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 void nullify_last_target_wait_ptid (void);
83 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
85 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
87 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
89 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
91 static void resume (gdb_signal sig
);
93 /* Asynchronous signal handler registered as event loop source for
94 when we have pending events ready to be passed to the core. */
95 static struct async_event_handler
*infrun_async_inferior_event_token
;
97 /* Stores whether infrun_async was previously enabled or disabled.
98 Starts off as -1, indicating "never enabled/disabled". */
99 static int infrun_is_async
= -1;
104 infrun_async (int enable
)
106 if (infrun_is_async
!= enable
)
108 infrun_is_async
= enable
;
111 fprintf_unfiltered (gdb_stdlog
,
112 "infrun: infrun_async(%d)\n",
116 mark_async_event_handler (infrun_async_inferior_event_token
);
118 clear_async_event_handler (infrun_async_inferior_event_token
);
125 mark_infrun_async_event_handler (void)
127 mark_async_event_handler (infrun_async_inferior_event_token
);
130 /* When set, stop the 'step' command if we enter a function which has
131 no line number information. The normal behavior is that we step
132 over such function. */
133 bool step_stop_if_no_debug
= false;
135 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
136 struct cmd_list_element
*c
, const char *value
)
138 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
141 /* proceed and normal_stop use this to notify the user when the
142 inferior stopped in a different thread than it had been running
145 static ptid_t previous_inferior_ptid
;
147 /* If set (default for legacy reasons), when following a fork, GDB
148 will detach from one of the fork branches, child or parent.
149 Exactly which branch is detached depends on 'set follow-fork-mode'
152 static bool detach_fork
= true;
154 bool debug_displaced
= false;
156 show_debug_displaced (struct ui_file
*file
, int from_tty
,
157 struct cmd_list_element
*c
, const char *value
)
159 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
162 unsigned int debug_infrun
= 0;
164 show_debug_infrun (struct ui_file
*file
, int from_tty
,
165 struct cmd_list_element
*c
, const char *value
)
167 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
171 /* Support for disabling address space randomization. */
173 bool disable_randomization
= true;
176 show_disable_randomization (struct ui_file
*file
, int from_tty
,
177 struct cmd_list_element
*c
, const char *value
)
179 if (target_supports_disable_randomization ())
180 fprintf_filtered (file
,
181 _("Disabling randomization of debuggee's "
182 "virtual address space is %s.\n"),
185 fputs_filtered (_("Disabling randomization of debuggee's "
186 "virtual address space is unsupported on\n"
187 "this platform.\n"), file
);
191 set_disable_randomization (const char *args
, int from_tty
,
192 struct cmd_list_element
*c
)
194 if (!target_supports_disable_randomization ())
195 error (_("Disabling randomization of debuggee's "
196 "virtual address space is unsupported on\n"
200 /* User interface for non-stop mode. */
202 bool non_stop
= false;
203 static bool non_stop_1
= false;
206 set_non_stop (const char *args
, int from_tty
,
207 struct cmd_list_element
*c
)
209 if (target_has_execution
)
211 non_stop_1
= non_stop
;
212 error (_("Cannot change this setting while the inferior is running."));
215 non_stop
= non_stop_1
;
219 show_non_stop (struct ui_file
*file
, int from_tty
,
220 struct cmd_list_element
*c
, const char *value
)
222 fprintf_filtered (file
,
223 _("Controlling the inferior in non-stop mode is %s.\n"),
227 /* "Observer mode" is somewhat like a more extreme version of
228 non-stop, in which all GDB operations that might affect the
229 target's execution have been disabled. */
231 bool observer_mode
= false;
232 static bool observer_mode_1
= false;
235 set_observer_mode (const char *args
, int from_tty
,
236 struct cmd_list_element
*c
)
238 if (target_has_execution
)
240 observer_mode_1
= observer_mode
;
241 error (_("Cannot change this setting while the inferior is running."));
244 observer_mode
= observer_mode_1
;
246 may_write_registers
= !observer_mode
;
247 may_write_memory
= !observer_mode
;
248 may_insert_breakpoints
= !observer_mode
;
249 may_insert_tracepoints
= !observer_mode
;
250 /* We can insert fast tracepoints in or out of observer mode,
251 but enable them if we're going into this mode. */
253 may_insert_fast_tracepoints
= true;
254 may_stop
= !observer_mode
;
255 update_target_permissions ();
257 /* Going *into* observer mode we must force non-stop, then
258 going out we leave it that way. */
261 pagination_enabled
= 0;
262 non_stop
= non_stop_1
= true;
266 printf_filtered (_("Observer mode is now %s.\n"),
267 (observer_mode
? "on" : "off"));
271 show_observer_mode (struct ui_file
*file
, int from_tty
,
272 struct cmd_list_element
*c
, const char *value
)
274 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
277 /* This updates the value of observer mode based on changes in
278 permissions. Note that we are deliberately ignoring the values of
279 may-write-registers and may-write-memory, since the user may have
280 reason to enable these during a session, for instance to turn on a
281 debugging-related global. */
284 update_observer_mode (void)
286 bool newval
= (!may_insert_breakpoints
287 && !may_insert_tracepoints
288 && may_insert_fast_tracepoints
292 /* Let the user know if things change. */
293 if (newval
!= observer_mode
)
294 printf_filtered (_("Observer mode is now %s.\n"),
295 (newval
? "on" : "off"));
297 observer_mode
= observer_mode_1
= newval
;
300 /* Tables of how to react to signals; the user sets them. */
302 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
303 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
304 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
306 /* Table of signals that are registered with "catch signal". A
307 non-zero entry indicates that the signal is caught by some "catch
309 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
311 /* Table of signals that the target may silently handle.
312 This is automatically determined from the flags above,
313 and simply cached here. */
314 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
316 #define SET_SIGS(nsigs,sigs,flags) \
318 int signum = (nsigs); \
319 while (signum-- > 0) \
320 if ((sigs)[signum]) \
321 (flags)[signum] = 1; \
324 #define UNSET_SIGS(nsigs,sigs,flags) \
326 int signum = (nsigs); \
327 while (signum-- > 0) \
328 if ((sigs)[signum]) \
329 (flags)[signum] = 0; \
332 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
333 this function is to avoid exporting `signal_program'. */
336 update_signals_program_target (void)
338 target_program_signals (signal_program
);
341 /* Value to pass to target_resume() to cause all threads to resume. */
343 #define RESUME_ALL minus_one_ptid
345 /* Command list pointer for the "stop" placeholder. */
347 static struct cmd_list_element
*stop_command
;
349 /* Nonzero if we want to give control to the user when we're notified
350 of shared library events by the dynamic linker. */
351 int stop_on_solib_events
;
353 /* Enable or disable optional shared library event breakpoints
354 as appropriate when the above flag is changed. */
357 set_stop_on_solib_events (const char *args
,
358 int from_tty
, struct cmd_list_element
*c
)
360 update_solib_breakpoints ();
364 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
365 struct cmd_list_element
*c
, const char *value
)
367 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
371 /* Nonzero after stop if current stack frame should be printed. */
373 static int stop_print_frame
;
375 /* This is a cached copy of the pid/waitstatus of the last event
376 returned by target_wait()/deprecated_target_wait_hook(). This
377 information is returned by get_last_target_status(). */
378 static ptid_t target_last_wait_ptid
;
379 static struct target_waitstatus target_last_waitstatus
;
381 void init_thread_stepping_state (struct thread_info
*tss
);
383 static const char follow_fork_mode_child
[] = "child";
384 static const char follow_fork_mode_parent
[] = "parent";
386 static const char *const follow_fork_mode_kind_names
[] = {
387 follow_fork_mode_child
,
388 follow_fork_mode_parent
,
392 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
394 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
395 struct cmd_list_element
*c
, const char *value
)
397 fprintf_filtered (file
,
398 _("Debugger response to a program "
399 "call of fork or vfork is \"%s\".\n"),
404 /* Handle changes to the inferior list based on the type of fork,
405 which process is being followed, and whether the other process
406 should be detached. On entry inferior_ptid must be the ptid of
407 the fork parent. At return inferior_ptid is the ptid of the
408 followed inferior. */
411 follow_fork_inferior (int follow_child
, int detach_fork
)
414 ptid_t parent_ptid
, child_ptid
;
416 has_vforked
= (inferior_thread ()->pending_follow
.kind
417 == TARGET_WAITKIND_VFORKED
);
418 parent_ptid
= inferior_ptid
;
419 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
422 && !non_stop
/* Non-stop always resumes both branches. */
423 && current_ui
->prompt_state
== PROMPT_BLOCKED
424 && !(follow_child
|| detach_fork
|| sched_multi
))
426 /* The parent stays blocked inside the vfork syscall until the
427 child execs or exits. If we don't let the child run, then
428 the parent stays blocked. If we're telling the parent to run
429 in the foreground, the user will not be able to ctrl-c to get
430 back the terminal, effectively hanging the debug session. */
431 fprintf_filtered (gdb_stderr
, _("\
432 Can not resume the parent process over vfork in the foreground while\n\
433 holding the child stopped. Try \"set detach-on-fork\" or \
434 \"set schedule-multiple\".\n"));
440 /* Detach new forked process? */
443 /* Before detaching from the child, remove all breakpoints
444 from it. If we forked, then this has already been taken
445 care of by infrun.c. If we vforked however, any
446 breakpoint inserted in the parent is visible in the
447 child, even those added while stopped in a vfork
448 catchpoint. This will remove the breakpoints from the
449 parent also, but they'll be reinserted below. */
452 /* Keep breakpoints list in sync. */
453 remove_breakpoints_inf (current_inferior ());
456 if (print_inferior_events
)
458 /* Ensure that we have a process ptid. */
459 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
461 target_terminal::ours_for_output ();
462 fprintf_filtered (gdb_stdlog
,
463 _("[Detaching after %s from child %s]\n"),
464 has_vforked
? "vfork" : "fork",
465 target_pid_to_str (process_ptid
).c_str ());
470 struct inferior
*parent_inf
, *child_inf
;
472 /* Add process to GDB's tables. */
473 child_inf
= add_inferior (child_ptid
.pid ());
475 parent_inf
= current_inferior ();
476 child_inf
->attach_flag
= parent_inf
->attach_flag
;
477 copy_terminal_info (child_inf
, parent_inf
);
478 child_inf
->gdbarch
= parent_inf
->gdbarch
;
479 copy_inferior_target_desc_info (child_inf
, parent_inf
);
481 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
483 inferior_ptid
= child_ptid
;
484 add_thread_silent (inferior_ptid
);
485 set_current_inferior (child_inf
);
486 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
488 /* If this is a vfork child, then the address-space is
489 shared with the parent. */
492 child_inf
->pspace
= parent_inf
->pspace
;
493 child_inf
->aspace
= parent_inf
->aspace
;
495 /* The parent will be frozen until the child is done
496 with the shared region. Keep track of the
498 child_inf
->vfork_parent
= parent_inf
;
499 child_inf
->pending_detach
= 0;
500 parent_inf
->vfork_child
= child_inf
;
501 parent_inf
->pending_detach
= 0;
505 child_inf
->aspace
= new_address_space ();
506 child_inf
->pspace
= new program_space (child_inf
->aspace
);
507 child_inf
->removable
= 1;
508 set_current_program_space (child_inf
->pspace
);
509 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
511 /* Let the shared library layer (e.g., solib-svr4) learn
512 about this new process, relocate the cloned exec, pull
513 in shared libraries, and install the solib event
514 breakpoint. If a "cloned-VM" event was propagated
515 better throughout the core, this wouldn't be
517 solib_create_inferior_hook (0);
523 struct inferior
*parent_inf
;
525 parent_inf
= current_inferior ();
527 /* If we detached from the child, then we have to be careful
528 to not insert breakpoints in the parent until the child
529 is done with the shared memory region. However, if we're
530 staying attached to the child, then we can and should
531 insert breakpoints, so that we can debug it. A
532 subsequent child exec or exit is enough to know when does
533 the child stops using the parent's address space. */
534 parent_inf
->waiting_for_vfork_done
= detach_fork
;
535 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
540 /* Follow the child. */
541 struct inferior
*parent_inf
, *child_inf
;
542 struct program_space
*parent_pspace
;
544 if (print_inferior_events
)
546 std::string parent_pid
= target_pid_to_str (parent_ptid
);
547 std::string child_pid
= target_pid_to_str (child_ptid
);
549 target_terminal::ours_for_output ();
550 fprintf_filtered (gdb_stdlog
,
551 _("[Attaching after %s %s to child %s]\n"),
553 has_vforked
? "vfork" : "fork",
557 /* Add the new inferior first, so that the target_detach below
558 doesn't unpush the target. */
560 child_inf
= add_inferior (child_ptid
.pid ());
562 parent_inf
= current_inferior ();
563 child_inf
->attach_flag
= parent_inf
->attach_flag
;
564 copy_terminal_info (child_inf
, parent_inf
);
565 child_inf
->gdbarch
= parent_inf
->gdbarch
;
566 copy_inferior_target_desc_info (child_inf
, parent_inf
);
568 parent_pspace
= parent_inf
->pspace
;
570 /* If we're vforking, we want to hold on to the parent until the
571 child exits or execs. At child exec or exit time we can
572 remove the old breakpoints from the parent and detach or
573 resume debugging it. Otherwise, detach the parent now; we'll
574 want to reuse it's program/address spaces, but we can't set
575 them to the child before removing breakpoints from the
576 parent, otherwise, the breakpoints module could decide to
577 remove breakpoints from the wrong process (since they'd be
578 assigned to the same address space). */
582 gdb_assert (child_inf
->vfork_parent
== NULL
);
583 gdb_assert (parent_inf
->vfork_child
== NULL
);
584 child_inf
->vfork_parent
= parent_inf
;
585 child_inf
->pending_detach
= 0;
586 parent_inf
->vfork_child
= child_inf
;
587 parent_inf
->pending_detach
= detach_fork
;
588 parent_inf
->waiting_for_vfork_done
= 0;
590 else if (detach_fork
)
592 if (print_inferior_events
)
594 /* Ensure that we have a process ptid. */
595 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
597 target_terminal::ours_for_output ();
598 fprintf_filtered (gdb_stdlog
,
599 _("[Detaching after fork from "
601 target_pid_to_str (process_ptid
).c_str ());
604 target_detach (parent_inf
, 0);
607 /* Note that the detach above makes PARENT_INF dangling. */
609 /* Add the child thread to the appropriate lists, and switch to
610 this new thread, before cloning the program space, and
611 informing the solib layer about this new process. */
613 inferior_ptid
= child_ptid
;
614 add_thread_silent (inferior_ptid
);
615 set_current_inferior (child_inf
);
617 /* If this is a vfork child, then the address-space is shared
618 with the parent. If we detached from the parent, then we can
619 reuse the parent's program/address spaces. */
620 if (has_vforked
|| detach_fork
)
622 child_inf
->pspace
= parent_pspace
;
623 child_inf
->aspace
= child_inf
->pspace
->aspace
;
627 child_inf
->aspace
= new_address_space ();
628 child_inf
->pspace
= new program_space (child_inf
->aspace
);
629 child_inf
->removable
= 1;
630 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
631 set_current_program_space (child_inf
->pspace
);
632 clone_program_space (child_inf
->pspace
, parent_pspace
);
634 /* Let the shared library layer (e.g., solib-svr4) learn
635 about this new process, relocate the cloned exec, pull in
636 shared libraries, and install the solib event breakpoint.
637 If a "cloned-VM" event was propagated better throughout
638 the core, this wouldn't be required. */
639 solib_create_inferior_hook (0);
643 return target_follow_fork (follow_child
, detach_fork
);
646 /* Tell the target to follow the fork we're stopped at. Returns true
647 if the inferior should be resumed; false, if the target for some
648 reason decided it's best not to resume. */
653 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
654 int should_resume
= 1;
655 struct thread_info
*tp
;
657 /* Copy user stepping state to the new inferior thread. FIXME: the
658 followed fork child thread should have a copy of most of the
659 parent thread structure's run control related fields, not just these.
660 Initialized to avoid "may be used uninitialized" warnings from gcc. */
661 struct breakpoint
*step_resume_breakpoint
= NULL
;
662 struct breakpoint
*exception_resume_breakpoint
= NULL
;
663 CORE_ADDR step_range_start
= 0;
664 CORE_ADDR step_range_end
= 0;
665 struct frame_id step_frame_id
= { 0 };
666 struct thread_fsm
*thread_fsm
= NULL
;
671 struct target_waitstatus wait_status
;
673 /* Get the last target status returned by target_wait(). */
674 get_last_target_status (&wait_ptid
, &wait_status
);
676 /* If not stopped at a fork event, then there's nothing else to
678 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
679 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
682 /* Check if we switched over from WAIT_PTID, since the event was
684 if (wait_ptid
!= minus_one_ptid
685 && inferior_ptid
!= wait_ptid
)
687 /* We did. Switch back to WAIT_PTID thread, to tell the
688 target to follow it (in either direction). We'll
689 afterwards refuse to resume, and inform the user what
691 thread_info
*wait_thread
692 = find_thread_ptid (wait_ptid
);
693 switch_to_thread (wait_thread
);
698 tp
= inferior_thread ();
700 /* If there were any forks/vforks that were caught and are now to be
701 followed, then do so now. */
702 switch (tp
->pending_follow
.kind
)
704 case TARGET_WAITKIND_FORKED
:
705 case TARGET_WAITKIND_VFORKED
:
707 ptid_t parent
, child
;
709 /* If the user did a next/step, etc, over a fork call,
710 preserve the stepping state in the fork child. */
711 if (follow_child
&& should_resume
)
713 step_resume_breakpoint
= clone_momentary_breakpoint
714 (tp
->control
.step_resume_breakpoint
);
715 step_range_start
= tp
->control
.step_range_start
;
716 step_range_end
= tp
->control
.step_range_end
;
717 step_frame_id
= tp
->control
.step_frame_id
;
718 exception_resume_breakpoint
719 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
720 thread_fsm
= tp
->thread_fsm
;
722 /* For now, delete the parent's sr breakpoint, otherwise,
723 parent/child sr breakpoints are considered duplicates,
724 and the child version will not be installed. Remove
725 this when the breakpoints module becomes aware of
726 inferiors and address spaces. */
727 delete_step_resume_breakpoint (tp
);
728 tp
->control
.step_range_start
= 0;
729 tp
->control
.step_range_end
= 0;
730 tp
->control
.step_frame_id
= null_frame_id
;
731 delete_exception_resume_breakpoint (tp
);
732 tp
->thread_fsm
= NULL
;
735 parent
= inferior_ptid
;
736 child
= tp
->pending_follow
.value
.related_pid
;
738 /* Set up inferior(s) as specified by the caller, and tell the
739 target to do whatever is necessary to follow either parent
741 if (follow_fork_inferior (follow_child
, detach_fork
))
743 /* Target refused to follow, or there's some other reason
744 we shouldn't resume. */
749 /* This pending follow fork event is now handled, one way
750 or another. The previous selected thread may be gone
751 from the lists by now, but if it is still around, need
752 to clear the pending follow request. */
753 tp
= find_thread_ptid (parent
);
755 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
757 /* This makes sure we don't try to apply the "Switched
758 over from WAIT_PID" logic above. */
759 nullify_last_target_wait_ptid ();
761 /* If we followed the child, switch to it... */
764 thread_info
*child_thr
= find_thread_ptid (child
);
765 switch_to_thread (child_thr
);
767 /* ... and preserve the stepping state, in case the
768 user was stepping over the fork call. */
771 tp
= inferior_thread ();
772 tp
->control
.step_resume_breakpoint
773 = step_resume_breakpoint
;
774 tp
->control
.step_range_start
= step_range_start
;
775 tp
->control
.step_range_end
= step_range_end
;
776 tp
->control
.step_frame_id
= step_frame_id
;
777 tp
->control
.exception_resume_breakpoint
778 = exception_resume_breakpoint
;
779 tp
->thread_fsm
= thread_fsm
;
783 /* If we get here, it was because we're trying to
784 resume from a fork catchpoint, but, the user
785 has switched threads away from the thread that
786 forked. In that case, the resume command
787 issued is most likely not applicable to the
788 child, so just warn, and refuse to resume. */
789 warning (_("Not resuming: switched threads "
790 "before following fork child."));
793 /* Reset breakpoints in the child as appropriate. */
794 follow_inferior_reset_breakpoints ();
799 case TARGET_WAITKIND_SPURIOUS
:
800 /* Nothing to follow. */
803 internal_error (__FILE__
, __LINE__
,
804 "Unexpected pending_follow.kind %d\n",
805 tp
->pending_follow
.kind
);
809 return should_resume
;
813 follow_inferior_reset_breakpoints (void)
815 struct thread_info
*tp
= inferior_thread ();
817 /* Was there a step_resume breakpoint? (There was if the user
818 did a "next" at the fork() call.) If so, explicitly reset its
819 thread number. Cloned step_resume breakpoints are disabled on
820 creation, so enable it here now that it is associated with the
823 step_resumes are a form of bp that are made to be per-thread.
824 Since we created the step_resume bp when the parent process
825 was being debugged, and now are switching to the child process,
826 from the breakpoint package's viewpoint, that's a switch of
827 "threads". We must update the bp's notion of which thread
828 it is for, or it'll be ignored when it triggers. */
830 if (tp
->control
.step_resume_breakpoint
)
832 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
833 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
836 /* Treat exception_resume breakpoints like step_resume breakpoints. */
837 if (tp
->control
.exception_resume_breakpoint
)
839 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
840 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
843 /* Reinsert all breakpoints in the child. The user may have set
844 breakpoints after catching the fork, in which case those
845 were never set in the child, but only in the parent. This makes
846 sure the inserted breakpoints match the breakpoint list. */
848 breakpoint_re_set ();
849 insert_breakpoints ();
852 /* The child has exited or execed: resume threads of the parent the
853 user wanted to be executing. */
856 proceed_after_vfork_done (struct thread_info
*thread
,
859 int pid
= * (int *) arg
;
861 if (thread
->ptid
.pid () == pid
862 && thread
->state
== THREAD_RUNNING
863 && !thread
->executing
864 && !thread
->stop_requested
865 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
868 fprintf_unfiltered (gdb_stdlog
,
869 "infrun: resuming vfork parent thread %s\n",
870 target_pid_to_str (thread
->ptid
).c_str ());
872 switch_to_thread (thread
);
873 clear_proceed_status (0);
874 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
880 /* Save/restore inferior_ptid, current program space and current
881 inferior. Only use this if the current context points at an exited
882 inferior (and therefore there's no current thread to save). */
883 class scoped_restore_exited_inferior
886 scoped_restore_exited_inferior ()
887 : m_saved_ptid (&inferior_ptid
)
891 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
892 scoped_restore_current_program_space m_pspace
;
893 scoped_restore_current_inferior m_inferior
;
896 /* Called whenever we notice an exec or exit event, to handle
897 detaching or resuming a vfork parent. */
900 handle_vfork_child_exec_or_exit (int exec
)
902 struct inferior
*inf
= current_inferior ();
904 if (inf
->vfork_parent
)
906 int resume_parent
= -1;
908 /* This exec or exit marks the end of the shared memory region
909 between the parent and the child. Break the bonds. */
910 inferior
*vfork_parent
= inf
->vfork_parent
;
911 inf
->vfork_parent
->vfork_child
= NULL
;
912 inf
->vfork_parent
= NULL
;
914 /* If the user wanted to detach from the parent, now is the
916 if (vfork_parent
->pending_detach
)
918 struct thread_info
*tp
;
919 struct program_space
*pspace
;
920 struct address_space
*aspace
;
922 /* follow-fork child, detach-on-fork on. */
924 vfork_parent
->pending_detach
= 0;
926 gdb::optional
<scoped_restore_exited_inferior
>
927 maybe_restore_inferior
;
928 gdb::optional
<scoped_restore_current_pspace_and_thread
>
929 maybe_restore_thread
;
931 /* If we're handling a child exit, then inferior_ptid points
932 at the inferior's pid, not to a thread. */
934 maybe_restore_inferior
.emplace ();
936 maybe_restore_thread
.emplace ();
938 /* We're letting loose of the parent. */
939 tp
= any_live_thread_of_inferior (vfork_parent
);
940 switch_to_thread (tp
);
942 /* We're about to detach from the parent, which implicitly
943 removes breakpoints from its address space. There's a
944 catch here: we want to reuse the spaces for the child,
945 but, parent/child are still sharing the pspace at this
946 point, although the exec in reality makes the kernel give
947 the child a fresh set of new pages. The problem here is
948 that the breakpoints module being unaware of this, would
949 likely chose the child process to write to the parent
950 address space. Swapping the child temporarily away from
951 the spaces has the desired effect. Yes, this is "sort
954 pspace
= inf
->pspace
;
955 aspace
= inf
->aspace
;
959 if (print_inferior_events
)
962 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
964 target_terminal::ours_for_output ();
968 fprintf_filtered (gdb_stdlog
,
969 _("[Detaching vfork parent %s "
970 "after child exec]\n"), pidstr
.c_str ());
974 fprintf_filtered (gdb_stdlog
,
975 _("[Detaching vfork parent %s "
976 "after child exit]\n"), pidstr
.c_str ());
980 target_detach (vfork_parent
, 0);
983 inf
->pspace
= pspace
;
984 inf
->aspace
= aspace
;
988 /* We're staying attached to the parent, so, really give the
989 child a new address space. */
990 inf
->pspace
= new program_space (maybe_new_address_space ());
991 inf
->aspace
= inf
->pspace
->aspace
;
993 set_current_program_space (inf
->pspace
);
995 resume_parent
= vfork_parent
->pid
;
999 struct program_space
*pspace
;
1001 /* If this is a vfork child exiting, then the pspace and
1002 aspaces were shared with the parent. Since we're
1003 reporting the process exit, we'll be mourning all that is
1004 found in the address space, and switching to null_ptid,
1005 preparing to start a new inferior. But, since we don't
1006 want to clobber the parent's address/program spaces, we
1007 go ahead and create a new one for this exiting
1010 /* Switch to null_ptid while running clone_program_space, so
1011 that clone_program_space doesn't want to read the
1012 selected frame of a dead process. */
1013 scoped_restore restore_ptid
1014 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1016 /* This inferior is dead, so avoid giving the breakpoints
1017 module the option to write through to it (cloning a
1018 program space resets breakpoints). */
1021 pspace
= new program_space (maybe_new_address_space ());
1022 set_current_program_space (pspace
);
1024 inf
->symfile_flags
= SYMFILE_NO_READ
;
1025 clone_program_space (pspace
, vfork_parent
->pspace
);
1026 inf
->pspace
= pspace
;
1027 inf
->aspace
= pspace
->aspace
;
1029 resume_parent
= vfork_parent
->pid
;
1032 gdb_assert (current_program_space
== inf
->pspace
);
1034 if (non_stop
&& resume_parent
!= -1)
1036 /* If the user wanted the parent to be running, let it go
1038 scoped_restore_current_thread restore_thread
;
1041 fprintf_unfiltered (gdb_stdlog
,
1042 "infrun: resuming vfork parent process %d\n",
1045 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1050 /* Enum strings for "set|show follow-exec-mode". */
1052 static const char follow_exec_mode_new
[] = "new";
1053 static const char follow_exec_mode_same
[] = "same";
1054 static const char *const follow_exec_mode_names
[] =
1056 follow_exec_mode_new
,
1057 follow_exec_mode_same
,
1061 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1063 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1064 struct cmd_list_element
*c
, const char *value
)
1066 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1069 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1072 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1074 struct inferior
*inf
= current_inferior ();
1075 int pid
= ptid
.pid ();
1076 ptid_t process_ptid
;
1078 /* Switch terminal for any messages produced e.g. by
1079 breakpoint_re_set. */
1080 target_terminal::ours_for_output ();
1082 /* This is an exec event that we actually wish to pay attention to.
1083 Refresh our symbol table to the newly exec'd program, remove any
1084 momentary bp's, etc.
1086 If there are breakpoints, they aren't really inserted now,
1087 since the exec() transformed our inferior into a fresh set
1090 We want to preserve symbolic breakpoints on the list, since
1091 we have hopes that they can be reset after the new a.out's
1092 symbol table is read.
1094 However, any "raw" breakpoints must be removed from the list
1095 (e.g., the solib bp's), since their address is probably invalid
1098 And, we DON'T want to call delete_breakpoints() here, since
1099 that may write the bp's "shadow contents" (the instruction
1100 value that was overwritten with a TRAP instruction). Since
1101 we now have a new a.out, those shadow contents aren't valid. */
1103 mark_breakpoints_out ();
1105 /* The target reports the exec event to the main thread, even if
1106 some other thread does the exec, and even if the main thread was
1107 stopped or already gone. We may still have non-leader threads of
1108 the process on our list. E.g., on targets that don't have thread
1109 exit events (like remote); or on native Linux in non-stop mode if
1110 there were only two threads in the inferior and the non-leader
1111 one is the one that execs (and nothing forces an update of the
1112 thread list up to here). When debugging remotely, it's best to
1113 avoid extra traffic, when possible, so avoid syncing the thread
1114 list with the target, and instead go ahead and delete all threads
1115 of the process but one that reported the event. Note this must
1116 be done before calling update_breakpoints_after_exec, as
1117 otherwise clearing the threads' resources would reference stale
1118 thread breakpoints -- it may have been one of these threads that
1119 stepped across the exec. We could just clear their stepping
1120 states, but as long as we're iterating, might as well delete
1121 them. Deleting them now rather than at the next user-visible
1122 stop provides a nicer sequence of events for user and MI
1124 for (thread_info
*th
: all_threads_safe ())
1125 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1128 /* We also need to clear any left over stale state for the
1129 leader/event thread. E.g., if there was any step-resume
1130 breakpoint or similar, it's gone now. We cannot truly
1131 step-to-next statement through an exec(). */
1132 thread_info
*th
= inferior_thread ();
1133 th
->control
.step_resume_breakpoint
= NULL
;
1134 th
->control
.exception_resume_breakpoint
= NULL
;
1135 th
->control
.single_step_breakpoints
= NULL
;
1136 th
->control
.step_range_start
= 0;
1137 th
->control
.step_range_end
= 0;
1139 /* The user may have had the main thread held stopped in the
1140 previous image (e.g., schedlock on, or non-stop). Release
1142 th
->stop_requested
= 0;
1144 update_breakpoints_after_exec ();
1146 /* What is this a.out's name? */
1147 process_ptid
= ptid_t (pid
);
1148 printf_unfiltered (_("%s is executing new program: %s\n"),
1149 target_pid_to_str (process_ptid
).c_str (),
1152 /* We've followed the inferior through an exec. Therefore, the
1153 inferior has essentially been killed & reborn. */
1155 breakpoint_init_inferior (inf_execd
);
1157 gdb::unique_xmalloc_ptr
<char> exec_file_host
1158 = exec_file_find (exec_file_target
, NULL
);
1160 /* If we were unable to map the executable target pathname onto a host
1161 pathname, tell the user that. Otherwise GDB's subsequent behavior
1162 is confusing. Maybe it would even be better to stop at this point
1163 so that the user can specify a file manually before continuing. */
1164 if (exec_file_host
== NULL
)
1165 warning (_("Could not load symbols for executable %s.\n"
1166 "Do you need \"set sysroot\"?"),
1169 /* Reset the shared library package. This ensures that we get a
1170 shlib event when the child reaches "_start", at which point the
1171 dld will have had a chance to initialize the child. */
1172 /* Also, loading a symbol file below may trigger symbol lookups, and
1173 we don't want those to be satisfied by the libraries of the
1174 previous incarnation of this process. */
1175 no_shared_libraries (NULL
, 0);
1177 if (follow_exec_mode_string
== follow_exec_mode_new
)
1179 /* The user wants to keep the old inferior and program spaces
1180 around. Create a new fresh one, and switch to it. */
1182 /* Do exit processing for the original inferior before setting the new
1183 inferior's pid. Having two inferiors with the same pid would confuse
1184 find_inferior_p(t)id. Transfer the terminal state and info from the
1185 old to the new inferior. */
1186 inf
= add_inferior_with_spaces ();
1187 swap_terminal_info (inf
, current_inferior ());
1188 exit_inferior_silent (current_inferior ());
1191 target_follow_exec (inf
, exec_file_target
);
1193 set_current_inferior (inf
);
1194 set_current_program_space (inf
->pspace
);
1199 /* The old description may no longer be fit for the new image.
1200 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1201 old description; we'll read a new one below. No need to do
1202 this on "follow-exec-mode new", as the old inferior stays
1203 around (its description is later cleared/refetched on
1205 target_clear_description ();
1208 gdb_assert (current_program_space
== inf
->pspace
);
1210 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1211 because the proper displacement for a PIE (Position Independent
1212 Executable) main symbol file will only be computed by
1213 solib_create_inferior_hook below. breakpoint_re_set would fail
1214 to insert the breakpoints with the zero displacement. */
1215 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1217 /* If the target can specify a description, read it. Must do this
1218 after flipping to the new executable (because the target supplied
1219 description must be compatible with the executable's
1220 architecture, and the old executable may e.g., be 32-bit, while
1221 the new one 64-bit), and before anything involving memory or
1223 target_find_description ();
1225 solib_create_inferior_hook (0);
1227 jit_inferior_created_hook ();
1229 breakpoint_re_set ();
1231 /* Reinsert all breakpoints. (Those which were symbolic have
1232 been reset to the proper address in the new a.out, thanks
1233 to symbol_file_command...). */
1234 insert_breakpoints ();
1236 /* The next resume of this inferior should bring it to the shlib
1237 startup breakpoints. (If the user had also set bp's on
1238 "main" from the old (parent) process, then they'll auto-
1239 matically get reset there in the new process.). */
1242 /* The queue of threads that need to do a step-over operation to get
1243 past e.g., a breakpoint. What technique is used to step over the
1244 breakpoint/watchpoint does not matter -- all threads end up in the
1245 same queue, to maintain rough temporal order of execution, in order
1246 to avoid starvation, otherwise, we could e.g., find ourselves
1247 constantly stepping the same couple threads past their breakpoints
1248 over and over, if the single-step finish fast enough. */
1249 struct thread_info
*step_over_queue_head
;
1251 /* Bit flags indicating what the thread needs to step over. */
1253 enum step_over_what_flag
1255 /* Step over a breakpoint. */
1256 STEP_OVER_BREAKPOINT
= 1,
1258 /* Step past a non-continuable watchpoint, in order to let the
1259 instruction execute so we can evaluate the watchpoint
1261 STEP_OVER_WATCHPOINT
= 2
1263 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1265 /* Info about an instruction that is being stepped over. */
1267 struct step_over_info
1269 /* If we're stepping past a breakpoint, this is the address space
1270 and address of the instruction the breakpoint is set at. We'll
1271 skip inserting all breakpoints here. Valid iff ASPACE is
1273 const address_space
*aspace
;
1276 /* The instruction being stepped over triggers a nonsteppable
1277 watchpoint. If true, we'll skip inserting watchpoints. */
1278 int nonsteppable_watchpoint_p
;
1280 /* The thread's global number. */
1284 /* The step-over info of the location that is being stepped over.
1286 Note that with async/breakpoint always-inserted mode, a user might
1287 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1288 being stepped over. As setting a new breakpoint inserts all
1289 breakpoints, we need to make sure the breakpoint being stepped over
1290 isn't inserted then. We do that by only clearing the step-over
1291 info when the step-over is actually finished (or aborted).
1293 Presently GDB can only step over one breakpoint at any given time.
1294 Given threads that can't run code in the same address space as the
1295 breakpoint's can't really miss the breakpoint, GDB could be taught
1296 to step-over at most one breakpoint per address space (so this info
1297 could move to the address space object if/when GDB is extended).
1298 The set of breakpoints being stepped over will normally be much
1299 smaller than the set of all breakpoints, so a flag in the
1300 breakpoint location structure would be wasteful. A separate list
1301 also saves complexity and run-time, as otherwise we'd have to go
1302 through all breakpoint locations clearing their flag whenever we
1303 start a new sequence. Similar considerations weigh against storing
1304 this info in the thread object. Plus, not all step overs actually
1305 have breakpoint locations -- e.g., stepping past a single-step
1306 breakpoint, or stepping to complete a non-continuable
1308 static struct step_over_info step_over_info
;
1310 /* Record the address of the breakpoint/instruction we're currently
1312 N.B. We record the aspace and address now, instead of say just the thread,
1313 because when we need the info later the thread may be running. */
1316 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1317 int nonsteppable_watchpoint_p
,
1320 step_over_info
.aspace
= aspace
;
1321 step_over_info
.address
= address
;
1322 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1323 step_over_info
.thread
= thread
;
1326 /* Called when we're not longer stepping over a breakpoint / an
1327 instruction, so all breakpoints are free to be (re)inserted. */
1330 clear_step_over_info (void)
1333 fprintf_unfiltered (gdb_stdlog
,
1334 "infrun: clear_step_over_info\n");
1335 step_over_info
.aspace
= NULL
;
1336 step_over_info
.address
= 0;
1337 step_over_info
.nonsteppable_watchpoint_p
= 0;
1338 step_over_info
.thread
= -1;
1344 stepping_past_instruction_at (struct address_space
*aspace
,
1347 return (step_over_info
.aspace
!= NULL
1348 && breakpoint_address_match (aspace
, address
,
1349 step_over_info
.aspace
,
1350 step_over_info
.address
));
1356 thread_is_stepping_over_breakpoint (int thread
)
1358 return (step_over_info
.thread
!= -1
1359 && thread
== step_over_info
.thread
);
1365 stepping_past_nonsteppable_watchpoint (void)
1367 return step_over_info
.nonsteppable_watchpoint_p
;
1370 /* Returns true if step-over info is valid. */
1373 step_over_info_valid_p (void)
1375 return (step_over_info
.aspace
!= NULL
1376 || stepping_past_nonsteppable_watchpoint ());
1380 /* Displaced stepping. */
1382 /* In non-stop debugging mode, we must take special care to manage
1383 breakpoints properly; in particular, the traditional strategy for
1384 stepping a thread past a breakpoint it has hit is unsuitable.
1385 'Displaced stepping' is a tactic for stepping one thread past a
1386 breakpoint it has hit while ensuring that other threads running
1387 concurrently will hit the breakpoint as they should.
1389 The traditional way to step a thread T off a breakpoint in a
1390 multi-threaded program in all-stop mode is as follows:
1392 a0) Initially, all threads are stopped, and breakpoints are not
1394 a1) We single-step T, leaving breakpoints uninserted.
1395 a2) We insert breakpoints, and resume all threads.
1397 In non-stop debugging, however, this strategy is unsuitable: we
1398 don't want to have to stop all threads in the system in order to
1399 continue or step T past a breakpoint. Instead, we use displaced
1402 n0) Initially, T is stopped, other threads are running, and
1403 breakpoints are inserted.
1404 n1) We copy the instruction "under" the breakpoint to a separate
1405 location, outside the main code stream, making any adjustments
1406 to the instruction, register, and memory state as directed by
1408 n2) We single-step T over the instruction at its new location.
1409 n3) We adjust the resulting register and memory state as directed
1410 by T's architecture. This includes resetting T's PC to point
1411 back into the main instruction stream.
1414 This approach depends on the following gdbarch methods:
1416 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1417 indicate where to copy the instruction, and how much space must
1418 be reserved there. We use these in step n1.
1420 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1421 address, and makes any necessary adjustments to the instruction,
1422 register contents, and memory. We use this in step n1.
1424 - gdbarch_displaced_step_fixup adjusts registers and memory after
1425 we have successfully single-stepped the instruction, to yield the
1426 same effect the instruction would have had if we had executed it
1427 at its original address. We use this in step n3.
1429 The gdbarch_displaced_step_copy_insn and
1430 gdbarch_displaced_step_fixup functions must be written so that
1431 copying an instruction with gdbarch_displaced_step_copy_insn,
1432 single-stepping across the copied instruction, and then applying
1433 gdbarch_displaced_insn_fixup should have the same effects on the
1434 thread's memory and registers as stepping the instruction in place
1435 would have. Exactly which responsibilities fall to the copy and
1436 which fall to the fixup is up to the author of those functions.
1438 See the comments in gdbarch.sh for details.
1440 Note that displaced stepping and software single-step cannot
1441 currently be used in combination, although with some care I think
1442 they could be made to. Software single-step works by placing
1443 breakpoints on all possible subsequent instructions; if the
1444 displaced instruction is a PC-relative jump, those breakpoints
1445 could fall in very strange places --- on pages that aren't
1446 executable, or at addresses that are not proper instruction
1447 boundaries. (We do generally let other threads run while we wait
1448 to hit the software single-step breakpoint, and they might
1449 encounter such a corrupted instruction.) One way to work around
1450 this would be to have gdbarch_displaced_step_copy_insn fully
1451 simulate the effect of PC-relative instructions (and return NULL)
1452 on architectures that use software single-stepping.
1454 In non-stop mode, we can have independent and simultaneous step
1455 requests, so more than one thread may need to simultaneously step
1456 over a breakpoint. The current implementation assumes there is
1457 only one scratch space per process. In this case, we have to
1458 serialize access to the scratch space. If thread A wants to step
1459 over a breakpoint, but we are currently waiting for some other
1460 thread to complete a displaced step, we leave thread A stopped and
1461 place it in the displaced_step_request_queue. Whenever a displaced
1462 step finishes, we pick the next thread in the queue and start a new
1463 displaced step operation on it. See displaced_step_prepare and
1464 displaced_step_fixup for details. */
1466 /* Default destructor for displaced_step_closure. */
1468 displaced_step_closure::~displaced_step_closure () = default;
1470 /* Get the displaced stepping state of process PID. */
1472 static displaced_step_inferior_state
*
1473 get_displaced_stepping_state (inferior
*inf
)
1475 return &inf
->displaced_step_state
;
1478 /* Returns true if any inferior has a thread doing a displaced
1482 displaced_step_in_progress_any_inferior ()
1484 for (inferior
*i
: all_inferiors ())
1486 if (i
->displaced_step_state
.step_thread
!= nullptr)
1493 /* Return true if thread represented by PTID is doing a displaced
1497 displaced_step_in_progress_thread (thread_info
*thread
)
1499 gdb_assert (thread
!= NULL
);
1501 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1504 /* Return true if process PID has a thread doing a displaced step. */
1507 displaced_step_in_progress (inferior
*inf
)
1509 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1512 /* If inferior is in displaced stepping, and ADDR equals to starting address
1513 of copy area, return corresponding displaced_step_closure. Otherwise,
1516 struct displaced_step_closure
*
1517 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1519 displaced_step_inferior_state
*displaced
1520 = get_displaced_stepping_state (current_inferior ());
1522 /* If checking the mode of displaced instruction in copy area. */
1523 if (displaced
->step_thread
!= nullptr
1524 && displaced
->step_copy
== addr
)
1525 return displaced
->step_closure
;
1531 infrun_inferior_exit (struct inferior
*inf
)
1533 inf
->displaced_step_state
.reset ();
1536 /* If ON, and the architecture supports it, GDB will use displaced
1537 stepping to step over breakpoints. If OFF, or if the architecture
1538 doesn't support it, GDB will instead use the traditional
1539 hold-and-step approach. If AUTO (which is the default), GDB will
1540 decide which technique to use to step over breakpoints depending on
1541 which of all-stop or non-stop mode is active --- displaced stepping
1542 in non-stop mode; hold-and-step in all-stop mode. */
1544 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1547 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1548 struct cmd_list_element
*c
,
1551 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1552 fprintf_filtered (file
,
1553 _("Debugger's willingness to use displaced stepping "
1554 "to step over breakpoints is %s (currently %s).\n"),
1555 value
, target_is_non_stop_p () ? "on" : "off");
1557 fprintf_filtered (file
,
1558 _("Debugger's willingness to use displaced stepping "
1559 "to step over breakpoints is %s.\n"), value
);
1562 /* Return non-zero if displaced stepping can/should be used to step
1563 over breakpoints of thread TP. */
1566 use_displaced_stepping (struct thread_info
*tp
)
1568 struct regcache
*regcache
= get_thread_regcache (tp
);
1569 struct gdbarch
*gdbarch
= regcache
->arch ();
1570 displaced_step_inferior_state
*displaced_state
1571 = get_displaced_stepping_state (tp
->inf
);
1573 return (((can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1574 && target_is_non_stop_p ())
1575 || can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1576 && gdbarch_displaced_step_copy_insn_p (gdbarch
)
1577 && find_record_target () == NULL
1578 && !displaced_state
->failed_before
);
1581 /* Clean out any stray displaced stepping state. */
1583 displaced_step_clear (struct displaced_step_inferior_state
*displaced
)
1585 /* Indicate that there is no cleanup pending. */
1586 displaced
->step_thread
= nullptr;
1588 delete displaced
->step_closure
;
1589 displaced
->step_closure
= NULL
;
1592 /* A cleanup that wraps displaced_step_clear. */
1593 using displaced_step_clear_cleanup
1594 = FORWARD_SCOPE_EXIT (displaced_step_clear
);
1596 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1598 displaced_step_dump_bytes (struct ui_file
*file
,
1599 const gdb_byte
*buf
,
1604 for (i
= 0; i
< len
; i
++)
1605 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1606 fputs_unfiltered ("\n", file
);
1609 /* Prepare to single-step, using displaced stepping.
1611 Note that we cannot use displaced stepping when we have a signal to
1612 deliver. If we have a signal to deliver and an instruction to step
1613 over, then after the step, there will be no indication from the
1614 target whether the thread entered a signal handler or ignored the
1615 signal and stepped over the instruction successfully --- both cases
1616 result in a simple SIGTRAP. In the first case we mustn't do a
1617 fixup, and in the second case we must --- but we can't tell which.
1618 Comments in the code for 'random signals' in handle_inferior_event
1619 explain how we handle this case instead.
1621 Returns 1 if preparing was successful -- this thread is going to be
1622 stepped now; 0 if displaced stepping this thread got queued; or -1
1623 if this instruction can't be displaced stepped. */
1626 displaced_step_prepare_throw (thread_info
*tp
)
1628 regcache
*regcache
= get_thread_regcache (tp
);
1629 struct gdbarch
*gdbarch
= regcache
->arch ();
1630 const address_space
*aspace
= regcache
->aspace ();
1631 CORE_ADDR original
, copy
;
1633 struct displaced_step_closure
*closure
;
1636 /* We should never reach this function if the architecture does not
1637 support displaced stepping. */
1638 gdb_assert (gdbarch_displaced_step_copy_insn_p (gdbarch
));
1640 /* Nor if the thread isn't meant to step over a breakpoint. */
1641 gdb_assert (tp
->control
.trap_expected
);
1643 /* Disable range stepping while executing in the scratch pad. We
1644 want a single-step even if executing the displaced instruction in
1645 the scratch buffer lands within the stepping range (e.g., a
1647 tp
->control
.may_range_step
= 0;
1649 /* We have to displaced step one thread at a time, as we only have
1650 access to a single scratch space per inferior. */
1652 displaced_step_inferior_state
*displaced
1653 = get_displaced_stepping_state (tp
->inf
);
1655 if (displaced
->step_thread
!= nullptr)
1657 /* Already waiting for a displaced step to finish. Defer this
1658 request and place in queue. */
1660 if (debug_displaced
)
1661 fprintf_unfiltered (gdb_stdlog
,
1662 "displaced: deferring step of %s\n",
1663 target_pid_to_str (tp
->ptid
).c_str ());
1665 thread_step_over_chain_enqueue (tp
);
1670 if (debug_displaced
)
1671 fprintf_unfiltered (gdb_stdlog
,
1672 "displaced: stepping %s now\n",
1673 target_pid_to_str (tp
->ptid
).c_str ());
1676 displaced_step_clear (displaced
);
1678 scoped_restore_current_thread restore_thread
;
1680 switch_to_thread (tp
);
1682 original
= regcache_read_pc (regcache
);
1684 copy
= gdbarch_displaced_step_location (gdbarch
);
1685 len
= gdbarch_max_insn_length (gdbarch
);
1687 if (breakpoint_in_range_p (aspace
, copy
, len
))
1689 /* There's a breakpoint set in the scratch pad location range
1690 (which is usually around the entry point). We'd either
1691 install it before resuming, which would overwrite/corrupt the
1692 scratch pad, or if it was already inserted, this displaced
1693 step would overwrite it. The latter is OK in the sense that
1694 we already assume that no thread is going to execute the code
1695 in the scratch pad range (after initial startup) anyway, but
1696 the former is unacceptable. Simply punt and fallback to
1697 stepping over this breakpoint in-line. */
1698 if (debug_displaced
)
1700 fprintf_unfiltered (gdb_stdlog
,
1701 "displaced: breakpoint set in scratch pad. "
1702 "Stepping over breakpoint in-line instead.\n");
1708 /* Save the original contents of the copy area. */
1709 displaced
->step_saved_copy
.resize (len
);
1710 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1712 throw_error (MEMORY_ERROR
,
1713 _("Error accessing memory address %s (%s) for "
1714 "displaced-stepping scratch space."),
1715 paddress (gdbarch
, copy
), safe_strerror (status
));
1716 if (debug_displaced
)
1718 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1719 paddress (gdbarch
, copy
));
1720 displaced_step_dump_bytes (gdb_stdlog
,
1721 displaced
->step_saved_copy
.data (),
1725 closure
= gdbarch_displaced_step_copy_insn (gdbarch
,
1726 original
, copy
, regcache
);
1727 if (closure
== NULL
)
1729 /* The architecture doesn't know how or want to displaced step
1730 this instruction or instruction sequence. Fallback to
1731 stepping over the breakpoint in-line. */
1735 /* Save the information we need to fix things up if the step
1737 displaced
->step_thread
= tp
;
1738 displaced
->step_gdbarch
= gdbarch
;
1739 displaced
->step_closure
= closure
;
1740 displaced
->step_original
= original
;
1741 displaced
->step_copy
= copy
;
1744 displaced_step_clear_cleanup
cleanup (displaced
);
1746 /* Resume execution at the copy. */
1747 regcache_write_pc (regcache
, copy
);
1752 if (debug_displaced
)
1753 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1754 paddress (gdbarch
, copy
));
1759 /* Wrapper for displaced_step_prepare_throw that disabled further
1760 attempts at displaced stepping if we get a memory error. */
1763 displaced_step_prepare (thread_info
*thread
)
1769 prepared
= displaced_step_prepare_throw (thread
);
1771 catch (const gdb_exception_error
&ex
)
1773 struct displaced_step_inferior_state
*displaced_state
;
1775 if (ex
.error
!= MEMORY_ERROR
1776 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1781 fprintf_unfiltered (gdb_stdlog
,
1782 "infrun: disabling displaced stepping: %s\n",
1786 /* Be verbose if "set displaced-stepping" is "on", silent if
1788 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1790 warning (_("disabling displaced stepping: %s"),
1794 /* Disable further displaced stepping attempts. */
1796 = get_displaced_stepping_state (thread
->inf
);
1797 displaced_state
->failed_before
= 1;
1804 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1805 const gdb_byte
*myaddr
, int len
)
1807 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1809 inferior_ptid
= ptid
;
1810 write_memory (memaddr
, myaddr
, len
);
1813 /* Restore the contents of the copy area for thread PTID. */
1816 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1819 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1821 write_memory_ptid (ptid
, displaced
->step_copy
,
1822 displaced
->step_saved_copy
.data (), len
);
1823 if (debug_displaced
)
1824 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1825 target_pid_to_str (ptid
).c_str (),
1826 paddress (displaced
->step_gdbarch
,
1827 displaced
->step_copy
));
1830 /* If we displaced stepped an instruction successfully, adjust
1831 registers and memory to yield the same effect the instruction would
1832 have had if we had executed it at its original address, and return
1833 1. If the instruction didn't complete, relocate the PC and return
1834 -1. If the thread wasn't displaced stepping, return 0. */
1837 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1839 struct displaced_step_inferior_state
*displaced
1840 = get_displaced_stepping_state (event_thread
->inf
);
1843 /* Was this event for the thread we displaced? */
1844 if (displaced
->step_thread
!= event_thread
)
1847 displaced_step_clear_cleanup
cleanup (displaced
);
1849 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1851 /* Fixup may need to read memory/registers. Switch to the thread
1852 that we're fixing up. Also, target_stopped_by_watchpoint checks
1853 the current thread. */
1854 switch_to_thread (event_thread
);
1856 /* Did the instruction complete successfully? */
1857 if (signal
== GDB_SIGNAL_TRAP
1858 && !(target_stopped_by_watchpoint ()
1859 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1860 || target_have_steppable_watchpoint
)))
1862 /* Fix up the resulting state. */
1863 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1864 displaced
->step_closure
,
1865 displaced
->step_original
,
1866 displaced
->step_copy
,
1867 get_thread_regcache (displaced
->step_thread
));
1872 /* Since the instruction didn't complete, all we can do is
1874 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1875 CORE_ADDR pc
= regcache_read_pc (regcache
);
1877 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1878 regcache_write_pc (regcache
, pc
);
1885 /* Data to be passed around while handling an event. This data is
1886 discarded between events. */
1887 struct execution_control_state
1890 /* The thread that got the event, if this was a thread event; NULL
1892 struct thread_info
*event_thread
;
1894 struct target_waitstatus ws
;
1895 int stop_func_filled_in
;
1896 CORE_ADDR stop_func_start
;
1897 CORE_ADDR stop_func_end
;
1898 const char *stop_func_name
;
1901 /* True if the event thread hit the single-step breakpoint of
1902 another thread. Thus the event doesn't cause a stop, the thread
1903 needs to be single-stepped past the single-step breakpoint before
1904 we can switch back to the original stepping thread. */
1905 int hit_singlestep_breakpoint
;
1908 /* Clear ECS and set it to point at TP. */
1911 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1913 memset (ecs
, 0, sizeof (*ecs
));
1914 ecs
->event_thread
= tp
;
1915 ecs
->ptid
= tp
->ptid
;
1918 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1919 static void prepare_to_wait (struct execution_control_state
*ecs
);
1920 static int keep_going_stepped_thread (struct thread_info
*tp
);
1921 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1923 /* Are there any pending step-over requests? If so, run all we can
1924 now and return true. Otherwise, return false. */
1927 start_step_over (void)
1929 struct thread_info
*tp
, *next
;
1931 /* Don't start a new step-over if we already have an in-line
1932 step-over operation ongoing. */
1933 if (step_over_info_valid_p ())
1936 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1938 struct execution_control_state ecss
;
1939 struct execution_control_state
*ecs
= &ecss
;
1940 step_over_what step_what
;
1941 int must_be_in_line
;
1943 gdb_assert (!tp
->stop_requested
);
1945 next
= thread_step_over_chain_next (tp
);
1947 /* If this inferior already has a displaced step in process,
1948 don't start a new one. */
1949 if (displaced_step_in_progress (tp
->inf
))
1952 step_what
= thread_still_needs_step_over (tp
);
1953 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1954 || ((step_what
& STEP_OVER_BREAKPOINT
)
1955 && !use_displaced_stepping (tp
)));
1957 /* We currently stop all threads of all processes to step-over
1958 in-line. If we need to start a new in-line step-over, let
1959 any pending displaced steps finish first. */
1960 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1963 thread_step_over_chain_remove (tp
);
1965 if (step_over_queue_head
== NULL
)
1968 fprintf_unfiltered (gdb_stdlog
,
1969 "infrun: step-over queue now empty\n");
1972 if (tp
->control
.trap_expected
1976 internal_error (__FILE__
, __LINE__
,
1977 "[%s] has inconsistent state: "
1978 "trap_expected=%d, resumed=%d, executing=%d\n",
1979 target_pid_to_str (tp
->ptid
).c_str (),
1980 tp
->control
.trap_expected
,
1986 fprintf_unfiltered (gdb_stdlog
,
1987 "infrun: resuming [%s] for step-over\n",
1988 target_pid_to_str (tp
->ptid
).c_str ());
1990 /* keep_going_pass_signal skips the step-over if the breakpoint
1991 is no longer inserted. In all-stop, we want to keep looking
1992 for a thread that needs a step-over instead of resuming TP,
1993 because we wouldn't be able to resume anything else until the
1994 target stops again. In non-stop, the resume always resumes
1995 only TP, so it's OK to let the thread resume freely. */
1996 if (!target_is_non_stop_p () && !step_what
)
1999 switch_to_thread (tp
);
2000 reset_ecs (ecs
, tp
);
2001 keep_going_pass_signal (ecs
);
2003 if (!ecs
->wait_some_more
)
2004 error (_("Command aborted."));
2006 gdb_assert (tp
->resumed
);
2008 /* If we started a new in-line step-over, we're done. */
2009 if (step_over_info_valid_p ())
2011 gdb_assert (tp
->control
.trap_expected
);
2015 if (!target_is_non_stop_p ())
2017 /* On all-stop, shouldn't have resumed unless we needed a
2019 gdb_assert (tp
->control
.trap_expected
2020 || tp
->step_after_step_resume_breakpoint
);
2022 /* With remote targets (at least), in all-stop, we can't
2023 issue any further remote commands until the program stops
2028 /* Either the thread no longer needed a step-over, or a new
2029 displaced stepping sequence started. Even in the latter
2030 case, continue looking. Maybe we can also start another
2031 displaced step on a thread of other process. */
2037 /* Update global variables holding ptids to hold NEW_PTID if they were
2038 holding OLD_PTID. */
2040 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2042 if (inferior_ptid
== old_ptid
)
2043 inferior_ptid
= new_ptid
;
2048 static const char schedlock_off
[] = "off";
2049 static const char schedlock_on
[] = "on";
2050 static const char schedlock_step
[] = "step";
2051 static const char schedlock_replay
[] = "replay";
2052 static const char *const scheduler_enums
[] = {
2059 static const char *scheduler_mode
= schedlock_replay
;
2061 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2062 struct cmd_list_element
*c
, const char *value
)
2064 fprintf_filtered (file
,
2065 _("Mode for locking scheduler "
2066 "during execution is \"%s\".\n"),
2071 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2073 if (!target_can_lock_scheduler
)
2075 scheduler_mode
= schedlock_off
;
2076 error (_("Target '%s' cannot support this command."), target_shortname
);
2080 /* True if execution commands resume all threads of all processes by
2081 default; otherwise, resume only threads of the current inferior
2083 bool sched_multi
= false;
2085 /* Try to setup for software single stepping over the specified location.
2086 Return 1 if target_resume() should use hardware single step.
2088 GDBARCH the current gdbarch.
2089 PC the location to step over. */
2092 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2096 if (execution_direction
== EXEC_FORWARD
2097 && gdbarch_software_single_step_p (gdbarch
))
2098 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2106 user_visible_resume_ptid (int step
)
2112 /* With non-stop mode on, threads are always handled
2114 resume_ptid
= inferior_ptid
;
2116 else if ((scheduler_mode
== schedlock_on
)
2117 || (scheduler_mode
== schedlock_step
&& step
))
2119 /* User-settable 'scheduler' mode requires solo thread
2121 resume_ptid
= inferior_ptid
;
2123 else if ((scheduler_mode
== schedlock_replay
)
2124 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2126 /* User-settable 'scheduler' mode requires solo thread resume in replay
2128 resume_ptid
= inferior_ptid
;
2130 else if (!sched_multi
&& target_supports_multi_process ())
2132 /* Resume all threads of the current process (and none of other
2134 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2138 /* Resume all threads of all processes. */
2139 resume_ptid
= RESUME_ALL
;
2145 /* Return a ptid representing the set of threads that we will resume,
2146 in the perspective of the target, assuming run control handling
2147 does not require leaving some threads stopped (e.g., stepping past
2148 breakpoint). USER_STEP indicates whether we're about to start the
2149 target for a stepping command. */
2152 internal_resume_ptid (int user_step
)
2154 /* In non-stop, we always control threads individually. Note that
2155 the target may always work in non-stop mode even with "set
2156 non-stop off", in which case user_visible_resume_ptid could
2157 return a wildcard ptid. */
2158 if (target_is_non_stop_p ())
2159 return inferior_ptid
;
2161 return user_visible_resume_ptid (user_step
);
2164 /* Wrapper for target_resume, that handles infrun-specific
2168 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2170 struct thread_info
*tp
= inferior_thread ();
2172 gdb_assert (!tp
->stop_requested
);
2174 /* Install inferior's terminal modes. */
2175 target_terminal::inferior ();
2177 /* Avoid confusing the next resume, if the next stop/resume
2178 happens to apply to another thread. */
2179 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2181 /* Advise target which signals may be handled silently.
2183 If we have removed breakpoints because we are stepping over one
2184 in-line (in any thread), we need to receive all signals to avoid
2185 accidentally skipping a breakpoint during execution of a signal
2188 Likewise if we're displaced stepping, otherwise a trap for a
2189 breakpoint in a signal handler might be confused with the
2190 displaced step finishing. We don't make the displaced_step_fixup
2191 step distinguish the cases instead, because:
2193 - a backtrace while stopped in the signal handler would show the
2194 scratch pad as frame older than the signal handler, instead of
2195 the real mainline code.
2197 - when the thread is later resumed, the signal handler would
2198 return to the scratch pad area, which would no longer be
2200 if (step_over_info_valid_p ()
2201 || displaced_step_in_progress (tp
->inf
))
2202 target_pass_signals ({});
2204 target_pass_signals (signal_pass
);
2206 target_resume (resume_ptid
, step
, sig
);
2208 target_commit_resume ();
2211 /* Resume the inferior. SIG is the signal to give the inferior
2212 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2213 call 'resume', which handles exceptions. */
2216 resume_1 (enum gdb_signal sig
)
2218 struct regcache
*regcache
= get_current_regcache ();
2219 struct gdbarch
*gdbarch
= regcache
->arch ();
2220 struct thread_info
*tp
= inferior_thread ();
2221 CORE_ADDR pc
= regcache_read_pc (regcache
);
2222 const address_space
*aspace
= regcache
->aspace ();
2224 /* This represents the user's step vs continue request. When
2225 deciding whether "set scheduler-locking step" applies, it's the
2226 user's intention that counts. */
2227 const int user_step
= tp
->control
.stepping_command
;
2228 /* This represents what we'll actually request the target to do.
2229 This can decay from a step to a continue, if e.g., we need to
2230 implement single-stepping with breakpoints (software
2234 gdb_assert (!tp
->stop_requested
);
2235 gdb_assert (!thread_is_in_step_over_chain (tp
));
2237 if (tp
->suspend
.waitstatus_pending_p
)
2242 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2244 fprintf_unfiltered (gdb_stdlog
,
2245 "infrun: resume: thread %s has pending wait "
2246 "status %s (currently_stepping=%d).\n",
2247 target_pid_to_str (tp
->ptid
).c_str (),
2249 currently_stepping (tp
));
2254 /* FIXME: What should we do if we are supposed to resume this
2255 thread with a signal? Maybe we should maintain a queue of
2256 pending signals to deliver. */
2257 if (sig
!= GDB_SIGNAL_0
)
2259 warning (_("Couldn't deliver signal %s to %s."),
2260 gdb_signal_to_name (sig
),
2261 target_pid_to_str (tp
->ptid
).c_str ());
2264 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2266 if (target_can_async_p ())
2269 /* Tell the event loop we have an event to process. */
2270 mark_async_event_handler (infrun_async_inferior_event_token
);
2275 tp
->stepped_breakpoint
= 0;
2277 /* Depends on stepped_breakpoint. */
2278 step
= currently_stepping (tp
);
2280 if (current_inferior ()->waiting_for_vfork_done
)
2282 /* Don't try to single-step a vfork parent that is waiting for
2283 the child to get out of the shared memory region (by exec'ing
2284 or exiting). This is particularly important on software
2285 single-step archs, as the child process would trip on the
2286 software single step breakpoint inserted for the parent
2287 process. Since the parent will not actually execute any
2288 instruction until the child is out of the shared region (such
2289 are vfork's semantics), it is safe to simply continue it.
2290 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2291 the parent, and tell it to `keep_going', which automatically
2292 re-sets it stepping. */
2294 fprintf_unfiltered (gdb_stdlog
,
2295 "infrun: resume : clear step\n");
2300 fprintf_unfiltered (gdb_stdlog
,
2301 "infrun: resume (step=%d, signal=%s), "
2302 "trap_expected=%d, current thread [%s] at %s\n",
2303 step
, gdb_signal_to_symbol_string (sig
),
2304 tp
->control
.trap_expected
,
2305 target_pid_to_str (inferior_ptid
).c_str (),
2306 paddress (gdbarch
, pc
));
2308 /* Normally, by the time we reach `resume', the breakpoints are either
2309 removed or inserted, as appropriate. The exception is if we're sitting
2310 at a permanent breakpoint; we need to step over it, but permanent
2311 breakpoints can't be removed. So we have to test for it here. */
2312 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2314 if (sig
!= GDB_SIGNAL_0
)
2316 /* We have a signal to pass to the inferior. The resume
2317 may, or may not take us to the signal handler. If this
2318 is a step, we'll need to stop in the signal handler, if
2319 there's one, (if the target supports stepping into
2320 handlers), or in the next mainline instruction, if
2321 there's no handler. If this is a continue, we need to be
2322 sure to run the handler with all breakpoints inserted.
2323 In all cases, set a breakpoint at the current address
2324 (where the handler returns to), and once that breakpoint
2325 is hit, resume skipping the permanent breakpoint. If
2326 that breakpoint isn't hit, then we've stepped into the
2327 signal handler (or hit some other event). We'll delete
2328 the step-resume breakpoint then. */
2331 fprintf_unfiltered (gdb_stdlog
,
2332 "infrun: resume: skipping permanent breakpoint, "
2333 "deliver signal first\n");
2335 clear_step_over_info ();
2336 tp
->control
.trap_expected
= 0;
2338 if (tp
->control
.step_resume_breakpoint
== NULL
)
2340 /* Set a "high-priority" step-resume, as we don't want
2341 user breakpoints at PC to trigger (again) when this
2343 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2344 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2346 tp
->step_after_step_resume_breakpoint
= step
;
2349 insert_breakpoints ();
2353 /* There's no signal to pass, we can go ahead and skip the
2354 permanent breakpoint manually. */
2356 fprintf_unfiltered (gdb_stdlog
,
2357 "infrun: resume: skipping permanent breakpoint\n");
2358 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2359 /* Update pc to reflect the new address from which we will
2360 execute instructions. */
2361 pc
= regcache_read_pc (regcache
);
2365 /* We've already advanced the PC, so the stepping part
2366 is done. Now we need to arrange for a trap to be
2367 reported to handle_inferior_event. Set a breakpoint
2368 at the current PC, and run to it. Don't update
2369 prev_pc, because if we end in
2370 switch_back_to_stepped_thread, we want the "expected
2371 thread advanced also" branch to be taken. IOW, we
2372 don't want this thread to step further from PC
2374 gdb_assert (!step_over_info_valid_p ());
2375 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2376 insert_breakpoints ();
2378 resume_ptid
= internal_resume_ptid (user_step
);
2379 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2386 /* If we have a breakpoint to step over, make sure to do a single
2387 step only. Same if we have software watchpoints. */
2388 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2389 tp
->control
.may_range_step
= 0;
2391 /* If enabled, step over breakpoints by executing a copy of the
2392 instruction at a different address.
2394 We can't use displaced stepping when we have a signal to deliver;
2395 the comments for displaced_step_prepare explain why. The
2396 comments in the handle_inferior event for dealing with 'random
2397 signals' explain what we do instead.
2399 We can't use displaced stepping when we are waiting for vfork_done
2400 event, displaced stepping breaks the vfork child similarly as single
2401 step software breakpoint. */
2402 if (tp
->control
.trap_expected
2403 && use_displaced_stepping (tp
)
2404 && !step_over_info_valid_p ()
2405 && sig
== GDB_SIGNAL_0
2406 && !current_inferior ()->waiting_for_vfork_done
)
2408 int prepared
= displaced_step_prepare (tp
);
2413 fprintf_unfiltered (gdb_stdlog
,
2414 "Got placed in step-over queue\n");
2416 tp
->control
.trap_expected
= 0;
2419 else if (prepared
< 0)
2421 /* Fallback to stepping over the breakpoint in-line. */
2423 if (target_is_non_stop_p ())
2424 stop_all_threads ();
2426 set_step_over_info (regcache
->aspace (),
2427 regcache_read_pc (regcache
), 0, tp
->global_num
);
2429 step
= maybe_software_singlestep (gdbarch
, pc
);
2431 insert_breakpoints ();
2433 else if (prepared
> 0)
2435 struct displaced_step_inferior_state
*displaced
;
2437 /* Update pc to reflect the new address from which we will
2438 execute instructions due to displaced stepping. */
2439 pc
= regcache_read_pc (get_thread_regcache (tp
));
2441 displaced
= get_displaced_stepping_state (tp
->inf
);
2442 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
,
2443 displaced
->step_closure
);
2447 /* Do we need to do it the hard way, w/temp breakpoints? */
2449 step
= maybe_software_singlestep (gdbarch
, pc
);
2451 /* Currently, our software single-step implementation leads to different
2452 results than hardware single-stepping in one situation: when stepping
2453 into delivering a signal which has an associated signal handler,
2454 hardware single-step will stop at the first instruction of the handler,
2455 while software single-step will simply skip execution of the handler.
2457 For now, this difference in behavior is accepted since there is no
2458 easy way to actually implement single-stepping into a signal handler
2459 without kernel support.
2461 However, there is one scenario where this difference leads to follow-on
2462 problems: if we're stepping off a breakpoint by removing all breakpoints
2463 and then single-stepping. In this case, the software single-step
2464 behavior means that even if there is a *breakpoint* in the signal
2465 handler, GDB still would not stop.
2467 Fortunately, we can at least fix this particular issue. We detect
2468 here the case where we are about to deliver a signal while software
2469 single-stepping with breakpoints removed. In this situation, we
2470 revert the decisions to remove all breakpoints and insert single-
2471 step breakpoints, and instead we install a step-resume breakpoint
2472 at the current address, deliver the signal without stepping, and
2473 once we arrive back at the step-resume breakpoint, actually step
2474 over the breakpoint we originally wanted to step over. */
2475 if (thread_has_single_step_breakpoints_set (tp
)
2476 && sig
!= GDB_SIGNAL_0
2477 && step_over_info_valid_p ())
2479 /* If we have nested signals or a pending signal is delivered
2480 immediately after a handler returns, might might already have
2481 a step-resume breakpoint set on the earlier handler. We cannot
2482 set another step-resume breakpoint; just continue on until the
2483 original breakpoint is hit. */
2484 if (tp
->control
.step_resume_breakpoint
== NULL
)
2486 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2487 tp
->step_after_step_resume_breakpoint
= 1;
2490 delete_single_step_breakpoints (tp
);
2492 clear_step_over_info ();
2493 tp
->control
.trap_expected
= 0;
2495 insert_breakpoints ();
2498 /* If STEP is set, it's a request to use hardware stepping
2499 facilities. But in that case, we should never
2500 use singlestep breakpoint. */
2501 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2503 /* Decide the set of threads to ask the target to resume. */
2504 if (tp
->control
.trap_expected
)
2506 /* We're allowing a thread to run past a breakpoint it has
2507 hit, either by single-stepping the thread with the breakpoint
2508 removed, or by displaced stepping, with the breakpoint inserted.
2509 In the former case, we need to single-step only this thread,
2510 and keep others stopped, as they can miss this breakpoint if
2511 allowed to run. That's not really a problem for displaced
2512 stepping, but, we still keep other threads stopped, in case
2513 another thread is also stopped for a breakpoint waiting for
2514 its turn in the displaced stepping queue. */
2515 resume_ptid
= inferior_ptid
;
2518 resume_ptid
= internal_resume_ptid (user_step
);
2520 if (execution_direction
!= EXEC_REVERSE
2521 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2523 /* There are two cases where we currently need to step a
2524 breakpoint instruction when we have a signal to deliver:
2526 - See handle_signal_stop where we handle random signals that
2527 could take out us out of the stepping range. Normally, in
2528 that case we end up continuing (instead of stepping) over the
2529 signal handler with a breakpoint at PC, but there are cases
2530 where we should _always_ single-step, even if we have a
2531 step-resume breakpoint, like when a software watchpoint is
2532 set. Assuming single-stepping and delivering a signal at the
2533 same time would takes us to the signal handler, then we could
2534 have removed the breakpoint at PC to step over it. However,
2535 some hardware step targets (like e.g., Mac OS) can't step
2536 into signal handlers, and for those, we need to leave the
2537 breakpoint at PC inserted, as otherwise if the handler
2538 recurses and executes PC again, it'll miss the breakpoint.
2539 So we leave the breakpoint inserted anyway, but we need to
2540 record that we tried to step a breakpoint instruction, so
2541 that adjust_pc_after_break doesn't end up confused.
2543 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2544 in one thread after another thread that was stepping had been
2545 momentarily paused for a step-over. When we re-resume the
2546 stepping thread, it may be resumed from that address with a
2547 breakpoint that hasn't trapped yet. Seen with
2548 gdb.threads/non-stop-fair-events.exp, on targets that don't
2549 do displaced stepping. */
2552 fprintf_unfiltered (gdb_stdlog
,
2553 "infrun: resume: [%s] stepped breakpoint\n",
2554 target_pid_to_str (tp
->ptid
).c_str ());
2556 tp
->stepped_breakpoint
= 1;
2558 /* Most targets can step a breakpoint instruction, thus
2559 executing it normally. But if this one cannot, just
2560 continue and we will hit it anyway. */
2561 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2566 && tp
->control
.trap_expected
2567 && use_displaced_stepping (tp
)
2568 && !step_over_info_valid_p ())
2570 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2571 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2572 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2575 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2576 paddress (resume_gdbarch
, actual_pc
));
2577 read_memory (actual_pc
, buf
, sizeof (buf
));
2578 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2581 if (tp
->control
.may_range_step
)
2583 /* If we're resuming a thread with the PC out of the step
2584 range, then we're doing some nested/finer run control
2585 operation, like stepping the thread out of the dynamic
2586 linker or the displaced stepping scratch pad. We
2587 shouldn't have allowed a range step then. */
2588 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2591 do_target_resume (resume_ptid
, step
, sig
);
2595 /* Resume the inferior. SIG is the signal to give the inferior
2596 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2597 rolls back state on error. */
2600 resume (gdb_signal sig
)
2606 catch (const gdb_exception
&ex
)
2608 /* If resuming is being aborted for any reason, delete any
2609 single-step breakpoint resume_1 may have created, to avoid
2610 confusing the following resumption, and to avoid leaving
2611 single-step breakpoints perturbing other threads, in case
2612 we're running in non-stop mode. */
2613 if (inferior_ptid
!= null_ptid
)
2614 delete_single_step_breakpoints (inferior_thread ());
2624 /* Counter that tracks number of user visible stops. This can be used
2625 to tell whether a command has proceeded the inferior past the
2626 current location. This allows e.g., inferior function calls in
2627 breakpoint commands to not interrupt the command list. When the
2628 call finishes successfully, the inferior is standing at the same
2629 breakpoint as if nothing happened (and so we don't call
2631 static ULONGEST current_stop_id
;
2638 return current_stop_id
;
2641 /* Called when we report a user visible stop. */
2649 /* Clear out all variables saying what to do when inferior is continued.
2650 First do this, then set the ones you want, then call `proceed'. */
2653 clear_proceed_status_thread (struct thread_info
*tp
)
2656 fprintf_unfiltered (gdb_stdlog
,
2657 "infrun: clear_proceed_status_thread (%s)\n",
2658 target_pid_to_str (tp
->ptid
).c_str ());
2660 /* If we're starting a new sequence, then the previous finished
2661 single-step is no longer relevant. */
2662 if (tp
->suspend
.waitstatus_pending_p
)
2664 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2667 fprintf_unfiltered (gdb_stdlog
,
2668 "infrun: clear_proceed_status: pending "
2669 "event of %s was a finished step. "
2671 target_pid_to_str (tp
->ptid
).c_str ());
2673 tp
->suspend
.waitstatus_pending_p
= 0;
2674 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2676 else if (debug_infrun
)
2679 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2681 fprintf_unfiltered (gdb_stdlog
,
2682 "infrun: clear_proceed_status_thread: thread %s "
2683 "has pending wait status %s "
2684 "(currently_stepping=%d).\n",
2685 target_pid_to_str (tp
->ptid
).c_str (),
2687 currently_stepping (tp
));
2691 /* If this signal should not be seen by program, give it zero.
2692 Used for debugging signals. */
2693 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2694 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2696 delete tp
->thread_fsm
;
2697 tp
->thread_fsm
= NULL
;
2699 tp
->control
.trap_expected
= 0;
2700 tp
->control
.step_range_start
= 0;
2701 tp
->control
.step_range_end
= 0;
2702 tp
->control
.may_range_step
= 0;
2703 tp
->control
.step_frame_id
= null_frame_id
;
2704 tp
->control
.step_stack_frame_id
= null_frame_id
;
2705 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2706 tp
->control
.step_start_function
= NULL
;
2707 tp
->stop_requested
= 0;
2709 tp
->control
.stop_step
= 0;
2711 tp
->control
.proceed_to_finish
= 0;
2713 tp
->control
.stepping_command
= 0;
2715 /* Discard any remaining commands or status from previous stop. */
2716 bpstat_clear (&tp
->control
.stop_bpstat
);
2720 clear_proceed_status (int step
)
2722 /* With scheduler-locking replay, stop replaying other threads if we're
2723 not replaying the user-visible resume ptid.
2725 This is a convenience feature to not require the user to explicitly
2726 stop replaying the other threads. We're assuming that the user's
2727 intent is to resume tracing the recorded process. */
2728 if (!non_stop
&& scheduler_mode
== schedlock_replay
2729 && target_record_is_replaying (minus_one_ptid
)
2730 && !target_record_will_replay (user_visible_resume_ptid (step
),
2731 execution_direction
))
2732 target_record_stop_replaying ();
2734 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2736 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2738 /* In all-stop mode, delete the per-thread status of all threads
2739 we're about to resume, implicitly and explicitly. */
2740 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
2741 clear_proceed_status_thread (tp
);
2744 if (inferior_ptid
!= null_ptid
)
2746 struct inferior
*inferior
;
2750 /* If in non-stop mode, only delete the per-thread status of
2751 the current thread. */
2752 clear_proceed_status_thread (inferior_thread ());
2755 inferior
= current_inferior ();
2756 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2759 gdb::observers::about_to_proceed
.notify ();
2762 /* Returns true if TP is still stopped at a breakpoint that needs
2763 stepping-over in order to make progress. If the breakpoint is gone
2764 meanwhile, we can skip the whole step-over dance. */
2767 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2769 if (tp
->stepping_over_breakpoint
)
2771 struct regcache
*regcache
= get_thread_regcache (tp
);
2773 if (breakpoint_here_p (regcache
->aspace (),
2774 regcache_read_pc (regcache
))
2775 == ordinary_breakpoint_here
)
2778 tp
->stepping_over_breakpoint
= 0;
2784 /* Check whether thread TP still needs to start a step-over in order
2785 to make progress when resumed. Returns an bitwise or of enum
2786 step_over_what bits, indicating what needs to be stepped over. */
2788 static step_over_what
2789 thread_still_needs_step_over (struct thread_info
*tp
)
2791 step_over_what what
= 0;
2793 if (thread_still_needs_step_over_bp (tp
))
2794 what
|= STEP_OVER_BREAKPOINT
;
2796 if (tp
->stepping_over_watchpoint
2797 && !target_have_steppable_watchpoint
)
2798 what
|= STEP_OVER_WATCHPOINT
;
2803 /* Returns true if scheduler locking applies. STEP indicates whether
2804 we're about to do a step/next-like command to a thread. */
2807 schedlock_applies (struct thread_info
*tp
)
2809 return (scheduler_mode
== schedlock_on
2810 || (scheduler_mode
== schedlock_step
2811 && tp
->control
.stepping_command
)
2812 || (scheduler_mode
== schedlock_replay
2813 && target_record_will_replay (minus_one_ptid
,
2814 execution_direction
)));
2817 /* Basic routine for continuing the program in various fashions.
2819 ADDR is the address to resume at, or -1 for resume where stopped.
2820 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2821 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2823 You should call clear_proceed_status before calling proceed. */
2826 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2828 struct regcache
*regcache
;
2829 struct gdbarch
*gdbarch
;
2832 struct execution_control_state ecss
;
2833 struct execution_control_state
*ecs
= &ecss
;
2836 /* If we're stopped at a fork/vfork, follow the branch set by the
2837 "set follow-fork-mode" command; otherwise, we'll just proceed
2838 resuming the current thread. */
2839 if (!follow_fork ())
2841 /* The target for some reason decided not to resume. */
2843 if (target_can_async_p ())
2844 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2848 /* We'll update this if & when we switch to a new thread. */
2849 previous_inferior_ptid
= inferior_ptid
;
2851 regcache
= get_current_regcache ();
2852 gdbarch
= regcache
->arch ();
2853 const address_space
*aspace
= regcache
->aspace ();
2855 pc
= regcache_read_pc (regcache
);
2856 thread_info
*cur_thr
= inferior_thread ();
2858 /* Fill in with reasonable starting values. */
2859 init_thread_stepping_state (cur_thr
);
2861 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2863 if (addr
== (CORE_ADDR
) -1)
2865 if (pc
== cur_thr
->suspend
.stop_pc
2866 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2867 && execution_direction
!= EXEC_REVERSE
)
2868 /* There is a breakpoint at the address we will resume at,
2869 step one instruction before inserting breakpoints so that
2870 we do not stop right away (and report a second hit at this
2873 Note, we don't do this in reverse, because we won't
2874 actually be executing the breakpoint insn anyway.
2875 We'll be (un-)executing the previous instruction. */
2876 cur_thr
->stepping_over_breakpoint
= 1;
2877 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2878 && gdbarch_single_step_through_delay (gdbarch
,
2879 get_current_frame ()))
2880 /* We stepped onto an instruction that needs to be stepped
2881 again before re-inserting the breakpoint, do so. */
2882 cur_thr
->stepping_over_breakpoint
= 1;
2886 regcache_write_pc (regcache
, addr
);
2889 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2890 cur_thr
->suspend
.stop_signal
= siggnal
;
2892 resume_ptid
= user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2894 /* If an exception is thrown from this point on, make sure to
2895 propagate GDB's knowledge of the executing state to the
2896 frontend/user running state. */
2897 scoped_finish_thread_state
finish_state (resume_ptid
);
2899 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2900 threads (e.g., we might need to set threads stepping over
2901 breakpoints first), from the user/frontend's point of view, all
2902 threads in RESUME_PTID are now running. Unless we're calling an
2903 inferior function, as in that case we pretend the inferior
2904 doesn't run at all. */
2905 if (!cur_thr
->control
.in_infcall
)
2906 set_running (resume_ptid
, 1);
2909 fprintf_unfiltered (gdb_stdlog
,
2910 "infrun: proceed (addr=%s, signal=%s)\n",
2911 paddress (gdbarch
, addr
),
2912 gdb_signal_to_symbol_string (siggnal
));
2914 annotate_starting ();
2916 /* Make sure that output from GDB appears before output from the
2918 gdb_flush (gdb_stdout
);
2920 /* Since we've marked the inferior running, give it the terminal. A
2921 QUIT/Ctrl-C from here on is forwarded to the target (which can
2922 still detect attempts to unblock a stuck connection with repeated
2923 Ctrl-C from within target_pass_ctrlc). */
2924 target_terminal::inferior ();
2926 /* In a multi-threaded task we may select another thread and
2927 then continue or step.
2929 But if a thread that we're resuming had stopped at a breakpoint,
2930 it will immediately cause another breakpoint stop without any
2931 execution (i.e. it will report a breakpoint hit incorrectly). So
2932 we must step over it first.
2934 Look for threads other than the current (TP) that reported a
2935 breakpoint hit and haven't been resumed yet since. */
2937 /* If scheduler locking applies, we can avoid iterating over all
2939 if (!non_stop
&& !schedlock_applies (cur_thr
))
2941 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
2943 switch_to_thread_no_regs (tp
);
2945 /* Ignore the current thread here. It's handled
2950 if (!thread_still_needs_step_over (tp
))
2953 gdb_assert (!thread_is_in_step_over_chain (tp
));
2956 fprintf_unfiltered (gdb_stdlog
,
2957 "infrun: need to step-over [%s] first\n",
2958 target_pid_to_str (tp
->ptid
).c_str ());
2960 thread_step_over_chain_enqueue (tp
);
2963 switch_to_thread (cur_thr
);
2966 /* Enqueue the current thread last, so that we move all other
2967 threads over their breakpoints first. */
2968 if (cur_thr
->stepping_over_breakpoint
)
2969 thread_step_over_chain_enqueue (cur_thr
);
2971 /* If the thread isn't started, we'll still need to set its prev_pc,
2972 so that switch_back_to_stepped_thread knows the thread hasn't
2973 advanced. Must do this before resuming any thread, as in
2974 all-stop/remote, once we resume we can't send any other packet
2975 until the target stops again. */
2976 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
2979 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
2981 started
= start_step_over ();
2983 if (step_over_info_valid_p ())
2985 /* Either this thread started a new in-line step over, or some
2986 other thread was already doing one. In either case, don't
2987 resume anything else until the step-over is finished. */
2989 else if (started
&& !target_is_non_stop_p ())
2991 /* A new displaced stepping sequence was started. In all-stop,
2992 we can't talk to the target anymore until it next stops. */
2994 else if (!non_stop
&& target_is_non_stop_p ())
2996 /* In all-stop, but the target is always in non-stop mode.
2997 Start all other threads that are implicitly resumed too. */
2998 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
3000 switch_to_thread_no_regs (tp
);
3005 fprintf_unfiltered (gdb_stdlog
,
3006 "infrun: proceed: [%s] resumed\n",
3007 target_pid_to_str (tp
->ptid
).c_str ());
3008 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3012 if (thread_is_in_step_over_chain (tp
))
3015 fprintf_unfiltered (gdb_stdlog
,
3016 "infrun: proceed: [%s] needs step-over\n",
3017 target_pid_to_str (tp
->ptid
).c_str ());
3022 fprintf_unfiltered (gdb_stdlog
,
3023 "infrun: proceed: resuming %s\n",
3024 target_pid_to_str (tp
->ptid
).c_str ());
3026 reset_ecs (ecs
, tp
);
3027 switch_to_thread (tp
);
3028 keep_going_pass_signal (ecs
);
3029 if (!ecs
->wait_some_more
)
3030 error (_("Command aborted."));
3033 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3035 /* The thread wasn't started, and isn't queued, run it now. */
3036 reset_ecs (ecs
, cur_thr
);
3037 switch_to_thread (cur_thr
);
3038 keep_going_pass_signal (ecs
);
3039 if (!ecs
->wait_some_more
)
3040 error (_("Command aborted."));
3044 target_commit_resume ();
3046 finish_state
.release ();
3048 /* If we've switched threads above, switch back to the previously
3049 current thread. We don't want the user to see a different
3051 switch_to_thread (cur_thr
);
3053 /* Tell the event loop to wait for it to stop. If the target
3054 supports asynchronous execution, it'll do this from within
3056 if (!target_can_async_p ())
3057 mark_async_event_handler (infrun_async_inferior_event_token
);
3061 /* Start remote-debugging of a machine over a serial link. */
3064 start_remote (int from_tty
)
3066 struct inferior
*inferior
;
3068 inferior
= current_inferior ();
3069 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3071 /* Always go on waiting for the target, regardless of the mode. */
3072 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3073 indicate to wait_for_inferior that a target should timeout if
3074 nothing is returned (instead of just blocking). Because of this,
3075 targets expecting an immediate response need to, internally, set
3076 things up so that the target_wait() is forced to eventually
3078 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3079 differentiate to its caller what the state of the target is after
3080 the initial open has been performed. Here we're assuming that
3081 the target has stopped. It should be possible to eventually have
3082 target_open() return to the caller an indication that the target
3083 is currently running and GDB state should be set to the same as
3084 for an async run. */
3085 wait_for_inferior ();
3087 /* Now that the inferior has stopped, do any bookkeeping like
3088 loading shared libraries. We want to do this before normal_stop,
3089 so that the displayed frame is up to date. */
3090 post_create_inferior (current_top_target (), from_tty
);
3095 /* Initialize static vars when a new inferior begins. */
3098 init_wait_for_inferior (void)
3100 /* These are meaningless until the first time through wait_for_inferior. */
3102 breakpoint_init_inferior (inf_starting
);
3104 clear_proceed_status (0);
3106 target_last_wait_ptid
= minus_one_ptid
;
3108 previous_inferior_ptid
= inferior_ptid
;
3113 static void handle_inferior_event (struct execution_control_state
*ecs
);
3115 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3116 struct execution_control_state
*ecs
);
3117 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3118 struct execution_control_state
*ecs
);
3119 static void handle_signal_stop (struct execution_control_state
*ecs
);
3120 static void check_exception_resume (struct execution_control_state
*,
3121 struct frame_info
*);
3123 static void end_stepping_range (struct execution_control_state
*ecs
);
3124 static void stop_waiting (struct execution_control_state
*ecs
);
3125 static void keep_going (struct execution_control_state
*ecs
);
3126 static void process_event_stop_test (struct execution_control_state
*ecs
);
3127 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3129 /* This function is attached as a "thread_stop_requested" observer.
3130 Cleanup local state that assumed the PTID was to be resumed, and
3131 report the stop to the frontend. */
3134 infrun_thread_stop_requested (ptid_t ptid
)
3136 /* PTID was requested to stop. If the thread was already stopped,
3137 but the user/frontend doesn't know about that yet (e.g., the
3138 thread had been temporarily paused for some step-over), set up
3139 for reporting the stop now. */
3140 for (thread_info
*tp
: all_threads (ptid
))
3142 if (tp
->state
!= THREAD_RUNNING
)
3147 /* Remove matching threads from the step-over queue, so
3148 start_step_over doesn't try to resume them
3150 if (thread_is_in_step_over_chain (tp
))
3151 thread_step_over_chain_remove (tp
);
3153 /* If the thread is stopped, but the user/frontend doesn't
3154 know about that yet, queue a pending event, as if the
3155 thread had just stopped now. Unless the thread already had
3157 if (!tp
->suspend
.waitstatus_pending_p
)
3159 tp
->suspend
.waitstatus_pending_p
= 1;
3160 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3161 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3164 /* Clear the inline-frame state, since we're re-processing the
3166 clear_inline_frame_state (tp
->ptid
);
3168 /* If this thread was paused because some other thread was
3169 doing an inline-step over, let that finish first. Once
3170 that happens, we'll restart all threads and consume pending
3171 stop events then. */
3172 if (step_over_info_valid_p ())
3175 /* Otherwise we can process the (new) pending event now. Set
3176 it so this pending event is considered by
3183 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3185 if (target_last_wait_ptid
== tp
->ptid
)
3186 nullify_last_target_wait_ptid ();
3189 /* Delete the step resume, single-step and longjmp/exception resume
3190 breakpoints of TP. */
3193 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3195 delete_step_resume_breakpoint (tp
);
3196 delete_exception_resume_breakpoint (tp
);
3197 delete_single_step_breakpoints (tp
);
3200 /* If the target still has execution, call FUNC for each thread that
3201 just stopped. In all-stop, that's all the non-exited threads; in
3202 non-stop, that's the current thread, only. */
3204 typedef void (*for_each_just_stopped_thread_callback_func
)
3205 (struct thread_info
*tp
);
3208 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3210 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3213 if (target_is_non_stop_p ())
3215 /* If in non-stop mode, only the current thread stopped. */
3216 func (inferior_thread ());
3220 /* In all-stop mode, all threads have stopped. */
3221 for (thread_info
*tp
: all_non_exited_threads ())
3226 /* Delete the step resume and longjmp/exception resume breakpoints of
3227 the threads that just stopped. */
3230 delete_just_stopped_threads_infrun_breakpoints (void)
3232 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3235 /* Delete the single-step breakpoints of the threads that just
3239 delete_just_stopped_threads_single_step_breakpoints (void)
3241 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3247 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3248 const struct target_waitstatus
*ws
)
3250 std::string status_string
= target_waitstatus_to_string (ws
);
3253 /* The text is split over several lines because it was getting too long.
3254 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3255 output as a unit; we want only one timestamp printed if debug_timestamp
3258 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3261 waiton_ptid
.tid ());
3262 if (waiton_ptid
.pid () != -1)
3263 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3264 stb
.printf (", status) =\n");
3265 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3269 target_pid_to_str (result_ptid
).c_str ());
3270 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3272 /* This uses %s in part to handle %'s in the text, but also to avoid
3273 a gcc error: the format attribute requires a string literal. */
3274 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3277 /* Select a thread at random, out of those which are resumed and have
3280 static struct thread_info
*
3281 random_pending_event_thread (ptid_t waiton_ptid
)
3285 auto has_event
= [] (thread_info
*tp
)
3288 && tp
->suspend
.waitstatus_pending_p
);
3291 /* First see how many events we have. Count only resumed threads
3292 that have an event pending. */
3293 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3297 if (num_events
== 0)
3300 /* Now randomly pick a thread out of those that have had events. */
3301 int random_selector
= (int) ((num_events
* (double) rand ())
3302 / (RAND_MAX
+ 1.0));
3304 if (debug_infrun
&& num_events
> 1)
3305 fprintf_unfiltered (gdb_stdlog
,
3306 "infrun: Found %d events, selecting #%d\n",
3307 num_events
, random_selector
);
3309 /* Select the Nth thread that has had an event. */
3310 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3312 if (random_selector
-- == 0)
3315 gdb_assert_not_reached ("event thread not found");
3318 /* Wrapper for target_wait that first checks whether threads have
3319 pending statuses to report before actually asking the target for
3323 do_target_wait (ptid_t ptid
, struct target_waitstatus
*status
, int options
)
3326 struct thread_info
*tp
;
3328 /* First check if there is a resumed thread with a wait status
3330 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3332 tp
= random_pending_event_thread (ptid
);
3337 fprintf_unfiltered (gdb_stdlog
,
3338 "infrun: Waiting for specific thread %s.\n",
3339 target_pid_to_str (ptid
).c_str ());
3341 /* We have a specific thread to check. */
3342 tp
= find_thread_ptid (ptid
);
3343 gdb_assert (tp
!= NULL
);
3344 if (!tp
->suspend
.waitstatus_pending_p
)
3349 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3350 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3352 struct regcache
*regcache
= get_thread_regcache (tp
);
3353 struct gdbarch
*gdbarch
= regcache
->arch ();
3357 pc
= regcache_read_pc (regcache
);
3359 if (pc
!= tp
->suspend
.stop_pc
)
3362 fprintf_unfiltered (gdb_stdlog
,
3363 "infrun: PC of %s changed. was=%s, now=%s\n",
3364 target_pid_to_str (tp
->ptid
).c_str (),
3365 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3366 paddress (gdbarch
, pc
));
3369 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3372 fprintf_unfiltered (gdb_stdlog
,
3373 "infrun: previous breakpoint of %s, at %s gone\n",
3374 target_pid_to_str (tp
->ptid
).c_str (),
3375 paddress (gdbarch
, pc
));
3383 fprintf_unfiltered (gdb_stdlog
,
3384 "infrun: pending event of %s cancelled.\n",
3385 target_pid_to_str (tp
->ptid
).c_str ());
3387 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3388 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3397 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3399 fprintf_unfiltered (gdb_stdlog
,
3400 "infrun: Using pending wait status %s for %s.\n",
3402 target_pid_to_str (tp
->ptid
).c_str ());
3405 /* Now that we've selected our final event LWP, un-adjust its PC
3406 if it was a software breakpoint (and the target doesn't
3407 always adjust the PC itself). */
3408 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3409 && !target_supports_stopped_by_sw_breakpoint ())
3411 struct regcache
*regcache
;
3412 struct gdbarch
*gdbarch
;
3415 regcache
= get_thread_regcache (tp
);
3416 gdbarch
= regcache
->arch ();
3418 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3423 pc
= regcache_read_pc (regcache
);
3424 regcache_write_pc (regcache
, pc
+ decr_pc
);
3428 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3429 *status
= tp
->suspend
.waitstatus
;
3430 tp
->suspend
.waitstatus_pending_p
= 0;
3432 /* Wake up the event loop again, until all pending events are
3434 if (target_is_async_p ())
3435 mark_async_event_handler (infrun_async_inferior_event_token
);
3439 /* But if we don't find one, we'll have to wait. */
3441 if (deprecated_target_wait_hook
)
3442 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3444 event_ptid
= target_wait (ptid
, status
, options
);
3449 /* Prepare and stabilize the inferior for detaching it. E.g.,
3450 detaching while a thread is displaced stepping is a recipe for
3451 crashing it, as nothing would readjust the PC out of the scratch
3455 prepare_for_detach (void)
3457 struct inferior
*inf
= current_inferior ();
3458 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3460 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3462 /* Is any thread of this process displaced stepping? If not,
3463 there's nothing else to do. */
3464 if (displaced
->step_thread
== nullptr)
3468 fprintf_unfiltered (gdb_stdlog
,
3469 "displaced-stepping in-process while detaching");
3471 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3473 while (displaced
->step_thread
!= nullptr)
3475 struct execution_control_state ecss
;
3476 struct execution_control_state
*ecs
;
3479 memset (ecs
, 0, sizeof (*ecs
));
3481 overlay_cache_invalid
= 1;
3482 /* Flush target cache before starting to handle each event.
3483 Target was running and cache could be stale. This is just a
3484 heuristic. Running threads may modify target memory, but we
3485 don't get any event. */
3486 target_dcache_invalidate ();
3488 ecs
->ptid
= do_target_wait (pid_ptid
, &ecs
->ws
, 0);
3491 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3493 /* If an error happens while handling the event, propagate GDB's
3494 knowledge of the executing state to the frontend/user running
3496 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3498 /* Now figure out what to do with the result of the result. */
3499 handle_inferior_event (ecs
);
3501 /* No error, don't finish the state yet. */
3502 finish_state
.release ();
3504 /* Breakpoints and watchpoints are not installed on the target
3505 at this point, and signals are passed directly to the
3506 inferior, so this must mean the process is gone. */
3507 if (!ecs
->wait_some_more
)
3509 restore_detaching
.release ();
3510 error (_("Program exited while detaching"));
3514 restore_detaching
.release ();
3517 /* Wait for control to return from inferior to debugger.
3519 If inferior gets a signal, we may decide to start it up again
3520 instead of returning. That is why there is a loop in this function.
3521 When this function actually returns it means the inferior
3522 should be left stopped and GDB should read more commands. */
3525 wait_for_inferior (void)
3529 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3531 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3533 /* If an error happens while handling the event, propagate GDB's
3534 knowledge of the executing state to the frontend/user running
3536 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3540 struct execution_control_state ecss
;
3541 struct execution_control_state
*ecs
= &ecss
;
3542 ptid_t waiton_ptid
= minus_one_ptid
;
3544 memset (ecs
, 0, sizeof (*ecs
));
3546 overlay_cache_invalid
= 1;
3548 /* Flush target cache before starting to handle each event.
3549 Target was running and cache could be stale. This is just a
3550 heuristic. Running threads may modify target memory, but we
3551 don't get any event. */
3552 target_dcache_invalidate ();
3554 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
, 0);
3557 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3559 /* Now figure out what to do with the result of the result. */
3560 handle_inferior_event (ecs
);
3562 if (!ecs
->wait_some_more
)
3566 /* No error, don't finish the state yet. */
3567 finish_state
.release ();
3570 /* Cleanup that reinstalls the readline callback handler, if the
3571 target is running in the background. If while handling the target
3572 event something triggered a secondary prompt, like e.g., a
3573 pagination prompt, we'll have removed the callback handler (see
3574 gdb_readline_wrapper_line). Need to do this as we go back to the
3575 event loop, ready to process further input. Note this has no
3576 effect if the handler hasn't actually been removed, because calling
3577 rl_callback_handler_install resets the line buffer, thus losing
3581 reinstall_readline_callback_handler_cleanup ()
3583 struct ui
*ui
= current_ui
;
3587 /* We're not going back to the top level event loop yet. Don't
3588 install the readline callback, as it'd prep the terminal,
3589 readline-style (raw, noecho) (e.g., --batch). We'll install
3590 it the next time the prompt is displayed, when we're ready
3595 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3596 gdb_rl_callback_handler_reinstall ();
3599 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3600 that's just the event thread. In all-stop, that's all threads. */
3603 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3605 if (ecs
->event_thread
!= NULL
3606 && ecs
->event_thread
->thread_fsm
!= NULL
)
3607 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3611 for (thread_info
*thr
: all_non_exited_threads ())
3613 if (thr
->thread_fsm
== NULL
)
3615 if (thr
== ecs
->event_thread
)
3618 switch_to_thread (thr
);
3619 thr
->thread_fsm
->clean_up (thr
);
3622 if (ecs
->event_thread
!= NULL
)
3623 switch_to_thread (ecs
->event_thread
);
3627 /* Helper for all_uis_check_sync_execution_done that works on the
3631 check_curr_ui_sync_execution_done (void)
3633 struct ui
*ui
= current_ui
;
3635 if (ui
->prompt_state
== PROMPT_NEEDED
3637 && !gdb_in_secondary_prompt_p (ui
))
3639 target_terminal::ours ();
3640 gdb::observers::sync_execution_done
.notify ();
3641 ui_register_input_event_handler (ui
);
3648 all_uis_check_sync_execution_done (void)
3650 SWITCH_THRU_ALL_UIS ()
3652 check_curr_ui_sync_execution_done ();
3659 all_uis_on_sync_execution_starting (void)
3661 SWITCH_THRU_ALL_UIS ()
3663 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3664 async_disable_stdin ();
3668 /* Asynchronous version of wait_for_inferior. It is called by the
3669 event loop whenever a change of state is detected on the file
3670 descriptor corresponding to the target. It can be called more than
3671 once to complete a single execution command. In such cases we need
3672 to keep the state in a global variable ECSS. If it is the last time
3673 that this function is called for a single execution command, then
3674 report to the user that the inferior has stopped, and do the
3675 necessary cleanups. */
3678 fetch_inferior_event (void *client_data
)
3680 struct execution_control_state ecss
;
3681 struct execution_control_state
*ecs
= &ecss
;
3683 ptid_t waiton_ptid
= minus_one_ptid
;
3685 memset (ecs
, 0, sizeof (*ecs
));
3687 /* Events are always processed with the main UI as current UI. This
3688 way, warnings, debug output, etc. are always consistently sent to
3689 the main console. */
3690 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3692 /* End up with readline processing input, if necessary. */
3694 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3696 /* We're handling a live event, so make sure we're doing live
3697 debugging. If we're looking at traceframes while the target is
3698 running, we're going to need to get back to that mode after
3699 handling the event. */
3700 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3703 maybe_restore_traceframe
.emplace ();
3704 set_current_traceframe (-1);
3707 /* The user/frontend should not notice a thread switch due to
3708 internal events. Make sure we revert to the user selected
3709 thread and frame after handling the event and running any
3710 breakpoint commands. */
3711 scoped_restore_current_thread restore_thread
;
3713 overlay_cache_invalid
= 1;
3714 /* Flush target cache before starting to handle each event. Target
3715 was running and cache could be stale. This is just a heuristic.
3716 Running threads may modify target memory, but we don't get any
3718 target_dcache_invalidate ();
3720 scoped_restore save_exec_dir
3721 = make_scoped_restore (&execution_direction
,
3722 target_execution_direction ());
3724 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
,
3725 target_can_async_p () ? TARGET_WNOHANG
: 0);
3728 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3730 /* If an error happens while handling the event, propagate GDB's
3731 knowledge of the executing state to the frontend/user running
3733 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3734 scoped_finish_thread_state
finish_state (finish_ptid
);
3736 /* Get executed before scoped_restore_current_thread above to apply
3737 still for the thread which has thrown the exception. */
3738 auto defer_bpstat_clear
3739 = make_scope_exit (bpstat_clear_actions
);
3740 auto defer_delete_threads
3741 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3743 /* Now figure out what to do with the result of the result. */
3744 handle_inferior_event (ecs
);
3746 if (!ecs
->wait_some_more
)
3748 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3749 int should_stop
= 1;
3750 struct thread_info
*thr
= ecs
->event_thread
;
3752 delete_just_stopped_threads_infrun_breakpoints ();
3756 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3758 if (thread_fsm
!= NULL
)
3759 should_stop
= thread_fsm
->should_stop (thr
);
3768 bool should_notify_stop
= true;
3771 clean_up_just_stopped_threads_fsms (ecs
);
3773 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3774 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3776 if (should_notify_stop
)
3778 /* We may not find an inferior if this was a process exit. */
3779 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3780 proceeded
= normal_stop ();
3785 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3789 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3790 previously selected thread is gone. We have two
3791 choices - switch to no thread selected, or restore the
3792 previously selected thread (now exited). We chose the
3793 later, just because that's what GDB used to do. After
3794 this, "info threads" says "The current thread <Thread
3795 ID 2> has terminated." instead of "No thread
3799 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3800 restore_thread
.dont_restore ();
3804 defer_delete_threads
.release ();
3805 defer_bpstat_clear
.release ();
3807 /* No error, don't finish the thread states yet. */
3808 finish_state
.release ();
3810 /* This scope is used to ensure that readline callbacks are
3811 reinstalled here. */
3814 /* If a UI was in sync execution mode, and now isn't, restore its
3815 prompt (a synchronous execution command has finished, and we're
3816 ready for input). */
3817 all_uis_check_sync_execution_done ();
3820 && exec_done_display_p
3821 && (inferior_ptid
== null_ptid
3822 || inferior_thread ()->state
!= THREAD_RUNNING
))
3823 printf_unfiltered (_("completed.\n"));
3826 /* Record the frame and location we're currently stepping through. */
3828 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
3830 struct thread_info
*tp
= inferior_thread ();
3832 tp
->control
.step_frame_id
= get_frame_id (frame
);
3833 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3835 tp
->current_symtab
= sal
.symtab
;
3836 tp
->current_line
= sal
.line
;
3839 /* Clear context switchable stepping state. */
3842 init_thread_stepping_state (struct thread_info
*tss
)
3844 tss
->stepped_breakpoint
= 0;
3845 tss
->stepping_over_breakpoint
= 0;
3846 tss
->stepping_over_watchpoint
= 0;
3847 tss
->step_after_step_resume_breakpoint
= 0;
3850 /* Set the cached copy of the last ptid/waitstatus. */
3853 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
3855 target_last_wait_ptid
= ptid
;
3856 target_last_waitstatus
= status
;
3859 /* Return the cached copy of the last pid/waitstatus returned by
3860 target_wait()/deprecated_target_wait_hook(). The data is actually
3861 cached by handle_inferior_event(), which gets called immediately
3862 after target_wait()/deprecated_target_wait_hook(). */
3865 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
3867 *ptidp
= target_last_wait_ptid
;
3868 *status
= target_last_waitstatus
;
3872 nullify_last_target_wait_ptid (void)
3874 target_last_wait_ptid
= minus_one_ptid
;
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_inferiors ())
4629 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4633 fprintf_unfiltered (gdb_stdlog
,
4634 "infrun: TARGET_WAITKIND_NO_RESUMED "
4635 "(expect process exit)\n");
4636 prepare_to_wait (ecs
);
4641 /* Go ahead and report the event. */
4645 /* Given an execution control state that has been freshly filled in by
4646 an event from the inferior, figure out what it means and take
4649 The alternatives are:
4651 1) stop_waiting and return; to really stop and return to the
4654 2) keep_going and return; to wait for the next event (set
4655 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4659 handle_inferior_event (struct execution_control_state
*ecs
)
4661 /* Make sure that all temporary struct value objects that were
4662 created during the handling of the event get deleted at the
4664 scoped_value_mark free_values
;
4666 enum stop_kind stop_soon
;
4669 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
4670 target_waitstatus_to_string (&ecs
->ws
).c_str ());
4672 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4674 /* We had an event in the inferior, but we are not interested in
4675 handling it at this level. The lower layers have already
4676 done what needs to be done, if anything.
4678 One of the possible circumstances for this is when the
4679 inferior produces output for the console. The inferior has
4680 not stopped, and we are ignoring the event. Another possible
4681 circumstance is any event which the lower level knows will be
4682 reported multiple times without an intervening resume. */
4683 prepare_to_wait (ecs
);
4687 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4689 prepare_to_wait (ecs
);
4693 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4694 && handle_no_resumed (ecs
))
4697 /* Cache the last pid/waitstatus. */
4698 set_last_target_status (ecs
->ptid
, ecs
->ws
);
4700 /* Always clear state belonging to the previous time we stopped. */
4701 stop_stack_dummy
= STOP_NONE
;
4703 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4705 /* No unwaited-for children left. IOW, all resumed children
4707 stop_print_frame
= 0;
4712 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
4713 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
4715 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
4716 /* If it's a new thread, add it to the thread database. */
4717 if (ecs
->event_thread
== NULL
)
4718 ecs
->event_thread
= add_thread (ecs
->ptid
);
4720 /* Disable range stepping. If the next step request could use a
4721 range, this will be end up re-enabled then. */
4722 ecs
->event_thread
->control
.may_range_step
= 0;
4725 /* Dependent on valid ECS->EVENT_THREAD. */
4726 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
4728 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4729 reinit_frame_cache ();
4731 breakpoint_retire_moribund ();
4733 /* First, distinguish signals caused by the debugger from signals
4734 that have to do with the program's own actions. Note that
4735 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4736 on the operating system version. Here we detect when a SIGILL or
4737 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4738 something similar for SIGSEGV, since a SIGSEGV will be generated
4739 when we're trying to execute a breakpoint instruction on a
4740 non-executable stack. This happens for call dummy breakpoints
4741 for architectures like SPARC that place call dummies on the
4743 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
4744 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
4745 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
4746 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
4748 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4750 if (breakpoint_inserted_here_p (regcache
->aspace (),
4751 regcache_read_pc (regcache
)))
4754 fprintf_unfiltered (gdb_stdlog
,
4755 "infrun: Treating signal as SIGTRAP\n");
4756 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
4760 /* Mark the non-executing threads accordingly. In all-stop, all
4761 threads of all processes are stopped when we get any event
4762 reported. In non-stop mode, only the event thread stops. */
4766 if (!target_is_non_stop_p ())
4767 mark_ptid
= minus_one_ptid
;
4768 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
4769 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4771 /* If we're handling a process exit in non-stop mode, even
4772 though threads haven't been deleted yet, one would think
4773 that there is nothing to do, as threads of the dead process
4774 will be soon deleted, and threads of any other process were
4775 left running. However, on some targets, threads survive a
4776 process exit event. E.g., for the "checkpoint" command,
4777 when the current checkpoint/fork exits, linux-fork.c
4778 automatically switches to another fork from within
4779 target_mourn_inferior, by associating the same
4780 inferior/thread to another fork. We haven't mourned yet at
4781 this point, but we must mark any threads left in the
4782 process as not-executing so that finish_thread_state marks
4783 them stopped (in the user's perspective) if/when we present
4784 the stop to the user. */
4785 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
4788 mark_ptid
= ecs
->ptid
;
4790 set_executing (mark_ptid
, 0);
4792 /* Likewise the resumed flag. */
4793 set_resumed (mark_ptid
, 0);
4796 switch (ecs
->ws
.kind
)
4798 case TARGET_WAITKIND_LOADED
:
4799 context_switch (ecs
);
4800 /* Ignore gracefully during startup of the inferior, as it might
4801 be the shell which has just loaded some objects, otherwise
4802 add the symbols for the newly loaded objects. Also ignore at
4803 the beginning of an attach or remote session; we will query
4804 the full list of libraries once the connection is
4807 stop_soon
= get_inferior_stop_soon (ecs
);
4808 if (stop_soon
== NO_STOP_QUIETLY
)
4810 struct regcache
*regcache
;
4812 regcache
= get_thread_regcache (ecs
->event_thread
);
4814 handle_solib_event ();
4816 ecs
->event_thread
->control
.stop_bpstat
4817 = bpstat_stop_status (regcache
->aspace (),
4818 ecs
->event_thread
->suspend
.stop_pc
,
4819 ecs
->event_thread
, &ecs
->ws
);
4821 if (handle_stop_requested (ecs
))
4824 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4826 /* A catchpoint triggered. */
4827 process_event_stop_test (ecs
);
4831 /* If requested, stop when the dynamic linker notifies
4832 gdb of events. This allows the user to get control
4833 and place breakpoints in initializer routines for
4834 dynamically loaded objects (among other things). */
4835 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4836 if (stop_on_solib_events
)
4838 /* Make sure we print "Stopped due to solib-event" in
4840 stop_print_frame
= 1;
4847 /* If we are skipping through a shell, or through shared library
4848 loading that we aren't interested in, resume the program. If
4849 we're running the program normally, also resume. */
4850 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
4852 /* Loading of shared libraries might have changed breakpoint
4853 addresses. Make sure new breakpoints are inserted. */
4854 if (stop_soon
== NO_STOP_QUIETLY
)
4855 insert_breakpoints ();
4856 resume (GDB_SIGNAL_0
);
4857 prepare_to_wait (ecs
);
4861 /* But stop if we're attaching or setting up a remote
4863 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4864 || stop_soon
== STOP_QUIETLY_REMOTE
)
4867 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4872 internal_error (__FILE__
, __LINE__
,
4873 _("unhandled stop_soon: %d"), (int) stop_soon
);
4875 case TARGET_WAITKIND_SPURIOUS
:
4876 if (handle_stop_requested (ecs
))
4878 context_switch (ecs
);
4879 resume (GDB_SIGNAL_0
);
4880 prepare_to_wait (ecs
);
4883 case TARGET_WAITKIND_THREAD_CREATED
:
4884 if (handle_stop_requested (ecs
))
4886 context_switch (ecs
);
4887 if (!switch_back_to_stepped_thread (ecs
))
4891 case TARGET_WAITKIND_EXITED
:
4892 case TARGET_WAITKIND_SIGNALLED
:
4893 inferior_ptid
= ecs
->ptid
;
4894 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
4895 set_current_program_space (current_inferior ()->pspace
);
4896 handle_vfork_child_exec_or_exit (0);
4897 target_terminal::ours (); /* Must do this before mourn anyway. */
4899 /* Clearing any previous state of convenience variables. */
4900 clear_exit_convenience_vars ();
4902 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4904 /* Record the exit code in the convenience variable $_exitcode, so
4905 that the user can inspect this again later. */
4906 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4907 (LONGEST
) ecs
->ws
.value
.integer
);
4909 /* Also record this in the inferior itself. */
4910 current_inferior ()->has_exit_code
= 1;
4911 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
4913 /* Support the --return-child-result option. */
4914 return_child_result_value
= ecs
->ws
.value
.integer
;
4916 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
4920 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
4922 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
4924 /* Set the value of the internal variable $_exitsignal,
4925 which holds the signal uncaught by the inferior. */
4926 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4927 gdbarch_gdb_signal_to_target (gdbarch
,
4928 ecs
->ws
.value
.sig
));
4932 /* We don't have access to the target's method used for
4933 converting between signal numbers (GDB's internal
4934 representation <-> target's representation).
4935 Therefore, we cannot do a good job at displaying this
4936 information to the user. It's better to just warn
4937 her about it (if infrun debugging is enabled), and
4940 fprintf_filtered (gdb_stdlog
, _("\
4941 Cannot fill $_exitsignal with the correct signal number.\n"));
4944 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
4947 gdb_flush (gdb_stdout
);
4948 target_mourn_inferior (inferior_ptid
);
4949 stop_print_frame
= 0;
4953 /* The following are the only cases in which we keep going;
4954 the above cases end in a continue or goto. */
4955 case TARGET_WAITKIND_FORKED
:
4956 case TARGET_WAITKIND_VFORKED
:
4957 /* Check whether the inferior is displaced stepping. */
4959 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4960 struct gdbarch
*gdbarch
= regcache
->arch ();
4962 /* If checking displaced stepping is supported, and thread
4963 ecs->ptid is displaced stepping. */
4964 if (displaced_step_in_progress_thread (ecs
->event_thread
))
4966 struct inferior
*parent_inf
4967 = find_inferior_ptid (ecs
->ptid
);
4968 struct regcache
*child_regcache
;
4969 CORE_ADDR parent_pc
;
4971 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4972 indicating that the displaced stepping of syscall instruction
4973 has been done. Perform cleanup for parent process here. Note
4974 that this operation also cleans up the child process for vfork,
4975 because their pages are shared. */
4976 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
4977 /* Start a new step-over in another thread if there's one
4981 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
4983 struct displaced_step_inferior_state
*displaced
4984 = get_displaced_stepping_state (parent_inf
);
4986 /* Restore scratch pad for child process. */
4987 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
4990 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4991 the child's PC is also within the scratchpad. Set the child's PC
4992 to the parent's PC value, which has already been fixed up.
4993 FIXME: we use the parent's aspace here, although we're touching
4994 the child, because the child hasn't been added to the inferior
4995 list yet at this point. */
4998 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
5000 parent_inf
->aspace
);
5001 /* Read PC value of parent process. */
5002 parent_pc
= regcache_read_pc (regcache
);
5004 if (debug_displaced
)
5005 fprintf_unfiltered (gdb_stdlog
,
5006 "displaced: write child pc from %s to %s\n",
5008 regcache_read_pc (child_regcache
)),
5009 paddress (gdbarch
, parent_pc
));
5011 regcache_write_pc (child_regcache
, parent_pc
);
5015 context_switch (ecs
);
5017 /* Immediately detach breakpoints from the child before there's
5018 any chance of letting the user delete breakpoints from the
5019 breakpoint lists. If we don't do this early, it's easy to
5020 leave left over traps in the child, vis: "break foo; catch
5021 fork; c; <fork>; del; c; <child calls foo>". We only follow
5022 the fork on the last `continue', and by that time the
5023 breakpoint at "foo" is long gone from the breakpoint table.
5024 If we vforked, then we don't need to unpatch here, since both
5025 parent and child are sharing the same memory pages; we'll
5026 need to unpatch at follow/detach time instead to be certain
5027 that new breakpoints added between catchpoint hit time and
5028 vfork follow are detached. */
5029 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5031 /* This won't actually modify the breakpoint list, but will
5032 physically remove the breakpoints from the child. */
5033 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5036 delete_just_stopped_threads_single_step_breakpoints ();
5038 /* In case the event is caught by a catchpoint, remember that
5039 the event is to be followed at the next resume of the thread,
5040 and not immediately. */
5041 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5043 ecs
->event_thread
->suspend
.stop_pc
5044 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5046 ecs
->event_thread
->control
.stop_bpstat
5047 = bpstat_stop_status (get_current_regcache ()->aspace (),
5048 ecs
->event_thread
->suspend
.stop_pc
,
5049 ecs
->event_thread
, &ecs
->ws
);
5051 if (handle_stop_requested (ecs
))
5054 /* If no catchpoint triggered for this, then keep going. Note
5055 that we're interested in knowing the bpstat actually causes a
5056 stop, not just if it may explain the signal. Software
5057 watchpoints, for example, always appear in the bpstat. */
5058 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5062 = (follow_fork_mode_string
== follow_fork_mode_child
);
5064 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5066 should_resume
= follow_fork ();
5068 thread_info
*parent
= ecs
->event_thread
;
5069 thread_info
*child
= find_thread_ptid (ecs
->ws
.value
.related_pid
);
5071 /* At this point, the parent is marked running, and the
5072 child is marked stopped. */
5074 /* If not resuming the parent, mark it stopped. */
5075 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5076 parent
->set_running (false);
5078 /* If resuming the child, mark it running. */
5079 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5080 child
->set_running (true);
5082 /* In non-stop mode, also resume the other branch. */
5083 if (!detach_fork
&& (non_stop
5084 || (sched_multi
&& target_is_non_stop_p ())))
5087 switch_to_thread (parent
);
5089 switch_to_thread (child
);
5091 ecs
->event_thread
= inferior_thread ();
5092 ecs
->ptid
= inferior_ptid
;
5097 switch_to_thread (child
);
5099 switch_to_thread (parent
);
5101 ecs
->event_thread
= inferior_thread ();
5102 ecs
->ptid
= inferior_ptid
;
5110 process_event_stop_test (ecs
);
5113 case TARGET_WAITKIND_VFORK_DONE
:
5114 /* Done with the shared memory region. Re-insert breakpoints in
5115 the parent, and keep going. */
5117 context_switch (ecs
);
5119 current_inferior ()->waiting_for_vfork_done
= 0;
5120 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5122 if (handle_stop_requested (ecs
))
5125 /* This also takes care of reinserting breakpoints in the
5126 previously locked inferior. */
5130 case TARGET_WAITKIND_EXECD
:
5132 /* Note we can't read registers yet (the stop_pc), because we
5133 don't yet know the inferior's post-exec architecture.
5134 'stop_pc' is explicitly read below instead. */
5135 switch_to_thread_no_regs (ecs
->event_thread
);
5137 /* Do whatever is necessary to the parent branch of the vfork. */
5138 handle_vfork_child_exec_or_exit (1);
5140 /* This causes the eventpoints and symbol table to be reset.
5141 Must do this now, before trying to determine whether to
5143 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5145 /* In follow_exec we may have deleted the original thread and
5146 created a new one. Make sure that the event thread is the
5147 execd thread for that case (this is a nop otherwise). */
5148 ecs
->event_thread
= inferior_thread ();
5150 ecs
->event_thread
->suspend
.stop_pc
5151 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5153 ecs
->event_thread
->control
.stop_bpstat
5154 = bpstat_stop_status (get_current_regcache ()->aspace (),
5155 ecs
->event_thread
->suspend
.stop_pc
,
5156 ecs
->event_thread
, &ecs
->ws
);
5158 /* Note that this may be referenced from inside
5159 bpstat_stop_status above, through inferior_has_execd. */
5160 xfree (ecs
->ws
.value
.execd_pathname
);
5161 ecs
->ws
.value
.execd_pathname
= NULL
;
5163 if (handle_stop_requested (ecs
))
5166 /* If no catchpoint triggered for this, then keep going. */
5167 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5169 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5173 process_event_stop_test (ecs
);
5176 /* Be careful not to try to gather much state about a thread
5177 that's in a syscall. It's frequently a losing proposition. */
5178 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5179 /* Getting the current syscall number. */
5180 if (handle_syscall_event (ecs
) == 0)
5181 process_event_stop_test (ecs
);
5184 /* Before examining the threads further, step this thread to
5185 get it entirely out of the syscall. (We get notice of the
5186 event when the thread is just on the verge of exiting a
5187 syscall. Stepping one instruction seems to get it back
5189 case TARGET_WAITKIND_SYSCALL_RETURN
:
5190 if (handle_syscall_event (ecs
) == 0)
5191 process_event_stop_test (ecs
);
5194 case TARGET_WAITKIND_STOPPED
:
5195 handle_signal_stop (ecs
);
5198 case TARGET_WAITKIND_NO_HISTORY
:
5199 /* Reverse execution: target ran out of history info. */
5201 /* Switch to the stopped thread. */
5202 context_switch (ecs
);
5204 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5206 delete_just_stopped_threads_single_step_breakpoints ();
5207 ecs
->event_thread
->suspend
.stop_pc
5208 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5210 if (handle_stop_requested (ecs
))
5213 gdb::observers::no_history
.notify ();
5219 /* Restart threads back to what they were trying to do back when we
5220 paused them for an in-line step-over. The EVENT_THREAD thread is
5224 restart_threads (struct thread_info
*event_thread
)
5226 /* In case the instruction just stepped spawned a new thread. */
5227 update_thread_list ();
5229 for (thread_info
*tp
: all_non_exited_threads ())
5231 switch_to_thread_no_regs (tp
);
5233 if (tp
== event_thread
)
5236 fprintf_unfiltered (gdb_stdlog
,
5237 "infrun: restart threads: "
5238 "[%s] is event thread\n",
5239 target_pid_to_str (tp
->ptid
).c_str ());
5243 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5246 fprintf_unfiltered (gdb_stdlog
,
5247 "infrun: restart threads: "
5248 "[%s] not meant to be running\n",
5249 target_pid_to_str (tp
->ptid
).c_str ());
5256 fprintf_unfiltered (gdb_stdlog
,
5257 "infrun: restart threads: [%s] resumed\n",
5258 target_pid_to_str (tp
->ptid
).c_str ());
5259 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5263 if (thread_is_in_step_over_chain (tp
))
5266 fprintf_unfiltered (gdb_stdlog
,
5267 "infrun: restart threads: "
5268 "[%s] needs step-over\n",
5269 target_pid_to_str (tp
->ptid
).c_str ());
5270 gdb_assert (!tp
->resumed
);
5275 if (tp
->suspend
.waitstatus_pending_p
)
5278 fprintf_unfiltered (gdb_stdlog
,
5279 "infrun: restart threads: "
5280 "[%s] has pending status\n",
5281 target_pid_to_str (tp
->ptid
).c_str ());
5286 gdb_assert (!tp
->stop_requested
);
5288 /* If some thread needs to start a step-over at this point, it
5289 should still be in the step-over queue, and thus skipped
5291 if (thread_still_needs_step_over (tp
))
5293 internal_error (__FILE__
, __LINE__
,
5294 "thread [%s] needs a step-over, but not in "
5295 "step-over queue\n",
5296 target_pid_to_str (tp
->ptid
).c_str ());
5299 if (currently_stepping (tp
))
5302 fprintf_unfiltered (gdb_stdlog
,
5303 "infrun: restart threads: [%s] was stepping\n",
5304 target_pid_to_str (tp
->ptid
).c_str ());
5305 keep_going_stepped_thread (tp
);
5309 struct execution_control_state ecss
;
5310 struct execution_control_state
*ecs
= &ecss
;
5313 fprintf_unfiltered (gdb_stdlog
,
5314 "infrun: restart threads: [%s] continuing\n",
5315 target_pid_to_str (tp
->ptid
).c_str ());
5316 reset_ecs (ecs
, tp
);
5317 switch_to_thread (tp
);
5318 keep_going_pass_signal (ecs
);
5323 /* Callback for iterate_over_threads. Find a resumed thread that has
5324 a pending waitstatus. */
5327 resumed_thread_with_pending_status (struct thread_info
*tp
,
5331 && tp
->suspend
.waitstatus_pending_p
);
5334 /* Called when we get an event that may finish an in-line or
5335 out-of-line (displaced stepping) step-over started previously.
5336 Return true if the event is processed and we should go back to the
5337 event loop; false if the caller should continue processing the
5341 finish_step_over (struct execution_control_state
*ecs
)
5343 int had_step_over_info
;
5345 displaced_step_fixup (ecs
->event_thread
,
5346 ecs
->event_thread
->suspend
.stop_signal
);
5348 had_step_over_info
= step_over_info_valid_p ();
5350 if (had_step_over_info
)
5352 /* If we're stepping over a breakpoint with all threads locked,
5353 then only the thread that was stepped should be reporting
5355 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5357 clear_step_over_info ();
5360 if (!target_is_non_stop_p ())
5363 /* Start a new step-over in another thread if there's one that
5367 /* If we were stepping over a breakpoint before, and haven't started
5368 a new in-line step-over sequence, then restart all other threads
5369 (except the event thread). We can't do this in all-stop, as then
5370 e.g., we wouldn't be able to issue any other remote packet until
5371 these other threads stop. */
5372 if (had_step_over_info
&& !step_over_info_valid_p ())
5374 struct thread_info
*pending
;
5376 /* If we only have threads with pending statuses, the restart
5377 below won't restart any thread and so nothing re-inserts the
5378 breakpoint we just stepped over. But we need it inserted
5379 when we later process the pending events, otherwise if
5380 another thread has a pending event for this breakpoint too,
5381 we'd discard its event (because the breakpoint that
5382 originally caused the event was no longer inserted). */
5383 context_switch (ecs
);
5384 insert_breakpoints ();
5386 restart_threads (ecs
->event_thread
);
5388 /* If we have events pending, go through handle_inferior_event
5389 again, picking up a pending event at random. This avoids
5390 thread starvation. */
5392 /* But not if we just stepped over a watchpoint in order to let
5393 the instruction execute so we can evaluate its expression.
5394 The set of watchpoints that triggered is recorded in the
5395 breakpoint objects themselves (see bp->watchpoint_triggered).
5396 If we processed another event first, that other event could
5397 clobber this info. */
5398 if (ecs
->event_thread
->stepping_over_watchpoint
)
5401 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5403 if (pending
!= NULL
)
5405 struct thread_info
*tp
= ecs
->event_thread
;
5406 struct regcache
*regcache
;
5410 fprintf_unfiltered (gdb_stdlog
,
5411 "infrun: found resumed threads with "
5412 "pending events, saving status\n");
5415 gdb_assert (pending
!= tp
);
5417 /* Record the event thread's event for later. */
5418 save_waitstatus (tp
, &ecs
->ws
);
5419 /* This was cleared early, by handle_inferior_event. Set it
5420 so this pending event is considered by
5424 gdb_assert (!tp
->executing
);
5426 regcache
= get_thread_regcache (tp
);
5427 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5431 fprintf_unfiltered (gdb_stdlog
,
5432 "infrun: saved stop_pc=%s for %s "
5433 "(currently_stepping=%d)\n",
5434 paddress (target_gdbarch (),
5435 tp
->suspend
.stop_pc
),
5436 target_pid_to_str (tp
->ptid
).c_str (),
5437 currently_stepping (tp
));
5440 /* This in-line step-over finished; clear this so we won't
5441 start a new one. This is what handle_signal_stop would
5442 do, if we returned false. */
5443 tp
->stepping_over_breakpoint
= 0;
5445 /* Wake up the event loop again. */
5446 mark_async_event_handler (infrun_async_inferior_event_token
);
5448 prepare_to_wait (ecs
);
5456 /* Come here when the program has stopped with a signal. */
5459 handle_signal_stop (struct execution_control_state
*ecs
)
5461 struct frame_info
*frame
;
5462 struct gdbarch
*gdbarch
;
5463 int stopped_by_watchpoint
;
5464 enum stop_kind stop_soon
;
5467 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5469 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5471 /* Do we need to clean up the state of a thread that has
5472 completed a displaced single-step? (Doing so usually affects
5473 the PC, so do it here, before we set stop_pc.) */
5474 if (finish_step_over (ecs
))
5477 /* If we either finished a single-step or hit a breakpoint, but
5478 the user wanted this thread to be stopped, pretend we got a
5479 SIG0 (generic unsignaled stop). */
5480 if (ecs
->event_thread
->stop_requested
5481 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5482 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5484 ecs
->event_thread
->suspend
.stop_pc
5485 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5489 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5490 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5492 switch_to_thread (ecs
->event_thread
);
5494 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5495 paddress (reg_gdbarch
,
5496 ecs
->event_thread
->suspend
.stop_pc
));
5497 if (target_stopped_by_watchpoint ())
5501 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5503 if (target_stopped_data_address (current_top_target (), &addr
))
5504 fprintf_unfiltered (gdb_stdlog
,
5505 "infrun: stopped data address = %s\n",
5506 paddress (reg_gdbarch
, addr
));
5508 fprintf_unfiltered (gdb_stdlog
,
5509 "infrun: (no data address available)\n");
5513 /* This is originated from start_remote(), start_inferior() and
5514 shared libraries hook functions. */
5515 stop_soon
= get_inferior_stop_soon (ecs
);
5516 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5518 context_switch (ecs
);
5520 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5521 stop_print_frame
= 1;
5526 /* This originates from attach_command(). We need to overwrite
5527 the stop_signal here, because some kernels don't ignore a
5528 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5529 See more comments in inferior.h. On the other hand, if we
5530 get a non-SIGSTOP, report it to the user - assume the backend
5531 will handle the SIGSTOP if it should show up later.
5533 Also consider that the attach is complete when we see a
5534 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5535 target extended-remote report it instead of a SIGSTOP
5536 (e.g. gdbserver). We already rely on SIGTRAP being our
5537 signal, so this is no exception.
5539 Also consider that the attach is complete when we see a
5540 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5541 the target to stop all threads of the inferior, in case the
5542 low level attach operation doesn't stop them implicitly. If
5543 they weren't stopped implicitly, then the stub will report a
5544 GDB_SIGNAL_0, meaning: stopped for no particular reason
5545 other than GDB's request. */
5546 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5547 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5548 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5549 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5551 stop_print_frame
= 1;
5553 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5557 /* See if something interesting happened to the non-current thread. If
5558 so, then switch to that thread. */
5559 if (ecs
->ptid
!= inferior_ptid
)
5562 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5564 context_switch (ecs
);
5566 if (deprecated_context_hook
)
5567 deprecated_context_hook (ecs
->event_thread
->global_num
);
5570 /* At this point, get hold of the now-current thread's frame. */
5571 frame
= get_current_frame ();
5572 gdbarch
= get_frame_arch (frame
);
5574 /* Pull the single step breakpoints out of the target. */
5575 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5577 struct regcache
*regcache
;
5580 regcache
= get_thread_regcache (ecs
->event_thread
);
5581 const address_space
*aspace
= regcache
->aspace ();
5583 pc
= regcache_read_pc (regcache
);
5585 /* However, before doing so, if this single-step breakpoint was
5586 actually for another thread, set this thread up for moving
5588 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5591 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5595 fprintf_unfiltered (gdb_stdlog
,
5596 "infrun: [%s] hit another thread's "
5597 "single-step breakpoint\n",
5598 target_pid_to_str (ecs
->ptid
).c_str ());
5600 ecs
->hit_singlestep_breakpoint
= 1;
5607 fprintf_unfiltered (gdb_stdlog
,
5608 "infrun: [%s] hit its "
5609 "single-step breakpoint\n",
5610 target_pid_to_str (ecs
->ptid
).c_str ());
5614 delete_just_stopped_threads_single_step_breakpoints ();
5616 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5617 && ecs
->event_thread
->control
.trap_expected
5618 && ecs
->event_thread
->stepping_over_watchpoint
)
5619 stopped_by_watchpoint
= 0;
5621 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5623 /* If necessary, step over this watchpoint. We'll be back to display
5625 if (stopped_by_watchpoint
5626 && (target_have_steppable_watchpoint
5627 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5629 /* At this point, we are stopped at an instruction which has
5630 attempted to write to a piece of memory under control of
5631 a watchpoint. The instruction hasn't actually executed
5632 yet. If we were to evaluate the watchpoint expression
5633 now, we would get the old value, and therefore no change
5634 would seem to have occurred.
5636 In order to make watchpoints work `right', we really need
5637 to complete the memory write, and then evaluate the
5638 watchpoint expression. We do this by single-stepping the
5641 It may not be necessary to disable the watchpoint to step over
5642 it. For example, the PA can (with some kernel cooperation)
5643 single step over a watchpoint without disabling the watchpoint.
5645 It is far more common to need to disable a watchpoint to step
5646 the inferior over it. If we have non-steppable watchpoints,
5647 we must disable the current watchpoint; it's simplest to
5648 disable all watchpoints.
5650 Any breakpoint at PC must also be stepped over -- if there's
5651 one, it will have already triggered before the watchpoint
5652 triggered, and we either already reported it to the user, or
5653 it didn't cause a stop and we called keep_going. In either
5654 case, if there was a breakpoint at PC, we must be trying to
5656 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5661 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5662 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5663 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5664 ecs
->event_thread
->control
.stop_step
= 0;
5665 stop_print_frame
= 1;
5666 stopped_by_random_signal
= 0;
5667 bpstat stop_chain
= NULL
;
5669 /* Hide inlined functions starting here, unless we just performed stepi or
5670 nexti. After stepi and nexti, always show the innermost frame (not any
5671 inline function call sites). */
5672 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5674 const address_space
*aspace
5675 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5677 /* skip_inline_frames is expensive, so we avoid it if we can
5678 determine that the address is one where functions cannot have
5679 been inlined. This improves performance with inferiors that
5680 load a lot of shared libraries, because the solib event
5681 breakpoint is defined as the address of a function (i.e. not
5682 inline). Note that we have to check the previous PC as well
5683 as the current one to catch cases when we have just
5684 single-stepped off a breakpoint prior to reinstating it.
5685 Note that we're assuming that the code we single-step to is
5686 not inline, but that's not definitive: there's nothing
5687 preventing the event breakpoint function from containing
5688 inlined code, and the single-step ending up there. If the
5689 user had set a breakpoint on that inlined code, the missing
5690 skip_inline_frames call would break things. Fortunately
5691 that's an extremely unlikely scenario. */
5692 if (!pc_at_non_inline_function (aspace
,
5693 ecs
->event_thread
->suspend
.stop_pc
,
5695 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5696 && ecs
->event_thread
->control
.trap_expected
5697 && pc_at_non_inline_function (aspace
,
5698 ecs
->event_thread
->prev_pc
,
5701 stop_chain
= build_bpstat_chain (aspace
,
5702 ecs
->event_thread
->suspend
.stop_pc
,
5704 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5706 /* Re-fetch current thread's frame in case that invalidated
5708 frame
= get_current_frame ();
5709 gdbarch
= get_frame_arch (frame
);
5713 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5714 && ecs
->event_thread
->control
.trap_expected
5715 && gdbarch_single_step_through_delay_p (gdbarch
)
5716 && currently_stepping (ecs
->event_thread
))
5718 /* We're trying to step off a breakpoint. Turns out that we're
5719 also on an instruction that needs to be stepped multiple
5720 times before it's been fully executing. E.g., architectures
5721 with a delay slot. It needs to be stepped twice, once for
5722 the instruction and once for the delay slot. */
5723 int step_through_delay
5724 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5726 if (debug_infrun
&& step_through_delay
)
5727 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
5728 if (ecs
->event_thread
->control
.step_range_end
== 0
5729 && step_through_delay
)
5731 /* The user issued a continue when stopped at a breakpoint.
5732 Set up for another trap and get out of here. */
5733 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5737 else if (step_through_delay
)
5739 /* The user issued a step when stopped at a breakpoint.
5740 Maybe we should stop, maybe we should not - the delay
5741 slot *might* correspond to a line of source. In any
5742 case, don't decide that here, just set
5743 ecs->stepping_over_breakpoint, making sure we
5744 single-step again before breakpoints are re-inserted. */
5745 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5749 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5750 handles this event. */
5751 ecs
->event_thread
->control
.stop_bpstat
5752 = bpstat_stop_status (get_current_regcache ()->aspace (),
5753 ecs
->event_thread
->suspend
.stop_pc
,
5754 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
5756 /* Following in case break condition called a
5758 stop_print_frame
= 1;
5760 /* This is where we handle "moribund" watchpoints. Unlike
5761 software breakpoints traps, hardware watchpoint traps are
5762 always distinguishable from random traps. If no high-level
5763 watchpoint is associated with the reported stop data address
5764 anymore, then the bpstat does not explain the signal ---
5765 simply make sure to ignore it if `stopped_by_watchpoint' is
5769 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5770 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5772 && stopped_by_watchpoint
)
5773 fprintf_unfiltered (gdb_stdlog
,
5774 "infrun: no user watchpoint explains "
5775 "watchpoint SIGTRAP, ignoring\n");
5777 /* NOTE: cagney/2003-03-29: These checks for a random signal
5778 at one stage in the past included checks for an inferior
5779 function call's call dummy's return breakpoint. The original
5780 comment, that went with the test, read:
5782 ``End of a stack dummy. Some systems (e.g. Sony news) give
5783 another signal besides SIGTRAP, so check here as well as
5786 If someone ever tries to get call dummys on a
5787 non-executable stack to work (where the target would stop
5788 with something like a SIGSEGV), then those tests might need
5789 to be re-instated. Given, however, that the tests were only
5790 enabled when momentary breakpoints were not being used, I
5791 suspect that it won't be the case.
5793 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5794 be necessary for call dummies on a non-executable stack on
5797 /* See if the breakpoints module can explain the signal. */
5799 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5800 ecs
->event_thread
->suspend
.stop_signal
);
5802 /* Maybe this was a trap for a software breakpoint that has since
5804 if (random_signal
&& target_stopped_by_sw_breakpoint ())
5806 if (program_breakpoint_here_p (gdbarch
,
5807 ecs
->event_thread
->suspend
.stop_pc
))
5809 struct regcache
*regcache
;
5812 /* Re-adjust PC to what the program would see if GDB was not
5814 regcache
= get_thread_regcache (ecs
->event_thread
);
5815 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
5818 gdb::optional
<scoped_restore_tmpl
<int>>
5819 restore_operation_disable
;
5821 if (record_full_is_used ())
5822 restore_operation_disable
.emplace
5823 (record_full_gdb_operation_disable_set ());
5825 regcache_write_pc (regcache
,
5826 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
5831 /* A delayed software breakpoint event. Ignore the trap. */
5833 fprintf_unfiltered (gdb_stdlog
,
5834 "infrun: delayed software breakpoint "
5835 "trap, ignoring\n");
5840 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5841 has since been removed. */
5842 if (random_signal
&& target_stopped_by_hw_breakpoint ())
5844 /* A delayed hardware breakpoint event. Ignore the trap. */
5846 fprintf_unfiltered (gdb_stdlog
,
5847 "infrun: delayed hardware breakpoint/watchpoint "
5848 "trap, ignoring\n");
5852 /* If not, perhaps stepping/nexting can. */
5854 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5855 && currently_stepping (ecs
->event_thread
));
5857 /* Perhaps the thread hit a single-step breakpoint of _another_
5858 thread. Single-step breakpoints are transparent to the
5859 breakpoints module. */
5861 random_signal
= !ecs
->hit_singlestep_breakpoint
;
5863 /* No? Perhaps we got a moribund watchpoint. */
5865 random_signal
= !stopped_by_watchpoint
;
5867 /* Always stop if the user explicitly requested this thread to
5869 if (ecs
->event_thread
->stop_requested
)
5873 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
5876 /* For the program's own signals, act according to
5877 the signal handling tables. */
5881 /* Signal not for debugging purposes. */
5882 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
5883 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
5886 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
5887 gdb_signal_to_symbol_string (stop_signal
));
5889 stopped_by_random_signal
= 1;
5891 /* Always stop on signals if we're either just gaining control
5892 of the program, or the user explicitly requested this thread
5893 to remain stopped. */
5894 if (stop_soon
!= NO_STOP_QUIETLY
5895 || ecs
->event_thread
->stop_requested
5897 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
5903 /* Notify observers the signal has "handle print" set. Note we
5904 returned early above if stopping; normal_stop handles the
5905 printing in that case. */
5906 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
5908 /* The signal table tells us to print about this signal. */
5909 target_terminal::ours_for_output ();
5910 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
5911 target_terminal::inferior ();
5914 /* Clear the signal if it should not be passed. */
5915 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
5916 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5918 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
5919 && ecs
->event_thread
->control
.trap_expected
5920 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5922 /* We were just starting a new sequence, attempting to
5923 single-step off of a breakpoint and expecting a SIGTRAP.
5924 Instead this signal arrives. This signal will take us out
5925 of the stepping range so GDB needs to remember to, when
5926 the signal handler returns, resume stepping off that
5928 /* To simplify things, "continue" is forced to use the same
5929 code paths as single-step - set a breakpoint at the
5930 signal return address and then, once hit, step off that
5933 fprintf_unfiltered (gdb_stdlog
,
5934 "infrun: signal arrived while stepping over "
5937 insert_hp_step_resume_breakpoint_at_frame (frame
);
5938 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5939 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5940 ecs
->event_thread
->control
.trap_expected
= 0;
5942 /* If we were nexting/stepping some other thread, switch to
5943 it, so that we don't continue it, losing control. */
5944 if (!switch_back_to_stepped_thread (ecs
))
5949 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
5950 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
5952 || ecs
->event_thread
->control
.step_range_end
== 1)
5953 && frame_id_eq (get_stack_frame_id (frame
),
5954 ecs
->event_thread
->control
.step_stack_frame_id
)
5955 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5957 /* The inferior is about to take a signal that will take it
5958 out of the single step range. Set a breakpoint at the
5959 current PC (which is presumably where the signal handler
5960 will eventually return) and then allow the inferior to
5963 Note that this is only needed for a signal delivered
5964 while in the single-step range. Nested signals aren't a
5965 problem as they eventually all return. */
5967 fprintf_unfiltered (gdb_stdlog
,
5968 "infrun: signal may take us out of "
5969 "single-step range\n");
5971 clear_step_over_info ();
5972 insert_hp_step_resume_breakpoint_at_frame (frame
);
5973 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5974 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5975 ecs
->event_thread
->control
.trap_expected
= 0;
5980 /* Note: step_resume_breakpoint may be non-NULL. This occurs
5981 when either there's a nested signal, or when there's a
5982 pending signal enabled just as the signal handler returns
5983 (leaving the inferior at the step-resume-breakpoint without
5984 actually executing it). Either way continue until the
5985 breakpoint is really hit. */
5987 if (!switch_back_to_stepped_thread (ecs
))
5990 fprintf_unfiltered (gdb_stdlog
,
5991 "infrun: random signal, keep going\n");
5998 process_event_stop_test (ecs
);
6001 /* Come here when we've got some debug event / signal we can explain
6002 (IOW, not a random signal), and test whether it should cause a
6003 stop, or whether we should resume the inferior (transparently).
6004 E.g., could be a breakpoint whose condition evaluates false; we
6005 could be still stepping within the line; etc. */
6008 process_event_stop_test (struct execution_control_state
*ecs
)
6010 struct symtab_and_line stop_pc_sal
;
6011 struct frame_info
*frame
;
6012 struct gdbarch
*gdbarch
;
6013 CORE_ADDR jmp_buf_pc
;
6014 struct bpstat_what what
;
6016 /* Handle cases caused by hitting a breakpoint. */
6018 frame
= get_current_frame ();
6019 gdbarch
= get_frame_arch (frame
);
6021 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6023 if (what
.call_dummy
)
6025 stop_stack_dummy
= what
.call_dummy
;
6028 /* A few breakpoint types have callbacks associated (e.g.,
6029 bp_jit_event). Run them now. */
6030 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6032 /* If we hit an internal event that triggers symbol changes, the
6033 current frame will be invalidated within bpstat_what (e.g., if we
6034 hit an internal solib event). Re-fetch it. */
6035 frame
= get_current_frame ();
6036 gdbarch
= get_frame_arch (frame
);
6038 switch (what
.main_action
)
6040 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6041 /* If we hit the breakpoint at longjmp while stepping, we
6042 install a momentary breakpoint at the target of the
6046 fprintf_unfiltered (gdb_stdlog
,
6047 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6049 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6051 if (what
.is_longjmp
)
6053 struct value
*arg_value
;
6055 /* If we set the longjmp breakpoint via a SystemTap probe,
6056 then use it to extract the arguments. The destination PC
6057 is the third argument to the probe. */
6058 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6061 jmp_buf_pc
= value_as_address (arg_value
);
6062 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6064 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6065 || !gdbarch_get_longjmp_target (gdbarch
,
6066 frame
, &jmp_buf_pc
))
6069 fprintf_unfiltered (gdb_stdlog
,
6070 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6071 "(!gdbarch_get_longjmp_target)\n");
6076 /* Insert a breakpoint at resume address. */
6077 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6080 check_exception_resume (ecs
, frame
);
6084 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6086 struct frame_info
*init_frame
;
6088 /* There are several cases to consider.
6090 1. The initiating frame no longer exists. In this case we
6091 must stop, because the exception or longjmp has gone too
6094 2. The initiating frame exists, and is the same as the
6095 current frame. We stop, because the exception or longjmp
6098 3. The initiating frame exists and is different from the
6099 current frame. This means the exception or longjmp has
6100 been caught beneath the initiating frame, so keep going.
6102 4. longjmp breakpoint has been placed just to protect
6103 against stale dummy frames and user is not interested in
6104 stopping around longjmps. */
6107 fprintf_unfiltered (gdb_stdlog
,
6108 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6110 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6112 delete_exception_resume_breakpoint (ecs
->event_thread
);
6114 if (what
.is_longjmp
)
6116 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6118 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6126 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6130 struct frame_id current_id
6131 = get_frame_id (get_current_frame ());
6132 if (frame_id_eq (current_id
,
6133 ecs
->event_thread
->initiating_frame
))
6135 /* Case 2. Fall through. */
6145 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6147 delete_step_resume_breakpoint (ecs
->event_thread
);
6149 end_stepping_range (ecs
);
6153 case BPSTAT_WHAT_SINGLE
:
6155 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6156 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6157 /* Still need to check other stuff, at least the case where we
6158 are stepping and step out of the right range. */
6161 case BPSTAT_WHAT_STEP_RESUME
:
6163 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6165 delete_step_resume_breakpoint (ecs
->event_thread
);
6166 if (ecs
->event_thread
->control
.proceed_to_finish
6167 && execution_direction
== EXEC_REVERSE
)
6169 struct thread_info
*tp
= ecs
->event_thread
;
6171 /* We are finishing a function in reverse, and just hit the
6172 step-resume breakpoint at the start address of the
6173 function, and we're almost there -- just need to back up
6174 by one more single-step, which should take us back to the
6176 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6180 fill_in_stop_func (gdbarch
, ecs
);
6181 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6182 && execution_direction
== EXEC_REVERSE
)
6184 /* We are stepping over a function call in reverse, and just
6185 hit the step-resume breakpoint at the start address of
6186 the function. Go back to single-stepping, which should
6187 take us back to the function call. */
6188 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6194 case BPSTAT_WHAT_STOP_NOISY
:
6196 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6197 stop_print_frame
= 1;
6199 /* Assume the thread stopped for a breapoint. We'll still check
6200 whether a/the breakpoint is there when the thread is next
6202 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6207 case BPSTAT_WHAT_STOP_SILENT
:
6209 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6210 stop_print_frame
= 0;
6212 /* Assume the thread stopped for a breapoint. We'll still check
6213 whether a/the breakpoint is there when the thread is next
6215 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6219 case BPSTAT_WHAT_HP_STEP_RESUME
:
6221 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6223 delete_step_resume_breakpoint (ecs
->event_thread
);
6224 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6226 /* Back when the step-resume breakpoint was inserted, we
6227 were trying to single-step off a breakpoint. Go back to
6229 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6230 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6236 case BPSTAT_WHAT_KEEP_CHECKING
:
6240 /* If we stepped a permanent breakpoint and we had a high priority
6241 step-resume breakpoint for the address we stepped, but we didn't
6242 hit it, then we must have stepped into the signal handler. The
6243 step-resume was only necessary to catch the case of _not_
6244 stepping into the handler, so delete it, and fall through to
6245 checking whether the step finished. */
6246 if (ecs
->event_thread
->stepped_breakpoint
)
6248 struct breakpoint
*sr_bp
6249 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6252 && sr_bp
->loc
->permanent
6253 && sr_bp
->type
== bp_hp_step_resume
6254 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6257 fprintf_unfiltered (gdb_stdlog
,
6258 "infrun: stepped permanent breakpoint, stopped in "
6260 delete_step_resume_breakpoint (ecs
->event_thread
);
6261 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6265 /* We come here if we hit a breakpoint but should not stop for it.
6266 Possibly we also were stepping and should stop for that. So fall
6267 through and test for stepping. But, if not stepping, do not
6270 /* In all-stop mode, if we're currently stepping but have stopped in
6271 some other thread, we need to switch back to the stepped thread. */
6272 if (switch_back_to_stepped_thread (ecs
))
6275 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6278 fprintf_unfiltered (gdb_stdlog
,
6279 "infrun: step-resume breakpoint is inserted\n");
6281 /* Having a step-resume breakpoint overrides anything
6282 else having to do with stepping commands until
6283 that breakpoint is reached. */
6288 if (ecs
->event_thread
->control
.step_range_end
== 0)
6291 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6292 /* Likewise if we aren't even stepping. */
6297 /* Re-fetch current thread's frame in case the code above caused
6298 the frame cache to be re-initialized, making our FRAME variable
6299 a dangling pointer. */
6300 frame
= get_current_frame ();
6301 gdbarch
= get_frame_arch (frame
);
6302 fill_in_stop_func (gdbarch
, ecs
);
6304 /* If stepping through a line, keep going if still within it.
6306 Note that step_range_end is the address of the first instruction
6307 beyond the step range, and NOT the address of the last instruction
6310 Note also that during reverse execution, we may be stepping
6311 through a function epilogue and therefore must detect when
6312 the current-frame changes in the middle of a line. */
6314 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6316 && (execution_direction
!= EXEC_REVERSE
6317 || frame_id_eq (get_frame_id (frame
),
6318 ecs
->event_thread
->control
.step_frame_id
)))
6322 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6323 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6324 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6326 /* Tentatively re-enable range stepping; `resume' disables it if
6327 necessary (e.g., if we're stepping over a breakpoint or we
6328 have software watchpoints). */
6329 ecs
->event_thread
->control
.may_range_step
= 1;
6331 /* When stepping backward, stop at beginning of line range
6332 (unless it's the function entry point, in which case
6333 keep going back to the call point). */
6334 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6335 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6336 && stop_pc
!= ecs
->stop_func_start
6337 && execution_direction
== EXEC_REVERSE
)
6338 end_stepping_range (ecs
);
6345 /* We stepped out of the stepping range. */
6347 /* If we are stepping at the source level and entered the runtime
6348 loader dynamic symbol resolution code...
6350 EXEC_FORWARD: we keep on single stepping until we exit the run
6351 time loader code and reach the callee's address.
6353 EXEC_REVERSE: we've already executed the callee (backward), and
6354 the runtime loader code is handled just like any other
6355 undebuggable function call. Now we need only keep stepping
6356 backward through the trampoline code, and that's handled further
6357 down, so there is nothing for us to do here. */
6359 if (execution_direction
!= EXEC_REVERSE
6360 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6361 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6363 CORE_ADDR pc_after_resolver
=
6364 gdbarch_skip_solib_resolver (gdbarch
,
6365 ecs
->event_thread
->suspend
.stop_pc
);
6368 fprintf_unfiltered (gdb_stdlog
,
6369 "infrun: stepped into dynsym resolve code\n");
6371 if (pc_after_resolver
)
6373 /* Set up a step-resume breakpoint at the address
6374 indicated by SKIP_SOLIB_RESOLVER. */
6375 symtab_and_line sr_sal
;
6376 sr_sal
.pc
= pc_after_resolver
;
6377 sr_sal
.pspace
= get_frame_program_space (frame
);
6379 insert_step_resume_breakpoint_at_sal (gdbarch
,
6380 sr_sal
, null_frame_id
);
6387 /* Step through an indirect branch thunk. */
6388 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6389 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6390 ecs
->event_thread
->suspend
.stop_pc
))
6393 fprintf_unfiltered (gdb_stdlog
,
6394 "infrun: stepped into indirect branch thunk\n");
6399 if (ecs
->event_thread
->control
.step_range_end
!= 1
6400 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6401 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6402 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6405 fprintf_unfiltered (gdb_stdlog
,
6406 "infrun: stepped into signal trampoline\n");
6407 /* The inferior, while doing a "step" or "next", has ended up in
6408 a signal trampoline (either by a signal being delivered or by
6409 the signal handler returning). Just single-step until the
6410 inferior leaves the trampoline (either by calling the handler
6416 /* If we're in the return path from a shared library trampoline,
6417 we want to proceed through the trampoline when stepping. */
6418 /* macro/2012-04-25: This needs to come before the subroutine
6419 call check below as on some targets return trampolines look
6420 like subroutine calls (MIPS16 return thunks). */
6421 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6422 ecs
->event_thread
->suspend
.stop_pc
,
6423 ecs
->stop_func_name
)
6424 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6426 /* Determine where this trampoline returns. */
6427 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6428 CORE_ADDR real_stop_pc
6429 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6432 fprintf_unfiltered (gdb_stdlog
,
6433 "infrun: stepped into solib return tramp\n");
6435 /* Only proceed through if we know where it's going. */
6438 /* And put the step-breakpoint there and go until there. */
6439 symtab_and_line sr_sal
;
6440 sr_sal
.pc
= real_stop_pc
;
6441 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6442 sr_sal
.pspace
= get_frame_program_space (frame
);
6444 /* Do not specify what the fp should be when we stop since
6445 on some machines the prologue is where the new fp value
6447 insert_step_resume_breakpoint_at_sal (gdbarch
,
6448 sr_sal
, null_frame_id
);
6450 /* Restart without fiddling with the step ranges or
6457 /* Check for subroutine calls. The check for the current frame
6458 equalling the step ID is not necessary - the check of the
6459 previous frame's ID is sufficient - but it is a common case and
6460 cheaper than checking the previous frame's ID.
6462 NOTE: frame_id_eq will never report two invalid frame IDs as
6463 being equal, so to get into this block, both the current and
6464 previous frame must have valid frame IDs. */
6465 /* The outer_frame_id check is a heuristic to detect stepping
6466 through startup code. If we step over an instruction which
6467 sets the stack pointer from an invalid value to a valid value,
6468 we may detect that as a subroutine call from the mythical
6469 "outermost" function. This could be fixed by marking
6470 outermost frames as !stack_p,code_p,special_p. Then the
6471 initial outermost frame, before sp was valid, would
6472 have code_addr == &_start. See the comment in frame_id_eq
6474 if (!frame_id_eq (get_stack_frame_id (frame
),
6475 ecs
->event_thread
->control
.step_stack_frame_id
)
6476 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6477 ecs
->event_thread
->control
.step_stack_frame_id
)
6478 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6480 || (ecs
->event_thread
->control
.step_start_function
6481 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6483 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6484 CORE_ADDR real_stop_pc
;
6487 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6489 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6491 /* I presume that step_over_calls is only 0 when we're
6492 supposed to be stepping at the assembly language level
6493 ("stepi"). Just stop. */
6494 /* And this works the same backward as frontward. MVS */
6495 end_stepping_range (ecs
);
6499 /* Reverse stepping through solib trampolines. */
6501 if (execution_direction
== EXEC_REVERSE
6502 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6503 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6504 || (ecs
->stop_func_start
== 0
6505 && in_solib_dynsym_resolve_code (stop_pc
))))
6507 /* Any solib trampoline code can be handled in reverse
6508 by simply continuing to single-step. We have already
6509 executed the solib function (backwards), and a few
6510 steps will take us back through the trampoline to the
6516 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6518 /* We're doing a "next".
6520 Normal (forward) execution: set a breakpoint at the
6521 callee's return address (the address at which the caller
6524 Reverse (backward) execution. set the step-resume
6525 breakpoint at the start of the function that we just
6526 stepped into (backwards), and continue to there. When we
6527 get there, we'll need to single-step back to the caller. */
6529 if (execution_direction
== EXEC_REVERSE
)
6531 /* If we're already at the start of the function, we've either
6532 just stepped backward into a single instruction function,
6533 or stepped back out of a signal handler to the first instruction
6534 of the function. Just keep going, which will single-step back
6536 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6538 /* Normal function call return (static or dynamic). */
6539 symtab_and_line sr_sal
;
6540 sr_sal
.pc
= ecs
->stop_func_start
;
6541 sr_sal
.pspace
= get_frame_program_space (frame
);
6542 insert_step_resume_breakpoint_at_sal (gdbarch
,
6543 sr_sal
, null_frame_id
);
6547 insert_step_resume_breakpoint_at_caller (frame
);
6553 /* If we are in a function call trampoline (a stub between the
6554 calling routine and the real function), locate the real
6555 function. That's what tells us (a) whether we want to step
6556 into it at all, and (b) what prologue we want to run to the
6557 end of, if we do step into it. */
6558 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6559 if (real_stop_pc
== 0)
6560 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6561 if (real_stop_pc
!= 0)
6562 ecs
->stop_func_start
= real_stop_pc
;
6564 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6566 symtab_and_line sr_sal
;
6567 sr_sal
.pc
= ecs
->stop_func_start
;
6568 sr_sal
.pspace
= get_frame_program_space (frame
);
6570 insert_step_resume_breakpoint_at_sal (gdbarch
,
6571 sr_sal
, null_frame_id
);
6576 /* If we have line number information for the function we are
6577 thinking of stepping into and the function isn't on the skip
6580 If there are several symtabs at that PC (e.g. with include
6581 files), just want to know whether *any* of them have line
6582 numbers. find_pc_line handles this. */
6584 struct symtab_and_line tmp_sal
;
6586 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6587 if (tmp_sal
.line
!= 0
6588 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6590 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6592 if (execution_direction
== EXEC_REVERSE
)
6593 handle_step_into_function_backward (gdbarch
, ecs
);
6595 handle_step_into_function (gdbarch
, ecs
);
6600 /* If we have no line number and the step-stop-if-no-debug is
6601 set, we stop the step so that the user has a chance to switch
6602 in assembly mode. */
6603 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6604 && step_stop_if_no_debug
)
6606 end_stepping_range (ecs
);
6610 if (execution_direction
== EXEC_REVERSE
)
6612 /* If we're already at the start of the function, we've either just
6613 stepped backward into a single instruction function without line
6614 number info, or stepped back out of a signal handler to the first
6615 instruction of the function without line number info. Just keep
6616 going, which will single-step back to the caller. */
6617 if (ecs
->stop_func_start
!= stop_pc
)
6619 /* Set a breakpoint at callee's start address.
6620 From there we can step once and be back in the caller. */
6621 symtab_and_line sr_sal
;
6622 sr_sal
.pc
= ecs
->stop_func_start
;
6623 sr_sal
.pspace
= get_frame_program_space (frame
);
6624 insert_step_resume_breakpoint_at_sal (gdbarch
,
6625 sr_sal
, null_frame_id
);
6629 /* Set a breakpoint at callee's return address (the address
6630 at which the caller will resume). */
6631 insert_step_resume_breakpoint_at_caller (frame
);
6637 /* Reverse stepping through solib trampolines. */
6639 if (execution_direction
== EXEC_REVERSE
6640 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6642 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6644 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6645 || (ecs
->stop_func_start
== 0
6646 && in_solib_dynsym_resolve_code (stop_pc
)))
6648 /* Any solib trampoline code can be handled in reverse
6649 by simply continuing to single-step. We have already
6650 executed the solib function (backwards), and a few
6651 steps will take us back through the trampoline to the
6656 else if (in_solib_dynsym_resolve_code (stop_pc
))
6658 /* Stepped backward into the solib dynsym resolver.
6659 Set a breakpoint at its start and continue, then
6660 one more step will take us out. */
6661 symtab_and_line sr_sal
;
6662 sr_sal
.pc
= ecs
->stop_func_start
;
6663 sr_sal
.pspace
= get_frame_program_space (frame
);
6664 insert_step_resume_breakpoint_at_sal (gdbarch
,
6665 sr_sal
, null_frame_id
);
6671 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6673 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6674 the trampoline processing logic, however, there are some trampolines
6675 that have no names, so we should do trampoline handling first. */
6676 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6677 && ecs
->stop_func_name
== NULL
6678 && stop_pc_sal
.line
== 0)
6681 fprintf_unfiltered (gdb_stdlog
,
6682 "infrun: stepped into undebuggable function\n");
6684 /* The inferior just stepped into, or returned to, an
6685 undebuggable function (where there is no debugging information
6686 and no line number corresponding to the address where the
6687 inferior stopped). Since we want to skip this kind of code,
6688 we keep going until the inferior returns from this
6689 function - unless the user has asked us not to (via
6690 set step-mode) or we no longer know how to get back
6691 to the call site. */
6692 if (step_stop_if_no_debug
6693 || !frame_id_p (frame_unwind_caller_id (frame
)))
6695 /* If we have no line number and the step-stop-if-no-debug
6696 is set, we stop the step so that the user has a chance to
6697 switch in assembly mode. */
6698 end_stepping_range (ecs
);
6703 /* Set a breakpoint at callee's return address (the address
6704 at which the caller will resume). */
6705 insert_step_resume_breakpoint_at_caller (frame
);
6711 if (ecs
->event_thread
->control
.step_range_end
== 1)
6713 /* It is stepi or nexti. We always want to stop stepping after
6716 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
6717 end_stepping_range (ecs
);
6721 if (stop_pc_sal
.line
== 0)
6723 /* We have no line number information. That means to stop
6724 stepping (does this always happen right after one instruction,
6725 when we do "s" in a function with no line numbers,
6726 or can this happen as a result of a return or longjmp?). */
6728 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
6729 end_stepping_range (ecs
);
6733 /* Look for "calls" to inlined functions, part one. If the inline
6734 frame machinery detected some skipped call sites, we have entered
6735 a new inline function. */
6737 if (frame_id_eq (get_frame_id (get_current_frame ()),
6738 ecs
->event_thread
->control
.step_frame_id
)
6739 && inline_skipped_frames (ecs
->event_thread
))
6742 fprintf_unfiltered (gdb_stdlog
,
6743 "infrun: stepped into inlined function\n");
6745 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6747 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6749 /* For "step", we're going to stop. But if the call site
6750 for this inlined function is on the same source line as
6751 we were previously stepping, go down into the function
6752 first. Otherwise stop at the call site. */
6754 if (call_sal
.line
== ecs
->event_thread
->current_line
6755 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6757 step_into_inline_frame (ecs
->event_thread
);
6758 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6765 end_stepping_range (ecs
);
6770 /* For "next", we should stop at the call site if it is on a
6771 different source line. Otherwise continue through the
6772 inlined function. */
6773 if (call_sal
.line
== ecs
->event_thread
->current_line
6774 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6777 end_stepping_range (ecs
);
6782 /* Look for "calls" to inlined functions, part two. If we are still
6783 in the same real function we were stepping through, but we have
6784 to go further up to find the exact frame ID, we are stepping
6785 through a more inlined call beyond its call site. */
6787 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6788 && !frame_id_eq (get_frame_id (get_current_frame ()),
6789 ecs
->event_thread
->control
.step_frame_id
)
6790 && stepped_in_from (get_current_frame (),
6791 ecs
->event_thread
->control
.step_frame_id
))
6794 fprintf_unfiltered (gdb_stdlog
,
6795 "infrun: stepping through inlined function\n");
6797 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
6798 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6801 end_stepping_range (ecs
);
6805 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
6806 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
6807 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
6809 /* We are at the start of a different line. So stop. Note that
6810 we don't stop if we step into the middle of a different line.
6811 That is said to make things like for (;;) statements work
6814 fprintf_unfiltered (gdb_stdlog
,
6815 "infrun: stepped to a different line\n");
6816 end_stepping_range (ecs
);
6820 /* We aren't done stepping.
6822 Optimize by setting the stepping range to the line.
6823 (We might not be in the original line, but if we entered a
6824 new line in mid-statement, we continue stepping. This makes
6825 things like for(;;) statements work better.) */
6827 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
6828 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
6829 ecs
->event_thread
->control
.may_range_step
= 1;
6830 set_step_info (frame
, stop_pc_sal
);
6833 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
6837 /* In all-stop mode, if we're currently stepping but have stopped in
6838 some other thread, we may need to switch back to the stepped
6839 thread. Returns true we set the inferior running, false if we left
6840 it stopped (and the event needs further processing). */
6843 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
6845 if (!target_is_non_stop_p ())
6847 struct thread_info
*stepping_thread
;
6849 /* If any thread is blocked on some internal breakpoint, and we
6850 simply need to step over that breakpoint to get it going
6851 again, do that first. */
6853 /* However, if we see an event for the stepping thread, then we
6854 know all other threads have been moved past their breakpoints
6855 already. Let the caller check whether the step is finished,
6856 etc., before deciding to move it past a breakpoint. */
6857 if (ecs
->event_thread
->control
.step_range_end
!= 0)
6860 /* Check if the current thread is blocked on an incomplete
6861 step-over, interrupted by a random signal. */
6862 if (ecs
->event_thread
->control
.trap_expected
6863 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
6867 fprintf_unfiltered (gdb_stdlog
,
6868 "infrun: need to finish step-over of [%s]\n",
6869 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
6875 /* Check if the current thread is blocked by a single-step
6876 breakpoint of another thread. */
6877 if (ecs
->hit_singlestep_breakpoint
)
6881 fprintf_unfiltered (gdb_stdlog
,
6882 "infrun: need to step [%s] over single-step "
6884 target_pid_to_str (ecs
->ptid
).c_str ());
6890 /* If this thread needs yet another step-over (e.g., stepping
6891 through a delay slot), do it first before moving on to
6893 if (thread_still_needs_step_over (ecs
->event_thread
))
6897 fprintf_unfiltered (gdb_stdlog
,
6898 "infrun: thread [%s] still needs step-over\n",
6899 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
6905 /* If scheduler locking applies even if not stepping, there's no
6906 need to walk over threads. Above we've checked whether the
6907 current thread is stepping. If some other thread not the
6908 event thread is stepping, then it must be that scheduler
6909 locking is not in effect. */
6910 if (schedlock_applies (ecs
->event_thread
))
6913 /* Otherwise, we no longer expect a trap in the current thread.
6914 Clear the trap_expected flag before switching back -- this is
6915 what keep_going does as well, if we call it. */
6916 ecs
->event_thread
->control
.trap_expected
= 0;
6918 /* Likewise, clear the signal if it should not be passed. */
6919 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
6920 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6922 /* Do all pending step-overs before actually proceeding with
6924 if (start_step_over ())
6926 prepare_to_wait (ecs
);
6930 /* Look for the stepping/nexting thread. */
6931 stepping_thread
= NULL
;
6933 for (thread_info
*tp
: all_non_exited_threads ())
6935 switch_to_thread_no_regs (tp
);
6937 /* Ignore threads of processes the caller is not
6940 && tp
->ptid
.pid () != ecs
->ptid
.pid ())
6943 /* When stepping over a breakpoint, we lock all threads
6944 except the one that needs to move past the breakpoint.
6945 If a non-event thread has this set, the "incomplete
6946 step-over" check above should have caught it earlier. */
6947 if (tp
->control
.trap_expected
)
6949 internal_error (__FILE__
, __LINE__
,
6950 "[%s] has inconsistent state: "
6951 "trap_expected=%d\n",
6952 target_pid_to_str (tp
->ptid
).c_str (),
6953 tp
->control
.trap_expected
);
6956 /* Did we find the stepping thread? */
6957 if (tp
->control
.step_range_end
)
6959 /* Yep. There should only one though. */
6960 gdb_assert (stepping_thread
== NULL
);
6962 /* The event thread is handled at the top, before we
6964 gdb_assert (tp
!= ecs
->event_thread
);
6966 /* If some thread other than the event thread is
6967 stepping, then scheduler locking can't be in effect,
6968 otherwise we wouldn't have resumed the current event
6969 thread in the first place. */
6970 gdb_assert (!schedlock_applies (tp
));
6972 stepping_thread
= tp
;
6976 if (stepping_thread
!= NULL
)
6979 fprintf_unfiltered (gdb_stdlog
,
6980 "infrun: switching back to stepped thread\n");
6982 if (keep_going_stepped_thread (stepping_thread
))
6984 prepare_to_wait (ecs
);
6989 switch_to_thread (ecs
->event_thread
);
6995 /* Set a previously stepped thread back to stepping. Returns true on
6996 success, false if the resume is not possible (e.g., the thread
7000 keep_going_stepped_thread (struct thread_info
*tp
)
7002 struct frame_info
*frame
;
7003 struct execution_control_state ecss
;
7004 struct execution_control_state
*ecs
= &ecss
;
7006 /* If the stepping thread exited, then don't try to switch back and
7007 resume it, which could fail in several different ways depending
7008 on the target. Instead, just keep going.
7010 We can find a stepping dead thread in the thread list in two
7013 - The target supports thread exit events, and when the target
7014 tries to delete the thread from the thread list, inferior_ptid
7015 pointed at the exiting thread. In such case, calling
7016 delete_thread does not really remove the thread from the list;
7017 instead, the thread is left listed, with 'exited' state.
7019 - The target's debug interface does not support thread exit
7020 events, and so we have no idea whatsoever if the previously
7021 stepping thread is still alive. For that reason, we need to
7022 synchronously query the target now. */
7024 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7027 fprintf_unfiltered (gdb_stdlog
,
7028 "infrun: not resuming previously "
7029 "stepped thread, it has vanished\n");
7036 fprintf_unfiltered (gdb_stdlog
,
7037 "infrun: resuming previously stepped thread\n");
7039 reset_ecs (ecs
, tp
);
7040 switch_to_thread (tp
);
7042 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7043 frame
= get_current_frame ();
7045 /* If the PC of the thread we were trying to single-step has
7046 changed, then that thread has trapped or been signaled, but the
7047 event has not been reported to GDB yet. Re-poll the target
7048 looking for this particular thread's event (i.e. temporarily
7049 enable schedlock) by:
7051 - setting a break at the current PC
7052 - resuming that particular thread, only (by setting trap
7055 This prevents us continuously moving the single-step breakpoint
7056 forward, one instruction at a time, overstepping. */
7058 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7063 fprintf_unfiltered (gdb_stdlog
,
7064 "infrun: expected thread advanced also (%s -> %s)\n",
7065 paddress (target_gdbarch (), tp
->prev_pc
),
7066 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7068 /* Clear the info of the previous step-over, as it's no longer
7069 valid (if the thread was trying to step over a breakpoint, it
7070 has already succeeded). It's what keep_going would do too,
7071 if we called it. Do this before trying to insert the sss
7072 breakpoint, otherwise if we were previously trying to step
7073 over this exact address in another thread, the breakpoint is
7075 clear_step_over_info ();
7076 tp
->control
.trap_expected
= 0;
7078 insert_single_step_breakpoint (get_frame_arch (frame
),
7079 get_frame_address_space (frame
),
7080 tp
->suspend
.stop_pc
);
7083 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7084 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7089 fprintf_unfiltered (gdb_stdlog
,
7090 "infrun: expected thread still hasn't advanced\n");
7092 keep_going_pass_signal (ecs
);
7097 /* Is thread TP in the middle of (software or hardware)
7098 single-stepping? (Note the result of this function must never be
7099 passed directly as target_resume's STEP parameter.) */
7102 currently_stepping (struct thread_info
*tp
)
7104 return ((tp
->control
.step_range_end
7105 && tp
->control
.step_resume_breakpoint
== NULL
)
7106 || tp
->control
.trap_expected
7107 || tp
->stepped_breakpoint
7108 || bpstat_should_step ());
7111 /* Inferior has stepped into a subroutine call with source code that
7112 we should not step over. Do step to the first line of code in
7116 handle_step_into_function (struct gdbarch
*gdbarch
,
7117 struct execution_control_state
*ecs
)
7119 fill_in_stop_func (gdbarch
, ecs
);
7121 compunit_symtab
*cust
7122 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7123 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7124 ecs
->stop_func_start
7125 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7127 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7128 /* Use the step_resume_break to step until the end of the prologue,
7129 even if that involves jumps (as it seems to on the vax under
7131 /* If the prologue ends in the middle of a source line, continue to
7132 the end of that source line (if it is still within the function).
7133 Otherwise, just go to end of prologue. */
7134 if (stop_func_sal
.end
7135 && stop_func_sal
.pc
!= ecs
->stop_func_start
7136 && stop_func_sal
.end
< ecs
->stop_func_end
)
7137 ecs
->stop_func_start
= stop_func_sal
.end
;
7139 /* Architectures which require breakpoint adjustment might not be able
7140 to place a breakpoint at the computed address. If so, the test
7141 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7142 ecs->stop_func_start to an address at which a breakpoint may be
7143 legitimately placed.
7145 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7146 made, GDB will enter an infinite loop when stepping through
7147 optimized code consisting of VLIW instructions which contain
7148 subinstructions corresponding to different source lines. On
7149 FR-V, it's not permitted to place a breakpoint on any but the
7150 first subinstruction of a VLIW instruction. When a breakpoint is
7151 set, GDB will adjust the breakpoint address to the beginning of
7152 the VLIW instruction. Thus, we need to make the corresponding
7153 adjustment here when computing the stop address. */
7155 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7157 ecs
->stop_func_start
7158 = gdbarch_adjust_breakpoint_address (gdbarch
,
7159 ecs
->stop_func_start
);
7162 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7164 /* We are already there: stop now. */
7165 end_stepping_range (ecs
);
7170 /* Put the step-breakpoint there and go until there. */
7171 symtab_and_line sr_sal
;
7172 sr_sal
.pc
= ecs
->stop_func_start
;
7173 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7174 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7176 /* Do not specify what the fp should be when we stop since on
7177 some machines the prologue is where the new fp value is
7179 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7181 /* And make sure stepping stops right away then. */
7182 ecs
->event_thread
->control
.step_range_end
7183 = ecs
->event_thread
->control
.step_range_start
;
7188 /* Inferior has stepped backward into a subroutine call with source
7189 code that we should not step over. Do step to the beginning of the
7190 last line of code in it. */
7193 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7194 struct execution_control_state
*ecs
)
7196 struct compunit_symtab
*cust
;
7197 struct symtab_and_line stop_func_sal
;
7199 fill_in_stop_func (gdbarch
, ecs
);
7201 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7202 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7203 ecs
->stop_func_start
7204 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7206 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7208 /* OK, we're just going to keep stepping here. */
7209 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7211 /* We're there already. Just stop stepping now. */
7212 end_stepping_range (ecs
);
7216 /* Else just reset the step range and keep going.
7217 No step-resume breakpoint, they don't work for
7218 epilogues, which can have multiple entry paths. */
7219 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7220 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7226 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7227 This is used to both functions and to skip over code. */
7230 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7231 struct symtab_and_line sr_sal
,
7232 struct frame_id sr_id
,
7233 enum bptype sr_type
)
7235 /* There should never be more than one step-resume or longjmp-resume
7236 breakpoint per thread, so we should never be setting a new
7237 step_resume_breakpoint when one is already active. */
7238 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7239 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7242 fprintf_unfiltered (gdb_stdlog
,
7243 "infrun: inserting step-resume breakpoint at %s\n",
7244 paddress (gdbarch
, sr_sal
.pc
));
7246 inferior_thread ()->control
.step_resume_breakpoint
7247 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7251 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7252 struct symtab_and_line sr_sal
,
7253 struct frame_id sr_id
)
7255 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7260 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7261 This is used to skip a potential signal handler.
7263 This is called with the interrupted function's frame. The signal
7264 handler, when it returns, will resume the interrupted function at
7268 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7270 gdb_assert (return_frame
!= NULL
);
7272 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7274 symtab_and_line sr_sal
;
7275 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7276 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7277 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7279 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7280 get_stack_frame_id (return_frame
),
7284 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7285 is used to skip a function after stepping into it (for "next" or if
7286 the called function has no debugging information).
7288 The current function has almost always been reached by single
7289 stepping a call or return instruction. NEXT_FRAME belongs to the
7290 current function, and the breakpoint will be set at the caller's
7293 This is a separate function rather than reusing
7294 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7295 get_prev_frame, which may stop prematurely (see the implementation
7296 of frame_unwind_caller_id for an example). */
7299 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7301 /* We shouldn't have gotten here if we don't know where the call site
7303 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7305 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7307 symtab_and_line sr_sal
;
7308 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7309 frame_unwind_caller_pc (next_frame
));
7310 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7311 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7313 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7314 frame_unwind_caller_id (next_frame
));
7317 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7318 new breakpoint at the target of a jmp_buf. The handling of
7319 longjmp-resume uses the same mechanisms used for handling
7320 "step-resume" breakpoints. */
7323 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7325 /* There should never be more than one longjmp-resume breakpoint per
7326 thread, so we should never be setting a new
7327 longjmp_resume_breakpoint when one is already active. */
7328 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7331 fprintf_unfiltered (gdb_stdlog
,
7332 "infrun: inserting longjmp-resume breakpoint at %s\n",
7333 paddress (gdbarch
, pc
));
7335 inferior_thread ()->control
.exception_resume_breakpoint
=
7336 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7339 /* Insert an exception resume breakpoint. TP is the thread throwing
7340 the exception. The block B is the block of the unwinder debug hook
7341 function. FRAME is the frame corresponding to the call to this
7342 function. SYM is the symbol of the function argument holding the
7343 target PC of the exception. */
7346 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7347 const struct block
*b
,
7348 struct frame_info
*frame
,
7353 struct block_symbol vsym
;
7354 struct value
*value
;
7356 struct breakpoint
*bp
;
7358 vsym
= lookup_symbol_search_name (sym
->search_name (),
7360 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7361 /* If the value was optimized out, revert to the old behavior. */
7362 if (! value_optimized_out (value
))
7364 handler
= value_as_address (value
);
7367 fprintf_unfiltered (gdb_stdlog
,
7368 "infrun: exception resume at %lx\n",
7369 (unsigned long) handler
);
7371 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7373 bp_exception_resume
).release ();
7375 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7378 bp
->thread
= tp
->global_num
;
7379 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7382 catch (const gdb_exception_error
&e
)
7384 /* We want to ignore errors here. */
7388 /* A helper for check_exception_resume that sets an
7389 exception-breakpoint based on a SystemTap probe. */
7392 insert_exception_resume_from_probe (struct thread_info
*tp
,
7393 const struct bound_probe
*probe
,
7394 struct frame_info
*frame
)
7396 struct value
*arg_value
;
7398 struct breakpoint
*bp
;
7400 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7404 handler
= value_as_address (arg_value
);
7407 fprintf_unfiltered (gdb_stdlog
,
7408 "infrun: exception resume at %s\n",
7409 paddress (get_objfile_arch (probe
->objfile
),
7412 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7413 handler
, bp_exception_resume
).release ();
7414 bp
->thread
= tp
->global_num
;
7415 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7418 /* This is called when an exception has been intercepted. Check to
7419 see whether the exception's destination is of interest, and if so,
7420 set an exception resume breakpoint there. */
7423 check_exception_resume (struct execution_control_state
*ecs
,
7424 struct frame_info
*frame
)
7426 struct bound_probe probe
;
7427 struct symbol
*func
;
7429 /* First see if this exception unwinding breakpoint was set via a
7430 SystemTap probe point. If so, the probe has two arguments: the
7431 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7432 set a breakpoint there. */
7433 probe
= find_probe_by_pc (get_frame_pc (frame
));
7436 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7440 func
= get_frame_function (frame
);
7446 const struct block
*b
;
7447 struct block_iterator iter
;
7451 /* The exception breakpoint is a thread-specific breakpoint on
7452 the unwinder's debug hook, declared as:
7454 void _Unwind_DebugHook (void *cfa, void *handler);
7456 The CFA argument indicates the frame to which control is
7457 about to be transferred. HANDLER is the destination PC.
7459 We ignore the CFA and set a temporary breakpoint at HANDLER.
7460 This is not extremely efficient but it avoids issues in gdb
7461 with computing the DWARF CFA, and it also works even in weird
7462 cases such as throwing an exception from inside a signal
7465 b
= SYMBOL_BLOCK_VALUE (func
);
7466 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7468 if (!SYMBOL_IS_ARGUMENT (sym
))
7475 insert_exception_resume_breakpoint (ecs
->event_thread
,
7481 catch (const gdb_exception_error
&e
)
7487 stop_waiting (struct execution_control_state
*ecs
)
7490 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7492 /* Let callers know we don't want to wait for the inferior anymore. */
7493 ecs
->wait_some_more
= 0;
7495 /* If all-stop, but the target is always in non-stop mode, stop all
7496 threads now that we're presenting the stop to the user. */
7497 if (!non_stop
&& target_is_non_stop_p ())
7498 stop_all_threads ();
7501 /* Like keep_going, but passes the signal to the inferior, even if the
7502 signal is set to nopass. */
7505 keep_going_pass_signal (struct execution_control_state
*ecs
)
7507 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7508 gdb_assert (!ecs
->event_thread
->resumed
);
7510 /* Save the pc before execution, to compare with pc after stop. */
7511 ecs
->event_thread
->prev_pc
7512 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7514 if (ecs
->event_thread
->control
.trap_expected
)
7516 struct thread_info
*tp
= ecs
->event_thread
;
7519 fprintf_unfiltered (gdb_stdlog
,
7520 "infrun: %s has trap_expected set, "
7521 "resuming to collect trap\n",
7522 target_pid_to_str (tp
->ptid
).c_str ());
7524 /* We haven't yet gotten our trap, and either: intercepted a
7525 non-signal event (e.g., a fork); or took a signal which we
7526 are supposed to pass through to the inferior. Simply
7528 resume (ecs
->event_thread
->suspend
.stop_signal
);
7530 else if (step_over_info_valid_p ())
7532 /* Another thread is stepping over a breakpoint in-line. If
7533 this thread needs a step-over too, queue the request. In
7534 either case, this resume must be deferred for later. */
7535 struct thread_info
*tp
= ecs
->event_thread
;
7537 if (ecs
->hit_singlestep_breakpoint
7538 || thread_still_needs_step_over (tp
))
7541 fprintf_unfiltered (gdb_stdlog
,
7542 "infrun: step-over already in progress: "
7543 "step-over for %s deferred\n",
7544 target_pid_to_str (tp
->ptid
).c_str ());
7545 thread_step_over_chain_enqueue (tp
);
7550 fprintf_unfiltered (gdb_stdlog
,
7551 "infrun: step-over in progress: "
7552 "resume of %s deferred\n",
7553 target_pid_to_str (tp
->ptid
).c_str ());
7558 struct regcache
*regcache
= get_current_regcache ();
7561 step_over_what step_what
;
7563 /* Either the trap was not expected, but we are continuing
7564 anyway (if we got a signal, the user asked it be passed to
7567 We got our expected trap, but decided we should resume from
7570 We're going to run this baby now!
7572 Note that insert_breakpoints won't try to re-insert
7573 already inserted breakpoints. Therefore, we don't
7574 care if breakpoints were already inserted, or not. */
7576 /* If we need to step over a breakpoint, and we're not using
7577 displaced stepping to do so, insert all breakpoints
7578 (watchpoints, etc.) but the one we're stepping over, step one
7579 instruction, and then re-insert the breakpoint when that step
7582 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7584 remove_bp
= (ecs
->hit_singlestep_breakpoint
7585 || (step_what
& STEP_OVER_BREAKPOINT
));
7586 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7588 /* We can't use displaced stepping if we need to step past a
7589 watchpoint. The instruction copied to the scratch pad would
7590 still trigger the watchpoint. */
7592 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7594 set_step_over_info (regcache
->aspace (),
7595 regcache_read_pc (regcache
), remove_wps
,
7596 ecs
->event_thread
->global_num
);
7598 else if (remove_wps
)
7599 set_step_over_info (NULL
, 0, remove_wps
, -1);
7601 /* If we now need to do an in-line step-over, we need to stop
7602 all other threads. Note this must be done before
7603 insert_breakpoints below, because that removes the breakpoint
7604 we're about to step over, otherwise other threads could miss
7606 if (step_over_info_valid_p () && target_is_non_stop_p ())
7607 stop_all_threads ();
7609 /* Stop stepping if inserting breakpoints fails. */
7612 insert_breakpoints ();
7614 catch (const gdb_exception_error
&e
)
7616 exception_print (gdb_stderr
, e
);
7618 clear_step_over_info ();
7622 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7624 resume (ecs
->event_thread
->suspend
.stop_signal
);
7627 prepare_to_wait (ecs
);
7630 /* Called when we should continue running the inferior, because the
7631 current event doesn't cause a user visible stop. This does the
7632 resuming part; waiting for the next event is done elsewhere. */
7635 keep_going (struct execution_control_state
*ecs
)
7637 if (ecs
->event_thread
->control
.trap_expected
7638 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7639 ecs
->event_thread
->control
.trap_expected
= 0;
7641 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7642 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7643 keep_going_pass_signal (ecs
);
7646 /* This function normally comes after a resume, before
7647 handle_inferior_event exits. It takes care of any last bits of
7648 housekeeping, and sets the all-important wait_some_more flag. */
7651 prepare_to_wait (struct execution_control_state
*ecs
)
7654 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7656 ecs
->wait_some_more
= 1;
7658 if (!target_is_async_p ())
7659 mark_infrun_async_event_handler ();
7662 /* We are done with the step range of a step/next/si/ni command.
7663 Called once for each n of a "step n" operation. */
7666 end_stepping_range (struct execution_control_state
*ecs
)
7668 ecs
->event_thread
->control
.stop_step
= 1;
7672 /* Several print_*_reason functions to print why the inferior has stopped.
7673 We always print something when the inferior exits, or receives a signal.
7674 The rest of the cases are dealt with later on in normal_stop and
7675 print_it_typical. Ideally there should be a call to one of these
7676 print_*_reason functions functions from handle_inferior_event each time
7677 stop_waiting is called.
7679 Note that we don't call these directly, instead we delegate that to
7680 the interpreters, through observers. Interpreters then call these
7681 with whatever uiout is right. */
7684 print_end_stepping_range_reason (struct ui_out
*uiout
)
7686 /* For CLI-like interpreters, print nothing. */
7688 if (uiout
->is_mi_like_p ())
7690 uiout
->field_string ("reason",
7691 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7696 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7698 annotate_signalled ();
7699 if (uiout
->is_mi_like_p ())
7701 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7702 uiout
->text ("\nProgram terminated with signal ");
7703 annotate_signal_name ();
7704 uiout
->field_string ("signal-name",
7705 gdb_signal_to_name (siggnal
));
7706 annotate_signal_name_end ();
7708 annotate_signal_string ();
7709 uiout
->field_string ("signal-meaning",
7710 gdb_signal_to_string (siggnal
));
7711 annotate_signal_string_end ();
7712 uiout
->text (".\n");
7713 uiout
->text ("The program no longer exists.\n");
7717 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7719 struct inferior
*inf
= current_inferior ();
7720 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7722 annotate_exited (exitstatus
);
7725 if (uiout
->is_mi_like_p ())
7726 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7727 std::string exit_code_str
7728 = string_printf ("0%o", (unsigned int) exitstatus
);
7729 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7730 plongest (inf
->num
), pidstr
.c_str (),
7731 string_field ("exit-code", exit_code_str
.c_str ()));
7735 if (uiout
->is_mi_like_p ())
7737 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7738 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7739 plongest (inf
->num
), pidstr
.c_str ());
7743 /* Some targets/architectures can do extra processing/display of
7744 segmentation faults. E.g., Intel MPX boundary faults.
7745 Call the architecture dependent function to handle the fault. */
7748 handle_segmentation_fault (struct ui_out
*uiout
)
7750 struct regcache
*regcache
= get_current_regcache ();
7751 struct gdbarch
*gdbarch
= regcache
->arch ();
7753 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7754 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7758 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7760 struct thread_info
*thr
= inferior_thread ();
7764 if (uiout
->is_mi_like_p ())
7766 else if (show_thread_that_caused_stop ())
7770 uiout
->text ("\nThread ");
7771 uiout
->field_string ("thread-id", print_thread_id (thr
));
7773 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7776 uiout
->text (" \"");
7777 uiout
->field_string ("name", name
);
7782 uiout
->text ("\nProgram");
7784 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
7785 uiout
->text (" stopped");
7788 uiout
->text (" received signal ");
7789 annotate_signal_name ();
7790 if (uiout
->is_mi_like_p ())
7792 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7793 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
7794 annotate_signal_name_end ();
7796 annotate_signal_string ();
7797 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
7799 if (siggnal
== GDB_SIGNAL_SEGV
)
7800 handle_segmentation_fault (uiout
);
7802 annotate_signal_string_end ();
7804 uiout
->text (".\n");
7808 print_no_history_reason (struct ui_out
*uiout
)
7810 uiout
->text ("\nNo more reverse-execution history.\n");
7813 /* Print current location without a level number, if we have changed
7814 functions or hit a breakpoint. Print source line if we have one.
7815 bpstat_print contains the logic deciding in detail what to print,
7816 based on the event(s) that just occurred. */
7819 print_stop_location (struct target_waitstatus
*ws
)
7822 enum print_what source_flag
;
7823 int do_frame_printing
= 1;
7824 struct thread_info
*tp
= inferior_thread ();
7826 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
7830 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7831 should) carry around the function and does (or should) use
7832 that when doing a frame comparison. */
7833 if (tp
->control
.stop_step
7834 && frame_id_eq (tp
->control
.step_frame_id
,
7835 get_frame_id (get_current_frame ()))
7836 && (tp
->control
.step_start_function
7837 == find_pc_function (tp
->suspend
.stop_pc
)))
7839 /* Finished step, just print source line. */
7840 source_flag
= SRC_LINE
;
7844 /* Print location and source line. */
7845 source_flag
= SRC_AND_LOC
;
7848 case PRINT_SRC_AND_LOC
:
7849 /* Print location and source line. */
7850 source_flag
= SRC_AND_LOC
;
7852 case PRINT_SRC_ONLY
:
7853 source_flag
= SRC_LINE
;
7856 /* Something bogus. */
7857 source_flag
= SRC_LINE
;
7858 do_frame_printing
= 0;
7861 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
7864 /* The behavior of this routine with respect to the source
7866 SRC_LINE: Print only source line
7867 LOCATION: Print only location
7868 SRC_AND_LOC: Print location and source line. */
7869 if (do_frame_printing
)
7870 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
7876 print_stop_event (struct ui_out
*uiout
, bool displays
)
7878 struct target_waitstatus last
;
7880 struct thread_info
*tp
;
7882 get_last_target_status (&last_ptid
, &last
);
7885 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
7887 print_stop_location (&last
);
7889 /* Display the auto-display expressions. */
7894 tp
= inferior_thread ();
7895 if (tp
->thread_fsm
!= NULL
7896 && tp
->thread_fsm
->finished_p ())
7898 struct return_value_info
*rv
;
7900 rv
= tp
->thread_fsm
->return_value ();
7902 print_return_value (uiout
, rv
);
7909 maybe_remove_breakpoints (void)
7911 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
7913 if (remove_breakpoints ())
7915 target_terminal::ours_for_output ();
7916 printf_filtered (_("Cannot remove breakpoints because "
7917 "program is no longer writable.\nFurther "
7918 "execution is probably impossible.\n"));
7923 /* The execution context that just caused a normal stop. */
7930 DISABLE_COPY_AND_ASSIGN (stop_context
);
7932 bool changed () const;
7937 /* The event PTID. */
7941 /* If stopp for a thread event, this is the thread that caused the
7943 struct thread_info
*thread
;
7945 /* The inferior that caused the stop. */
7949 /* Initializes a new stop context. If stopped for a thread event, this
7950 takes a strong reference to the thread. */
7952 stop_context::stop_context ()
7954 stop_id
= get_stop_id ();
7955 ptid
= inferior_ptid
;
7956 inf_num
= current_inferior ()->num
;
7958 if (inferior_ptid
!= null_ptid
)
7960 /* Take a strong reference so that the thread can't be deleted
7962 thread
= inferior_thread ();
7969 /* Release a stop context previously created with save_stop_context.
7970 Releases the strong reference to the thread as well. */
7972 stop_context::~stop_context ()
7978 /* Return true if the current context no longer matches the saved stop
7982 stop_context::changed () const
7984 if (ptid
!= inferior_ptid
)
7986 if (inf_num
!= current_inferior ()->num
)
7988 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
7990 if (get_stop_id () != stop_id
)
8000 struct target_waitstatus last
;
8003 get_last_target_status (&last_ptid
, &last
);
8007 /* If an exception is thrown from this point on, make sure to
8008 propagate GDB's knowledge of the executing state to the
8009 frontend/user running state. A QUIT is an easy exception to see
8010 here, so do this before any filtered output. */
8012 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8015 maybe_finish_thread_state
.emplace (minus_one_ptid
);
8016 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8017 || last
.kind
== TARGET_WAITKIND_EXITED
)
8019 /* On some targets, we may still have live threads in the
8020 inferior when we get a process exit event. E.g., for
8021 "checkpoint", when the current checkpoint/fork exits,
8022 linux-fork.c automatically switches to another fork from
8023 within target_mourn_inferior. */
8024 if (inferior_ptid
!= null_ptid
)
8025 maybe_finish_thread_state
.emplace (ptid_t (inferior_ptid
.pid ()));
8027 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8028 maybe_finish_thread_state
.emplace (inferior_ptid
);
8030 /* As we're presenting a stop, and potentially removing breakpoints,
8031 update the thread list so we can tell whether there are threads
8032 running on the target. With target remote, for example, we can
8033 only learn about new threads when we explicitly update the thread
8034 list. Do this before notifying the interpreters about signal
8035 stops, end of stepping ranges, etc., so that the "new thread"
8036 output is emitted before e.g., "Program received signal FOO",
8037 instead of after. */
8038 update_thread_list ();
8040 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8041 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8043 /* As with the notification of thread events, we want to delay
8044 notifying the user that we've switched thread context until
8045 the inferior actually stops.
8047 There's no point in saying anything if the inferior has exited.
8048 Note that SIGNALLED here means "exited with a signal", not
8049 "received a signal".
8051 Also skip saying anything in non-stop mode. In that mode, as we
8052 don't want GDB to switch threads behind the user's back, to avoid
8053 races where the user is typing a command to apply to thread x,
8054 but GDB switches to thread y before the user finishes entering
8055 the command, fetch_inferior_event installs a cleanup to restore
8056 the current thread back to the thread the user had selected right
8057 after this event is handled, so we're not really switching, only
8058 informing of a stop. */
8060 && previous_inferior_ptid
!= inferior_ptid
8061 && target_has_execution
8062 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8063 && last
.kind
!= TARGET_WAITKIND_EXITED
8064 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8066 SWITCH_THRU_ALL_UIS ()
8068 target_terminal::ours_for_output ();
8069 printf_filtered (_("[Switching to %s]\n"),
8070 target_pid_to_str (inferior_ptid
).c_str ());
8071 annotate_thread_changed ();
8073 previous_inferior_ptid
= inferior_ptid
;
8076 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8078 SWITCH_THRU_ALL_UIS ()
8079 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8081 target_terminal::ours_for_output ();
8082 printf_filtered (_("No unwaited-for children left.\n"));
8086 /* Note: this depends on the update_thread_list call above. */
8087 maybe_remove_breakpoints ();
8089 /* If an auto-display called a function and that got a signal,
8090 delete that auto-display to avoid an infinite recursion. */
8092 if (stopped_by_random_signal
)
8093 disable_current_display ();
8095 SWITCH_THRU_ALL_UIS ()
8097 async_enable_stdin ();
8100 /* Let the user/frontend see the threads as stopped. */
8101 maybe_finish_thread_state
.reset ();
8103 /* Select innermost stack frame - i.e., current frame is frame 0,
8104 and current location is based on that. Handle the case where the
8105 dummy call is returning after being stopped. E.g. the dummy call
8106 previously hit a breakpoint. (If the dummy call returns
8107 normally, we won't reach here.) Do this before the stop hook is
8108 run, so that it doesn't get to see the temporary dummy frame,
8109 which is not where we'll present the stop. */
8110 if (has_stack_frames ())
8112 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8114 /* Pop the empty frame that contains the stack dummy. This
8115 also restores inferior state prior to the call (struct
8116 infcall_suspend_state). */
8117 struct frame_info
*frame
= get_current_frame ();
8119 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8121 /* frame_pop calls reinit_frame_cache as the last thing it
8122 does which means there's now no selected frame. */
8125 select_frame (get_current_frame ());
8127 /* Set the current source location. */
8128 set_current_sal_from_frame (get_current_frame ());
8131 /* Look up the hook_stop and run it (CLI internally handles problem
8132 of stop_command's pre-hook not existing). */
8133 if (stop_command
!= NULL
)
8135 stop_context saved_context
;
8139 execute_cmd_pre_hook (stop_command
);
8141 catch (const gdb_exception
&ex
)
8143 exception_fprintf (gdb_stderr
, ex
,
8144 "Error while running hook_stop:\n");
8147 /* If the stop hook resumes the target, then there's no point in
8148 trying to notify about the previous stop; its context is
8149 gone. Likewise if the command switches thread or inferior --
8150 the observers would print a stop for the wrong
8152 if (saved_context
.changed ())
8156 /* Notify observers about the stop. This is where the interpreters
8157 print the stop event. */
8158 if (inferior_ptid
!= null_ptid
)
8159 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8162 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8164 annotate_stopped ();
8166 if (target_has_execution
)
8168 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8169 && last
.kind
!= TARGET_WAITKIND_EXITED
8170 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8171 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8172 Delete any breakpoint that is to be deleted at the next stop. */
8173 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8176 /* Try to get rid of automatically added inferiors that are no
8177 longer needed. Keeping those around slows down things linearly.
8178 Note that this never removes the current inferior. */
8185 signal_stop_state (int signo
)
8187 return signal_stop
[signo
];
8191 signal_print_state (int signo
)
8193 return signal_print
[signo
];
8197 signal_pass_state (int signo
)
8199 return signal_program
[signo
];
8203 signal_cache_update (int signo
)
8207 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8208 signal_cache_update (signo
);
8213 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8214 && signal_print
[signo
] == 0
8215 && signal_program
[signo
] == 1
8216 && signal_catch
[signo
] == 0);
8220 signal_stop_update (int signo
, int state
)
8222 int ret
= signal_stop
[signo
];
8224 signal_stop
[signo
] = state
;
8225 signal_cache_update (signo
);
8230 signal_print_update (int signo
, int state
)
8232 int ret
= signal_print
[signo
];
8234 signal_print
[signo
] = state
;
8235 signal_cache_update (signo
);
8240 signal_pass_update (int signo
, int state
)
8242 int ret
= signal_program
[signo
];
8244 signal_program
[signo
] = state
;
8245 signal_cache_update (signo
);
8249 /* Update the global 'signal_catch' from INFO and notify the
8253 signal_catch_update (const unsigned int *info
)
8257 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8258 signal_catch
[i
] = info
[i
] > 0;
8259 signal_cache_update (-1);
8260 target_pass_signals (signal_pass
);
8264 sig_print_header (void)
8266 printf_filtered (_("Signal Stop\tPrint\tPass "
8267 "to program\tDescription\n"));
8271 sig_print_info (enum gdb_signal oursig
)
8273 const char *name
= gdb_signal_to_name (oursig
);
8274 int name_padding
= 13 - strlen (name
);
8276 if (name_padding
<= 0)
8279 printf_filtered ("%s", name
);
8280 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8281 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8282 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8283 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8284 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8287 /* Specify how various signals in the inferior should be handled. */
8290 handle_command (const char *args
, int from_tty
)
8292 int digits
, wordlen
;
8293 int sigfirst
, siglast
;
8294 enum gdb_signal oursig
;
8299 error_no_arg (_("signal to handle"));
8302 /* Allocate and zero an array of flags for which signals to handle. */
8304 const size_t nsigs
= GDB_SIGNAL_LAST
;
8305 unsigned char sigs
[nsigs
] {};
8307 /* Break the command line up into args. */
8309 gdb_argv
built_argv (args
);
8311 /* Walk through the args, looking for signal oursigs, signal names, and
8312 actions. Signal numbers and signal names may be interspersed with
8313 actions, with the actions being performed for all signals cumulatively
8314 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8316 for (char *arg
: built_argv
)
8318 wordlen
= strlen (arg
);
8319 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8323 sigfirst
= siglast
= -1;
8325 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8327 /* Apply action to all signals except those used by the
8328 debugger. Silently skip those. */
8331 siglast
= nsigs
- 1;
8333 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8335 SET_SIGS (nsigs
, sigs
, signal_stop
);
8336 SET_SIGS (nsigs
, sigs
, signal_print
);
8338 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8340 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8342 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8344 SET_SIGS (nsigs
, sigs
, signal_print
);
8346 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8348 SET_SIGS (nsigs
, sigs
, signal_program
);
8350 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8352 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8354 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8356 SET_SIGS (nsigs
, sigs
, signal_program
);
8358 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8360 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8361 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8363 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8365 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8367 else if (digits
> 0)
8369 /* It is numeric. The numeric signal refers to our own
8370 internal signal numbering from target.h, not to host/target
8371 signal number. This is a feature; users really should be
8372 using symbolic names anyway, and the common ones like
8373 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8375 sigfirst
= siglast
= (int)
8376 gdb_signal_from_command (atoi (arg
));
8377 if (arg
[digits
] == '-')
8380 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8382 if (sigfirst
> siglast
)
8384 /* Bet he didn't figure we'd think of this case... */
8385 std::swap (sigfirst
, siglast
);
8390 oursig
= gdb_signal_from_name (arg
);
8391 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8393 sigfirst
= siglast
= (int) oursig
;
8397 /* Not a number and not a recognized flag word => complain. */
8398 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8402 /* If any signal numbers or symbol names were found, set flags for
8403 which signals to apply actions to. */
8405 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8407 switch ((enum gdb_signal
) signum
)
8409 case GDB_SIGNAL_TRAP
:
8410 case GDB_SIGNAL_INT
:
8411 if (!allsigs
&& !sigs
[signum
])
8413 if (query (_("%s is used by the debugger.\n\
8414 Are you sure you want to change it? "),
8415 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8420 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8424 case GDB_SIGNAL_DEFAULT
:
8425 case GDB_SIGNAL_UNKNOWN
:
8426 /* Make sure that "all" doesn't print these. */
8435 for (int signum
= 0; signum
< nsigs
; signum
++)
8438 signal_cache_update (-1);
8439 target_pass_signals (signal_pass
);
8440 target_program_signals (signal_program
);
8444 /* Show the results. */
8445 sig_print_header ();
8446 for (; signum
< nsigs
; signum
++)
8448 sig_print_info ((enum gdb_signal
) signum
);
8455 /* Complete the "handle" command. */
8458 handle_completer (struct cmd_list_element
*ignore
,
8459 completion_tracker
&tracker
,
8460 const char *text
, const char *word
)
8462 static const char * const keywords
[] =
8476 signal_completer (ignore
, tracker
, text
, word
);
8477 complete_on_enum (tracker
, keywords
, word
, word
);
8481 gdb_signal_from_command (int num
)
8483 if (num
>= 1 && num
<= 15)
8484 return (enum gdb_signal
) num
;
8485 error (_("Only signals 1-15 are valid as numeric signals.\n\
8486 Use \"info signals\" for a list of symbolic signals."));
8489 /* Print current contents of the tables set by the handle command.
8490 It is possible we should just be printing signals actually used
8491 by the current target (but for things to work right when switching
8492 targets, all signals should be in the signal tables). */
8495 info_signals_command (const char *signum_exp
, int from_tty
)
8497 enum gdb_signal oursig
;
8499 sig_print_header ();
8503 /* First see if this is a symbol name. */
8504 oursig
= gdb_signal_from_name (signum_exp
);
8505 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8507 /* No, try numeric. */
8509 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8511 sig_print_info (oursig
);
8515 printf_filtered ("\n");
8516 /* These ugly casts brought to you by the native VAX compiler. */
8517 for (oursig
= GDB_SIGNAL_FIRST
;
8518 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8519 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8523 if (oursig
!= GDB_SIGNAL_UNKNOWN
8524 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8525 sig_print_info (oursig
);
8528 printf_filtered (_("\nUse the \"handle\" command "
8529 "to change these tables.\n"));
8532 /* The $_siginfo convenience variable is a bit special. We don't know
8533 for sure the type of the value until we actually have a chance to
8534 fetch the data. The type can change depending on gdbarch, so it is
8535 also dependent on which thread you have selected.
8537 1. making $_siginfo be an internalvar that creates a new value on
8540 2. making the value of $_siginfo be an lval_computed value. */
8542 /* This function implements the lval_computed support for reading a
8546 siginfo_value_read (struct value
*v
)
8548 LONGEST transferred
;
8550 /* If we can access registers, so can we access $_siginfo. Likewise
8552 validate_registers_access ();
8555 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8557 value_contents_all_raw (v
),
8559 TYPE_LENGTH (value_type (v
)));
8561 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8562 error (_("Unable to read siginfo"));
8565 /* This function implements the lval_computed support for writing a
8569 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8571 LONGEST transferred
;
8573 /* If we can access registers, so can we access $_siginfo. Likewise
8575 validate_registers_access ();
8577 transferred
= target_write (current_top_target (),
8578 TARGET_OBJECT_SIGNAL_INFO
,
8580 value_contents_all_raw (fromval
),
8582 TYPE_LENGTH (value_type (fromval
)));
8584 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8585 error (_("Unable to write siginfo"));
8588 static const struct lval_funcs siginfo_value_funcs
=
8594 /* Return a new value with the correct type for the siginfo object of
8595 the current thread using architecture GDBARCH. Return a void value
8596 if there's no object available. */
8598 static struct value
*
8599 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8602 if (target_has_stack
8603 && inferior_ptid
!= null_ptid
8604 && gdbarch_get_siginfo_type_p (gdbarch
))
8606 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8608 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8611 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8615 /* infcall_suspend_state contains state about the program itself like its
8616 registers and any signal it received when it last stopped.
8617 This state must be restored regardless of how the inferior function call
8618 ends (either successfully, or after it hits a breakpoint or signal)
8619 if the program is to properly continue where it left off. */
8621 class infcall_suspend_state
8624 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8625 once the inferior function call has finished. */
8626 infcall_suspend_state (struct gdbarch
*gdbarch
,
8627 const struct thread_info
*tp
,
8628 struct regcache
*regcache
)
8629 : m_thread_suspend (tp
->suspend
),
8630 m_registers (new readonly_detached_regcache (*regcache
))
8632 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8634 if (gdbarch_get_siginfo_type_p (gdbarch
))
8636 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8637 size_t len
= TYPE_LENGTH (type
);
8639 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8641 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8642 siginfo_data
.get (), 0, len
) != len
)
8644 /* Errors ignored. */
8645 siginfo_data
.reset (nullptr);
8651 m_siginfo_gdbarch
= gdbarch
;
8652 m_siginfo_data
= std::move (siginfo_data
);
8656 /* Return a pointer to the stored register state. */
8658 readonly_detached_regcache
*registers () const
8660 return m_registers
.get ();
8663 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8665 void restore (struct gdbarch
*gdbarch
,
8666 struct thread_info
*tp
,
8667 struct regcache
*regcache
) const
8669 tp
->suspend
= m_thread_suspend
;
8671 if (m_siginfo_gdbarch
== gdbarch
)
8673 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8675 /* Errors ignored. */
8676 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8677 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8680 /* The inferior can be gone if the user types "print exit(0)"
8681 (and perhaps other times). */
8682 if (target_has_execution
)
8683 /* NB: The register write goes through to the target. */
8684 regcache
->restore (registers ());
8688 /* How the current thread stopped before the inferior function call was
8690 struct thread_suspend_state m_thread_suspend
;
8692 /* The registers before the inferior function call was executed. */
8693 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8695 /* Format of SIGINFO_DATA or NULL if it is not present. */
8696 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8698 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8699 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8700 content would be invalid. */
8701 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8704 infcall_suspend_state_up
8705 save_infcall_suspend_state ()
8707 struct thread_info
*tp
= inferior_thread ();
8708 struct regcache
*regcache
= get_current_regcache ();
8709 struct gdbarch
*gdbarch
= regcache
->arch ();
8711 infcall_suspend_state_up inf_state
8712 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8714 /* Having saved the current state, adjust the thread state, discarding
8715 any stop signal information. The stop signal is not useful when
8716 starting an inferior function call, and run_inferior_call will not use
8717 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8718 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8723 /* Restore inferior session state to INF_STATE. */
8726 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8728 struct thread_info
*tp
= inferior_thread ();
8729 struct regcache
*regcache
= get_current_regcache ();
8730 struct gdbarch
*gdbarch
= regcache
->arch ();
8732 inf_state
->restore (gdbarch
, tp
, regcache
);
8733 discard_infcall_suspend_state (inf_state
);
8737 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8742 readonly_detached_regcache
*
8743 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8745 return inf_state
->registers ();
8748 /* infcall_control_state contains state regarding gdb's control of the
8749 inferior itself like stepping control. It also contains session state like
8750 the user's currently selected frame. */
8752 struct infcall_control_state
8754 struct thread_control_state thread_control
;
8755 struct inferior_control_state inferior_control
;
8758 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8759 int stopped_by_random_signal
= 0;
8761 /* ID if the selected frame when the inferior function call was made. */
8762 struct frame_id selected_frame_id
{};
8765 /* Save all of the information associated with the inferior<==>gdb
8768 infcall_control_state_up
8769 save_infcall_control_state ()
8771 infcall_control_state_up
inf_status (new struct infcall_control_state
);
8772 struct thread_info
*tp
= inferior_thread ();
8773 struct inferior
*inf
= current_inferior ();
8775 inf_status
->thread_control
= tp
->control
;
8776 inf_status
->inferior_control
= inf
->control
;
8778 tp
->control
.step_resume_breakpoint
= NULL
;
8779 tp
->control
.exception_resume_breakpoint
= NULL
;
8781 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8782 chain. If caller's caller is walking the chain, they'll be happier if we
8783 hand them back the original chain when restore_infcall_control_state is
8785 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
8788 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
8789 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
8791 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
8797 restore_selected_frame (const frame_id
&fid
)
8799 frame_info
*frame
= frame_find_by_id (fid
);
8801 /* If inf_status->selected_frame_id is NULL, there was no previously
8805 warning (_("Unable to restore previously selected frame."));
8809 select_frame (frame
);
8812 /* Restore inferior session state to INF_STATUS. */
8815 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
8817 struct thread_info
*tp
= inferior_thread ();
8818 struct inferior
*inf
= current_inferior ();
8820 if (tp
->control
.step_resume_breakpoint
)
8821 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
8823 if (tp
->control
.exception_resume_breakpoint
)
8824 tp
->control
.exception_resume_breakpoint
->disposition
8825 = disp_del_at_next_stop
;
8827 /* Handle the bpstat_copy of the chain. */
8828 bpstat_clear (&tp
->control
.stop_bpstat
);
8830 tp
->control
= inf_status
->thread_control
;
8831 inf
->control
= inf_status
->inferior_control
;
8834 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
8835 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
8837 if (target_has_stack
)
8839 /* The point of the try/catch is that if the stack is clobbered,
8840 walking the stack might encounter a garbage pointer and
8841 error() trying to dereference it. */
8844 restore_selected_frame (inf_status
->selected_frame_id
);
8846 catch (const gdb_exception_error
&ex
)
8848 exception_fprintf (gdb_stderr
, ex
,
8849 "Unable to restore previously selected frame:\n");
8850 /* Error in restoring the selected frame. Select the
8852 select_frame (get_current_frame ());
8860 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
8862 if (inf_status
->thread_control
.step_resume_breakpoint
)
8863 inf_status
->thread_control
.step_resume_breakpoint
->disposition
8864 = disp_del_at_next_stop
;
8866 if (inf_status
->thread_control
.exception_resume_breakpoint
)
8867 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
8868 = disp_del_at_next_stop
;
8870 /* See save_infcall_control_state for info on stop_bpstat. */
8871 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
8879 clear_exit_convenience_vars (void)
8881 clear_internalvar (lookup_internalvar ("_exitsignal"));
8882 clear_internalvar (lookup_internalvar ("_exitcode"));
8886 /* User interface for reverse debugging:
8887 Set exec-direction / show exec-direction commands
8888 (returns error unless target implements to_set_exec_direction method). */
8890 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
8891 static const char exec_forward
[] = "forward";
8892 static const char exec_reverse
[] = "reverse";
8893 static const char *exec_direction
= exec_forward
;
8894 static const char *const exec_direction_names
[] = {
8901 set_exec_direction_func (const char *args
, int from_tty
,
8902 struct cmd_list_element
*cmd
)
8904 if (target_can_execute_reverse
)
8906 if (!strcmp (exec_direction
, exec_forward
))
8907 execution_direction
= EXEC_FORWARD
;
8908 else if (!strcmp (exec_direction
, exec_reverse
))
8909 execution_direction
= EXEC_REVERSE
;
8913 exec_direction
= exec_forward
;
8914 error (_("Target does not support this operation."));
8919 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
8920 struct cmd_list_element
*cmd
, const char *value
)
8922 switch (execution_direction
) {
8924 fprintf_filtered (out
, _("Forward.\n"));
8927 fprintf_filtered (out
, _("Reverse.\n"));
8930 internal_error (__FILE__
, __LINE__
,
8931 _("bogus execution_direction value: %d"),
8932 (int) execution_direction
);
8937 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
8938 struct cmd_list_element
*c
, const char *value
)
8940 fprintf_filtered (file
, _("Resuming the execution of threads "
8941 "of all processes is %s.\n"), value
);
8944 /* Implementation of `siginfo' variable. */
8946 static const struct internalvar_funcs siginfo_funcs
=
8953 /* Callback for infrun's target events source. This is marked when a
8954 thread has a pending status to process. */
8957 infrun_async_inferior_event_handler (gdb_client_data data
)
8959 inferior_event_handler (INF_REG_EVENT
, NULL
);
8963 _initialize_infrun (void)
8965 struct cmd_list_element
*c
;
8967 /* Register extra event sources in the event loop. */
8968 infrun_async_inferior_event_token
8969 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
8971 add_info ("signals", info_signals_command
, _("\
8972 What debugger does when program gets various signals.\n\
8973 Specify a signal as argument to print info on that signal only."));
8974 add_info_alias ("handle", "signals", 0);
8976 c
= add_com ("handle", class_run
, handle_command
, _("\
8977 Specify how to handle signals.\n\
8978 Usage: handle SIGNAL [ACTIONS]\n\
8979 Args are signals and actions to apply to those signals.\n\
8980 If no actions are specified, the current settings for the specified signals\n\
8981 will be displayed instead.\n\
8983 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8984 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8985 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8986 The special arg \"all\" is recognized to mean all signals except those\n\
8987 used by the debugger, typically SIGTRAP and SIGINT.\n\
8989 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8990 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8991 Stop means reenter debugger if this signal happens (implies print).\n\
8992 Print means print a message if this signal happens.\n\
8993 Pass means let program see this signal; otherwise program doesn't know.\n\
8994 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8995 Pass and Stop may be combined.\n\
8997 Multiple signals may be specified. Signal numbers and signal names\n\
8998 may be interspersed with actions, with the actions being performed for\n\
8999 all signals cumulatively specified."));
9000 set_cmd_completer (c
, handle_completer
);
9003 stop_command
= add_cmd ("stop", class_obscure
,
9004 not_just_help_class_command
, _("\
9005 There is no `stop' command, but you can set a hook on `stop'.\n\
9006 This allows you to set a list of commands to be run each time execution\n\
9007 of the program stops."), &cmdlist
);
9009 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9010 Set inferior debugging."), _("\
9011 Show inferior debugging."), _("\
9012 When non-zero, inferior specific debugging is enabled."),
9015 &setdebuglist
, &showdebuglist
);
9017 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9018 &debug_displaced
, _("\
9019 Set displaced stepping debugging."), _("\
9020 Show displaced stepping debugging."), _("\
9021 When non-zero, displaced stepping specific debugging is enabled."),
9023 show_debug_displaced
,
9024 &setdebuglist
, &showdebuglist
);
9026 add_setshow_boolean_cmd ("non-stop", no_class
,
9028 Set whether gdb controls the inferior in non-stop mode."), _("\
9029 Show whether gdb controls the inferior in non-stop mode."), _("\
9030 When debugging a multi-threaded program and this setting is\n\
9031 off (the default, also called all-stop mode), when one thread stops\n\
9032 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9033 all other threads in the program while you interact with the thread of\n\
9034 interest. When you continue or step a thread, you can allow the other\n\
9035 threads to run, or have them remain stopped, but while you inspect any\n\
9036 thread's state, all threads stop.\n\
9038 In non-stop mode, when one thread stops, other threads can continue\n\
9039 to run freely. You'll be able to step each thread independently,\n\
9040 leave it stopped or free to run as needed."),
9046 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9049 signal_print
[i
] = 1;
9050 signal_program
[i
] = 1;
9051 signal_catch
[i
] = 0;
9054 /* Signals caused by debugger's own actions should not be given to
9055 the program afterwards.
9057 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9058 explicitly specifies that it should be delivered to the target
9059 program. Typically, that would occur when a user is debugging a
9060 target monitor on a simulator: the target monitor sets a
9061 breakpoint; the simulator encounters this breakpoint and halts
9062 the simulation handing control to GDB; GDB, noting that the stop
9063 address doesn't map to any known breakpoint, returns control back
9064 to the simulator; the simulator then delivers the hardware
9065 equivalent of a GDB_SIGNAL_TRAP to the program being
9067 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9068 signal_program
[GDB_SIGNAL_INT
] = 0;
9070 /* Signals that are not errors should not normally enter the debugger. */
9071 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9072 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9073 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9074 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9075 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9076 signal_print
[GDB_SIGNAL_PROF
] = 0;
9077 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9078 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9079 signal_stop
[GDB_SIGNAL_IO
] = 0;
9080 signal_print
[GDB_SIGNAL_IO
] = 0;
9081 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9082 signal_print
[GDB_SIGNAL_POLL
] = 0;
9083 signal_stop
[GDB_SIGNAL_URG
] = 0;
9084 signal_print
[GDB_SIGNAL_URG
] = 0;
9085 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9086 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9087 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9088 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9090 /* These signals are used internally by user-level thread
9091 implementations. (See signal(5) on Solaris.) Like the above
9092 signals, a healthy program receives and handles them as part of
9093 its normal operation. */
9094 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9095 signal_print
[GDB_SIGNAL_LWP
] = 0;
9096 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9097 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9098 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9099 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9100 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9101 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9103 /* Update cached state. */
9104 signal_cache_update (-1);
9106 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9107 &stop_on_solib_events
, _("\
9108 Set stopping for shared library events."), _("\
9109 Show stopping for shared library events."), _("\
9110 If nonzero, gdb will give control to the user when the dynamic linker\n\
9111 notifies gdb of shared library events. The most common event of interest\n\
9112 to the user would be loading/unloading of a new library."),
9113 set_stop_on_solib_events
,
9114 show_stop_on_solib_events
,
9115 &setlist
, &showlist
);
9117 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9118 follow_fork_mode_kind_names
,
9119 &follow_fork_mode_string
, _("\
9120 Set debugger response to a program call of fork or vfork."), _("\
9121 Show debugger response to a program call of fork or vfork."), _("\
9122 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9123 parent - the original process is debugged after a fork\n\
9124 child - the new process is debugged after a fork\n\
9125 The unfollowed process will continue to run.\n\
9126 By default, the debugger will follow the parent process."),
9128 show_follow_fork_mode_string
,
9129 &setlist
, &showlist
);
9131 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9132 follow_exec_mode_names
,
9133 &follow_exec_mode_string
, _("\
9134 Set debugger response to a program call of exec."), _("\
9135 Show debugger response to a program call of exec."), _("\
9136 An exec call replaces the program image of a process.\n\
9138 follow-exec-mode can be:\n\
9140 new - the debugger creates a new inferior and rebinds the process\n\
9141 to this new inferior. The program the process was running before\n\
9142 the exec call can be restarted afterwards by restarting the original\n\
9145 same - the debugger keeps the process bound to the same inferior.\n\
9146 The new executable image replaces the previous executable loaded in\n\
9147 the inferior. Restarting the inferior after the exec call restarts\n\
9148 the executable the process was running after the exec call.\n\
9150 By default, the debugger will use the same inferior."),
9152 show_follow_exec_mode_string
,
9153 &setlist
, &showlist
);
9155 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9156 scheduler_enums
, &scheduler_mode
, _("\
9157 Set mode for locking scheduler during execution."), _("\
9158 Show mode for locking scheduler during execution."), _("\
9159 off == no locking (threads may preempt at any time)\n\
9160 on == full locking (no thread except the current thread may run)\n\
9161 This applies to both normal execution and replay mode.\n\
9162 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9163 In this mode, other threads may run during other commands.\n\
9164 This applies to both normal execution and replay mode.\n\
9165 replay == scheduler locked in replay mode and unlocked during normal execution."),
9166 set_schedlock_func
, /* traps on target vector */
9167 show_scheduler_mode
,
9168 &setlist
, &showlist
);
9170 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9171 Set mode for resuming threads of all processes."), _("\
9172 Show mode for resuming threads of all processes."), _("\
9173 When on, execution commands (such as 'continue' or 'next') resume all\n\
9174 threads of all processes. When off (which is the default), execution\n\
9175 commands only resume the threads of the current process. The set of\n\
9176 threads that are resumed is further refined by the scheduler-locking\n\
9177 mode (see help set scheduler-locking)."),
9179 show_schedule_multiple
,
9180 &setlist
, &showlist
);
9182 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9183 Set mode of the step operation."), _("\
9184 Show mode of the step operation."), _("\
9185 When set, doing a step over a function without debug line information\n\
9186 will stop at the first instruction of that function. Otherwise, the\n\
9187 function is skipped and the step command stops at a different source line."),
9189 show_step_stop_if_no_debug
,
9190 &setlist
, &showlist
);
9192 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9193 &can_use_displaced_stepping
, _("\
9194 Set debugger's willingness to use displaced stepping."), _("\
9195 Show debugger's willingness to use displaced stepping."), _("\
9196 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9197 supported by the target architecture. If off, gdb will not use displaced\n\
9198 stepping to step over breakpoints, even if such is supported by the target\n\
9199 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9200 if the target architecture supports it and non-stop mode is active, but will not\n\
9201 use it in all-stop mode (see help set non-stop)."),
9203 show_can_use_displaced_stepping
,
9204 &setlist
, &showlist
);
9206 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9207 &exec_direction
, _("Set direction of execution.\n\
9208 Options are 'forward' or 'reverse'."),
9209 _("Show direction of execution (forward/reverse)."),
9210 _("Tells gdb whether to execute forward or backward."),
9211 set_exec_direction_func
, show_exec_direction_func
,
9212 &setlist
, &showlist
);
9214 /* Set/show detach-on-fork: user-settable mode. */
9216 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9217 Set whether gdb will detach the child of a fork."), _("\
9218 Show whether gdb will detach the child of a fork."), _("\
9219 Tells gdb whether to detach the child of a fork."),
9220 NULL
, NULL
, &setlist
, &showlist
);
9222 /* Set/show disable address space randomization mode. */
9224 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9225 &disable_randomization
, _("\
9226 Set disabling of debuggee's virtual address space randomization."), _("\
9227 Show disabling of debuggee's virtual address space randomization."), _("\
9228 When this mode is on (which is the default), randomization of the virtual\n\
9229 address space is disabled. Standalone programs run with the randomization\n\
9230 enabled by default on some platforms."),
9231 &set_disable_randomization
,
9232 &show_disable_randomization
,
9233 &setlist
, &showlist
);
9235 /* ptid initializations */
9236 inferior_ptid
= null_ptid
;
9237 target_last_wait_ptid
= minus_one_ptid
;
9239 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9240 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9241 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9242 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9244 /* Explicitly create without lookup, since that tries to create a
9245 value with a void typed value, and when we get here, gdbarch
9246 isn't initialized yet. At this point, we're quite sure there
9247 isn't another convenience variable of the same name. */
9248 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9250 add_setshow_boolean_cmd ("observer", no_class
,
9251 &observer_mode_1
, _("\
9252 Set whether gdb controls the inferior in observer mode."), _("\
9253 Show whether gdb controls the inferior in observer mode."), _("\
9254 In observer mode, GDB can get data from the inferior, but not\n\
9255 affect its execution. Registers and memory may not be changed,\n\
9256 breakpoints may not be set, and the program cannot be interrupted\n\