (fork_kind
== TARGET_WAITKIND_FORKED
409 || fork_kind
== TARGET_WAITKIND_VFORKED
);
410 bool has_vforked
= fork_kind
== TARGET_WAITKIND_VFORKED
;
411 ptid_t parent_ptid
= inferior_ptid
;
412 ptid_t child_ptid
= inferior_thread ()->pending_follow
.child_ptid ();
415 && !non_stop
/* Non-stop always resumes both branches. */
416 && current_ui
->prompt_state
== PROMPT_BLOCKED
417 && !(follow_child
|| detach_fork
|| sched_multi
))
419 /* The parent stays blocked inside the vfork syscall until the
420 child execs or exits. If we don't let the child run, then
421 the parent stays blocked. If we're telling the parent to run
422 in the foreground, the user will not be able to ctrl-c to get
423 back the terminal, effectively hanging the debug session. */
424 fprintf_filtered (gdb_stderr
, _("\
425 Can not resume the parent process over vfork in the foreground while\n\
426 holding the child stopped. Try \"set detach-on-fork\" or \
427 \"set schedule-multiple\".\n"));
431 inferior
*parent_inf
= current_inferior ();
432 inferior
*child_inf
= nullptr;
436 /* Detach new forked process? */
439 /* Before detaching from the child, remove all breakpoints
440 from it. If we forked, then this has already been taken
441 care of by infrun.c. If we vforked however, any
442 breakpoint inserted in the parent is visible in the
443 child, even those added while stopped in a vfork
444 catchpoint. This will remove the breakpoints from the
445 parent also, but they'll be reinserted below. */
448 /* Keep breakpoints list in sync. */
449 remove_breakpoints_inf (current_inferior ());
452 if (print_inferior_events
)
454 /* Ensure that we have a process ptid. */
455 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
457 target_terminal::ours_for_output ();
458 printf_filtered (_("[Detaching after %s from child %s]\n"),
459 has_vforked
? "vfork" : "fork",
460 target_pid_to_str (process_ptid
).c_str ());
465 /* Add process to GDB's tables. */
466 child_inf
= add_inferior (child_ptid
.pid ());
468 child_inf
->attach_flag
= parent_inf
->attach_flag
;
469 copy_terminal_info (child_inf
, parent_inf
);
470 child_inf
->gdbarch
= parent_inf
->gdbarch
;
471 copy_inferior_target_desc_info (child_inf
, parent_inf
);
473 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
475 /* If this is a vfork child, then the address-space is
476 shared with the parent. */
479 child_inf
->pspace
= parent_inf
->pspace
;
480 child_inf
->aspace
= parent_inf
->aspace
;
482 exec_on_vfork (child_inf
);
484 /* The parent will be frozen until the child is done
485 with the shared region. Keep track of the
487 child_inf
->vfork_parent
= parent_inf
;
488 child_inf
->pending_detach
= 0;
489 parent_inf
->vfork_child
= child_inf
;
490 parent_inf
->pending_detach
= 0;
494 child_inf
->aspace
= new_address_space ();
495 child_inf
->pspace
= new program_space (child_inf
->aspace
);
496 child_inf
->removable
= 1;
497 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
503 /* If we detached from the child, then we have to be careful
504 to not insert breakpoints in the parent until the child
505 is done with the shared memory region. However, if we're
506 staying attached to the child, then we can and should
507 insert breakpoints, so that we can debug it. A
508 subsequent child exec or exit is enough to know when does
509 the child stops using the parent's address space. */
510 parent_inf
->waiting_for_vfork_done
= detach_fork
;
511 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
516 /* Follow the child. */
518 if (print_inferior_events
)
520 std::string parent_pid
= target_pid_to_str (parent_ptid
);
521 std::string child_pid
= target_pid_to_str (child_ptid
);
523 target_terminal::ours_for_output ();
524 printf_filtered (_("[Attaching after %s %s to child %s]\n"),
526 has_vforked
? "vfork" : "fork",
530 /* Add the new inferior first, so that the target_detach below
531 doesn't unpush the target. */
533 child_inf
= add_inferior (child_ptid
.pid ());
535 child_inf
->attach_flag
= parent_inf
->attach_flag
;
536 copy_terminal_info (child_inf
, parent_inf
);
537 child_inf
->gdbarch
= parent_inf
->gdbarch
;
538 copy_inferior_target_desc_info (child_inf
, parent_inf
);
542 /* If this is a vfork child, then the address-space is shared
544 child_inf
->aspace
= parent_inf
->aspace
;
545 child_inf
->pspace
= parent_inf
->pspace
;
547 exec_on_vfork (child_inf
);
549 else if (detach_fork
)
551 /* We follow the child and detach from the parent: move the parent's
552 program space to the child. This simplifies some things, like
553 doing "next" over fork() and landing on the expected line in the
554 child (note, that is broken with "set detach-on-fork off").
556 Before assigning brand new spaces for the parent, remove
557 breakpoints from it: because the new pspace won't match
558 currently inserted locations, the normal detach procedure
559 wouldn't remove them, and we would leave them inserted when
561 remove_breakpoints_inf (parent_inf
);
563 child_inf
->aspace
= parent_inf
->aspace
;
564 child_inf
->pspace
= parent_inf
->pspace
;
565 parent_inf
->aspace
= new_address_space ();
566 parent_inf
->pspace
= new program_space (parent_inf
->aspace
);
567 clone_program_space (parent_inf
->pspace
, child_inf
->pspace
);
569 /* The parent inferior is still the current one, so keep things
571 set_current_program_space (parent_inf
->pspace
);
575 child_inf
->aspace
= new_address_space ();
576 child_inf
->pspace
= new program_space (child_inf
->aspace
);
577 child_inf
->removable
= 1;
578 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
579 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
583 gdb_assert (current_inferior () == parent_inf
);
585 /* If we are setting up an inferior for the child, target_follow_fork is
586 responsible for pushing the appropriate targets on the new inferior's
587 target stack and adding the initial thread (with ptid CHILD_PTID).
589 If we are not setting up an inferior for the child (because following
590 the parent and detach_fork is true), it is responsible for detaching
592 target_follow_fork (child_inf
, child_ptid
, fork_kind
, follow_child
,
595 /* target_follow_fork must leave the parent as the current inferior. If we
596 want to follow the child, we make it the current one below. */
597 gdb_assert (current_inferior () == parent_inf
);
599 /* If there is a child inferior, target_follow_fork must have created a thread
601 if (child_inf
!= nullptr)
602 gdb_assert (!child_inf
->thread_list
.empty ());
604 /* Detach the parent if needed. */
607 /* If we're vforking, we want to hold on to the parent until
608 the child exits or execs. At child exec or exit time we
609 can remove the old breakpoints from the parent and detach
610 or resume debugging it. Otherwise, detach the parent now;
611 we'll want to reuse it's program/address spaces, but we
612 can't set them to the child before removing breakpoints
613 from the parent, otherwise, the breakpoints module could
614 decide to remove breakpoints from the wrong process (since
615 they'd be assigned to the same address space). */
619 gdb_assert (child_inf
->vfork_parent
== NULL
);
620 gdb_assert (parent_inf
->vfork_child
== NULL
);
621 child_inf
->vfork_parent
= parent_inf
;
622 child_inf
->pending_detach
= 0;
623 parent_inf
->vfork_child
= child_inf
;
624 parent_inf
->pending_detach
= detach_fork
;
625 parent_inf
->waiting_for_vfork_done
= 0;
627 else if (detach_fork
)
629 if (print_inferior_events
)
631 /* Ensure that we have a process ptid. */
632 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
634 target_terminal::ours_for_output ();
635 printf_filtered (_("[Detaching after fork from "
637 target_pid_to_str (process_ptid
).c_str ());
640 target_detach (parent_inf
, 0);
644 /* If we ended up creating a new inferior, call post_create_inferior to inform
645 the various subcomponents. */
646 if (child_inf
!= nullptr)
648 /* If FOLLOW_CHILD, we leave CHILD_INF as the current inferior
649 (do not restore the parent as the current inferior). */
650 gdb::optional
<scoped_restore_current_thread
> maybe_restore
;
653 maybe_restore
.emplace ();
655 switch_to_thread (*child_inf
->threads ().begin ());
656 post_create_inferior (0);
662 /* Tell the target to follow the fork we're stopped at. Returns true
663 if the inferior should be resumed; false, if the target for some
664 reason decided it's best not to resume. */
669 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
670 bool should_resume
= true;
671 struct thread_info
*tp
;
673 /* Copy user stepping state to the new inferior thread. FIXME: the
674 followed fork child thread should have a copy of most of the
675 parent thread structure's run control related fields, not just these.
676 Initialized to avoid "may be used uninitialized" warnings from gcc. */
677 struct breakpoint
*step_resume_breakpoint
= NULL
;
678 struct breakpoint
*exception_resume_breakpoint
= NULL
;
679 CORE_ADDR step_range_start
= 0;
680 CORE_ADDR step_range_end
= 0;
681 int current_line
= 0;
682 symtab
*current_symtab
= NULL
;
683 struct frame_id step_frame_id
= { 0 };
684 struct thread_fsm
*thread_fsm
= NULL
;
688 process_stratum_target
*wait_target
;
690 struct target_waitstatus wait_status
;
692 /* Get the last target status returned by target_wait(). */
693 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
695 /* If not stopped at a fork event, then there's nothing else to
697 if (wait_status
.kind () != TARGET_WAITKIND_FORKED
698 && wait_status
.kind () != TARGET_WAITKIND_VFORKED
)
701 /* Check if we switched over from WAIT_PTID, since the event was
703 if (wait_ptid
!= minus_one_ptid
704 && (current_inferior ()->process_target () != wait_target
705 || inferior_ptid
!= wait_ptid
))
707 /* We did. Switch back to WAIT_PTID thread, to tell the
708 target to follow it (in either direction). We'll
709 afterwards refuse to resume, and inform the user what
711 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
712 switch_to_thread (wait_thread
);
713 should_resume
= false;
717 tp
= inferior_thread ();
719 /* If there were any forks/vforks that were caught and are now to be
720 followed, then do so now. */
721 switch (tp
->pending_follow
.kind ())
723 case TARGET_WAITKIND_FORKED
:
724 case TARGET_WAITKIND_VFORKED
:
726 ptid_t parent
, child
;
728 /* If the user did a next/step, etc, over a fork call,
729 preserve the stepping state in the fork child. */
730 if (follow_child
&& should_resume
)
732 step_resume_breakpoint
= clone_momentary_breakpoint
733 (tp
->control
.step_resume_breakpoint
);
734 step_range_start
= tp
->control
.step_range_start
;
735 step_range_end
= tp
->control
.step_range_end
;
736 current_line
= tp
->current_line
;
737 current_symtab
= tp
->current_symtab
;
738 step_frame_id
= tp
->control
.step_frame_id
;
739 exception_resume_breakpoint
740 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
741 thread_fsm
= tp
->thread_fsm
;
743 /* For now, delete the parent's sr breakpoint, otherwise,
744 parent/child sr breakpoints are considered duplicates,
745 and the child version will not be installed. Remove
746 this when the breakpoints module becomes aware of
747 inferiors and address spaces. */
748 delete_step_resume_breakpoint (tp
);
749 tp
->control
.step_range_start
= 0;
750 tp
->control
.step_range_end
= 0;
751 tp
->control
.step_frame_id
= null_frame_id
;
752 delete_exception_resume_breakpoint (tp
);
753 tp
->thread_fsm
= NULL
;
756 parent
= inferior_ptid
;
757 child
= tp
->pending_follow
.child_ptid ();
759 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
760 /* Set up inferior(s) as specified by the caller, and tell the
761 target to do whatever is necessary to follow either parent
763 if (follow_fork_inferior (follow_child
, detach_fork
))
765 /* Target refused to follow, or there's some other reason
766 we shouldn't resume. */
771 /* This pending follow fork event is now handled, one way
772 or another. The previous selected thread may be gone
773 from the lists by now, but if it is still around, need
774 to clear the pending follow request. */
775 tp
= find_thread_ptid (parent_targ
, parent
);
777 tp
->pending_follow
.set_spurious ();
779 /* This makes sure we don't try to apply the "Switched
780 over from WAIT_PID" logic above. */
781 nullify_last_target_wait_ptid ();
783 /* If we followed the child, switch to it... */
786 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
787 switch_to_thread (child_thr
);
789 /* ... and preserve the stepping state, in case the
790 user was stepping over the fork call. */
793 tp
= inferior_thread ();
794 tp
->control
.step_resume_breakpoint
795 = step_resume_breakpoint
;
796 tp
->control
.step_range_start
= step_range_start
;
797 tp
->control
.step_range_end
= step_range_end
;
798 tp
->current_line
= current_line
;
799 tp
->current_symtab
= current_symtab
;
800 tp
->control
.step_frame_id
= step_frame_id
;
801 tp
->control
.exception_resume_breakpoint
802 = exception_resume_breakpoint
;
803 tp
->thread_fsm
= thread_fsm
;
807 /* If we get here, it was because we're trying to
808 resume from a fork catchpoint, but, the user
809 has switched threads away from the thread that
810 forked. In that case, the resume command
811 issued is most likely not applicable to the
812 child, so just warn, and refuse to resume. */
813 warning (_("Not resuming: switched threads "
814 "before following fork child."));
817 /* Reset breakpoints in the child as appropriate. */
818 follow_inferior_reset_breakpoints ();
823 case TARGET_WAITKIND_SPURIOUS
:
824 /* Nothing to follow. */
827 internal_error (__FILE__
, __LINE__
,
828 "Unexpected pending_follow.kind %d\n",
829 tp
->pending_follow
.kind ());
833 return should_resume
;
837 follow_inferior_reset_breakpoints (void)
839 struct thread_info
*tp
= inferior_thread ();
841 /* Was there a step_resume breakpoint? (There was if the user
842 did a "next" at the fork() call.) If so, explicitly reset its
843 thread number. Cloned step_resume breakpoints are disabled on
844 creation, so enable it here now that it is associated with the
847 step_resumes are a form of bp that are made to be per-thread.
848 Since we created the step_resume bp when the parent process
849 was being debugged, and now are switching to the child process,
850 from the breakpoint package's viewpoint, that's a switch of
851 "threads". We must update the bp's notion of which thread
852 it is for, or it'll be ignored when it triggers. */
854 if (tp
->control
.step_resume_breakpoint
)
856 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
857 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
860 /* Treat exception_resume breakpoints like step_resume breakpoints. */
861 if (tp
->control
.exception_resume_breakpoint
)
863 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
864 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
867 /* Reinsert all breakpoints in the child. The user may have set
868 breakpoints after catching the fork, in which case those
869 were never set in the child, but only in the parent. This makes
870 sure the inserted breakpoints match the breakpoint list. */
872 breakpoint_re_set ();
873 insert_breakpoints ();
876 /* The child has exited or execed: resume THREAD, a thread of the parent,
877 if it was meant to be executing. */
880 proceed_after_vfork_done (thread_info
*thread
)
882 if (thread
->state
== THREAD_RUNNING
883 && !thread
->executing ()
884 && !thread
->stop_requested
885 && thread
->stop_signal () == GDB_SIGNAL_0
)
887 infrun_debug_printf ("resuming vfork parent thread %s",
888 thread
->ptid
.to_string ().c_str ());
890 switch_to_thread (thread
);
891 clear_proceed_status (0);
892 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
896 /* Called whenever we notice an exec or exit event, to handle
897 detaching or resuming a vfork parent. */
900 handle_vfork_child_exec_or_exit (int exec
)
902 struct inferior
*inf
= current_inferior ();
904 if (inf
->vfork_parent
)
906 inferior
*resume_parent
= nullptr;
908 /* This exec or exit marks the end of the shared memory region
909 between the parent and the child. Break the bonds. */
910 inferior
*vfork_parent
= inf
->vfork_parent
;
911 inf
->vfork_parent
->vfork_child
= NULL
;
912 inf
->vfork_parent
= NULL
;
914 /* If the user wanted to detach from the parent, now is the
916 if (vfork_parent
->pending_detach
)
918 struct program_space
*pspace
;
919 struct address_space
*aspace
;
921 /* follow-fork child, detach-on-fork on. */
923 vfork_parent
->pending_detach
= 0;
925 scoped_restore_current_pspace_and_thread restore_thread
;
927 /* We're letting loose of the parent. */
928 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
929 switch_to_thread (tp
);
931 /* We're about to detach from the parent, which implicitly
932 removes breakpoints from its address space. There's a
933 catch here: we want to reuse the spaces for the child,
934 but, parent/child are still sharing the pspace at this
935 point, although the exec in reality makes the kernel give
936 the child a fresh set of new pages. The problem here is
937 that the breakpoints module being unaware of this, would
938 likely chose the child process to write to the parent
939 address space. Swapping the child temporarily away from
940 the spaces has the desired effect. Yes, this is "sort
943 pspace
= inf
->pspace
;
944 aspace
= inf
->aspace
;
948 if (print_inferior_events
)
951 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
953 target_terminal::ours_for_output ();
957 printf_filtered (_("[Detaching vfork parent %s "
958 "after child exec]\n"), pidstr
.c_str ());
962 printf_filtered (_("[Detaching vfork parent %s "
963 "after child exit]\n"), pidstr
.c_str ());
967 target_detach (vfork_parent
, 0);
970 inf
->pspace
= pspace
;
971 inf
->aspace
= aspace
;
975 /* We're staying attached to the parent, so, really give the
976 child a new address space. */
977 inf
->pspace
= new program_space (maybe_new_address_space ());
978 inf
->aspace
= inf
->pspace
->aspace
;
980 set_current_program_space (inf
->pspace
);
982 resume_parent
= vfork_parent
;
986 /* If this is a vfork child exiting, then the pspace and
987 aspaces were shared with the parent. Since we're
988 reporting the process exit, we'll be mourning all that is
989 found in the address space, and switching to null_ptid,
990 preparing to start a new inferior. But, since we don't
991 want to clobber the parent's address/program spaces, we
992 go ahead and create a new one for this exiting
995 /* Switch to no-thread while running clone_program_space, so
996 that clone_program_space doesn't want to read the
997 selected frame of a dead process. */
998 scoped_restore_current_thread restore_thread
;
999 switch_to_no_thread ();
1001 inf
->pspace
= new program_space (maybe_new_address_space ());
1002 inf
->aspace
= inf
->pspace
->aspace
;
1003 set_current_program_space (inf
->pspace
);
1005 inf
->symfile_flags
= SYMFILE_NO_READ
;
1006 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1008 resume_parent
= vfork_parent
;
1011 gdb_assert (current_program_space
== inf
->pspace
);
1013 if (non_stop
&& resume_parent
!= nullptr)
1015 /* If the user wanted the parent to be running, let it go
1017 scoped_restore_current_thread restore_thread
;
1019 infrun_debug_printf ("resuming vfork parent process %d",
1020 resume_parent
->pid
);
1022 for (thread_info
*thread
: resume_parent
->threads ())
1023 proceed_after_vfork_done (thread
);
1028 /* Enum strings for "set|show follow-exec-mode". */
1030 static const char follow_exec_mode_new
[] = "new";
1031 static const char follow_exec_mode_same
[] = "same";
1032 static const char *const follow_exec_mode_names
[] =
1034 follow_exec_mode_new
,
1035 follow_exec_mode_same
,
1039 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1041 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1042 struct cmd_list_element
*c
, const char *value
)
1044 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1047 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1050 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1052 int pid
= ptid
.pid ();
1053 ptid_t process_ptid
;
1055 /* Switch terminal for any messages produced e.g. by
1056 breakpoint_re_set. */
1057 target_terminal::ours_for_output ();
1059 /* This is an exec event that we actually wish to pay attention to.
1060 Refresh our symbol table to the newly exec'd program, remove any
1061 momentary bp's, etc.
1063 If there are breakpoints, they aren't really inserted now,
1064 since the exec() transformed our inferior into a fresh set
1067 We want to preserve symbolic breakpoints on the list, since
1068 we have hopes that they can be reset after the new a.out's
1069 symbol table is read.
1071 However, any "raw" breakpoints must be removed from the list
1072 (e.g., the solib bp's), since their address is probably invalid
1075 And, we DON'T want to call delete_breakpoints() here, since
1076 that may write the bp's "shadow contents" (the instruction
1077 value that was overwritten with a TRAP instruction). Since
1078 we now have a new a.out, those shadow contents aren't valid. */
1080 mark_breakpoints_out ();
1082 /* The target reports the exec event to the main thread, even if
1083 some other thread does the exec, and even if the main thread was
1084 stopped or already gone. We may still have non-leader threads of
1085 the process on our list. E.g., on targets that don't have thread
1086 exit events (like remote); or on native Linux in non-stop mode if
1087 there were only two threads in the inferior and the non-leader
1088 one is the one that execs (and nothing forces an update of the
1089 thread list up to here). When debugging remotely, it's best to
1090 avoid extra traffic, when possible, so avoid syncing the thread
1091 list with the target, and instead go ahead and delete all threads
1092 of the process but one that reported the event. Note this must
1093 be done before calling update_breakpoints_after_exec, as
1094 otherwise clearing the threads' resources would reference stale
1095 thread breakpoints -- it may have been one of these threads that
1096 stepped across the exec. We could just clear their stepping
1097 states, but as long as we're iterating, might as well delete
1098 them. Deleting them now rather than at the next user-visible
1099 stop provides a nicer sequence of events for user and MI
1101 for (thread_info
*th
: all_threads_safe ())
1102 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1105 /* We also need to clear any left over stale state for the
1106 leader/event thread. E.g., if there was any step-resume
1107 breakpoint or similar, it's gone now. We cannot truly
1108 step-to-next statement through an exec(). */
1109 thread_info
*th
= inferior_thread ();
1110 th
->control
.step_resume_breakpoint
= NULL
;
1111 th
->control
.exception_resume_breakpoint
= NULL
;
1112 th
->control
.single_step_breakpoints
= NULL
;
1113 th
->control
.step_range_start
= 0;
1114 th
->control
.step_range_end
= 0;
1116 /* The user may have had the main thread held stopped in the
1117 previous image (e.g., schedlock on, or non-stop). Release
1119 th
->stop_requested
= 0;
1121 update_breakpoints_after_exec ();
1123 /* What is this a.out's name? */
1124 process_ptid
= ptid_t (pid
);
1125 printf_unfiltered (_("%s is executing new program: %s\n"),
1126 target_pid_to_str (process_ptid
).c_str (),
1129 /* We've followed the inferior through an exec. Therefore, the
1130 inferior has essentially been killed & reborn. */
1132 breakpoint_init_inferior (inf_execd
);
1134 gdb::unique_xmalloc_ptr
<char> exec_file_host
1135 = exec_file_find (exec_file_target
, NULL
);
1137 /* If we were unable to map the executable target pathname onto a host
1138 pathname, tell the user that. Otherwise GDB's subsequent behavior
1139 is confusing. Maybe it would even be better to stop at this point
1140 so that the user can specify a file manually before continuing. */
1141 if (exec_file_host
== NULL
)
1142 warning (_("Could not load symbols for executable %s.\n"
1143 "Do you need \"set sysroot\"?"),
1146 /* Reset the shared library package. This ensures that we get a
1147 shlib event when the child reaches "_start", at which point the
1148 dld will have had a chance to initialize the child. */
1149 /* Also, loading a symbol file below may trigger symbol lookups, and
1150 we don't want those to be satisfied by the libraries of the
1151 previous incarnation of this process. */
1152 no_shared_libraries (NULL
, 0);
1154 struct inferior
*inf
= current_inferior ();
1156 if (follow_exec_mode_string
== follow_exec_mode_new
)
1158 /* The user wants to keep the old inferior and program spaces
1159 around. Create a new fresh one, and switch to it. */
1161 /* Do exit processing for the original inferior before setting the new
1162 inferior's pid. Having two inferiors with the same pid would confuse
1163 find_inferior_p(t)id. Transfer the terminal state and info from the
1164 old to the new inferior. */
1165 inferior
*new_inferior
= add_inferior_with_spaces ();
1167 swap_terminal_info (new_inferior
, inf
);
1168 exit_inferior_silent (inf
);
1170 new_inferior
->pid
= pid
;
1171 target_follow_exec (new_inferior
, ptid
, exec_file_target
);
1173 /* We continue with the new inferior. */
1178 /* The old description may no longer be fit for the new image.
1179 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1180 old description; we'll read a new one below. No need to do
1181 this on "follow-exec-mode new", as the old inferior stays
1182 around (its description is later cleared/refetched on
1184 target_clear_description ();
1185 target_follow_exec (inf
, ptid
, exec_file_target
);
1188 gdb_assert (current_inferior () == inf
);
1189 gdb_assert (current_program_space
== inf
->pspace
);
1191 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1192 because the proper displacement for a PIE (Position Independent
1193 Executable) main symbol file will only be computed by
1194 solib_create_inferior_hook below. breakpoint_re_set would fail
1195 to insert the breakpoints with the zero displacement. */
1196 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1198 /* If the target can specify a description, read it. Must do this
1199 after flipping to the new executable (because the target supplied
1200 description must be compatible with the executable's
1201 architecture, and the old executable may e.g., be 32-bit, while
1202 the new one 64-bit), and before anything involving memory or
1204 target_find_description ();
1206 gdb::observers::inferior_execd
.notify (inf
);
1208 breakpoint_re_set ();
1210 /* Reinsert all breakpoints. (Those which were symbolic have
1211 been reset to the proper address in the new a.out, thanks
1212 to symbol_file_command...). */
1213 insert_breakpoints ();
1215 /* The next resume of this inferior should bring it to the shlib
1216 startup breakpoints. (If the user had also set bp's on
1217 "main" from the old (parent) process, then they'll auto-
1218 matically get reset there in the new process.). */
1221 /* The chain of threads that need to do a step-over operation to get
1222 past e.g., a breakpoint. What technique is used to step over the
1223 breakpoint/watchpoint does not matter -- all threads end up in the
1224 same queue, to maintain rough temporal order of execution, in order
1225 to avoid starvation, otherwise, we could e.g., find ourselves
1226 constantly stepping the same couple threads past their breakpoints
1227 over and over, if the single-step finish fast enough. */
1228 thread_step_over_list global_thread_step_over_list
;
1230 /* Bit flags indicating what the thread needs to step over. */
1232 enum step_over_what_flag
1234 /* Step over a breakpoint. */
1235 STEP_OVER_BREAKPOINT
= 1,
1237 /* Step past a non-continuable watchpoint, in order to let the
1238 instruction execute so we can evaluate the watchpoint
1240 STEP_OVER_WATCHPOINT
= 2
1242 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1244 /* Info about an instruction that is being stepped over. */
1246 struct step_over_info
1248 /* If we're stepping past a breakpoint, this is the address space
1249 and address of the instruction the breakpoint is set at. We'll
1250 skip inserting all breakpoints here. Valid iff ASPACE is
1252 const address_space
*aspace
= nullptr;
1253 CORE_ADDR address
= 0;
1255 /* The instruction being stepped over triggers a nonsteppable
1256 watchpoint. If true, we'll skip inserting watchpoints. */
1257 int nonsteppable_watchpoint_p
= 0;
1259 /* The thread's global number. */
1263 /* The step-over info of the location that is being stepped over.
1265 Note that with async/breakpoint always-inserted mode, a user might
1266 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1267 being stepped over. As setting a new breakpoint inserts all
1268 breakpoints, we need to make sure the breakpoint being stepped over
1269 isn't inserted then. We do that by only clearing the step-over
1270 info when the step-over is actually finished (or aborted).
1272 Presently GDB can only step over one breakpoint at any given time.
1273 Given threads that can't run code in the same address space as the
1274 breakpoint's can't really miss the breakpoint, GDB could be taught
1275 to step-over at most one breakpoint per address space (so this info
1276 could move to the address space object if/when GDB is extended).
1277 The set of breakpoints being stepped over will normally be much
1278 smaller than the set of all breakpoints, so a flag in the
1279 breakpoint location structure would be wasteful. A separate list
1280 also saves complexity and run-time, as otherwise we'd have to go
1281 through all breakpoint locations clearing their flag whenever we
1282 start a new sequence. Similar considerations weigh against storing
1283 this info in the thread object. Plus, not all step overs actually
1284 have breakpoint locations -- e.g., stepping past a single-step
1285 breakpoint, or stepping to complete a non-continuable
1287 static struct step_over_info step_over_info
;
1289 /* Record the address of the breakpoint/instruction we're currently
1291 N.B. We record the aspace and address now, instead of say just the thread,
1292 because when we need the info later the thread may be running. */
1295 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1296 int nonsteppable_watchpoint_p
,
1299 step_over_info
.aspace
= aspace
;
1300 step_over_info
.address
= address
;
1301 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1302 step_over_info
.thread
= thread
;
1305 /* Called when we're not longer stepping over a breakpoint / an
1306 instruction, so all breakpoints are free to be (re)inserted. */
1309 clear_step_over_info (void)
1311 infrun_debug_printf ("clearing step over info");
1312 step_over_info
.aspace
= NULL
;
1313 step_over_info
.address
= 0;
1314 step_over_info
.nonsteppable_watchpoint_p
= 0;
1315 step_over_info
.thread
= -1;
1321 stepping_past_instruction_at (struct address_space
*aspace
,
1324 return (step_over_info
.aspace
!= NULL
1325 && breakpoint_address_match (aspace
, address
,
1326 step_over_info
.aspace
,
1327 step_over_info
.address
));
1333 thread_is_stepping_over_breakpoint (int thread
)
1335 return (step_over_info
.thread
!= -1
1336 && thread
== step_over_info
.thread
);
1342 stepping_past_nonsteppable_watchpoint (void)
1344 return step_over_info
.nonsteppable_watchpoint_p
;
1347 /* Returns true if step-over info is valid. */
1350 step_over_info_valid_p (void)
1352 return (step_over_info
.aspace
!= NULL
1353 || stepping_past_nonsteppable_watchpoint ());
1357 /* Displaced stepping. */
1359 /* In non-stop debugging mode, we must take special care to manage
1360 breakpoints properly; in particular, the traditional strategy for
1361 stepping a thread past a breakpoint it has hit is unsuitable.
1362 'Displaced stepping' is a tactic for stepping one thread past a
1363 breakpoint it has hit while ensuring that other threads running
1364 concurrently will hit the breakpoint as they should.
1366 The traditional way to step a thread T off a breakpoint in a
1367 multi-threaded program in all-stop mode is as follows:
1369 a0) Initially, all threads are stopped, and breakpoints are not
1371 a1) We single-step T, leaving breakpoints uninserted.
1372 a2) We insert breakpoints, and resume all threads.
1374 In non-stop debugging, however, this strategy is unsuitable: we
1375 don't want to have to stop all threads in the system in order to
1376 continue or step T past a breakpoint. Instead, we use displaced
1379 n0) Initially, T is stopped, other threads are running, and
1380 breakpoints are inserted.
1381 n1) We copy the instruction "under" the breakpoint to a separate
1382 location, outside the main code stream, making any adjustments
1383 to the instruction, register, and memory state as directed by
1385 n2) We single-step T over the instruction at its new location.
1386 n3) We adjust the resulting register and memory state as directed
1387 by T's architecture. This includes resetting T's PC to point
1388 back into the main instruction stream.
1391 This approach depends on the following gdbarch methods:
1393 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1394 indicate where to copy the instruction, and how much space must
1395 be reserved there. We use these in step n1.
1397 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1398 address, and makes any necessary adjustments to the instruction,
1399 register contents, and memory. We use this in step n1.
1401 - gdbarch_displaced_step_fixup adjusts registers and memory after
1402 we have successfully single-stepped the instruction, to yield the
1403 same effect the instruction would have had if we had executed it
1404 at its original address. We use this in step n3.
1406 The gdbarch_displaced_step_copy_insn and
1407 gdbarch_displaced_step_fixup functions must be written so that
1408 copying an instruction with gdbarch_displaced_step_copy_insn,
1409 single-stepping across the copied instruction, and then applying
1410 gdbarch_displaced_insn_fixup should have the same effects on the
1411 thread's memory and registers as stepping the instruction in place
1412 would have. Exactly which responsibilities fall to the copy and
1413 which fall to the fixup is up to the author of those functions.
1415 See the comments in gdbarch.sh for details.
1417 Note that displaced stepping and software single-step cannot
1418 currently be used in combination, although with some care I think
1419 they could be made to. Software single-step works by placing
1420 breakpoints on all possible subsequent instructions; if the
1421 displaced instruction is a PC-relative jump, those breakpoints
1422 could fall in very strange places --- on pages that aren't
1423 executable, or at addresses that are not proper instruction
1424 boundaries. (We do generally let other threads run while we wait
1425 to hit the software single-step breakpoint, and they might
1426 encounter such a corrupted instruction.) One way to work around
1427 this would be to have gdbarch_displaced_step_copy_insn fully
1428 simulate the effect of PC-relative instructions (and return NULL)
1429 on architectures that use software single-stepping.
1431 In non-stop mode, we can have independent and simultaneous step
1432 requests, so more than one thread may need to simultaneously step
1433 over a breakpoint. The current implementation assumes there is
1434 only one scratch space per process. In this case, we have to
1435 serialize access to the scratch space. If thread A wants to step
1436 over a breakpoint, but we are currently waiting for some other
1437 thread to complete a displaced step, we leave thread A stopped and
1438 place it in the displaced_step_request_queue. Whenever a displaced
1439 step finishes, we pick the next thread in the queue and start a new
1440 displaced step operation on it. See displaced_step_prepare and
1441 displaced_step_finish for details. */
1443 /* Return true if THREAD is doing a displaced step. */
1446 displaced_step_in_progress_thread (thread_info
*thread
)
1448 gdb_assert (thread
!= NULL
);
1450 return thread
->displaced_step_state
.in_progress ();
1453 /* Return true if INF has a thread doing a displaced step. */
1456 displaced_step_in_progress (inferior
*inf
)
1458 return inf
->displaced_step_state
.in_progress_count
> 0;
1461 /* Return true if any thread is doing a displaced step. */
1464 displaced_step_in_progress_any_thread ()
1466 for (inferior
*inf
: all_non_exited_inferiors ())
1468 if (displaced_step_in_progress (inf
))
1476 infrun_inferior_exit (struct inferior
*inf
)
1478 inf
->displaced_step_state
.reset ();
1482 infrun_inferior_execd (inferior
*inf
)
1484 /* If some threads where was doing a displaced step in this inferior at the
1485 moment of the exec, they no longer exist. Even if the exec'ing thread
1486 doing a displaced step, we don't want to to any fixup nor restore displaced
1487 stepping buffer bytes. */
1488 inf
->displaced_step_state
.reset ();
1490 for (thread_info
*thread
: inf
->threads ())
1491 thread
->displaced_step_state
.reset ();
1493 /* Since an in-line step is done with everything else stopped, if there was
1494 one in progress at the time of the exec, it must have been the exec'ing
1496 clear_step_over_info ();
1499 /* If ON, and the architecture supports it, GDB will use displaced
1500 stepping to step over breakpoints. If OFF, or if the architecture
1501 doesn't support it, GDB will instead use the traditional
1502 hold-and-step approach. If AUTO (which is the default), GDB will
1503 decide which technique to use to step over breakpoints depending on
1504 whether the target works in a non-stop way (see use_displaced_stepping). */
1506 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1509 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1510 struct cmd_list_element
*c
,
1513 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1514 fprintf_filtered (file
,
1515 _("Debugger's willingness to use displaced stepping "
1516 "to step over breakpoints is %s (currently %s).\n"),
1517 value
, target_is_non_stop_p () ? "on" : "off");
1519 fprintf_filtered (file
,
1520 _("Debugger's willingness to use displaced stepping "
1521 "to step over breakpoints is %s.\n"), value
);
1524 /* Return true if the gdbarch implements the required methods to use
1525 displaced stepping. */
1528 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1530 /* Only check for the presence of `prepare`. The gdbarch verification ensures
1531 that if `prepare` is provided, so is `finish`. */
1532 return gdbarch_displaced_step_prepare_p (arch
);
1535 /* Return non-zero if displaced stepping can/should be used to step
1536 over breakpoints of thread TP. */
1539 use_displaced_stepping (thread_info
*tp
)
1541 /* If the user disabled it explicitly, don't use displaced stepping. */
1542 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1545 /* If "auto", only use displaced stepping if the target operates in a non-stop
1547 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1548 && !target_is_non_stop_p ())
1551 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1553 /* If the architecture doesn't implement displaced stepping, don't use
1555 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1558 /* If recording, don't use displaced stepping. */
1559 if (find_record_target () != nullptr)
1562 /* If displaced stepping failed before for this inferior, don't bother trying
1564 if (tp
->inf
->displaced_step_state
.failed_before
)
1570 /* Simple function wrapper around displaced_step_thread_state::reset. */
1573 displaced_step_reset (displaced_step_thread_state
*displaced
)
1575 displaced
->reset ();
1578 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1579 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1581 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1586 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1590 for (size_t i
= 0; i
< len
; i
++)
1593 ret
+= string_printf ("%02x", buf
[i
]);
1595 ret
+= string_printf (" %02x", buf
[i
]);
1601 /* Prepare to single-step, using displaced stepping.
1603 Note that we cannot use displaced stepping when we have a signal to
1604 deliver. If we have a signal to deliver and an instruction to step
1605 over, then after the step, there will be no indication from the
1606 target whether the thread entered a signal handler or ignored the
1607 signal and stepped over the instruction successfully --- both cases
1608 result in a simple SIGTRAP. In the first case we mustn't do a
1609 fixup, and in the second case we must --- but we can't tell which.
1610 Comments in the code for 'random signals' in handle_inferior_event
1611 explain how we handle this case instead.
1613 Returns DISPLACED_STEP_PREPARE_STATUS_OK if preparing was successful -- this
1614 thread is going to be stepped now; DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
1615 if displaced stepping this thread got queued; or
1616 DISPLACED_STEP_PREPARE_STATUS_CANT if this instruction can't be displaced
1619 static displaced_step_prepare_status
1620 displaced_step_prepare_throw (thread_info
*tp
)
1622 regcache
*regcache
= get_thread_regcache (tp
);
1623 struct gdbarch
*gdbarch
= regcache
->arch ();
1624 displaced_step_thread_state
&disp_step_thread_state
1625 = tp
->displaced_step_state
;
1627 /* We should never reach this function if the architecture does not
1628 support displaced stepping. */
1629 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1631 /* Nor if the thread isn't meant to step over a breakpoint. */
1632 gdb_assert (tp
->control
.trap_expected
);
1634 /* Disable range stepping while executing in the scratch pad. We
1635 want a single-step even if executing the displaced instruction in
1636 the scratch buffer lands within the stepping range (e.g., a
1638 tp
->control
.may_range_step
= 0;
1640 /* We are about to start a displaced step for this thread. If one is already
1641 in progress, something's wrong. */
1642 gdb_assert (!disp_step_thread_state
.in_progress ());
1644 if (tp
->inf
->displaced_step_state
.unavailable
)
1646 /* The gdbarch tells us it's not worth asking to try a prepare because
1647 it is likely that it will return unavailable, so don't bother asking. */
1649 displaced_debug_printf ("deferring step of %s",
1650 tp
->ptid
.to_string ().c_str ());
1652 global_thread_step_over_chain_enqueue (tp
);
1653 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1656 displaced_debug_printf ("displaced-stepping %s now",
1657 tp
->ptid
.to_string ().c_str ());
1659 scoped_restore_current_thread restore_thread
;
1661 switch_to_thread (tp
);
1663 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1664 CORE_ADDR displaced_pc
;
1666 displaced_step_prepare_status status
1667 = gdbarch_displaced_step_prepare (gdbarch
, tp
, displaced_pc
);
1669 if (status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
1671 displaced_debug_printf ("failed to prepare (%s)",
1672 tp
->ptid
.to_string ().c_str ());
1674 return DISPLACED_STEP_PREPARE_STATUS_CANT
;
1676 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1678 /* Not enough displaced stepping resources available, defer this
1679 request by placing it the queue. */
1681 displaced_debug_printf ("not enough resources available, "
1682 "deferring step of %s",
1683 tp
->ptid
.to_string ().c_str ());
1685 global_thread_step_over_chain_enqueue (tp
);
1687 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1690 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1692 /* Save the information we need to fix things up if the step
1694 disp_step_thread_state
.set (gdbarch
);
1696 tp
->inf
->displaced_step_state
.in_progress_count
++;
1698 displaced_debug_printf ("prepared successfully thread=%s, "
1699 "original_pc=%s, displaced_pc=%s",
1700 tp
->ptid
.to_string ().c_str (),
1701 paddress (gdbarch
, original_pc
),
1702 paddress (gdbarch
, displaced_pc
));
1704 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1707 /* Wrapper for displaced_step_prepare_throw that disabled further
1708 attempts at displaced stepping if we get a memory error. */
1710 static displaced_step_prepare_status
1711 displaced_step_prepare (thread_info
*thread
)
1713 displaced_step_prepare_status status
1714 = DISPLACED_STEP_PREPARE_STATUS_CANT
;
1718 status
= displaced_step_prepare_throw (thread
);
1720 catch (const gdb_exception_error
&ex
)
1722 if (ex
.error
!= MEMORY_ERROR
1723 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1726 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1729 /* Be verbose if "set displaced-stepping" is "on", silent if
1731 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1733 warning (_("disabling displaced stepping: %s"),
1737 /* Disable further displaced stepping attempts. */
1738 thread
->inf
->displaced_step_state
.failed_before
= 1;
1744 /* If we displaced stepped an instruction successfully, adjust registers and
1745 memory to yield the same effect the instruction would have had if we had
1746 executed it at its original address, and return
1747 DISPLACED_STEP_FINISH_STATUS_OK. If the instruction didn't complete,
1748 relocate the PC and return DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED.
1750 If the thread wasn't displaced stepping, return
1751 DISPLACED_STEP_FINISH_STATUS_OK as well. */
1753 static displaced_step_finish_status
1754 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1756 displaced_step_thread_state
*displaced
= &event_thread
->displaced_step_state
;
1758 /* Was this thread performing a displaced step? */
1759 if (!displaced
->in_progress ())
1760 return DISPLACED_STEP_FINISH_STATUS_OK
;
1762 gdb_assert (event_thread
->inf
->displaced_step_state
.in_progress_count
> 0);
1763 event_thread
->inf
->displaced_step_state
.in_progress_count
--;
1765 /* Fixup may need to read memory/registers. Switch to the thread
1766 that we're fixing up. Also, target_stopped_by_watchpoint checks
1767 the current thread, and displaced_step_restore performs ptid-dependent
1768 memory accesses using current_inferior(). */
1769 switch_to_thread (event_thread
);
1771 displaced_step_reset_cleanup
cleanup (displaced
);
1773 /* Do the fixup, and release the resources acquired to do the displaced
1775 return gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1776 event_thread
, signal
);
1779 /* Data to be passed around while handling an event. This data is
1780 discarded between events. */
1781 struct execution_control_state
1783 execution_control_state ()
1790 this->target
= nullptr;
1791 this->ptid
= null_ptid
;
1792 this->event_thread
= nullptr;
1793 ws
= target_waitstatus ();
1794 stop_func_filled_in
= 0;
1795 stop_func_start
= 0;
1797 stop_func_name
= nullptr;
1799 hit_singlestep_breakpoint
= 0;
1802 process_stratum_target
*target
;
1804 /* The thread that got the event, if this was a thread event; NULL
1806 struct thread_info
*event_thread
;
1808 struct target_waitstatus ws
;
1809 int stop_func_filled_in
;
1810 CORE_ADDR stop_func_start
;
1811 CORE_ADDR stop_func_end
;
1812 const char *stop_func_name
;
1815 /* True if the event thread hit the single-step breakpoint of
1816 another thread. Thus the event doesn't cause a stop, the thread
1817 needs to be single-stepped past the single-step breakpoint before
1818 we can switch back to the original stepping thread. */
1819 int hit_singlestep_breakpoint
;
1822 /* Clear ECS and set it to point at TP. */
1825 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1828 ecs
->event_thread
= tp
;
1829 ecs
->ptid
= tp
->ptid
;
1832 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1833 static void prepare_to_wait (struct execution_control_state
*ecs
);
1834 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1835 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1837 /* Are there any pending step-over requests? If so, run all we can
1838 now and return true. Otherwise, return false. */
1841 start_step_over (void)
1843 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
1845 /* Don't start a new step-over if we already have an in-line
1846 step-over operation ongoing. */
1847 if (step_over_info_valid_p ())
1850 /* Steal the global thread step over chain. As we try to initiate displaced
1851 steps, threads will be enqueued in the global chain if no buffers are
1852 available. If we iterated on the global chain directly, we might iterate
1854 thread_step_over_list threads_to_step
1855 = std::move (global_thread_step_over_list
);
1857 infrun_debug_printf ("stealing global queue of threads to step, length = %d",
1858 thread_step_over_chain_length (threads_to_step
));
1860 bool started
= false;
1862 /* On scope exit (whatever the reason, return or exception), if there are
1863 threads left in the THREADS_TO_STEP chain, put back these threads in the
1867 if (threads_to_step
.empty ())
1868 infrun_debug_printf ("step-over queue now empty");
1871 infrun_debug_printf ("putting back %d threads to step in global queue",
1872 thread_step_over_chain_length (threads_to_step
));
1874 global_thread_step_over_chain_enqueue_chain
1875 (std::move (threads_to_step
));
1879 thread_step_over_list_safe_range range
1880 = make_thread_step_over_list_safe_range (threads_to_step
);
1882 for (thread_info
*tp
: range
)
1884 struct execution_control_state ecss
;
1885 struct execution_control_state
*ecs
= &ecss
;
1886 step_over_what step_what
;
1887 int must_be_in_line
;
1889 gdb_assert (!tp
->stop_requested
);
1891 if (tp
->inf
->displaced_step_state
.unavailable
)
1893 /* The arch told us to not even try preparing another displaced step
1894 for this inferior. Just leave the thread in THREADS_TO_STEP, it
1895 will get moved to the global chain on scope exit. */
1899 /* Remove thread from the THREADS_TO_STEP chain. If anything goes wrong
1900 while we try to prepare the displaced step, we don't add it back to
1901 the global step over chain. This is to avoid a thread staying in the
1902 step over chain indefinitely if something goes wrong when resuming it
1903 If the error is intermittent and it still needs a step over, it will
1904 get enqueued again when we try to resume it normally. */
1905 threads_to_step
.erase (threads_to_step
.iterator_to (*tp
));
1907 step_what
= thread_still_needs_step_over (tp
);
1908 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1909 || ((step_what
& STEP_OVER_BREAKPOINT
)
1910 && !use_displaced_stepping (tp
)));
1912 /* We currently stop all threads of all processes to step-over
1913 in-line. If we need to start a new in-line step-over, let
1914 any pending displaced steps finish first. */
1915 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1917 global_thread_step_over_chain_enqueue (tp
);
1921 if (tp
->control
.trap_expected
1923 || tp
->executing ())
1925 internal_error (__FILE__
, __LINE__
,
1926 "[%s] has inconsistent state: "
1927 "trap_expected=%d, resumed=%d, executing=%d\n",
1928 tp
->ptid
.to_string ().c_str (),
1929 tp
->control
.trap_expected
,
1934 infrun_debug_printf ("resuming [%s] for step-over",
1935 tp
->ptid
.to_string ().c_str ());
1937 /* keep_going_pass_signal skips the step-over if the breakpoint
1938 is no longer inserted. In all-stop, we want to keep looking
1939 for a thread that needs a step-over instead of resuming TP,
1940 because we wouldn't be able to resume anything else until the
1941 target stops again. In non-stop, the resume always resumes
1942 only TP, so it's OK to let the thread resume freely. */
1943 if (!target_is_non_stop_p () && !step_what
)
1946 switch_to_thread (tp
);
1947 reset_ecs (ecs
, tp
);
1948 keep_going_pass_signal (ecs
);
1950 if (!ecs
->wait_some_more
)
1951 error (_("Command aborted."));
1953 /* If the thread's step over could not be initiated because no buffers
1954 were available, it was re-added to the global step over chain. */
1957 infrun_debug_printf ("[%s] was resumed.",
1958 tp
->ptid
.to_string ().c_str ());
1959 gdb_assert (!thread_is_in_step_over_chain (tp
));
1963 infrun_debug_printf ("[%s] was NOT resumed.",
1964 tp
->ptid
.to_string ().c_str ());
1965 gdb_assert (thread_is_in_step_over_chain (tp
));
1968 /* If we started a new in-line step-over, we're done. */
1969 if (step_over_info_valid_p ())
1971 gdb_assert (tp
->control
.trap_expected
);
1976 if (!target_is_non_stop_p ())
1978 /* On all-stop, shouldn't have resumed unless we needed a
1980 gdb_assert (tp
->control
.trap_expected
1981 || tp
->step_after_step_resume_breakpoint
);
1983 /* With remote targets (at least), in all-stop, we can't
1984 issue any further remote commands until the program stops
1990 /* Either the thread no longer needed a step-over, or a new
1991 displaced stepping sequence started. Even in the latter
1992 case, continue looking. Maybe we can also start another
1993 displaced step on a thread of other process. */
1999 /* Update global variables holding ptids to hold NEW_PTID if they were
2000 holding OLD_PTID. */
2002 infrun_thread_ptid_changed (process_stratum_target
*target
,
2003 ptid_t old_ptid
, ptid_t new_ptid
)
2005 if (inferior_ptid
== old_ptid
2006 && current_inferior ()->process_target () == target
)
2007 inferior_ptid
= new_ptid
;
2012 static const char schedlock_off
[] = "off";
2013 static const char schedlock_on
[] = "on";
2014 static const char schedlock_step
[] = "step";
2015 static const char schedlock_replay
[] = "replay";
2016 static const char *const scheduler_enums
[] = {
2023 static const char *scheduler_mode
= schedlock_replay
;
2025 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2026 struct cmd_list_element
*c
, const char *value
)
2028 fprintf_filtered (file
,
2029 _("Mode for locking scheduler "
2030 "during execution is \"%s\".\n"),
2035 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2037 if (!target_can_lock_scheduler ())
2039 scheduler_mode
= schedlock_off
;
2040 error (_("Target '%s' cannot support this command."),
2041 target_shortname ());
2045 /* True if execution commands resume all threads of all processes by
2046 default; otherwise, resume only threads of the current inferior
2048 bool sched_multi
= false;
2050 /* Try to setup for software single stepping. Return true if target_resume()
2051 should use hardware single step.
2053 GDBARCH the current gdbarch. */
2056 maybe_software_singlestep (struct gdbarch
*gdbarch
)
2058 bool hw_step
= true;
2060 if (execution_direction
== EXEC_FORWARD
2061 && gdbarch_software_single_step_p (gdbarch
))
2062 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2070 user_visible_resume_ptid (int step
)
2076 /* With non-stop mode on, threads are always handled
2078 resume_ptid
= inferior_ptid
;
2080 else if ((scheduler_mode
== schedlock_on
)
2081 || (scheduler_mode
== schedlock_step
&& step
))
2083 /* User-settable 'scheduler' mode requires solo thread
2085 resume_ptid
= inferior_ptid
;
2087 else if ((scheduler_mode
== schedlock_replay
)
2088 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2090 /* User-settable 'scheduler' mode requires solo thread resume in replay
2092 resume_ptid
= inferior_ptid
;
2094 else if (!sched_multi
&& target_supports_multi_process ())
2096 /* Resume all threads of the current process (and none of other
2098 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2102 /* Resume all threads of all processes. */
2103 resume_ptid
= RESUME_ALL
;
2111 process_stratum_target
*
2112 user_visible_resume_target (ptid_t resume_ptid
)
2114 return (resume_ptid
== minus_one_ptid
&& sched_multi
2116 : current_inferior ()->process_target ());
2119 /* Return a ptid representing the set of threads that we will resume,
2120 in the perspective of the target, assuming run control handling
2121 does not require leaving some threads stopped (e.g., stepping past
2122 breakpoint). USER_STEP indicates whether we're about to start the
2123 target for a stepping command. */
2126 internal_resume_ptid (int user_step
)
2128 /* In non-stop, we always control threads individually. Note that
2129 the target may always work in non-stop mode even with "set
2130 non-stop off", in which case user_visible_resume_ptid could
2131 return a wildcard ptid. */
2132 if (target_is_non_stop_p ())
2133 return inferior_ptid
;
2135 return user_visible_resume_ptid (user_step
);
2138 /* Wrapper for target_resume, that handles infrun-specific
2142 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2144 struct thread_info
*tp
= inferior_thread ();
2146 gdb_assert (!tp
->stop_requested
);
2148 /* Install inferior's terminal modes. */
2149 target_terminal::inferior ();
2151 /* Avoid confusing the next resume, if the next stop/resume
2152 happens to apply to another thread. */
2153 tp
->set_stop_signal (GDB_SIGNAL_0
);
2155 /* Advise target which signals may be handled silently.
2157 If we have removed breakpoints because we are stepping over one
2158 in-line (in any thread), we need to receive all signals to avoid
2159 accidentally skipping a breakpoint during execution of a signal
2162 Likewise if we're displaced stepping, otherwise a trap for a
2163 breakpoint in a signal handler might be confused with the
2164 displaced step finishing. We don't make the displaced_step_finish
2165 step distinguish the cases instead, because:
2167 - a backtrace while stopped in the signal handler would show the
2168 scratch pad as frame older than the signal handler, instead of
2169 the real mainline code.
2171 - when the thread is later resumed, the signal handler would
2172 return to the scratch pad area, which would no longer be
2174 if (step_over_info_valid_p ()
2175 || displaced_step_in_progress (tp
->inf
))
2176 target_pass_signals ({});
2178 target_pass_signals (signal_pass
);
2180 target_resume (resume_ptid
, step
, sig
);
2182 if (target_can_async_p ())
2186 /* Resume the inferior. SIG is the signal to give the inferior
2187 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2188 call 'resume', which handles exceptions. */
2191 resume_1 (enum gdb_signal sig
)
2193 struct regcache
*regcache
= get_current_regcache ();
2194 struct gdbarch
*gdbarch
= regcache
->arch ();
2195 struct thread_info
*tp
= inferior_thread ();
2196 const address_space
*aspace
= regcache
->aspace ();
2198 /* This represents the user's step vs continue request. When
2199 deciding whether "set scheduler-locking step" applies, it's the
2200 user's intention that counts. */
2201 const int user_step
= tp
->control
.stepping_command
;
2202 /* This represents what we'll actually request the target to do.
2203 This can decay from a step to a continue, if e.g., we need to
2204 implement single-stepping with breakpoints (software
2208 gdb_assert (!tp
->stop_requested
);
2209 gdb_assert (!thread_is_in_step_over_chain (tp
));
2211 if (tp
->has_pending_waitstatus ())
2214 ("thread %s has pending wait "
2215 "status %s (currently_stepping=%d).",
2216 tp
->ptid
.to_string ().c_str (),
2217 target_waitstatus_to_string (&tp
->pending_waitstatus ()).c_str (),
2218 currently_stepping (tp
));
2220 tp
->inf
->process_target ()->threads_executing
= true;
2221 tp
->set_resumed (true);
2223 /* FIXME: What should we do if we are supposed to resume this
2224 thread with a signal? Maybe we should maintain a queue of
2225 pending signals to deliver. */
2226 if (sig
!= GDB_SIGNAL_0
)
2228 warning (_("Couldn't deliver signal %s to %s."),
2229 gdb_signal_to_name (sig
),
2230 tp
->ptid
.to_string ().c_str ());
2233 tp
->set_stop_signal (GDB_SIGNAL_0
);
2235 if (target_can_async_p ())
2238 /* Tell the event loop we have an event to process. */
2239 mark_async_event_handler (infrun_async_inferior_event_token
);
2244 tp
->stepped_breakpoint
= 0;
2246 /* Depends on stepped_breakpoint. */
2247 step
= currently_stepping (tp
);
2249 if (current_inferior ()->waiting_for_vfork_done
)
2251 /* Don't try to single-step a vfork parent that is waiting for
2252 the child to get out of the shared memory region (by exec'ing
2253 or exiting). This is particularly important on software
2254 single-step archs, as the child process would trip on the
2255 software single step breakpoint inserted for the parent
2256 process. Since the parent will not actually execute any
2257 instruction until the child is out of the shared region (such
2258 are vfork's semantics), it is safe to simply continue it.
2259 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2260 the parent, and tell it to `keep_going', which automatically
2261 re-sets it stepping. */
2262 infrun_debug_printf ("resume : clear step");
2266 CORE_ADDR pc
= regcache_read_pc (regcache
);
2268 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2269 "current thread [%s] at %s",
2270 step
, gdb_signal_to_symbol_string (sig
),
2271 tp
->control
.trap_expected
,
2272 inferior_ptid
.to_string ().c_str (),
2273 paddress (gdbarch
, pc
));
2275 /* Normally, by the time we reach `resume', the breakpoints are either
2276 removed or inserted, as appropriate. The exception is if we're sitting
2277 at a permanent breakpoint; we need to step over it, but permanent
2278 breakpoints can't be removed. So we have to test for it here. */
2279 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2281 if (sig
!= GDB_SIGNAL_0
)
2283 /* We have a signal to pass to the inferior. The resume
2284 may, or may not take us to the signal handler. If this
2285 is a step, we'll need to stop in the signal handler, if
2286 there's one, (if the target supports stepping into
2287 handlers), or in the next mainline instruction, if
2288 there's no handler. If this is a continue, we need to be
2289 sure to run the handler with all breakpoints inserted.
2290 In all cases, set a breakpoint at the current address
2291 (where the handler returns to), and once that breakpoint
2292 is hit, resume skipping the permanent breakpoint. If
2293 that breakpoint isn't hit, then we've stepped into the
2294 signal handler (or hit some other event). We'll delete
2295 the step-resume breakpoint then. */
2297 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2298 "deliver signal first");
2300 clear_step_over_info ();
2301 tp
->control
.trap_expected
= 0;
2303 if (tp
->control
.step_resume_breakpoint
== NULL
)
2305 /* Set a "high-priority" step-resume, as we don't want
2306 user breakpoints at PC to trigger (again) when this
2308 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2309 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2311 tp
->step_after_step_resume_breakpoint
= step
;
2314 insert_breakpoints ();
2318 /* There's no signal to pass, we can go ahead and skip the
2319 permanent breakpoint manually. */
2320 infrun_debug_printf ("skipping permanent breakpoint");
2321 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2322 /* Update pc to reflect the new address from which we will
2323 execute instructions. */
2324 pc
= regcache_read_pc (regcache
);
2328 /* We've already advanced the PC, so the stepping part
2329 is done. Now we need to arrange for a trap to be
2330 reported to handle_inferior_event. Set a breakpoint
2331 at the current PC, and run to it. Don't update
2332 prev_pc, because if we end in
2333 switch_back_to_stepped_thread, we want the "expected
2334 thread advanced also" branch to be taken. IOW, we
2335 don't want this thread to step further from PC
2337 gdb_assert (!step_over_info_valid_p ());
2338 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2339 insert_breakpoints ();
2341 resume_ptid
= internal_resume_ptid (user_step
);
2342 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2343 tp
->set_resumed (true);
2349 /* If we have a breakpoint to step over, make sure to do a single
2350 step only. Same if we have software watchpoints. */
2351 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2352 tp
->control
.may_range_step
= 0;
2354 /* If displaced stepping is enabled, step over breakpoints by executing a
2355 copy of the instruction at a different address.
2357 We can't use displaced stepping when we have a signal to deliver;
2358 the comments for displaced_step_prepare explain why. The
2359 comments in the handle_inferior event for dealing with 'random
2360 signals' explain what we do instead.
2362 We can't use displaced stepping when we are waiting for vfork_done
2363 event, displaced stepping breaks the vfork child similarly as single
2364 step software breakpoint. */
2365 if (tp
->control
.trap_expected
2366 && use_displaced_stepping (tp
)
2367 && !step_over_info_valid_p ()
2368 && sig
== GDB_SIGNAL_0
2369 && !current_inferior ()->waiting_for_vfork_done
)
2371 displaced_step_prepare_status prepare_status
2372 = displaced_step_prepare (tp
);
2374 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2376 infrun_debug_printf ("Got placed in step-over queue");
2378 tp
->control
.trap_expected
= 0;
2381 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_CANT
)
2383 /* Fallback to stepping over the breakpoint in-line. */
2385 if (target_is_non_stop_p ())
2386 stop_all_threads ();
2388 set_step_over_info (regcache
->aspace (),
2389 regcache_read_pc (regcache
), 0, tp
->global_num
);
2391 step
= maybe_software_singlestep (gdbarch
);
2393 insert_breakpoints ();
2395 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2397 /* Update pc to reflect the new address from which we will
2398 execute instructions due to displaced stepping. */
2399 pc
= regcache_read_pc (get_thread_regcache (tp
));
2401 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2404 gdb_assert_not_reached ("Invalid displaced_step_prepare_status "
2408 /* Do we need to do it the hard way, w/temp breakpoints? */
2410 step
= maybe_software_singlestep (gdbarch
);
2412 /* Currently, our software single-step implementation leads to different
2413 results than hardware single-stepping in one situation: when stepping
2414 into delivering a signal which has an associated signal handler,
2415 hardware single-step will stop at the first instruction of the handler,
2416 while software single-step will simply skip execution of the handler.
2418 For now, this difference in behavior is accepted since there is no
2419 easy way to actually implement single-stepping into a signal handler
2420 without kernel support.
2422 However, there is one scenario where this difference leads to follow-on
2423 problems: if we're stepping off a breakpoint by removing all breakpoints
2424 and then single-stepping. In this case, the software single-step
2425 behavior means that even if there is a *breakpoint* in the signal
2426 handler, GDB still would not stop.
2428 Fortunately, we can at least fix this particular issue. We detect
2429 here the case where we are about to deliver a signal while software
2430 single-stepping with breakpoints removed. In this situation, we
2431 revert the decisions to remove all breakpoints and insert single-
2432 step breakpoints, and instead we install a step-resume breakpoint
2433 at the current address, deliver the signal without stepping, and
2434 once we arrive back at the step-resume breakpoint, actually step
2435 over the breakpoint we originally wanted to step over. */
2436 if (thread_has_single_step_breakpoints_set (tp
)
2437 && sig
!= GDB_SIGNAL_0
2438 && step_over_info_valid_p ())
2440 /* If we have nested signals or a pending signal is delivered
2441 immediately after a handler returns, might already have
2442 a step-resume breakpoint set on the earlier handler. We cannot
2443 set another step-resume breakpoint; just continue on until the
2444 original breakpoint is hit. */
2445 if (tp
->control
.step_resume_breakpoint
== NULL
)
2447 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2448 tp
->step_after_step_resume_breakpoint
= 1;
2451 delete_single_step_breakpoints (tp
);
2453 clear_step_over_info ();
2454 tp
->control
.trap_expected
= 0;
2456 insert_breakpoints ();
2459 /* If STEP is set, it's a request to use hardware stepping
2460 facilities. But in that case, we should never
2461 use singlestep breakpoint. */
2462 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2464 /* Decide the set of threads to ask the target to resume. */
2465 if (tp
->control
.trap_expected
)
2467 /* We're allowing a thread to run past a breakpoint it has
2468 hit, either by single-stepping the thread with the breakpoint
2469 removed, or by displaced stepping, with the breakpoint inserted.
2470 In the former case, we need to single-step only this thread,
2471 and keep others stopped, as they can miss this breakpoint if
2472 allowed to run. That's not really a problem for displaced
2473 stepping, but, we still keep other threads stopped, in case
2474 another thread is also stopped for a breakpoint waiting for
2475 its turn in the displaced stepping queue. */
2476 resume_ptid
= inferior_ptid
;
2479 resume_ptid
= internal_resume_ptid (user_step
);
2481 if (execution_direction
!= EXEC_REVERSE
2482 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2484 /* There are two cases where we currently need to step a
2485 breakpoint instruction when we have a signal to deliver:
2487 - See handle_signal_stop where we handle random signals that
2488 could take out us out of the stepping range. Normally, in
2489 that case we end up continuing (instead of stepping) over the
2490 signal handler with a breakpoint at PC, but there are cases
2491 where we should _always_ single-step, even if we have a
2492 step-resume breakpoint, like when a software watchpoint is
2493 set. Assuming single-stepping and delivering a signal at the
2494 same time would takes us to the signal handler, then we could
2495 have removed the breakpoint at PC to step over it. However,
2496 some hardware step targets (like e.g., Mac OS) can't step
2497 into signal handlers, and for those, we need to leave the
2498 breakpoint at PC inserted, as otherwise if the handler
2499 recurses and executes PC again, it'll miss the breakpoint.
2500 So we leave the breakpoint inserted anyway, but we need to
2501 record that we tried to step a breakpoint instruction, so
2502 that adjust_pc_after_break doesn't end up confused.
2504 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2505 in one thread after another thread that was stepping had been
2506 momentarily paused for a step-over. When we re-resume the
2507 stepping thread, it may be resumed from that address with a
2508 breakpoint that hasn't trapped yet. Seen with
2509 gdb.threads/non-stop-fair-events.exp, on targets that don't
2510 do displaced stepping. */
2512 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2513 tp
->ptid
.to_string ().c_str ());
2515 tp
->stepped_breakpoint
= 1;
2517 /* Most targets can step a breakpoint instruction, thus
2518 executing it normally. But if this one cannot, just
2519 continue and we will hit it anyway. */
2520 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2525 && tp
->control
.trap_expected
2526 && use_displaced_stepping (tp
)
2527 && !step_over_info_valid_p ())
2529 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2530 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2531 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2534 read_memory (actual_pc
, buf
, sizeof (buf
));
2535 displaced_debug_printf ("run %s: %s",
2536 paddress (resume_gdbarch
, actual_pc
),
2537 displaced_step_dump_bytes
2538 (buf
, sizeof (buf
)).c_str ());
2541 if (tp
->control
.may_range_step
)
2543 /* If we're resuming a thread with the PC out of the step
2544 range, then we're doing some nested/finer run control
2545 operation, like stepping the thread out of the dynamic
2546 linker or the displaced stepping scratch pad. We
2547 shouldn't have allowed a range step then. */
2548 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2551 do_target_resume (resume_ptid
, step
, sig
);
2552 tp
->set_resumed (true);
2555 /* Resume the inferior. SIG is the signal to give the inferior
2556 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2557 rolls back state on error. */
2560 resume (gdb_signal sig
)
2566 catch (const gdb_exception
&ex
)
2568 /* If resuming is being aborted for any reason, delete any
2569 single-step breakpoint resume_1 may have created, to avoid
2570 confusing the following resumption, and to avoid leaving
2571 single-step breakpoints perturbing other threads, in case
2572 we're running in non-stop mode. */
2573 if (inferior_ptid
!= null_ptid
)
2574 delete_single_step_breakpoints (inferior_thread ());
2584 /* Counter that tracks number of user visible stops. This can be used
2585 to tell whether a command has proceeded the inferior past the
2586 current location. This allows e.g., inferior function calls in
2587 breakpoint commands to not interrupt the command list. When the
2588 call finishes successfully, the inferior is standing at the same
2589 breakpoint as if nothing happened (and so we don't call
2591 static ULONGEST current_stop_id
;
2598 return current_stop_id
;
2601 /* Called when we report a user visible stop. */
2609 /* Clear out all variables saying what to do when inferior is continued.
2610 First do this, then set the ones you want, then call `proceed'. */
2613 clear_proceed_status_thread (struct thread_info
*tp
)
2615 infrun_debug_printf ("%s", tp
->ptid
.to_string ().c_str ());
2617 /* If we're starting a new sequence, then the previous finished
2618 single-step is no longer relevant. */
2619 if (tp
->has_pending_waitstatus ())
2621 if (tp
->stop_reason () == TARGET_STOPPED_BY_SINGLE_STEP
)
2623 infrun_debug_printf ("pending event of %s was a finished step. "
2625 tp
->ptid
.to_string ().c_str ());
2627 tp
->clear_pending_waitstatus ();
2628 tp
->set_stop_reason (TARGET_STOPPED_BY_NO_REASON
);
2633 ("thread %s has pending wait status %s (currently_stepping=%d).",
2634 tp
->ptid
.to_string ().c_str (),
2635 target_waitstatus_to_string (&tp
->pending_waitstatus ()).c_str (),
2636 currently_stepping (tp
));
2640 /* If this signal should not be seen by program, give it zero.
2641 Used for debugging signals. */
2642 if (!signal_pass_state (tp
->stop_signal ()))
2643 tp
->set_stop_signal (GDB_SIGNAL_0
);
2645 delete tp
->thread_fsm
;
2646 tp
->thread_fsm
= NULL
;
2648 tp
->control
.trap_expected
= 0;
2649 tp
->control
.step_range_start
= 0;
2650 tp
->control
.step_range_end
= 0;
2651 tp
->control
.may_range_step
= 0;
2652 tp
->control
.step_frame_id
= null_frame_id
;
2653 tp
->control
.step_stack_frame_id
= null_frame_id
;
2654 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2655 tp
->control
.step_start_function
= NULL
;
2656 tp
->stop_requested
= 0;
2658 tp
->control
.stop_step
= 0;
2660 tp
->control
.proceed_to_finish
= 0;
2662 tp
->control
.stepping_command
= 0;
2664 /* Discard any remaining commands or status from previous stop. */
2665 bpstat_clear (&tp
->control
.stop_bpstat
);
2669 clear_proceed_status (int step
)
2671 /* With scheduler-locking replay, stop replaying other threads if we're
2672 not replaying the user-visible resume ptid.
2674 This is a convenience feature to not require the user to explicitly
2675 stop replaying the other threads. We're assuming that the user's
2676 intent is to resume tracing the recorded process. */
2677 if (!non_stop
&& scheduler_mode
== schedlock_replay
2678 && target_record_is_replaying (minus_one_ptid
)
2679 && !target_record_will_replay (user_visible_resume_ptid (step
),
2680 execution_direction
))
2681 target_record_stop_replaying ();
2683 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2685 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2686 process_stratum_target
*resume_target
2687 = user_visible_resume_target (resume_ptid
);
2689 /* In all-stop mode, delete the per-thread status of all threads
2690 we're about to resume, implicitly and explicitly. */
2691 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2692 clear_proceed_status_thread (tp
);
2695 if (inferior_ptid
!= null_ptid
)
2697 struct inferior
*inferior
;
2701 /* If in non-stop mode, only delete the per-thread status of
2702 the current thread. */
2703 clear_proceed_status_thread (inferior_thread ());
2706 inferior
= current_inferior ();
2707 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2710 gdb::observers::about_to_proceed
.notify ();
2713 /* Returns true if TP is still stopped at a breakpoint that needs
2714 stepping-over in order to make progress. If the breakpoint is gone
2715 meanwhile, we can skip the whole step-over dance. */
2718 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2720 if (tp
->stepping_over_breakpoint
)
2722 struct regcache
*regcache
= get_thread_regcache (tp
);
2724 if (breakpoint_here_p (regcache
->aspace (),
2725 regcache_read_pc (regcache
))
2726 == ordinary_breakpoint_here
)
2729 tp
->stepping_over_breakpoint
= 0;
2735 /* Check whether thread TP still needs to start a step-over in order
2736 to make progress when resumed. Returns an bitwise or of enum
2737 step_over_what bits, indicating what needs to be stepped over. */
2739 static step_over_what
2740 thread_still_needs_step_over (struct thread_info
*tp
)
2742 step_over_what what
= 0;
2744 if (thread_still_needs_step_over_bp (tp
))
2745 what
|= STEP_OVER_BREAKPOINT
;
2747 if (tp
->stepping_over_watchpoint
2748 && !target_have_steppable_watchpoint ())
2749 what
|= STEP_OVER_WATCHPOINT
;
2754 /* Returns true if scheduler locking applies. STEP indicates whether
2755 we're about to do a step/next-like command to a thread. */
2758 schedlock_applies (struct thread_info
*tp
)
2760 return (scheduler_mode
== schedlock_on
2761 || (scheduler_mode
== schedlock_step
2762 && tp
->control
.stepping_command
)
2763 || (scheduler_mode
== schedlock_replay
2764 && target_record_will_replay (minus_one_ptid
,
2765 execution_direction
)));
2768 /* Set process_stratum_target::COMMIT_RESUMED_STATE in all target
2769 stacks that have threads executing and don't have threads with
2773 maybe_set_commit_resumed_all_targets ()
2775 scoped_restore_current_thread restore_thread
;
2777 for (inferior
*inf
: all_non_exited_inferiors ())
2779 process_stratum_target
*proc_target
= inf
->process_target ();
2781 if (proc_target
->commit_resumed_state
)
2783 /* We already set this in a previous iteration, via another
2784 inferior sharing the process_stratum target. */
2788 /* If the target has no resumed threads, it would be useless to
2789 ask it to commit the resumed threads. */
2790 if (!proc_target
->threads_executing
)
2792 infrun_debug_printf ("not requesting commit-resumed for target "
2793 "%s, no resumed threads",
2794 proc_target
->shortname ());
2798 /* As an optimization, if a thread from this target has some
2799 status to report, handle it before requiring the target to
2800 commit its resumed threads: handling the status might lead to
2801 resuming more threads. */
2802 if (proc_target
->has_resumed_with_pending_wait_status ())
2804 infrun_debug_printf ("not requesting commit-resumed for target %s, a"
2805 " thread has a pending waitstatus",
2806 proc_target
->shortname ());
2810 switch_to_inferior_no_thread (inf
);
2812 if (target_has_pending_events ())
2814 infrun_debug_printf ("not requesting commit-resumed for target %s, "
2815 "target has pending events",
2816 proc_target
->shortname ());
2820 infrun_debug_printf ("enabling commit-resumed for target %s",
2821 proc_target
->shortname ());
2823 proc_target
->commit_resumed_state
= true;
2830 maybe_call_commit_resumed_all_targets ()
2832 scoped_restore_current_thread restore_thread
;
2834 for (inferior
*inf
: all_non_exited_inferiors ())
2836 process_stratum_target
*proc_target
= inf
->process_target ();
2838 if (!proc_target
->commit_resumed_state
)
2841 switch_to_inferior_no_thread (inf
);
2843 infrun_debug_printf ("calling commit_resumed for target %s",
2844 proc_target
->shortname());
2846 target_commit_resumed ();
2850 /* To track nesting of scoped_disable_commit_resumed objects, ensuring
2851 that only the outermost one attempts to re-enable
2853 static bool enable_commit_resumed
= true;
2857 scoped_disable_commit_resumed::scoped_disable_commit_resumed
2858 (const char *reason
)
2859 : m_reason (reason
),
2860 m_prev_enable_commit_resumed (enable_commit_resumed
)
2862 infrun_debug_printf ("reason=%s", m_reason
);
2864 enable_commit_resumed
= false;
2866 for (inferior
*inf
: all_non_exited_inferiors ())
2868 process_stratum_target
*proc_target
= inf
->process_target ();
2870 if (m_prev_enable_commit_resumed
)
2872 /* This is the outermost instance: force all
2873 COMMIT_RESUMED_STATE to false. */
2874 proc_target
->commit_resumed_state
= false;
2878 /* This is not the outermost instance, we expect
2879 COMMIT_RESUMED_STATE to have been cleared by the
2880 outermost instance. */
2881 gdb_assert (!proc_target
->commit_resumed_state
);
2889 scoped_disable_commit_resumed::reset ()
2895 infrun_debug_printf ("reason=%s", m_reason
);
2897 gdb_assert (!enable_commit_resumed
);
2899 enable_commit_resumed
= m_prev_enable_commit_resumed
;
2901 if (m_prev_enable_commit_resumed
)
2903 /* This is the outermost instance, re-enable
2904 COMMIT_RESUMED_STATE on the targets where it's possible. */
2905 maybe_set_commit_resumed_all_targets ();
2909 /* This is not the outermost instance, we expect
2910 COMMIT_RESUMED_STATE to still be false. */
2911 for (inferior
*inf
: all_non_exited_inferiors ())
2913 process_stratum_target
*proc_target
= inf
->process_target ();
2914 gdb_assert (!proc_target
->commit_resumed_state
);
2921 scoped_disable_commit_resumed::~scoped_disable_commit_resumed ()
2929 scoped_disable_commit_resumed::reset_and_commit ()
2932 maybe_call_commit_resumed_all_targets ();
2937 scoped_enable_commit_resumed::scoped_enable_commit_resumed
2938 (const char *reason
)
2939 : m_reason (reason
),
2940 m_prev_enable_commit_resumed (enable_commit_resumed
)
2942 infrun_debug_printf ("reason=%s", m_reason
);
2944 if (!enable_commit_resumed
)
2946 enable_commit_resumed
= true;
2948 /* Re-enable COMMIT_RESUMED_STATE on the targets where it's
2950 maybe_set_commit_resumed_all_targets ();
2952 maybe_call_commit_resumed_all_targets ();
2958 scoped_enable_commit_resumed::~scoped_enable_commit_resumed ()
2960 infrun_debug_printf ("reason=%s", m_reason
);
2962 gdb_assert (enable_commit_resumed
);
2964 enable_commit_resumed
= m_prev_enable_commit_resumed
;
2966 if (!enable_commit_resumed
)
2968 /* Force all COMMIT_RESUMED_STATE back to false. */
2969 for (inferior
*inf
: all_non_exited_inferiors ())
2971 process_stratum_target
*proc_target
= inf
->process_target ();
2972 proc_target
->commit_resumed_state
= false;
2977 /* Check that all the targets we're about to resume are in non-stop
2978 mode. Ideally, we'd only care whether all targets support
2979 target-async, but we're not there yet. E.g., stop_all_threads
2980 doesn't know how to handle all-stop targets. Also, the remote
2981 protocol in all-stop mode is synchronous, irrespective of
2982 target-async, which means that things like a breakpoint re-set
2983 triggered by one target would try to read memory from all targets
2987 check_multi_target_resumption (process_stratum_target
*resume_target
)
2989 if (!non_stop
&& resume_target
== nullptr)
2991 scoped_restore_current_thread restore_thread
;
2993 /* This is used to track whether we're resuming more than one
2995 process_stratum_target
*first_connection
= nullptr;
2997 /* The first inferior we see with a target that does not work in
2998 always-non-stop mode. */
2999 inferior
*first_not_non_stop
= nullptr;
3001 for (inferior
*inf
: all_non_exited_inferiors ())
3003 switch_to_inferior_no_thread (inf
);
3005 if (!target_has_execution ())
3008 process_stratum_target
*proc_target
3009 = current_inferior ()->process_target();
3011 if (!target_is_non_stop_p ())
3012 first_not_non_stop
= inf
;
3014 if (first_connection
== nullptr)
3015 first_connection
= proc_target
;
3016 else if (first_connection
!= proc_target
3017 && first_not_non_stop
!= nullptr)
3019 switch_to_inferior_no_thread (first_not_non_stop
);
3021 proc_target
= current_inferior ()->process_target();
3023 error (_("Connection %d (%s) does not support "
3024 "multi-target resumption."),
3025 proc_target
->connection_number
,
3026 make_target_connection_string (proc_target
).c_str ());
3032 /* Basic routine for continuing the program in various fashions.
3034 ADDR is the address to resume at, or -1 for resume where stopped.
3035 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
3036 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
3038 You should call clear_proceed_status before calling proceed. */
3041 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
3043 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
3045 struct regcache
*regcache
;
3046 struct gdbarch
*gdbarch
;
3048 struct execution_control_state ecss
;
3049 struct execution_control_state
*ecs
= &ecss
;
3052 /* If we're stopped at a fork/vfork, follow the branch set by the
3053 "set follow-fork-mode" command; otherwise, we'll just proceed
3054 resuming the current thread. */
3055 if (!follow_fork ())
3057 /* The target for some reason decided not to resume. */
3059 if (target_can_async_p ())
3060 inferior_event_handler (INF_EXEC_COMPLETE
);
3064 /* We'll update this if & when we switch to a new thread. */
3065 previous_inferior_ptid
= inferior_ptid
;
3067 regcache
= get_current_regcache ();
3068 gdbarch
= regcache
->arch ();
3069 const address_space
*aspace
= regcache
->aspace ();
3071 pc
= regcache_read_pc_protected (regcache
);
3073 thread_info
*cur_thr
= inferior_thread ();
3075 /* Fill in with reasonable starting values. */
3076 init_thread_stepping_state (cur_thr
);
3078 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
3081 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
3082 process_stratum_target
*resume_target
3083 = user_visible_resume_target (resume_ptid
);
3085 check_multi_target_resumption (resume_target
);
3087 if (addr
== (CORE_ADDR
) -1)
3089 if (cur_thr
->stop_pc_p ()
3090 && pc
== cur_thr
->stop_pc ()
3091 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3092 && execution_direction
!= EXEC_REVERSE
)
3093 /* There is a breakpoint at the address we will resume at,
3094 step one instruction before inserting breakpoints so that
3095 we do not stop right away (and report a second hit at this
3098 Note, we don't do this in reverse, because we won't
3099 actually be executing the breakpoint insn anyway.
3100 We'll be (un-)executing the previous instruction. */
3101 cur_thr
->stepping_over_breakpoint
= 1;
3102 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3103 && gdbarch_single_step_through_delay (gdbarch
,
3104 get_current_frame ()))
3105 /* We stepped onto an instruction that needs to be stepped
3106 again before re-inserting the breakpoint, do so. */
3107 cur_thr
->stepping_over_breakpoint
= 1;
3111 regcache_write_pc (regcache
, addr
);
3114 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3115 cur_thr
->set_stop_signal (siggnal
);
3117 /* If an exception is thrown from this point on, make sure to
3118 propagate GDB's knowledge of the executing state to the
3119 frontend/user running state. */
3120 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3122 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3123 threads (e.g., we might need to set threads stepping over
3124 breakpoints first), from the user/frontend's point of view, all
3125 threads in RESUME_PTID are now running. Unless we're calling an
3126 inferior function, as in that case we pretend the inferior
3127 doesn't run at all. */
3128 if (!cur_thr
->control
.in_infcall
)
3129 set_running (resume_target
, resume_ptid
, true);
3131 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3132 gdb_signal_to_symbol_string (siggnal
));
3134 annotate_starting ();
3136 /* Make sure that output from GDB appears before output from the
3138 gdb_flush (gdb_stdout
);
3140 /* Since we've marked the inferior running, give it the terminal. A
3141 QUIT/Ctrl-C from here on is forwarded to the target (which can
3142 still detect attempts to unblock a stuck connection with repeated
3143 Ctrl-C from within target_pass_ctrlc). */
3144 target_terminal::inferior ();
3146 /* In a multi-threaded task we may select another thread and
3147 then continue or step.
3149 But if a thread that we're resuming had stopped at a breakpoint,
3150 it will immediately cause another breakpoint stop without any
3151 execution (i.e. it will report a breakpoint hit incorrectly). So
3152 we must step over it first.
3154 Look for threads other than the current (TP) that reported a
3155 breakpoint hit and haven't been resumed yet since. */
3157 /* If scheduler locking applies, we can avoid iterating over all
3159 if (!non_stop
&& !schedlock_applies (cur_thr
))
3161 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3164 switch_to_thread_no_regs (tp
);
3166 /* Ignore the current thread here. It's handled
3171 if (!thread_still_needs_step_over (tp
))
3174 gdb_assert (!thread_is_in_step_over_chain (tp
));
3176 infrun_debug_printf ("need to step-over [%s] first",
3177 tp
->ptid
.to_string ().c_str ());
3179 global_thread_step_over_chain_enqueue (tp
);
3182 switch_to_thread (cur_thr
);
3185 /* Enqueue the current thread last, so that we move all other
3186 threads over their breakpoints first. */
3187 if (cur_thr
->stepping_over_breakpoint
)
3188 global_thread_step_over_chain_enqueue (cur_thr
);
3190 /* If the thread isn't started, we'll still need to set its prev_pc,
3191 so that switch_back_to_stepped_thread knows the thread hasn't
3192 advanced. Must do this before resuming any thread, as in
3193 all-stop/remote, once we resume we can't send any other packet
3194 until the target stops again. */
3195 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3198 scoped_disable_commit_resumed
disable_commit_resumed ("proceeding");
3200 started
= start_step_over ();
3202 if (step_over_info_valid_p ())
3204 /* Either this thread started a new in-line step over, or some
3205 other thread was already doing one. In either case, don't
3206 resume anything else until the step-over is finished. */
3208 else if (started
&& !target_is_non_stop_p ())
3210 /* A new displaced stepping sequence was started. In all-stop,
3211 we can't talk to the target anymore until it next stops. */
3213 else if (!non_stop
&& target_is_non_stop_p ())
3215 INFRUN_SCOPED_DEBUG_START_END
3216 ("resuming threads, all-stop-on-top-of-non-stop");
3218 /* In all-stop, but the target is always in non-stop mode.
3219 Start all other threads that are implicitly resumed too. */
3220 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3223 switch_to_thread_no_regs (tp
);
3225 if (!tp
->inf
->has_execution ())
3227 infrun_debug_printf ("[%s] target has no execution",
3228 tp
->ptid
.to_string ().c_str ());
3234 infrun_debug_printf ("[%s] resumed",
3235 tp
->ptid
.to_string ().c_str ());
3236 gdb_assert (tp
->executing () || tp
->has_pending_waitstatus ());
3240 if (thread_is_in_step_over_chain (tp
))
3242 infrun_debug_printf ("[%s] needs step-over",
3243 tp
->ptid
.to_string ().c_str ());
3247 infrun_debug_printf ("resuming %s",
3248 tp
->ptid
.to_string ().c_str ());
3250 reset_ecs (ecs
, tp
);
3251 switch_to_thread (tp
);
3252 keep_going_pass_signal (ecs
);
3253 if (!ecs
->wait_some_more
)
3254 error (_("Command aborted."));
3257 else if (!cur_thr
->resumed () && !thread_is_in_step_over_chain (cur_thr
))
3259 /* The thread wasn't started, and isn't queued, run it now. */
3260 reset_ecs (ecs
, cur_thr
);
3261 switch_to_thread (cur_thr
);
3262 keep_going_pass_signal (ecs
);
3263 if (!ecs
->wait_some_more
)
3264 error (_("Command aborted."));
3267 disable_commit_resumed
.reset_and_commit ();
3270 finish_state
.release ();
3272 /* If we've switched threads above, switch back to the previously
3273 current thread. We don't want the user to see a different
3275 switch_to_thread (cur_thr
);
3277 /* Tell the event loop to wait for it to stop. If the target
3278 supports asynchronous execution, it'll do this from within
3280 if (!target_can_async_p ())
3281 mark_async_event_handler (infrun_async_inferior_event_token
);
3285 /* Start remote-debugging of a machine over a serial link. */
3288 start_remote (int from_tty
)
3290 inferior
*inf
= current_inferior ();
3291 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3293 /* Always go on waiting for the target, regardless of the mode. */
3294 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3295 indicate to wait_for_inferior that a target should timeout if
3296 nothing is returned (instead of just blocking). Because of this,
3297 targets expecting an immediate response need to, internally, set
3298 things up so that the target_wait() is forced to eventually
3300 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3301 differentiate to its caller what the state of the target is after
3302 the initial open has been performed. Here we're assuming that
3303 the target has stopped. It should be possible to eventually have
3304 target_open() return to the caller an indication that the target
3305 is currently running and GDB state should be set to the same as
3306 for an async run. */
3307 wait_for_inferior (inf
);
3309 /* Now that the inferior has stopped, do any bookkeeping like
3310 loading shared libraries. We want to do this before normal_stop,
3311 so that the displayed frame is up to date. */
3312 post_create_inferior (from_tty
);
3317 /* Initialize static vars when a new inferior begins. */
3320 init_wait_for_inferior (void)
3322 /* These are meaningless until the first time through wait_for_inferior. */
3324 breakpoint_init_inferior (inf_starting
);
3326 clear_proceed_status (0);
3328 nullify_last_target_wait_ptid ();
3330 previous_inferior_ptid
= inferior_ptid
;
3335 static void handle_inferior_event (struct execution_control_state
*ecs
);
3337 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3338 struct execution_control_state
*ecs
);
3339 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3340 struct execution_control_state
*ecs
);
3341 static void handle_signal_stop (struct execution_control_state
*ecs
);
3342 static void check_exception_resume (struct execution_control_state
*,
3343 struct frame_info
*);
3345 static void end_stepping_range (struct execution_control_state
*ecs
);
3346 static void stop_waiting (struct execution_control_state
*ecs
);
3347 static void keep_going (struct execution_control_state
*ecs
);
3348 static void process_event_stop_test (struct execution_control_state
*ecs
);
3349 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3351 /* This function is attached as a "thread_stop_requested" observer.
3352 Cleanup local state that assumed the PTID was to be resumed, and
3353 report the stop to the frontend. */
3356 infrun_thread_stop_requested (ptid_t ptid
)
3358 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3360 /* PTID was requested to stop. If the thread was already stopped,
3361 but the user/frontend doesn't know about that yet (e.g., the
3362 thread had been temporarily paused for some step-over), set up
3363 for reporting the stop now. */
3364 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3366 if (tp
->state
!= THREAD_RUNNING
)
3368 if (tp
->executing ())
3371 /* Remove matching threads from the step-over queue, so
3372 start_step_over doesn't try to resume them
3374 if (thread_is_in_step_over_chain (tp
))
3375 global_thread_step_over_chain_remove (tp
);
3377 /* If the thread is stopped, but the user/frontend doesn't
3378 know about that yet, queue a pending event, as if the
3379 thread had just stopped now. Unless the thread already had
3381 if (!tp
->has_pending_waitstatus ())
3383 target_waitstatus ws
;
3384 ws
.set_stopped (GDB_SIGNAL_0
);
3385 tp
->set_pending_waitstatus (ws
);
3388 /* Clear the inline-frame state, since we're re-processing the
3390 clear_inline_frame_state (tp
);
3392 /* If this thread was paused because some other thread was
3393 doing an inline-step over, let that finish first. Once
3394 that happens, we'll restart all threads and consume pending
3395 stop events then. */
3396 if (step_over_info_valid_p ())
3399 /* Otherwise we can process the (new) pending event now. Set
3400 it so this pending event is considered by
3402 tp
->set_resumed (true);
3407 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3409 if (target_last_proc_target
== tp
->inf
->process_target ()
3410 && target_last_wait_ptid
== tp
->ptid
)
3411 nullify_last_target_wait_ptid ();
3414 /* Delete the step resume, single-step and longjmp/exception resume
3415 breakpoints of TP. */
3418 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3420 delete_step_resume_breakpoint (tp
);
3421 delete_exception_resume_breakpoint (tp
);
3422 delete_single_step_breakpoints (tp
);
3425 /* If the target still has execution, call FUNC for each thread that
3426 just stopped. In all-stop, that's all the non-exited threads; in
3427 non-stop, that's the current thread, only. */
3429 typedef void (*for_each_just_stopped_thread_callback_func
)
3430 (struct thread_info
*tp
);
3433 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3435 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3438 if (target_is_non_stop_p ())
3440 /* If in non-stop mode, only the current thread stopped. */
3441 func (inferior_thread ());
3445 /* In all-stop mode, all threads have stopped. */
3446 for (thread_info
*tp
: all_non_exited_threads ())
3451 /* Delete the step resume and longjmp/exception resume breakpoints of
3452 the threads that just stopped. */
3455 delete_just_stopped_threads_infrun_breakpoints (void)
3457 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3460 /* Delete the single-step breakpoints of the threads that just
3464 delete_just_stopped_threads_single_step_breakpoints (void)
3466 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3472 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3473 const struct target_waitstatus
*ws
)
3475 infrun_debug_printf ("target_wait (%s [%s], status) =",
3476 waiton_ptid
.to_string ().c_str (),
3477 target_pid_to_str (waiton_ptid
).c_str ());
3478 infrun_debug_printf (" %s [%s],",
3479 result_ptid
.to_string ().c_str (),
3480 target_pid_to_str (result_ptid
).c_str ());
3481 infrun_debug_printf (" %s", target_waitstatus_to_string (ws
).c_str ());
3484 /* Select a thread at random, out of those which are resumed and have
3487 static struct thread_info
*
3488 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3490 process_stratum_target
*proc_target
= inf
->process_target ();
3492 = proc_target
->random_resumed_with_pending_wait_status (inf
, waiton_ptid
);
3494 if (thread
== nullptr)
3496 infrun_debug_printf ("None found.");
3500 infrun_debug_printf ("Found %s.", thread
->ptid
.to_string ().c_str ());
3501 gdb_assert (thread
->resumed ());
3502 gdb_assert (thread
->has_pending_waitstatus ());
3507 /* Wrapper for target_wait that first checks whether threads have
3508 pending statuses to report before actually asking the target for
3509 more events. INF is the inferior we're using to call target_wait
3513 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3514 target_waitstatus
*status
, target_wait_flags options
)
3517 struct thread_info
*tp
;
3519 /* We know that we are looking for an event in the target of inferior
3520 INF, but we don't know which thread the event might come from. As
3521 such we want to make sure that INFERIOR_PTID is reset so that none of
3522 the wait code relies on it - doing so is always a mistake. */
3523 switch_to_inferior_no_thread (inf
);
3525 /* First check if there is a resumed thread with a wait status
3527 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3529 tp
= random_pending_event_thread (inf
, ptid
);
3533 infrun_debug_printf ("Waiting for specific thread %s.",
3534 ptid
.to_string ().c_str ());
3536 /* We have a specific thread to check. */
3537 tp
= find_thread_ptid (inf
, ptid
);
3538 gdb_assert (tp
!= NULL
);
3539 if (!tp
->has_pending_waitstatus ())
3544 && (tp
->stop_reason () == TARGET_STOPPED_BY_SW_BREAKPOINT
3545 || tp
->stop_reason () == TARGET_STOPPED_BY_HW_BREAKPOINT
))
3547 struct regcache
*regcache
= get_thread_regcache (tp
);
3548 struct gdbarch
*gdbarch
= regcache
->arch ();
3552 pc
= regcache_read_pc (regcache
);
3554 if (pc
!= tp
->stop_pc ())
3556 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3557 tp
->ptid
.to_string ().c_str (),
3558 paddress (gdbarch
, tp
->stop_pc ()),
3559 paddress (gdbarch
, pc
));
3562 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3564 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3565 tp
->ptid
.to_string ().c_str (),
3566 paddress (gdbarch
, pc
));
3573 infrun_debug_printf ("pending event of %s cancelled.",
3574 tp
->ptid
.to_string ().c_str ());
3576 tp
->clear_pending_waitstatus ();
3577 target_waitstatus ws
;
3579 tp
->set_pending_waitstatus (ws
);
3580 tp
->set_stop_reason (TARGET_STOPPED_BY_NO_REASON
);
3586 infrun_debug_printf ("Using pending wait status %s for %s.",
3587 target_waitstatus_to_string
3588 (&tp
->pending_waitstatus ()).c_str (),
3589 tp
->ptid
.to_string ().c_str ());
3591 /* Now that we've selected our final event LWP, un-adjust its PC
3592 if it was a software breakpoint (and the target doesn't
3593 always adjust the PC itself). */
3594 if (tp
->stop_reason () == TARGET_STOPPED_BY_SW_BREAKPOINT
3595 && !target_supports_stopped_by_sw_breakpoint ())
3597 struct regcache
*regcache
;
3598 struct gdbarch
*gdbarch
;
3601 regcache
= get_thread_regcache (tp
);
3602 gdbarch
= regcache
->arch ();
3604 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3609 pc
= regcache_read_pc (regcache
);
3610 regcache_write_pc (regcache
, pc
+ decr_pc
);
3614 tp
->set_stop_reason (TARGET_STOPPED_BY_NO_REASON
);
3615 *status
= tp
->pending_waitstatus ();
3616 tp
->clear_pending_waitstatus ();
3618 /* Wake up the event loop again, until all pending events are
3620 if (target_is_async_p ())
3621 mark_async_event_handler (infrun_async_inferior_event_token
);
3625 /* But if we don't find one, we'll have to wait. */
3627 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3629 if (!target_can_async_p ())
3630 options
&= ~TARGET_WNOHANG
;
3632 if (deprecated_target_wait_hook
)
3633 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3635 event_ptid
= target_wait (ptid
, status
, options
);
3640 /* Wrapper for target_wait that first checks whether threads have
3641 pending statuses to report before actually asking the target for
3642 more events. Polls for events from all inferiors/targets. */
3645 do_target_wait (execution_control_state
*ecs
, target_wait_flags options
)
3647 int num_inferiors
= 0;
3648 int random_selector
;
3650 /* For fairness, we pick the first inferior/target to poll at random
3651 out of all inferiors that may report events, and then continue
3652 polling the rest of the inferior list starting from that one in a
3653 circular fashion until the whole list is polled once. */
3655 auto inferior_matches
= [] (inferior
*inf
)
3657 return inf
->process_target () != nullptr;
3660 /* First see how many matching inferiors we have. */
3661 for (inferior
*inf
: all_inferiors ())
3662 if (inferior_matches (inf
))
3665 if (num_inferiors
== 0)
3667 ecs
->ws
.set_ignore ();
3671 /* Now randomly pick an inferior out of those that matched. */
3672 random_selector
= (int)
3673 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3675 if (num_inferiors
> 1)
3676 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3677 num_inferiors
, random_selector
);
3679 /* Select the Nth inferior that matched. */
3681 inferior
*selected
= nullptr;
3683 for (inferior
*inf
: all_inferiors ())
3684 if (inferior_matches (inf
))
3685 if (random_selector
-- == 0)
3691 /* Now poll for events out of each of the matching inferior's
3692 targets, starting from the selected one. */
3694 auto do_wait
= [&] (inferior
*inf
)
3696 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, options
);
3697 ecs
->target
= inf
->process_target ();
3698 return (ecs
->ws
.kind () != TARGET_WAITKIND_IGNORE
);
3701 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3702 here spuriously after the target is all stopped and we've already
3703 reported the stop to the user, polling for events. */
3704 scoped_restore_current_thread restore_thread
;
3706 intrusive_list_iterator
<inferior
> start
3707 = inferior_list
.iterator_to (*selected
);
3709 for (intrusive_list_iterator
<inferior
> it
= start
;
3710 it
!= inferior_list
.end ();
3713 inferior
*inf
= &*it
;
3715 if (inferior_matches (inf
) && do_wait (inf
))
3719 for (intrusive_list_iterator
<inferior
> it
= inferior_list
.begin ();
3723 inferior
*inf
= &*it
;
3725 if (inferior_matches (inf
) && do_wait (inf
))
3729 ecs
->ws
.set_ignore ();
3733 /* An event reported by wait_one. */
3735 struct wait_one_event
3737 /* The target the event came out of. */
3738 process_stratum_target
*target
;
3740 /* The PTID the event was for. */
3743 /* The waitstatus. */
3744 target_waitstatus ws
;
3747 static bool handle_one (const wait_one_event
&event
);
3748 static void restart_threads (struct thread_info
*event_thread
);
3750 /* Prepare and stabilize the inferior for detaching it. E.g.,
3751 detaching while a thread is displaced stepping is a recipe for
3752 crashing it, as nothing would readjust the PC out of the scratch
3756 prepare_for_detach (void)
3758 struct inferior
*inf
= current_inferior ();
3759 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3760 scoped_restore_current_thread restore_thread
;
3762 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3764 /* Remove all threads of INF from the global step-over chain. We
3765 want to stop any ongoing step-over, not start any new one. */
3766 thread_step_over_list_safe_range range
3767 = make_thread_step_over_list_safe_range (global_thread_step_over_list
);
3769 for (thread_info
*tp
: range
)
3772 infrun_debug_printf ("removing thread %s from global step over chain",
3773 tp
->ptid
.to_string ().c_str ());
3774 global_thread_step_over_chain_remove (tp
);
3777 /* If we were already in the middle of an inline step-over, and the
3778 thread stepping belongs to the inferior we're detaching, we need
3779 to restart the threads of other inferiors. */
3780 if (step_over_info
.thread
!= -1)
3782 infrun_debug_printf ("inline step-over in-process while detaching");
3784 thread_info
*thr
= find_thread_global_id (step_over_info
.thread
);
3785 if (thr
->inf
== inf
)
3787 /* Since we removed threads of INF from the step-over chain,
3788 we know this won't start a step-over for INF. */
3789 clear_step_over_info ();
3791 if (target_is_non_stop_p ())
3793 /* Start a new step-over in another thread if there's
3794 one that needs it. */
3797 /* Restart all other threads (except the
3798 previously-stepping thread, since that one is still
3800 if (!step_over_info_valid_p ())
3801 restart_threads (thr
);
3806 if (displaced_step_in_progress (inf
))
3808 infrun_debug_printf ("displaced-stepping in-process while detaching");
3810 /* Stop threads currently displaced stepping, aborting it. */
3812 for (thread_info
*thr
: inf
->non_exited_threads ())
3814 if (thr
->displaced_step_state
.in_progress ())
3816 if (thr
->executing ())
3818 if (!thr
->stop_requested
)
3820 target_stop (thr
->ptid
);
3821 thr
->stop_requested
= true;
3825 thr
->set_resumed (false);
3829 while (displaced_step_in_progress (inf
))
3831 wait_one_event event
;
3833 event
.target
= inf
->process_target ();
3834 event
.ptid
= do_target_wait_1 (inf
, pid_ptid
, &event
.ws
, 0);
3837 print_target_wait_results (pid_ptid
, event
.ptid
, &event
.ws
);
3842 /* It's OK to leave some of the threads of INF stopped, since
3843 they'll be detached shortly. */
3847 /* Wait for control to return from inferior to debugger.
3849 If inferior gets a signal, we may decide to start it up again
3850 instead of returning. That is why there is a loop in this function.
3851 When this function actually returns it means the inferior
3852 should be left stopped and GDB should read more commands. */
3855 wait_for_inferior (inferior
*inf
)
3857 infrun_debug_printf ("wait_for_inferior ()");
3859 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3861 /* If an error happens while handling the event, propagate GDB's
3862 knowledge of the executing state to the frontend/user running
3864 scoped_finish_thread_state finish_state
3865 (inf
->process_target (), minus_one_ptid
);
3869 struct execution_control_state ecss
;
3870 struct execution_control_state
*ecs
= &ecss
;
3872 overlay_cache_invalid
= 1;
3874 /* Flush target cache before starting to handle each event.
3875 Target was running and cache could be stale. This is just a
3876 heuristic. Running threads may modify target memory, but we
3877 don't get any event. */
3878 target_dcache_invalidate ();
3880 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3881 ecs
->target
= inf
->process_target ();
3884 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3886 /* Now figure out what to do with the result of the result. */
3887 handle_inferior_event (ecs
);
3889 if (!ecs
->wait_some_more
)
3893 /* No error, don't finish the state yet. */
3894 finish_state
.release ();
3897 /* Cleanup that reinstalls the readline callback handler, if the
3898 target is running in the background. If while handling the target
3899 event something triggered a secondary prompt, like e.g., a
3900 pagination prompt, we'll have removed the callback handler (see
3901 gdb_readline_wrapper_line). Need to do this as we go back to the
3902 event loop, ready to process further input. Note this has no
3903 effect if the handler hasn't actually been removed, because calling
3904 rl_callback_handler_install resets the line buffer, thus losing
3908 reinstall_readline_callback_handler_cleanup ()
3910 struct ui
*ui
= current_ui
;
3914 /* We're not going back to the top level event loop yet. Don't
3915 install the readline callback, as it'd prep the terminal,
3916 readline-style (raw, noecho) (e.g., --batch). We'll install
3917 it the next time the prompt is displayed, when we're ready
3922 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3923 gdb_rl_callback_handler_reinstall ();
3926 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3927 that's just the event thread. In all-stop, that's all threads. */
3930 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3932 if (ecs
->event_thread
!= NULL
3933 && ecs
->event_thread
->thread_fsm
!= NULL
)
3934 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3938 for (thread_info
*thr
: all_non_exited_threads ())
3940 if (thr
->thread_fsm
== NULL
)
3942 if (thr
== ecs
->event_thread
)
3945 switch_to_thread (thr
);
3946 thr
->thread_fsm
->clean_up (thr
);
3949 if (ecs
->event_thread
!= NULL
)
3950 switch_to_thread (ecs
->event_thread
);
3954 /* Helper for all_uis_check_sync_execution_done that works on the
3958 check_curr_ui_sync_execution_done (void)
3960 struct ui
*ui
= current_ui
;
3962 if (ui
->prompt_state
== PROMPT_NEEDED
3964 && !gdb_in_secondary_prompt_p (ui
))
3966 target_terminal::ours ();
3967 gdb::observers::sync_execution_done
.notify ();
3968 ui_register_input_event_handler (ui
);
3975 all_uis_check_sync_execution_done (void)
3977 SWITCH_THRU_ALL_UIS ()
3979 check_curr_ui_sync_execution_done ();
3986 all_uis_on_sync_execution_starting (void)
3988 SWITCH_THRU_ALL_UIS ()
3990 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3991 async_disable_stdin ();
3995 /* Asynchronous version of wait_for_inferior. It is called by the
3996 event loop whenever a change of state is detected on the file
3997 descriptor corresponding to the target. It can be called more than
3998 once to complete a single execution command. In such cases we need
3999 to keep the state in a global variable ECSS. If it is the last time
4000 that this function is called for a single execution command, then
4001 report to the user that the inferior has stopped, and do the
4002 necessary cleanups. */
4005 fetch_inferior_event ()
4007 INFRUN_SCOPED_DEBUG_ENTER_EXIT
;
4009 struct execution_control_state ecss
;
4010 struct execution_control_state
*ecs
= &ecss
;
4013 /* Events are always processed with the main UI as current UI. This
4014 way, warnings, debug output, etc. are always consistently sent to
4015 the main console. */
4016 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
4018 /* Temporarily disable pagination. Otherwise, the user would be
4019 given an option to press 'q' to quit, which would cause an early
4020 exit and could leave GDB in a half-baked state. */
4021 scoped_restore save_pagination
4022 = make_scoped_restore (&pagination_enabled
, false);
4024 /* End up with readline processing input, if necessary. */
4026 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
4028 /* We're handling a live event, so make sure we're doing live
4029 debugging. If we're looking at traceframes while the target is
4030 running, we're going to need to get back to that mode after
4031 handling the event. */
4032 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
4035 maybe_restore_traceframe
.emplace ();
4036 set_current_traceframe (-1);
4039 /* The user/frontend should not notice a thread switch due to
4040 internal events. Make sure we revert to the user selected
4041 thread and frame after handling the event and running any
4042 breakpoint commands. */
4043 scoped_restore_current_thread restore_thread
;
4045 overlay_cache_invalid
= 1;
4046 /* Flush target cache before starting to handle each event. Target
4047 was running and cache could be stale. This is just a heuristic.
4048 Running threads may modify target memory, but we don't get any
4050 target_dcache_invalidate ();
4052 scoped_restore save_exec_dir
4053 = make_scoped_restore (&execution_direction
,
4054 target_execution_direction ());
4056 /* Allow targets to pause their resumed threads while we handle
4058 scoped_disable_commit_resumed
disable_commit_resumed ("handling event");
4060 if (!do_target_wait (ecs
, TARGET_WNOHANG
))
4062 infrun_debug_printf ("do_target_wait returned no event");
4063 disable_commit_resumed
.reset_and_commit ();
4067 gdb_assert (ecs
->ws
.kind () != TARGET_WAITKIND_IGNORE
);
4069 /* Switch to the target that generated the event, so we can do
4071 switch_to_target_no_thread (ecs
->target
);
4074 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
4076 /* If an error happens while handling the event, propagate GDB's
4077 knowledge of the executing state to the frontend/user running
4079 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
4080 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
4082 /* Get executed before scoped_restore_current_thread above to apply
4083 still for the thread which has thrown the exception. */
4084 auto defer_bpstat_clear
4085 = make_scope_exit (bpstat_clear_actions
);
4086 auto defer_delete_threads
4087 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
4089 /* Now figure out what to do with the result of the result. */
4090 handle_inferior_event (ecs
);
4092 if (!ecs
->wait_some_more
)
4094 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4095 bool should_stop
= true;
4096 struct thread_info
*thr
= ecs
->event_thread
;
4098 delete_just_stopped_threads_infrun_breakpoints ();
4102 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4104 if (thread_fsm
!= NULL
)
4105 should_stop
= thread_fsm
->should_stop (thr
);
4114 bool should_notify_stop
= true;
4117 clean_up_just_stopped_threads_fsms (ecs
);
4119 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4120 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4122 if (should_notify_stop
)
4124 /* We may not find an inferior if this was a process exit. */
4125 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4126 proceeded
= normal_stop ();
4131 inferior_event_handler (INF_EXEC_COMPLETE
);
4135 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4136 previously selected thread is gone. We have two
4137 choices - switch to no thread selected, or restore the
4138 previously selected thread (now exited). We chose the
4139 later, just because that's what GDB used to do. After
4140 this, "info threads" says "The current thread <Thread
4141 ID 2> has terminated." instead of "No thread
4145 && ecs
->ws
.kind () != TARGET_WAITKIND_NO_RESUMED
)
4146 restore_thread
.dont_restore ();
4150 defer_delete_threads
.release ();
4151 defer_bpstat_clear
.release ();
4153 /* No error, don't finish the thread states yet. */
4154 finish_state
.release ();
4156 disable_commit_resumed
.reset_and_commit ();
4158 /* This scope is used to ensure that readline callbacks are
4159 reinstalled here. */
4162 /* If a UI was in sync execution mode, and now isn't, restore its
4163 prompt (a synchronous execution command has finished, and we're
4164 ready for input). */
4165 all_uis_check_sync_execution_done ();
4168 && exec_done_display_p
4169 && (inferior_ptid
== null_ptid
4170 || inferior_thread ()->state
!= THREAD_RUNNING
))
4171 printf_unfiltered (_("completed.\n"));
4177 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4178 struct symtab_and_line sal
)
4180 /* This can be removed once this function no longer implicitly relies on the
4181 inferior_ptid value. */
4182 gdb_assert (inferior_ptid
== tp
->ptid
);
4184 tp
->control
.step_frame_id
= get_frame_id (frame
);
4185 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4187 tp
->current_symtab
= sal
.symtab
;
4188 tp
->current_line
= sal
.line
;
4191 /* Clear context switchable stepping state. */
4194 init_thread_stepping_state (struct thread_info
*tss
)
4196 tss
->stepped_breakpoint
= 0;
4197 tss
->stepping_over_breakpoint
= 0;
4198 tss
->stepping_over_watchpoint
= 0;
4199 tss
->step_after_step_resume_breakpoint
= 0;
4205 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4206 const target_waitstatus
&status
)
4208 target_last_proc_target
= target
;
4209 target_last_wait_ptid
= ptid
;
4210 target_last_waitstatus
= status
;
4216 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4217 target_waitstatus
*status
)
4219 if (target
!= nullptr)
4220 *target
= target_last_proc_target
;
4221 if (ptid
!= nullptr)
4222 *ptid
= target_last_wait_ptid
;
4223 if (status
!= nullptr)
4224 *status
= target_last_waitstatus
;
4230 nullify_last_target_wait_ptid (void)
4232 target_last_proc_target
= nullptr;
4233 target_last_wait_ptid
= minus_one_ptid
;
4234 target_last_waitstatus
= {};
4237 /* Switch thread contexts. */
4240 context_switch (execution_control_state
*ecs
)
4242 if (ecs
->ptid
!= inferior_ptid
4243 && (inferior_ptid
== null_ptid
4244 || ecs
->event_thread
!= inferior_thread ()))
4246 infrun_debug_printf ("Switching context from %s to %s",
4247 inferior_ptid
.to_string ().c_str (),
4248 ecs
->ptid
.to_string ().c_str ());
4251 switch_to_thread (ecs
->event_thread
);
4254 /* If the target can't tell whether we've hit breakpoints
4255 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4256 check whether that could have been caused by a breakpoint. If so,
4257 adjust the PC, per gdbarch_decr_pc_after_break. */
4260 adjust_pc_after_break (struct thread_info
*thread
,
4261 const target_waitstatus
*ws
)
4263 struct regcache
*regcache
;
4264 struct gdbarch
*gdbarch
;
4265 CORE_ADDR breakpoint_pc
, decr_pc
;
4267 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4268 we aren't, just return.
4270 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4271 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4272 implemented by software breakpoints should be handled through the normal
4275 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4276 different signals (SIGILL or SIGEMT for instance), but it is less
4277 clear where the PC is pointing afterwards. It may not match
4278 gdbarch_decr_pc_after_break. I don't know any specific target that
4279 generates these signals at breakpoints (the code has been in GDB since at
4280 least 1992) so I can not guess how to handle them here.
4282 In earlier versions of GDB, a target with
4283 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4284 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4285 target with both of these set in GDB history, and it seems unlikely to be
4286 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4288 if (ws
->kind () != TARGET_WAITKIND_STOPPED
)
4291 if (ws
->sig () != GDB_SIGNAL_TRAP
)
4294 /* In reverse execution, when a breakpoint is hit, the instruction
4295 under it has already been de-executed. The reported PC always
4296 points at the breakpoint address, so adjusting it further would
4297 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4300 B1 0x08000000 : INSN1
4301 B2 0x08000001 : INSN2
4303 PC -> 0x08000003 : INSN4
4305 Say you're stopped at 0x08000003 as above. Reverse continuing
4306 from that point should hit B2 as below. Reading the PC when the
4307 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4308 been de-executed already.
4310 B1 0x08000000 : INSN1
4311 B2 PC -> 0x08000001 : INSN2
4315 We can't apply the same logic as for forward execution, because
4316 we would wrongly adjust the PC to 0x08000000, since there's a
4317 breakpoint at PC - 1. We'd then report a hit on B1, although
4318 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4320 if (execution_direction
== EXEC_REVERSE
)
4323 /* If the target can tell whether the thread hit a SW breakpoint,
4324 trust it. Targets that can tell also adjust the PC
4326 if (target_supports_stopped_by_sw_breakpoint ())
4329 /* Note that relying on whether a breakpoint is planted in memory to
4330 determine this can fail. E.g,. the breakpoint could have been
4331 removed since. Or the thread could have been told to step an
4332 instruction the size of a breakpoint instruction, and only
4333 _after_ was a breakpoint inserted at its address. */
4335 /* If this target does not decrement the PC after breakpoints, then
4336 we have nothing to do. */
4337 regcache
= get_thread_regcache (thread
);
4338 gdbarch
= regcache
->arch ();
4340 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4344 const address_space
*aspace
= regcache
->aspace ();
4346 /* Find the location where (if we've hit a breakpoint) the
4347 breakpoint would be. */
4348 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4350 /* If the target can't tell whether a software breakpoint triggered,
4351 fallback to figuring it out based on breakpoints we think were
4352 inserted in the target, and on whether the thread was stepped or
4355 /* Check whether there actually is a software breakpoint inserted at
4358 If in non-stop mode, a race condition is possible where we've
4359 removed a breakpoint, but stop events for that breakpoint were
4360 already queued and arrive later. To suppress those spurious
4361 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4362 and retire them after a number of stop events are reported. Note
4363 this is an heuristic and can thus get confused. The real fix is
4364 to get the "stopped by SW BP and needs adjustment" info out of
4365 the target/kernel (and thus never reach here; see above). */
4366 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4367 || (target_is_non_stop_p ()
4368 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4370 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4372 if (record_full_is_used ())
4373 restore_operation_disable
.emplace
4374 (record_full_gdb_operation_disable_set ());
4376 /* When using hardware single-step, a SIGTRAP is reported for both
4377 a completed single-step and a software breakpoint. Need to
4378 differentiate between the two, as the latter needs adjusting
4379 but the former does not.
4381 The SIGTRAP can be due to a completed hardware single-step only if
4382 - we didn't insert software single-step breakpoints
4383 - this thread is currently being stepped
4385 If any of these events did not occur, we must have stopped due
4386 to hitting a software breakpoint, and have to back up to the
4389 As a special case, we could have hardware single-stepped a
4390 software breakpoint. In this case (prev_pc == breakpoint_pc),
4391 we also need to back up to the breakpoint address. */
4393 if (thread_has_single_step_breakpoints_set (thread
)
4394 || !currently_stepping (thread
)
4395 || (thread
->stepped_breakpoint
4396 && thread
->prev_pc
== breakpoint_pc
))
4397 regcache_write_pc (regcache
, breakpoint_pc
);
4402 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4404 for (frame
= get_prev_frame (frame
);
4406 frame
= get_prev_frame (frame
))
4408 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4411 if (get_frame_type (frame
) != INLINE_FRAME
)
4418 /* Look for an inline frame that is marked for skip.
4419 If PREV_FRAME is TRUE start at the previous frame,
4420 otherwise start at the current frame. Stop at the
4421 first non-inline frame, or at the frame where the
4425 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4427 struct frame_info
*frame
= get_current_frame ();
4430 frame
= get_prev_frame (frame
);
4432 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4434 const char *fn
= NULL
;
4435 symtab_and_line sal
;
4438 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4440 if (get_frame_type (frame
) != INLINE_FRAME
)
4443 sal
= find_frame_sal (frame
);
4444 sym
= get_frame_function (frame
);
4447 fn
= sym
->print_name ();
4450 && function_name_is_marked_for_skip (fn
, sal
))
4457 /* If the event thread has the stop requested flag set, pretend it
4458 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4462 handle_stop_requested (struct execution_control_state
*ecs
)
4464 if (ecs
->event_thread
->stop_requested
)
4466 ecs
->ws
.set_stopped (GDB_SIGNAL_0
);
4467 handle_signal_stop (ecs
);
4473 /* Auxiliary function that handles syscall entry/return events.
4474 It returns true if the inferior should keep going (and GDB
4475 should ignore the event), or false if the event deserves to be
4479 handle_syscall_event (struct execution_control_state
*ecs
)
4481 struct regcache
*regcache
;
4484 context_switch (ecs
);
4486 regcache
= get_thread_regcache (ecs
->event_thread
);
4487 syscall_number
= ecs
->ws
.syscall_number ();
4488 ecs
->event_thread
->set_stop_pc (regcache_read_pc (regcache
));
4490 if (catch_syscall_enabled () > 0
4491 && catching_syscall_number (syscall_number
))
4493 infrun_debug_printf ("syscall number=%d", syscall_number
);
4495 ecs
->event_thread
->control
.stop_bpstat
4496 = bpstat_stop_status (regcache
->aspace (),
4497 ecs
->event_thread
->stop_pc (),
4498 ecs
->event_thread
, &ecs
->ws
);
4500 if (handle_stop_requested (ecs
))
4503 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4505 /* Catchpoint hit. */
4510 if (handle_stop_requested (ecs
))
4513 /* If no catchpoint triggered for this, then keep going. */
4519 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4522 fill_in_stop_func (struct gdbarch
*gdbarch
,
4523 struct execution_control_state
*ecs
)
4525 if (!ecs
->stop_func_filled_in
)
4528 const general_symbol_info
*gsi
;
4530 /* Don't care about return value; stop_func_start and stop_func_name
4531 will both be 0 if it doesn't work. */
4532 find_pc_partial_function_sym (ecs
->event_thread
->stop_pc (),
4534 &ecs
->stop_func_start
,
4535 &ecs
->stop_func_end
,
4537 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4539 /* The call to find_pc_partial_function, above, will set
4540 stop_func_start and stop_func_end to the start and end
4541 of the range containing the stop pc. If this range
4542 contains the entry pc for the block (which is always the
4543 case for contiguous blocks), advance stop_func_start past
4544 the function's start offset and entrypoint. Note that
4545 stop_func_start is NOT advanced when in a range of a
4546 non-contiguous block that does not contain the entry pc. */
4547 if (block
!= nullptr
4548 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4549 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4551 ecs
->stop_func_start
4552 += gdbarch_deprecated_function_start_offset (gdbarch
);
4554 if (gdbarch_skip_entrypoint_p (gdbarch
))
4555 ecs
->stop_func_start
4556 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4559 ecs
->stop_func_filled_in
= 1;
4564 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4566 static enum stop_kind
4567 get_inferior_stop_soon (execution_control_state
*ecs
)
4569 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4571 gdb_assert (inf
!= NULL
);
4572 return inf
->control
.stop_soon
;
4575 /* Poll for one event out of the current target. Store the resulting
4576 waitstatus in WS, and return the event ptid. Does not block. */
4579 poll_one_curr_target (struct target_waitstatus
*ws
)
4583 overlay_cache_invalid
= 1;
4585 /* Flush target cache before starting to handle each event.
4586 Target was running and cache could be stale. This is just a
4587 heuristic. Running threads may modify target memory, but we
4588 don't get any event. */
4589 target_dcache_invalidate ();
4591 if (deprecated_target_wait_hook
)
4592 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4594 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4597 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4602 /* Wait for one event out of any target. */
4604 static wait_one_event
4609 for (inferior
*inf
: all_inferiors ())
4611 process_stratum_target
*target
= inf
->process_target ();
4613 || !target
->is_async_p ()
4614 || !target
->threads_executing
)
4617 switch_to_inferior_no_thread (inf
);
4619 wait_one_event event
;
4620 event
.target
= target
;
4621 event
.ptid
= poll_one_curr_target (&event
.ws
);
4623 if (event
.ws
.kind () == TARGET_WAITKIND_NO_RESUMED
)
4625 /* If nothing is resumed, remove the target from the
4629 else if (event
.ws
.kind () != TARGET_WAITKIND_IGNORE
)
4633 /* Block waiting for some event. */
4640 for (inferior
*inf
: all_inferiors ())
4642 process_stratum_target
*target
= inf
->process_target ();
4644 || !target
->is_async_p ()
4645 || !target
->threads_executing
)
4648 int fd
= target
->async_wait_fd ();
4649 FD_SET (fd
, &readfds
);
4656 /* No waitable targets left. All must be stopped. */
4657 target_waitstatus ws
;
4658 ws
.set_no_resumed ();
4659 return {NULL
, minus_one_ptid
, std::move (ws
)};
4664 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4670 perror_with_name ("interruptible_select");
4675 /* Save the thread's event and stop reason to process it later. */
4678 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4680 infrun_debug_printf ("saving status %s for %s",
4681 target_waitstatus_to_string (ws
).c_str (),
4682 tp
->ptid
.to_string ().c_str ());
4684 /* Record for later. */
4685 tp
->set_pending_waitstatus (*ws
);
4687 if (ws
->kind () == TARGET_WAITKIND_STOPPED
4688 && ws
->sig () == GDB_SIGNAL_TRAP
)
4690 struct regcache
*regcache
= get_thread_regcache (tp
);
4691 const address_space
*aspace
= regcache
->aspace ();
4692 CORE_ADDR pc
= regcache_read_pc (regcache
);
4694 adjust_pc_after_break (tp
, &tp
->pending_waitstatus ());
4696 scoped_restore_current_thread restore_thread
;
4697 switch_to_thread (tp
);
4699 if (target_stopped_by_watchpoint ())
4700 tp
->set_stop_reason (TARGET_STOPPED_BY_WATCHPOINT
);
4701 else if (target_supports_stopped_by_sw_breakpoint ()
4702 && target_stopped_by_sw_breakpoint ())
4703 tp
->set_stop_reason (TARGET_STOPPED_BY_SW_BREAKPOINT
);
4704 else if (target_supports_stopped_by_hw_breakpoint ()
4705 && target_stopped_by_hw_breakpoint ())
4706 tp
->set_stop_reason (TARGET_STOPPED_BY_HW_BREAKPOINT
);
4707 else if (!target_supports_stopped_by_hw_breakpoint ()
4708 && hardware_breakpoint_inserted_here_p (aspace
, pc
))
4709 tp
->set_stop_reason (TARGET_STOPPED_BY_HW_BREAKPOINT
);
4710 else if (!target_supports_stopped_by_sw_breakpoint ()
4711 && software_breakpoint_inserted_here_p (aspace
, pc
))
4712 tp
->set_stop_reason (TARGET_STOPPED_BY_SW_BREAKPOINT
);
4713 else if (!thread_has_single_step_breakpoints_set (tp
)
4714 && currently_stepping (tp
))
4715 tp
->set_stop_reason (TARGET_STOPPED_BY_SINGLE_STEP
);
4719 /* Mark the non-executing threads accordingly. In all-stop, all
4720 threads of all processes are stopped when we get any event
4721 reported. In non-stop mode, only the event thread stops. */
4724 mark_non_executing_threads (process_stratum_target
*target
,
4726 const target_waitstatus
&ws
)
4730 if (!target_is_non_stop_p ())
4731 mark_ptid
= minus_one_ptid
;
4732 else if (ws
.kind () == TARGET_WAITKIND_SIGNALLED
4733 || ws
.kind () == TARGET_WAITKIND_EXITED
)
4735 /* If we're handling a process exit in non-stop mode, even
4736 though threads haven't been deleted yet, one would think
4737 that there is nothing to do, as threads of the dead process
4738 will be soon deleted, and threads of any other process were
4739 left running. However, on some targets, threads survive a
4740 process exit event. E.g., for the "checkpoint" command,
4741 when the current checkpoint/fork exits, linux-fork.c
4742 automatically switches to another fork from within
4743 target_mourn_inferior, by associating the same
4744 inferior/thread to another fork. We haven't mourned yet at
4745 this point, but we must mark any threads left in the
4746 process as not-executing so that finish_thread_state marks
4747 them stopped (in the user's perspective) if/when we present
4748 the stop to the user. */
4749 mark_ptid
= ptid_t (event_ptid
.pid ());
4752 mark_ptid
= event_ptid
;
4754 set_executing (target
, mark_ptid
, false);
4756 /* Likewise the resumed flag. */
4757 set_resumed (target
, mark_ptid
, false);
4760 /* Handle one event after stopping threads. If the eventing thread
4761 reports back any interesting event, we leave it pending. If the
4762 eventing thread was in the middle of a displaced step, we
4763 cancel/finish it, and unless the thread's inferior is being
4764 detached, put the thread back in the step-over chain. Returns true
4765 if there are no resumed threads left in the target (thus there's no
4766 point in waiting further), false otherwise. */
4769 handle_one (const wait_one_event
&event
)
4772 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4773 event
.ptid
.to_string ().c_str ());
4775 if (event
.ws
.kind () == TARGET_WAITKIND_NO_RESUMED
)
4777 /* All resumed threads exited. */
4780 else if (event
.ws
.kind () == TARGET_WAITKIND_THREAD_EXITED
4781 || event
.ws
.kind () == TARGET_WAITKIND_EXITED
4782 || event
.ws
.kind () == TARGET_WAITKIND_SIGNALLED
)
4784 /* One thread/process exited/signalled. */
4786 thread_info
*t
= nullptr;
4788 /* The target may have reported just a pid. If so, try
4789 the first non-exited thread. */
4790 if (event
.ptid
.is_pid ())
4792 int pid
= event
.ptid
.pid ();
4793 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4794 for (thread_info
*tp
: inf
->non_exited_threads ())
4800 /* If there is no available thread, the event would
4801 have to be appended to a per-inferior event list,
4802 which does not exist (and if it did, we'd have
4803 to adjust run control command to be able to
4804 resume such an inferior). We assert here instead
4805 of going into an infinite loop. */
4806 gdb_assert (t
!= nullptr);
4809 ("using %s", t
->ptid
.to_string ().c_str ());
4813 t
= find_thread_ptid (event
.target
, event
.ptid
);
4814 /* Check if this is the first time we see this thread.
4815 Don't bother adding if it individually exited. */
4817 && event
.ws
.kind () != TARGET_WAITKIND_THREAD_EXITED
)
4818 t
= add_thread (event
.target
, event
.ptid
);
4823 /* Set the threads as non-executing to avoid
4824 another stop attempt on them. */
4825 switch_to_thread_no_regs (t
);
4826 mark_non_executing_threads (event
.target
, event
.ptid
,
4828 save_waitstatus (t
, &event
.ws
);
4829 t
->stop_requested
= false;
4834 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4836 t
= add_thread (event
.target
, event
.ptid
);
4838 t
->stop_requested
= 0;
4839 t
->set_executing (false);
4840 t
->set_resumed (false);
4841 t
->control
.may_range_step
= 0;
4843 /* This may be the first time we see the inferior report
4845 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4846 if (inf
->needs_setup
)
4848 switch_to_thread_no_regs (t
);
4852 if (event
.ws
.kind () == TARGET_WAITKIND_STOPPED
4853 && event
.ws
.sig () == GDB_SIGNAL_0
)
4855 /* We caught the event that we intended to catch, so
4856 there's no event to save as pending. */
4858 if (displaced_step_finish (t
, GDB_SIGNAL_0
)
4859 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4861 /* Add it back to the step-over queue. */
4863 ("displaced-step of %s canceled",
4864 t
->ptid
.to_string ().c_str ());
4866 t
->control
.trap_expected
= 0;
4867 if (!t
->inf
->detaching
)
4868 global_thread_step_over_chain_enqueue (t
);
4873 enum gdb_signal sig
;
4874 struct regcache
*regcache
;
4877 ("target_wait %s, saving status for %s",
4878 target_waitstatus_to_string (&event
.ws
).c_str (),
4879 t
->ptid
.to_string ().c_str ());
4881 /* Record for later. */
4882 save_waitstatus (t
, &event
.ws
);
4884 sig
= (event
.ws
.kind () == TARGET_WAITKIND_STOPPED
4885 ? event
.ws
.sig () : GDB_SIGNAL_0
);
4887 if (displaced_step_finish (t
, sig
)
4888 == DISPLACED_STEP_FINISH_STATUS_NOT_EXECUTED
)
4890 /* Add it back to the step-over queue. */
4891 t
->control
.trap_expected
= 0;
4892 if (!t
->inf
->detaching
)
4893 global_thread_step_over_chain_enqueue (t
);
4896 regcache
= get_thread_regcache (t
);
4897 t
->set_stop_pc (regcache_read_pc (regcache
));
4899 infrun_debug_printf ("saved stop_pc=%s for %s "
4900 "(currently_stepping=%d)",
4901 paddress (target_gdbarch (), t
->stop_pc ()),
4902 t
->ptid
.to_string ().c_str (),
4903 currently_stepping (t
));
4913 stop_all_threads (void)
4915 /* We may need multiple passes to discover all threads. */
4919 gdb_assert (exists_non_stop_target ());
4921 infrun_debug_printf ("starting");
4923 scoped_restore_current_thread restore_thread
;
4925 /* Enable thread events of all targets. */
4926 for (auto *target
: all_non_exited_process_targets ())
4928 switch_to_target_no_thread (target
);
4929 target_thread_events (true);
4934 /* Disable thread events of all targets. */
4935 for (auto *target
: all_non_exited_process_targets ())
4937 switch_to_target_no_thread (target
);
4938 target_thread_events (false);
4941 /* Use debug_prefixed_printf directly to get a meaningful function
4944 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
4947 /* Request threads to stop, and then wait for the stops. Because
4948 threads we already know about can spawn more threads while we're
4949 trying to stop them, and we only learn about new threads when we
4950 update the thread list, do this in a loop, and keep iterating
4951 until two passes find no threads that need to be stopped. */
4952 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4954 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4957 int waits_needed
= 0;
4959 for (auto *target
: all_non_exited_process_targets ())
4961 switch_to_target_no_thread (target
);
4962 update_thread_list ();
4965 /* Go through all threads looking for threads that we need
4966 to tell the target to stop. */
4967 for (thread_info
*t
: all_non_exited_threads ())
4969 /* For a single-target setting with an all-stop target,
4970 we would not even arrive here. For a multi-target
4971 setting, until GDB is able to handle a mixture of
4972 all-stop and non-stop targets, simply skip all-stop
4973 targets' threads. This should be fine due to the
4974 protection of 'check_multi_target_resumption'. */
4976 switch_to_thread_no_regs (t
);
4977 if (!target_is_non_stop_p ())
4980 if (t
->executing ())
4982 /* If already stopping, don't request a stop again.
4983 We just haven't seen the notification yet. */
4984 if (!t
->stop_requested
)
4986 infrun_debug_printf (" %s executing, need stop",
4987 t
->ptid
.to_string ().c_str ());
4988 target_stop (t
->ptid
);
4989 t
->stop_requested
= 1;
4993 infrun_debug_printf (" %s executing, already stopping",
4994 t
->ptid
.to_string ().c_str ());
4997 if (t
->stop_requested
)
5002 infrun_debug_printf (" %s not executing",
5003 t
->ptid
.to_string ().c_str ());
5005 /* The thread may be not executing, but still be
5006 resumed with a pending status to process. */
5007 t
->set_resumed (false);
5011 if (waits_needed
== 0)
5014 /* If we find new threads on the second iteration, restart
5015 over. We want to see two iterations in a row with all
5020 for (int i
= 0; i
< waits_needed
; i
++)
5022 wait_one_event event
= wait_one ();
5023 if (handle_one (event
))
5030 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
5033 handle_no_resumed (struct execution_control_state
*ecs
)
5035 if (target_can_async_p ())
5037 bool any_sync
= false;
5039 for (ui
*ui
: all_uis ())
5041 if (ui
->prompt_state
== PROMPT_BLOCKED
)
5049 /* There were no unwaited-for children left in the target, but,
5050 we're not synchronously waiting for events either. Just
5053 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
5054 prepare_to_wait (ecs
);
5059 /* Otherwise, if we were running a synchronous execution command, we
5060 may need to cancel it and give the user back the terminal.
5062 In non-stop mode, the target can't tell whether we've already
5063 consumed previous stop events, so it can end up sending us a
5064 no-resumed event like so:
5066 #0 - thread 1 is left stopped
5068 #1 - thread 2 is resumed and hits breakpoint
5069 -> TARGET_WAITKIND_STOPPED
5071 #2 - thread 3 is resumed and exits
5072 this is the last resumed thread, so
5073 -> TARGET_WAITKIND_NO_RESUMED
5075 #3 - gdb processes stop for thread 2 and decides to re-resume
5078 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
5079 thread 2 is now resumed, so the event should be ignored.
5081 IOW, if the stop for thread 2 doesn't end a foreground command,
5082 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
5083 event. But it could be that the event meant that thread 2 itself
5084 (or whatever other thread was the last resumed thread) exited.
5086 To address this we refresh the thread list and check whether we
5087 have resumed threads _now_. In the example above, this removes
5088 thread 3 from the thread list. If thread 2 was re-resumed, we
5089 ignore this event. If we find no thread resumed, then we cancel
5090 the synchronous command and show "no unwaited-for " to the
5093 inferior
*curr_inf
= current_inferior ();
5095 scoped_restore_current_thread restore_thread
;
5097 for (auto *target
: all_non_exited_process_targets ())
5099 switch_to_target_no_thread (target
);
5100 update_thread_list ();
5105 - the current target has no thread executing, and
5106 - the current inferior is native, and
5107 - the current inferior is the one which has the terminal, and
5110 then a Ctrl-C from this point on would remain stuck in the
5111 kernel, until a thread resumes and dequeues it. That would
5112 result in the GDB CLI not reacting to Ctrl-C, not able to
5113 interrupt the program. To address this, if the current inferior
5114 no longer has any thread executing, we give the terminal to some
5115 other inferior that has at least one thread executing. */
5116 bool swap_terminal
= true;
5118 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
5119 whether to report it to the user. */
5120 bool ignore_event
= false;
5122 for (thread_info
*thread
: all_non_exited_threads ())
5124 if (swap_terminal
&& thread
->executing ())
5126 if (thread
->inf
!= curr_inf
)
5128 target_terminal::ours ();
5130 switch_to_thread (thread
);
5131 target_terminal::inferior ();
5133 swap_terminal
= false;
5136 if (!ignore_event
&& thread
->resumed ())
5138 /* Either there were no unwaited-for children left in the
5139 target at some point, but there are now, or some target
5140 other than the eventing one has unwaited-for children
5141 left. Just ignore. */
5142 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
5143 "(ignoring: found resumed)");
5145 ignore_event
= true;
5148 if (ignore_event
&& !swap_terminal
)
5154 switch_to_inferior_no_thread (curr_inf
);
5155 prepare_to_wait (ecs
);
5159 /* Go ahead and report the event. */
5163 /* Given an execution control state that has been freshly filled in by
5164 an event from the inferior, figure out what it means and take
5167 The alternatives are:
5169 1) stop_waiting and return; to really stop and return to the
5172 2) keep_going and return; to wait for the next event (set
5173 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5177 handle_inferior_event (struct execution_control_state
*ecs
)
5179 /* Make sure that all temporary struct value objects that were
5180 created during the handling of the event get deleted at the
5182 scoped_value_mark free_values
;
5184 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5186 if (ecs
->ws
.kind () == TARGET_WAITKIND_IGNORE
)
5188 /* We had an event in the inferior, but we are not interested in
5189 handling it at this level. The lower layers have already
5190 done what needs to be done, if anything.
5192 One of the possible circumstances for this is when the
5193 inferior produces output for the console. The inferior has
5194 not stopped, and we are ignoring the event. Another possible
5195 circumstance is any event which the lower level knows will be
5196 reported multiple times without an intervening resume. */
5197 prepare_to_wait (ecs
);
5201 if (ecs
->ws
.kind () == TARGET_WAITKIND_THREAD_EXITED
)
5203 prepare_to_wait (ecs
);
5207 if (ecs
->ws
.kind () == TARGET_WAITKIND_NO_RESUMED
5208 && handle_no_resumed (ecs
))
5211 /* Cache the last target/ptid/waitstatus. */
5212 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5214 /* Always clear state belonging to the previous time we stopped. */
5215 stop_stack_dummy
= STOP_NONE
;
5217 if (ecs
->ws
.kind () == TARGET_WAITKIND_NO_RESUMED
)
5219 /* No unwaited-for children left. IOW, all resumed children
5221 stop_print_frame
= false;
5226 if (ecs
->ws
.kind () != TARGET_WAITKIND_EXITED
5227 && ecs
->ws
.kind () != TARGET_WAITKIND_SIGNALLED
)
5229 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5230 /* If it's a new thread, add it to the thread database. */
5231 if (ecs
->event_thread
== NULL
)
5232 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5234 /* Disable range stepping. If the next step request could use a
5235 range, this will be end up re-enabled then. */
5236 ecs
->event_thread
->control
.may_range_step
= 0;
5239 /* Dependent on valid ECS->EVENT_THREAD. */
5240 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5242 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5243 reinit_frame_cache ();
5245 breakpoint_retire_moribund ();
5247 /* First, distinguish signals caused by the debugger from signals
5248 that have to do with the program's own actions. Note that
5249 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5250 on the operating system version. Here we detect when a SIGILL or
5251 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5252 something similar for SIGSEGV, since a SIGSEGV will be generated
5253 when we're trying to execute a breakpoint instruction on a
5254 non-executable stack. This happens for call dummy breakpoints
5255 for architectures like SPARC that place call dummies on the
5257 if (ecs
->ws
.kind () == TARGET_WAITKIND_STOPPED
5258 && (ecs
->ws
.sig () == GDB_SIGNAL_ILL
5259 || ecs
->ws
.sig () == GDB_SIGNAL_SEGV
5260 || ecs
->ws
.sig () == GDB_SIGNAL_EMT
))
5262 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5264 if (breakpoint_inserted_here_p (regcache
->aspace (),
5265 regcache_read_pc (regcache
)))
5267 infrun_debug_printf ("Treating signal as SIGTRAP");
5268 ecs
->ws
.set_stopped (GDB_SIGNAL_TRAP
);
5272 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5274 switch (ecs
->ws
.kind ())
5276 case TARGET_WAITKIND_LOADED
:
5278 context_switch (ecs
);
5279 /* Ignore gracefully during startup of the inferior, as it might
5280 be the shell which has just loaded some objects, otherwise
5281 add the symbols for the newly loaded objects. Also ignore at
5282 the beginning of an attach or remote session; we will query
5283 the full list of libraries once the connection is
5286 stop_kind stop_soon
= get_inferior_stop_soon (ecs
);
5287 if (stop_soon
== NO_STOP_QUIETLY
)
5289 struct regcache
*regcache
;
5291 regcache
= get_thread_regcache (ecs
->event_thread
);
5293 handle_solib_event ();
5295 ecs
->event_thread
->set_stop_pc (regcache_read_pc (regcache
));
5296 ecs
->event_thread
->control
.stop_bpstat
5297 = bpstat_stop_status (regcache
->aspace (),
5298 ecs
->event_thread
->stop_pc (),
5299 ecs
->event_thread
, &ecs
->ws
);
5301 if (handle_stop_requested (ecs
))
5304 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5306 /* A catchpoint triggered. */
5307 process_event_stop_test (ecs
);
5311 /* If requested, stop when the dynamic linker notifies
5312 gdb of events. This allows the user to get control
5313 and place breakpoints in initializer routines for
5314 dynamically loaded objects (among other things). */
5315 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
5316 if (stop_on_solib_events
)
5318 /* Make sure we print "Stopped due to solib-event" in
5320 stop_print_frame
= true;
5327 /* If we are skipping through a shell, or through shared library
5328 loading that we aren't interested in, resume the program. If
5329 we're running the program normally, also resume. */
5330 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5332 /* Loading of shared libraries might have changed breakpoint
5333 addresses. Make sure new breakpoints are inserted. */
5334 if (stop_soon
== NO_STOP_QUIETLY
)
5335 insert_breakpoints ();
5336 resume (GDB_SIGNAL_0
);
5337 prepare_to_wait (ecs
);
5341 /* But stop if we're attaching or setting up a remote
5343 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5344 || stop_soon
== STOP_QUIETLY_REMOTE
)
5346 infrun_debug_printf ("quietly stopped");
5351 internal_error (__FILE__
, __LINE__
,
5352 _("unhandled stop_soon: %d"), (int) stop_soon
);
5355 case TARGET_WAITKIND_SPURIOUS
:
5356 if (handle_stop_requested (ecs
))
5358 context_switch (ecs
);
5359 resume (GDB_SIGNAL_0
);
5360 prepare_to_wait (ecs
);
5363 case TARGET_WAITKIND_THREAD_CREATED
:
5364 if (handle_stop_requested (ecs
))
5366 context_switch (ecs
);
5367 if (!switch_back_to_stepped_thread (ecs
))
5371 case TARGET_WAITKIND_EXITED
:
5372 case TARGET_WAITKIND_SIGNALLED
:
5374 /* Depending on the system, ecs->ptid may point to a thread or
5375 to a process. On some targets, target_mourn_inferior may
5376 need to have access to the just-exited thread. That is the
5377 case of GNU/Linux's "checkpoint" support, for example.
5378 Call the switch_to_xxx routine as appropriate. */
5379 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5381 switch_to_thread (thr
);
5384 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5385 switch_to_inferior_no_thread (inf
);
5388 handle_vfork_child_exec_or_exit (0);
5389 target_terminal::ours (); /* Must do this before mourn anyway. */
5391 /* Clearing any previous state of convenience variables. */
5392 clear_exit_convenience_vars ();
5394 if (ecs
->ws
.kind () == TARGET_WAITKIND_EXITED
)
5396 /* Record the exit code in the convenience variable $_exitcode, so
5397 that the user can inspect this again later. */
5398 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5399 (LONGEST
) ecs
->ws
.exit_status ());
5401 /* Also record this in the inferior itself. */
5402 current_inferior ()->has_exit_code
= 1;
5403 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.exit_status ();
5405 /* Support the --return-child-result option. */
5406 return_child_result_value
= ecs
->ws
.exit_status ();
5408 gdb::observers::exited
.notify (ecs
->ws
.exit_status ());
5412 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5414 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5416 /* Set the value of the internal variable $_exitsignal,
5417 which holds the signal uncaught by the inferior. */
5418 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5419 gdbarch_gdb_signal_to_target (gdbarch
,
5424 /* We don't have access to the target's method used for
5425 converting between signal numbers (GDB's internal
5426 representation <-> target's representation).
5427 Therefore, we cannot do a good job at displaying this
5428 information to the user. It's better to just warn
5429 her about it (if infrun debugging is enabled), and
5431 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5435 gdb::observers::signal_exited
.notify (ecs
->ws
.sig ());
5438 gdb_flush (gdb_stdout
);
5439 target_mourn_inferior (inferior_ptid
);
5440 stop_print_frame
= false;
5444 case TARGET_WAITKIND_FORKED
:
5445 case TARGET_WAITKIND_VFORKED
:
5446 /* Check whether the inferior is displaced stepping. */
5448 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5449 struct gdbarch
*gdbarch
= regcache
->arch ();
5450 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5452 /* If this is a fork (child gets its own address space copy)
5453 and some displaced step buffers were in use at the time of
5454 the fork, restore the displaced step buffer bytes in the
5457 Architectures which support displaced stepping and fork
5458 events must supply an implementation of
5459 gdbarch_displaced_step_restore_all_in_ptid. This is not
5460 enforced during gdbarch validation to support architectures
5461 which support displaced stepping but not forks. */
5462 if (ecs
->ws
.kind () == TARGET_WAITKIND_FORKED
5463 && gdbarch_supports_displaced_stepping (gdbarch
))
5464 gdbarch_displaced_step_restore_all_in_ptid
5465 (gdbarch
, parent_inf
, ecs
->ws
.child_ptid ());
5467 /* If displaced stepping is supported, and thread ecs->ptid is
5468 displaced stepping. */
5469 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5471 struct regcache
*child_regcache
;
5472 CORE_ADDR parent_pc
;
5474 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5475 indicating that the displaced stepping of syscall instruction
5476 has been done. Perform cleanup for parent process here. Note
5477 that this operation also cleans up the child process for vfork,
5478 because their pages are shared. */
5479 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5480 /* Start a new step-over in another thread if there's one
5484 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5485 the child's PC is also within the scratchpad. Set the child's PC
5486 to the parent's PC value, which has already been fixed up.
5487 FIXME: we use the parent's aspace here, although we're touching
5488 the child, because the child hasn't been added to the inferior
5489 list yet at this point. */
5492 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5493 ecs
->ws
.child_ptid (),
5495 parent_inf
->aspace
);
5496 /* Read PC value of parent process. */
5497 parent_pc
= regcache_read_pc (regcache
);
5499 displaced_debug_printf ("write child pc from %s to %s",
5501 regcache_read_pc (child_regcache
)),
5502 paddress (gdbarch
, parent_pc
));
5504 regcache_write_pc (child_regcache
, parent_pc
);
5508 context_switch (ecs
);
5510 /* Immediately detach breakpoints from the child before there's
5511 any chance of letting the user delete breakpoints from the
5512 breakpoint lists. If we don't do this early, it's easy to
5513 leave left over traps in the child, vis: "break foo; catch
5514 fork; c; <fork>; del; c; <child calls foo>". We only follow
5515 the fork on the last `continue', and by that time the
5516 breakpoint at "foo" is long gone from the breakpoint table.
5517 If we vforked, then we don't need to unpatch here, since both
5518 parent and child are sharing the same memory pages; we'll
5519 need to unpatch at follow/detach time instead to be certain
5520 that new breakpoints added between catchpoint hit time and
5521 vfork follow are detached. */
5522 if (ecs
->ws
.kind () != TARGET_WAITKIND_VFORKED
)
5524 /* This won't actually modify the breakpoint list, but will
5525 physically remove the breakpoints from the child. */
5526 detach_breakpoints (ecs
->ws
.child_ptid ());
5529 delete_just_stopped_threads_single_step_breakpoints ();
5531 /* In case the event is caught by a catchpoint, remember that
5532 the event is to be followed at the next resume of the thread,
5533 and not immediately. */
5534 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5536 ecs
->event_thread
->set_stop_pc
5537 (regcache_read_pc (get_thread_regcache (ecs
->event_thread
)));
5539 ecs
->event_thread
->control
.stop_bpstat
5540 = bpstat_stop_status (get_current_regcache ()->aspace (),
5541 ecs
->event_thread
->stop_pc (),
5542 ecs
->event_thread
, &ecs
->ws
);
5544 if (handle_stop_requested (ecs
))
5547 /* If no catchpoint triggered for this, then keep going. Note
5548 that we're interested in knowing the bpstat actually causes a
5549 stop, not just if it may explain the signal. Software
5550 watchpoints, for example, always appear in the bpstat. */
5551 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5554 = (follow_fork_mode_string
== follow_fork_mode_child
);
5556 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
5558 process_stratum_target
*targ
5559 = ecs
->event_thread
->inf
->process_target ();
5561 bool should_resume
= follow_fork ();
5563 /* Note that one of these may be an invalid pointer,
5564 depending on detach_fork. */
5565 thread_info
*parent
= ecs
->event_thread
;
5566 thread_info
*child
= find_thread_ptid (targ
, ecs
->ws
.child_ptid ());
5568 /* At this point, the parent is marked running, and the
5569 child is marked stopped. */
5571 /* If not resuming the parent, mark it stopped. */
5572 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5573 parent
->set_running (false);
5575 /* If resuming the child, mark it running. */
5576 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5577 child
->set_running (true);
5579 /* In non-stop mode, also resume the other branch. */
5580 if (!detach_fork
&& (non_stop
5581 || (sched_multi
&& target_is_non_stop_p ())))
5584 switch_to_thread (parent
);
5586 switch_to_thread (child
);
5588 ecs
->event_thread
= inferior_thread ();
5589 ecs
->ptid
= inferior_ptid
;
5594 switch_to_thread (child
);
5596 switch_to_thread (parent
);
5598 ecs
->event_thread
= inferior_thread ();
5599 ecs
->ptid
= inferior_ptid
;
5607 process_event_stop_test (ecs
);
5610 case TARGET_WAITKIND_VFORK_DONE
:
5611 /* Done with the shared memory region. Re-insert breakpoints in
5612 the parent, and keep going. */
5614 context_switch (ecs
);
5616 current_inferior ()->waiting_for_vfork_done
= 0;
5617 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5619 if (handle_stop_requested (ecs
))
5622 /* This also takes care of reinserting breakpoints in the
5623 previously locked inferior. */
5627 case TARGET_WAITKIND_EXECD
:
5629 /* Note we can't read registers yet (the stop_pc), because we
5630 don't yet know the inferior's post-exec architecture.
5631 'stop_pc' is explicitly read below instead. */
5632 switch_to_thread_no_regs (ecs
->event_thread
);
5634 /* Do whatever is necessary to the parent branch of the vfork. */
5635 handle_vfork_child_exec_or_exit (1);
5637 /* This causes the eventpoints and symbol table to be reset.
5638 Must do this now, before trying to determine whether to
5640 follow_exec (inferior_ptid
, ecs
->ws
.execd_pathname ());
5642 /* In follow_exec we may have deleted the original thread and
5643 created a new one. Make sure that the event thread is the
5644 execd thread for that case (this is a nop otherwise). */
5645 ecs
->event_thread
= inferior_thread ();
5647 ecs
->event_thread
->set_stop_pc
5648 (regcache_read_pc (get_thread_regcache (ecs
->event_thread
)));
5650 ecs
->event_thread
->control
.stop_bpstat
5651 = bpstat_stop_status (get_current_regcache ()->aspace (),
5652 ecs
->event_thread
->stop_pc (),
5653 ecs
->event_thread
, &ecs
->ws
);
5655 if (handle_stop_requested (ecs
))
5658 /* If no catchpoint triggered for this, then keep going. */
5659 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5661 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
5665 process_event_stop_test (ecs
);
5668 /* Be careful not to try to gather much state about a thread
5669 that's in a syscall. It's frequently a losing proposition. */
5670 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5671 /* Getting the current syscall number. */
5672 if (handle_syscall_event (ecs
) == 0)
5673 process_event_stop_test (ecs
);
5676 /* Before examining the threads further, step this thread to
5677 get it entirely out of the syscall. (We get notice of the
5678 event when the thread is just on the verge of exiting a
5679 syscall. Stepping one instruction seems to get it back
5681 case TARGET_WAITKIND_SYSCALL_RETURN
:
5682 if (handle_syscall_event (ecs
) == 0)
5683 process_event_stop_test (ecs
);
5686 case TARGET_WAITKIND_STOPPED
:
5687 handle_signal_stop (ecs
);
5690 case TARGET_WAITKIND_NO_HISTORY
:
5691 /* Reverse execution: target ran out of history info. */
5693 /* Switch to the stopped thread. */
5694 context_switch (ecs
);
5695 infrun_debug_printf ("stopped");
5697 delete_just_stopped_threads_single_step_breakpoints ();
5698 ecs
->event_thread
->set_stop_pc
5699 (regcache_read_pc (get_thread_regcache (inferior_thread ())));
5701 if (handle_stop_requested (ecs
))
5704 gdb::observers::no_history
.notify ();
5710 /* Restart threads back to what they were trying to do back when we
5711 paused them for an in-line step-over. The EVENT_THREAD thread is
5715 restart_threads (struct thread_info
*event_thread
)
5717 /* In case the instruction just stepped spawned a new thread. */
5718 update_thread_list ();
5720 for (thread_info
*tp
: all_non_exited_threads ())
5722 if (tp
->inf
->detaching
)
5724 infrun_debug_printf ("restart threads: [%s] inferior detaching",
5725 tp
->ptid
.to_string ().c_str ());
5729 switch_to_thread_no_regs (tp
);
5731 if (tp
== event_thread
)
5733 infrun_debug_printf ("restart threads: [%s] is event thread",
5734 tp
->ptid
.to_string ().c_str ());
5738 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5740 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5741 tp
->ptid
.to_string ().c_str ());
5747 infrun_debug_printf ("restart threads: [%s] resumed",
5748 tp
->ptid
.to_string ().c_str ());
5749 gdb_assert (tp
->executing () || tp
->has_pending_waitstatus ());
5753 if (thread_is_in_step_over_chain (tp
))
5755 infrun_debug_printf ("restart threads: [%s] needs step-over",
5756 tp
->ptid
.to_string ().c_str ());
5757 gdb_assert (!tp
->resumed ());
5762 if (tp
->has_pending_waitstatus ())
5764 infrun_debug_printf ("restart threads: [%s] has pending status",
5765 tp
->ptid
.to_string ().c_str ());
5766 tp
->set_resumed (true);
5770 gdb_assert (!tp
->stop_requested
);
5772 /* If some thread needs to start a step-over at this point, it
5773 should still be in the step-over queue, and thus skipped
5775 if (thread_still_needs_step_over (tp
))
5777 internal_error (__FILE__
, __LINE__
,
5778 "thread [%s] needs a step-over, but not in "
5779 "step-over queue\n",
5780 tp
->ptid
.to_string ().c_str ());
5783 if (currently_stepping (tp
))
5785 infrun_debug_printf ("restart threads: [%s] was stepping",
5786 tp
->ptid
.to_string ().c_str ());
5787 keep_going_stepped_thread (tp
);
5791 struct execution_control_state ecss
;
5792 struct execution_control_state
*ecs
= &ecss
;
5794 infrun_debug_printf ("restart threads: [%s] continuing",
5795 tp
->ptid
.to_string ().c_str ());
5796 reset_ecs (ecs
, tp
);
5797 switch_to_thread (tp
);
5798 keep_going_pass_signal (ecs
);
5803 /* Callback for iterate_over_threads. Find a resumed thread that has
5804 a pending waitstatus. */
5807 resumed_thread_with_pending_status (struct thread_info
*tp
,
5810 return tp
->resumed () && tp
->has_pending_waitstatus ();
5813 /* Called when we get an event that may finish an in-line or
5814 out-of-line (displaced stepping) step-over started previously.
5815 Return true if the event is processed and we should go back to the
5816 event loop; false if the caller should continue processing the
5820 finish_step_over (struct execution_control_state
*ecs
)
5822 displaced_step_finish (ecs
->event_thread
, ecs
->event_thread
->stop_signal ());
5824 bool had_step_over_info
= step_over_info_valid_p ();
5826 if (had_step_over_info
)
5828 /* If we're stepping over a breakpoint with all threads locked,
5829 then only the thread that was stepped should be reporting
5831 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5833 clear_step_over_info ();
5836 if (!target_is_non_stop_p ())
5839 /* Start a new step-over in another thread if there's one that
5843 /* If we were stepping over a breakpoint before, and haven't started
5844 a new in-line step-over sequence, then restart all other threads
5845 (except the event thread). We can't do this in all-stop, as then
5846 e.g., we wouldn't be able to issue any other remote packet until
5847 these other threads stop. */
5848 if (had_step_over_info
&& !step_over_info_valid_p ())
5850 struct thread_info
*pending
;
5852 /* If we only have threads with pending statuses, the restart
5853 below won't restart any thread and so nothing re-inserts the
5854 breakpoint we just stepped over. But we need it inserted
5855 when we later process the pending events, otherwise if
5856 another thread has a pending event for this breakpoint too,
5857 we'd discard its event (because the breakpoint that
5858 originally caused the event was no longer inserted). */
5859 context_switch (ecs
);
5860 insert_breakpoints ();
5862 restart_threads (ecs
->event_thread
);
5864 /* If we have events pending, go through handle_inferior_event
5865 again, picking up a pending event at random. This avoids
5866 thread starvation. */
5868 /* But not if we just stepped over a watchpoint in order to let
5869 the instruction execute so we can evaluate its expression.
5870 The set of watchpoints that triggered is recorded in the
5871 breakpoint objects themselves (see bp->watchpoint_triggered).
5872 If we processed another event first, that other event could
5873 clobber this info. */
5874 if (ecs
->event_thread
->stepping_over_watchpoint
)
5877 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5879 if (pending
!= NULL
)
5881 struct thread_info
*tp
= ecs
->event_thread
;
5882 struct regcache
*regcache
;
5884 infrun_debug_printf ("found resumed threads with "
5885 "pending events, saving status");
5887 gdb_assert (pending
!= tp
);
5889 /* Record the event thread's event for later. */
5890 save_waitstatus (tp
, &ecs
->ws
);
5891 /* This was cleared early, by handle_inferior_event. Set it
5892 so this pending event is considered by
5894 tp
->set_resumed (true);
5896 gdb_assert (!tp
->executing ());
5898 regcache
= get_thread_regcache (tp
);
5899 tp
->set_stop_pc (regcache_read_pc (regcache
));
5901 infrun_debug_printf ("saved stop_pc=%s for %s "
5902 "(currently_stepping=%d)",
5903 paddress (target_gdbarch (), tp
->stop_pc ()),
5904 tp
->ptid
.to_string ().c_str (),
5905 currently_stepping (tp
));
5907 /* This in-line step-over finished; clear this so we won't
5908 start a new one. This is what handle_signal_stop would
5909 do, if we returned false. */
5910 tp
->stepping_over_breakpoint
= 0;
5912 /* Wake up the event loop again. */
5913 mark_async_event_handler (infrun_async_inferior_event_token
);
5915 prepare_to_wait (ecs
);
5923 /* Come here when the program has stopped with a signal. */
5926 handle_signal_stop (struct execution_control_state
*ecs
)
5928 struct frame_info
*frame
;
5929 struct gdbarch
*gdbarch
;
5930 int stopped_by_watchpoint
;
5931 enum stop_kind stop_soon
;
5934 gdb_assert (ecs
->ws
.kind () == TARGET_WAITKIND_STOPPED
);
5936 ecs
->event_thread
->set_stop_signal (ecs
->ws
.sig ());
5938 /* Do we need to clean up the state of a thread that has
5939 completed a displaced single-step? (Doing so usually affects
5940 the PC, so do it here, before we set stop_pc.) */
5941 if (finish_step_over (ecs
))
5944 /* If we either finished a single-step or hit a breakpoint, but
5945 the user wanted this thread to be stopped, pretend we got a
5946 SIG0 (generic unsignaled stop). */
5947 if (ecs
->event_thread
->stop_requested
5948 && ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
)
5949 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
5951 ecs
->event_thread
->set_stop_pc
5952 (regcache_read_pc (get_thread_regcache (ecs
->event_thread
)));
5954 context_switch (ecs
);
5956 if (deprecated_context_hook
)
5957 deprecated_context_hook (ecs
->event_thread
->global_num
);
5961 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5962 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5965 ("stop_pc=%s", paddress (reg_gdbarch
, ecs
->event_thread
->stop_pc ()));
5966 if (target_stopped_by_watchpoint ())
5970 infrun_debug_printf ("stopped by watchpoint");
5972 if (target_stopped_data_address (current_inferior ()->top_target (),
5974 infrun_debug_printf ("stopped data address=%s",
5975 paddress (reg_gdbarch
, addr
));
5977 infrun_debug_printf ("(no data address available)");
5981 /* This is originated from start_remote(), start_inferior() and
5982 shared libraries hook functions. */
5983 stop_soon
= get_inferior_stop_soon (ecs
);
5984 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5986 infrun_debug_printf ("quietly stopped");
5987 stop_print_frame
= true;
5992 /* This originates from attach_command(). We need to overwrite
5993 the stop_signal here, because some kernels don't ignore a
5994 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5995 See more comments in inferior.h. On the other hand, if we
5996 get a non-SIGSTOP, report it to the user - assume the backend
5997 will handle the SIGSTOP if it should show up later.
5999 Also consider that the attach is complete when we see a
6000 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
6001 target extended-remote report it instead of a SIGSTOP
6002 (e.g. gdbserver). We already rely on SIGTRAP being our
6003 signal, so this is no exception.
6005 Also consider that the attach is complete when we see a
6006 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
6007 the target to stop all threads of the inferior, in case the
6008 low level attach operation doesn't stop them implicitly. If
6009 they weren't stopped implicitly, then the stub will report a
6010 GDB_SIGNAL_0, meaning: stopped for no particular reason
6011 other than GDB's request. */
6012 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
6013 && (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_STOP
6014 || ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6015 || ecs
->event_thread
->stop_signal () == GDB_SIGNAL_0
))
6017 stop_print_frame
= true;
6019 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
6023 /* At this point, get hold of the now-current thread's frame. */
6024 frame
= get_current_frame ();
6025 gdbarch
= get_frame_arch (frame
);
6027 /* Pull the single step breakpoints out of the target. */
6028 if (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
)
6030 struct regcache
*regcache
;
6033 regcache
= get_thread_regcache (ecs
->event_thread
);
6034 const address_space
*aspace
= regcache
->aspace ();
6036 pc
= regcache_read_pc (regcache
);
6038 /* However, before doing so, if this single-step breakpoint was
6039 actually for another thread, set this thread up for moving
6041 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
6044 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
6046 infrun_debug_printf ("[%s] hit another thread's single-step "
6048 ecs
->ptid
.to_string ().c_str ());
6049 ecs
->hit_singlestep_breakpoint
= 1;
6054 infrun_debug_printf ("[%s] hit its single-step breakpoint",
6055 ecs
->ptid
.to_string ().c_str ());
6058 delete_just_stopped_threads_single_step_breakpoints ();
6060 if (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6061 && ecs
->event_thread
->control
.trap_expected
6062 && ecs
->event_thread
->stepping_over_watchpoint
)
6063 stopped_by_watchpoint
= 0;
6065 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
6067 /* If necessary, step over this watchpoint. We'll be back to display
6069 if (stopped_by_watchpoint
6070 && (target_have_steppable_watchpoint ()
6071 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6073 /* At this point, we are stopped at an instruction which has
6074 attempted to write to a piece of memory under control of
6075 a watchpoint. The instruction hasn't actually executed
6076 yet. If we were to evaluate the watchpoint expression
6077 now, we would get the old value, and therefore no change
6078 would seem to have occurred.
6080 In order to make watchpoints work `right', we really need
6081 to complete the memory write, and then evaluate the
6082 watchpoint expression. We do this by single-stepping the
6085 It may not be necessary to disable the watchpoint to step over
6086 it. For example, the PA can (with some kernel cooperation)
6087 single step over a watchpoint without disabling the watchpoint.
6089 It is far more common to need to disable a watchpoint to step
6090 the inferior over it. If we have non-steppable watchpoints,
6091 we must disable the current watchpoint; it's simplest to
6092 disable all watchpoints.
6094 Any breakpoint at PC must also be stepped over -- if there's
6095 one, it will have already triggered before the watchpoint
6096 triggered, and we either already reported it to the user, or
6097 it didn't cause a stop and we called keep_going. In either
6098 case, if there was a breakpoint at PC, we must be trying to
6100 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6105 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6106 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6107 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6108 ecs
->event_thread
->control
.stop_step
= 0;
6109 stop_print_frame
= true;
6110 stopped_by_random_signal
= 0;
6111 bpstat
*stop_chain
= nullptr;
6113 /* Hide inlined functions starting here, unless we just performed stepi or
6114 nexti. After stepi and nexti, always show the innermost frame (not any
6115 inline function call sites). */
6116 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6118 const address_space
*aspace
6119 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6121 /* skip_inline_frames is expensive, so we avoid it if we can
6122 determine that the address is one where functions cannot have
6123 been inlined. This improves performance with inferiors that
6124 load a lot of shared libraries, because the solib event
6125 breakpoint is defined as the address of a function (i.e. not
6126 inline). Note that we have to check the previous PC as well
6127 as the current one to catch cases when we have just
6128 single-stepped off a breakpoint prior to reinstating it.
6129 Note that we're assuming that the code we single-step to is
6130 not inline, but that's not definitive: there's nothing
6131 preventing the event breakpoint function from containing
6132 inlined code, and the single-step ending up there. If the
6133 user had set a breakpoint on that inlined code, the missing
6134 skip_inline_frames call would break things. Fortunately
6135 that's an extremely unlikely scenario. */
6136 if (!pc_at_non_inline_function (aspace
,
6137 ecs
->event_thread
->stop_pc (),
6139 && !(ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6140 && ecs
->event_thread
->control
.trap_expected
6141 && pc_at_non_inline_function (aspace
,
6142 ecs
->event_thread
->prev_pc
,
6145 stop_chain
= build_bpstat_chain (aspace
,
6146 ecs
->event_thread
->stop_pc (),
6148 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6150 /* Re-fetch current thread's frame in case that invalidated
6152 frame
= get_current_frame ();
6153 gdbarch
= get_frame_arch (frame
);
6157 if (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6158 && ecs
->event_thread
->control
.trap_expected
6159 && gdbarch_single_step_through_delay_p (gdbarch
)
6160 && currently_stepping (ecs
->event_thread
))
6162 /* We're trying to step off a breakpoint. Turns out that we're
6163 also on an instruction that needs to be stepped multiple
6164 times before it's been fully executing. E.g., architectures
6165 with a delay slot. It needs to be stepped twice, once for
6166 the instruction and once for the delay slot. */
6167 int step_through_delay
6168 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6170 if (step_through_delay
)
6171 infrun_debug_printf ("step through delay");
6173 if (ecs
->event_thread
->control
.step_range_end
== 0
6174 && step_through_delay
)
6176 /* The user issued a continue when stopped at a breakpoint.
6177 Set up for another trap and get out of here. */
6178 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6182 else if (step_through_delay
)
6184 /* The user issued a step when stopped at a breakpoint.
6185 Maybe we should stop, maybe we should not - the delay
6186 slot *might* correspond to a line of source. In any
6187 case, don't decide that here, just set
6188 ecs->stepping_over_breakpoint, making sure we
6189 single-step again before breakpoints are re-inserted. */
6190 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6194 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6195 handles this event. */
6196 ecs
->event_thread
->control
.stop_bpstat
6197 = bpstat_stop_status (get_current_regcache ()->aspace (),
6198 ecs
->event_thread
->stop_pc (),
6199 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6201 /* Following in case break condition called a
6203 stop_print_frame
= true;
6205 /* This is where we handle "moribund" watchpoints. Unlike
6206 software breakpoints traps, hardware watchpoint traps are
6207 always distinguishable from random traps. If no high-level
6208 watchpoint is associated with the reported stop data address
6209 anymore, then the bpstat does not explain the signal ---
6210 simply make sure to ignore it if `stopped_by_watchpoint' is
6213 if (ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6214 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6216 && stopped_by_watchpoint
)
6218 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6222 /* NOTE: cagney/2003-03-29: These checks for a random signal
6223 at one stage in the past included checks for an inferior
6224 function call's call dummy's return breakpoint. The original
6225 comment, that went with the test, read:
6227 ``End of a stack dummy. Some systems (e.g. Sony news) give
6228 another signal besides SIGTRAP, so check here as well as
6231 If someone ever tries to get call dummys on a
6232 non-executable stack to work (where the target would stop
6233 with something like a SIGSEGV), then those tests might need
6234 to be re-instated. Given, however, that the tests were only
6235 enabled when momentary breakpoints were not being used, I
6236 suspect that it won't be the case.
6238 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6239 be necessary for call dummies on a non-executable stack on
6242 /* See if the breakpoints module can explain the signal. */
6244 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6245 ecs
->event_thread
->stop_signal ());
6247 /* Maybe this was a trap for a software breakpoint that has since
6249 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6251 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6252 ecs
->event_thread
->stop_pc ()))
6254 struct regcache
*regcache
;
6257 /* Re-adjust PC to what the program would see if GDB was not
6259 regcache
= get_thread_regcache (ecs
->event_thread
);
6260 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6263 gdb::optional
<scoped_restore_tmpl
<int>>
6264 restore_operation_disable
;
6266 if (record_full_is_used ())
6267 restore_operation_disable
.emplace
6268 (record_full_gdb_operation_disable_set ());
6270 regcache_write_pc (regcache
,
6271 ecs
->event_thread
->stop_pc () + decr_pc
);
6276 /* A delayed software breakpoint event. Ignore the trap. */
6277 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6282 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6283 has since been removed. */
6284 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6286 /* A delayed hardware breakpoint event. Ignore the trap. */
6287 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6292 /* If not, perhaps stepping/nexting can. */
6294 random_signal
= !(ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
6295 && currently_stepping (ecs
->event_thread
));
6297 /* Perhaps the thread hit a single-step breakpoint of _another_
6298 thread. Single-step breakpoints are transparent to the
6299 breakpoints module. */
6301 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6303 /* No? Perhaps we got a moribund watchpoint. */
6305 random_signal
= !stopped_by_watchpoint
;
6307 /* Always stop if the user explicitly requested this thread to
6309 if (ecs
->event_thread
->stop_requested
)
6312 infrun_debug_printf ("user-requested stop");
6315 /* For the program's own signals, act according to
6316 the signal handling tables. */
6320 /* Signal not for debugging purposes. */
6321 enum gdb_signal stop_signal
= ecs
->event_thread
->stop_signal ();
6323 infrun_debug_printf ("random signal (%s)",
6324 gdb_signal_to_symbol_string (stop_signal
));
6326 stopped_by_random_signal
= 1;
6328 /* Always stop on signals if we're either just gaining control
6329 of the program, or the user explicitly requested this thread
6330 to remain stopped. */
6331 if (stop_soon
!= NO_STOP_QUIETLY
6332 || ecs
->event_thread
->stop_requested
6333 || signal_stop_state (ecs
->event_thread
->stop_signal ()))
6339 /* Notify observers the signal has "handle print" set. Note we
6340 returned early above if stopping; normal_stop handles the
6341 printing in that case. */
6342 if (signal_print
[ecs
->event_thread
->stop_signal ()])
6344 /* The signal table tells us to print about this signal. */
6345 target_terminal::ours_for_output ();
6346 gdb::observers::signal_received
.notify (ecs
->event_thread
->stop_signal ());
6347 target_terminal::inferior ();
6350 /* Clear the signal if it should not be passed. */
6351 if (signal_program
[ecs
->event_thread
->stop_signal ()] == 0)
6352 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
6354 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->stop_pc ()
6355 && ecs
->event_thread
->control
.trap_expected
6356 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6358 /* We were just starting a new sequence, attempting to
6359 single-step off of a breakpoint and expecting a SIGTRAP.
6360 Instead this signal arrives. This signal will take us out
6361 of the stepping range so GDB needs to remember to, when
6362 the signal handler returns, resume stepping off that
6364 /* To simplify things, "continue" is forced to use the same
6365 code paths as single-step - set a breakpoint at the
6366 signal return address and then, once hit, step off that
6368 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6370 insert_hp_step_resume_breakpoint_at_frame (frame
);
6371 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6372 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6373 ecs
->event_thread
->control
.trap_expected
= 0;
6375 /* If we were nexting/stepping some other thread, switch to
6376 it, so that we don't continue it, losing control. */
6377 if (!switch_back_to_stepped_thread (ecs
))
6382 if (ecs
->event_thread
->stop_signal () != GDB_SIGNAL_0
6383 && (pc_in_thread_step_range (ecs
->event_thread
->stop_pc (),
6385 || ecs
->event_thread
->control
.step_range_end
== 1)
6386 && frame_id_eq (get_stack_frame_id (frame
),
6387 ecs
->event_thread
->control
.step_stack_frame_id
)
6388 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6390 /* The inferior is about to take a signal that will take it
6391 out of the single step range. Set a breakpoint at the
6392 current PC (which is presumably where the signal handler
6393 will eventually return) and then allow the inferior to
6396 Note that this is only needed for a signal delivered
6397 while in the single-step range. Nested signals aren't a
6398 problem as they eventually all return. */
6399 infrun_debug_printf ("signal may take us out of single-step range");
6401 clear_step_over_info ();
6402 insert_hp_step_resume_breakpoint_at_frame (frame
);
6403 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6404 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6405 ecs
->event_thread
->control
.trap_expected
= 0;
6410 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6411 when either there's a nested signal, or when there's a
6412 pending signal enabled just as the signal handler returns
6413 (leaving the inferior at the step-resume-breakpoint without
6414 actually executing it). Either way continue until the
6415 breakpoint is really hit. */
6417 if (!switch_back_to_stepped_thread (ecs
))
6419 infrun_debug_printf ("random signal, keep going");
6426 process_event_stop_test (ecs
);
6429 /* Come here when we've got some debug event / signal we can explain
6430 (IOW, not a random signal), and test whether it should cause a
6431 stop, or whether we should resume the inferior (transparently).
6432 E.g., could be a breakpoint whose condition evaluates false; we
6433 could be still stepping within the line; etc. */
6436 process_event_stop_test (struct execution_control_state
*ecs
)
6438 struct symtab_and_line stop_pc_sal
;
6439 struct frame_info
*frame
;
6440 struct gdbarch
*gdbarch
;
6441 CORE_ADDR jmp_buf_pc
;
6442 struct bpstat_what what
;
6444 /* Handle cases caused by hitting a breakpoint. */
6446 frame
= get_current_frame ();
6447 gdbarch
= get_frame_arch (frame
);
6449 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6451 if (what
.call_dummy
)
6453 stop_stack_dummy
= what
.call_dummy
;
6456 /* A few breakpoint types have callbacks associated (e.g.,
6457 bp_jit_event). Run them now. */
6458 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6460 /* If we hit an internal event that triggers symbol changes, the
6461 current frame will be invalidated within bpstat_what (e.g., if we
6462 hit an internal solib event). Re-fetch it. */
6463 frame
= get_current_frame ();
6464 gdbarch
= get_frame_arch (frame
);
6466 switch (what
.main_action
)
6468 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6469 /* If we hit the breakpoint at longjmp while stepping, we
6470 install a momentary breakpoint at the target of the
6473 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6475 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6477 if (what
.is_longjmp
)
6479 struct value
*arg_value
;
6481 /* If we set the longjmp breakpoint via a SystemTap probe,
6482 then use it to extract the arguments. The destination PC
6483 is the third argument to the probe. */
6484 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6487 jmp_buf_pc
= value_as_address (arg_value
);
6488 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6490 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6491 || !gdbarch_get_longjmp_target (gdbarch
,
6492 frame
, &jmp_buf_pc
))
6494 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6495 "(!gdbarch_get_longjmp_target)");
6500 /* Insert a breakpoint at resume address. */
6501 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6504 check_exception_resume (ecs
, frame
);
6508 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6510 struct frame_info
*init_frame
;
6512 /* There are several cases to consider.
6514 1. The initiating frame no longer exists. In this case we
6515 must stop, because the exception or longjmp has gone too
6518 2. The initiating frame exists, and is the same as the
6519 current frame. We stop, because the exception or longjmp
6522 3. The initiating frame exists and is different from the
6523 current frame. This means the exception or longjmp has
6524 been caught beneath the initiating frame, so keep going.
6526 4. longjmp breakpoint has been placed just to protect
6527 against stale dummy frames and user is not interested in
6528 stopping around longjmps. */
6530 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6532 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6534 delete_exception_resume_breakpoint (ecs
->event_thread
);
6536 if (what
.is_longjmp
)
6538 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6540 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6548 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6552 struct frame_id current_id
6553 = get_frame_id (get_current_frame ());
6554 if (frame_id_eq (current_id
,
6555 ecs
->event_thread
->initiating_frame
))
6557 /* Case 2. Fall through. */
6567 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6569 delete_step_resume_breakpoint (ecs
->event_thread
);
6571 end_stepping_range (ecs
);
6575 case BPSTAT_WHAT_SINGLE
:
6576 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6577 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6578 /* Still need to check other stuff, at least the case where we
6579 are stepping and step out of the right range. */
6582 case BPSTAT_WHAT_STEP_RESUME
:
6583 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6585 delete_step_resume_breakpoint (ecs
->event_thread
);
6586 if (ecs
->event_thread
->control
.proceed_to_finish
6587 && execution_direction
== EXEC_REVERSE
)
6589 struct thread_info
*tp
= ecs
->event_thread
;
6591 /* We are finishing a function in reverse, and just hit the
6592 step-resume breakpoint at the start address of the
6593 function, and we're almost there -- just need to back up
6594 by one more single-step, which should take us back to the
6596 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6600 fill_in_stop_func (gdbarch
, ecs
);
6601 if (ecs
->event_thread
->stop_pc () == ecs
->stop_func_start
6602 && execution_direction
== EXEC_REVERSE
)
6604 /* We are stepping over a function call in reverse, and just
6605 hit the step-resume breakpoint at the start address of
6606 the function. Go back to single-stepping, which should
6607 take us back to the function call. */
6608 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6614 case BPSTAT_WHAT_STOP_NOISY
:
6615 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6616 stop_print_frame
= true;
6618 /* Assume the thread stopped for a breakpoint. We'll still check
6619 whether a/the breakpoint is there when the thread is next
6621 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6626 case BPSTAT_WHAT_STOP_SILENT
:
6627 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6628 stop_print_frame
= false;
6630 /* Assume the thread stopped for a breakpoint. We'll still check
6631 whether a/the breakpoint is there when the thread is next
6633 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6637 case BPSTAT_WHAT_HP_STEP_RESUME
:
6638 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6640 delete_step_resume_breakpoint (ecs
->event_thread
);
6641 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6643 /* Back when the step-resume breakpoint was inserted, we
6644 were trying to single-step off a breakpoint. Go back to
6646 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6647 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6653 case BPSTAT_WHAT_KEEP_CHECKING
:
6657 /* If we stepped a permanent breakpoint and we had a high priority
6658 step-resume breakpoint for the address we stepped, but we didn't
6659 hit it, then we must have stepped into the signal handler. The
6660 step-resume was only necessary to catch the case of _not_
6661 stepping into the handler, so delete it, and fall through to
6662 checking whether the step finished. */
6663 if (ecs
->event_thread
->stepped_breakpoint
)
6665 struct breakpoint
*sr_bp
6666 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6669 && sr_bp
->loc
->permanent
6670 && sr_bp
->type
== bp_hp_step_resume
6671 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6673 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6674 delete_step_resume_breakpoint (ecs
->event_thread
);
6675 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6679 /* We come here if we hit a breakpoint but should not stop for it.
6680 Possibly we also were stepping and should stop for that. So fall
6681 through and test for stepping. But, if not stepping, do not
6684 /* In all-stop mode, if we're currently stepping but have stopped in
6685 some other thread, we need to switch back to the stepped thread. */
6686 if (switch_back_to_stepped_thread (ecs
))
6689 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6691 infrun_debug_printf ("step-resume breakpoint is inserted");
6693 /* Having a step-resume breakpoint overrides anything
6694 else having to do with stepping commands until
6695 that breakpoint is reached. */
6700 if (ecs
->event_thread
->control
.step_range_end
== 0)
6702 infrun_debug_printf ("no stepping, continue");
6703 /* Likewise if we aren't even stepping. */
6708 /* Re-fetch current thread's frame in case the code above caused
6709 the frame cache to be re-initialized, making our FRAME variable
6710 a dangling pointer. */
6711 frame
= get_current_frame ();
6712 gdbarch
= get_frame_arch (frame
);
6713 fill_in_stop_func (gdbarch
, ecs
);
6715 /* If stepping through a line, keep going if still within it.
6717 Note that step_range_end is the address of the first instruction
6718 beyond the step range, and NOT the address of the last instruction
6721 Note also that during reverse execution, we may be stepping
6722 through a function epilogue and therefore must detect when
6723 the current-frame changes in the middle of a line. */
6725 if (pc_in_thread_step_range (ecs
->event_thread
->stop_pc (),
6727 && (execution_direction
!= EXEC_REVERSE
6728 || frame_id_eq (get_frame_id (frame
),
6729 ecs
->event_thread
->control
.step_frame_id
)))
6732 ("stepping inside range [%s-%s]",
6733 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6734 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6736 /* Tentatively re-enable range stepping; `resume' disables it if
6737 necessary (e.g., if we're stepping over a breakpoint or we
6738 have software watchpoints). */
6739 ecs
->event_thread
->control
.may_range_step
= 1;
6741 /* When stepping backward, stop at beginning of line range
6742 (unless it's the function entry point, in which case
6743 keep going back to the call point). */
6744 CORE_ADDR stop_pc
= ecs
->event_thread
->stop_pc ();
6745 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6746 && stop_pc
!= ecs
->stop_func_start
6747 && execution_direction
== EXEC_REVERSE
)
6748 end_stepping_range (ecs
);
6755 /* We stepped out of the stepping range. */
6757 /* If we are stepping at the source level and entered the runtime
6758 loader dynamic symbol resolution code...
6760 EXEC_FORWARD: we keep on single stepping until we exit the run
6761 time loader code and reach the callee's address.
6763 EXEC_REVERSE: we've already executed the callee (backward), and
6764 the runtime loader code is handled just like any other
6765 undebuggable function call. Now we need only keep stepping
6766 backward through the trampoline code, and that's handled further
6767 down, so there is nothing for us to do here. */
6769 if (execution_direction
!= EXEC_REVERSE
6770 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6771 && in_solib_dynsym_resolve_code (ecs
->event_thread
->stop_pc ()))
6773 CORE_ADDR pc_after_resolver
=
6774 gdbarch_skip_solib_resolver (gdbarch
, ecs
->event_thread
->stop_pc ());
6776 infrun_debug_printf ("stepped into dynsym resolve code");
6778 if (pc_after_resolver
)
6780 /* Set up a step-resume breakpoint at the address
6781 indicated by SKIP_SOLIB_RESOLVER. */
6782 symtab_and_line sr_sal
;
6783 sr_sal
.pc
= pc_after_resolver
;
6784 sr_sal
.pspace
= get_frame_program_space (frame
);
6786 insert_step_resume_breakpoint_at_sal (gdbarch
,
6787 sr_sal
, null_frame_id
);
6794 /* Step through an indirect branch thunk. */
6795 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6796 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6797 ecs
->event_thread
->stop_pc ()))
6799 infrun_debug_printf ("stepped into indirect branch thunk");
6804 if (ecs
->event_thread
->control
.step_range_end
!= 1
6805 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6806 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6807 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6809 infrun_debug_printf ("stepped into signal trampoline");
6810 /* The inferior, while doing a "step" or "next", has ended up in
6811 a signal trampoline (either by a signal being delivered or by
6812 the signal handler returning). Just single-step until the
6813 inferior leaves the trampoline (either by calling the handler
6819 /* If we're in the return path from a shared library trampoline,
6820 we want to proceed through the trampoline when stepping. */
6821 /* macro/2012-04-25: This needs to come before the subroutine
6822 call check below as on some targets return trampolines look
6823 like subroutine calls (MIPS16 return thunks). */
6824 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6825 ecs
->event_thread
->stop_pc (),
6826 ecs
->stop_func_name
)
6827 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6829 /* Determine where this trampoline returns. */
6830 CORE_ADDR stop_pc
= ecs
->event_thread
->stop_pc ();
6831 CORE_ADDR real_stop_pc
6832 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6834 infrun_debug_printf ("stepped into solib return tramp");
6836 /* Only proceed through if we know where it's going. */
6839 /* And put the step-breakpoint there and go until there. */
6840 symtab_and_line sr_sal
;
6841 sr_sal
.pc
= real_stop_pc
;
6842 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6843 sr_sal
.pspace
= get_frame_program_space (frame
);
6845 /* Do not specify what the fp should be when we stop since
6846 on some machines the prologue is where the new fp value
6848 insert_step_resume_breakpoint_at_sal (gdbarch
,
6849 sr_sal
, null_frame_id
);
6851 /* Restart without fiddling with the step ranges or
6858 /* Check for subroutine calls. The check for the current frame
6859 equalling the step ID is not necessary - the check of the
6860 previous frame's ID is sufficient - but it is a common case and
6861 cheaper than checking the previous frame's ID.
6863 NOTE: frame_id_eq will never report two invalid frame IDs as
6864 being equal, so to get into this block, both the current and
6865 previous frame must have valid frame IDs. */
6866 /* The outer_frame_id check is a heuristic to detect stepping
6867 through startup code. If we step over an instruction which
6868 sets the stack pointer from an invalid value to a valid value,
6869 we may detect that as a subroutine call from the mythical
6870 "outermost" function. This could be fixed by marking
6871 outermost frames as !stack_p,code_p,special_p. Then the
6872 initial outermost frame, before sp was valid, would
6873 have code_addr == &_start. See the comment in frame_id_eq
6875 if (!frame_id_eq (get_stack_frame_id (frame
),
6876 ecs
->event_thread
->control
.step_stack_frame_id
)
6877 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6878 ecs
->event_thread
->control
.step_stack_frame_id
)
6879 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6881 || (ecs
->event_thread
->control
.step_start_function
6882 != find_pc_function (ecs
->event_thread
->stop_pc ())))))
6884 CORE_ADDR stop_pc
= ecs
->event_thread
->stop_pc ();
6885 CORE_ADDR real_stop_pc
;
6887 infrun_debug_printf ("stepped into subroutine");
6889 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6891 /* I presume that step_over_calls is only 0 when we're
6892 supposed to be stepping at the assembly language level
6893 ("stepi"). Just stop. */
6894 /* And this works the same backward as frontward. MVS */
6895 end_stepping_range (ecs
);
6899 /* Reverse stepping through solib trampolines. */
6901 if (execution_direction
== EXEC_REVERSE
6902 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6903 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6904 || (ecs
->stop_func_start
== 0
6905 && in_solib_dynsym_resolve_code (stop_pc
))))
6907 /* Any solib trampoline code can be handled in reverse
6908 by simply continuing to single-step. We have already
6909 executed the solib function (backwards), and a few
6910 steps will take us back through the trampoline to the
6916 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6918 /* We're doing a "next".
6920 Normal (forward) execution: set a breakpoint at the
6921 callee's return address (the address at which the caller
6924 Reverse (backward) execution. set the step-resume
6925 breakpoint at the start of the function that we just
6926 stepped into (backwards), and continue to there. When we
6927 get there, we'll need to single-step back to the caller. */
6929 if (execution_direction
== EXEC_REVERSE
)
6931 /* If we're already at the start of the function, we've either
6932 just stepped backward into a single instruction function,
6933 or stepped back out of a signal handler to the first instruction
6934 of the function. Just keep going, which will single-step back
6936 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6938 /* Normal function call return (static or dynamic). */
6939 symtab_and_line sr_sal
;
6940 sr_sal
.pc
= ecs
->stop_func_start
;
6941 sr_sal
.pspace
= get_frame_program_space (frame
);
6942 insert_step_resume_breakpoint_at_sal (gdbarch
,
6943 sr_sal
, null_frame_id
);
6947 insert_step_resume_breakpoint_at_caller (frame
);
6953 /* If we are in a function call trampoline (a stub between the
6954 calling routine and the real function), locate the real
6955 function. That's what tells us (a) whether we want to step
6956 into it at all, and (b) what prologue we want to run to the
6957 end of, if we do step into it. */
6958 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6959 if (real_stop_pc
== 0)
6960 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6961 if (real_stop_pc
!= 0)
6962 ecs
->stop_func_start
= real_stop_pc
;
6964 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6966 symtab_and_line sr_sal
;
6967 sr_sal
.pc
= ecs
->stop_func_start
;
6968 sr_sal
.pspace
= get_frame_program_space (frame
);
6970 insert_step_resume_breakpoint_at_sal (gdbarch
,
6971 sr_sal
, null_frame_id
);
6976 /* If we have line number information for the function we are
6977 thinking of stepping into and the function isn't on the skip
6980 If there are several symtabs at that PC (e.g. with include
6981 files), just want to know whether *any* of them have line
6982 numbers. find_pc_line handles this. */
6984 struct symtab_and_line tmp_sal
;
6986 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6987 if (tmp_sal
.line
!= 0
6988 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6990 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6992 if (execution_direction
== EXEC_REVERSE
)
6993 handle_step_into_function_backward (gdbarch
, ecs
);
6995 handle_step_into_function (gdbarch
, ecs
);
7000 /* If we have no line number and the step-stop-if-no-debug is
7001 set, we stop the step so that the user has a chance to switch
7002 in assembly mode. */
7003 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7004 && step_stop_if_no_debug
)
7006 end_stepping_range (ecs
);
7010 if (execution_direction
== EXEC_REVERSE
)
7012 /* If we're already at the start of the function, we've either just
7013 stepped backward into a single instruction function without line
7014 number info, or stepped back out of a signal handler to the first
7015 instruction of the function without line number info. Just keep
7016 going, which will single-step back to the caller. */
7017 if (ecs
->stop_func_start
!= stop_pc
)
7019 /* Set a breakpoint at callee's start address.
7020 From there we can step once and be back in the caller. */
7021 symtab_and_line sr_sal
;
7022 sr_sal
.pc
= ecs
->stop_func_start
;
7023 sr_sal
.pspace
= get_frame_program_space (frame
);
7024 insert_step_resume_breakpoint_at_sal (gdbarch
,
7025 sr_sal
, null_frame_id
);
7029 /* Set a breakpoint at callee's return address (the address
7030 at which the caller will resume). */
7031 insert_step_resume_breakpoint_at_caller (frame
);
7037 /* Reverse stepping through solib trampolines. */
7039 if (execution_direction
== EXEC_REVERSE
7040 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7042 CORE_ADDR stop_pc
= ecs
->event_thread
->stop_pc ();
7044 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7045 || (ecs
->stop_func_start
== 0
7046 && in_solib_dynsym_resolve_code (stop_pc
)))
7048 /* Any solib trampoline code can be handled in reverse
7049 by simply continuing to single-step. We have already
7050 executed the solib function (backwards), and a few
7051 steps will take us back through the trampoline to the
7056 else if (in_solib_dynsym_resolve_code (stop_pc
))
7058 /* Stepped backward into the solib dynsym resolver.
7059 Set a breakpoint at its start and continue, then
7060 one more step will take us out. */
7061 symtab_and_line sr_sal
;
7062 sr_sal
.pc
= ecs
->stop_func_start
;
7063 sr_sal
.pspace
= get_frame_program_space (frame
);
7064 insert_step_resume_breakpoint_at_sal (gdbarch
,
7065 sr_sal
, null_frame_id
);
7071 /* This always returns the sal for the inner-most frame when we are in a
7072 stack of inlined frames, even if GDB actually believes that it is in a
7073 more outer frame. This is checked for below by calls to
7074 inline_skipped_frames. */
7075 stop_pc_sal
= find_pc_line (ecs
->event_thread
->stop_pc (), 0);
7077 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7078 the trampoline processing logic, however, there are some trampolines
7079 that have no names, so we should do trampoline handling first. */
7080 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7081 && ecs
->stop_func_name
== NULL
7082 && stop_pc_sal
.line
== 0)
7084 infrun_debug_printf ("stepped into undebuggable function");
7086 /* The inferior just stepped into, or returned to, an
7087 undebuggable function (where there is no debugging information
7088 and no line number corresponding to the address where the
7089 inferior stopped). Since we want to skip this kind of code,
7090 we keep going until the inferior returns from this
7091 function - unless the user has asked us not to (via
7092 set step-mode) or we no longer know how to get back
7093 to the call site. */
7094 if (step_stop_if_no_debug
7095 || !frame_id_p (frame_unwind_caller_id (frame
)))
7097 /* If we have no line number and the step-stop-if-no-debug
7098 is set, we stop the step so that the user has a chance to
7099 switch in assembly mode. */
7100 end_stepping_range (ecs
);
7105 /* Set a breakpoint at callee's return address (the address
7106 at which the caller will resume). */
7107 insert_step_resume_breakpoint_at_caller (frame
);
7113 if (ecs
->event_thread
->control
.step_range_end
== 1)
7115 /* It is stepi or nexti. We always want to stop stepping after
7117 infrun_debug_printf ("stepi/nexti");
7118 end_stepping_range (ecs
);
7122 if (stop_pc_sal
.line
== 0)
7124 /* We have no line number information. That means to stop
7125 stepping (does this always happen right after one instruction,
7126 when we do "s" in a function with no line numbers,
7127 or can this happen as a result of a return or longjmp?). */
7128 infrun_debug_printf ("line number info");
7129 end_stepping_range (ecs
);
7133 /* Look for "calls" to inlined functions, part one. If the inline
7134 frame machinery detected some skipped call sites, we have entered
7135 a new inline function. */
7137 if (frame_id_eq (get_frame_id (get_current_frame ()),
7138 ecs
->event_thread
->control
.step_frame_id
)
7139 && inline_skipped_frames (ecs
->event_thread
))
7141 infrun_debug_printf ("stepped into inlined function");
7143 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7145 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7147 /* For "step", we're going to stop. But if the call site
7148 for this inlined function is on the same source line as
7149 we were previously stepping, go down into the function
7150 first. Otherwise stop at the call site. */
7152 if (call_sal
.line
== ecs
->event_thread
->current_line
7153 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7155 step_into_inline_frame (ecs
->event_thread
);
7156 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7163 end_stepping_range (ecs
);
7168 /* For "next", we should stop at the call site if it is on a
7169 different source line. Otherwise continue through the
7170 inlined function. */
7171 if (call_sal
.line
== ecs
->event_thread
->current_line
7172 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7175 end_stepping_range (ecs
);
7180 /* Look for "calls" to inlined functions, part two. If we are still
7181 in the same real function we were stepping through, but we have
7182 to go further up to find the exact frame ID, we are stepping
7183 through a more inlined call beyond its call site. */
7185 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7186 && !frame_id_eq (get_frame_id (get_current_frame ()),
7187 ecs
->event_thread
->control
.step_frame_id
)
7188 && stepped_in_from (get_current_frame (),
7189 ecs
->event_thread
->control
.step_frame_id
))
7191 infrun_debug_printf ("stepping through inlined function");
7193 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7194 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7197 end_stepping_range (ecs
);
7201 bool refresh_step_info
= true;
7202 if ((ecs
->event_thread
->stop_pc () == stop_pc_sal
.pc
)
7203 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7204 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7206 /* We are at a different line. */
7208 if (stop_pc_sal
.is_stmt
)
7210 /* We are at the start of a statement.
7212 So stop. Note that we don't stop if we step into the middle of a
7213 statement. That is said to make things like for (;;) statements
7215 infrun_debug_printf ("stepped to a different line");
7216 end_stepping_range (ecs
);
7219 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7220 ecs
->event_thread
->control
.step_frame_id
))
7222 /* We are not at the start of a statement, and we have not changed
7225 We ignore this line table entry, and continue stepping forward,
7226 looking for a better place to stop. */
7227 refresh_step_info
= false;
7228 infrun_debug_printf ("stepped to a different line, but "
7229 "it's not the start of a statement");
7233 /* We are not the start of a statement, and we have changed frame.
7235 We ignore this line table entry, and continue stepping forward,
7236 looking for a better place to stop. Keep refresh_step_info at
7237 true to note that the frame has changed, but ignore the line
7238 number to make sure we don't ignore a subsequent entry with the
7239 same line number. */
7240 stop_pc_sal
.line
= 0;
7241 infrun_debug_printf ("stepped to a different frame, but "
7242 "it's not the start of a statement");
7246 /* We aren't done stepping.
7248 Optimize by setting the stepping range to the line.
7249 (We might not be in the original line, but if we entered a
7250 new line in mid-statement, we continue stepping. This makes
7251 things like for(;;) statements work better.)
7253 If we entered a SAL that indicates a non-statement line table entry,
7254 then we update the stepping range, but we don't update the step info,
7255 which includes things like the line number we are stepping away from.
7256 This means we will stop when we find a line table entry that is marked
7257 as is-statement, even if it matches the non-statement one we just
7260 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7261 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7262 ecs
->event_thread
->control
.may_range_step
= 1;
7263 if (refresh_step_info
)
7264 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7266 infrun_debug_printf ("keep going");
7270 static bool restart_stepped_thread (process_stratum_target
*resume_target
,
7271 ptid_t resume_ptid
);
7273 /* In all-stop mode, if we're currently stepping but have stopped in
7274 some other thread, we may need to switch back to the stepped
7275 thread. Returns true we set the inferior running, false if we left
7276 it stopped (and the event needs further processing). */
7279 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7281 if (!target_is_non_stop_p ())
7283 /* If any thread is blocked on some internal breakpoint, and we
7284 simply need to step over that breakpoint to get it going
7285 again, do that first. */
7287 /* However, if we see an event for the stepping thread, then we
7288 know all other threads have been moved past their breakpoints
7289 already. Let the caller check whether the step is finished,
7290 etc., before deciding to move it past a breakpoint. */
7291 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7294 /* Check if the current thread is blocked on an incomplete
7295 step-over, interrupted by a random signal. */
7296 if (ecs
->event_thread
->control
.trap_expected
7297 && ecs
->event_thread
->stop_signal () != GDB_SIGNAL_TRAP
)
7300 ("need to finish step-over of [%s]",
7301 ecs
->event_thread
->ptid
.to_string ().c_str ());
7306 /* Check if the current thread is blocked by a single-step
7307 breakpoint of another thread. */
7308 if (ecs
->hit_singlestep_breakpoint
)
7310 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7311 ecs
->ptid
.to_string ().c_str ());
7316 /* If this thread needs yet another step-over (e.g., stepping
7317 through a delay slot), do it first before moving on to
7319 if (thread_still_needs_step_over (ecs
->event_thread
))
7322 ("thread [%s] still needs step-over",
7323 ecs
->event_thread
->ptid
.to_string ().c_str ());
7328 /* If scheduler locking applies even if not stepping, there's no
7329 need to walk over threads. Above we've checked whether the
7330 current thread is stepping. If some other thread not the
7331 event thread is stepping, then it must be that scheduler
7332 locking is not in effect. */
7333 if (schedlock_applies (ecs
->event_thread
))
7336 /* Otherwise, we no longer expect a trap in the current thread.
7337 Clear the trap_expected flag before switching back -- this is
7338 what keep_going does as well, if we call it. */
7339 ecs
->event_thread
->control
.trap_expected
= 0;
7341 /* Likewise, clear the signal if it should not be passed. */
7342 if (!signal_program
[ecs
->event_thread
->stop_signal ()])
7343 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
7345 if (restart_stepped_thread (ecs
->target
, ecs
->ptid
))
7347 prepare_to_wait (ecs
);
7351 switch_to_thread (ecs
->event_thread
);
7357 /* Look for the thread that was stepping, and resume it.
7358 RESUME_TARGET / RESUME_PTID indicate the set of threads the caller
7359 is resuming. Return true if a thread was started, false
7363 restart_stepped_thread (process_stratum_target
*resume_target
,
7366 /* Do all pending step-overs before actually proceeding with
7368 if (start_step_over ())
7371 for (thread_info
*tp
: all_threads_safe ())
7373 if (tp
->state
== THREAD_EXITED
)
7376 if (tp
->has_pending_waitstatus ())
7379 /* Ignore threads of processes the caller is not
7382 && (tp
->inf
->process_target () != resume_target
7383 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7386 if (tp
->control
.trap_expected
)
7388 infrun_debug_printf ("switching back to stepped thread (step-over)");
7390 if (keep_going_stepped_thread (tp
))
7395 for (thread_info
*tp
: all_threads_safe ())
7397 if (tp
->state
== THREAD_EXITED
)
7400 if (tp
->has_pending_waitstatus ())
7403 /* Ignore threads of processes the caller is not
7406 && (tp
->inf
->process_target () != resume_target
7407 || tp
->inf
->pid
!= resume_ptid
.pid ()))
7410 /* Did we find the stepping thread? */
7411 if (tp
->control
.step_range_end
)
7413 infrun_debug_printf ("switching back to stepped thread (stepping)");
7415 if (keep_going_stepped_thread (tp
))
7426 restart_after_all_stop_detach (process_stratum_target
*proc_target
)
7428 /* Note we don't check target_is_non_stop_p() here, because the
7429 current inferior may no longer have a process_stratum target
7430 pushed, as we just detached. */
7432 /* See if we have a THREAD_RUNNING thread that need to be
7433 re-resumed. If we have any thread that is already executing,
7434 then we don't need to resume the target -- it is already been
7435 resumed. With the remote target (in all-stop), it's even
7436 impossible to issue another resumption if the target is already
7437 resumed, until the target reports a stop. */
7438 for (thread_info
*thr
: all_threads (proc_target
))
7440 if (thr
->state
!= THREAD_RUNNING
)
7443 /* If we have any thread that is already executing, then we
7444 don't need to resume the target -- it is already been
7446 if (thr
->executing ())
7449 /* If we have a pending event to process, skip resuming the
7450 target and go straight to processing it. */
7451 if (thr
->resumed () && thr
->has_pending_waitstatus ())
7455 /* Alright, we need to re-resume the target. If a thread was
7456 stepping, we need to restart it stepping. */
7457 if (restart_stepped_thread (proc_target
, minus_one_ptid
))
7460 /* Otherwise, find the first THREAD_RUNNING thread and resume
7462 for (thread_info
*thr
: all_threads (proc_target
))
7464 if (thr
->state
!= THREAD_RUNNING
)
7467 execution_control_state ecs
;
7468 reset_ecs (&ecs
, thr
);
7469 switch_to_thread (thr
);
7475 /* Set a previously stepped thread back to stepping. Returns true on
7476 success, false if the resume is not possible (e.g., the thread
7480 keep_going_stepped_thread (struct thread_info
*tp
)
7482 struct frame_info
*frame
;
7483 struct execution_control_state ecss
;
7484 struct execution_control_state
*ecs
= &ecss
;
7486 /* If the stepping thread exited, then don't try to switch back and
7487 resume it, which could fail in several different ways depending
7488 on the target. Instead, just keep going.
7490 We can find a stepping dead thread in the thread list in two
7493 - The target supports thread exit events, and when the target
7494 tries to delete the thread from the thread list, inferior_ptid
7495 pointed at the exiting thread. In such case, calling
7496 delete_thread does not really remove the thread from the list;
7497 instead, the thread is left listed, with 'exited' state.
7499 - The target's debug interface does not support thread exit
7500 events, and so we have no idea whatsoever if the previously
7501 stepping thread is still alive. For that reason, we need to
7502 synchronously query the target now. */
7504 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7506 infrun_debug_printf ("not resuming previously stepped thread, it has "
7513 infrun_debug_printf ("resuming previously stepped thread");
7515 reset_ecs (ecs
, tp
);
7516 switch_to_thread (tp
);
7518 tp
->set_stop_pc (regcache_read_pc (get_thread_regcache (tp
)));
7519 frame
= get_current_frame ();
7521 /* If the PC of the thread we were trying to single-step has
7522 changed, then that thread has trapped or been signaled, but the
7523 event has not been reported to GDB yet. Re-poll the target
7524 looking for this particular thread's event (i.e. temporarily
7525 enable schedlock) by:
7527 - setting a break at the current PC
7528 - resuming that particular thread, only (by setting trap
7531 This prevents us continuously moving the single-step breakpoint
7532 forward, one instruction at a time, overstepping. */
7534 if (tp
->stop_pc () != tp
->prev_pc
)
7538 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7539 paddress (target_gdbarch (), tp
->prev_pc
),
7540 paddress (target_gdbarch (), tp
->stop_pc ()));
7542 /* Clear the info of the previous step-over, as it's no longer
7543 valid (if the thread was trying to step over a breakpoint, it
7544 has already succeeded). It's what keep_going would do too,
7545 if we called it. Do this before trying to insert the sss
7546 breakpoint, otherwise if we were previously trying to step
7547 over this exact address in another thread, the breakpoint is
7549 clear_step_over_info ();
7550 tp
->control
.trap_expected
= 0;
7552 insert_single_step_breakpoint (get_frame_arch (frame
),
7553 get_frame_address_space (frame
),
7556 tp
->set_resumed (true);
7557 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7558 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7562 infrun_debug_printf ("expected thread still hasn't advanced");
7564 keep_going_pass_signal (ecs
);
7570 /* Is thread TP in the middle of (software or hardware)
7571 single-stepping? (Note the result of this function must never be
7572 passed directly as target_resume's STEP parameter.) */
7575 currently_stepping (struct thread_info
*tp
)
7577 return ((tp
->control
.step_range_end
7578 && tp
->control
.step_resume_breakpoint
== NULL
)
7579 || tp
->control
.trap_expected
7580 || tp
->stepped_breakpoint
7581 || bpstat_should_step ());
7584 /* Inferior has stepped into a subroutine call with source code that
7585 we should not step over. Do step to the first line of code in
7589 handle_step_into_function (struct gdbarch
*gdbarch
,
7590 struct execution_control_state
*ecs
)
7592 fill_in_stop_func (gdbarch
, ecs
);
7594 compunit_symtab
*cust
7595 = find_pc_compunit_symtab (ecs
->event_thread
->stop_pc ());
7596 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7597 ecs
->stop_func_start
7598 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7600 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7601 /* Use the step_resume_break to step until the end of the prologue,
7602 even if that involves jumps (as it seems to on the vax under
7604 /* If the prologue ends in the middle of a source line, continue to
7605 the end of that source line (if it is still within the function).
7606 Otherwise, just go to end of prologue. */
7607 if (stop_func_sal
.end
7608 && stop_func_sal
.pc
!= ecs
->stop_func_start
7609 && stop_func_sal
.end
< ecs
->stop_func_end
)
7610 ecs
->stop_func_start
= stop_func_sal
.end
;
7612 /* Architectures which require breakpoint adjustment might not be able
7613 to place a breakpoint at the computed address. If so, the test
7614 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7615 ecs->stop_func_start to an address at which a breakpoint may be
7616 legitimately placed.
7618 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7619 made, GDB will enter an infinite loop when stepping through
7620 optimized code consisting of VLIW instructions which contain
7621 subinstructions corresponding to different source lines. On
7622 FR-V, it's not permitted to place a breakpoint on any but the
7623 first subinstruction of a VLIW instruction. When a breakpoint is
7624 set, GDB will adjust the breakpoint address to the beginning of
7625 the VLIW instruction. Thus, we need to make the corresponding
7626 adjustment here when computing the stop address. */
7628 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7630 ecs
->stop_func_start
7631 = gdbarch_adjust_breakpoint_address (gdbarch
,
7632 ecs
->stop_func_start
);
7635 if (ecs
->stop_func_start
== ecs
->event_thread
->stop_pc ())
7637 /* We are already there: stop now. */
7638 end_stepping_range (ecs
);
7643 /* Put the step-breakpoint there and go until there. */
7644 symtab_and_line sr_sal
;
7645 sr_sal
.pc
= ecs
->stop_func_start
;
7646 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7647 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7649 /* Do not specify what the fp should be when we stop since on
7650 some machines the prologue is where the new fp value is
7652 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7654 /* And make sure stepping stops right away then. */
7655 ecs
->event_thread
->control
.step_range_end
7656 = ecs
->event_thread
->control
.step_range_start
;
7661 /* Inferior has stepped backward into a subroutine call with source
7662 code that we should not step over. Do step to the beginning of the
7663 last line of code in it. */
7666 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7667 struct execution_control_state
*ecs
)
7669 struct compunit_symtab
*cust
;
7670 struct symtab_and_line stop_func_sal
;
7672 fill_in_stop_func (gdbarch
, ecs
);
7674 cust
= find_pc_compunit_symtab (ecs
->event_thread
->stop_pc ());
7675 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7676 ecs
->stop_func_start
7677 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7679 stop_func_sal
= find_pc_line (ecs
->event_thread
->stop_pc (), 0);
7681 /* OK, we're just going to keep stepping here. */
7682 if (stop_func_sal
.pc
== ecs
->event_thread
->stop_pc ())
7684 /* We're there already. Just stop stepping now. */
7685 end_stepping_range (ecs
);
7689 /* Else just reset the step range and keep going.
7690 No step-resume breakpoint, they don't work for
7691 epilogues, which can have multiple entry paths. */
7692 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7693 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7699 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7700 This is used to both functions and to skip over code. */
7703 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7704 struct symtab_and_line sr_sal
,
7705 struct frame_id sr_id
,
7706 enum bptype sr_type
)
7708 /* There should never be more than one step-resume or longjmp-resume
7709 breakpoint per thread, so we should never be setting a new
7710 step_resume_breakpoint when one is already active. */
7711 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7712 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7714 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7715 paddress (gdbarch
, sr_sal
.pc
));
7717 inferior_thread ()->control
.step_resume_breakpoint
7718 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7722 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7723 struct symtab_and_line sr_sal
,
7724 struct frame_id sr_id
)
7726 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7731 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7732 This is used to skip a potential signal handler.
7734 This is called with the interrupted function's frame. The signal
7735 handler, when it returns, will resume the interrupted function at
7739 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7741 gdb_assert (return_frame
!= NULL
);
7743 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7745 symtab_and_line sr_sal
;
7746 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7747 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7748 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7750 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7751 get_stack_frame_id (return_frame
),
7755 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7756 is used to skip a function after stepping into it (for "next" or if
7757 the called function has no debugging information).
7759 The current function has almost always been reached by single
7760 stepping a call or return instruction. NEXT_FRAME belongs to the
7761 current function, and the breakpoint will be set at the caller's
7764 This is a separate function rather than reusing
7765 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7766 get_prev_frame, which may stop prematurely (see the implementation
7767 of frame_unwind_caller_id for an example). */
7770 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7772 /* We shouldn't have gotten here if we don't know where the call site
7774 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7776 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7778 symtab_and_line sr_sal
;
7779 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7780 frame_unwind_caller_pc (next_frame
));
7781 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7782 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7784 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7785 frame_unwind_caller_id (next_frame
));
7788 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7789 new breakpoint at the target of a jmp_buf. The handling of
7790 longjmp-resume uses the same mechanisms used for handling
7791 "step-resume" breakpoints. */
7794 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7796 /* There should never be more than one longjmp-resume breakpoint per
7797 thread, so we should never be setting a new
7798 longjmp_resume_breakpoint when one is already active. */
7799 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7801 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7802 paddress (gdbarch
, pc
));
7804 inferior_thread ()->control
.exception_resume_breakpoint
=
7805 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7808 /* Insert an exception resume breakpoint. TP is the thread throwing
7809 the exception. The block B is the block of the unwinder debug hook
7810 function. FRAME is the frame corresponding to the call to this
7811 function. SYM is the symbol of the function argument holding the
7812 target PC of the exception. */
7815 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7816 const struct block
*b
,
7817 struct frame_info
*frame
,
7822 struct block_symbol vsym
;
7823 struct value
*value
;
7825 struct breakpoint
*bp
;
7827 vsym
= lookup_symbol_search_name (sym
->search_name (),
7829 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7830 /* If the value was optimized out, revert to the old behavior. */
7831 if (! value_optimized_out (value
))
7833 handler
= value_as_address (value
);
7835 infrun_debug_printf ("exception resume at %lx",
7836 (unsigned long) handler
);
7838 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7840 bp_exception_resume
).release ();
7842 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7845 bp
->thread
= tp
->global_num
;
7846 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7849 catch (const gdb_exception_error
&e
)
7851 /* We want to ignore errors here. */
7855 /* A helper for check_exception_resume that sets an
7856 exception-breakpoint based on a SystemTap probe. */
7859 insert_exception_resume_from_probe (struct thread_info
*tp
,
7860 const struct bound_probe
*probe
,
7861 struct frame_info
*frame
)
7863 struct value
*arg_value
;
7865 struct breakpoint
*bp
;
7867 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7871 handler
= value_as_address (arg_value
);
7873 infrun_debug_printf ("exception resume at %s",
7874 paddress (probe
->objfile
->arch (), handler
));
7876 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7877 handler
, bp_exception_resume
).release ();
7878 bp
->thread
= tp
->global_num
;
7879 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7882 /* This is called when an exception has been intercepted. Check to
7883 see whether the exception's destination is of interest, and if so,
7884 set an exception resume breakpoint there. */
7887 check_exception_resume (struct execution_control_state
*ecs
,
7888 struct frame_info
*frame
)
7890 struct bound_probe probe
;
7891 struct symbol
*func
;
7893 /* First see if this exception unwinding breakpoint was set via a
7894 SystemTap probe point. If so, the probe has two arguments: the
7895 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7896 set a breakpoint there. */
7897 probe
= find_probe_by_pc (get_frame_pc (frame
));
7900 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7904 func
= get_frame_function (frame
);
7910 const struct block
*b
;
7911 struct block_iterator iter
;
7915 /* The exception breakpoint is a thread-specific breakpoint on
7916 the unwinder's debug hook, declared as:
7918 void _Unwind_DebugHook (void *cfa, void *handler);
7920 The CFA argument indicates the frame to which control is
7921 about to be transferred. HANDLER is the destination PC.
7923 We ignore the CFA and set a temporary breakpoint at HANDLER.
7924 This is not extremely efficient but it avoids issues in gdb
7925 with computing the DWARF CFA, and it also works even in weird
7926 cases such as throwing an exception from inside a signal
7929 b
= SYMBOL_BLOCK_VALUE (func
);
7930 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7932 if (!SYMBOL_IS_ARGUMENT (sym
))
7939 insert_exception_resume_breakpoint (ecs
->event_thread
,
7945 catch (const gdb_exception_error
&e
)
7951 stop_waiting (struct execution_control_state
*ecs
)
7953 infrun_debug_printf ("stop_waiting");
7955 /* Let callers know we don't want to wait for the inferior anymore. */
7956 ecs
->wait_some_more
= 0;
7958 /* If all-stop, but there exists a non-stop target, stop all
7959 threads now that we're presenting the stop to the user. */
7960 if (!non_stop
&& exists_non_stop_target ())
7961 stop_all_threads ();
7964 /* Like keep_going, but passes the signal to the inferior, even if the
7965 signal is set to nopass. */
7968 keep_going_pass_signal (struct execution_control_state
*ecs
)
7970 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7971 gdb_assert (!ecs
->event_thread
->resumed ());
7973 /* Save the pc before execution, to compare with pc after stop. */
7974 ecs
->event_thread
->prev_pc
7975 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7977 if (ecs
->event_thread
->control
.trap_expected
)
7979 struct thread_info
*tp
= ecs
->event_thread
;
7981 infrun_debug_printf ("%s has trap_expected set, "
7982 "resuming to collect trap",
7983 tp
->ptid
.to_string ().c_str ());
7985 /* We haven't yet gotten our trap, and either: intercepted a
7986 non-signal event (e.g., a fork); or took a signal which we
7987 are supposed to pass through to the inferior. Simply
7989 resume (ecs
->event_thread
->stop_signal ());
7991 else if (step_over_info_valid_p ())
7993 /* Another thread is stepping over a breakpoint in-line. If
7994 this thread needs a step-over too, queue the request. In
7995 either case, this resume must be deferred for later. */
7996 struct thread_info
*tp
= ecs
->event_thread
;
7998 if (ecs
->hit_singlestep_breakpoint
7999 || thread_still_needs_step_over (tp
))
8001 infrun_debug_printf ("step-over already in progress: "
8002 "step-over for %s deferred",
8003 tp
->ptid
.to_string ().c_str ());
8004 global_thread_step_over_chain_enqueue (tp
);
8007 infrun_debug_printf ("step-over in progress: resume of %s deferred",
8008 tp
->ptid
.to_string ().c_str ());
8012 struct regcache
*regcache
= get_current_regcache ();
8015 step_over_what step_what
;
8017 /* Either the trap was not expected, but we are continuing
8018 anyway (if we got a signal, the user asked it be passed to
8021 We got our expected trap, but decided we should resume from
8024 We're going to run this baby now!
8026 Note that insert_breakpoints won't try to re-insert
8027 already inserted breakpoints. Therefore, we don't
8028 care if breakpoints were already inserted, or not. */
8030 /* If we need to step over a breakpoint, and we're not using
8031 displaced stepping to do so, insert all breakpoints
8032 (watchpoints, etc.) but the one we're stepping over, step one
8033 instruction, and then re-insert the breakpoint when that step
8036 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
8038 remove_bp
= (ecs
->hit_singlestep_breakpoint
8039 || (step_what
& STEP_OVER_BREAKPOINT
));
8040 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
8042 /* We can't use displaced stepping if we need to step past a
8043 watchpoint. The instruction copied to the scratch pad would
8044 still trigger the watchpoint. */
8046 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
8048 set_step_over_info (regcache
->aspace (),
8049 regcache_read_pc (regcache
), remove_wps
,
8050 ecs
->event_thread
->global_num
);
8052 else if (remove_wps
)
8053 set_step_over_info (NULL
, 0, remove_wps
, -1);
8055 /* If we now need to do an in-line step-over, we need to stop
8056 all other threads. Note this must be done before
8057 insert_breakpoints below, because that removes the breakpoint
8058 we're about to step over, otherwise other threads could miss
8060 if (step_over_info_valid_p () && target_is_non_stop_p ())
8061 stop_all_threads ();
8063 /* Stop stepping if inserting breakpoints fails. */
8066 insert_breakpoints ();
8068 catch (const gdb_exception_error
&e
)
8070 exception_print (gdb_stderr
, e
);
8072 clear_step_over_info ();
8076 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8078 resume (ecs
->event_thread
->stop_signal ());
8081 prepare_to_wait (ecs
);
8084 /* Called when we should continue running the inferior, because the
8085 current event doesn't cause a user visible stop. This does the
8086 resuming part; waiting for the next event is done elsewhere. */
8089 keep_going (struct execution_control_state
*ecs
)
8091 if (ecs
->event_thread
->control
.trap_expected
8092 && ecs
->event_thread
->stop_signal () == GDB_SIGNAL_TRAP
)
8093 ecs
->event_thread
->control
.trap_expected
= 0;
8095 if (!signal_program
[ecs
->event_thread
->stop_signal ()])
8096 ecs
->event_thread
->set_stop_signal (GDB_SIGNAL_0
);
8097 keep_going_pass_signal (ecs
);
8100 /* This function normally comes after a resume, before
8101 handle_inferior_event exits. It takes care of any last bits of
8102 housekeeping, and sets the all-important wait_some_more flag. */
8105 prepare_to_wait (struct execution_control_state
*ecs
)
8107 infrun_debug_printf ("prepare_to_wait");
8109 ecs
->wait_some_more
= 1;
8111 /* If the target can't async, emulate it by marking the infrun event
8112 handler such that as soon as we get back to the event-loop, we
8113 immediately end up in fetch_inferior_event again calling
8115 if (!target_can_async_p ())
8116 mark_infrun_async_event_handler ();
8119 /* We are done with the step range of a step/next/si/ni command.
8120 Called once for each n of a "step n" operation. */
8123 end_stepping_range (struct execution_control_state
*ecs
)
8125 ecs
->event_thread
->control
.stop_step
= 1;
8129 /* Several print_*_reason functions to print why the inferior has stopped.
8130 We always print something when the inferior exits, or receives a signal.
8131 The rest of the cases are dealt with later on in normal_stop and
8132 print_it_typical. Ideally there should be a call to one of these
8133 print_*_reason functions functions from handle_inferior_event each time
8134 stop_waiting is called.
8136 Note that we don't call these directly, instead we delegate that to
8137 the interpreters, through observers. Interpreters then call these
8138 with whatever uiout is right. */
8141 print_end_stepping_range_reason (struct ui_out
*uiout
)
8143 /* For CLI-like interpreters, print nothing. */
8145 if (uiout
->is_mi_like_p ())
8147 uiout
->field_string ("reason",
8148 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8153 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8155 annotate_signalled ();
8156 if (uiout
->is_mi_like_p ())
8158 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8159 uiout
->text ("\nProgram terminated with signal ");
8160 annotate_signal_name ();
8161 uiout
->field_string ("signal-name",
8162 gdb_signal_to_name (siggnal
));
8163 annotate_signal_name_end ();
8165 annotate_signal_string ();
8166 uiout
->field_string ("signal-meaning",
8167 gdb_signal_to_string (siggnal
));
8168 annotate_signal_string_end ();
8169 uiout
->text (".\n");
8170 uiout
->text ("The program no longer exists.\n");
8174 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8176 struct inferior
*inf
= current_inferior ();
8177 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8179 annotate_exited (exitstatus
);
8182 if (uiout
->is_mi_like_p ())
8183 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8184 std::string exit_code_str
8185 = string_printf ("0%o", (unsigned int) exitstatus
);
8186 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8187 plongest (inf
->num
), pidstr
.c_str (),
8188 string_field ("exit-code", exit_code_str
.c_str ()));
8192 if (uiout
->is_mi_like_p ())
8194 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8195 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8196 plongest (inf
->num
), pidstr
.c_str ());
8201 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8203 struct thread_info
*thr
= inferior_thread ();
8207 if (uiout
->is_mi_like_p ())
8209 else if (show_thread_that_caused_stop ())
8211 uiout
->text ("\nThread ");
8212 uiout
->field_string ("thread-id", print_thread_id (thr
));
8214 const char *name
= thread_name (thr
);
8217 uiout
->text (" \"");
8218 uiout
->field_string ("name", name
);
8223 uiout
->text ("\nProgram");
8225 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8226 uiout
->text (" stopped");
8229 uiout
->text (" received signal ");
8230 annotate_signal_name ();
8231 if (uiout
->is_mi_like_p ())
8233 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8234 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8235 annotate_signal_name_end ();
8237 annotate_signal_string ();
8238 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8240 struct regcache
*regcache
= get_current_regcache ();
8241 struct gdbarch
*gdbarch
= regcache
->arch ();
8242 if (gdbarch_report_signal_info_p (gdbarch
))
8243 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8245 annotate_signal_string_end ();
8247 uiout
->text (".\n");
8251 print_no_history_reason (struct ui_out
*uiout
)
8253 uiout
->text ("\nNo more reverse-execution history.\n");
8256 /* Print current location without a level number, if we have changed
8257 functions or hit a breakpoint. Print source line if we have one.
8258 bpstat_print contains the logic deciding in detail what to print,
8259 based on the event(s) that just occurred. */
8262 print_stop_location (struct target_waitstatus
*ws
)
8265 enum print_what source_flag
;
8266 int do_frame_printing
= 1;
8267 struct thread_info
*tp
= inferior_thread ();
8269 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind ());
8273 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8274 should) carry around the function and does (or should) use
8275 that when doing a frame comparison. */
8276 if (tp
->control
.stop_step
8277 && frame_id_eq (tp
->control
.step_frame_id
,
8278 get_frame_id (get_current_frame ()))
8279 && (tp
->control
.step_start_function
8280 == find_pc_function (tp
->stop_pc ())))
8282 /* Finished step, just print source line. */
8283 source_flag
= SRC_LINE
;
8287 /* Print location and source line. */
8288 source_flag
= SRC_AND_LOC
;
8291 case PRINT_SRC_AND_LOC
:
8292 /* Print location and source line. */
8293 source_flag
= SRC_AND_LOC
;
8295 case PRINT_SRC_ONLY
:
8296 source_flag
= SRC_LINE
;
8299 /* Something bogus. */
8300 source_flag
= SRC_LINE
;
8301 do_frame_printing
= 0;
8304 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8307 /* The behavior of this routine with respect to the source
8309 SRC_LINE: Print only source line
8310 LOCATION: Print only location
8311 SRC_AND_LOC: Print location and source line. */
8312 if (do_frame_printing
)
8313 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8319 print_stop_event (struct ui_out
*uiout
, bool displays
)
8321 struct target_waitstatus last
;
8322 struct thread_info
*tp
;
8324 get_last_target_status (nullptr, nullptr, &last
);
8327 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8329 print_stop_location (&last
);
8331 /* Display the auto-display expressions. */
8336 tp
= inferior_thread ();
8337 if (tp
->thread_fsm
!= NULL
8338 && tp
->thread_fsm
->finished_p ())
8340 struct return_value_info
*rv
;
8342 rv
= tp
->thread_fsm
->return_value ();
8344 print_return_value (uiout
, rv
);
8351 maybe_remove_breakpoints (void)
8353 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8355 if (remove_breakpoints ())
8357 target_terminal::ours_for_output ();
8358 printf_filtered (_("Cannot remove breakpoints because "
8359 "program is no longer writable.\nFurther "
8360 "execution is probably impossible.\n"));
8365 /* The execution context that just caused a normal stop. */
8371 DISABLE_COPY_AND_ASSIGN (stop_context
);
8373 bool changed () const;
8378 /* The event PTID. */
8382 /* If stopp for a thread event, this is the thread that caused the
8384 thread_info_ref thread
;
8386 /* The inferior that caused the stop. */
8390 /* Initializes a new stop context. If stopped for a thread event, this
8391 takes a strong reference to the thread. */
8393 stop_context::stop_context ()
8395 stop_id
= get_stop_id ();
8396 ptid
= inferior_ptid
;
8397 inf_num
= current_inferior ()->num
;
8399 if (inferior_ptid
!= null_ptid
)
8401 /* Take a strong reference so that the thread can't be deleted
8403 thread
= thread_info_ref::new_reference (inferior_thread ());
8407 /* Return true if the current context no longer matches the saved stop
8411 stop_context::changed () const
8413 if (ptid
!= inferior_ptid
)
8415 if (inf_num
!= current_inferior ()->num
)
8417 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8419 if (get_stop_id () != stop_id
)
8429 struct target_waitstatus last
;
8431 get_last_target_status (nullptr, nullptr, &last
);
8435 /* If an exception is thrown from this point on, make sure to
8436 propagate GDB's knowledge of the executing state to the
8437 frontend/user running state. A QUIT is an easy exception to see
8438 here, so do this before any filtered output. */
8440 ptid_t finish_ptid
= null_ptid
;
8443 finish_ptid
= minus_one_ptid
;
8444 else if (last
.kind () == TARGET_WAITKIND_SIGNALLED
8445 || last
.kind () == TARGET_WAITKIND_EXITED
)
8447 /* On some targets, we may still have live threads in the
8448 inferior when we get a process exit event. E.g., for
8449 "checkpoint", when the current checkpoint/fork exits,
8450 linux-fork.c automatically switches to another fork from
8451 within target_mourn_inferior. */
8452 if (inferior_ptid
!= null_ptid
)
8453 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8455 else if (last
.kind () != TARGET_WAITKIND_NO_RESUMED
)
8456 finish_ptid
= inferior_ptid
;
8458 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8459 if (finish_ptid
!= null_ptid
)
8461 maybe_finish_thread_state
.emplace
8462 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8465 /* As we're presenting a stop, and potentially removing breakpoints,
8466 update the thread list so we can tell whether there are threads
8467 running on the target. With target remote, for example, we can
8468 only learn about new threads when we explicitly update the thread
8469 list. Do this before notifying the interpreters about signal
8470 stops, end of stepping ranges, etc., so that the "new thread"
8471 output is emitted before e.g., "Program received signal FOO",
8472 instead of after. */
8473 update_thread_list ();
8475 if (last
.kind () == TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8476 gdb::observers::signal_received
.notify (inferior_thread ()->stop_signal ());
8478 /* As with the notification of thread events, we want to delay
8479 notifying the user that we've switched thread context until
8480 the inferior actually stops.
8482 There's no point in saying anything if the inferior has exited.
8483 Note that SIGNALLED here means "exited with a signal", not
8484 "received a signal".
8486 Also skip saying anything in non-stop mode. In that mode, as we
8487 don't want GDB to switch threads behind the user's back, to avoid
8488 races where the user is typing a command to apply to thread x,
8489 but GDB switches to thread y before the user finishes entering
8490 the command, fetch_inferior_event installs a cleanup to restore
8491 the current thread back to the thread the user had selected right
8492 after this event is handled, so we're not really switching, only
8493 informing of a stop. */
8495 && previous_inferior_ptid
!= inferior_ptid
8496 && target_has_execution ()
8497 && last
.kind () != TARGET_WAITKIND_SIGNALLED
8498 && last
.kind () != TARGET_WAITKIND_EXITED
8499 && last
.kind () != TARGET_WAITKIND_NO_RESUMED
)
8501 SWITCH_THRU_ALL_UIS ()
8503 target_terminal::ours_for_output ();
8504 printf_filtered (_("[Switching to %s]\n"),
8505 target_pid_to_str (inferior_ptid
).c_str ());
8506 annotate_thread_changed ();
8508 previous_inferior_ptid
= inferior_ptid
;
8511 if (last
.kind () == TARGET_WAITKIND_NO_RESUMED
)
8513 SWITCH_THRU_ALL_UIS ()
8514 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8516 target_terminal::ours_for_output ();
8517 printf_filtered (_("No unwaited-for children left.\n"));
8521 /* Note: this depends on the update_thread_list call above. */
8522 maybe_remove_breakpoints ();
8524 /* If an auto-display called a function and that got a signal,
8525 delete that auto-display to avoid an infinite recursion. */
8527 if (stopped_by_random_signal
)
8528 disable_current_display ();
8530 SWITCH_THRU_ALL_UIS ()
8532 async_enable_stdin ();
8535 /* Let the user/frontend see the threads as stopped. */
8536 maybe_finish_thread_state
.reset ();
8538 /* Select innermost stack frame - i.e., current frame is frame 0,
8539 and current location is based on that. Handle the case where the
8540 dummy call is returning after being stopped. E.g. the dummy call
8541 previously hit a breakpoint. (If the dummy call returns
8542 normally, we won't reach here.) Do this before the stop hook is
8543 run, so that it doesn't get to see the temporary dummy frame,
8544 which is not where we'll present the stop. */
8545 if (has_stack_frames ())
8547 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8549 /* Pop the empty frame that contains the stack dummy. This
8550 also restores inferior state prior to the call (struct
8551 infcall_suspend_state). */
8552 struct frame_info
*frame
= get_current_frame ();
8554 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8556 /* frame_pop calls reinit_frame_cache as the last thing it
8557 does which means there's now no selected frame. */
8560 select_frame (get_current_frame ());
8562 /* Set the current source location. */
8563 set_current_sal_from_frame (get_current_frame ());
8566 /* Look up the hook_stop and run it (CLI internally handles problem
8567 of stop_command's pre-hook not existing). */
8568 if (stop_command
!= NULL
)
8570 stop_context saved_context
;
8574 execute_cmd_pre_hook (stop_command
);
8576 catch (const gdb_exception
&ex
)
8578 exception_fprintf (gdb_stderr
, ex
,
8579 "Error while running hook_stop:\n");
8582 /* If the stop hook resumes the target, then there's no point in
8583 trying to notify about the previous stop; its context is
8584 gone. Likewise if the command switches thread or inferior --
8585 the observers would print a stop for the wrong
8587 if (saved_context
.changed ())
8591 /* Notify observers about the stop. This is where the interpreters
8592 print the stop event. */
8593 if (inferior_ptid
!= null_ptid
)
8594 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8597 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8599 annotate_stopped ();
8601 if (target_has_execution ())
8603 if (last
.kind () != TARGET_WAITKIND_SIGNALLED
8604 && last
.kind () != TARGET_WAITKIND_EXITED
8605 && last
.kind () != TARGET_WAITKIND_NO_RESUMED
)
8606 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8607 Delete any breakpoint that is to be deleted at the next stop. */
8608 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8611 /* Try to get rid of automatically added inferiors that are no
8612 longer needed. Keeping those around slows down things linearly.
8613 Note that this never removes the current inferior. */
8620 signal_stop_state (int signo
)
8622 return signal_stop
[signo
];
8626 signal_print_state (int signo
)
8628 return signal_print
[signo
];
8632 signal_pass_state (int signo
)
8634 return signal_program
[signo
];
8638 signal_cache_update (int signo
)
8642 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8643 signal_cache_update (signo
);
8648 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8649 && signal_print
[signo
] == 0
8650 && signal_program
[signo
] == 1
8651 && signal_catch
[signo
] == 0);
8655 signal_stop_update (int signo
, int state
)
8657 int ret
= signal_stop
[signo
];
8659 signal_stop
[signo
] = state
;
8660 signal_cache_update (signo
);
8665 signal_print_update (int signo
, int state
)
8667 int ret
= signal_print
[signo
];
8669 signal_print
[signo
] = state
;
8670 signal_cache_update (signo
);
8675 signal_pass_update (int signo
, int state
)
8677 int ret
= signal_program
[signo
];
8679 signal_program
[signo
] = state
;
8680 signal_cache_update (signo
);
8684 /* Update the global 'signal_catch' from INFO and notify the
8688 signal_catch_update (const unsigned int *info
)
8692 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8693 signal_catch
[i
] = info
[i
] > 0;
8694 signal_cache_update (-1);
8695 target_pass_signals (signal_pass
);
8699 sig_print_header (void)
8701 printf_filtered (_("Signal Stop\tPrint\tPass "
8702 "to program\tDescription\n"));
8706 sig_print_info (enum gdb_signal oursig
)
8708 const char *name
= gdb_signal_to_name (oursig
);
8709 int name_padding
= 13 - strlen (name
);
8711 if (name_padding
<= 0)
8714 printf_filtered ("%s", name
);
8715 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8716 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8717 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8718 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8719 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8722 /* Specify how various signals in the inferior should be handled. */
8725 handle_command (const char *args
, int from_tty
)
8727 int digits
, wordlen
;
8728 int sigfirst
, siglast
;
8729 enum gdb_signal oursig
;
8734 error_no_arg (_("signal to handle"));
8737 /* Allocate and zero an array of flags for which signals to handle. */
8739 const size_t nsigs
= GDB_SIGNAL_LAST
;
8740 unsigned char sigs
[nsigs
] {};
8742 /* Break the command line up into args. */
8744 gdb_argv
built_argv (args
);
8746 /* Walk through the args, looking for signal oursigs, signal names, and
8747 actions. Signal numbers and signal names may be interspersed with
8748 actions, with the actions being performed for all signals cumulatively
8749 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8751 for (char *arg
: built_argv
)
8753 wordlen
= strlen (arg
);
8754 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8758 sigfirst
= siglast
= -1;
8760 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8762 /* Apply action to all signals except those used by the
8763 debugger. Silently skip those. */
8766 siglast
= nsigs
- 1;
8768 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8770 SET_SIGS (nsigs
, sigs
, signal_stop
);
8771 SET_SIGS (nsigs
, sigs
, signal_print
);
8773 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8775 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8777 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8779 SET_SIGS (nsigs
, sigs
, signal_print
);
8781 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8783 SET_SIGS (nsigs
, sigs
, signal_program
);
8785 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8787 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8789 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8791 SET_SIGS (nsigs
, sigs
, signal_program
);
8793 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8795 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8796 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8798 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8800 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8802 else if (digits
> 0)
8804 /* It is numeric. The numeric signal refers to our own
8805 internal signal numbering from target.h, not to host/target
8806 signal number. This is a feature; users really should be
8807 using symbolic names anyway, and the common ones like
8808 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8810 sigfirst
= siglast
= (int)
8811 gdb_signal_from_command (atoi (arg
));
8812 if (arg
[digits
] == '-')
8815 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8817 if (sigfirst
> siglast
)
8819 /* Bet he didn't figure we'd think of this case... */
8820 std::swap (sigfirst
, siglast
);
8825 oursig
= gdb_signal_from_name (arg
);
8826 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8828 sigfirst
= siglast
= (int) oursig
;
8832 /* Not a number and not a recognized flag word => complain. */
8833 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8837 /* If any signal numbers or symbol names were found, set flags for
8838 which signals to apply actions to. */
8840 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8842 switch ((enum gdb_signal
) signum
)
8844 case GDB_SIGNAL_TRAP
:
8845 case GDB_SIGNAL_INT
:
8846 if (!allsigs
&& !sigs
[signum
])
8848 if (query (_("%s is used by the debugger.\n\
8849 Are you sure you want to change it? "),
8850 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8855 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8859 case GDB_SIGNAL_DEFAULT
:
8860 case GDB_SIGNAL_UNKNOWN
:
8861 /* Make sure that "all" doesn't print these. */
8870 for (int signum
= 0; signum
< nsigs
; signum
++)
8873 signal_cache_update (-1);
8874 target_pass_signals (signal_pass
);
8875 target_program_signals (signal_program
);
8879 /* Show the results. */
8880 sig_print_header ();
8881 for (; signum
< nsigs
; signum
++)
8883 sig_print_info ((enum gdb_signal
) signum
);
8890 /* Complete the "handle" command. */
8893 handle_completer (struct cmd_list_element
*ignore
,
8894 completion_tracker
&tracker
,
8895 const char *text
, const char *word
)
8897 static const char * const keywords
[] =
8911 signal_completer (ignore
, tracker
, text
, word
);
8912 complete_on_enum (tracker
, keywords
, word
, word
);
8916 gdb_signal_from_command (int num
)
8918 if (num
>= 1 && num
<= 15)
8919 return (enum gdb_signal
) num
;
8920 error (_("Only signals 1-15 are valid as numeric signals.\n\
8921 Use \"info signals\" for a list of symbolic signals."));
8924 /* Print current contents of the tables set by the handle command.
8925 It is possible we should just be printing signals actually used
8926 by the current target (but for things to work right when switching
8927 targets, all signals should be in the signal tables). */
8930 info_signals_command (const char *signum_exp
, int from_tty
)
8932 enum gdb_signal oursig
;
8934 sig_print_header ();
8938 /* First see if this is a symbol name. */
8939 oursig
= gdb_signal_from_name (signum_exp
);
8940 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8942 /* No, try numeric. */
8944 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8946 sig_print_info (oursig
);
8950 printf_filtered ("\n");
8951 /* These ugly casts brought to you by the native VAX compiler. */
8952 for (oursig
= GDB_SIGNAL_FIRST
;
8953 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8954 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8958 if (oursig
!= GDB_SIGNAL_UNKNOWN
8959 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8960 sig_print_info (oursig
);
8963 printf_filtered (_("\nUse the \"handle\" command "
8964 "to change these tables.\n"));
8967 /* The $_siginfo convenience variable is a bit special. We don't know
8968 for sure the type of the value until we actually have a chance to
8969 fetch the data. The type can change depending on gdbarch, so it is
8970 also dependent on which thread you have selected.
8972 1. making $_siginfo be an internalvar that creates a new value on
8975 2. making the value of $_siginfo be an lval_computed value. */
8977 /* This function implements the lval_computed support for reading a
8981 siginfo_value_read (struct value
*v
)
8983 LONGEST transferred
;
8985 /* If we can access registers, so can we access $_siginfo. Likewise
8987 validate_registers_access ();
8990 target_read (current_inferior ()->top_target (),
8991 TARGET_OBJECT_SIGNAL_INFO
,
8993 value_contents_all_raw (v
).data (),
8995 TYPE_LENGTH (value_type (v
)));
8997 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8998 error (_("Unable to read siginfo"));
9001 /* This function implements the lval_computed support for writing a
9005 siginfo_value_write (struct value
*v
, struct value
*fromval
)
9007 LONGEST transferred
;
9009 /* If we can access registers, so can we access $_siginfo. Likewise
9011 validate_registers_access ();
9013 transferred
= target_write (current_inferior ()->top_target (),
9014 TARGET_OBJECT_SIGNAL_INFO
,
9016 value_contents_all_raw (fromval
).data (),
9018 TYPE_LENGTH (value_type (fromval
)));
9020 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
9021 error (_("Unable to write siginfo"));
9024 static const struct lval_funcs siginfo_value_funcs
=
9030 /* Return a new value with the correct type for the siginfo object of
9031 the current thread using architecture GDBARCH. Return a void value
9032 if there's no object available. */
9034 static struct value
*
9035 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9038 if (target_has_stack ()
9039 && inferior_ptid
!= null_ptid
9040 && gdbarch_get_siginfo_type_p (gdbarch
))
9042 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9044 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
9047 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
9051 /* infcall_suspend_state contains state about the program itself like its
9052 registers and any signal it received when it last stopped.
9053 This state must be restored regardless of how the inferior function call
9054 ends (either successfully, or after it hits a breakpoint or signal)
9055 if the program is to properly continue where it left off. */
9057 class infcall_suspend_state
9060 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9061 once the inferior function call has finished. */
9062 infcall_suspend_state (struct gdbarch
*gdbarch
,
9063 const struct thread_info
*tp
,
9064 struct regcache
*regcache
)
9065 : m_registers (new readonly_detached_regcache (*regcache
))
9067 tp
->save_suspend_to (m_thread_suspend
);
9069 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9071 if (gdbarch_get_siginfo_type_p (gdbarch
))
9073 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9074 size_t len
= TYPE_LENGTH (type
);
9076 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9078 if (target_read (current_inferior ()->top_target (),
9079 TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9080 siginfo_data
.get (), 0, len
) != len
)
9082 /* Errors ignored. */
9083 siginfo_data
.reset (nullptr);
9089 m_siginfo_gdbarch
= gdbarch
;
9090 m_siginfo_data
= std::move (siginfo_data
);
9094 /* Return a pointer to the stored register state. */
9096 readonly_detached_regcache
*registers () const
9098 return m_registers
.get ();
9101 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9103 void restore (struct gdbarch
*gdbarch
,
9104 struct thread_info
*tp
,
9105 struct regcache
*regcache
) const
9107 tp
->restore_suspend_from (m_thread_suspend
);
9109 if (m_siginfo_gdbarch
== gdbarch
)
9111 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9113 /* Errors ignored. */
9114 target_write (current_inferior ()->top_target (),
9115 TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9116 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9119 /* The inferior can be gone if the user types "print exit(0)"
9120 (and perhaps other times). */
9121 if (target_has_execution ())
9122 /* NB: The register write goes through to the target. */
9123 regcache
->restore (registers ());
9127 /* How the current thread stopped before the inferior function call was
9129 struct thread_suspend_state m_thread_suspend
;
9131 /* The registers before the inferior function call was executed. */
9132 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9134 /* Format of SIGINFO_DATA or NULL if it is not present. */
9135 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9137 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9138 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9139 content would be invalid. */
9140 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9143 infcall_suspend_state_up
9144 save_infcall_suspend_state ()
9146 struct thread_info
*tp
= inferior_thread ();
9147 struct regcache
*regcache
= get_current_regcache ();
9148 struct gdbarch
*gdbarch
= regcache
->arch ();
9150 infcall_suspend_state_up inf_state
9151 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9153 /* Having saved the current state, adjust the thread state, discarding
9154 any stop signal information. The stop signal is not useful when
9155 starting an inferior function call, and run_inferior_call will not use
9156 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9157 tp
->set_stop_signal (GDB_SIGNAL_0
);
9162 /* Restore inferior session state to INF_STATE. */
9165 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9167 struct thread_info
*tp
= inferior_thread ();
9168 struct regcache
*regcache
= get_current_regcache ();
9169 struct gdbarch
*gdbarch
= regcache
->arch ();
9171 inf_state
->restore (gdbarch
, tp
, regcache
);
9172 discard_infcall_suspend_state (inf_state
);
9176 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9181 readonly_detached_regcache
*
9182 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9184 return inf_state
->registers ();
9187 /* infcall_control_state contains state regarding gdb's control of the
9188 inferior itself like stepping control. It also contains session state like
9189 the user's currently selected frame. */
9191 struct infcall_control_state
9193 struct thread_control_state thread_control
;
9194 struct inferior_control_state inferior_control
;
9197 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9198 int stopped_by_random_signal
= 0;
9200 /* ID and level of the selected frame when the inferior function
9202 struct frame_id selected_frame_id
{};
9203 int selected_frame_level
= -1;
9206 /* Save all of the information associated with the inferior<==>gdb
9209 infcall_control_state_up
9210 save_infcall_control_state ()
9212 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9213 struct thread_info
*tp
= inferior_thread ();
9214 struct inferior
*inf
= current_inferior ();
9216 inf_status
->thread_control
= tp
->control
;
9217 inf_status
->inferior_control
= inf
->control
;
9219 tp
->control
.step_resume_breakpoint
= NULL
;
9220 tp
->control
.exception_resume_breakpoint
= NULL
;
9222 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9223 chain. If caller's caller is walking the chain, they'll be happier if we
9224 hand them back the original chain when restore_infcall_control_state is
9226 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9229 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9230 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9232 save_selected_frame (&inf_status
->selected_frame_id
,
9233 &inf_status
->selected_frame_level
);
9238 /* Restore inferior session state to INF_STATUS. */
9241 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9243 struct thread_info
*tp
= inferior_thread ();
9244 struct inferior
*inf
= current_inferior ();
9246 if (tp
->control
.step_resume_breakpoint
)
9247 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9249 if (tp
->control
.exception_resume_breakpoint
)
9250 tp
->control
.exception_resume_breakpoint
->disposition
9251 = disp_del_at_next_stop
;
9253 /* Handle the bpstat_copy of the chain. */
9254 bpstat_clear (&tp
->control
.stop_bpstat
);
9256 tp
->control
= inf_status
->thread_control
;
9257 inf
->control
= inf_status
->inferior_control
;
9260 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9261 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9263 if (target_has_stack ())
9265 restore_selected_frame (inf_status
->selected_frame_id
,
9266 inf_status
->selected_frame_level
);
9273 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9275 if (inf_status
->thread_control
.step_resume_breakpoint
)
9276 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9277 = disp_del_at_next_stop
;
9279 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9280 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9281 = disp_del_at_next_stop
;
9283 /* See save_infcall_control_state for info on stop_bpstat. */
9284 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9292 clear_exit_convenience_vars (void)
9294 clear_internalvar (lookup_internalvar ("_exitsignal"));
9295 clear_internalvar (lookup_internalvar ("_exitcode"));
9299 /* User interface for reverse debugging:
9300 Set exec-direction / show exec-direction commands
9301 (returns error unless target implements to_set_exec_direction method). */
9303 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9304 static const char exec_forward
[] = "forward";
9305 static const char exec_reverse
[] = "reverse";
9306 static const char *exec_direction
= exec_forward
;
9307 static const char *const exec_direction_names
[] = {
9314 set_exec_direction_func (const char *args
, int from_tty
,
9315 struct cmd_list_element
*cmd
)
9317 if (target_can_execute_reverse ())
9319 if (!strcmp (exec_direction
, exec_forward
))
9320 execution_direction
= EXEC_FORWARD
;
9321 else if (!strcmp (exec_direction
, exec_reverse
))
9322 execution_direction
= EXEC_REVERSE
;
9326 exec_direction
= exec_forward
;
9327 error (_("Target does not support this operation."));
9332 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9333 struct cmd_list_element
*cmd
, const char *value
)
9335 switch (execution_direction
) {
9337 fprintf_filtered (out
, _("Forward.\n"));
9340 fprintf_filtered (out
, _("Reverse.\n"));
9343 internal_error (__FILE__
, __LINE__
,
9344 _("bogus execution_direction value: %d"),
9345 (int) execution_direction
);
9350 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9351 struct cmd_list_element
*c
, const char *value
)
9353 fprintf_filtered (file
, _("Resuming the execution of threads "
9354 "of all processes is %s.\n"), value
);
9357 /* Implementation of `siginfo' variable. */
9359 static const struct internalvar_funcs siginfo_funcs
=
9366 /* Callback for infrun's target events source. This is marked when a
9367 thread has a pending status to process. */
9370 infrun_async_inferior_event_handler (gdb_client_data data
)
9372 clear_async_event_handler (infrun_async_inferior_event_token
);
9373 inferior_event_handler (INF_REG_EVENT
);
9380 /* Verify that when two threads with the same ptid exist (from two different
9381 targets) and one of them changes ptid, we only update inferior_ptid if
9382 it is appropriate. */
9385 infrun_thread_ptid_changed ()
9387 gdbarch
*arch
= current_inferior ()->gdbarch
;
9389 /* The thread which inferior_ptid represents changes ptid. */
9391 scoped_restore_current_pspace_and_thread restore
;
9393 scoped_mock_context
<test_target_ops
> target1 (arch
);
9394 scoped_mock_context
<test_target_ops
> target2 (arch
);
9396 ptid_t
old_ptid (111, 222);
9397 ptid_t
new_ptid (111, 333);
9399 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9400 target1
.mock_thread
.ptid
= old_ptid
;
9401 target1
.mock_inferior
.ptid_thread_map
.clear ();
9402 target1
.mock_inferior
.ptid_thread_map
[old_ptid
] = &target1
.mock_thread
;
9404 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9405 target2
.mock_thread
.ptid
= old_ptid
;
9406 target2
.mock_inferior
.ptid_thread_map
.clear ();
9407 target2
.mock_inferior
.ptid_thread_map
[old_ptid
] = &target2
.mock_thread
;
9409 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9410 set_current_inferior (&target1
.mock_inferior
);
9412 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9414 gdb_assert (inferior_ptid
== new_ptid
);
9417 /* A thread with the same ptid as inferior_ptid, but from another target,
9420 scoped_restore_current_pspace_and_thread restore
;
9422 scoped_mock_context
<test_target_ops
> target1 (arch
);
9423 scoped_mock_context
<test_target_ops
> target2 (arch
);
9425 ptid_t
old_ptid (111, 222);
9426 ptid_t
new_ptid (111, 333);
9428 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9429 target1
.mock_thread
.ptid
= old_ptid
;
9430 target1
.mock_inferior
.ptid_thread_map
.clear ();
9431 target1
.mock_inferior
.ptid_thread_map
[old_ptid
] = &target1
.mock_thread
;
9433 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9434 target2
.mock_thread
.ptid
= old_ptid
;
9435 target2
.mock_inferior
.ptid_thread_map
.clear ();
9436 target2
.mock_inferior
.ptid_thread_map
[old_ptid
] = &target2
.mock_thread
;
9438 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9439 set_current_inferior (&target2
.mock_inferior
);
9441 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9443 gdb_assert (inferior_ptid
== old_ptid
);
9447 } /* namespace selftests */
9449 #endif /* GDB_SELF_TEST */
9451 void _initialize_infrun ();
9453 _initialize_infrun ()
9455 struct cmd_list_element
*c
;
9457 /* Register extra event sources in the event loop. */
9458 infrun_async_inferior_event_token
9459 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9462 cmd_list_element
*info_signals_cmd
9463 = add_info ("signals", info_signals_command
, _("\
9464 What debugger does when program gets various signals.\n\
9465 Specify a signal as argument to print info on that signal only."));
9466 add_info_alias ("handle", info_signals_cmd
, 0);
9468 c
= add_com ("handle", class_run
, handle_command
, _("\
9469 Specify how to handle signals.\n\
9470 Usage: handle SIGNAL [ACTIONS]\n\
9471 Args are signals and actions to apply to those signals.\n\
9472 If no actions are specified, the current settings for the specified signals\n\
9473 will be displayed instead.\n\
9475 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9476 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9477 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9478 The special arg \"all\" is recognized to mean all signals except those\n\
9479 used by the debugger, typically SIGTRAP and SIGINT.\n\
9481 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9482 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9483 Stop means reenter debugger if this signal happens (implies print).\n\
9484 Print means print a message if this signal happens.\n\
9485 Pass means let program see this signal; otherwise program doesn't know.\n\
9486 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9487 Pass and Stop may be combined.\n\
9489 Multiple signals may be specified. Signal numbers and signal names\n\
9490 may be interspersed with actions, with the actions being performed for\n\
9491 all signals cumulatively specified."));
9492 set_cmd_completer (c
, handle_completer
);
9495 stop_command
= add_cmd ("stop", class_obscure
,
9496 not_just_help_class_command
, _("\
9497 There is no `stop' command, but you can set a hook on `stop'.\n\
9498 This allows you to set a list of commands to be run each time execution\n\
9499 of the program stops."), &cmdlist
);
9501 add_setshow_boolean_cmd
9502 ("infrun", class_maintenance
, &debug_infrun
,
9503 _("Set inferior debugging."),
9504 _("Show inferior debugging."),
9505 _("When non-zero, inferior specific debugging is enabled."),
9506 NULL
, show_debug_infrun
, &setdebuglist
, &showdebuglist
);
9508 add_setshow_boolean_cmd ("non-stop", no_class
,
9510 Set whether gdb controls the inferior in non-stop mode."), _("\
9511 Show whether gdb controls the inferior in non-stop mode."), _("\
9512 When debugging a multi-threaded program and this setting is\n\
9513 off (the default, also called all-stop mode), when one thread stops\n\
9514 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9515 all other threads in the program while you interact with the thread of\n\
9516 interest. When you continue or step a thread, you can allow the other\n\
9517 threads to run, or have them remain stopped, but while you inspect any\n\
9518 thread's state, all threads stop.\n\
9520 In non-stop mode, when one thread stops, other threads can continue\n\
9521 to run freely. You'll be able to step each thread independently,\n\
9522 leave it stopped or free to run as needed."),
9528 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9531 signal_print
[i
] = 1;
9532 signal_program
[i
] = 1;
9533 signal_catch
[i
] = 0;
9536 /* Signals caused by debugger's own actions should not be given to
9537 the program afterwards.
9539 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9540 explicitly specifies that it should be delivered to the target
9541 program. Typically, that would occur when a user is debugging a
9542 target monitor on a simulator: the target monitor sets a
9543 breakpoint; the simulator encounters this breakpoint and halts
9544 the simulation handing control to GDB; GDB, noting that the stop
9545 address doesn't map to any known breakpoint, returns control back
9546 to the simulator; the simulator then delivers the hardware
9547 equivalent of a GDB_SIGNAL_TRAP to the program being
9549 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9550 signal_program
[GDB_SIGNAL_INT
] = 0;
9552 /* Signals that are not errors should not normally enter the debugger. */
9553 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9554 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9555 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9556 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9557 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9558 signal_print
[GDB_SIGNAL_PROF
] = 0;
9559 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9560 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9561 signal_stop
[GDB_SIGNAL_IO
] = 0;
9562 signal_print
[GDB_SIGNAL_IO
] = 0;
9563 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9564 signal_print
[GDB_SIGNAL_POLL
] = 0;
9565 signal_stop
[GDB_SIGNAL_URG
] = 0;
9566 signal_print
[GDB_SIGNAL_URG
] = 0;
9567 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9568 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9569 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9570 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9572 /* These signals are used internally by user-level thread
9573 implementations. (See signal(5) on Solaris.) Like the above
9574 signals, a healthy program receives and handles them as part of
9575 its normal operation. */
9576 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9577 signal_print
[GDB_SIGNAL_LWP
] = 0;
9578 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9579 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9580 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9581 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9582 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9583 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9585 /* Update cached state. */
9586 signal_cache_update (-1);
9588 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9589 &stop_on_solib_events
, _("\
9590 Set stopping for shared library events."), _("\
9591 Show stopping for shared library events."), _("\
9592 If nonzero, gdb will give control to the user when the dynamic linker\n\
9593 notifies gdb of shared library events. The most common event of interest\n\
9594 to the user would be loading/unloading of a new library."),
9595 set_stop_on_solib_events
,
9596 show_stop_on_solib_events
,
9597 &setlist
, &showlist
);
9599 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9600 follow_fork_mode_kind_names
,
9601 &follow_fork_mode_string
, _("\
9602 Set debugger response to a program call of fork or vfork."), _("\
9603 Show debugger response to a program call of fork or vfork."), _("\
9604 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9605 parent - the original process is debugged after a fork\n\
9606 child - the new process is debugged after a fork\n\
9607 The unfollowed process will continue to run.\n\
9608 By default, the debugger will follow the parent process."),
9610 show_follow_fork_mode_string
,
9611 &setlist
, &showlist
);
9613 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9614 follow_exec_mode_names
,
9615 &follow_exec_mode_string
, _("\
9616 Set debugger response to a program call of exec."), _("\
9617 Show debugger response to a program call of exec."), _("\
9618 An exec call replaces the program image of a process.\n\
9620 follow-exec-mode can be:\n\
9622 new - the debugger creates a new inferior and rebinds the process\n\
9623 to this new inferior. The program the process was running before\n\
9624 the exec call can be restarted afterwards by restarting the original\n\
9627 same - the debugger keeps the process bound to the same inferior.\n\
9628 The new executable image replaces the previous executable loaded in\n\
9629 the inferior. Restarting the inferior after the exec call restarts\n\
9630 the executable the process was running after the exec call.\n\
9632 By default, the debugger will use the same inferior."),
9634 show_follow_exec_mode_string
,
9635 &setlist
, &showlist
);
9637 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9638 scheduler_enums
, &scheduler_mode
, _("\
9639 Set mode for locking scheduler during execution."), _("\
9640 Show mode for locking scheduler during execution."), _("\
9641 off == no locking (threads may preempt at any time)\n\
9642 on == full locking (no thread except the current thread may run)\n\
9643 This applies to both normal execution and replay mode.\n\
9644 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9645 In this mode, other threads may run during other commands.\n\
9646 This applies to both normal execution and replay mode.\n\
9647 replay == scheduler locked in replay mode and unlocked during normal execution."),
9648 set_schedlock_func
, /* traps on target vector */
9649 show_scheduler_mode
,
9650 &setlist
, &showlist
);
9652 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9653 Set mode for resuming threads of all processes."), _("\
9654 Show mode for resuming threads of all processes."), _("\
9655 When on, execution commands (such as 'continue' or 'next') resume all\n\
9656 threads of all processes. When off (which is the default), execution\n\
9657 commands only resume the threads of the current process. The set of\n\
9658 threads that are resumed is further refined by the scheduler-locking\n\
9659 mode (see help set scheduler-locking)."),
9661 show_schedule_multiple
,
9662 &setlist
, &showlist
);
9664 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9665 Set mode of the step operation."), _("\
9666 Show mode of the step operation."), _("\
9667 When set, doing a step over a function without debug line information\n\
9668 will stop at the first instruction of that function. Otherwise, the\n\
9669 function is skipped and the step command stops at a different source line."),
9671 show_step_stop_if_no_debug
,
9672 &setlist
, &showlist
);
9674 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9675 &can_use_displaced_stepping
, _("\
9676 Set debugger's willingness to use displaced stepping."), _("\
9677 Show debugger's willingness to use displaced stepping."), _("\
9678 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9679 supported by the target architecture. If off, gdb will not use displaced\n\
9680 stepping to step over breakpoints, even if such is supported by the target\n\
9681 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9682 if the target architecture supports it and non-stop mode is active, but will not\n\
9683 use it in all-stop mode (see help set non-stop)."),
9685 show_can_use_displaced_stepping
,
9686 &setlist
, &showlist
);
9688 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9689 &exec_direction
, _("Set direction of execution.\n\
9690 Options are 'forward' or 'reverse'."),
9691 _("Show direction of execution (forward/reverse)."),
9692 _("Tells gdb whether to execute forward or backward."),
9693 set_exec_direction_func
, show_exec_direction_func
,
9694 &setlist
, &showlist
);
9696 /* Set/show detach-on-fork: user-settable mode. */
9698 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9699 Set whether gdb will detach the child of a fork."), _("\
9700 Show whether gdb will detach the child of a fork."), _("\
9701 Tells gdb whether to detach the child of a fork."),
9702 NULL
, NULL
, &setlist
, &showlist
);
9704 /* Set/show disable address space randomization mode. */
9706 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9707 &disable_randomization
, _("\
9708 Set disabling of debuggee's virtual address space randomization."), _("\
9709 Show disabling of debuggee's virtual address space randomization."), _("\
9710 When this mode is on (which is the default), randomization of the virtual\n\
9711 address space is disabled. Standalone programs run with the randomization\n\
9712 enabled by default on some platforms."),
9713 &set_disable_randomization
,
9714 &show_disable_randomization
,
9715 &setlist
, &showlist
);
9717 /* ptid initializations */
9718 inferior_ptid
= null_ptid
;
9719 target_last_wait_ptid
= minus_one_ptid
;
9721 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
,
9723 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
,
9725 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
, "infrun");
9726 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
, "infrun");
9727 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
, "infrun");
9729 /* Explicitly create without lookup, since that tries to create a
9730 value with a void typed value, and when we get here, gdbarch
9731 isn't initialized yet. At this point, we're quite sure there
9732 isn't another convenience variable of the same name. */
9733 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9735 add_setshow_boolean_cmd ("observer", no_class
,
9736 &observer_mode_1
, _("\
9737 Set whether gdb controls the inferior in observer mode."), _("\
9738 Show whether gdb controls the inferior in observer mode."), _("\
9739 In observer mode, GDB can get data from the inferior, but not\n\
9740 affect its execution. Registers and memory may not be changed,\n\
9741 breakpoints may not be set, and the program cannot be interrupted\n\
9749 selftests::register_test ("infrun_thread_ptid_changed",
9750 selftests::infrun_thread_ptid_changed
);