1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "gdbthread.h"
38 #include "observable.h"
43 #include "mi/mi-common.h"
44 #include "event-top.h"
46 #include "record-full.h"
47 #include "inline-frame.h"
49 #include "tracepoint.h"
53 #include "completer.h"
54 #include "target-descriptions.h"
55 #include "target-dcache.h"
58 #include "event-loop.h"
59 #include "thread-fsm.h"
60 #include "gdbsupport/enum-flags.h"
61 #include "progspace-and-thread.h"
62 #include "gdbsupport/gdb_optional.h"
63 #include "arch-utils.h"
64 #include "gdbsupport/scope-exit.h"
65 #include "gdbsupport/forward-scope-exit.h"
67 /* Prototypes for local functions */
69 static void sig_print_info (enum gdb_signal
);
71 static void sig_print_header (void);
73 static int follow_fork (void);
75 static int follow_fork_inferior (int follow_child
, int detach_fork
);
77 static void follow_inferior_reset_breakpoints (void);
79 static int currently_stepping (struct thread_info
*tp
);
81 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
83 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
85 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
87 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
89 static void resume (gdb_signal sig
);
91 /* Asynchronous signal handler registered as event loop source for
92 when we have pending events ready to be passed to the core. */
93 static struct async_event_handler
*infrun_async_inferior_event_token
;
95 /* Stores whether infrun_async was previously enabled or disabled.
96 Starts off as -1, indicating "never enabled/disabled". */
97 static int infrun_is_async
= -1;
102 infrun_async (int enable
)
104 if (infrun_is_async
!= enable
)
106 infrun_is_async
= enable
;
109 fprintf_unfiltered (gdb_stdlog
,
110 "infrun: infrun_async(%d)\n",
114 mark_async_event_handler (infrun_async_inferior_event_token
);
116 clear_async_event_handler (infrun_async_inferior_event_token
);
123 mark_infrun_async_event_handler (void)
125 mark_async_event_handler (infrun_async_inferior_event_token
);
128 /* When set, stop the 'step' command if we enter a function which has
129 no line number information. The normal behavior is that we step
130 over such function. */
131 bool step_stop_if_no_debug
= false;
133 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
134 struct cmd_list_element
*c
, const char *value
)
136 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
139 /* proceed and normal_stop use this to notify the user when the
140 inferior stopped in a different thread than it had been running
143 static ptid_t previous_inferior_ptid
;
145 /* If set (default for legacy reasons), when following a fork, GDB
146 will detach from one of the fork branches, child or parent.
147 Exactly which branch is detached depends on 'set follow-fork-mode'
150 static bool detach_fork
= true;
152 bool debug_displaced
= false;
154 show_debug_displaced (struct ui_file
*file
, int from_tty
,
155 struct cmd_list_element
*c
, const char *value
)
157 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
160 unsigned int debug_infrun
= 0;
162 show_debug_infrun (struct ui_file
*file
, int from_tty
,
163 struct cmd_list_element
*c
, const char *value
)
165 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
169 /* Support for disabling address space randomization. */
171 bool disable_randomization
= true;
174 show_disable_randomization (struct ui_file
*file
, int from_tty
,
175 struct cmd_list_element
*c
, const char *value
)
177 if (target_supports_disable_randomization ())
178 fprintf_filtered (file
,
179 _("Disabling randomization of debuggee's "
180 "virtual address space is %s.\n"),
183 fputs_filtered (_("Disabling randomization of debuggee's "
184 "virtual address space is unsupported on\n"
185 "this platform.\n"), file
);
189 set_disable_randomization (const char *args
, int from_tty
,
190 struct cmd_list_element
*c
)
192 if (!target_supports_disable_randomization ())
193 error (_("Disabling randomization of debuggee's "
194 "virtual address space is unsupported on\n"
198 /* User interface for non-stop mode. */
200 bool non_stop
= false;
201 static bool non_stop_1
= false;
204 set_non_stop (const char *args
, int from_tty
,
205 struct cmd_list_element
*c
)
207 if (target_has_execution
)
209 non_stop_1
= non_stop
;
210 error (_("Cannot change this setting while the inferior is running."));
213 non_stop
= non_stop_1
;
217 show_non_stop (struct ui_file
*file
, int from_tty
,
218 struct cmd_list_element
*c
, const char *value
)
220 fprintf_filtered (file
,
221 _("Controlling the inferior in non-stop mode is %s.\n"),
225 /* "Observer mode" is somewhat like a more extreme version of
226 non-stop, in which all GDB operations that might affect the
227 target's execution have been disabled. */
229 bool observer_mode
= false;
230 static bool observer_mode_1
= false;
233 set_observer_mode (const char *args
, int from_tty
,
234 struct cmd_list_element
*c
)
236 if (target_has_execution
)
238 observer_mode_1
= observer_mode
;
239 error (_("Cannot change this setting while the inferior is running."));
242 observer_mode
= observer_mode_1
;
244 may_write_registers
= !observer_mode
;
245 may_write_memory
= !observer_mode
;
246 may_insert_breakpoints
= !observer_mode
;
247 may_insert_tracepoints
= !observer_mode
;
248 /* We can insert fast tracepoints in or out of observer mode,
249 but enable them if we're going into this mode. */
251 may_insert_fast_tracepoints
= true;
252 may_stop
= !observer_mode
;
253 update_target_permissions ();
255 /* Going *into* observer mode we must force non-stop, then
256 going out we leave it that way. */
259 pagination_enabled
= 0;
260 non_stop
= non_stop_1
= true;
264 printf_filtered (_("Observer mode is now %s.\n"),
265 (observer_mode
? "on" : "off"));
269 show_observer_mode (struct ui_file
*file
, int from_tty
,
270 struct cmd_list_element
*c
, const char *value
)
272 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
275 /* This updates the value of observer mode based on changes in
276 permissions. Note that we are deliberately ignoring the values of
277 may-write-registers and may-write-memory, since the user may have
278 reason to enable these during a session, for instance to turn on a
279 debugging-related global. */
282 update_observer_mode (void)
284 bool newval
= (!may_insert_breakpoints
285 && !may_insert_tracepoints
286 && may_insert_fast_tracepoints
290 /* Let the user know if things change. */
291 if (newval
!= observer_mode
)
292 printf_filtered (_("Observer mode is now %s.\n"),
293 (newval
? "on" : "off"));
295 observer_mode
= observer_mode_1
= newval
;
298 /* Tables of how to react to signals; the user sets them. */
300 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
301 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
302 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
304 /* Table of signals that are registered with "catch signal". A
305 non-zero entry indicates that the signal is caught by some "catch
307 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
309 /* Table of signals that the target may silently handle.
310 This is automatically determined from the flags above,
311 and simply cached here. */
312 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
314 #define SET_SIGS(nsigs,sigs,flags) \
316 int signum = (nsigs); \
317 while (signum-- > 0) \
318 if ((sigs)[signum]) \
319 (flags)[signum] = 1; \
322 #define UNSET_SIGS(nsigs,sigs,flags) \
324 int signum = (nsigs); \
325 while (signum-- > 0) \
326 if ((sigs)[signum]) \
327 (flags)[signum] = 0; \
330 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
331 this function is to avoid exporting `signal_program'. */
334 update_signals_program_target (void)
336 target_program_signals (signal_program
);
339 /* Value to pass to target_resume() to cause all threads to resume. */
341 #define RESUME_ALL minus_one_ptid
343 /* Command list pointer for the "stop" placeholder. */
345 static struct cmd_list_element
*stop_command
;
347 /* Nonzero if we want to give control to the user when we're notified
348 of shared library events by the dynamic linker. */
349 int stop_on_solib_events
;
351 /* Enable or disable optional shared library event breakpoints
352 as appropriate when the above flag is changed. */
355 set_stop_on_solib_events (const char *args
,
356 int from_tty
, struct cmd_list_element
*c
)
358 update_solib_breakpoints ();
362 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
363 struct cmd_list_element
*c
, const char *value
)
365 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
369 /* Nonzero after stop if current stack frame should be printed. */
371 static int stop_print_frame
;
373 /* This is a cached copy of the pid/waitstatus of the last event
374 returned by target_wait()/deprecated_target_wait_hook(). This
375 information is returned by get_last_target_status(). */
376 static ptid_t target_last_wait_ptid
;
377 static struct target_waitstatus target_last_waitstatus
;
379 void init_thread_stepping_state (struct thread_info
*tss
);
381 static const char follow_fork_mode_child
[] = "child";
382 static const char follow_fork_mode_parent
[] = "parent";
384 static const char *const follow_fork_mode_kind_names
[] = {
385 follow_fork_mode_child
,
386 follow_fork_mode_parent
,
390 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
392 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
393 struct cmd_list_element
*c
, const char *value
)
395 fprintf_filtered (file
,
396 _("Debugger response to a program "
397 "call of fork or vfork is \"%s\".\n"),
402 /* Handle changes to the inferior list based on the type of fork,
403 which process is being followed, and whether the other process
404 should be detached. On entry inferior_ptid must be the ptid of
405 the fork parent. At return inferior_ptid is the ptid of the
406 followed inferior. */
409 follow_fork_inferior (int follow_child
, int detach_fork
)
412 ptid_t parent_ptid
, child_ptid
;
414 has_vforked
= (inferior_thread ()->pending_follow
.kind
415 == TARGET_WAITKIND_VFORKED
);
416 parent_ptid
= inferior_ptid
;
417 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
420 && !non_stop
/* Non-stop always resumes both branches. */
421 && current_ui
->prompt_state
== PROMPT_BLOCKED
422 && !(follow_child
|| detach_fork
|| sched_multi
))
424 /* The parent stays blocked inside the vfork syscall until the
425 child execs or exits. If we don't let the child run, then
426 the parent stays blocked. If we're telling the parent to run
427 in the foreground, the user will not be able to ctrl-c to get
428 back the terminal, effectively hanging the debug session. */
429 fprintf_filtered (gdb_stderr
, _("\
430 Can not resume the parent process over vfork in the foreground while\n\
431 holding the child stopped. Try \"set detach-on-fork\" or \
432 \"set schedule-multiple\".\n"));
438 /* Detach new forked process? */
441 /* Before detaching from the child, remove all breakpoints
442 from it. If we forked, then this has already been taken
443 care of by infrun.c. If we vforked however, any
444 breakpoint inserted in the parent is visible in the
445 child, even those added while stopped in a vfork
446 catchpoint. This will remove the breakpoints from the
447 parent also, but they'll be reinserted below. */
450 /* Keep breakpoints list in sync. */
451 remove_breakpoints_inf (current_inferior ());
454 if (print_inferior_events
)
456 /* Ensure that we have a process ptid. */
457 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
459 target_terminal::ours_for_output ();
460 fprintf_filtered (gdb_stdlog
,
461 _("[Detaching after %s from child %s]\n"),
462 has_vforked
? "vfork" : "fork",
463 target_pid_to_str (process_ptid
).c_str ());
468 struct inferior
*parent_inf
, *child_inf
;
470 /* Add process to GDB's tables. */
471 child_inf
= add_inferior (child_ptid
.pid ());
473 parent_inf
= current_inferior ();
474 child_inf
->attach_flag
= parent_inf
->attach_flag
;
475 copy_terminal_info (child_inf
, parent_inf
);
476 child_inf
->gdbarch
= parent_inf
->gdbarch
;
477 copy_inferior_target_desc_info (child_inf
, parent_inf
);
479 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
481 inferior_ptid
= child_ptid
;
482 add_thread_silent (inferior_ptid
);
483 set_current_inferior (child_inf
);
484 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
486 /* If this is a vfork child, then the address-space is
487 shared with the parent. */
490 child_inf
->pspace
= parent_inf
->pspace
;
491 child_inf
->aspace
= parent_inf
->aspace
;
493 /* The parent will be frozen until the child is done
494 with the shared region. Keep track of the
496 child_inf
->vfork_parent
= parent_inf
;
497 child_inf
->pending_detach
= 0;
498 parent_inf
->vfork_child
= child_inf
;
499 parent_inf
->pending_detach
= 0;
503 child_inf
->aspace
= new_address_space ();
504 child_inf
->pspace
= new program_space (child_inf
->aspace
);
505 child_inf
->removable
= 1;
506 set_current_program_space (child_inf
->pspace
);
507 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
509 /* Let the shared library layer (e.g., solib-svr4) learn
510 about this new process, relocate the cloned exec, pull
511 in shared libraries, and install the solib event
512 breakpoint. If a "cloned-VM" event was propagated
513 better throughout the core, this wouldn't be
515 solib_create_inferior_hook (0);
521 struct inferior
*parent_inf
;
523 parent_inf
= current_inferior ();
525 /* If we detached from the child, then we have to be careful
526 to not insert breakpoints in the parent until the child
527 is done with the shared memory region. However, if we're
528 staying attached to the child, then we can and should
529 insert breakpoints, so that we can debug it. A
530 subsequent child exec or exit is enough to know when does
531 the child stops using the parent's address space. */
532 parent_inf
->waiting_for_vfork_done
= detach_fork
;
533 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
538 /* Follow the child. */
539 struct inferior
*parent_inf
, *child_inf
;
540 struct program_space
*parent_pspace
;
542 if (print_inferior_events
)
544 std::string parent_pid
= target_pid_to_str (parent_ptid
);
545 std::string child_pid
= target_pid_to_str (child_ptid
);
547 target_terminal::ours_for_output ();
548 fprintf_filtered (gdb_stdlog
,
549 _("[Attaching after %s %s to child %s]\n"),
551 has_vforked
? "vfork" : "fork",
555 /* Add the new inferior first, so that the target_detach below
556 doesn't unpush the target. */
558 child_inf
= add_inferior (child_ptid
.pid ());
560 parent_inf
= current_inferior ();
561 child_inf
->attach_flag
= parent_inf
->attach_flag
;
562 copy_terminal_info (child_inf
, parent_inf
);
563 child_inf
->gdbarch
= parent_inf
->gdbarch
;
564 copy_inferior_target_desc_info (child_inf
, parent_inf
);
566 parent_pspace
= parent_inf
->pspace
;
568 /* If we're vforking, we want to hold on to the parent until the
569 child exits or execs. At child exec or exit time we can
570 remove the old breakpoints from the parent and detach or
571 resume debugging it. Otherwise, detach the parent now; we'll
572 want to reuse it's program/address spaces, but we can't set
573 them to the child before removing breakpoints from the
574 parent, otherwise, the breakpoints module could decide to
575 remove breakpoints from the wrong process (since they'd be
576 assigned to the same address space). */
580 gdb_assert (child_inf
->vfork_parent
== NULL
);
581 gdb_assert (parent_inf
->vfork_child
== NULL
);
582 child_inf
->vfork_parent
= parent_inf
;
583 child_inf
->pending_detach
= 0;
584 parent_inf
->vfork_child
= child_inf
;
585 parent_inf
->pending_detach
= detach_fork
;
586 parent_inf
->waiting_for_vfork_done
= 0;
588 else if (detach_fork
)
590 if (print_inferior_events
)
592 /* Ensure that we have a process ptid. */
593 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
595 target_terminal::ours_for_output ();
596 fprintf_filtered (gdb_stdlog
,
597 _("[Detaching after fork from "
599 target_pid_to_str (process_ptid
).c_str ());
602 target_detach (parent_inf
, 0);
605 /* Note that the detach above makes PARENT_INF dangling. */
607 /* Add the child thread to the appropriate lists, and switch to
608 this new thread, before cloning the program space, and
609 informing the solib layer about this new process. */
611 inferior_ptid
= child_ptid
;
612 add_thread_silent (inferior_ptid
);
613 set_current_inferior (child_inf
);
615 /* If this is a vfork child, then the address-space is shared
616 with the parent. If we detached from the parent, then we can
617 reuse the parent's program/address spaces. */
618 if (has_vforked
|| detach_fork
)
620 child_inf
->pspace
= parent_pspace
;
621 child_inf
->aspace
= child_inf
->pspace
->aspace
;
625 child_inf
->aspace
= new_address_space ();
626 child_inf
->pspace
= new program_space (child_inf
->aspace
);
627 child_inf
->removable
= 1;
628 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
629 set_current_program_space (child_inf
->pspace
);
630 clone_program_space (child_inf
->pspace
, parent_pspace
);
632 /* Let the shared library layer (e.g., solib-svr4) learn
633 about this new process, relocate the cloned exec, pull in
634 shared libraries, and install the solib event breakpoint.
635 If a "cloned-VM" event was propagated better throughout
636 the core, this wouldn't be required. */
637 solib_create_inferior_hook (0);
641 return target_follow_fork (follow_child
, detach_fork
);
644 /* Tell the target to follow the fork we're stopped at. Returns true
645 if the inferior should be resumed; false, if the target for some
646 reason decided it's best not to resume. */
651 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
652 int should_resume
= 1;
653 struct thread_info
*tp
;
655 /* Copy user stepping state to the new inferior thread. FIXME: the
656 followed fork child thread should have a copy of most of the
657 parent thread structure's run control related fields, not just these.
658 Initialized to avoid "may be used uninitialized" warnings from gcc. */
659 struct breakpoint
*step_resume_breakpoint
= NULL
;
660 struct breakpoint
*exception_resume_breakpoint
= NULL
;
661 CORE_ADDR step_range_start
= 0;
662 CORE_ADDR step_range_end
= 0;
663 struct frame_id step_frame_id
= { 0 };
664 struct thread_fsm
*thread_fsm
= NULL
;
669 struct target_waitstatus wait_status
;
671 /* Get the last target status returned by target_wait(). */
672 get_last_target_status (&wait_ptid
, &wait_status
);
674 /* If not stopped at a fork event, then there's nothing else to
676 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
677 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
680 /* Check if we switched over from WAIT_PTID, since the event was
682 if (wait_ptid
!= minus_one_ptid
683 && inferior_ptid
!= wait_ptid
)
685 /* We did. Switch back to WAIT_PTID thread, to tell the
686 target to follow it (in either direction). We'll
687 afterwards refuse to resume, and inform the user what
689 thread_info
*wait_thread
690 = find_thread_ptid (wait_ptid
);
691 switch_to_thread (wait_thread
);
696 tp
= inferior_thread ();
698 /* If there were any forks/vforks that were caught and are now to be
699 followed, then do so now. */
700 switch (tp
->pending_follow
.kind
)
702 case TARGET_WAITKIND_FORKED
:
703 case TARGET_WAITKIND_VFORKED
:
705 ptid_t parent
, child
;
707 /* If the user did a next/step, etc, over a fork call,
708 preserve the stepping state in the fork child. */
709 if (follow_child
&& should_resume
)
711 step_resume_breakpoint
= clone_momentary_breakpoint
712 (tp
->control
.step_resume_breakpoint
);
713 step_range_start
= tp
->control
.step_range_start
;
714 step_range_end
= tp
->control
.step_range_end
;
715 step_frame_id
= tp
->control
.step_frame_id
;
716 exception_resume_breakpoint
717 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
718 thread_fsm
= tp
->thread_fsm
;
720 /* For now, delete the parent's sr breakpoint, otherwise,
721 parent/child sr breakpoints are considered duplicates,
722 and the child version will not be installed. Remove
723 this when the breakpoints module becomes aware of
724 inferiors and address spaces. */
725 delete_step_resume_breakpoint (tp
);
726 tp
->control
.step_range_start
= 0;
727 tp
->control
.step_range_end
= 0;
728 tp
->control
.step_frame_id
= null_frame_id
;
729 delete_exception_resume_breakpoint (tp
);
730 tp
->thread_fsm
= NULL
;
733 parent
= inferior_ptid
;
734 child
= tp
->pending_follow
.value
.related_pid
;
736 /* Set up inferior(s) as specified by the caller, and tell the
737 target to do whatever is necessary to follow either parent
739 if (follow_fork_inferior (follow_child
, detach_fork
))
741 /* Target refused to follow, or there's some other reason
742 we shouldn't resume. */
747 /* This pending follow fork event is now handled, one way
748 or another. The previous selected thread may be gone
749 from the lists by now, but if it is still around, need
750 to clear the pending follow request. */
751 tp
= find_thread_ptid (parent
);
753 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
755 /* This makes sure we don't try to apply the "Switched
756 over from WAIT_PID" logic above. */
757 nullify_last_target_wait_ptid ();
759 /* If we followed the child, switch to it... */
762 thread_info
*child_thr
= find_thread_ptid (child
);
763 switch_to_thread (child_thr
);
765 /* ... and preserve the stepping state, in case the
766 user was stepping over the fork call. */
769 tp
= inferior_thread ();
770 tp
->control
.step_resume_breakpoint
771 = step_resume_breakpoint
;
772 tp
->control
.step_range_start
= step_range_start
;
773 tp
->control
.step_range_end
= step_range_end
;
774 tp
->control
.step_frame_id
= step_frame_id
;
775 tp
->control
.exception_resume_breakpoint
776 = exception_resume_breakpoint
;
777 tp
->thread_fsm
= thread_fsm
;
781 /* If we get here, it was because we're trying to
782 resume from a fork catchpoint, but, the user
783 has switched threads away from the thread that
784 forked. In that case, the resume command
785 issued is most likely not applicable to the
786 child, so just warn, and refuse to resume. */
787 warning (_("Not resuming: switched threads "
788 "before following fork child."));
791 /* Reset breakpoints in the child as appropriate. */
792 follow_inferior_reset_breakpoints ();
797 case TARGET_WAITKIND_SPURIOUS
:
798 /* Nothing to follow. */
801 internal_error (__FILE__
, __LINE__
,
802 "Unexpected pending_follow.kind %d\n",
803 tp
->pending_follow
.kind
);
807 return should_resume
;
811 follow_inferior_reset_breakpoints (void)
813 struct thread_info
*tp
= inferior_thread ();
815 /* Was there a step_resume breakpoint? (There was if the user
816 did a "next" at the fork() call.) If so, explicitly reset its
817 thread number. Cloned step_resume breakpoints are disabled on
818 creation, so enable it here now that it is associated with the
821 step_resumes are a form of bp that are made to be per-thread.
822 Since we created the step_resume bp when the parent process
823 was being debugged, and now are switching to the child process,
824 from the breakpoint package's viewpoint, that's a switch of
825 "threads". We must update the bp's notion of which thread
826 it is for, or it'll be ignored when it triggers. */
828 if (tp
->control
.step_resume_breakpoint
)
830 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
831 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
834 /* Treat exception_resume breakpoints like step_resume breakpoints. */
835 if (tp
->control
.exception_resume_breakpoint
)
837 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
838 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
841 /* Reinsert all breakpoints in the child. The user may have set
842 breakpoints after catching the fork, in which case those
843 were never set in the child, but only in the parent. This makes
844 sure the inserted breakpoints match the breakpoint list. */
846 breakpoint_re_set ();
847 insert_breakpoints ();
850 /* The child has exited or execed: resume threads of the parent the
851 user wanted to be executing. */
854 proceed_after_vfork_done (struct thread_info
*thread
,
857 int pid
= * (int *) arg
;
859 if (thread
->ptid
.pid () == pid
860 && thread
->state
== THREAD_RUNNING
861 && !thread
->executing
862 && !thread
->stop_requested
863 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
866 fprintf_unfiltered (gdb_stdlog
,
867 "infrun: resuming vfork parent thread %s\n",
868 target_pid_to_str (thread
->ptid
).c_str ());
870 switch_to_thread (thread
);
871 clear_proceed_status (0);
872 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
878 /* Save/restore inferior_ptid, current program space and current
879 inferior. Only use this if the current context points at an exited
880 inferior (and therefore there's no current thread to save). */
881 class scoped_restore_exited_inferior
884 scoped_restore_exited_inferior ()
885 : m_saved_ptid (&inferior_ptid
)
889 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
890 scoped_restore_current_program_space m_pspace
;
891 scoped_restore_current_inferior m_inferior
;
894 /* Called whenever we notice an exec or exit event, to handle
895 detaching or resuming a vfork parent. */
898 handle_vfork_child_exec_or_exit (int exec
)
900 struct inferior
*inf
= current_inferior ();
902 if (inf
->vfork_parent
)
904 int resume_parent
= -1;
906 /* This exec or exit marks the end of the shared memory region
907 between the parent and the child. Break the bonds. */
908 inferior
*vfork_parent
= inf
->vfork_parent
;
909 inf
->vfork_parent
->vfork_child
= NULL
;
910 inf
->vfork_parent
= NULL
;
912 /* If the user wanted to detach from the parent, now is the
914 if (vfork_parent
->pending_detach
)
916 struct thread_info
*tp
;
917 struct program_space
*pspace
;
918 struct address_space
*aspace
;
920 /* follow-fork child, detach-on-fork on. */
922 vfork_parent
->pending_detach
= 0;
924 gdb::optional
<scoped_restore_exited_inferior
>
925 maybe_restore_inferior
;
926 gdb::optional
<scoped_restore_current_pspace_and_thread
>
927 maybe_restore_thread
;
929 /* If we're handling a child exit, then inferior_ptid points
930 at the inferior's pid, not to a thread. */
932 maybe_restore_inferior
.emplace ();
934 maybe_restore_thread
.emplace ();
936 /* We're letting loose of the parent. */
937 tp
= any_live_thread_of_inferior (vfork_parent
);
938 switch_to_thread (tp
);
940 /* We're about to detach from the parent, which implicitly
941 removes breakpoints from its address space. There's a
942 catch here: we want to reuse the spaces for the child,
943 but, parent/child are still sharing the pspace at this
944 point, although the exec in reality makes the kernel give
945 the child a fresh set of new pages. The problem here is
946 that the breakpoints module being unaware of this, would
947 likely chose the child process to write to the parent
948 address space. Swapping the child temporarily away from
949 the spaces has the desired effect. Yes, this is "sort
952 pspace
= inf
->pspace
;
953 aspace
= inf
->aspace
;
957 if (print_inferior_events
)
960 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
962 target_terminal::ours_for_output ();
966 fprintf_filtered (gdb_stdlog
,
967 _("[Detaching vfork parent %s "
968 "after child exec]\n"), pidstr
.c_str ());
972 fprintf_filtered (gdb_stdlog
,
973 _("[Detaching vfork parent %s "
974 "after child exit]\n"), pidstr
.c_str ());
978 target_detach (vfork_parent
, 0);
981 inf
->pspace
= pspace
;
982 inf
->aspace
= aspace
;
986 /* We're staying attached to the parent, so, really give the
987 child a new address space. */
988 inf
->pspace
= new program_space (maybe_new_address_space ());
989 inf
->aspace
= inf
->pspace
->aspace
;
991 set_current_program_space (inf
->pspace
);
993 resume_parent
= vfork_parent
->pid
;
997 struct program_space
*pspace
;
999 /* If this is a vfork child exiting, then the pspace and
1000 aspaces were shared with the parent. Since we're
1001 reporting the process exit, we'll be mourning all that is
1002 found in the address space, and switching to null_ptid,
1003 preparing to start a new inferior. But, since we don't
1004 want to clobber the parent's address/program spaces, we
1005 go ahead and create a new one for this exiting
1008 /* Switch to null_ptid while running clone_program_space, so
1009 that clone_program_space doesn't want to read the
1010 selected frame of a dead process. */
1011 scoped_restore restore_ptid
1012 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1014 /* This inferior is dead, so avoid giving the breakpoints
1015 module the option to write through to it (cloning a
1016 program space resets breakpoints). */
1019 pspace
= new program_space (maybe_new_address_space ());
1020 set_current_program_space (pspace
);
1022 inf
->symfile_flags
= SYMFILE_NO_READ
;
1023 clone_program_space (pspace
, vfork_parent
->pspace
);
1024 inf
->pspace
= pspace
;
1025 inf
->aspace
= pspace
->aspace
;
1027 resume_parent
= vfork_parent
->pid
;
1030 gdb_assert (current_program_space
== inf
->pspace
);
1032 if (non_stop
&& resume_parent
!= -1)
1034 /* If the user wanted the parent to be running, let it go
1036 scoped_restore_current_thread restore_thread
;
1039 fprintf_unfiltered (gdb_stdlog
,
1040 "infrun: resuming vfork parent process %d\n",
1043 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1048 /* Enum strings for "set|show follow-exec-mode". */
1050 static const char follow_exec_mode_new
[] = "new";
1051 static const char follow_exec_mode_same
[] = "same";
1052 static const char *const follow_exec_mode_names
[] =
1054 follow_exec_mode_new
,
1055 follow_exec_mode_same
,
1059 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1061 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1062 struct cmd_list_element
*c
, const char *value
)
1064 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1067 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1070 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1072 struct inferior
*inf
= current_inferior ();
1073 int pid
= ptid
.pid ();
1074 ptid_t process_ptid
;
1076 /* Switch terminal for any messages produced e.g. by
1077 breakpoint_re_set. */
1078 target_terminal::ours_for_output ();
1080 /* This is an exec event that we actually wish to pay attention to.
1081 Refresh our symbol table to the newly exec'd program, remove any
1082 momentary bp's, etc.
1084 If there are breakpoints, they aren't really inserted now,
1085 since the exec() transformed our inferior into a fresh set
1088 We want to preserve symbolic breakpoints on the list, since
1089 we have hopes that they can be reset after the new a.out's
1090 symbol table is read.
1092 However, any "raw" breakpoints must be removed from the list
1093 (e.g., the solib bp's), since their address is probably invalid
1096 And, we DON'T want to call delete_breakpoints() here, since
1097 that may write the bp's "shadow contents" (the instruction
1098 value that was overwritten with a TRAP instruction). Since
1099 we now have a new a.out, those shadow contents aren't valid. */
1101 mark_breakpoints_out ();
1103 /* The target reports the exec event to the main thread, even if
1104 some other thread does the exec, and even if the main thread was
1105 stopped or already gone. We may still have non-leader threads of
1106 the process on our list. E.g., on targets that don't have thread
1107 exit events (like remote); or on native Linux in non-stop mode if
1108 there were only two threads in the inferior and the non-leader
1109 one is the one that execs (and nothing forces an update of the
1110 thread list up to here). When debugging remotely, it's best to
1111 avoid extra traffic, when possible, so avoid syncing the thread
1112 list with the target, and instead go ahead and delete all threads
1113 of the process but one that reported the event. Note this must
1114 be done before calling update_breakpoints_after_exec, as
1115 otherwise clearing the threads' resources would reference stale
1116 thread breakpoints -- it may have been one of these threads that
1117 stepped across the exec. We could just clear their stepping
1118 states, but as long as we're iterating, might as well delete
1119 them. Deleting them now rather than at the next user-visible
1120 stop provides a nicer sequence of events for user and MI
1122 for (thread_info
*th
: all_threads_safe ())
1123 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1126 /* We also need to clear any left over stale state for the
1127 leader/event thread. E.g., if there was any step-resume
1128 breakpoint or similar, it's gone now. We cannot truly
1129 step-to-next statement through an exec(). */
1130 thread_info
*th
= inferior_thread ();
1131 th
->control
.step_resume_breakpoint
= NULL
;
1132 th
->control
.exception_resume_breakpoint
= NULL
;
1133 th
->control
.single_step_breakpoints
= NULL
;
1134 th
->control
.step_range_start
= 0;
1135 th
->control
.step_range_end
= 0;
1137 /* The user may have had the main thread held stopped in the
1138 previous image (e.g., schedlock on, or non-stop). Release
1140 th
->stop_requested
= 0;
1142 update_breakpoints_after_exec ();
1144 /* What is this a.out's name? */
1145 process_ptid
= ptid_t (pid
);
1146 printf_unfiltered (_("%s is executing new program: %s\n"),
1147 target_pid_to_str (process_ptid
).c_str (),
1150 /* We've followed the inferior through an exec. Therefore, the
1151 inferior has essentially been killed & reborn. */
1153 breakpoint_init_inferior (inf_execd
);
1155 gdb::unique_xmalloc_ptr
<char> exec_file_host
1156 = exec_file_find (exec_file_target
, NULL
);
1158 /* If we were unable to map the executable target pathname onto a host
1159 pathname, tell the user that. Otherwise GDB's subsequent behavior
1160 is confusing. Maybe it would even be better to stop at this point
1161 so that the user can specify a file manually before continuing. */
1162 if (exec_file_host
== NULL
)
1163 warning (_("Could not load symbols for executable %s.\n"
1164 "Do you need \"set sysroot\"?"),
1167 /* Reset the shared library package. This ensures that we get a
1168 shlib event when the child reaches "_start", at which point the
1169 dld will have had a chance to initialize the child. */
1170 /* Also, loading a symbol file below may trigger symbol lookups, and
1171 we don't want those to be satisfied by the libraries of the
1172 previous incarnation of this process. */
1173 no_shared_libraries (NULL
, 0);
1175 if (follow_exec_mode_string
== follow_exec_mode_new
)
1177 /* The user wants to keep the old inferior and program spaces
1178 around. Create a new fresh one, and switch to it. */
1180 /* Do exit processing for the original inferior before setting the new
1181 inferior's pid. Having two inferiors with the same pid would confuse
1182 find_inferior_p(t)id. Transfer the terminal state and info from the
1183 old to the new inferior. */
1184 inf
= add_inferior_with_spaces ();
1185 swap_terminal_info (inf
, current_inferior ());
1186 exit_inferior_silent (current_inferior ());
1189 target_follow_exec (inf
, exec_file_target
);
1191 set_current_inferior (inf
);
1192 set_current_program_space (inf
->pspace
);
1197 /* The old description may no longer be fit for the new image.
1198 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1199 old description; we'll read a new one below. No need to do
1200 this on "follow-exec-mode new", as the old inferior stays
1201 around (its description is later cleared/refetched on
1203 target_clear_description ();
1206 gdb_assert (current_program_space
== inf
->pspace
);
1208 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1209 because the proper displacement for a PIE (Position Independent
1210 Executable) main symbol file will only be computed by
1211 solib_create_inferior_hook below. breakpoint_re_set would fail
1212 to insert the breakpoints with the zero displacement. */
1213 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1215 /* If the target can specify a description, read it. Must do this
1216 after flipping to the new executable (because the target supplied
1217 description must be compatible with the executable's
1218 architecture, and the old executable may e.g., be 32-bit, while
1219 the new one 64-bit), and before anything involving memory or
1221 target_find_description ();
1223 solib_create_inferior_hook (0);
1225 jit_inferior_created_hook ();
1227 breakpoint_re_set ();
1229 /* Reinsert all breakpoints. (Those which were symbolic have
1230 been reset to the proper address in the new a.out, thanks
1231 to symbol_file_command...). */
1232 insert_breakpoints ();
1234 /* The next resume of this inferior should bring it to the shlib
1235 startup breakpoints. (If the user had also set bp's on
1236 "main" from the old (parent) process, then they'll auto-
1237 matically get reset there in the new process.). */
1240 /* The queue of threads that need to do a step-over operation to get
1241 past e.g., a breakpoint. What technique is used to step over the
1242 breakpoint/watchpoint does not matter -- all threads end up in the
1243 same queue, to maintain rough temporal order of execution, in order
1244 to avoid starvation, otherwise, we could e.g., find ourselves
1245 constantly stepping the same couple threads past their breakpoints
1246 over and over, if the single-step finish fast enough. */
1247 struct thread_info
*step_over_queue_head
;
1249 /* Bit flags indicating what the thread needs to step over. */
1251 enum step_over_what_flag
1253 /* Step over a breakpoint. */
1254 STEP_OVER_BREAKPOINT
= 1,
1256 /* Step past a non-continuable watchpoint, in order to let the
1257 instruction execute so we can evaluate the watchpoint
1259 STEP_OVER_WATCHPOINT
= 2
1261 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1263 /* Info about an instruction that is being stepped over. */
1265 struct step_over_info
1267 /* If we're stepping past a breakpoint, this is the address space
1268 and address of the instruction the breakpoint is set at. We'll
1269 skip inserting all breakpoints here. Valid iff ASPACE is
1271 const address_space
*aspace
;
1274 /* The instruction being stepped over triggers a nonsteppable
1275 watchpoint. If true, we'll skip inserting watchpoints. */
1276 int nonsteppable_watchpoint_p
;
1278 /* The thread's global number. */
1282 /* The step-over info of the location that is being stepped over.
1284 Note that with async/breakpoint always-inserted mode, a user might
1285 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1286 being stepped over. As setting a new breakpoint inserts all
1287 breakpoints, we need to make sure the breakpoint being stepped over
1288 isn't inserted then. We do that by only clearing the step-over
1289 info when the step-over is actually finished (or aborted).
1291 Presently GDB can only step over one breakpoint at any given time.
1292 Given threads that can't run code in the same address space as the
1293 breakpoint's can't really miss the breakpoint, GDB could be taught
1294 to step-over at most one breakpoint per address space (so this info
1295 could move to the address space object if/when GDB is extended).
1296 The set of breakpoints being stepped over will normally be much
1297 smaller than the set of all breakpoints, so a flag in the
1298 breakpoint location structure would be wasteful. A separate list
1299 also saves complexity and run-time, as otherwise we'd have to go
1300 through all breakpoint locations clearing their flag whenever we
1301 start a new sequence. Similar considerations weigh against storing
1302 this info in the thread object. Plus, not all step overs actually
1303 have breakpoint locations -- e.g., stepping past a single-step
1304 breakpoint, or stepping to complete a non-continuable
1306 static struct step_over_info step_over_info
;
1308 /* Record the address of the breakpoint/instruction we're currently
1310 N.B. We record the aspace and address now, instead of say just the thread,
1311 because when we need the info later the thread may be running. */
1314 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1315 int nonsteppable_watchpoint_p
,
1318 step_over_info
.aspace
= aspace
;
1319 step_over_info
.address
= address
;
1320 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1321 step_over_info
.thread
= thread
;
1324 /* Called when we're not longer stepping over a breakpoint / an
1325 instruction, so all breakpoints are free to be (re)inserted. */
1328 clear_step_over_info (void)
1331 fprintf_unfiltered (gdb_stdlog
,
1332 "infrun: clear_step_over_info\n");
1333 step_over_info
.aspace
= NULL
;
1334 step_over_info
.address
= 0;
1335 step_over_info
.nonsteppable_watchpoint_p
= 0;
1336 step_over_info
.thread
= -1;
1342 stepping_past_instruction_at (struct address_space
*aspace
,
1345 return (step_over_info
.aspace
!= NULL
1346 && breakpoint_address_match (aspace
, address
,
1347 step_over_info
.aspace
,
1348 step_over_info
.address
));
1354 thread_is_stepping_over_breakpoint (int thread
)
1356 return (step_over_info
.thread
!= -1
1357 && thread
== step_over_info
.thread
);
1363 stepping_past_nonsteppable_watchpoint (void)
1365 return step_over_info
.nonsteppable_watchpoint_p
;
1368 /* Returns true if step-over info is valid. */
1371 step_over_info_valid_p (void)
1373 return (step_over_info
.aspace
!= NULL
1374 || stepping_past_nonsteppable_watchpoint ());
1378 /* Displaced stepping. */
1380 /* In non-stop debugging mode, we must take special care to manage
1381 breakpoints properly; in particular, the traditional strategy for
1382 stepping a thread past a breakpoint it has hit is unsuitable.
1383 'Displaced stepping' is a tactic for stepping one thread past a
1384 breakpoint it has hit while ensuring that other threads running
1385 concurrently will hit the breakpoint as they should.
1387 The traditional way to step a thread T off a breakpoint in a
1388 multi-threaded program in all-stop mode is as follows:
1390 a0) Initially, all threads are stopped, and breakpoints are not
1392 a1) We single-step T, leaving breakpoints uninserted.
1393 a2) We insert breakpoints, and resume all threads.
1395 In non-stop debugging, however, this strategy is unsuitable: we
1396 don't want to have to stop all threads in the system in order to
1397 continue or step T past a breakpoint. Instead, we use displaced
1400 n0) Initially, T is stopped, other threads are running, and
1401 breakpoints are inserted.
1402 n1) We copy the instruction "under" the breakpoint to a separate
1403 location, outside the main code stream, making any adjustments
1404 to the instruction, register, and memory state as directed by
1406 n2) We single-step T over the instruction at its new location.
1407 n3) We adjust the resulting register and memory state as directed
1408 by T's architecture. This includes resetting T's PC to point
1409 back into the main instruction stream.
1412 This approach depends on the following gdbarch methods:
1414 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1415 indicate where to copy the instruction, and how much space must
1416 be reserved there. We use these in step n1.
1418 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1419 address, and makes any necessary adjustments to the instruction,
1420 register contents, and memory. We use this in step n1.
1422 - gdbarch_displaced_step_fixup adjusts registers and memory after
1423 we have successfully single-stepped the instruction, to yield the
1424 same effect the instruction would have had if we had executed it
1425 at its original address. We use this in step n3.
1427 The gdbarch_displaced_step_copy_insn and
1428 gdbarch_displaced_step_fixup functions must be written so that
1429 copying an instruction with gdbarch_displaced_step_copy_insn,
1430 single-stepping across the copied instruction, and then applying
1431 gdbarch_displaced_insn_fixup should have the same effects on the
1432 thread's memory and registers as stepping the instruction in place
1433 would have. Exactly which responsibilities fall to the copy and
1434 which fall to the fixup is up to the author of those functions.
1436 See the comments in gdbarch.sh for details.
1438 Note that displaced stepping and software single-step cannot
1439 currently be used in combination, although with some care I think
1440 they could be made to. Software single-step works by placing
1441 breakpoints on all possible subsequent instructions; if the
1442 displaced instruction is a PC-relative jump, those breakpoints
1443 could fall in very strange places --- on pages that aren't
1444 executable, or at addresses that are not proper instruction
1445 boundaries. (We do generally let other threads run while we wait
1446 to hit the software single-step breakpoint, and they might
1447 encounter such a corrupted instruction.) One way to work around
1448 this would be to have gdbarch_displaced_step_copy_insn fully
1449 simulate the effect of PC-relative instructions (and return NULL)
1450 on architectures that use software single-stepping.
1452 In non-stop mode, we can have independent and simultaneous step
1453 requests, so more than one thread may need to simultaneously step
1454 over a breakpoint. The current implementation assumes there is
1455 only one scratch space per process. In this case, we have to
1456 serialize access to the scratch space. If thread A wants to step
1457 over a breakpoint, but we are currently waiting for some other
1458 thread to complete a displaced step, we leave thread A stopped and
1459 place it in the displaced_step_request_queue. Whenever a displaced
1460 step finishes, we pick the next thread in the queue and start a new
1461 displaced step operation on it. See displaced_step_prepare and
1462 displaced_step_fixup for details. */
1464 /* Default destructor for displaced_step_closure. */
1466 displaced_step_closure::~displaced_step_closure () = default;
1468 /* Get the displaced stepping state of process PID. */
1470 static displaced_step_inferior_state
*
1471 get_displaced_stepping_state (inferior
*inf
)
1473 return &inf
->displaced_step_state
;
1476 /* Returns true if any inferior has a thread doing a displaced
1480 displaced_step_in_progress_any_inferior ()
1482 for (inferior
*i
: all_inferiors ())
1484 if (i
->displaced_step_state
.step_thread
!= nullptr)
1491 /* Return true if thread represented by PTID is doing a displaced
1495 displaced_step_in_progress_thread (thread_info
*thread
)
1497 gdb_assert (thread
!= NULL
);
1499 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1502 /* Return true if process PID has a thread doing a displaced step. */
1505 displaced_step_in_progress (inferior
*inf
)
1507 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1510 /* If inferior is in displaced stepping, and ADDR equals to starting address
1511 of copy area, return corresponding displaced_step_closure. Otherwise,
1514 struct displaced_step_closure
*
1515 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1517 displaced_step_inferior_state
*displaced
1518 = get_displaced_stepping_state (current_inferior ());
1520 /* If checking the mode of displaced instruction in copy area. */
1521 if (displaced
->step_thread
!= nullptr
1522 && displaced
->step_copy
== addr
)
1523 return displaced
->step_closure
;
1529 infrun_inferior_exit (struct inferior
*inf
)
1531 inf
->displaced_step_state
.reset ();
1534 /* If ON, and the architecture supports it, GDB will use displaced
1535 stepping to step over breakpoints. If OFF, or if the architecture
1536 doesn't support it, GDB will instead use the traditional
1537 hold-and-step approach. If AUTO (which is the default), GDB will
1538 decide which technique to use to step over breakpoints depending on
1539 which of all-stop or non-stop mode is active --- displaced stepping
1540 in non-stop mode; hold-and-step in all-stop mode. */
1542 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1545 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1546 struct cmd_list_element
*c
,
1549 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1550 fprintf_filtered (file
,
1551 _("Debugger's willingness to use displaced stepping "
1552 "to step over breakpoints is %s (currently %s).\n"),
1553 value
, target_is_non_stop_p () ? "on" : "off");
1555 fprintf_filtered (file
,
1556 _("Debugger's willingness to use displaced stepping "
1557 "to step over breakpoints is %s.\n"), value
);
1560 /* Return non-zero if displaced stepping can/should be used to step
1561 over breakpoints of thread TP. */
1564 use_displaced_stepping (struct thread_info
*tp
)
1566 struct regcache
*regcache
= get_thread_regcache (tp
);
1567 struct gdbarch
*gdbarch
= regcache
->arch ();
1568 displaced_step_inferior_state
*displaced_state
1569 = get_displaced_stepping_state (tp
->inf
);
1571 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1572 && target_is_non_stop_p ())
1573 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1574 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1575 && find_record_target () == NULL
1576 && !displaced_state
->failed_before
);
1579 /* Clean out any stray displaced stepping state. */
1581 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1583 /* Indicate that there is no cleanup pending. */
1584 displaced
->step_thread
= nullptr;
1586 delete displaced
->step_closure
;
1587 displaced
->step_closure
= NULL
;
1590 /* A cleanup that wraps displaced_step_clear. */
1591 using displaced_step_clear_cleanup
1592 = FORWARD_SCOPE_EXIT (displaced_step_clear
);
1594 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1596 displaced_step_dump_bytes (struct ui_file
*file
,
1597 const gdb_byte
*buf
,
1602 for (i
= 0; i
< len
; i
++)
1603 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1604 fputs_unfiltered ("\n", file
);
1607 /* Prepare to single-step, using displaced stepping.
1609 Note that we cannot use displaced stepping when we have a signal to
1610 deliver. If we have a signal to deliver and an instruction to step
1611 over, then after the step, there will be no indication from the
1612 target whether the thread entered a signal handler or ignored the
1613 signal and stepped over the instruction successfully --- both cases
1614 result in a simple SIGTRAP. In the first case we mustn't do a
1615 fixup, and in the second case we must --- but we can't tell which.
1616 Comments in the code for 'random signals' in handle_inferior_event
1617 explain how we handle this case instead.
1619 Returns 1 if preparing was successful -- this thread is going to be
1620 stepped now; 0 if displaced stepping this thread got queued; or -1
1621 if this instruction can't be displaced stepped. */
1624 displaced_step_prepare_throw (thread_info
*tp
)
1626 regcache
*regcache
= get_thread_regcache (tp
);
1627 struct gdbarch
*gdbarch
= regcache
->arch ();
1628 const address_space
*aspace
= regcache
->aspace ();
1629 CORE_ADDR original
, copy
;
1631 struct displaced_step_closure
*closure
;
1634 /* We should never reach this function if the architecture does not
1635 support displaced stepping. */
1636 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1638 /* Nor if the thread isn't meant to step over a breakpoint. */
1639 gdb_assert (tp
->control
.trap_expected
);
1641 /* Disable range stepping while executing in the scratch pad. We
1642 want a single-step even if executing the displaced instruction in
1643 the scratch buffer lands within the stepping range (e.g., a
1645 tp
->control
.may_range_step
= 0;
1647 /* We have to displaced step one thread at a time, as we only have
1648 access to a single scratch space per inferior. */
1650 displaced_step_inferior_state
*displaced
1651 = get_displaced_stepping_state (tp
->inf
);
1653 if (displaced
->step_thread
!= nullptr)
1655 /* Already waiting for a displaced step to finish. Defer this
1656 request and place in queue. */
1658 if (debug_displaced
)
1659 fprintf_unfiltered (gdb_stdlog
,
1660 "displaced: deferring step of %s\n",
1661 target_pid_to_str (tp
->ptid
).c_str ());
1663 thread_step_over_chain_enqueue (tp
);
1668 if (debug_displaced
)
1669 fprintf_unfiltered (gdb_stdlog
,
1670 "displaced: stepping %s now\n",
1671 target_pid_to_str (tp
->ptid
).c_str ());
1674 displaced_step_clear (displaced
);
1676 scoped_restore_current_thread restore_thread
;
1678 switch_to_thread (tp
);
1680 original
= regcache_read_pc (regcache
);
1682 copy
= gdbarch_displaced_step_location (gdbarch
);
1683 len
= gdbarch_max_insn_length (gdbarch
);
1685 if (breakpoint_in_range_p (aspace
, copy
, len
))
1687 /* There's a breakpoint set in the scratch pad location range
1688 (which is usually around the entry point). We'd either
1689 install it before resuming, which would overwrite/corrupt the
1690 scratch pad, or if it was already inserted, this displaced
1691 step would overwrite it. The latter is OK in the sense that
1692 we already assume that no thread is going to execute the code
1693 in the scratch pad range (after initial startup) anyway, but
1694 the former is unacceptable. Simply punt and fallback to
1695 stepping over this breakpoint in-line. */
1696 if (debug_displaced
)
1698 fprintf_unfiltered (gdb_stdlog
,
1699 "displaced: breakpoint set in scratch pad. "
1700 "Stepping over breakpoint in-line instead.\n");
1706 /* Save the original contents of the copy area. */
1707 displaced
->step_saved_copy
.resize (len
);
1708 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1710 throw_error (MEMORY_ERROR
,
1711 _("Error accessing memory address %s (%s) for "
1712 "displaced-stepping scratch space."),
1713 paddress (gdbarch
, copy
), safe_strerror (status
));
1714 if (debug_displaced
)
1716 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1717 paddress (gdbarch
, copy
));
1718 displaced_step_dump_bytes (gdb_stdlog
,
1719 displaced
->step_saved_copy
.data (),
1723 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1724 original
, copy
, regcache
);
1725 if (closure
== NULL
)
1727 /* The architecture doesn't know how or want to displaced step
1728 this instruction or instruction sequence. Fallback to
1729 stepping over the breakpoint in-line. */
1733 /* Save the information we need to fix things up if the step
1735 displaced
->step_thread
= tp
;
1736 displaced
->step_gdbarch
= gdbarch
;
1737 displaced
->step_closure
= closure
;
1738 displaced
->step_original
= original
;
1739 displaced
->step_copy
= copy
;
1742 displaced_step_clear_cleanup
cleanup (displaced
);
1744 /* Resume execution at the copy. */
1745 regcache_write_pc (regcache
, copy
);
1750 if (debug_displaced
)
1751 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1752 paddress (gdbarch
, copy
));
1757 /* Wrapper for displaced_step_prepare_throw that disabled further
1758 attempts at displaced stepping if we get a memory error. */
1761 displaced_step_prepare (thread_info
*thread
)
1767 prepared
= displaced_step_prepare_throw (thread
);
1769 catch (const gdb_exception_error
&ex
)
1771 struct displaced_step_inferior_state
*displaced_state
;
1773 if (ex
.error
!= MEMORY_ERROR
1774 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1779 fprintf_unfiltered (gdb_stdlog
,
1780 "infrun: disabling displaced stepping: %s\n",
1784 /* Be verbose if "set displaced-stepping" is "on", silent if
1786 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1788 warning (_("disabling displaced stepping: %s"),
1792 /* Disable further displaced stepping attempts. */
1794 = get_displaced_stepping_state (thread
->inf
);
1795 displaced_state
->failed_before
= 1;
1802 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1803 const gdb_byte
*myaddr
, int len
)
1805 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1807 inferior_ptid
= ptid
;
1808 write_memory (memaddr
, myaddr
, len
);
1811 /* Restore the contents of the copy area for thread PTID. */
1814 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1817 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1819 write_memory_ptid (ptid
, displaced
->step_copy
,
1820 displaced
->step_saved_copy
.data (), len
);
1821 if (debug_displaced
)
1822 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1823 target_pid_to_str (ptid
).c_str (),
1824 paddress (displaced
->step_gdbarch
,
1825 displaced
->step_copy
));
1828 /* If we displaced stepped an instruction successfully, adjust
1829 registers and memory to yield the same effect the instruction would
1830 have had if we had executed it at its original address, and return
1831 1. If the instruction didn't complete, relocate the PC and return
1832 -1. If the thread wasn't displaced stepping, return 0. */
1835 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1837 struct displaced_step_inferior_state
*displaced
1838 = get_displaced_stepping_state (event_thread
->inf
);
1841 /* Was this event for the thread we displaced? */
1842 if (displaced
->step_thread
!= event_thread
)
1845 displaced_step_clear_cleanup
cleanup (displaced
);
1847 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1849 /* Fixup may need to read memory/registers. Switch to the thread
1850 that we're fixing up. Also, target_stopped_by_watchpoint checks
1851 the current thread. */
1852 switch_to_thread (event_thread
);
1854 /* Did the instruction complete successfully? */
1855 if (signal
== GDB_SIGNAL_TRAP
1856 && !(target_stopped_by_watchpoint ()
1857 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1858 || target_have_steppable_watchpoint
)))
1860 /* Fix up the resulting state. */
1861 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1862 displaced
->step_closure
,
1863 displaced
->step_original
,
1864 displaced
->step_copy
,
1865 get_thread_regcache (displaced
->step_thread
));
1870 /* Since the instruction didn't complete, all we can do is
1872 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1873 CORE_ADDR pc
= regcache_read_pc (regcache
);
1875 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1876 regcache_write_pc (regcache
, pc
);
1883 /* Data to be passed around while handling an event. This data is
1884 discarded between events. */
1885 struct execution_control_state
1888 /* The thread that got the event, if this was a thread event; NULL
1890 struct thread_info
*event_thread
;
1892 struct target_waitstatus ws
;
1893 int stop_func_filled_in
;
1894 CORE_ADDR stop_func_start
;
1895 CORE_ADDR stop_func_end
;
1896 const char *stop_func_name
;
1899 /* True if the event thread hit the single-step breakpoint of
1900 another thread. Thus the event doesn't cause a stop, the thread
1901 needs to be single-stepped past the single-step breakpoint before
1902 we can switch back to the original stepping thread. */
1903 int hit_singlestep_breakpoint
;
1906 /* Clear ECS and set it to point at TP. */
1909 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1911 memset (ecs
, 0, sizeof (*ecs
));
1912 ecs
->event_thread
= tp
;
1913 ecs
->ptid
= tp
->ptid
;
1916 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1917 static void prepare_to_wait (struct execution_control_state
*ecs
);
1918 static int keep_going_stepped_thread (struct thread_info
*tp
);
1919 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1921 /* Are there any pending step-over requests? If so, run all we can
1922 now and return true. Otherwise, return false. */
1925 start_step_over (void)
1927 struct thread_info
*tp
, *next
;
1929 /* Don't start a new step-over if we already have an in-line
1930 step-over operation ongoing. */
1931 if (step_over_info_valid_p ())
1934 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1936 struct execution_control_state ecss
;
1937 struct execution_control_state
*ecs
= &ecss
;
1938 step_over_what step_what
;
1939 int must_be_in_line
;
1941 gdb_assert (!tp
->stop_requested
);
1943 next
= thread_step_over_chain_next (tp
);
1945 /* If this inferior already has a displaced step in process,
1946 don't start a new one. */
1947 if (displaced_step_in_progress (tp
->inf
))
1950 step_what
= thread_still_needs_step_over (tp
);
1951 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1952 || ((step_what
& STEP_OVER_BREAKPOINT
)
1953 && !use_displaced_stepping (tp
)));
1955 /* We currently stop all threads of all processes to step-over
1956 in-line. If we need to start a new in-line step-over, let
1957 any pending displaced steps finish first. */
1958 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1961 thread_step_over_chain_remove (tp
);
1963 if (step_over_queue_head
== NULL
)
1966 fprintf_unfiltered (gdb_stdlog
,
1967 "infrun: step-over queue now empty\n");
1970 if (tp
->control
.trap_expected
1974 internal_error (__FILE__
, __LINE__
,
1975 "[%s] has inconsistent state: "
1976 "trap_expected=%d, resumed=%d, executing=%d\n",
1977 target_pid_to_str (tp
->ptid
).c_str (),
1978 tp
->control
.trap_expected
,
1984 fprintf_unfiltered (gdb_stdlog
,
1985 "infrun: resuming [%s] for step-over\n",
1986 target_pid_to_str (tp
->ptid
).c_str ());
1988 /* keep_going_pass_signal skips the step-over if the breakpoint
1989 is no longer inserted. In all-stop, we want to keep looking
1990 for a thread that needs a step-over instead of resuming TP,
1991 because we wouldn't be able to resume anything else until the
1992 target stops again. In non-stop, the resume always resumes
1993 only TP, so it's OK to let the thread resume freely. */
1994 if (!target_is_non_stop_p () && !step_what
)
1997 switch_to_thread (tp
);
1998 reset_ecs (ecs
, tp
);
1999 keep_going_pass_signal (ecs
);
2001 if (!ecs
->wait_some_more
)
2002 error (_("Command aborted."));
2004 gdb_assert (tp
->resumed
);
2006 /* If we started a new in-line step-over, we're done. */
2007 if (step_over_info_valid_p ())
2009 gdb_assert (tp
->control
.trap_expected
);
2013 if (!target_is_non_stop_p ())
2015 /* On all-stop, shouldn't have resumed unless we needed a
2017 gdb_assert (tp
->control
.trap_expected
2018 || tp
->step_after_step_resume_breakpoint
);
2020 /* With remote targets (at least), in all-stop, we can't
2021 issue any further remote commands until the program stops
2026 /* Either the thread no longer needed a step-over, or a new
2027 displaced stepping sequence started. Even in the latter
2028 case, continue looking. Maybe we can also start another
2029 displaced step on a thread of other process. */
2035 /* Update global variables holding ptids to hold NEW_PTID if they were
2036 holding OLD_PTID. */
2038 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2040 if (inferior_ptid
== old_ptid
)
2041 inferior_ptid
= new_ptid
;
2046 static const char schedlock_off
[] = "off";
2047 static const char schedlock_on
[] = "on";
2048 static const char schedlock_step
[] = "step";
2049 static const char schedlock_replay
[] = "replay";
2050 static const char *const scheduler_enums
[] = {
2057 static const char *scheduler_mode
= schedlock_replay
;
2059 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2060 struct cmd_list_element
*c
, const char *value
)
2062 fprintf_filtered (file
,
2063 _("Mode for locking scheduler "
2064 "during execution is \"%s\".\n"),
2069 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2071 if (!target_can_lock_scheduler
)
2073 scheduler_mode
= schedlock_off
;
2074 error (_("Target '%s' cannot support this command."), target_shortname
);
2078 /* True if execution commands resume all threads of all processes by
2079 default; otherwise, resume only threads of the current inferior
2081 bool sched_multi
= false;
2083 /* Try to setup for software single stepping over the specified location.
2084 Return 1 if target_resume() should use hardware single step.
2086 GDBARCH the current gdbarch.
2087 PC the location to step over. */
2090 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2094 if (execution_direction
== EXEC_FORWARD
2095 && gdbarch_software_single_step_p (gdbarch
))
2096 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2104 user_visible_resume_ptid (int step
)
2110 /* With non-stop mode on, threads are always handled
2112 resume_ptid
= inferior_ptid
;
2114 else if ((scheduler_mode
== schedlock_on
)
2115 || (scheduler_mode
== schedlock_step
&& step
))
2117 /* User-settable 'scheduler' mode requires solo thread
2119 resume_ptid
= inferior_ptid
;
2121 else if ((scheduler_mode
== schedlock_replay
)
2122 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2124 /* User-settable 'scheduler' mode requires solo thread resume in replay
2126 resume_ptid
= inferior_ptid
;
2128 else if (!sched_multi
&& target_supports_multi_process ())
2130 /* Resume all threads of the current process (and none of other
2132 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2136 /* Resume all threads of all processes. */
2137 resume_ptid
= RESUME_ALL
;
2143 /* Return a ptid representing the set of threads that we will resume,
2144 in the perspective of the target, assuming run control handling
2145 does not require leaving some threads stopped (e.g., stepping past
2146 breakpoint). USER_STEP indicates whether we're about to start the
2147 target for a stepping command. */
2150 internal_resume_ptid (int user_step
)
2152 /* In non-stop, we always control threads individually. Note that
2153 the target may always work in non-stop mode even with "set
2154 non-stop off", in which case user_visible_resume_ptid could
2155 return a wildcard ptid. */
2156 if (target_is_non_stop_p ())
2157 return inferior_ptid
;
2159 return user_visible_resume_ptid (user_step
);
2162 /* Wrapper for target_resume, that handles infrun-specific
2166 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2168 struct thread_info
*tp
= inferior_thread ();
2170 gdb_assert (!tp
->stop_requested
);
2172 /* Install inferior's terminal modes. */
2173 target_terminal::inferior ();
2175 /* Avoid confusing the next resume, if the next stop/resume
2176 happens to apply to another thread. */
2177 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2179 /* Advise target which signals may be handled silently.
2181 If we have removed breakpoints because we are stepping over one
2182 in-line (in any thread), we need to receive all signals to avoid
2183 accidentally skipping a breakpoint during execution of a signal
2186 Likewise if we're displaced stepping, otherwise a trap for a
2187 breakpoint in a signal handler might be confused with the
2188 displaced step finishing. We don't make the displaced_step_fixup
2189 step distinguish the cases instead, because:
2191 - a backtrace while stopped in the signal handler would show the
2192 scratch pad as frame older than the signal handler, instead of
2193 the real mainline code.
2195 - when the thread is later resumed, the signal handler would
2196 return to the scratch pad area, which would no longer be
2198 if (step_over_info_valid_p ()
2199 || displaced_step_in_progress (tp
->inf
))
2200 target_pass_signals ({});
2202 target_pass_signals (signal_pass
);
2204 target_resume (resume_ptid
, step
, sig
);
2206 target_commit_resume ();
2209 /* Resume the inferior. SIG is the signal to give the inferior
2210 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2211 call 'resume', which handles exceptions. */
2214 resume_1 (enum gdb_signal sig
)
2216 struct regcache
*regcache
= get_current_regcache ();
2217 struct gdbarch
*gdbarch
= regcache
->arch ();
2218 struct thread_info
*tp
= inferior_thread ();
2219 CORE_ADDR pc
= regcache_read_pc (regcache
);
2220 const address_space
*aspace
= regcache
->aspace ();
2222 /* This represents the user's step vs continue request. When
2223 deciding whether "set scheduler-locking step" applies, it's the
2224 user's intention that counts. */
2225 const int user_step
= tp
->control
.stepping_command
;
2226 /* This represents what we'll actually request the target to do.
2227 This can decay from a step to a continue, if e.g., we need to
2228 implement single-stepping with breakpoints (software
2232 gdb_assert (!tp
->stop_requested
);
2233 gdb_assert (!thread_is_in_step_over_chain (tp
));
2235 if (tp
->suspend
.waitstatus_pending_p
)
2240 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2242 fprintf_unfiltered (gdb_stdlog
,
2243 "infrun: resume: thread %s has pending wait "
2244 "status %s (currently_stepping=%d).\n",
2245 target_pid_to_str (tp
->ptid
).c_str (),
2247 currently_stepping (tp
));
2252 /* FIXME: What should we do if we are supposed to resume this
2253 thread with a signal? Maybe we should maintain a queue of
2254 pending signals to deliver. */
2255 if (sig
!= GDB_SIGNAL_0
)
2257 warning (_("Couldn't deliver signal %s to %s."),
2258 gdb_signal_to_name (sig
),
2259 target_pid_to_str (tp
->ptid
).c_str ());
2262 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2264 if (target_can_async_p ())
2267 /* Tell the event loop we have an event to process. */
2268 mark_async_event_handler (infrun_async_inferior_event_token
);
2273 tp
->stepped_breakpoint
= 0;
2275 /* Depends on stepped_breakpoint. */
2276 step
= currently_stepping (tp
);
2278 if (current_inferior ()->waiting_for_vfork_done
)
2280 /* Don't try to single-step a vfork parent that is waiting for
2281 the child to get out of the shared memory region (by exec'ing
2282 or exiting). This is particularly important on software
2283 single-step archs, as the child process would trip on the
2284 software single step breakpoint inserted for the parent
2285 process. Since the parent will not actually execute any
2286 instruction until the child is out of the shared region (such
2287 are vfork's semantics), it is safe to simply continue it.
2288 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2289 the parent, and tell it to `keep_going', which automatically
2290 re-sets it stepping. */
2292 fprintf_unfiltered (gdb_stdlog
,
2293 "infrun: resume : clear step\n");
2298 fprintf_unfiltered (gdb_stdlog
,
2299 "infrun: resume (step=%d, signal=%s), "
2300 "trap_expected=%d, current thread [%s] at %s\n",
2301 step
, gdb_signal_to_symbol_string (sig
),
2302 tp
->control
.trap_expected
,
2303 target_pid_to_str (inferior_ptid
).c_str (),
2304 paddress (gdbarch
, pc
));
2306 /* Normally, by the time we reach `resume', the breakpoints are either
2307 removed or inserted, as appropriate. The exception is if we're sitting
2308 at a permanent breakpoint; we need to step over it, but permanent
2309 breakpoints can't be removed. So we have to test for it here. */
2310 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2312 if (sig
!= GDB_SIGNAL_0
)
2314 /* We have a signal to pass to the inferior. The resume
2315 may, or may not take us to the signal handler. If this
2316 is a step, we'll need to stop in the signal handler, if
2317 there's one, (if the target supports stepping into
2318 handlers), or in the next mainline instruction, if
2319 there's no handler. If this is a continue, we need to be
2320 sure to run the handler with all breakpoints inserted.
2321 In all cases, set a breakpoint at the current address
2322 (where the handler returns to), and once that breakpoint
2323 is hit, resume skipping the permanent breakpoint. If
2324 that breakpoint isn't hit, then we've stepped into the
2325 signal handler (or hit some other event). We'll delete
2326 the step-resume breakpoint then. */
2329 fprintf_unfiltered (gdb_stdlog
,
2330 "infrun: resume: skipping permanent breakpoint, "
2331 "deliver signal first\n");
2333 clear_step_over_info ();
2334 tp
->control
.trap_expected
= 0;
2336 if (tp
->control
.step_resume_breakpoint
== NULL
)
2338 /* Set a "high-priority" step-resume, as we don't want
2339 user breakpoints at PC to trigger (again) when this
2341 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2342 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2344 tp
->step_after_step_resume_breakpoint
= step
;
2347 insert_breakpoints ();
2351 /* There's no signal to pass, we can go ahead and skip the
2352 permanent breakpoint manually. */
2354 fprintf_unfiltered (gdb_stdlog
,
2355 "infrun: resume: skipping permanent breakpoint\n");
2356 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2357 /* Update pc to reflect the new address from which we will
2358 execute instructions. */
2359 pc
= regcache_read_pc (regcache
);
2363 /* We've already advanced the PC, so the stepping part
2364 is done. Now we need to arrange for a trap to be
2365 reported to handle_inferior_event. Set a breakpoint
2366 at the current PC, and run to it. Don't update
2367 prev_pc, because if we end in
2368 switch_back_to_stepped_thread, we want the "expected
2369 thread advanced also" branch to be taken. IOW, we
2370 don't want this thread to step further from PC
2372 gdb_assert (!step_over_info_valid_p ());
2373 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2374 insert_breakpoints ();
2376 resume_ptid
= internal_resume_ptid (user_step
);
2377 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2384 /* If we have a breakpoint to step over, make sure to do a single
2385 step only. Same if we have software watchpoints. */
2386 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2387 tp
->control
.may_range_step
= 0;
2389 /* If enabled, step over breakpoints by executing a copy of the
2390 instruction at a different address.
2392 We can't use displaced stepping when we have a signal to deliver;
2393 the comments for displaced_step_prepare explain why. The
2394 comments in the handle_inferior event for dealing with 'random
2395 signals' explain what we do instead.
2397 We can't use displaced stepping when we are waiting for vfork_done
2398 event, displaced stepping breaks the vfork child similarly as single
2399 step software breakpoint. */
2400 if (tp
->control
.trap_expected
2401 && use_displaced_stepping (tp
)
2402 && !step_over_info_valid_p ()
2403 && sig
== GDB_SIGNAL_0
2404 && !current_inferior ()->waiting_for_vfork_done
)
2406 int prepared
= displaced_step_prepare (tp
);
2411 fprintf_unfiltered (gdb_stdlog
,
2412 "Got placed in step-over queue\n");
2414 tp
->control
.trap_expected
= 0;
2417 else if (prepared
< 0)
2419 /* Fallback to stepping over the breakpoint in-line. */
2421 if (target_is_non_stop_p ())
2422 stop_all_threads ();
2424 set_step_over_info (regcache
->aspace (),
2425 regcache_read_pc (regcache
), 0, tp
->global_num
);
2427 step
= maybe_software_singlestep (gdbarch
, pc
);
2429 insert_breakpoints ();
2431 else if (prepared
> 0)
2433 struct displaced_step_inferior_state
*displaced
;
2435 /* Update pc to reflect the new address from which we will
2436 execute instructions due to displaced stepping. */
2437 pc
= regcache_read_pc (get_thread_regcache (tp
));
2439 displaced
= get_displaced_stepping_state (tp
->inf
);
2440 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2441 displaced
->step_closure
);
2445 /* Do we need to do it the hard way, w/temp breakpoints? */
2447 step
= maybe_software_singlestep (gdbarch
, pc
);
2449 /* Currently, our software single-step implementation leads to different
2450 results than hardware single-stepping in one situation: when stepping
2451 into delivering a signal which has an associated signal handler,
2452 hardware single-step will stop at the first instruction of the handler,
2453 while software single-step will simply skip execution of the handler.
2455 For now, this difference in behavior is accepted since there is no
2456 easy way to actually implement single-stepping into a signal handler
2457 without kernel support.
2459 However, there is one scenario where this difference leads to follow-on
2460 problems: if we're stepping off a breakpoint by removing all breakpoints
2461 and then single-stepping. In this case, the software single-step
2462 behavior means that even if there is a *breakpoint* in the signal
2463 handler, GDB still would not stop.
2465 Fortunately, we can at least fix this particular issue. We detect
2466 here the case where we are about to deliver a signal while software
2467 single-stepping with breakpoints removed. In this situation, we
2468 revert the decisions to remove all breakpoints and insert single-
2469 step breakpoints, and instead we install a step-resume breakpoint
2470 at the current address, deliver the signal without stepping, and
2471 once we arrive back at the step-resume breakpoint, actually step
2472 over the breakpoint we originally wanted to step over. */
2473 if (thread_has_single_step_breakpoints_set (tp
)
2474 && sig
!= GDB_SIGNAL_0
2475 && step_over_info_valid_p ())
2477 /* If we have nested signals or a pending signal is delivered
2478 immediately after a handler returns, might might already have
2479 a step-resume breakpoint set on the earlier handler. We cannot
2480 set another step-resume breakpoint; just continue on until the
2481 original breakpoint is hit. */
2482 if (tp
->control
.step_resume_breakpoint
== NULL
)
2484 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2485 tp
->step_after_step_resume_breakpoint
= 1;
2488 delete_single_step_breakpoints (tp
);
2490 clear_step_over_info ();
2491 tp
->control
.trap_expected
= 0;
2493 insert_breakpoints ();
2496 /* If STEP is set, it's a request to use hardware stepping
2497 facilities. But in that case, we should never
2498 use singlestep breakpoint. */
2499 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2501 /* Decide the set of threads to ask the target to resume. */
2502 if (tp
->control
.trap_expected
)
2504 /* We're allowing a thread to run past a breakpoint it has
2505 hit, either by single-stepping the thread with the breakpoint
2506 removed, or by displaced stepping, with the breakpoint inserted.
2507 In the former case, we need to single-step only this thread,
2508 and keep others stopped, as they can miss this breakpoint if
2509 allowed to run. That's not really a problem for displaced
2510 stepping, but, we still keep other threads stopped, in case
2511 another thread is also stopped for a breakpoint waiting for
2512 its turn in the displaced stepping queue. */
2513 resume_ptid
= inferior_ptid
;
2516 resume_ptid
= internal_resume_ptid (user_step
);
2518 if (execution_direction
!= EXEC_REVERSE
2519 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2521 /* There are two cases where we currently need to step a
2522 breakpoint instruction when we have a signal to deliver:
2524 - See handle_signal_stop where we handle random signals that
2525 could take out us out of the stepping range. Normally, in
2526 that case we end up continuing (instead of stepping) over the
2527 signal handler with a breakpoint at PC, but there are cases
2528 where we should _always_ single-step, even if we have a
2529 step-resume breakpoint, like when a software watchpoint is
2530 set. Assuming single-stepping and delivering a signal at the
2531 same time would takes us to the signal handler, then we could
2532 have removed the breakpoint at PC to step over it. However,
2533 some hardware step targets (like e.g., Mac OS) can't step
2534 into signal handlers, and for those, we need to leave the
2535 breakpoint at PC inserted, as otherwise if the handler
2536 recurses and executes PC again, it'll miss the breakpoint.
2537 So we leave the breakpoint inserted anyway, but we need to
2538 record that we tried to step a breakpoint instruction, so
2539 that adjust_pc_after_break doesn't end up confused.
2541 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2542 in one thread after another thread that was stepping had been
2543 momentarily paused for a step-over. When we re-resume the
2544 stepping thread, it may be resumed from that address with a
2545 breakpoint that hasn't trapped yet. Seen with
2546 gdb.threads/non-stop-fair-events.exp, on targets that don't
2547 do displaced stepping. */
2550 fprintf_unfiltered (gdb_stdlog
,
2551 "infrun: resume: [%s] stepped breakpoint\n",
2552 target_pid_to_str (tp
->ptid
).c_str ());
2554 tp
->stepped_breakpoint
= 1;
2556 /* Most targets can step a breakpoint instruction, thus
2557 executing it normally. But if this one cannot, just
2558 continue and we will hit it anyway. */
2559 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2564 && tp
->control
.trap_expected
2565 && use_displaced_stepping (tp
)
2566 && !step_over_info_valid_p ())
2568 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2569 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2570 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2573 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2574 paddress (resume_gdbarch
, actual_pc
));
2575 read_memory (actual_pc
, buf
, sizeof (buf
));
2576 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2579 if (tp
->control
.may_range_step
)
2581 /* If we're resuming a thread with the PC out of the step
2582 range, then we're doing some nested/finer run control
2583 operation, like stepping the thread out of the dynamic
2584 linker or the displaced stepping scratch pad. We
2585 shouldn't have allowed a range step then. */
2586 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2589 do_target_resume (resume_ptid
, step
, sig
);
2593 /* Resume the inferior. SIG is the signal to give the inferior
2594 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2595 rolls back state on error. */
2598 resume (gdb_signal sig
)
2604 catch (const gdb_exception
&ex
)
2606 /* If resuming is being aborted for any reason, delete any
2607 single-step breakpoint resume_1 may have created, to avoid
2608 confusing the following resumption, and to avoid leaving
2609 single-step breakpoints perturbing other threads, in case
2610 we're running in non-stop mode. */
2611 if (inferior_ptid
!= null_ptid
)
2612 delete_single_step_breakpoints (inferior_thread ());
2622 /* Counter that tracks number of user visible stops. This can be used
2623 to tell whether a command has proceeded the inferior past the
2624 current location. This allows e.g., inferior function calls in
2625 breakpoint commands to not interrupt the command list. When the
2626 call finishes successfully, the inferior is standing at the same
2627 breakpoint as if nothing happened (and so we don't call
2629 static ULONGEST current_stop_id
;
2636 return current_stop_id
;
2639 /* Called when we report a user visible stop. */
2647 /* Clear out all variables saying what to do when inferior is continued.
2648 First do this, then set the ones you want, then call `proceed'. */
2651 clear_proceed_status_thread (struct thread_info
*tp
)
2654 fprintf_unfiltered (gdb_stdlog
,
2655 "infrun: clear_proceed_status_thread (%s)\n",
2656 target_pid_to_str (tp
->ptid
).c_str ());
2658 /* If we're starting a new sequence, then the previous finished
2659 single-step is no longer relevant. */
2660 if (tp
->suspend
.waitstatus_pending_p
)
2662 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2665 fprintf_unfiltered (gdb_stdlog
,
2666 "infrun: clear_proceed_status: pending "
2667 "event of %s was a finished step. "
2669 target_pid_to_str (tp
->ptid
).c_str ());
2671 tp
->suspend
.waitstatus_pending_p
= 0;
2672 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2674 else if (debug_infrun
)
2677 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2679 fprintf_unfiltered (gdb_stdlog
,
2680 "infrun: clear_proceed_status_thread: thread %s "
2681 "has pending wait status %s "
2682 "(currently_stepping=%d).\n",
2683 target_pid_to_str (tp
->ptid
).c_str (),
2685 currently_stepping (tp
));
2689 /* If this signal should not be seen by program, give it zero.
2690 Used for debugging signals. */
2691 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2692 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2694 delete tp
->thread_fsm
;
2695 tp
->thread_fsm
= NULL
;
2697 tp
->control
.trap_expected
= 0;
2698 tp
->control
.step_range_start
= 0;
2699 tp
->control
.step_range_end
= 0;
2700 tp
->control
.may_range_step
= 0;
2701 tp
->control
.step_frame_id
= null_frame_id
;
2702 tp
->control
.step_stack_frame_id
= null_frame_id
;
2703 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2704 tp
->control
.step_start_function
= NULL
;
2705 tp
->stop_requested
= 0;
2707 tp
->control
.stop_step
= 0;
2709 tp
->control
.proceed_to_finish
= 0;
2711 tp
->control
.stepping_command
= 0;
2713 /* Discard any remaining commands or status from previous stop. */
2714 bpstat_clear (&tp
->control
.stop_bpstat
);
2718 clear_proceed_status (int step
)
2720 /* With scheduler-locking replay, stop replaying other threads if we're
2721 not replaying the user-visible resume ptid.
2723 This is a convenience feature to not require the user to explicitly
2724 stop replaying the other threads. We're assuming that the user's
2725 intent is to resume tracing the recorded process. */
2726 if (!non_stop
&& scheduler_mode
== schedlock_replay
2727 && target_record_is_replaying (minus_one_ptid
)
2728 && !target_record_will_replay (user_visible_resume_ptid (step
),
2729 execution_direction
))
2730 target_record_stop_replaying ();
2732 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2734 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2736 /* In all-stop mode, delete the per-thread status of all threads
2737 we're about to resume, implicitly and explicitly. */
2738 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
2739 clear_proceed_status_thread (tp
);
2742 if (inferior_ptid
!= null_ptid
)
2744 struct inferior
*inferior
;
2748 /* If in non-stop mode, only delete the per-thread status of
2749 the current thread. */
2750 clear_proceed_status_thread (inferior_thread ());
2753 inferior
= current_inferior ();
2754 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2757 gdb::observers::about_to_proceed
.notify ();
2760 /* Returns true if TP is still stopped at a breakpoint that needs
2761 stepping-over in order to make progress. If the breakpoint is gone
2762 meanwhile, we can skip the whole step-over dance. */
2765 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2767 if (tp
->stepping_over_breakpoint
)
2769 struct regcache
*regcache
= get_thread_regcache (tp
);
2771 if (breakpoint_here_p (regcache
->aspace (),
2772 regcache_read_pc (regcache
))
2773 == ordinary_breakpoint_here
)
2776 tp
->stepping_over_breakpoint
= 0;
2782 /* Check whether thread TP still needs to start a step-over in order
2783 to make progress when resumed. Returns an bitwise or of enum
2784 step_over_what bits, indicating what needs to be stepped over. */
2786 static step_over_what
2787 thread_still_needs_step_over (struct thread_info
*tp
)
2789 step_over_what what
= 0;
2791 if (thread_still_needs_step_over_bp (tp
))
2792 what
|= STEP_OVER_BREAKPOINT
;
2794 if (tp
->stepping_over_watchpoint
2795 && !target_have_steppable_watchpoint
)
2796 what
|= STEP_OVER_WATCHPOINT
;
2801 /* Returns true if scheduler locking applies. STEP indicates whether
2802 we're about to do a step/next-like command to a thread. */
2805 schedlock_applies (struct thread_info
*tp
)
2807 return (scheduler_mode
== schedlock_on
2808 || (scheduler_mode
== schedlock_step
2809 && tp
->control
.stepping_command
)
2810 || (scheduler_mode
== schedlock_replay
2811 && target_record_will_replay (minus_one_ptid
,
2812 execution_direction
)));
2815 /* Basic routine for continuing the program in various fashions.
2817 ADDR is the address to resume at, or -1 for resume where stopped.
2818 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2819 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2821 You should call clear_proceed_status before calling proceed. */
2824 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2826 struct regcache
*regcache
;
2827 struct gdbarch
*gdbarch
;
2830 struct execution_control_state ecss
;
2831 struct execution_control_state
*ecs
= &ecss
;
2834 /* If we're stopped at a fork/vfork, follow the branch set by the
2835 "set follow-fork-mode" command; otherwise, we'll just proceed
2836 resuming the current thread. */
2837 if (!follow_fork ())
2839 /* The target for some reason decided not to resume. */
2841 if (target_can_async_p ())
2842 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2846 /* We'll update this if & when we switch to a new thread. */
2847 previous_inferior_ptid
= inferior_ptid
;
2849 regcache
= get_current_regcache ();
2850 gdbarch
= regcache
->arch ();
2851 const address_space
*aspace
= regcache
->aspace ();
2853 pc
= regcache_read_pc (regcache
);
2854 thread_info
*cur_thr
= inferior_thread ();
2856 /* Fill in with reasonable starting values. */
2857 init_thread_stepping_state (cur_thr
);
2859 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2861 if (addr
== (CORE_ADDR
) -1)
2863 if (pc
== cur_thr
->suspend
.stop_pc
2864 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2865 && execution_direction
!= EXEC_REVERSE
)
2866 /* There is a breakpoint at the address we will resume at,
2867 step one instruction before inserting breakpoints so that
2868 we do not stop right away (and report a second hit at this
2871 Note, we don't do this in reverse, because we won't
2872 actually be executing the breakpoint insn anyway.
2873 We'll be (un-)executing the previous instruction. */
2874 cur_thr
->stepping_over_breakpoint
= 1;
2875 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2876 && gdbarch_single_step_through_delay (gdbarch
,
2877 get_current_frame ()))
2878 /* We stepped onto an instruction that needs to be stepped
2879 again before re-inserting the breakpoint, do so. */
2880 cur_thr
->stepping_over_breakpoint
= 1;
2884 regcache_write_pc (regcache
, addr
);
2887 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2888 cur_thr
->suspend
.stop_signal
= siggnal
;
2890 resume_ptid
= user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2892 /* If an exception is thrown from this point on, make sure to
2893 propagate GDB's knowledge of the executing state to the
2894 frontend/user running state. */
2895 scoped_finish_thread_state
finish_state (resume_ptid
);
2897 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2898 threads (e.g., we might need to set threads stepping over
2899 breakpoints first), from the user/frontend's point of view, all
2900 threads in RESUME_PTID are now running. Unless we're calling an
2901 inferior function, as in that case we pretend the inferior
2902 doesn't run at all. */
2903 if (!cur_thr
->control
.in_infcall
)
2904 set_running (resume_ptid
, 1);
2907 fprintf_unfiltered (gdb_stdlog
,
2908 "infrun: proceed (addr=%s, signal=%s)\n",
2909 paddress (gdbarch
, addr
),
2910 gdb_signal_to_symbol_string (siggnal
));
2912 annotate_starting ();
2914 /* Make sure that output from GDB appears before output from the
2916 gdb_flush (gdb_stdout
);
2918 /* Since we've marked the inferior running, give it the terminal. A
2919 QUIT/Ctrl-C from here on is forwarded to the target (which can
2920 still detect attempts to unblock a stuck connection with repeated
2921 Ctrl-C from within target_pass_ctrlc). */
2922 target_terminal::inferior ();
2924 /* In a multi-threaded task we may select another thread and
2925 then continue or step.
2927 But if a thread that we're resuming had stopped at a breakpoint,
2928 it will immediately cause another breakpoint stop without any
2929 execution (i.e. it will report a breakpoint hit incorrectly). So
2930 we must step over it first.
2932 Look for threads other than the current (TP) that reported a
2933 breakpoint hit and haven't been resumed yet since. */
2935 /* If scheduler locking applies, we can avoid iterating over all
2937 if (!non_stop
&& !schedlock_applies (cur_thr
))
2939 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
2941 switch_to_thread_no_regs (tp
);
2943 /* Ignore the current thread here. It's handled
2948 if (!thread_still_needs_step_over (tp
))
2951 gdb_assert (!thread_is_in_step_over_chain (tp
));
2954 fprintf_unfiltered (gdb_stdlog
,
2955 "infrun: need to step-over [%s] first\n",
2956 target_pid_to_str (tp
->ptid
).c_str ());
2958 thread_step_over_chain_enqueue (tp
);
2961 switch_to_thread (cur_thr
);
2964 /* Enqueue the current thread last, so that we move all other
2965 threads over their breakpoints first. */
2966 if (cur_thr
->stepping_over_breakpoint
)
2967 thread_step_over_chain_enqueue (cur_thr
);
2969 /* If the thread isn't started, we'll still need to set its prev_pc,
2970 so that switch_back_to_stepped_thread knows the thread hasn't
2971 advanced. Must do this before resuming any thread, as in
2972 all-stop/remote, once we resume we can't send any other packet
2973 until the target stops again. */
2974 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
2977 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
2979 started
= start_step_over ();
2981 if (step_over_info_valid_p ())
2983 /* Either this thread started a new in-line step over, or some
2984 other thread was already doing one. In either case, don't
2985 resume anything else until the step-over is finished. */
2987 else if (started
&& !target_is_non_stop_p ())
2989 /* A new displaced stepping sequence was started. In all-stop,
2990 we can't talk to the target anymore until it next stops. */
2992 else if (!non_stop
&& target_is_non_stop_p ())
2994 /* In all-stop, but the target is always in non-stop mode.
2995 Start all other threads that are implicitly resumed too. */
2996 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
2998 switch_to_thread_no_regs (tp
);
3003 fprintf_unfiltered (gdb_stdlog
,
3004 "infrun: proceed: [%s] resumed\n",
3005 target_pid_to_str (tp
->ptid
).c_str ());
3006 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3010 if (thread_is_in_step_over_chain (tp
))
3013 fprintf_unfiltered (gdb_stdlog
,
3014 "infrun: proceed: [%s] needs step-over\n",
3015 target_pid_to_str (tp
->ptid
).c_str ());
3020 fprintf_unfiltered (gdb_stdlog
,
3021 "infrun: proceed: resuming %s\n",
3022 target_pid_to_str (tp
->ptid
).c_str ());
3024 reset_ecs (ecs
, tp
);
3025 switch_to_thread (tp
);
3026 keep_going_pass_signal (ecs
);
3027 if (!ecs
->wait_some_more
)
3028 error (_("Command aborted."));
3031 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3033 /* The thread wasn't started, and isn't queued, run it now. */
3034 reset_ecs (ecs
, cur_thr
);
3035 switch_to_thread (cur_thr
);
3036 keep_going_pass_signal (ecs
);
3037 if (!ecs
->wait_some_more
)
3038 error (_("Command aborted."));
3042 target_commit_resume ();
3044 finish_state
.release ();
3046 /* If we've switched threads above, switch back to the previously
3047 current thread. We don't want the user to see a different
3049 switch_to_thread (cur_thr
);
3051 /* Tell the event loop to wait for it to stop. If the target
3052 supports asynchronous execution, it'll do this from within
3054 if (!target_can_async_p ())
3055 mark_async_event_handler (infrun_async_inferior_event_token
);
3059 /* Start remote-debugging of a machine over a serial link. */
3062 start_remote (int from_tty
)
3064 struct inferior
*inferior
;
3066 inferior
= current_inferior ();
3067 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3069 /* Always go on waiting for the target, regardless of the mode. */
3070 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3071 indicate to wait_for_inferior that a target should timeout if
3072 nothing is returned (instead of just blocking). Because of this,
3073 targets expecting an immediate response need to, internally, set
3074 things up so that the target_wait() is forced to eventually
3076 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3077 differentiate to its caller what the state of the target is after
3078 the initial open has been performed. Here we're assuming that
3079 the target has stopped. It should be possible to eventually have
3080 target_open() return to the caller an indication that the target
3081 is currently running and GDB state should be set to the same as
3082 for an async run. */
3083 wait_for_inferior ();
3085 /* Now that the inferior has stopped, do any bookkeeping like
3086 loading shared libraries. We want to do this before normal_stop,
3087 so that the displayed frame is up to date. */
3088 post_create_inferior (current_top_target (), from_tty
);
3093 /* Initialize static vars when a new inferior begins. */
3096 init_wait_for_inferior (void)
3098 /* These are meaningless until the first time through wait_for_inferior. */
3100 breakpoint_init_inferior (inf_starting
);
3102 clear_proceed_status (0);
3104 nullify_last_target_wait_ptid ();
3106 previous_inferior_ptid
= inferior_ptid
;
3111 static void handle_inferior_event (struct execution_control_state
*ecs
);
3113 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3114 struct execution_control_state
*ecs
);
3115 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3116 struct execution_control_state
*ecs
);
3117 static void handle_signal_stop (struct execution_control_state
*ecs
);
3118 static void check_exception_resume (struct execution_control_state
*,
3119 struct frame_info
*);
3121 static void end_stepping_range (struct execution_control_state
*ecs
);
3122 static void stop_waiting (struct execution_control_state
*ecs
);
3123 static void keep_going (struct execution_control_state
*ecs
);
3124 static void process_event_stop_test (struct execution_control_state
*ecs
);
3125 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3127 /* This function is attached as a "thread_stop_requested" observer.
3128 Cleanup local state that assumed the PTID was to be resumed, and
3129 report the stop to the frontend. */
3132 infrun_thread_stop_requested (ptid_t ptid
)
3134 /* PTID was requested to stop. If the thread was already stopped,
3135 but the user/frontend doesn't know about that yet (e.g., the
3136 thread had been temporarily paused for some step-over), set up
3137 for reporting the stop now. */
3138 for (thread_info
*tp
: all_threads (ptid
))
3140 if (tp
->state
!= THREAD_RUNNING
)
3145 /* Remove matching threads from the step-over queue, so
3146 start_step_over doesn't try to resume them
3148 if (thread_is_in_step_over_chain (tp
))
3149 thread_step_over_chain_remove (tp
);
3151 /* If the thread is stopped, but the user/frontend doesn't
3152 know about that yet, queue a pending event, as if the
3153 thread had just stopped now. Unless the thread already had
3155 if (!tp
->suspend
.waitstatus_pending_p
)
3157 tp
->suspend
.waitstatus_pending_p
= 1;
3158 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3159 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3162 /* Clear the inline-frame state, since we're re-processing the
3164 clear_inline_frame_state (tp
->ptid
);
3166 /* If this thread was paused because some other thread was
3167 doing an inline-step over, let that finish first. Once
3168 that happens, we'll restart all threads and consume pending
3169 stop events then. */
3170 if (step_over_info_valid_p ())
3173 /* Otherwise we can process the (new) pending event now. Set
3174 it so this pending event is considered by
3181 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3183 if (target_last_wait_ptid
== tp
->ptid
)
3184 nullify_last_target_wait_ptid ();
3187 /* Delete the step resume, single-step and longjmp/exception resume
3188 breakpoints of TP. */
3191 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3193 delete_step_resume_breakpoint (tp
);
3194 delete_exception_resume_breakpoint (tp
);
3195 delete_single_step_breakpoints (tp
);
3198 /* If the target still has execution, call FUNC for each thread that
3199 just stopped. In all-stop, that's all the non-exited threads; in
3200 non-stop, that's the current thread, only. */
3202 typedef void (*for_each_just_stopped_thread_callback_func
)
3203 (struct thread_info
*tp
);
3206 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3208 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3211 if (target_is_non_stop_p ())
3213 /* If in non-stop mode, only the current thread stopped. */
3214 func (inferior_thread ());
3218 /* In all-stop mode, all threads have stopped. */
3219 for (thread_info
*tp
: all_non_exited_threads ())
3224 /* Delete the step resume and longjmp/exception resume breakpoints of
3225 the threads that just stopped. */
3228 delete_just_stopped_threads_infrun_breakpoints (void)
3230 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3233 /* Delete the single-step breakpoints of the threads that just
3237 delete_just_stopped_threads_single_step_breakpoints (void)
3239 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3245 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3246 const struct target_waitstatus
*ws
)
3248 std::string status_string
= target_waitstatus_to_string (ws
);
3251 /* The text is split over several lines because it was getting too long.
3252 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3253 output as a unit; we want only one timestamp printed if debug_timestamp
3256 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3259 waiton_ptid
.tid ());
3260 if (waiton_ptid
.pid () != -1)
3261 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3262 stb
.printf (", status) =\n");
3263 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3267 target_pid_to_str (result_ptid
).c_str ());
3268 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3270 /* This uses %s in part to handle %'s in the text, but also to avoid
3271 a gcc error: the format attribute requires a string literal. */
3272 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3275 /* Select a thread at random, out of those which are resumed and have
3278 static struct thread_info
*
3279 random_pending_event_thread (ptid_t waiton_ptid
)
3283 auto has_event
= [] (thread_info
*tp
)
3286 && tp
->suspend
.waitstatus_pending_p
);
3289 /* First see how many events we have. Count only resumed threads
3290 that have an event pending. */
3291 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3295 if (num_events
== 0)
3298 /* Now randomly pick a thread out of those that have had events. */
3299 int random_selector
= (int) ((num_events
* (double) rand ())
3300 / (RAND_MAX
+ 1.0));
3302 if (debug_infrun
&& num_events
> 1)
3303 fprintf_unfiltered (gdb_stdlog
,
3304 "infrun: Found %d events, selecting #%d\n",
3305 num_events
, random_selector
);
3307 /* Select the Nth thread that has had an event. */
3308 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3310 if (random_selector
-- == 0)
3313 gdb_assert_not_reached ("event thread not found");
3316 /* Wrapper for target_wait that first checks whether threads have
3317 pending statuses to report before actually asking the target for
3321 do_target_wait (ptid_t ptid
, struct target_waitstatus
*status
, int options
)
3324 struct thread_info
*tp
;
3326 /* First check if there is a resumed thread with a wait status
3328 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3330 tp
= random_pending_event_thread (ptid
);
3335 fprintf_unfiltered (gdb_stdlog
,
3336 "infrun: Waiting for specific thread %s.\n",
3337 target_pid_to_str (ptid
).c_str ());
3339 /* We have a specific thread to check. */
3340 tp
= find_thread_ptid (ptid
);
3341 gdb_assert (tp
!= NULL
);
3342 if (!tp
->suspend
.waitstatus_pending_p
)
3347 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3348 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3350 struct regcache
*regcache
= get_thread_regcache (tp
);
3351 struct gdbarch
*gdbarch
= regcache
->arch ();
3355 pc
= regcache_read_pc (regcache
);
3357 if (pc
!= tp
->suspend
.stop_pc
)
3360 fprintf_unfiltered (gdb_stdlog
,
3361 "infrun: PC of %s changed. was=%s, now=%s\n",
3362 target_pid_to_str (tp
->ptid
).c_str (),
3363 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3364 paddress (gdbarch
, pc
));
3367 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3370 fprintf_unfiltered (gdb_stdlog
,
3371 "infrun: previous breakpoint of %s, at %s gone\n",
3372 target_pid_to_str (tp
->ptid
).c_str (),
3373 paddress (gdbarch
, pc
));
3381 fprintf_unfiltered (gdb_stdlog
,
3382 "infrun: pending event of %s cancelled.\n",
3383 target_pid_to_str (tp
->ptid
).c_str ());
3385 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3386 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3395 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3397 fprintf_unfiltered (gdb_stdlog
,
3398 "infrun: Using pending wait status %s for %s.\n",
3400 target_pid_to_str (tp
->ptid
).c_str ());
3403 /* Now that we've selected our final event LWP, un-adjust its PC
3404 if it was a software breakpoint (and the target doesn't
3405 always adjust the PC itself). */
3406 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3407 && !target_supports_stopped_by_sw_breakpoint ())
3409 struct regcache
*regcache
;
3410 struct gdbarch
*gdbarch
;
3413 regcache
= get_thread_regcache (tp
);
3414 gdbarch
= regcache
->arch ();
3416 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3421 pc
= regcache_read_pc (regcache
);
3422 regcache_write_pc (regcache
, pc
+ decr_pc
);
3426 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3427 *status
= tp
->suspend
.waitstatus
;
3428 tp
->suspend
.waitstatus_pending_p
= 0;
3430 /* Wake up the event loop again, until all pending events are
3432 if (target_is_async_p ())
3433 mark_async_event_handler (infrun_async_inferior_event_token
);
3437 /* But if we don't find one, we'll have to wait. */
3439 if (deprecated_target_wait_hook
)
3440 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3442 event_ptid
= target_wait (ptid
, status
, options
);
3447 /* Prepare and stabilize the inferior for detaching it. E.g.,
3448 detaching while a thread is displaced stepping is a recipe for
3449 crashing it, as nothing would readjust the PC out of the scratch
3453 prepare_for_detach (void)
3455 struct inferior
*inf
= current_inferior ();
3456 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3458 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3460 /* Is any thread of this process displaced stepping? If not,
3461 there's nothing else to do. */
3462 if (displaced
->step_thread
== nullptr)
3466 fprintf_unfiltered (gdb_stdlog
,
3467 "displaced-stepping in-process while detaching");
3469 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3471 while (displaced
->step_thread
!= nullptr)
3473 struct execution_control_state ecss
;
3474 struct execution_control_state
*ecs
;
3477 memset (ecs
, 0, sizeof (*ecs
));
3479 overlay_cache_invalid
= 1;
3480 /* Flush target cache before starting to handle each event.
3481 Target was running and cache could be stale. This is just a
3482 heuristic. Running threads may modify target memory, but we
3483 don't get any event. */
3484 target_dcache_invalidate ();
3486 ecs
->ptid
= do_target_wait (pid_ptid
, &ecs
->ws
, 0);
3489 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3491 /* If an error happens while handling the event, propagate GDB's
3492 knowledge of the executing state to the frontend/user running
3494 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3496 /* Now figure out what to do with the result of the result. */
3497 handle_inferior_event (ecs
);
3499 /* No error, don't finish the state yet. */
3500 finish_state
.release ();
3502 /* Breakpoints and watchpoints are not installed on the target
3503 at this point, and signals are passed directly to the
3504 inferior, so this must mean the process is gone. */
3505 if (!ecs
->wait_some_more
)
3507 restore_detaching
.release ();
3508 error (_("Program exited while detaching"));
3512 restore_detaching
.release ();
3515 /* Wait for control to return from inferior to debugger.
3517 If inferior gets a signal, we may decide to start it up again
3518 instead of returning. That is why there is a loop in this function.
3519 When this function actually returns it means the inferior
3520 should be left stopped and GDB should read more commands. */
3523 wait_for_inferior (void)
3527 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3529 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3531 /* If an error happens while handling the event, propagate GDB's
3532 knowledge of the executing state to the frontend/user running
3534 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3538 struct execution_control_state ecss
;
3539 struct execution_control_state
*ecs
= &ecss
;
3540 ptid_t waiton_ptid
= minus_one_ptid
;
3542 memset (ecs
, 0, sizeof (*ecs
));
3544 overlay_cache_invalid
= 1;
3546 /* Flush target cache before starting to handle each event.
3547 Target was running and cache could be stale. This is just a
3548 heuristic. Running threads may modify target memory, but we
3549 don't get any event. */
3550 target_dcache_invalidate ();
3552 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
, 0);
3555 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3557 /* Now figure out what to do with the result of the result. */
3558 handle_inferior_event (ecs
);
3560 if (!ecs
->wait_some_more
)
3564 /* No error, don't finish the state yet. */
3565 finish_state
.release ();
3568 /* Cleanup that reinstalls the readline callback handler, if the
3569 target is running in the background. If while handling the target
3570 event something triggered a secondary prompt, like e.g., a
3571 pagination prompt, we'll have removed the callback handler (see
3572 gdb_readline_wrapper_line). Need to do this as we go back to the
3573 event loop, ready to process further input. Note this has no
3574 effect if the handler hasn't actually been removed, because calling
3575 rl_callback_handler_install resets the line buffer, thus losing
3579 reinstall_readline_callback_handler_cleanup ()
3581 struct ui
*ui
= current_ui
;
3585 /* We're not going back to the top level event loop yet. Don't
3586 install the readline callback, as it'd prep the terminal,
3587 readline-style (raw, noecho) (e.g., --batch). We'll install
3588 it the next time the prompt is displayed, when we're ready
3593 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3594 gdb_rl_callback_handler_reinstall ();
3597 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3598 that's just the event thread. In all-stop, that's all threads. */
3601 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3603 if (ecs
->event_thread
!= NULL
3604 && ecs
->event_thread
->thread_fsm
!= NULL
)
3605 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3609 for (thread_info
*thr
: all_non_exited_threads ())
3611 if (thr
->thread_fsm
== NULL
)
3613 if (thr
== ecs
->event_thread
)
3616 switch_to_thread (thr
);
3617 thr
->thread_fsm
->clean_up (thr
);
3620 if (ecs
->event_thread
!= NULL
)
3621 switch_to_thread (ecs
->event_thread
);
3625 /* Helper for all_uis_check_sync_execution_done that works on the
3629 check_curr_ui_sync_execution_done (void)
3631 struct ui
*ui
= current_ui
;
3633 if (ui
->prompt_state
== PROMPT_NEEDED
3635 && !gdb_in_secondary_prompt_p (ui
))
3637 target_terminal::ours ();
3638 gdb::observers::sync_execution_done
.notify ();
3639 ui_register_input_event_handler (ui
);
3646 all_uis_check_sync_execution_done (void)
3648 SWITCH_THRU_ALL_UIS ()
3650 check_curr_ui_sync_execution_done ();
3657 all_uis_on_sync_execution_starting (void)
3659 SWITCH_THRU_ALL_UIS ()
3661 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3662 async_disable_stdin ();
3666 /* Asynchronous version of wait_for_inferior. It is called by the
3667 event loop whenever a change of state is detected on the file
3668 descriptor corresponding to the target. It can be called more than
3669 once to complete a single execution command. In such cases we need
3670 to keep the state in a global variable ECSS. If it is the last time
3671 that this function is called for a single execution command, then
3672 report to the user that the inferior has stopped, and do the
3673 necessary cleanups. */
3676 fetch_inferior_event (void *client_data
)
3678 struct execution_control_state ecss
;
3679 struct execution_control_state
*ecs
= &ecss
;
3681 ptid_t waiton_ptid
= minus_one_ptid
;
3683 memset (ecs
, 0, sizeof (*ecs
));
3685 /* Events are always processed with the main UI as current UI. This
3686 way, warnings, debug output, etc. are always consistently sent to
3687 the main console. */
3688 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3690 /* End up with readline processing input, if necessary. */
3692 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3694 /* We're handling a live event, so make sure we're doing live
3695 debugging. If we're looking at traceframes while the target is
3696 running, we're going to need to get back to that mode after
3697 handling the event. */
3698 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3701 maybe_restore_traceframe
.emplace ();
3702 set_current_traceframe (-1);
3705 /* The user/frontend should not notice a thread switch due to
3706 internal events. Make sure we revert to the user selected
3707 thread and frame after handling the event and running any
3708 breakpoint commands. */
3709 scoped_restore_current_thread restore_thread
;
3711 overlay_cache_invalid
= 1;
3712 /* Flush target cache before starting to handle each event. Target
3713 was running and cache could be stale. This is just a heuristic.
3714 Running threads may modify target memory, but we don't get any
3716 target_dcache_invalidate ();
3718 scoped_restore save_exec_dir
3719 = make_scoped_restore (&execution_direction
,
3720 target_execution_direction ());
3722 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
,
3723 target_can_async_p () ? TARGET_WNOHANG
: 0);
3726 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3728 /* If an error happens while handling the event, propagate GDB's
3729 knowledge of the executing state to the frontend/user running
3731 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3732 scoped_finish_thread_state
finish_state (finish_ptid
);
3734 /* Get executed before scoped_restore_current_thread above to apply
3735 still for the thread which has thrown the exception. */
3736 auto defer_bpstat_clear
3737 = make_scope_exit (bpstat_clear_actions
);
3738 auto defer_delete_threads
3739 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3741 /* Now figure out what to do with the result of the result. */
3742 handle_inferior_event (ecs
);
3744 if (!ecs
->wait_some_more
)
3746 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3747 int should_stop
= 1;
3748 struct thread_info
*thr
= ecs
->event_thread
;
3750 delete_just_stopped_threads_infrun_breakpoints ();
3754 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3756 if (thread_fsm
!= NULL
)
3757 should_stop
= thread_fsm
->should_stop (thr
);
3766 bool should_notify_stop
= true;
3769 clean_up_just_stopped_threads_fsms (ecs
);
3771 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3772 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3774 if (should_notify_stop
)
3776 /* We may not find an inferior if this was a process exit. */
3777 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3778 proceeded
= normal_stop ();
3783 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3787 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3788 previously selected thread is gone. We have two
3789 choices - switch to no thread selected, or restore the
3790 previously selected thread (now exited). We chose the
3791 later, just because that's what GDB used to do. After
3792 this, "info threads" says "The current thread <Thread
3793 ID 2> has terminated." instead of "No thread
3797 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3798 restore_thread
.dont_restore ();
3802 defer_delete_threads
.release ();
3803 defer_bpstat_clear
.release ();
3805 /* No error, don't finish the thread states yet. */
3806 finish_state
.release ();
3808 /* This scope is used to ensure that readline callbacks are
3809 reinstalled here. */
3812 /* If a UI was in sync execution mode, and now isn't, restore its
3813 prompt (a synchronous execution command has finished, and we're
3814 ready for input). */
3815 all_uis_check_sync_execution_done ();
3818 && exec_done_display_p
3819 && (inferior_ptid
== null_ptid
3820 || inferior_thread ()->state
!= THREAD_RUNNING
))
3821 printf_unfiltered (_("completed.\n"));
3824 /* Record the frame and location we're currently stepping through. */
3826 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
3828 struct thread_info
*tp
= inferior_thread ();
3830 tp
->control
.step_frame_id
= get_frame_id (frame
);
3831 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3833 tp
->current_symtab
= sal
.symtab
;
3834 tp
->current_line
= sal
.line
;
3837 /* Clear context switchable stepping state. */
3840 init_thread_stepping_state (struct thread_info
*tss
)
3842 tss
->stepped_breakpoint
= 0;
3843 tss
->stepping_over_breakpoint
= 0;
3844 tss
->stepping_over_watchpoint
= 0;
3845 tss
->step_after_step_resume_breakpoint
= 0;
3851 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
3853 target_last_wait_ptid
= ptid
;
3854 target_last_waitstatus
= status
;
3860 get_last_target_status (ptid_t
*ptid
, struct target_waitstatus
*status
)
3862 if (ptid
!= nullptr)
3863 *ptid
= target_last_wait_ptid
;
3864 if (status
!= nullptr)
3865 *status
= target_last_waitstatus
;
3871 nullify_last_target_wait_ptid (void)
3873 target_last_wait_ptid
= minus_one_ptid
;
3874 target_last_waitstatus
= {};
3877 /* Switch thread contexts. */
3880 context_switch (execution_control_state
*ecs
)
3883 && ecs
->ptid
!= inferior_ptid
3884 && ecs
->event_thread
!= inferior_thread ())
3886 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
3887 target_pid_to_str (inferior_ptid
).c_str ());
3888 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
3889 target_pid_to_str (ecs
->ptid
).c_str ());
3892 switch_to_thread (ecs
->event_thread
);
3895 /* If the target can't tell whether we've hit breakpoints
3896 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3897 check whether that could have been caused by a breakpoint. If so,
3898 adjust the PC, per gdbarch_decr_pc_after_break. */
3901 adjust_pc_after_break (struct thread_info
*thread
,
3902 struct target_waitstatus
*ws
)
3904 struct regcache
*regcache
;
3905 struct gdbarch
*gdbarch
;
3906 CORE_ADDR breakpoint_pc
, decr_pc
;
3908 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3909 we aren't, just return.
3911 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3912 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3913 implemented by software breakpoints should be handled through the normal
3916 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3917 different signals (SIGILL or SIGEMT for instance), but it is less
3918 clear where the PC is pointing afterwards. It may not match
3919 gdbarch_decr_pc_after_break. I don't know any specific target that
3920 generates these signals at breakpoints (the code has been in GDB since at
3921 least 1992) so I can not guess how to handle them here.
3923 In earlier versions of GDB, a target with
3924 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3925 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3926 target with both of these set in GDB history, and it seems unlikely to be
3927 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3929 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
3932 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
3935 /* In reverse execution, when a breakpoint is hit, the instruction
3936 under it has already been de-executed. The reported PC always
3937 points at the breakpoint address, so adjusting it further would
3938 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3941 B1 0x08000000 : INSN1
3942 B2 0x08000001 : INSN2
3944 PC -> 0x08000003 : INSN4
3946 Say you're stopped at 0x08000003 as above. Reverse continuing
3947 from that point should hit B2 as below. Reading the PC when the
3948 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3949 been de-executed already.
3951 B1 0x08000000 : INSN1
3952 B2 PC -> 0x08000001 : INSN2
3956 We can't apply the same logic as for forward execution, because
3957 we would wrongly adjust the PC to 0x08000000, since there's a
3958 breakpoint at PC - 1. We'd then report a hit on B1, although
3959 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3961 if (execution_direction
== EXEC_REVERSE
)
3964 /* If the target can tell whether the thread hit a SW breakpoint,
3965 trust it. Targets that can tell also adjust the PC
3967 if (target_supports_stopped_by_sw_breakpoint ())
3970 /* Note that relying on whether a breakpoint is planted in memory to
3971 determine this can fail. E.g,. the breakpoint could have been
3972 removed since. Or the thread could have been told to step an
3973 instruction the size of a breakpoint instruction, and only
3974 _after_ was a breakpoint inserted at its address. */
3976 /* If this target does not decrement the PC after breakpoints, then
3977 we have nothing to do. */
3978 regcache
= get_thread_regcache (thread
);
3979 gdbarch
= regcache
->arch ();
3981 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3985 const address_space
*aspace
= regcache
->aspace ();
3987 /* Find the location where (if we've hit a breakpoint) the
3988 breakpoint would be. */
3989 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
3991 /* If the target can't tell whether a software breakpoint triggered,
3992 fallback to figuring it out based on breakpoints we think were
3993 inserted in the target, and on whether the thread was stepped or
3996 /* Check whether there actually is a software breakpoint inserted at
3999 If in non-stop mode, a race condition is possible where we've
4000 removed a breakpoint, but stop events for that breakpoint were
4001 already queued and arrive later. To suppress those spurious
4002 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4003 and retire them after a number of stop events are reported. Note
4004 this is an heuristic and can thus get confused. The real fix is
4005 to get the "stopped by SW BP and needs adjustment" info out of
4006 the target/kernel (and thus never reach here; see above). */
4007 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4008 || (target_is_non_stop_p ()
4009 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4011 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4013 if (record_full_is_used ())
4014 restore_operation_disable
.emplace
4015 (record_full_gdb_operation_disable_set ());
4017 /* When using hardware single-step, a SIGTRAP is reported for both
4018 a completed single-step and a software breakpoint. Need to
4019 differentiate between the two, as the latter needs adjusting
4020 but the former does not.
4022 The SIGTRAP can be due to a completed hardware single-step only if
4023 - we didn't insert software single-step breakpoints
4024 - this thread is currently being stepped
4026 If any of these events did not occur, we must have stopped due
4027 to hitting a software breakpoint, and have to back up to the
4030 As a special case, we could have hardware single-stepped a
4031 software breakpoint. In this case (prev_pc == breakpoint_pc),
4032 we also need to back up to the breakpoint address. */
4034 if (thread_has_single_step_breakpoints_set (thread
)
4035 || !currently_stepping (thread
)
4036 || (thread
->stepped_breakpoint
4037 && thread
->prev_pc
== breakpoint_pc
))
4038 regcache_write_pc (regcache
, breakpoint_pc
);
4043 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4045 for (frame
= get_prev_frame (frame
);
4047 frame
= get_prev_frame (frame
))
4049 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4051 if (get_frame_type (frame
) != INLINE_FRAME
)
4058 /* Look for an inline frame that is marked for skip.
4059 If PREV_FRAME is TRUE start at the previous frame,
4060 otherwise start at the current frame. Stop at the
4061 first non-inline frame, or at the frame where the
4065 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4067 struct frame_info
*frame
= get_current_frame ();
4070 frame
= get_prev_frame (frame
);
4072 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4074 const char *fn
= NULL
;
4075 symtab_and_line sal
;
4078 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4080 if (get_frame_type (frame
) != INLINE_FRAME
)
4083 sal
= find_frame_sal (frame
);
4084 sym
= get_frame_function (frame
);
4087 fn
= sym
->print_name ();
4090 && function_name_is_marked_for_skip (fn
, sal
))
4097 /* If the event thread has the stop requested flag set, pretend it
4098 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4102 handle_stop_requested (struct execution_control_state
*ecs
)
4104 if (ecs
->event_thread
->stop_requested
)
4106 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4107 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4108 handle_signal_stop (ecs
);
4114 /* Auxiliary function that handles syscall entry/return events.
4115 It returns 1 if the inferior should keep going (and GDB
4116 should ignore the event), or 0 if the event deserves to be
4120 handle_syscall_event (struct execution_control_state
*ecs
)
4122 struct regcache
*regcache
;
4125 context_switch (ecs
);
4127 regcache
= get_thread_regcache (ecs
->event_thread
);
4128 syscall_number
= ecs
->ws
.value
.syscall_number
;
4129 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4131 if (catch_syscall_enabled () > 0
4132 && catching_syscall_number (syscall_number
) > 0)
4135 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4138 ecs
->event_thread
->control
.stop_bpstat
4139 = bpstat_stop_status (regcache
->aspace (),
4140 ecs
->event_thread
->suspend
.stop_pc
,
4141 ecs
->event_thread
, &ecs
->ws
);
4143 if (handle_stop_requested (ecs
))
4146 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4148 /* Catchpoint hit. */
4153 if (handle_stop_requested (ecs
))
4156 /* If no catchpoint triggered for this, then keep going. */
4161 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4164 fill_in_stop_func (struct gdbarch
*gdbarch
,
4165 struct execution_control_state
*ecs
)
4167 if (!ecs
->stop_func_filled_in
)
4171 /* Don't care about return value; stop_func_start and stop_func_name
4172 will both be 0 if it doesn't work. */
4173 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4174 &ecs
->stop_func_name
,
4175 &ecs
->stop_func_start
,
4176 &ecs
->stop_func_end
,
4179 /* The call to find_pc_partial_function, above, will set
4180 stop_func_start and stop_func_end to the start and end
4181 of the range containing the stop pc. If this range
4182 contains the entry pc for the block (which is always the
4183 case for contiguous blocks), advance stop_func_start past
4184 the function's start offset and entrypoint. Note that
4185 stop_func_start is NOT advanced when in a range of a
4186 non-contiguous block that does not contain the entry pc. */
4187 if (block
!= nullptr
4188 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4189 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4191 ecs
->stop_func_start
4192 += gdbarch_deprecated_function_start_offset (gdbarch
);
4194 if (gdbarch_skip_entrypoint_p (gdbarch
))
4195 ecs
->stop_func_start
4196 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4199 ecs
->stop_func_filled_in
= 1;
4204 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4206 static enum stop_kind
4207 get_inferior_stop_soon (execution_control_state
*ecs
)
4209 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
4211 gdb_assert (inf
!= NULL
);
4212 return inf
->control
.stop_soon
;
4215 /* Wait for one event. Store the resulting waitstatus in WS, and
4216 return the event ptid. */
4219 wait_one (struct target_waitstatus
*ws
)
4222 ptid_t wait_ptid
= minus_one_ptid
;
4224 overlay_cache_invalid
= 1;
4226 /* Flush target cache before starting to handle each event.
4227 Target was running and cache could be stale. This is just a
4228 heuristic. Running threads may modify target memory, but we
4229 don't get any event. */
4230 target_dcache_invalidate ();
4232 if (deprecated_target_wait_hook
)
4233 event_ptid
= deprecated_target_wait_hook (wait_ptid
, ws
, 0);
4235 event_ptid
= target_wait (wait_ptid
, ws
, 0);
4238 print_target_wait_results (wait_ptid
, event_ptid
, ws
);
4243 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4244 instead of the current thread. */
4245 #define THREAD_STOPPED_BY(REASON) \
4247 thread_stopped_by_ ## REASON (ptid_t ptid) \
4249 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4250 inferior_ptid = ptid; \
4252 return target_stopped_by_ ## REASON (); \
4255 /* Generate thread_stopped_by_watchpoint. */
4256 THREAD_STOPPED_BY (watchpoint
)
4257 /* Generate thread_stopped_by_sw_breakpoint. */
4258 THREAD_STOPPED_BY (sw_breakpoint
)
4259 /* Generate thread_stopped_by_hw_breakpoint. */
4260 THREAD_STOPPED_BY (hw_breakpoint
)
4262 /* Save the thread's event and stop reason to process it later. */
4265 save_waitstatus (struct thread_info
*tp
, struct target_waitstatus
*ws
)
4269 std::string statstr
= target_waitstatus_to_string (ws
);
4271 fprintf_unfiltered (gdb_stdlog
,
4272 "infrun: saving status %s for %d.%ld.%ld\n",
4279 /* Record for later. */
4280 tp
->suspend
.waitstatus
= *ws
;
4281 tp
->suspend
.waitstatus_pending_p
= 1;
4283 struct regcache
*regcache
= get_thread_regcache (tp
);
4284 const address_space
*aspace
= regcache
->aspace ();
4286 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4287 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4289 CORE_ADDR pc
= regcache_read_pc (regcache
);
4291 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4293 if (thread_stopped_by_watchpoint (tp
->ptid
))
4295 tp
->suspend
.stop_reason
4296 = TARGET_STOPPED_BY_WATCHPOINT
;
4298 else if (target_supports_stopped_by_sw_breakpoint ()
4299 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4301 tp
->suspend
.stop_reason
4302 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4304 else if (target_supports_stopped_by_hw_breakpoint ()
4305 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4307 tp
->suspend
.stop_reason
4308 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4310 else if (!target_supports_stopped_by_hw_breakpoint ()
4311 && hardware_breakpoint_inserted_here_p (aspace
,
4314 tp
->suspend
.stop_reason
4315 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4317 else if (!target_supports_stopped_by_sw_breakpoint ()
4318 && software_breakpoint_inserted_here_p (aspace
,
4321 tp
->suspend
.stop_reason
4322 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4324 else if (!thread_has_single_step_breakpoints_set (tp
)
4325 && currently_stepping (tp
))
4327 tp
->suspend
.stop_reason
4328 = TARGET_STOPPED_BY_SINGLE_STEP
;
4336 stop_all_threads (void)
4338 /* We may need multiple passes to discover all threads. */
4342 gdb_assert (target_is_non_stop_p ());
4345 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4347 scoped_restore_current_thread restore_thread
;
4349 target_thread_events (1);
4350 SCOPE_EXIT
{ target_thread_events (0); };
4352 /* Request threads to stop, and then wait for the stops. Because
4353 threads we already know about can spawn more threads while we're
4354 trying to stop them, and we only learn about new threads when we
4355 update the thread list, do this in a loop, and keep iterating
4356 until two passes find no threads that need to be stopped. */
4357 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4360 fprintf_unfiltered (gdb_stdlog
,
4361 "infrun: stop_all_threads, pass=%d, "
4362 "iterations=%d\n", pass
, iterations
);
4366 struct target_waitstatus ws
;
4369 update_thread_list ();
4371 /* Go through all threads looking for threads that we need
4372 to tell the target to stop. */
4373 for (thread_info
*t
: all_non_exited_threads ())
4377 /* If already stopping, don't request a stop again.
4378 We just haven't seen the notification yet. */
4379 if (!t
->stop_requested
)
4382 fprintf_unfiltered (gdb_stdlog
,
4383 "infrun: %s executing, "
4385 target_pid_to_str (t
->ptid
).c_str ());
4386 switch_to_thread_no_regs (t
);
4387 target_stop (t
->ptid
);
4388 t
->stop_requested
= 1;
4393 fprintf_unfiltered (gdb_stdlog
,
4394 "infrun: %s executing, "
4395 "already stopping\n",
4396 target_pid_to_str (t
->ptid
).c_str ());
4399 if (t
->stop_requested
)
4405 fprintf_unfiltered (gdb_stdlog
,
4406 "infrun: %s not executing\n",
4407 target_pid_to_str (t
->ptid
).c_str ());
4409 /* The thread may be not executing, but still be
4410 resumed with a pending status to process. */
4418 /* If we find new threads on the second iteration, restart
4419 over. We want to see two iterations in a row with all
4424 event_ptid
= wait_one (&ws
);
4427 fprintf_unfiltered (gdb_stdlog
,
4428 "infrun: stop_all_threads %s %s\n",
4429 target_waitstatus_to_string (&ws
).c_str (),
4430 target_pid_to_str (event_ptid
).c_str ());
4433 if (ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4434 || ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4435 || ws
.kind
== TARGET_WAITKIND_EXITED
4436 || ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4438 /* All resumed threads exited
4439 or one thread/process exited/signalled. */
4443 thread_info
*t
= find_thread_ptid (event_ptid
);
4445 t
= add_thread (event_ptid
);
4447 t
->stop_requested
= 0;
4450 t
->control
.may_range_step
= 0;
4452 /* This may be the first time we see the inferior report
4454 inferior
*inf
= find_inferior_ptid (event_ptid
);
4455 if (inf
->needs_setup
)
4457 switch_to_thread_no_regs (t
);
4461 if (ws
.kind
== TARGET_WAITKIND_STOPPED
4462 && ws
.value
.sig
== GDB_SIGNAL_0
)
4464 /* We caught the event that we intended to catch, so
4465 there's no event pending. */
4466 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4467 t
->suspend
.waitstatus_pending_p
= 0;
4469 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4471 /* Add it back to the step-over queue. */
4474 fprintf_unfiltered (gdb_stdlog
,
4475 "infrun: displaced-step of %s "
4476 "canceled: adding back to the "
4477 "step-over queue\n",
4478 target_pid_to_str (t
->ptid
).c_str ());
4480 t
->control
.trap_expected
= 0;
4481 thread_step_over_chain_enqueue (t
);
4486 enum gdb_signal sig
;
4487 struct regcache
*regcache
;
4491 std::string statstr
= target_waitstatus_to_string (&ws
);
4493 fprintf_unfiltered (gdb_stdlog
,
4494 "infrun: target_wait %s, saving "
4495 "status for %d.%ld.%ld\n",
4502 /* Record for later. */
4503 save_waitstatus (t
, &ws
);
4505 sig
= (ws
.kind
== TARGET_WAITKIND_STOPPED
4506 ? ws
.value
.sig
: GDB_SIGNAL_0
);
4508 if (displaced_step_fixup (t
, sig
) < 0)
4510 /* Add it back to the step-over queue. */
4511 t
->control
.trap_expected
= 0;
4512 thread_step_over_chain_enqueue (t
);
4515 regcache
= get_thread_regcache (t
);
4516 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4520 fprintf_unfiltered (gdb_stdlog
,
4521 "infrun: saved stop_pc=%s for %s "
4522 "(currently_stepping=%d)\n",
4523 paddress (target_gdbarch (),
4524 t
->suspend
.stop_pc
),
4525 target_pid_to_str (t
->ptid
).c_str (),
4526 currently_stepping (t
));
4534 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4537 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4540 handle_no_resumed (struct execution_control_state
*ecs
)
4542 if (target_can_async_p ())
4549 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4557 /* There were no unwaited-for children left in the target, but,
4558 we're not synchronously waiting for events either. Just
4562 fprintf_unfiltered (gdb_stdlog
,
4563 "infrun: TARGET_WAITKIND_NO_RESUMED "
4564 "(ignoring: bg)\n");
4565 prepare_to_wait (ecs
);
4570 /* Otherwise, if we were running a synchronous execution command, we
4571 may need to cancel it and give the user back the terminal.
4573 In non-stop mode, the target can't tell whether we've already
4574 consumed previous stop events, so it can end up sending us a
4575 no-resumed event like so:
4577 #0 - thread 1 is left stopped
4579 #1 - thread 2 is resumed and hits breakpoint
4580 -> TARGET_WAITKIND_STOPPED
4582 #2 - thread 3 is resumed and exits
4583 this is the last resumed thread, so
4584 -> TARGET_WAITKIND_NO_RESUMED
4586 #3 - gdb processes stop for thread 2 and decides to re-resume
4589 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4590 thread 2 is now resumed, so the event should be ignored.
4592 IOW, if the stop for thread 2 doesn't end a foreground command,
4593 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4594 event. But it could be that the event meant that thread 2 itself
4595 (or whatever other thread was the last resumed thread) exited.
4597 To address this we refresh the thread list and check whether we
4598 have resumed threads _now_. In the example above, this removes
4599 thread 3 from the thread list. If thread 2 was re-resumed, we
4600 ignore this event. If we find no thread resumed, then we cancel
4601 the synchronous command show "no unwaited-for " to the user. */
4602 update_thread_list ();
4604 for (thread_info
*thread
: all_non_exited_threads ())
4606 if (thread
->executing
4607 || thread
->suspend
.waitstatus_pending_p
)
4609 /* There were no unwaited-for children left in the target at
4610 some point, but there are now. Just ignore. */
4612 fprintf_unfiltered (gdb_stdlog
,
4613 "infrun: TARGET_WAITKIND_NO_RESUMED "
4614 "(ignoring: found resumed)\n");
4615 prepare_to_wait (ecs
);
4620 /* Note however that we may find no resumed thread because the whole
4621 process exited meanwhile (thus updating the thread list results
4622 in an empty thread list). In this case we know we'll be getting
4623 a process exit event shortly. */
4624 for (inferior
*inf
: all_non_exited_inferiors ())
4626 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4630 fprintf_unfiltered (gdb_stdlog
,
4631 "infrun: TARGET_WAITKIND_NO_RESUMED "
4632 "(expect process exit)\n");
4633 prepare_to_wait (ecs
);
4638 /* Go ahead and report the event. */
4642 /* Given an execution control state that has been freshly filled in by
4643 an event from the inferior, figure out what it means and take
4646 The alternatives are:
4648 1) stop_waiting and return; to really stop and return to the
4651 2) keep_going and return; to wait for the next event (set
4652 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4656 handle_inferior_event (struct execution_control_state
*ecs
)
4658 /* Make sure that all temporary struct value objects that were
4659 created during the handling of the event get deleted at the
4661 scoped_value_mark free_values
;
4663 enum stop_kind stop_soon
;
4666 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
4667 target_waitstatus_to_string (&ecs
->ws
).c_str ());
4669 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4671 /* We had an event in the inferior, but we are not interested in
4672 handling it at this level. The lower layers have already
4673 done what needs to be done, if anything.
4675 One of the possible circumstances for this is when the
4676 inferior produces output for the console. The inferior has
4677 not stopped, and we are ignoring the event. Another possible
4678 circumstance is any event which the lower level knows will be
4679 reported multiple times without an intervening resume. */
4680 prepare_to_wait (ecs
);
4684 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4686 prepare_to_wait (ecs
);
4690 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4691 && handle_no_resumed (ecs
))
4694 /* Cache the last pid/waitstatus. */
4695 set_last_target_status (ecs
->ptid
, ecs
->ws
);
4697 /* Always clear state belonging to the previous time we stopped. */
4698 stop_stack_dummy
= STOP_NONE
;
4700 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4702 /* No unwaited-for children left. IOW, all resumed children
4704 stop_print_frame
= 0;
4709 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
4710 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
4712 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
4713 /* If it's a new thread, add it to the thread database. */
4714 if (ecs
->event_thread
== NULL
)
4715 ecs
->event_thread
= add_thread (ecs
->ptid
);
4717 /* Disable range stepping. If the next step request could use a
4718 range, this will be end up re-enabled then. */
4719 ecs
->event_thread
->control
.may_range_step
= 0;
4722 /* Dependent on valid ECS->EVENT_THREAD. */
4723 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
4725 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4726 reinit_frame_cache ();
4728 breakpoint_retire_moribund ();
4730 /* First, distinguish signals caused by the debugger from signals
4731 that have to do with the program's own actions. Note that
4732 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4733 on the operating system version. Here we detect when a SIGILL or
4734 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4735 something similar for SIGSEGV, since a SIGSEGV will be generated
4736 when we're trying to execute a breakpoint instruction on a
4737 non-executable stack. This happens for call dummy breakpoints
4738 for architectures like SPARC that place call dummies on the
4740 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
4741 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
4742 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
4743 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
4745 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4747 if (breakpoint_inserted_here_p (regcache
->aspace (),
4748 regcache_read_pc (regcache
)))
4751 fprintf_unfiltered (gdb_stdlog
,
4752 "infrun: Treating signal as SIGTRAP\n");
4753 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
4757 /* Mark the non-executing threads accordingly. In all-stop, all
4758 threads of all processes are stopped when we get any event
4759 reported. In non-stop mode, only the event thread stops. */
4763 if (!target_is_non_stop_p ())
4764 mark_ptid
= minus_one_ptid
;
4765 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
4766 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4768 /* If we're handling a process exit in non-stop mode, even
4769 though threads haven't been deleted yet, one would think
4770 that there is nothing to do, as threads of the dead process
4771 will be soon deleted, and threads of any other process were
4772 left running. However, on some targets, threads survive a
4773 process exit event. E.g., for the "checkpoint" command,
4774 when the current checkpoint/fork exits, linux-fork.c
4775 automatically switches to another fork from within
4776 target_mourn_inferior, by associating the same
4777 inferior/thread to another fork. We haven't mourned yet at
4778 this point, but we must mark any threads left in the
4779 process as not-executing so that finish_thread_state marks
4780 them stopped (in the user's perspective) if/when we present
4781 the stop to the user. */
4782 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
4785 mark_ptid
= ecs
->ptid
;
4787 set_executing (mark_ptid
, 0);
4789 /* Likewise the resumed flag. */
4790 set_resumed (mark_ptid
, 0);
4793 switch (ecs
->ws
.kind
)
4795 case TARGET_WAITKIND_LOADED
:
4796 context_switch (ecs
);
4797 /* Ignore gracefully during startup of the inferior, as it might
4798 be the shell which has just loaded some objects, otherwise
4799 add the symbols for the newly loaded objects. Also ignore at
4800 the beginning of an attach or remote session; we will query
4801 the full list of libraries once the connection is
4804 stop_soon
= get_inferior_stop_soon (ecs
);
4805 if (stop_soon
== NO_STOP_QUIETLY
)
4807 struct regcache
*regcache
;
4809 regcache
= get_thread_regcache (ecs
->event_thread
);
4811 handle_solib_event ();
4813 ecs
->event_thread
->control
.stop_bpstat
4814 = bpstat_stop_status (regcache
->aspace (),
4815 ecs
->event_thread
->suspend
.stop_pc
,
4816 ecs
->event_thread
, &ecs
->ws
);
4818 if (handle_stop_requested (ecs
))
4821 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4823 /* A catchpoint triggered. */
4824 process_event_stop_test (ecs
);
4828 /* If requested, stop when the dynamic linker notifies
4829 gdb of events. This allows the user to get control
4830 and place breakpoints in initializer routines for
4831 dynamically loaded objects (among other things). */
4832 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4833 if (stop_on_solib_events
)
4835 /* Make sure we print "Stopped due to solib-event" in
4837 stop_print_frame
= 1;
4844 /* If we are skipping through a shell, or through shared library
4845 loading that we aren't interested in, resume the program. If
4846 we're running the program normally, also resume. */
4847 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
4849 /* Loading of shared libraries might have changed breakpoint
4850 addresses. Make sure new breakpoints are inserted. */
4851 if (stop_soon
== NO_STOP_QUIETLY
)
4852 insert_breakpoints ();
4853 resume (GDB_SIGNAL_0
);
4854 prepare_to_wait (ecs
);
4858 /* But stop if we're attaching or setting up a remote
4860 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4861 || stop_soon
== STOP_QUIETLY_REMOTE
)
4864 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4869 internal_error (__FILE__
, __LINE__
,
4870 _("unhandled stop_soon: %d"), (int) stop_soon
);
4872 case TARGET_WAITKIND_SPURIOUS
:
4873 if (handle_stop_requested (ecs
))
4875 context_switch (ecs
);
4876 resume (GDB_SIGNAL_0
);
4877 prepare_to_wait (ecs
);
4880 case TARGET_WAITKIND_THREAD_CREATED
:
4881 if (handle_stop_requested (ecs
))
4883 context_switch (ecs
);
4884 if (!switch_back_to_stepped_thread (ecs
))
4888 case TARGET_WAITKIND_EXITED
:
4889 case TARGET_WAITKIND_SIGNALLED
:
4890 inferior_ptid
= ecs
->ptid
;
4891 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
4892 set_current_program_space (current_inferior ()->pspace
);
4893 handle_vfork_child_exec_or_exit (0);
4894 target_terminal::ours (); /* Must do this before mourn anyway. */
4896 /* Clearing any previous state of convenience variables. */
4897 clear_exit_convenience_vars ();
4899 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4901 /* Record the exit code in the convenience variable $_exitcode, so
4902 that the user can inspect this again later. */
4903 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4904 (LONGEST
) ecs
->ws
.value
.integer
);
4906 /* Also record this in the inferior itself. */
4907 current_inferior ()->has_exit_code
= 1;
4908 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
4910 /* Support the --return-child-result option. */
4911 return_child_result_value
= ecs
->ws
.value
.integer
;
4913 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
4917 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
4919 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
4921 /* Set the value of the internal variable $_exitsignal,
4922 which holds the signal uncaught by the inferior. */
4923 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4924 gdbarch_gdb_signal_to_target (gdbarch
,
4925 ecs
->ws
.value
.sig
));
4929 /* We don't have access to the target's method used for
4930 converting between signal numbers (GDB's internal
4931 representation <-> target's representation).
4932 Therefore, we cannot do a good job at displaying this
4933 information to the user. It's better to just warn
4934 her about it (if infrun debugging is enabled), and
4937 fprintf_filtered (gdb_stdlog
, _("\
4938 Cannot fill $_exitsignal with the correct signal number.\n"));
4941 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
4944 gdb_flush (gdb_stdout
);
4945 target_mourn_inferior (inferior_ptid
);
4946 stop_print_frame
= 0;
4950 /* The following are the only cases in which we keep going;
4951 the above cases end in a continue or goto. */
4952 case TARGET_WAITKIND_FORKED
:
4953 case TARGET_WAITKIND_VFORKED
:
4954 /* Check whether the inferior is displaced stepping. */
4956 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4957 struct gdbarch
*gdbarch
= regcache
->arch ();
4959 /* If checking displaced stepping is supported, and thread
4960 ecs->ptid is displaced stepping. */
4961 if (displaced_step_in_progress_thread (ecs
->event_thread
))
4963 struct inferior
*parent_inf
4964 = find_inferior_ptid (ecs
->ptid
);
4965 struct regcache
*child_regcache
;
4966 CORE_ADDR parent_pc
;
4968 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4969 indicating that the displaced stepping of syscall instruction
4970 has been done. Perform cleanup for parent process here. Note
4971 that this operation also cleans up the child process for vfork,
4972 because their pages are shared. */
4973 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
4974 /* Start a new step-over in another thread if there's one
4978 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
4980 struct displaced_step_inferior_state
*displaced
4981 = get_displaced_stepping_state (parent_inf
);
4983 /* Restore scratch pad for child process. */
4984 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
4987 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4988 the child's PC is also within the scratchpad. Set the child's PC
4989 to the parent's PC value, which has already been fixed up.
4990 FIXME: we use the parent's aspace here, although we're touching
4991 the child, because the child hasn't been added to the inferior
4992 list yet at this point. */
4995 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
4997 parent_inf
->aspace
);
4998 /* Read PC value of parent process. */
4999 parent_pc
= regcache_read_pc (regcache
);
5001 if (debug_displaced
)
5002 fprintf_unfiltered (gdb_stdlog
,
5003 "displaced: write child pc from %s to %s\n",
5005 regcache_read_pc (child_regcache
)),
5006 paddress (gdbarch
, parent_pc
));
5008 regcache_write_pc (child_regcache
, parent_pc
);
5012 context_switch (ecs
);
5014 /* Immediately detach breakpoints from the child before there's
5015 any chance of letting the user delete breakpoints from the
5016 breakpoint lists. If we don't do this early, it's easy to
5017 leave left over traps in the child, vis: "break foo; catch
5018 fork; c; <fork>; del; c; <child calls foo>". We only follow
5019 the fork on the last `continue', and by that time the
5020 breakpoint at "foo" is long gone from the breakpoint table.
5021 If we vforked, then we don't need to unpatch here, since both
5022 parent and child are sharing the same memory pages; we'll
5023 need to unpatch at follow/detach time instead to be certain
5024 that new breakpoints added between catchpoint hit time and
5025 vfork follow are detached. */
5026 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5028 /* This won't actually modify the breakpoint list, but will
5029 physically remove the breakpoints from the child. */
5030 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5033 delete_just_stopped_threads_single_step_breakpoints ();
5035 /* In case the event is caught by a catchpoint, remember that
5036 the event is to be followed at the next resume of the thread,
5037 and not immediately. */
5038 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5040 ecs
->event_thread
->suspend
.stop_pc
5041 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5043 ecs
->event_thread
->control
.stop_bpstat
5044 = bpstat_stop_status (get_current_regcache ()->aspace (),
5045 ecs
->event_thread
->suspend
.stop_pc
,
5046 ecs
->event_thread
, &ecs
->ws
);
5048 if (handle_stop_requested (ecs
))
5051 /* If no catchpoint triggered for this, then keep going. Note
5052 that we're interested in knowing the bpstat actually causes a
5053 stop, not just if it may explain the signal. Software
5054 watchpoints, for example, always appear in the bpstat. */
5055 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5059 = (follow_fork_mode_string
== follow_fork_mode_child
);
5061 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5063 should_resume
= follow_fork ();
5065 thread_info
*parent
= ecs
->event_thread
;
5066 thread_info
*child
= find_thread_ptid (ecs
->ws
.value
.related_pid
);
5068 /* At this point, the parent is marked running, and the
5069 child is marked stopped. */
5071 /* If not resuming the parent, mark it stopped. */
5072 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5073 parent
->set_running (false);
5075 /* If resuming the child, mark it running. */
5076 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5077 child
->set_running (true);
5079 /* In non-stop mode, also resume the other branch. */
5080 if (!detach_fork
&& (non_stop
5081 || (sched_multi
&& target_is_non_stop_p ())))
5084 switch_to_thread (parent
);
5086 switch_to_thread (child
);
5088 ecs
->event_thread
= inferior_thread ();
5089 ecs
->ptid
= inferior_ptid
;
5094 switch_to_thread (child
);
5096 switch_to_thread (parent
);
5098 ecs
->event_thread
= inferior_thread ();
5099 ecs
->ptid
= inferior_ptid
;
5107 process_event_stop_test (ecs
);
5110 case TARGET_WAITKIND_VFORK_DONE
:
5111 /* Done with the shared memory region. Re-insert breakpoints in
5112 the parent, and keep going. */
5114 context_switch (ecs
);
5116 current_inferior ()->waiting_for_vfork_done
= 0;
5117 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5119 if (handle_stop_requested (ecs
))
5122 /* This also takes care of reinserting breakpoints in the
5123 previously locked inferior. */
5127 case TARGET_WAITKIND_EXECD
:
5129 /* Note we can't read registers yet (the stop_pc), because we
5130 don't yet know the inferior's post-exec architecture.
5131 'stop_pc' is explicitly read below instead. */
5132 switch_to_thread_no_regs (ecs
->event_thread
);
5134 /* Do whatever is necessary to the parent branch of the vfork. */
5135 handle_vfork_child_exec_or_exit (1);
5137 /* This causes the eventpoints and symbol table to be reset.
5138 Must do this now, before trying to determine whether to
5140 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5142 /* In follow_exec we may have deleted the original thread and
5143 created a new one. Make sure that the event thread is the
5144 execd thread for that case (this is a nop otherwise). */
5145 ecs
->event_thread
= inferior_thread ();
5147 ecs
->event_thread
->suspend
.stop_pc
5148 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5150 ecs
->event_thread
->control
.stop_bpstat
5151 = bpstat_stop_status (get_current_regcache ()->aspace (),
5152 ecs
->event_thread
->suspend
.stop_pc
,
5153 ecs
->event_thread
, &ecs
->ws
);
5155 /* Note that this may be referenced from inside
5156 bpstat_stop_status above, through inferior_has_execd. */
5157 xfree (ecs
->ws
.value
.execd_pathname
);
5158 ecs
->ws
.value
.execd_pathname
= NULL
;
5160 if (handle_stop_requested (ecs
))
5163 /* If no catchpoint triggered for this, then keep going. */
5164 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5166 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5170 process_event_stop_test (ecs
);
5173 /* Be careful not to try to gather much state about a thread
5174 that's in a syscall. It's frequently a losing proposition. */
5175 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5176 /* Getting the current syscall number. */
5177 if (handle_syscall_event (ecs
) == 0)
5178 process_event_stop_test (ecs
);
5181 /* Before examining the threads further, step this thread to
5182 get it entirely out of the syscall. (We get notice of the
5183 event when the thread is just on the verge of exiting a
5184 syscall. Stepping one instruction seems to get it back
5186 case TARGET_WAITKIND_SYSCALL_RETURN
:
5187 if (handle_syscall_event (ecs
) == 0)
5188 process_event_stop_test (ecs
);
5191 case TARGET_WAITKIND_STOPPED
:
5192 handle_signal_stop (ecs
);
5195 case TARGET_WAITKIND_NO_HISTORY
:
5196 /* Reverse execution: target ran out of history info. */
5198 /* Switch to the stopped thread. */
5199 context_switch (ecs
);
5201 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5203 delete_just_stopped_threads_single_step_breakpoints ();
5204 ecs
->event_thread
->suspend
.stop_pc
5205 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5207 if (handle_stop_requested (ecs
))
5210 gdb::observers::no_history
.notify ();
5216 /* Restart threads back to what they were trying to do back when we
5217 paused them for an in-line step-over. The EVENT_THREAD thread is
5221 restart_threads (struct thread_info
*event_thread
)
5223 /* In case the instruction just stepped spawned a new thread. */
5224 update_thread_list ();
5226 for (thread_info
*tp
: all_non_exited_threads ())
5228 switch_to_thread_no_regs (tp
);
5230 if (tp
== event_thread
)
5233 fprintf_unfiltered (gdb_stdlog
,
5234 "infrun: restart threads: "
5235 "[%s] is event thread\n",
5236 target_pid_to_str (tp
->ptid
).c_str ());
5240 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5243 fprintf_unfiltered (gdb_stdlog
,
5244 "infrun: restart threads: "
5245 "[%s] not meant to be running\n",
5246 target_pid_to_str (tp
->ptid
).c_str ());
5253 fprintf_unfiltered (gdb_stdlog
,
5254 "infrun: restart threads: [%s] resumed\n",
5255 target_pid_to_str (tp
->ptid
).c_str ());
5256 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5260 if (thread_is_in_step_over_chain (tp
))
5263 fprintf_unfiltered (gdb_stdlog
,
5264 "infrun: restart threads: "
5265 "[%s] needs step-over\n",
5266 target_pid_to_str (tp
->ptid
).c_str ());
5267 gdb_assert (!tp
->resumed
);
5272 if (tp
->suspend
.waitstatus_pending_p
)
5275 fprintf_unfiltered (gdb_stdlog
,
5276 "infrun: restart threads: "
5277 "[%s] has pending status\n",
5278 target_pid_to_str (tp
->ptid
).c_str ());
5283 gdb_assert (!tp
->stop_requested
);
5285 /* If some thread needs to start a step-over at this point, it
5286 should still be in the step-over queue, and thus skipped
5288 if (thread_still_needs_step_over (tp
))
5290 internal_error (__FILE__
, __LINE__
,
5291 "thread [%s] needs a step-over, but not in "
5292 "step-over queue\n",
5293 target_pid_to_str (tp
->ptid
).c_str ());
5296 if (currently_stepping (tp
))
5299 fprintf_unfiltered (gdb_stdlog
,
5300 "infrun: restart threads: [%s] was stepping\n",
5301 target_pid_to_str (tp
->ptid
).c_str ());
5302 keep_going_stepped_thread (tp
);
5306 struct execution_control_state ecss
;
5307 struct execution_control_state
*ecs
= &ecss
;
5310 fprintf_unfiltered (gdb_stdlog
,
5311 "infrun: restart threads: [%s] continuing\n",
5312 target_pid_to_str (tp
->ptid
).c_str ());
5313 reset_ecs (ecs
, tp
);
5314 switch_to_thread (tp
);
5315 keep_going_pass_signal (ecs
);
5320 /* Callback for iterate_over_threads. Find a resumed thread that has
5321 a pending waitstatus. */
5324 resumed_thread_with_pending_status (struct thread_info
*tp
,
5328 && tp
->suspend
.waitstatus_pending_p
);
5331 /* Called when we get an event that may finish an in-line or
5332 out-of-line (displaced stepping) step-over started previously.
5333 Return true if the event is processed and we should go back to the
5334 event loop; false if the caller should continue processing the
5338 finish_step_over (struct execution_control_state
*ecs
)
5340 int had_step_over_info
;
5342 displaced_step_fixup (ecs
->event_thread
,
5343 ecs
->event_thread
->suspend
.stop_signal
);
5345 had_step_over_info
= step_over_info_valid_p ();
5347 if (had_step_over_info
)
5349 /* If we're stepping over a breakpoint with all threads locked,
5350 then only the thread that was stepped should be reporting
5352 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5354 clear_step_over_info ();
5357 if (!target_is_non_stop_p ())
5360 /* Start a new step-over in another thread if there's one that
5364 /* If we were stepping over a breakpoint before, and haven't started
5365 a new in-line step-over sequence, then restart all other threads
5366 (except the event thread). We can't do this in all-stop, as then
5367 e.g., we wouldn't be able to issue any other remote packet until
5368 these other threads stop. */
5369 if (had_step_over_info
&& !step_over_info_valid_p ())
5371 struct thread_info
*pending
;
5373 /* If we only have threads with pending statuses, the restart
5374 below won't restart any thread and so nothing re-inserts the
5375 breakpoint we just stepped over. But we need it inserted
5376 when we later process the pending events, otherwise if
5377 another thread has a pending event for this breakpoint too,
5378 we'd discard its event (because the breakpoint that
5379 originally caused the event was no longer inserted). */
5380 context_switch (ecs
);
5381 insert_breakpoints ();
5383 restart_threads (ecs
->event_thread
);
5385 /* If we have events pending, go through handle_inferior_event
5386 again, picking up a pending event at random. This avoids
5387 thread starvation. */
5389 /* But not if we just stepped over a watchpoint in order to let
5390 the instruction execute so we can evaluate its expression.
5391 The set of watchpoints that triggered is recorded in the
5392 breakpoint objects themselves (see bp->watchpoint_triggered).
5393 If we processed another event first, that other event could
5394 clobber this info. */
5395 if (ecs
->event_thread
->stepping_over_watchpoint
)
5398 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5400 if (pending
!= NULL
)
5402 struct thread_info
*tp
= ecs
->event_thread
;
5403 struct regcache
*regcache
;
5407 fprintf_unfiltered (gdb_stdlog
,
5408 "infrun: found resumed threads with "
5409 "pending events, saving status\n");
5412 gdb_assert (pending
!= tp
);
5414 /* Record the event thread's event for later. */
5415 save_waitstatus (tp
, &ecs
->ws
);
5416 /* This was cleared early, by handle_inferior_event. Set it
5417 so this pending event is considered by
5421 gdb_assert (!tp
->executing
);
5423 regcache
= get_thread_regcache (tp
);
5424 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5428 fprintf_unfiltered (gdb_stdlog
,
5429 "infrun: saved stop_pc=%s for %s "
5430 "(currently_stepping=%d)\n",
5431 paddress (target_gdbarch (),
5432 tp
->suspend
.stop_pc
),
5433 target_pid_to_str (tp
->ptid
).c_str (),
5434 currently_stepping (tp
));
5437 /* This in-line step-over finished; clear this so we won't
5438 start a new one. This is what handle_signal_stop would
5439 do, if we returned false. */
5440 tp
->stepping_over_breakpoint
= 0;
5442 /* Wake up the event loop again. */
5443 mark_async_event_handler (infrun_async_inferior_event_token
);
5445 prepare_to_wait (ecs
);
5453 /* Come here when the program has stopped with a signal. */
5456 handle_signal_stop (struct execution_control_state
*ecs
)
5458 struct frame_info
*frame
;
5459 struct gdbarch
*gdbarch
;
5460 int stopped_by_watchpoint
;
5461 enum stop_kind stop_soon
;
5464 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5466 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5468 /* Do we need to clean up the state of a thread that has
5469 completed a displaced single-step? (Doing so usually affects
5470 the PC, so do it here, before we set stop_pc.) */
5471 if (finish_step_over (ecs
))
5474 /* If we either finished a single-step or hit a breakpoint, but
5475 the user wanted this thread to be stopped, pretend we got a
5476 SIG0 (generic unsignaled stop). */
5477 if (ecs
->event_thread
->stop_requested
5478 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5479 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5481 ecs
->event_thread
->suspend
.stop_pc
5482 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5486 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5487 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5489 switch_to_thread (ecs
->event_thread
);
5491 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5492 paddress (reg_gdbarch
,
5493 ecs
->event_thread
->suspend
.stop_pc
));
5494 if (target_stopped_by_watchpoint ())
5498 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5500 if (target_stopped_data_address (current_top_target (), &addr
))
5501 fprintf_unfiltered (gdb_stdlog
,
5502 "infrun: stopped data address = %s\n",
5503 paddress (reg_gdbarch
, addr
));
5505 fprintf_unfiltered (gdb_stdlog
,
5506 "infrun: (no data address available)\n");
5510 /* This is originated from start_remote(), start_inferior() and
5511 shared libraries hook functions. */
5512 stop_soon
= get_inferior_stop_soon (ecs
);
5513 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5515 context_switch (ecs
);
5517 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5518 stop_print_frame
= 1;
5523 /* This originates from attach_command(). We need to overwrite
5524 the stop_signal here, because some kernels don't ignore a
5525 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5526 See more comments in inferior.h. On the other hand, if we
5527 get a non-SIGSTOP, report it to the user - assume the backend
5528 will handle the SIGSTOP if it should show up later.
5530 Also consider that the attach is complete when we see a
5531 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5532 target extended-remote report it instead of a SIGSTOP
5533 (e.g. gdbserver). We already rely on SIGTRAP being our
5534 signal, so this is no exception.
5536 Also consider that the attach is complete when we see a
5537 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5538 the target to stop all threads of the inferior, in case the
5539 low level attach operation doesn't stop them implicitly. If
5540 they weren't stopped implicitly, then the stub will report a
5541 GDB_SIGNAL_0, meaning: stopped for no particular reason
5542 other than GDB's request. */
5543 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5544 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5545 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5546 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5548 stop_print_frame
= 1;
5550 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5554 /* See if something interesting happened to the non-current thread. If
5555 so, then switch to that thread. */
5556 if (ecs
->ptid
!= inferior_ptid
)
5559 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5561 context_switch (ecs
);
5563 if (deprecated_context_hook
)
5564 deprecated_context_hook (ecs
->event_thread
->global_num
);
5567 /* At this point, get hold of the now-current thread's frame. */
5568 frame
= get_current_frame ();
5569 gdbarch
= get_frame_arch (frame
);
5571 /* Pull the single step breakpoints out of the target. */
5572 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5574 struct regcache
*regcache
;
5577 regcache
= get_thread_regcache (ecs
->event_thread
);
5578 const address_space
*aspace
= regcache
->aspace ();
5580 pc
= regcache_read_pc (regcache
);
5582 /* However, before doing so, if this single-step breakpoint was
5583 actually for another thread, set this thread up for moving
5585 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5588 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5592 fprintf_unfiltered (gdb_stdlog
,
5593 "infrun: [%s] hit another thread's "
5594 "single-step breakpoint\n",
5595 target_pid_to_str (ecs
->ptid
).c_str ());
5597 ecs
->hit_singlestep_breakpoint
= 1;
5604 fprintf_unfiltered (gdb_stdlog
,
5605 "infrun: [%s] hit its "
5606 "single-step breakpoint\n",
5607 target_pid_to_str (ecs
->ptid
).c_str ());
5611 delete_just_stopped_threads_single_step_breakpoints ();
5613 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5614 && ecs
->event_thread
->control
.trap_expected
5615 && ecs
->event_thread
->stepping_over_watchpoint
)
5616 stopped_by_watchpoint
= 0;
5618 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5620 /* If necessary, step over this watchpoint. We'll be back to display
5622 if (stopped_by_watchpoint
5623 && (target_have_steppable_watchpoint
5624 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5626 /* At this point, we are stopped at an instruction which has
5627 attempted to write to a piece of memory under control of
5628 a watchpoint. The instruction hasn't actually executed
5629 yet. If we were to evaluate the watchpoint expression
5630 now, we would get the old value, and therefore no change
5631 would seem to have occurred.
5633 In order to make watchpoints work `right', we really need
5634 to complete the memory write, and then evaluate the
5635 watchpoint expression. We do this by single-stepping the
5638 It may not be necessary to disable the watchpoint to step over
5639 it. For example, the PA can (with some kernel cooperation)
5640 single step over a watchpoint without disabling the watchpoint.
5642 It is far more common to need to disable a watchpoint to step
5643 the inferior over it. If we have non-steppable watchpoints,
5644 we must disable the current watchpoint; it's simplest to
5645 disable all watchpoints.
5647 Any breakpoint at PC must also be stepped over -- if there's
5648 one, it will have already triggered before the watchpoint
5649 triggered, and we either already reported it to the user, or
5650 it didn't cause a stop and we called keep_going. In either
5651 case, if there was a breakpoint at PC, we must be trying to
5653 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5658 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5659 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5660 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5661 ecs
->event_thread
->control
.stop_step
= 0;
5662 stop_print_frame
= 1;
5663 stopped_by_random_signal
= 0;
5664 bpstat stop_chain
= NULL
;
5666 /* Hide inlined functions starting here, unless we just performed stepi or
5667 nexti. After stepi and nexti, always show the innermost frame (not any
5668 inline function call sites). */
5669 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5671 const address_space
*aspace
5672 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5674 /* skip_inline_frames is expensive, so we avoid it if we can
5675 determine that the address is one where functions cannot have
5676 been inlined. This improves performance with inferiors that
5677 load a lot of shared libraries, because the solib event
5678 breakpoint is defined as the address of a function (i.e. not
5679 inline). Note that we have to check the previous PC as well
5680 as the current one to catch cases when we have just
5681 single-stepped off a breakpoint prior to reinstating it.
5682 Note that we're assuming that the code we single-step to is
5683 not inline, but that's not definitive: there's nothing
5684 preventing the event breakpoint function from containing
5685 inlined code, and the single-step ending up there. If the
5686 user had set a breakpoint on that inlined code, the missing
5687 skip_inline_frames call would break things. Fortunately
5688 that's an extremely unlikely scenario. */
5689 if (!pc_at_non_inline_function (aspace
,
5690 ecs
->event_thread
->suspend
.stop_pc
,
5692 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5693 && ecs
->event_thread
->control
.trap_expected
5694 && pc_at_non_inline_function (aspace
,
5695 ecs
->event_thread
->prev_pc
,
5698 stop_chain
= build_bpstat_chain (aspace
,
5699 ecs
->event_thread
->suspend
.stop_pc
,
5701 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5703 /* Re-fetch current thread's frame in case that invalidated
5705 frame
= get_current_frame ();
5706 gdbarch
= get_frame_arch (frame
);
5710 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5711 && ecs
->event_thread
->control
.trap_expected
5712 && gdbarch_single_step_through_delay_p (gdbarch
)
5713 && currently_stepping (ecs
->event_thread
))
5715 /* We're trying to step off a breakpoint. Turns out that we're
5716 also on an instruction that needs to be stepped multiple
5717 times before it's been fully executing. E.g., architectures
5718 with a delay slot. It needs to be stepped twice, once for
5719 the instruction and once for the delay slot. */
5720 int step_through_delay
5721 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5723 if (debug_infrun
&& step_through_delay
)
5724 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
5725 if (ecs
->event_thread
->control
.step_range_end
== 0
5726 && step_through_delay
)
5728 /* The user issued a continue when stopped at a breakpoint.
5729 Set up for another trap and get out of here. */
5730 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5734 else if (step_through_delay
)
5736 /* The user issued a step when stopped at a breakpoint.
5737 Maybe we should stop, maybe we should not - the delay
5738 slot *might* correspond to a line of source. In any
5739 case, don't decide that here, just set
5740 ecs->stepping_over_breakpoint, making sure we
5741 single-step again before breakpoints are re-inserted. */
5742 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5746 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5747 handles this event. */
5748 ecs
->event_thread
->control
.stop_bpstat
5749 = bpstat_stop_status (get_current_regcache ()->aspace (),
5750 ecs
->event_thread
->suspend
.stop_pc
,
5751 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
5753 /* Following in case break condition called a
5755 stop_print_frame
= 1;
5757 /* This is where we handle "moribund" watchpoints. Unlike
5758 software breakpoints traps, hardware watchpoint traps are
5759 always distinguishable from random traps. If no high-level
5760 watchpoint is associated with the reported stop data address
5761 anymore, then the bpstat does not explain the signal ---
5762 simply make sure to ignore it if `stopped_by_watchpoint' is
5766 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5767 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5769 && stopped_by_watchpoint
)
5770 fprintf_unfiltered (gdb_stdlog
,
5771 "infrun: no user watchpoint explains "
5772 "watchpoint SIGTRAP, ignoring\n");
5774 /* NOTE: cagney/2003-03-29: These checks for a random signal
5775 at one stage in the past included checks for an inferior
5776 function call's call dummy's return breakpoint. The original
5777 comment, that went with the test, read:
5779 ``End of a stack dummy. Some systems (e.g. Sony news) give
5780 another signal besides SIGTRAP, so check here as well as
5783 If someone ever tries to get call dummys on a
5784 non-executable stack to work (where the target would stop
5785 with something like a SIGSEGV), then those tests might need
5786 to be re-instated. Given, however, that the tests were only
5787 enabled when momentary breakpoints were not being used, I
5788 suspect that it won't be the case.
5790 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5791 be necessary for call dummies on a non-executable stack on
5794 /* See if the breakpoints module can explain the signal. */
5796 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5797 ecs
->event_thread
->suspend
.stop_signal
);
5799 /* Maybe this was a trap for a software breakpoint that has since
5801 if (random_signal
&& target_stopped_by_sw_breakpoint ())
5803 if (program_breakpoint_here_p (gdbarch
,
5804 ecs
->event_thread
->suspend
.stop_pc
))
5806 struct regcache
*regcache
;
5809 /* Re-adjust PC to what the program would see if GDB was not
5811 regcache
= get_thread_regcache (ecs
->event_thread
);
5812 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
5815 gdb::optional
<scoped_restore_tmpl
<int>>
5816 restore_operation_disable
;
5818 if (record_full_is_used ())
5819 restore_operation_disable
.emplace
5820 (record_full_gdb_operation_disable_set ());
5822 regcache_write_pc (regcache
,
5823 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
5828 /* A delayed software breakpoint event. Ignore the trap. */
5830 fprintf_unfiltered (gdb_stdlog
,
5831 "infrun: delayed software breakpoint "
5832 "trap, ignoring\n");
5837 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5838 has since been removed. */
5839 if (random_signal
&& target_stopped_by_hw_breakpoint ())
5841 /* A delayed hardware breakpoint event. Ignore the trap. */
5843 fprintf_unfiltered (gdb_stdlog
,
5844 "infrun: delayed hardware breakpoint/watchpoint "
5845 "trap, ignoring\n");
5849 /* If not, perhaps stepping/nexting can. */
5851 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5852 && currently_stepping (ecs
->event_thread
));
5854 /* Perhaps the thread hit a single-step breakpoint of _another_
5855 thread. Single-step breakpoints are transparent to the
5856 breakpoints module. */
5858 random_signal
= !ecs
->hit_singlestep_breakpoint
;
5860 /* No? Perhaps we got a moribund watchpoint. */
5862 random_signal
= !stopped_by_watchpoint
;
5864 /* Always stop if the user explicitly requested this thread to
5866 if (ecs
->event_thread
->stop_requested
)
5870 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
5873 /* For the program's own signals, act according to
5874 the signal handling tables. */
5878 /* Signal not for debugging purposes. */
5879 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
5880 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
5883 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
5884 gdb_signal_to_symbol_string (stop_signal
));
5886 stopped_by_random_signal
= 1;
5888 /* Always stop on signals if we're either just gaining control
5889 of the program, or the user explicitly requested this thread
5890 to remain stopped. */
5891 if (stop_soon
!= NO_STOP_QUIETLY
5892 || ecs
->event_thread
->stop_requested
5894 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
5900 /* Notify observers the signal has "handle print" set. Note we
5901 returned early above if stopping; normal_stop handles the
5902 printing in that case. */
5903 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
5905 /* The signal table tells us to print about this signal. */
5906 target_terminal::ours_for_output ();
5907 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
5908 target_terminal::inferior ();
5911 /* Clear the signal if it should not be passed. */
5912 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
5913 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5915 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
5916 && ecs
->event_thread
->control
.trap_expected
5917 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5919 /* We were just starting a new sequence, attempting to
5920 single-step off of a breakpoint and expecting a SIGTRAP.
5921 Instead this signal arrives. This signal will take us out
5922 of the stepping range so GDB needs to remember to, when
5923 the signal handler returns, resume stepping off that
5925 /* To simplify things, "continue" is forced to use the same
5926 code paths as single-step - set a breakpoint at the
5927 signal return address and then, once hit, step off that
5930 fprintf_unfiltered (gdb_stdlog
,
5931 "infrun: signal arrived while stepping over "
5934 insert_hp_step_resume_breakpoint_at_frame (frame
);
5935 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5936 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5937 ecs
->event_thread
->control
.trap_expected
= 0;
5939 /* If we were nexting/stepping some other thread, switch to
5940 it, so that we don't continue it, losing control. */
5941 if (!switch_back_to_stepped_thread (ecs
))
5946 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
5947 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
5949 || ecs
->event_thread
->control
.step_range_end
== 1)
5950 && frame_id_eq (get_stack_frame_id (frame
),
5951 ecs
->event_thread
->control
.step_stack_frame_id
)
5952 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5954 /* The inferior is about to take a signal that will take it
5955 out of the single step range. Set a breakpoint at the
5956 current PC (which is presumably where the signal handler
5957 will eventually return) and then allow the inferior to
5960 Note that this is only needed for a signal delivered
5961 while in the single-step range. Nested signals aren't a
5962 problem as they eventually all return. */
5964 fprintf_unfiltered (gdb_stdlog
,
5965 "infrun: signal may take us out of "
5966 "single-step range\n");
5968 clear_step_over_info ();
5969 insert_hp_step_resume_breakpoint_at_frame (frame
);
5970 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5971 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5972 ecs
->event_thread
->control
.trap_expected
= 0;
5977 /* Note: step_resume_breakpoint may be non-NULL. This occurs
5978 when either there's a nested signal, or when there's a
5979 pending signal enabled just as the signal handler returns
5980 (leaving the inferior at the step-resume-breakpoint without
5981 actually executing it). Either way continue until the
5982 breakpoint is really hit. */
5984 if (!switch_back_to_stepped_thread (ecs
))
5987 fprintf_unfiltered (gdb_stdlog
,
5988 "infrun: random signal, keep going\n");
5995 process_event_stop_test (ecs
);
5998 /* Come here when we've got some debug event / signal we can explain
5999 (IOW, not a random signal), and test whether it should cause a
6000 stop, or whether we should resume the inferior (transparently).
6001 E.g., could be a breakpoint whose condition evaluates false; we
6002 could be still stepping within the line; etc. */
6005 process_event_stop_test (struct execution_control_state
*ecs
)
6007 struct symtab_and_line stop_pc_sal
;
6008 struct frame_info
*frame
;
6009 struct gdbarch
*gdbarch
;
6010 CORE_ADDR jmp_buf_pc
;
6011 struct bpstat_what what
;
6013 /* Handle cases caused by hitting a breakpoint. */
6015 frame
= get_current_frame ();
6016 gdbarch
= get_frame_arch (frame
);
6018 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6020 if (what
.call_dummy
)
6022 stop_stack_dummy
= what
.call_dummy
;
6025 /* A few breakpoint types have callbacks associated (e.g.,
6026 bp_jit_event). Run them now. */
6027 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6029 /* If we hit an internal event that triggers symbol changes, the
6030 current frame will be invalidated within bpstat_what (e.g., if we
6031 hit an internal solib event). Re-fetch it. */
6032 frame
= get_current_frame ();
6033 gdbarch
= get_frame_arch (frame
);
6035 switch (what
.main_action
)
6037 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6038 /* If we hit the breakpoint at longjmp while stepping, we
6039 install a momentary breakpoint at the target of the
6043 fprintf_unfiltered (gdb_stdlog
,
6044 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6046 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6048 if (what
.is_longjmp
)
6050 struct value
*arg_value
;
6052 /* If we set the longjmp breakpoint via a SystemTap probe,
6053 then use it to extract the arguments. The destination PC
6054 is the third argument to the probe. */
6055 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6058 jmp_buf_pc
= value_as_address (arg_value
);
6059 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6061 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6062 || !gdbarch_get_longjmp_target (gdbarch
,
6063 frame
, &jmp_buf_pc
))
6066 fprintf_unfiltered (gdb_stdlog
,
6067 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6068 "(!gdbarch_get_longjmp_target)\n");
6073 /* Insert a breakpoint at resume address. */
6074 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6077 check_exception_resume (ecs
, frame
);
6081 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6083 struct frame_info
*init_frame
;
6085 /* There are several cases to consider.
6087 1. The initiating frame no longer exists. In this case we
6088 must stop, because the exception or longjmp has gone too
6091 2. The initiating frame exists, and is the same as the
6092 current frame. We stop, because the exception or longjmp
6095 3. The initiating frame exists and is different from the
6096 current frame. This means the exception or longjmp has
6097 been caught beneath the initiating frame, so keep going.
6099 4. longjmp breakpoint has been placed just to protect
6100 against stale dummy frames and user is not interested in
6101 stopping around longjmps. */
6104 fprintf_unfiltered (gdb_stdlog
,
6105 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6107 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6109 delete_exception_resume_breakpoint (ecs
->event_thread
);
6111 if (what
.is_longjmp
)
6113 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6115 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6123 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6127 struct frame_id current_id
6128 = get_frame_id (get_current_frame ());
6129 if (frame_id_eq (current_id
,
6130 ecs
->event_thread
->initiating_frame
))
6132 /* Case 2. Fall through. */
6142 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6144 delete_step_resume_breakpoint (ecs
->event_thread
);
6146 end_stepping_range (ecs
);
6150 case BPSTAT_WHAT_SINGLE
:
6152 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6153 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6154 /* Still need to check other stuff, at least the case where we
6155 are stepping and step out of the right range. */
6158 case BPSTAT_WHAT_STEP_RESUME
:
6160 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6162 delete_step_resume_breakpoint (ecs
->event_thread
);
6163 if (ecs
->event_thread
->control
.proceed_to_finish
6164 && execution_direction
== EXEC_REVERSE
)
6166 struct thread_info
*tp
= ecs
->event_thread
;
6168 /* We are finishing a function in reverse, and just hit the
6169 step-resume breakpoint at the start address of the
6170 function, and we're almost there -- just need to back up
6171 by one more single-step, which should take us back to the
6173 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6177 fill_in_stop_func (gdbarch
, ecs
);
6178 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6179 && execution_direction
== EXEC_REVERSE
)
6181 /* We are stepping over a function call in reverse, and just
6182 hit the step-resume breakpoint at the start address of
6183 the function. Go back to single-stepping, which should
6184 take us back to the function call. */
6185 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6191 case BPSTAT_WHAT_STOP_NOISY
:
6193 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6194 stop_print_frame
= 1;
6196 /* Assume the thread stopped for a breapoint. We'll still check
6197 whether a/the breakpoint is there when the thread is next
6199 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6204 case BPSTAT_WHAT_STOP_SILENT
:
6206 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6207 stop_print_frame
= 0;
6209 /* Assume the thread stopped for a breapoint. We'll still check
6210 whether a/the breakpoint is there when the thread is next
6212 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6216 case BPSTAT_WHAT_HP_STEP_RESUME
:
6218 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6220 delete_step_resume_breakpoint (ecs
->event_thread
);
6221 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6223 /* Back when the step-resume breakpoint was inserted, we
6224 were trying to single-step off a breakpoint. Go back to
6226 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6227 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6233 case BPSTAT_WHAT_KEEP_CHECKING
:
6237 /* If we stepped a permanent breakpoint and we had a high priority
6238 step-resume breakpoint for the address we stepped, but we didn't
6239 hit it, then we must have stepped into the signal handler. The
6240 step-resume was only necessary to catch the case of _not_
6241 stepping into the handler, so delete it, and fall through to
6242 checking whether the step finished. */
6243 if (ecs
->event_thread
->stepped_breakpoint
)
6245 struct breakpoint
*sr_bp
6246 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6249 && sr_bp
->loc
->permanent
6250 && sr_bp
->type
== bp_hp_step_resume
6251 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6254 fprintf_unfiltered (gdb_stdlog
,
6255 "infrun: stepped permanent breakpoint, stopped in "
6257 delete_step_resume_breakpoint (ecs
->event_thread
);
6258 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6262 /* We come here if we hit a breakpoint but should not stop for it.
6263 Possibly we also were stepping and should stop for that. So fall
6264 through and test for stepping. But, if not stepping, do not
6267 /* In all-stop mode, if we're currently stepping but have stopped in
6268 some other thread, we need to switch back to the stepped thread. */
6269 if (switch_back_to_stepped_thread (ecs
))
6272 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6275 fprintf_unfiltered (gdb_stdlog
,
6276 "infrun: step-resume breakpoint is inserted\n");
6278 /* Having a step-resume breakpoint overrides anything
6279 else having to do with stepping commands until
6280 that breakpoint is reached. */
6285 if (ecs
->event_thread
->control
.step_range_end
== 0)
6288 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6289 /* Likewise if we aren't even stepping. */
6294 /* Re-fetch current thread's frame in case the code above caused
6295 the frame cache to be re-initialized, making our FRAME variable
6296 a dangling pointer. */
6297 frame
= get_current_frame ();
6298 gdbarch
= get_frame_arch (frame
);
6299 fill_in_stop_func (gdbarch
, ecs
);
6301 /* If stepping through a line, keep going if still within it.
6303 Note that step_range_end is the address of the first instruction
6304 beyond the step range, and NOT the address of the last instruction
6307 Note also that during reverse execution, we may be stepping
6308 through a function epilogue and therefore must detect when
6309 the current-frame changes in the middle of a line. */
6311 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6313 && (execution_direction
!= EXEC_REVERSE
6314 || frame_id_eq (get_frame_id (frame
),
6315 ecs
->event_thread
->control
.step_frame_id
)))
6319 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6320 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6321 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6323 /* Tentatively re-enable range stepping; `resume' disables it if
6324 necessary (e.g., if we're stepping over a breakpoint or we
6325 have software watchpoints). */
6326 ecs
->event_thread
->control
.may_range_step
= 1;
6328 /* When stepping backward, stop at beginning of line range
6329 (unless it's the function entry point, in which case
6330 keep going back to the call point). */
6331 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6332 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6333 && stop_pc
!= ecs
->stop_func_start
6334 && execution_direction
== EXEC_REVERSE
)
6335 end_stepping_range (ecs
);
6342 /* We stepped out of the stepping range. */
6344 /* If we are stepping at the source level and entered the runtime
6345 loader dynamic symbol resolution code...
6347 EXEC_FORWARD: we keep on single stepping until we exit the run
6348 time loader code and reach the callee's address.
6350 EXEC_REVERSE: we've already executed the callee (backward), and
6351 the runtime loader code is handled just like any other
6352 undebuggable function call. Now we need only keep stepping
6353 backward through the trampoline code, and that's handled further
6354 down, so there is nothing for us to do here. */
6356 if (execution_direction
!= EXEC_REVERSE
6357 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6358 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6360 CORE_ADDR pc_after_resolver
=
6361 gdbarch_skip_solib_resolver (gdbarch
,
6362 ecs
->event_thread
->suspend
.stop_pc
);
6365 fprintf_unfiltered (gdb_stdlog
,
6366 "infrun: stepped into dynsym resolve code\n");
6368 if (pc_after_resolver
)
6370 /* Set up a step-resume breakpoint at the address
6371 indicated by SKIP_SOLIB_RESOLVER. */
6372 symtab_and_line sr_sal
;
6373 sr_sal
.pc
= pc_after_resolver
;
6374 sr_sal
.pspace
= get_frame_program_space (frame
);
6376 insert_step_resume_breakpoint_at_sal (gdbarch
,
6377 sr_sal
, null_frame_id
);
6384 /* Step through an indirect branch thunk. */
6385 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6386 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6387 ecs
->event_thread
->suspend
.stop_pc
))
6390 fprintf_unfiltered (gdb_stdlog
,
6391 "infrun: stepped into indirect branch thunk\n");
6396 if (ecs
->event_thread
->control
.step_range_end
!= 1
6397 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6398 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6399 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6402 fprintf_unfiltered (gdb_stdlog
,
6403 "infrun: stepped into signal trampoline\n");
6404 /* The inferior, while doing a "step" or "next", has ended up in
6405 a signal trampoline (either by a signal being delivered or by
6406 the signal handler returning). Just single-step until the
6407 inferior leaves the trampoline (either by calling the handler
6413 /* If we're in the return path from a shared library trampoline,
6414 we want to proceed through the trampoline when stepping. */
6415 /* macro/2012-04-25: This needs to come before the subroutine
6416 call check below as on some targets return trampolines look
6417 like subroutine calls (MIPS16 return thunks). */
6418 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6419 ecs
->event_thread
->suspend
.stop_pc
,
6420 ecs
->stop_func_name
)
6421 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6423 /* Determine where this trampoline returns. */
6424 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6425 CORE_ADDR real_stop_pc
6426 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6429 fprintf_unfiltered (gdb_stdlog
,
6430 "infrun: stepped into solib return tramp\n");
6432 /* Only proceed through if we know where it's going. */
6435 /* And put the step-breakpoint there and go until there. */
6436 symtab_and_line sr_sal
;
6437 sr_sal
.pc
= real_stop_pc
;
6438 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6439 sr_sal
.pspace
= get_frame_program_space (frame
);
6441 /* Do not specify what the fp should be when we stop since
6442 on some machines the prologue is where the new fp value
6444 insert_step_resume_breakpoint_at_sal (gdbarch
,
6445 sr_sal
, null_frame_id
);
6447 /* Restart without fiddling with the step ranges or
6454 /* Check for subroutine calls. The check for the current frame
6455 equalling the step ID is not necessary - the check of the
6456 previous frame's ID is sufficient - but it is a common case and
6457 cheaper than checking the previous frame's ID.
6459 NOTE: frame_id_eq will never report two invalid frame IDs as
6460 being equal, so to get into this block, both the current and
6461 previous frame must have valid frame IDs. */
6462 /* The outer_frame_id check is a heuristic to detect stepping
6463 through startup code. If we step over an instruction which
6464 sets the stack pointer from an invalid value to a valid value,
6465 we may detect that as a subroutine call from the mythical
6466 "outermost" function. This could be fixed by marking
6467 outermost frames as !stack_p,code_p,special_p. Then the
6468 initial outermost frame, before sp was valid, would
6469 have code_addr == &_start. See the comment in frame_id_eq
6471 if (!frame_id_eq (get_stack_frame_id (frame
),
6472 ecs
->event_thread
->control
.step_stack_frame_id
)
6473 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6474 ecs
->event_thread
->control
.step_stack_frame_id
)
6475 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6477 || (ecs
->event_thread
->control
.step_start_function
6478 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6480 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6481 CORE_ADDR real_stop_pc
;
6484 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6486 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6488 /* I presume that step_over_calls is only 0 when we're
6489 supposed to be stepping at the assembly language level
6490 ("stepi"). Just stop. */
6491 /* And this works the same backward as frontward. MVS */
6492 end_stepping_range (ecs
);
6496 /* Reverse stepping through solib trampolines. */
6498 if (execution_direction
== EXEC_REVERSE
6499 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6500 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6501 || (ecs
->stop_func_start
== 0
6502 && in_solib_dynsym_resolve_code (stop_pc
))))
6504 /* Any solib trampoline code can be handled in reverse
6505 by simply continuing to single-step. We have already
6506 executed the solib function (backwards), and a few
6507 steps will take us back through the trampoline to the
6513 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6515 /* We're doing a "next".
6517 Normal (forward) execution: set a breakpoint at the
6518 callee's return address (the address at which the caller
6521 Reverse (backward) execution. set the step-resume
6522 breakpoint at the start of the function that we just
6523 stepped into (backwards), and continue to there. When we
6524 get there, we'll need to single-step back to the caller. */
6526 if (execution_direction
== EXEC_REVERSE
)
6528 /* If we're already at the start of the function, we've either
6529 just stepped backward into a single instruction function,
6530 or stepped back out of a signal handler to the first instruction
6531 of the function. Just keep going, which will single-step back
6533 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6535 /* Normal function call return (static or dynamic). */
6536 symtab_and_line sr_sal
;
6537 sr_sal
.pc
= ecs
->stop_func_start
;
6538 sr_sal
.pspace
= get_frame_program_space (frame
);
6539 insert_step_resume_breakpoint_at_sal (gdbarch
,
6540 sr_sal
, null_frame_id
);
6544 insert_step_resume_breakpoint_at_caller (frame
);
6550 /* If we are in a function call trampoline (a stub between the
6551 calling routine and the real function), locate the real
6552 function. That's what tells us (a) whether we want to step
6553 into it at all, and (b) what prologue we want to run to the
6554 end of, if we do step into it. */
6555 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6556 if (real_stop_pc
== 0)
6557 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6558 if (real_stop_pc
!= 0)
6559 ecs
->stop_func_start
= real_stop_pc
;
6561 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6563 symtab_and_line sr_sal
;
6564 sr_sal
.pc
= ecs
->stop_func_start
;
6565 sr_sal
.pspace
= get_frame_program_space (frame
);
6567 insert_step_resume_breakpoint_at_sal (gdbarch
,
6568 sr_sal
, null_frame_id
);
6573 /* If we have line number information for the function we are
6574 thinking of stepping into and the function isn't on the skip
6577 If there are several symtabs at that PC (e.g. with include
6578 files), just want to know whether *any* of them have line
6579 numbers. find_pc_line handles this. */
6581 struct symtab_and_line tmp_sal
;
6583 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6584 if (tmp_sal
.line
!= 0
6585 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6587 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6589 if (execution_direction
== EXEC_REVERSE
)
6590 handle_step_into_function_backward (gdbarch
, ecs
);
6592 handle_step_into_function (gdbarch
, ecs
);
6597 /* If we have no line number and the step-stop-if-no-debug is
6598 set, we stop the step so that the user has a chance to switch
6599 in assembly mode. */
6600 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6601 && step_stop_if_no_debug
)
6603 end_stepping_range (ecs
);
6607 if (execution_direction
== EXEC_REVERSE
)
6609 /* If we're already at the start of the function, we've either just
6610 stepped backward into a single instruction function without line
6611 number info, or stepped back out of a signal handler to the first
6612 instruction of the function without line number info. Just keep
6613 going, which will single-step back to the caller. */
6614 if (ecs
->stop_func_start
!= stop_pc
)
6616 /* Set a breakpoint at callee's start address.
6617 From there we can step once and be back in the caller. */
6618 symtab_and_line sr_sal
;
6619 sr_sal
.pc
= ecs
->stop_func_start
;
6620 sr_sal
.pspace
= get_frame_program_space (frame
);
6621 insert_step_resume_breakpoint_at_sal (gdbarch
,
6622 sr_sal
, null_frame_id
);
6626 /* Set a breakpoint at callee's return address (the address
6627 at which the caller will resume). */
6628 insert_step_resume_breakpoint_at_caller (frame
);
6634 /* Reverse stepping through solib trampolines. */
6636 if (execution_direction
== EXEC_REVERSE
6637 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6639 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6641 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6642 || (ecs
->stop_func_start
== 0
6643 && in_solib_dynsym_resolve_code (stop_pc
)))
6645 /* Any solib trampoline code can be handled in reverse
6646 by simply continuing to single-step. We have already
6647 executed the solib function (backwards), and a few
6648 steps will take us back through the trampoline to the
6653 else if (in_solib_dynsym_resolve_code (stop_pc
))
6655 /* Stepped backward into the solib dynsym resolver.
6656 Set a breakpoint at its start and continue, then
6657 one more step will take us out. */
6658 symtab_and_line sr_sal
;
6659 sr_sal
.pc
= ecs
->stop_func_start
;
6660 sr_sal
.pspace
= get_frame_program_space (frame
);
6661 insert_step_resume_breakpoint_at_sal (gdbarch
,
6662 sr_sal
, null_frame_id
);
6668 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6670 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6671 the trampoline processing logic, however, there are some trampolines
6672 that have no names, so we should do trampoline handling first. */
6673 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6674 && ecs
->stop_func_name
== NULL
6675 && stop_pc_sal
.line
== 0)
6678 fprintf_unfiltered (gdb_stdlog
,
6679 "infrun: stepped into undebuggable function\n");
6681 /* The inferior just stepped into, or returned to, an
6682 undebuggable function (where there is no debugging information
6683 and no line number corresponding to the address where the
6684 inferior stopped). Since we want to skip this kind of code,
6685 we keep going until the inferior returns from this
6686 function - unless the user has asked us not to (via
6687 set step-mode) or we no longer know how to get back
6688 to the call site. */
6689 if (step_stop_if_no_debug
6690 || !frame_id_p (frame_unwind_caller_id (frame
)))
6692 /* If we have no line number and the step-stop-if-no-debug
6693 is set, we stop the step so that the user has a chance to
6694 switch in assembly mode. */
6695 end_stepping_range (ecs
);
6700 /* Set a breakpoint at callee's return address (the address
6701 at which the caller will resume). */
6702 insert_step_resume_breakpoint_at_caller (frame
);
6708 if (ecs
->event_thread
->control
.step_range_end
== 1)
6710 /* It is stepi or nexti. We always want to stop stepping after
6713 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
6714 end_stepping_range (ecs
);
6718 if (stop_pc_sal
.line
== 0)
6720 /* We have no line number information. That means to stop
6721 stepping (does this always happen right after one instruction,
6722 when we do "s" in a function with no line numbers,
6723 or can this happen as a result of a return or longjmp?). */
6725 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
6726 end_stepping_range (ecs
);
6730 /* Look for "calls" to inlined functions, part one. If the inline
6731 frame machinery detected some skipped call sites, we have entered
6732 a new inline function. */
6734 if (frame_id_eq (get_frame_id (get_current_frame ()),
6735 ecs
->event_thread
->control
.step_frame_id
)
6736 && inline_skipped_frames (ecs
->event_thread
))
6739 fprintf_unfiltered (gdb_stdlog
,
6740 "infrun: stepped into inlined function\n");
6742 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6744 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6746 /* For "step", we're going to stop. But if the call site
6747 for this inlined function is on the same source line as
6748 we were previously stepping, go down into the function
6749 first. Otherwise stop at the call site. */
6751 if (call_sal
.line
== ecs
->event_thread
->current_line
6752 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6754 step_into_inline_frame (ecs
->event_thread
);
6755 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6762 end_stepping_range (ecs
);
6767 /* For "next", we should stop at the call site if it is on a
6768 different source line. Otherwise continue through the
6769 inlined function. */
6770 if (call_sal
.line
== ecs
->event_thread
->current_line
6771 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6774 end_stepping_range (ecs
);
6779 /* Look for "calls" to inlined functions, part two. If we are still
6780 in the same real function we were stepping through, but we have
6781 to go further up to find the exact frame ID, we are stepping
6782 through a more inlined call beyond its call site. */
6784 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6785 && !frame_id_eq (get_frame_id (get_current_frame ()),
6786 ecs
->event_thread
->control
.step_frame_id
)
6787 && stepped_in_from (get_current_frame (),
6788 ecs
->event_thread
->control
.step_frame_id
))
6791 fprintf_unfiltered (gdb_stdlog
,
6792 "infrun: stepping through inlined function\n");
6794 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
6795 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6798 end_stepping_range (ecs
);
6802 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
6803 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
6804 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
6806 /* We are at the start of a different line. So stop. Note that
6807 we don't stop if we step into the middle of a different line.
6808 That is said to make things like for (;;) statements work
6811 fprintf_unfiltered (gdb_stdlog
,
6812 "infrun: stepped to a different line\n");
6813 end_stepping_range (ecs
);
6817 /* We aren't done stepping.
6819 Optimize by setting the stepping range to the line.
6820 (We might not be in the original line, but if we entered a
6821 new line in mid-statement, we continue stepping. This makes
6822 things like for(;;) statements work better.) */
6824 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
6825 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
6826 ecs
->event_thread
->control
.may_range_step
= 1;
6827 set_step_info (frame
, stop_pc_sal
);
6830 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
6834 /* In all-stop mode, if we're currently stepping but have stopped in
6835 some other thread, we may need to switch back to the stepped
6836 thread. Returns true we set the inferior running, false if we left
6837 it stopped (and the event needs further processing). */
6840 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
6842 if (!target_is_non_stop_p ())
6844 struct thread_info
*stepping_thread
;
6846 /* If any thread is blocked on some internal breakpoint, and we
6847 simply need to step over that breakpoint to get it going
6848 again, do that first. */
6850 /* However, if we see an event for the stepping thread, then we
6851 know all other threads have been moved past their breakpoints
6852 already. Let the caller check whether the step is finished,
6853 etc., before deciding to move it past a breakpoint. */
6854 if (ecs
->event_thread
->control
.step_range_end
!= 0)
6857 /* Check if the current thread is blocked on an incomplete
6858 step-over, interrupted by a random signal. */
6859 if (ecs
->event_thread
->control
.trap_expected
6860 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
6864 fprintf_unfiltered (gdb_stdlog
,
6865 "infrun: need to finish step-over of [%s]\n",
6866 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
6872 /* Check if the current thread is blocked by a single-step
6873 breakpoint of another thread. */
6874 if (ecs
->hit_singlestep_breakpoint
)
6878 fprintf_unfiltered (gdb_stdlog
,
6879 "infrun: need to step [%s] over single-step "
6881 target_pid_to_str (ecs
->ptid
).c_str ());
6887 /* If this thread needs yet another step-over (e.g., stepping
6888 through a delay slot), do it first before moving on to
6890 if (thread_still_needs_step_over (ecs
->event_thread
))
6894 fprintf_unfiltered (gdb_stdlog
,
6895 "infrun: thread [%s] still needs step-over\n",
6896 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
6902 /* If scheduler locking applies even if not stepping, there's no
6903 need to walk over threads. Above we've checked whether the
6904 current thread is stepping. If some other thread not the
6905 event thread is stepping, then it must be that scheduler
6906 locking is not in effect. */
6907 if (schedlock_applies (ecs
->event_thread
))
6910 /* Otherwise, we no longer expect a trap in the current thread.
6911 Clear the trap_expected flag before switching back -- this is
6912 what keep_going does as well, if we call it. */
6913 ecs
->event_thread
->control
.trap_expected
= 0;
6915 /* Likewise, clear the signal if it should not be passed. */
6916 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
6917 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6919 /* Do all pending step-overs before actually proceeding with
6921 if (start_step_over ())
6923 prepare_to_wait (ecs
);
6927 /* Look for the stepping/nexting thread. */
6928 stepping_thread
= NULL
;
6930 for (thread_info
*tp
: all_non_exited_threads ())
6932 switch_to_thread_no_regs (tp
);
6934 /* Ignore threads of processes the caller is not
6937 && tp
->ptid
.pid () != ecs
->ptid
.pid ())
6940 /* When stepping over a breakpoint, we lock all threads
6941 except the one that needs to move past the breakpoint.
6942 If a non-event thread has this set, the "incomplete
6943 step-over" check above should have caught it earlier. */
6944 if (tp
->control
.trap_expected
)
6946 internal_error (__FILE__
, __LINE__
,
6947 "[%s] has inconsistent state: "
6948 "trap_expected=%d\n",
6949 target_pid_to_str (tp
->ptid
).c_str (),
6950 tp
->control
.trap_expected
);
6953 /* Did we find the stepping thread? */
6954 if (tp
->control
.step_range_end
)
6956 /* Yep. There should only one though. */
6957 gdb_assert (stepping_thread
== NULL
);
6959 /* The event thread is handled at the top, before we
6961 gdb_assert (tp
!= ecs
->event_thread
);
6963 /* If some thread other than the event thread is
6964 stepping, then scheduler locking can't be in effect,
6965 otherwise we wouldn't have resumed the current event
6966 thread in the first place. */
6967 gdb_assert (!schedlock_applies (tp
));
6969 stepping_thread
= tp
;
6973 if (stepping_thread
!= NULL
)
6976 fprintf_unfiltered (gdb_stdlog
,
6977 "infrun: switching back to stepped thread\n");
6979 if (keep_going_stepped_thread (stepping_thread
))
6981 prepare_to_wait (ecs
);
6986 switch_to_thread (ecs
->event_thread
);
6992 /* Set a previously stepped thread back to stepping. Returns true on
6993 success, false if the resume is not possible (e.g., the thread
6997 keep_going_stepped_thread (struct thread_info
*tp
)
6999 struct frame_info
*frame
;
7000 struct execution_control_state ecss
;
7001 struct execution_control_state
*ecs
= &ecss
;
7003 /* If the stepping thread exited, then don't try to switch back and
7004 resume it, which could fail in several different ways depending
7005 on the target. Instead, just keep going.
7007 We can find a stepping dead thread in the thread list in two
7010 - The target supports thread exit events, and when the target
7011 tries to delete the thread from the thread list, inferior_ptid
7012 pointed at the exiting thread. In such case, calling
7013 delete_thread does not really remove the thread from the list;
7014 instead, the thread is left listed, with 'exited' state.
7016 - The target's debug interface does not support thread exit
7017 events, and so we have no idea whatsoever if the previously
7018 stepping thread is still alive. For that reason, we need to
7019 synchronously query the target now. */
7021 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7024 fprintf_unfiltered (gdb_stdlog
,
7025 "infrun: not resuming previously "
7026 "stepped thread, it has vanished\n");
7033 fprintf_unfiltered (gdb_stdlog
,
7034 "infrun: resuming previously stepped thread\n");
7036 reset_ecs (ecs
, tp
);
7037 switch_to_thread (tp
);
7039 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7040 frame
= get_current_frame ();
7042 /* If the PC of the thread we were trying to single-step has
7043 changed, then that thread has trapped or been signaled, but the
7044 event has not been reported to GDB yet. Re-poll the target
7045 looking for this particular thread's event (i.e. temporarily
7046 enable schedlock) by:
7048 - setting a break at the current PC
7049 - resuming that particular thread, only (by setting trap
7052 This prevents us continuously moving the single-step breakpoint
7053 forward, one instruction at a time, overstepping. */
7055 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7060 fprintf_unfiltered (gdb_stdlog
,
7061 "infrun: expected thread advanced also (%s -> %s)\n",
7062 paddress (target_gdbarch (), tp
->prev_pc
),
7063 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7065 /* Clear the info of the previous step-over, as it's no longer
7066 valid (if the thread was trying to step over a breakpoint, it
7067 has already succeeded). It's what keep_going would do too,
7068 if we called it. Do this before trying to insert the sss
7069 breakpoint, otherwise if we were previously trying to step
7070 over this exact address in another thread, the breakpoint is
7072 clear_step_over_info ();
7073 tp
->control
.trap_expected
= 0;
7075 insert_single_step_breakpoint (get_frame_arch (frame
),
7076 get_frame_address_space (frame
),
7077 tp
->suspend
.stop_pc
);
7080 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7081 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7086 fprintf_unfiltered (gdb_stdlog
,
7087 "infrun: expected thread still hasn't advanced\n");
7089 keep_going_pass_signal (ecs
);
7094 /* Is thread TP in the middle of (software or hardware)
7095 single-stepping? (Note the result of this function must never be
7096 passed directly as target_resume's STEP parameter.) */
7099 currently_stepping (struct thread_info
*tp
)
7101 return ((tp
->control
.step_range_end
7102 && tp
->control
.step_resume_breakpoint
== NULL
)
7103 || tp
->control
.trap_expected
7104 || tp
->stepped_breakpoint
7105 || bpstat_should_step ());
7108 /* Inferior has stepped into a subroutine call with source code that
7109 we should not step over. Do step to the first line of code in
7113 handle_step_into_function (struct gdbarch
*gdbarch
,
7114 struct execution_control_state
*ecs
)
7116 fill_in_stop_func (gdbarch
, ecs
);
7118 compunit_symtab
*cust
7119 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7120 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7121 ecs
->stop_func_start
7122 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7124 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7125 /* Use the step_resume_break to step until the end of the prologue,
7126 even if that involves jumps (as it seems to on the vax under
7128 /* If the prologue ends in the middle of a source line, continue to
7129 the end of that source line (if it is still within the function).
7130 Otherwise, just go to end of prologue. */
7131 if (stop_func_sal
.end
7132 && stop_func_sal
.pc
!= ecs
->stop_func_start
7133 && stop_func_sal
.end
< ecs
->stop_func_end
)
7134 ecs
->stop_func_start
= stop_func_sal
.end
;
7136 /* Architectures which require breakpoint adjustment might not be able
7137 to place a breakpoint at the computed address. If so, the test
7138 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7139 ecs->stop_func_start to an address at which a breakpoint may be
7140 legitimately placed.
7142 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7143 made, GDB will enter an infinite loop when stepping through
7144 optimized code consisting of VLIW instructions which contain
7145 subinstructions corresponding to different source lines. On
7146 FR-V, it's not permitted to place a breakpoint on any but the
7147 first subinstruction of a VLIW instruction. When a breakpoint is
7148 set, GDB will adjust the breakpoint address to the beginning of
7149 the VLIW instruction. Thus, we need to make the corresponding
7150 adjustment here when computing the stop address. */
7152 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7154 ecs
->stop_func_start
7155 = gdbarch_adjust_breakpoint_address (gdbarch
,
7156 ecs
->stop_func_start
);
7159 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7161 /* We are already there: stop now. */
7162 end_stepping_range (ecs
);
7167 /* Put the step-breakpoint there and go until there. */
7168 symtab_and_line sr_sal
;
7169 sr_sal
.pc
= ecs
->stop_func_start
;
7170 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7171 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7173 /* Do not specify what the fp should be when we stop since on
7174 some machines the prologue is where the new fp value is
7176 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7178 /* And make sure stepping stops right away then. */
7179 ecs
->event_thread
->control
.step_range_end
7180 = ecs
->event_thread
->control
.step_range_start
;
7185 /* Inferior has stepped backward into a subroutine call with source
7186 code that we should not step over. Do step to the beginning of the
7187 last line of code in it. */
7190 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7191 struct execution_control_state
*ecs
)
7193 struct compunit_symtab
*cust
;
7194 struct symtab_and_line stop_func_sal
;
7196 fill_in_stop_func (gdbarch
, ecs
);
7198 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7199 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7200 ecs
->stop_func_start
7201 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7203 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7205 /* OK, we're just going to keep stepping here. */
7206 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7208 /* We're there already. Just stop stepping now. */
7209 end_stepping_range (ecs
);
7213 /* Else just reset the step range and keep going.
7214 No step-resume breakpoint, they don't work for
7215 epilogues, which can have multiple entry paths. */
7216 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7217 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7223 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7224 This is used to both functions and to skip over code. */
7227 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7228 struct symtab_and_line sr_sal
,
7229 struct frame_id sr_id
,
7230 enum bptype sr_type
)
7232 /* There should never be more than one step-resume or longjmp-resume
7233 breakpoint per thread, so we should never be setting a new
7234 step_resume_breakpoint when one is already active. */
7235 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7236 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7239 fprintf_unfiltered (gdb_stdlog
,
7240 "infrun: inserting step-resume breakpoint at %s\n",
7241 paddress (gdbarch
, sr_sal
.pc
));
7243 inferior_thread ()->control
.step_resume_breakpoint
7244 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7248 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7249 struct symtab_and_line sr_sal
,
7250 struct frame_id sr_id
)
7252 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7257 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7258 This is used to skip a potential signal handler.
7260 This is called with the interrupted function's frame. The signal
7261 handler, when it returns, will resume the interrupted function at
7265 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7267 gdb_assert (return_frame
!= NULL
);
7269 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7271 symtab_and_line sr_sal
;
7272 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7273 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7274 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7276 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7277 get_stack_frame_id (return_frame
),
7281 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7282 is used to skip a function after stepping into it (for "next" or if
7283 the called function has no debugging information).
7285 The current function has almost always been reached by single
7286 stepping a call or return instruction. NEXT_FRAME belongs to the
7287 current function, and the breakpoint will be set at the caller's
7290 This is a separate function rather than reusing
7291 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7292 get_prev_frame, which may stop prematurely (see the implementation
7293 of frame_unwind_caller_id for an example). */
7296 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7298 /* We shouldn't have gotten here if we don't know where the call site
7300 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7302 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7304 symtab_and_line sr_sal
;
7305 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7306 frame_unwind_caller_pc (next_frame
));
7307 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7308 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7310 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7311 frame_unwind_caller_id (next_frame
));
7314 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7315 new breakpoint at the target of a jmp_buf. The handling of
7316 longjmp-resume uses the same mechanisms used for handling
7317 "step-resume" breakpoints. */
7320 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7322 /* There should never be more than one longjmp-resume breakpoint per
7323 thread, so we should never be setting a new
7324 longjmp_resume_breakpoint when one is already active. */
7325 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7328 fprintf_unfiltered (gdb_stdlog
,
7329 "infrun: inserting longjmp-resume breakpoint at %s\n",
7330 paddress (gdbarch
, pc
));
7332 inferior_thread ()->control
.exception_resume_breakpoint
=
7333 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7336 /* Insert an exception resume breakpoint. TP is the thread throwing
7337 the exception. The block B is the block of the unwinder debug hook
7338 function. FRAME is the frame corresponding to the call to this
7339 function. SYM is the symbol of the function argument holding the
7340 target PC of the exception. */
7343 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7344 const struct block
*b
,
7345 struct frame_info
*frame
,
7350 struct block_symbol vsym
;
7351 struct value
*value
;
7353 struct breakpoint
*bp
;
7355 vsym
= lookup_symbol_search_name (sym
->search_name (),
7357 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7358 /* If the value was optimized out, revert to the old behavior. */
7359 if (! value_optimized_out (value
))
7361 handler
= value_as_address (value
);
7364 fprintf_unfiltered (gdb_stdlog
,
7365 "infrun: exception resume at %lx\n",
7366 (unsigned long) handler
);
7368 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7370 bp_exception_resume
).release ();
7372 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7375 bp
->thread
= tp
->global_num
;
7376 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7379 catch (const gdb_exception_error
&e
)
7381 /* We want to ignore errors here. */
7385 /* A helper for check_exception_resume that sets an
7386 exception-breakpoint based on a SystemTap probe. */
7389 insert_exception_resume_from_probe (struct thread_info
*tp
,
7390 const struct bound_probe
*probe
,
7391 struct frame_info
*frame
)
7393 struct value
*arg_value
;
7395 struct breakpoint
*bp
;
7397 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7401 handler
= value_as_address (arg_value
);
7404 fprintf_unfiltered (gdb_stdlog
,
7405 "infrun: exception resume at %s\n",
7406 paddress (get_objfile_arch (probe
->objfile
),
7409 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7410 handler
, bp_exception_resume
).release ();
7411 bp
->thread
= tp
->global_num
;
7412 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7415 /* This is called when an exception has been intercepted. Check to
7416 see whether the exception's destination is of interest, and if so,
7417 set an exception resume breakpoint there. */
7420 check_exception_resume (struct execution_control_state
*ecs
,
7421 struct frame_info
*frame
)
7423 struct bound_probe probe
;
7424 struct symbol
*func
;
7426 /* First see if this exception unwinding breakpoint was set via a
7427 SystemTap probe point. If so, the probe has two arguments: the
7428 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7429 set a breakpoint there. */
7430 probe
= find_probe_by_pc (get_frame_pc (frame
));
7433 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7437 func
= get_frame_function (frame
);
7443 const struct block
*b
;
7444 struct block_iterator iter
;
7448 /* The exception breakpoint is a thread-specific breakpoint on
7449 the unwinder's debug hook, declared as:
7451 void _Unwind_DebugHook (void *cfa, void *handler);
7453 The CFA argument indicates the frame to which control is
7454 about to be transferred. HANDLER is the destination PC.
7456 We ignore the CFA and set a temporary breakpoint at HANDLER.
7457 This is not extremely efficient but it avoids issues in gdb
7458 with computing the DWARF CFA, and it also works even in weird
7459 cases such as throwing an exception from inside a signal
7462 b
= SYMBOL_BLOCK_VALUE (func
);
7463 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7465 if (!SYMBOL_IS_ARGUMENT (sym
))
7472 insert_exception_resume_breakpoint (ecs
->event_thread
,
7478 catch (const gdb_exception_error
&e
)
7484 stop_waiting (struct execution_control_state
*ecs
)
7487 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7489 /* Let callers know we don't want to wait for the inferior anymore. */
7490 ecs
->wait_some_more
= 0;
7492 /* If all-stop, but the target is always in non-stop mode, stop all
7493 threads now that we're presenting the stop to the user. */
7494 if (!non_stop
&& target_is_non_stop_p ())
7495 stop_all_threads ();
7498 /* Like keep_going, but passes the signal to the inferior, even if the
7499 signal is set to nopass. */
7502 keep_going_pass_signal (struct execution_control_state
*ecs
)
7504 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7505 gdb_assert (!ecs
->event_thread
->resumed
);
7507 /* Save the pc before execution, to compare with pc after stop. */
7508 ecs
->event_thread
->prev_pc
7509 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7511 if (ecs
->event_thread
->control
.trap_expected
)
7513 struct thread_info
*tp
= ecs
->event_thread
;
7516 fprintf_unfiltered (gdb_stdlog
,
7517 "infrun: %s has trap_expected set, "
7518 "resuming to collect trap\n",
7519 target_pid_to_str (tp
->ptid
).c_str ());
7521 /* We haven't yet gotten our trap, and either: intercepted a
7522 non-signal event (e.g., a fork); or took a signal which we
7523 are supposed to pass through to the inferior. Simply
7525 resume (ecs
->event_thread
->suspend
.stop_signal
);
7527 else if (step_over_info_valid_p ())
7529 /* Another thread is stepping over a breakpoint in-line. If
7530 this thread needs a step-over too, queue the request. In
7531 either case, this resume must be deferred for later. */
7532 struct thread_info
*tp
= ecs
->event_thread
;
7534 if (ecs
->hit_singlestep_breakpoint
7535 || thread_still_needs_step_over (tp
))
7538 fprintf_unfiltered (gdb_stdlog
,
7539 "infrun: step-over already in progress: "
7540 "step-over for %s deferred\n",
7541 target_pid_to_str (tp
->ptid
).c_str ());
7542 thread_step_over_chain_enqueue (tp
);
7547 fprintf_unfiltered (gdb_stdlog
,
7548 "infrun: step-over in progress: "
7549 "resume of %s deferred\n",
7550 target_pid_to_str (tp
->ptid
).c_str ());
7555 struct regcache
*regcache
= get_current_regcache ();
7558 step_over_what step_what
;
7560 /* Either the trap was not expected, but we are continuing
7561 anyway (if we got a signal, the user asked it be passed to
7564 We got our expected trap, but decided we should resume from
7567 We're going to run this baby now!
7569 Note that insert_breakpoints won't try to re-insert
7570 already inserted breakpoints. Therefore, we don't
7571 care if breakpoints were already inserted, or not. */
7573 /* If we need to step over a breakpoint, and we're not using
7574 displaced stepping to do so, insert all breakpoints
7575 (watchpoints, etc.) but the one we're stepping over, step one
7576 instruction, and then re-insert the breakpoint when that step
7579 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7581 remove_bp
= (ecs
->hit_singlestep_breakpoint
7582 || (step_what
& STEP_OVER_BREAKPOINT
));
7583 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7585 /* We can't use displaced stepping if we need to step past a
7586 watchpoint. The instruction copied to the scratch pad would
7587 still trigger the watchpoint. */
7589 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7591 set_step_over_info (regcache
->aspace (),
7592 regcache_read_pc (regcache
), remove_wps
,
7593 ecs
->event_thread
->global_num
);
7595 else if (remove_wps
)
7596 set_step_over_info (NULL
, 0, remove_wps
, -1);
7598 /* If we now need to do an in-line step-over, we need to stop
7599 all other threads. Note this must be done before
7600 insert_breakpoints below, because that removes the breakpoint
7601 we're about to step over, otherwise other threads could miss
7603 if (step_over_info_valid_p () && target_is_non_stop_p ())
7604 stop_all_threads ();
7606 /* Stop stepping if inserting breakpoints fails. */
7609 insert_breakpoints ();
7611 catch (const gdb_exception_error
&e
)
7613 exception_print (gdb_stderr
, e
);
7615 clear_step_over_info ();
7619 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7621 resume (ecs
->event_thread
->suspend
.stop_signal
);
7624 prepare_to_wait (ecs
);
7627 /* Called when we should continue running the inferior, because the
7628 current event doesn't cause a user visible stop. This does the
7629 resuming part; waiting for the next event is done elsewhere. */
7632 keep_going (struct execution_control_state
*ecs
)
7634 if (ecs
->event_thread
->control
.trap_expected
7635 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7636 ecs
->event_thread
->control
.trap_expected
= 0;
7638 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7639 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7640 keep_going_pass_signal (ecs
);
7643 /* This function normally comes after a resume, before
7644 handle_inferior_event exits. It takes care of any last bits of
7645 housekeeping, and sets the all-important wait_some_more flag. */
7648 prepare_to_wait (struct execution_control_state
*ecs
)
7651 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7653 ecs
->wait_some_more
= 1;
7655 if (!target_is_async_p ())
7656 mark_infrun_async_event_handler ();
7659 /* We are done with the step range of a step/next/si/ni command.
7660 Called once for each n of a "step n" operation. */
7663 end_stepping_range (struct execution_control_state
*ecs
)
7665 ecs
->event_thread
->control
.stop_step
= 1;
7669 /* Several print_*_reason functions to print why the inferior has stopped.
7670 We always print something when the inferior exits, or receives a signal.
7671 The rest of the cases are dealt with later on in normal_stop and
7672 print_it_typical. Ideally there should be a call to one of these
7673 print_*_reason functions functions from handle_inferior_event each time
7674 stop_waiting is called.
7676 Note that we don't call these directly, instead we delegate that to
7677 the interpreters, through observers. Interpreters then call these
7678 with whatever uiout is right. */
7681 print_end_stepping_range_reason (struct ui_out
*uiout
)
7683 /* For CLI-like interpreters, print nothing. */
7685 if (uiout
->is_mi_like_p ())
7687 uiout
->field_string ("reason",
7688 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7693 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7695 annotate_signalled ();
7696 if (uiout
->is_mi_like_p ())
7698 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7699 uiout
->text ("\nProgram terminated with signal ");
7700 annotate_signal_name ();
7701 uiout
->field_string ("signal-name",
7702 gdb_signal_to_name (siggnal
));
7703 annotate_signal_name_end ();
7705 annotate_signal_string ();
7706 uiout
->field_string ("signal-meaning",
7707 gdb_signal_to_string (siggnal
));
7708 annotate_signal_string_end ();
7709 uiout
->text (".\n");
7710 uiout
->text ("The program no longer exists.\n");
7714 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7716 struct inferior
*inf
= current_inferior ();
7717 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7719 annotate_exited (exitstatus
);
7722 if (uiout
->is_mi_like_p ())
7723 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7724 std::string exit_code_str
7725 = string_printf ("0%o", (unsigned int) exitstatus
);
7726 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7727 plongest (inf
->num
), pidstr
.c_str (),
7728 string_field ("exit-code", exit_code_str
.c_str ()));
7732 if (uiout
->is_mi_like_p ())
7734 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7735 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7736 plongest (inf
->num
), pidstr
.c_str ());
7740 /* Some targets/architectures can do extra processing/display of
7741 segmentation faults. E.g., Intel MPX boundary faults.
7742 Call the architecture dependent function to handle the fault. */
7745 handle_segmentation_fault (struct ui_out
*uiout
)
7747 struct regcache
*regcache
= get_current_regcache ();
7748 struct gdbarch
*gdbarch
= regcache
->arch ();
7750 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7751 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7755 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7757 struct thread_info
*thr
= inferior_thread ();
7761 if (uiout
->is_mi_like_p ())
7763 else if (show_thread_that_caused_stop ())
7767 uiout
->text ("\nThread ");
7768 uiout
->field_string ("thread-id", print_thread_id (thr
));
7770 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7773 uiout
->text (" \"");
7774 uiout
->field_string ("name", name
);
7779 uiout
->text ("\nProgram");
7781 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
7782 uiout
->text (" stopped");
7785 uiout
->text (" received signal ");
7786 annotate_signal_name ();
7787 if (uiout
->is_mi_like_p ())
7789 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7790 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
7791 annotate_signal_name_end ();
7793 annotate_signal_string ();
7794 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
7796 if (siggnal
== GDB_SIGNAL_SEGV
)
7797 handle_segmentation_fault (uiout
);
7799 annotate_signal_string_end ();
7801 uiout
->text (".\n");
7805 print_no_history_reason (struct ui_out
*uiout
)
7807 uiout
->text ("\nNo more reverse-execution history.\n");
7810 /* Print current location without a level number, if we have changed
7811 functions or hit a breakpoint. Print source line if we have one.
7812 bpstat_print contains the logic deciding in detail what to print,
7813 based on the event(s) that just occurred. */
7816 print_stop_location (struct target_waitstatus
*ws
)
7819 enum print_what source_flag
;
7820 int do_frame_printing
= 1;
7821 struct thread_info
*tp
= inferior_thread ();
7823 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
7827 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7828 should) carry around the function and does (or should) use
7829 that when doing a frame comparison. */
7830 if (tp
->control
.stop_step
7831 && frame_id_eq (tp
->control
.step_frame_id
,
7832 get_frame_id (get_current_frame ()))
7833 && (tp
->control
.step_start_function
7834 == find_pc_function (tp
->suspend
.stop_pc
)))
7836 /* Finished step, just print source line. */
7837 source_flag
= SRC_LINE
;
7841 /* Print location and source line. */
7842 source_flag
= SRC_AND_LOC
;
7845 case PRINT_SRC_AND_LOC
:
7846 /* Print location and source line. */
7847 source_flag
= SRC_AND_LOC
;
7849 case PRINT_SRC_ONLY
:
7850 source_flag
= SRC_LINE
;
7853 /* Something bogus. */
7854 source_flag
= SRC_LINE
;
7855 do_frame_printing
= 0;
7858 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
7861 /* The behavior of this routine with respect to the source
7863 SRC_LINE: Print only source line
7864 LOCATION: Print only location
7865 SRC_AND_LOC: Print location and source line. */
7866 if (do_frame_printing
)
7867 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
7873 print_stop_event (struct ui_out
*uiout
, bool displays
)
7875 struct target_waitstatus last
;
7876 struct thread_info
*tp
;
7878 get_last_target_status (nullptr, &last
);
7881 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
7883 print_stop_location (&last
);
7885 /* Display the auto-display expressions. */
7890 tp
= inferior_thread ();
7891 if (tp
->thread_fsm
!= NULL
7892 && tp
->thread_fsm
->finished_p ())
7894 struct return_value_info
*rv
;
7896 rv
= tp
->thread_fsm
->return_value ();
7898 print_return_value (uiout
, rv
);
7905 maybe_remove_breakpoints (void)
7907 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
7909 if (remove_breakpoints ())
7911 target_terminal::ours_for_output ();
7912 printf_filtered (_("Cannot remove breakpoints because "
7913 "program is no longer writable.\nFurther "
7914 "execution is probably impossible.\n"));
7919 /* The execution context that just caused a normal stop. */
7926 DISABLE_COPY_AND_ASSIGN (stop_context
);
7928 bool changed () const;
7933 /* The event PTID. */
7937 /* If stopp for a thread event, this is the thread that caused the
7939 struct thread_info
*thread
;
7941 /* The inferior that caused the stop. */
7945 /* Initializes a new stop context. If stopped for a thread event, this
7946 takes a strong reference to the thread. */
7948 stop_context::stop_context ()
7950 stop_id
= get_stop_id ();
7951 ptid
= inferior_ptid
;
7952 inf_num
= current_inferior ()->num
;
7954 if (inferior_ptid
!= null_ptid
)
7956 /* Take a strong reference so that the thread can't be deleted
7958 thread
= inferior_thread ();
7965 /* Release a stop context previously created with save_stop_context.
7966 Releases the strong reference to the thread as well. */
7968 stop_context::~stop_context ()
7974 /* Return true if the current context no longer matches the saved stop
7978 stop_context::changed () const
7980 if (ptid
!= inferior_ptid
)
7982 if (inf_num
!= current_inferior ()->num
)
7984 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
7986 if (get_stop_id () != stop_id
)
7996 struct target_waitstatus last
;
7998 get_last_target_status (nullptr, &last
);
8002 /* If an exception is thrown from this point on, make sure to
8003 propagate GDB's knowledge of the executing state to the
8004 frontend/user running state. A QUIT is an easy exception to see
8005 here, so do this before any filtered output. */
8007 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8010 maybe_finish_thread_state
.emplace (minus_one_ptid
);
8011 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8012 || last
.kind
== TARGET_WAITKIND_EXITED
)
8014 /* On some targets, we may still have live threads in the
8015 inferior when we get a process exit event. E.g., for
8016 "checkpoint", when the current checkpoint/fork exits,
8017 linux-fork.c automatically switches to another fork from
8018 within target_mourn_inferior. */
8019 if (inferior_ptid
!= null_ptid
)
8020 maybe_finish_thread_state
.emplace (ptid_t (inferior_ptid
.pid ()));
8022 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8023 maybe_finish_thread_state
.emplace (inferior_ptid
);
8025 /* As we're presenting a stop, and potentially removing breakpoints,
8026 update the thread list so we can tell whether there are threads
8027 running on the target. With target remote, for example, we can
8028 only learn about new threads when we explicitly update the thread
8029 list. Do this before notifying the interpreters about signal
8030 stops, end of stepping ranges, etc., so that the "new thread"
8031 output is emitted before e.g., "Program received signal FOO",
8032 instead of after. */
8033 update_thread_list ();
8035 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8036 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8038 /* As with the notification of thread events, we want to delay
8039 notifying the user that we've switched thread context until
8040 the inferior actually stops.
8042 There's no point in saying anything if the inferior has exited.
8043 Note that SIGNALLED here means "exited with a signal", not
8044 "received a signal".
8046 Also skip saying anything in non-stop mode. In that mode, as we
8047 don't want GDB to switch threads behind the user's back, to avoid
8048 races where the user is typing a command to apply to thread x,
8049 but GDB switches to thread y before the user finishes entering
8050 the command, fetch_inferior_event installs a cleanup to restore
8051 the current thread back to the thread the user had selected right
8052 after this event is handled, so we're not really switching, only
8053 informing of a stop. */
8055 && previous_inferior_ptid
!= inferior_ptid
8056 && target_has_execution
8057 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8058 && last
.kind
!= TARGET_WAITKIND_EXITED
8059 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8061 SWITCH_THRU_ALL_UIS ()
8063 target_terminal::ours_for_output ();
8064 printf_filtered (_("[Switching to %s]\n"),
8065 target_pid_to_str (inferior_ptid
).c_str ());
8066 annotate_thread_changed ();
8068 previous_inferior_ptid
= inferior_ptid
;
8071 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8073 SWITCH_THRU_ALL_UIS ()
8074 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8076 target_terminal::ours_for_output ();
8077 printf_filtered (_("No unwaited-for children left.\n"));
8081 /* Note: this depends on the update_thread_list call above. */
8082 maybe_remove_breakpoints ();
8084 /* If an auto-display called a function and that got a signal,
8085 delete that auto-display to avoid an infinite recursion. */
8087 if (stopped_by_random_signal
)
8088 disable_current_display ();
8090 SWITCH_THRU_ALL_UIS ()
8092 async_enable_stdin ();
8095 /* Let the user/frontend see the threads as stopped. */
8096 maybe_finish_thread_state
.reset ();
8098 /* Select innermost stack frame - i.e., current frame is frame 0,
8099 and current location is based on that. Handle the case where the
8100 dummy call is returning after being stopped. E.g. the dummy call
8101 previously hit a breakpoint. (If the dummy call returns
8102 normally, we won't reach here.) Do this before the stop hook is
8103 run, so that it doesn't get to see the temporary dummy frame,
8104 which is not where we'll present the stop. */
8105 if (has_stack_frames ())
8107 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8109 /* Pop the empty frame that contains the stack dummy. This
8110 also restores inferior state prior to the call (struct
8111 infcall_suspend_state). */
8112 struct frame_info
*frame
= get_current_frame ();
8114 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8116 /* frame_pop calls reinit_frame_cache as the last thing it
8117 does which means there's now no selected frame. */
8120 select_frame (get_current_frame ());
8122 /* Set the current source location. */
8123 set_current_sal_from_frame (get_current_frame ());
8126 /* Look up the hook_stop and run it (CLI internally handles problem
8127 of stop_command's pre-hook not existing). */
8128 if (stop_command
!= NULL
)
8130 stop_context saved_context
;
8134 execute_cmd_pre_hook (stop_command
);
8136 catch (const gdb_exception
&ex
)
8138 exception_fprintf (gdb_stderr
, ex
,
8139 "Error while running hook_stop:\n");
8142 /* If the stop hook resumes the target, then there's no point in
8143 trying to notify about the previous stop; its context is
8144 gone. Likewise if the command switches thread or inferior --
8145 the observers would print a stop for the wrong
8147 if (saved_context
.changed ())
8151 /* Notify observers about the stop. This is where the interpreters
8152 print the stop event. */
8153 if (inferior_ptid
!= null_ptid
)
8154 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8157 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8159 annotate_stopped ();
8161 if (target_has_execution
)
8163 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8164 && last
.kind
!= TARGET_WAITKIND_EXITED
8165 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8166 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8167 Delete any breakpoint that is to be deleted at the next stop. */
8168 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8171 /* Try to get rid of automatically added inferiors that are no
8172 longer needed. Keeping those around slows down things linearly.
8173 Note that this never removes the current inferior. */
8180 signal_stop_state (int signo
)
8182 return signal_stop
[signo
];
8186 signal_print_state (int signo
)
8188 return signal_print
[signo
];
8192 signal_pass_state (int signo
)
8194 return signal_program
[signo
];
8198 signal_cache_update (int signo
)
8202 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8203 signal_cache_update (signo
);
8208 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8209 && signal_print
[signo
] == 0
8210 && signal_program
[signo
] == 1
8211 && signal_catch
[signo
] == 0);
8215 signal_stop_update (int signo
, int state
)
8217 int ret
= signal_stop
[signo
];
8219 signal_stop
[signo
] = state
;
8220 signal_cache_update (signo
);
8225 signal_print_update (int signo
, int state
)
8227 int ret
= signal_print
[signo
];
8229 signal_print
[signo
] = state
;
8230 signal_cache_update (signo
);
8235 signal_pass_update (int signo
, int state
)
8237 int ret
= signal_program
[signo
];
8239 signal_program
[signo
] = state
;
8240 signal_cache_update (signo
);
8244 /* Update the global 'signal_catch' from INFO and notify the
8248 signal_catch_update (const unsigned int *info
)
8252 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8253 signal_catch
[i
] = info
[i
] > 0;
8254 signal_cache_update (-1);
8255 target_pass_signals (signal_pass
);
8259 sig_print_header (void)
8261 printf_filtered (_("Signal Stop\tPrint\tPass "
8262 "to program\tDescription\n"));
8266 sig_print_info (enum gdb_signal oursig
)
8268 const char *name
= gdb_signal_to_name (oursig
);
8269 int name_padding
= 13 - strlen (name
);
8271 if (name_padding
<= 0)
8274 printf_filtered ("%s", name
);
8275 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8276 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8277 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8278 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8279 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8282 /* Specify how various signals in the inferior should be handled. */
8285 handle_command (const char *args
, int from_tty
)
8287 int digits
, wordlen
;
8288 int sigfirst
, siglast
;
8289 enum gdb_signal oursig
;
8294 error_no_arg (_("signal to handle"));
8297 /* Allocate and zero an array of flags for which signals to handle. */
8299 const size_t nsigs
= GDB_SIGNAL_LAST
;
8300 unsigned char sigs
[nsigs
] {};
8302 /* Break the command line up into args. */
8304 gdb_argv
built_argv (args
);
8306 /* Walk through the args, looking for signal oursigs, signal names, and
8307 actions. Signal numbers and signal names may be interspersed with
8308 actions, with the actions being performed for all signals cumulatively
8309 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8311 for (char *arg
: built_argv
)
8313 wordlen
= strlen (arg
);
8314 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8318 sigfirst
= siglast
= -1;
8320 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8322 /* Apply action to all signals except those used by the
8323 debugger. Silently skip those. */
8326 siglast
= nsigs
- 1;
8328 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8330 SET_SIGS (nsigs
, sigs
, signal_stop
);
8331 SET_SIGS (nsigs
, sigs
, signal_print
);
8333 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8335 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8337 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8339 SET_SIGS (nsigs
, sigs
, signal_print
);
8341 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8343 SET_SIGS (nsigs
, sigs
, signal_program
);
8345 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8347 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8349 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8351 SET_SIGS (nsigs
, sigs
, signal_program
);
8353 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8355 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8356 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8358 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8360 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8362 else if (digits
> 0)
8364 /* It is numeric. The numeric signal refers to our own
8365 internal signal numbering from target.h, not to host/target
8366 signal number. This is a feature; users really should be
8367 using symbolic names anyway, and the common ones like
8368 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8370 sigfirst
= siglast
= (int)
8371 gdb_signal_from_command (atoi (arg
));
8372 if (arg
[digits
] == '-')
8375 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8377 if (sigfirst
> siglast
)
8379 /* Bet he didn't figure we'd think of this case... */
8380 std::swap (sigfirst
, siglast
);
8385 oursig
= gdb_signal_from_name (arg
);
8386 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8388 sigfirst
= siglast
= (int) oursig
;
8392 /* Not a number and not a recognized flag word => complain. */
8393 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8397 /* If any signal numbers or symbol names were found, set flags for
8398 which signals to apply actions to. */
8400 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8402 switch ((enum gdb_signal
) signum
)
8404 case GDB_SIGNAL_TRAP
:
8405 case GDB_SIGNAL_INT
:
8406 if (!allsigs
&& !sigs
[signum
])
8408 if (query (_("%s is used by the debugger.\n\
8409 Are you sure you want to change it? "),
8410 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8415 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8419 case GDB_SIGNAL_DEFAULT
:
8420 case GDB_SIGNAL_UNKNOWN
:
8421 /* Make sure that "all" doesn't print these. */
8430 for (int signum
= 0; signum
< nsigs
; signum
++)
8433 signal_cache_update (-1);
8434 target_pass_signals (signal_pass
);
8435 target_program_signals (signal_program
);
8439 /* Show the results. */
8440 sig_print_header ();
8441 for (; signum
< nsigs
; signum
++)
8443 sig_print_info ((enum gdb_signal
) signum
);
8450 /* Complete the "handle" command. */
8453 handle_completer (struct cmd_list_element
*ignore
,
8454 completion_tracker
&tracker
,
8455 const char *text
, const char *word
)
8457 static const char * const keywords
[] =
8471 signal_completer (ignore
, tracker
, text
, word
);
8472 complete_on_enum (tracker
, keywords
, word
, word
);
8476 gdb_signal_from_command (int num
)
8478 if (num
>= 1 && num
<= 15)
8479 return (enum gdb_signal
) num
;
8480 error (_("Only signals 1-15 are valid as numeric signals.\n\
8481 Use \"info signals\" for a list of symbolic signals."));
8484 /* Print current contents of the tables set by the handle command.
8485 It is possible we should just be printing signals actually used
8486 by the current target (but for things to work right when switching
8487 targets, all signals should be in the signal tables). */
8490 info_signals_command (const char *signum_exp
, int from_tty
)
8492 enum gdb_signal oursig
;
8494 sig_print_header ();
8498 /* First see if this is a symbol name. */
8499 oursig
= gdb_signal_from_name (signum_exp
);
8500 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8502 /* No, try numeric. */
8504 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8506 sig_print_info (oursig
);
8510 printf_filtered ("\n");
8511 /* These ugly casts brought to you by the native VAX compiler. */
8512 for (oursig
= GDB_SIGNAL_FIRST
;
8513 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8514 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8518 if (oursig
!= GDB_SIGNAL_UNKNOWN
8519 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8520 sig_print_info (oursig
);
8523 printf_filtered (_("\nUse the \"handle\" command "
8524 "to change these tables.\n"));
8527 /* The $_siginfo convenience variable is a bit special. We don't know
8528 for sure the type of the value until we actually have a chance to
8529 fetch the data. The type can change depending on gdbarch, so it is
8530 also dependent on which thread you have selected.
8532 1. making $_siginfo be an internalvar that creates a new value on
8535 2. making the value of $_siginfo be an lval_computed value. */
8537 /* This function implements the lval_computed support for reading a
8541 siginfo_value_read (struct value
*v
)
8543 LONGEST transferred
;
8545 /* If we can access registers, so can we access $_siginfo. Likewise
8547 validate_registers_access ();
8550 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8552 value_contents_all_raw (v
),
8554 TYPE_LENGTH (value_type (v
)));
8556 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8557 error (_("Unable to read siginfo"));
8560 /* This function implements the lval_computed support for writing a
8564 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8566 LONGEST transferred
;
8568 /* If we can access registers, so can we access $_siginfo. Likewise
8570 validate_registers_access ();
8572 transferred
= target_write (current_top_target (),
8573 TARGET_OBJECT_SIGNAL_INFO
,
8575 value_contents_all_raw (fromval
),
8577 TYPE_LENGTH (value_type (fromval
)));
8579 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8580 error (_("Unable to write siginfo"));
8583 static const struct lval_funcs siginfo_value_funcs
=
8589 /* Return a new value with the correct type for the siginfo object of
8590 the current thread using architecture GDBARCH. Return a void value
8591 if there's no object available. */
8593 static struct value
*
8594 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8597 if (target_has_stack
8598 && inferior_ptid
!= null_ptid
8599 && gdbarch_get_siginfo_type_p (gdbarch
))
8601 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8603 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8606 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8610 /* infcall_suspend_state contains state about the program itself like its
8611 registers and any signal it received when it last stopped.
8612 This state must be restored regardless of how the inferior function call
8613 ends (either successfully, or after it hits a breakpoint or signal)
8614 if the program is to properly continue where it left off. */
8616 class infcall_suspend_state
8619 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8620 once the inferior function call has finished. */
8621 infcall_suspend_state (struct gdbarch
*gdbarch
,
8622 const struct thread_info
*tp
,
8623 struct regcache
*regcache
)
8624 : m_thread_suspend (tp
->suspend
),
8625 m_registers (new readonly_detached_regcache (*regcache
))
8627 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8629 if (gdbarch_get_siginfo_type_p (gdbarch
))
8631 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8632 size_t len
= TYPE_LENGTH (type
);
8634 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8636 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8637 siginfo_data
.get (), 0, len
) != len
)
8639 /* Errors ignored. */
8640 siginfo_data
.reset (nullptr);
8646 m_siginfo_gdbarch
= gdbarch
;
8647 m_siginfo_data
= std::move (siginfo_data
);
8651 /* Return a pointer to the stored register state. */
8653 readonly_detached_regcache
*registers () const
8655 return m_registers
.get ();
8658 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8660 void restore (struct gdbarch
*gdbarch
,
8661 struct thread_info
*tp
,
8662 struct regcache
*regcache
) const
8664 tp
->suspend
= m_thread_suspend
;
8666 if (m_siginfo_gdbarch
== gdbarch
)
8668 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8670 /* Errors ignored. */
8671 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8672 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8675 /* The inferior can be gone if the user types "print exit(0)"
8676 (and perhaps other times). */
8677 if (target_has_execution
)
8678 /* NB: The register write goes through to the target. */
8679 regcache
->restore (registers ());
8683 /* How the current thread stopped before the inferior function call was
8685 struct thread_suspend_state m_thread_suspend
;
8687 /* The registers before the inferior function call was executed. */
8688 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8690 /* Format of SIGINFO_DATA or NULL if it is not present. */
8691 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8693 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8694 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8695 content would be invalid. */
8696 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8699 infcall_suspend_state_up
8700 save_infcall_suspend_state ()
8702 struct thread_info
*tp
= inferior_thread ();
8703 struct regcache
*regcache
= get_current_regcache ();
8704 struct gdbarch
*gdbarch
= regcache
->arch ();
8706 infcall_suspend_state_up inf_state
8707 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8709 /* Having saved the current state, adjust the thread state, discarding
8710 any stop signal information. The stop signal is not useful when
8711 starting an inferior function call, and run_inferior_call will not use
8712 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8713 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8718 /* Restore inferior session state to INF_STATE. */
8721 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8723 struct thread_info
*tp
= inferior_thread ();
8724 struct regcache
*regcache
= get_current_regcache ();
8725 struct gdbarch
*gdbarch
= regcache
->arch ();
8727 inf_state
->restore (gdbarch
, tp
, regcache
);
8728 discard_infcall_suspend_state (inf_state
);
8732 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8737 readonly_detached_regcache
*
8738 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8740 return inf_state
->registers ();
8743 /* infcall_control_state contains state regarding gdb's control of the
8744 inferior itself like stepping control. It also contains session state like
8745 the user's currently selected frame. */
8747 struct infcall_control_state
8749 struct thread_control_state thread_control
;
8750 struct inferior_control_state inferior_control
;
8753 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8754 int stopped_by_random_signal
= 0;
8756 /* ID if the selected frame when the inferior function call was made. */
8757 struct frame_id selected_frame_id
{};
8760 /* Save all of the information associated with the inferior<==>gdb
8763 infcall_control_state_up
8764 save_infcall_control_state ()
8766 infcall_control_state_up
inf_status (new struct infcall_control_state
);
8767 struct thread_info
*tp
= inferior_thread ();
8768 struct inferior
*inf
= current_inferior ();
8770 inf_status
->thread_control
= tp
->control
;
8771 inf_status
->inferior_control
= inf
->control
;
8773 tp
->control
.step_resume_breakpoint
= NULL
;
8774 tp
->control
.exception_resume_breakpoint
= NULL
;
8776 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8777 chain. If caller's caller is walking the chain, they'll be happier if we
8778 hand them back the original chain when restore_infcall_control_state is
8780 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
8783 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
8784 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
8786 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
8792 restore_selected_frame (const frame_id
&fid
)
8794 frame_info
*frame
= frame_find_by_id (fid
);
8796 /* If inf_status->selected_frame_id is NULL, there was no previously
8800 warning (_("Unable to restore previously selected frame."));
8804 select_frame (frame
);
8807 /* Restore inferior session state to INF_STATUS. */
8810 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
8812 struct thread_info
*tp
= inferior_thread ();
8813 struct inferior
*inf
= current_inferior ();
8815 if (tp
->control
.step_resume_breakpoint
)
8816 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
8818 if (tp
->control
.exception_resume_breakpoint
)
8819 tp
->control
.exception_resume_breakpoint
->disposition
8820 = disp_del_at_next_stop
;
8822 /* Handle the bpstat_copy of the chain. */
8823 bpstat_clear (&tp
->control
.stop_bpstat
);
8825 tp
->control
= inf_status
->thread_control
;
8826 inf
->control
= inf_status
->inferior_control
;
8829 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
8830 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
8832 if (target_has_stack
)
8834 /* The point of the try/catch is that if the stack is clobbered,
8835 walking the stack might encounter a garbage pointer and
8836 error() trying to dereference it. */
8839 restore_selected_frame (inf_status
->selected_frame_id
);
8841 catch (const gdb_exception_error
&ex
)
8843 exception_fprintf (gdb_stderr
, ex
,
8844 "Unable to restore previously selected frame:\n");
8845 /* Error in restoring the selected frame. Select the
8847 select_frame (get_current_frame ());
8855 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
8857 if (inf_status
->thread_control
.step_resume_breakpoint
)
8858 inf_status
->thread_control
.step_resume_breakpoint
->disposition
8859 = disp_del_at_next_stop
;
8861 if (inf_status
->thread_control
.exception_resume_breakpoint
)
8862 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
8863 = disp_del_at_next_stop
;
8865 /* See save_infcall_control_state for info on stop_bpstat. */
8866 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
8874 clear_exit_convenience_vars (void)
8876 clear_internalvar (lookup_internalvar ("_exitsignal"));
8877 clear_internalvar (lookup_internalvar ("_exitcode"));
8881 /* User interface for reverse debugging:
8882 Set exec-direction / show exec-direction commands
8883 (returns error unless target implements to_set_exec_direction method). */
8885 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
8886 static const char exec_forward
[] = "forward";
8887 static const char exec_reverse
[] = "reverse";
8888 static const char *exec_direction
= exec_forward
;
8889 static const char *const exec_direction_names
[] = {
8896 set_exec_direction_func (const char *args
, int from_tty
,
8897 struct cmd_list_element
*cmd
)
8899 if (target_can_execute_reverse
)
8901 if (!strcmp (exec_direction
, exec_forward
))
8902 execution_direction
= EXEC_FORWARD
;
8903 else if (!strcmp (exec_direction
, exec_reverse
))
8904 execution_direction
= EXEC_REVERSE
;
8908 exec_direction
= exec_forward
;
8909 error (_("Target does not support this operation."));
8914 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
8915 struct cmd_list_element
*cmd
, const char *value
)
8917 switch (execution_direction
) {
8919 fprintf_filtered (out
, _("Forward.\n"));
8922 fprintf_filtered (out
, _("Reverse.\n"));
8925 internal_error (__FILE__
, __LINE__
,
8926 _("bogus execution_direction value: %d"),
8927 (int) execution_direction
);
8932 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
8933 struct cmd_list_element
*c
, const char *value
)
8935 fprintf_filtered (file
, _("Resuming the execution of threads "
8936 "of all processes is %s.\n"), value
);
8939 /* Implementation of `siginfo' variable. */
8941 static const struct internalvar_funcs siginfo_funcs
=
8948 /* Callback for infrun's target events source. This is marked when a
8949 thread has a pending status to process. */
8952 infrun_async_inferior_event_handler (gdb_client_data data
)
8954 inferior_event_handler (INF_REG_EVENT
, NULL
);
8958 _initialize_infrun (void)
8960 struct cmd_list_element
*c
;
8962 /* Register extra event sources in the event loop. */
8963 infrun_async_inferior_event_token
8964 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
8966 add_info ("signals", info_signals_command
, _("\
8967 What debugger does when program gets various signals.\n\
8968 Specify a signal as argument to print info on that signal only."));
8969 add_info_alias ("handle", "signals", 0);
8971 c
= add_com ("handle", class_run
, handle_command
, _("\
8972 Specify how to handle signals.\n\
8973 Usage: handle SIGNAL [ACTIONS]\n\
8974 Args are signals and actions to apply to those signals.\n\
8975 If no actions are specified, the current settings for the specified signals\n\
8976 will be displayed instead.\n\
8978 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8979 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8980 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8981 The special arg \"all\" is recognized to mean all signals except those\n\
8982 used by the debugger, typically SIGTRAP and SIGINT.\n\
8984 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8985 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8986 Stop means reenter debugger if this signal happens (implies print).\n\
8987 Print means print a message if this signal happens.\n\
8988 Pass means let program see this signal; otherwise program doesn't know.\n\
8989 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8990 Pass and Stop may be combined.\n\
8992 Multiple signals may be specified. Signal numbers and signal names\n\
8993 may be interspersed with actions, with the actions being performed for\n\
8994 all signals cumulatively specified."));
8995 set_cmd_completer (c
, handle_completer
);
8998 stop_command
= add_cmd ("stop", class_obscure
,
8999 not_just_help_class_command
, _("\
9000 There is no `stop' command, but you can set a hook on `stop'.\n\
9001 This allows you to set a list of commands to be run each time execution\n\
9002 of the program stops."), &cmdlist
);
9004 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9005 Set inferior debugging."), _("\
9006 Show inferior debugging."), _("\
9007 When non-zero, inferior specific debugging is enabled."),
9010 &setdebuglist
, &showdebuglist
);
9012 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9013 &debug_displaced
, _("\
9014 Set displaced stepping debugging."), _("\
9015 Show displaced stepping debugging."), _("\
9016 When non-zero, displaced stepping specific debugging is enabled."),
9018 show_debug_displaced
,
9019 &setdebuglist
, &showdebuglist
);
9021 add_setshow_boolean_cmd ("non-stop", no_class
,
9023 Set whether gdb controls the inferior in non-stop mode."), _("\
9024 Show whether gdb controls the inferior in non-stop mode."), _("\
9025 When debugging a multi-threaded program and this setting is\n\
9026 off (the default, also called all-stop mode), when one thread stops\n\
9027 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9028 all other threads in the program while you interact with the thread of\n\
9029 interest. When you continue or step a thread, you can allow the other\n\
9030 threads to run, or have them remain stopped, but while you inspect any\n\
9031 thread's state, all threads stop.\n\
9033 In non-stop mode, when one thread stops, other threads can continue\n\
9034 to run freely. You'll be able to step each thread independently,\n\
9035 leave it stopped or free to run as needed."),
9041 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9044 signal_print
[i
] = 1;
9045 signal_program
[i
] = 1;
9046 signal_catch
[i
] = 0;
9049 /* Signals caused by debugger's own actions should not be given to
9050 the program afterwards.
9052 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9053 explicitly specifies that it should be delivered to the target
9054 program. Typically, that would occur when a user is debugging a
9055 target monitor on a simulator: the target monitor sets a
9056 breakpoint; the simulator encounters this breakpoint and halts
9057 the simulation handing control to GDB; GDB, noting that the stop
9058 address doesn't map to any known breakpoint, returns control back
9059 to the simulator; the simulator then delivers the hardware
9060 equivalent of a GDB_SIGNAL_TRAP to the program being
9062 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9063 signal_program
[GDB_SIGNAL_INT
] = 0;
9065 /* Signals that are not errors should not normally enter the debugger. */
9066 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9067 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9068 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9069 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9070 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9071 signal_print
[GDB_SIGNAL_PROF
] = 0;
9072 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9073 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9074 signal_stop
[GDB_SIGNAL_IO
] = 0;
9075 signal_print
[GDB_SIGNAL_IO
] = 0;
9076 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9077 signal_print
[GDB_SIGNAL_POLL
] = 0;
9078 signal_stop
[GDB_SIGNAL_URG
] = 0;
9079 signal_print
[GDB_SIGNAL_URG
] = 0;
9080 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9081 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9082 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9083 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9085 /* These signals are used internally by user-level thread
9086 implementations. (See signal(5) on Solaris.) Like the above
9087 signals, a healthy program receives and handles them as part of
9088 its normal operation. */
9089 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9090 signal_print
[GDB_SIGNAL_LWP
] = 0;
9091 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9092 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9093 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9094 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9095 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9096 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9098 /* Update cached state. */
9099 signal_cache_update (-1);
9101 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9102 &stop_on_solib_events
, _("\
9103 Set stopping for shared library events."), _("\
9104 Show stopping for shared library events."), _("\
9105 If nonzero, gdb will give control to the user when the dynamic linker\n\
9106 notifies gdb of shared library events. The most common event of interest\n\
9107 to the user would be loading/unloading of a new library."),
9108 set_stop_on_solib_events
,
9109 show_stop_on_solib_events
,
9110 &setlist
, &showlist
);
9112 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9113 follow_fork_mode_kind_names
,
9114 &follow_fork_mode_string
, _("\
9115 Set debugger response to a program call of fork or vfork."), _("\
9116 Show debugger response to a program call of fork or vfork."), _("\
9117 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9118 parent - the original process is debugged after a fork\n\
9119 child - the new process is debugged after a fork\n\
9120 The unfollowed process will continue to run.\n\
9121 By default, the debugger will follow the parent process."),
9123 show_follow_fork_mode_string
,
9124 &setlist
, &showlist
);
9126 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9127 follow_exec_mode_names
,
9128 &follow_exec_mode_string
, _("\
9129 Set debugger response to a program call of exec."), _("\
9130 Show debugger response to a program call of exec."), _("\
9131 An exec call replaces the program image of a process.\n\
9133 follow-exec-mode can be:\n\
9135 new - the debugger creates a new inferior and rebinds the process\n\
9136 to this new inferior. The program the process was running before\n\
9137 the exec call can be restarted afterwards by restarting the original\n\
9140 same - the debugger keeps the process bound to the same inferior.\n\
9141 The new executable image replaces the previous executable loaded in\n\
9142 the inferior. Restarting the inferior after the exec call restarts\n\
9143 the executable the process was running after the exec call.\n\
9145 By default, the debugger will use the same inferior."),
9147 show_follow_exec_mode_string
,
9148 &setlist
, &showlist
);
9150 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9151 scheduler_enums
, &scheduler_mode
, _("\
9152 Set mode for locking scheduler during execution."), _("\
9153 Show mode for locking scheduler during execution."), _("\
9154 off == no locking (threads may preempt at any time)\n\
9155 on == full locking (no thread except the current thread may run)\n\
9156 This applies to both normal execution and replay mode.\n\
9157 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9158 In this mode, other threads may run during other commands.\n\
9159 This applies to both normal execution and replay mode.\n\
9160 replay == scheduler locked in replay mode and unlocked during normal execution."),
9161 set_schedlock_func
, /* traps on target vector */
9162 show_scheduler_mode
,
9163 &setlist
, &showlist
);
9165 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9166 Set mode for resuming threads of all processes."), _("\
9167 Show mode for resuming threads of all processes."), _("\
9168 When on, execution commands (such as 'continue' or 'next') resume all\n\
9169 threads of all processes. When off (which is the default), execution\n\
9170 commands only resume the threads of the current process. The set of\n\
9171 threads that are resumed is further refined by the scheduler-locking\n\
9172 mode (see help set scheduler-locking)."),
9174 show_schedule_multiple
,
9175 &setlist
, &showlist
);
9177 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9178 Set mode of the step operation."), _("\
9179 Show mode of the step operation."), _("\
9180 When set, doing a step over a function without debug line information\n\
9181 will stop at the first instruction of that function. Otherwise, the\n\
9182 function is skipped and the step command stops at a different source line."),
9184 show_step_stop_if_no_debug
,
9185 &setlist
, &showlist
);
9187 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9188 &can_use_displaced_stepping
, _("\
9189 Set debugger's willingness to use displaced stepping."), _("\
9190 Show debugger's willingness to use displaced stepping."), _("\
9191 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9192 supported by the target architecture. If off, gdb will not use displaced\n\
9193 stepping to step over breakpoints, even if such is supported by the target\n\
9194 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9195 if the target architecture supports it and non-stop mode is active, but will not\n\
9196 use it in all-stop mode (see help set non-stop)."),
9198 show_can_use_displaced_stepping
,
9199 &setlist
, &showlist
);
9201 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9202 &exec_direction
, _("Set direction of execution.\n\
9203 Options are 'forward' or 'reverse'."),
9204 _("Show direction of execution (forward/reverse)."),
9205 _("Tells gdb whether to execute forward or backward."),
9206 set_exec_direction_func
, show_exec_direction_func
,
9207 &setlist
, &showlist
);
9209 /* Set/show detach-on-fork: user-settable mode. */
9211 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9212 Set whether gdb will detach the child of a fork."), _("\
9213 Show whether gdb will detach the child of a fork."), _("\
9214 Tells gdb whether to detach the child of a fork."),
9215 NULL
, NULL
, &setlist
, &showlist
);
9217 /* Set/show disable address space randomization mode. */
9219 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9220 &disable_randomization
, _("\
9221 Set disabling of debuggee's virtual address space randomization."), _("\
9222 Show disabling of debuggee's virtual address space randomization."), _("\
9223 When this mode is on (which is the default), randomization of the virtual\n\
9224 address space is disabled. Standalone programs run with the randomization\n\
9225 enabled by default on some platforms."),
9226 &set_disable_randomization
,
9227 &show_disable_randomization
,
9228 &setlist
, &showlist
);
9230 /* ptid initializations */
9231 inferior_ptid
= null_ptid
;
9232 target_last_wait_ptid
= minus_one_ptid
;
9234 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9235 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9236 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9237 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9239 /* Explicitly create without lookup, since that tries to create a
9240 value with a void typed value, and when we get here, gdbarch
9241 isn't initialized yet. At this point, we're quite sure there
9242 isn't another convenience variable of the same name. */
9243 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9245 add_setshow_boolean_cmd ("observer", no_class
,
9246 &observer_mode_1
, _("\
9247 Set whether gdb controls the inferior in observer mode."), _("\
9248 Show whether gdb controls the inferior in observer mode."), _("\
9249 In observer mode, GDB can get data from the inferior, but not\n\
9250 affect its execution. Registers and memory may not be changed,\n\
9251 breakpoints may not be set, and the program cannot be interrupted\n\