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 /* Ignore the current thread here. It's handled
2948 if (!thread_still_needs_step_over (tp
))
2951 gdb_assert (!thread_is_in_step_over_chain (tp
));
2954 fprintf_unfiltered (gdb_stdlog
,
2955 "infrun: need to step-over [%s] first\n",
2956 target_pid_to_str (tp
->ptid
).c_str ());
2958 thread_step_over_chain_enqueue (tp
);
2962 /* Enqueue the current thread last, so that we move all other
2963 threads over their breakpoints first. */
2964 if (cur_thr
->stepping_over_breakpoint
)
2965 thread_step_over_chain_enqueue (cur_thr
);
2967 /* If the thread isn't started, we'll still need to set its prev_pc,
2968 so that switch_back_to_stepped_thread knows the thread hasn't
2969 advanced. Must do this before resuming any thread, as in
2970 all-stop/remote, once we resume we can't send any other packet
2971 until the target stops again. */
2972 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
2975 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
2977 started
= start_step_over ();
2979 if (step_over_info_valid_p ())
2981 /* Either this thread started a new in-line step over, or some
2982 other thread was already doing one. In either case, don't
2983 resume anything else until the step-over is finished. */
2985 else if (started
&& !target_is_non_stop_p ())
2987 /* A new displaced stepping sequence was started. In all-stop,
2988 we can't talk to the target anymore until it next stops. */
2990 else if (!non_stop
&& target_is_non_stop_p ())
2992 /* In all-stop, but the target is always in non-stop mode.
2993 Start all other threads that are implicitly resumed too. */
2994 for (thread_info
*tp
: all_non_exited_threads (resume_ptid
))
2999 fprintf_unfiltered (gdb_stdlog
,
3000 "infrun: proceed: [%s] resumed\n",
3001 target_pid_to_str (tp
->ptid
).c_str ());
3002 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3006 if (thread_is_in_step_over_chain (tp
))
3009 fprintf_unfiltered (gdb_stdlog
,
3010 "infrun: proceed: [%s] needs step-over\n",
3011 target_pid_to_str (tp
->ptid
).c_str ());
3016 fprintf_unfiltered (gdb_stdlog
,
3017 "infrun: proceed: resuming %s\n",
3018 target_pid_to_str (tp
->ptid
).c_str ());
3020 reset_ecs (ecs
, tp
);
3021 switch_to_thread (tp
);
3022 keep_going_pass_signal (ecs
);
3023 if (!ecs
->wait_some_more
)
3024 error (_("Command aborted."));
3027 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3029 /* The thread wasn't started, and isn't queued, run it now. */
3030 reset_ecs (ecs
, cur_thr
);
3031 switch_to_thread (cur_thr
);
3032 keep_going_pass_signal (ecs
);
3033 if (!ecs
->wait_some_more
)
3034 error (_("Command aborted."));
3038 target_commit_resume ();
3040 finish_state
.release ();
3042 /* If we've switched threads above, switch back to the previously
3043 current thread. We don't want the user to see a different
3045 switch_to_thread (cur_thr
);
3047 /* Tell the event loop to wait for it to stop. If the target
3048 supports asynchronous execution, it'll do this from within
3050 if (!target_can_async_p ())
3051 mark_async_event_handler (infrun_async_inferior_event_token
);
3055 /* Start remote-debugging of a machine over a serial link. */
3058 start_remote (int from_tty
)
3060 struct inferior
*inferior
;
3062 inferior
= current_inferior ();
3063 inferior
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3065 /* Always go on waiting for the target, regardless of the mode. */
3066 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3067 indicate to wait_for_inferior that a target should timeout if
3068 nothing is returned (instead of just blocking). Because of this,
3069 targets expecting an immediate response need to, internally, set
3070 things up so that the target_wait() is forced to eventually
3072 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3073 differentiate to its caller what the state of the target is after
3074 the initial open has been performed. Here we're assuming that
3075 the target has stopped. It should be possible to eventually have
3076 target_open() return to the caller an indication that the target
3077 is currently running and GDB state should be set to the same as
3078 for an async run. */
3079 wait_for_inferior ();
3081 /* Now that the inferior has stopped, do any bookkeeping like
3082 loading shared libraries. We want to do this before normal_stop,
3083 so that the displayed frame is up to date. */
3084 post_create_inferior (current_top_target (), from_tty
);
3089 /* Initialize static vars when a new inferior begins. */
3092 init_wait_for_inferior (void)
3094 /* These are meaningless until the first time through wait_for_inferior. */
3096 breakpoint_init_inferior (inf_starting
);
3098 clear_proceed_status (0);
3100 target_last_wait_ptid
= minus_one_ptid
;
3102 previous_inferior_ptid
= inferior_ptid
;
3107 static void handle_inferior_event (struct execution_control_state
*ecs
);
3109 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3110 struct execution_control_state
*ecs
);
3111 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3112 struct execution_control_state
*ecs
);
3113 static void handle_signal_stop (struct execution_control_state
*ecs
);
3114 static void check_exception_resume (struct execution_control_state
*,
3115 struct frame_info
*);
3117 static void end_stepping_range (struct execution_control_state
*ecs
);
3118 static void stop_waiting (struct execution_control_state
*ecs
);
3119 static void keep_going (struct execution_control_state
*ecs
);
3120 static void process_event_stop_test (struct execution_control_state
*ecs
);
3121 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3123 /* This function is attached as a "thread_stop_requested" observer.
3124 Cleanup local state that assumed the PTID was to be resumed, and
3125 report the stop to the frontend. */
3128 infrun_thread_stop_requested (ptid_t ptid
)
3130 /* PTID was requested to stop. If the thread was already stopped,
3131 but the user/frontend doesn't know about that yet (e.g., the
3132 thread had been temporarily paused for some step-over), set up
3133 for reporting the stop now. */
3134 for (thread_info
*tp
: all_threads (ptid
))
3136 if (tp
->state
!= THREAD_RUNNING
)
3141 /* Remove matching threads from the step-over queue, so
3142 start_step_over doesn't try to resume them
3144 if (thread_is_in_step_over_chain (tp
))
3145 thread_step_over_chain_remove (tp
);
3147 /* If the thread is stopped, but the user/frontend doesn't
3148 know about that yet, queue a pending event, as if the
3149 thread had just stopped now. Unless the thread already had
3151 if (!tp
->suspend
.waitstatus_pending_p
)
3153 tp
->suspend
.waitstatus_pending_p
= 1;
3154 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3155 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3158 /* Clear the inline-frame state, since we're re-processing the
3160 clear_inline_frame_state (tp
->ptid
);
3162 /* If this thread was paused because some other thread was
3163 doing an inline-step over, let that finish first. Once
3164 that happens, we'll restart all threads and consume pending
3165 stop events then. */
3166 if (step_over_info_valid_p ())
3169 /* Otherwise we can process the (new) pending event now. Set
3170 it so this pending event is considered by
3177 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3179 if (target_last_wait_ptid
== tp
->ptid
)
3180 nullify_last_target_wait_ptid ();
3183 /* Delete the step resume, single-step and longjmp/exception resume
3184 breakpoints of TP. */
3187 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3189 delete_step_resume_breakpoint (tp
);
3190 delete_exception_resume_breakpoint (tp
);
3191 delete_single_step_breakpoints (tp
);
3194 /* If the target still has execution, call FUNC for each thread that
3195 just stopped. In all-stop, that's all the non-exited threads; in
3196 non-stop, that's the current thread, only. */
3198 typedef void (*for_each_just_stopped_thread_callback_func
)
3199 (struct thread_info
*tp
);
3202 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3204 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3207 if (target_is_non_stop_p ())
3209 /* If in non-stop mode, only the current thread stopped. */
3210 func (inferior_thread ());
3214 /* In all-stop mode, all threads have stopped. */
3215 for (thread_info
*tp
: all_non_exited_threads ())
3220 /* Delete the step resume and longjmp/exception resume breakpoints of
3221 the threads that just stopped. */
3224 delete_just_stopped_threads_infrun_breakpoints (void)
3226 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3229 /* Delete the single-step breakpoints of the threads that just
3233 delete_just_stopped_threads_single_step_breakpoints (void)
3235 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3241 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3242 const struct target_waitstatus
*ws
)
3244 std::string status_string
= target_waitstatus_to_string (ws
);
3247 /* The text is split over several lines because it was getting too long.
3248 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3249 output as a unit; we want only one timestamp printed if debug_timestamp
3252 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3255 waiton_ptid
.tid ());
3256 if (waiton_ptid
.pid () != -1)
3257 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3258 stb
.printf (", status) =\n");
3259 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3263 target_pid_to_str (result_ptid
).c_str ());
3264 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3266 /* This uses %s in part to handle %'s in the text, but also to avoid
3267 a gcc error: the format attribute requires a string literal. */
3268 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3271 /* Select a thread at random, out of those which are resumed and have
3274 static struct thread_info
*
3275 random_pending_event_thread (ptid_t waiton_ptid
)
3279 auto has_event
= [] (thread_info
*tp
)
3282 && tp
->suspend
.waitstatus_pending_p
);
3285 /* First see how many events we have. Count only resumed threads
3286 that have an event pending. */
3287 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3291 if (num_events
== 0)
3294 /* Now randomly pick a thread out of those that have had events. */
3295 int random_selector
= (int) ((num_events
* (double) rand ())
3296 / (RAND_MAX
+ 1.0));
3298 if (debug_infrun
&& num_events
> 1)
3299 fprintf_unfiltered (gdb_stdlog
,
3300 "infrun: Found %d events, selecting #%d\n",
3301 num_events
, random_selector
);
3303 /* Select the Nth thread that has had an event. */
3304 for (thread_info
*tp
: all_non_exited_threads (waiton_ptid
))
3306 if (random_selector
-- == 0)
3309 gdb_assert_not_reached ("event thread not found");
3312 /* Wrapper for target_wait that first checks whether threads have
3313 pending statuses to report before actually asking the target for
3317 do_target_wait (ptid_t ptid
, struct target_waitstatus
*status
, int options
)
3320 struct thread_info
*tp
;
3322 /* First check if there is a resumed thread with a wait status
3324 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3326 tp
= random_pending_event_thread (ptid
);
3331 fprintf_unfiltered (gdb_stdlog
,
3332 "infrun: Waiting for specific thread %s.\n",
3333 target_pid_to_str (ptid
).c_str ());
3335 /* We have a specific thread to check. */
3336 tp
= find_thread_ptid (ptid
);
3337 gdb_assert (tp
!= NULL
);
3338 if (!tp
->suspend
.waitstatus_pending_p
)
3343 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3344 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3346 struct regcache
*regcache
= get_thread_regcache (tp
);
3347 struct gdbarch
*gdbarch
= regcache
->arch ();
3351 pc
= regcache_read_pc (regcache
);
3353 if (pc
!= tp
->suspend
.stop_pc
)
3356 fprintf_unfiltered (gdb_stdlog
,
3357 "infrun: PC of %s changed. was=%s, now=%s\n",
3358 target_pid_to_str (tp
->ptid
).c_str (),
3359 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3360 paddress (gdbarch
, pc
));
3363 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3366 fprintf_unfiltered (gdb_stdlog
,
3367 "infrun: previous breakpoint of %s, at %s gone\n",
3368 target_pid_to_str (tp
->ptid
).c_str (),
3369 paddress (gdbarch
, pc
));
3377 fprintf_unfiltered (gdb_stdlog
,
3378 "infrun: pending event of %s cancelled.\n",
3379 target_pid_to_str (tp
->ptid
).c_str ());
3381 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3382 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3391 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3393 fprintf_unfiltered (gdb_stdlog
,
3394 "infrun: Using pending wait status %s for %s.\n",
3396 target_pid_to_str (tp
->ptid
).c_str ());
3399 /* Now that we've selected our final event LWP, un-adjust its PC
3400 if it was a software breakpoint (and the target doesn't
3401 always adjust the PC itself). */
3402 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3403 && !target_supports_stopped_by_sw_breakpoint ())
3405 struct regcache
*regcache
;
3406 struct gdbarch
*gdbarch
;
3409 regcache
= get_thread_regcache (tp
);
3410 gdbarch
= regcache
->arch ();
3412 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3417 pc
= regcache_read_pc (regcache
);
3418 regcache_write_pc (regcache
, pc
+ decr_pc
);
3422 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3423 *status
= tp
->suspend
.waitstatus
;
3424 tp
->suspend
.waitstatus_pending_p
= 0;
3426 /* Wake up the event loop again, until all pending events are
3428 if (target_is_async_p ())
3429 mark_async_event_handler (infrun_async_inferior_event_token
);
3433 /* But if we don't find one, we'll have to wait. */
3435 if (deprecated_target_wait_hook
)
3436 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3438 event_ptid
= target_wait (ptid
, status
, options
);
3443 /* Prepare and stabilize the inferior for detaching it. E.g.,
3444 detaching while a thread is displaced stepping is a recipe for
3445 crashing it, as nothing would readjust the PC out of the scratch
3449 prepare_for_detach (void)
3451 struct inferior
*inf
= current_inferior ();
3452 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3454 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3456 /* Is any thread of this process displaced stepping? If not,
3457 there's nothing else to do. */
3458 if (displaced
->step_thread
== nullptr)
3462 fprintf_unfiltered (gdb_stdlog
,
3463 "displaced-stepping in-process while detaching");
3465 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3467 while (displaced
->step_thread
!= nullptr)
3469 struct execution_control_state ecss
;
3470 struct execution_control_state
*ecs
;
3473 memset (ecs
, 0, sizeof (*ecs
));
3475 overlay_cache_invalid
= 1;
3476 /* Flush target cache before starting to handle each event.
3477 Target was running and cache could be stale. This is just a
3478 heuristic. Running threads may modify target memory, but we
3479 don't get any event. */
3480 target_dcache_invalidate ();
3482 ecs
->ptid
= do_target_wait (pid_ptid
, &ecs
->ws
, 0);
3485 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3487 /* If an error happens while handling the event, propagate GDB's
3488 knowledge of the executing state to the frontend/user running
3490 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3492 /* Now figure out what to do with the result of the result. */
3493 handle_inferior_event (ecs
);
3495 /* No error, don't finish the state yet. */
3496 finish_state
.release ();
3498 /* Breakpoints and watchpoints are not installed on the target
3499 at this point, and signals are passed directly to the
3500 inferior, so this must mean the process is gone. */
3501 if (!ecs
->wait_some_more
)
3503 restore_detaching
.release ();
3504 error (_("Program exited while detaching"));
3508 restore_detaching
.release ();
3511 /* Wait for control to return from inferior to debugger.
3513 If inferior gets a signal, we may decide to start it up again
3514 instead of returning. That is why there is a loop in this function.
3515 When this function actually returns it means the inferior
3516 should be left stopped and GDB should read more commands. */
3519 wait_for_inferior (void)
3523 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3525 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3527 /* If an error happens while handling the event, propagate GDB's
3528 knowledge of the executing state to the frontend/user running
3530 scoped_finish_thread_state
finish_state (minus_one_ptid
);
3534 struct execution_control_state ecss
;
3535 struct execution_control_state
*ecs
= &ecss
;
3536 ptid_t waiton_ptid
= minus_one_ptid
;
3538 memset (ecs
, 0, sizeof (*ecs
));
3540 overlay_cache_invalid
= 1;
3542 /* Flush target cache before starting to handle each event.
3543 Target was running and cache could be stale. This is just a
3544 heuristic. Running threads may modify target memory, but we
3545 don't get any event. */
3546 target_dcache_invalidate ();
3548 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
, 0);
3551 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3553 /* Now figure out what to do with the result of the result. */
3554 handle_inferior_event (ecs
);
3556 if (!ecs
->wait_some_more
)
3560 /* No error, don't finish the state yet. */
3561 finish_state
.release ();
3564 /* Cleanup that reinstalls the readline callback handler, if the
3565 target is running in the background. If while handling the target
3566 event something triggered a secondary prompt, like e.g., a
3567 pagination prompt, we'll have removed the callback handler (see
3568 gdb_readline_wrapper_line). Need to do this as we go back to the
3569 event loop, ready to process further input. Note this has no
3570 effect if the handler hasn't actually been removed, because calling
3571 rl_callback_handler_install resets the line buffer, thus losing
3575 reinstall_readline_callback_handler_cleanup ()
3577 struct ui
*ui
= current_ui
;
3581 /* We're not going back to the top level event loop yet. Don't
3582 install the readline callback, as it'd prep the terminal,
3583 readline-style (raw, noecho) (e.g., --batch). We'll install
3584 it the next time the prompt is displayed, when we're ready
3589 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3590 gdb_rl_callback_handler_reinstall ();
3593 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3594 that's just the event thread. In all-stop, that's all threads. */
3597 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3599 if (ecs
->event_thread
!= NULL
3600 && ecs
->event_thread
->thread_fsm
!= NULL
)
3601 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3605 for (thread_info
*thr
: all_non_exited_threads ())
3607 if (thr
->thread_fsm
== NULL
)
3609 if (thr
== ecs
->event_thread
)
3612 switch_to_thread (thr
);
3613 thr
->thread_fsm
->clean_up (thr
);
3616 if (ecs
->event_thread
!= NULL
)
3617 switch_to_thread (ecs
->event_thread
);
3621 /* Helper for all_uis_check_sync_execution_done that works on the
3625 check_curr_ui_sync_execution_done (void)
3627 struct ui
*ui
= current_ui
;
3629 if (ui
->prompt_state
== PROMPT_NEEDED
3631 && !gdb_in_secondary_prompt_p (ui
))
3633 target_terminal::ours ();
3634 gdb::observers::sync_execution_done
.notify ();
3635 ui_register_input_event_handler (ui
);
3642 all_uis_check_sync_execution_done (void)
3644 SWITCH_THRU_ALL_UIS ()
3646 check_curr_ui_sync_execution_done ();
3653 all_uis_on_sync_execution_starting (void)
3655 SWITCH_THRU_ALL_UIS ()
3657 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3658 async_disable_stdin ();
3662 /* Asynchronous version of wait_for_inferior. It is called by the
3663 event loop whenever a change of state is detected on the file
3664 descriptor corresponding to the target. It can be called more than
3665 once to complete a single execution command. In such cases we need
3666 to keep the state in a global variable ECSS. If it is the last time
3667 that this function is called for a single execution command, then
3668 report to the user that the inferior has stopped, and do the
3669 necessary cleanups. */
3672 fetch_inferior_event (void *client_data
)
3674 struct execution_control_state ecss
;
3675 struct execution_control_state
*ecs
= &ecss
;
3677 ptid_t waiton_ptid
= minus_one_ptid
;
3679 memset (ecs
, 0, sizeof (*ecs
));
3681 /* Events are always processed with the main UI as current UI. This
3682 way, warnings, debug output, etc. are always consistently sent to
3683 the main console. */
3684 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3686 /* End up with readline processing input, if necessary. */
3688 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3690 /* We're handling a live event, so make sure we're doing live
3691 debugging. If we're looking at traceframes while the target is
3692 running, we're going to need to get back to that mode after
3693 handling the event. */
3694 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3697 maybe_restore_traceframe
.emplace ();
3698 set_current_traceframe (-1);
3701 /* The user/frontend should not notice a thread switch due to
3702 internal events. Make sure we revert to the user selected
3703 thread and frame after handling the event and running any
3704 breakpoint commands. */
3705 scoped_restore_current_thread restore_thread
;
3707 overlay_cache_invalid
= 1;
3708 /* Flush target cache before starting to handle each event. Target
3709 was running and cache could be stale. This is just a heuristic.
3710 Running threads may modify target memory, but we don't get any
3712 target_dcache_invalidate ();
3714 scoped_restore save_exec_dir
3715 = make_scoped_restore (&execution_direction
,
3716 target_execution_direction ());
3718 ecs
->ptid
= do_target_wait (waiton_ptid
, &ecs
->ws
,
3719 target_can_async_p () ? TARGET_WNOHANG
: 0);
3722 print_target_wait_results (waiton_ptid
, ecs
->ptid
, &ecs
->ws
);
3724 /* If an error happens while handling the event, propagate GDB's
3725 knowledge of the executing state to the frontend/user running
3727 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3728 scoped_finish_thread_state
finish_state (finish_ptid
);
3730 /* Get executed before scoped_restore_current_thread above to apply
3731 still for the thread which has thrown the exception. */
3732 auto defer_bpstat_clear
3733 = make_scope_exit (bpstat_clear_actions
);
3734 auto defer_delete_threads
3735 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3737 /* Now figure out what to do with the result of the result. */
3738 handle_inferior_event (ecs
);
3740 if (!ecs
->wait_some_more
)
3742 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
3743 int should_stop
= 1;
3744 struct thread_info
*thr
= ecs
->event_thread
;
3746 delete_just_stopped_threads_infrun_breakpoints ();
3750 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3752 if (thread_fsm
!= NULL
)
3753 should_stop
= thread_fsm
->should_stop (thr
);
3762 bool should_notify_stop
= true;
3765 clean_up_just_stopped_threads_fsms (ecs
);
3767 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3768 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3770 if (should_notify_stop
)
3772 /* We may not find an inferior if this was a process exit. */
3773 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3774 proceeded
= normal_stop ();
3779 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3783 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3784 previously selected thread is gone. We have two
3785 choices - switch to no thread selected, or restore the
3786 previously selected thread (now exited). We chose the
3787 later, just because that's what GDB used to do. After
3788 this, "info threads" says "The current thread <Thread
3789 ID 2> has terminated." instead of "No thread
3793 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3794 restore_thread
.dont_restore ();
3798 defer_delete_threads
.release ();
3799 defer_bpstat_clear
.release ();
3801 /* No error, don't finish the thread states yet. */
3802 finish_state
.release ();
3804 /* This scope is used to ensure that readline callbacks are
3805 reinstalled here. */
3808 /* If a UI was in sync execution mode, and now isn't, restore its
3809 prompt (a synchronous execution command has finished, and we're
3810 ready for input). */
3811 all_uis_check_sync_execution_done ();
3814 && exec_done_display_p
3815 && (inferior_ptid
== null_ptid
3816 || inferior_thread ()->state
!= THREAD_RUNNING
))
3817 printf_unfiltered (_("completed.\n"));
3820 /* Record the frame and location we're currently stepping through. */
3822 set_step_info (struct frame_info
*frame
, struct symtab_and_line sal
)
3824 struct thread_info
*tp
= inferior_thread ();
3826 tp
->control
.step_frame_id
= get_frame_id (frame
);
3827 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
3829 tp
->current_symtab
= sal
.symtab
;
3830 tp
->current_line
= sal
.line
;
3833 /* Clear context switchable stepping state. */
3836 init_thread_stepping_state (struct thread_info
*tss
)
3838 tss
->stepped_breakpoint
= 0;
3839 tss
->stepping_over_breakpoint
= 0;
3840 tss
->stepping_over_watchpoint
= 0;
3841 tss
->step_after_step_resume_breakpoint
= 0;
3844 /* Set the cached copy of the last ptid/waitstatus. */
3847 set_last_target_status (ptid_t ptid
, struct target_waitstatus status
)
3849 target_last_wait_ptid
= ptid
;
3850 target_last_waitstatus
= status
;
3853 /* Return the cached copy of the last pid/waitstatus returned by
3854 target_wait()/deprecated_target_wait_hook(). The data is actually
3855 cached by handle_inferior_event(), which gets called immediately
3856 after target_wait()/deprecated_target_wait_hook(). */
3859 get_last_target_status (ptid_t
*ptidp
, struct target_waitstatus
*status
)
3861 *ptidp
= target_last_wait_ptid
;
3862 *status
= target_last_waitstatus
;
3866 nullify_last_target_wait_ptid (void)
3868 target_last_wait_ptid
= minus_one_ptid
;
3871 /* Switch thread contexts. */
3874 context_switch (execution_control_state
*ecs
)
3877 && ecs
->ptid
!= inferior_ptid
3878 && ecs
->event_thread
!= inferior_thread ())
3880 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
3881 target_pid_to_str (inferior_ptid
).c_str ());
3882 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
3883 target_pid_to_str (ecs
->ptid
).c_str ());
3886 switch_to_thread (ecs
->event_thread
);
3889 /* If the target can't tell whether we've hit breakpoints
3890 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
3891 check whether that could have been caused by a breakpoint. If so,
3892 adjust the PC, per gdbarch_decr_pc_after_break. */
3895 adjust_pc_after_break (struct thread_info
*thread
,
3896 struct target_waitstatus
*ws
)
3898 struct regcache
*regcache
;
3899 struct gdbarch
*gdbarch
;
3900 CORE_ADDR breakpoint_pc
, decr_pc
;
3902 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
3903 we aren't, just return.
3905 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
3906 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
3907 implemented by software breakpoints should be handled through the normal
3910 NOTE drow/2004-01-31: On some targets, breakpoints may generate
3911 different signals (SIGILL or SIGEMT for instance), but it is less
3912 clear where the PC is pointing afterwards. It may not match
3913 gdbarch_decr_pc_after_break. I don't know any specific target that
3914 generates these signals at breakpoints (the code has been in GDB since at
3915 least 1992) so I can not guess how to handle them here.
3917 In earlier versions of GDB, a target with
3918 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
3919 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
3920 target with both of these set in GDB history, and it seems unlikely to be
3921 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
3923 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
3926 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
3929 /* In reverse execution, when a breakpoint is hit, the instruction
3930 under it has already been de-executed. The reported PC always
3931 points at the breakpoint address, so adjusting it further would
3932 be wrong. E.g., consider this case on a decr_pc_after_break == 1
3935 B1 0x08000000 : INSN1
3936 B2 0x08000001 : INSN2
3938 PC -> 0x08000003 : INSN4
3940 Say you're stopped at 0x08000003 as above. Reverse continuing
3941 from that point should hit B2 as below. Reading the PC when the
3942 SIGTRAP is reported should read 0x08000001 and INSN2 should have
3943 been de-executed already.
3945 B1 0x08000000 : INSN1
3946 B2 PC -> 0x08000001 : INSN2
3950 We can't apply the same logic as for forward execution, because
3951 we would wrongly adjust the PC to 0x08000000, since there's a
3952 breakpoint at PC - 1. We'd then report a hit on B1, although
3953 INSN1 hadn't been de-executed yet. Doing nothing is the correct
3955 if (execution_direction
== EXEC_REVERSE
)
3958 /* If the target can tell whether the thread hit a SW breakpoint,
3959 trust it. Targets that can tell also adjust the PC
3961 if (target_supports_stopped_by_sw_breakpoint ())
3964 /* Note that relying on whether a breakpoint is planted in memory to
3965 determine this can fail. E.g,. the breakpoint could have been
3966 removed since. Or the thread could have been told to step an
3967 instruction the size of a breakpoint instruction, and only
3968 _after_ was a breakpoint inserted at its address. */
3970 /* If this target does not decrement the PC after breakpoints, then
3971 we have nothing to do. */
3972 regcache
= get_thread_regcache (thread
);
3973 gdbarch
= regcache
->arch ();
3975 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3979 const address_space
*aspace
= regcache
->aspace ();
3981 /* Find the location where (if we've hit a breakpoint) the
3982 breakpoint would be. */
3983 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
3985 /* If the target can't tell whether a software breakpoint triggered,
3986 fallback to figuring it out based on breakpoints we think were
3987 inserted in the target, and on whether the thread was stepped or
3990 /* Check whether there actually is a software breakpoint inserted at
3993 If in non-stop mode, a race condition is possible where we've
3994 removed a breakpoint, but stop events for that breakpoint were
3995 already queued and arrive later. To suppress those spurious
3996 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
3997 and retire them after a number of stop events are reported. Note
3998 this is an heuristic and can thus get confused. The real fix is
3999 to get the "stopped by SW BP and needs adjustment" info out of
4000 the target/kernel (and thus never reach here; see above). */
4001 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4002 || (target_is_non_stop_p ()
4003 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4005 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4007 if (record_full_is_used ())
4008 restore_operation_disable
.emplace
4009 (record_full_gdb_operation_disable_set ());
4011 /* When using hardware single-step, a SIGTRAP is reported for both
4012 a completed single-step and a software breakpoint. Need to
4013 differentiate between the two, as the latter needs adjusting
4014 but the former does not.
4016 The SIGTRAP can be due to a completed hardware single-step only if
4017 - we didn't insert software single-step breakpoints
4018 - this thread is currently being stepped
4020 If any of these events did not occur, we must have stopped due
4021 to hitting a software breakpoint, and have to back up to the
4024 As a special case, we could have hardware single-stepped a
4025 software breakpoint. In this case (prev_pc == breakpoint_pc),
4026 we also need to back up to the breakpoint address. */
4028 if (thread_has_single_step_breakpoints_set (thread
)
4029 || !currently_stepping (thread
)
4030 || (thread
->stepped_breakpoint
4031 && thread
->prev_pc
== breakpoint_pc
))
4032 regcache_write_pc (regcache
, breakpoint_pc
);
4037 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4039 for (frame
= get_prev_frame (frame
);
4041 frame
= get_prev_frame (frame
))
4043 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4045 if (get_frame_type (frame
) != INLINE_FRAME
)
4052 /* Look for an inline frame that is marked for skip.
4053 If PREV_FRAME is TRUE start at the previous frame,
4054 otherwise start at the current frame. Stop at the
4055 first non-inline frame, or at the frame where the
4059 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4061 struct frame_info
*frame
= get_current_frame ();
4064 frame
= get_prev_frame (frame
);
4066 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4068 const char *fn
= NULL
;
4069 symtab_and_line sal
;
4072 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4074 if (get_frame_type (frame
) != INLINE_FRAME
)
4077 sal
= find_frame_sal (frame
);
4078 sym
= get_frame_function (frame
);
4081 fn
= sym
->print_name ();
4084 && function_name_is_marked_for_skip (fn
, sal
))
4091 /* If the event thread has the stop requested flag set, pretend it
4092 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4096 handle_stop_requested (struct execution_control_state
*ecs
)
4098 if (ecs
->event_thread
->stop_requested
)
4100 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4101 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4102 handle_signal_stop (ecs
);
4108 /* Auxiliary function that handles syscall entry/return events.
4109 It returns 1 if the inferior should keep going (and GDB
4110 should ignore the event), or 0 if the event deserves to be
4114 handle_syscall_event (struct execution_control_state
*ecs
)
4116 struct regcache
*regcache
;
4119 context_switch (ecs
);
4121 regcache
= get_thread_regcache (ecs
->event_thread
);
4122 syscall_number
= ecs
->ws
.value
.syscall_number
;
4123 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4125 if (catch_syscall_enabled () > 0
4126 && catching_syscall_number (syscall_number
) > 0)
4129 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4132 ecs
->event_thread
->control
.stop_bpstat
4133 = bpstat_stop_status (regcache
->aspace (),
4134 ecs
->event_thread
->suspend
.stop_pc
,
4135 ecs
->event_thread
, &ecs
->ws
);
4137 if (handle_stop_requested (ecs
))
4140 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4142 /* Catchpoint hit. */
4147 if (handle_stop_requested (ecs
))
4150 /* If no catchpoint triggered for this, then keep going. */
4155 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4158 fill_in_stop_func (struct gdbarch
*gdbarch
,
4159 struct execution_control_state
*ecs
)
4161 if (!ecs
->stop_func_filled_in
)
4165 /* Don't care about return value; stop_func_start and stop_func_name
4166 will both be 0 if it doesn't work. */
4167 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4168 &ecs
->stop_func_name
,
4169 &ecs
->stop_func_start
,
4170 &ecs
->stop_func_end
,
4173 /* The call to find_pc_partial_function, above, will set
4174 stop_func_start and stop_func_end to the start and end
4175 of the range containing the stop pc. If this range
4176 contains the entry pc for the block (which is always the
4177 case for contiguous blocks), advance stop_func_start past
4178 the function's start offset and entrypoint. Note that
4179 stop_func_start is NOT advanced when in a range of a
4180 non-contiguous block that does not contain the entry pc. */
4181 if (block
!= nullptr
4182 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4183 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4185 ecs
->stop_func_start
4186 += gdbarch_deprecated_function_start_offset (gdbarch
);
4188 if (gdbarch_skip_entrypoint_p (gdbarch
))
4189 ecs
->stop_func_start
4190 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4193 ecs
->stop_func_filled_in
= 1;
4198 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4200 static enum stop_kind
4201 get_inferior_stop_soon (execution_control_state
*ecs
)
4203 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
4205 gdb_assert (inf
!= NULL
);
4206 return inf
->control
.stop_soon
;
4209 /* Wait for one event. Store the resulting waitstatus in WS, and
4210 return the event ptid. */
4213 wait_one (struct target_waitstatus
*ws
)
4216 ptid_t wait_ptid
= minus_one_ptid
;
4218 overlay_cache_invalid
= 1;
4220 /* Flush target cache before starting to handle each event.
4221 Target was running and cache could be stale. This is just a
4222 heuristic. Running threads may modify target memory, but we
4223 don't get any event. */
4224 target_dcache_invalidate ();
4226 if (deprecated_target_wait_hook
)
4227 event_ptid
= deprecated_target_wait_hook (wait_ptid
, ws
, 0);
4229 event_ptid
= target_wait (wait_ptid
, ws
, 0);
4232 print_target_wait_results (wait_ptid
, event_ptid
, ws
);
4237 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4238 instead of the current thread. */
4239 #define THREAD_STOPPED_BY(REASON) \
4241 thread_stopped_by_ ## REASON (ptid_t ptid) \
4243 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4244 inferior_ptid = ptid; \
4246 return target_stopped_by_ ## REASON (); \
4249 /* Generate thread_stopped_by_watchpoint. */
4250 THREAD_STOPPED_BY (watchpoint
)
4251 /* Generate thread_stopped_by_sw_breakpoint. */
4252 THREAD_STOPPED_BY (sw_breakpoint
)
4253 /* Generate thread_stopped_by_hw_breakpoint. */
4254 THREAD_STOPPED_BY (hw_breakpoint
)
4256 /* Save the thread's event and stop reason to process it later. */
4259 save_waitstatus (struct thread_info
*tp
, struct target_waitstatus
*ws
)
4263 std::string statstr
= target_waitstatus_to_string (ws
);
4265 fprintf_unfiltered (gdb_stdlog
,
4266 "infrun: saving status %s for %d.%ld.%ld\n",
4273 /* Record for later. */
4274 tp
->suspend
.waitstatus
= *ws
;
4275 tp
->suspend
.waitstatus_pending_p
= 1;
4277 struct regcache
*regcache
= get_thread_regcache (tp
);
4278 const address_space
*aspace
= regcache
->aspace ();
4280 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4281 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4283 CORE_ADDR pc
= regcache_read_pc (regcache
);
4285 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4287 if (thread_stopped_by_watchpoint (tp
->ptid
))
4289 tp
->suspend
.stop_reason
4290 = TARGET_STOPPED_BY_WATCHPOINT
;
4292 else if (target_supports_stopped_by_sw_breakpoint ()
4293 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4295 tp
->suspend
.stop_reason
4296 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4298 else if (target_supports_stopped_by_hw_breakpoint ()
4299 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4301 tp
->suspend
.stop_reason
4302 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4304 else if (!target_supports_stopped_by_hw_breakpoint ()
4305 && hardware_breakpoint_inserted_here_p (aspace
,
4308 tp
->suspend
.stop_reason
4309 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4311 else if (!target_supports_stopped_by_sw_breakpoint ()
4312 && software_breakpoint_inserted_here_p (aspace
,
4315 tp
->suspend
.stop_reason
4316 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4318 else if (!thread_has_single_step_breakpoints_set (tp
)
4319 && currently_stepping (tp
))
4321 tp
->suspend
.stop_reason
4322 = TARGET_STOPPED_BY_SINGLE_STEP
;
4330 stop_all_threads (void)
4332 /* We may need multiple passes to discover all threads. */
4336 gdb_assert (target_is_non_stop_p ());
4339 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4341 scoped_restore_current_thread restore_thread
;
4343 target_thread_events (1);
4344 SCOPE_EXIT
{ target_thread_events (0); };
4346 /* Request threads to stop, and then wait for the stops. Because
4347 threads we already know about can spawn more threads while we're
4348 trying to stop them, and we only learn about new threads when we
4349 update the thread list, do this in a loop, and keep iterating
4350 until two passes find no threads that need to be stopped. */
4351 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4354 fprintf_unfiltered (gdb_stdlog
,
4355 "infrun: stop_all_threads, pass=%d, "
4356 "iterations=%d\n", pass
, iterations
);
4360 struct target_waitstatus ws
;
4363 update_thread_list ();
4365 /* Go through all threads looking for threads that we need
4366 to tell the target to stop. */
4367 for (thread_info
*t
: all_non_exited_threads ())
4371 /* If already stopping, don't request a stop again.
4372 We just haven't seen the notification yet. */
4373 if (!t
->stop_requested
)
4376 fprintf_unfiltered (gdb_stdlog
,
4377 "infrun: %s executing, "
4379 target_pid_to_str (t
->ptid
).c_str ());
4380 target_stop (t
->ptid
);
4381 t
->stop_requested
= 1;
4386 fprintf_unfiltered (gdb_stdlog
,
4387 "infrun: %s executing, "
4388 "already stopping\n",
4389 target_pid_to_str (t
->ptid
).c_str ());
4392 if (t
->stop_requested
)
4398 fprintf_unfiltered (gdb_stdlog
,
4399 "infrun: %s not executing\n",
4400 target_pid_to_str (t
->ptid
).c_str ());
4402 /* The thread may be not executing, but still be
4403 resumed with a pending status to process. */
4411 /* If we find new threads on the second iteration, restart
4412 over. We want to see two iterations in a row with all
4417 event_ptid
= wait_one (&ws
);
4420 fprintf_unfiltered (gdb_stdlog
,
4421 "infrun: stop_all_threads %s %s\n",
4422 target_waitstatus_to_string (&ws
).c_str (),
4423 target_pid_to_str (event_ptid
).c_str ());
4426 if (ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4427 || ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4428 || ws
.kind
== TARGET_WAITKIND_EXITED
4429 || ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4431 /* All resumed threads exited
4432 or one thread/process exited/signalled. */
4436 thread_info
*t
= find_thread_ptid (event_ptid
);
4438 t
= add_thread (event_ptid
);
4440 t
->stop_requested
= 0;
4443 t
->control
.may_range_step
= 0;
4445 /* This may be the first time we see the inferior report
4447 inferior
*inf
= find_inferior_ptid (event_ptid
);
4448 if (inf
->needs_setup
)
4450 switch_to_thread_no_regs (t
);
4454 if (ws
.kind
== TARGET_WAITKIND_STOPPED
4455 && ws
.value
.sig
== GDB_SIGNAL_0
)
4457 /* We caught the event that we intended to catch, so
4458 there's no event pending. */
4459 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4460 t
->suspend
.waitstatus_pending_p
= 0;
4462 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4464 /* Add it back to the step-over queue. */
4467 fprintf_unfiltered (gdb_stdlog
,
4468 "infrun: displaced-step of %s "
4469 "canceled: adding back to the "
4470 "step-over queue\n",
4471 target_pid_to_str (t
->ptid
).c_str ());
4473 t
->control
.trap_expected
= 0;
4474 thread_step_over_chain_enqueue (t
);
4479 enum gdb_signal sig
;
4480 struct regcache
*regcache
;
4484 std::string statstr
= target_waitstatus_to_string (&ws
);
4486 fprintf_unfiltered (gdb_stdlog
,
4487 "infrun: target_wait %s, saving "
4488 "status for %d.%ld.%ld\n",
4495 /* Record for later. */
4496 save_waitstatus (t
, &ws
);
4498 sig
= (ws
.kind
== TARGET_WAITKIND_STOPPED
4499 ? ws
.value
.sig
: GDB_SIGNAL_0
);
4501 if (displaced_step_fixup (t
, sig
) < 0)
4503 /* Add it back to the step-over queue. */
4504 t
->control
.trap_expected
= 0;
4505 thread_step_over_chain_enqueue (t
);
4508 regcache
= get_thread_regcache (t
);
4509 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4513 fprintf_unfiltered (gdb_stdlog
,
4514 "infrun: saved stop_pc=%s for %s "
4515 "(currently_stepping=%d)\n",
4516 paddress (target_gdbarch (),
4517 t
->suspend
.stop_pc
),
4518 target_pid_to_str (t
->ptid
).c_str (),
4519 currently_stepping (t
));
4527 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4530 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4533 handle_no_resumed (struct execution_control_state
*ecs
)
4535 if (target_can_async_p ())
4542 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4550 /* There were no unwaited-for children left in the target, but,
4551 we're not synchronously waiting for events either. Just
4555 fprintf_unfiltered (gdb_stdlog
,
4556 "infrun: TARGET_WAITKIND_NO_RESUMED "
4557 "(ignoring: bg)\n");
4558 prepare_to_wait (ecs
);
4563 /* Otherwise, if we were running a synchronous execution command, we
4564 may need to cancel it and give the user back the terminal.
4566 In non-stop mode, the target can't tell whether we've already
4567 consumed previous stop events, so it can end up sending us a
4568 no-resumed event like so:
4570 #0 - thread 1 is left stopped
4572 #1 - thread 2 is resumed and hits breakpoint
4573 -> TARGET_WAITKIND_STOPPED
4575 #2 - thread 3 is resumed and exits
4576 this is the last resumed thread, so
4577 -> TARGET_WAITKIND_NO_RESUMED
4579 #3 - gdb processes stop for thread 2 and decides to re-resume
4582 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4583 thread 2 is now resumed, so the event should be ignored.
4585 IOW, if the stop for thread 2 doesn't end a foreground command,
4586 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4587 event. But it could be that the event meant that thread 2 itself
4588 (or whatever other thread was the last resumed thread) exited.
4590 To address this we refresh the thread list and check whether we
4591 have resumed threads _now_. In the example above, this removes
4592 thread 3 from the thread list. If thread 2 was re-resumed, we
4593 ignore this event. If we find no thread resumed, then we cancel
4594 the synchronous command show "no unwaited-for " to the user. */
4595 update_thread_list ();
4597 for (thread_info
*thread
: all_non_exited_threads ())
4599 if (thread
->executing
4600 || thread
->suspend
.waitstatus_pending_p
)
4602 /* There were no unwaited-for children left in the target at
4603 some point, but there are now. Just ignore. */
4605 fprintf_unfiltered (gdb_stdlog
,
4606 "infrun: TARGET_WAITKIND_NO_RESUMED "
4607 "(ignoring: found resumed)\n");
4608 prepare_to_wait (ecs
);
4613 /* Note however that we may find no resumed thread because the whole
4614 process exited meanwhile (thus updating the thread list results
4615 in an empty thread list). In this case we know we'll be getting
4616 a process exit event shortly. */
4617 for (inferior
*inf
: all_inferiors ())
4622 thread_info
*thread
= any_live_thread_of_inferior (inf
);
4626 fprintf_unfiltered (gdb_stdlog
,
4627 "infrun: TARGET_WAITKIND_NO_RESUMED "
4628 "(expect process exit)\n");
4629 prepare_to_wait (ecs
);
4634 /* Go ahead and report the event. */
4638 /* Given an execution control state that has been freshly filled in by
4639 an event from the inferior, figure out what it means and take
4642 The alternatives are:
4644 1) stop_waiting and return; to really stop and return to the
4647 2) keep_going and return; to wait for the next event (set
4648 ecs->event_thread->stepping_over_breakpoint to 1 to single step
4652 handle_inferior_event (struct execution_control_state
*ecs
)
4654 /* Make sure that all temporary struct value objects that were
4655 created during the handling of the event get deleted at the
4657 scoped_value_mark free_values
;
4659 enum stop_kind stop_soon
;
4662 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
4663 target_waitstatus_to_string (&ecs
->ws
).c_str ());
4665 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
4667 /* We had an event in the inferior, but we are not interested in
4668 handling it at this level. The lower layers have already
4669 done what needs to be done, if anything.
4671 One of the possible circumstances for this is when the
4672 inferior produces output for the console. The inferior has
4673 not stopped, and we are ignoring the event. Another possible
4674 circumstance is any event which the lower level knows will be
4675 reported multiple times without an intervening resume. */
4676 prepare_to_wait (ecs
);
4680 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
4682 prepare_to_wait (ecs
);
4686 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4687 && handle_no_resumed (ecs
))
4690 /* Cache the last pid/waitstatus. */
4691 set_last_target_status (ecs
->ptid
, ecs
->ws
);
4693 /* Always clear state belonging to the previous time we stopped. */
4694 stop_stack_dummy
= STOP_NONE
;
4696 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4698 /* No unwaited-for children left. IOW, all resumed children
4700 stop_print_frame
= 0;
4705 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
4706 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
4708 ecs
->event_thread
= find_thread_ptid (ecs
->ptid
);
4709 /* If it's a new thread, add it to the thread database. */
4710 if (ecs
->event_thread
== NULL
)
4711 ecs
->event_thread
= add_thread (ecs
->ptid
);
4713 /* Disable range stepping. If the next step request could use a
4714 range, this will be end up re-enabled then. */
4715 ecs
->event_thread
->control
.may_range_step
= 0;
4718 /* Dependent on valid ECS->EVENT_THREAD. */
4719 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
4721 /* Dependent on the current PC value modified by adjust_pc_after_break. */
4722 reinit_frame_cache ();
4724 breakpoint_retire_moribund ();
4726 /* First, distinguish signals caused by the debugger from signals
4727 that have to do with the program's own actions. Note that
4728 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
4729 on the operating system version. Here we detect when a SIGILL or
4730 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
4731 something similar for SIGSEGV, since a SIGSEGV will be generated
4732 when we're trying to execute a breakpoint instruction on a
4733 non-executable stack. This happens for call dummy breakpoints
4734 for architectures like SPARC that place call dummies on the
4736 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
4737 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
4738 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
4739 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
4741 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4743 if (breakpoint_inserted_here_p (regcache
->aspace (),
4744 regcache_read_pc (regcache
)))
4747 fprintf_unfiltered (gdb_stdlog
,
4748 "infrun: Treating signal as SIGTRAP\n");
4749 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
4753 /* Mark the non-executing threads accordingly. In all-stop, all
4754 threads of all processes are stopped when we get any event
4755 reported. In non-stop mode, only the event thread stops. */
4759 if (!target_is_non_stop_p ())
4760 mark_ptid
= minus_one_ptid
;
4761 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
4762 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4764 /* If we're handling a process exit in non-stop mode, even
4765 though threads haven't been deleted yet, one would think
4766 that there is nothing to do, as threads of the dead process
4767 will be soon deleted, and threads of any other process were
4768 left running. However, on some targets, threads survive a
4769 process exit event. E.g., for the "checkpoint" command,
4770 when the current checkpoint/fork exits, linux-fork.c
4771 automatically switches to another fork from within
4772 target_mourn_inferior, by associating the same
4773 inferior/thread to another fork. We haven't mourned yet at
4774 this point, but we must mark any threads left in the
4775 process as not-executing so that finish_thread_state marks
4776 them stopped (in the user's perspective) if/when we present
4777 the stop to the user. */
4778 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
4781 mark_ptid
= ecs
->ptid
;
4783 set_executing (mark_ptid
, 0);
4785 /* Likewise the resumed flag. */
4786 set_resumed (mark_ptid
, 0);
4789 switch (ecs
->ws
.kind
)
4791 case TARGET_WAITKIND_LOADED
:
4792 context_switch (ecs
);
4793 /* Ignore gracefully during startup of the inferior, as it might
4794 be the shell which has just loaded some objects, otherwise
4795 add the symbols for the newly loaded objects. Also ignore at
4796 the beginning of an attach or remote session; we will query
4797 the full list of libraries once the connection is
4800 stop_soon
= get_inferior_stop_soon (ecs
);
4801 if (stop_soon
== NO_STOP_QUIETLY
)
4803 struct regcache
*regcache
;
4805 regcache
= get_thread_regcache (ecs
->event_thread
);
4807 handle_solib_event ();
4809 ecs
->event_thread
->control
.stop_bpstat
4810 = bpstat_stop_status (regcache
->aspace (),
4811 ecs
->event_thread
->suspend
.stop_pc
,
4812 ecs
->event_thread
, &ecs
->ws
);
4814 if (handle_stop_requested (ecs
))
4817 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4819 /* A catchpoint triggered. */
4820 process_event_stop_test (ecs
);
4824 /* If requested, stop when the dynamic linker notifies
4825 gdb of events. This allows the user to get control
4826 and place breakpoints in initializer routines for
4827 dynamically loaded objects (among other things). */
4828 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
4829 if (stop_on_solib_events
)
4831 /* Make sure we print "Stopped due to solib-event" in
4833 stop_print_frame
= 1;
4840 /* If we are skipping through a shell, or through shared library
4841 loading that we aren't interested in, resume the program. If
4842 we're running the program normally, also resume. */
4843 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
4845 /* Loading of shared libraries might have changed breakpoint
4846 addresses. Make sure new breakpoints are inserted. */
4847 if (stop_soon
== NO_STOP_QUIETLY
)
4848 insert_breakpoints ();
4849 resume (GDB_SIGNAL_0
);
4850 prepare_to_wait (ecs
);
4854 /* But stop if we're attaching or setting up a remote
4856 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
4857 || stop_soon
== STOP_QUIETLY_REMOTE
)
4860 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
4865 internal_error (__FILE__
, __LINE__
,
4866 _("unhandled stop_soon: %d"), (int) stop_soon
);
4868 case TARGET_WAITKIND_SPURIOUS
:
4869 if (handle_stop_requested (ecs
))
4871 context_switch (ecs
);
4872 resume (GDB_SIGNAL_0
);
4873 prepare_to_wait (ecs
);
4876 case TARGET_WAITKIND_THREAD_CREATED
:
4877 if (handle_stop_requested (ecs
))
4879 context_switch (ecs
);
4880 if (!switch_back_to_stepped_thread (ecs
))
4884 case TARGET_WAITKIND_EXITED
:
4885 case TARGET_WAITKIND_SIGNALLED
:
4886 inferior_ptid
= ecs
->ptid
;
4887 set_current_inferior (find_inferior_ptid (ecs
->ptid
));
4888 set_current_program_space (current_inferior ()->pspace
);
4889 handle_vfork_child_exec_or_exit (0);
4890 target_terminal::ours (); /* Must do this before mourn anyway. */
4892 /* Clearing any previous state of convenience variables. */
4893 clear_exit_convenience_vars ();
4895 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
4897 /* Record the exit code in the convenience variable $_exitcode, so
4898 that the user can inspect this again later. */
4899 set_internalvar_integer (lookup_internalvar ("_exitcode"),
4900 (LONGEST
) ecs
->ws
.value
.integer
);
4902 /* Also record this in the inferior itself. */
4903 current_inferior ()->has_exit_code
= 1;
4904 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
4906 /* Support the --return-child-result option. */
4907 return_child_result_value
= ecs
->ws
.value
.integer
;
4909 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
4913 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
4915 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
4917 /* Set the value of the internal variable $_exitsignal,
4918 which holds the signal uncaught by the inferior. */
4919 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
4920 gdbarch_gdb_signal_to_target (gdbarch
,
4921 ecs
->ws
.value
.sig
));
4925 /* We don't have access to the target's method used for
4926 converting between signal numbers (GDB's internal
4927 representation <-> target's representation).
4928 Therefore, we cannot do a good job at displaying this
4929 information to the user. It's better to just warn
4930 her about it (if infrun debugging is enabled), and
4933 fprintf_filtered (gdb_stdlog
, _("\
4934 Cannot fill $_exitsignal with the correct signal number.\n"));
4937 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
4940 gdb_flush (gdb_stdout
);
4941 target_mourn_inferior (inferior_ptid
);
4942 stop_print_frame
= 0;
4946 /* The following are the only cases in which we keep going;
4947 the above cases end in a continue or goto. */
4948 case TARGET_WAITKIND_FORKED
:
4949 case TARGET_WAITKIND_VFORKED
:
4950 /* Check whether the inferior is displaced stepping. */
4952 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
4953 struct gdbarch
*gdbarch
= regcache
->arch ();
4955 /* If checking displaced stepping is supported, and thread
4956 ecs->ptid is displaced stepping. */
4957 if (displaced_step_in_progress_thread (ecs
->event_thread
))
4959 struct inferior
*parent_inf
4960 = find_inferior_ptid (ecs
->ptid
);
4961 struct regcache
*child_regcache
;
4962 CORE_ADDR parent_pc
;
4964 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
4965 indicating that the displaced stepping of syscall instruction
4966 has been done. Perform cleanup for parent process here. Note
4967 that this operation also cleans up the child process for vfork,
4968 because their pages are shared. */
4969 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
4970 /* Start a new step-over in another thread if there's one
4974 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
4976 struct displaced_step_inferior_state
*displaced
4977 = get_displaced_stepping_state (parent_inf
);
4979 /* Restore scratch pad for child process. */
4980 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
4983 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
4984 the child's PC is also within the scratchpad. Set the child's PC
4985 to the parent's PC value, which has already been fixed up.
4986 FIXME: we use the parent's aspace here, although we're touching
4987 the child, because the child hasn't been added to the inferior
4988 list yet at this point. */
4991 = get_thread_arch_aspace_regcache (ecs
->ws
.value
.related_pid
,
4993 parent_inf
->aspace
);
4994 /* Read PC value of parent process. */
4995 parent_pc
= regcache_read_pc (regcache
);
4997 if (debug_displaced
)
4998 fprintf_unfiltered (gdb_stdlog
,
4999 "displaced: write child pc from %s to %s\n",
5001 regcache_read_pc (child_regcache
)),
5002 paddress (gdbarch
, parent_pc
));
5004 regcache_write_pc (child_regcache
, parent_pc
);
5008 context_switch (ecs
);
5010 /* Immediately detach breakpoints from the child before there's
5011 any chance of letting the user delete breakpoints from the
5012 breakpoint lists. If we don't do this early, it's easy to
5013 leave left over traps in the child, vis: "break foo; catch
5014 fork; c; <fork>; del; c; <child calls foo>". We only follow
5015 the fork on the last `continue', and by that time the
5016 breakpoint at "foo" is long gone from the breakpoint table.
5017 If we vforked, then we don't need to unpatch here, since both
5018 parent and child are sharing the same memory pages; we'll
5019 need to unpatch at follow/detach time instead to be certain
5020 that new breakpoints added between catchpoint hit time and
5021 vfork follow are detached. */
5022 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5024 /* This won't actually modify the breakpoint list, but will
5025 physically remove the breakpoints from the child. */
5026 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5029 delete_just_stopped_threads_single_step_breakpoints ();
5031 /* In case the event is caught by a catchpoint, remember that
5032 the event is to be followed at the next resume of the thread,
5033 and not immediately. */
5034 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5036 ecs
->event_thread
->suspend
.stop_pc
5037 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5039 ecs
->event_thread
->control
.stop_bpstat
5040 = bpstat_stop_status (get_current_regcache ()->aspace (),
5041 ecs
->event_thread
->suspend
.stop_pc
,
5042 ecs
->event_thread
, &ecs
->ws
);
5044 if (handle_stop_requested (ecs
))
5047 /* If no catchpoint triggered for this, then keep going. Note
5048 that we're interested in knowing the bpstat actually causes a
5049 stop, not just if it may explain the signal. Software
5050 watchpoints, for example, always appear in the bpstat. */
5051 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5055 = (follow_fork_mode_string
== follow_fork_mode_child
);
5057 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5059 should_resume
= follow_fork ();
5061 thread_info
*parent
= ecs
->event_thread
;
5062 thread_info
*child
= find_thread_ptid (ecs
->ws
.value
.related_pid
);
5064 /* At this point, the parent is marked running, and the
5065 child is marked stopped. */
5067 /* If not resuming the parent, mark it stopped. */
5068 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5069 parent
->set_running (false);
5071 /* If resuming the child, mark it running. */
5072 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5073 child
->set_running (true);
5075 /* In non-stop mode, also resume the other branch. */
5076 if (!detach_fork
&& (non_stop
5077 || (sched_multi
&& target_is_non_stop_p ())))
5080 switch_to_thread (parent
);
5082 switch_to_thread (child
);
5084 ecs
->event_thread
= inferior_thread ();
5085 ecs
->ptid
= inferior_ptid
;
5090 switch_to_thread (child
);
5092 switch_to_thread (parent
);
5094 ecs
->event_thread
= inferior_thread ();
5095 ecs
->ptid
= inferior_ptid
;
5103 process_event_stop_test (ecs
);
5106 case TARGET_WAITKIND_VFORK_DONE
:
5107 /* Done with the shared memory region. Re-insert breakpoints in
5108 the parent, and keep going. */
5110 context_switch (ecs
);
5112 current_inferior ()->waiting_for_vfork_done
= 0;
5113 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5115 if (handle_stop_requested (ecs
))
5118 /* This also takes care of reinserting breakpoints in the
5119 previously locked inferior. */
5123 case TARGET_WAITKIND_EXECD
:
5125 /* Note we can't read registers yet (the stop_pc), because we
5126 don't yet know the inferior's post-exec architecture.
5127 'stop_pc' is explicitly read below instead. */
5128 switch_to_thread_no_regs (ecs
->event_thread
);
5130 /* Do whatever is necessary to the parent branch of the vfork. */
5131 handle_vfork_child_exec_or_exit (1);
5133 /* This causes the eventpoints and symbol table to be reset.
5134 Must do this now, before trying to determine whether to
5136 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5138 /* In follow_exec we may have deleted the original thread and
5139 created a new one. Make sure that the event thread is the
5140 execd thread for that case (this is a nop otherwise). */
5141 ecs
->event_thread
= inferior_thread ();
5143 ecs
->event_thread
->suspend
.stop_pc
5144 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5146 ecs
->event_thread
->control
.stop_bpstat
5147 = bpstat_stop_status (get_current_regcache ()->aspace (),
5148 ecs
->event_thread
->suspend
.stop_pc
,
5149 ecs
->event_thread
, &ecs
->ws
);
5151 /* Note that this may be referenced from inside
5152 bpstat_stop_status above, through inferior_has_execd. */
5153 xfree (ecs
->ws
.value
.execd_pathname
);
5154 ecs
->ws
.value
.execd_pathname
= NULL
;
5156 if (handle_stop_requested (ecs
))
5159 /* If no catchpoint triggered for this, then keep going. */
5160 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5162 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5166 process_event_stop_test (ecs
);
5169 /* Be careful not to try to gather much state about a thread
5170 that's in a syscall. It's frequently a losing proposition. */
5171 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5172 /* Getting the current syscall number. */
5173 if (handle_syscall_event (ecs
) == 0)
5174 process_event_stop_test (ecs
);
5177 /* Before examining the threads further, step this thread to
5178 get it entirely out of the syscall. (We get notice of the
5179 event when the thread is just on the verge of exiting a
5180 syscall. Stepping one instruction seems to get it back
5182 case TARGET_WAITKIND_SYSCALL_RETURN
:
5183 if (handle_syscall_event (ecs
) == 0)
5184 process_event_stop_test (ecs
);
5187 case TARGET_WAITKIND_STOPPED
:
5188 handle_signal_stop (ecs
);
5191 case TARGET_WAITKIND_NO_HISTORY
:
5192 /* Reverse execution: target ran out of history info. */
5194 /* Switch to the stopped thread. */
5195 context_switch (ecs
);
5197 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5199 delete_just_stopped_threads_single_step_breakpoints ();
5200 ecs
->event_thread
->suspend
.stop_pc
5201 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5203 if (handle_stop_requested (ecs
))
5206 gdb::observers::no_history
.notify ();
5212 /* Restart threads back to what they were trying to do back when we
5213 paused them for an in-line step-over. The EVENT_THREAD thread is
5217 restart_threads (struct thread_info
*event_thread
)
5219 /* In case the instruction just stepped spawned a new thread. */
5220 update_thread_list ();
5222 for (thread_info
*tp
: all_non_exited_threads ())
5224 if (tp
== event_thread
)
5227 fprintf_unfiltered (gdb_stdlog
,
5228 "infrun: restart threads: "
5229 "[%s] is event thread\n",
5230 target_pid_to_str (tp
->ptid
).c_str ());
5234 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5237 fprintf_unfiltered (gdb_stdlog
,
5238 "infrun: restart threads: "
5239 "[%s] not meant to be running\n",
5240 target_pid_to_str (tp
->ptid
).c_str ());
5247 fprintf_unfiltered (gdb_stdlog
,
5248 "infrun: restart threads: [%s] resumed\n",
5249 target_pid_to_str (tp
->ptid
).c_str ());
5250 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5254 if (thread_is_in_step_over_chain (tp
))
5257 fprintf_unfiltered (gdb_stdlog
,
5258 "infrun: restart threads: "
5259 "[%s] needs step-over\n",
5260 target_pid_to_str (tp
->ptid
).c_str ());
5261 gdb_assert (!tp
->resumed
);
5266 if (tp
->suspend
.waitstatus_pending_p
)
5269 fprintf_unfiltered (gdb_stdlog
,
5270 "infrun: restart threads: "
5271 "[%s] has pending status\n",
5272 target_pid_to_str (tp
->ptid
).c_str ());
5277 gdb_assert (!tp
->stop_requested
);
5279 /* If some thread needs to start a step-over at this point, it
5280 should still be in the step-over queue, and thus skipped
5282 if (thread_still_needs_step_over (tp
))
5284 internal_error (__FILE__
, __LINE__
,
5285 "thread [%s] needs a step-over, but not in "
5286 "step-over queue\n",
5287 target_pid_to_str (tp
->ptid
).c_str ());
5290 if (currently_stepping (tp
))
5293 fprintf_unfiltered (gdb_stdlog
,
5294 "infrun: restart threads: [%s] was stepping\n",
5295 target_pid_to_str (tp
->ptid
).c_str ());
5296 keep_going_stepped_thread (tp
);
5300 struct execution_control_state ecss
;
5301 struct execution_control_state
*ecs
= &ecss
;
5304 fprintf_unfiltered (gdb_stdlog
,
5305 "infrun: restart threads: [%s] continuing\n",
5306 target_pid_to_str (tp
->ptid
).c_str ());
5307 reset_ecs (ecs
, tp
);
5308 switch_to_thread (tp
);
5309 keep_going_pass_signal (ecs
);
5314 /* Callback for iterate_over_threads. Find a resumed thread that has
5315 a pending waitstatus. */
5318 resumed_thread_with_pending_status (struct thread_info
*tp
,
5322 && tp
->suspend
.waitstatus_pending_p
);
5325 /* Called when we get an event that may finish an in-line or
5326 out-of-line (displaced stepping) step-over started previously.
5327 Return true if the event is processed and we should go back to the
5328 event loop; false if the caller should continue processing the
5332 finish_step_over (struct execution_control_state
*ecs
)
5334 int had_step_over_info
;
5336 displaced_step_fixup (ecs
->event_thread
,
5337 ecs
->event_thread
->suspend
.stop_signal
);
5339 had_step_over_info
= step_over_info_valid_p ();
5341 if (had_step_over_info
)
5343 /* If we're stepping over a breakpoint with all threads locked,
5344 then only the thread that was stepped should be reporting
5346 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5348 clear_step_over_info ();
5351 if (!target_is_non_stop_p ())
5354 /* Start a new step-over in another thread if there's one that
5358 /* If we were stepping over a breakpoint before, and haven't started
5359 a new in-line step-over sequence, then restart all other threads
5360 (except the event thread). We can't do this in all-stop, as then
5361 e.g., we wouldn't be able to issue any other remote packet until
5362 these other threads stop. */
5363 if (had_step_over_info
&& !step_over_info_valid_p ())
5365 struct thread_info
*pending
;
5367 /* If we only have threads with pending statuses, the restart
5368 below won't restart any thread and so nothing re-inserts the
5369 breakpoint we just stepped over. But we need it inserted
5370 when we later process the pending events, otherwise if
5371 another thread has a pending event for this breakpoint too,
5372 we'd discard its event (because the breakpoint that
5373 originally caused the event was no longer inserted). */
5374 context_switch (ecs
);
5375 insert_breakpoints ();
5377 restart_threads (ecs
->event_thread
);
5379 /* If we have events pending, go through handle_inferior_event
5380 again, picking up a pending event at random. This avoids
5381 thread starvation. */
5383 /* But not if we just stepped over a watchpoint in order to let
5384 the instruction execute so we can evaluate its expression.
5385 The set of watchpoints that triggered is recorded in the
5386 breakpoint objects themselves (see bp->watchpoint_triggered).
5387 If we processed another event first, that other event could
5388 clobber this info. */
5389 if (ecs
->event_thread
->stepping_over_watchpoint
)
5392 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5394 if (pending
!= NULL
)
5396 struct thread_info
*tp
= ecs
->event_thread
;
5397 struct regcache
*regcache
;
5401 fprintf_unfiltered (gdb_stdlog
,
5402 "infrun: found resumed threads with "
5403 "pending events, saving status\n");
5406 gdb_assert (pending
!= tp
);
5408 /* Record the event thread's event for later. */
5409 save_waitstatus (tp
, &ecs
->ws
);
5410 /* This was cleared early, by handle_inferior_event. Set it
5411 so this pending event is considered by
5415 gdb_assert (!tp
->executing
);
5417 regcache
= get_thread_regcache (tp
);
5418 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5422 fprintf_unfiltered (gdb_stdlog
,
5423 "infrun: saved stop_pc=%s for %s "
5424 "(currently_stepping=%d)\n",
5425 paddress (target_gdbarch (),
5426 tp
->suspend
.stop_pc
),
5427 target_pid_to_str (tp
->ptid
).c_str (),
5428 currently_stepping (tp
));
5431 /* This in-line step-over finished; clear this so we won't
5432 start a new one. This is what handle_signal_stop would
5433 do, if we returned false. */
5434 tp
->stepping_over_breakpoint
= 0;
5436 /* Wake up the event loop again. */
5437 mark_async_event_handler (infrun_async_inferior_event_token
);
5439 prepare_to_wait (ecs
);
5447 /* Come here when the program has stopped with a signal. */
5450 handle_signal_stop (struct execution_control_state
*ecs
)
5452 struct frame_info
*frame
;
5453 struct gdbarch
*gdbarch
;
5454 int stopped_by_watchpoint
;
5455 enum stop_kind stop_soon
;
5458 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5460 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5462 /* Do we need to clean up the state of a thread that has
5463 completed a displaced single-step? (Doing so usually affects
5464 the PC, so do it here, before we set stop_pc.) */
5465 if (finish_step_over (ecs
))
5468 /* If we either finished a single-step or hit a breakpoint, but
5469 the user wanted this thread to be stopped, pretend we got a
5470 SIG0 (generic unsignaled stop). */
5471 if (ecs
->event_thread
->stop_requested
5472 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5473 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5475 ecs
->event_thread
->suspend
.stop_pc
5476 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5480 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5481 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5482 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
5484 inferior_ptid
= ecs
->ptid
;
5486 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5487 paddress (reg_gdbarch
,
5488 ecs
->event_thread
->suspend
.stop_pc
));
5489 if (target_stopped_by_watchpoint ())
5493 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5495 if (target_stopped_data_address (current_top_target (), &addr
))
5496 fprintf_unfiltered (gdb_stdlog
,
5497 "infrun: stopped data address = %s\n",
5498 paddress (reg_gdbarch
, addr
));
5500 fprintf_unfiltered (gdb_stdlog
,
5501 "infrun: (no data address available)\n");
5505 /* This is originated from start_remote(), start_inferior() and
5506 shared libraries hook functions. */
5507 stop_soon
= get_inferior_stop_soon (ecs
);
5508 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5510 context_switch (ecs
);
5512 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5513 stop_print_frame
= 1;
5518 /* This originates from attach_command(). We need to overwrite
5519 the stop_signal here, because some kernels don't ignore a
5520 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5521 See more comments in inferior.h. On the other hand, if we
5522 get a non-SIGSTOP, report it to the user - assume the backend
5523 will handle the SIGSTOP if it should show up later.
5525 Also consider that the attach is complete when we see a
5526 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5527 target extended-remote report it instead of a SIGSTOP
5528 (e.g. gdbserver). We already rely on SIGTRAP being our
5529 signal, so this is no exception.
5531 Also consider that the attach is complete when we see a
5532 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5533 the target to stop all threads of the inferior, in case the
5534 low level attach operation doesn't stop them implicitly. If
5535 they weren't stopped implicitly, then the stub will report a
5536 GDB_SIGNAL_0, meaning: stopped for no particular reason
5537 other than GDB's request. */
5538 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5539 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5540 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5541 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5543 stop_print_frame
= 1;
5545 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5549 /* See if something interesting happened to the non-current thread. If
5550 so, then switch to that thread. */
5551 if (ecs
->ptid
!= inferior_ptid
)
5554 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5556 context_switch (ecs
);
5558 if (deprecated_context_hook
)
5559 deprecated_context_hook (ecs
->event_thread
->global_num
);
5562 /* At this point, get hold of the now-current thread's frame. */
5563 frame
= get_current_frame ();
5564 gdbarch
= get_frame_arch (frame
);
5566 /* Pull the single step breakpoints out of the target. */
5567 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5569 struct regcache
*regcache
;
5572 regcache
= get_thread_regcache (ecs
->event_thread
);
5573 const address_space
*aspace
= regcache
->aspace ();
5575 pc
= regcache_read_pc (regcache
);
5577 /* However, before doing so, if this single-step breakpoint was
5578 actually for another thread, set this thread up for moving
5580 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5583 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5587 fprintf_unfiltered (gdb_stdlog
,
5588 "infrun: [%s] hit another thread's "
5589 "single-step breakpoint\n",
5590 target_pid_to_str (ecs
->ptid
).c_str ());
5592 ecs
->hit_singlestep_breakpoint
= 1;
5599 fprintf_unfiltered (gdb_stdlog
,
5600 "infrun: [%s] hit its "
5601 "single-step breakpoint\n",
5602 target_pid_to_str (ecs
->ptid
).c_str ());
5606 delete_just_stopped_threads_single_step_breakpoints ();
5608 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5609 && ecs
->event_thread
->control
.trap_expected
5610 && ecs
->event_thread
->stepping_over_watchpoint
)
5611 stopped_by_watchpoint
= 0;
5613 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5615 /* If necessary, step over this watchpoint. We'll be back to display
5617 if (stopped_by_watchpoint
5618 && (target_have_steppable_watchpoint
5619 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5621 /* At this point, we are stopped at an instruction which has
5622 attempted to write to a piece of memory under control of
5623 a watchpoint. The instruction hasn't actually executed
5624 yet. If we were to evaluate the watchpoint expression
5625 now, we would get the old value, and therefore no change
5626 would seem to have occurred.
5628 In order to make watchpoints work `right', we really need
5629 to complete the memory write, and then evaluate the
5630 watchpoint expression. We do this by single-stepping the
5633 It may not be necessary to disable the watchpoint to step over
5634 it. For example, the PA can (with some kernel cooperation)
5635 single step over a watchpoint without disabling the watchpoint.
5637 It is far more common to need to disable a watchpoint to step
5638 the inferior over it. If we have non-steppable watchpoints,
5639 we must disable the current watchpoint; it's simplest to
5640 disable all watchpoints.
5642 Any breakpoint at PC must also be stepped over -- if there's
5643 one, it will have already triggered before the watchpoint
5644 triggered, and we either already reported it to the user, or
5645 it didn't cause a stop and we called keep_going. In either
5646 case, if there was a breakpoint at PC, we must be trying to
5648 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5653 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5654 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5655 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5656 ecs
->event_thread
->control
.stop_step
= 0;
5657 stop_print_frame
= 1;
5658 stopped_by_random_signal
= 0;
5659 bpstat stop_chain
= NULL
;
5661 /* Hide inlined functions starting here, unless we just performed stepi or
5662 nexti. After stepi and nexti, always show the innermost frame (not any
5663 inline function call sites). */
5664 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5666 const address_space
*aspace
5667 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5669 /* skip_inline_frames is expensive, so we avoid it if we can
5670 determine that the address is one where functions cannot have
5671 been inlined. This improves performance with inferiors that
5672 load a lot of shared libraries, because the solib event
5673 breakpoint is defined as the address of a function (i.e. not
5674 inline). Note that we have to check the previous PC as well
5675 as the current one to catch cases when we have just
5676 single-stepped off a breakpoint prior to reinstating it.
5677 Note that we're assuming that the code we single-step to is
5678 not inline, but that's not definitive: there's nothing
5679 preventing the event breakpoint function from containing
5680 inlined code, and the single-step ending up there. If the
5681 user had set a breakpoint on that inlined code, the missing
5682 skip_inline_frames call would break things. Fortunately
5683 that's an extremely unlikely scenario. */
5684 if (!pc_at_non_inline_function (aspace
,
5685 ecs
->event_thread
->suspend
.stop_pc
,
5687 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5688 && ecs
->event_thread
->control
.trap_expected
5689 && pc_at_non_inline_function (aspace
,
5690 ecs
->event_thread
->prev_pc
,
5693 stop_chain
= build_bpstat_chain (aspace
,
5694 ecs
->event_thread
->suspend
.stop_pc
,
5696 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5698 /* Re-fetch current thread's frame in case that invalidated
5700 frame
= get_current_frame ();
5701 gdbarch
= get_frame_arch (frame
);
5705 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5706 && ecs
->event_thread
->control
.trap_expected
5707 && gdbarch_single_step_through_delay_p (gdbarch
)
5708 && currently_stepping (ecs
->event_thread
))
5710 /* We're trying to step off a breakpoint. Turns out that we're
5711 also on an instruction that needs to be stepped multiple
5712 times before it's been fully executing. E.g., architectures
5713 with a delay slot. It needs to be stepped twice, once for
5714 the instruction and once for the delay slot. */
5715 int step_through_delay
5716 = gdbarch_single_step_through_delay (gdbarch
, frame
);
5718 if (debug_infrun
&& step_through_delay
)
5719 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
5720 if (ecs
->event_thread
->control
.step_range_end
== 0
5721 && step_through_delay
)
5723 /* The user issued a continue when stopped at a breakpoint.
5724 Set up for another trap and get out of here. */
5725 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5729 else if (step_through_delay
)
5731 /* The user issued a step when stopped at a breakpoint.
5732 Maybe we should stop, maybe we should not - the delay
5733 slot *might* correspond to a line of source. In any
5734 case, don't decide that here, just set
5735 ecs->stepping_over_breakpoint, making sure we
5736 single-step again before breakpoints are re-inserted. */
5737 ecs
->event_thread
->stepping_over_breakpoint
= 1;
5741 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
5742 handles this event. */
5743 ecs
->event_thread
->control
.stop_bpstat
5744 = bpstat_stop_status (get_current_regcache ()->aspace (),
5745 ecs
->event_thread
->suspend
.stop_pc
,
5746 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
5748 /* Following in case break condition called a
5750 stop_print_frame
= 1;
5752 /* This is where we handle "moribund" watchpoints. Unlike
5753 software breakpoints traps, hardware watchpoint traps are
5754 always distinguishable from random traps. If no high-level
5755 watchpoint is associated with the reported stop data address
5756 anymore, then the bpstat does not explain the signal ---
5757 simply make sure to ignore it if `stopped_by_watchpoint' is
5761 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5762 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5764 && stopped_by_watchpoint
)
5765 fprintf_unfiltered (gdb_stdlog
,
5766 "infrun: no user watchpoint explains "
5767 "watchpoint SIGTRAP, ignoring\n");
5769 /* NOTE: cagney/2003-03-29: These checks for a random signal
5770 at one stage in the past included checks for an inferior
5771 function call's call dummy's return breakpoint. The original
5772 comment, that went with the test, read:
5774 ``End of a stack dummy. Some systems (e.g. Sony news) give
5775 another signal besides SIGTRAP, so check here as well as
5778 If someone ever tries to get call dummys on a
5779 non-executable stack to work (where the target would stop
5780 with something like a SIGSEGV), then those tests might need
5781 to be re-instated. Given, however, that the tests were only
5782 enabled when momentary breakpoints were not being used, I
5783 suspect that it won't be the case.
5785 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
5786 be necessary for call dummies on a non-executable stack on
5789 /* See if the breakpoints module can explain the signal. */
5791 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
5792 ecs
->event_thread
->suspend
.stop_signal
);
5794 /* Maybe this was a trap for a software breakpoint that has since
5796 if (random_signal
&& target_stopped_by_sw_breakpoint ())
5798 if (program_breakpoint_here_p (gdbarch
,
5799 ecs
->event_thread
->suspend
.stop_pc
))
5801 struct regcache
*regcache
;
5804 /* Re-adjust PC to what the program would see if GDB was not
5806 regcache
= get_thread_regcache (ecs
->event_thread
);
5807 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
5810 gdb::optional
<scoped_restore_tmpl
<int>>
5811 restore_operation_disable
;
5813 if (record_full_is_used ())
5814 restore_operation_disable
.emplace
5815 (record_full_gdb_operation_disable_set ());
5817 regcache_write_pc (regcache
,
5818 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
5823 /* A delayed software breakpoint event. Ignore the trap. */
5825 fprintf_unfiltered (gdb_stdlog
,
5826 "infrun: delayed software breakpoint "
5827 "trap, ignoring\n");
5832 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
5833 has since been removed. */
5834 if (random_signal
&& target_stopped_by_hw_breakpoint ())
5836 /* A delayed hardware breakpoint event. Ignore the trap. */
5838 fprintf_unfiltered (gdb_stdlog
,
5839 "infrun: delayed hardware breakpoint/watchpoint "
5840 "trap, ignoring\n");
5844 /* If not, perhaps stepping/nexting can. */
5846 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5847 && currently_stepping (ecs
->event_thread
));
5849 /* Perhaps the thread hit a single-step breakpoint of _another_
5850 thread. Single-step breakpoints are transparent to the
5851 breakpoints module. */
5853 random_signal
= !ecs
->hit_singlestep_breakpoint
;
5855 /* No? Perhaps we got a moribund watchpoint. */
5857 random_signal
= !stopped_by_watchpoint
;
5859 /* Always stop if the user explicitly requested this thread to
5861 if (ecs
->event_thread
->stop_requested
)
5865 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
5868 /* For the program's own signals, act according to
5869 the signal handling tables. */
5873 /* Signal not for debugging purposes. */
5874 struct inferior
*inf
= find_inferior_ptid (ecs
->ptid
);
5875 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
5878 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
5879 gdb_signal_to_symbol_string (stop_signal
));
5881 stopped_by_random_signal
= 1;
5883 /* Always stop on signals if we're either just gaining control
5884 of the program, or the user explicitly requested this thread
5885 to remain stopped. */
5886 if (stop_soon
!= NO_STOP_QUIETLY
5887 || ecs
->event_thread
->stop_requested
5889 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
5895 /* Notify observers the signal has "handle print" set. Note we
5896 returned early above if stopping; normal_stop handles the
5897 printing in that case. */
5898 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
5900 /* The signal table tells us to print about this signal. */
5901 target_terminal::ours_for_output ();
5902 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
5903 target_terminal::inferior ();
5906 /* Clear the signal if it should not be passed. */
5907 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
5908 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5910 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
5911 && ecs
->event_thread
->control
.trap_expected
5912 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5914 /* We were just starting a new sequence, attempting to
5915 single-step off of a breakpoint and expecting a SIGTRAP.
5916 Instead this signal arrives. This signal will take us out
5917 of the stepping range so GDB needs to remember to, when
5918 the signal handler returns, resume stepping off that
5920 /* To simplify things, "continue" is forced to use the same
5921 code paths as single-step - set a breakpoint at the
5922 signal return address and then, once hit, step off that
5925 fprintf_unfiltered (gdb_stdlog
,
5926 "infrun: signal arrived while stepping over "
5929 insert_hp_step_resume_breakpoint_at_frame (frame
);
5930 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5931 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5932 ecs
->event_thread
->control
.trap_expected
= 0;
5934 /* If we were nexting/stepping some other thread, switch to
5935 it, so that we don't continue it, losing control. */
5936 if (!switch_back_to_stepped_thread (ecs
))
5941 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
5942 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
5944 || ecs
->event_thread
->control
.step_range_end
== 1)
5945 && frame_id_eq (get_stack_frame_id (frame
),
5946 ecs
->event_thread
->control
.step_stack_frame_id
)
5947 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
5949 /* The inferior is about to take a signal that will take it
5950 out of the single step range. Set a breakpoint at the
5951 current PC (which is presumably where the signal handler
5952 will eventually return) and then allow the inferior to
5955 Note that this is only needed for a signal delivered
5956 while in the single-step range. Nested signals aren't a
5957 problem as they eventually all return. */
5959 fprintf_unfiltered (gdb_stdlog
,
5960 "infrun: signal may take us out of "
5961 "single-step range\n");
5963 clear_step_over_info ();
5964 insert_hp_step_resume_breakpoint_at_frame (frame
);
5965 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
5966 /* Reset trap_expected to ensure breakpoints are re-inserted. */
5967 ecs
->event_thread
->control
.trap_expected
= 0;
5972 /* Note: step_resume_breakpoint may be non-NULL. This occurs
5973 when either there's a nested signal, or when there's a
5974 pending signal enabled just as the signal handler returns
5975 (leaving the inferior at the step-resume-breakpoint without
5976 actually executing it). Either way continue until the
5977 breakpoint is really hit. */
5979 if (!switch_back_to_stepped_thread (ecs
))
5982 fprintf_unfiltered (gdb_stdlog
,
5983 "infrun: random signal, keep going\n");
5990 process_event_stop_test (ecs
);
5993 /* Come here when we've got some debug event / signal we can explain
5994 (IOW, not a random signal), and test whether it should cause a
5995 stop, or whether we should resume the inferior (transparently).
5996 E.g., could be a breakpoint whose condition evaluates false; we
5997 could be still stepping within the line; etc. */
6000 process_event_stop_test (struct execution_control_state
*ecs
)
6002 struct symtab_and_line stop_pc_sal
;
6003 struct frame_info
*frame
;
6004 struct gdbarch
*gdbarch
;
6005 CORE_ADDR jmp_buf_pc
;
6006 struct bpstat_what what
;
6008 /* Handle cases caused by hitting a breakpoint. */
6010 frame
= get_current_frame ();
6011 gdbarch
= get_frame_arch (frame
);
6013 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6015 if (what
.call_dummy
)
6017 stop_stack_dummy
= what
.call_dummy
;
6020 /* A few breakpoint types have callbacks associated (e.g.,
6021 bp_jit_event). Run them now. */
6022 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6024 /* If we hit an internal event that triggers symbol changes, the
6025 current frame will be invalidated within bpstat_what (e.g., if we
6026 hit an internal solib event). Re-fetch it. */
6027 frame
= get_current_frame ();
6028 gdbarch
= get_frame_arch (frame
);
6030 switch (what
.main_action
)
6032 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6033 /* If we hit the breakpoint at longjmp while stepping, we
6034 install a momentary breakpoint at the target of the
6038 fprintf_unfiltered (gdb_stdlog
,
6039 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6041 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6043 if (what
.is_longjmp
)
6045 struct value
*arg_value
;
6047 /* If we set the longjmp breakpoint via a SystemTap probe,
6048 then use it to extract the arguments. The destination PC
6049 is the third argument to the probe. */
6050 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6053 jmp_buf_pc
= value_as_address (arg_value
);
6054 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6056 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6057 || !gdbarch_get_longjmp_target (gdbarch
,
6058 frame
, &jmp_buf_pc
))
6061 fprintf_unfiltered (gdb_stdlog
,
6062 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6063 "(!gdbarch_get_longjmp_target)\n");
6068 /* Insert a breakpoint at resume address. */
6069 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6072 check_exception_resume (ecs
, frame
);
6076 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6078 struct frame_info
*init_frame
;
6080 /* There are several cases to consider.
6082 1. The initiating frame no longer exists. In this case we
6083 must stop, because the exception or longjmp has gone too
6086 2. The initiating frame exists, and is the same as the
6087 current frame. We stop, because the exception or longjmp
6090 3. The initiating frame exists and is different from the
6091 current frame. This means the exception or longjmp has
6092 been caught beneath the initiating frame, so keep going.
6094 4. longjmp breakpoint has been placed just to protect
6095 against stale dummy frames and user is not interested in
6096 stopping around longjmps. */
6099 fprintf_unfiltered (gdb_stdlog
,
6100 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6102 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6104 delete_exception_resume_breakpoint (ecs
->event_thread
);
6106 if (what
.is_longjmp
)
6108 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6110 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6118 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6122 struct frame_id current_id
6123 = get_frame_id (get_current_frame ());
6124 if (frame_id_eq (current_id
,
6125 ecs
->event_thread
->initiating_frame
))
6127 /* Case 2. Fall through. */
6137 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6139 delete_step_resume_breakpoint (ecs
->event_thread
);
6141 end_stepping_range (ecs
);
6145 case BPSTAT_WHAT_SINGLE
:
6147 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6148 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6149 /* Still need to check other stuff, at least the case where we
6150 are stepping and step out of the right range. */
6153 case BPSTAT_WHAT_STEP_RESUME
:
6155 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6157 delete_step_resume_breakpoint (ecs
->event_thread
);
6158 if (ecs
->event_thread
->control
.proceed_to_finish
6159 && execution_direction
== EXEC_REVERSE
)
6161 struct thread_info
*tp
= ecs
->event_thread
;
6163 /* We are finishing a function in reverse, and just hit the
6164 step-resume breakpoint at the start address of the
6165 function, and we're almost there -- just need to back up
6166 by one more single-step, which should take us back to the
6168 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6172 fill_in_stop_func (gdbarch
, ecs
);
6173 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6174 && execution_direction
== EXEC_REVERSE
)
6176 /* We are stepping over a function call in reverse, and just
6177 hit the step-resume breakpoint at the start address of
6178 the function. Go back to single-stepping, which should
6179 take us back to the function call. */
6180 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6186 case BPSTAT_WHAT_STOP_NOISY
:
6188 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6189 stop_print_frame
= 1;
6191 /* Assume the thread stopped for a breapoint. We'll still check
6192 whether a/the breakpoint is there when the thread is next
6194 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6199 case BPSTAT_WHAT_STOP_SILENT
:
6201 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6202 stop_print_frame
= 0;
6204 /* Assume the thread stopped for a breapoint. We'll still check
6205 whether a/the breakpoint is there when the thread is next
6207 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6211 case BPSTAT_WHAT_HP_STEP_RESUME
:
6213 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6215 delete_step_resume_breakpoint (ecs
->event_thread
);
6216 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6218 /* Back when the step-resume breakpoint was inserted, we
6219 were trying to single-step off a breakpoint. Go back to
6221 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6222 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6228 case BPSTAT_WHAT_KEEP_CHECKING
:
6232 /* If we stepped a permanent breakpoint and we had a high priority
6233 step-resume breakpoint for the address we stepped, but we didn't
6234 hit it, then we must have stepped into the signal handler. The
6235 step-resume was only necessary to catch the case of _not_
6236 stepping into the handler, so delete it, and fall through to
6237 checking whether the step finished. */
6238 if (ecs
->event_thread
->stepped_breakpoint
)
6240 struct breakpoint
*sr_bp
6241 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6244 && sr_bp
->loc
->permanent
6245 && sr_bp
->type
== bp_hp_step_resume
6246 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6249 fprintf_unfiltered (gdb_stdlog
,
6250 "infrun: stepped permanent breakpoint, stopped in "
6252 delete_step_resume_breakpoint (ecs
->event_thread
);
6253 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6257 /* We come here if we hit a breakpoint but should not stop for it.
6258 Possibly we also were stepping and should stop for that. So fall
6259 through and test for stepping. But, if not stepping, do not
6262 /* In all-stop mode, if we're currently stepping but have stopped in
6263 some other thread, we need to switch back to the stepped thread. */
6264 if (switch_back_to_stepped_thread (ecs
))
6267 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6270 fprintf_unfiltered (gdb_stdlog
,
6271 "infrun: step-resume breakpoint is inserted\n");
6273 /* Having a step-resume breakpoint overrides anything
6274 else having to do with stepping commands until
6275 that breakpoint is reached. */
6280 if (ecs
->event_thread
->control
.step_range_end
== 0)
6283 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6284 /* Likewise if we aren't even stepping. */
6289 /* Re-fetch current thread's frame in case the code above caused
6290 the frame cache to be re-initialized, making our FRAME variable
6291 a dangling pointer. */
6292 frame
= get_current_frame ();
6293 gdbarch
= get_frame_arch (frame
);
6294 fill_in_stop_func (gdbarch
, ecs
);
6296 /* If stepping through a line, keep going if still within it.
6298 Note that step_range_end is the address of the first instruction
6299 beyond the step range, and NOT the address of the last instruction
6302 Note also that during reverse execution, we may be stepping
6303 through a function epilogue and therefore must detect when
6304 the current-frame changes in the middle of a line. */
6306 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6308 && (execution_direction
!= EXEC_REVERSE
6309 || frame_id_eq (get_frame_id (frame
),
6310 ecs
->event_thread
->control
.step_frame_id
)))
6314 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6315 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6316 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6318 /* Tentatively re-enable range stepping; `resume' disables it if
6319 necessary (e.g., if we're stepping over a breakpoint or we
6320 have software watchpoints). */
6321 ecs
->event_thread
->control
.may_range_step
= 1;
6323 /* When stepping backward, stop at beginning of line range
6324 (unless it's the function entry point, in which case
6325 keep going back to the call point). */
6326 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6327 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6328 && stop_pc
!= ecs
->stop_func_start
6329 && execution_direction
== EXEC_REVERSE
)
6330 end_stepping_range (ecs
);
6337 /* We stepped out of the stepping range. */
6339 /* If we are stepping at the source level and entered the runtime
6340 loader dynamic symbol resolution code...
6342 EXEC_FORWARD: we keep on single stepping until we exit the run
6343 time loader code and reach the callee's address.
6345 EXEC_REVERSE: we've already executed the callee (backward), and
6346 the runtime loader code is handled just like any other
6347 undebuggable function call. Now we need only keep stepping
6348 backward through the trampoline code, and that's handled further
6349 down, so there is nothing for us to do here. */
6351 if (execution_direction
!= EXEC_REVERSE
6352 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6353 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6355 CORE_ADDR pc_after_resolver
=
6356 gdbarch_skip_solib_resolver (gdbarch
,
6357 ecs
->event_thread
->suspend
.stop_pc
);
6360 fprintf_unfiltered (gdb_stdlog
,
6361 "infrun: stepped into dynsym resolve code\n");
6363 if (pc_after_resolver
)
6365 /* Set up a step-resume breakpoint at the address
6366 indicated by SKIP_SOLIB_RESOLVER. */
6367 symtab_and_line sr_sal
;
6368 sr_sal
.pc
= pc_after_resolver
;
6369 sr_sal
.pspace
= get_frame_program_space (frame
);
6371 insert_step_resume_breakpoint_at_sal (gdbarch
,
6372 sr_sal
, null_frame_id
);
6379 /* Step through an indirect branch thunk. */
6380 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6381 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6382 ecs
->event_thread
->suspend
.stop_pc
))
6385 fprintf_unfiltered (gdb_stdlog
,
6386 "infrun: stepped into indirect branch thunk\n");
6391 if (ecs
->event_thread
->control
.step_range_end
!= 1
6392 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6393 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6394 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6397 fprintf_unfiltered (gdb_stdlog
,
6398 "infrun: stepped into signal trampoline\n");
6399 /* The inferior, while doing a "step" or "next", has ended up in
6400 a signal trampoline (either by a signal being delivered or by
6401 the signal handler returning). Just single-step until the
6402 inferior leaves the trampoline (either by calling the handler
6408 /* If we're in the return path from a shared library trampoline,
6409 we want to proceed through the trampoline when stepping. */
6410 /* macro/2012-04-25: This needs to come before the subroutine
6411 call check below as on some targets return trampolines look
6412 like subroutine calls (MIPS16 return thunks). */
6413 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6414 ecs
->event_thread
->suspend
.stop_pc
,
6415 ecs
->stop_func_name
)
6416 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6418 /* Determine where this trampoline returns. */
6419 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6420 CORE_ADDR real_stop_pc
6421 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6424 fprintf_unfiltered (gdb_stdlog
,
6425 "infrun: stepped into solib return tramp\n");
6427 /* Only proceed through if we know where it's going. */
6430 /* And put the step-breakpoint there and go until there. */
6431 symtab_and_line sr_sal
;
6432 sr_sal
.pc
= real_stop_pc
;
6433 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6434 sr_sal
.pspace
= get_frame_program_space (frame
);
6436 /* Do not specify what the fp should be when we stop since
6437 on some machines the prologue is where the new fp value
6439 insert_step_resume_breakpoint_at_sal (gdbarch
,
6440 sr_sal
, null_frame_id
);
6442 /* Restart without fiddling with the step ranges or
6449 /* Check for subroutine calls. The check for the current frame
6450 equalling the step ID is not necessary - the check of the
6451 previous frame's ID is sufficient - but it is a common case and
6452 cheaper than checking the previous frame's ID.
6454 NOTE: frame_id_eq will never report two invalid frame IDs as
6455 being equal, so to get into this block, both the current and
6456 previous frame must have valid frame IDs. */
6457 /* The outer_frame_id check is a heuristic to detect stepping
6458 through startup code. If we step over an instruction which
6459 sets the stack pointer from an invalid value to a valid value,
6460 we may detect that as a subroutine call from the mythical
6461 "outermost" function. This could be fixed by marking
6462 outermost frames as !stack_p,code_p,special_p. Then the
6463 initial outermost frame, before sp was valid, would
6464 have code_addr == &_start. See the comment in frame_id_eq
6466 if (!frame_id_eq (get_stack_frame_id (frame
),
6467 ecs
->event_thread
->control
.step_stack_frame_id
)
6468 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6469 ecs
->event_thread
->control
.step_stack_frame_id
)
6470 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6472 || (ecs
->event_thread
->control
.step_start_function
6473 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6475 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6476 CORE_ADDR real_stop_pc
;
6479 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6481 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6483 /* I presume that step_over_calls is only 0 when we're
6484 supposed to be stepping at the assembly language level
6485 ("stepi"). Just stop. */
6486 /* And this works the same backward as frontward. MVS */
6487 end_stepping_range (ecs
);
6491 /* Reverse stepping through solib trampolines. */
6493 if (execution_direction
== EXEC_REVERSE
6494 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6495 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6496 || (ecs
->stop_func_start
== 0
6497 && in_solib_dynsym_resolve_code (stop_pc
))))
6499 /* Any solib trampoline code can be handled in reverse
6500 by simply continuing to single-step. We have already
6501 executed the solib function (backwards), and a few
6502 steps will take us back through the trampoline to the
6508 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6510 /* We're doing a "next".
6512 Normal (forward) execution: set a breakpoint at the
6513 callee's return address (the address at which the caller
6516 Reverse (backward) execution. set the step-resume
6517 breakpoint at the start of the function that we just
6518 stepped into (backwards), and continue to there. When we
6519 get there, we'll need to single-step back to the caller. */
6521 if (execution_direction
== EXEC_REVERSE
)
6523 /* If we're already at the start of the function, we've either
6524 just stepped backward into a single instruction function,
6525 or stepped back out of a signal handler to the first instruction
6526 of the function. Just keep going, which will single-step back
6528 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6530 /* Normal function call return (static or dynamic). */
6531 symtab_and_line sr_sal
;
6532 sr_sal
.pc
= ecs
->stop_func_start
;
6533 sr_sal
.pspace
= get_frame_program_space (frame
);
6534 insert_step_resume_breakpoint_at_sal (gdbarch
,
6535 sr_sal
, null_frame_id
);
6539 insert_step_resume_breakpoint_at_caller (frame
);
6545 /* If we are in a function call trampoline (a stub between the
6546 calling routine and the real function), locate the real
6547 function. That's what tells us (a) whether we want to step
6548 into it at all, and (b) what prologue we want to run to the
6549 end of, if we do step into it. */
6550 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6551 if (real_stop_pc
== 0)
6552 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6553 if (real_stop_pc
!= 0)
6554 ecs
->stop_func_start
= real_stop_pc
;
6556 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6558 symtab_and_line sr_sal
;
6559 sr_sal
.pc
= ecs
->stop_func_start
;
6560 sr_sal
.pspace
= get_frame_program_space (frame
);
6562 insert_step_resume_breakpoint_at_sal (gdbarch
,
6563 sr_sal
, null_frame_id
);
6568 /* If we have line number information for the function we are
6569 thinking of stepping into and the function isn't on the skip
6572 If there are several symtabs at that PC (e.g. with include
6573 files), just want to know whether *any* of them have line
6574 numbers. find_pc_line handles this. */
6576 struct symtab_and_line tmp_sal
;
6578 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6579 if (tmp_sal
.line
!= 0
6580 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6582 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6584 if (execution_direction
== EXEC_REVERSE
)
6585 handle_step_into_function_backward (gdbarch
, ecs
);
6587 handle_step_into_function (gdbarch
, ecs
);
6592 /* If we have no line number and the step-stop-if-no-debug is
6593 set, we stop the step so that the user has a chance to switch
6594 in assembly mode. */
6595 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6596 && step_stop_if_no_debug
)
6598 end_stepping_range (ecs
);
6602 if (execution_direction
== EXEC_REVERSE
)
6604 /* If we're already at the start of the function, we've either just
6605 stepped backward into a single instruction function without line
6606 number info, or stepped back out of a signal handler to the first
6607 instruction of the function without line number info. Just keep
6608 going, which will single-step back to the caller. */
6609 if (ecs
->stop_func_start
!= stop_pc
)
6611 /* Set a breakpoint at callee's start address.
6612 From there we can step once and be back in the caller. */
6613 symtab_and_line sr_sal
;
6614 sr_sal
.pc
= ecs
->stop_func_start
;
6615 sr_sal
.pspace
= get_frame_program_space (frame
);
6616 insert_step_resume_breakpoint_at_sal (gdbarch
,
6617 sr_sal
, null_frame_id
);
6621 /* Set a breakpoint at callee's return address (the address
6622 at which the caller will resume). */
6623 insert_step_resume_breakpoint_at_caller (frame
);
6629 /* Reverse stepping through solib trampolines. */
6631 if (execution_direction
== EXEC_REVERSE
6632 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6634 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6636 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6637 || (ecs
->stop_func_start
== 0
6638 && in_solib_dynsym_resolve_code (stop_pc
)))
6640 /* Any solib trampoline code can be handled in reverse
6641 by simply continuing to single-step. We have already
6642 executed the solib function (backwards), and a few
6643 steps will take us back through the trampoline to the
6648 else if (in_solib_dynsym_resolve_code (stop_pc
))
6650 /* Stepped backward into the solib dynsym resolver.
6651 Set a breakpoint at its start and continue, then
6652 one more step will take us out. */
6653 symtab_and_line sr_sal
;
6654 sr_sal
.pc
= ecs
->stop_func_start
;
6655 sr_sal
.pspace
= get_frame_program_space (frame
);
6656 insert_step_resume_breakpoint_at_sal (gdbarch
,
6657 sr_sal
, null_frame_id
);
6663 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6665 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6666 the trampoline processing logic, however, there are some trampolines
6667 that have no names, so we should do trampoline handling first. */
6668 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6669 && ecs
->stop_func_name
== NULL
6670 && stop_pc_sal
.line
== 0)
6673 fprintf_unfiltered (gdb_stdlog
,
6674 "infrun: stepped into undebuggable function\n");
6676 /* The inferior just stepped into, or returned to, an
6677 undebuggable function (where there is no debugging information
6678 and no line number corresponding to the address where the
6679 inferior stopped). Since we want to skip this kind of code,
6680 we keep going until the inferior returns from this
6681 function - unless the user has asked us not to (via
6682 set step-mode) or we no longer know how to get back
6683 to the call site. */
6684 if (step_stop_if_no_debug
6685 || !frame_id_p (frame_unwind_caller_id (frame
)))
6687 /* If we have no line number and the step-stop-if-no-debug
6688 is set, we stop the step so that the user has a chance to
6689 switch in assembly mode. */
6690 end_stepping_range (ecs
);
6695 /* Set a breakpoint at callee's return address (the address
6696 at which the caller will resume). */
6697 insert_step_resume_breakpoint_at_caller (frame
);
6703 if (ecs
->event_thread
->control
.step_range_end
== 1)
6705 /* It is stepi or nexti. We always want to stop stepping after
6708 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
6709 end_stepping_range (ecs
);
6713 if (stop_pc_sal
.line
== 0)
6715 /* We have no line number information. That means to stop
6716 stepping (does this always happen right after one instruction,
6717 when we do "s" in a function with no line numbers,
6718 or can this happen as a result of a return or longjmp?). */
6720 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
6721 end_stepping_range (ecs
);
6725 /* Look for "calls" to inlined functions, part one. If the inline
6726 frame machinery detected some skipped call sites, we have entered
6727 a new inline function. */
6729 if (frame_id_eq (get_frame_id (get_current_frame ()),
6730 ecs
->event_thread
->control
.step_frame_id
)
6731 && inline_skipped_frames (ecs
->event_thread
))
6734 fprintf_unfiltered (gdb_stdlog
,
6735 "infrun: stepped into inlined function\n");
6737 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6739 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6741 /* For "step", we're going to stop. But if the call site
6742 for this inlined function is on the same source line as
6743 we were previously stepping, go down into the function
6744 first. Otherwise stop at the call site. */
6746 if (call_sal
.line
== ecs
->event_thread
->current_line
6747 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6749 step_into_inline_frame (ecs
->event_thread
);
6750 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6757 end_stepping_range (ecs
);
6762 /* For "next", we should stop at the call site if it is on a
6763 different source line. Otherwise continue through the
6764 inlined function. */
6765 if (call_sal
.line
== ecs
->event_thread
->current_line
6766 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
6769 end_stepping_range (ecs
);
6774 /* Look for "calls" to inlined functions, part two. If we are still
6775 in the same real function we were stepping through, but we have
6776 to go further up to find the exact frame ID, we are stepping
6777 through a more inlined call beyond its call site. */
6779 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
6780 && !frame_id_eq (get_frame_id (get_current_frame ()),
6781 ecs
->event_thread
->control
.step_frame_id
)
6782 && stepped_in_from (get_current_frame (),
6783 ecs
->event_thread
->control
.step_frame_id
))
6786 fprintf_unfiltered (gdb_stdlog
,
6787 "infrun: stepping through inlined function\n");
6789 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
6790 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
6793 end_stepping_range (ecs
);
6797 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
6798 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
6799 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
6801 /* We are at the start of a different line. So stop. Note that
6802 we don't stop if we step into the middle of a different line.
6803 That is said to make things like for (;;) statements work
6806 fprintf_unfiltered (gdb_stdlog
,
6807 "infrun: stepped to a different line\n");
6808 end_stepping_range (ecs
);
6812 /* We aren't done stepping.
6814 Optimize by setting the stepping range to the line.
6815 (We might not be in the original line, but if we entered a
6816 new line in mid-statement, we continue stepping. This makes
6817 things like for(;;) statements work better.) */
6819 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
6820 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
6821 ecs
->event_thread
->control
.may_range_step
= 1;
6822 set_step_info (frame
, stop_pc_sal
);
6825 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
6829 /* In all-stop mode, if we're currently stepping but have stopped in
6830 some other thread, we may need to switch back to the stepped
6831 thread. Returns true we set the inferior running, false if we left
6832 it stopped (and the event needs further processing). */
6835 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
6837 if (!target_is_non_stop_p ())
6839 struct thread_info
*stepping_thread
;
6841 /* If any thread is blocked on some internal breakpoint, and we
6842 simply need to step over that breakpoint to get it going
6843 again, do that first. */
6845 /* However, if we see an event for the stepping thread, then we
6846 know all other threads have been moved past their breakpoints
6847 already. Let the caller check whether the step is finished,
6848 etc., before deciding to move it past a breakpoint. */
6849 if (ecs
->event_thread
->control
.step_range_end
!= 0)
6852 /* Check if the current thread is blocked on an incomplete
6853 step-over, interrupted by a random signal. */
6854 if (ecs
->event_thread
->control
.trap_expected
6855 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
6859 fprintf_unfiltered (gdb_stdlog
,
6860 "infrun: need to finish step-over of [%s]\n",
6861 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
6867 /* Check if the current thread is blocked by a single-step
6868 breakpoint of another thread. */
6869 if (ecs
->hit_singlestep_breakpoint
)
6873 fprintf_unfiltered (gdb_stdlog
,
6874 "infrun: need to step [%s] over single-step "
6876 target_pid_to_str (ecs
->ptid
).c_str ());
6882 /* If this thread needs yet another step-over (e.g., stepping
6883 through a delay slot), do it first before moving on to
6885 if (thread_still_needs_step_over (ecs
->event_thread
))
6889 fprintf_unfiltered (gdb_stdlog
,
6890 "infrun: thread [%s] still needs step-over\n",
6891 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
6897 /* If scheduler locking applies even if not stepping, there's no
6898 need to walk over threads. Above we've checked whether the
6899 current thread is stepping. If some other thread not the
6900 event thread is stepping, then it must be that scheduler
6901 locking is not in effect. */
6902 if (schedlock_applies (ecs
->event_thread
))
6905 /* Otherwise, we no longer expect a trap in the current thread.
6906 Clear the trap_expected flag before switching back -- this is
6907 what keep_going does as well, if we call it. */
6908 ecs
->event_thread
->control
.trap_expected
= 0;
6910 /* Likewise, clear the signal if it should not be passed. */
6911 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
6912 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6914 /* Do all pending step-overs before actually proceeding with
6916 if (start_step_over ())
6918 prepare_to_wait (ecs
);
6922 /* Look for the stepping/nexting thread. */
6923 stepping_thread
= NULL
;
6925 for (thread_info
*tp
: all_non_exited_threads ())
6927 /* Ignore threads of processes the caller is not
6930 && tp
->ptid
.pid () != ecs
->ptid
.pid ())
6933 /* When stepping over a breakpoint, we lock all threads
6934 except the one that needs to move past the breakpoint.
6935 If a non-event thread has this set, the "incomplete
6936 step-over" check above should have caught it earlier. */
6937 if (tp
->control
.trap_expected
)
6939 internal_error (__FILE__
, __LINE__
,
6940 "[%s] has inconsistent state: "
6941 "trap_expected=%d\n",
6942 target_pid_to_str (tp
->ptid
).c_str (),
6943 tp
->control
.trap_expected
);
6946 /* Did we find the stepping thread? */
6947 if (tp
->control
.step_range_end
)
6949 /* Yep. There should only one though. */
6950 gdb_assert (stepping_thread
== NULL
);
6952 /* The event thread is handled at the top, before we
6954 gdb_assert (tp
!= ecs
->event_thread
);
6956 /* If some thread other than the event thread is
6957 stepping, then scheduler locking can't be in effect,
6958 otherwise we wouldn't have resumed the current event
6959 thread in the first place. */
6960 gdb_assert (!schedlock_applies (tp
));
6962 stepping_thread
= tp
;
6966 if (stepping_thread
!= NULL
)
6969 fprintf_unfiltered (gdb_stdlog
,
6970 "infrun: switching back to stepped thread\n");
6972 if (keep_going_stepped_thread (stepping_thread
))
6974 prepare_to_wait (ecs
);
6983 /* Set a previously stepped thread back to stepping. Returns true on
6984 success, false if the resume is not possible (e.g., the thread
6988 keep_going_stepped_thread (struct thread_info
*tp
)
6990 struct frame_info
*frame
;
6991 struct execution_control_state ecss
;
6992 struct execution_control_state
*ecs
= &ecss
;
6994 /* If the stepping thread exited, then don't try to switch back and
6995 resume it, which could fail in several different ways depending
6996 on the target. Instead, just keep going.
6998 We can find a stepping dead thread in the thread list in two
7001 - The target supports thread exit events, and when the target
7002 tries to delete the thread from the thread list, inferior_ptid
7003 pointed at the exiting thread. In such case, calling
7004 delete_thread does not really remove the thread from the list;
7005 instead, the thread is left listed, with 'exited' state.
7007 - The target's debug interface does not support thread exit
7008 events, and so we have no idea whatsoever if the previously
7009 stepping thread is still alive. For that reason, we need to
7010 synchronously query the target now. */
7012 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7015 fprintf_unfiltered (gdb_stdlog
,
7016 "infrun: not resuming previously "
7017 "stepped thread, it has vanished\n");
7024 fprintf_unfiltered (gdb_stdlog
,
7025 "infrun: resuming previously stepped thread\n");
7027 reset_ecs (ecs
, tp
);
7028 switch_to_thread (tp
);
7030 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7031 frame
= get_current_frame ();
7033 /* If the PC of the thread we were trying to single-step has
7034 changed, then that thread has trapped or been signaled, but the
7035 event has not been reported to GDB yet. Re-poll the target
7036 looking for this particular thread's event (i.e. temporarily
7037 enable schedlock) by:
7039 - setting a break at the current PC
7040 - resuming that particular thread, only (by setting trap
7043 This prevents us continuously moving the single-step breakpoint
7044 forward, one instruction at a time, overstepping. */
7046 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7051 fprintf_unfiltered (gdb_stdlog
,
7052 "infrun: expected thread advanced also (%s -> %s)\n",
7053 paddress (target_gdbarch (), tp
->prev_pc
),
7054 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7056 /* Clear the info of the previous step-over, as it's no longer
7057 valid (if the thread was trying to step over a breakpoint, it
7058 has already succeeded). It's what keep_going would do too,
7059 if we called it. Do this before trying to insert the sss
7060 breakpoint, otherwise if we were previously trying to step
7061 over this exact address in another thread, the breakpoint is
7063 clear_step_over_info ();
7064 tp
->control
.trap_expected
= 0;
7066 insert_single_step_breakpoint (get_frame_arch (frame
),
7067 get_frame_address_space (frame
),
7068 tp
->suspend
.stop_pc
);
7071 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7072 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7077 fprintf_unfiltered (gdb_stdlog
,
7078 "infrun: expected thread still hasn't advanced\n");
7080 keep_going_pass_signal (ecs
);
7085 /* Is thread TP in the middle of (software or hardware)
7086 single-stepping? (Note the result of this function must never be
7087 passed directly as target_resume's STEP parameter.) */
7090 currently_stepping (struct thread_info
*tp
)
7092 return ((tp
->control
.step_range_end
7093 && tp
->control
.step_resume_breakpoint
== NULL
)
7094 || tp
->control
.trap_expected
7095 || tp
->stepped_breakpoint
7096 || bpstat_should_step ());
7099 /* Inferior has stepped into a subroutine call with source code that
7100 we should not step over. Do step to the first line of code in
7104 handle_step_into_function (struct gdbarch
*gdbarch
,
7105 struct execution_control_state
*ecs
)
7107 fill_in_stop_func (gdbarch
, ecs
);
7109 compunit_symtab
*cust
7110 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7111 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7112 ecs
->stop_func_start
7113 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7115 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7116 /* Use the step_resume_break to step until the end of the prologue,
7117 even if that involves jumps (as it seems to on the vax under
7119 /* If the prologue ends in the middle of a source line, continue to
7120 the end of that source line (if it is still within the function).
7121 Otherwise, just go to end of prologue. */
7122 if (stop_func_sal
.end
7123 && stop_func_sal
.pc
!= ecs
->stop_func_start
7124 && stop_func_sal
.end
< ecs
->stop_func_end
)
7125 ecs
->stop_func_start
= stop_func_sal
.end
;
7127 /* Architectures which require breakpoint adjustment might not be able
7128 to place a breakpoint at the computed address. If so, the test
7129 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7130 ecs->stop_func_start to an address at which a breakpoint may be
7131 legitimately placed.
7133 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7134 made, GDB will enter an infinite loop when stepping through
7135 optimized code consisting of VLIW instructions which contain
7136 subinstructions corresponding to different source lines. On
7137 FR-V, it's not permitted to place a breakpoint on any but the
7138 first subinstruction of a VLIW instruction. When a breakpoint is
7139 set, GDB will adjust the breakpoint address to the beginning of
7140 the VLIW instruction. Thus, we need to make the corresponding
7141 adjustment here when computing the stop address. */
7143 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7145 ecs
->stop_func_start
7146 = gdbarch_adjust_breakpoint_address (gdbarch
,
7147 ecs
->stop_func_start
);
7150 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7152 /* We are already there: stop now. */
7153 end_stepping_range (ecs
);
7158 /* Put the step-breakpoint there and go until there. */
7159 symtab_and_line sr_sal
;
7160 sr_sal
.pc
= ecs
->stop_func_start
;
7161 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7162 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7164 /* Do not specify what the fp should be when we stop since on
7165 some machines the prologue is where the new fp value is
7167 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7169 /* And make sure stepping stops right away then. */
7170 ecs
->event_thread
->control
.step_range_end
7171 = ecs
->event_thread
->control
.step_range_start
;
7176 /* Inferior has stepped backward into a subroutine call with source
7177 code that we should not step over. Do step to the beginning of the
7178 last line of code in it. */
7181 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7182 struct execution_control_state
*ecs
)
7184 struct compunit_symtab
*cust
;
7185 struct symtab_and_line stop_func_sal
;
7187 fill_in_stop_func (gdbarch
, ecs
);
7189 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7190 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7191 ecs
->stop_func_start
7192 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7194 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7196 /* OK, we're just going to keep stepping here. */
7197 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7199 /* We're there already. Just stop stepping now. */
7200 end_stepping_range (ecs
);
7204 /* Else just reset the step range and keep going.
7205 No step-resume breakpoint, they don't work for
7206 epilogues, which can have multiple entry paths. */
7207 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7208 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7214 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7215 This is used to both functions and to skip over code. */
7218 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7219 struct symtab_and_line sr_sal
,
7220 struct frame_id sr_id
,
7221 enum bptype sr_type
)
7223 /* There should never be more than one step-resume or longjmp-resume
7224 breakpoint per thread, so we should never be setting a new
7225 step_resume_breakpoint when one is already active. */
7226 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7227 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7230 fprintf_unfiltered (gdb_stdlog
,
7231 "infrun: inserting step-resume breakpoint at %s\n",
7232 paddress (gdbarch
, sr_sal
.pc
));
7234 inferior_thread ()->control
.step_resume_breakpoint
7235 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7239 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7240 struct symtab_and_line sr_sal
,
7241 struct frame_id sr_id
)
7243 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7248 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7249 This is used to skip a potential signal handler.
7251 This is called with the interrupted function's frame. The signal
7252 handler, when it returns, will resume the interrupted function at
7256 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7258 gdb_assert (return_frame
!= NULL
);
7260 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7262 symtab_and_line sr_sal
;
7263 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7264 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7265 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7267 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7268 get_stack_frame_id (return_frame
),
7272 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7273 is used to skip a function after stepping into it (for "next" or if
7274 the called function has no debugging information).
7276 The current function has almost always been reached by single
7277 stepping a call or return instruction. NEXT_FRAME belongs to the
7278 current function, and the breakpoint will be set at the caller's
7281 This is a separate function rather than reusing
7282 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7283 get_prev_frame, which may stop prematurely (see the implementation
7284 of frame_unwind_caller_id for an example). */
7287 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7289 /* We shouldn't have gotten here if we don't know where the call site
7291 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7293 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7295 symtab_and_line sr_sal
;
7296 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7297 frame_unwind_caller_pc (next_frame
));
7298 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7299 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7301 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7302 frame_unwind_caller_id (next_frame
));
7305 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7306 new breakpoint at the target of a jmp_buf. The handling of
7307 longjmp-resume uses the same mechanisms used for handling
7308 "step-resume" breakpoints. */
7311 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7313 /* There should never be more than one longjmp-resume breakpoint per
7314 thread, so we should never be setting a new
7315 longjmp_resume_breakpoint when one is already active. */
7316 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7319 fprintf_unfiltered (gdb_stdlog
,
7320 "infrun: inserting longjmp-resume breakpoint at %s\n",
7321 paddress (gdbarch
, pc
));
7323 inferior_thread ()->control
.exception_resume_breakpoint
=
7324 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7327 /* Insert an exception resume breakpoint. TP is the thread throwing
7328 the exception. The block B is the block of the unwinder debug hook
7329 function. FRAME is the frame corresponding to the call to this
7330 function. SYM is the symbol of the function argument holding the
7331 target PC of the exception. */
7334 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7335 const struct block
*b
,
7336 struct frame_info
*frame
,
7341 struct block_symbol vsym
;
7342 struct value
*value
;
7344 struct breakpoint
*bp
;
7346 vsym
= lookup_symbol_search_name (sym
->search_name (),
7348 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7349 /* If the value was optimized out, revert to the old behavior. */
7350 if (! value_optimized_out (value
))
7352 handler
= value_as_address (value
);
7355 fprintf_unfiltered (gdb_stdlog
,
7356 "infrun: exception resume at %lx\n",
7357 (unsigned long) handler
);
7359 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7361 bp_exception_resume
).release ();
7363 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7366 bp
->thread
= tp
->global_num
;
7367 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7370 catch (const gdb_exception_error
&e
)
7372 /* We want to ignore errors here. */
7376 /* A helper for check_exception_resume that sets an
7377 exception-breakpoint based on a SystemTap probe. */
7380 insert_exception_resume_from_probe (struct thread_info
*tp
,
7381 const struct bound_probe
*probe
,
7382 struct frame_info
*frame
)
7384 struct value
*arg_value
;
7386 struct breakpoint
*bp
;
7388 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7392 handler
= value_as_address (arg_value
);
7395 fprintf_unfiltered (gdb_stdlog
,
7396 "infrun: exception resume at %s\n",
7397 paddress (get_objfile_arch (probe
->objfile
),
7400 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7401 handler
, bp_exception_resume
).release ();
7402 bp
->thread
= tp
->global_num
;
7403 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7406 /* This is called when an exception has been intercepted. Check to
7407 see whether the exception's destination is of interest, and if so,
7408 set an exception resume breakpoint there. */
7411 check_exception_resume (struct execution_control_state
*ecs
,
7412 struct frame_info
*frame
)
7414 struct bound_probe probe
;
7415 struct symbol
*func
;
7417 /* First see if this exception unwinding breakpoint was set via a
7418 SystemTap probe point. If so, the probe has two arguments: the
7419 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7420 set a breakpoint there. */
7421 probe
= find_probe_by_pc (get_frame_pc (frame
));
7424 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7428 func
= get_frame_function (frame
);
7434 const struct block
*b
;
7435 struct block_iterator iter
;
7439 /* The exception breakpoint is a thread-specific breakpoint on
7440 the unwinder's debug hook, declared as:
7442 void _Unwind_DebugHook (void *cfa, void *handler);
7444 The CFA argument indicates the frame to which control is
7445 about to be transferred. HANDLER is the destination PC.
7447 We ignore the CFA and set a temporary breakpoint at HANDLER.
7448 This is not extremely efficient but it avoids issues in gdb
7449 with computing the DWARF CFA, and it also works even in weird
7450 cases such as throwing an exception from inside a signal
7453 b
= SYMBOL_BLOCK_VALUE (func
);
7454 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7456 if (!SYMBOL_IS_ARGUMENT (sym
))
7463 insert_exception_resume_breakpoint (ecs
->event_thread
,
7469 catch (const gdb_exception_error
&e
)
7475 stop_waiting (struct execution_control_state
*ecs
)
7478 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7480 /* Let callers know we don't want to wait for the inferior anymore. */
7481 ecs
->wait_some_more
= 0;
7483 /* If all-stop, but the target is always in non-stop mode, stop all
7484 threads now that we're presenting the stop to the user. */
7485 if (!non_stop
&& target_is_non_stop_p ())
7486 stop_all_threads ();
7489 /* Like keep_going, but passes the signal to the inferior, even if the
7490 signal is set to nopass. */
7493 keep_going_pass_signal (struct execution_control_state
*ecs
)
7495 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7496 gdb_assert (!ecs
->event_thread
->resumed
);
7498 /* Save the pc before execution, to compare with pc after stop. */
7499 ecs
->event_thread
->prev_pc
7500 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7502 if (ecs
->event_thread
->control
.trap_expected
)
7504 struct thread_info
*tp
= ecs
->event_thread
;
7507 fprintf_unfiltered (gdb_stdlog
,
7508 "infrun: %s has trap_expected set, "
7509 "resuming to collect trap\n",
7510 target_pid_to_str (tp
->ptid
).c_str ());
7512 /* We haven't yet gotten our trap, and either: intercepted a
7513 non-signal event (e.g., a fork); or took a signal which we
7514 are supposed to pass through to the inferior. Simply
7516 resume (ecs
->event_thread
->suspend
.stop_signal
);
7518 else if (step_over_info_valid_p ())
7520 /* Another thread is stepping over a breakpoint in-line. If
7521 this thread needs a step-over too, queue the request. In
7522 either case, this resume must be deferred for later. */
7523 struct thread_info
*tp
= ecs
->event_thread
;
7525 if (ecs
->hit_singlestep_breakpoint
7526 || thread_still_needs_step_over (tp
))
7529 fprintf_unfiltered (gdb_stdlog
,
7530 "infrun: step-over already in progress: "
7531 "step-over for %s deferred\n",
7532 target_pid_to_str (tp
->ptid
).c_str ());
7533 thread_step_over_chain_enqueue (tp
);
7538 fprintf_unfiltered (gdb_stdlog
,
7539 "infrun: step-over in progress: "
7540 "resume of %s deferred\n",
7541 target_pid_to_str (tp
->ptid
).c_str ());
7546 struct regcache
*regcache
= get_current_regcache ();
7549 step_over_what step_what
;
7551 /* Either the trap was not expected, but we are continuing
7552 anyway (if we got a signal, the user asked it be passed to
7555 We got our expected trap, but decided we should resume from
7558 We're going to run this baby now!
7560 Note that insert_breakpoints won't try to re-insert
7561 already inserted breakpoints. Therefore, we don't
7562 care if breakpoints were already inserted, or not. */
7564 /* If we need to step over a breakpoint, and we're not using
7565 displaced stepping to do so, insert all breakpoints
7566 (watchpoints, etc.) but the one we're stepping over, step one
7567 instruction, and then re-insert the breakpoint when that step
7570 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7572 remove_bp
= (ecs
->hit_singlestep_breakpoint
7573 || (step_what
& STEP_OVER_BREAKPOINT
));
7574 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7576 /* We can't use displaced stepping if we need to step past a
7577 watchpoint. The instruction copied to the scratch pad would
7578 still trigger the watchpoint. */
7580 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7582 set_step_over_info (regcache
->aspace (),
7583 regcache_read_pc (regcache
), remove_wps
,
7584 ecs
->event_thread
->global_num
);
7586 else if (remove_wps
)
7587 set_step_over_info (NULL
, 0, remove_wps
, -1);
7589 /* If we now need to do an in-line step-over, we need to stop
7590 all other threads. Note this must be done before
7591 insert_breakpoints below, because that removes the breakpoint
7592 we're about to step over, otherwise other threads could miss
7594 if (step_over_info_valid_p () && target_is_non_stop_p ())
7595 stop_all_threads ();
7597 /* Stop stepping if inserting breakpoints fails. */
7600 insert_breakpoints ();
7602 catch (const gdb_exception_error
&e
)
7604 exception_print (gdb_stderr
, e
);
7606 clear_step_over_info ();
7610 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7612 resume (ecs
->event_thread
->suspend
.stop_signal
);
7615 prepare_to_wait (ecs
);
7618 /* Called when we should continue running the inferior, because the
7619 current event doesn't cause a user visible stop. This does the
7620 resuming part; waiting for the next event is done elsewhere. */
7623 keep_going (struct execution_control_state
*ecs
)
7625 if (ecs
->event_thread
->control
.trap_expected
7626 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7627 ecs
->event_thread
->control
.trap_expected
= 0;
7629 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7630 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7631 keep_going_pass_signal (ecs
);
7634 /* This function normally comes after a resume, before
7635 handle_inferior_event exits. It takes care of any last bits of
7636 housekeeping, and sets the all-important wait_some_more flag. */
7639 prepare_to_wait (struct execution_control_state
*ecs
)
7642 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
7644 ecs
->wait_some_more
= 1;
7646 if (!target_is_async_p ())
7647 mark_infrun_async_event_handler ();
7650 /* We are done with the step range of a step/next/si/ni command.
7651 Called once for each n of a "step n" operation. */
7654 end_stepping_range (struct execution_control_state
*ecs
)
7656 ecs
->event_thread
->control
.stop_step
= 1;
7660 /* Several print_*_reason functions to print why the inferior has stopped.
7661 We always print something when the inferior exits, or receives a signal.
7662 The rest of the cases are dealt with later on in normal_stop and
7663 print_it_typical. Ideally there should be a call to one of these
7664 print_*_reason functions functions from handle_inferior_event each time
7665 stop_waiting is called.
7667 Note that we don't call these directly, instead we delegate that to
7668 the interpreters, through observers. Interpreters then call these
7669 with whatever uiout is right. */
7672 print_end_stepping_range_reason (struct ui_out
*uiout
)
7674 /* For CLI-like interpreters, print nothing. */
7676 if (uiout
->is_mi_like_p ())
7678 uiout
->field_string ("reason",
7679 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7684 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7686 annotate_signalled ();
7687 if (uiout
->is_mi_like_p ())
7689 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7690 uiout
->text ("\nProgram terminated with signal ");
7691 annotate_signal_name ();
7692 uiout
->field_string ("signal-name",
7693 gdb_signal_to_name (siggnal
));
7694 annotate_signal_name_end ();
7696 annotate_signal_string ();
7697 uiout
->field_string ("signal-meaning",
7698 gdb_signal_to_string (siggnal
));
7699 annotate_signal_string_end ();
7700 uiout
->text (".\n");
7701 uiout
->text ("The program no longer exists.\n");
7705 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7707 struct inferior
*inf
= current_inferior ();
7708 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7710 annotate_exited (exitstatus
);
7713 if (uiout
->is_mi_like_p ())
7714 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7715 std::string exit_code_str
7716 = string_printf ("0%o", (unsigned int) exitstatus
);
7717 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7718 plongest (inf
->num
), pidstr
.c_str (),
7719 string_field ("exit-code", exit_code_str
.c_str ()));
7723 if (uiout
->is_mi_like_p ())
7725 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7726 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7727 plongest (inf
->num
), pidstr
.c_str ());
7731 /* Some targets/architectures can do extra processing/display of
7732 segmentation faults. E.g., Intel MPX boundary faults.
7733 Call the architecture dependent function to handle the fault. */
7736 handle_segmentation_fault (struct ui_out
*uiout
)
7738 struct regcache
*regcache
= get_current_regcache ();
7739 struct gdbarch
*gdbarch
= regcache
->arch ();
7741 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7742 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7746 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7748 struct thread_info
*thr
= inferior_thread ();
7752 if (uiout
->is_mi_like_p ())
7754 else if (show_thread_that_caused_stop ())
7758 uiout
->text ("\nThread ");
7759 uiout
->field_string ("thread-id", print_thread_id (thr
));
7761 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7764 uiout
->text (" \"");
7765 uiout
->field_string ("name", name
);
7770 uiout
->text ("\nProgram");
7772 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
7773 uiout
->text (" stopped");
7776 uiout
->text (" received signal ");
7777 annotate_signal_name ();
7778 if (uiout
->is_mi_like_p ())
7780 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
7781 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
7782 annotate_signal_name_end ();
7784 annotate_signal_string ();
7785 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
7787 if (siggnal
== GDB_SIGNAL_SEGV
)
7788 handle_segmentation_fault (uiout
);
7790 annotate_signal_string_end ();
7792 uiout
->text (".\n");
7796 print_no_history_reason (struct ui_out
*uiout
)
7798 uiout
->text ("\nNo more reverse-execution history.\n");
7801 /* Print current location without a level number, if we have changed
7802 functions or hit a breakpoint. Print source line if we have one.
7803 bpstat_print contains the logic deciding in detail what to print,
7804 based on the event(s) that just occurred. */
7807 print_stop_location (struct target_waitstatus
*ws
)
7810 enum print_what source_flag
;
7811 int do_frame_printing
= 1;
7812 struct thread_info
*tp
= inferior_thread ();
7814 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
7818 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
7819 should) carry around the function and does (or should) use
7820 that when doing a frame comparison. */
7821 if (tp
->control
.stop_step
7822 && frame_id_eq (tp
->control
.step_frame_id
,
7823 get_frame_id (get_current_frame ()))
7824 && (tp
->control
.step_start_function
7825 == find_pc_function (tp
->suspend
.stop_pc
)))
7827 /* Finished step, just print source line. */
7828 source_flag
= SRC_LINE
;
7832 /* Print location and source line. */
7833 source_flag
= SRC_AND_LOC
;
7836 case PRINT_SRC_AND_LOC
:
7837 /* Print location and source line. */
7838 source_flag
= SRC_AND_LOC
;
7840 case PRINT_SRC_ONLY
:
7841 source_flag
= SRC_LINE
;
7844 /* Something bogus. */
7845 source_flag
= SRC_LINE
;
7846 do_frame_printing
= 0;
7849 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
7852 /* The behavior of this routine with respect to the source
7854 SRC_LINE: Print only source line
7855 LOCATION: Print only location
7856 SRC_AND_LOC: Print location and source line. */
7857 if (do_frame_printing
)
7858 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
7864 print_stop_event (struct ui_out
*uiout
, bool displays
)
7866 struct target_waitstatus last
;
7868 struct thread_info
*tp
;
7870 get_last_target_status (&last_ptid
, &last
);
7873 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
7875 print_stop_location (&last
);
7877 /* Display the auto-display expressions. */
7882 tp
= inferior_thread ();
7883 if (tp
->thread_fsm
!= NULL
7884 && tp
->thread_fsm
->finished_p ())
7886 struct return_value_info
*rv
;
7888 rv
= tp
->thread_fsm
->return_value ();
7890 print_return_value (uiout
, rv
);
7897 maybe_remove_breakpoints (void)
7899 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
7901 if (remove_breakpoints ())
7903 target_terminal::ours_for_output ();
7904 printf_filtered (_("Cannot remove breakpoints because "
7905 "program is no longer writable.\nFurther "
7906 "execution is probably impossible.\n"));
7911 /* The execution context that just caused a normal stop. */
7918 DISABLE_COPY_AND_ASSIGN (stop_context
);
7920 bool changed () const;
7925 /* The event PTID. */
7929 /* If stopp for a thread event, this is the thread that caused the
7931 struct thread_info
*thread
;
7933 /* The inferior that caused the stop. */
7937 /* Initializes a new stop context. If stopped for a thread event, this
7938 takes a strong reference to the thread. */
7940 stop_context::stop_context ()
7942 stop_id
= get_stop_id ();
7943 ptid
= inferior_ptid
;
7944 inf_num
= current_inferior ()->num
;
7946 if (inferior_ptid
!= null_ptid
)
7948 /* Take a strong reference so that the thread can't be deleted
7950 thread
= inferior_thread ();
7957 /* Release a stop context previously created with save_stop_context.
7958 Releases the strong reference to the thread as well. */
7960 stop_context::~stop_context ()
7966 /* Return true if the current context no longer matches the saved stop
7970 stop_context::changed () const
7972 if (ptid
!= inferior_ptid
)
7974 if (inf_num
!= current_inferior ()->num
)
7976 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
7978 if (get_stop_id () != stop_id
)
7988 struct target_waitstatus last
;
7991 get_last_target_status (&last_ptid
, &last
);
7995 /* If an exception is thrown from this point on, make sure to
7996 propagate GDB's knowledge of the executing state to the
7997 frontend/user running state. A QUIT is an easy exception to see
7998 here, so do this before any filtered output. */
8000 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8003 maybe_finish_thread_state
.emplace (minus_one_ptid
);
8004 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8005 || last
.kind
== TARGET_WAITKIND_EXITED
)
8007 /* On some targets, we may still have live threads in the
8008 inferior when we get a process exit event. E.g., for
8009 "checkpoint", when the current checkpoint/fork exits,
8010 linux-fork.c automatically switches to another fork from
8011 within target_mourn_inferior. */
8012 if (inferior_ptid
!= null_ptid
)
8013 maybe_finish_thread_state
.emplace (ptid_t (inferior_ptid
.pid ()));
8015 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8016 maybe_finish_thread_state
.emplace (inferior_ptid
);
8018 /* As we're presenting a stop, and potentially removing breakpoints,
8019 update the thread list so we can tell whether there are threads
8020 running on the target. With target remote, for example, we can
8021 only learn about new threads when we explicitly update the thread
8022 list. Do this before notifying the interpreters about signal
8023 stops, end of stepping ranges, etc., so that the "new thread"
8024 output is emitted before e.g., "Program received signal FOO",
8025 instead of after. */
8026 update_thread_list ();
8028 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8029 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8031 /* As with the notification of thread events, we want to delay
8032 notifying the user that we've switched thread context until
8033 the inferior actually stops.
8035 There's no point in saying anything if the inferior has exited.
8036 Note that SIGNALLED here means "exited with a signal", not
8037 "received a signal".
8039 Also skip saying anything in non-stop mode. In that mode, as we
8040 don't want GDB to switch threads behind the user's back, to avoid
8041 races where the user is typing a command to apply to thread x,
8042 but GDB switches to thread y before the user finishes entering
8043 the command, fetch_inferior_event installs a cleanup to restore
8044 the current thread back to the thread the user had selected right
8045 after this event is handled, so we're not really switching, only
8046 informing of a stop. */
8048 && previous_inferior_ptid
!= inferior_ptid
8049 && target_has_execution
8050 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8051 && last
.kind
!= TARGET_WAITKIND_EXITED
8052 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8054 SWITCH_THRU_ALL_UIS ()
8056 target_terminal::ours_for_output ();
8057 printf_filtered (_("[Switching to %s]\n"),
8058 target_pid_to_str (inferior_ptid
).c_str ());
8059 annotate_thread_changed ();
8061 previous_inferior_ptid
= inferior_ptid
;
8064 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8066 SWITCH_THRU_ALL_UIS ()
8067 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8069 target_terminal::ours_for_output ();
8070 printf_filtered (_("No unwaited-for children left.\n"));
8074 /* Note: this depends on the update_thread_list call above. */
8075 maybe_remove_breakpoints ();
8077 /* If an auto-display called a function and that got a signal,
8078 delete that auto-display to avoid an infinite recursion. */
8080 if (stopped_by_random_signal
)
8081 disable_current_display ();
8083 SWITCH_THRU_ALL_UIS ()
8085 async_enable_stdin ();
8088 /* Let the user/frontend see the threads as stopped. */
8089 maybe_finish_thread_state
.reset ();
8091 /* Select innermost stack frame - i.e., current frame is frame 0,
8092 and current location is based on that. Handle the case where the
8093 dummy call is returning after being stopped. E.g. the dummy call
8094 previously hit a breakpoint. (If the dummy call returns
8095 normally, we won't reach here.) Do this before the stop hook is
8096 run, so that it doesn't get to see the temporary dummy frame,
8097 which is not where we'll present the stop. */
8098 if (has_stack_frames ())
8100 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8102 /* Pop the empty frame that contains the stack dummy. This
8103 also restores inferior state prior to the call (struct
8104 infcall_suspend_state). */
8105 struct frame_info
*frame
= get_current_frame ();
8107 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8109 /* frame_pop calls reinit_frame_cache as the last thing it
8110 does which means there's now no selected frame. */
8113 select_frame (get_current_frame ());
8115 /* Set the current source location. */
8116 set_current_sal_from_frame (get_current_frame ());
8119 /* Look up the hook_stop and run it (CLI internally handles problem
8120 of stop_command's pre-hook not existing). */
8121 if (stop_command
!= NULL
)
8123 stop_context saved_context
;
8127 execute_cmd_pre_hook (stop_command
);
8129 catch (const gdb_exception
&ex
)
8131 exception_fprintf (gdb_stderr
, ex
,
8132 "Error while running hook_stop:\n");
8135 /* If the stop hook resumes the target, then there's no point in
8136 trying to notify about the previous stop; its context is
8137 gone. Likewise if the command switches thread or inferior --
8138 the observers would print a stop for the wrong
8140 if (saved_context
.changed ())
8144 /* Notify observers about the stop. This is where the interpreters
8145 print the stop event. */
8146 if (inferior_ptid
!= null_ptid
)
8147 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8150 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8152 annotate_stopped ();
8154 if (target_has_execution
)
8156 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8157 && last
.kind
!= TARGET_WAITKIND_EXITED
8158 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8159 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8160 Delete any breakpoint that is to be deleted at the next stop. */
8161 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8164 /* Try to get rid of automatically added inferiors that are no
8165 longer needed. Keeping those around slows down things linearly.
8166 Note that this never removes the current inferior. */
8173 signal_stop_state (int signo
)
8175 return signal_stop
[signo
];
8179 signal_print_state (int signo
)
8181 return signal_print
[signo
];
8185 signal_pass_state (int signo
)
8187 return signal_program
[signo
];
8191 signal_cache_update (int signo
)
8195 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8196 signal_cache_update (signo
);
8201 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8202 && signal_print
[signo
] == 0
8203 && signal_program
[signo
] == 1
8204 && signal_catch
[signo
] == 0);
8208 signal_stop_update (int signo
, int state
)
8210 int ret
= signal_stop
[signo
];
8212 signal_stop
[signo
] = state
;
8213 signal_cache_update (signo
);
8218 signal_print_update (int signo
, int state
)
8220 int ret
= signal_print
[signo
];
8222 signal_print
[signo
] = state
;
8223 signal_cache_update (signo
);
8228 signal_pass_update (int signo
, int state
)
8230 int ret
= signal_program
[signo
];
8232 signal_program
[signo
] = state
;
8233 signal_cache_update (signo
);
8237 /* Update the global 'signal_catch' from INFO and notify the
8241 signal_catch_update (const unsigned int *info
)
8245 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8246 signal_catch
[i
] = info
[i
] > 0;
8247 signal_cache_update (-1);
8248 target_pass_signals (signal_pass
);
8252 sig_print_header (void)
8254 printf_filtered (_("Signal Stop\tPrint\tPass "
8255 "to program\tDescription\n"));
8259 sig_print_info (enum gdb_signal oursig
)
8261 const char *name
= gdb_signal_to_name (oursig
);
8262 int name_padding
= 13 - strlen (name
);
8264 if (name_padding
<= 0)
8267 printf_filtered ("%s", name
);
8268 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8269 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8270 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8271 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8272 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8275 /* Specify how various signals in the inferior should be handled. */
8278 handle_command (const char *args
, int from_tty
)
8280 int digits
, wordlen
;
8281 int sigfirst
, siglast
;
8282 enum gdb_signal oursig
;
8287 error_no_arg (_("signal to handle"));
8290 /* Allocate and zero an array of flags for which signals to handle. */
8292 const size_t nsigs
= GDB_SIGNAL_LAST
;
8293 unsigned char sigs
[nsigs
] {};
8295 /* Break the command line up into args. */
8297 gdb_argv
built_argv (args
);
8299 /* Walk through the args, looking for signal oursigs, signal names, and
8300 actions. Signal numbers and signal names may be interspersed with
8301 actions, with the actions being performed for all signals cumulatively
8302 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8304 for (char *arg
: built_argv
)
8306 wordlen
= strlen (arg
);
8307 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8311 sigfirst
= siglast
= -1;
8313 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8315 /* Apply action to all signals except those used by the
8316 debugger. Silently skip those. */
8319 siglast
= nsigs
- 1;
8321 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8323 SET_SIGS (nsigs
, sigs
, signal_stop
);
8324 SET_SIGS (nsigs
, sigs
, signal_print
);
8326 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8328 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8330 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8332 SET_SIGS (nsigs
, sigs
, signal_print
);
8334 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8336 SET_SIGS (nsigs
, sigs
, signal_program
);
8338 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8340 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8342 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8344 SET_SIGS (nsigs
, sigs
, signal_program
);
8346 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8348 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8349 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8351 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8353 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8355 else if (digits
> 0)
8357 /* It is numeric. The numeric signal refers to our own
8358 internal signal numbering from target.h, not to host/target
8359 signal number. This is a feature; users really should be
8360 using symbolic names anyway, and the common ones like
8361 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8363 sigfirst
= siglast
= (int)
8364 gdb_signal_from_command (atoi (arg
));
8365 if (arg
[digits
] == '-')
8368 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8370 if (sigfirst
> siglast
)
8372 /* Bet he didn't figure we'd think of this case... */
8373 std::swap (sigfirst
, siglast
);
8378 oursig
= gdb_signal_from_name (arg
);
8379 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8381 sigfirst
= siglast
= (int) oursig
;
8385 /* Not a number and not a recognized flag word => complain. */
8386 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8390 /* If any signal numbers or symbol names were found, set flags for
8391 which signals to apply actions to. */
8393 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8395 switch ((enum gdb_signal
) signum
)
8397 case GDB_SIGNAL_TRAP
:
8398 case GDB_SIGNAL_INT
:
8399 if (!allsigs
&& !sigs
[signum
])
8401 if (query (_("%s is used by the debugger.\n\
8402 Are you sure you want to change it? "),
8403 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8408 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8412 case GDB_SIGNAL_DEFAULT
:
8413 case GDB_SIGNAL_UNKNOWN
:
8414 /* Make sure that "all" doesn't print these. */
8423 for (int signum
= 0; signum
< nsigs
; signum
++)
8426 signal_cache_update (-1);
8427 target_pass_signals (signal_pass
);
8428 target_program_signals (signal_program
);
8432 /* Show the results. */
8433 sig_print_header ();
8434 for (; signum
< nsigs
; signum
++)
8436 sig_print_info ((enum gdb_signal
) signum
);
8443 /* Complete the "handle" command. */
8446 handle_completer (struct cmd_list_element
*ignore
,
8447 completion_tracker
&tracker
,
8448 const char *text
, const char *word
)
8450 static const char * const keywords
[] =
8464 signal_completer (ignore
, tracker
, text
, word
);
8465 complete_on_enum (tracker
, keywords
, word
, word
);
8469 gdb_signal_from_command (int num
)
8471 if (num
>= 1 && num
<= 15)
8472 return (enum gdb_signal
) num
;
8473 error (_("Only signals 1-15 are valid as numeric signals.\n\
8474 Use \"info signals\" for a list of symbolic signals."));
8477 /* Print current contents of the tables set by the handle command.
8478 It is possible we should just be printing signals actually used
8479 by the current target (but for things to work right when switching
8480 targets, all signals should be in the signal tables). */
8483 info_signals_command (const char *signum_exp
, int from_tty
)
8485 enum gdb_signal oursig
;
8487 sig_print_header ();
8491 /* First see if this is a symbol name. */
8492 oursig
= gdb_signal_from_name (signum_exp
);
8493 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8495 /* No, try numeric. */
8497 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8499 sig_print_info (oursig
);
8503 printf_filtered ("\n");
8504 /* These ugly casts brought to you by the native VAX compiler. */
8505 for (oursig
= GDB_SIGNAL_FIRST
;
8506 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8507 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8511 if (oursig
!= GDB_SIGNAL_UNKNOWN
8512 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8513 sig_print_info (oursig
);
8516 printf_filtered (_("\nUse the \"handle\" command "
8517 "to change these tables.\n"));
8520 /* The $_siginfo convenience variable is a bit special. We don't know
8521 for sure the type of the value until we actually have a chance to
8522 fetch the data. The type can change depending on gdbarch, so it is
8523 also dependent on which thread you have selected.
8525 1. making $_siginfo be an internalvar that creates a new value on
8528 2. making the value of $_siginfo be an lval_computed value. */
8530 /* This function implements the lval_computed support for reading a
8534 siginfo_value_read (struct value
*v
)
8536 LONGEST transferred
;
8538 /* If we can access registers, so can we access $_siginfo. Likewise
8540 validate_registers_access ();
8543 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8545 value_contents_all_raw (v
),
8547 TYPE_LENGTH (value_type (v
)));
8549 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8550 error (_("Unable to read siginfo"));
8553 /* This function implements the lval_computed support for writing a
8557 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8559 LONGEST transferred
;
8561 /* If we can access registers, so can we access $_siginfo. Likewise
8563 validate_registers_access ();
8565 transferred
= target_write (current_top_target (),
8566 TARGET_OBJECT_SIGNAL_INFO
,
8568 value_contents_all_raw (fromval
),
8570 TYPE_LENGTH (value_type (fromval
)));
8572 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8573 error (_("Unable to write siginfo"));
8576 static const struct lval_funcs siginfo_value_funcs
=
8582 /* Return a new value with the correct type for the siginfo object of
8583 the current thread using architecture GDBARCH. Return a void value
8584 if there's no object available. */
8586 static struct value
*
8587 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8590 if (target_has_stack
8591 && inferior_ptid
!= null_ptid
8592 && gdbarch_get_siginfo_type_p (gdbarch
))
8594 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8596 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8599 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8603 /* infcall_suspend_state contains state about the program itself like its
8604 registers and any signal it received when it last stopped.
8605 This state must be restored regardless of how the inferior function call
8606 ends (either successfully, or after it hits a breakpoint or signal)
8607 if the program is to properly continue where it left off. */
8609 class infcall_suspend_state
8612 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8613 once the inferior function call has finished. */
8614 infcall_suspend_state (struct gdbarch
*gdbarch
,
8615 const struct thread_info
*tp
,
8616 struct regcache
*regcache
)
8617 : m_thread_suspend (tp
->suspend
),
8618 m_registers (new readonly_detached_regcache (*regcache
))
8620 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8622 if (gdbarch_get_siginfo_type_p (gdbarch
))
8624 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8625 size_t len
= TYPE_LENGTH (type
);
8627 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8629 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8630 siginfo_data
.get (), 0, len
) != len
)
8632 /* Errors ignored. */
8633 siginfo_data
.reset (nullptr);
8639 m_siginfo_gdbarch
= gdbarch
;
8640 m_siginfo_data
= std::move (siginfo_data
);
8644 /* Return a pointer to the stored register state. */
8646 readonly_detached_regcache
*registers () const
8648 return m_registers
.get ();
8651 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8653 void restore (struct gdbarch
*gdbarch
,
8654 struct thread_info
*tp
,
8655 struct regcache
*regcache
) const
8657 tp
->suspend
= m_thread_suspend
;
8659 if (m_siginfo_gdbarch
== gdbarch
)
8661 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8663 /* Errors ignored. */
8664 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8665 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8668 /* The inferior can be gone if the user types "print exit(0)"
8669 (and perhaps other times). */
8670 if (target_has_execution
)
8671 /* NB: The register write goes through to the target. */
8672 regcache
->restore (registers ());
8676 /* How the current thread stopped before the inferior function call was
8678 struct thread_suspend_state m_thread_suspend
;
8680 /* The registers before the inferior function call was executed. */
8681 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8683 /* Format of SIGINFO_DATA or NULL if it is not present. */
8684 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8686 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8687 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8688 content would be invalid. */
8689 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8692 infcall_suspend_state_up
8693 save_infcall_suspend_state ()
8695 struct thread_info
*tp
= inferior_thread ();
8696 struct regcache
*regcache
= get_current_regcache ();
8697 struct gdbarch
*gdbarch
= regcache
->arch ();
8699 infcall_suspend_state_up inf_state
8700 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8702 /* Having saved the current state, adjust the thread state, discarding
8703 any stop signal information. The stop signal is not useful when
8704 starting an inferior function call, and run_inferior_call will not use
8705 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8706 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8711 /* Restore inferior session state to INF_STATE. */
8714 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8716 struct thread_info
*tp
= inferior_thread ();
8717 struct regcache
*regcache
= get_current_regcache ();
8718 struct gdbarch
*gdbarch
= regcache
->arch ();
8720 inf_state
->restore (gdbarch
, tp
, regcache
);
8721 discard_infcall_suspend_state (inf_state
);
8725 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8730 readonly_detached_regcache
*
8731 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8733 return inf_state
->registers ();
8736 /* infcall_control_state contains state regarding gdb's control of the
8737 inferior itself like stepping control. It also contains session state like
8738 the user's currently selected frame. */
8740 struct infcall_control_state
8742 struct thread_control_state thread_control
;
8743 struct inferior_control_state inferior_control
;
8746 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8747 int stopped_by_random_signal
= 0;
8749 /* ID if the selected frame when the inferior function call was made. */
8750 struct frame_id selected_frame_id
{};
8753 /* Save all of the information associated with the inferior<==>gdb
8756 infcall_control_state_up
8757 save_infcall_control_state ()
8759 infcall_control_state_up
inf_status (new struct infcall_control_state
);
8760 struct thread_info
*tp
= inferior_thread ();
8761 struct inferior
*inf
= current_inferior ();
8763 inf_status
->thread_control
= tp
->control
;
8764 inf_status
->inferior_control
= inf
->control
;
8766 tp
->control
.step_resume_breakpoint
= NULL
;
8767 tp
->control
.exception_resume_breakpoint
= NULL
;
8769 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
8770 chain. If caller's caller is walking the chain, they'll be happier if we
8771 hand them back the original chain when restore_infcall_control_state is
8773 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
8776 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
8777 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
8779 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
8785 restore_selected_frame (const frame_id
&fid
)
8787 frame_info
*frame
= frame_find_by_id (fid
);
8789 /* If inf_status->selected_frame_id is NULL, there was no previously
8793 warning (_("Unable to restore previously selected frame."));
8797 select_frame (frame
);
8800 /* Restore inferior session state to INF_STATUS. */
8803 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
8805 struct thread_info
*tp
= inferior_thread ();
8806 struct inferior
*inf
= current_inferior ();
8808 if (tp
->control
.step_resume_breakpoint
)
8809 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
8811 if (tp
->control
.exception_resume_breakpoint
)
8812 tp
->control
.exception_resume_breakpoint
->disposition
8813 = disp_del_at_next_stop
;
8815 /* Handle the bpstat_copy of the chain. */
8816 bpstat_clear (&tp
->control
.stop_bpstat
);
8818 tp
->control
= inf_status
->thread_control
;
8819 inf
->control
= inf_status
->inferior_control
;
8822 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
8823 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
8825 if (target_has_stack
)
8827 /* The point of the try/catch is that if the stack is clobbered,
8828 walking the stack might encounter a garbage pointer and
8829 error() trying to dereference it. */
8832 restore_selected_frame (inf_status
->selected_frame_id
);
8834 catch (const gdb_exception_error
&ex
)
8836 exception_fprintf (gdb_stderr
, ex
,
8837 "Unable to restore previously selected frame:\n");
8838 /* Error in restoring the selected frame. Select the
8840 select_frame (get_current_frame ());
8848 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
8850 if (inf_status
->thread_control
.step_resume_breakpoint
)
8851 inf_status
->thread_control
.step_resume_breakpoint
->disposition
8852 = disp_del_at_next_stop
;
8854 if (inf_status
->thread_control
.exception_resume_breakpoint
)
8855 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
8856 = disp_del_at_next_stop
;
8858 /* See save_infcall_control_state for info on stop_bpstat. */
8859 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
8867 clear_exit_convenience_vars (void)
8869 clear_internalvar (lookup_internalvar ("_exitsignal"));
8870 clear_internalvar (lookup_internalvar ("_exitcode"));
8874 /* User interface for reverse debugging:
8875 Set exec-direction / show exec-direction commands
8876 (returns error unless target implements to_set_exec_direction method). */
8878 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
8879 static const char exec_forward
[] = "forward";
8880 static const char exec_reverse
[] = "reverse";
8881 static const char *exec_direction
= exec_forward
;
8882 static const char *const exec_direction_names
[] = {
8889 set_exec_direction_func (const char *args
, int from_tty
,
8890 struct cmd_list_element
*cmd
)
8892 if (target_can_execute_reverse
)
8894 if (!strcmp (exec_direction
, exec_forward
))
8895 execution_direction
= EXEC_FORWARD
;
8896 else if (!strcmp (exec_direction
, exec_reverse
))
8897 execution_direction
= EXEC_REVERSE
;
8901 exec_direction
= exec_forward
;
8902 error (_("Target does not support this operation."));
8907 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
8908 struct cmd_list_element
*cmd
, const char *value
)
8910 switch (execution_direction
) {
8912 fprintf_filtered (out
, _("Forward.\n"));
8915 fprintf_filtered (out
, _("Reverse.\n"));
8918 internal_error (__FILE__
, __LINE__
,
8919 _("bogus execution_direction value: %d"),
8920 (int) execution_direction
);
8925 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
8926 struct cmd_list_element
*c
, const char *value
)
8928 fprintf_filtered (file
, _("Resuming the execution of threads "
8929 "of all processes is %s.\n"), value
);
8932 /* Implementation of `siginfo' variable. */
8934 static const struct internalvar_funcs siginfo_funcs
=
8941 /* Callback for infrun's target events source. This is marked when a
8942 thread has a pending status to process. */
8945 infrun_async_inferior_event_handler (gdb_client_data data
)
8947 inferior_event_handler (INF_REG_EVENT
, NULL
);
8951 _initialize_infrun (void)
8953 struct cmd_list_element
*c
;
8955 /* Register extra event sources in the event loop. */
8956 infrun_async_inferior_event_token
8957 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
8959 add_info ("signals", info_signals_command
, _("\
8960 What debugger does when program gets various signals.\n\
8961 Specify a signal as argument to print info on that signal only."));
8962 add_info_alias ("handle", "signals", 0);
8964 c
= add_com ("handle", class_run
, handle_command
, _("\
8965 Specify how to handle signals.\n\
8966 Usage: handle SIGNAL [ACTIONS]\n\
8967 Args are signals and actions to apply to those signals.\n\
8968 If no actions are specified, the current settings for the specified signals\n\
8969 will be displayed instead.\n\
8971 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
8972 from 1-15 are allowed for compatibility with old versions of GDB.\n\
8973 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
8974 The special arg \"all\" is recognized to mean all signals except those\n\
8975 used by the debugger, typically SIGTRAP and SIGINT.\n\
8977 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
8978 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
8979 Stop means reenter debugger if this signal happens (implies print).\n\
8980 Print means print a message if this signal happens.\n\
8981 Pass means let program see this signal; otherwise program doesn't know.\n\
8982 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
8983 Pass and Stop may be combined.\n\
8985 Multiple signals may be specified. Signal numbers and signal names\n\
8986 may be interspersed with actions, with the actions being performed for\n\
8987 all signals cumulatively specified."));
8988 set_cmd_completer (c
, handle_completer
);
8991 stop_command
= add_cmd ("stop", class_obscure
,
8992 not_just_help_class_command
, _("\
8993 There is no `stop' command, but you can set a hook on `stop'.\n\
8994 This allows you to set a list of commands to be run each time execution\n\
8995 of the program stops."), &cmdlist
);
8997 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
8998 Set inferior debugging."), _("\
8999 Show inferior debugging."), _("\
9000 When non-zero, inferior specific debugging is enabled."),
9003 &setdebuglist
, &showdebuglist
);
9005 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9006 &debug_displaced
, _("\
9007 Set displaced stepping debugging."), _("\
9008 Show displaced stepping debugging."), _("\
9009 When non-zero, displaced stepping specific debugging is enabled."),
9011 show_debug_displaced
,
9012 &setdebuglist
, &showdebuglist
);
9014 add_setshow_boolean_cmd ("non-stop", no_class
,
9016 Set whether gdb controls the inferior in non-stop mode."), _("\
9017 Show whether gdb controls the inferior in non-stop mode."), _("\
9018 When debugging a multi-threaded program and this setting is\n\
9019 off (the default, also called all-stop mode), when one thread stops\n\
9020 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9021 all other threads in the program while you interact with the thread of\n\
9022 interest. When you continue or step a thread, you can allow the other\n\
9023 threads to run, or have them remain stopped, but while you inspect any\n\
9024 thread's state, all threads stop.\n\
9026 In non-stop mode, when one thread stops, other threads can continue\n\
9027 to run freely. You'll be able to step each thread independently,\n\
9028 leave it stopped or free to run as needed."),
9034 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9037 signal_print
[i
] = 1;
9038 signal_program
[i
] = 1;
9039 signal_catch
[i
] = 0;
9042 /* Signals caused by debugger's own actions should not be given to
9043 the program afterwards.
9045 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9046 explicitly specifies that it should be delivered to the target
9047 program. Typically, that would occur when a user is debugging a
9048 target monitor on a simulator: the target monitor sets a
9049 breakpoint; the simulator encounters this breakpoint and halts
9050 the simulation handing control to GDB; GDB, noting that the stop
9051 address doesn't map to any known breakpoint, returns control back
9052 to the simulator; the simulator then delivers the hardware
9053 equivalent of a GDB_SIGNAL_TRAP to the program being
9055 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9056 signal_program
[GDB_SIGNAL_INT
] = 0;
9058 /* Signals that are not errors should not normally enter the debugger. */
9059 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9060 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9061 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9062 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9063 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9064 signal_print
[GDB_SIGNAL_PROF
] = 0;
9065 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9066 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9067 signal_stop
[GDB_SIGNAL_IO
] = 0;
9068 signal_print
[GDB_SIGNAL_IO
] = 0;
9069 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9070 signal_print
[GDB_SIGNAL_POLL
] = 0;
9071 signal_stop
[GDB_SIGNAL_URG
] = 0;
9072 signal_print
[GDB_SIGNAL_URG
] = 0;
9073 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9074 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9075 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9076 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9078 /* These signals are used internally by user-level thread
9079 implementations. (See signal(5) on Solaris.) Like the above
9080 signals, a healthy program receives and handles them as part of
9081 its normal operation. */
9082 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9083 signal_print
[GDB_SIGNAL_LWP
] = 0;
9084 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9085 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9086 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9087 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9088 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9089 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9091 /* Update cached state. */
9092 signal_cache_update (-1);
9094 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9095 &stop_on_solib_events
, _("\
9096 Set stopping for shared library events."), _("\
9097 Show stopping for shared library events."), _("\
9098 If nonzero, gdb will give control to the user when the dynamic linker\n\
9099 notifies gdb of shared library events. The most common event of interest\n\
9100 to the user would be loading/unloading of a new library."),
9101 set_stop_on_solib_events
,
9102 show_stop_on_solib_events
,
9103 &setlist
, &showlist
);
9105 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9106 follow_fork_mode_kind_names
,
9107 &follow_fork_mode_string
, _("\
9108 Set debugger response to a program call of fork or vfork."), _("\
9109 Show debugger response to a program call of fork or vfork."), _("\
9110 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9111 parent - the original process is debugged after a fork\n\
9112 child - the new process is debugged after a fork\n\
9113 The unfollowed process will continue to run.\n\
9114 By default, the debugger will follow the parent process."),
9116 show_follow_fork_mode_string
,
9117 &setlist
, &showlist
);
9119 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9120 follow_exec_mode_names
,
9121 &follow_exec_mode_string
, _("\
9122 Set debugger response to a program call of exec."), _("\
9123 Show debugger response to a program call of exec."), _("\
9124 An exec call replaces the program image of a process.\n\
9126 follow-exec-mode can be:\n\
9128 new - the debugger creates a new inferior and rebinds the process\n\
9129 to this new inferior. The program the process was running before\n\
9130 the exec call can be restarted afterwards by restarting the original\n\
9133 same - the debugger keeps the process bound to the same inferior.\n\
9134 The new executable image replaces the previous executable loaded in\n\
9135 the inferior. Restarting the inferior after the exec call restarts\n\
9136 the executable the process was running after the exec call.\n\
9138 By default, the debugger will use the same inferior."),
9140 show_follow_exec_mode_string
,
9141 &setlist
, &showlist
);
9143 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9144 scheduler_enums
, &scheduler_mode
, _("\
9145 Set mode for locking scheduler during execution."), _("\
9146 Show mode for locking scheduler during execution."), _("\
9147 off == no locking (threads may preempt at any time)\n\
9148 on == full locking (no thread except the current thread may run)\n\
9149 This applies to both normal execution and replay mode.\n\
9150 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9151 In this mode, other threads may run during other commands.\n\
9152 This applies to both normal execution and replay mode.\n\
9153 replay == scheduler locked in replay mode and unlocked during normal execution."),
9154 set_schedlock_func
, /* traps on target vector */
9155 show_scheduler_mode
,
9156 &setlist
, &showlist
);
9158 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9159 Set mode for resuming threads of all processes."), _("\
9160 Show mode for resuming threads of all processes."), _("\
9161 When on, execution commands (such as 'continue' or 'next') resume all\n\
9162 threads of all processes. When off (which is the default), execution\n\
9163 commands only resume the threads of the current process. The set of\n\
9164 threads that are resumed is further refined by the scheduler-locking\n\
9165 mode (see help set scheduler-locking)."),
9167 show_schedule_multiple
,
9168 &setlist
, &showlist
);
9170 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9171 Set mode of the step operation."), _("\
9172 Show mode of the step operation."), _("\
9173 When set, doing a step over a function without debug line information\n\
9174 will stop at the first instruction of that function. Otherwise, the\n\
9175 function is skipped and the step command stops at a different source line."),
9177 show_step_stop_if_no_debug
,
9178 &setlist
, &showlist
);
9180 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9181 &can_use_displaced_stepping
, _("\
9182 Set debugger's willingness to use displaced stepping."), _("\
9183 Show debugger's willingness to use displaced stepping."), _("\
9184 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9185 supported by the target architecture. If off, gdb will not use displaced\n\
9186 stepping to step over breakpoints, even if such is supported by the target\n\
9187 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9188 if the target architecture supports it and non-stop mode is active, but will not\n\
9189 use it in all-stop mode (see help set non-stop)."),
9191 show_can_use_displaced_stepping
,
9192 &setlist
, &showlist
);
9194 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9195 &exec_direction
, _("Set direction of execution.\n\
9196 Options are 'forward' or 'reverse'."),
9197 _("Show direction of execution (forward/reverse)."),
9198 _("Tells gdb whether to execute forward or backward."),
9199 set_exec_direction_func
, show_exec_direction_func
,
9200 &setlist
, &showlist
);
9202 /* Set/show detach-on-fork: user-settable mode. */
9204 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9205 Set whether gdb will detach the child of a fork."), _("\
9206 Show whether gdb will detach the child of a fork."), _("\
9207 Tells gdb whether to detach the child of a fork."),
9208 NULL
, NULL
, &setlist
, &showlist
);
9210 /* Set/show disable address space randomization mode. */
9212 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9213 &disable_randomization
, _("\
9214 Set disabling of debuggee's virtual address space randomization."), _("\
9215 Show disabling of debuggee's virtual address space randomization."), _("\
9216 When this mode is on (which is the default), randomization of the virtual\n\
9217 address space is disabled. Standalone programs run with the randomization\n\
9218 enabled by default on some platforms."),
9219 &set_disable_randomization
,
9220 &show_disable_randomization
,
9221 &setlist
, &showlist
);
9223 /* ptid initializations */
9224 inferior_ptid
= null_ptid
;
9225 target_last_wait_ptid
= minus_one_ptid
;
9227 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9228 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9229 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9230 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9232 /* Explicitly create without lookup, since that tries to create a
9233 value with a void typed value, and when we get here, gdbarch
9234 isn't initialized yet. At this point, we're quite sure there
9235 isn't another convenience variable of the same name. */
9236 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9238 add_setshow_boolean_cmd ("observer", no_class
,
9239 &observer_mode_1
, _("\
9240 Set whether gdb controls the inferior in observer mode."), _("\
9241 Show whether gdb controls the inferior in observer mode."), _("\
9242 In observer mode, GDB can get data from the inferior, but not\n\
9243 affect its execution. Registers and memory may not be changed,\n\
9244 breakpoints may not be set, and the program cannot be interrupted\n\