1 /* Target-struct-independent code to start (run) and stop an inferior
4 Copyright (C) 1986-2020 Free Software Foundation, Inc.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
27 #include "breakpoint.h"
31 #include "target-connection.h"
32 #include "gdbthread.h"
39 #include "observable.h"
44 #include "mi/mi-common.h"
45 #include "event-top.h"
47 #include "record-full.h"
48 #include "inline-frame.h"
50 #include "tracepoint.h"
54 #include "completer.h"
55 #include "target-descriptions.h"
56 #include "target-dcache.h"
59 #include "event-loop.h"
60 #include "thread-fsm.h"
61 #include "gdbsupport/enum-flags.h"
62 #include "progspace-and-thread.h"
63 #include "gdbsupport/gdb_optional.h"
64 #include "arch-utils.h"
65 #include "gdbsupport/scope-exit.h"
66 #include "gdbsupport/forward-scope-exit.h"
67 #include "gdb_select.h"
68 #include <unordered_map>
70 /* Prototypes for local functions */
72 static void sig_print_info (enum gdb_signal
);
74 static void sig_print_header (void);
76 static int follow_fork (void);
78 static int follow_fork_inferior (int follow_child
, int detach_fork
);
80 static void follow_inferior_reset_breakpoints (void);
82 static int currently_stepping (struct thread_info
*tp
);
84 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
86 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
88 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
90 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
92 static void resume (gdb_signal sig
);
94 static void wait_for_inferior (inferior
*inf
);
96 /* Asynchronous signal handler registered as event loop source for
97 when we have pending events ready to be passed to the core. */
98 static struct async_event_handler
*infrun_async_inferior_event_token
;
100 /* Stores whether infrun_async was previously enabled or disabled.
101 Starts off as -1, indicating "never enabled/disabled". */
102 static int infrun_is_async
= -1;
107 infrun_async (int enable
)
109 if (infrun_is_async
!= enable
)
111 infrun_is_async
= enable
;
114 fprintf_unfiltered (gdb_stdlog
,
115 "infrun: infrun_async(%d)\n",
119 mark_async_event_handler (infrun_async_inferior_event_token
);
121 clear_async_event_handler (infrun_async_inferior_event_token
);
128 mark_infrun_async_event_handler (void)
130 mark_async_event_handler (infrun_async_inferior_event_token
);
133 /* When set, stop the 'step' command if we enter a function which has
134 no line number information. The normal behavior is that we step
135 over such function. */
136 bool step_stop_if_no_debug
= false;
138 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
139 struct cmd_list_element
*c
, const char *value
)
141 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
144 /* proceed and normal_stop use this to notify the user when the
145 inferior stopped in a different thread than it had been running
148 static ptid_t previous_inferior_ptid
;
150 /* If set (default for legacy reasons), when following a fork, GDB
151 will detach from one of the fork branches, child or parent.
152 Exactly which branch is detached depends on 'set follow-fork-mode'
155 static bool detach_fork
= true;
157 bool debug_displaced
= false;
159 show_debug_displaced (struct ui_file
*file
, int from_tty
,
160 struct cmd_list_element
*c
, const char *value
)
162 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
165 unsigned int debug_infrun
= 0;
167 show_debug_infrun (struct ui_file
*file
, int from_tty
,
168 struct cmd_list_element
*c
, const char *value
)
170 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
174 /* Support for disabling address space randomization. */
176 bool disable_randomization
= true;
179 show_disable_randomization (struct ui_file
*file
, int from_tty
,
180 struct cmd_list_element
*c
, const char *value
)
182 if (target_supports_disable_randomization ())
183 fprintf_filtered (file
,
184 _("Disabling randomization of debuggee's "
185 "virtual address space is %s.\n"),
188 fputs_filtered (_("Disabling randomization of debuggee's "
189 "virtual address space is unsupported on\n"
190 "this platform.\n"), file
);
194 set_disable_randomization (const char *args
, int from_tty
,
195 struct cmd_list_element
*c
)
197 if (!target_supports_disable_randomization ())
198 error (_("Disabling randomization of debuggee's "
199 "virtual address space is unsupported on\n"
203 /* User interface for non-stop mode. */
205 bool non_stop
= false;
206 static bool non_stop_1
= false;
209 set_non_stop (const char *args
, int from_tty
,
210 struct cmd_list_element
*c
)
212 if (target_has_execution
)
214 non_stop_1
= non_stop
;
215 error (_("Cannot change this setting while the inferior is running."));
218 non_stop
= non_stop_1
;
222 show_non_stop (struct ui_file
*file
, int from_tty
,
223 struct cmd_list_element
*c
, const char *value
)
225 fprintf_filtered (file
,
226 _("Controlling the inferior in non-stop mode is %s.\n"),
230 /* "Observer mode" is somewhat like a more extreme version of
231 non-stop, in which all GDB operations that might affect the
232 target's execution have been disabled. */
234 bool observer_mode
= false;
235 static bool observer_mode_1
= false;
238 set_observer_mode (const char *args
, int from_tty
,
239 struct cmd_list_element
*c
)
241 if (target_has_execution
)
243 observer_mode_1
= observer_mode
;
244 error (_("Cannot change this setting while the inferior is running."));
247 observer_mode
= observer_mode_1
;
249 may_write_registers
= !observer_mode
;
250 may_write_memory
= !observer_mode
;
251 may_insert_breakpoints
= !observer_mode
;
252 may_insert_tracepoints
= !observer_mode
;
253 /* We can insert fast tracepoints in or out of observer mode,
254 but enable them if we're going into this mode. */
256 may_insert_fast_tracepoints
= true;
257 may_stop
= !observer_mode
;
258 update_target_permissions ();
260 /* Going *into* observer mode we must force non-stop, then
261 going out we leave it that way. */
264 pagination_enabled
= 0;
265 non_stop
= non_stop_1
= true;
269 printf_filtered (_("Observer mode is now %s.\n"),
270 (observer_mode
? "on" : "off"));
274 show_observer_mode (struct ui_file
*file
, int from_tty
,
275 struct cmd_list_element
*c
, const char *value
)
277 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
280 /* This updates the value of observer mode based on changes in
281 permissions. Note that we are deliberately ignoring the values of
282 may-write-registers and may-write-memory, since the user may have
283 reason to enable these during a session, for instance to turn on a
284 debugging-related global. */
287 update_observer_mode (void)
289 bool newval
= (!may_insert_breakpoints
290 && !may_insert_tracepoints
291 && may_insert_fast_tracepoints
295 /* Let the user know if things change. */
296 if (newval
!= observer_mode
)
297 printf_filtered (_("Observer mode is now %s.\n"),
298 (newval
? "on" : "off"));
300 observer_mode
= observer_mode_1
= newval
;
303 /* Tables of how to react to signals; the user sets them. */
305 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
306 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
307 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
309 /* Table of signals that are registered with "catch signal". A
310 non-zero entry indicates that the signal is caught by some "catch
312 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
314 /* Table of signals that the target may silently handle.
315 This is automatically determined from the flags above,
316 and simply cached here. */
317 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
319 #define SET_SIGS(nsigs,sigs,flags) \
321 int signum = (nsigs); \
322 while (signum-- > 0) \
323 if ((sigs)[signum]) \
324 (flags)[signum] = 1; \
327 #define UNSET_SIGS(nsigs,sigs,flags) \
329 int signum = (nsigs); \
330 while (signum-- > 0) \
331 if ((sigs)[signum]) \
332 (flags)[signum] = 0; \
335 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
336 this function is to avoid exporting `signal_program'. */
339 update_signals_program_target (void)
341 target_program_signals (signal_program
);
344 /* Value to pass to target_resume() to cause all threads to resume. */
346 #define RESUME_ALL minus_one_ptid
348 /* Command list pointer for the "stop" placeholder. */
350 static struct cmd_list_element
*stop_command
;
352 /* Nonzero if we want to give control to the user when we're notified
353 of shared library events by the dynamic linker. */
354 int stop_on_solib_events
;
356 /* Enable or disable optional shared library event breakpoints
357 as appropriate when the above flag is changed. */
360 set_stop_on_solib_events (const char *args
,
361 int from_tty
, struct cmd_list_element
*c
)
363 update_solib_breakpoints ();
367 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
368 struct cmd_list_element
*c
, const char *value
)
370 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
374 /* Nonzero after stop if current stack frame should be printed. */
376 static int stop_print_frame
;
378 /* This is a cached copy of the target/ptid/waitstatus of the last
379 event returned by target_wait()/deprecated_target_wait_hook().
380 This information is returned by get_last_target_status(). */
381 static process_stratum_target
*target_last_proc_target
;
382 static ptid_t target_last_wait_ptid
;
383 static struct target_waitstatus target_last_waitstatus
;
385 void init_thread_stepping_state (struct thread_info
*tss
);
387 static const char follow_fork_mode_child
[] = "child";
388 static const char follow_fork_mode_parent
[] = "parent";
390 static const char *const follow_fork_mode_kind_names
[] = {
391 follow_fork_mode_child
,
392 follow_fork_mode_parent
,
396 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
398 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
399 struct cmd_list_element
*c
, const char *value
)
401 fprintf_filtered (file
,
402 _("Debugger response to a program "
403 "call of fork or vfork is \"%s\".\n"),
408 /* Handle changes to the inferior list based on the type of fork,
409 which process is being followed, and whether the other process
410 should be detached. On entry inferior_ptid must be the ptid of
411 the fork parent. At return inferior_ptid is the ptid of the
412 followed inferior. */
415 follow_fork_inferior (int follow_child
, int detach_fork
)
418 ptid_t parent_ptid
, child_ptid
;
420 has_vforked
= (inferior_thread ()->pending_follow
.kind
421 == TARGET_WAITKIND_VFORKED
);
422 parent_ptid
= inferior_ptid
;
423 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
426 && !non_stop
/* Non-stop always resumes both branches. */
427 && current_ui
->prompt_state
== PROMPT_BLOCKED
428 && !(follow_child
|| detach_fork
|| sched_multi
))
430 /* The parent stays blocked inside the vfork syscall until the
431 child execs or exits. If we don't let the child run, then
432 the parent stays blocked. If we're telling the parent to run
433 in the foreground, the user will not be able to ctrl-c to get
434 back the terminal, effectively hanging the debug session. */
435 fprintf_filtered (gdb_stderr
, _("\
436 Can not resume the parent process over vfork in the foreground while\n\
437 holding the child stopped. Try \"set detach-on-fork\" or \
438 \"set schedule-multiple\".\n"));
444 /* Detach new forked process? */
447 /* Before detaching from the child, remove all breakpoints
448 from it. If we forked, then this has already been taken
449 care of by infrun.c. If we vforked however, any
450 breakpoint inserted in the parent is visible in the
451 child, even those added while stopped in a vfork
452 catchpoint. This will remove the breakpoints from the
453 parent also, but they'll be reinserted below. */
456 /* Keep breakpoints list in sync. */
457 remove_breakpoints_inf (current_inferior ());
460 if (print_inferior_events
)
462 /* Ensure that we have a process ptid. */
463 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
465 target_terminal::ours_for_output ();
466 fprintf_filtered (gdb_stdlog
,
467 _("[Detaching after %s from child %s]\n"),
468 has_vforked
? "vfork" : "fork",
469 target_pid_to_str (process_ptid
).c_str ());
474 struct inferior
*parent_inf
, *child_inf
;
476 /* Add process to GDB's tables. */
477 child_inf
= add_inferior (child_ptid
.pid ());
479 parent_inf
= current_inferior ();
480 child_inf
->attach_flag
= parent_inf
->attach_flag
;
481 copy_terminal_info (child_inf
, parent_inf
);
482 child_inf
->gdbarch
= parent_inf
->gdbarch
;
483 copy_inferior_target_desc_info (child_inf
, parent_inf
);
485 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
487 set_current_inferior (child_inf
);
488 switch_to_no_thread ();
489 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
490 push_target (parent_inf
->process_target ());
491 add_thread_silent (child_inf
->process_target (), child_ptid
);
492 inferior_ptid
= child_ptid
;
494 /* If this is a vfork child, then the address-space is
495 shared with the parent. */
498 child_inf
->pspace
= parent_inf
->pspace
;
499 child_inf
->aspace
= parent_inf
->aspace
;
503 /* The parent will be frozen until the child is done
504 with the shared region. Keep track of the
506 child_inf
->vfork_parent
= parent_inf
;
507 child_inf
->pending_detach
= 0;
508 parent_inf
->vfork_child
= child_inf
;
509 parent_inf
->pending_detach
= 0;
513 child_inf
->aspace
= new_address_space ();
514 child_inf
->pspace
= new program_space (child_inf
->aspace
);
515 child_inf
->removable
= 1;
516 set_current_program_space (child_inf
->pspace
);
517 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
519 /* Let the shared library layer (e.g., solib-svr4) learn
520 about this new process, relocate the cloned exec, pull
521 in shared libraries, and install the solib event
522 breakpoint. If a "cloned-VM" event was propagated
523 better throughout the core, this wouldn't be
525 solib_create_inferior_hook (0);
531 struct inferior
*parent_inf
;
533 parent_inf
= current_inferior ();
535 /* If we detached from the child, then we have to be careful
536 to not insert breakpoints in the parent until the child
537 is done with the shared memory region. However, if we're
538 staying attached to the child, then we can and should
539 insert breakpoints, so that we can debug it. A
540 subsequent child exec or exit is enough to know when does
541 the child stops using the parent's address space. */
542 parent_inf
->waiting_for_vfork_done
= detach_fork
;
543 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
548 /* Follow the child. */
549 struct inferior
*parent_inf
, *child_inf
;
550 struct program_space
*parent_pspace
;
552 if (print_inferior_events
)
554 std::string parent_pid
= target_pid_to_str (parent_ptid
);
555 std::string child_pid
= target_pid_to_str (child_ptid
);
557 target_terminal::ours_for_output ();
558 fprintf_filtered (gdb_stdlog
,
559 _("[Attaching after %s %s to child %s]\n"),
561 has_vforked
? "vfork" : "fork",
565 /* Add the new inferior first, so that the target_detach below
566 doesn't unpush the target. */
568 child_inf
= add_inferior (child_ptid
.pid ());
570 parent_inf
= current_inferior ();
571 child_inf
->attach_flag
= parent_inf
->attach_flag
;
572 copy_terminal_info (child_inf
, parent_inf
);
573 child_inf
->gdbarch
= parent_inf
->gdbarch
;
574 copy_inferior_target_desc_info (child_inf
, parent_inf
);
576 parent_pspace
= parent_inf
->pspace
;
578 process_stratum_target
*target
= parent_inf
->process_target ();
581 /* Hold a strong reference to the target while (maybe)
582 detaching the parent. Otherwise detaching could close the
584 auto target_ref
= target_ops_ref::new_reference (target
);
586 /* If we're vforking, we want to hold on to the parent until
587 the child exits or execs. At child exec or exit time we
588 can remove the old breakpoints from the parent and detach
589 or resume debugging it. Otherwise, detach the parent now;
590 we'll want to reuse it's program/address spaces, but we
591 can't set them to the child before removing breakpoints
592 from the parent, otherwise, the breakpoints module could
593 decide to remove breakpoints from the wrong process (since
594 they'd be assigned to the same address space). */
598 gdb_assert (child_inf
->vfork_parent
== NULL
);
599 gdb_assert (parent_inf
->vfork_child
== NULL
);
600 child_inf
->vfork_parent
= parent_inf
;
601 child_inf
->pending_detach
= 0;
602 parent_inf
->vfork_child
= child_inf
;
603 parent_inf
->pending_detach
= detach_fork
;
604 parent_inf
->waiting_for_vfork_done
= 0;
606 else if (detach_fork
)
608 if (print_inferior_events
)
610 /* Ensure that we have a process ptid. */
611 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
613 target_terminal::ours_for_output ();
614 fprintf_filtered (gdb_stdlog
,
615 _("[Detaching after fork from "
617 target_pid_to_str (process_ptid
).c_str ());
620 target_detach (parent_inf
, 0);
624 /* Note that the detach above makes PARENT_INF dangling. */
626 /* Add the child thread to the appropriate lists, and switch
627 to this new thread, before cloning the program space, and
628 informing the solib layer about this new process. */
630 set_current_inferior (child_inf
);
631 push_target (target
);
634 add_thread_silent (target
, child_ptid
);
635 inferior_ptid
= child_ptid
;
637 /* If this is a vfork child, then the address-space is shared
638 with the parent. If we detached from the parent, then we can
639 reuse the parent's program/address spaces. */
640 if (has_vforked
|| detach_fork
)
642 child_inf
->pspace
= parent_pspace
;
643 child_inf
->aspace
= child_inf
->pspace
->aspace
;
649 child_inf
->aspace
= new_address_space ();
650 child_inf
->pspace
= new program_space (child_inf
->aspace
);
651 child_inf
->removable
= 1;
652 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
653 set_current_program_space (child_inf
->pspace
);
654 clone_program_space (child_inf
->pspace
, parent_pspace
);
656 /* Let the shared library layer (e.g., solib-svr4) learn
657 about this new process, relocate the cloned exec, pull in
658 shared libraries, and install the solib event breakpoint.
659 If a "cloned-VM" event was propagated better throughout
660 the core, this wouldn't be required. */
661 solib_create_inferior_hook (0);
665 return target_follow_fork (follow_child
, detach_fork
);
668 /* Tell the target to follow the fork we're stopped at. Returns true
669 if the inferior should be resumed; false, if the target for some
670 reason decided it's best not to resume. */
675 int follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
676 int should_resume
= 1;
677 struct thread_info
*tp
;
679 /* Copy user stepping state to the new inferior thread. FIXME: the
680 followed fork child thread should have a copy of most of the
681 parent thread structure's run control related fields, not just these.
682 Initialized to avoid "may be used uninitialized" warnings from gcc. */
683 struct breakpoint
*step_resume_breakpoint
= NULL
;
684 struct breakpoint
*exception_resume_breakpoint
= NULL
;
685 CORE_ADDR step_range_start
= 0;
686 CORE_ADDR step_range_end
= 0;
687 struct frame_id step_frame_id
= { 0 };
688 struct thread_fsm
*thread_fsm
= NULL
;
692 process_stratum_target
*wait_target
;
694 struct target_waitstatus wait_status
;
696 /* Get the last target status returned by target_wait(). */
697 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
699 /* If not stopped at a fork event, then there's nothing else to
701 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
702 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
705 /* Check if we switched over from WAIT_PTID, since the event was
707 if (wait_ptid
!= minus_one_ptid
708 && (current_inferior ()->process_target () != wait_target
709 || inferior_ptid
!= wait_ptid
))
711 /* We did. Switch back to WAIT_PTID thread, to tell the
712 target to follow it (in either direction). We'll
713 afterwards refuse to resume, and inform the user what
715 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
716 switch_to_thread (wait_thread
);
721 tp
= inferior_thread ();
723 /* If there were any forks/vforks that were caught and are now to be
724 followed, then do so now. */
725 switch (tp
->pending_follow
.kind
)
727 case TARGET_WAITKIND_FORKED
:
728 case TARGET_WAITKIND_VFORKED
:
730 ptid_t parent
, child
;
732 /* If the user did a next/step, etc, over a fork call,
733 preserve the stepping state in the fork child. */
734 if (follow_child
&& should_resume
)
736 step_resume_breakpoint
= clone_momentary_breakpoint
737 (tp
->control
.step_resume_breakpoint
);
738 step_range_start
= tp
->control
.step_range_start
;
739 step_range_end
= tp
->control
.step_range_end
;
740 step_frame_id
= tp
->control
.step_frame_id
;
741 exception_resume_breakpoint
742 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
743 thread_fsm
= tp
->thread_fsm
;
745 /* For now, delete the parent's sr breakpoint, otherwise,
746 parent/child sr breakpoints are considered duplicates,
747 and the child version will not be installed. Remove
748 this when the breakpoints module becomes aware of
749 inferiors and address spaces. */
750 delete_step_resume_breakpoint (tp
);
751 tp
->control
.step_range_start
= 0;
752 tp
->control
.step_range_end
= 0;
753 tp
->control
.step_frame_id
= null_frame_id
;
754 delete_exception_resume_breakpoint (tp
);
755 tp
->thread_fsm
= NULL
;
758 parent
= inferior_ptid
;
759 child
= tp
->pending_follow
.value
.related_pid
;
761 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
762 /* Set up inferior(s) as specified by the caller, and tell the
763 target to do whatever is necessary to follow either parent
765 if (follow_fork_inferior (follow_child
, detach_fork
))
767 /* Target refused to follow, or there's some other reason
768 we shouldn't resume. */
773 /* This pending follow fork event is now handled, one way
774 or another. The previous selected thread may be gone
775 from the lists by now, but if it is still around, need
776 to clear the pending follow request. */
777 tp
= find_thread_ptid (parent_targ
, parent
);
779 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
781 /* This makes sure we don't try to apply the "Switched
782 over from WAIT_PID" logic above. */
783 nullify_last_target_wait_ptid ();
785 /* If we followed the child, switch to it... */
788 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
789 switch_to_thread (child_thr
);
791 /* ... and preserve the stepping state, in case the
792 user was stepping over the fork call. */
795 tp
= inferior_thread ();
796 tp
->control
.step_resume_breakpoint
797 = step_resume_breakpoint
;
798 tp
->control
.step_range_start
= step_range_start
;
799 tp
->control
.step_range_end
= step_range_end
;
800 tp
->control
.step_frame_id
= step_frame_id
;
801 tp
->control
.exception_resume_breakpoint
802 = exception_resume_breakpoint
;
803 tp
->thread_fsm
= thread_fsm
;
807 /* If we get here, it was because we're trying to
808 resume from a fork catchpoint, but, the user
809 has switched threads away from the thread that
810 forked. In that case, the resume command
811 issued is most likely not applicable to the
812 child, so just warn, and refuse to resume. */
813 warning (_("Not resuming: switched threads "
814 "before following fork child."));
817 /* Reset breakpoints in the child as appropriate. */
818 follow_inferior_reset_breakpoints ();
823 case TARGET_WAITKIND_SPURIOUS
:
824 /* Nothing to follow. */
827 internal_error (__FILE__
, __LINE__
,
828 "Unexpected pending_follow.kind %d\n",
829 tp
->pending_follow
.kind
);
833 return should_resume
;
837 follow_inferior_reset_breakpoints (void)
839 struct thread_info
*tp
= inferior_thread ();
841 /* Was there a step_resume breakpoint? (There was if the user
842 did a "next" at the fork() call.) If so, explicitly reset its
843 thread number. Cloned step_resume breakpoints are disabled on
844 creation, so enable it here now that it is associated with the
847 step_resumes are a form of bp that are made to be per-thread.
848 Since we created the step_resume bp when the parent process
849 was being debugged, and now are switching to the child process,
850 from the breakpoint package's viewpoint, that's a switch of
851 "threads". We must update the bp's notion of which thread
852 it is for, or it'll be ignored when it triggers. */
854 if (tp
->control
.step_resume_breakpoint
)
856 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
857 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
860 /* Treat exception_resume breakpoints like step_resume breakpoints. */
861 if (tp
->control
.exception_resume_breakpoint
)
863 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
864 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
867 /* Reinsert all breakpoints in the child. The user may have set
868 breakpoints after catching the fork, in which case those
869 were never set in the child, but only in the parent. This makes
870 sure the inserted breakpoints match the breakpoint list. */
872 breakpoint_re_set ();
873 insert_breakpoints ();
876 /* The child has exited or execed: resume threads of the parent the
877 user wanted to be executing. */
880 proceed_after_vfork_done (struct thread_info
*thread
,
883 int pid
= * (int *) arg
;
885 if (thread
->ptid
.pid () == pid
886 && thread
->state
== THREAD_RUNNING
887 && !thread
->executing
888 && !thread
->stop_requested
889 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
892 fprintf_unfiltered (gdb_stdlog
,
893 "infrun: resuming vfork parent thread %s\n",
894 target_pid_to_str (thread
->ptid
).c_str ());
896 switch_to_thread (thread
);
897 clear_proceed_status (0);
898 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
904 /* Save/restore inferior_ptid, current program space and current
905 inferior. Only use this if the current context points at an exited
906 inferior (and therefore there's no current thread to save). */
907 class scoped_restore_exited_inferior
910 scoped_restore_exited_inferior ()
911 : m_saved_ptid (&inferior_ptid
)
915 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
916 scoped_restore_current_program_space m_pspace
;
917 scoped_restore_current_inferior m_inferior
;
920 /* Called whenever we notice an exec or exit event, to handle
921 detaching or resuming a vfork parent. */
924 handle_vfork_child_exec_or_exit (int exec
)
926 struct inferior
*inf
= current_inferior ();
928 if (inf
->vfork_parent
)
930 int resume_parent
= -1;
932 /* This exec or exit marks the end of the shared memory region
933 between the parent and the child. Break the bonds. */
934 inferior
*vfork_parent
= inf
->vfork_parent
;
935 inf
->vfork_parent
->vfork_child
= NULL
;
936 inf
->vfork_parent
= NULL
;
938 /* If the user wanted to detach from the parent, now is the
940 if (vfork_parent
->pending_detach
)
942 struct thread_info
*tp
;
943 struct program_space
*pspace
;
944 struct address_space
*aspace
;
946 /* follow-fork child, detach-on-fork on. */
948 vfork_parent
->pending_detach
= 0;
950 gdb::optional
<scoped_restore_exited_inferior
>
951 maybe_restore_inferior
;
952 gdb::optional
<scoped_restore_current_pspace_and_thread
>
953 maybe_restore_thread
;
955 /* If we're handling a child exit, then inferior_ptid points
956 at the inferior's pid, not to a thread. */
958 maybe_restore_inferior
.emplace ();
960 maybe_restore_thread
.emplace ();
962 /* We're letting loose of the parent. */
963 tp
= any_live_thread_of_inferior (vfork_parent
);
964 switch_to_thread (tp
);
966 /* We're about to detach from the parent, which implicitly
967 removes breakpoints from its address space. There's a
968 catch here: we want to reuse the spaces for the child,
969 but, parent/child are still sharing the pspace at this
970 point, although the exec in reality makes the kernel give
971 the child a fresh set of new pages. The problem here is
972 that the breakpoints module being unaware of this, would
973 likely chose the child process to write to the parent
974 address space. Swapping the child temporarily away from
975 the spaces has the desired effect. Yes, this is "sort
978 pspace
= inf
->pspace
;
979 aspace
= inf
->aspace
;
983 if (print_inferior_events
)
986 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
988 target_terminal::ours_for_output ();
992 fprintf_filtered (gdb_stdlog
,
993 _("[Detaching vfork parent %s "
994 "after child exec]\n"), pidstr
.c_str ());
998 fprintf_filtered (gdb_stdlog
,
999 _("[Detaching vfork parent %s "
1000 "after child exit]\n"), pidstr
.c_str ());
1004 target_detach (vfork_parent
, 0);
1007 inf
->pspace
= pspace
;
1008 inf
->aspace
= aspace
;
1012 /* We're staying attached to the parent, so, really give the
1013 child a new address space. */
1014 inf
->pspace
= new program_space (maybe_new_address_space ());
1015 inf
->aspace
= inf
->pspace
->aspace
;
1017 set_current_program_space (inf
->pspace
);
1019 resume_parent
= vfork_parent
->pid
;
1023 /* If this is a vfork child exiting, then the pspace and
1024 aspaces were shared with the parent. Since we're
1025 reporting the process exit, we'll be mourning all that is
1026 found in the address space, and switching to null_ptid,
1027 preparing to start a new inferior. But, since we don't
1028 want to clobber the parent's address/program spaces, we
1029 go ahead and create a new one for this exiting
1032 /* Switch to null_ptid while running clone_program_space, so
1033 that clone_program_space doesn't want to read the
1034 selected frame of a dead process. */
1035 scoped_restore restore_ptid
1036 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1038 inf
->pspace
= new program_space (maybe_new_address_space ());
1039 inf
->aspace
= inf
->pspace
->aspace
;
1040 set_current_program_space (inf
->pspace
);
1042 inf
->symfile_flags
= SYMFILE_NO_READ
;
1043 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1045 resume_parent
= vfork_parent
->pid
;
1048 gdb_assert (current_program_space
== inf
->pspace
);
1050 if (non_stop
&& resume_parent
!= -1)
1052 /* If the user wanted the parent to be running, let it go
1054 scoped_restore_current_thread restore_thread
;
1057 fprintf_unfiltered (gdb_stdlog
,
1058 "infrun: resuming vfork parent process %d\n",
1061 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1066 /* Enum strings for "set|show follow-exec-mode". */
1068 static const char follow_exec_mode_new
[] = "new";
1069 static const char follow_exec_mode_same
[] = "same";
1070 static const char *const follow_exec_mode_names
[] =
1072 follow_exec_mode_new
,
1073 follow_exec_mode_same
,
1077 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1079 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1080 struct cmd_list_element
*c
, const char *value
)
1082 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1085 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1088 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1090 struct inferior
*inf
= current_inferior ();
1091 int pid
= ptid
.pid ();
1092 ptid_t process_ptid
;
1094 /* Switch terminal for any messages produced e.g. by
1095 breakpoint_re_set. */
1096 target_terminal::ours_for_output ();
1098 /* This is an exec event that we actually wish to pay attention to.
1099 Refresh our symbol table to the newly exec'd program, remove any
1100 momentary bp's, etc.
1102 If there are breakpoints, they aren't really inserted now,
1103 since the exec() transformed our inferior into a fresh set
1106 We want to preserve symbolic breakpoints on the list, since
1107 we have hopes that they can be reset after the new a.out's
1108 symbol table is read.
1110 However, any "raw" breakpoints must be removed from the list
1111 (e.g., the solib bp's), since their address is probably invalid
1114 And, we DON'T want to call delete_breakpoints() here, since
1115 that may write the bp's "shadow contents" (the instruction
1116 value that was overwritten with a TRAP instruction). Since
1117 we now have a new a.out, those shadow contents aren't valid. */
1119 mark_breakpoints_out ();
1121 /* The target reports the exec event to the main thread, even if
1122 some other thread does the exec, and even if the main thread was
1123 stopped or already gone. We may still have non-leader threads of
1124 the process on our list. E.g., on targets that don't have thread
1125 exit events (like remote); or on native Linux in non-stop mode if
1126 there were only two threads in the inferior and the non-leader
1127 one is the one that execs (and nothing forces an update of the
1128 thread list up to here). When debugging remotely, it's best to
1129 avoid extra traffic, when possible, so avoid syncing the thread
1130 list with the target, and instead go ahead and delete all threads
1131 of the process but one that reported the event. Note this must
1132 be done before calling update_breakpoints_after_exec, as
1133 otherwise clearing the threads' resources would reference stale
1134 thread breakpoints -- it may have been one of these threads that
1135 stepped across the exec. We could just clear their stepping
1136 states, but as long as we're iterating, might as well delete
1137 them. Deleting them now rather than at the next user-visible
1138 stop provides a nicer sequence of events for user and MI
1140 for (thread_info
*th
: all_threads_safe ())
1141 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1144 /* We also need to clear any left over stale state for the
1145 leader/event thread. E.g., if there was any step-resume
1146 breakpoint or similar, it's gone now. We cannot truly
1147 step-to-next statement through an exec(). */
1148 thread_info
*th
= inferior_thread ();
1149 th
->control
.step_resume_breakpoint
= NULL
;
1150 th
->control
.exception_resume_breakpoint
= NULL
;
1151 th
->control
.single_step_breakpoints
= NULL
;
1152 th
->control
.step_range_start
= 0;
1153 th
->control
.step_range_end
= 0;
1155 /* The user may have had the main thread held stopped in the
1156 previous image (e.g., schedlock on, or non-stop). Release
1158 th
->stop_requested
= 0;
1160 update_breakpoints_after_exec ();
1162 /* What is this a.out's name? */
1163 process_ptid
= ptid_t (pid
);
1164 printf_unfiltered (_("%s is executing new program: %s\n"),
1165 target_pid_to_str (process_ptid
).c_str (),
1168 /* We've followed the inferior through an exec. Therefore, the
1169 inferior has essentially been killed & reborn. */
1171 breakpoint_init_inferior (inf_execd
);
1173 gdb::unique_xmalloc_ptr
<char> exec_file_host
1174 = exec_file_find (exec_file_target
, NULL
);
1176 /* If we were unable to map the executable target pathname onto a host
1177 pathname, tell the user that. Otherwise GDB's subsequent behavior
1178 is confusing. Maybe it would even be better to stop at this point
1179 so that the user can specify a file manually before continuing. */
1180 if (exec_file_host
== NULL
)
1181 warning (_("Could not load symbols for executable %s.\n"
1182 "Do you need \"set sysroot\"?"),
1185 /* Reset the shared library package. This ensures that we get a
1186 shlib event when the child reaches "_start", at which point the
1187 dld will have had a chance to initialize the child. */
1188 /* Also, loading a symbol file below may trigger symbol lookups, and
1189 we don't want those to be satisfied by the libraries of the
1190 previous incarnation of this process. */
1191 no_shared_libraries (NULL
, 0);
1193 if (follow_exec_mode_string
== follow_exec_mode_new
)
1195 /* The user wants to keep the old inferior and program spaces
1196 around. Create a new fresh one, and switch to it. */
1198 /* Do exit processing for the original inferior before setting the new
1199 inferior's pid. Having two inferiors with the same pid would confuse
1200 find_inferior_p(t)id. Transfer the terminal state and info from the
1201 old to the new inferior. */
1202 inf
= add_inferior_with_spaces ();
1203 swap_terminal_info (inf
, current_inferior ());
1204 exit_inferior_silent (current_inferior ());
1207 target_follow_exec (inf
, exec_file_target
);
1209 inferior
*org_inferior
= current_inferior ();
1210 switch_to_inferior_no_thread (inf
);
1211 push_target (org_inferior
->process_target ());
1212 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1213 switch_to_thread (thr
);
1217 /* The old description may no longer be fit for the new image.
1218 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1219 old description; we'll read a new one below. No need to do
1220 this on "follow-exec-mode new", as the old inferior stays
1221 around (its description is later cleared/refetched on
1223 target_clear_description ();
1226 gdb_assert (current_program_space
== inf
->pspace
);
1228 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1229 because the proper displacement for a PIE (Position Independent
1230 Executable) main symbol file will only be computed by
1231 solib_create_inferior_hook below. breakpoint_re_set would fail
1232 to insert the breakpoints with the zero displacement. */
1233 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1235 /* If the target can specify a description, read it. Must do this
1236 after flipping to the new executable (because the target supplied
1237 description must be compatible with the executable's
1238 architecture, and the old executable may e.g., be 32-bit, while
1239 the new one 64-bit), and before anything involving memory or
1241 target_find_description ();
1243 solib_create_inferior_hook (0);
1245 jit_inferior_created_hook ();
1247 breakpoint_re_set ();
1249 /* Reinsert all breakpoints. (Those which were symbolic have
1250 been reset to the proper address in the new a.out, thanks
1251 to symbol_file_command...). */
1252 insert_breakpoints ();
1254 /* The next resume of this inferior should bring it to the shlib
1255 startup breakpoints. (If the user had also set bp's on
1256 "main" from the old (parent) process, then they'll auto-
1257 matically get reset there in the new process.). */
1260 /* The queue of threads that need to do a step-over operation to get
1261 past e.g., a breakpoint. What technique is used to step over the
1262 breakpoint/watchpoint does not matter -- all threads end up in the
1263 same queue, to maintain rough temporal order of execution, in order
1264 to avoid starvation, otherwise, we could e.g., find ourselves
1265 constantly stepping the same couple threads past their breakpoints
1266 over and over, if the single-step finish fast enough. */
1267 struct thread_info
*step_over_queue_head
;
1269 /* Bit flags indicating what the thread needs to step over. */
1271 enum step_over_what_flag
1273 /* Step over a breakpoint. */
1274 STEP_OVER_BREAKPOINT
= 1,
1276 /* Step past a non-continuable watchpoint, in order to let the
1277 instruction execute so we can evaluate the watchpoint
1279 STEP_OVER_WATCHPOINT
= 2
1281 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1283 /* Info about an instruction that is being stepped over. */
1285 struct step_over_info
1287 /* If we're stepping past a breakpoint, this is the address space
1288 and address of the instruction the breakpoint is set at. We'll
1289 skip inserting all breakpoints here. Valid iff ASPACE is
1291 const address_space
*aspace
;
1294 /* The instruction being stepped over triggers a nonsteppable
1295 watchpoint. If true, we'll skip inserting watchpoints. */
1296 int nonsteppable_watchpoint_p
;
1298 /* The thread's global number. */
1302 /* The step-over info of the location that is being stepped over.
1304 Note that with async/breakpoint always-inserted mode, a user might
1305 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1306 being stepped over. As setting a new breakpoint inserts all
1307 breakpoints, we need to make sure the breakpoint being stepped over
1308 isn't inserted then. We do that by only clearing the step-over
1309 info when the step-over is actually finished (or aborted).
1311 Presently GDB can only step over one breakpoint at any given time.
1312 Given threads that can't run code in the same address space as the
1313 breakpoint's can't really miss the breakpoint, GDB could be taught
1314 to step-over at most one breakpoint per address space (so this info
1315 could move to the address space object if/when GDB is extended).
1316 The set of breakpoints being stepped over will normally be much
1317 smaller than the set of all breakpoints, so a flag in the
1318 breakpoint location structure would be wasteful. A separate list
1319 also saves complexity and run-time, as otherwise we'd have to go
1320 through all breakpoint locations clearing their flag whenever we
1321 start a new sequence. Similar considerations weigh against storing
1322 this info in the thread object. Plus, not all step overs actually
1323 have breakpoint locations -- e.g., stepping past a single-step
1324 breakpoint, or stepping to complete a non-continuable
1326 static struct step_over_info step_over_info
;
1328 /* Record the address of the breakpoint/instruction we're currently
1330 N.B. We record the aspace and address now, instead of say just the thread,
1331 because when we need the info later the thread may be running. */
1334 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1335 int nonsteppable_watchpoint_p
,
1338 step_over_info
.aspace
= aspace
;
1339 step_over_info
.address
= address
;
1340 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1341 step_over_info
.thread
= thread
;
1344 /* Called when we're not longer stepping over a breakpoint / an
1345 instruction, so all breakpoints are free to be (re)inserted. */
1348 clear_step_over_info (void)
1351 fprintf_unfiltered (gdb_stdlog
,
1352 "infrun: clear_step_over_info\n");
1353 step_over_info
.aspace
= NULL
;
1354 step_over_info
.address
= 0;
1355 step_over_info
.nonsteppable_watchpoint_p
= 0;
1356 step_over_info
.thread
= -1;
1362 stepping_past_instruction_at (struct address_space
*aspace
,
1365 return (step_over_info
.aspace
!= NULL
1366 && breakpoint_address_match (aspace
, address
,
1367 step_over_info
.aspace
,
1368 step_over_info
.address
));
1374 thread_is_stepping_over_breakpoint (int thread
)
1376 return (step_over_info
.thread
!= -1
1377 && thread
== step_over_info
.thread
);
1383 stepping_past_nonsteppable_watchpoint (void)
1385 return step_over_info
.nonsteppable_watchpoint_p
;
1388 /* Returns true if step-over info is valid. */
1391 step_over_info_valid_p (void)
1393 return (step_over_info
.aspace
!= NULL
1394 || stepping_past_nonsteppable_watchpoint ());
1398 /* Displaced stepping. */
1400 /* In non-stop debugging mode, we must take special care to manage
1401 breakpoints properly; in particular, the traditional strategy for
1402 stepping a thread past a breakpoint it has hit is unsuitable.
1403 'Displaced stepping' is a tactic for stepping one thread past a
1404 breakpoint it has hit while ensuring that other threads running
1405 concurrently will hit the breakpoint as they should.
1407 The traditional way to step a thread T off a breakpoint in a
1408 multi-threaded program in all-stop mode is as follows:
1410 a0) Initially, all threads are stopped, and breakpoints are not
1412 a1) We single-step T, leaving breakpoints uninserted.
1413 a2) We insert breakpoints, and resume all threads.
1415 In non-stop debugging, however, this strategy is unsuitable: we
1416 don't want to have to stop all threads in the system in order to
1417 continue or step T past a breakpoint. Instead, we use displaced
1420 n0) Initially, T is stopped, other threads are running, and
1421 breakpoints are inserted.
1422 n1) We copy the instruction "under" the breakpoint to a separate
1423 location, outside the main code stream, making any adjustments
1424 to the instruction, register, and memory state as directed by
1426 n2) We single-step T over the instruction at its new location.
1427 n3) We adjust the resulting register and memory state as directed
1428 by T's architecture. This includes resetting T's PC to point
1429 back into the main instruction stream.
1432 This approach depends on the following gdbarch methods:
1434 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1435 indicate where to copy the instruction, and how much space must
1436 be reserved there. We use these in step n1.
1438 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1439 address, and makes any necessary adjustments to the instruction,
1440 register contents, and memory. We use this in step n1.
1442 - gdbarch_displaced_step_fixup adjusts registers and memory after
1443 we have successfully single-stepped the instruction, to yield the
1444 same effect the instruction would have had if we had executed it
1445 at its original address. We use this in step n3.
1447 The gdbarch_displaced_step_copy_insn and
1448 gdbarch_displaced_step_fixup functions must be written so that
1449 copying an instruction with gdbarch_displaced_step_copy_insn,
1450 single-stepping across the copied instruction, and then applying
1451 gdbarch_displaced_insn_fixup should have the same effects on the
1452 thread's memory and registers as stepping the instruction in place
1453 would have. Exactly which responsibilities fall to the copy and
1454 which fall to the fixup is up to the author of those functions.
1456 See the comments in gdbarch.sh for details.
1458 Note that displaced stepping and software single-step cannot
1459 currently be used in combination, although with some care I think
1460 they could be made to. Software single-step works by placing
1461 breakpoints on all possible subsequent instructions; if the
1462 displaced instruction is a PC-relative jump, those breakpoints
1463 could fall in very strange places --- on pages that aren't
1464 executable, or at addresses that are not proper instruction
1465 boundaries. (We do generally let other threads run while we wait
1466 to hit the software single-step breakpoint, and they might
1467 encounter such a corrupted instruction.) One way to work around
1468 this would be to have gdbarch_displaced_step_copy_insn fully
1469 simulate the effect of PC-relative instructions (and return NULL)
1470 on architectures that use software single-stepping.
1472 In non-stop mode, we can have independent and simultaneous step
1473 requests, so more than one thread may need to simultaneously step
1474 over a breakpoint. The current implementation assumes there is
1475 only one scratch space per process. In this case, we have to
1476 serialize access to the scratch space. If thread A wants to step
1477 over a breakpoint, but we are currently waiting for some other
1478 thread to complete a displaced step, we leave thread A stopped and
1479 place it in the displaced_step_request_queue. Whenever a displaced
1480 step finishes, we pick the next thread in the queue and start a new
1481 displaced step operation on it. See displaced_step_prepare and
1482 displaced_step_fixup for details. */
1484 /* Default destructor for displaced_step_closure. */
1486 displaced_step_closure::~displaced_step_closure () = default;
1488 /* Get the displaced stepping state of process PID. */
1490 static displaced_step_inferior_state
*
1491 get_displaced_stepping_state (inferior
*inf
)
1493 return &inf
->displaced_step_state
;
1496 /* Returns true if any inferior has a thread doing a displaced
1500 displaced_step_in_progress_any_inferior ()
1502 for (inferior
*i
: all_inferiors ())
1504 if (i
->displaced_step_state
.step_thread
!= nullptr)
1511 /* Return true if thread represented by PTID is doing a displaced
1515 displaced_step_in_progress_thread (thread_info
*thread
)
1517 gdb_assert (thread
!= NULL
);
1519 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1522 /* Return true if process PID has a thread doing a displaced step. */
1525 displaced_step_in_progress (inferior
*inf
)
1527 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1530 /* If inferior is in displaced stepping, and ADDR equals to starting address
1531 of copy area, return corresponding displaced_step_closure. Otherwise,
1534 struct displaced_step_closure
*
1535 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1537 displaced_step_inferior_state
*displaced
1538 = get_displaced_stepping_state (current_inferior ());
1540 /* If checking the mode of displaced instruction in copy area. */
1541 if (displaced
->step_thread
!= nullptr
1542 && displaced
->step_copy
== addr
)
1543 return displaced
->step_closure
.get ();
1549 infrun_inferior_exit (struct inferior
*inf
)
1551 inf
->displaced_step_state
.reset ();
1554 /* If ON, and the architecture supports it, GDB will use displaced
1555 stepping to step over breakpoints. If OFF, or if the architecture
1556 doesn't support it, GDB will instead use the traditional
1557 hold-and-step approach. If AUTO (which is the default), GDB will
1558 decide which technique to use to step over breakpoints depending on
1559 whether the target works in a non-stop way (see use_displaced_stepping). */
1561 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1564 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1565 struct cmd_list_element
*c
,
1568 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1569 fprintf_filtered (file
,
1570 _("Debugger's willingness to use displaced stepping "
1571 "to step over breakpoints is %s (currently %s).\n"),
1572 value
, target_is_non_stop_p () ? "on" : "off");
1574 fprintf_filtered (file
,
1575 _("Debugger's willingness to use displaced stepping "
1576 "to step over breakpoints is %s.\n"), value
);
1579 /* Return true if the gdbarch implements the required methods to use
1580 displaced stepping. */
1583 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1585 /* Only check for the presence of step_copy_insn. Other required methods
1586 are checked by the gdbarch validation. */
1587 return gdbarch_displaced_step_copy_insn_p (arch
);
1590 /* Return non-zero if displaced stepping can/should be used to step
1591 over breakpoints of thread TP. */
1594 use_displaced_stepping (thread_info
*tp
)
1596 /* If the user disabled it explicitly, don't use displaced stepping. */
1597 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1600 /* If "auto", only use displaced stepping if the target operates in a non-stop
1602 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1603 && !target_is_non_stop_p ())
1606 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1608 /* If the architecture doesn't implement displaced stepping, don't use
1610 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1613 /* If recording, don't use displaced stepping. */
1614 if (find_record_target () != nullptr)
1617 displaced_step_inferior_state
*displaced_state
1618 = get_displaced_stepping_state (tp
->inf
);
1620 /* If displaced stepping failed before for this inferior, don't bother trying
1622 if (displaced_state
->failed_before
)
1628 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1631 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1633 displaced
->reset ();
1636 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1637 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1639 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1641 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1643 displaced_step_dump_bytes (struct ui_file
*file
,
1644 const gdb_byte
*buf
,
1649 for (i
= 0; i
< len
; i
++)
1650 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1651 fputs_unfiltered ("\n", file
);
1654 /* Prepare to single-step, using displaced stepping.
1656 Note that we cannot use displaced stepping when we have a signal to
1657 deliver. If we have a signal to deliver and an instruction to step
1658 over, then after the step, there will be no indication from the
1659 target whether the thread entered a signal handler or ignored the
1660 signal and stepped over the instruction successfully --- both cases
1661 result in a simple SIGTRAP. In the first case we mustn't do a
1662 fixup, and in the second case we must --- but we can't tell which.
1663 Comments in the code for 'random signals' in handle_inferior_event
1664 explain how we handle this case instead.
1666 Returns 1 if preparing was successful -- this thread is going to be
1667 stepped now; 0 if displaced stepping this thread got queued; or -1
1668 if this instruction can't be displaced stepped. */
1671 displaced_step_prepare_throw (thread_info
*tp
)
1673 regcache
*regcache
= get_thread_regcache (tp
);
1674 struct gdbarch
*gdbarch
= regcache
->arch ();
1675 const address_space
*aspace
= regcache
->aspace ();
1676 CORE_ADDR original
, copy
;
1680 /* We should never reach this function if the architecture does not
1681 support displaced stepping. */
1682 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1684 /* Nor if the thread isn't meant to step over a breakpoint. */
1685 gdb_assert (tp
->control
.trap_expected
);
1687 /* Disable range stepping while executing in the scratch pad. We
1688 want a single-step even if executing the displaced instruction in
1689 the scratch buffer lands within the stepping range (e.g., a
1691 tp
->control
.may_range_step
= 0;
1693 /* We have to displaced step one thread at a time, as we only have
1694 access to a single scratch space per inferior. */
1696 displaced_step_inferior_state
*displaced
1697 = get_displaced_stepping_state (tp
->inf
);
1699 if (displaced
->step_thread
!= nullptr)
1701 /* Already waiting for a displaced step to finish. Defer this
1702 request and place in queue. */
1704 if (debug_displaced
)
1705 fprintf_unfiltered (gdb_stdlog
,
1706 "displaced: deferring step of %s\n",
1707 target_pid_to_str (tp
->ptid
).c_str ());
1709 thread_step_over_chain_enqueue (tp
);
1714 if (debug_displaced
)
1715 fprintf_unfiltered (gdb_stdlog
,
1716 "displaced: stepping %s now\n",
1717 target_pid_to_str (tp
->ptid
).c_str ());
1720 displaced_step_reset (displaced
);
1722 scoped_restore_current_thread restore_thread
;
1724 switch_to_thread (tp
);
1726 original
= regcache_read_pc (regcache
);
1728 copy
= gdbarch_displaced_step_location (gdbarch
);
1729 len
= gdbarch_max_insn_length (gdbarch
);
1731 if (breakpoint_in_range_p (aspace
, copy
, len
))
1733 /* There's a breakpoint set in the scratch pad location range
1734 (which is usually around the entry point). We'd either
1735 install it before resuming, which would overwrite/corrupt the
1736 scratch pad, or if it was already inserted, this displaced
1737 step would overwrite it. The latter is OK in the sense that
1738 we already assume that no thread is going to execute the code
1739 in the scratch pad range (after initial startup) anyway, but
1740 the former is unacceptable. Simply punt and fallback to
1741 stepping over this breakpoint in-line. */
1742 if (debug_displaced
)
1744 fprintf_unfiltered (gdb_stdlog
,
1745 "displaced: breakpoint set in scratch pad. "
1746 "Stepping over breakpoint in-line instead.\n");
1752 /* Save the original contents of the copy area. */
1753 displaced
->step_saved_copy
.resize (len
);
1754 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1756 throw_error (MEMORY_ERROR
,
1757 _("Error accessing memory address %s (%s) for "
1758 "displaced-stepping scratch space."),
1759 paddress (gdbarch
, copy
), safe_strerror (status
));
1760 if (debug_displaced
)
1762 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1763 paddress (gdbarch
, copy
));
1764 displaced_step_dump_bytes (gdb_stdlog
,
1765 displaced
->step_saved_copy
.data (),
1769 displaced
->step_closure
1770 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1771 if (displaced
->step_closure
== NULL
)
1773 /* The architecture doesn't know how or want to displaced step
1774 this instruction or instruction sequence. Fallback to
1775 stepping over the breakpoint in-line. */
1779 /* Save the information we need to fix things up if the step
1781 displaced
->step_thread
= tp
;
1782 displaced
->step_gdbarch
= gdbarch
;
1783 displaced
->step_original
= original
;
1784 displaced
->step_copy
= copy
;
1787 displaced_step_reset_cleanup
cleanup (displaced
);
1789 /* Resume execution at the copy. */
1790 regcache_write_pc (regcache
, copy
);
1795 if (debug_displaced
)
1796 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1797 paddress (gdbarch
, copy
));
1802 /* Wrapper for displaced_step_prepare_throw that disabled further
1803 attempts at displaced stepping if we get a memory error. */
1806 displaced_step_prepare (thread_info
*thread
)
1812 prepared
= displaced_step_prepare_throw (thread
);
1814 catch (const gdb_exception_error
&ex
)
1816 struct displaced_step_inferior_state
*displaced_state
;
1818 if (ex
.error
!= MEMORY_ERROR
1819 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1824 fprintf_unfiltered (gdb_stdlog
,
1825 "infrun: disabling displaced stepping: %s\n",
1829 /* Be verbose if "set displaced-stepping" is "on", silent if
1831 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1833 warning (_("disabling displaced stepping: %s"),
1837 /* Disable further displaced stepping attempts. */
1839 = get_displaced_stepping_state (thread
->inf
);
1840 displaced_state
->failed_before
= 1;
1847 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1848 const gdb_byte
*myaddr
, int len
)
1850 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1852 inferior_ptid
= ptid
;
1853 write_memory (memaddr
, myaddr
, len
);
1856 /* Restore the contents of the copy area for thread PTID. */
1859 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1862 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1864 write_memory_ptid (ptid
, displaced
->step_copy
,
1865 displaced
->step_saved_copy
.data (), len
);
1866 if (debug_displaced
)
1867 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1868 target_pid_to_str (ptid
).c_str (),
1869 paddress (displaced
->step_gdbarch
,
1870 displaced
->step_copy
));
1873 /* If we displaced stepped an instruction successfully, adjust
1874 registers and memory to yield the same effect the instruction would
1875 have had if we had executed it at its original address, and return
1876 1. If the instruction didn't complete, relocate the PC and return
1877 -1. If the thread wasn't displaced stepping, return 0. */
1880 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1882 struct displaced_step_inferior_state
*displaced
1883 = get_displaced_stepping_state (event_thread
->inf
);
1886 /* Was this event for the thread we displaced? */
1887 if (displaced
->step_thread
!= event_thread
)
1890 displaced_step_reset_cleanup
cleanup (displaced
);
1892 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1894 /* Fixup may need to read memory/registers. Switch to the thread
1895 that we're fixing up. Also, target_stopped_by_watchpoint checks
1896 the current thread. */
1897 switch_to_thread (event_thread
);
1899 /* Did the instruction complete successfully? */
1900 if (signal
== GDB_SIGNAL_TRAP
1901 && !(target_stopped_by_watchpoint ()
1902 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1903 || target_have_steppable_watchpoint
)))
1905 /* Fix up the resulting state. */
1906 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1907 displaced
->step_closure
.get (),
1908 displaced
->step_original
,
1909 displaced
->step_copy
,
1910 get_thread_regcache (displaced
->step_thread
));
1915 /* Since the instruction didn't complete, all we can do is
1917 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1918 CORE_ADDR pc
= regcache_read_pc (regcache
);
1920 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1921 regcache_write_pc (regcache
, pc
);
1928 /* Data to be passed around while handling an event. This data is
1929 discarded between events. */
1930 struct execution_control_state
1932 process_stratum_target
*target
;
1934 /* The thread that got the event, if this was a thread event; NULL
1936 struct thread_info
*event_thread
;
1938 struct target_waitstatus ws
;
1939 int stop_func_filled_in
;
1940 CORE_ADDR stop_func_start
;
1941 CORE_ADDR stop_func_end
;
1942 const char *stop_func_name
;
1945 /* True if the event thread hit the single-step breakpoint of
1946 another thread. Thus the event doesn't cause a stop, the thread
1947 needs to be single-stepped past the single-step breakpoint before
1948 we can switch back to the original stepping thread. */
1949 int hit_singlestep_breakpoint
;
1952 /* Clear ECS and set it to point at TP. */
1955 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1957 memset (ecs
, 0, sizeof (*ecs
));
1958 ecs
->event_thread
= tp
;
1959 ecs
->ptid
= tp
->ptid
;
1962 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1963 static void prepare_to_wait (struct execution_control_state
*ecs
);
1964 static int keep_going_stepped_thread (struct thread_info
*tp
);
1965 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1967 /* Are there any pending step-over requests? If so, run all we can
1968 now and return true. Otherwise, return false. */
1971 start_step_over (void)
1973 struct thread_info
*tp
, *next
;
1975 /* Don't start a new step-over if we already have an in-line
1976 step-over operation ongoing. */
1977 if (step_over_info_valid_p ())
1980 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1982 struct execution_control_state ecss
;
1983 struct execution_control_state
*ecs
= &ecss
;
1984 step_over_what step_what
;
1985 int must_be_in_line
;
1987 gdb_assert (!tp
->stop_requested
);
1989 next
= thread_step_over_chain_next (tp
);
1991 /* If this inferior already has a displaced step in process,
1992 don't start a new one. */
1993 if (displaced_step_in_progress (tp
->inf
))
1996 step_what
= thread_still_needs_step_over (tp
);
1997 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1998 || ((step_what
& STEP_OVER_BREAKPOINT
)
1999 && !use_displaced_stepping (tp
)));
2001 /* We currently stop all threads of all processes to step-over
2002 in-line. If we need to start a new in-line step-over, let
2003 any pending displaced steps finish first. */
2004 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
2007 thread_step_over_chain_remove (tp
);
2009 if (step_over_queue_head
== NULL
)
2012 fprintf_unfiltered (gdb_stdlog
,
2013 "infrun: step-over queue now empty\n");
2016 if (tp
->control
.trap_expected
2020 internal_error (__FILE__
, __LINE__
,
2021 "[%s] has inconsistent state: "
2022 "trap_expected=%d, resumed=%d, executing=%d\n",
2023 target_pid_to_str (tp
->ptid
).c_str (),
2024 tp
->control
.trap_expected
,
2030 fprintf_unfiltered (gdb_stdlog
,
2031 "infrun: resuming [%s] for step-over\n",
2032 target_pid_to_str (tp
->ptid
).c_str ());
2034 /* keep_going_pass_signal skips the step-over if the breakpoint
2035 is no longer inserted. In all-stop, we want to keep looking
2036 for a thread that needs a step-over instead of resuming TP,
2037 because we wouldn't be able to resume anything else until the
2038 target stops again. In non-stop, the resume always resumes
2039 only TP, so it's OK to let the thread resume freely. */
2040 if (!target_is_non_stop_p () && !step_what
)
2043 switch_to_thread (tp
);
2044 reset_ecs (ecs
, tp
);
2045 keep_going_pass_signal (ecs
);
2047 if (!ecs
->wait_some_more
)
2048 error (_("Command aborted."));
2050 gdb_assert (tp
->resumed
);
2052 /* If we started a new in-line step-over, we're done. */
2053 if (step_over_info_valid_p ())
2055 gdb_assert (tp
->control
.trap_expected
);
2059 if (!target_is_non_stop_p ())
2061 /* On all-stop, shouldn't have resumed unless we needed a
2063 gdb_assert (tp
->control
.trap_expected
2064 || tp
->step_after_step_resume_breakpoint
);
2066 /* With remote targets (at least), in all-stop, we can't
2067 issue any further remote commands until the program stops
2072 /* Either the thread no longer needed a step-over, or a new
2073 displaced stepping sequence started. Even in the latter
2074 case, continue looking. Maybe we can also start another
2075 displaced step on a thread of other process. */
2081 /* Update global variables holding ptids to hold NEW_PTID if they were
2082 holding OLD_PTID. */
2084 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2086 if (inferior_ptid
== old_ptid
)
2087 inferior_ptid
= new_ptid
;
2092 static const char schedlock_off
[] = "off";
2093 static const char schedlock_on
[] = "on";
2094 static const char schedlock_step
[] = "step";
2095 static const char schedlock_replay
[] = "replay";
2096 static const char *const scheduler_enums
[] = {
2103 static const char *scheduler_mode
= schedlock_replay
;
2105 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2106 struct cmd_list_element
*c
, const char *value
)
2108 fprintf_filtered (file
,
2109 _("Mode for locking scheduler "
2110 "during execution is \"%s\".\n"),
2115 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2117 if (!target_can_lock_scheduler
)
2119 scheduler_mode
= schedlock_off
;
2120 error (_("Target '%s' cannot support this command."), target_shortname
);
2124 /* True if execution commands resume all threads of all processes by
2125 default; otherwise, resume only threads of the current inferior
2127 bool sched_multi
= false;
2129 /* Try to setup for software single stepping over the specified location.
2130 Return 1 if target_resume() should use hardware single step.
2132 GDBARCH the current gdbarch.
2133 PC the location to step over. */
2136 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2140 if (execution_direction
== EXEC_FORWARD
2141 && gdbarch_software_single_step_p (gdbarch
))
2142 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2150 user_visible_resume_ptid (int step
)
2156 /* With non-stop mode on, threads are always handled
2158 resume_ptid
= inferior_ptid
;
2160 else if ((scheduler_mode
== schedlock_on
)
2161 || (scheduler_mode
== schedlock_step
&& step
))
2163 /* User-settable 'scheduler' mode requires solo thread
2165 resume_ptid
= inferior_ptid
;
2167 else if ((scheduler_mode
== schedlock_replay
)
2168 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2170 /* User-settable 'scheduler' mode requires solo thread resume in replay
2172 resume_ptid
= inferior_ptid
;
2174 else if (!sched_multi
&& target_supports_multi_process ())
2176 /* Resume all threads of the current process (and none of other
2178 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2182 /* Resume all threads of all processes. */
2183 resume_ptid
= RESUME_ALL
;
2191 process_stratum_target
*
2192 user_visible_resume_target (ptid_t resume_ptid
)
2194 return (resume_ptid
== minus_one_ptid
&& sched_multi
2196 : current_inferior ()->process_target ());
2199 /* Return a ptid representing the set of threads that we will resume,
2200 in the perspective of the target, assuming run control handling
2201 does not require leaving some threads stopped (e.g., stepping past
2202 breakpoint). USER_STEP indicates whether we're about to start the
2203 target for a stepping command. */
2206 internal_resume_ptid (int user_step
)
2208 /* In non-stop, we always control threads individually. Note that
2209 the target may always work in non-stop mode even with "set
2210 non-stop off", in which case user_visible_resume_ptid could
2211 return a wildcard ptid. */
2212 if (target_is_non_stop_p ())
2213 return inferior_ptid
;
2215 return user_visible_resume_ptid (user_step
);
2218 /* Wrapper for target_resume, that handles infrun-specific
2222 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2224 struct thread_info
*tp
= inferior_thread ();
2226 gdb_assert (!tp
->stop_requested
);
2228 /* Install inferior's terminal modes. */
2229 target_terminal::inferior ();
2231 /* Avoid confusing the next resume, if the next stop/resume
2232 happens to apply to another thread. */
2233 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2235 /* Advise target which signals may be handled silently.
2237 If we have removed breakpoints because we are stepping over one
2238 in-line (in any thread), we need to receive all signals to avoid
2239 accidentally skipping a breakpoint during execution of a signal
2242 Likewise if we're displaced stepping, otherwise a trap for a
2243 breakpoint in a signal handler might be confused with the
2244 displaced step finishing. We don't make the displaced_step_fixup
2245 step distinguish the cases instead, because:
2247 - a backtrace while stopped in the signal handler would show the
2248 scratch pad as frame older than the signal handler, instead of
2249 the real mainline code.
2251 - when the thread is later resumed, the signal handler would
2252 return to the scratch pad area, which would no longer be
2254 if (step_over_info_valid_p ()
2255 || displaced_step_in_progress (tp
->inf
))
2256 target_pass_signals ({});
2258 target_pass_signals (signal_pass
);
2260 target_resume (resume_ptid
, step
, sig
);
2262 target_commit_resume ();
2264 if (target_can_async_p ())
2268 /* Resume the inferior. SIG is the signal to give the inferior
2269 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2270 call 'resume', which handles exceptions. */
2273 resume_1 (enum gdb_signal sig
)
2275 struct regcache
*regcache
= get_current_regcache ();
2276 struct gdbarch
*gdbarch
= regcache
->arch ();
2277 struct thread_info
*tp
= inferior_thread ();
2278 CORE_ADDR pc
= regcache_read_pc (regcache
);
2279 const address_space
*aspace
= regcache
->aspace ();
2281 /* This represents the user's step vs continue request. When
2282 deciding whether "set scheduler-locking step" applies, it's the
2283 user's intention that counts. */
2284 const int user_step
= tp
->control
.stepping_command
;
2285 /* This represents what we'll actually request the target to do.
2286 This can decay from a step to a continue, if e.g., we need to
2287 implement single-stepping with breakpoints (software
2291 gdb_assert (!tp
->stop_requested
);
2292 gdb_assert (!thread_is_in_step_over_chain (tp
));
2294 if (tp
->suspend
.waitstatus_pending_p
)
2299 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2301 fprintf_unfiltered (gdb_stdlog
,
2302 "infrun: resume: thread %s has pending wait "
2303 "status %s (currently_stepping=%d).\n",
2304 target_pid_to_str (tp
->ptid
).c_str (),
2306 currently_stepping (tp
));
2309 tp
->inf
->process_target ()->threads_executing
= true;
2312 /* FIXME: What should we do if we are supposed to resume this
2313 thread with a signal? Maybe we should maintain a queue of
2314 pending signals to deliver. */
2315 if (sig
!= GDB_SIGNAL_0
)
2317 warning (_("Couldn't deliver signal %s to %s."),
2318 gdb_signal_to_name (sig
),
2319 target_pid_to_str (tp
->ptid
).c_str ());
2322 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2324 if (target_can_async_p ())
2327 /* Tell the event loop we have an event to process. */
2328 mark_async_event_handler (infrun_async_inferior_event_token
);
2333 tp
->stepped_breakpoint
= 0;
2335 /* Depends on stepped_breakpoint. */
2336 step
= currently_stepping (tp
);
2338 if (current_inferior ()->waiting_for_vfork_done
)
2340 /* Don't try to single-step a vfork parent that is waiting for
2341 the child to get out of the shared memory region (by exec'ing
2342 or exiting). This is particularly important on software
2343 single-step archs, as the child process would trip on the
2344 software single step breakpoint inserted for the parent
2345 process. Since the parent will not actually execute any
2346 instruction until the child is out of the shared region (such
2347 are vfork's semantics), it is safe to simply continue it.
2348 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2349 the parent, and tell it to `keep_going', which automatically
2350 re-sets it stepping. */
2352 fprintf_unfiltered (gdb_stdlog
,
2353 "infrun: resume : clear step\n");
2358 fprintf_unfiltered (gdb_stdlog
,
2359 "infrun: resume (step=%d, signal=%s), "
2360 "trap_expected=%d, current thread [%s] at %s\n",
2361 step
, gdb_signal_to_symbol_string (sig
),
2362 tp
->control
.trap_expected
,
2363 target_pid_to_str (inferior_ptid
).c_str (),
2364 paddress (gdbarch
, pc
));
2366 /* Normally, by the time we reach `resume', the breakpoints are either
2367 removed or inserted, as appropriate. The exception is if we're sitting
2368 at a permanent breakpoint; we need to step over it, but permanent
2369 breakpoints can't be removed. So we have to test for it here. */
2370 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2372 if (sig
!= GDB_SIGNAL_0
)
2374 /* We have a signal to pass to the inferior. The resume
2375 may, or may not take us to the signal handler. If this
2376 is a step, we'll need to stop in the signal handler, if
2377 there's one, (if the target supports stepping into
2378 handlers), or in the next mainline instruction, if
2379 there's no handler. If this is a continue, we need to be
2380 sure to run the handler with all breakpoints inserted.
2381 In all cases, set a breakpoint at the current address
2382 (where the handler returns to), and once that breakpoint
2383 is hit, resume skipping the permanent breakpoint. If
2384 that breakpoint isn't hit, then we've stepped into the
2385 signal handler (or hit some other event). We'll delete
2386 the step-resume breakpoint then. */
2389 fprintf_unfiltered (gdb_stdlog
,
2390 "infrun: resume: skipping permanent breakpoint, "
2391 "deliver signal first\n");
2393 clear_step_over_info ();
2394 tp
->control
.trap_expected
= 0;
2396 if (tp
->control
.step_resume_breakpoint
== NULL
)
2398 /* Set a "high-priority" step-resume, as we don't want
2399 user breakpoints at PC to trigger (again) when this
2401 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2402 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2404 tp
->step_after_step_resume_breakpoint
= step
;
2407 insert_breakpoints ();
2411 /* There's no signal to pass, we can go ahead and skip the
2412 permanent breakpoint manually. */
2414 fprintf_unfiltered (gdb_stdlog
,
2415 "infrun: resume: skipping permanent breakpoint\n");
2416 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2417 /* Update pc to reflect the new address from which we will
2418 execute instructions. */
2419 pc
= regcache_read_pc (regcache
);
2423 /* We've already advanced the PC, so the stepping part
2424 is done. Now we need to arrange for a trap to be
2425 reported to handle_inferior_event. Set a breakpoint
2426 at the current PC, and run to it. Don't update
2427 prev_pc, because if we end in
2428 switch_back_to_stepped_thread, we want the "expected
2429 thread advanced also" branch to be taken. IOW, we
2430 don't want this thread to step further from PC
2432 gdb_assert (!step_over_info_valid_p ());
2433 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2434 insert_breakpoints ();
2436 resume_ptid
= internal_resume_ptid (user_step
);
2437 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2444 /* If we have a breakpoint to step over, make sure to do a single
2445 step only. Same if we have software watchpoints. */
2446 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2447 tp
->control
.may_range_step
= 0;
2449 /* If displaced stepping is enabled, step over breakpoints by executing a
2450 copy of the instruction at a different address.
2452 We can't use displaced stepping when we have a signal to deliver;
2453 the comments for displaced_step_prepare explain why. The
2454 comments in the handle_inferior event for dealing with 'random
2455 signals' explain what we do instead.
2457 We can't use displaced stepping when we are waiting for vfork_done
2458 event, displaced stepping breaks the vfork child similarly as single
2459 step software breakpoint. */
2460 if (tp
->control
.trap_expected
2461 && use_displaced_stepping (tp
)
2462 && !step_over_info_valid_p ()
2463 && sig
== GDB_SIGNAL_0
2464 && !current_inferior ()->waiting_for_vfork_done
)
2466 int prepared
= displaced_step_prepare (tp
);
2471 fprintf_unfiltered (gdb_stdlog
,
2472 "Got placed in step-over queue\n");
2474 tp
->control
.trap_expected
= 0;
2477 else if (prepared
< 0)
2479 /* Fallback to stepping over the breakpoint in-line. */
2481 if (target_is_non_stop_p ())
2482 stop_all_threads ();
2484 set_step_over_info (regcache
->aspace (),
2485 regcache_read_pc (regcache
), 0, tp
->global_num
);
2487 step
= maybe_software_singlestep (gdbarch
, pc
);
2489 insert_breakpoints ();
2491 else if (prepared
> 0)
2493 struct displaced_step_inferior_state
*displaced
;
2495 /* Update pc to reflect the new address from which we will
2496 execute instructions due to displaced stepping. */
2497 pc
= regcache_read_pc (get_thread_regcache (tp
));
2499 displaced
= get_displaced_stepping_state (tp
->inf
);
2500 step
= gdbarch_displaced_step_hw_singlestep
2501 (gdbarch
, displaced
->step_closure
.get ());
2505 /* Do we need to do it the hard way, w/temp breakpoints? */
2507 step
= maybe_software_singlestep (gdbarch
, pc
);
2509 /* Currently, our software single-step implementation leads to different
2510 results than hardware single-stepping in one situation: when stepping
2511 into delivering a signal which has an associated signal handler,
2512 hardware single-step will stop at the first instruction of the handler,
2513 while software single-step will simply skip execution of the handler.
2515 For now, this difference in behavior is accepted since there is no
2516 easy way to actually implement single-stepping into a signal handler
2517 without kernel support.
2519 However, there is one scenario where this difference leads to follow-on
2520 problems: if we're stepping off a breakpoint by removing all breakpoints
2521 and then single-stepping. In this case, the software single-step
2522 behavior means that even if there is a *breakpoint* in the signal
2523 handler, GDB still would not stop.
2525 Fortunately, we can at least fix this particular issue. We detect
2526 here the case where we are about to deliver a signal while software
2527 single-stepping with breakpoints removed. In this situation, we
2528 revert the decisions to remove all breakpoints and insert single-
2529 step breakpoints, and instead we install a step-resume breakpoint
2530 at the current address, deliver the signal without stepping, and
2531 once we arrive back at the step-resume breakpoint, actually step
2532 over the breakpoint we originally wanted to step over. */
2533 if (thread_has_single_step_breakpoints_set (tp
)
2534 && sig
!= GDB_SIGNAL_0
2535 && step_over_info_valid_p ())
2537 /* If we have nested signals or a pending signal is delivered
2538 immediately after a handler returns, might already have
2539 a step-resume breakpoint set on the earlier handler. We cannot
2540 set another step-resume breakpoint; just continue on until the
2541 original breakpoint is hit. */
2542 if (tp
->control
.step_resume_breakpoint
== NULL
)
2544 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2545 tp
->step_after_step_resume_breakpoint
= 1;
2548 delete_single_step_breakpoints (tp
);
2550 clear_step_over_info ();
2551 tp
->control
.trap_expected
= 0;
2553 insert_breakpoints ();
2556 /* If STEP is set, it's a request to use hardware stepping
2557 facilities. But in that case, we should never
2558 use singlestep breakpoint. */
2559 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2561 /* Decide the set of threads to ask the target to resume. */
2562 if (tp
->control
.trap_expected
)
2564 /* We're allowing a thread to run past a breakpoint it has
2565 hit, either by single-stepping the thread with the breakpoint
2566 removed, or by displaced stepping, with the breakpoint inserted.
2567 In the former case, we need to single-step only this thread,
2568 and keep others stopped, as they can miss this breakpoint if
2569 allowed to run. That's not really a problem for displaced
2570 stepping, but, we still keep other threads stopped, in case
2571 another thread is also stopped for a breakpoint waiting for
2572 its turn in the displaced stepping queue. */
2573 resume_ptid
= inferior_ptid
;
2576 resume_ptid
= internal_resume_ptid (user_step
);
2578 if (execution_direction
!= EXEC_REVERSE
2579 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2581 /* There are two cases where we currently need to step a
2582 breakpoint instruction when we have a signal to deliver:
2584 - See handle_signal_stop where we handle random signals that
2585 could take out us out of the stepping range. Normally, in
2586 that case we end up continuing (instead of stepping) over the
2587 signal handler with a breakpoint at PC, but there are cases
2588 where we should _always_ single-step, even if we have a
2589 step-resume breakpoint, like when a software watchpoint is
2590 set. Assuming single-stepping and delivering a signal at the
2591 same time would takes us to the signal handler, then we could
2592 have removed the breakpoint at PC to step over it. However,
2593 some hardware step targets (like e.g., Mac OS) can't step
2594 into signal handlers, and for those, we need to leave the
2595 breakpoint at PC inserted, as otherwise if the handler
2596 recurses and executes PC again, it'll miss the breakpoint.
2597 So we leave the breakpoint inserted anyway, but we need to
2598 record that we tried to step a breakpoint instruction, so
2599 that adjust_pc_after_break doesn't end up confused.
2601 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2602 in one thread after another thread that was stepping had been
2603 momentarily paused for a step-over. When we re-resume the
2604 stepping thread, it may be resumed from that address with a
2605 breakpoint that hasn't trapped yet. Seen with
2606 gdb.threads/non-stop-fair-events.exp, on targets that don't
2607 do displaced stepping. */
2610 fprintf_unfiltered (gdb_stdlog
,
2611 "infrun: resume: [%s] stepped breakpoint\n",
2612 target_pid_to_str (tp
->ptid
).c_str ());
2614 tp
->stepped_breakpoint
= 1;
2616 /* Most targets can step a breakpoint instruction, thus
2617 executing it normally. But if this one cannot, just
2618 continue and we will hit it anyway. */
2619 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2624 && tp
->control
.trap_expected
2625 && use_displaced_stepping (tp
)
2626 && !step_over_info_valid_p ())
2628 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2629 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2630 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2633 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2634 paddress (resume_gdbarch
, actual_pc
));
2635 read_memory (actual_pc
, buf
, sizeof (buf
));
2636 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2639 if (tp
->control
.may_range_step
)
2641 /* If we're resuming a thread with the PC out of the step
2642 range, then we're doing some nested/finer run control
2643 operation, like stepping the thread out of the dynamic
2644 linker or the displaced stepping scratch pad. We
2645 shouldn't have allowed a range step then. */
2646 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2649 do_target_resume (resume_ptid
, step
, sig
);
2653 /* Resume the inferior. SIG is the signal to give the inferior
2654 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2655 rolls back state on error. */
2658 resume (gdb_signal sig
)
2664 catch (const gdb_exception
&ex
)
2666 /* If resuming is being aborted for any reason, delete any
2667 single-step breakpoint resume_1 may have created, to avoid
2668 confusing the following resumption, and to avoid leaving
2669 single-step breakpoints perturbing other threads, in case
2670 we're running in non-stop mode. */
2671 if (inferior_ptid
!= null_ptid
)
2672 delete_single_step_breakpoints (inferior_thread ());
2682 /* Counter that tracks number of user visible stops. This can be used
2683 to tell whether a command has proceeded the inferior past the
2684 current location. This allows e.g., inferior function calls in
2685 breakpoint commands to not interrupt the command list. When the
2686 call finishes successfully, the inferior is standing at the same
2687 breakpoint as if nothing happened (and so we don't call
2689 static ULONGEST current_stop_id
;
2696 return current_stop_id
;
2699 /* Called when we report a user visible stop. */
2707 /* Clear out all variables saying what to do when inferior is continued.
2708 First do this, then set the ones you want, then call `proceed'. */
2711 clear_proceed_status_thread (struct thread_info
*tp
)
2714 fprintf_unfiltered (gdb_stdlog
,
2715 "infrun: clear_proceed_status_thread (%s)\n",
2716 target_pid_to_str (tp
->ptid
).c_str ());
2718 /* If we're starting a new sequence, then the previous finished
2719 single-step is no longer relevant. */
2720 if (tp
->suspend
.waitstatus_pending_p
)
2722 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2725 fprintf_unfiltered (gdb_stdlog
,
2726 "infrun: clear_proceed_status: pending "
2727 "event of %s was a finished step. "
2729 target_pid_to_str (tp
->ptid
).c_str ());
2731 tp
->suspend
.waitstatus_pending_p
= 0;
2732 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2734 else if (debug_infrun
)
2737 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2739 fprintf_unfiltered (gdb_stdlog
,
2740 "infrun: clear_proceed_status_thread: thread %s "
2741 "has pending wait status %s "
2742 "(currently_stepping=%d).\n",
2743 target_pid_to_str (tp
->ptid
).c_str (),
2745 currently_stepping (tp
));
2749 /* If this signal should not be seen by program, give it zero.
2750 Used for debugging signals. */
2751 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2752 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2754 delete tp
->thread_fsm
;
2755 tp
->thread_fsm
= NULL
;
2757 tp
->control
.trap_expected
= 0;
2758 tp
->control
.step_range_start
= 0;
2759 tp
->control
.step_range_end
= 0;
2760 tp
->control
.may_range_step
= 0;
2761 tp
->control
.step_frame_id
= null_frame_id
;
2762 tp
->control
.step_stack_frame_id
= null_frame_id
;
2763 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2764 tp
->control
.step_start_function
= NULL
;
2765 tp
->stop_requested
= 0;
2767 tp
->control
.stop_step
= 0;
2769 tp
->control
.proceed_to_finish
= 0;
2771 tp
->control
.stepping_command
= 0;
2773 /* Discard any remaining commands or status from previous stop. */
2774 bpstat_clear (&tp
->control
.stop_bpstat
);
2778 clear_proceed_status (int step
)
2780 /* With scheduler-locking replay, stop replaying other threads if we're
2781 not replaying the user-visible resume ptid.
2783 This is a convenience feature to not require the user to explicitly
2784 stop replaying the other threads. We're assuming that the user's
2785 intent is to resume tracing the recorded process. */
2786 if (!non_stop
&& scheduler_mode
== schedlock_replay
2787 && target_record_is_replaying (minus_one_ptid
)
2788 && !target_record_will_replay (user_visible_resume_ptid (step
),
2789 execution_direction
))
2790 target_record_stop_replaying ();
2792 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2794 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2795 process_stratum_target
*resume_target
2796 = user_visible_resume_target (resume_ptid
);
2798 /* In all-stop mode, delete the per-thread status of all threads
2799 we're about to resume, implicitly and explicitly. */
2800 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2801 clear_proceed_status_thread (tp
);
2804 if (inferior_ptid
!= null_ptid
)
2806 struct inferior
*inferior
;
2810 /* If in non-stop mode, only delete the per-thread status of
2811 the current thread. */
2812 clear_proceed_status_thread (inferior_thread ());
2815 inferior
= current_inferior ();
2816 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2819 gdb::observers::about_to_proceed
.notify ();
2822 /* Returns true if TP is still stopped at a breakpoint that needs
2823 stepping-over in order to make progress. If the breakpoint is gone
2824 meanwhile, we can skip the whole step-over dance. */
2827 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2829 if (tp
->stepping_over_breakpoint
)
2831 struct regcache
*regcache
= get_thread_regcache (tp
);
2833 if (breakpoint_here_p (regcache
->aspace (),
2834 regcache_read_pc (regcache
))
2835 == ordinary_breakpoint_here
)
2838 tp
->stepping_over_breakpoint
= 0;
2844 /* Check whether thread TP still needs to start a step-over in order
2845 to make progress when resumed. Returns an bitwise or of enum
2846 step_over_what bits, indicating what needs to be stepped over. */
2848 static step_over_what
2849 thread_still_needs_step_over (struct thread_info
*tp
)
2851 step_over_what what
= 0;
2853 if (thread_still_needs_step_over_bp (tp
))
2854 what
|= STEP_OVER_BREAKPOINT
;
2856 if (tp
->stepping_over_watchpoint
2857 && !target_have_steppable_watchpoint
)
2858 what
|= STEP_OVER_WATCHPOINT
;
2863 /* Returns true if scheduler locking applies. STEP indicates whether
2864 we're about to do a step/next-like command to a thread. */
2867 schedlock_applies (struct thread_info
*tp
)
2869 return (scheduler_mode
== schedlock_on
2870 || (scheduler_mode
== schedlock_step
2871 && tp
->control
.stepping_command
)
2872 || (scheduler_mode
== schedlock_replay
2873 && target_record_will_replay (minus_one_ptid
,
2874 execution_direction
)));
2877 /* Calls target_commit_resume on all targets. */
2880 commit_resume_all_targets ()
2882 scoped_restore_current_thread restore_thread
;
2884 /* Map between process_target and a representative inferior. This
2885 is to avoid committing a resume in the same target more than
2886 once. Resumptions must be idempotent, so this is an
2888 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2890 for (inferior
*inf
: all_non_exited_inferiors ())
2891 if (inf
->has_execution ())
2892 conn_inf
[inf
->process_target ()] = inf
;
2894 for (const auto &ci
: conn_inf
)
2896 inferior
*inf
= ci
.second
;
2897 switch_to_inferior_no_thread (inf
);
2898 target_commit_resume ();
2902 /* Check that all the targets we're about to resume are in non-stop
2903 mode. Ideally, we'd only care whether all targets support
2904 target-async, but we're not there yet. E.g., stop_all_threads
2905 doesn't know how to handle all-stop targets. Also, the remote
2906 protocol in all-stop mode is synchronous, irrespective of
2907 target-async, which means that things like a breakpoint re-set
2908 triggered by one target would try to read memory from all targets
2912 check_multi_target_resumption (process_stratum_target
*resume_target
)
2914 if (!non_stop
&& resume_target
== nullptr)
2916 scoped_restore_current_thread restore_thread
;
2918 /* This is used to track whether we're resuming more than one
2920 process_stratum_target
*first_connection
= nullptr;
2922 /* The first inferior we see with a target that does not work in
2923 always-non-stop mode. */
2924 inferior
*first_not_non_stop
= nullptr;
2926 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2928 switch_to_inferior_no_thread (inf
);
2930 if (!target_has_execution
)
2933 process_stratum_target
*proc_target
2934 = current_inferior ()->process_target();
2936 if (!target_is_non_stop_p ())
2937 first_not_non_stop
= inf
;
2939 if (first_connection
== nullptr)
2940 first_connection
= proc_target
;
2941 else if (first_connection
!= proc_target
2942 && first_not_non_stop
!= nullptr)
2944 switch_to_inferior_no_thread (first_not_non_stop
);
2946 proc_target
= current_inferior ()->process_target();
2948 error (_("Connection %d (%s) does not support "
2949 "multi-target resumption."),
2950 proc_target
->connection_number
,
2951 make_target_connection_string (proc_target
).c_str ());
2957 /* Basic routine for continuing the program in various fashions.
2959 ADDR is the address to resume at, or -1 for resume where stopped.
2960 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2961 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2963 You should call clear_proceed_status before calling proceed. */
2966 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2968 struct regcache
*regcache
;
2969 struct gdbarch
*gdbarch
;
2971 struct execution_control_state ecss
;
2972 struct execution_control_state
*ecs
= &ecss
;
2975 /* If we're stopped at a fork/vfork, follow the branch set by the
2976 "set follow-fork-mode" command; otherwise, we'll just proceed
2977 resuming the current thread. */
2978 if (!follow_fork ())
2980 /* The target for some reason decided not to resume. */
2982 if (target_can_async_p ())
2983 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2987 /* We'll update this if & when we switch to a new thread. */
2988 previous_inferior_ptid
= inferior_ptid
;
2990 regcache
= get_current_regcache ();
2991 gdbarch
= regcache
->arch ();
2992 const address_space
*aspace
= regcache
->aspace ();
2994 pc
= regcache_read_pc (regcache
);
2995 thread_info
*cur_thr
= inferior_thread ();
2997 /* Fill in with reasonable starting values. */
2998 init_thread_stepping_state (cur_thr
);
3000 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
3003 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
3004 process_stratum_target
*resume_target
3005 = user_visible_resume_target (resume_ptid
);
3007 check_multi_target_resumption (resume_target
);
3009 if (addr
== (CORE_ADDR
) -1)
3011 if (pc
== cur_thr
->suspend
.stop_pc
3012 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3013 && execution_direction
!= EXEC_REVERSE
)
3014 /* There is a breakpoint at the address we will resume at,
3015 step one instruction before inserting breakpoints so that
3016 we do not stop right away (and report a second hit at this
3019 Note, we don't do this in reverse, because we won't
3020 actually be executing the breakpoint insn anyway.
3021 We'll be (un-)executing the previous instruction. */
3022 cur_thr
->stepping_over_breakpoint
= 1;
3023 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3024 && gdbarch_single_step_through_delay (gdbarch
,
3025 get_current_frame ()))
3026 /* We stepped onto an instruction that needs to be stepped
3027 again before re-inserting the breakpoint, do so. */
3028 cur_thr
->stepping_over_breakpoint
= 1;
3032 regcache_write_pc (regcache
, addr
);
3035 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3036 cur_thr
->suspend
.stop_signal
= siggnal
;
3038 /* If an exception is thrown from this point on, make sure to
3039 propagate GDB's knowledge of the executing state to the
3040 frontend/user running state. */
3041 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3043 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3044 threads (e.g., we might need to set threads stepping over
3045 breakpoints first), from the user/frontend's point of view, all
3046 threads in RESUME_PTID are now running. Unless we're calling an
3047 inferior function, as in that case we pretend the inferior
3048 doesn't run at all. */
3049 if (!cur_thr
->control
.in_infcall
)
3050 set_running (resume_target
, resume_ptid
, true);
3053 fprintf_unfiltered (gdb_stdlog
,
3054 "infrun: proceed (addr=%s, signal=%s)\n",
3055 paddress (gdbarch
, addr
),
3056 gdb_signal_to_symbol_string (siggnal
));
3058 annotate_starting ();
3060 /* Make sure that output from GDB appears before output from the
3062 gdb_flush (gdb_stdout
);
3064 /* Since we've marked the inferior running, give it the terminal. A
3065 QUIT/Ctrl-C from here on is forwarded to the target (which can
3066 still detect attempts to unblock a stuck connection with repeated
3067 Ctrl-C from within target_pass_ctrlc). */
3068 target_terminal::inferior ();
3070 /* In a multi-threaded task we may select another thread and
3071 then continue or step.
3073 But if a thread that we're resuming had stopped at a breakpoint,
3074 it will immediately cause another breakpoint stop without any
3075 execution (i.e. it will report a breakpoint hit incorrectly). So
3076 we must step over it first.
3078 Look for threads other than the current (TP) that reported a
3079 breakpoint hit and haven't been resumed yet since. */
3081 /* If scheduler locking applies, we can avoid iterating over all
3083 if (!non_stop
&& !schedlock_applies (cur_thr
))
3085 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3088 switch_to_thread_no_regs (tp
);
3090 /* Ignore the current thread here. It's handled
3095 if (!thread_still_needs_step_over (tp
))
3098 gdb_assert (!thread_is_in_step_over_chain (tp
));
3101 fprintf_unfiltered (gdb_stdlog
,
3102 "infrun: need to step-over [%s] first\n",
3103 target_pid_to_str (tp
->ptid
).c_str ());
3105 thread_step_over_chain_enqueue (tp
);
3108 switch_to_thread (cur_thr
);
3111 /* Enqueue the current thread last, so that we move all other
3112 threads over their breakpoints first. */
3113 if (cur_thr
->stepping_over_breakpoint
)
3114 thread_step_over_chain_enqueue (cur_thr
);
3116 /* If the thread isn't started, we'll still need to set its prev_pc,
3117 so that switch_back_to_stepped_thread knows the thread hasn't
3118 advanced. Must do this before resuming any thread, as in
3119 all-stop/remote, once we resume we can't send any other packet
3120 until the target stops again. */
3121 cur_thr
->prev_pc
= regcache_read_pc (regcache
);
3124 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3126 started
= start_step_over ();
3128 if (step_over_info_valid_p ())
3130 /* Either this thread started a new in-line step over, or some
3131 other thread was already doing one. In either case, don't
3132 resume anything else until the step-over is finished. */
3134 else if (started
&& !target_is_non_stop_p ())
3136 /* A new displaced stepping sequence was started. In all-stop,
3137 we can't talk to the target anymore until it next stops. */
3139 else if (!non_stop
&& target_is_non_stop_p ())
3141 /* In all-stop, but the target is always in non-stop mode.
3142 Start all other threads that are implicitly resumed too. */
3143 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3146 switch_to_thread_no_regs (tp
);
3148 if (!tp
->inf
->has_execution ())
3151 fprintf_unfiltered (gdb_stdlog
,
3152 "infrun: proceed: [%s] target has "
3154 target_pid_to_str (tp
->ptid
).c_str ());
3161 fprintf_unfiltered (gdb_stdlog
,
3162 "infrun: proceed: [%s] resumed\n",
3163 target_pid_to_str (tp
->ptid
).c_str ());
3164 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3168 if (thread_is_in_step_over_chain (tp
))
3171 fprintf_unfiltered (gdb_stdlog
,
3172 "infrun: proceed: [%s] needs step-over\n",
3173 target_pid_to_str (tp
->ptid
).c_str ());
3178 fprintf_unfiltered (gdb_stdlog
,
3179 "infrun: proceed: resuming %s\n",
3180 target_pid_to_str (tp
->ptid
).c_str ());
3182 reset_ecs (ecs
, tp
);
3183 switch_to_thread (tp
);
3184 keep_going_pass_signal (ecs
);
3185 if (!ecs
->wait_some_more
)
3186 error (_("Command aborted."));
3189 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3191 /* The thread wasn't started, and isn't queued, run it now. */
3192 reset_ecs (ecs
, cur_thr
);
3193 switch_to_thread (cur_thr
);
3194 keep_going_pass_signal (ecs
);
3195 if (!ecs
->wait_some_more
)
3196 error (_("Command aborted."));
3200 commit_resume_all_targets ();
3202 finish_state
.release ();
3204 /* If we've switched threads above, switch back to the previously
3205 current thread. We don't want the user to see a different
3207 switch_to_thread (cur_thr
);
3209 /* Tell the event loop to wait for it to stop. If the target
3210 supports asynchronous execution, it'll do this from within
3212 if (!target_can_async_p ())
3213 mark_async_event_handler (infrun_async_inferior_event_token
);
3217 /* Start remote-debugging of a machine over a serial link. */
3220 start_remote (int from_tty
)
3222 inferior
*inf
= current_inferior ();
3223 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3225 /* Always go on waiting for the target, regardless of the mode. */
3226 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3227 indicate to wait_for_inferior that a target should timeout if
3228 nothing is returned (instead of just blocking). Because of this,
3229 targets expecting an immediate response need to, internally, set
3230 things up so that the target_wait() is forced to eventually
3232 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3233 differentiate to its caller what the state of the target is after
3234 the initial open has been performed. Here we're assuming that
3235 the target has stopped. It should be possible to eventually have
3236 target_open() return to the caller an indication that the target
3237 is currently running and GDB state should be set to the same as
3238 for an async run. */
3239 wait_for_inferior (inf
);
3241 /* Now that the inferior has stopped, do any bookkeeping like
3242 loading shared libraries. We want to do this before normal_stop,
3243 so that the displayed frame is up to date. */
3244 post_create_inferior (current_top_target (), from_tty
);
3249 /* Initialize static vars when a new inferior begins. */
3252 init_wait_for_inferior (void)
3254 /* These are meaningless until the first time through wait_for_inferior. */
3256 breakpoint_init_inferior (inf_starting
);
3258 clear_proceed_status (0);
3260 nullify_last_target_wait_ptid ();
3262 previous_inferior_ptid
= inferior_ptid
;
3267 static void handle_inferior_event (struct execution_control_state
*ecs
);
3269 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3270 struct execution_control_state
*ecs
);
3271 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3272 struct execution_control_state
*ecs
);
3273 static void handle_signal_stop (struct execution_control_state
*ecs
);
3274 static void check_exception_resume (struct execution_control_state
*,
3275 struct frame_info
*);
3277 static void end_stepping_range (struct execution_control_state
*ecs
);
3278 static void stop_waiting (struct execution_control_state
*ecs
);
3279 static void keep_going (struct execution_control_state
*ecs
);
3280 static void process_event_stop_test (struct execution_control_state
*ecs
);
3281 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3283 /* This function is attached as a "thread_stop_requested" observer.
3284 Cleanup local state that assumed the PTID was to be resumed, and
3285 report the stop to the frontend. */
3288 infrun_thread_stop_requested (ptid_t ptid
)
3290 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3292 /* PTID was requested to stop. If the thread was already stopped,
3293 but the user/frontend doesn't know about that yet (e.g., the
3294 thread had been temporarily paused for some step-over), set up
3295 for reporting the stop now. */
3296 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3298 if (tp
->state
!= THREAD_RUNNING
)
3303 /* Remove matching threads from the step-over queue, so
3304 start_step_over doesn't try to resume them
3306 if (thread_is_in_step_over_chain (tp
))
3307 thread_step_over_chain_remove (tp
);
3309 /* If the thread is stopped, but the user/frontend doesn't
3310 know about that yet, queue a pending event, as if the
3311 thread had just stopped now. Unless the thread already had
3313 if (!tp
->suspend
.waitstatus_pending_p
)
3315 tp
->suspend
.waitstatus_pending_p
= 1;
3316 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3317 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3320 /* Clear the inline-frame state, since we're re-processing the
3322 clear_inline_frame_state (tp
);
3324 /* If this thread was paused because some other thread was
3325 doing an inline-step over, let that finish first. Once
3326 that happens, we'll restart all threads and consume pending
3327 stop events then. */
3328 if (step_over_info_valid_p ())
3331 /* Otherwise we can process the (new) pending event now. Set
3332 it so this pending event is considered by
3339 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3341 if (target_last_proc_target
== tp
->inf
->process_target ()
3342 && target_last_wait_ptid
== tp
->ptid
)
3343 nullify_last_target_wait_ptid ();
3346 /* Delete the step resume, single-step and longjmp/exception resume
3347 breakpoints of TP. */
3350 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3352 delete_step_resume_breakpoint (tp
);
3353 delete_exception_resume_breakpoint (tp
);
3354 delete_single_step_breakpoints (tp
);
3357 /* If the target still has execution, call FUNC for each thread that
3358 just stopped. In all-stop, that's all the non-exited threads; in
3359 non-stop, that's the current thread, only. */
3361 typedef void (*for_each_just_stopped_thread_callback_func
)
3362 (struct thread_info
*tp
);
3365 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3367 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3370 if (target_is_non_stop_p ())
3372 /* If in non-stop mode, only the current thread stopped. */
3373 func (inferior_thread ());
3377 /* In all-stop mode, all threads have stopped. */
3378 for (thread_info
*tp
: all_non_exited_threads ())
3383 /* Delete the step resume and longjmp/exception resume breakpoints of
3384 the threads that just stopped. */
3387 delete_just_stopped_threads_infrun_breakpoints (void)
3389 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3392 /* Delete the single-step breakpoints of the threads that just
3396 delete_just_stopped_threads_single_step_breakpoints (void)
3398 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3404 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3405 const struct target_waitstatus
*ws
)
3407 std::string status_string
= target_waitstatus_to_string (ws
);
3410 /* The text is split over several lines because it was getting too long.
3411 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3412 output as a unit; we want only one timestamp printed if debug_timestamp
3415 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3418 waiton_ptid
.tid ());
3419 if (waiton_ptid
.pid () != -1)
3420 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3421 stb
.printf (", status) =\n");
3422 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3426 target_pid_to_str (result_ptid
).c_str ());
3427 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3429 /* This uses %s in part to handle %'s in the text, but also to avoid
3430 a gcc error: the format attribute requires a string literal. */
3431 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3434 /* Select a thread at random, out of those which are resumed and have
3437 static struct thread_info
*
3438 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3442 auto has_event
= [&] (thread_info
*tp
)
3444 return (tp
->ptid
.matches (waiton_ptid
)
3446 && tp
->suspend
.waitstatus_pending_p
);
3449 /* First see how many events we have. Count only resumed threads
3450 that have an event pending. */
3451 for (thread_info
*tp
: inf
->non_exited_threads ())
3455 if (num_events
== 0)
3458 /* Now randomly pick a thread out of those that have had events. */
3459 int random_selector
= (int) ((num_events
* (double) rand ())
3460 / (RAND_MAX
+ 1.0));
3462 if (debug_infrun
&& num_events
> 1)
3463 fprintf_unfiltered (gdb_stdlog
,
3464 "infrun: Found %d events, selecting #%d\n",
3465 num_events
, random_selector
);
3467 /* Select the Nth thread that has had an event. */
3468 for (thread_info
*tp
: inf
->non_exited_threads ())
3470 if (random_selector
-- == 0)
3473 gdb_assert_not_reached ("event thread not found");
3476 /* Wrapper for target_wait that first checks whether threads have
3477 pending statuses to report before actually asking the target for
3478 more events. INF is the inferior we're using to call target_wait
3482 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3483 target_waitstatus
*status
, int options
)
3486 struct thread_info
*tp
;
3488 /* We know that we are looking for an event in the target of inferior
3489 INF, but we don't know which thread the event might come from. As
3490 such we want to make sure that INFERIOR_PTID is reset so that none of
3491 the wait code relies on it - doing so is always a mistake. */
3492 switch_to_inferior_no_thread (inf
);
3494 /* First check if there is a resumed thread with a wait status
3496 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3498 tp
= random_pending_event_thread (inf
, ptid
);
3503 fprintf_unfiltered (gdb_stdlog
,
3504 "infrun: Waiting for specific thread %s.\n",
3505 target_pid_to_str (ptid
).c_str ());
3507 /* We have a specific thread to check. */
3508 tp
= find_thread_ptid (inf
, ptid
);
3509 gdb_assert (tp
!= NULL
);
3510 if (!tp
->suspend
.waitstatus_pending_p
)
3515 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3516 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3518 struct regcache
*regcache
= get_thread_regcache (tp
);
3519 struct gdbarch
*gdbarch
= regcache
->arch ();
3523 pc
= regcache_read_pc (regcache
);
3525 if (pc
!= tp
->suspend
.stop_pc
)
3528 fprintf_unfiltered (gdb_stdlog
,
3529 "infrun: PC of %s changed. was=%s, now=%s\n",
3530 target_pid_to_str (tp
->ptid
).c_str (),
3531 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3532 paddress (gdbarch
, pc
));
3535 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3538 fprintf_unfiltered (gdb_stdlog
,
3539 "infrun: previous breakpoint of %s, at %s gone\n",
3540 target_pid_to_str (tp
->ptid
).c_str (),
3541 paddress (gdbarch
, pc
));
3549 fprintf_unfiltered (gdb_stdlog
,
3550 "infrun: pending event of %s cancelled.\n",
3551 target_pid_to_str (tp
->ptid
).c_str ());
3553 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3554 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3563 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3565 fprintf_unfiltered (gdb_stdlog
,
3566 "infrun: Using pending wait status %s for %s.\n",
3568 target_pid_to_str (tp
->ptid
).c_str ());
3571 /* Now that we've selected our final event LWP, un-adjust its PC
3572 if it was a software breakpoint (and the target doesn't
3573 always adjust the PC itself). */
3574 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3575 && !target_supports_stopped_by_sw_breakpoint ())
3577 struct regcache
*regcache
;
3578 struct gdbarch
*gdbarch
;
3581 regcache
= get_thread_regcache (tp
);
3582 gdbarch
= regcache
->arch ();
3584 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3589 pc
= regcache_read_pc (regcache
);
3590 regcache_write_pc (regcache
, pc
+ decr_pc
);
3594 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3595 *status
= tp
->suspend
.waitstatus
;
3596 tp
->suspend
.waitstatus_pending_p
= 0;
3598 /* Wake up the event loop again, until all pending events are
3600 if (target_is_async_p ())
3601 mark_async_event_handler (infrun_async_inferior_event_token
);
3605 /* But if we don't find one, we'll have to wait. */
3607 if (deprecated_target_wait_hook
)
3608 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3610 event_ptid
= target_wait (ptid
, status
, options
);
3615 /* Returns true if INF has any resumed thread with a status
3619 threads_are_resumed_pending_p (inferior
*inf
)
3621 for (thread_info
*tp
: inf
->non_exited_threads ())
3623 && tp
->suspend
.waitstatus_pending_p
)
3629 /* Wrapper for target_wait that first checks whether threads have
3630 pending statuses to report before actually asking the target for
3631 more events. Polls for events from all inferiors/targets. */
3634 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3636 int num_inferiors
= 0;
3637 int random_selector
;
3639 /* For fairness, we pick the first inferior/target to poll at
3640 random, and then continue polling the rest of the inferior list
3641 starting from that one in a circular fashion until the whole list
3644 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3646 return (inf
->process_target () != NULL
3647 && (threads_are_executing (inf
->process_target ())
3648 || threads_are_resumed_pending_p (inf
))
3649 && ptid_t (inf
->pid
).matches (wait_ptid
));
3652 /* First see how many resumed inferiors we have. */
3653 for (inferior
*inf
: all_inferiors ())
3654 if (inferior_matches (inf
))
3657 if (num_inferiors
== 0)
3659 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3663 /* Now randomly pick an inferior out of those that were resumed. */
3664 random_selector
= (int)
3665 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3667 if (debug_infrun
&& num_inferiors
> 1)
3668 fprintf_unfiltered (gdb_stdlog
,
3669 "infrun: Found %d inferiors, starting at #%d\n",
3670 num_inferiors
, random_selector
);
3672 /* Select the Nth inferior that was resumed. */
3674 inferior
*selected
= nullptr;
3676 for (inferior
*inf
: all_inferiors ())
3677 if (inferior_matches (inf
))
3678 if (random_selector
-- == 0)
3684 /* Now poll for events out of each of the resumed inferior's
3685 targets, starting from the selected one. */
3687 auto do_wait
= [&] (inferior
*inf
)
3689 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3690 ecs
->target
= inf
->process_target ();
3691 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3694 /* Needed in all-stop+target-non-stop mode, because we end up here
3695 spuriously after the target is all stopped and we've already
3696 reported the stop to the user, polling for events. */
3697 scoped_restore_current_thread restore_thread
;
3699 int inf_num
= selected
->num
;
3700 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3701 if (inferior_matches (inf
))
3705 for (inferior
*inf
= inferior_list
;
3706 inf
!= NULL
&& inf
->num
< inf_num
;
3708 if (inferior_matches (inf
))
3712 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3716 /* Prepare and stabilize the inferior for detaching it. E.g.,
3717 detaching while a thread is displaced stepping is a recipe for
3718 crashing it, as nothing would readjust the PC out of the scratch
3722 prepare_for_detach (void)
3724 struct inferior
*inf
= current_inferior ();
3725 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3727 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3729 /* Is any thread of this process displaced stepping? If not,
3730 there's nothing else to do. */
3731 if (displaced
->step_thread
== nullptr)
3735 fprintf_unfiltered (gdb_stdlog
,
3736 "displaced-stepping in-process while detaching");
3738 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3740 while (displaced
->step_thread
!= nullptr)
3742 struct execution_control_state ecss
;
3743 struct execution_control_state
*ecs
;
3746 memset (ecs
, 0, sizeof (*ecs
));
3748 overlay_cache_invalid
= 1;
3749 /* Flush target cache before starting to handle each event.
3750 Target was running and cache could be stale. This is just a
3751 heuristic. Running threads may modify target memory, but we
3752 don't get any event. */
3753 target_dcache_invalidate ();
3755 do_target_wait (pid_ptid
, ecs
, 0);
3758 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3760 /* If an error happens while handling the event, propagate GDB's
3761 knowledge of the executing state to the frontend/user running
3763 scoped_finish_thread_state
finish_state (inf
->process_target (),
3766 /* Now figure out what to do with the result of the result. */
3767 handle_inferior_event (ecs
);
3769 /* No error, don't finish the state yet. */
3770 finish_state
.release ();
3772 /* Breakpoints and watchpoints are not installed on the target
3773 at this point, and signals are passed directly to the
3774 inferior, so this must mean the process is gone. */
3775 if (!ecs
->wait_some_more
)
3777 restore_detaching
.release ();
3778 error (_("Program exited while detaching"));
3782 restore_detaching
.release ();
3785 /* Wait for control to return from inferior to debugger.
3787 If inferior gets a signal, we may decide to start it up again
3788 instead of returning. That is why there is a loop in this function.
3789 When this function actually returns it means the inferior
3790 should be left stopped and GDB should read more commands. */
3793 wait_for_inferior (inferior
*inf
)
3797 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3799 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3801 /* If an error happens while handling the event, propagate GDB's
3802 knowledge of the executing state to the frontend/user running
3804 scoped_finish_thread_state finish_state
3805 (inf
->process_target (), minus_one_ptid
);
3809 struct execution_control_state ecss
;
3810 struct execution_control_state
*ecs
= &ecss
;
3812 memset (ecs
, 0, sizeof (*ecs
));
3814 overlay_cache_invalid
= 1;
3816 /* Flush target cache before starting to handle each event.
3817 Target was running and cache could be stale. This is just a
3818 heuristic. Running threads may modify target memory, but we
3819 don't get any event. */
3820 target_dcache_invalidate ();
3822 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3823 ecs
->target
= inf
->process_target ();
3826 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3828 /* Now figure out what to do with the result of the result. */
3829 handle_inferior_event (ecs
);
3831 if (!ecs
->wait_some_more
)
3835 /* No error, don't finish the state yet. */
3836 finish_state
.release ();
3839 /* Cleanup that reinstalls the readline callback handler, if the
3840 target is running in the background. If while handling the target
3841 event something triggered a secondary prompt, like e.g., a
3842 pagination prompt, we'll have removed the callback handler (see
3843 gdb_readline_wrapper_line). Need to do this as we go back to the
3844 event loop, ready to process further input. Note this has no
3845 effect if the handler hasn't actually been removed, because calling
3846 rl_callback_handler_install resets the line buffer, thus losing
3850 reinstall_readline_callback_handler_cleanup ()
3852 struct ui
*ui
= current_ui
;
3856 /* We're not going back to the top level event loop yet. Don't
3857 install the readline callback, as it'd prep the terminal,
3858 readline-style (raw, noecho) (e.g., --batch). We'll install
3859 it the next time the prompt is displayed, when we're ready
3864 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3865 gdb_rl_callback_handler_reinstall ();
3868 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3869 that's just the event thread. In all-stop, that's all threads. */
3872 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3874 if (ecs
->event_thread
!= NULL
3875 && ecs
->event_thread
->thread_fsm
!= NULL
)
3876 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3880 for (thread_info
*thr
: all_non_exited_threads ())
3882 if (thr
->thread_fsm
== NULL
)
3884 if (thr
== ecs
->event_thread
)
3887 switch_to_thread (thr
);
3888 thr
->thread_fsm
->clean_up (thr
);
3891 if (ecs
->event_thread
!= NULL
)
3892 switch_to_thread (ecs
->event_thread
);
3896 /* Helper for all_uis_check_sync_execution_done that works on the
3900 check_curr_ui_sync_execution_done (void)
3902 struct ui
*ui
= current_ui
;
3904 if (ui
->prompt_state
== PROMPT_NEEDED
3906 && !gdb_in_secondary_prompt_p (ui
))
3908 target_terminal::ours ();
3909 gdb::observers::sync_execution_done
.notify ();
3910 ui_register_input_event_handler (ui
);
3917 all_uis_check_sync_execution_done (void)
3919 SWITCH_THRU_ALL_UIS ()
3921 check_curr_ui_sync_execution_done ();
3928 all_uis_on_sync_execution_starting (void)
3930 SWITCH_THRU_ALL_UIS ()
3932 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3933 async_disable_stdin ();
3937 /* Asynchronous version of wait_for_inferior. It is called by the
3938 event loop whenever a change of state is detected on the file
3939 descriptor corresponding to the target. It can be called more than
3940 once to complete a single execution command. In such cases we need
3941 to keep the state in a global variable ECSS. If it is the last time
3942 that this function is called for a single execution command, then
3943 report to the user that the inferior has stopped, and do the
3944 necessary cleanups. */
3947 fetch_inferior_event (void *client_data
)
3949 struct execution_control_state ecss
;
3950 struct execution_control_state
*ecs
= &ecss
;
3953 memset (ecs
, 0, sizeof (*ecs
));
3955 /* Events are always processed with the main UI as current UI. This
3956 way, warnings, debug output, etc. are always consistently sent to
3957 the main console. */
3958 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3960 /* End up with readline processing input, if necessary. */
3962 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3964 /* We're handling a live event, so make sure we're doing live
3965 debugging. If we're looking at traceframes while the target is
3966 running, we're going to need to get back to that mode after
3967 handling the event. */
3968 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3971 maybe_restore_traceframe
.emplace ();
3972 set_current_traceframe (-1);
3975 /* The user/frontend should not notice a thread switch due to
3976 internal events. Make sure we revert to the user selected
3977 thread and frame after handling the event and running any
3978 breakpoint commands. */
3979 scoped_restore_current_thread restore_thread
;
3981 overlay_cache_invalid
= 1;
3982 /* Flush target cache before starting to handle each event. Target
3983 was running and cache could be stale. This is just a heuristic.
3984 Running threads may modify target memory, but we don't get any
3986 target_dcache_invalidate ();
3988 scoped_restore save_exec_dir
3989 = make_scoped_restore (&execution_direction
,
3990 target_execution_direction ());
3992 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3995 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3997 /* Switch to the target that generated the event, so we can do
3998 target calls. Any inferior bound to the target will do, so we
3999 just switch to the first we find. */
4000 for (inferior
*inf
: all_inferiors (ecs
->target
))
4002 switch_to_inferior_no_thread (inf
);
4007 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
4009 /* If an error happens while handling the event, propagate GDB's
4010 knowledge of the executing state to the frontend/user running
4012 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
4013 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
4015 /* Get executed before scoped_restore_current_thread above to apply
4016 still for the thread which has thrown the exception. */
4017 auto defer_bpstat_clear
4018 = make_scope_exit (bpstat_clear_actions
);
4019 auto defer_delete_threads
4020 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
4022 /* Now figure out what to do with the result of the result. */
4023 handle_inferior_event (ecs
);
4025 if (!ecs
->wait_some_more
)
4027 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4028 int should_stop
= 1;
4029 struct thread_info
*thr
= ecs
->event_thread
;
4031 delete_just_stopped_threads_infrun_breakpoints ();
4035 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4037 if (thread_fsm
!= NULL
)
4038 should_stop
= thread_fsm
->should_stop (thr
);
4047 bool should_notify_stop
= true;
4050 clean_up_just_stopped_threads_fsms (ecs
);
4052 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4053 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4055 if (should_notify_stop
)
4057 /* We may not find an inferior if this was a process exit. */
4058 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4059 proceeded
= normal_stop ();
4064 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4068 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4069 previously selected thread is gone. We have two
4070 choices - switch to no thread selected, or restore the
4071 previously selected thread (now exited). We chose the
4072 later, just because that's what GDB used to do. After
4073 this, "info threads" says "The current thread <Thread
4074 ID 2> has terminated." instead of "No thread
4078 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4079 restore_thread
.dont_restore ();
4083 defer_delete_threads
.release ();
4084 defer_bpstat_clear
.release ();
4086 /* No error, don't finish the thread states yet. */
4087 finish_state
.release ();
4089 /* This scope is used to ensure that readline callbacks are
4090 reinstalled here. */
4093 /* If a UI was in sync execution mode, and now isn't, restore its
4094 prompt (a synchronous execution command has finished, and we're
4095 ready for input). */
4096 all_uis_check_sync_execution_done ();
4099 && exec_done_display_p
4100 && (inferior_ptid
== null_ptid
4101 || inferior_thread ()->state
!= THREAD_RUNNING
))
4102 printf_unfiltered (_("completed.\n"));
4108 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4109 struct symtab_and_line sal
)
4111 /* This can be removed once this function no longer implicitly relies on the
4112 inferior_ptid value. */
4113 gdb_assert (inferior_ptid
== tp
->ptid
);
4115 tp
->control
.step_frame_id
= get_frame_id (frame
);
4116 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4118 tp
->current_symtab
= sal
.symtab
;
4119 tp
->current_line
= sal
.line
;
4122 /* Clear context switchable stepping state. */
4125 init_thread_stepping_state (struct thread_info
*tss
)
4127 tss
->stepped_breakpoint
= 0;
4128 tss
->stepping_over_breakpoint
= 0;
4129 tss
->stepping_over_watchpoint
= 0;
4130 tss
->step_after_step_resume_breakpoint
= 0;
4136 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4137 target_waitstatus status
)
4139 target_last_proc_target
= target
;
4140 target_last_wait_ptid
= ptid
;
4141 target_last_waitstatus
= status
;
4147 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4148 target_waitstatus
*status
)
4150 if (target
!= nullptr)
4151 *target
= target_last_proc_target
;
4152 if (ptid
!= nullptr)
4153 *ptid
= target_last_wait_ptid
;
4154 if (status
!= nullptr)
4155 *status
= target_last_waitstatus
;
4161 nullify_last_target_wait_ptid (void)
4163 target_last_proc_target
= nullptr;
4164 target_last_wait_ptid
= minus_one_ptid
;
4165 target_last_waitstatus
= {};
4168 /* Switch thread contexts. */
4171 context_switch (execution_control_state
*ecs
)
4174 && ecs
->ptid
!= inferior_ptid
4175 && (inferior_ptid
== null_ptid
4176 || ecs
->event_thread
!= inferior_thread ()))
4178 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4179 target_pid_to_str (inferior_ptid
).c_str ());
4180 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4181 target_pid_to_str (ecs
->ptid
).c_str ());
4184 switch_to_thread (ecs
->event_thread
);
4187 /* If the target can't tell whether we've hit breakpoints
4188 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4189 check whether that could have been caused by a breakpoint. If so,
4190 adjust the PC, per gdbarch_decr_pc_after_break. */
4193 adjust_pc_after_break (struct thread_info
*thread
,
4194 struct target_waitstatus
*ws
)
4196 struct regcache
*regcache
;
4197 struct gdbarch
*gdbarch
;
4198 CORE_ADDR breakpoint_pc
, decr_pc
;
4200 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4201 we aren't, just return.
4203 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4204 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4205 implemented by software breakpoints should be handled through the normal
4208 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4209 different signals (SIGILL or SIGEMT for instance), but it is less
4210 clear where the PC is pointing afterwards. It may not match
4211 gdbarch_decr_pc_after_break. I don't know any specific target that
4212 generates these signals at breakpoints (the code has been in GDB since at
4213 least 1992) so I can not guess how to handle them here.
4215 In earlier versions of GDB, a target with
4216 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4217 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4218 target with both of these set in GDB history, and it seems unlikely to be
4219 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4221 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4224 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4227 /* In reverse execution, when a breakpoint is hit, the instruction
4228 under it has already been de-executed. The reported PC always
4229 points at the breakpoint address, so adjusting it further would
4230 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4233 B1 0x08000000 : INSN1
4234 B2 0x08000001 : INSN2
4236 PC -> 0x08000003 : INSN4
4238 Say you're stopped at 0x08000003 as above. Reverse continuing
4239 from that point should hit B2 as below. Reading the PC when the
4240 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4241 been de-executed already.
4243 B1 0x08000000 : INSN1
4244 B2 PC -> 0x08000001 : INSN2
4248 We can't apply the same logic as for forward execution, because
4249 we would wrongly adjust the PC to 0x08000000, since there's a
4250 breakpoint at PC - 1. We'd then report a hit on B1, although
4251 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4253 if (execution_direction
== EXEC_REVERSE
)
4256 /* If the target can tell whether the thread hit a SW breakpoint,
4257 trust it. Targets that can tell also adjust the PC
4259 if (target_supports_stopped_by_sw_breakpoint ())
4262 /* Note that relying on whether a breakpoint is planted in memory to
4263 determine this can fail. E.g,. the breakpoint could have been
4264 removed since. Or the thread could have been told to step an
4265 instruction the size of a breakpoint instruction, and only
4266 _after_ was a breakpoint inserted at its address. */
4268 /* If this target does not decrement the PC after breakpoints, then
4269 we have nothing to do. */
4270 regcache
= get_thread_regcache (thread
);
4271 gdbarch
= regcache
->arch ();
4273 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4277 const address_space
*aspace
= regcache
->aspace ();
4279 /* Find the location where (if we've hit a breakpoint) the
4280 breakpoint would be. */
4281 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4283 /* If the target can't tell whether a software breakpoint triggered,
4284 fallback to figuring it out based on breakpoints we think were
4285 inserted in the target, and on whether the thread was stepped or
4288 /* Check whether there actually is a software breakpoint inserted at
4291 If in non-stop mode, a race condition is possible where we've
4292 removed a breakpoint, but stop events for that breakpoint were
4293 already queued and arrive later. To suppress those spurious
4294 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4295 and retire them after a number of stop events are reported. Note
4296 this is an heuristic and can thus get confused. The real fix is
4297 to get the "stopped by SW BP and needs adjustment" info out of
4298 the target/kernel (and thus never reach here; see above). */
4299 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4300 || (target_is_non_stop_p ()
4301 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4303 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4305 if (record_full_is_used ())
4306 restore_operation_disable
.emplace
4307 (record_full_gdb_operation_disable_set ());
4309 /* When using hardware single-step, a SIGTRAP is reported for both
4310 a completed single-step and a software breakpoint. Need to
4311 differentiate between the two, as the latter needs adjusting
4312 but the former does not.
4314 The SIGTRAP can be due to a completed hardware single-step only if
4315 - we didn't insert software single-step breakpoints
4316 - this thread is currently being stepped
4318 If any of these events did not occur, we must have stopped due
4319 to hitting a software breakpoint, and have to back up to the
4322 As a special case, we could have hardware single-stepped a
4323 software breakpoint. In this case (prev_pc == breakpoint_pc),
4324 we also need to back up to the breakpoint address. */
4326 if (thread_has_single_step_breakpoints_set (thread
)
4327 || !currently_stepping (thread
)
4328 || (thread
->stepped_breakpoint
4329 && thread
->prev_pc
== breakpoint_pc
))
4330 regcache_write_pc (regcache
, breakpoint_pc
);
4335 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4337 for (frame
= get_prev_frame (frame
);
4339 frame
= get_prev_frame (frame
))
4341 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4343 if (get_frame_type (frame
) != INLINE_FRAME
)
4350 /* Look for an inline frame that is marked for skip.
4351 If PREV_FRAME is TRUE start at the previous frame,
4352 otherwise start at the current frame. Stop at the
4353 first non-inline frame, or at the frame where the
4357 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4359 struct frame_info
*frame
= get_current_frame ();
4362 frame
= get_prev_frame (frame
);
4364 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4366 const char *fn
= NULL
;
4367 symtab_and_line sal
;
4370 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4372 if (get_frame_type (frame
) != INLINE_FRAME
)
4375 sal
= find_frame_sal (frame
);
4376 sym
= get_frame_function (frame
);
4379 fn
= sym
->print_name ();
4382 && function_name_is_marked_for_skip (fn
, sal
))
4389 /* If the event thread has the stop requested flag set, pretend it
4390 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4394 handle_stop_requested (struct execution_control_state
*ecs
)
4396 if (ecs
->event_thread
->stop_requested
)
4398 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4399 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4400 handle_signal_stop (ecs
);
4406 /* Auxiliary function that handles syscall entry/return events.
4407 It returns 1 if the inferior should keep going (and GDB
4408 should ignore the event), or 0 if the event deserves to be
4412 handle_syscall_event (struct execution_control_state
*ecs
)
4414 struct regcache
*regcache
;
4417 context_switch (ecs
);
4419 regcache
= get_thread_regcache (ecs
->event_thread
);
4420 syscall_number
= ecs
->ws
.value
.syscall_number
;
4421 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4423 if (catch_syscall_enabled () > 0
4424 && catching_syscall_number (syscall_number
) > 0)
4427 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4430 ecs
->event_thread
->control
.stop_bpstat
4431 = bpstat_stop_status (regcache
->aspace (),
4432 ecs
->event_thread
->suspend
.stop_pc
,
4433 ecs
->event_thread
, &ecs
->ws
);
4435 if (handle_stop_requested (ecs
))
4438 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4440 /* Catchpoint hit. */
4445 if (handle_stop_requested (ecs
))
4448 /* If no catchpoint triggered for this, then keep going. */
4453 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4456 fill_in_stop_func (struct gdbarch
*gdbarch
,
4457 struct execution_control_state
*ecs
)
4459 if (!ecs
->stop_func_filled_in
)
4463 /* Don't care about return value; stop_func_start and stop_func_name
4464 will both be 0 if it doesn't work. */
4465 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4466 &ecs
->stop_func_name
,
4467 &ecs
->stop_func_start
,
4468 &ecs
->stop_func_end
,
4471 /* The call to find_pc_partial_function, above, will set
4472 stop_func_start and stop_func_end to the start and end
4473 of the range containing the stop pc. If this range
4474 contains the entry pc for the block (which is always the
4475 case for contiguous blocks), advance stop_func_start past
4476 the function's start offset and entrypoint. Note that
4477 stop_func_start is NOT advanced when in a range of a
4478 non-contiguous block that does not contain the entry pc. */
4479 if (block
!= nullptr
4480 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4481 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4483 ecs
->stop_func_start
4484 += gdbarch_deprecated_function_start_offset (gdbarch
);
4486 if (gdbarch_skip_entrypoint_p (gdbarch
))
4487 ecs
->stop_func_start
4488 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4491 ecs
->stop_func_filled_in
= 1;
4496 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4498 static enum stop_kind
4499 get_inferior_stop_soon (execution_control_state
*ecs
)
4501 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4503 gdb_assert (inf
!= NULL
);
4504 return inf
->control
.stop_soon
;
4507 /* Poll for one event out of the current target. Store the resulting
4508 waitstatus in WS, and return the event ptid. Does not block. */
4511 poll_one_curr_target (struct target_waitstatus
*ws
)
4515 overlay_cache_invalid
= 1;
4517 /* Flush target cache before starting to handle each event.
4518 Target was running and cache could be stale. This is just a
4519 heuristic. Running threads may modify target memory, but we
4520 don't get any event. */
4521 target_dcache_invalidate ();
4523 if (deprecated_target_wait_hook
)
4524 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4526 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4529 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4534 /* An event reported by wait_one. */
4536 struct wait_one_event
4538 /* The target the event came out of. */
4539 process_stratum_target
*target
;
4541 /* The PTID the event was for. */
4544 /* The waitstatus. */
4545 target_waitstatus ws
;
4548 /* Wait for one event out of any target. */
4550 static wait_one_event
4555 for (inferior
*inf
: all_inferiors ())
4557 process_stratum_target
*target
= inf
->process_target ();
4559 || !target
->is_async_p ()
4560 || !target
->threads_executing
)
4563 switch_to_inferior_no_thread (inf
);
4565 wait_one_event event
;
4566 event
.target
= target
;
4567 event
.ptid
= poll_one_curr_target (&event
.ws
);
4569 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4571 /* If nothing is resumed, remove the target from the
4575 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4579 /* Block waiting for some event. */
4586 for (inferior
*inf
: all_inferiors ())
4588 process_stratum_target
*target
= inf
->process_target ();
4590 || !target
->is_async_p ()
4591 || !target
->threads_executing
)
4594 int fd
= target
->async_wait_fd ();
4595 FD_SET (fd
, &readfds
);
4602 /* No waitable targets left. All must be stopped. */
4603 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4608 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4614 perror_with_name ("interruptible_select");
4619 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4620 instead of the current thread. */
4621 #define THREAD_STOPPED_BY(REASON) \
4623 thread_stopped_by_ ## REASON (ptid_t ptid) \
4625 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4626 inferior_ptid = ptid; \
4628 return target_stopped_by_ ## REASON (); \
4631 /* Generate thread_stopped_by_watchpoint. */
4632 THREAD_STOPPED_BY (watchpoint
)
4633 /* Generate thread_stopped_by_sw_breakpoint. */
4634 THREAD_STOPPED_BY (sw_breakpoint
)
4635 /* Generate thread_stopped_by_hw_breakpoint. */
4636 THREAD_STOPPED_BY (hw_breakpoint
)
4638 /* Save the thread's event and stop reason to process it later. */
4641 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4645 std::string statstr
= target_waitstatus_to_string (ws
);
4647 fprintf_unfiltered (gdb_stdlog
,
4648 "infrun: saving status %s for %d.%ld.%ld\n",
4655 /* Record for later. */
4656 tp
->suspend
.waitstatus
= *ws
;
4657 tp
->suspend
.waitstatus_pending_p
= 1;
4659 struct regcache
*regcache
= get_thread_regcache (tp
);
4660 const address_space
*aspace
= regcache
->aspace ();
4662 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4663 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4665 CORE_ADDR pc
= regcache_read_pc (regcache
);
4667 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4669 if (thread_stopped_by_watchpoint (tp
->ptid
))
4671 tp
->suspend
.stop_reason
4672 = TARGET_STOPPED_BY_WATCHPOINT
;
4674 else if (target_supports_stopped_by_sw_breakpoint ()
4675 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4677 tp
->suspend
.stop_reason
4678 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4680 else if (target_supports_stopped_by_hw_breakpoint ()
4681 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4683 tp
->suspend
.stop_reason
4684 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4686 else if (!target_supports_stopped_by_hw_breakpoint ()
4687 && hardware_breakpoint_inserted_here_p (aspace
,
4690 tp
->suspend
.stop_reason
4691 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4693 else if (!target_supports_stopped_by_sw_breakpoint ()
4694 && software_breakpoint_inserted_here_p (aspace
,
4697 tp
->suspend
.stop_reason
4698 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4700 else if (!thread_has_single_step_breakpoints_set (tp
)
4701 && currently_stepping (tp
))
4703 tp
->suspend
.stop_reason
4704 = TARGET_STOPPED_BY_SINGLE_STEP
;
4712 stop_all_threads (void)
4714 /* We may need multiple passes to discover all threads. */
4718 gdb_assert (target_is_non_stop_p ());
4721 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4723 scoped_restore_current_thread restore_thread
;
4725 target_thread_events (1);
4726 SCOPE_EXIT
{ target_thread_events (0); };
4728 /* Request threads to stop, and then wait for the stops. Because
4729 threads we already know about can spawn more threads while we're
4730 trying to stop them, and we only learn about new threads when we
4731 update the thread list, do this in a loop, and keep iterating
4732 until two passes find no threads that need to be stopped. */
4733 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4736 fprintf_unfiltered (gdb_stdlog
,
4737 "infrun: stop_all_threads, pass=%d, "
4738 "iterations=%d\n", pass
, iterations
);
4743 update_thread_list ();
4745 /* Go through all threads looking for threads that we need
4746 to tell the target to stop. */
4747 for (thread_info
*t
: all_non_exited_threads ())
4751 /* If already stopping, don't request a stop again.
4752 We just haven't seen the notification yet. */
4753 if (!t
->stop_requested
)
4756 fprintf_unfiltered (gdb_stdlog
,
4757 "infrun: %s executing, "
4759 target_pid_to_str (t
->ptid
).c_str ());
4760 switch_to_thread_no_regs (t
);
4761 target_stop (t
->ptid
);
4762 t
->stop_requested
= 1;
4767 fprintf_unfiltered (gdb_stdlog
,
4768 "infrun: %s executing, "
4769 "already stopping\n",
4770 target_pid_to_str (t
->ptid
).c_str ());
4773 if (t
->stop_requested
)
4779 fprintf_unfiltered (gdb_stdlog
,
4780 "infrun: %s not executing\n",
4781 target_pid_to_str (t
->ptid
).c_str ());
4783 /* The thread may be not executing, but still be
4784 resumed with a pending status to process. */
4792 /* If we find new threads on the second iteration, restart
4793 over. We want to see two iterations in a row with all
4798 wait_one_event event
= wait_one ();
4802 fprintf_unfiltered (gdb_stdlog
,
4803 "infrun: stop_all_threads %s %s\n",
4804 target_waitstatus_to_string (&event
.ws
).c_str (),
4805 target_pid_to_str (event
.ptid
).c_str ());
4808 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
4809 || event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4810 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4811 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4813 /* All resumed threads exited
4814 or one thread/process exited/signalled. */
4818 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4820 t
= add_thread (event
.target
, event
.ptid
);
4822 t
->stop_requested
= 0;
4825 t
->control
.may_range_step
= 0;
4827 /* This may be the first time we see the inferior report
4829 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4830 if (inf
->needs_setup
)
4832 switch_to_thread_no_regs (t
);
4836 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4837 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4839 /* We caught the event that we intended to catch, so
4840 there's no event pending. */
4841 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4842 t
->suspend
.waitstatus_pending_p
= 0;
4844 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4846 /* Add it back to the step-over queue. */
4849 fprintf_unfiltered (gdb_stdlog
,
4850 "infrun: displaced-step of %s "
4851 "canceled: adding back to the "
4852 "step-over queue\n",
4853 target_pid_to_str (t
->ptid
).c_str ());
4855 t
->control
.trap_expected
= 0;
4856 thread_step_over_chain_enqueue (t
);
4861 enum gdb_signal sig
;
4862 struct regcache
*regcache
;
4866 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4868 fprintf_unfiltered (gdb_stdlog
,
4869 "infrun: target_wait %s, saving "
4870 "status for %d.%ld.%ld\n",
4877 /* Record for later. */
4878 save_waitstatus (t
, &event
.ws
);
4880 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4881 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4883 if (displaced_step_fixup (t
, sig
) < 0)
4885 /* Add it back to the step-over queue. */
4886 t
->control
.trap_expected
= 0;
4887 thread_step_over_chain_enqueue (t
);
4890 regcache
= get_thread_regcache (t
);
4891 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4895 fprintf_unfiltered (gdb_stdlog
,
4896 "infrun: saved stop_pc=%s for %s "
4897 "(currently_stepping=%d)\n",
4898 paddress (target_gdbarch (),
4899 t
->suspend
.stop_pc
),
4900 target_pid_to_str (t
->ptid
).c_str (),
4901 currently_stepping (t
));
4909 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4912 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4915 handle_no_resumed (struct execution_control_state
*ecs
)
4917 if (target_can_async_p ())
4924 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4932 /* There were no unwaited-for children left in the target, but,
4933 we're not synchronously waiting for events either. Just
4937 fprintf_unfiltered (gdb_stdlog
,
4938 "infrun: TARGET_WAITKIND_NO_RESUMED "
4939 "(ignoring: bg)\n");
4940 prepare_to_wait (ecs
);
4945 /* Otherwise, if we were running a synchronous execution command, we
4946 may need to cancel it and give the user back the terminal.
4948 In non-stop mode, the target can't tell whether we've already
4949 consumed previous stop events, so it can end up sending us a
4950 no-resumed event like so:
4952 #0 - thread 1 is left stopped
4954 #1 - thread 2 is resumed and hits breakpoint
4955 -> TARGET_WAITKIND_STOPPED
4957 #2 - thread 3 is resumed and exits
4958 this is the last resumed thread, so
4959 -> TARGET_WAITKIND_NO_RESUMED
4961 #3 - gdb processes stop for thread 2 and decides to re-resume
4964 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4965 thread 2 is now resumed, so the event should be ignored.
4967 IOW, if the stop for thread 2 doesn't end a foreground command,
4968 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4969 event. But it could be that the event meant that thread 2 itself
4970 (or whatever other thread was the last resumed thread) exited.
4972 To address this we refresh the thread list and check whether we
4973 have resumed threads _now_. In the example above, this removes
4974 thread 3 from the thread list. If thread 2 was re-resumed, we
4975 ignore this event. If we find no thread resumed, then we cancel
4976 the synchronous command show "no unwaited-for " to the user. */
4977 update_thread_list ();
4979 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4981 if (thread
->executing
4982 || thread
->suspend
.waitstatus_pending_p
)
4984 /* There were no unwaited-for children left in the target at
4985 some point, but there are now. Just ignore. */
4987 fprintf_unfiltered (gdb_stdlog
,
4988 "infrun: TARGET_WAITKIND_NO_RESUMED "
4989 "(ignoring: found resumed)\n");
4990 prepare_to_wait (ecs
);
4995 /* Note however that we may find no resumed thread because the whole
4996 process exited meanwhile (thus updating the thread list results
4997 in an empty thread list). In this case we know we'll be getting
4998 a process exit event shortly. */
4999 for (inferior
*inf
: all_non_exited_inferiors (ecs
->target
))
5001 thread_info
*thread
= any_live_thread_of_inferior (inf
);
5005 fprintf_unfiltered (gdb_stdlog
,
5006 "infrun: TARGET_WAITKIND_NO_RESUMED "
5007 "(expect process exit)\n");
5008 prepare_to_wait (ecs
);
5013 /* Go ahead and report the event. */
5017 /* Given an execution control state that has been freshly filled in by
5018 an event from the inferior, figure out what it means and take
5021 The alternatives are:
5023 1) stop_waiting and return; to really stop and return to the
5026 2) keep_going and return; to wait for the next event (set
5027 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5031 handle_inferior_event (struct execution_control_state
*ecs
)
5033 /* Make sure that all temporary struct value objects that were
5034 created during the handling of the event get deleted at the
5036 scoped_value_mark free_values
;
5038 enum stop_kind stop_soon
;
5041 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5042 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5044 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5046 /* We had an event in the inferior, but we are not interested in
5047 handling it at this level. The lower layers have already
5048 done what needs to be done, if anything.
5050 One of the possible circumstances for this is when the
5051 inferior produces output for the console. The inferior has
5052 not stopped, and we are ignoring the event. Another possible
5053 circumstance is any event which the lower level knows will be
5054 reported multiple times without an intervening resume. */
5055 prepare_to_wait (ecs
);
5059 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5061 prepare_to_wait (ecs
);
5065 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5066 && handle_no_resumed (ecs
))
5069 /* Cache the last target/ptid/waitstatus. */
5070 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5072 /* Always clear state belonging to the previous time we stopped. */
5073 stop_stack_dummy
= STOP_NONE
;
5075 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5077 /* No unwaited-for children left. IOW, all resumed children
5079 stop_print_frame
= 0;
5084 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5085 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5087 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5088 /* If it's a new thread, add it to the thread database. */
5089 if (ecs
->event_thread
== NULL
)
5090 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5092 /* Disable range stepping. If the next step request could use a
5093 range, this will be end up re-enabled then. */
5094 ecs
->event_thread
->control
.may_range_step
= 0;
5097 /* Dependent on valid ECS->EVENT_THREAD. */
5098 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5100 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5101 reinit_frame_cache ();
5103 breakpoint_retire_moribund ();
5105 /* First, distinguish signals caused by the debugger from signals
5106 that have to do with the program's own actions. Note that
5107 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5108 on the operating system version. Here we detect when a SIGILL or
5109 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5110 something similar for SIGSEGV, since a SIGSEGV will be generated
5111 when we're trying to execute a breakpoint instruction on a
5112 non-executable stack. This happens for call dummy breakpoints
5113 for architectures like SPARC that place call dummies on the
5115 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5116 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5117 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5118 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5120 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5122 if (breakpoint_inserted_here_p (regcache
->aspace (),
5123 regcache_read_pc (regcache
)))
5126 fprintf_unfiltered (gdb_stdlog
,
5127 "infrun: Treating signal as SIGTRAP\n");
5128 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5132 /* Mark the non-executing threads accordingly. In all-stop, all
5133 threads of all processes are stopped when we get any event
5134 reported. In non-stop mode, only the event thread stops. */
5138 if (!target_is_non_stop_p ())
5139 mark_ptid
= minus_one_ptid
;
5140 else if (ecs
->ws
.kind
== TARGET_WAITKIND_SIGNALLED
5141 || ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5143 /* If we're handling a process exit in non-stop mode, even
5144 though threads haven't been deleted yet, one would think
5145 that there is nothing to do, as threads of the dead process
5146 will be soon deleted, and threads of any other process were
5147 left running. However, on some targets, threads survive a
5148 process exit event. E.g., for the "checkpoint" command,
5149 when the current checkpoint/fork exits, linux-fork.c
5150 automatically switches to another fork from within
5151 target_mourn_inferior, by associating the same
5152 inferior/thread to another fork. We haven't mourned yet at
5153 this point, but we must mark any threads left in the
5154 process as not-executing so that finish_thread_state marks
5155 them stopped (in the user's perspective) if/when we present
5156 the stop to the user. */
5157 mark_ptid
= ptid_t (ecs
->ptid
.pid ());
5160 mark_ptid
= ecs
->ptid
;
5162 set_executing (ecs
->target
, mark_ptid
, false);
5164 /* Likewise the resumed flag. */
5165 set_resumed (ecs
->target
, mark_ptid
, false);
5168 switch (ecs
->ws
.kind
)
5170 case TARGET_WAITKIND_LOADED
:
5171 context_switch (ecs
);
5172 /* Ignore gracefully during startup of the inferior, as it might
5173 be the shell which has just loaded some objects, otherwise
5174 add the symbols for the newly loaded objects. Also ignore at
5175 the beginning of an attach or remote session; we will query
5176 the full list of libraries once the connection is
5179 stop_soon
= get_inferior_stop_soon (ecs
);
5180 if (stop_soon
== NO_STOP_QUIETLY
)
5182 struct regcache
*regcache
;
5184 regcache
= get_thread_regcache (ecs
->event_thread
);
5186 handle_solib_event ();
5188 ecs
->event_thread
->control
.stop_bpstat
5189 = bpstat_stop_status (regcache
->aspace (),
5190 ecs
->event_thread
->suspend
.stop_pc
,
5191 ecs
->event_thread
, &ecs
->ws
);
5193 if (handle_stop_requested (ecs
))
5196 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5198 /* A catchpoint triggered. */
5199 process_event_stop_test (ecs
);
5203 /* If requested, stop when the dynamic linker notifies
5204 gdb of events. This allows the user to get control
5205 and place breakpoints in initializer routines for
5206 dynamically loaded objects (among other things). */
5207 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5208 if (stop_on_solib_events
)
5210 /* Make sure we print "Stopped due to solib-event" in
5212 stop_print_frame
= 1;
5219 /* If we are skipping through a shell, or through shared library
5220 loading that we aren't interested in, resume the program. If
5221 we're running the program normally, also resume. */
5222 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5224 /* Loading of shared libraries might have changed breakpoint
5225 addresses. Make sure new breakpoints are inserted. */
5226 if (stop_soon
== NO_STOP_QUIETLY
)
5227 insert_breakpoints ();
5228 resume (GDB_SIGNAL_0
);
5229 prepare_to_wait (ecs
);
5233 /* But stop if we're attaching or setting up a remote
5235 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5236 || stop_soon
== STOP_QUIETLY_REMOTE
)
5239 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5244 internal_error (__FILE__
, __LINE__
,
5245 _("unhandled stop_soon: %d"), (int) stop_soon
);
5247 case TARGET_WAITKIND_SPURIOUS
:
5248 if (handle_stop_requested (ecs
))
5250 context_switch (ecs
);
5251 resume (GDB_SIGNAL_0
);
5252 prepare_to_wait (ecs
);
5255 case TARGET_WAITKIND_THREAD_CREATED
:
5256 if (handle_stop_requested (ecs
))
5258 context_switch (ecs
);
5259 if (!switch_back_to_stepped_thread (ecs
))
5263 case TARGET_WAITKIND_EXITED
:
5264 case TARGET_WAITKIND_SIGNALLED
:
5265 inferior_ptid
= ecs
->ptid
;
5266 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5267 set_current_program_space (current_inferior ()->pspace
);
5268 handle_vfork_child_exec_or_exit (0);
5269 target_terminal::ours (); /* Must do this before mourn anyway. */
5271 /* Clearing any previous state of convenience variables. */
5272 clear_exit_convenience_vars ();
5274 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5276 /* Record the exit code in the convenience variable $_exitcode, so
5277 that the user can inspect this again later. */
5278 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5279 (LONGEST
) ecs
->ws
.value
.integer
);
5281 /* Also record this in the inferior itself. */
5282 current_inferior ()->has_exit_code
= 1;
5283 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5285 /* Support the --return-child-result option. */
5286 return_child_result_value
= ecs
->ws
.value
.integer
;
5288 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5292 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5294 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5296 /* Set the value of the internal variable $_exitsignal,
5297 which holds the signal uncaught by the inferior. */
5298 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5299 gdbarch_gdb_signal_to_target (gdbarch
,
5300 ecs
->ws
.value
.sig
));
5304 /* We don't have access to the target's method used for
5305 converting between signal numbers (GDB's internal
5306 representation <-> target's representation).
5307 Therefore, we cannot do a good job at displaying this
5308 information to the user. It's better to just warn
5309 her about it (if infrun debugging is enabled), and
5312 fprintf_filtered (gdb_stdlog
, _("\
5313 Cannot fill $_exitsignal with the correct signal number.\n"));
5316 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5319 gdb_flush (gdb_stdout
);
5320 target_mourn_inferior (inferior_ptid
);
5321 stop_print_frame
= 0;
5325 case TARGET_WAITKIND_FORKED
:
5326 case TARGET_WAITKIND_VFORKED
:
5327 /* Check whether the inferior is displaced stepping. */
5329 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5330 struct gdbarch
*gdbarch
= regcache
->arch ();
5332 /* If checking displaced stepping is supported, and thread
5333 ecs->ptid is displaced stepping. */
5334 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5336 struct inferior
*parent_inf
5337 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5338 struct regcache
*child_regcache
;
5339 CORE_ADDR parent_pc
;
5341 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5343 struct displaced_step_inferior_state
*displaced
5344 = get_displaced_stepping_state (parent_inf
);
5346 /* Restore scratch pad for child process. */
5347 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5350 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5351 indicating that the displaced stepping of syscall instruction
5352 has been done. Perform cleanup for parent process here. Note
5353 that this operation also cleans up the child process for vfork,
5354 because their pages are shared. */
5355 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5356 /* Start a new step-over in another thread if there's one
5360 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5361 the child's PC is also within the scratchpad. Set the child's PC
5362 to the parent's PC value, which has already been fixed up.
5363 FIXME: we use the parent's aspace here, although we're touching
5364 the child, because the child hasn't been added to the inferior
5365 list yet at this point. */
5368 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5369 ecs
->ws
.value
.related_pid
,
5371 parent_inf
->aspace
);
5372 /* Read PC value of parent process. */
5373 parent_pc
= regcache_read_pc (regcache
);
5375 if (debug_displaced
)
5376 fprintf_unfiltered (gdb_stdlog
,
5377 "displaced: write child pc from %s to %s\n",
5379 regcache_read_pc (child_regcache
)),
5380 paddress (gdbarch
, parent_pc
));
5382 regcache_write_pc (child_regcache
, parent_pc
);
5386 context_switch (ecs
);
5388 /* Immediately detach breakpoints from the child before there's
5389 any chance of letting the user delete breakpoints from the
5390 breakpoint lists. If we don't do this early, it's easy to
5391 leave left over traps in the child, vis: "break foo; catch
5392 fork; c; <fork>; del; c; <child calls foo>". We only follow
5393 the fork on the last `continue', and by that time the
5394 breakpoint at "foo" is long gone from the breakpoint table.
5395 If we vforked, then we don't need to unpatch here, since both
5396 parent and child are sharing the same memory pages; we'll
5397 need to unpatch at follow/detach time instead to be certain
5398 that new breakpoints added between catchpoint hit time and
5399 vfork follow are detached. */
5400 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5402 /* This won't actually modify the breakpoint list, but will
5403 physically remove the breakpoints from the child. */
5404 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5407 delete_just_stopped_threads_single_step_breakpoints ();
5409 /* In case the event is caught by a catchpoint, remember that
5410 the event is to be followed at the next resume of the thread,
5411 and not immediately. */
5412 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5414 ecs
->event_thread
->suspend
.stop_pc
5415 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5417 ecs
->event_thread
->control
.stop_bpstat
5418 = bpstat_stop_status (get_current_regcache ()->aspace (),
5419 ecs
->event_thread
->suspend
.stop_pc
,
5420 ecs
->event_thread
, &ecs
->ws
);
5422 if (handle_stop_requested (ecs
))
5425 /* If no catchpoint triggered for this, then keep going. Note
5426 that we're interested in knowing the bpstat actually causes a
5427 stop, not just if it may explain the signal. Software
5428 watchpoints, for example, always appear in the bpstat. */
5429 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5433 = (follow_fork_mode_string
== follow_fork_mode_child
);
5435 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5437 process_stratum_target
*targ
5438 = ecs
->event_thread
->inf
->process_target ();
5440 should_resume
= follow_fork ();
5442 /* Note that one of these may be an invalid pointer,
5443 depending on detach_fork. */
5444 thread_info
*parent
= ecs
->event_thread
;
5446 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5448 /* At this point, the parent is marked running, and the
5449 child is marked stopped. */
5451 /* If not resuming the parent, mark it stopped. */
5452 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5453 parent
->set_running (false);
5455 /* If resuming the child, mark it running. */
5456 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5457 child
->set_running (true);
5459 /* In non-stop mode, also resume the other branch. */
5460 if (!detach_fork
&& (non_stop
5461 || (sched_multi
&& target_is_non_stop_p ())))
5464 switch_to_thread (parent
);
5466 switch_to_thread (child
);
5468 ecs
->event_thread
= inferior_thread ();
5469 ecs
->ptid
= inferior_ptid
;
5474 switch_to_thread (child
);
5476 switch_to_thread (parent
);
5478 ecs
->event_thread
= inferior_thread ();
5479 ecs
->ptid
= inferior_ptid
;
5487 process_event_stop_test (ecs
);
5490 case TARGET_WAITKIND_VFORK_DONE
:
5491 /* Done with the shared memory region. Re-insert breakpoints in
5492 the parent, and keep going. */
5494 context_switch (ecs
);
5496 current_inferior ()->waiting_for_vfork_done
= 0;
5497 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5499 if (handle_stop_requested (ecs
))
5502 /* This also takes care of reinserting breakpoints in the
5503 previously locked inferior. */
5507 case TARGET_WAITKIND_EXECD
:
5509 /* Note we can't read registers yet (the stop_pc), because we
5510 don't yet know the inferior's post-exec architecture.
5511 'stop_pc' is explicitly read below instead. */
5512 switch_to_thread_no_regs (ecs
->event_thread
);
5514 /* Do whatever is necessary to the parent branch of the vfork. */
5515 handle_vfork_child_exec_or_exit (1);
5517 /* This causes the eventpoints and symbol table to be reset.
5518 Must do this now, before trying to determine whether to
5520 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5522 /* In follow_exec we may have deleted the original thread and
5523 created a new one. Make sure that the event thread is the
5524 execd thread for that case (this is a nop otherwise). */
5525 ecs
->event_thread
= inferior_thread ();
5527 ecs
->event_thread
->suspend
.stop_pc
5528 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5530 ecs
->event_thread
->control
.stop_bpstat
5531 = bpstat_stop_status (get_current_regcache ()->aspace (),
5532 ecs
->event_thread
->suspend
.stop_pc
,
5533 ecs
->event_thread
, &ecs
->ws
);
5535 /* Note that this may be referenced from inside
5536 bpstat_stop_status above, through inferior_has_execd. */
5537 xfree (ecs
->ws
.value
.execd_pathname
);
5538 ecs
->ws
.value
.execd_pathname
= NULL
;
5540 if (handle_stop_requested (ecs
))
5543 /* If no catchpoint triggered for this, then keep going. */
5544 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5546 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5550 process_event_stop_test (ecs
);
5553 /* Be careful not to try to gather much state about a thread
5554 that's in a syscall. It's frequently a losing proposition. */
5555 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5556 /* Getting the current syscall number. */
5557 if (handle_syscall_event (ecs
) == 0)
5558 process_event_stop_test (ecs
);
5561 /* Before examining the threads further, step this thread to
5562 get it entirely out of the syscall. (We get notice of the
5563 event when the thread is just on the verge of exiting a
5564 syscall. Stepping one instruction seems to get it back
5566 case TARGET_WAITKIND_SYSCALL_RETURN
:
5567 if (handle_syscall_event (ecs
) == 0)
5568 process_event_stop_test (ecs
);
5571 case TARGET_WAITKIND_STOPPED
:
5572 handle_signal_stop (ecs
);
5575 case TARGET_WAITKIND_NO_HISTORY
:
5576 /* Reverse execution: target ran out of history info. */
5578 /* Switch to the stopped thread. */
5579 context_switch (ecs
);
5581 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5583 delete_just_stopped_threads_single_step_breakpoints ();
5584 ecs
->event_thread
->suspend
.stop_pc
5585 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5587 if (handle_stop_requested (ecs
))
5590 gdb::observers::no_history
.notify ();
5596 /* Restart threads back to what they were trying to do back when we
5597 paused them for an in-line step-over. The EVENT_THREAD thread is
5601 restart_threads (struct thread_info
*event_thread
)
5603 /* In case the instruction just stepped spawned a new thread. */
5604 update_thread_list ();
5606 for (thread_info
*tp
: all_non_exited_threads ())
5608 switch_to_thread_no_regs (tp
);
5610 if (tp
== event_thread
)
5613 fprintf_unfiltered (gdb_stdlog
,
5614 "infrun: restart threads: "
5615 "[%s] is event thread\n",
5616 target_pid_to_str (tp
->ptid
).c_str ());
5620 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5623 fprintf_unfiltered (gdb_stdlog
,
5624 "infrun: restart threads: "
5625 "[%s] not meant to be running\n",
5626 target_pid_to_str (tp
->ptid
).c_str ());
5633 fprintf_unfiltered (gdb_stdlog
,
5634 "infrun: restart threads: [%s] resumed\n",
5635 target_pid_to_str (tp
->ptid
).c_str ());
5636 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5640 if (thread_is_in_step_over_chain (tp
))
5643 fprintf_unfiltered (gdb_stdlog
,
5644 "infrun: restart threads: "
5645 "[%s] needs step-over\n",
5646 target_pid_to_str (tp
->ptid
).c_str ());
5647 gdb_assert (!tp
->resumed
);
5652 if (tp
->suspend
.waitstatus_pending_p
)
5655 fprintf_unfiltered (gdb_stdlog
,
5656 "infrun: restart threads: "
5657 "[%s] has pending status\n",
5658 target_pid_to_str (tp
->ptid
).c_str ());
5663 gdb_assert (!tp
->stop_requested
);
5665 /* If some thread needs to start a step-over at this point, it
5666 should still be in the step-over queue, and thus skipped
5668 if (thread_still_needs_step_over (tp
))
5670 internal_error (__FILE__
, __LINE__
,
5671 "thread [%s] needs a step-over, but not in "
5672 "step-over queue\n",
5673 target_pid_to_str (tp
->ptid
).c_str ());
5676 if (currently_stepping (tp
))
5679 fprintf_unfiltered (gdb_stdlog
,
5680 "infrun: restart threads: [%s] was stepping\n",
5681 target_pid_to_str (tp
->ptid
).c_str ());
5682 keep_going_stepped_thread (tp
);
5686 struct execution_control_state ecss
;
5687 struct execution_control_state
*ecs
= &ecss
;
5690 fprintf_unfiltered (gdb_stdlog
,
5691 "infrun: restart threads: [%s] continuing\n",
5692 target_pid_to_str (tp
->ptid
).c_str ());
5693 reset_ecs (ecs
, tp
);
5694 switch_to_thread (tp
);
5695 keep_going_pass_signal (ecs
);
5700 /* Callback for iterate_over_threads. Find a resumed thread that has
5701 a pending waitstatus. */
5704 resumed_thread_with_pending_status (struct thread_info
*tp
,
5708 && tp
->suspend
.waitstatus_pending_p
);
5711 /* Called when we get an event that may finish an in-line or
5712 out-of-line (displaced stepping) step-over started previously.
5713 Return true if the event is processed and we should go back to the
5714 event loop; false if the caller should continue processing the
5718 finish_step_over (struct execution_control_state
*ecs
)
5720 int had_step_over_info
;
5722 displaced_step_fixup (ecs
->event_thread
,
5723 ecs
->event_thread
->suspend
.stop_signal
);
5725 had_step_over_info
= step_over_info_valid_p ();
5727 if (had_step_over_info
)
5729 /* If we're stepping over a breakpoint with all threads locked,
5730 then only the thread that was stepped should be reporting
5732 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5734 clear_step_over_info ();
5737 if (!target_is_non_stop_p ())
5740 /* Start a new step-over in another thread if there's one that
5744 /* If we were stepping over a breakpoint before, and haven't started
5745 a new in-line step-over sequence, then restart all other threads
5746 (except the event thread). We can't do this in all-stop, as then
5747 e.g., we wouldn't be able to issue any other remote packet until
5748 these other threads stop. */
5749 if (had_step_over_info
&& !step_over_info_valid_p ())
5751 struct thread_info
*pending
;
5753 /* If we only have threads with pending statuses, the restart
5754 below won't restart any thread and so nothing re-inserts the
5755 breakpoint we just stepped over. But we need it inserted
5756 when we later process the pending events, otherwise if
5757 another thread has a pending event for this breakpoint too,
5758 we'd discard its event (because the breakpoint that
5759 originally caused the event was no longer inserted). */
5760 context_switch (ecs
);
5761 insert_breakpoints ();
5763 restart_threads (ecs
->event_thread
);
5765 /* If we have events pending, go through handle_inferior_event
5766 again, picking up a pending event at random. This avoids
5767 thread starvation. */
5769 /* But not if we just stepped over a watchpoint in order to let
5770 the instruction execute so we can evaluate its expression.
5771 The set of watchpoints that triggered is recorded in the
5772 breakpoint objects themselves (see bp->watchpoint_triggered).
5773 If we processed another event first, that other event could
5774 clobber this info. */
5775 if (ecs
->event_thread
->stepping_over_watchpoint
)
5778 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5780 if (pending
!= NULL
)
5782 struct thread_info
*tp
= ecs
->event_thread
;
5783 struct regcache
*regcache
;
5787 fprintf_unfiltered (gdb_stdlog
,
5788 "infrun: found resumed threads with "
5789 "pending events, saving status\n");
5792 gdb_assert (pending
!= tp
);
5794 /* Record the event thread's event for later. */
5795 save_waitstatus (tp
, &ecs
->ws
);
5796 /* This was cleared early, by handle_inferior_event. Set it
5797 so this pending event is considered by
5801 gdb_assert (!tp
->executing
);
5803 regcache
= get_thread_regcache (tp
);
5804 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5808 fprintf_unfiltered (gdb_stdlog
,
5809 "infrun: saved stop_pc=%s for %s "
5810 "(currently_stepping=%d)\n",
5811 paddress (target_gdbarch (),
5812 tp
->suspend
.stop_pc
),
5813 target_pid_to_str (tp
->ptid
).c_str (),
5814 currently_stepping (tp
));
5817 /* This in-line step-over finished; clear this so we won't
5818 start a new one. This is what handle_signal_stop would
5819 do, if we returned false. */
5820 tp
->stepping_over_breakpoint
= 0;
5822 /* Wake up the event loop again. */
5823 mark_async_event_handler (infrun_async_inferior_event_token
);
5825 prepare_to_wait (ecs
);
5833 /* Come here when the program has stopped with a signal. */
5836 handle_signal_stop (struct execution_control_state
*ecs
)
5838 struct frame_info
*frame
;
5839 struct gdbarch
*gdbarch
;
5840 int stopped_by_watchpoint
;
5841 enum stop_kind stop_soon
;
5844 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5846 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5848 /* Do we need to clean up the state of a thread that has
5849 completed a displaced single-step? (Doing so usually affects
5850 the PC, so do it here, before we set stop_pc.) */
5851 if (finish_step_over (ecs
))
5854 /* If we either finished a single-step or hit a breakpoint, but
5855 the user wanted this thread to be stopped, pretend we got a
5856 SIG0 (generic unsignaled stop). */
5857 if (ecs
->event_thread
->stop_requested
5858 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5859 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5861 ecs
->event_thread
->suspend
.stop_pc
5862 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5866 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5867 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5869 switch_to_thread (ecs
->event_thread
);
5871 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5872 paddress (reg_gdbarch
,
5873 ecs
->event_thread
->suspend
.stop_pc
));
5874 if (target_stopped_by_watchpoint ())
5878 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5880 if (target_stopped_data_address (current_top_target (), &addr
))
5881 fprintf_unfiltered (gdb_stdlog
,
5882 "infrun: stopped data address = %s\n",
5883 paddress (reg_gdbarch
, addr
));
5885 fprintf_unfiltered (gdb_stdlog
,
5886 "infrun: (no data address available)\n");
5890 /* This is originated from start_remote(), start_inferior() and
5891 shared libraries hook functions. */
5892 stop_soon
= get_inferior_stop_soon (ecs
);
5893 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5895 context_switch (ecs
);
5897 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5898 stop_print_frame
= 1;
5903 /* This originates from attach_command(). We need to overwrite
5904 the stop_signal here, because some kernels don't ignore a
5905 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5906 See more comments in inferior.h. On the other hand, if we
5907 get a non-SIGSTOP, report it to the user - assume the backend
5908 will handle the SIGSTOP if it should show up later.
5910 Also consider that the attach is complete when we see a
5911 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5912 target extended-remote report it instead of a SIGSTOP
5913 (e.g. gdbserver). We already rely on SIGTRAP being our
5914 signal, so this is no exception.
5916 Also consider that the attach is complete when we see a
5917 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5918 the target to stop all threads of the inferior, in case the
5919 low level attach operation doesn't stop them implicitly. If
5920 they weren't stopped implicitly, then the stub will report a
5921 GDB_SIGNAL_0, meaning: stopped for no particular reason
5922 other than GDB's request. */
5923 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5924 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5925 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5926 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5928 stop_print_frame
= 1;
5930 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5934 /* See if something interesting happened to the non-current thread. If
5935 so, then switch to that thread. */
5936 if (ecs
->ptid
!= inferior_ptid
)
5939 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5941 context_switch (ecs
);
5943 if (deprecated_context_hook
)
5944 deprecated_context_hook (ecs
->event_thread
->global_num
);
5947 /* At this point, get hold of the now-current thread's frame. */
5948 frame
= get_current_frame ();
5949 gdbarch
= get_frame_arch (frame
);
5951 /* Pull the single step breakpoints out of the target. */
5952 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5954 struct regcache
*regcache
;
5957 regcache
= get_thread_regcache (ecs
->event_thread
);
5958 const address_space
*aspace
= regcache
->aspace ();
5960 pc
= regcache_read_pc (regcache
);
5962 /* However, before doing so, if this single-step breakpoint was
5963 actually for another thread, set this thread up for moving
5965 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5968 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5972 fprintf_unfiltered (gdb_stdlog
,
5973 "infrun: [%s] hit another thread's "
5974 "single-step breakpoint\n",
5975 target_pid_to_str (ecs
->ptid
).c_str ());
5977 ecs
->hit_singlestep_breakpoint
= 1;
5984 fprintf_unfiltered (gdb_stdlog
,
5985 "infrun: [%s] hit its "
5986 "single-step breakpoint\n",
5987 target_pid_to_str (ecs
->ptid
).c_str ());
5991 delete_just_stopped_threads_single_step_breakpoints ();
5993 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5994 && ecs
->event_thread
->control
.trap_expected
5995 && ecs
->event_thread
->stepping_over_watchpoint
)
5996 stopped_by_watchpoint
= 0;
5998 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
6000 /* If necessary, step over this watchpoint. We'll be back to display
6002 if (stopped_by_watchpoint
6003 && (target_have_steppable_watchpoint
6004 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6006 /* At this point, we are stopped at an instruction which has
6007 attempted to write to a piece of memory under control of
6008 a watchpoint. The instruction hasn't actually executed
6009 yet. If we were to evaluate the watchpoint expression
6010 now, we would get the old value, and therefore no change
6011 would seem to have occurred.
6013 In order to make watchpoints work `right', we really need
6014 to complete the memory write, and then evaluate the
6015 watchpoint expression. We do this by single-stepping the
6018 It may not be necessary to disable the watchpoint to step over
6019 it. For example, the PA can (with some kernel cooperation)
6020 single step over a watchpoint without disabling the watchpoint.
6022 It is far more common to need to disable a watchpoint to step
6023 the inferior over it. If we have non-steppable watchpoints,
6024 we must disable the current watchpoint; it's simplest to
6025 disable all watchpoints.
6027 Any breakpoint at PC must also be stepped over -- if there's
6028 one, it will have already triggered before the watchpoint
6029 triggered, and we either already reported it to the user, or
6030 it didn't cause a stop and we called keep_going. In either
6031 case, if there was a breakpoint at PC, we must be trying to
6033 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6038 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6039 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6040 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6041 ecs
->event_thread
->control
.stop_step
= 0;
6042 stop_print_frame
= 1;
6043 stopped_by_random_signal
= 0;
6044 bpstat stop_chain
= NULL
;
6046 /* Hide inlined functions starting here, unless we just performed stepi or
6047 nexti. After stepi and nexti, always show the innermost frame (not any
6048 inline function call sites). */
6049 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6051 const address_space
*aspace
6052 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6054 /* skip_inline_frames is expensive, so we avoid it if we can
6055 determine that the address is one where functions cannot have
6056 been inlined. This improves performance with inferiors that
6057 load a lot of shared libraries, because the solib event
6058 breakpoint is defined as the address of a function (i.e. not
6059 inline). Note that we have to check the previous PC as well
6060 as the current one to catch cases when we have just
6061 single-stepped off a breakpoint prior to reinstating it.
6062 Note that we're assuming that the code we single-step to is
6063 not inline, but that's not definitive: there's nothing
6064 preventing the event breakpoint function from containing
6065 inlined code, and the single-step ending up there. If the
6066 user had set a breakpoint on that inlined code, the missing
6067 skip_inline_frames call would break things. Fortunately
6068 that's an extremely unlikely scenario. */
6069 if (!pc_at_non_inline_function (aspace
,
6070 ecs
->event_thread
->suspend
.stop_pc
,
6072 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6073 && ecs
->event_thread
->control
.trap_expected
6074 && pc_at_non_inline_function (aspace
,
6075 ecs
->event_thread
->prev_pc
,
6078 stop_chain
= build_bpstat_chain (aspace
,
6079 ecs
->event_thread
->suspend
.stop_pc
,
6081 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6083 /* Re-fetch current thread's frame in case that invalidated
6085 frame
= get_current_frame ();
6086 gdbarch
= get_frame_arch (frame
);
6090 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6091 && ecs
->event_thread
->control
.trap_expected
6092 && gdbarch_single_step_through_delay_p (gdbarch
)
6093 && currently_stepping (ecs
->event_thread
))
6095 /* We're trying to step off a breakpoint. Turns out that we're
6096 also on an instruction that needs to be stepped multiple
6097 times before it's been fully executing. E.g., architectures
6098 with a delay slot. It needs to be stepped twice, once for
6099 the instruction and once for the delay slot. */
6100 int step_through_delay
6101 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6103 if (debug_infrun
&& step_through_delay
)
6104 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6105 if (ecs
->event_thread
->control
.step_range_end
== 0
6106 && step_through_delay
)
6108 /* The user issued a continue when stopped at a breakpoint.
6109 Set up for another trap and get out of here. */
6110 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6114 else if (step_through_delay
)
6116 /* The user issued a step when stopped at a breakpoint.
6117 Maybe we should stop, maybe we should not - the delay
6118 slot *might* correspond to a line of source. In any
6119 case, don't decide that here, just set
6120 ecs->stepping_over_breakpoint, making sure we
6121 single-step again before breakpoints are re-inserted. */
6122 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6126 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6127 handles this event. */
6128 ecs
->event_thread
->control
.stop_bpstat
6129 = bpstat_stop_status (get_current_regcache ()->aspace (),
6130 ecs
->event_thread
->suspend
.stop_pc
,
6131 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6133 /* Following in case break condition called a
6135 stop_print_frame
= 1;
6137 /* This is where we handle "moribund" watchpoints. Unlike
6138 software breakpoints traps, hardware watchpoint traps are
6139 always distinguishable from random traps. If no high-level
6140 watchpoint is associated with the reported stop data address
6141 anymore, then the bpstat does not explain the signal ---
6142 simply make sure to ignore it if `stopped_by_watchpoint' is
6146 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6147 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6149 && stopped_by_watchpoint
)
6150 fprintf_unfiltered (gdb_stdlog
,
6151 "infrun: no user watchpoint explains "
6152 "watchpoint SIGTRAP, ignoring\n");
6154 /* NOTE: cagney/2003-03-29: These checks for a random signal
6155 at one stage in the past included checks for an inferior
6156 function call's call dummy's return breakpoint. The original
6157 comment, that went with the test, read:
6159 ``End of a stack dummy. Some systems (e.g. Sony news) give
6160 another signal besides SIGTRAP, so check here as well as
6163 If someone ever tries to get call dummys on a
6164 non-executable stack to work (where the target would stop
6165 with something like a SIGSEGV), then those tests might need
6166 to be re-instated. Given, however, that the tests were only
6167 enabled when momentary breakpoints were not being used, I
6168 suspect that it won't be the case.
6170 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6171 be necessary for call dummies on a non-executable stack on
6174 /* See if the breakpoints module can explain the signal. */
6176 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6177 ecs
->event_thread
->suspend
.stop_signal
);
6179 /* Maybe this was a trap for a software breakpoint that has since
6181 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6183 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6184 ecs
->event_thread
->suspend
.stop_pc
))
6186 struct regcache
*regcache
;
6189 /* Re-adjust PC to what the program would see if GDB was not
6191 regcache
= get_thread_regcache (ecs
->event_thread
);
6192 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6195 gdb::optional
<scoped_restore_tmpl
<int>>
6196 restore_operation_disable
;
6198 if (record_full_is_used ())
6199 restore_operation_disable
.emplace
6200 (record_full_gdb_operation_disable_set ());
6202 regcache_write_pc (regcache
,
6203 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6208 /* A delayed software breakpoint event. Ignore the trap. */
6210 fprintf_unfiltered (gdb_stdlog
,
6211 "infrun: delayed software breakpoint "
6212 "trap, ignoring\n");
6217 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6218 has since been removed. */
6219 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6221 /* A delayed hardware breakpoint event. Ignore the trap. */
6223 fprintf_unfiltered (gdb_stdlog
,
6224 "infrun: delayed hardware breakpoint/watchpoint "
6225 "trap, ignoring\n");
6229 /* If not, perhaps stepping/nexting can. */
6231 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6232 && currently_stepping (ecs
->event_thread
));
6234 /* Perhaps the thread hit a single-step breakpoint of _another_
6235 thread. Single-step breakpoints are transparent to the
6236 breakpoints module. */
6238 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6240 /* No? Perhaps we got a moribund watchpoint. */
6242 random_signal
= !stopped_by_watchpoint
;
6244 /* Always stop if the user explicitly requested this thread to
6246 if (ecs
->event_thread
->stop_requested
)
6250 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6253 /* For the program's own signals, act according to
6254 the signal handling tables. */
6258 /* Signal not for debugging purposes. */
6259 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6260 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6263 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6264 gdb_signal_to_symbol_string (stop_signal
));
6266 stopped_by_random_signal
= 1;
6268 /* Always stop on signals if we're either just gaining control
6269 of the program, or the user explicitly requested this thread
6270 to remain stopped. */
6271 if (stop_soon
!= NO_STOP_QUIETLY
6272 || ecs
->event_thread
->stop_requested
6274 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6280 /* Notify observers the signal has "handle print" set. Note we
6281 returned early above if stopping; normal_stop handles the
6282 printing in that case. */
6283 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6285 /* The signal table tells us to print about this signal. */
6286 target_terminal::ours_for_output ();
6287 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6288 target_terminal::inferior ();
6291 /* Clear the signal if it should not be passed. */
6292 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6293 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6295 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6296 && ecs
->event_thread
->control
.trap_expected
6297 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6299 /* We were just starting a new sequence, attempting to
6300 single-step off of a breakpoint and expecting a SIGTRAP.
6301 Instead this signal arrives. This signal will take us out
6302 of the stepping range so GDB needs to remember to, when
6303 the signal handler returns, resume stepping off that
6305 /* To simplify things, "continue" is forced to use the same
6306 code paths as single-step - set a breakpoint at the
6307 signal return address and then, once hit, step off that
6310 fprintf_unfiltered (gdb_stdlog
,
6311 "infrun: signal arrived while stepping over "
6314 insert_hp_step_resume_breakpoint_at_frame (frame
);
6315 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6316 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6317 ecs
->event_thread
->control
.trap_expected
= 0;
6319 /* If we were nexting/stepping some other thread, switch to
6320 it, so that we don't continue it, losing control. */
6321 if (!switch_back_to_stepped_thread (ecs
))
6326 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6327 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6329 || ecs
->event_thread
->control
.step_range_end
== 1)
6330 && frame_id_eq (get_stack_frame_id (frame
),
6331 ecs
->event_thread
->control
.step_stack_frame_id
)
6332 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6334 /* The inferior is about to take a signal that will take it
6335 out of the single step range. Set a breakpoint at the
6336 current PC (which is presumably where the signal handler
6337 will eventually return) and then allow the inferior to
6340 Note that this is only needed for a signal delivered
6341 while in the single-step range. Nested signals aren't a
6342 problem as they eventually all return. */
6344 fprintf_unfiltered (gdb_stdlog
,
6345 "infrun: signal may take us out of "
6346 "single-step range\n");
6348 clear_step_over_info ();
6349 insert_hp_step_resume_breakpoint_at_frame (frame
);
6350 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6351 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6352 ecs
->event_thread
->control
.trap_expected
= 0;
6357 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6358 when either there's a nested signal, or when there's a
6359 pending signal enabled just as the signal handler returns
6360 (leaving the inferior at the step-resume-breakpoint without
6361 actually executing it). Either way continue until the
6362 breakpoint is really hit. */
6364 if (!switch_back_to_stepped_thread (ecs
))
6367 fprintf_unfiltered (gdb_stdlog
,
6368 "infrun: random signal, keep going\n");
6375 process_event_stop_test (ecs
);
6378 /* Come here when we've got some debug event / signal we can explain
6379 (IOW, not a random signal), and test whether it should cause a
6380 stop, or whether we should resume the inferior (transparently).
6381 E.g., could be a breakpoint whose condition evaluates false; we
6382 could be still stepping within the line; etc. */
6385 process_event_stop_test (struct execution_control_state
*ecs
)
6387 struct symtab_and_line stop_pc_sal
;
6388 struct frame_info
*frame
;
6389 struct gdbarch
*gdbarch
;
6390 CORE_ADDR jmp_buf_pc
;
6391 struct bpstat_what what
;
6393 /* Handle cases caused by hitting a breakpoint. */
6395 frame
= get_current_frame ();
6396 gdbarch
= get_frame_arch (frame
);
6398 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6400 if (what
.call_dummy
)
6402 stop_stack_dummy
= what
.call_dummy
;
6405 /* A few breakpoint types have callbacks associated (e.g.,
6406 bp_jit_event). Run them now. */
6407 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6409 /* If we hit an internal event that triggers symbol changes, the
6410 current frame will be invalidated within bpstat_what (e.g., if we
6411 hit an internal solib event). Re-fetch it. */
6412 frame
= get_current_frame ();
6413 gdbarch
= get_frame_arch (frame
);
6415 switch (what
.main_action
)
6417 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6418 /* If we hit the breakpoint at longjmp while stepping, we
6419 install a momentary breakpoint at the target of the
6423 fprintf_unfiltered (gdb_stdlog
,
6424 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6426 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6428 if (what
.is_longjmp
)
6430 struct value
*arg_value
;
6432 /* If we set the longjmp breakpoint via a SystemTap probe,
6433 then use it to extract the arguments. The destination PC
6434 is the third argument to the probe. */
6435 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6438 jmp_buf_pc
= value_as_address (arg_value
);
6439 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6441 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6442 || !gdbarch_get_longjmp_target (gdbarch
,
6443 frame
, &jmp_buf_pc
))
6446 fprintf_unfiltered (gdb_stdlog
,
6447 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6448 "(!gdbarch_get_longjmp_target)\n");
6453 /* Insert a breakpoint at resume address. */
6454 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6457 check_exception_resume (ecs
, frame
);
6461 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6463 struct frame_info
*init_frame
;
6465 /* There are several cases to consider.
6467 1. The initiating frame no longer exists. In this case we
6468 must stop, because the exception or longjmp has gone too
6471 2. The initiating frame exists, and is the same as the
6472 current frame. We stop, because the exception or longjmp
6475 3. The initiating frame exists and is different from the
6476 current frame. This means the exception or longjmp has
6477 been caught beneath the initiating frame, so keep going.
6479 4. longjmp breakpoint has been placed just to protect
6480 against stale dummy frames and user is not interested in
6481 stopping around longjmps. */
6484 fprintf_unfiltered (gdb_stdlog
,
6485 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6487 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6489 delete_exception_resume_breakpoint (ecs
->event_thread
);
6491 if (what
.is_longjmp
)
6493 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6495 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6503 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6507 struct frame_id current_id
6508 = get_frame_id (get_current_frame ());
6509 if (frame_id_eq (current_id
,
6510 ecs
->event_thread
->initiating_frame
))
6512 /* Case 2. Fall through. */
6522 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6524 delete_step_resume_breakpoint (ecs
->event_thread
);
6526 end_stepping_range (ecs
);
6530 case BPSTAT_WHAT_SINGLE
:
6532 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6533 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6534 /* Still need to check other stuff, at least the case where we
6535 are stepping and step out of the right range. */
6538 case BPSTAT_WHAT_STEP_RESUME
:
6540 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6542 delete_step_resume_breakpoint (ecs
->event_thread
);
6543 if (ecs
->event_thread
->control
.proceed_to_finish
6544 && execution_direction
== EXEC_REVERSE
)
6546 struct thread_info
*tp
= ecs
->event_thread
;
6548 /* We are finishing a function in reverse, and just hit the
6549 step-resume breakpoint at the start address of the
6550 function, and we're almost there -- just need to back up
6551 by one more single-step, which should take us back to the
6553 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6557 fill_in_stop_func (gdbarch
, ecs
);
6558 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6559 && execution_direction
== EXEC_REVERSE
)
6561 /* We are stepping over a function call in reverse, and just
6562 hit the step-resume breakpoint at the start address of
6563 the function. Go back to single-stepping, which should
6564 take us back to the function call. */
6565 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6571 case BPSTAT_WHAT_STOP_NOISY
:
6573 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6574 stop_print_frame
= 1;
6576 /* Assume the thread stopped for a breapoint. We'll still check
6577 whether a/the breakpoint is there when the thread is next
6579 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6584 case BPSTAT_WHAT_STOP_SILENT
:
6586 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6587 stop_print_frame
= 0;
6589 /* Assume the thread stopped for a breapoint. We'll still check
6590 whether a/the breakpoint is there when the thread is next
6592 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6596 case BPSTAT_WHAT_HP_STEP_RESUME
:
6598 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6600 delete_step_resume_breakpoint (ecs
->event_thread
);
6601 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6603 /* Back when the step-resume breakpoint was inserted, we
6604 were trying to single-step off a breakpoint. Go back to
6606 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6607 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6613 case BPSTAT_WHAT_KEEP_CHECKING
:
6617 /* If we stepped a permanent breakpoint and we had a high priority
6618 step-resume breakpoint for the address we stepped, but we didn't
6619 hit it, then we must have stepped into the signal handler. The
6620 step-resume was only necessary to catch the case of _not_
6621 stepping into the handler, so delete it, and fall through to
6622 checking whether the step finished. */
6623 if (ecs
->event_thread
->stepped_breakpoint
)
6625 struct breakpoint
*sr_bp
6626 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6629 && sr_bp
->loc
->permanent
6630 && sr_bp
->type
== bp_hp_step_resume
6631 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6634 fprintf_unfiltered (gdb_stdlog
,
6635 "infrun: stepped permanent breakpoint, stopped in "
6637 delete_step_resume_breakpoint (ecs
->event_thread
);
6638 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6642 /* We come here if we hit a breakpoint but should not stop for it.
6643 Possibly we also were stepping and should stop for that. So fall
6644 through and test for stepping. But, if not stepping, do not
6647 /* In all-stop mode, if we're currently stepping but have stopped in
6648 some other thread, we need to switch back to the stepped thread. */
6649 if (switch_back_to_stepped_thread (ecs
))
6652 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6655 fprintf_unfiltered (gdb_stdlog
,
6656 "infrun: step-resume breakpoint is inserted\n");
6658 /* Having a step-resume breakpoint overrides anything
6659 else having to do with stepping commands until
6660 that breakpoint is reached. */
6665 if (ecs
->event_thread
->control
.step_range_end
== 0)
6668 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6669 /* Likewise if we aren't even stepping. */
6674 /* Re-fetch current thread's frame in case the code above caused
6675 the frame cache to be re-initialized, making our FRAME variable
6676 a dangling pointer. */
6677 frame
= get_current_frame ();
6678 gdbarch
= get_frame_arch (frame
);
6679 fill_in_stop_func (gdbarch
, ecs
);
6681 /* If stepping through a line, keep going if still within it.
6683 Note that step_range_end is the address of the first instruction
6684 beyond the step range, and NOT the address of the last instruction
6687 Note also that during reverse execution, we may be stepping
6688 through a function epilogue and therefore must detect when
6689 the current-frame changes in the middle of a line. */
6691 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6693 && (execution_direction
!= EXEC_REVERSE
6694 || frame_id_eq (get_frame_id (frame
),
6695 ecs
->event_thread
->control
.step_frame_id
)))
6699 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6700 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6701 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6703 /* Tentatively re-enable range stepping; `resume' disables it if
6704 necessary (e.g., if we're stepping over a breakpoint or we
6705 have software watchpoints). */
6706 ecs
->event_thread
->control
.may_range_step
= 1;
6708 /* When stepping backward, stop at beginning of line range
6709 (unless it's the function entry point, in which case
6710 keep going back to the call point). */
6711 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6712 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6713 && stop_pc
!= ecs
->stop_func_start
6714 && execution_direction
== EXEC_REVERSE
)
6715 end_stepping_range (ecs
);
6722 /* We stepped out of the stepping range. */
6724 /* If we are stepping at the source level and entered the runtime
6725 loader dynamic symbol resolution code...
6727 EXEC_FORWARD: we keep on single stepping until we exit the run
6728 time loader code and reach the callee's address.
6730 EXEC_REVERSE: we've already executed the callee (backward), and
6731 the runtime loader code is handled just like any other
6732 undebuggable function call. Now we need only keep stepping
6733 backward through the trampoline code, and that's handled further
6734 down, so there is nothing for us to do here. */
6736 if (execution_direction
!= EXEC_REVERSE
6737 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6738 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6740 CORE_ADDR pc_after_resolver
=
6741 gdbarch_skip_solib_resolver (gdbarch
,
6742 ecs
->event_thread
->suspend
.stop_pc
);
6745 fprintf_unfiltered (gdb_stdlog
,
6746 "infrun: stepped into dynsym resolve code\n");
6748 if (pc_after_resolver
)
6750 /* Set up a step-resume breakpoint at the address
6751 indicated by SKIP_SOLIB_RESOLVER. */
6752 symtab_and_line sr_sal
;
6753 sr_sal
.pc
= pc_after_resolver
;
6754 sr_sal
.pspace
= get_frame_program_space (frame
);
6756 insert_step_resume_breakpoint_at_sal (gdbarch
,
6757 sr_sal
, null_frame_id
);
6764 /* Step through an indirect branch thunk. */
6765 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6766 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6767 ecs
->event_thread
->suspend
.stop_pc
))
6770 fprintf_unfiltered (gdb_stdlog
,
6771 "infrun: stepped into indirect branch thunk\n");
6776 if (ecs
->event_thread
->control
.step_range_end
!= 1
6777 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6778 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6779 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6782 fprintf_unfiltered (gdb_stdlog
,
6783 "infrun: stepped into signal trampoline\n");
6784 /* The inferior, while doing a "step" or "next", has ended up in
6785 a signal trampoline (either by a signal being delivered or by
6786 the signal handler returning). Just single-step until the
6787 inferior leaves the trampoline (either by calling the handler
6793 /* If we're in the return path from a shared library trampoline,
6794 we want to proceed through the trampoline when stepping. */
6795 /* macro/2012-04-25: This needs to come before the subroutine
6796 call check below as on some targets return trampolines look
6797 like subroutine calls (MIPS16 return thunks). */
6798 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6799 ecs
->event_thread
->suspend
.stop_pc
,
6800 ecs
->stop_func_name
)
6801 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6803 /* Determine where this trampoline returns. */
6804 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6805 CORE_ADDR real_stop_pc
6806 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6809 fprintf_unfiltered (gdb_stdlog
,
6810 "infrun: stepped into solib return tramp\n");
6812 /* Only proceed through if we know where it's going. */
6815 /* And put the step-breakpoint there and go until there. */
6816 symtab_and_line sr_sal
;
6817 sr_sal
.pc
= real_stop_pc
;
6818 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6819 sr_sal
.pspace
= get_frame_program_space (frame
);
6821 /* Do not specify what the fp should be when we stop since
6822 on some machines the prologue is where the new fp value
6824 insert_step_resume_breakpoint_at_sal (gdbarch
,
6825 sr_sal
, null_frame_id
);
6827 /* Restart without fiddling with the step ranges or
6834 /* Check for subroutine calls. The check for the current frame
6835 equalling the step ID is not necessary - the check of the
6836 previous frame's ID is sufficient - but it is a common case and
6837 cheaper than checking the previous frame's ID.
6839 NOTE: frame_id_eq will never report two invalid frame IDs as
6840 being equal, so to get into this block, both the current and
6841 previous frame must have valid frame IDs. */
6842 /* The outer_frame_id check is a heuristic to detect stepping
6843 through startup code. If we step over an instruction which
6844 sets the stack pointer from an invalid value to a valid value,
6845 we may detect that as a subroutine call from the mythical
6846 "outermost" function. This could be fixed by marking
6847 outermost frames as !stack_p,code_p,special_p. Then the
6848 initial outermost frame, before sp was valid, would
6849 have code_addr == &_start. See the comment in frame_id_eq
6851 if (!frame_id_eq (get_stack_frame_id (frame
),
6852 ecs
->event_thread
->control
.step_stack_frame_id
)
6853 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6854 ecs
->event_thread
->control
.step_stack_frame_id
)
6855 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6857 || (ecs
->event_thread
->control
.step_start_function
6858 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6860 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6861 CORE_ADDR real_stop_pc
;
6864 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6866 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6868 /* I presume that step_over_calls is only 0 when we're
6869 supposed to be stepping at the assembly language level
6870 ("stepi"). Just stop. */
6871 /* And this works the same backward as frontward. MVS */
6872 end_stepping_range (ecs
);
6876 /* Reverse stepping through solib trampolines. */
6878 if (execution_direction
== EXEC_REVERSE
6879 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6880 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6881 || (ecs
->stop_func_start
== 0
6882 && in_solib_dynsym_resolve_code (stop_pc
))))
6884 /* Any solib trampoline code can be handled in reverse
6885 by simply continuing to single-step. We have already
6886 executed the solib function (backwards), and a few
6887 steps will take us back through the trampoline to the
6893 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6895 /* We're doing a "next".
6897 Normal (forward) execution: set a breakpoint at the
6898 callee's return address (the address at which the caller
6901 Reverse (backward) execution. set the step-resume
6902 breakpoint at the start of the function that we just
6903 stepped into (backwards), and continue to there. When we
6904 get there, we'll need to single-step back to the caller. */
6906 if (execution_direction
== EXEC_REVERSE
)
6908 /* If we're already at the start of the function, we've either
6909 just stepped backward into a single instruction function,
6910 or stepped back out of a signal handler to the first instruction
6911 of the function. Just keep going, which will single-step back
6913 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6915 /* Normal function call return (static or dynamic). */
6916 symtab_and_line sr_sal
;
6917 sr_sal
.pc
= ecs
->stop_func_start
;
6918 sr_sal
.pspace
= get_frame_program_space (frame
);
6919 insert_step_resume_breakpoint_at_sal (gdbarch
,
6920 sr_sal
, null_frame_id
);
6924 insert_step_resume_breakpoint_at_caller (frame
);
6930 /* If we are in a function call trampoline (a stub between the
6931 calling routine and the real function), locate the real
6932 function. That's what tells us (a) whether we want to step
6933 into it at all, and (b) what prologue we want to run to the
6934 end of, if we do step into it. */
6935 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6936 if (real_stop_pc
== 0)
6937 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6938 if (real_stop_pc
!= 0)
6939 ecs
->stop_func_start
= real_stop_pc
;
6941 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6943 symtab_and_line sr_sal
;
6944 sr_sal
.pc
= ecs
->stop_func_start
;
6945 sr_sal
.pspace
= get_frame_program_space (frame
);
6947 insert_step_resume_breakpoint_at_sal (gdbarch
,
6948 sr_sal
, null_frame_id
);
6953 /* If we have line number information for the function we are
6954 thinking of stepping into and the function isn't on the skip
6957 If there are several symtabs at that PC (e.g. with include
6958 files), just want to know whether *any* of them have line
6959 numbers. find_pc_line handles this. */
6961 struct symtab_and_line tmp_sal
;
6963 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6964 if (tmp_sal
.line
!= 0
6965 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6967 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6969 if (execution_direction
== EXEC_REVERSE
)
6970 handle_step_into_function_backward (gdbarch
, ecs
);
6972 handle_step_into_function (gdbarch
, ecs
);
6977 /* If we have no line number and the step-stop-if-no-debug is
6978 set, we stop the step so that the user has a chance to switch
6979 in assembly mode. */
6980 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6981 && step_stop_if_no_debug
)
6983 end_stepping_range (ecs
);
6987 if (execution_direction
== EXEC_REVERSE
)
6989 /* If we're already at the start of the function, we've either just
6990 stepped backward into a single instruction function without line
6991 number info, or stepped back out of a signal handler to the first
6992 instruction of the function without line number info. Just keep
6993 going, which will single-step back to the caller. */
6994 if (ecs
->stop_func_start
!= stop_pc
)
6996 /* Set a breakpoint at callee's start address.
6997 From there we can step once and be back in the caller. */
6998 symtab_and_line sr_sal
;
6999 sr_sal
.pc
= ecs
->stop_func_start
;
7000 sr_sal
.pspace
= get_frame_program_space (frame
);
7001 insert_step_resume_breakpoint_at_sal (gdbarch
,
7002 sr_sal
, null_frame_id
);
7006 /* Set a breakpoint at callee's return address (the address
7007 at which the caller will resume). */
7008 insert_step_resume_breakpoint_at_caller (frame
);
7014 /* Reverse stepping through solib trampolines. */
7016 if (execution_direction
== EXEC_REVERSE
7017 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7019 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
7021 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7022 || (ecs
->stop_func_start
== 0
7023 && in_solib_dynsym_resolve_code (stop_pc
)))
7025 /* Any solib trampoline code can be handled in reverse
7026 by simply continuing to single-step. We have already
7027 executed the solib function (backwards), and a few
7028 steps will take us back through the trampoline to the
7033 else if (in_solib_dynsym_resolve_code (stop_pc
))
7035 /* Stepped backward into the solib dynsym resolver.
7036 Set a breakpoint at its start and continue, then
7037 one more step will take us out. */
7038 symtab_and_line sr_sal
;
7039 sr_sal
.pc
= ecs
->stop_func_start
;
7040 sr_sal
.pspace
= get_frame_program_space (frame
);
7041 insert_step_resume_breakpoint_at_sal (gdbarch
,
7042 sr_sal
, null_frame_id
);
7048 /* This always returns the sal for the inner-most frame when we are in a
7049 stack of inlined frames, even if GDB actually believes that it is in a
7050 more outer frame. This is checked for below by calls to
7051 inline_skipped_frames. */
7052 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7054 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7055 the trampoline processing logic, however, there are some trampolines
7056 that have no names, so we should do trampoline handling first. */
7057 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7058 && ecs
->stop_func_name
== NULL
7059 && stop_pc_sal
.line
== 0)
7062 fprintf_unfiltered (gdb_stdlog
,
7063 "infrun: stepped into undebuggable function\n");
7065 /* The inferior just stepped into, or returned to, an
7066 undebuggable function (where there is no debugging information
7067 and no line number corresponding to the address where the
7068 inferior stopped). Since we want to skip this kind of code,
7069 we keep going until the inferior returns from this
7070 function - unless the user has asked us not to (via
7071 set step-mode) or we no longer know how to get back
7072 to the call site. */
7073 if (step_stop_if_no_debug
7074 || !frame_id_p (frame_unwind_caller_id (frame
)))
7076 /* If we have no line number and the step-stop-if-no-debug
7077 is set, we stop the step so that the user has a chance to
7078 switch in assembly mode. */
7079 end_stepping_range (ecs
);
7084 /* Set a breakpoint at callee's return address (the address
7085 at which the caller will resume). */
7086 insert_step_resume_breakpoint_at_caller (frame
);
7092 if (ecs
->event_thread
->control
.step_range_end
== 1)
7094 /* It is stepi or nexti. We always want to stop stepping after
7097 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7098 end_stepping_range (ecs
);
7102 if (stop_pc_sal
.line
== 0)
7104 /* We have no line number information. That means to stop
7105 stepping (does this always happen right after one instruction,
7106 when we do "s" in a function with no line numbers,
7107 or can this happen as a result of a return or longjmp?). */
7109 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7110 end_stepping_range (ecs
);
7114 /* Look for "calls" to inlined functions, part one. If the inline
7115 frame machinery detected some skipped call sites, we have entered
7116 a new inline function. */
7118 if (frame_id_eq (get_frame_id (get_current_frame ()),
7119 ecs
->event_thread
->control
.step_frame_id
)
7120 && inline_skipped_frames (ecs
->event_thread
))
7123 fprintf_unfiltered (gdb_stdlog
,
7124 "infrun: stepped into inlined function\n");
7126 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7128 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7130 /* For "step", we're going to stop. But if the call site
7131 for this inlined function is on the same source line as
7132 we were previously stepping, go down into the function
7133 first. Otherwise stop at the call site. */
7135 if (call_sal
.line
== ecs
->event_thread
->current_line
7136 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7138 step_into_inline_frame (ecs
->event_thread
);
7139 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7146 end_stepping_range (ecs
);
7151 /* For "next", we should stop at the call site if it is on a
7152 different source line. Otherwise continue through the
7153 inlined function. */
7154 if (call_sal
.line
== ecs
->event_thread
->current_line
7155 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7158 end_stepping_range (ecs
);
7163 /* Look for "calls" to inlined functions, part two. If we are still
7164 in the same real function we were stepping through, but we have
7165 to go further up to find the exact frame ID, we are stepping
7166 through a more inlined call beyond its call site. */
7168 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7169 && !frame_id_eq (get_frame_id (get_current_frame ()),
7170 ecs
->event_thread
->control
.step_frame_id
)
7171 && stepped_in_from (get_current_frame (),
7172 ecs
->event_thread
->control
.step_frame_id
))
7175 fprintf_unfiltered (gdb_stdlog
,
7176 "infrun: stepping through inlined function\n");
7178 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7179 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7182 end_stepping_range (ecs
);
7186 bool refresh_step_info
= true;
7187 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7188 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7189 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7191 if (stop_pc_sal
.is_stmt
)
7193 /* We are at the start of a different line. So stop. Note that
7194 we don't stop if we step into the middle of a different line.
7195 That is said to make things like for (;;) statements work
7198 fprintf_unfiltered (gdb_stdlog
,
7199 "infrun: stepped to a different line\n");
7200 end_stepping_range (ecs
);
7203 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7204 ecs
->event_thread
->control
.step_frame_id
))
7206 /* We are at the start of a different line, however, this line is
7207 not marked as a statement, and we have not changed frame. We
7208 ignore this line table entry, and continue stepping forward,
7209 looking for a better place to stop. */
7210 refresh_step_info
= false;
7212 fprintf_unfiltered (gdb_stdlog
,
7213 "infrun: stepped to a different line, but "
7214 "it's not the start of a statement\n");
7218 /* We aren't done stepping.
7220 Optimize by setting the stepping range to the line.
7221 (We might not be in the original line, but if we entered a
7222 new line in mid-statement, we continue stepping. This makes
7223 things like for(;;) statements work better.)
7225 If we entered a SAL that indicates a non-statement line table entry,
7226 then we update the stepping range, but we don't update the step info,
7227 which includes things like the line number we are stepping away from.
7228 This means we will stop when we find a line table entry that is marked
7229 as is-statement, even if it matches the non-statement one we just
7232 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7233 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7234 ecs
->event_thread
->control
.may_range_step
= 1;
7235 if (refresh_step_info
)
7236 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7239 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7243 /* In all-stop mode, if we're currently stepping but have stopped in
7244 some other thread, we may need to switch back to the stepped
7245 thread. Returns true we set the inferior running, false if we left
7246 it stopped (and the event needs further processing). */
7249 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7251 if (!target_is_non_stop_p ())
7253 struct thread_info
*stepping_thread
;
7255 /* If any thread is blocked on some internal breakpoint, and we
7256 simply need to step over that breakpoint to get it going
7257 again, do that first. */
7259 /* However, if we see an event for the stepping thread, then we
7260 know all other threads have been moved past their breakpoints
7261 already. Let the caller check whether the step is finished,
7262 etc., before deciding to move it past a breakpoint. */
7263 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7266 /* Check if the current thread is blocked on an incomplete
7267 step-over, interrupted by a random signal. */
7268 if (ecs
->event_thread
->control
.trap_expected
7269 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7273 fprintf_unfiltered (gdb_stdlog
,
7274 "infrun: need to finish step-over of [%s]\n",
7275 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7281 /* Check if the current thread is blocked by a single-step
7282 breakpoint of another thread. */
7283 if (ecs
->hit_singlestep_breakpoint
)
7287 fprintf_unfiltered (gdb_stdlog
,
7288 "infrun: need to step [%s] over single-step "
7290 target_pid_to_str (ecs
->ptid
).c_str ());
7296 /* If this thread needs yet another step-over (e.g., stepping
7297 through a delay slot), do it first before moving on to
7299 if (thread_still_needs_step_over (ecs
->event_thread
))
7303 fprintf_unfiltered (gdb_stdlog
,
7304 "infrun: thread [%s] still needs step-over\n",
7305 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7311 /* If scheduler locking applies even if not stepping, there's no
7312 need to walk over threads. Above we've checked whether the
7313 current thread is stepping. If some other thread not the
7314 event thread is stepping, then it must be that scheduler
7315 locking is not in effect. */
7316 if (schedlock_applies (ecs
->event_thread
))
7319 /* Otherwise, we no longer expect a trap in the current thread.
7320 Clear the trap_expected flag before switching back -- this is
7321 what keep_going does as well, if we call it. */
7322 ecs
->event_thread
->control
.trap_expected
= 0;
7324 /* Likewise, clear the signal if it should not be passed. */
7325 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7326 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7328 /* Do all pending step-overs before actually proceeding with
7330 if (start_step_over ())
7332 prepare_to_wait (ecs
);
7336 /* Look for the stepping/nexting thread. */
7337 stepping_thread
= NULL
;
7339 for (thread_info
*tp
: all_non_exited_threads ())
7341 switch_to_thread_no_regs (tp
);
7343 /* Ignore threads of processes the caller is not
7346 && (tp
->inf
->process_target () != ecs
->target
7347 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7350 /* When stepping over a breakpoint, we lock all threads
7351 except the one that needs to move past the breakpoint.
7352 If a non-event thread has this set, the "incomplete
7353 step-over" check above should have caught it earlier. */
7354 if (tp
->control
.trap_expected
)
7356 internal_error (__FILE__
, __LINE__
,
7357 "[%s] has inconsistent state: "
7358 "trap_expected=%d\n",
7359 target_pid_to_str (tp
->ptid
).c_str (),
7360 tp
->control
.trap_expected
);
7363 /* Did we find the stepping thread? */
7364 if (tp
->control
.step_range_end
)
7366 /* Yep. There should only one though. */
7367 gdb_assert (stepping_thread
== NULL
);
7369 /* The event thread is handled at the top, before we
7371 gdb_assert (tp
!= ecs
->event_thread
);
7373 /* If some thread other than the event thread is
7374 stepping, then scheduler locking can't be in effect,
7375 otherwise we wouldn't have resumed the current event
7376 thread in the first place. */
7377 gdb_assert (!schedlock_applies (tp
));
7379 stepping_thread
= tp
;
7383 if (stepping_thread
!= NULL
)
7386 fprintf_unfiltered (gdb_stdlog
,
7387 "infrun: switching back to stepped thread\n");
7389 if (keep_going_stepped_thread (stepping_thread
))
7391 prepare_to_wait (ecs
);
7396 switch_to_thread (ecs
->event_thread
);
7402 /* Set a previously stepped thread back to stepping. Returns true on
7403 success, false if the resume is not possible (e.g., the thread
7407 keep_going_stepped_thread (struct thread_info
*tp
)
7409 struct frame_info
*frame
;
7410 struct execution_control_state ecss
;
7411 struct execution_control_state
*ecs
= &ecss
;
7413 /* If the stepping thread exited, then don't try to switch back and
7414 resume it, which could fail in several different ways depending
7415 on the target. Instead, just keep going.
7417 We can find a stepping dead thread in the thread list in two
7420 - The target supports thread exit events, and when the target
7421 tries to delete the thread from the thread list, inferior_ptid
7422 pointed at the exiting thread. In such case, calling
7423 delete_thread does not really remove the thread from the list;
7424 instead, the thread is left listed, with 'exited' state.
7426 - The target's debug interface does not support thread exit
7427 events, and so we have no idea whatsoever if the previously
7428 stepping thread is still alive. For that reason, we need to
7429 synchronously query the target now. */
7431 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7434 fprintf_unfiltered (gdb_stdlog
,
7435 "infrun: not resuming previously "
7436 "stepped thread, it has vanished\n");
7443 fprintf_unfiltered (gdb_stdlog
,
7444 "infrun: resuming previously stepped thread\n");
7446 reset_ecs (ecs
, tp
);
7447 switch_to_thread (tp
);
7449 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7450 frame
= get_current_frame ();
7452 /* If the PC of the thread we were trying to single-step has
7453 changed, then that thread has trapped or been signaled, but the
7454 event has not been reported to GDB yet. Re-poll the target
7455 looking for this particular thread's event (i.e. temporarily
7456 enable schedlock) by:
7458 - setting a break at the current PC
7459 - resuming that particular thread, only (by setting trap
7462 This prevents us continuously moving the single-step breakpoint
7463 forward, one instruction at a time, overstepping. */
7465 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7470 fprintf_unfiltered (gdb_stdlog
,
7471 "infrun: expected thread advanced also (%s -> %s)\n",
7472 paddress (target_gdbarch (), tp
->prev_pc
),
7473 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7475 /* Clear the info of the previous step-over, as it's no longer
7476 valid (if the thread was trying to step over a breakpoint, it
7477 has already succeeded). It's what keep_going would do too,
7478 if we called it. Do this before trying to insert the sss
7479 breakpoint, otherwise if we were previously trying to step
7480 over this exact address in another thread, the breakpoint is
7482 clear_step_over_info ();
7483 tp
->control
.trap_expected
= 0;
7485 insert_single_step_breakpoint (get_frame_arch (frame
),
7486 get_frame_address_space (frame
),
7487 tp
->suspend
.stop_pc
);
7490 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7491 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7496 fprintf_unfiltered (gdb_stdlog
,
7497 "infrun: expected thread still hasn't advanced\n");
7499 keep_going_pass_signal (ecs
);
7504 /* Is thread TP in the middle of (software or hardware)
7505 single-stepping? (Note the result of this function must never be
7506 passed directly as target_resume's STEP parameter.) */
7509 currently_stepping (struct thread_info
*tp
)
7511 return ((tp
->control
.step_range_end
7512 && tp
->control
.step_resume_breakpoint
== NULL
)
7513 || tp
->control
.trap_expected
7514 || tp
->stepped_breakpoint
7515 || bpstat_should_step ());
7518 /* Inferior has stepped into a subroutine call with source code that
7519 we should not step over. Do step to the first line of code in
7523 handle_step_into_function (struct gdbarch
*gdbarch
,
7524 struct execution_control_state
*ecs
)
7526 fill_in_stop_func (gdbarch
, ecs
);
7528 compunit_symtab
*cust
7529 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7530 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7531 ecs
->stop_func_start
7532 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7534 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7535 /* Use the step_resume_break to step until the end of the prologue,
7536 even if that involves jumps (as it seems to on the vax under
7538 /* If the prologue ends in the middle of a source line, continue to
7539 the end of that source line (if it is still within the function).
7540 Otherwise, just go to end of prologue. */
7541 if (stop_func_sal
.end
7542 && stop_func_sal
.pc
!= ecs
->stop_func_start
7543 && stop_func_sal
.end
< ecs
->stop_func_end
)
7544 ecs
->stop_func_start
= stop_func_sal
.end
;
7546 /* Architectures which require breakpoint adjustment might not be able
7547 to place a breakpoint at the computed address. If so, the test
7548 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7549 ecs->stop_func_start to an address at which a breakpoint may be
7550 legitimately placed.
7552 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7553 made, GDB will enter an infinite loop when stepping through
7554 optimized code consisting of VLIW instructions which contain
7555 subinstructions corresponding to different source lines. On
7556 FR-V, it's not permitted to place a breakpoint on any but the
7557 first subinstruction of a VLIW instruction. When a breakpoint is
7558 set, GDB will adjust the breakpoint address to the beginning of
7559 the VLIW instruction. Thus, we need to make the corresponding
7560 adjustment here when computing the stop address. */
7562 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7564 ecs
->stop_func_start
7565 = gdbarch_adjust_breakpoint_address (gdbarch
,
7566 ecs
->stop_func_start
);
7569 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7571 /* We are already there: stop now. */
7572 end_stepping_range (ecs
);
7577 /* Put the step-breakpoint there and go until there. */
7578 symtab_and_line sr_sal
;
7579 sr_sal
.pc
= ecs
->stop_func_start
;
7580 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7581 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7583 /* Do not specify what the fp should be when we stop since on
7584 some machines the prologue is where the new fp value is
7586 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7588 /* And make sure stepping stops right away then. */
7589 ecs
->event_thread
->control
.step_range_end
7590 = ecs
->event_thread
->control
.step_range_start
;
7595 /* Inferior has stepped backward into a subroutine call with source
7596 code that we should not step over. Do step to the beginning of the
7597 last line of code in it. */
7600 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7601 struct execution_control_state
*ecs
)
7603 struct compunit_symtab
*cust
;
7604 struct symtab_and_line stop_func_sal
;
7606 fill_in_stop_func (gdbarch
, ecs
);
7608 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7609 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7610 ecs
->stop_func_start
7611 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7613 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7615 /* OK, we're just going to keep stepping here. */
7616 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7618 /* We're there already. Just stop stepping now. */
7619 end_stepping_range (ecs
);
7623 /* Else just reset the step range and keep going.
7624 No step-resume breakpoint, they don't work for
7625 epilogues, which can have multiple entry paths. */
7626 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7627 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7633 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7634 This is used to both functions and to skip over code. */
7637 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7638 struct symtab_and_line sr_sal
,
7639 struct frame_id sr_id
,
7640 enum bptype sr_type
)
7642 /* There should never be more than one step-resume or longjmp-resume
7643 breakpoint per thread, so we should never be setting a new
7644 step_resume_breakpoint when one is already active. */
7645 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7646 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7649 fprintf_unfiltered (gdb_stdlog
,
7650 "infrun: inserting step-resume breakpoint at %s\n",
7651 paddress (gdbarch
, sr_sal
.pc
));
7653 inferior_thread ()->control
.step_resume_breakpoint
7654 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7658 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7659 struct symtab_and_line sr_sal
,
7660 struct frame_id sr_id
)
7662 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7667 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7668 This is used to skip a potential signal handler.
7670 This is called with the interrupted function's frame. The signal
7671 handler, when it returns, will resume the interrupted function at
7675 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7677 gdb_assert (return_frame
!= NULL
);
7679 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7681 symtab_and_line sr_sal
;
7682 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7683 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7684 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7686 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7687 get_stack_frame_id (return_frame
),
7691 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7692 is used to skip a function after stepping into it (for "next" or if
7693 the called function has no debugging information).
7695 The current function has almost always been reached by single
7696 stepping a call or return instruction. NEXT_FRAME belongs to the
7697 current function, and the breakpoint will be set at the caller's
7700 This is a separate function rather than reusing
7701 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7702 get_prev_frame, which may stop prematurely (see the implementation
7703 of frame_unwind_caller_id for an example). */
7706 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7708 /* We shouldn't have gotten here if we don't know where the call site
7710 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7712 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7714 symtab_and_line sr_sal
;
7715 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7716 frame_unwind_caller_pc (next_frame
));
7717 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7718 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7720 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7721 frame_unwind_caller_id (next_frame
));
7724 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7725 new breakpoint at the target of a jmp_buf. The handling of
7726 longjmp-resume uses the same mechanisms used for handling
7727 "step-resume" breakpoints. */
7730 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7732 /* There should never be more than one longjmp-resume breakpoint per
7733 thread, so we should never be setting a new
7734 longjmp_resume_breakpoint when one is already active. */
7735 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7738 fprintf_unfiltered (gdb_stdlog
,
7739 "infrun: inserting longjmp-resume breakpoint at %s\n",
7740 paddress (gdbarch
, pc
));
7742 inferior_thread ()->control
.exception_resume_breakpoint
=
7743 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7746 /* Insert an exception resume breakpoint. TP is the thread throwing
7747 the exception. The block B is the block of the unwinder debug hook
7748 function. FRAME is the frame corresponding to the call to this
7749 function. SYM is the symbol of the function argument holding the
7750 target PC of the exception. */
7753 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7754 const struct block
*b
,
7755 struct frame_info
*frame
,
7760 struct block_symbol vsym
;
7761 struct value
*value
;
7763 struct breakpoint
*bp
;
7765 vsym
= lookup_symbol_search_name (sym
->search_name (),
7767 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7768 /* If the value was optimized out, revert to the old behavior. */
7769 if (! value_optimized_out (value
))
7771 handler
= value_as_address (value
);
7774 fprintf_unfiltered (gdb_stdlog
,
7775 "infrun: exception resume at %lx\n",
7776 (unsigned long) handler
);
7778 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7780 bp_exception_resume
).release ();
7782 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7785 bp
->thread
= tp
->global_num
;
7786 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7789 catch (const gdb_exception_error
&e
)
7791 /* We want to ignore errors here. */
7795 /* A helper for check_exception_resume that sets an
7796 exception-breakpoint based on a SystemTap probe. */
7799 insert_exception_resume_from_probe (struct thread_info
*tp
,
7800 const struct bound_probe
*probe
,
7801 struct frame_info
*frame
)
7803 struct value
*arg_value
;
7805 struct breakpoint
*bp
;
7807 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7811 handler
= value_as_address (arg_value
);
7814 fprintf_unfiltered (gdb_stdlog
,
7815 "infrun: exception resume at %s\n",
7816 paddress (get_objfile_arch (probe
->objfile
),
7819 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7820 handler
, bp_exception_resume
).release ();
7821 bp
->thread
= tp
->global_num
;
7822 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7825 /* This is called when an exception has been intercepted. Check to
7826 see whether the exception's destination is of interest, and if so,
7827 set an exception resume breakpoint there. */
7830 check_exception_resume (struct execution_control_state
*ecs
,
7831 struct frame_info
*frame
)
7833 struct bound_probe probe
;
7834 struct symbol
*func
;
7836 /* First see if this exception unwinding breakpoint was set via a
7837 SystemTap probe point. If so, the probe has two arguments: the
7838 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7839 set a breakpoint there. */
7840 probe
= find_probe_by_pc (get_frame_pc (frame
));
7843 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7847 func
= get_frame_function (frame
);
7853 const struct block
*b
;
7854 struct block_iterator iter
;
7858 /* The exception breakpoint is a thread-specific breakpoint on
7859 the unwinder's debug hook, declared as:
7861 void _Unwind_DebugHook (void *cfa, void *handler);
7863 The CFA argument indicates the frame to which control is
7864 about to be transferred. HANDLER is the destination PC.
7866 We ignore the CFA and set a temporary breakpoint at HANDLER.
7867 This is not extremely efficient but it avoids issues in gdb
7868 with computing the DWARF CFA, and it also works even in weird
7869 cases such as throwing an exception from inside a signal
7872 b
= SYMBOL_BLOCK_VALUE (func
);
7873 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7875 if (!SYMBOL_IS_ARGUMENT (sym
))
7882 insert_exception_resume_breakpoint (ecs
->event_thread
,
7888 catch (const gdb_exception_error
&e
)
7894 stop_waiting (struct execution_control_state
*ecs
)
7897 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7899 /* Let callers know we don't want to wait for the inferior anymore. */
7900 ecs
->wait_some_more
= 0;
7902 /* If all-stop, but the target is always in non-stop mode, stop all
7903 threads now that we're presenting the stop to the user. */
7904 if (!non_stop
&& target_is_non_stop_p ())
7905 stop_all_threads ();
7908 /* Like keep_going, but passes the signal to the inferior, even if the
7909 signal is set to nopass. */
7912 keep_going_pass_signal (struct execution_control_state
*ecs
)
7914 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7915 gdb_assert (!ecs
->event_thread
->resumed
);
7917 /* Save the pc before execution, to compare with pc after stop. */
7918 ecs
->event_thread
->prev_pc
7919 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
7921 if (ecs
->event_thread
->control
.trap_expected
)
7923 struct thread_info
*tp
= ecs
->event_thread
;
7926 fprintf_unfiltered (gdb_stdlog
,
7927 "infrun: %s has trap_expected set, "
7928 "resuming to collect trap\n",
7929 target_pid_to_str (tp
->ptid
).c_str ());
7931 /* We haven't yet gotten our trap, and either: intercepted a
7932 non-signal event (e.g., a fork); or took a signal which we
7933 are supposed to pass through to the inferior. Simply
7935 resume (ecs
->event_thread
->suspend
.stop_signal
);
7937 else if (step_over_info_valid_p ())
7939 /* Another thread is stepping over a breakpoint in-line. If
7940 this thread needs a step-over too, queue the request. In
7941 either case, this resume must be deferred for later. */
7942 struct thread_info
*tp
= ecs
->event_thread
;
7944 if (ecs
->hit_singlestep_breakpoint
7945 || thread_still_needs_step_over (tp
))
7948 fprintf_unfiltered (gdb_stdlog
,
7949 "infrun: step-over already in progress: "
7950 "step-over for %s deferred\n",
7951 target_pid_to_str (tp
->ptid
).c_str ());
7952 thread_step_over_chain_enqueue (tp
);
7957 fprintf_unfiltered (gdb_stdlog
,
7958 "infrun: step-over in progress: "
7959 "resume of %s deferred\n",
7960 target_pid_to_str (tp
->ptid
).c_str ());
7965 struct regcache
*regcache
= get_current_regcache ();
7968 step_over_what step_what
;
7970 /* Either the trap was not expected, but we are continuing
7971 anyway (if we got a signal, the user asked it be passed to
7974 We got our expected trap, but decided we should resume from
7977 We're going to run this baby now!
7979 Note that insert_breakpoints won't try to re-insert
7980 already inserted breakpoints. Therefore, we don't
7981 care if breakpoints were already inserted, or not. */
7983 /* If we need to step over a breakpoint, and we're not using
7984 displaced stepping to do so, insert all breakpoints
7985 (watchpoints, etc.) but the one we're stepping over, step one
7986 instruction, and then re-insert the breakpoint when that step
7989 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7991 remove_bp
= (ecs
->hit_singlestep_breakpoint
7992 || (step_what
& STEP_OVER_BREAKPOINT
));
7993 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7995 /* We can't use displaced stepping if we need to step past a
7996 watchpoint. The instruction copied to the scratch pad would
7997 still trigger the watchpoint. */
7999 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
8001 set_step_over_info (regcache
->aspace (),
8002 regcache_read_pc (regcache
), remove_wps
,
8003 ecs
->event_thread
->global_num
);
8005 else if (remove_wps
)
8006 set_step_over_info (NULL
, 0, remove_wps
, -1);
8008 /* If we now need to do an in-line step-over, we need to stop
8009 all other threads. Note this must be done before
8010 insert_breakpoints below, because that removes the breakpoint
8011 we're about to step over, otherwise other threads could miss
8013 if (step_over_info_valid_p () && target_is_non_stop_p ())
8014 stop_all_threads ();
8016 /* Stop stepping if inserting breakpoints fails. */
8019 insert_breakpoints ();
8021 catch (const gdb_exception_error
&e
)
8023 exception_print (gdb_stderr
, e
);
8025 clear_step_over_info ();
8029 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8031 resume (ecs
->event_thread
->suspend
.stop_signal
);
8034 prepare_to_wait (ecs
);
8037 /* Called when we should continue running the inferior, because the
8038 current event doesn't cause a user visible stop. This does the
8039 resuming part; waiting for the next event is done elsewhere. */
8042 keep_going (struct execution_control_state
*ecs
)
8044 if (ecs
->event_thread
->control
.trap_expected
8045 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
8046 ecs
->event_thread
->control
.trap_expected
= 0;
8048 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
8049 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8050 keep_going_pass_signal (ecs
);
8053 /* This function normally comes after a resume, before
8054 handle_inferior_event exits. It takes care of any last bits of
8055 housekeeping, and sets the all-important wait_some_more flag. */
8058 prepare_to_wait (struct execution_control_state
*ecs
)
8061 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
8063 ecs
->wait_some_more
= 1;
8065 if (!target_is_async_p ())
8066 mark_infrun_async_event_handler ();
8069 /* We are done with the step range of a step/next/si/ni command.
8070 Called once for each n of a "step n" operation. */
8073 end_stepping_range (struct execution_control_state
*ecs
)
8075 ecs
->event_thread
->control
.stop_step
= 1;
8079 /* Several print_*_reason functions to print why the inferior has stopped.
8080 We always print something when the inferior exits, or receives a signal.
8081 The rest of the cases are dealt with later on in normal_stop and
8082 print_it_typical. Ideally there should be a call to one of these
8083 print_*_reason functions functions from handle_inferior_event each time
8084 stop_waiting is called.
8086 Note that we don't call these directly, instead we delegate that to
8087 the interpreters, through observers. Interpreters then call these
8088 with whatever uiout is right. */
8091 print_end_stepping_range_reason (struct ui_out
*uiout
)
8093 /* For CLI-like interpreters, print nothing. */
8095 if (uiout
->is_mi_like_p ())
8097 uiout
->field_string ("reason",
8098 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8103 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8105 annotate_signalled ();
8106 if (uiout
->is_mi_like_p ())
8108 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8109 uiout
->text ("\nProgram terminated with signal ");
8110 annotate_signal_name ();
8111 uiout
->field_string ("signal-name",
8112 gdb_signal_to_name (siggnal
));
8113 annotate_signal_name_end ();
8115 annotate_signal_string ();
8116 uiout
->field_string ("signal-meaning",
8117 gdb_signal_to_string (siggnal
));
8118 annotate_signal_string_end ();
8119 uiout
->text (".\n");
8120 uiout
->text ("The program no longer exists.\n");
8124 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8126 struct inferior
*inf
= current_inferior ();
8127 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8129 annotate_exited (exitstatus
);
8132 if (uiout
->is_mi_like_p ())
8133 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8134 std::string exit_code_str
8135 = string_printf ("0%o", (unsigned int) exitstatus
);
8136 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8137 plongest (inf
->num
), pidstr
.c_str (),
8138 string_field ("exit-code", exit_code_str
.c_str ()));
8142 if (uiout
->is_mi_like_p ())
8144 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8145 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8146 plongest (inf
->num
), pidstr
.c_str ());
8150 /* Some targets/architectures can do extra processing/display of
8151 segmentation faults. E.g., Intel MPX boundary faults.
8152 Call the architecture dependent function to handle the fault. */
8155 handle_segmentation_fault (struct ui_out
*uiout
)
8157 struct regcache
*regcache
= get_current_regcache ();
8158 struct gdbarch
*gdbarch
= regcache
->arch ();
8160 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8161 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8165 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8167 struct thread_info
*thr
= inferior_thread ();
8171 if (uiout
->is_mi_like_p ())
8173 else if (show_thread_that_caused_stop ())
8177 uiout
->text ("\nThread ");
8178 uiout
->field_string ("thread-id", print_thread_id (thr
));
8180 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8183 uiout
->text (" \"");
8184 uiout
->field_string ("name", name
);
8189 uiout
->text ("\nProgram");
8191 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8192 uiout
->text (" stopped");
8195 uiout
->text (" received signal ");
8196 annotate_signal_name ();
8197 if (uiout
->is_mi_like_p ())
8199 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8200 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8201 annotate_signal_name_end ();
8203 annotate_signal_string ();
8204 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8206 if (siggnal
== GDB_SIGNAL_SEGV
)
8207 handle_segmentation_fault (uiout
);
8209 annotate_signal_string_end ();
8211 uiout
->text (".\n");
8215 print_no_history_reason (struct ui_out
*uiout
)
8217 uiout
->text ("\nNo more reverse-execution history.\n");
8220 /* Print current location without a level number, if we have changed
8221 functions or hit a breakpoint. Print source line if we have one.
8222 bpstat_print contains the logic deciding in detail what to print,
8223 based on the event(s) that just occurred. */
8226 print_stop_location (struct target_waitstatus
*ws
)
8229 enum print_what source_flag
;
8230 int do_frame_printing
= 1;
8231 struct thread_info
*tp
= inferior_thread ();
8233 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8237 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8238 should) carry around the function and does (or should) use
8239 that when doing a frame comparison. */
8240 if (tp
->control
.stop_step
8241 && frame_id_eq (tp
->control
.step_frame_id
,
8242 get_frame_id (get_current_frame ()))
8243 && (tp
->control
.step_start_function
8244 == find_pc_function (tp
->suspend
.stop_pc
)))
8246 /* Finished step, just print source line. */
8247 source_flag
= SRC_LINE
;
8251 /* Print location and source line. */
8252 source_flag
= SRC_AND_LOC
;
8255 case PRINT_SRC_AND_LOC
:
8256 /* Print location and source line. */
8257 source_flag
= SRC_AND_LOC
;
8259 case PRINT_SRC_ONLY
:
8260 source_flag
= SRC_LINE
;
8263 /* Something bogus. */
8264 source_flag
= SRC_LINE
;
8265 do_frame_printing
= 0;
8268 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8271 /* The behavior of this routine with respect to the source
8273 SRC_LINE: Print only source line
8274 LOCATION: Print only location
8275 SRC_AND_LOC: Print location and source line. */
8276 if (do_frame_printing
)
8277 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8283 print_stop_event (struct ui_out
*uiout
, bool displays
)
8285 struct target_waitstatus last
;
8286 struct thread_info
*tp
;
8288 get_last_target_status (nullptr, nullptr, &last
);
8291 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8293 print_stop_location (&last
);
8295 /* Display the auto-display expressions. */
8300 tp
= inferior_thread ();
8301 if (tp
->thread_fsm
!= NULL
8302 && tp
->thread_fsm
->finished_p ())
8304 struct return_value_info
*rv
;
8306 rv
= tp
->thread_fsm
->return_value ();
8308 print_return_value (uiout
, rv
);
8315 maybe_remove_breakpoints (void)
8317 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8319 if (remove_breakpoints ())
8321 target_terminal::ours_for_output ();
8322 printf_filtered (_("Cannot remove breakpoints because "
8323 "program is no longer writable.\nFurther "
8324 "execution is probably impossible.\n"));
8329 /* The execution context that just caused a normal stop. */
8336 DISABLE_COPY_AND_ASSIGN (stop_context
);
8338 bool changed () const;
8343 /* The event PTID. */
8347 /* If stopp for a thread event, this is the thread that caused the
8349 struct thread_info
*thread
;
8351 /* The inferior that caused the stop. */
8355 /* Initializes a new stop context. If stopped for a thread event, this
8356 takes a strong reference to the thread. */
8358 stop_context::stop_context ()
8360 stop_id
= get_stop_id ();
8361 ptid
= inferior_ptid
;
8362 inf_num
= current_inferior ()->num
;
8364 if (inferior_ptid
!= null_ptid
)
8366 /* Take a strong reference so that the thread can't be deleted
8368 thread
= inferior_thread ();
8375 /* Release a stop context previously created with save_stop_context.
8376 Releases the strong reference to the thread as well. */
8378 stop_context::~stop_context ()
8384 /* Return true if the current context no longer matches the saved stop
8388 stop_context::changed () const
8390 if (ptid
!= inferior_ptid
)
8392 if (inf_num
!= current_inferior ()->num
)
8394 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8396 if (get_stop_id () != stop_id
)
8406 struct target_waitstatus last
;
8408 get_last_target_status (nullptr, nullptr, &last
);
8412 /* If an exception is thrown from this point on, make sure to
8413 propagate GDB's knowledge of the executing state to the
8414 frontend/user running state. A QUIT is an easy exception to see
8415 here, so do this before any filtered output. */
8417 ptid_t finish_ptid
= null_ptid
;
8420 finish_ptid
= minus_one_ptid
;
8421 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8422 || last
.kind
== TARGET_WAITKIND_EXITED
)
8424 /* On some targets, we may still have live threads in the
8425 inferior when we get a process exit event. E.g., for
8426 "checkpoint", when the current checkpoint/fork exits,
8427 linux-fork.c automatically switches to another fork from
8428 within target_mourn_inferior. */
8429 if (inferior_ptid
!= null_ptid
)
8430 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8432 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8433 finish_ptid
= inferior_ptid
;
8435 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8436 if (finish_ptid
!= null_ptid
)
8438 maybe_finish_thread_state
.emplace
8439 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8442 /* As we're presenting a stop, and potentially removing breakpoints,
8443 update the thread list so we can tell whether there are threads
8444 running on the target. With target remote, for example, we can
8445 only learn about new threads when we explicitly update the thread
8446 list. Do this before notifying the interpreters about signal
8447 stops, end of stepping ranges, etc., so that the "new thread"
8448 output is emitted before e.g., "Program received signal FOO",
8449 instead of after. */
8450 update_thread_list ();
8452 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8453 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8455 /* As with the notification of thread events, we want to delay
8456 notifying the user that we've switched thread context until
8457 the inferior actually stops.
8459 There's no point in saying anything if the inferior has exited.
8460 Note that SIGNALLED here means "exited with a signal", not
8461 "received a signal".
8463 Also skip saying anything in non-stop mode. In that mode, as we
8464 don't want GDB to switch threads behind the user's back, to avoid
8465 races where the user is typing a command to apply to thread x,
8466 but GDB switches to thread y before the user finishes entering
8467 the command, fetch_inferior_event installs a cleanup to restore
8468 the current thread back to the thread the user had selected right
8469 after this event is handled, so we're not really switching, only
8470 informing of a stop. */
8472 && previous_inferior_ptid
!= inferior_ptid
8473 && target_has_execution
8474 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8475 && last
.kind
!= TARGET_WAITKIND_EXITED
8476 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8478 SWITCH_THRU_ALL_UIS ()
8480 target_terminal::ours_for_output ();
8481 printf_filtered (_("[Switching to %s]\n"),
8482 target_pid_to_str (inferior_ptid
).c_str ());
8483 annotate_thread_changed ();
8485 previous_inferior_ptid
= inferior_ptid
;
8488 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8490 SWITCH_THRU_ALL_UIS ()
8491 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8493 target_terminal::ours_for_output ();
8494 printf_filtered (_("No unwaited-for children left.\n"));
8498 /* Note: this depends on the update_thread_list call above. */
8499 maybe_remove_breakpoints ();
8501 /* If an auto-display called a function and that got a signal,
8502 delete that auto-display to avoid an infinite recursion. */
8504 if (stopped_by_random_signal
)
8505 disable_current_display ();
8507 SWITCH_THRU_ALL_UIS ()
8509 async_enable_stdin ();
8512 /* Let the user/frontend see the threads as stopped. */
8513 maybe_finish_thread_state
.reset ();
8515 /* Select innermost stack frame - i.e., current frame is frame 0,
8516 and current location is based on that. Handle the case where the
8517 dummy call is returning after being stopped. E.g. the dummy call
8518 previously hit a breakpoint. (If the dummy call returns
8519 normally, we won't reach here.) Do this before the stop hook is
8520 run, so that it doesn't get to see the temporary dummy frame,
8521 which is not where we'll present the stop. */
8522 if (has_stack_frames ())
8524 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8526 /* Pop the empty frame that contains the stack dummy. This
8527 also restores inferior state prior to the call (struct
8528 infcall_suspend_state). */
8529 struct frame_info
*frame
= get_current_frame ();
8531 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8533 /* frame_pop calls reinit_frame_cache as the last thing it
8534 does which means there's now no selected frame. */
8537 select_frame (get_current_frame ());
8539 /* Set the current source location. */
8540 set_current_sal_from_frame (get_current_frame ());
8543 /* Look up the hook_stop and run it (CLI internally handles problem
8544 of stop_command's pre-hook not existing). */
8545 if (stop_command
!= NULL
)
8547 stop_context saved_context
;
8551 execute_cmd_pre_hook (stop_command
);
8553 catch (const gdb_exception
&ex
)
8555 exception_fprintf (gdb_stderr
, ex
,
8556 "Error while running hook_stop:\n");
8559 /* If the stop hook resumes the target, then there's no point in
8560 trying to notify about the previous stop; its context is
8561 gone. Likewise if the command switches thread or inferior --
8562 the observers would print a stop for the wrong
8564 if (saved_context
.changed ())
8568 /* Notify observers about the stop. This is where the interpreters
8569 print the stop event. */
8570 if (inferior_ptid
!= null_ptid
)
8571 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8574 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8576 annotate_stopped ();
8578 if (target_has_execution
)
8580 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8581 && last
.kind
!= TARGET_WAITKIND_EXITED
8582 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8583 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8584 Delete any breakpoint that is to be deleted at the next stop. */
8585 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8588 /* Try to get rid of automatically added inferiors that are no
8589 longer needed. Keeping those around slows down things linearly.
8590 Note that this never removes the current inferior. */
8597 signal_stop_state (int signo
)
8599 return signal_stop
[signo
];
8603 signal_print_state (int signo
)
8605 return signal_print
[signo
];
8609 signal_pass_state (int signo
)
8611 return signal_program
[signo
];
8615 signal_cache_update (int signo
)
8619 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8620 signal_cache_update (signo
);
8625 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8626 && signal_print
[signo
] == 0
8627 && signal_program
[signo
] == 1
8628 && signal_catch
[signo
] == 0);
8632 signal_stop_update (int signo
, int state
)
8634 int ret
= signal_stop
[signo
];
8636 signal_stop
[signo
] = state
;
8637 signal_cache_update (signo
);
8642 signal_print_update (int signo
, int state
)
8644 int ret
= signal_print
[signo
];
8646 signal_print
[signo
] = state
;
8647 signal_cache_update (signo
);
8652 signal_pass_update (int signo
, int state
)
8654 int ret
= signal_program
[signo
];
8656 signal_program
[signo
] = state
;
8657 signal_cache_update (signo
);
8661 /* Update the global 'signal_catch' from INFO and notify the
8665 signal_catch_update (const unsigned int *info
)
8669 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8670 signal_catch
[i
] = info
[i
] > 0;
8671 signal_cache_update (-1);
8672 target_pass_signals (signal_pass
);
8676 sig_print_header (void)
8678 printf_filtered (_("Signal Stop\tPrint\tPass "
8679 "to program\tDescription\n"));
8683 sig_print_info (enum gdb_signal oursig
)
8685 const char *name
= gdb_signal_to_name (oursig
);
8686 int name_padding
= 13 - strlen (name
);
8688 if (name_padding
<= 0)
8691 printf_filtered ("%s", name
);
8692 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8693 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8694 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8695 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8696 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8699 /* Specify how various signals in the inferior should be handled. */
8702 handle_command (const char *args
, int from_tty
)
8704 int digits
, wordlen
;
8705 int sigfirst
, siglast
;
8706 enum gdb_signal oursig
;
8711 error_no_arg (_("signal to handle"));
8714 /* Allocate and zero an array of flags for which signals to handle. */
8716 const size_t nsigs
= GDB_SIGNAL_LAST
;
8717 unsigned char sigs
[nsigs
] {};
8719 /* Break the command line up into args. */
8721 gdb_argv
built_argv (args
);
8723 /* Walk through the args, looking for signal oursigs, signal names, and
8724 actions. Signal numbers and signal names may be interspersed with
8725 actions, with the actions being performed for all signals cumulatively
8726 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8728 for (char *arg
: built_argv
)
8730 wordlen
= strlen (arg
);
8731 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8735 sigfirst
= siglast
= -1;
8737 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8739 /* Apply action to all signals except those used by the
8740 debugger. Silently skip those. */
8743 siglast
= nsigs
- 1;
8745 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8747 SET_SIGS (nsigs
, sigs
, signal_stop
);
8748 SET_SIGS (nsigs
, sigs
, signal_print
);
8750 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8752 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8754 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8756 SET_SIGS (nsigs
, sigs
, signal_print
);
8758 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8760 SET_SIGS (nsigs
, sigs
, signal_program
);
8762 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8764 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8766 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8768 SET_SIGS (nsigs
, sigs
, signal_program
);
8770 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8772 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8773 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8775 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8777 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8779 else if (digits
> 0)
8781 /* It is numeric. The numeric signal refers to our own
8782 internal signal numbering from target.h, not to host/target
8783 signal number. This is a feature; users really should be
8784 using symbolic names anyway, and the common ones like
8785 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8787 sigfirst
= siglast
= (int)
8788 gdb_signal_from_command (atoi (arg
));
8789 if (arg
[digits
] == '-')
8792 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8794 if (sigfirst
> siglast
)
8796 /* Bet he didn't figure we'd think of this case... */
8797 std::swap (sigfirst
, siglast
);
8802 oursig
= gdb_signal_from_name (arg
);
8803 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8805 sigfirst
= siglast
= (int) oursig
;
8809 /* Not a number and not a recognized flag word => complain. */
8810 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8814 /* If any signal numbers or symbol names were found, set flags for
8815 which signals to apply actions to. */
8817 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8819 switch ((enum gdb_signal
) signum
)
8821 case GDB_SIGNAL_TRAP
:
8822 case GDB_SIGNAL_INT
:
8823 if (!allsigs
&& !sigs
[signum
])
8825 if (query (_("%s is used by the debugger.\n\
8826 Are you sure you want to change it? "),
8827 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8832 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8836 case GDB_SIGNAL_DEFAULT
:
8837 case GDB_SIGNAL_UNKNOWN
:
8838 /* Make sure that "all" doesn't print these. */
8847 for (int signum
= 0; signum
< nsigs
; signum
++)
8850 signal_cache_update (-1);
8851 target_pass_signals (signal_pass
);
8852 target_program_signals (signal_program
);
8856 /* Show the results. */
8857 sig_print_header ();
8858 for (; signum
< nsigs
; signum
++)
8860 sig_print_info ((enum gdb_signal
) signum
);
8867 /* Complete the "handle" command. */
8870 handle_completer (struct cmd_list_element
*ignore
,
8871 completion_tracker
&tracker
,
8872 const char *text
, const char *word
)
8874 static const char * const keywords
[] =
8888 signal_completer (ignore
, tracker
, text
, word
);
8889 complete_on_enum (tracker
, keywords
, word
, word
);
8893 gdb_signal_from_command (int num
)
8895 if (num
>= 1 && num
<= 15)
8896 return (enum gdb_signal
) num
;
8897 error (_("Only signals 1-15 are valid as numeric signals.\n\
8898 Use \"info signals\" for a list of symbolic signals."));
8901 /* Print current contents of the tables set by the handle command.
8902 It is possible we should just be printing signals actually used
8903 by the current target (but for things to work right when switching
8904 targets, all signals should be in the signal tables). */
8907 info_signals_command (const char *signum_exp
, int from_tty
)
8909 enum gdb_signal oursig
;
8911 sig_print_header ();
8915 /* First see if this is a symbol name. */
8916 oursig
= gdb_signal_from_name (signum_exp
);
8917 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8919 /* No, try numeric. */
8921 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8923 sig_print_info (oursig
);
8927 printf_filtered ("\n");
8928 /* These ugly casts brought to you by the native VAX compiler. */
8929 for (oursig
= GDB_SIGNAL_FIRST
;
8930 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8931 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8935 if (oursig
!= GDB_SIGNAL_UNKNOWN
8936 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8937 sig_print_info (oursig
);
8940 printf_filtered (_("\nUse the \"handle\" command "
8941 "to change these tables.\n"));
8944 /* The $_siginfo convenience variable is a bit special. We don't know
8945 for sure the type of the value until we actually have a chance to
8946 fetch the data. The type can change depending on gdbarch, so it is
8947 also dependent on which thread you have selected.
8949 1. making $_siginfo be an internalvar that creates a new value on
8952 2. making the value of $_siginfo be an lval_computed value. */
8954 /* This function implements the lval_computed support for reading a
8958 siginfo_value_read (struct value
*v
)
8960 LONGEST transferred
;
8962 /* If we can access registers, so can we access $_siginfo. Likewise
8964 validate_registers_access ();
8967 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8969 value_contents_all_raw (v
),
8971 TYPE_LENGTH (value_type (v
)));
8973 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8974 error (_("Unable to read siginfo"));
8977 /* This function implements the lval_computed support for writing a
8981 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8983 LONGEST transferred
;
8985 /* If we can access registers, so can we access $_siginfo. Likewise
8987 validate_registers_access ();
8989 transferred
= target_write (current_top_target (),
8990 TARGET_OBJECT_SIGNAL_INFO
,
8992 value_contents_all_raw (fromval
),
8994 TYPE_LENGTH (value_type (fromval
)));
8996 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8997 error (_("Unable to write siginfo"));
9000 static const struct lval_funcs siginfo_value_funcs
=
9006 /* Return a new value with the correct type for the siginfo object of
9007 the current thread using architecture GDBARCH. Return a void value
9008 if there's no object available. */
9010 static struct value
*
9011 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9014 if (target_has_stack
9015 && inferior_ptid
!= null_ptid
9016 && gdbarch_get_siginfo_type_p (gdbarch
))
9018 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9020 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
9023 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
9027 /* infcall_suspend_state contains state about the program itself like its
9028 registers and any signal it received when it last stopped.
9029 This state must be restored regardless of how the inferior function call
9030 ends (either successfully, or after it hits a breakpoint or signal)
9031 if the program is to properly continue where it left off. */
9033 class infcall_suspend_state
9036 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9037 once the inferior function call has finished. */
9038 infcall_suspend_state (struct gdbarch
*gdbarch
,
9039 const struct thread_info
*tp
,
9040 struct regcache
*regcache
)
9041 : m_thread_suspend (tp
->suspend
),
9042 m_registers (new readonly_detached_regcache (*regcache
))
9044 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9046 if (gdbarch_get_siginfo_type_p (gdbarch
))
9048 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9049 size_t len
= TYPE_LENGTH (type
);
9051 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9053 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9054 siginfo_data
.get (), 0, len
) != len
)
9056 /* Errors ignored. */
9057 siginfo_data
.reset (nullptr);
9063 m_siginfo_gdbarch
= gdbarch
;
9064 m_siginfo_data
= std::move (siginfo_data
);
9068 /* Return a pointer to the stored register state. */
9070 readonly_detached_regcache
*registers () const
9072 return m_registers
.get ();
9075 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9077 void restore (struct gdbarch
*gdbarch
,
9078 struct thread_info
*tp
,
9079 struct regcache
*regcache
) const
9081 tp
->suspend
= m_thread_suspend
;
9083 if (m_siginfo_gdbarch
== gdbarch
)
9085 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9087 /* Errors ignored. */
9088 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9089 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9092 /* The inferior can be gone if the user types "print exit(0)"
9093 (and perhaps other times). */
9094 if (target_has_execution
)
9095 /* NB: The register write goes through to the target. */
9096 regcache
->restore (registers ());
9100 /* How the current thread stopped before the inferior function call was
9102 struct thread_suspend_state m_thread_suspend
;
9104 /* The registers before the inferior function call was executed. */
9105 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9107 /* Format of SIGINFO_DATA or NULL if it is not present. */
9108 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9110 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9111 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9112 content would be invalid. */
9113 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9116 infcall_suspend_state_up
9117 save_infcall_suspend_state ()
9119 struct thread_info
*tp
= inferior_thread ();
9120 struct regcache
*regcache
= get_current_regcache ();
9121 struct gdbarch
*gdbarch
= regcache
->arch ();
9123 infcall_suspend_state_up inf_state
9124 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9126 /* Having saved the current state, adjust the thread state, discarding
9127 any stop signal information. The stop signal is not useful when
9128 starting an inferior function call, and run_inferior_call will not use
9129 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9130 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9135 /* Restore inferior session state to INF_STATE. */
9138 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9140 struct thread_info
*tp
= inferior_thread ();
9141 struct regcache
*regcache
= get_current_regcache ();
9142 struct gdbarch
*gdbarch
= regcache
->arch ();
9144 inf_state
->restore (gdbarch
, tp
, regcache
);
9145 discard_infcall_suspend_state (inf_state
);
9149 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9154 readonly_detached_regcache
*
9155 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9157 return inf_state
->registers ();
9160 /* infcall_control_state contains state regarding gdb's control of the
9161 inferior itself like stepping control. It also contains session state like
9162 the user's currently selected frame. */
9164 struct infcall_control_state
9166 struct thread_control_state thread_control
;
9167 struct inferior_control_state inferior_control
;
9170 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9171 int stopped_by_random_signal
= 0;
9173 /* ID if the selected frame when the inferior function call was made. */
9174 struct frame_id selected_frame_id
{};
9177 /* Save all of the information associated with the inferior<==>gdb
9180 infcall_control_state_up
9181 save_infcall_control_state ()
9183 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9184 struct thread_info
*tp
= inferior_thread ();
9185 struct inferior
*inf
= current_inferior ();
9187 inf_status
->thread_control
= tp
->control
;
9188 inf_status
->inferior_control
= inf
->control
;
9190 tp
->control
.step_resume_breakpoint
= NULL
;
9191 tp
->control
.exception_resume_breakpoint
= NULL
;
9193 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9194 chain. If caller's caller is walking the chain, they'll be happier if we
9195 hand them back the original chain when restore_infcall_control_state is
9197 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9200 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9201 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9203 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9209 restore_selected_frame (const frame_id
&fid
)
9211 frame_info
*frame
= frame_find_by_id (fid
);
9213 /* If inf_status->selected_frame_id is NULL, there was no previously
9217 warning (_("Unable to restore previously selected frame."));
9221 select_frame (frame
);
9224 /* Restore inferior session state to INF_STATUS. */
9227 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9229 struct thread_info
*tp
= inferior_thread ();
9230 struct inferior
*inf
= current_inferior ();
9232 if (tp
->control
.step_resume_breakpoint
)
9233 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9235 if (tp
->control
.exception_resume_breakpoint
)
9236 tp
->control
.exception_resume_breakpoint
->disposition
9237 = disp_del_at_next_stop
;
9239 /* Handle the bpstat_copy of the chain. */
9240 bpstat_clear (&tp
->control
.stop_bpstat
);
9242 tp
->control
= inf_status
->thread_control
;
9243 inf
->control
= inf_status
->inferior_control
;
9246 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9247 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9249 if (target_has_stack
)
9251 /* The point of the try/catch is that if the stack is clobbered,
9252 walking the stack might encounter a garbage pointer and
9253 error() trying to dereference it. */
9256 restore_selected_frame (inf_status
->selected_frame_id
);
9258 catch (const gdb_exception_error
&ex
)
9260 exception_fprintf (gdb_stderr
, ex
,
9261 "Unable to restore previously selected frame:\n");
9262 /* Error in restoring the selected frame. Select the
9264 select_frame (get_current_frame ());
9272 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9274 if (inf_status
->thread_control
.step_resume_breakpoint
)
9275 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9276 = disp_del_at_next_stop
;
9278 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9279 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9280 = disp_del_at_next_stop
;
9282 /* See save_infcall_control_state for info on stop_bpstat. */
9283 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9291 clear_exit_convenience_vars (void)
9293 clear_internalvar (lookup_internalvar ("_exitsignal"));
9294 clear_internalvar (lookup_internalvar ("_exitcode"));
9298 /* User interface for reverse debugging:
9299 Set exec-direction / show exec-direction commands
9300 (returns error unless target implements to_set_exec_direction method). */
9302 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9303 static const char exec_forward
[] = "forward";
9304 static const char exec_reverse
[] = "reverse";
9305 static const char *exec_direction
= exec_forward
;
9306 static const char *const exec_direction_names
[] = {
9313 set_exec_direction_func (const char *args
, int from_tty
,
9314 struct cmd_list_element
*cmd
)
9316 if (target_can_execute_reverse
)
9318 if (!strcmp (exec_direction
, exec_forward
))
9319 execution_direction
= EXEC_FORWARD
;
9320 else if (!strcmp (exec_direction
, exec_reverse
))
9321 execution_direction
= EXEC_REVERSE
;
9325 exec_direction
= exec_forward
;
9326 error (_("Target does not support this operation."));
9331 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9332 struct cmd_list_element
*cmd
, const char *value
)
9334 switch (execution_direction
) {
9336 fprintf_filtered (out
, _("Forward.\n"));
9339 fprintf_filtered (out
, _("Reverse.\n"));
9342 internal_error (__FILE__
, __LINE__
,
9343 _("bogus execution_direction value: %d"),
9344 (int) execution_direction
);
9349 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9350 struct cmd_list_element
*c
, const char *value
)
9352 fprintf_filtered (file
, _("Resuming the execution of threads "
9353 "of all processes is %s.\n"), value
);
9356 /* Implementation of `siginfo' variable. */
9358 static const struct internalvar_funcs siginfo_funcs
=
9365 /* Callback for infrun's target events source. This is marked when a
9366 thread has a pending status to process. */
9369 infrun_async_inferior_event_handler (gdb_client_data data
)
9371 inferior_event_handler (INF_REG_EVENT
, NULL
);
9374 void _initialize_infrun ();
9376 _initialize_infrun ()
9378 struct cmd_list_element
*c
;
9380 /* Register extra event sources in the event loop. */
9381 infrun_async_inferior_event_token
9382 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9384 add_info ("signals", info_signals_command
, _("\
9385 What debugger does when program gets various signals.\n\
9386 Specify a signal as argument to print info on that signal only."));
9387 add_info_alias ("handle", "signals", 0);
9389 c
= add_com ("handle", class_run
, handle_command
, _("\
9390 Specify how to handle signals.\n\
9391 Usage: handle SIGNAL [ACTIONS]\n\
9392 Args are signals and actions to apply to those signals.\n\
9393 If no actions are specified, the current settings for the specified signals\n\
9394 will be displayed instead.\n\
9396 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9397 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9398 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9399 The special arg \"all\" is recognized to mean all signals except those\n\
9400 used by the debugger, typically SIGTRAP and SIGINT.\n\
9402 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9403 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9404 Stop means reenter debugger if this signal happens (implies print).\n\
9405 Print means print a message if this signal happens.\n\
9406 Pass means let program see this signal; otherwise program doesn't know.\n\
9407 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9408 Pass and Stop may be combined.\n\
9410 Multiple signals may be specified. Signal numbers and signal names\n\
9411 may be interspersed with actions, with the actions being performed for\n\
9412 all signals cumulatively specified."));
9413 set_cmd_completer (c
, handle_completer
);
9416 stop_command
= add_cmd ("stop", class_obscure
,
9417 not_just_help_class_command
, _("\
9418 There is no `stop' command, but you can set a hook on `stop'.\n\
9419 This allows you to set a list of commands to be run each time execution\n\
9420 of the program stops."), &cmdlist
);
9422 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9423 Set inferior debugging."), _("\
9424 Show inferior debugging."), _("\
9425 When non-zero, inferior specific debugging is enabled."),
9428 &setdebuglist
, &showdebuglist
);
9430 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9431 &debug_displaced
, _("\
9432 Set displaced stepping debugging."), _("\
9433 Show displaced stepping debugging."), _("\
9434 When non-zero, displaced stepping specific debugging is enabled."),
9436 show_debug_displaced
,
9437 &setdebuglist
, &showdebuglist
);
9439 add_setshow_boolean_cmd ("non-stop", no_class
,
9441 Set whether gdb controls the inferior in non-stop mode."), _("\
9442 Show whether gdb controls the inferior in non-stop mode."), _("\
9443 When debugging a multi-threaded program and this setting is\n\
9444 off (the default, also called all-stop mode), when one thread stops\n\
9445 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9446 all other threads in the program while you interact with the thread of\n\
9447 interest. When you continue or step a thread, you can allow the other\n\
9448 threads to run, or have them remain stopped, but while you inspect any\n\
9449 thread's state, all threads stop.\n\
9451 In non-stop mode, when one thread stops, other threads can continue\n\
9452 to run freely. You'll be able to step each thread independently,\n\
9453 leave it stopped or free to run as needed."),
9459 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9462 signal_print
[i
] = 1;
9463 signal_program
[i
] = 1;
9464 signal_catch
[i
] = 0;
9467 /* Signals caused by debugger's own actions should not be given to
9468 the program afterwards.
9470 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9471 explicitly specifies that it should be delivered to the target
9472 program. Typically, that would occur when a user is debugging a
9473 target monitor on a simulator: the target monitor sets a
9474 breakpoint; the simulator encounters this breakpoint and halts
9475 the simulation handing control to GDB; GDB, noting that the stop
9476 address doesn't map to any known breakpoint, returns control back
9477 to the simulator; the simulator then delivers the hardware
9478 equivalent of a GDB_SIGNAL_TRAP to the program being
9480 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9481 signal_program
[GDB_SIGNAL_INT
] = 0;
9483 /* Signals that are not errors should not normally enter the debugger. */
9484 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9485 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9486 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9487 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9488 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9489 signal_print
[GDB_SIGNAL_PROF
] = 0;
9490 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9491 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9492 signal_stop
[GDB_SIGNAL_IO
] = 0;
9493 signal_print
[GDB_SIGNAL_IO
] = 0;
9494 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9495 signal_print
[GDB_SIGNAL_POLL
] = 0;
9496 signal_stop
[GDB_SIGNAL_URG
] = 0;
9497 signal_print
[GDB_SIGNAL_URG
] = 0;
9498 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9499 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9500 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9501 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9503 /* These signals are used internally by user-level thread
9504 implementations. (See signal(5) on Solaris.) Like the above
9505 signals, a healthy program receives and handles them as part of
9506 its normal operation. */
9507 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9508 signal_print
[GDB_SIGNAL_LWP
] = 0;
9509 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9510 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9511 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9512 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9513 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9514 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9516 /* Update cached state. */
9517 signal_cache_update (-1);
9519 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9520 &stop_on_solib_events
, _("\
9521 Set stopping for shared library events."), _("\
9522 Show stopping for shared library events."), _("\
9523 If nonzero, gdb will give control to the user when the dynamic linker\n\
9524 notifies gdb of shared library events. The most common event of interest\n\
9525 to the user would be loading/unloading of a new library."),
9526 set_stop_on_solib_events
,
9527 show_stop_on_solib_events
,
9528 &setlist
, &showlist
);
9530 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9531 follow_fork_mode_kind_names
,
9532 &follow_fork_mode_string
, _("\
9533 Set debugger response to a program call of fork or vfork."), _("\
9534 Show debugger response to a program call of fork or vfork."), _("\
9535 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9536 parent - the original process is debugged after a fork\n\
9537 child - the new process is debugged after a fork\n\
9538 The unfollowed process will continue to run.\n\
9539 By default, the debugger will follow the parent process."),
9541 show_follow_fork_mode_string
,
9542 &setlist
, &showlist
);
9544 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9545 follow_exec_mode_names
,
9546 &follow_exec_mode_string
, _("\
9547 Set debugger response to a program call of exec."), _("\
9548 Show debugger response to a program call of exec."), _("\
9549 An exec call replaces the program image of a process.\n\
9551 follow-exec-mode can be:\n\
9553 new - the debugger creates a new inferior and rebinds the process\n\
9554 to this new inferior. The program the process was running before\n\
9555 the exec call can be restarted afterwards by restarting the original\n\
9558 same - the debugger keeps the process bound to the same inferior.\n\
9559 The new executable image replaces the previous executable loaded in\n\
9560 the inferior. Restarting the inferior after the exec call restarts\n\
9561 the executable the process was running after the exec call.\n\
9563 By default, the debugger will use the same inferior."),
9565 show_follow_exec_mode_string
,
9566 &setlist
, &showlist
);
9568 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9569 scheduler_enums
, &scheduler_mode
, _("\
9570 Set mode for locking scheduler during execution."), _("\
9571 Show mode for locking scheduler during execution."), _("\
9572 off == no locking (threads may preempt at any time)\n\
9573 on == full locking (no thread except the current thread may run)\n\
9574 This applies to both normal execution and replay mode.\n\
9575 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9576 In this mode, other threads may run during other commands.\n\
9577 This applies to both normal execution and replay mode.\n\
9578 replay == scheduler locked in replay mode and unlocked during normal execution."),
9579 set_schedlock_func
, /* traps on target vector */
9580 show_scheduler_mode
,
9581 &setlist
, &showlist
);
9583 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9584 Set mode for resuming threads of all processes."), _("\
9585 Show mode for resuming threads of all processes."), _("\
9586 When on, execution commands (such as 'continue' or 'next') resume all\n\
9587 threads of all processes. When off (which is the default), execution\n\
9588 commands only resume the threads of the current process. The set of\n\
9589 threads that are resumed is further refined by the scheduler-locking\n\
9590 mode (see help set scheduler-locking)."),
9592 show_schedule_multiple
,
9593 &setlist
, &showlist
);
9595 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9596 Set mode of the step operation."), _("\
9597 Show mode of the step operation."), _("\
9598 When set, doing a step over a function without debug line information\n\
9599 will stop at the first instruction of that function. Otherwise, the\n\
9600 function is skipped and the step command stops at a different source line."),
9602 show_step_stop_if_no_debug
,
9603 &setlist
, &showlist
);
9605 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9606 &can_use_displaced_stepping
, _("\
9607 Set debugger's willingness to use displaced stepping."), _("\
9608 Show debugger's willingness to use displaced stepping."), _("\
9609 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9610 supported by the target architecture. If off, gdb will not use displaced\n\
9611 stepping to step over breakpoints, even if such is supported by the target\n\
9612 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9613 if the target architecture supports it and non-stop mode is active, but will not\n\
9614 use it in all-stop mode (see help set non-stop)."),
9616 show_can_use_displaced_stepping
,
9617 &setlist
, &showlist
);
9619 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9620 &exec_direction
, _("Set direction of execution.\n\
9621 Options are 'forward' or 'reverse'."),
9622 _("Show direction of execution (forward/reverse)."),
9623 _("Tells gdb whether to execute forward or backward."),
9624 set_exec_direction_func
, show_exec_direction_func
,
9625 &setlist
, &showlist
);
9627 /* Set/show detach-on-fork: user-settable mode. */
9629 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9630 Set whether gdb will detach the child of a fork."), _("\
9631 Show whether gdb will detach the child of a fork."), _("\
9632 Tells gdb whether to detach the child of a fork."),
9633 NULL
, NULL
, &setlist
, &showlist
);
9635 /* Set/show disable address space randomization mode. */
9637 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9638 &disable_randomization
, _("\
9639 Set disabling of debuggee's virtual address space randomization."), _("\
9640 Show disabling of debuggee's virtual address space randomization."), _("\
9641 When this mode is on (which is the default), randomization of the virtual\n\
9642 address space is disabled. Standalone programs run with the randomization\n\
9643 enabled by default on some platforms."),
9644 &set_disable_randomization
,
9645 &show_disable_randomization
,
9646 &setlist
, &showlist
);
9648 /* ptid initializations */
9649 inferior_ptid
= null_ptid
;
9650 target_last_wait_ptid
= minus_one_ptid
;
9652 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9653 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9654 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9655 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9657 /* Explicitly create without lookup, since that tries to create a
9658 value with a void typed value, and when we get here, gdbarch
9659 isn't initialized yet. At this point, we're quite sure there
9660 isn't another convenience variable of the same name. */
9661 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9663 add_setshow_boolean_cmd ("observer", no_class
,
9664 &observer_mode_1
, _("\
9665 Set whether gdb controls the inferior in observer mode."), _("\
9666 Show whether gdb controls the inferior in observer mode."), _("\
9667 In observer mode, GDB can get data from the inferior, but not\n\
9668 affect its execution. Registers and memory may not be changed,\n\
9669 breakpoints may not be set, and the program cannot be interrupted\n\