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 "gdbsupport/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 "gdbsupport/gdb_select.h"
68 #include <unordered_map>
69 #include "async-event.h"
71 /* Prototypes for local functions */
73 static void sig_print_info (enum gdb_signal
);
75 static void sig_print_header (void);
77 static void follow_inferior_reset_breakpoints (void);
79 static int currently_stepping (struct thread_info
*tp
);
81 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
83 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
85 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
87 static int maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
89 static void resume (gdb_signal sig
);
91 static void wait_for_inferior (inferior
*inf
);
93 /* Asynchronous signal handler registered as event loop source for
94 when we have pending events ready to be passed to the core. */
95 static struct async_event_handler
*infrun_async_inferior_event_token
;
97 /* Stores whether infrun_async was previously enabled or disabled.
98 Starts off as -1, indicating "never enabled/disabled". */
99 static int infrun_is_async
= -1;
104 infrun_async (int enable
)
106 if (infrun_is_async
!= enable
)
108 infrun_is_async
= enable
;
111 fprintf_unfiltered (gdb_stdlog
,
112 "infrun: infrun_async(%d)\n",
116 mark_async_event_handler (infrun_async_inferior_event_token
);
118 clear_async_event_handler (infrun_async_inferior_event_token
);
125 mark_infrun_async_event_handler (void)
127 mark_async_event_handler (infrun_async_inferior_event_token
);
130 /* When set, stop the 'step' command if we enter a function which has
131 no line number information. The normal behavior is that we step
132 over such function. */
133 bool step_stop_if_no_debug
= false;
135 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
136 struct cmd_list_element
*c
, const char *value
)
138 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
141 /* proceed and normal_stop use this to notify the user when the
142 inferior stopped in a different thread than it had been running
145 static ptid_t previous_inferior_ptid
;
147 /* If set (default for legacy reasons), when following a fork, GDB
148 will detach from one of the fork branches, child or parent.
149 Exactly which branch is detached depends on 'set follow-fork-mode'
152 static bool detach_fork
= true;
154 bool debug_displaced
= false;
156 show_debug_displaced (struct ui_file
*file
, int from_tty
,
157 struct cmd_list_element
*c
, const char *value
)
159 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
162 unsigned int debug_infrun
= 0;
164 show_debug_infrun (struct ui_file
*file
, int from_tty
,
165 struct cmd_list_element
*c
, const char *value
)
167 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
171 /* Support for disabling address space randomization. */
173 bool disable_randomization
= true;
176 show_disable_randomization (struct ui_file
*file
, int from_tty
,
177 struct cmd_list_element
*c
, const char *value
)
179 if (target_supports_disable_randomization ())
180 fprintf_filtered (file
,
181 _("Disabling randomization of debuggee's "
182 "virtual address space is %s.\n"),
185 fputs_filtered (_("Disabling randomization of debuggee's "
186 "virtual address space is unsupported on\n"
187 "this platform.\n"), file
);
191 set_disable_randomization (const char *args
, int from_tty
,
192 struct cmd_list_element
*c
)
194 if (!target_supports_disable_randomization ())
195 error (_("Disabling randomization of debuggee's "
196 "virtual address space is unsupported on\n"
200 /* User interface for non-stop mode. */
202 bool non_stop
= false;
203 static bool non_stop_1
= false;
206 set_non_stop (const char *args
, int from_tty
,
207 struct cmd_list_element
*c
)
209 if (target_has_execution
)
211 non_stop_1
= non_stop
;
212 error (_("Cannot change this setting while the inferior is running."));
215 non_stop
= non_stop_1
;
219 show_non_stop (struct ui_file
*file
, int from_tty
,
220 struct cmd_list_element
*c
, const char *value
)
222 fprintf_filtered (file
,
223 _("Controlling the inferior in non-stop mode is %s.\n"),
227 /* "Observer mode" is somewhat like a more extreme version of
228 non-stop, in which all GDB operations that might affect the
229 target's execution have been disabled. */
231 bool observer_mode
= false;
232 static bool observer_mode_1
= false;
235 set_observer_mode (const char *args
, int from_tty
,
236 struct cmd_list_element
*c
)
238 if (target_has_execution
)
240 observer_mode_1
= observer_mode
;
241 error (_("Cannot change this setting while the inferior is running."));
244 observer_mode
= observer_mode_1
;
246 may_write_registers
= !observer_mode
;
247 may_write_memory
= !observer_mode
;
248 may_insert_breakpoints
= !observer_mode
;
249 may_insert_tracepoints
= !observer_mode
;
250 /* We can insert fast tracepoints in or out of observer mode,
251 but enable them if we're going into this mode. */
253 may_insert_fast_tracepoints
= true;
254 may_stop
= !observer_mode
;
255 update_target_permissions ();
257 /* Going *into* observer mode we must force non-stop, then
258 going out we leave it that way. */
261 pagination_enabled
= 0;
262 non_stop
= non_stop_1
= true;
266 printf_filtered (_("Observer mode is now %s.\n"),
267 (observer_mode
? "on" : "off"));
271 show_observer_mode (struct ui_file
*file
, int from_tty
,
272 struct cmd_list_element
*c
, const char *value
)
274 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
277 /* This updates the value of observer mode based on changes in
278 permissions. Note that we are deliberately ignoring the values of
279 may-write-registers and may-write-memory, since the user may have
280 reason to enable these during a session, for instance to turn on a
281 debugging-related global. */
284 update_observer_mode (void)
286 bool newval
= (!may_insert_breakpoints
287 && !may_insert_tracepoints
288 && may_insert_fast_tracepoints
292 /* Let the user know if things change. */
293 if (newval
!= observer_mode
)
294 printf_filtered (_("Observer mode is now %s.\n"),
295 (newval
? "on" : "off"));
297 observer_mode
= observer_mode_1
= newval
;
300 /* Tables of how to react to signals; the user sets them. */
302 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
303 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
304 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
306 /* Table of signals that are registered with "catch signal". A
307 non-zero entry indicates that the signal is caught by some "catch
309 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
311 /* Table of signals that the target may silently handle.
312 This is automatically determined from the flags above,
313 and simply cached here. */
314 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
316 #define SET_SIGS(nsigs,sigs,flags) \
318 int signum = (nsigs); \
319 while (signum-- > 0) \
320 if ((sigs)[signum]) \
321 (flags)[signum] = 1; \
324 #define UNSET_SIGS(nsigs,sigs,flags) \
326 int signum = (nsigs); \
327 while (signum-- > 0) \
328 if ((sigs)[signum]) \
329 (flags)[signum] = 0; \
332 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
333 this function is to avoid exporting `signal_program'. */
336 update_signals_program_target (void)
338 target_program_signals (signal_program
);
341 /* Value to pass to target_resume() to cause all threads to resume. */
343 #define RESUME_ALL minus_one_ptid
345 /* Command list pointer for the "stop" placeholder. */
347 static struct cmd_list_element
*stop_command
;
349 /* Nonzero if we want to give control to the user when we're notified
350 of shared library events by the dynamic linker. */
351 int stop_on_solib_events
;
353 /* Enable or disable optional shared library event breakpoints
354 as appropriate when the above flag is changed. */
357 set_stop_on_solib_events (const char *args
,
358 int from_tty
, struct cmd_list_element
*c
)
360 update_solib_breakpoints ();
364 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
365 struct cmd_list_element
*c
, const char *value
)
367 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
371 /* Nonzero after stop if current stack frame should be printed. */
373 static int stop_print_frame
;
375 /* This is a cached copy of the target/ptid/waitstatus of the last
376 event returned by target_wait()/deprecated_target_wait_hook().
377 This information is returned by get_last_target_status(). */
378 static process_stratum_target
*target_last_proc_target
;
379 static ptid_t target_last_wait_ptid
;
380 static struct target_waitstatus target_last_waitstatus
;
382 void init_thread_stepping_state (struct thread_info
*tss
);
384 static const char follow_fork_mode_child
[] = "child";
385 static const char follow_fork_mode_parent
[] = "parent";
387 static const char *const follow_fork_mode_kind_names
[] = {
388 follow_fork_mode_child
,
389 follow_fork_mode_parent
,
393 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
395 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
396 struct cmd_list_element
*c
, const char *value
)
398 fprintf_filtered (file
,
399 _("Debugger response to a program "
400 "call of fork or vfork is \"%s\".\n"),
405 /* Handle changes to the inferior list based on the type of fork,
406 which process is being followed, and whether the other process
407 should be detached. On entry inferior_ptid must be the ptid of
408 the fork parent. At return inferior_ptid is the ptid of the
409 followed inferior. */
412 follow_fork_inferior (bool follow_child
, bool detach_fork
)
415 ptid_t parent_ptid
, child_ptid
;
417 has_vforked
= (inferior_thread ()->pending_follow
.kind
418 == TARGET_WAITKIND_VFORKED
);
419 parent_ptid
= inferior_ptid
;
420 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
423 && !non_stop
/* Non-stop always resumes both branches. */
424 && current_ui
->prompt_state
== PROMPT_BLOCKED
425 && !(follow_child
|| detach_fork
|| sched_multi
))
427 /* The parent stays blocked inside the vfork syscall until the
428 child execs or exits. If we don't let the child run, then
429 the parent stays blocked. If we're telling the parent to run
430 in the foreground, the user will not be able to ctrl-c to get
431 back the terminal, effectively hanging the debug session. */
432 fprintf_filtered (gdb_stderr
, _("\
433 Can not resume the parent process over vfork in the foreground while\n\
434 holding the child stopped. Try \"set detach-on-fork\" or \
435 \"set schedule-multiple\".\n"));
441 /* Detach new forked process? */
444 /* Before detaching from the child, remove all breakpoints
445 from it. If we forked, then this has already been taken
446 care of by infrun.c. If we vforked however, any
447 breakpoint inserted in the parent is visible in the
448 child, even those added while stopped in a vfork
449 catchpoint. This will remove the breakpoints from the
450 parent also, but they'll be reinserted below. */
453 /* Keep breakpoints list in sync. */
454 remove_breakpoints_inf (current_inferior ());
457 if (print_inferior_events
)
459 /* Ensure that we have a process ptid. */
460 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
462 target_terminal::ours_for_output ();
463 fprintf_filtered (gdb_stdlog
,
464 _("[Detaching after %s from child %s]\n"),
465 has_vforked
? "vfork" : "fork",
466 target_pid_to_str (process_ptid
).c_str ());
471 struct inferior
*parent_inf
, *child_inf
;
473 /* Add process to GDB's tables. */
474 child_inf
= add_inferior (child_ptid
.pid ());
476 parent_inf
= current_inferior ();
477 child_inf
->attach_flag
= parent_inf
->attach_flag
;
478 copy_terminal_info (child_inf
, parent_inf
);
479 child_inf
->gdbarch
= parent_inf
->gdbarch
;
480 copy_inferior_target_desc_info (child_inf
, parent_inf
);
482 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
484 set_current_inferior (child_inf
);
485 switch_to_no_thread ();
486 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
487 push_target (parent_inf
->process_target ());
488 thread_info
*child_thr
489 = add_thread_silent (child_inf
->process_target (), child_ptid
);
491 /* If this is a vfork child, then the address-space is
492 shared with the parent. */
495 child_inf
->pspace
= parent_inf
->pspace
;
496 child_inf
->aspace
= parent_inf
->aspace
;
500 /* The parent will be frozen until the child is done
501 with the shared region. Keep track of the
503 child_inf
->vfork_parent
= parent_inf
;
504 child_inf
->pending_detach
= 0;
505 parent_inf
->vfork_child
= child_inf
;
506 parent_inf
->pending_detach
= 0;
508 /* Now that the inferiors and program spaces are all
509 wired up, we can switch to the child thread (which
510 switches inferior and program space too). */
511 switch_to_thread (child_thr
);
515 child_inf
->aspace
= new_address_space ();
516 child_inf
->pspace
= new program_space (child_inf
->aspace
);
517 child_inf
->removable
= 1;
518 set_current_program_space (child_inf
->pspace
);
519 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
521 /* solib_create_inferior_hook relies on the current
523 switch_to_thread (child_thr
);
525 /* Let the shared library layer (e.g., solib-svr4) learn
526 about this new process, relocate the cloned exec, pull
527 in shared libraries, and install the solib event
528 breakpoint. If a "cloned-VM" event was propagated
529 better throughout the core, this wouldn't be
531 solib_create_inferior_hook (0);
537 struct inferior
*parent_inf
;
539 parent_inf
= current_inferior ();
541 /* If we detached from the child, then we have to be careful
542 to not insert breakpoints in the parent until the child
543 is done with the shared memory region. However, if we're
544 staying attached to the child, then we can and should
545 insert breakpoints, so that we can debug it. A
546 subsequent child exec or exit is enough to know when does
547 the child stops using the parent's address space. */
548 parent_inf
->waiting_for_vfork_done
= detach_fork
;
549 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
554 /* Follow the child. */
555 struct inferior
*parent_inf
, *child_inf
;
556 struct program_space
*parent_pspace
;
558 if (print_inferior_events
)
560 std::string parent_pid
= target_pid_to_str (parent_ptid
);
561 std::string child_pid
= target_pid_to_str (child_ptid
);
563 target_terminal::ours_for_output ();
564 fprintf_filtered (gdb_stdlog
,
565 _("[Attaching after %s %s to child %s]\n"),
567 has_vforked
? "vfork" : "fork",
571 /* Add the new inferior first, so that the target_detach below
572 doesn't unpush the target. */
574 child_inf
= add_inferior (child_ptid
.pid ());
576 parent_inf
= current_inferior ();
577 child_inf
->attach_flag
= parent_inf
->attach_flag
;
578 copy_terminal_info (child_inf
, parent_inf
);
579 child_inf
->gdbarch
= parent_inf
->gdbarch
;
580 copy_inferior_target_desc_info (child_inf
, parent_inf
);
582 parent_pspace
= parent_inf
->pspace
;
584 process_stratum_target
*target
= parent_inf
->process_target ();
587 /* Hold a strong reference to the target while (maybe)
588 detaching the parent. Otherwise detaching could close the
590 auto target_ref
= target_ops_ref::new_reference (target
);
592 /* If we're vforking, we want to hold on to the parent until
593 the child exits or execs. At child exec or exit time we
594 can remove the old breakpoints from the parent and detach
595 or resume debugging it. Otherwise, detach the parent now;
596 we'll want to reuse it's program/address spaces, but we
597 can't set them to the child before removing breakpoints
598 from the parent, otherwise, the breakpoints module could
599 decide to remove breakpoints from the wrong process (since
600 they'd be assigned to the same address space). */
604 gdb_assert (child_inf
->vfork_parent
== NULL
);
605 gdb_assert (parent_inf
->vfork_child
== NULL
);
606 child_inf
->vfork_parent
= parent_inf
;
607 child_inf
->pending_detach
= 0;
608 parent_inf
->vfork_child
= child_inf
;
609 parent_inf
->pending_detach
= detach_fork
;
610 parent_inf
->waiting_for_vfork_done
= 0;
612 else if (detach_fork
)
614 if (print_inferior_events
)
616 /* Ensure that we have a process ptid. */
617 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
619 target_terminal::ours_for_output ();
620 fprintf_filtered (gdb_stdlog
,
621 _("[Detaching after fork from "
623 target_pid_to_str (process_ptid
).c_str ());
626 target_detach (parent_inf
, 0);
630 /* Note that the detach above makes PARENT_INF dangling. */
632 /* Add the child thread to the appropriate lists, and switch
633 to this new thread, before cloning the program space, and
634 informing the solib layer about this new process. */
636 set_current_inferior (child_inf
);
637 push_target (target
);
640 thread_info
*child_thr
= add_thread_silent (target
, child_ptid
);
642 /* If this is a vfork child, then the address-space is shared
643 with the parent. If we detached from the parent, then we can
644 reuse the parent's program/address spaces. */
645 if (has_vforked
|| detach_fork
)
647 child_inf
->pspace
= parent_pspace
;
648 child_inf
->aspace
= child_inf
->pspace
->aspace
;
654 child_inf
->aspace
= new_address_space ();
655 child_inf
->pspace
= new program_space (child_inf
->aspace
);
656 child_inf
->removable
= 1;
657 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
658 set_current_program_space (child_inf
->pspace
);
659 clone_program_space (child_inf
->pspace
, parent_pspace
);
661 /* Let the shared library layer (e.g., solib-svr4) learn
662 about this new process, relocate the cloned exec, pull in
663 shared libraries, and install the solib event breakpoint.
664 If a "cloned-VM" event was propagated better throughout
665 the core, this wouldn't be required. */
666 solib_create_inferior_hook (0);
669 switch_to_thread (child_thr
);
672 return target_follow_fork (follow_child
, detach_fork
);
675 /* Tell the target to follow the fork we're stopped at. Returns true
676 if the inferior should be resumed; false, if the target for some
677 reason decided it's best not to resume. */
682 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
683 bool should_resume
= true;
684 struct thread_info
*tp
;
686 /* Copy user stepping state to the new inferior thread. FIXME: the
687 followed fork child thread should have a copy of most of the
688 parent thread structure's run control related fields, not just these.
689 Initialized to avoid "may be used uninitialized" warnings from gcc. */
690 struct breakpoint
*step_resume_breakpoint
= NULL
;
691 struct breakpoint
*exception_resume_breakpoint
= NULL
;
692 CORE_ADDR step_range_start
= 0;
693 CORE_ADDR step_range_end
= 0;
694 int current_line
= 0;
695 symtab
*current_symtab
= NULL
;
696 struct frame_id step_frame_id
= { 0 };
697 struct thread_fsm
*thread_fsm
= NULL
;
701 process_stratum_target
*wait_target
;
703 struct target_waitstatus wait_status
;
705 /* Get the last target status returned by target_wait(). */
706 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
708 /* If not stopped at a fork event, then there's nothing else to
710 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
711 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
714 /* Check if we switched over from WAIT_PTID, since the event was
716 if (wait_ptid
!= minus_one_ptid
717 && (current_inferior ()->process_target () != wait_target
718 || inferior_ptid
!= wait_ptid
))
720 /* We did. Switch back to WAIT_PTID thread, to tell the
721 target to follow it (in either direction). We'll
722 afterwards refuse to resume, and inform the user what
724 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
725 switch_to_thread (wait_thread
);
726 should_resume
= false;
730 tp
= inferior_thread ();
732 /* If there were any forks/vforks that were caught and are now to be
733 followed, then do so now. */
734 switch (tp
->pending_follow
.kind
)
736 case TARGET_WAITKIND_FORKED
:
737 case TARGET_WAITKIND_VFORKED
:
739 ptid_t parent
, child
;
741 /* If the user did a next/step, etc, over a fork call,
742 preserve the stepping state in the fork child. */
743 if (follow_child
&& should_resume
)
745 step_resume_breakpoint
= clone_momentary_breakpoint
746 (tp
->control
.step_resume_breakpoint
);
747 step_range_start
= tp
->control
.step_range_start
;
748 step_range_end
= tp
->control
.step_range_end
;
749 current_line
= tp
->current_line
;
750 current_symtab
= tp
->current_symtab
;
751 step_frame_id
= tp
->control
.step_frame_id
;
752 exception_resume_breakpoint
753 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
754 thread_fsm
= tp
->thread_fsm
;
756 /* For now, delete the parent's sr breakpoint, otherwise,
757 parent/child sr breakpoints are considered duplicates,
758 and the child version will not be installed. Remove
759 this when the breakpoints module becomes aware of
760 inferiors and address spaces. */
761 delete_step_resume_breakpoint (tp
);
762 tp
->control
.step_range_start
= 0;
763 tp
->control
.step_range_end
= 0;
764 tp
->control
.step_frame_id
= null_frame_id
;
765 delete_exception_resume_breakpoint (tp
);
766 tp
->thread_fsm
= NULL
;
769 parent
= inferior_ptid
;
770 child
= tp
->pending_follow
.value
.related_pid
;
772 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
773 /* Set up inferior(s) as specified by the caller, and tell the
774 target to do whatever is necessary to follow either parent
776 if (follow_fork_inferior (follow_child
, detach_fork
))
778 /* Target refused to follow, or there's some other reason
779 we shouldn't resume. */
784 /* This pending follow fork event is now handled, one way
785 or another. The previous selected thread may be gone
786 from the lists by now, but if it is still around, need
787 to clear the pending follow request. */
788 tp
= find_thread_ptid (parent_targ
, parent
);
790 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
792 /* This makes sure we don't try to apply the "Switched
793 over from WAIT_PID" logic above. */
794 nullify_last_target_wait_ptid ();
796 /* If we followed the child, switch to it... */
799 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
800 switch_to_thread (child_thr
);
802 /* ... and preserve the stepping state, in case the
803 user was stepping over the fork call. */
806 tp
= inferior_thread ();
807 tp
->control
.step_resume_breakpoint
808 = step_resume_breakpoint
;
809 tp
->control
.step_range_start
= step_range_start
;
810 tp
->control
.step_range_end
= step_range_end
;
811 tp
->current_line
= current_line
;
812 tp
->current_symtab
= current_symtab
;
813 tp
->control
.step_frame_id
= step_frame_id
;
814 tp
->control
.exception_resume_breakpoint
815 = exception_resume_breakpoint
;
816 tp
->thread_fsm
= thread_fsm
;
820 /* If we get here, it was because we're trying to
821 resume from a fork catchpoint, but, the user
822 has switched threads away from the thread that
823 forked. In that case, the resume command
824 issued is most likely not applicable to the
825 child, so just warn, and refuse to resume. */
826 warning (_("Not resuming: switched threads "
827 "before following fork child."));
830 /* Reset breakpoints in the child as appropriate. */
831 follow_inferior_reset_breakpoints ();
836 case TARGET_WAITKIND_SPURIOUS
:
837 /* Nothing to follow. */
840 internal_error (__FILE__
, __LINE__
,
841 "Unexpected pending_follow.kind %d\n",
842 tp
->pending_follow
.kind
);
846 return should_resume
;
850 follow_inferior_reset_breakpoints (void)
852 struct thread_info
*tp
= inferior_thread ();
854 /* Was there a step_resume breakpoint? (There was if the user
855 did a "next" at the fork() call.) If so, explicitly reset its
856 thread number. Cloned step_resume breakpoints are disabled on
857 creation, so enable it here now that it is associated with the
860 step_resumes are a form of bp that are made to be per-thread.
861 Since we created the step_resume bp when the parent process
862 was being debugged, and now are switching to the child process,
863 from the breakpoint package's viewpoint, that's a switch of
864 "threads". We must update the bp's notion of which thread
865 it is for, or it'll be ignored when it triggers. */
867 if (tp
->control
.step_resume_breakpoint
)
869 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
870 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
873 /* Treat exception_resume breakpoints like step_resume breakpoints. */
874 if (tp
->control
.exception_resume_breakpoint
)
876 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
877 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
880 /* Reinsert all breakpoints in the child. The user may have set
881 breakpoints after catching the fork, in which case those
882 were never set in the child, but only in the parent. This makes
883 sure the inserted breakpoints match the breakpoint list. */
885 breakpoint_re_set ();
886 insert_breakpoints ();
889 /* The child has exited or execed: resume threads of the parent the
890 user wanted to be executing. */
893 proceed_after_vfork_done (struct thread_info
*thread
,
896 int pid
= * (int *) arg
;
898 if (thread
->ptid
.pid () == pid
899 && thread
->state
== THREAD_RUNNING
900 && !thread
->executing
901 && !thread
->stop_requested
902 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
905 fprintf_unfiltered (gdb_stdlog
,
906 "infrun: resuming vfork parent thread %s\n",
907 target_pid_to_str (thread
->ptid
).c_str ());
909 switch_to_thread (thread
);
910 clear_proceed_status (0);
911 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
917 /* Called whenever we notice an exec or exit event, to handle
918 detaching or resuming a vfork parent. */
921 handle_vfork_child_exec_or_exit (int exec
)
923 struct inferior
*inf
= current_inferior ();
925 if (inf
->vfork_parent
)
927 int resume_parent
= -1;
929 /* This exec or exit marks the end of the shared memory region
930 between the parent and the child. Break the bonds. */
931 inferior
*vfork_parent
= inf
->vfork_parent
;
932 inf
->vfork_parent
->vfork_child
= NULL
;
933 inf
->vfork_parent
= NULL
;
935 /* If the user wanted to detach from the parent, now is the
937 if (vfork_parent
->pending_detach
)
939 struct program_space
*pspace
;
940 struct address_space
*aspace
;
942 /* follow-fork child, detach-on-fork on. */
944 vfork_parent
->pending_detach
= 0;
946 scoped_restore_current_pspace_and_thread restore_thread
;
948 /* We're letting loose of the parent. */
949 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
950 switch_to_thread (tp
);
952 /* We're about to detach from the parent, which implicitly
953 removes breakpoints from its address space. There's a
954 catch here: we want to reuse the spaces for the child,
955 but, parent/child are still sharing the pspace at this
956 point, although the exec in reality makes the kernel give
957 the child a fresh set of new pages. The problem here is
958 that the breakpoints module being unaware of this, would
959 likely chose the child process to write to the parent
960 address space. Swapping the child temporarily away from
961 the spaces has the desired effect. Yes, this is "sort
964 pspace
= inf
->pspace
;
965 aspace
= inf
->aspace
;
969 if (print_inferior_events
)
972 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
974 target_terminal::ours_for_output ();
978 fprintf_filtered (gdb_stdlog
,
979 _("[Detaching vfork parent %s "
980 "after child exec]\n"), pidstr
.c_str ());
984 fprintf_filtered (gdb_stdlog
,
985 _("[Detaching vfork parent %s "
986 "after child exit]\n"), pidstr
.c_str ());
990 target_detach (vfork_parent
, 0);
993 inf
->pspace
= pspace
;
994 inf
->aspace
= aspace
;
998 /* We're staying attached to the parent, so, really give the
999 child a new address space. */
1000 inf
->pspace
= new program_space (maybe_new_address_space ());
1001 inf
->aspace
= inf
->pspace
->aspace
;
1003 set_current_program_space (inf
->pspace
);
1005 resume_parent
= vfork_parent
->pid
;
1009 /* If this is a vfork child exiting, then the pspace and
1010 aspaces were shared with the parent. Since we're
1011 reporting the process exit, we'll be mourning all that is
1012 found in the address space, and switching to null_ptid,
1013 preparing to start a new inferior. But, since we don't
1014 want to clobber the parent's address/program spaces, we
1015 go ahead and create a new one for this exiting
1018 /* Switch to no-thread while running clone_program_space, so
1019 that clone_program_space doesn't want to read the
1020 selected frame of a dead process. */
1021 scoped_restore_current_thread restore_thread
;
1022 switch_to_no_thread ();
1024 inf
->pspace
= new program_space (maybe_new_address_space ());
1025 inf
->aspace
= inf
->pspace
->aspace
;
1026 set_current_program_space (inf
->pspace
);
1028 inf
->symfile_flags
= SYMFILE_NO_READ
;
1029 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1031 resume_parent
= vfork_parent
->pid
;
1034 gdb_assert (current_program_space
== inf
->pspace
);
1036 if (non_stop
&& resume_parent
!= -1)
1038 /* If the user wanted the parent to be running, let it go
1040 scoped_restore_current_thread restore_thread
;
1043 fprintf_unfiltered (gdb_stdlog
,
1044 "infrun: resuming vfork parent process %d\n",
1047 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1052 /* Enum strings for "set|show follow-exec-mode". */
1054 static const char follow_exec_mode_new
[] = "new";
1055 static const char follow_exec_mode_same
[] = "same";
1056 static const char *const follow_exec_mode_names
[] =
1058 follow_exec_mode_new
,
1059 follow_exec_mode_same
,
1063 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1065 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1066 struct cmd_list_element
*c
, const char *value
)
1068 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1071 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1074 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1076 struct inferior
*inf
= current_inferior ();
1077 int pid
= ptid
.pid ();
1078 ptid_t process_ptid
;
1080 /* Switch terminal for any messages produced e.g. by
1081 breakpoint_re_set. */
1082 target_terminal::ours_for_output ();
1084 /* This is an exec event that we actually wish to pay attention to.
1085 Refresh our symbol table to the newly exec'd program, remove any
1086 momentary bp's, etc.
1088 If there are breakpoints, they aren't really inserted now,
1089 since the exec() transformed our inferior into a fresh set
1092 We want to preserve symbolic breakpoints on the list, since
1093 we have hopes that they can be reset after the new a.out's
1094 symbol table is read.
1096 However, any "raw" breakpoints must be removed from the list
1097 (e.g., the solib bp's), since their address is probably invalid
1100 And, we DON'T want to call delete_breakpoints() here, since
1101 that may write the bp's "shadow contents" (the instruction
1102 value that was overwritten with a TRAP instruction). Since
1103 we now have a new a.out, those shadow contents aren't valid. */
1105 mark_breakpoints_out ();
1107 /* The target reports the exec event to the main thread, even if
1108 some other thread does the exec, and even if the main thread was
1109 stopped or already gone. We may still have non-leader threads of
1110 the process on our list. E.g., on targets that don't have thread
1111 exit events (like remote); or on native Linux in non-stop mode if
1112 there were only two threads in the inferior and the non-leader
1113 one is the one that execs (and nothing forces an update of the
1114 thread list up to here). When debugging remotely, it's best to
1115 avoid extra traffic, when possible, so avoid syncing the thread
1116 list with the target, and instead go ahead and delete all threads
1117 of the process but one that reported the event. Note this must
1118 be done before calling update_breakpoints_after_exec, as
1119 otherwise clearing the threads' resources would reference stale
1120 thread breakpoints -- it may have been one of these threads that
1121 stepped across the exec. We could just clear their stepping
1122 states, but as long as we're iterating, might as well delete
1123 them. Deleting them now rather than at the next user-visible
1124 stop provides a nicer sequence of events for user and MI
1126 for (thread_info
*th
: all_threads_safe ())
1127 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1130 /* We also need to clear any left over stale state for the
1131 leader/event thread. E.g., if there was any step-resume
1132 breakpoint or similar, it's gone now. We cannot truly
1133 step-to-next statement through an exec(). */
1134 thread_info
*th
= inferior_thread ();
1135 th
->control
.step_resume_breakpoint
= NULL
;
1136 th
->control
.exception_resume_breakpoint
= NULL
;
1137 th
->control
.single_step_breakpoints
= NULL
;
1138 th
->control
.step_range_start
= 0;
1139 th
->control
.step_range_end
= 0;
1141 /* The user may have had the main thread held stopped in the
1142 previous image (e.g., schedlock on, or non-stop). Release
1144 th
->stop_requested
= 0;
1146 update_breakpoints_after_exec ();
1148 /* What is this a.out's name? */
1149 process_ptid
= ptid_t (pid
);
1150 printf_unfiltered (_("%s is executing new program: %s\n"),
1151 target_pid_to_str (process_ptid
).c_str (),
1154 /* We've followed the inferior through an exec. Therefore, the
1155 inferior has essentially been killed & reborn. */
1157 breakpoint_init_inferior (inf_execd
);
1159 gdb::unique_xmalloc_ptr
<char> exec_file_host
1160 = exec_file_find (exec_file_target
, NULL
);
1162 /* If we were unable to map the executable target pathname onto a host
1163 pathname, tell the user that. Otherwise GDB's subsequent behavior
1164 is confusing. Maybe it would even be better to stop at this point
1165 so that the user can specify a file manually before continuing. */
1166 if (exec_file_host
== NULL
)
1167 warning (_("Could not load symbols for executable %s.\n"
1168 "Do you need \"set sysroot\"?"),
1171 /* Reset the shared library package. This ensures that we get a
1172 shlib event when the child reaches "_start", at which point the
1173 dld will have had a chance to initialize the child. */
1174 /* Also, loading a symbol file below may trigger symbol lookups, and
1175 we don't want those to be satisfied by the libraries of the
1176 previous incarnation of this process. */
1177 no_shared_libraries (NULL
, 0);
1179 if (follow_exec_mode_string
== follow_exec_mode_new
)
1181 /* The user wants to keep the old inferior and program spaces
1182 around. Create a new fresh one, and switch to it. */
1184 /* Do exit processing for the original inferior before setting the new
1185 inferior's pid. Having two inferiors with the same pid would confuse
1186 find_inferior_p(t)id. Transfer the terminal state and info from the
1187 old to the new inferior. */
1188 inf
= add_inferior_with_spaces ();
1189 swap_terminal_info (inf
, current_inferior ());
1190 exit_inferior_silent (current_inferior ());
1193 target_follow_exec (inf
, exec_file_target
);
1195 inferior
*org_inferior
= current_inferior ();
1196 switch_to_inferior_no_thread (inf
);
1197 push_target (org_inferior
->process_target ());
1198 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1199 switch_to_thread (thr
);
1203 /* The old description may no longer be fit for the new image.
1204 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1205 old description; we'll read a new one below. No need to do
1206 this on "follow-exec-mode new", as the old inferior stays
1207 around (its description is later cleared/refetched on
1209 target_clear_description ();
1212 gdb_assert (current_program_space
== inf
->pspace
);
1214 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1215 because the proper displacement for a PIE (Position Independent
1216 Executable) main symbol file will only be computed by
1217 solib_create_inferior_hook below. breakpoint_re_set would fail
1218 to insert the breakpoints with the zero displacement. */
1219 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1221 /* If the target can specify a description, read it. Must do this
1222 after flipping to the new executable (because the target supplied
1223 description must be compatible with the executable's
1224 architecture, and the old executable may e.g., be 32-bit, while
1225 the new one 64-bit), and before anything involving memory or
1227 target_find_description ();
1229 solib_create_inferior_hook (0);
1231 jit_inferior_created_hook ();
1233 breakpoint_re_set ();
1235 /* Reinsert all breakpoints. (Those which were symbolic have
1236 been reset to the proper address in the new a.out, thanks
1237 to symbol_file_command...). */
1238 insert_breakpoints ();
1240 /* The next resume of this inferior should bring it to the shlib
1241 startup breakpoints. (If the user had also set bp's on
1242 "main" from the old (parent) process, then they'll auto-
1243 matically get reset there in the new process.). */
1246 /* The queue of threads that need to do a step-over operation to get
1247 past e.g., a breakpoint. What technique is used to step over the
1248 breakpoint/watchpoint does not matter -- all threads end up in the
1249 same queue, to maintain rough temporal order of execution, in order
1250 to avoid starvation, otherwise, we could e.g., find ourselves
1251 constantly stepping the same couple threads past their breakpoints
1252 over and over, if the single-step finish fast enough. */
1253 struct thread_info
*step_over_queue_head
;
1255 /* Bit flags indicating what the thread needs to step over. */
1257 enum step_over_what_flag
1259 /* Step over a breakpoint. */
1260 STEP_OVER_BREAKPOINT
= 1,
1262 /* Step past a non-continuable watchpoint, in order to let the
1263 instruction execute so we can evaluate the watchpoint
1265 STEP_OVER_WATCHPOINT
= 2
1267 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1269 /* Info about an instruction that is being stepped over. */
1271 struct step_over_info
1273 /* If we're stepping past a breakpoint, this is the address space
1274 and address of the instruction the breakpoint is set at. We'll
1275 skip inserting all breakpoints here. Valid iff ASPACE is
1277 const address_space
*aspace
;
1280 /* The instruction being stepped over triggers a nonsteppable
1281 watchpoint. If true, we'll skip inserting watchpoints. */
1282 int nonsteppable_watchpoint_p
;
1284 /* The thread's global number. */
1288 /* The step-over info of the location that is being stepped over.
1290 Note that with async/breakpoint always-inserted mode, a user might
1291 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1292 being stepped over. As setting a new breakpoint inserts all
1293 breakpoints, we need to make sure the breakpoint being stepped over
1294 isn't inserted then. We do that by only clearing the step-over
1295 info when the step-over is actually finished (or aborted).
1297 Presently GDB can only step over one breakpoint at any given time.
1298 Given threads that can't run code in the same address space as the
1299 breakpoint's can't really miss the breakpoint, GDB could be taught
1300 to step-over at most one breakpoint per address space (so this info
1301 could move to the address space object if/when GDB is extended).
1302 The set of breakpoints being stepped over will normally be much
1303 smaller than the set of all breakpoints, so a flag in the
1304 breakpoint location structure would be wasteful. A separate list
1305 also saves complexity and run-time, as otherwise we'd have to go
1306 through all breakpoint locations clearing their flag whenever we
1307 start a new sequence. Similar considerations weigh against storing
1308 this info in the thread object. Plus, not all step overs actually
1309 have breakpoint locations -- e.g., stepping past a single-step
1310 breakpoint, or stepping to complete a non-continuable
1312 static struct step_over_info step_over_info
;
1314 /* Record the address of the breakpoint/instruction we're currently
1316 N.B. We record the aspace and address now, instead of say just the thread,
1317 because when we need the info later the thread may be running. */
1320 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1321 int nonsteppable_watchpoint_p
,
1324 step_over_info
.aspace
= aspace
;
1325 step_over_info
.address
= address
;
1326 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1327 step_over_info
.thread
= thread
;
1330 /* Called when we're not longer stepping over a breakpoint / an
1331 instruction, so all breakpoints are free to be (re)inserted. */
1334 clear_step_over_info (void)
1337 fprintf_unfiltered (gdb_stdlog
,
1338 "infrun: clear_step_over_info\n");
1339 step_over_info
.aspace
= NULL
;
1340 step_over_info
.address
= 0;
1341 step_over_info
.nonsteppable_watchpoint_p
= 0;
1342 step_over_info
.thread
= -1;
1348 stepping_past_instruction_at (struct address_space
*aspace
,
1351 return (step_over_info
.aspace
!= NULL
1352 && breakpoint_address_match (aspace
, address
,
1353 step_over_info
.aspace
,
1354 step_over_info
.address
));
1360 thread_is_stepping_over_breakpoint (int thread
)
1362 return (step_over_info
.thread
!= -1
1363 && thread
== step_over_info
.thread
);
1369 stepping_past_nonsteppable_watchpoint (void)
1371 return step_over_info
.nonsteppable_watchpoint_p
;
1374 /* Returns true if step-over info is valid. */
1377 step_over_info_valid_p (void)
1379 return (step_over_info
.aspace
!= NULL
1380 || stepping_past_nonsteppable_watchpoint ());
1384 /* Displaced stepping. */
1386 /* In non-stop debugging mode, we must take special care to manage
1387 breakpoints properly; in particular, the traditional strategy for
1388 stepping a thread past a breakpoint it has hit is unsuitable.
1389 'Displaced stepping' is a tactic for stepping one thread past a
1390 breakpoint it has hit while ensuring that other threads running
1391 concurrently will hit the breakpoint as they should.
1393 The traditional way to step a thread T off a breakpoint in a
1394 multi-threaded program in all-stop mode is as follows:
1396 a0) Initially, all threads are stopped, and breakpoints are not
1398 a1) We single-step T, leaving breakpoints uninserted.
1399 a2) We insert breakpoints, and resume all threads.
1401 In non-stop debugging, however, this strategy is unsuitable: we
1402 don't want to have to stop all threads in the system in order to
1403 continue or step T past a breakpoint. Instead, we use displaced
1406 n0) Initially, T is stopped, other threads are running, and
1407 breakpoints are inserted.
1408 n1) We copy the instruction "under" the breakpoint to a separate
1409 location, outside the main code stream, making any adjustments
1410 to the instruction, register, and memory state as directed by
1412 n2) We single-step T over the instruction at its new location.
1413 n3) We adjust the resulting register and memory state as directed
1414 by T's architecture. This includes resetting T's PC to point
1415 back into the main instruction stream.
1418 This approach depends on the following gdbarch methods:
1420 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1421 indicate where to copy the instruction, and how much space must
1422 be reserved there. We use these in step n1.
1424 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1425 address, and makes any necessary adjustments to the instruction,
1426 register contents, and memory. We use this in step n1.
1428 - gdbarch_displaced_step_fixup adjusts registers and memory after
1429 we have successfully single-stepped the instruction, to yield the
1430 same effect the instruction would have had if we had executed it
1431 at its original address. We use this in step n3.
1433 The gdbarch_displaced_step_copy_insn and
1434 gdbarch_displaced_step_fixup functions must be written so that
1435 copying an instruction with gdbarch_displaced_step_copy_insn,
1436 single-stepping across the copied instruction, and then applying
1437 gdbarch_displaced_insn_fixup should have the same effects on the
1438 thread's memory and registers as stepping the instruction in place
1439 would have. Exactly which responsibilities fall to the copy and
1440 which fall to the fixup is up to the author of those functions.
1442 See the comments in gdbarch.sh for details.
1444 Note that displaced stepping and software single-step cannot
1445 currently be used in combination, although with some care I think
1446 they could be made to. Software single-step works by placing
1447 breakpoints on all possible subsequent instructions; if the
1448 displaced instruction is a PC-relative jump, those breakpoints
1449 could fall in very strange places --- on pages that aren't
1450 executable, or at addresses that are not proper instruction
1451 boundaries. (We do generally let other threads run while we wait
1452 to hit the software single-step breakpoint, and they might
1453 encounter such a corrupted instruction.) One way to work around
1454 this would be to have gdbarch_displaced_step_copy_insn fully
1455 simulate the effect of PC-relative instructions (and return NULL)
1456 on architectures that use software single-stepping.
1458 In non-stop mode, we can have independent and simultaneous step
1459 requests, so more than one thread may need to simultaneously step
1460 over a breakpoint. The current implementation assumes there is
1461 only one scratch space per process. In this case, we have to
1462 serialize access to the scratch space. If thread A wants to step
1463 over a breakpoint, but we are currently waiting for some other
1464 thread to complete a displaced step, we leave thread A stopped and
1465 place it in the displaced_step_request_queue. Whenever a displaced
1466 step finishes, we pick the next thread in the queue and start a new
1467 displaced step operation on it. See displaced_step_prepare and
1468 displaced_step_fixup for details. */
1470 /* Default destructor for displaced_step_closure. */
1472 displaced_step_closure::~displaced_step_closure () = default;
1474 /* Get the displaced stepping state of process PID. */
1476 static displaced_step_inferior_state
*
1477 get_displaced_stepping_state (inferior
*inf
)
1479 return &inf
->displaced_step_state
;
1482 /* Returns true if any inferior has a thread doing a displaced
1486 displaced_step_in_progress_any_inferior ()
1488 for (inferior
*i
: all_inferiors ())
1490 if (i
->displaced_step_state
.step_thread
!= nullptr)
1497 /* Return true if thread represented by PTID is doing a displaced
1501 displaced_step_in_progress_thread (thread_info
*thread
)
1503 gdb_assert (thread
!= NULL
);
1505 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1508 /* Return true if process PID has a thread doing a displaced step. */
1511 displaced_step_in_progress (inferior
*inf
)
1513 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1516 /* If inferior is in displaced stepping, and ADDR equals to starting address
1517 of copy area, return corresponding displaced_step_closure. Otherwise,
1520 struct displaced_step_closure
*
1521 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1523 displaced_step_inferior_state
*displaced
1524 = get_displaced_stepping_state (current_inferior ());
1526 /* If checking the mode of displaced instruction in copy area. */
1527 if (displaced
->step_thread
!= nullptr
1528 && displaced
->step_copy
== addr
)
1529 return displaced
->step_closure
.get ();
1535 infrun_inferior_exit (struct inferior
*inf
)
1537 inf
->displaced_step_state
.reset ();
1540 /* If ON, and the architecture supports it, GDB will use displaced
1541 stepping to step over breakpoints. If OFF, or if the architecture
1542 doesn't support it, GDB will instead use the traditional
1543 hold-and-step approach. If AUTO (which is the default), GDB will
1544 decide which technique to use to step over breakpoints depending on
1545 whether the target works in a non-stop way (see use_displaced_stepping). */
1547 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1550 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1551 struct cmd_list_element
*c
,
1554 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1555 fprintf_filtered (file
,
1556 _("Debugger's willingness to use displaced stepping "
1557 "to step over breakpoints is %s (currently %s).\n"),
1558 value
, target_is_non_stop_p () ? "on" : "off");
1560 fprintf_filtered (file
,
1561 _("Debugger's willingness to use displaced stepping "
1562 "to step over breakpoints is %s.\n"), value
);
1565 /* Return true if the gdbarch implements the required methods to use
1566 displaced stepping. */
1569 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1571 /* Only check for the presence of step_copy_insn. Other required methods
1572 are checked by the gdbarch validation. */
1573 return gdbarch_displaced_step_copy_insn_p (arch
);
1576 /* Return non-zero if displaced stepping can/should be used to step
1577 over breakpoints of thread TP. */
1580 use_displaced_stepping (thread_info
*tp
)
1582 /* If the user disabled it explicitly, don't use displaced stepping. */
1583 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1586 /* If "auto", only use displaced stepping if the target operates in a non-stop
1588 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1589 && !target_is_non_stop_p ())
1592 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1594 /* If the architecture doesn't implement displaced stepping, don't use
1596 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1599 /* If recording, don't use displaced stepping. */
1600 if (find_record_target () != nullptr)
1603 displaced_step_inferior_state
*displaced_state
1604 = get_displaced_stepping_state (tp
->inf
);
1606 /* If displaced stepping failed before for this inferior, don't bother trying
1608 if (displaced_state
->failed_before
)
1614 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1617 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1619 displaced
->reset ();
1622 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1623 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1625 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1627 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1629 displaced_step_dump_bytes (struct ui_file
*file
,
1630 const gdb_byte
*buf
,
1635 for (i
= 0; i
< len
; i
++)
1636 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1637 fputs_unfiltered ("\n", file
);
1640 /* Prepare to single-step, using displaced stepping.
1642 Note that we cannot use displaced stepping when we have a signal to
1643 deliver. If we have a signal to deliver and an instruction to step
1644 over, then after the step, there will be no indication from the
1645 target whether the thread entered a signal handler or ignored the
1646 signal and stepped over the instruction successfully --- both cases
1647 result in a simple SIGTRAP. In the first case we mustn't do a
1648 fixup, and in the second case we must --- but we can't tell which.
1649 Comments in the code for 'random signals' in handle_inferior_event
1650 explain how we handle this case instead.
1652 Returns 1 if preparing was successful -- this thread is going to be
1653 stepped now; 0 if displaced stepping this thread got queued; or -1
1654 if this instruction can't be displaced stepped. */
1657 displaced_step_prepare_throw (thread_info
*tp
)
1659 regcache
*regcache
= get_thread_regcache (tp
);
1660 struct gdbarch
*gdbarch
= regcache
->arch ();
1661 const address_space
*aspace
= regcache
->aspace ();
1662 CORE_ADDR original
, copy
;
1666 /* We should never reach this function if the architecture does not
1667 support displaced stepping. */
1668 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1670 /* Nor if the thread isn't meant to step over a breakpoint. */
1671 gdb_assert (tp
->control
.trap_expected
);
1673 /* Disable range stepping while executing in the scratch pad. We
1674 want a single-step even if executing the displaced instruction in
1675 the scratch buffer lands within the stepping range (e.g., a
1677 tp
->control
.may_range_step
= 0;
1679 /* We have to displaced step one thread at a time, as we only have
1680 access to a single scratch space per inferior. */
1682 displaced_step_inferior_state
*displaced
1683 = get_displaced_stepping_state (tp
->inf
);
1685 if (displaced
->step_thread
!= nullptr)
1687 /* Already waiting for a displaced step to finish. Defer this
1688 request and place in queue. */
1690 if (debug_displaced
)
1691 fprintf_unfiltered (gdb_stdlog
,
1692 "displaced: deferring step of %s\n",
1693 target_pid_to_str (tp
->ptid
).c_str ());
1695 thread_step_over_chain_enqueue (tp
);
1700 if (debug_displaced
)
1701 fprintf_unfiltered (gdb_stdlog
,
1702 "displaced: stepping %s now\n",
1703 target_pid_to_str (tp
->ptid
).c_str ());
1706 displaced_step_reset (displaced
);
1708 scoped_restore_current_thread restore_thread
;
1710 switch_to_thread (tp
);
1712 original
= regcache_read_pc (regcache
);
1714 copy
= gdbarch_displaced_step_location (gdbarch
);
1715 len
= gdbarch_max_insn_length (gdbarch
);
1717 if (breakpoint_in_range_p (aspace
, copy
, len
))
1719 /* There's a breakpoint set in the scratch pad location range
1720 (which is usually around the entry point). We'd either
1721 install it before resuming, which would overwrite/corrupt the
1722 scratch pad, or if it was already inserted, this displaced
1723 step would overwrite it. The latter is OK in the sense that
1724 we already assume that no thread is going to execute the code
1725 in the scratch pad range (after initial startup) anyway, but
1726 the former is unacceptable. Simply punt and fallback to
1727 stepping over this breakpoint in-line. */
1728 if (debug_displaced
)
1730 fprintf_unfiltered (gdb_stdlog
,
1731 "displaced: breakpoint set in scratch pad. "
1732 "Stepping over breakpoint in-line instead.\n");
1738 /* Save the original contents of the copy area. */
1739 displaced
->step_saved_copy
.resize (len
);
1740 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1742 throw_error (MEMORY_ERROR
,
1743 _("Error accessing memory address %s (%s) for "
1744 "displaced-stepping scratch space."),
1745 paddress (gdbarch
, copy
), safe_strerror (status
));
1746 if (debug_displaced
)
1748 fprintf_unfiltered (gdb_stdlog
, "displaced: saved %s: ",
1749 paddress (gdbarch
, copy
));
1750 displaced_step_dump_bytes (gdb_stdlog
,
1751 displaced
->step_saved_copy
.data (),
1755 displaced
->step_closure
1756 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1757 if (displaced
->step_closure
== NULL
)
1759 /* The architecture doesn't know how or want to displaced step
1760 this instruction or instruction sequence. Fallback to
1761 stepping over the breakpoint in-line. */
1765 /* Save the information we need to fix things up if the step
1767 displaced
->step_thread
= tp
;
1768 displaced
->step_gdbarch
= gdbarch
;
1769 displaced
->step_original
= original
;
1770 displaced
->step_copy
= copy
;
1773 displaced_step_reset_cleanup
cleanup (displaced
);
1775 /* Resume execution at the copy. */
1776 regcache_write_pc (regcache
, copy
);
1781 if (debug_displaced
)
1782 fprintf_unfiltered (gdb_stdlog
, "displaced: displaced pc to %s\n",
1783 paddress (gdbarch
, copy
));
1788 /* Wrapper for displaced_step_prepare_throw that disabled further
1789 attempts at displaced stepping if we get a memory error. */
1792 displaced_step_prepare (thread_info
*thread
)
1798 prepared
= displaced_step_prepare_throw (thread
);
1800 catch (const gdb_exception_error
&ex
)
1802 struct displaced_step_inferior_state
*displaced_state
;
1804 if (ex
.error
!= MEMORY_ERROR
1805 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1810 fprintf_unfiltered (gdb_stdlog
,
1811 "infrun: disabling displaced stepping: %s\n",
1815 /* Be verbose if "set displaced-stepping" is "on", silent if
1817 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1819 warning (_("disabling displaced stepping: %s"),
1823 /* Disable further displaced stepping attempts. */
1825 = get_displaced_stepping_state (thread
->inf
);
1826 displaced_state
->failed_before
= 1;
1833 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1834 const gdb_byte
*myaddr
, int len
)
1836 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1838 inferior_ptid
= ptid
;
1839 write_memory (memaddr
, myaddr
, len
);
1842 /* Restore the contents of the copy area for thread PTID. */
1845 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1848 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1850 write_memory_ptid (ptid
, displaced
->step_copy
,
1851 displaced
->step_saved_copy
.data (), len
);
1852 if (debug_displaced
)
1853 fprintf_unfiltered (gdb_stdlog
, "displaced: restored %s %s\n",
1854 target_pid_to_str (ptid
).c_str (),
1855 paddress (displaced
->step_gdbarch
,
1856 displaced
->step_copy
));
1859 /* If we displaced stepped an instruction successfully, adjust
1860 registers and memory to yield the same effect the instruction would
1861 have had if we had executed it at its original address, and return
1862 1. If the instruction didn't complete, relocate the PC and return
1863 -1. If the thread wasn't displaced stepping, return 0. */
1866 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1868 struct displaced_step_inferior_state
*displaced
1869 = get_displaced_stepping_state (event_thread
->inf
);
1872 /* Was this event for the thread we displaced? */
1873 if (displaced
->step_thread
!= event_thread
)
1876 /* Fixup may need to read memory/registers. Switch to the thread
1877 that we're fixing up. Also, target_stopped_by_watchpoint checks
1878 the current thread, and displaced_step_restore performs ptid-dependent
1879 memory accesses using current_inferior() and current_top_target(). */
1880 switch_to_thread (event_thread
);
1882 displaced_step_reset_cleanup
cleanup (displaced
);
1884 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1886 /* Did the instruction complete successfully? */
1887 if (signal
== GDB_SIGNAL_TRAP
1888 && !(target_stopped_by_watchpoint ()
1889 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1890 || target_have_steppable_watchpoint
)))
1892 /* Fix up the resulting state. */
1893 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1894 displaced
->step_closure
.get (),
1895 displaced
->step_original
,
1896 displaced
->step_copy
,
1897 get_thread_regcache (displaced
->step_thread
));
1902 /* Since the instruction didn't complete, all we can do is
1904 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1905 CORE_ADDR pc
= regcache_read_pc (regcache
);
1907 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1908 regcache_write_pc (regcache
, pc
);
1915 /* Data to be passed around while handling an event. This data is
1916 discarded between events. */
1917 struct execution_control_state
1919 process_stratum_target
*target
;
1921 /* The thread that got the event, if this was a thread event; NULL
1923 struct thread_info
*event_thread
;
1925 struct target_waitstatus ws
;
1926 int stop_func_filled_in
;
1927 CORE_ADDR stop_func_start
;
1928 CORE_ADDR stop_func_end
;
1929 const char *stop_func_name
;
1932 /* True if the event thread hit the single-step breakpoint of
1933 another thread. Thus the event doesn't cause a stop, the thread
1934 needs to be single-stepped past the single-step breakpoint before
1935 we can switch back to the original stepping thread. */
1936 int hit_singlestep_breakpoint
;
1939 /* Clear ECS and set it to point at TP. */
1942 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1944 memset (ecs
, 0, sizeof (*ecs
));
1945 ecs
->event_thread
= tp
;
1946 ecs
->ptid
= tp
->ptid
;
1949 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1950 static void prepare_to_wait (struct execution_control_state
*ecs
);
1951 static int keep_going_stepped_thread (struct thread_info
*tp
);
1952 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1954 /* Are there any pending step-over requests? If so, run all we can
1955 now and return true. Otherwise, return false. */
1958 start_step_over (void)
1960 struct thread_info
*tp
, *next
;
1962 /* Don't start a new step-over if we already have an in-line
1963 step-over operation ongoing. */
1964 if (step_over_info_valid_p ())
1967 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1969 struct execution_control_state ecss
;
1970 struct execution_control_state
*ecs
= &ecss
;
1971 step_over_what step_what
;
1972 int must_be_in_line
;
1974 gdb_assert (!tp
->stop_requested
);
1976 next
= thread_step_over_chain_next (tp
);
1978 /* If this inferior already has a displaced step in process,
1979 don't start a new one. */
1980 if (displaced_step_in_progress (tp
->inf
))
1983 step_what
= thread_still_needs_step_over (tp
);
1984 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1985 || ((step_what
& STEP_OVER_BREAKPOINT
)
1986 && !use_displaced_stepping (tp
)));
1988 /* We currently stop all threads of all processes to step-over
1989 in-line. If we need to start a new in-line step-over, let
1990 any pending displaced steps finish first. */
1991 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1994 thread_step_over_chain_remove (tp
);
1996 if (step_over_queue_head
== NULL
)
1999 fprintf_unfiltered (gdb_stdlog
,
2000 "infrun: step-over queue now empty\n");
2003 if (tp
->control
.trap_expected
2007 internal_error (__FILE__
, __LINE__
,
2008 "[%s] has inconsistent state: "
2009 "trap_expected=%d, resumed=%d, executing=%d\n",
2010 target_pid_to_str (tp
->ptid
).c_str (),
2011 tp
->control
.trap_expected
,
2017 fprintf_unfiltered (gdb_stdlog
,
2018 "infrun: resuming [%s] for step-over\n",
2019 target_pid_to_str (tp
->ptid
).c_str ());
2021 /* keep_going_pass_signal skips the step-over if the breakpoint
2022 is no longer inserted. In all-stop, we want to keep looking
2023 for a thread that needs a step-over instead of resuming TP,
2024 because we wouldn't be able to resume anything else until the
2025 target stops again. In non-stop, the resume always resumes
2026 only TP, so it's OK to let the thread resume freely. */
2027 if (!target_is_non_stop_p () && !step_what
)
2030 switch_to_thread (tp
);
2031 reset_ecs (ecs
, tp
);
2032 keep_going_pass_signal (ecs
);
2034 if (!ecs
->wait_some_more
)
2035 error (_("Command aborted."));
2037 gdb_assert (tp
->resumed
);
2039 /* If we started a new in-line step-over, we're done. */
2040 if (step_over_info_valid_p ())
2042 gdb_assert (tp
->control
.trap_expected
);
2046 if (!target_is_non_stop_p ())
2048 /* On all-stop, shouldn't have resumed unless we needed a
2050 gdb_assert (tp
->control
.trap_expected
2051 || tp
->step_after_step_resume_breakpoint
);
2053 /* With remote targets (at least), in all-stop, we can't
2054 issue any further remote commands until the program stops
2059 /* Either the thread no longer needed a step-over, or a new
2060 displaced stepping sequence started. Even in the latter
2061 case, continue looking. Maybe we can also start another
2062 displaced step on a thread of other process. */
2068 /* Update global variables holding ptids to hold NEW_PTID if they were
2069 holding OLD_PTID. */
2071 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2073 if (inferior_ptid
== old_ptid
)
2074 inferior_ptid
= new_ptid
;
2079 static const char schedlock_off
[] = "off";
2080 static const char schedlock_on
[] = "on";
2081 static const char schedlock_step
[] = "step";
2082 static const char schedlock_replay
[] = "replay";
2083 static const char *const scheduler_enums
[] = {
2090 static const char *scheduler_mode
= schedlock_replay
;
2092 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2093 struct cmd_list_element
*c
, const char *value
)
2095 fprintf_filtered (file
,
2096 _("Mode for locking scheduler "
2097 "during execution is \"%s\".\n"),
2102 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2104 if (!target_can_lock_scheduler
)
2106 scheduler_mode
= schedlock_off
;
2107 error (_("Target '%s' cannot support this command."), target_shortname
);
2111 /* True if execution commands resume all threads of all processes by
2112 default; otherwise, resume only threads of the current inferior
2114 bool sched_multi
= false;
2116 /* Try to setup for software single stepping over the specified location.
2117 Return 1 if target_resume() should use hardware single step.
2119 GDBARCH the current gdbarch.
2120 PC the location to step over. */
2123 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2127 if (execution_direction
== EXEC_FORWARD
2128 && gdbarch_software_single_step_p (gdbarch
))
2129 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2137 user_visible_resume_ptid (int step
)
2143 /* With non-stop mode on, threads are always handled
2145 resume_ptid
= inferior_ptid
;
2147 else if ((scheduler_mode
== schedlock_on
)
2148 || (scheduler_mode
== schedlock_step
&& step
))
2150 /* User-settable 'scheduler' mode requires solo thread
2152 resume_ptid
= inferior_ptid
;
2154 else if ((scheduler_mode
== schedlock_replay
)
2155 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2157 /* User-settable 'scheduler' mode requires solo thread resume in replay
2159 resume_ptid
= inferior_ptid
;
2161 else if (!sched_multi
&& target_supports_multi_process ())
2163 /* Resume all threads of the current process (and none of other
2165 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2169 /* Resume all threads of all processes. */
2170 resume_ptid
= RESUME_ALL
;
2178 process_stratum_target
*
2179 user_visible_resume_target (ptid_t resume_ptid
)
2181 return (resume_ptid
== minus_one_ptid
&& sched_multi
2183 : current_inferior ()->process_target ());
2186 /* Return a ptid representing the set of threads that we will resume,
2187 in the perspective of the target, assuming run control handling
2188 does not require leaving some threads stopped (e.g., stepping past
2189 breakpoint). USER_STEP indicates whether we're about to start the
2190 target for a stepping command. */
2193 internal_resume_ptid (int user_step
)
2195 /* In non-stop, we always control threads individually. Note that
2196 the target may always work in non-stop mode even with "set
2197 non-stop off", in which case user_visible_resume_ptid could
2198 return a wildcard ptid. */
2199 if (target_is_non_stop_p ())
2200 return inferior_ptid
;
2202 return user_visible_resume_ptid (user_step
);
2205 /* Wrapper for target_resume, that handles infrun-specific
2209 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2211 struct thread_info
*tp
= inferior_thread ();
2213 gdb_assert (!tp
->stop_requested
);
2215 /* Install inferior's terminal modes. */
2216 target_terminal::inferior ();
2218 /* Avoid confusing the next resume, if the next stop/resume
2219 happens to apply to another thread. */
2220 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2222 /* Advise target which signals may be handled silently.
2224 If we have removed breakpoints because we are stepping over one
2225 in-line (in any thread), we need to receive all signals to avoid
2226 accidentally skipping a breakpoint during execution of a signal
2229 Likewise if we're displaced stepping, otherwise a trap for a
2230 breakpoint in a signal handler might be confused with the
2231 displaced step finishing. We don't make the displaced_step_fixup
2232 step distinguish the cases instead, because:
2234 - a backtrace while stopped in the signal handler would show the
2235 scratch pad as frame older than the signal handler, instead of
2236 the real mainline code.
2238 - when the thread is later resumed, the signal handler would
2239 return to the scratch pad area, which would no longer be
2241 if (step_over_info_valid_p ()
2242 || displaced_step_in_progress (tp
->inf
))
2243 target_pass_signals ({});
2245 target_pass_signals (signal_pass
);
2247 target_resume (resume_ptid
, step
, sig
);
2249 target_commit_resume ();
2251 if (target_can_async_p ())
2255 /* Resume the inferior. SIG is the signal to give the inferior
2256 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2257 call 'resume', which handles exceptions. */
2260 resume_1 (enum gdb_signal sig
)
2262 struct regcache
*regcache
= get_current_regcache ();
2263 struct gdbarch
*gdbarch
= regcache
->arch ();
2264 struct thread_info
*tp
= inferior_thread ();
2265 const address_space
*aspace
= regcache
->aspace ();
2267 /* This represents the user's step vs continue request. When
2268 deciding whether "set scheduler-locking step" applies, it's the
2269 user's intention that counts. */
2270 const int user_step
= tp
->control
.stepping_command
;
2271 /* This represents what we'll actually request the target to do.
2272 This can decay from a step to a continue, if e.g., we need to
2273 implement single-stepping with breakpoints (software
2277 gdb_assert (!tp
->stop_requested
);
2278 gdb_assert (!thread_is_in_step_over_chain (tp
));
2280 if (tp
->suspend
.waitstatus_pending_p
)
2285 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2287 fprintf_unfiltered (gdb_stdlog
,
2288 "infrun: resume: thread %s has pending wait "
2289 "status %s (currently_stepping=%d).\n",
2290 target_pid_to_str (tp
->ptid
).c_str (),
2292 currently_stepping (tp
));
2295 tp
->inf
->process_target ()->threads_executing
= true;
2298 /* FIXME: What should we do if we are supposed to resume this
2299 thread with a signal? Maybe we should maintain a queue of
2300 pending signals to deliver. */
2301 if (sig
!= GDB_SIGNAL_0
)
2303 warning (_("Couldn't deliver signal %s to %s."),
2304 gdb_signal_to_name (sig
),
2305 target_pid_to_str (tp
->ptid
).c_str ());
2308 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2310 if (target_can_async_p ())
2313 /* Tell the event loop we have an event to process. */
2314 mark_async_event_handler (infrun_async_inferior_event_token
);
2319 tp
->stepped_breakpoint
= 0;
2321 /* Depends on stepped_breakpoint. */
2322 step
= currently_stepping (tp
);
2324 if (current_inferior ()->waiting_for_vfork_done
)
2326 /* Don't try to single-step a vfork parent that is waiting for
2327 the child to get out of the shared memory region (by exec'ing
2328 or exiting). This is particularly important on software
2329 single-step archs, as the child process would trip on the
2330 software single step breakpoint inserted for the parent
2331 process. Since the parent will not actually execute any
2332 instruction until the child is out of the shared region (such
2333 are vfork's semantics), it is safe to simply continue it.
2334 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2335 the parent, and tell it to `keep_going', which automatically
2336 re-sets it stepping. */
2338 fprintf_unfiltered (gdb_stdlog
,
2339 "infrun: resume : clear step\n");
2343 CORE_ADDR pc
= regcache_read_pc (regcache
);
2346 fprintf_unfiltered (gdb_stdlog
,
2347 "infrun: resume (step=%d, signal=%s), "
2348 "trap_expected=%d, current thread [%s] at %s\n",
2349 step
, gdb_signal_to_symbol_string (sig
),
2350 tp
->control
.trap_expected
,
2351 target_pid_to_str (inferior_ptid
).c_str (),
2352 paddress (gdbarch
, pc
));
2354 /* Normally, by the time we reach `resume', the breakpoints are either
2355 removed or inserted, as appropriate. The exception is if we're sitting
2356 at a permanent breakpoint; we need to step over it, but permanent
2357 breakpoints can't be removed. So we have to test for it here. */
2358 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2360 if (sig
!= GDB_SIGNAL_0
)
2362 /* We have a signal to pass to the inferior. The resume
2363 may, or may not take us to the signal handler. If this
2364 is a step, we'll need to stop in the signal handler, if
2365 there's one, (if the target supports stepping into
2366 handlers), or in the next mainline instruction, if
2367 there's no handler. If this is a continue, we need to be
2368 sure to run the handler with all breakpoints inserted.
2369 In all cases, set a breakpoint at the current address
2370 (where the handler returns to), and once that breakpoint
2371 is hit, resume skipping the permanent breakpoint. If
2372 that breakpoint isn't hit, then we've stepped into the
2373 signal handler (or hit some other event). We'll delete
2374 the step-resume breakpoint then. */
2377 fprintf_unfiltered (gdb_stdlog
,
2378 "infrun: resume: skipping permanent breakpoint, "
2379 "deliver signal first\n");
2381 clear_step_over_info ();
2382 tp
->control
.trap_expected
= 0;
2384 if (tp
->control
.step_resume_breakpoint
== NULL
)
2386 /* Set a "high-priority" step-resume, as we don't want
2387 user breakpoints at PC to trigger (again) when this
2389 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2390 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2392 tp
->step_after_step_resume_breakpoint
= step
;
2395 insert_breakpoints ();
2399 /* There's no signal to pass, we can go ahead and skip the
2400 permanent breakpoint manually. */
2402 fprintf_unfiltered (gdb_stdlog
,
2403 "infrun: resume: skipping permanent breakpoint\n");
2404 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2405 /* Update pc to reflect the new address from which we will
2406 execute instructions. */
2407 pc
= regcache_read_pc (regcache
);
2411 /* We've already advanced the PC, so the stepping part
2412 is done. Now we need to arrange for a trap to be
2413 reported to handle_inferior_event. Set a breakpoint
2414 at the current PC, and run to it. Don't update
2415 prev_pc, because if we end in
2416 switch_back_to_stepped_thread, we want the "expected
2417 thread advanced also" branch to be taken. IOW, we
2418 don't want this thread to step further from PC
2420 gdb_assert (!step_over_info_valid_p ());
2421 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2422 insert_breakpoints ();
2424 resume_ptid
= internal_resume_ptid (user_step
);
2425 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2432 /* If we have a breakpoint to step over, make sure to do a single
2433 step only. Same if we have software watchpoints. */
2434 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2435 tp
->control
.may_range_step
= 0;
2437 /* If displaced stepping is enabled, step over breakpoints by executing a
2438 copy of the instruction at a different address.
2440 We can't use displaced stepping when we have a signal to deliver;
2441 the comments for displaced_step_prepare explain why. The
2442 comments in the handle_inferior event for dealing with 'random
2443 signals' explain what we do instead.
2445 We can't use displaced stepping when we are waiting for vfork_done
2446 event, displaced stepping breaks the vfork child similarly as single
2447 step software breakpoint. */
2448 if (tp
->control
.trap_expected
2449 && use_displaced_stepping (tp
)
2450 && !step_over_info_valid_p ()
2451 && sig
== GDB_SIGNAL_0
2452 && !current_inferior ()->waiting_for_vfork_done
)
2454 int prepared
= displaced_step_prepare (tp
);
2459 fprintf_unfiltered (gdb_stdlog
,
2460 "Got placed in step-over queue\n");
2462 tp
->control
.trap_expected
= 0;
2465 else if (prepared
< 0)
2467 /* Fallback to stepping over the breakpoint in-line. */
2469 if (target_is_non_stop_p ())
2470 stop_all_threads ();
2472 set_step_over_info (regcache
->aspace (),
2473 regcache_read_pc (regcache
), 0, tp
->global_num
);
2475 step
= maybe_software_singlestep (gdbarch
, pc
);
2477 insert_breakpoints ();
2479 else if (prepared
> 0)
2481 struct displaced_step_inferior_state
*displaced
;
2483 /* Update pc to reflect the new address from which we will
2484 execute instructions due to displaced stepping. */
2485 pc
= regcache_read_pc (get_thread_regcache (tp
));
2487 displaced
= get_displaced_stepping_state (tp
->inf
);
2488 step
= gdbarch_displaced_step_hw_singlestep
2489 (gdbarch
, displaced
->step_closure
.get ());
2493 /* Do we need to do it the hard way, w/temp breakpoints? */
2495 step
= maybe_software_singlestep (gdbarch
, pc
);
2497 /* Currently, our software single-step implementation leads to different
2498 results than hardware single-stepping in one situation: when stepping
2499 into delivering a signal which has an associated signal handler,
2500 hardware single-step will stop at the first instruction of the handler,
2501 while software single-step will simply skip execution of the handler.
2503 For now, this difference in behavior is accepted since there is no
2504 easy way to actually implement single-stepping into a signal handler
2505 without kernel support.
2507 However, there is one scenario where this difference leads to follow-on
2508 problems: if we're stepping off a breakpoint by removing all breakpoints
2509 and then single-stepping. In this case, the software single-step
2510 behavior means that even if there is a *breakpoint* in the signal
2511 handler, GDB still would not stop.
2513 Fortunately, we can at least fix this particular issue. We detect
2514 here the case where we are about to deliver a signal while software
2515 single-stepping with breakpoints removed. In this situation, we
2516 revert the decisions to remove all breakpoints and insert single-
2517 step breakpoints, and instead we install a step-resume breakpoint
2518 at the current address, deliver the signal without stepping, and
2519 once we arrive back at the step-resume breakpoint, actually step
2520 over the breakpoint we originally wanted to step over. */
2521 if (thread_has_single_step_breakpoints_set (tp
)
2522 && sig
!= GDB_SIGNAL_0
2523 && step_over_info_valid_p ())
2525 /* If we have nested signals or a pending signal is delivered
2526 immediately after a handler returns, might already have
2527 a step-resume breakpoint set on the earlier handler. We cannot
2528 set another step-resume breakpoint; just continue on until the
2529 original breakpoint is hit. */
2530 if (tp
->control
.step_resume_breakpoint
== NULL
)
2532 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2533 tp
->step_after_step_resume_breakpoint
= 1;
2536 delete_single_step_breakpoints (tp
);
2538 clear_step_over_info ();
2539 tp
->control
.trap_expected
= 0;
2541 insert_breakpoints ();
2544 /* If STEP is set, it's a request to use hardware stepping
2545 facilities. But in that case, we should never
2546 use singlestep breakpoint. */
2547 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2549 /* Decide the set of threads to ask the target to resume. */
2550 if (tp
->control
.trap_expected
)
2552 /* We're allowing a thread to run past a breakpoint it has
2553 hit, either by single-stepping the thread with the breakpoint
2554 removed, or by displaced stepping, with the breakpoint inserted.
2555 In the former case, we need to single-step only this thread,
2556 and keep others stopped, as they can miss this breakpoint if
2557 allowed to run. That's not really a problem for displaced
2558 stepping, but, we still keep other threads stopped, in case
2559 another thread is also stopped for a breakpoint waiting for
2560 its turn in the displaced stepping queue. */
2561 resume_ptid
= inferior_ptid
;
2564 resume_ptid
= internal_resume_ptid (user_step
);
2566 if (execution_direction
!= EXEC_REVERSE
2567 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2569 /* There are two cases where we currently need to step a
2570 breakpoint instruction when we have a signal to deliver:
2572 - See handle_signal_stop where we handle random signals that
2573 could take out us out of the stepping range. Normally, in
2574 that case we end up continuing (instead of stepping) over the
2575 signal handler with a breakpoint at PC, but there are cases
2576 where we should _always_ single-step, even if we have a
2577 step-resume breakpoint, like when a software watchpoint is
2578 set. Assuming single-stepping and delivering a signal at the
2579 same time would takes us to the signal handler, then we could
2580 have removed the breakpoint at PC to step over it. However,
2581 some hardware step targets (like e.g., Mac OS) can't step
2582 into signal handlers, and for those, we need to leave the
2583 breakpoint at PC inserted, as otherwise if the handler
2584 recurses and executes PC again, it'll miss the breakpoint.
2585 So we leave the breakpoint inserted anyway, but we need to
2586 record that we tried to step a breakpoint instruction, so
2587 that adjust_pc_after_break doesn't end up confused.
2589 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2590 in one thread after another thread that was stepping had been
2591 momentarily paused for a step-over. When we re-resume the
2592 stepping thread, it may be resumed from that address with a
2593 breakpoint that hasn't trapped yet. Seen with
2594 gdb.threads/non-stop-fair-events.exp, on targets that don't
2595 do displaced stepping. */
2598 fprintf_unfiltered (gdb_stdlog
,
2599 "infrun: resume: [%s] stepped breakpoint\n",
2600 target_pid_to_str (tp
->ptid
).c_str ());
2602 tp
->stepped_breakpoint
= 1;
2604 /* Most targets can step a breakpoint instruction, thus
2605 executing it normally. But if this one cannot, just
2606 continue and we will hit it anyway. */
2607 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2612 && tp
->control
.trap_expected
2613 && use_displaced_stepping (tp
)
2614 && !step_over_info_valid_p ())
2616 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2617 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2618 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2621 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2622 paddress (resume_gdbarch
, actual_pc
));
2623 read_memory (actual_pc
, buf
, sizeof (buf
));
2624 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2627 if (tp
->control
.may_range_step
)
2629 /* If we're resuming a thread with the PC out of the step
2630 range, then we're doing some nested/finer run control
2631 operation, like stepping the thread out of the dynamic
2632 linker or the displaced stepping scratch pad. We
2633 shouldn't have allowed a range step then. */
2634 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2637 do_target_resume (resume_ptid
, step
, sig
);
2641 /* Resume the inferior. SIG is the signal to give the inferior
2642 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2643 rolls back state on error. */
2646 resume (gdb_signal sig
)
2652 catch (const gdb_exception
&ex
)
2654 /* If resuming is being aborted for any reason, delete any
2655 single-step breakpoint resume_1 may have created, to avoid
2656 confusing the following resumption, and to avoid leaving
2657 single-step breakpoints perturbing other threads, in case
2658 we're running in non-stop mode. */
2659 if (inferior_ptid
!= null_ptid
)
2660 delete_single_step_breakpoints (inferior_thread ());
2670 /* Counter that tracks number of user visible stops. This can be used
2671 to tell whether a command has proceeded the inferior past the
2672 current location. This allows e.g., inferior function calls in
2673 breakpoint commands to not interrupt the command list. When the
2674 call finishes successfully, the inferior is standing at the same
2675 breakpoint as if nothing happened (and so we don't call
2677 static ULONGEST current_stop_id
;
2684 return current_stop_id
;
2687 /* Called when we report a user visible stop. */
2695 /* Clear out all variables saying what to do when inferior is continued.
2696 First do this, then set the ones you want, then call `proceed'. */
2699 clear_proceed_status_thread (struct thread_info
*tp
)
2702 fprintf_unfiltered (gdb_stdlog
,
2703 "infrun: clear_proceed_status_thread (%s)\n",
2704 target_pid_to_str (tp
->ptid
).c_str ());
2706 /* If we're starting a new sequence, then the previous finished
2707 single-step is no longer relevant. */
2708 if (tp
->suspend
.waitstatus_pending_p
)
2710 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2713 fprintf_unfiltered (gdb_stdlog
,
2714 "infrun: clear_proceed_status: pending "
2715 "event of %s was a finished step. "
2717 target_pid_to_str (tp
->ptid
).c_str ());
2719 tp
->suspend
.waitstatus_pending_p
= 0;
2720 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2722 else if (debug_infrun
)
2725 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
2727 fprintf_unfiltered (gdb_stdlog
,
2728 "infrun: clear_proceed_status_thread: thread %s "
2729 "has pending wait status %s "
2730 "(currently_stepping=%d).\n",
2731 target_pid_to_str (tp
->ptid
).c_str (),
2733 currently_stepping (tp
));
2737 /* If this signal should not be seen by program, give it zero.
2738 Used for debugging signals. */
2739 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2740 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2742 delete tp
->thread_fsm
;
2743 tp
->thread_fsm
= NULL
;
2745 tp
->control
.trap_expected
= 0;
2746 tp
->control
.step_range_start
= 0;
2747 tp
->control
.step_range_end
= 0;
2748 tp
->control
.may_range_step
= 0;
2749 tp
->control
.step_frame_id
= null_frame_id
;
2750 tp
->control
.step_stack_frame_id
= null_frame_id
;
2751 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2752 tp
->control
.step_start_function
= NULL
;
2753 tp
->stop_requested
= 0;
2755 tp
->control
.stop_step
= 0;
2757 tp
->control
.proceed_to_finish
= 0;
2759 tp
->control
.stepping_command
= 0;
2761 /* Discard any remaining commands or status from previous stop. */
2762 bpstat_clear (&tp
->control
.stop_bpstat
);
2766 clear_proceed_status (int step
)
2768 /* With scheduler-locking replay, stop replaying other threads if we're
2769 not replaying the user-visible resume ptid.
2771 This is a convenience feature to not require the user to explicitly
2772 stop replaying the other threads. We're assuming that the user's
2773 intent is to resume tracing the recorded process. */
2774 if (!non_stop
&& scheduler_mode
== schedlock_replay
2775 && target_record_is_replaying (minus_one_ptid
)
2776 && !target_record_will_replay (user_visible_resume_ptid (step
),
2777 execution_direction
))
2778 target_record_stop_replaying ();
2780 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2782 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2783 process_stratum_target
*resume_target
2784 = user_visible_resume_target (resume_ptid
);
2786 /* In all-stop mode, delete the per-thread status of all threads
2787 we're about to resume, implicitly and explicitly. */
2788 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2789 clear_proceed_status_thread (tp
);
2792 if (inferior_ptid
!= null_ptid
)
2794 struct inferior
*inferior
;
2798 /* If in non-stop mode, only delete the per-thread status of
2799 the current thread. */
2800 clear_proceed_status_thread (inferior_thread ());
2803 inferior
= current_inferior ();
2804 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2807 gdb::observers::about_to_proceed
.notify ();
2810 /* Returns true if TP is still stopped at a breakpoint that needs
2811 stepping-over in order to make progress. If the breakpoint is gone
2812 meanwhile, we can skip the whole step-over dance. */
2815 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2817 if (tp
->stepping_over_breakpoint
)
2819 struct regcache
*regcache
= get_thread_regcache (tp
);
2821 if (breakpoint_here_p (regcache
->aspace (),
2822 regcache_read_pc (regcache
))
2823 == ordinary_breakpoint_here
)
2826 tp
->stepping_over_breakpoint
= 0;
2832 /* Check whether thread TP still needs to start a step-over in order
2833 to make progress when resumed. Returns an bitwise or of enum
2834 step_over_what bits, indicating what needs to be stepped over. */
2836 static step_over_what
2837 thread_still_needs_step_over (struct thread_info
*tp
)
2839 step_over_what what
= 0;
2841 if (thread_still_needs_step_over_bp (tp
))
2842 what
|= STEP_OVER_BREAKPOINT
;
2844 if (tp
->stepping_over_watchpoint
2845 && !target_have_steppable_watchpoint
)
2846 what
|= STEP_OVER_WATCHPOINT
;
2851 /* Returns true if scheduler locking applies. STEP indicates whether
2852 we're about to do a step/next-like command to a thread. */
2855 schedlock_applies (struct thread_info
*tp
)
2857 return (scheduler_mode
== schedlock_on
2858 || (scheduler_mode
== schedlock_step
2859 && tp
->control
.stepping_command
)
2860 || (scheduler_mode
== schedlock_replay
2861 && target_record_will_replay (minus_one_ptid
,
2862 execution_direction
)));
2865 /* Calls target_commit_resume on all targets. */
2868 commit_resume_all_targets ()
2870 scoped_restore_current_thread restore_thread
;
2872 /* Map between process_target and a representative inferior. This
2873 is to avoid committing a resume in the same target more than
2874 once. Resumptions must be idempotent, so this is an
2876 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2878 for (inferior
*inf
: all_non_exited_inferiors ())
2879 if (inf
->has_execution ())
2880 conn_inf
[inf
->process_target ()] = inf
;
2882 for (const auto &ci
: conn_inf
)
2884 inferior
*inf
= ci
.second
;
2885 switch_to_inferior_no_thread (inf
);
2886 target_commit_resume ();
2890 /* Check that all the targets we're about to resume are in non-stop
2891 mode. Ideally, we'd only care whether all targets support
2892 target-async, but we're not there yet. E.g., stop_all_threads
2893 doesn't know how to handle all-stop targets. Also, the remote
2894 protocol in all-stop mode is synchronous, irrespective of
2895 target-async, which means that things like a breakpoint re-set
2896 triggered by one target would try to read memory from all targets
2900 check_multi_target_resumption (process_stratum_target
*resume_target
)
2902 if (!non_stop
&& resume_target
== nullptr)
2904 scoped_restore_current_thread restore_thread
;
2906 /* This is used to track whether we're resuming more than one
2908 process_stratum_target
*first_connection
= nullptr;
2910 /* The first inferior we see with a target that does not work in
2911 always-non-stop mode. */
2912 inferior
*first_not_non_stop
= nullptr;
2914 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2916 switch_to_inferior_no_thread (inf
);
2918 if (!target_has_execution
)
2921 process_stratum_target
*proc_target
2922 = current_inferior ()->process_target();
2924 if (!target_is_non_stop_p ())
2925 first_not_non_stop
= inf
;
2927 if (first_connection
== nullptr)
2928 first_connection
= proc_target
;
2929 else if (first_connection
!= proc_target
2930 && first_not_non_stop
!= nullptr)
2932 switch_to_inferior_no_thread (first_not_non_stop
);
2934 proc_target
= current_inferior ()->process_target();
2936 error (_("Connection %d (%s) does not support "
2937 "multi-target resumption."),
2938 proc_target
->connection_number
,
2939 make_target_connection_string (proc_target
).c_str ());
2945 /* Basic routine for continuing the program in various fashions.
2947 ADDR is the address to resume at, or -1 for resume where stopped.
2948 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2949 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2951 You should call clear_proceed_status before calling proceed. */
2954 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2956 struct regcache
*regcache
;
2957 struct gdbarch
*gdbarch
;
2959 struct execution_control_state ecss
;
2960 struct execution_control_state
*ecs
= &ecss
;
2963 /* If we're stopped at a fork/vfork, follow the branch set by the
2964 "set follow-fork-mode" command; otherwise, we'll just proceed
2965 resuming the current thread. */
2966 if (!follow_fork ())
2968 /* The target for some reason decided not to resume. */
2970 if (target_can_async_p ())
2971 inferior_event_handler (INF_EXEC_COMPLETE
);
2975 /* We'll update this if & when we switch to a new thread. */
2976 previous_inferior_ptid
= inferior_ptid
;
2978 regcache
= get_current_regcache ();
2979 gdbarch
= regcache
->arch ();
2980 const address_space
*aspace
= regcache
->aspace ();
2982 pc
= regcache_read_pc_protected (regcache
);
2984 thread_info
*cur_thr
= inferior_thread ();
2986 /* Fill in with reasonable starting values. */
2987 init_thread_stepping_state (cur_thr
);
2989 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2992 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2993 process_stratum_target
*resume_target
2994 = user_visible_resume_target (resume_ptid
);
2996 check_multi_target_resumption (resume_target
);
2998 if (addr
== (CORE_ADDR
) -1)
3000 if (pc
== cur_thr
->suspend
.stop_pc
3001 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
3002 && execution_direction
!= EXEC_REVERSE
)
3003 /* There is a breakpoint at the address we will resume at,
3004 step one instruction before inserting breakpoints so that
3005 we do not stop right away (and report a second hit at this
3008 Note, we don't do this in reverse, because we won't
3009 actually be executing the breakpoint insn anyway.
3010 We'll be (un-)executing the previous instruction. */
3011 cur_thr
->stepping_over_breakpoint
= 1;
3012 else if (gdbarch_single_step_through_delay_p (gdbarch
)
3013 && gdbarch_single_step_through_delay (gdbarch
,
3014 get_current_frame ()))
3015 /* We stepped onto an instruction that needs to be stepped
3016 again before re-inserting the breakpoint, do so. */
3017 cur_thr
->stepping_over_breakpoint
= 1;
3021 regcache_write_pc (regcache
, addr
);
3024 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3025 cur_thr
->suspend
.stop_signal
= siggnal
;
3027 /* If an exception is thrown from this point on, make sure to
3028 propagate GDB's knowledge of the executing state to the
3029 frontend/user running state. */
3030 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3032 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3033 threads (e.g., we might need to set threads stepping over
3034 breakpoints first), from the user/frontend's point of view, all
3035 threads in RESUME_PTID are now running. Unless we're calling an
3036 inferior function, as in that case we pretend the inferior
3037 doesn't run at all. */
3038 if (!cur_thr
->control
.in_infcall
)
3039 set_running (resume_target
, resume_ptid
, true);
3042 fprintf_unfiltered (gdb_stdlog
,
3043 "infrun: proceed (addr=%s, signal=%s)\n",
3044 paddress (gdbarch
, addr
),
3045 gdb_signal_to_symbol_string (siggnal
));
3047 annotate_starting ();
3049 /* Make sure that output from GDB appears before output from the
3051 gdb_flush (gdb_stdout
);
3053 /* Since we've marked the inferior running, give it the terminal. A
3054 QUIT/Ctrl-C from here on is forwarded to the target (which can
3055 still detect attempts to unblock a stuck connection with repeated
3056 Ctrl-C from within target_pass_ctrlc). */
3057 target_terminal::inferior ();
3059 /* In a multi-threaded task we may select another thread and
3060 then continue or step.
3062 But if a thread that we're resuming had stopped at a breakpoint,
3063 it will immediately cause another breakpoint stop without any
3064 execution (i.e. it will report a breakpoint hit incorrectly). So
3065 we must step over it first.
3067 Look for threads other than the current (TP) that reported a
3068 breakpoint hit and haven't been resumed yet since. */
3070 /* If scheduler locking applies, we can avoid iterating over all
3072 if (!non_stop
&& !schedlock_applies (cur_thr
))
3074 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3077 switch_to_thread_no_regs (tp
);
3079 /* Ignore the current thread here. It's handled
3084 if (!thread_still_needs_step_over (tp
))
3087 gdb_assert (!thread_is_in_step_over_chain (tp
));
3090 fprintf_unfiltered (gdb_stdlog
,
3091 "infrun: need to step-over [%s] first\n",
3092 target_pid_to_str (tp
->ptid
).c_str ());
3094 thread_step_over_chain_enqueue (tp
);
3097 switch_to_thread (cur_thr
);
3100 /* Enqueue the current thread last, so that we move all other
3101 threads over their breakpoints first. */
3102 if (cur_thr
->stepping_over_breakpoint
)
3103 thread_step_over_chain_enqueue (cur_thr
);
3105 /* If the thread isn't started, we'll still need to set its prev_pc,
3106 so that switch_back_to_stepped_thread knows the thread hasn't
3107 advanced. Must do this before resuming any thread, as in
3108 all-stop/remote, once we resume we can't send any other packet
3109 until the target stops again. */
3110 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3113 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3115 started
= start_step_over ();
3117 if (step_over_info_valid_p ())
3119 /* Either this thread started a new in-line step over, or some
3120 other thread was already doing one. In either case, don't
3121 resume anything else until the step-over is finished. */
3123 else if (started
&& !target_is_non_stop_p ())
3125 /* A new displaced stepping sequence was started. In all-stop,
3126 we can't talk to the target anymore until it next stops. */
3128 else if (!non_stop
&& target_is_non_stop_p ())
3130 /* In all-stop, but the target is always in non-stop mode.
3131 Start all other threads that are implicitly resumed too. */
3132 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3135 switch_to_thread_no_regs (tp
);
3137 if (!tp
->inf
->has_execution ())
3140 fprintf_unfiltered (gdb_stdlog
,
3141 "infrun: proceed: [%s] target has "
3143 target_pid_to_str (tp
->ptid
).c_str ());
3150 fprintf_unfiltered (gdb_stdlog
,
3151 "infrun: proceed: [%s] resumed\n",
3152 target_pid_to_str (tp
->ptid
).c_str ());
3153 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3157 if (thread_is_in_step_over_chain (tp
))
3160 fprintf_unfiltered (gdb_stdlog
,
3161 "infrun: proceed: [%s] needs step-over\n",
3162 target_pid_to_str (tp
->ptid
).c_str ());
3167 fprintf_unfiltered (gdb_stdlog
,
3168 "infrun: proceed: resuming %s\n",
3169 target_pid_to_str (tp
->ptid
).c_str ());
3171 reset_ecs (ecs
, tp
);
3172 switch_to_thread (tp
);
3173 keep_going_pass_signal (ecs
);
3174 if (!ecs
->wait_some_more
)
3175 error (_("Command aborted."));
3178 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3180 /* The thread wasn't started, and isn't queued, run it now. */
3181 reset_ecs (ecs
, cur_thr
);
3182 switch_to_thread (cur_thr
);
3183 keep_going_pass_signal (ecs
);
3184 if (!ecs
->wait_some_more
)
3185 error (_("Command aborted."));
3189 commit_resume_all_targets ();
3191 finish_state
.release ();
3193 /* If we've switched threads above, switch back to the previously
3194 current thread. We don't want the user to see a different
3196 switch_to_thread (cur_thr
);
3198 /* Tell the event loop to wait for it to stop. If the target
3199 supports asynchronous execution, it'll do this from within
3201 if (!target_can_async_p ())
3202 mark_async_event_handler (infrun_async_inferior_event_token
);
3206 /* Start remote-debugging of a machine over a serial link. */
3209 start_remote (int from_tty
)
3211 inferior
*inf
= current_inferior ();
3212 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3214 /* Always go on waiting for the target, regardless of the mode. */
3215 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3216 indicate to wait_for_inferior that a target should timeout if
3217 nothing is returned (instead of just blocking). Because of this,
3218 targets expecting an immediate response need to, internally, set
3219 things up so that the target_wait() is forced to eventually
3221 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3222 differentiate to its caller what the state of the target is after
3223 the initial open has been performed. Here we're assuming that
3224 the target has stopped. It should be possible to eventually have
3225 target_open() return to the caller an indication that the target
3226 is currently running and GDB state should be set to the same as
3227 for an async run. */
3228 wait_for_inferior (inf
);
3230 /* Now that the inferior has stopped, do any bookkeeping like
3231 loading shared libraries. We want to do this before normal_stop,
3232 so that the displayed frame is up to date. */
3233 post_create_inferior (current_top_target (), from_tty
);
3238 /* Initialize static vars when a new inferior begins. */
3241 init_wait_for_inferior (void)
3243 /* These are meaningless until the first time through wait_for_inferior. */
3245 breakpoint_init_inferior (inf_starting
);
3247 clear_proceed_status (0);
3249 nullify_last_target_wait_ptid ();
3251 previous_inferior_ptid
= inferior_ptid
;
3256 static void handle_inferior_event (struct execution_control_state
*ecs
);
3258 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3259 struct execution_control_state
*ecs
);
3260 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3261 struct execution_control_state
*ecs
);
3262 static void handle_signal_stop (struct execution_control_state
*ecs
);
3263 static void check_exception_resume (struct execution_control_state
*,
3264 struct frame_info
*);
3266 static void end_stepping_range (struct execution_control_state
*ecs
);
3267 static void stop_waiting (struct execution_control_state
*ecs
);
3268 static void keep_going (struct execution_control_state
*ecs
);
3269 static void process_event_stop_test (struct execution_control_state
*ecs
);
3270 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3272 /* This function is attached as a "thread_stop_requested" observer.
3273 Cleanup local state that assumed the PTID was to be resumed, and
3274 report the stop to the frontend. */
3277 infrun_thread_stop_requested (ptid_t ptid
)
3279 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3281 /* PTID was requested to stop. If the thread was already stopped,
3282 but the user/frontend doesn't know about that yet (e.g., the
3283 thread had been temporarily paused for some step-over), set up
3284 for reporting the stop now. */
3285 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3287 if (tp
->state
!= THREAD_RUNNING
)
3292 /* Remove matching threads from the step-over queue, so
3293 start_step_over doesn't try to resume them
3295 if (thread_is_in_step_over_chain (tp
))
3296 thread_step_over_chain_remove (tp
);
3298 /* If the thread is stopped, but the user/frontend doesn't
3299 know about that yet, queue a pending event, as if the
3300 thread had just stopped now. Unless the thread already had
3302 if (!tp
->suspend
.waitstatus_pending_p
)
3304 tp
->suspend
.waitstatus_pending_p
= 1;
3305 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3306 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3309 /* Clear the inline-frame state, since we're re-processing the
3311 clear_inline_frame_state (tp
);
3313 /* If this thread was paused because some other thread was
3314 doing an inline-step over, let that finish first. Once
3315 that happens, we'll restart all threads and consume pending
3316 stop events then. */
3317 if (step_over_info_valid_p ())
3320 /* Otherwise we can process the (new) pending event now. Set
3321 it so this pending event is considered by
3328 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3330 if (target_last_proc_target
== tp
->inf
->process_target ()
3331 && target_last_wait_ptid
== tp
->ptid
)
3332 nullify_last_target_wait_ptid ();
3335 /* Delete the step resume, single-step and longjmp/exception resume
3336 breakpoints of TP. */
3339 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3341 delete_step_resume_breakpoint (tp
);
3342 delete_exception_resume_breakpoint (tp
);
3343 delete_single_step_breakpoints (tp
);
3346 /* If the target still has execution, call FUNC for each thread that
3347 just stopped. In all-stop, that's all the non-exited threads; in
3348 non-stop, that's the current thread, only. */
3350 typedef void (*for_each_just_stopped_thread_callback_func
)
3351 (struct thread_info
*tp
);
3354 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3356 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3359 if (target_is_non_stop_p ())
3361 /* If in non-stop mode, only the current thread stopped. */
3362 func (inferior_thread ());
3366 /* In all-stop mode, all threads have stopped. */
3367 for (thread_info
*tp
: all_non_exited_threads ())
3372 /* Delete the step resume and longjmp/exception resume breakpoints of
3373 the threads that just stopped. */
3376 delete_just_stopped_threads_infrun_breakpoints (void)
3378 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3381 /* Delete the single-step breakpoints of the threads that just
3385 delete_just_stopped_threads_single_step_breakpoints (void)
3387 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3393 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3394 const struct target_waitstatus
*ws
)
3396 std::string status_string
= target_waitstatus_to_string (ws
);
3399 /* The text is split over several lines because it was getting too long.
3400 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3401 output as a unit; we want only one timestamp printed if debug_timestamp
3404 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3407 waiton_ptid
.tid ());
3408 if (waiton_ptid
.pid () != -1)
3409 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3410 stb
.printf (", status) =\n");
3411 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3415 target_pid_to_str (result_ptid
).c_str ());
3416 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3418 /* This uses %s in part to handle %'s in the text, but also to avoid
3419 a gcc error: the format attribute requires a string literal. */
3420 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3423 /* Select a thread at random, out of those which are resumed and have
3426 static struct thread_info
*
3427 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3431 auto has_event
= [&] (thread_info
*tp
)
3433 return (tp
->ptid
.matches (waiton_ptid
)
3435 && tp
->suspend
.waitstatus_pending_p
);
3438 /* First see how many events we have. Count only resumed threads
3439 that have an event pending. */
3440 for (thread_info
*tp
: inf
->non_exited_threads ())
3444 if (num_events
== 0)
3447 /* Now randomly pick a thread out of those that have had events. */
3448 int random_selector
= (int) ((num_events
* (double) rand ())
3449 / (RAND_MAX
+ 1.0));
3451 if (debug_infrun
&& num_events
> 1)
3452 fprintf_unfiltered (gdb_stdlog
,
3453 "infrun: Found %d events, selecting #%d\n",
3454 num_events
, random_selector
);
3456 /* Select the Nth thread that has had an event. */
3457 for (thread_info
*tp
: inf
->non_exited_threads ())
3459 if (random_selector
-- == 0)
3462 gdb_assert_not_reached ("event thread not found");
3465 /* Wrapper for target_wait that first checks whether threads have
3466 pending statuses to report before actually asking the target for
3467 more events. INF is the inferior we're using to call target_wait
3471 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3472 target_waitstatus
*status
, int options
)
3475 struct thread_info
*tp
;
3477 /* We know that we are looking for an event in the target of inferior
3478 INF, but we don't know which thread the event might come from. As
3479 such we want to make sure that INFERIOR_PTID is reset so that none of
3480 the wait code relies on it - doing so is always a mistake. */
3481 switch_to_inferior_no_thread (inf
);
3483 /* First check if there is a resumed thread with a wait status
3485 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3487 tp
= random_pending_event_thread (inf
, ptid
);
3492 fprintf_unfiltered (gdb_stdlog
,
3493 "infrun: Waiting for specific thread %s.\n",
3494 target_pid_to_str (ptid
).c_str ());
3496 /* We have a specific thread to check. */
3497 tp
= find_thread_ptid (inf
, ptid
);
3498 gdb_assert (tp
!= NULL
);
3499 if (!tp
->suspend
.waitstatus_pending_p
)
3504 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3505 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3507 struct regcache
*regcache
= get_thread_regcache (tp
);
3508 struct gdbarch
*gdbarch
= regcache
->arch ();
3512 pc
= regcache_read_pc (regcache
);
3514 if (pc
!= tp
->suspend
.stop_pc
)
3517 fprintf_unfiltered (gdb_stdlog
,
3518 "infrun: PC of %s changed. was=%s, now=%s\n",
3519 target_pid_to_str (tp
->ptid
).c_str (),
3520 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3521 paddress (gdbarch
, pc
));
3524 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3527 fprintf_unfiltered (gdb_stdlog
,
3528 "infrun: previous breakpoint of %s, at %s gone\n",
3529 target_pid_to_str (tp
->ptid
).c_str (),
3530 paddress (gdbarch
, pc
));
3538 fprintf_unfiltered (gdb_stdlog
,
3539 "infrun: pending event of %s cancelled.\n",
3540 target_pid_to_str (tp
->ptid
).c_str ());
3542 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3543 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3552 = target_waitstatus_to_string (&tp
->suspend
.waitstatus
);
3554 fprintf_unfiltered (gdb_stdlog
,
3555 "infrun: Using pending wait status %s for %s.\n",
3557 target_pid_to_str (tp
->ptid
).c_str ());
3560 /* Now that we've selected our final event LWP, un-adjust its PC
3561 if it was a software breakpoint (and the target doesn't
3562 always adjust the PC itself). */
3563 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3564 && !target_supports_stopped_by_sw_breakpoint ())
3566 struct regcache
*regcache
;
3567 struct gdbarch
*gdbarch
;
3570 regcache
= get_thread_regcache (tp
);
3571 gdbarch
= regcache
->arch ();
3573 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3578 pc
= regcache_read_pc (regcache
);
3579 regcache_write_pc (regcache
, pc
+ decr_pc
);
3583 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3584 *status
= tp
->suspend
.waitstatus
;
3585 tp
->suspend
.waitstatus_pending_p
= 0;
3587 /* Wake up the event loop again, until all pending events are
3589 if (target_is_async_p ())
3590 mark_async_event_handler (infrun_async_inferior_event_token
);
3594 /* But if we don't find one, we'll have to wait. */
3596 if (deprecated_target_wait_hook
)
3597 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3599 event_ptid
= target_wait (ptid
, status
, options
);
3604 /* Returns true if INF has any resumed thread with a status
3608 threads_are_resumed_pending_p (inferior
*inf
)
3610 for (thread_info
*tp
: inf
->non_exited_threads ())
3612 && tp
->suspend
.waitstatus_pending_p
)
3618 /* Wrapper for target_wait that first checks whether threads have
3619 pending statuses to report before actually asking the target for
3620 more events. Polls for events from all inferiors/targets. */
3623 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3625 int num_inferiors
= 0;
3626 int random_selector
;
3628 /* For fairness, we pick the first inferior/target to poll at
3629 random, and then continue polling the rest of the inferior list
3630 starting from that one in a circular fashion until the whole list
3633 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3635 return (inf
->process_target () != NULL
3636 && (threads_are_executing (inf
->process_target ())
3637 || threads_are_resumed_pending_p (inf
))
3638 && ptid_t (inf
->pid
).matches (wait_ptid
));
3641 /* First see how many resumed inferiors we have. */
3642 for (inferior
*inf
: all_inferiors ())
3643 if (inferior_matches (inf
))
3646 if (num_inferiors
== 0)
3648 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3652 /* Now randomly pick an inferior out of those that were resumed. */
3653 random_selector
= (int)
3654 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3656 if (debug_infrun
&& num_inferiors
> 1)
3657 fprintf_unfiltered (gdb_stdlog
,
3658 "infrun: Found %d inferiors, starting at #%d\n",
3659 num_inferiors
, random_selector
);
3661 /* Select the Nth inferior that was resumed. */
3663 inferior
*selected
= nullptr;
3665 for (inferior
*inf
: all_inferiors ())
3666 if (inferior_matches (inf
))
3667 if (random_selector
-- == 0)
3673 /* Now poll for events out of each of the resumed inferior's
3674 targets, starting from the selected one. */
3676 auto do_wait
= [&] (inferior
*inf
)
3678 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3679 ecs
->target
= inf
->process_target ();
3680 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3683 /* Needed in all-stop+target-non-stop mode, because we end up here
3684 spuriously after the target is all stopped and we've already
3685 reported the stop to the user, polling for events. */
3686 scoped_restore_current_thread restore_thread
;
3688 int inf_num
= selected
->num
;
3689 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3690 if (inferior_matches (inf
))
3694 for (inferior
*inf
= inferior_list
;
3695 inf
!= NULL
&& inf
->num
< inf_num
;
3697 if (inferior_matches (inf
))
3701 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3705 /* Prepare and stabilize the inferior for detaching it. E.g.,
3706 detaching while a thread is displaced stepping is a recipe for
3707 crashing it, as nothing would readjust the PC out of the scratch
3711 prepare_for_detach (void)
3713 struct inferior
*inf
= current_inferior ();
3714 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3716 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3718 /* Is any thread of this process displaced stepping? If not,
3719 there's nothing else to do. */
3720 if (displaced
->step_thread
== nullptr)
3724 fprintf_unfiltered (gdb_stdlog
,
3725 "displaced-stepping in-process while detaching");
3727 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3729 while (displaced
->step_thread
!= nullptr)
3731 struct execution_control_state ecss
;
3732 struct execution_control_state
*ecs
;
3735 memset (ecs
, 0, sizeof (*ecs
));
3737 overlay_cache_invalid
= 1;
3738 /* Flush target cache before starting to handle each event.
3739 Target was running and cache could be stale. This is just a
3740 heuristic. Running threads may modify target memory, but we
3741 don't get any event. */
3742 target_dcache_invalidate ();
3744 do_target_wait (pid_ptid
, ecs
, 0);
3747 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3749 /* If an error happens while handling the event, propagate GDB's
3750 knowledge of the executing state to the frontend/user running
3752 scoped_finish_thread_state
finish_state (inf
->process_target (),
3755 /* Now figure out what to do with the result of the result. */
3756 handle_inferior_event (ecs
);
3758 /* No error, don't finish the state yet. */
3759 finish_state
.release ();
3761 /* Breakpoints and watchpoints are not installed on the target
3762 at this point, and signals are passed directly to the
3763 inferior, so this must mean the process is gone. */
3764 if (!ecs
->wait_some_more
)
3766 restore_detaching
.release ();
3767 error (_("Program exited while detaching"));
3771 restore_detaching
.release ();
3774 /* Wait for control to return from inferior to debugger.
3776 If inferior gets a signal, we may decide to start it up again
3777 instead of returning. That is why there is a loop in this function.
3778 When this function actually returns it means the inferior
3779 should be left stopped and GDB should read more commands. */
3782 wait_for_inferior (inferior
*inf
)
3786 (gdb_stdlog
, "infrun: wait_for_inferior ()\n");
3788 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3790 /* If an error happens while handling the event, propagate GDB's
3791 knowledge of the executing state to the frontend/user running
3793 scoped_finish_thread_state finish_state
3794 (inf
->process_target (), minus_one_ptid
);
3798 struct execution_control_state ecss
;
3799 struct execution_control_state
*ecs
= &ecss
;
3801 memset (ecs
, 0, sizeof (*ecs
));
3803 overlay_cache_invalid
= 1;
3805 /* Flush target cache before starting to handle each event.
3806 Target was running and cache could be stale. This is just a
3807 heuristic. Running threads may modify target memory, but we
3808 don't get any event. */
3809 target_dcache_invalidate ();
3811 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3812 ecs
->target
= inf
->process_target ();
3815 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3817 /* Now figure out what to do with the result of the result. */
3818 handle_inferior_event (ecs
);
3820 if (!ecs
->wait_some_more
)
3824 /* No error, don't finish the state yet. */
3825 finish_state
.release ();
3828 /* Cleanup that reinstalls the readline callback handler, if the
3829 target is running in the background. If while handling the target
3830 event something triggered a secondary prompt, like e.g., a
3831 pagination prompt, we'll have removed the callback handler (see
3832 gdb_readline_wrapper_line). Need to do this as we go back to the
3833 event loop, ready to process further input. Note this has no
3834 effect if the handler hasn't actually been removed, because calling
3835 rl_callback_handler_install resets the line buffer, thus losing
3839 reinstall_readline_callback_handler_cleanup ()
3841 struct ui
*ui
= current_ui
;
3845 /* We're not going back to the top level event loop yet. Don't
3846 install the readline callback, as it'd prep the terminal,
3847 readline-style (raw, noecho) (e.g., --batch). We'll install
3848 it the next time the prompt is displayed, when we're ready
3853 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3854 gdb_rl_callback_handler_reinstall ();
3857 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3858 that's just the event thread. In all-stop, that's all threads. */
3861 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3863 if (ecs
->event_thread
!= NULL
3864 && ecs
->event_thread
->thread_fsm
!= NULL
)
3865 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3869 for (thread_info
*thr
: all_non_exited_threads ())
3871 if (thr
->thread_fsm
== NULL
)
3873 if (thr
== ecs
->event_thread
)
3876 switch_to_thread (thr
);
3877 thr
->thread_fsm
->clean_up (thr
);
3880 if (ecs
->event_thread
!= NULL
)
3881 switch_to_thread (ecs
->event_thread
);
3885 /* Helper for all_uis_check_sync_execution_done that works on the
3889 check_curr_ui_sync_execution_done (void)
3891 struct ui
*ui
= current_ui
;
3893 if (ui
->prompt_state
== PROMPT_NEEDED
3895 && !gdb_in_secondary_prompt_p (ui
))
3897 target_terminal::ours ();
3898 gdb::observers::sync_execution_done
.notify ();
3899 ui_register_input_event_handler (ui
);
3906 all_uis_check_sync_execution_done (void)
3908 SWITCH_THRU_ALL_UIS ()
3910 check_curr_ui_sync_execution_done ();
3917 all_uis_on_sync_execution_starting (void)
3919 SWITCH_THRU_ALL_UIS ()
3921 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3922 async_disable_stdin ();
3926 /* Asynchronous version of wait_for_inferior. It is called by the
3927 event loop whenever a change of state is detected on the file
3928 descriptor corresponding to the target. It can be called more than
3929 once to complete a single execution command. In such cases we need
3930 to keep the state in a global variable ECSS. If it is the last time
3931 that this function is called for a single execution command, then
3932 report to the user that the inferior has stopped, and do the
3933 necessary cleanups. */
3936 fetch_inferior_event ()
3938 struct execution_control_state ecss
;
3939 struct execution_control_state
*ecs
= &ecss
;
3942 memset (ecs
, 0, sizeof (*ecs
));
3944 /* Events are always processed with the main UI as current UI. This
3945 way, warnings, debug output, etc. are always consistently sent to
3946 the main console. */
3947 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3949 /* End up with readline processing input, if necessary. */
3951 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3953 /* We're handling a live event, so make sure we're doing live
3954 debugging. If we're looking at traceframes while the target is
3955 running, we're going to need to get back to that mode after
3956 handling the event. */
3957 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3960 maybe_restore_traceframe
.emplace ();
3961 set_current_traceframe (-1);
3964 /* The user/frontend should not notice a thread switch due to
3965 internal events. Make sure we revert to the user selected
3966 thread and frame after handling the event and running any
3967 breakpoint commands. */
3968 scoped_restore_current_thread restore_thread
;
3970 overlay_cache_invalid
= 1;
3971 /* Flush target cache before starting to handle each event. Target
3972 was running and cache could be stale. This is just a heuristic.
3973 Running threads may modify target memory, but we don't get any
3975 target_dcache_invalidate ();
3977 scoped_restore save_exec_dir
3978 = make_scoped_restore (&execution_direction
,
3979 target_execution_direction ());
3981 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3984 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3986 /* Switch to the target that generated the event, so we can do
3987 target calls. Any inferior bound to the target will do, so we
3988 just switch to the first we find. */
3989 for (inferior
*inf
: all_inferiors (ecs
->target
))
3991 switch_to_inferior_no_thread (inf
);
3996 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3998 /* If an error happens while handling the event, propagate GDB's
3999 knowledge of the executing state to the frontend/user running
4001 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
4002 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
4004 /* Get executed before scoped_restore_current_thread above to apply
4005 still for the thread which has thrown the exception. */
4006 auto defer_bpstat_clear
4007 = make_scope_exit (bpstat_clear_actions
);
4008 auto defer_delete_threads
4009 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
4011 /* Now figure out what to do with the result of the result. */
4012 handle_inferior_event (ecs
);
4014 if (!ecs
->wait_some_more
)
4016 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4017 int should_stop
= 1;
4018 struct thread_info
*thr
= ecs
->event_thread
;
4020 delete_just_stopped_threads_infrun_breakpoints ();
4024 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
4026 if (thread_fsm
!= NULL
)
4027 should_stop
= thread_fsm
->should_stop (thr
);
4036 bool should_notify_stop
= true;
4039 clean_up_just_stopped_threads_fsms (ecs
);
4041 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
4042 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
4044 if (should_notify_stop
)
4046 /* We may not find an inferior if this was a process exit. */
4047 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
4048 proceeded
= normal_stop ();
4053 inferior_event_handler (INF_EXEC_COMPLETE
);
4057 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4058 previously selected thread is gone. We have two
4059 choices - switch to no thread selected, or restore the
4060 previously selected thread (now exited). We chose the
4061 later, just because that's what GDB used to do. After
4062 this, "info threads" says "The current thread <Thread
4063 ID 2> has terminated." instead of "No thread
4067 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4068 restore_thread
.dont_restore ();
4072 defer_delete_threads
.release ();
4073 defer_bpstat_clear
.release ();
4075 /* No error, don't finish the thread states yet. */
4076 finish_state
.release ();
4078 /* This scope is used to ensure that readline callbacks are
4079 reinstalled here. */
4082 /* If a UI was in sync execution mode, and now isn't, restore its
4083 prompt (a synchronous execution command has finished, and we're
4084 ready for input). */
4085 all_uis_check_sync_execution_done ();
4088 && exec_done_display_p
4089 && (inferior_ptid
== null_ptid
4090 || inferior_thread ()->state
!= THREAD_RUNNING
))
4091 printf_unfiltered (_("completed.\n"));
4097 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4098 struct symtab_and_line sal
)
4100 /* This can be removed once this function no longer implicitly relies on the
4101 inferior_ptid value. */
4102 gdb_assert (inferior_ptid
== tp
->ptid
);
4104 tp
->control
.step_frame_id
= get_frame_id (frame
);
4105 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4107 tp
->current_symtab
= sal
.symtab
;
4108 tp
->current_line
= sal
.line
;
4111 /* Clear context switchable stepping state. */
4114 init_thread_stepping_state (struct thread_info
*tss
)
4116 tss
->stepped_breakpoint
= 0;
4117 tss
->stepping_over_breakpoint
= 0;
4118 tss
->stepping_over_watchpoint
= 0;
4119 tss
->step_after_step_resume_breakpoint
= 0;
4125 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4126 target_waitstatus status
)
4128 target_last_proc_target
= target
;
4129 target_last_wait_ptid
= ptid
;
4130 target_last_waitstatus
= status
;
4136 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4137 target_waitstatus
*status
)
4139 if (target
!= nullptr)
4140 *target
= target_last_proc_target
;
4141 if (ptid
!= nullptr)
4142 *ptid
= target_last_wait_ptid
;
4143 if (status
!= nullptr)
4144 *status
= target_last_waitstatus
;
4150 nullify_last_target_wait_ptid (void)
4152 target_last_proc_target
= nullptr;
4153 target_last_wait_ptid
= minus_one_ptid
;
4154 target_last_waitstatus
= {};
4157 /* Switch thread contexts. */
4160 context_switch (execution_control_state
*ecs
)
4163 && ecs
->ptid
!= inferior_ptid
4164 && (inferior_ptid
== null_ptid
4165 || ecs
->event_thread
!= inferior_thread ()))
4167 fprintf_unfiltered (gdb_stdlog
, "infrun: Switching context from %s ",
4168 target_pid_to_str (inferior_ptid
).c_str ());
4169 fprintf_unfiltered (gdb_stdlog
, "to %s\n",
4170 target_pid_to_str (ecs
->ptid
).c_str ());
4173 switch_to_thread (ecs
->event_thread
);
4176 /* If the target can't tell whether we've hit breakpoints
4177 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4178 check whether that could have been caused by a breakpoint. If so,
4179 adjust the PC, per gdbarch_decr_pc_after_break. */
4182 adjust_pc_after_break (struct thread_info
*thread
,
4183 struct target_waitstatus
*ws
)
4185 struct regcache
*regcache
;
4186 struct gdbarch
*gdbarch
;
4187 CORE_ADDR breakpoint_pc
, decr_pc
;
4189 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4190 we aren't, just return.
4192 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4193 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4194 implemented by software breakpoints should be handled through the normal
4197 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4198 different signals (SIGILL or SIGEMT for instance), but it is less
4199 clear where the PC is pointing afterwards. It may not match
4200 gdbarch_decr_pc_after_break. I don't know any specific target that
4201 generates these signals at breakpoints (the code has been in GDB since at
4202 least 1992) so I can not guess how to handle them here.
4204 In earlier versions of GDB, a target with
4205 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4206 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4207 target with both of these set in GDB history, and it seems unlikely to be
4208 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4210 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4213 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4216 /* In reverse execution, when a breakpoint is hit, the instruction
4217 under it has already been de-executed. The reported PC always
4218 points at the breakpoint address, so adjusting it further would
4219 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4222 B1 0x08000000 : INSN1
4223 B2 0x08000001 : INSN2
4225 PC -> 0x08000003 : INSN4
4227 Say you're stopped at 0x08000003 as above. Reverse continuing
4228 from that point should hit B2 as below. Reading the PC when the
4229 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4230 been de-executed already.
4232 B1 0x08000000 : INSN1
4233 B2 PC -> 0x08000001 : INSN2
4237 We can't apply the same logic as for forward execution, because
4238 we would wrongly adjust the PC to 0x08000000, since there's a
4239 breakpoint at PC - 1. We'd then report a hit on B1, although
4240 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4242 if (execution_direction
== EXEC_REVERSE
)
4245 /* If the target can tell whether the thread hit a SW breakpoint,
4246 trust it. Targets that can tell also adjust the PC
4248 if (target_supports_stopped_by_sw_breakpoint ())
4251 /* Note that relying on whether a breakpoint is planted in memory to
4252 determine this can fail. E.g,. the breakpoint could have been
4253 removed since. Or the thread could have been told to step an
4254 instruction the size of a breakpoint instruction, and only
4255 _after_ was a breakpoint inserted at its address. */
4257 /* If this target does not decrement the PC after breakpoints, then
4258 we have nothing to do. */
4259 regcache
= get_thread_regcache (thread
);
4260 gdbarch
= regcache
->arch ();
4262 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4266 const address_space
*aspace
= regcache
->aspace ();
4268 /* Find the location where (if we've hit a breakpoint) the
4269 breakpoint would be. */
4270 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4272 /* If the target can't tell whether a software breakpoint triggered,
4273 fallback to figuring it out based on breakpoints we think were
4274 inserted in the target, and on whether the thread was stepped or
4277 /* Check whether there actually is a software breakpoint inserted at
4280 If in non-stop mode, a race condition is possible where we've
4281 removed a breakpoint, but stop events for that breakpoint were
4282 already queued and arrive later. To suppress those spurious
4283 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4284 and retire them after a number of stop events are reported. Note
4285 this is an heuristic and can thus get confused. The real fix is
4286 to get the "stopped by SW BP and needs adjustment" info out of
4287 the target/kernel (and thus never reach here; see above). */
4288 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4289 || (target_is_non_stop_p ()
4290 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4292 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4294 if (record_full_is_used ())
4295 restore_operation_disable
.emplace
4296 (record_full_gdb_operation_disable_set ());
4298 /* When using hardware single-step, a SIGTRAP is reported for both
4299 a completed single-step and a software breakpoint. Need to
4300 differentiate between the two, as the latter needs adjusting
4301 but the former does not.
4303 The SIGTRAP can be due to a completed hardware single-step only if
4304 - we didn't insert software single-step breakpoints
4305 - this thread is currently being stepped
4307 If any of these events did not occur, we must have stopped due
4308 to hitting a software breakpoint, and have to back up to the
4311 As a special case, we could have hardware single-stepped a
4312 software breakpoint. In this case (prev_pc == breakpoint_pc),
4313 we also need to back up to the breakpoint address. */
4315 if (thread_has_single_step_breakpoints_set (thread
)
4316 || !currently_stepping (thread
)
4317 || (thread
->stepped_breakpoint
4318 && thread
->prev_pc
== breakpoint_pc
))
4319 regcache_write_pc (regcache
, breakpoint_pc
);
4324 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4326 for (frame
= get_prev_frame (frame
);
4328 frame
= get_prev_frame (frame
))
4330 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4332 if (get_frame_type (frame
) != INLINE_FRAME
)
4339 /* Look for an inline frame that is marked for skip.
4340 If PREV_FRAME is TRUE start at the previous frame,
4341 otherwise start at the current frame. Stop at the
4342 first non-inline frame, or at the frame where the
4346 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4348 struct frame_info
*frame
= get_current_frame ();
4351 frame
= get_prev_frame (frame
);
4353 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4355 const char *fn
= NULL
;
4356 symtab_and_line sal
;
4359 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4361 if (get_frame_type (frame
) != INLINE_FRAME
)
4364 sal
= find_frame_sal (frame
);
4365 sym
= get_frame_function (frame
);
4368 fn
= sym
->print_name ();
4371 && function_name_is_marked_for_skip (fn
, sal
))
4378 /* If the event thread has the stop requested flag set, pretend it
4379 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4383 handle_stop_requested (struct execution_control_state
*ecs
)
4385 if (ecs
->event_thread
->stop_requested
)
4387 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4388 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4389 handle_signal_stop (ecs
);
4395 /* Auxiliary function that handles syscall entry/return events.
4396 It returns 1 if the inferior should keep going (and GDB
4397 should ignore the event), or 0 if the event deserves to be
4401 handle_syscall_event (struct execution_control_state
*ecs
)
4403 struct regcache
*regcache
;
4406 context_switch (ecs
);
4408 regcache
= get_thread_regcache (ecs
->event_thread
);
4409 syscall_number
= ecs
->ws
.value
.syscall_number
;
4410 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4412 if (catch_syscall_enabled () > 0
4413 && catching_syscall_number (syscall_number
) > 0)
4416 fprintf_unfiltered (gdb_stdlog
, "infrun: syscall number = '%d'\n",
4419 ecs
->event_thread
->control
.stop_bpstat
4420 = bpstat_stop_status (regcache
->aspace (),
4421 ecs
->event_thread
->suspend
.stop_pc
,
4422 ecs
->event_thread
, &ecs
->ws
);
4424 if (handle_stop_requested (ecs
))
4427 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4429 /* Catchpoint hit. */
4434 if (handle_stop_requested (ecs
))
4437 /* If no catchpoint triggered for this, then keep going. */
4442 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4445 fill_in_stop_func (struct gdbarch
*gdbarch
,
4446 struct execution_control_state
*ecs
)
4448 if (!ecs
->stop_func_filled_in
)
4452 /* Don't care about return value; stop_func_start and stop_func_name
4453 will both be 0 if it doesn't work. */
4454 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4455 &ecs
->stop_func_name
,
4456 &ecs
->stop_func_start
,
4457 &ecs
->stop_func_end
,
4460 /* The call to find_pc_partial_function, above, will set
4461 stop_func_start and stop_func_end to the start and end
4462 of the range containing the stop pc. If this range
4463 contains the entry pc for the block (which is always the
4464 case for contiguous blocks), advance stop_func_start past
4465 the function's start offset and entrypoint. Note that
4466 stop_func_start is NOT advanced when in a range of a
4467 non-contiguous block that does not contain the entry pc. */
4468 if (block
!= nullptr
4469 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4470 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4472 ecs
->stop_func_start
4473 += gdbarch_deprecated_function_start_offset (gdbarch
);
4475 if (gdbarch_skip_entrypoint_p (gdbarch
))
4476 ecs
->stop_func_start
4477 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4480 ecs
->stop_func_filled_in
= 1;
4485 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4487 static enum stop_kind
4488 get_inferior_stop_soon (execution_control_state
*ecs
)
4490 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4492 gdb_assert (inf
!= NULL
);
4493 return inf
->control
.stop_soon
;
4496 /* Poll for one event out of the current target. Store the resulting
4497 waitstatus in WS, and return the event ptid. Does not block. */
4500 poll_one_curr_target (struct target_waitstatus
*ws
)
4504 overlay_cache_invalid
= 1;
4506 /* Flush target cache before starting to handle each event.
4507 Target was running and cache could be stale. This is just a
4508 heuristic. Running threads may modify target memory, but we
4509 don't get any event. */
4510 target_dcache_invalidate ();
4512 if (deprecated_target_wait_hook
)
4513 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4515 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4518 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4523 /* An event reported by wait_one. */
4525 struct wait_one_event
4527 /* The target the event came out of. */
4528 process_stratum_target
*target
;
4530 /* The PTID the event was for. */
4533 /* The waitstatus. */
4534 target_waitstatus ws
;
4537 /* Wait for one event out of any target. */
4539 static wait_one_event
4544 for (inferior
*inf
: all_inferiors ())
4546 process_stratum_target
*target
= inf
->process_target ();
4548 || !target
->is_async_p ()
4549 || !target
->threads_executing
)
4552 switch_to_inferior_no_thread (inf
);
4554 wait_one_event event
;
4555 event
.target
= target
;
4556 event
.ptid
= poll_one_curr_target (&event
.ws
);
4558 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4560 /* If nothing is resumed, remove the target from the
4564 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4568 /* Block waiting for some event. */
4575 for (inferior
*inf
: all_inferiors ())
4577 process_stratum_target
*target
= inf
->process_target ();
4579 || !target
->is_async_p ()
4580 || !target
->threads_executing
)
4583 int fd
= target
->async_wait_fd ();
4584 FD_SET (fd
, &readfds
);
4591 /* No waitable targets left. All must be stopped. */
4592 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4597 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4603 perror_with_name ("interruptible_select");
4608 /* Save the thread's event and stop reason to process it later. */
4611 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4615 std::string statstr
= target_waitstatus_to_string (ws
);
4617 fprintf_unfiltered (gdb_stdlog
,
4618 "infrun: saving status %s for %d.%ld.%ld\n",
4625 /* Record for later. */
4626 tp
->suspend
.waitstatus
= *ws
;
4627 tp
->suspend
.waitstatus_pending_p
= 1;
4629 struct regcache
*regcache
= get_thread_regcache (tp
);
4630 const address_space
*aspace
= regcache
->aspace ();
4632 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4633 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4635 CORE_ADDR pc
= regcache_read_pc (regcache
);
4637 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4639 scoped_restore_current_thread restore_thread
;
4640 switch_to_thread (tp
);
4642 if (target_stopped_by_watchpoint ())
4644 tp
->suspend
.stop_reason
4645 = TARGET_STOPPED_BY_WATCHPOINT
;
4647 else if (target_supports_stopped_by_sw_breakpoint ()
4648 && target_stopped_by_sw_breakpoint ())
4650 tp
->suspend
.stop_reason
4651 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4653 else if (target_supports_stopped_by_hw_breakpoint ()
4654 && target_stopped_by_hw_breakpoint ())
4656 tp
->suspend
.stop_reason
4657 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4659 else if (!target_supports_stopped_by_hw_breakpoint ()
4660 && hardware_breakpoint_inserted_here_p (aspace
,
4663 tp
->suspend
.stop_reason
4664 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4666 else if (!target_supports_stopped_by_sw_breakpoint ()
4667 && software_breakpoint_inserted_here_p (aspace
,
4670 tp
->suspend
.stop_reason
4671 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4673 else if (!thread_has_single_step_breakpoints_set (tp
)
4674 && currently_stepping (tp
))
4676 tp
->suspend
.stop_reason
4677 = TARGET_STOPPED_BY_SINGLE_STEP
;
4682 /* Mark the non-executing threads accordingly. In all-stop, all
4683 threads of all processes are stopped when we get any event
4684 reported. In non-stop mode, only the event thread stops. */
4687 mark_non_executing_threads (process_stratum_target
*target
,
4689 struct target_waitstatus ws
)
4693 if (!target_is_non_stop_p ())
4694 mark_ptid
= minus_one_ptid
;
4695 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4696 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4698 /* If we're handling a process exit in non-stop mode, even
4699 though threads haven't been deleted yet, one would think
4700 that there is nothing to do, as threads of the dead process
4701 will be soon deleted, and threads of any other process were
4702 left running. However, on some targets, threads survive a
4703 process exit event. E.g., for the "checkpoint" command,
4704 when the current checkpoint/fork exits, linux-fork.c
4705 automatically switches to another fork from within
4706 target_mourn_inferior, by associating the same
4707 inferior/thread to another fork. We haven't mourned yet at
4708 this point, but we must mark any threads left in the
4709 process as not-executing so that finish_thread_state marks
4710 them stopped (in the user's perspective) if/when we present
4711 the stop to the user. */
4712 mark_ptid
= ptid_t (event_ptid
.pid ());
4715 mark_ptid
= event_ptid
;
4717 set_executing (target
, mark_ptid
, false);
4719 /* Likewise the resumed flag. */
4720 set_resumed (target
, mark_ptid
, false);
4726 stop_all_threads (void)
4728 /* We may need multiple passes to discover all threads. */
4732 gdb_assert (exists_non_stop_target ());
4735 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads\n");
4737 scoped_restore_current_thread restore_thread
;
4739 /* Enable thread events of all targets. */
4740 for (auto *target
: all_non_exited_process_targets ())
4742 switch_to_target_no_thread (target
);
4743 target_thread_events (true);
4748 /* Disable thread events of all targets. */
4749 for (auto *target
: all_non_exited_process_targets ())
4751 switch_to_target_no_thread (target
);
4752 target_thread_events (false);
4756 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_all_threads done\n");
4759 /* Request threads to stop, and then wait for the stops. Because
4760 threads we already know about can spawn more threads while we're
4761 trying to stop them, and we only learn about new threads when we
4762 update the thread list, do this in a loop, and keep iterating
4763 until two passes find no threads that need to be stopped. */
4764 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4767 fprintf_unfiltered (gdb_stdlog
,
4768 "infrun: stop_all_threads, pass=%d, "
4769 "iterations=%d\n", pass
, iterations
);
4772 int waits_needed
= 0;
4774 for (auto *target
: all_non_exited_process_targets ())
4776 switch_to_target_no_thread (target
);
4777 update_thread_list ();
4780 /* Go through all threads looking for threads that we need
4781 to tell the target to stop. */
4782 for (thread_info
*t
: all_non_exited_threads ())
4784 /* For a single-target setting with an all-stop target,
4785 we would not even arrive here. For a multi-target
4786 setting, until GDB is able to handle a mixture of
4787 all-stop and non-stop targets, simply skip all-stop
4788 targets' threads. This should be fine due to the
4789 protection of 'check_multi_target_resumption'. */
4791 switch_to_thread_no_regs (t
);
4792 if (!target_is_non_stop_p ())
4797 /* If already stopping, don't request a stop again.
4798 We just haven't seen the notification yet. */
4799 if (!t
->stop_requested
)
4802 fprintf_unfiltered (gdb_stdlog
,
4803 "infrun: %s executing, "
4805 target_pid_to_str (t
->ptid
).c_str ());
4806 target_stop (t
->ptid
);
4807 t
->stop_requested
= 1;
4812 fprintf_unfiltered (gdb_stdlog
,
4813 "infrun: %s executing, "
4814 "already stopping\n",
4815 target_pid_to_str (t
->ptid
).c_str ());
4818 if (t
->stop_requested
)
4824 fprintf_unfiltered (gdb_stdlog
,
4825 "infrun: %s not executing\n",
4826 target_pid_to_str (t
->ptid
).c_str ());
4828 /* The thread may be not executing, but still be
4829 resumed with a pending status to process. */
4834 if (waits_needed
== 0)
4837 /* If we find new threads on the second iteration, restart
4838 over. We want to see two iterations in a row with all
4843 for (int i
= 0; i
< waits_needed
; i
++)
4845 wait_one_event event
= wait_one ();
4849 fprintf_unfiltered (gdb_stdlog
,
4850 "infrun: stop_all_threads %s %s\n",
4851 target_waitstatus_to_string (&event
.ws
).c_str (),
4852 target_pid_to_str (event
.ptid
).c_str ());
4855 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4857 /* All resumed threads exited. */
4860 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4861 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4862 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4864 /* One thread/process exited/signalled. */
4866 thread_info
*t
= nullptr;
4868 /* The target may have reported just a pid. If so, try
4869 the first non-exited thread. */
4870 if (event
.ptid
.is_pid ())
4872 int pid
= event
.ptid
.pid ();
4873 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4874 for (thread_info
*tp
: inf
->non_exited_threads ())
4880 /* If there is no available thread, the event would
4881 have to be appended to a per-inferior event list,
4882 which does not exist (and if it did, we'd have
4883 to adjust run control command to be able to
4884 resume such an inferior). We assert here instead
4885 of going into an infinite loop. */
4886 gdb_assert (t
!= nullptr);
4889 fprintf_unfiltered (gdb_stdlog
,
4890 "infrun: stop_all_threads, using %s\n",
4891 target_pid_to_str (t
->ptid
).c_str ());
4895 t
= find_thread_ptid (event
.target
, event
.ptid
);
4896 /* Check if this is the first time we see this thread.
4897 Don't bother adding if it individually exited. */
4899 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4900 t
= add_thread (event
.target
, event
.ptid
);
4905 /* Set the threads as non-executing to avoid
4906 another stop attempt on them. */
4907 switch_to_thread_no_regs (t
);
4908 mark_non_executing_threads (event
.target
, event
.ptid
,
4910 save_waitstatus (t
, &event
.ws
);
4911 t
->stop_requested
= false;
4916 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4918 t
= add_thread (event
.target
, event
.ptid
);
4920 t
->stop_requested
= 0;
4923 t
->control
.may_range_step
= 0;
4925 /* This may be the first time we see the inferior report
4927 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4928 if (inf
->needs_setup
)
4930 switch_to_thread_no_regs (t
);
4934 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4935 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4937 /* We caught the event that we intended to catch, so
4938 there's no event pending. */
4939 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4940 t
->suspend
.waitstatus_pending_p
= 0;
4942 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4944 /* Add it back to the step-over queue. */
4947 fprintf_unfiltered (gdb_stdlog
,
4948 "infrun: displaced-step of %s "
4949 "canceled: adding back to the "
4950 "step-over queue\n",
4951 target_pid_to_str (t
->ptid
).c_str ());
4953 t
->control
.trap_expected
= 0;
4954 thread_step_over_chain_enqueue (t
);
4959 enum gdb_signal sig
;
4960 struct regcache
*regcache
;
4964 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4966 fprintf_unfiltered (gdb_stdlog
,
4967 "infrun: target_wait %s, saving "
4968 "status for %d.%ld.%ld\n",
4975 /* Record for later. */
4976 save_waitstatus (t
, &event
.ws
);
4978 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4979 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4981 if (displaced_step_fixup (t
, sig
) < 0)
4983 /* Add it back to the step-over queue. */
4984 t
->control
.trap_expected
= 0;
4985 thread_step_over_chain_enqueue (t
);
4988 regcache
= get_thread_regcache (t
);
4989 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4993 fprintf_unfiltered (gdb_stdlog
,
4994 "infrun: saved stop_pc=%s for %s "
4995 "(currently_stepping=%d)\n",
4996 paddress (target_gdbarch (),
4997 t
->suspend
.stop_pc
),
4998 target_pid_to_str (t
->ptid
).c_str (),
4999 currently_stepping (t
));
5008 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
5011 handle_no_resumed (struct execution_control_state
*ecs
)
5013 if (target_can_async_p ())
5017 for (ui
*ui
: all_uis ())
5019 if (ui
->prompt_state
== PROMPT_BLOCKED
)
5027 /* There were no unwaited-for children left in the target, but,
5028 we're not synchronously waiting for events either. Just
5032 fprintf_unfiltered (gdb_stdlog
,
5033 "infrun: TARGET_WAITKIND_NO_RESUMED "
5034 "(ignoring: bg)\n");
5035 prepare_to_wait (ecs
);
5040 /* Otherwise, if we were running a synchronous execution command, we
5041 may need to cancel it and give the user back the terminal.
5043 In non-stop mode, the target can't tell whether we've already
5044 consumed previous stop events, so it can end up sending us a
5045 no-resumed event like so:
5047 #0 - thread 1 is left stopped
5049 #1 - thread 2 is resumed and hits breakpoint
5050 -> TARGET_WAITKIND_STOPPED
5052 #2 - thread 3 is resumed and exits
5053 this is the last resumed thread, so
5054 -> TARGET_WAITKIND_NO_RESUMED
5056 #3 - gdb processes stop for thread 2 and decides to re-resume
5059 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
5060 thread 2 is now resumed, so the event should be ignored.
5062 IOW, if the stop for thread 2 doesn't end a foreground command,
5063 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
5064 event. But it could be that the event meant that thread 2 itself
5065 (or whatever other thread was the last resumed thread) exited.
5067 To address this we refresh the thread list and check whether we
5068 have resumed threads _now_. In the example above, this removes
5069 thread 3 from the thread list. If thread 2 was re-resumed, we
5070 ignore this event. If we find no thread resumed, then we cancel
5071 the synchronous command and show "no unwaited-for " to the
5075 scoped_restore_current_thread restore_thread
;
5077 for (auto *target
: all_non_exited_process_targets ())
5079 switch_to_target_no_thread (target
);
5080 update_thread_list ();
5084 for (thread_info
*thread
: all_non_exited_threads ())
5086 if (thread
->executing
5087 || thread
->suspend
.waitstatus_pending_p
)
5089 /* Either there were no unwaited-for children left in the
5090 target at some point, but there are now, or some target
5091 other than the eventing one has unwaited-for children
5092 left. Just ignore. */
5094 fprintf_unfiltered (gdb_stdlog
,
5095 "infrun: TARGET_WAITKIND_NO_RESUMED "
5096 "(ignoring: found resumed)\n");
5097 prepare_to_wait (ecs
);
5102 /* Go ahead and report the event. */
5106 /* Given an execution control state that has been freshly filled in by
5107 an event from the inferior, figure out what it means and take
5110 The alternatives are:
5112 1) stop_waiting and return; to really stop and return to the
5115 2) keep_going and return; to wait for the next event (set
5116 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5120 handle_inferior_event (struct execution_control_state
*ecs
)
5122 /* Make sure that all temporary struct value objects that were
5123 created during the handling of the event get deleted at the
5125 scoped_value_mark free_values
;
5127 enum stop_kind stop_soon
;
5130 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5131 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5133 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5135 /* We had an event in the inferior, but we are not interested in
5136 handling it at this level. The lower layers have already
5137 done what needs to be done, if anything.
5139 One of the possible circumstances for this is when the
5140 inferior produces output for the console. The inferior has
5141 not stopped, and we are ignoring the event. Another possible
5142 circumstance is any event which the lower level knows will be
5143 reported multiple times without an intervening resume. */
5144 prepare_to_wait (ecs
);
5148 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5150 prepare_to_wait (ecs
);
5154 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5155 && handle_no_resumed (ecs
))
5158 /* Cache the last target/ptid/waitstatus. */
5159 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5161 /* Always clear state belonging to the previous time we stopped. */
5162 stop_stack_dummy
= STOP_NONE
;
5164 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5166 /* No unwaited-for children left. IOW, all resumed children
5168 stop_print_frame
= 0;
5173 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5174 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5176 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5177 /* If it's a new thread, add it to the thread database. */
5178 if (ecs
->event_thread
== NULL
)
5179 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5181 /* Disable range stepping. If the next step request could use a
5182 range, this will be end up re-enabled then. */
5183 ecs
->event_thread
->control
.may_range_step
= 0;
5186 /* Dependent on valid ECS->EVENT_THREAD. */
5187 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5189 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5190 reinit_frame_cache ();
5192 breakpoint_retire_moribund ();
5194 /* First, distinguish signals caused by the debugger from signals
5195 that have to do with the program's own actions. Note that
5196 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5197 on the operating system version. Here we detect when a SIGILL or
5198 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5199 something similar for SIGSEGV, since a SIGSEGV will be generated
5200 when we're trying to execute a breakpoint instruction on a
5201 non-executable stack. This happens for call dummy breakpoints
5202 for architectures like SPARC that place call dummies on the
5204 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5205 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5206 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5207 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5209 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5211 if (breakpoint_inserted_here_p (regcache
->aspace (),
5212 regcache_read_pc (regcache
)))
5215 fprintf_unfiltered (gdb_stdlog
,
5216 "infrun: Treating signal as SIGTRAP\n");
5217 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5221 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5223 switch (ecs
->ws
.kind
)
5225 case TARGET_WAITKIND_LOADED
:
5226 context_switch (ecs
);
5227 /* Ignore gracefully during startup of the inferior, as it might
5228 be the shell which has just loaded some objects, otherwise
5229 add the symbols for the newly loaded objects. Also ignore at
5230 the beginning of an attach or remote session; we will query
5231 the full list of libraries once the connection is
5234 stop_soon
= get_inferior_stop_soon (ecs
);
5235 if (stop_soon
== NO_STOP_QUIETLY
)
5237 struct regcache
*regcache
;
5239 regcache
= get_thread_regcache (ecs
->event_thread
);
5241 handle_solib_event ();
5243 ecs
->event_thread
->control
.stop_bpstat
5244 = bpstat_stop_status (regcache
->aspace (),
5245 ecs
->event_thread
->suspend
.stop_pc
,
5246 ecs
->event_thread
, &ecs
->ws
);
5248 if (handle_stop_requested (ecs
))
5251 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5253 /* A catchpoint triggered. */
5254 process_event_stop_test (ecs
);
5258 /* If requested, stop when the dynamic linker notifies
5259 gdb of events. This allows the user to get control
5260 and place breakpoints in initializer routines for
5261 dynamically loaded objects (among other things). */
5262 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5263 if (stop_on_solib_events
)
5265 /* Make sure we print "Stopped due to solib-event" in
5267 stop_print_frame
= 1;
5274 /* If we are skipping through a shell, or through shared library
5275 loading that we aren't interested in, resume the program. If
5276 we're running the program normally, also resume. */
5277 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5279 /* Loading of shared libraries might have changed breakpoint
5280 addresses. Make sure new breakpoints are inserted. */
5281 if (stop_soon
== NO_STOP_QUIETLY
)
5282 insert_breakpoints ();
5283 resume (GDB_SIGNAL_0
);
5284 prepare_to_wait (ecs
);
5288 /* But stop if we're attaching or setting up a remote
5290 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5291 || stop_soon
== STOP_QUIETLY_REMOTE
)
5294 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5299 internal_error (__FILE__
, __LINE__
,
5300 _("unhandled stop_soon: %d"), (int) stop_soon
);
5302 case TARGET_WAITKIND_SPURIOUS
:
5303 if (handle_stop_requested (ecs
))
5305 context_switch (ecs
);
5306 resume (GDB_SIGNAL_0
);
5307 prepare_to_wait (ecs
);
5310 case TARGET_WAITKIND_THREAD_CREATED
:
5311 if (handle_stop_requested (ecs
))
5313 context_switch (ecs
);
5314 if (!switch_back_to_stepped_thread (ecs
))
5318 case TARGET_WAITKIND_EXITED
:
5319 case TARGET_WAITKIND_SIGNALLED
:
5321 /* Depending on the system, ecs->ptid may point to a thread or
5322 to a process. On some targets, target_mourn_inferior may
5323 need to have access to the just-exited thread. That is the
5324 case of GNU/Linux's "checkpoint" support, for example.
5325 Call the switch_to_xxx routine as appropriate. */
5326 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5328 switch_to_thread (thr
);
5331 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5332 switch_to_inferior_no_thread (inf
);
5335 handle_vfork_child_exec_or_exit (0);
5336 target_terminal::ours (); /* Must do this before mourn anyway. */
5338 /* Clearing any previous state of convenience variables. */
5339 clear_exit_convenience_vars ();
5341 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5343 /* Record the exit code in the convenience variable $_exitcode, so
5344 that the user can inspect this again later. */
5345 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5346 (LONGEST
) ecs
->ws
.value
.integer
);
5348 /* Also record this in the inferior itself. */
5349 current_inferior ()->has_exit_code
= 1;
5350 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5352 /* Support the --return-child-result option. */
5353 return_child_result_value
= ecs
->ws
.value
.integer
;
5355 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5359 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5361 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5363 /* Set the value of the internal variable $_exitsignal,
5364 which holds the signal uncaught by the inferior. */
5365 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5366 gdbarch_gdb_signal_to_target (gdbarch
,
5367 ecs
->ws
.value
.sig
));
5371 /* We don't have access to the target's method used for
5372 converting between signal numbers (GDB's internal
5373 representation <-> target's representation).
5374 Therefore, we cannot do a good job at displaying this
5375 information to the user. It's better to just warn
5376 her about it (if infrun debugging is enabled), and
5379 fprintf_filtered (gdb_stdlog
, _("\
5380 Cannot fill $_exitsignal with the correct signal number.\n"));
5383 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5386 gdb_flush (gdb_stdout
);
5387 target_mourn_inferior (inferior_ptid
);
5388 stop_print_frame
= 0;
5392 case TARGET_WAITKIND_FORKED
:
5393 case TARGET_WAITKIND_VFORKED
:
5394 /* Check whether the inferior is displaced stepping. */
5396 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5397 struct gdbarch
*gdbarch
= regcache
->arch ();
5399 /* If checking displaced stepping is supported, and thread
5400 ecs->ptid is displaced stepping. */
5401 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5403 struct inferior
*parent_inf
5404 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5405 struct regcache
*child_regcache
;
5406 CORE_ADDR parent_pc
;
5408 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5410 struct displaced_step_inferior_state
*displaced
5411 = get_displaced_stepping_state (parent_inf
);
5413 /* Restore scratch pad for child process. */
5414 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5417 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5418 indicating that the displaced stepping of syscall instruction
5419 has been done. Perform cleanup for parent process here. Note
5420 that this operation also cleans up the child process for vfork,
5421 because their pages are shared. */
5422 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5423 /* Start a new step-over in another thread if there's one
5427 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5428 the child's PC is also within the scratchpad. Set the child's PC
5429 to the parent's PC value, which has already been fixed up.
5430 FIXME: we use the parent's aspace here, although we're touching
5431 the child, because the child hasn't been added to the inferior
5432 list yet at this point. */
5435 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5436 ecs
->ws
.value
.related_pid
,
5438 parent_inf
->aspace
);
5439 /* Read PC value of parent process. */
5440 parent_pc
= regcache_read_pc (regcache
);
5442 if (debug_displaced
)
5443 fprintf_unfiltered (gdb_stdlog
,
5444 "displaced: write child pc from %s to %s\n",
5446 regcache_read_pc (child_regcache
)),
5447 paddress (gdbarch
, parent_pc
));
5449 regcache_write_pc (child_regcache
, parent_pc
);
5453 context_switch (ecs
);
5455 /* Immediately detach breakpoints from the child before there's
5456 any chance of letting the user delete breakpoints from the
5457 breakpoint lists. If we don't do this early, it's easy to
5458 leave left over traps in the child, vis: "break foo; catch
5459 fork; c; <fork>; del; c; <child calls foo>". We only follow
5460 the fork on the last `continue', and by that time the
5461 breakpoint at "foo" is long gone from the breakpoint table.
5462 If we vforked, then we don't need to unpatch here, since both
5463 parent and child are sharing the same memory pages; we'll
5464 need to unpatch at follow/detach time instead to be certain
5465 that new breakpoints added between catchpoint hit time and
5466 vfork follow are detached. */
5467 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5469 /* This won't actually modify the breakpoint list, but will
5470 physically remove the breakpoints from the child. */
5471 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5474 delete_just_stopped_threads_single_step_breakpoints ();
5476 /* In case the event is caught by a catchpoint, remember that
5477 the event is to be followed at the next resume of the thread,
5478 and not immediately. */
5479 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5481 ecs
->event_thread
->suspend
.stop_pc
5482 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5484 ecs
->event_thread
->control
.stop_bpstat
5485 = bpstat_stop_status (get_current_regcache ()->aspace (),
5486 ecs
->event_thread
->suspend
.stop_pc
,
5487 ecs
->event_thread
, &ecs
->ws
);
5489 if (handle_stop_requested (ecs
))
5492 /* If no catchpoint triggered for this, then keep going. Note
5493 that we're interested in knowing the bpstat actually causes a
5494 stop, not just if it may explain the signal. Software
5495 watchpoints, for example, always appear in the bpstat. */
5496 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5499 = (follow_fork_mode_string
== follow_fork_mode_child
);
5501 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5503 process_stratum_target
*targ
5504 = ecs
->event_thread
->inf
->process_target ();
5506 bool should_resume
= follow_fork ();
5508 /* Note that one of these may be an invalid pointer,
5509 depending on detach_fork. */
5510 thread_info
*parent
= ecs
->event_thread
;
5512 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5514 /* At this point, the parent is marked running, and the
5515 child is marked stopped. */
5517 /* If not resuming the parent, mark it stopped. */
5518 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5519 parent
->set_running (false);
5521 /* If resuming the child, mark it running. */
5522 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5523 child
->set_running (true);
5525 /* In non-stop mode, also resume the other branch. */
5526 if (!detach_fork
&& (non_stop
5527 || (sched_multi
&& target_is_non_stop_p ())))
5530 switch_to_thread (parent
);
5532 switch_to_thread (child
);
5534 ecs
->event_thread
= inferior_thread ();
5535 ecs
->ptid
= inferior_ptid
;
5540 switch_to_thread (child
);
5542 switch_to_thread (parent
);
5544 ecs
->event_thread
= inferior_thread ();
5545 ecs
->ptid
= inferior_ptid
;
5553 process_event_stop_test (ecs
);
5556 case TARGET_WAITKIND_VFORK_DONE
:
5557 /* Done with the shared memory region. Re-insert breakpoints in
5558 the parent, and keep going. */
5560 context_switch (ecs
);
5562 current_inferior ()->waiting_for_vfork_done
= 0;
5563 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5565 if (handle_stop_requested (ecs
))
5568 /* This also takes care of reinserting breakpoints in the
5569 previously locked inferior. */
5573 case TARGET_WAITKIND_EXECD
:
5575 /* Note we can't read registers yet (the stop_pc), because we
5576 don't yet know the inferior's post-exec architecture.
5577 'stop_pc' is explicitly read below instead. */
5578 switch_to_thread_no_regs (ecs
->event_thread
);
5580 /* Do whatever is necessary to the parent branch of the vfork. */
5581 handle_vfork_child_exec_or_exit (1);
5583 /* This causes the eventpoints and symbol table to be reset.
5584 Must do this now, before trying to determine whether to
5586 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5588 /* In follow_exec we may have deleted the original thread and
5589 created a new one. Make sure that the event thread is the
5590 execd thread for that case (this is a nop otherwise). */
5591 ecs
->event_thread
= inferior_thread ();
5593 ecs
->event_thread
->suspend
.stop_pc
5594 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5596 ecs
->event_thread
->control
.stop_bpstat
5597 = bpstat_stop_status (get_current_regcache ()->aspace (),
5598 ecs
->event_thread
->suspend
.stop_pc
,
5599 ecs
->event_thread
, &ecs
->ws
);
5601 /* Note that this may be referenced from inside
5602 bpstat_stop_status above, through inferior_has_execd. */
5603 xfree (ecs
->ws
.value
.execd_pathname
);
5604 ecs
->ws
.value
.execd_pathname
= NULL
;
5606 if (handle_stop_requested (ecs
))
5609 /* If no catchpoint triggered for this, then keep going. */
5610 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5612 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5616 process_event_stop_test (ecs
);
5619 /* Be careful not to try to gather much state about a thread
5620 that's in a syscall. It's frequently a losing proposition. */
5621 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5622 /* Getting the current syscall number. */
5623 if (handle_syscall_event (ecs
) == 0)
5624 process_event_stop_test (ecs
);
5627 /* Before examining the threads further, step this thread to
5628 get it entirely out of the syscall. (We get notice of the
5629 event when the thread is just on the verge of exiting a
5630 syscall. Stepping one instruction seems to get it back
5632 case TARGET_WAITKIND_SYSCALL_RETURN
:
5633 if (handle_syscall_event (ecs
) == 0)
5634 process_event_stop_test (ecs
);
5637 case TARGET_WAITKIND_STOPPED
:
5638 handle_signal_stop (ecs
);
5641 case TARGET_WAITKIND_NO_HISTORY
:
5642 /* Reverse execution: target ran out of history info. */
5644 /* Switch to the stopped thread. */
5645 context_switch (ecs
);
5647 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5649 delete_just_stopped_threads_single_step_breakpoints ();
5650 ecs
->event_thread
->suspend
.stop_pc
5651 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5653 if (handle_stop_requested (ecs
))
5656 gdb::observers::no_history
.notify ();
5662 /* Restart threads back to what they were trying to do back when we
5663 paused them for an in-line step-over. The EVENT_THREAD thread is
5667 restart_threads (struct thread_info
*event_thread
)
5669 /* In case the instruction just stepped spawned a new thread. */
5670 update_thread_list ();
5672 for (thread_info
*tp
: all_non_exited_threads ())
5674 switch_to_thread_no_regs (tp
);
5676 if (tp
== event_thread
)
5679 fprintf_unfiltered (gdb_stdlog
,
5680 "infrun: restart threads: "
5681 "[%s] is event thread\n",
5682 target_pid_to_str (tp
->ptid
).c_str ());
5686 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5689 fprintf_unfiltered (gdb_stdlog
,
5690 "infrun: restart threads: "
5691 "[%s] not meant to be running\n",
5692 target_pid_to_str (tp
->ptid
).c_str ());
5699 fprintf_unfiltered (gdb_stdlog
,
5700 "infrun: restart threads: [%s] resumed\n",
5701 target_pid_to_str (tp
->ptid
).c_str ());
5702 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5706 if (thread_is_in_step_over_chain (tp
))
5709 fprintf_unfiltered (gdb_stdlog
,
5710 "infrun: restart threads: "
5711 "[%s] needs step-over\n",
5712 target_pid_to_str (tp
->ptid
).c_str ());
5713 gdb_assert (!tp
->resumed
);
5718 if (tp
->suspend
.waitstatus_pending_p
)
5721 fprintf_unfiltered (gdb_stdlog
,
5722 "infrun: restart threads: "
5723 "[%s] has pending status\n",
5724 target_pid_to_str (tp
->ptid
).c_str ());
5729 gdb_assert (!tp
->stop_requested
);
5731 /* If some thread needs to start a step-over at this point, it
5732 should still be in the step-over queue, and thus skipped
5734 if (thread_still_needs_step_over (tp
))
5736 internal_error (__FILE__
, __LINE__
,
5737 "thread [%s] needs a step-over, but not in "
5738 "step-over queue\n",
5739 target_pid_to_str (tp
->ptid
).c_str ());
5742 if (currently_stepping (tp
))
5745 fprintf_unfiltered (gdb_stdlog
,
5746 "infrun: restart threads: [%s] was stepping\n",
5747 target_pid_to_str (tp
->ptid
).c_str ());
5748 keep_going_stepped_thread (tp
);
5752 struct execution_control_state ecss
;
5753 struct execution_control_state
*ecs
= &ecss
;
5756 fprintf_unfiltered (gdb_stdlog
,
5757 "infrun: restart threads: [%s] continuing\n",
5758 target_pid_to_str (tp
->ptid
).c_str ());
5759 reset_ecs (ecs
, tp
);
5760 switch_to_thread (tp
);
5761 keep_going_pass_signal (ecs
);
5766 /* Callback for iterate_over_threads. Find a resumed thread that has
5767 a pending waitstatus. */
5770 resumed_thread_with_pending_status (struct thread_info
*tp
,
5774 && tp
->suspend
.waitstatus_pending_p
);
5777 /* Called when we get an event that may finish an in-line or
5778 out-of-line (displaced stepping) step-over started previously.
5779 Return true if the event is processed and we should go back to the
5780 event loop; false if the caller should continue processing the
5784 finish_step_over (struct execution_control_state
*ecs
)
5786 int had_step_over_info
;
5788 displaced_step_fixup (ecs
->event_thread
,
5789 ecs
->event_thread
->suspend
.stop_signal
);
5791 had_step_over_info
= step_over_info_valid_p ();
5793 if (had_step_over_info
)
5795 /* If we're stepping over a breakpoint with all threads locked,
5796 then only the thread that was stepped should be reporting
5798 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5800 clear_step_over_info ();
5803 if (!target_is_non_stop_p ())
5806 /* Start a new step-over in another thread if there's one that
5810 /* If we were stepping over a breakpoint before, and haven't started
5811 a new in-line step-over sequence, then restart all other threads
5812 (except the event thread). We can't do this in all-stop, as then
5813 e.g., we wouldn't be able to issue any other remote packet until
5814 these other threads stop. */
5815 if (had_step_over_info
&& !step_over_info_valid_p ())
5817 struct thread_info
*pending
;
5819 /* If we only have threads with pending statuses, the restart
5820 below won't restart any thread and so nothing re-inserts the
5821 breakpoint we just stepped over. But we need it inserted
5822 when we later process the pending events, otherwise if
5823 another thread has a pending event for this breakpoint too,
5824 we'd discard its event (because the breakpoint that
5825 originally caused the event was no longer inserted). */
5826 context_switch (ecs
);
5827 insert_breakpoints ();
5829 restart_threads (ecs
->event_thread
);
5831 /* If we have events pending, go through handle_inferior_event
5832 again, picking up a pending event at random. This avoids
5833 thread starvation. */
5835 /* But not if we just stepped over a watchpoint in order to let
5836 the instruction execute so we can evaluate its expression.
5837 The set of watchpoints that triggered is recorded in the
5838 breakpoint objects themselves (see bp->watchpoint_triggered).
5839 If we processed another event first, that other event could
5840 clobber this info. */
5841 if (ecs
->event_thread
->stepping_over_watchpoint
)
5844 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5846 if (pending
!= NULL
)
5848 struct thread_info
*tp
= ecs
->event_thread
;
5849 struct regcache
*regcache
;
5853 fprintf_unfiltered (gdb_stdlog
,
5854 "infrun: found resumed threads with "
5855 "pending events, saving status\n");
5858 gdb_assert (pending
!= tp
);
5860 /* Record the event thread's event for later. */
5861 save_waitstatus (tp
, &ecs
->ws
);
5862 /* This was cleared early, by handle_inferior_event. Set it
5863 so this pending event is considered by
5867 gdb_assert (!tp
->executing
);
5869 regcache
= get_thread_regcache (tp
);
5870 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5874 fprintf_unfiltered (gdb_stdlog
,
5875 "infrun: saved stop_pc=%s for %s "
5876 "(currently_stepping=%d)\n",
5877 paddress (target_gdbarch (),
5878 tp
->suspend
.stop_pc
),
5879 target_pid_to_str (tp
->ptid
).c_str (),
5880 currently_stepping (tp
));
5883 /* This in-line step-over finished; clear this so we won't
5884 start a new one. This is what handle_signal_stop would
5885 do, if we returned false. */
5886 tp
->stepping_over_breakpoint
= 0;
5888 /* Wake up the event loop again. */
5889 mark_async_event_handler (infrun_async_inferior_event_token
);
5891 prepare_to_wait (ecs
);
5899 /* Come here when the program has stopped with a signal. */
5902 handle_signal_stop (struct execution_control_state
*ecs
)
5904 struct frame_info
*frame
;
5905 struct gdbarch
*gdbarch
;
5906 int stopped_by_watchpoint
;
5907 enum stop_kind stop_soon
;
5910 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5912 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5914 /* Do we need to clean up the state of a thread that has
5915 completed a displaced single-step? (Doing so usually affects
5916 the PC, so do it here, before we set stop_pc.) */
5917 if (finish_step_over (ecs
))
5920 /* If we either finished a single-step or hit a breakpoint, but
5921 the user wanted this thread to be stopped, pretend we got a
5922 SIG0 (generic unsignaled stop). */
5923 if (ecs
->event_thread
->stop_requested
5924 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5925 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5927 ecs
->event_thread
->suspend
.stop_pc
5928 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5932 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5933 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5935 switch_to_thread (ecs
->event_thread
);
5937 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5938 paddress (reg_gdbarch
,
5939 ecs
->event_thread
->suspend
.stop_pc
));
5940 if (target_stopped_by_watchpoint ())
5944 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5946 if (target_stopped_data_address (current_top_target (), &addr
))
5947 fprintf_unfiltered (gdb_stdlog
,
5948 "infrun: stopped data address = %s\n",
5949 paddress (reg_gdbarch
, addr
));
5951 fprintf_unfiltered (gdb_stdlog
,
5952 "infrun: (no data address available)\n");
5956 /* This is originated from start_remote(), start_inferior() and
5957 shared libraries hook functions. */
5958 stop_soon
= get_inferior_stop_soon (ecs
);
5959 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5961 context_switch (ecs
);
5963 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5964 stop_print_frame
= 1;
5969 /* This originates from attach_command(). We need to overwrite
5970 the stop_signal here, because some kernels don't ignore a
5971 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5972 See more comments in inferior.h. On the other hand, if we
5973 get a non-SIGSTOP, report it to the user - assume the backend
5974 will handle the SIGSTOP if it should show up later.
5976 Also consider that the attach is complete when we see a
5977 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5978 target extended-remote report it instead of a SIGSTOP
5979 (e.g. gdbserver). We already rely on SIGTRAP being our
5980 signal, so this is no exception.
5982 Also consider that the attach is complete when we see a
5983 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5984 the target to stop all threads of the inferior, in case the
5985 low level attach operation doesn't stop them implicitly. If
5986 they weren't stopped implicitly, then the stub will report a
5987 GDB_SIGNAL_0, meaning: stopped for no particular reason
5988 other than GDB's request. */
5989 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5990 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5991 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5992 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5994 stop_print_frame
= 1;
5996 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6000 /* See if something interesting happened to the non-current thread. If
6001 so, then switch to that thread. */
6002 if (ecs
->ptid
!= inferior_ptid
)
6005 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
6007 context_switch (ecs
);
6009 if (deprecated_context_hook
)
6010 deprecated_context_hook (ecs
->event_thread
->global_num
);
6013 /* At this point, get hold of the now-current thread's frame. */
6014 frame
= get_current_frame ();
6015 gdbarch
= get_frame_arch (frame
);
6017 /* Pull the single step breakpoints out of the target. */
6018 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
6020 struct regcache
*regcache
;
6023 regcache
= get_thread_regcache (ecs
->event_thread
);
6024 const address_space
*aspace
= regcache
->aspace ();
6026 pc
= regcache_read_pc (regcache
);
6028 /* However, before doing so, if this single-step breakpoint was
6029 actually for another thread, set this thread up for moving
6031 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
6034 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
6038 fprintf_unfiltered (gdb_stdlog
,
6039 "infrun: [%s] hit another thread's "
6040 "single-step breakpoint\n",
6041 target_pid_to_str (ecs
->ptid
).c_str ());
6043 ecs
->hit_singlestep_breakpoint
= 1;
6050 fprintf_unfiltered (gdb_stdlog
,
6051 "infrun: [%s] hit its "
6052 "single-step breakpoint\n",
6053 target_pid_to_str (ecs
->ptid
).c_str ());
6057 delete_just_stopped_threads_single_step_breakpoints ();
6059 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6060 && ecs
->event_thread
->control
.trap_expected
6061 && ecs
->event_thread
->stepping_over_watchpoint
)
6062 stopped_by_watchpoint
= 0;
6064 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
6066 /* If necessary, step over this watchpoint. We'll be back to display
6068 if (stopped_by_watchpoint
6069 && (target_have_steppable_watchpoint
6070 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6072 /* At this point, we are stopped at an instruction which has
6073 attempted to write to a piece of memory under control of
6074 a watchpoint. The instruction hasn't actually executed
6075 yet. If we were to evaluate the watchpoint expression
6076 now, we would get the old value, and therefore no change
6077 would seem to have occurred.
6079 In order to make watchpoints work `right', we really need
6080 to complete the memory write, and then evaluate the
6081 watchpoint expression. We do this by single-stepping the
6084 It may not be necessary to disable the watchpoint to step over
6085 it. For example, the PA can (with some kernel cooperation)
6086 single step over a watchpoint without disabling the watchpoint.
6088 It is far more common to need to disable a watchpoint to step
6089 the inferior over it. If we have non-steppable watchpoints,
6090 we must disable the current watchpoint; it's simplest to
6091 disable all watchpoints.
6093 Any breakpoint at PC must also be stepped over -- if there's
6094 one, it will have already triggered before the watchpoint
6095 triggered, and we either already reported it to the user, or
6096 it didn't cause a stop and we called keep_going. In either
6097 case, if there was a breakpoint at PC, we must be trying to
6099 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6104 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6105 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6106 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6107 ecs
->event_thread
->control
.stop_step
= 0;
6108 stop_print_frame
= 1;
6109 stopped_by_random_signal
= 0;
6110 bpstat stop_chain
= NULL
;
6112 /* Hide inlined functions starting here, unless we just performed stepi or
6113 nexti. After stepi and nexti, always show the innermost frame (not any
6114 inline function call sites). */
6115 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6117 const address_space
*aspace
6118 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6120 /* skip_inline_frames is expensive, so we avoid it if we can
6121 determine that the address is one where functions cannot have
6122 been inlined. This improves performance with inferiors that
6123 load a lot of shared libraries, because the solib event
6124 breakpoint is defined as the address of a function (i.e. not
6125 inline). Note that we have to check the previous PC as well
6126 as the current one to catch cases when we have just
6127 single-stepped off a breakpoint prior to reinstating it.
6128 Note that we're assuming that the code we single-step to is
6129 not inline, but that's not definitive: there's nothing
6130 preventing the event breakpoint function from containing
6131 inlined code, and the single-step ending up there. If the
6132 user had set a breakpoint on that inlined code, the missing
6133 skip_inline_frames call would break things. Fortunately
6134 that's an extremely unlikely scenario. */
6135 if (!pc_at_non_inline_function (aspace
,
6136 ecs
->event_thread
->suspend
.stop_pc
,
6138 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6139 && ecs
->event_thread
->control
.trap_expected
6140 && pc_at_non_inline_function (aspace
,
6141 ecs
->event_thread
->prev_pc
,
6144 stop_chain
= build_bpstat_chain (aspace
,
6145 ecs
->event_thread
->suspend
.stop_pc
,
6147 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6149 /* Re-fetch current thread's frame in case that invalidated
6151 frame
= get_current_frame ();
6152 gdbarch
= get_frame_arch (frame
);
6156 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6157 && ecs
->event_thread
->control
.trap_expected
6158 && gdbarch_single_step_through_delay_p (gdbarch
)
6159 && currently_stepping (ecs
->event_thread
))
6161 /* We're trying to step off a breakpoint. Turns out that we're
6162 also on an instruction that needs to be stepped multiple
6163 times before it's been fully executing. E.g., architectures
6164 with a delay slot. It needs to be stepped twice, once for
6165 the instruction and once for the delay slot. */
6166 int step_through_delay
6167 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6169 if (debug_infrun
&& step_through_delay
)
6170 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6171 if (ecs
->event_thread
->control
.step_range_end
== 0
6172 && step_through_delay
)
6174 /* The user issued a continue when stopped at a breakpoint.
6175 Set up for another trap and get out of here. */
6176 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6180 else if (step_through_delay
)
6182 /* The user issued a step when stopped at a breakpoint.
6183 Maybe we should stop, maybe we should not - the delay
6184 slot *might* correspond to a line of source. In any
6185 case, don't decide that here, just set
6186 ecs->stepping_over_breakpoint, making sure we
6187 single-step again before breakpoints are re-inserted. */
6188 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6192 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6193 handles this event. */
6194 ecs
->event_thread
->control
.stop_bpstat
6195 = bpstat_stop_status (get_current_regcache ()->aspace (),
6196 ecs
->event_thread
->suspend
.stop_pc
,
6197 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6199 /* Following in case break condition called a
6201 stop_print_frame
= 1;
6203 /* This is where we handle "moribund" watchpoints. Unlike
6204 software breakpoints traps, hardware watchpoint traps are
6205 always distinguishable from random traps. If no high-level
6206 watchpoint is associated with the reported stop data address
6207 anymore, then the bpstat does not explain the signal ---
6208 simply make sure to ignore it if `stopped_by_watchpoint' is
6212 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6213 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6215 && stopped_by_watchpoint
)
6216 fprintf_unfiltered (gdb_stdlog
,
6217 "infrun: no user watchpoint explains "
6218 "watchpoint SIGTRAP, ignoring\n");
6220 /* NOTE: cagney/2003-03-29: These checks for a random signal
6221 at one stage in the past included checks for an inferior
6222 function call's call dummy's return breakpoint. The original
6223 comment, that went with the test, read:
6225 ``End of a stack dummy. Some systems (e.g. Sony news) give
6226 another signal besides SIGTRAP, so check here as well as
6229 If someone ever tries to get call dummys on a
6230 non-executable stack to work (where the target would stop
6231 with something like a SIGSEGV), then those tests might need
6232 to be re-instated. Given, however, that the tests were only
6233 enabled when momentary breakpoints were not being used, I
6234 suspect that it won't be the case.
6236 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6237 be necessary for call dummies on a non-executable stack on
6240 /* See if the breakpoints module can explain the signal. */
6242 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6243 ecs
->event_thread
->suspend
.stop_signal
);
6245 /* Maybe this was a trap for a software breakpoint that has since
6247 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6249 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6250 ecs
->event_thread
->suspend
.stop_pc
))
6252 struct regcache
*regcache
;
6255 /* Re-adjust PC to what the program would see if GDB was not
6257 regcache
= get_thread_regcache (ecs
->event_thread
);
6258 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6261 gdb::optional
<scoped_restore_tmpl
<int>>
6262 restore_operation_disable
;
6264 if (record_full_is_used ())
6265 restore_operation_disable
.emplace
6266 (record_full_gdb_operation_disable_set ());
6268 regcache_write_pc (regcache
,
6269 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6274 /* A delayed software breakpoint event. Ignore the trap. */
6276 fprintf_unfiltered (gdb_stdlog
,
6277 "infrun: delayed software breakpoint "
6278 "trap, ignoring\n");
6283 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6284 has since been removed. */
6285 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6287 /* A delayed hardware breakpoint event. Ignore the trap. */
6289 fprintf_unfiltered (gdb_stdlog
,
6290 "infrun: delayed hardware breakpoint/watchpoint "
6291 "trap, ignoring\n");
6295 /* If not, perhaps stepping/nexting can. */
6297 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6298 && currently_stepping (ecs
->event_thread
));
6300 /* Perhaps the thread hit a single-step breakpoint of _another_
6301 thread. Single-step breakpoints are transparent to the
6302 breakpoints module. */
6304 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6306 /* No? Perhaps we got a moribund watchpoint. */
6308 random_signal
= !stopped_by_watchpoint
;
6310 /* Always stop if the user explicitly requested this thread to
6312 if (ecs
->event_thread
->stop_requested
)
6316 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6319 /* For the program's own signals, act according to
6320 the signal handling tables. */
6324 /* Signal not for debugging purposes. */
6325 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6326 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6329 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6330 gdb_signal_to_symbol_string (stop_signal
));
6332 stopped_by_random_signal
= 1;
6334 /* Always stop on signals if we're either just gaining control
6335 of the program, or the user explicitly requested this thread
6336 to remain stopped. */
6337 if (stop_soon
!= NO_STOP_QUIETLY
6338 || ecs
->event_thread
->stop_requested
6340 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6346 /* Notify observers the signal has "handle print" set. Note we
6347 returned early above if stopping; normal_stop handles the
6348 printing in that case. */
6349 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6351 /* The signal table tells us to print about this signal. */
6352 target_terminal::ours_for_output ();
6353 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6354 target_terminal::inferior ();
6357 /* Clear the signal if it should not be passed. */
6358 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6359 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6361 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6362 && ecs
->event_thread
->control
.trap_expected
6363 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6365 /* We were just starting a new sequence, attempting to
6366 single-step off of a breakpoint and expecting a SIGTRAP.
6367 Instead this signal arrives. This signal will take us out
6368 of the stepping range so GDB needs to remember to, when
6369 the signal handler returns, resume stepping off that
6371 /* To simplify things, "continue" is forced to use the same
6372 code paths as single-step - set a breakpoint at the
6373 signal return address and then, once hit, step off that
6376 fprintf_unfiltered (gdb_stdlog
,
6377 "infrun: signal arrived while stepping over "
6380 insert_hp_step_resume_breakpoint_at_frame (frame
);
6381 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6382 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6383 ecs
->event_thread
->control
.trap_expected
= 0;
6385 /* If we were nexting/stepping some other thread, switch to
6386 it, so that we don't continue it, losing control. */
6387 if (!switch_back_to_stepped_thread (ecs
))
6392 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6393 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6395 || ecs
->event_thread
->control
.step_range_end
== 1)
6396 && frame_id_eq (get_stack_frame_id (frame
),
6397 ecs
->event_thread
->control
.step_stack_frame_id
)
6398 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6400 /* The inferior is about to take a signal that will take it
6401 out of the single step range. Set a breakpoint at the
6402 current PC (which is presumably where the signal handler
6403 will eventually return) and then allow the inferior to
6406 Note that this is only needed for a signal delivered
6407 while in the single-step range. Nested signals aren't a
6408 problem as they eventually all return. */
6410 fprintf_unfiltered (gdb_stdlog
,
6411 "infrun: signal may take us out of "
6412 "single-step range\n");
6414 clear_step_over_info ();
6415 insert_hp_step_resume_breakpoint_at_frame (frame
);
6416 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6417 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6418 ecs
->event_thread
->control
.trap_expected
= 0;
6423 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6424 when either there's a nested signal, or when there's a
6425 pending signal enabled just as the signal handler returns
6426 (leaving the inferior at the step-resume-breakpoint without
6427 actually executing it). Either way continue until the
6428 breakpoint is really hit. */
6430 if (!switch_back_to_stepped_thread (ecs
))
6433 fprintf_unfiltered (gdb_stdlog
,
6434 "infrun: random signal, keep going\n");
6441 process_event_stop_test (ecs
);
6444 /* Come here when we've got some debug event / signal we can explain
6445 (IOW, not a random signal), and test whether it should cause a
6446 stop, or whether we should resume the inferior (transparently).
6447 E.g., could be a breakpoint whose condition evaluates false; we
6448 could be still stepping within the line; etc. */
6451 process_event_stop_test (struct execution_control_state
*ecs
)
6453 struct symtab_and_line stop_pc_sal
;
6454 struct frame_info
*frame
;
6455 struct gdbarch
*gdbarch
;
6456 CORE_ADDR jmp_buf_pc
;
6457 struct bpstat_what what
;
6459 /* Handle cases caused by hitting a breakpoint. */
6461 frame
= get_current_frame ();
6462 gdbarch
= get_frame_arch (frame
);
6464 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6466 if (what
.call_dummy
)
6468 stop_stack_dummy
= what
.call_dummy
;
6471 /* A few breakpoint types have callbacks associated (e.g.,
6472 bp_jit_event). Run them now. */
6473 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6475 /* If we hit an internal event that triggers symbol changes, the
6476 current frame will be invalidated within bpstat_what (e.g., if we
6477 hit an internal solib event). Re-fetch it. */
6478 frame
= get_current_frame ();
6479 gdbarch
= get_frame_arch (frame
);
6481 switch (what
.main_action
)
6483 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6484 /* If we hit the breakpoint at longjmp while stepping, we
6485 install a momentary breakpoint at the target of the
6489 fprintf_unfiltered (gdb_stdlog
,
6490 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6492 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6494 if (what
.is_longjmp
)
6496 struct value
*arg_value
;
6498 /* If we set the longjmp breakpoint via a SystemTap probe,
6499 then use it to extract the arguments. The destination PC
6500 is the third argument to the probe. */
6501 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6504 jmp_buf_pc
= value_as_address (arg_value
);
6505 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6507 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6508 || !gdbarch_get_longjmp_target (gdbarch
,
6509 frame
, &jmp_buf_pc
))
6512 fprintf_unfiltered (gdb_stdlog
,
6513 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6514 "(!gdbarch_get_longjmp_target)\n");
6519 /* Insert a breakpoint at resume address. */
6520 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6523 check_exception_resume (ecs
, frame
);
6527 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6529 struct frame_info
*init_frame
;
6531 /* There are several cases to consider.
6533 1. The initiating frame no longer exists. In this case we
6534 must stop, because the exception or longjmp has gone too
6537 2. The initiating frame exists, and is the same as the
6538 current frame. We stop, because the exception or longjmp
6541 3. The initiating frame exists and is different from the
6542 current frame. This means the exception or longjmp has
6543 been caught beneath the initiating frame, so keep going.
6545 4. longjmp breakpoint has been placed just to protect
6546 against stale dummy frames and user is not interested in
6547 stopping around longjmps. */
6550 fprintf_unfiltered (gdb_stdlog
,
6551 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6553 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6555 delete_exception_resume_breakpoint (ecs
->event_thread
);
6557 if (what
.is_longjmp
)
6559 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6561 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6569 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6573 struct frame_id current_id
6574 = get_frame_id (get_current_frame ());
6575 if (frame_id_eq (current_id
,
6576 ecs
->event_thread
->initiating_frame
))
6578 /* Case 2. Fall through. */
6588 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6590 delete_step_resume_breakpoint (ecs
->event_thread
);
6592 end_stepping_range (ecs
);
6596 case BPSTAT_WHAT_SINGLE
:
6598 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6599 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6600 /* Still need to check other stuff, at least the case where we
6601 are stepping and step out of the right range. */
6604 case BPSTAT_WHAT_STEP_RESUME
:
6606 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6608 delete_step_resume_breakpoint (ecs
->event_thread
);
6609 if (ecs
->event_thread
->control
.proceed_to_finish
6610 && execution_direction
== EXEC_REVERSE
)
6612 struct thread_info
*tp
= ecs
->event_thread
;
6614 /* We are finishing a function in reverse, and just hit the
6615 step-resume breakpoint at the start address of the
6616 function, and we're almost there -- just need to back up
6617 by one more single-step, which should take us back to the
6619 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6623 fill_in_stop_func (gdbarch
, ecs
);
6624 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6625 && execution_direction
== EXEC_REVERSE
)
6627 /* We are stepping over a function call in reverse, and just
6628 hit the step-resume breakpoint at the start address of
6629 the function. Go back to single-stepping, which should
6630 take us back to the function call. */
6631 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6637 case BPSTAT_WHAT_STOP_NOISY
:
6639 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6640 stop_print_frame
= 1;
6642 /* Assume the thread stopped for a breapoint. We'll still check
6643 whether a/the breakpoint is there when the thread is next
6645 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6650 case BPSTAT_WHAT_STOP_SILENT
:
6652 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6653 stop_print_frame
= 0;
6655 /* Assume the thread stopped for a breapoint. We'll still check
6656 whether a/the breakpoint is there when the thread is next
6658 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6662 case BPSTAT_WHAT_HP_STEP_RESUME
:
6664 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6666 delete_step_resume_breakpoint (ecs
->event_thread
);
6667 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6669 /* Back when the step-resume breakpoint was inserted, we
6670 were trying to single-step off a breakpoint. Go back to
6672 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6673 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6679 case BPSTAT_WHAT_KEEP_CHECKING
:
6683 /* If we stepped a permanent breakpoint and we had a high priority
6684 step-resume breakpoint for the address we stepped, but we didn't
6685 hit it, then we must have stepped into the signal handler. The
6686 step-resume was only necessary to catch the case of _not_
6687 stepping into the handler, so delete it, and fall through to
6688 checking whether the step finished. */
6689 if (ecs
->event_thread
->stepped_breakpoint
)
6691 struct breakpoint
*sr_bp
6692 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6695 && sr_bp
->loc
->permanent
6696 && sr_bp
->type
== bp_hp_step_resume
6697 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6700 fprintf_unfiltered (gdb_stdlog
,
6701 "infrun: stepped permanent breakpoint, stopped in "
6703 delete_step_resume_breakpoint (ecs
->event_thread
);
6704 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6708 /* We come here if we hit a breakpoint but should not stop for it.
6709 Possibly we also were stepping and should stop for that. So fall
6710 through and test for stepping. But, if not stepping, do not
6713 /* In all-stop mode, if we're currently stepping but have stopped in
6714 some other thread, we need to switch back to the stepped thread. */
6715 if (switch_back_to_stepped_thread (ecs
))
6718 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6721 fprintf_unfiltered (gdb_stdlog
,
6722 "infrun: step-resume breakpoint is inserted\n");
6724 /* Having a step-resume breakpoint overrides anything
6725 else having to do with stepping commands until
6726 that breakpoint is reached. */
6731 if (ecs
->event_thread
->control
.step_range_end
== 0)
6734 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6735 /* Likewise if we aren't even stepping. */
6740 /* Re-fetch current thread's frame in case the code above caused
6741 the frame cache to be re-initialized, making our FRAME variable
6742 a dangling pointer. */
6743 frame
= get_current_frame ();
6744 gdbarch
= get_frame_arch (frame
);
6745 fill_in_stop_func (gdbarch
, ecs
);
6747 /* If stepping through a line, keep going if still within it.
6749 Note that step_range_end is the address of the first instruction
6750 beyond the step range, and NOT the address of the last instruction
6753 Note also that during reverse execution, we may be stepping
6754 through a function epilogue and therefore must detect when
6755 the current-frame changes in the middle of a line. */
6757 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6759 && (execution_direction
!= EXEC_REVERSE
6760 || frame_id_eq (get_frame_id (frame
),
6761 ecs
->event_thread
->control
.step_frame_id
)))
6765 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6766 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6767 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6769 /* Tentatively re-enable range stepping; `resume' disables it if
6770 necessary (e.g., if we're stepping over a breakpoint or we
6771 have software watchpoints). */
6772 ecs
->event_thread
->control
.may_range_step
= 1;
6774 /* When stepping backward, stop at beginning of line range
6775 (unless it's the function entry point, in which case
6776 keep going back to the call point). */
6777 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6778 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6779 && stop_pc
!= ecs
->stop_func_start
6780 && execution_direction
== EXEC_REVERSE
)
6781 end_stepping_range (ecs
);
6788 /* We stepped out of the stepping range. */
6790 /* If we are stepping at the source level and entered the runtime
6791 loader dynamic symbol resolution code...
6793 EXEC_FORWARD: we keep on single stepping until we exit the run
6794 time loader code and reach the callee's address.
6796 EXEC_REVERSE: we've already executed the callee (backward), and
6797 the runtime loader code is handled just like any other
6798 undebuggable function call. Now we need only keep stepping
6799 backward through the trampoline code, and that's handled further
6800 down, so there is nothing for us to do here. */
6802 if (execution_direction
!= EXEC_REVERSE
6803 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6804 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6806 CORE_ADDR pc_after_resolver
=
6807 gdbarch_skip_solib_resolver (gdbarch
,
6808 ecs
->event_thread
->suspend
.stop_pc
);
6811 fprintf_unfiltered (gdb_stdlog
,
6812 "infrun: stepped into dynsym resolve code\n");
6814 if (pc_after_resolver
)
6816 /* Set up a step-resume breakpoint at the address
6817 indicated by SKIP_SOLIB_RESOLVER. */
6818 symtab_and_line sr_sal
;
6819 sr_sal
.pc
= pc_after_resolver
;
6820 sr_sal
.pspace
= get_frame_program_space (frame
);
6822 insert_step_resume_breakpoint_at_sal (gdbarch
,
6823 sr_sal
, null_frame_id
);
6830 /* Step through an indirect branch thunk. */
6831 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6832 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6833 ecs
->event_thread
->suspend
.stop_pc
))
6836 fprintf_unfiltered (gdb_stdlog
,
6837 "infrun: stepped into indirect branch thunk\n");
6842 if (ecs
->event_thread
->control
.step_range_end
!= 1
6843 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6844 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6845 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6848 fprintf_unfiltered (gdb_stdlog
,
6849 "infrun: stepped into signal trampoline\n");
6850 /* The inferior, while doing a "step" or "next", has ended up in
6851 a signal trampoline (either by a signal being delivered or by
6852 the signal handler returning). Just single-step until the
6853 inferior leaves the trampoline (either by calling the handler
6859 /* If we're in the return path from a shared library trampoline,
6860 we want to proceed through the trampoline when stepping. */
6861 /* macro/2012-04-25: This needs to come before the subroutine
6862 call check below as on some targets return trampolines look
6863 like subroutine calls (MIPS16 return thunks). */
6864 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6865 ecs
->event_thread
->suspend
.stop_pc
,
6866 ecs
->stop_func_name
)
6867 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6869 /* Determine where this trampoline returns. */
6870 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6871 CORE_ADDR real_stop_pc
6872 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6875 fprintf_unfiltered (gdb_stdlog
,
6876 "infrun: stepped into solib return tramp\n");
6878 /* Only proceed through if we know where it's going. */
6881 /* And put the step-breakpoint there and go until there. */
6882 symtab_and_line sr_sal
;
6883 sr_sal
.pc
= real_stop_pc
;
6884 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6885 sr_sal
.pspace
= get_frame_program_space (frame
);
6887 /* Do not specify what the fp should be when we stop since
6888 on some machines the prologue is where the new fp value
6890 insert_step_resume_breakpoint_at_sal (gdbarch
,
6891 sr_sal
, null_frame_id
);
6893 /* Restart without fiddling with the step ranges or
6900 /* Check for subroutine calls. The check for the current frame
6901 equalling the step ID is not necessary - the check of the
6902 previous frame's ID is sufficient - but it is a common case and
6903 cheaper than checking the previous frame's ID.
6905 NOTE: frame_id_eq will never report two invalid frame IDs as
6906 being equal, so to get into this block, both the current and
6907 previous frame must have valid frame IDs. */
6908 /* The outer_frame_id check is a heuristic to detect stepping
6909 through startup code. If we step over an instruction which
6910 sets the stack pointer from an invalid value to a valid value,
6911 we may detect that as a subroutine call from the mythical
6912 "outermost" function. This could be fixed by marking
6913 outermost frames as !stack_p,code_p,special_p. Then the
6914 initial outermost frame, before sp was valid, would
6915 have code_addr == &_start. See the comment in frame_id_eq
6917 if (!frame_id_eq (get_stack_frame_id (frame
),
6918 ecs
->event_thread
->control
.step_stack_frame_id
)
6919 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6920 ecs
->event_thread
->control
.step_stack_frame_id
)
6921 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6923 || (ecs
->event_thread
->control
.step_start_function
6924 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6926 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6927 CORE_ADDR real_stop_pc
;
6930 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6932 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6934 /* I presume that step_over_calls is only 0 when we're
6935 supposed to be stepping at the assembly language level
6936 ("stepi"). Just stop. */
6937 /* And this works the same backward as frontward. MVS */
6938 end_stepping_range (ecs
);
6942 /* Reverse stepping through solib trampolines. */
6944 if (execution_direction
== EXEC_REVERSE
6945 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6946 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6947 || (ecs
->stop_func_start
== 0
6948 && in_solib_dynsym_resolve_code (stop_pc
))))
6950 /* Any solib trampoline code can be handled in reverse
6951 by simply continuing to single-step. We have already
6952 executed the solib function (backwards), and a few
6953 steps will take us back through the trampoline to the
6959 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6961 /* We're doing a "next".
6963 Normal (forward) execution: set a breakpoint at the
6964 callee's return address (the address at which the caller
6967 Reverse (backward) execution. set the step-resume
6968 breakpoint at the start of the function that we just
6969 stepped into (backwards), and continue to there. When we
6970 get there, we'll need to single-step back to the caller. */
6972 if (execution_direction
== EXEC_REVERSE
)
6974 /* If we're already at the start of the function, we've either
6975 just stepped backward into a single instruction function,
6976 or stepped back out of a signal handler to the first instruction
6977 of the function. Just keep going, which will single-step back
6979 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6981 /* Normal function call return (static or dynamic). */
6982 symtab_and_line sr_sal
;
6983 sr_sal
.pc
= ecs
->stop_func_start
;
6984 sr_sal
.pspace
= get_frame_program_space (frame
);
6985 insert_step_resume_breakpoint_at_sal (gdbarch
,
6986 sr_sal
, null_frame_id
);
6990 insert_step_resume_breakpoint_at_caller (frame
);
6996 /* If we are in a function call trampoline (a stub between the
6997 calling routine and the real function), locate the real
6998 function. That's what tells us (a) whether we want to step
6999 into it at all, and (b) what prologue we want to run to the
7000 end of, if we do step into it. */
7001 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
7002 if (real_stop_pc
== 0)
7003 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
7004 if (real_stop_pc
!= 0)
7005 ecs
->stop_func_start
= real_stop_pc
;
7007 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
7009 symtab_and_line sr_sal
;
7010 sr_sal
.pc
= ecs
->stop_func_start
;
7011 sr_sal
.pspace
= get_frame_program_space (frame
);
7013 insert_step_resume_breakpoint_at_sal (gdbarch
,
7014 sr_sal
, null_frame_id
);
7019 /* If we have line number information for the function we are
7020 thinking of stepping into and the function isn't on the skip
7023 If there are several symtabs at that PC (e.g. with include
7024 files), just want to know whether *any* of them have line
7025 numbers. find_pc_line handles this. */
7027 struct symtab_and_line tmp_sal
;
7029 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7030 if (tmp_sal
.line
!= 0
7031 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
7033 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
7035 if (execution_direction
== EXEC_REVERSE
)
7036 handle_step_into_function_backward (gdbarch
, ecs
);
7038 handle_step_into_function (gdbarch
, ecs
);
7043 /* If we have no line number and the step-stop-if-no-debug is
7044 set, we stop the step so that the user has a chance to switch
7045 in assembly mode. */
7046 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7047 && step_stop_if_no_debug
)
7049 end_stepping_range (ecs
);
7053 if (execution_direction
== EXEC_REVERSE
)
7055 /* If we're already at the start of the function, we've either just
7056 stepped backward into a single instruction function without line
7057 number info, or stepped back out of a signal handler to the first
7058 instruction of the function without line number info. Just keep
7059 going, which will single-step back to the caller. */
7060 if (ecs
->stop_func_start
!= stop_pc
)
7062 /* Set a breakpoint at callee's start address.
7063 From there we can step once and be back in the caller. */
7064 symtab_and_line sr_sal
;
7065 sr_sal
.pc
= ecs
->stop_func_start
;
7066 sr_sal
.pspace
= get_frame_program_space (frame
);
7067 insert_step_resume_breakpoint_at_sal (gdbarch
,
7068 sr_sal
, null_frame_id
);
7072 /* Set a breakpoint at callee's return address (the address
7073 at which the caller will resume). */
7074 insert_step_resume_breakpoint_at_caller (frame
);
7080 /* Reverse stepping through solib trampolines. */
7082 if (execution_direction
== EXEC_REVERSE
7083 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7085 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
7087 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7088 || (ecs
->stop_func_start
== 0
7089 && in_solib_dynsym_resolve_code (stop_pc
)))
7091 /* Any solib trampoline code can be handled in reverse
7092 by simply continuing to single-step. We have already
7093 executed the solib function (backwards), and a few
7094 steps will take us back through the trampoline to the
7099 else if (in_solib_dynsym_resolve_code (stop_pc
))
7101 /* Stepped backward into the solib dynsym resolver.
7102 Set a breakpoint at its start and continue, then
7103 one more step will take us out. */
7104 symtab_and_line sr_sal
;
7105 sr_sal
.pc
= ecs
->stop_func_start
;
7106 sr_sal
.pspace
= get_frame_program_space (frame
);
7107 insert_step_resume_breakpoint_at_sal (gdbarch
,
7108 sr_sal
, null_frame_id
);
7114 /* This always returns the sal for the inner-most frame when we are in a
7115 stack of inlined frames, even if GDB actually believes that it is in a
7116 more outer frame. This is checked for below by calls to
7117 inline_skipped_frames. */
7118 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7120 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7121 the trampoline processing logic, however, there are some trampolines
7122 that have no names, so we should do trampoline handling first. */
7123 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7124 && ecs
->stop_func_name
== NULL
7125 && stop_pc_sal
.line
== 0)
7128 fprintf_unfiltered (gdb_stdlog
,
7129 "infrun: stepped into undebuggable function\n");
7131 /* The inferior just stepped into, or returned to, an
7132 undebuggable function (where there is no debugging information
7133 and no line number corresponding to the address where the
7134 inferior stopped). Since we want to skip this kind of code,
7135 we keep going until the inferior returns from this
7136 function - unless the user has asked us not to (via
7137 set step-mode) or we no longer know how to get back
7138 to the call site. */
7139 if (step_stop_if_no_debug
7140 || !frame_id_p (frame_unwind_caller_id (frame
)))
7142 /* If we have no line number and the step-stop-if-no-debug
7143 is set, we stop the step so that the user has a chance to
7144 switch in assembly mode. */
7145 end_stepping_range (ecs
);
7150 /* Set a breakpoint at callee's return address (the address
7151 at which the caller will resume). */
7152 insert_step_resume_breakpoint_at_caller (frame
);
7158 if (ecs
->event_thread
->control
.step_range_end
== 1)
7160 /* It is stepi or nexti. We always want to stop stepping after
7163 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7164 end_stepping_range (ecs
);
7168 if (stop_pc_sal
.line
== 0)
7170 /* We have no line number information. That means to stop
7171 stepping (does this always happen right after one instruction,
7172 when we do "s" in a function with no line numbers,
7173 or can this happen as a result of a return or longjmp?). */
7175 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7176 end_stepping_range (ecs
);
7180 /* Look for "calls" to inlined functions, part one. If the inline
7181 frame machinery detected some skipped call sites, we have entered
7182 a new inline function. */
7184 if (frame_id_eq (get_frame_id (get_current_frame ()),
7185 ecs
->event_thread
->control
.step_frame_id
)
7186 && inline_skipped_frames (ecs
->event_thread
))
7189 fprintf_unfiltered (gdb_stdlog
,
7190 "infrun: stepped into inlined function\n");
7192 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7194 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7196 /* For "step", we're going to stop. But if the call site
7197 for this inlined function is on the same source line as
7198 we were previously stepping, go down into the function
7199 first. Otherwise stop at the call site. */
7201 if (call_sal
.line
== ecs
->event_thread
->current_line
7202 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7204 step_into_inline_frame (ecs
->event_thread
);
7205 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7212 end_stepping_range (ecs
);
7217 /* For "next", we should stop at the call site if it is on a
7218 different source line. Otherwise continue through the
7219 inlined function. */
7220 if (call_sal
.line
== ecs
->event_thread
->current_line
7221 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7224 end_stepping_range (ecs
);
7229 /* Look for "calls" to inlined functions, part two. If we are still
7230 in the same real function we were stepping through, but we have
7231 to go further up to find the exact frame ID, we are stepping
7232 through a more inlined call beyond its call site. */
7234 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7235 && !frame_id_eq (get_frame_id (get_current_frame ()),
7236 ecs
->event_thread
->control
.step_frame_id
)
7237 && stepped_in_from (get_current_frame (),
7238 ecs
->event_thread
->control
.step_frame_id
))
7241 fprintf_unfiltered (gdb_stdlog
,
7242 "infrun: stepping through inlined function\n");
7244 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7245 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7248 end_stepping_range (ecs
);
7252 bool refresh_step_info
= true;
7253 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7254 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7255 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7257 if (stop_pc_sal
.is_stmt
)
7259 /* We are at the start of a different line. So stop. Note that
7260 we don't stop if we step into the middle of a different line.
7261 That is said to make things like for (;;) statements work
7264 fprintf_unfiltered (gdb_stdlog
,
7265 "infrun: stepped to a different line\n");
7266 end_stepping_range (ecs
);
7269 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7270 ecs
->event_thread
->control
.step_frame_id
))
7272 /* We are at the start of a different line, however, this line is
7273 not marked as a statement, and we have not changed frame. We
7274 ignore this line table entry, and continue stepping forward,
7275 looking for a better place to stop. */
7276 refresh_step_info
= false;
7278 fprintf_unfiltered (gdb_stdlog
,
7279 "infrun: stepped to a different line, but "
7280 "it's not the start of a statement\n");
7284 /* We aren't done stepping.
7286 Optimize by setting the stepping range to the line.
7287 (We might not be in the original line, but if we entered a
7288 new line in mid-statement, we continue stepping. This makes
7289 things like for(;;) statements work better.)
7291 If we entered a SAL that indicates a non-statement line table entry,
7292 then we update the stepping range, but we don't update the step info,
7293 which includes things like the line number we are stepping away from.
7294 This means we will stop when we find a line table entry that is marked
7295 as is-statement, even if it matches the non-statement one we just
7298 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7299 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7300 ecs
->event_thread
->control
.may_range_step
= 1;
7301 if (refresh_step_info
)
7302 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7305 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7309 /* In all-stop mode, if we're currently stepping but have stopped in
7310 some other thread, we may need to switch back to the stepped
7311 thread. Returns true we set the inferior running, false if we left
7312 it stopped (and the event needs further processing). */
7315 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7317 if (!target_is_non_stop_p ())
7319 struct thread_info
*stepping_thread
;
7321 /* If any thread is blocked on some internal breakpoint, and we
7322 simply need to step over that breakpoint to get it going
7323 again, do that first. */
7325 /* However, if we see an event for the stepping thread, then we
7326 know all other threads have been moved past their breakpoints
7327 already. Let the caller check whether the step is finished,
7328 etc., before deciding to move it past a breakpoint. */
7329 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7332 /* Check if the current thread is blocked on an incomplete
7333 step-over, interrupted by a random signal. */
7334 if (ecs
->event_thread
->control
.trap_expected
7335 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7339 fprintf_unfiltered (gdb_stdlog
,
7340 "infrun: need to finish step-over of [%s]\n",
7341 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7347 /* Check if the current thread is blocked by a single-step
7348 breakpoint of another thread. */
7349 if (ecs
->hit_singlestep_breakpoint
)
7353 fprintf_unfiltered (gdb_stdlog
,
7354 "infrun: need to step [%s] over single-step "
7356 target_pid_to_str (ecs
->ptid
).c_str ());
7362 /* If this thread needs yet another step-over (e.g., stepping
7363 through a delay slot), do it first before moving on to
7365 if (thread_still_needs_step_over (ecs
->event_thread
))
7369 fprintf_unfiltered (gdb_stdlog
,
7370 "infrun: thread [%s] still needs step-over\n",
7371 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7377 /* If scheduler locking applies even if not stepping, there's no
7378 need to walk over threads. Above we've checked whether the
7379 current thread is stepping. If some other thread not the
7380 event thread is stepping, then it must be that scheduler
7381 locking is not in effect. */
7382 if (schedlock_applies (ecs
->event_thread
))
7385 /* Otherwise, we no longer expect a trap in the current thread.
7386 Clear the trap_expected flag before switching back -- this is
7387 what keep_going does as well, if we call it. */
7388 ecs
->event_thread
->control
.trap_expected
= 0;
7390 /* Likewise, clear the signal if it should not be passed. */
7391 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7392 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7394 /* Do all pending step-overs before actually proceeding with
7396 if (start_step_over ())
7398 prepare_to_wait (ecs
);
7402 /* Look for the stepping/nexting thread. */
7403 stepping_thread
= NULL
;
7405 for (thread_info
*tp
: all_non_exited_threads ())
7407 switch_to_thread_no_regs (tp
);
7409 /* Ignore threads of processes the caller is not
7412 && (tp
->inf
->process_target () != ecs
->target
7413 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7416 /* When stepping over a breakpoint, we lock all threads
7417 except the one that needs to move past the breakpoint.
7418 If a non-event thread has this set, the "incomplete
7419 step-over" check above should have caught it earlier. */
7420 if (tp
->control
.trap_expected
)
7422 internal_error (__FILE__
, __LINE__
,
7423 "[%s] has inconsistent state: "
7424 "trap_expected=%d\n",
7425 target_pid_to_str (tp
->ptid
).c_str (),
7426 tp
->control
.trap_expected
);
7429 /* Did we find the stepping thread? */
7430 if (tp
->control
.step_range_end
)
7432 /* Yep. There should only one though. */
7433 gdb_assert (stepping_thread
== NULL
);
7435 /* The event thread is handled at the top, before we
7437 gdb_assert (tp
!= ecs
->event_thread
);
7439 /* If some thread other than the event thread is
7440 stepping, then scheduler locking can't be in effect,
7441 otherwise we wouldn't have resumed the current event
7442 thread in the first place. */
7443 gdb_assert (!schedlock_applies (tp
));
7445 stepping_thread
= tp
;
7449 if (stepping_thread
!= NULL
)
7452 fprintf_unfiltered (gdb_stdlog
,
7453 "infrun: switching back to stepped thread\n");
7455 if (keep_going_stepped_thread (stepping_thread
))
7457 prepare_to_wait (ecs
);
7462 switch_to_thread (ecs
->event_thread
);
7468 /* Set a previously stepped thread back to stepping. Returns true on
7469 success, false if the resume is not possible (e.g., the thread
7473 keep_going_stepped_thread (struct thread_info
*tp
)
7475 struct frame_info
*frame
;
7476 struct execution_control_state ecss
;
7477 struct execution_control_state
*ecs
= &ecss
;
7479 /* If the stepping thread exited, then don't try to switch back and
7480 resume it, which could fail in several different ways depending
7481 on the target. Instead, just keep going.
7483 We can find a stepping dead thread in the thread list in two
7486 - The target supports thread exit events, and when the target
7487 tries to delete the thread from the thread list, inferior_ptid
7488 pointed at the exiting thread. In such case, calling
7489 delete_thread does not really remove the thread from the list;
7490 instead, the thread is left listed, with 'exited' state.
7492 - The target's debug interface does not support thread exit
7493 events, and so we have no idea whatsoever if the previously
7494 stepping thread is still alive. For that reason, we need to
7495 synchronously query the target now. */
7497 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7500 fprintf_unfiltered (gdb_stdlog
,
7501 "infrun: not resuming previously "
7502 "stepped thread, it has vanished\n");
7509 fprintf_unfiltered (gdb_stdlog
,
7510 "infrun: resuming previously stepped thread\n");
7512 reset_ecs (ecs
, tp
);
7513 switch_to_thread (tp
);
7515 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7516 frame
= get_current_frame ();
7518 /* If the PC of the thread we were trying to single-step has
7519 changed, then that thread has trapped or been signaled, but the
7520 event has not been reported to GDB yet. Re-poll the target
7521 looking for this particular thread's event (i.e. temporarily
7522 enable schedlock) by:
7524 - setting a break at the current PC
7525 - resuming that particular thread, only (by setting trap
7528 This prevents us continuously moving the single-step breakpoint
7529 forward, one instruction at a time, overstepping. */
7531 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7536 fprintf_unfiltered (gdb_stdlog
,
7537 "infrun: expected thread advanced also (%s -> %s)\n",
7538 paddress (target_gdbarch (), tp
->prev_pc
),
7539 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7541 /* Clear the info of the previous step-over, as it's no longer
7542 valid (if the thread was trying to step over a breakpoint, it
7543 has already succeeded). It's what keep_going would do too,
7544 if we called it. Do this before trying to insert the sss
7545 breakpoint, otherwise if we were previously trying to step
7546 over this exact address in another thread, the breakpoint is
7548 clear_step_over_info ();
7549 tp
->control
.trap_expected
= 0;
7551 insert_single_step_breakpoint (get_frame_arch (frame
),
7552 get_frame_address_space (frame
),
7553 tp
->suspend
.stop_pc
);
7556 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7557 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7562 fprintf_unfiltered (gdb_stdlog
,
7563 "infrun: expected thread still hasn't advanced\n");
7565 keep_going_pass_signal (ecs
);
7570 /* Is thread TP in the middle of (software or hardware)
7571 single-stepping? (Note the result of this function must never be
7572 passed directly as target_resume's STEP parameter.) */
7575 currently_stepping (struct thread_info
*tp
)
7577 return ((tp
->control
.step_range_end
7578 && tp
->control
.step_resume_breakpoint
== NULL
)
7579 || tp
->control
.trap_expected
7580 || tp
->stepped_breakpoint
7581 || bpstat_should_step ());
7584 /* Inferior has stepped into a subroutine call with source code that
7585 we should not step over. Do step to the first line of code in
7589 handle_step_into_function (struct gdbarch
*gdbarch
,
7590 struct execution_control_state
*ecs
)
7592 fill_in_stop_func (gdbarch
, ecs
);
7594 compunit_symtab
*cust
7595 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7596 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7597 ecs
->stop_func_start
7598 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7600 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7601 /* Use the step_resume_break to step until the end of the prologue,
7602 even if that involves jumps (as it seems to on the vax under
7604 /* If the prologue ends in the middle of a source line, continue to
7605 the end of that source line (if it is still within the function).
7606 Otherwise, just go to end of prologue. */
7607 if (stop_func_sal
.end
7608 && stop_func_sal
.pc
!= ecs
->stop_func_start
7609 && stop_func_sal
.end
< ecs
->stop_func_end
)
7610 ecs
->stop_func_start
= stop_func_sal
.end
;
7612 /* Architectures which require breakpoint adjustment might not be able
7613 to place a breakpoint at the computed address. If so, the test
7614 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7615 ecs->stop_func_start to an address at which a breakpoint may be
7616 legitimately placed.
7618 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7619 made, GDB will enter an infinite loop when stepping through
7620 optimized code consisting of VLIW instructions which contain
7621 subinstructions corresponding to different source lines. On
7622 FR-V, it's not permitted to place a breakpoint on any but the
7623 first subinstruction of a VLIW instruction. When a breakpoint is
7624 set, GDB will adjust the breakpoint address to the beginning of
7625 the VLIW instruction. Thus, we need to make the corresponding
7626 adjustment here when computing the stop address. */
7628 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7630 ecs
->stop_func_start
7631 = gdbarch_adjust_breakpoint_address (gdbarch
,
7632 ecs
->stop_func_start
);
7635 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7637 /* We are already there: stop now. */
7638 end_stepping_range (ecs
);
7643 /* Put the step-breakpoint there and go until there. */
7644 symtab_and_line sr_sal
;
7645 sr_sal
.pc
= ecs
->stop_func_start
;
7646 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7647 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7649 /* Do not specify what the fp should be when we stop since on
7650 some machines the prologue is where the new fp value is
7652 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7654 /* And make sure stepping stops right away then. */
7655 ecs
->event_thread
->control
.step_range_end
7656 = ecs
->event_thread
->control
.step_range_start
;
7661 /* Inferior has stepped backward into a subroutine call with source
7662 code that we should not step over. Do step to the beginning of the
7663 last line of code in it. */
7666 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7667 struct execution_control_state
*ecs
)
7669 struct compunit_symtab
*cust
;
7670 struct symtab_and_line stop_func_sal
;
7672 fill_in_stop_func (gdbarch
, ecs
);
7674 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7675 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7676 ecs
->stop_func_start
7677 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7679 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7681 /* OK, we're just going to keep stepping here. */
7682 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7684 /* We're there already. Just stop stepping now. */
7685 end_stepping_range (ecs
);
7689 /* Else just reset the step range and keep going.
7690 No step-resume breakpoint, they don't work for
7691 epilogues, which can have multiple entry paths. */
7692 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7693 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7699 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7700 This is used to both functions and to skip over code. */
7703 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7704 struct symtab_and_line sr_sal
,
7705 struct frame_id sr_id
,
7706 enum bptype sr_type
)
7708 /* There should never be more than one step-resume or longjmp-resume
7709 breakpoint per thread, so we should never be setting a new
7710 step_resume_breakpoint when one is already active. */
7711 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7712 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7715 fprintf_unfiltered (gdb_stdlog
,
7716 "infrun: inserting step-resume breakpoint at %s\n",
7717 paddress (gdbarch
, sr_sal
.pc
));
7719 inferior_thread ()->control
.step_resume_breakpoint
7720 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7724 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7725 struct symtab_and_line sr_sal
,
7726 struct frame_id sr_id
)
7728 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7733 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7734 This is used to skip a potential signal handler.
7736 This is called with the interrupted function's frame. The signal
7737 handler, when it returns, will resume the interrupted function at
7741 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7743 gdb_assert (return_frame
!= NULL
);
7745 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7747 symtab_and_line sr_sal
;
7748 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7749 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7750 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7752 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7753 get_stack_frame_id (return_frame
),
7757 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7758 is used to skip a function after stepping into it (for "next" or if
7759 the called function has no debugging information).
7761 The current function has almost always been reached by single
7762 stepping a call or return instruction. NEXT_FRAME belongs to the
7763 current function, and the breakpoint will be set at the caller's
7766 This is a separate function rather than reusing
7767 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7768 get_prev_frame, which may stop prematurely (see the implementation
7769 of frame_unwind_caller_id for an example). */
7772 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7774 /* We shouldn't have gotten here if we don't know where the call site
7776 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7778 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7780 symtab_and_line sr_sal
;
7781 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7782 frame_unwind_caller_pc (next_frame
));
7783 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7784 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7786 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7787 frame_unwind_caller_id (next_frame
));
7790 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7791 new breakpoint at the target of a jmp_buf. The handling of
7792 longjmp-resume uses the same mechanisms used for handling
7793 "step-resume" breakpoints. */
7796 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7798 /* There should never be more than one longjmp-resume breakpoint per
7799 thread, so we should never be setting a new
7800 longjmp_resume_breakpoint when one is already active. */
7801 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7804 fprintf_unfiltered (gdb_stdlog
,
7805 "infrun: inserting longjmp-resume breakpoint at %s\n",
7806 paddress (gdbarch
, pc
));
7808 inferior_thread ()->control
.exception_resume_breakpoint
=
7809 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7812 /* Insert an exception resume breakpoint. TP is the thread throwing
7813 the exception. The block B is the block of the unwinder debug hook
7814 function. FRAME is the frame corresponding to the call to this
7815 function. SYM is the symbol of the function argument holding the
7816 target PC of the exception. */
7819 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7820 const struct block
*b
,
7821 struct frame_info
*frame
,
7826 struct block_symbol vsym
;
7827 struct value
*value
;
7829 struct breakpoint
*bp
;
7831 vsym
= lookup_symbol_search_name (sym
->search_name (),
7833 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7834 /* If the value was optimized out, revert to the old behavior. */
7835 if (! value_optimized_out (value
))
7837 handler
= value_as_address (value
);
7840 fprintf_unfiltered (gdb_stdlog
,
7841 "infrun: exception resume at %lx\n",
7842 (unsigned long) handler
);
7844 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7846 bp_exception_resume
).release ();
7848 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7851 bp
->thread
= tp
->global_num
;
7852 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7855 catch (const gdb_exception_error
&e
)
7857 /* We want to ignore errors here. */
7861 /* A helper for check_exception_resume that sets an
7862 exception-breakpoint based on a SystemTap probe. */
7865 insert_exception_resume_from_probe (struct thread_info
*tp
,
7866 const struct bound_probe
*probe
,
7867 struct frame_info
*frame
)
7869 struct value
*arg_value
;
7871 struct breakpoint
*bp
;
7873 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7877 handler
= value_as_address (arg_value
);
7880 fprintf_unfiltered (gdb_stdlog
,
7881 "infrun: exception resume at %s\n",
7882 paddress (probe
->objfile
->arch (),
7885 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7886 handler
, bp_exception_resume
).release ();
7887 bp
->thread
= tp
->global_num
;
7888 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7891 /* This is called when an exception has been intercepted. Check to
7892 see whether the exception's destination is of interest, and if so,
7893 set an exception resume breakpoint there. */
7896 check_exception_resume (struct execution_control_state
*ecs
,
7897 struct frame_info
*frame
)
7899 struct bound_probe probe
;
7900 struct symbol
*func
;
7902 /* First see if this exception unwinding breakpoint was set via a
7903 SystemTap probe point. If so, the probe has two arguments: the
7904 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7905 set a breakpoint there. */
7906 probe
= find_probe_by_pc (get_frame_pc (frame
));
7909 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7913 func
= get_frame_function (frame
);
7919 const struct block
*b
;
7920 struct block_iterator iter
;
7924 /* The exception breakpoint is a thread-specific breakpoint on
7925 the unwinder's debug hook, declared as:
7927 void _Unwind_DebugHook (void *cfa, void *handler);
7929 The CFA argument indicates the frame to which control is
7930 about to be transferred. HANDLER is the destination PC.
7932 We ignore the CFA and set a temporary breakpoint at HANDLER.
7933 This is not extremely efficient but it avoids issues in gdb
7934 with computing the DWARF CFA, and it also works even in weird
7935 cases such as throwing an exception from inside a signal
7938 b
= SYMBOL_BLOCK_VALUE (func
);
7939 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7941 if (!SYMBOL_IS_ARGUMENT (sym
))
7948 insert_exception_resume_breakpoint (ecs
->event_thread
,
7954 catch (const gdb_exception_error
&e
)
7960 stop_waiting (struct execution_control_state
*ecs
)
7963 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7965 /* Let callers know we don't want to wait for the inferior anymore. */
7966 ecs
->wait_some_more
= 0;
7968 /* If all-stop, but there exists a non-stop target, stop all
7969 threads now that we're presenting the stop to the user. */
7970 if (!non_stop
&& exists_non_stop_target ())
7971 stop_all_threads ();
7974 /* Like keep_going, but passes the signal to the inferior, even if the
7975 signal is set to nopass. */
7978 keep_going_pass_signal (struct execution_control_state
*ecs
)
7980 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7981 gdb_assert (!ecs
->event_thread
->resumed
);
7983 /* Save the pc before execution, to compare with pc after stop. */
7984 ecs
->event_thread
->prev_pc
7985 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7987 if (ecs
->event_thread
->control
.trap_expected
)
7989 struct thread_info
*tp
= ecs
->event_thread
;
7992 fprintf_unfiltered (gdb_stdlog
,
7993 "infrun: %s has trap_expected set, "
7994 "resuming to collect trap\n",
7995 target_pid_to_str (tp
->ptid
).c_str ());
7997 /* We haven't yet gotten our trap, and either: intercepted a
7998 non-signal event (e.g., a fork); or took a signal which we
7999 are supposed to pass through to the inferior. Simply
8001 resume (ecs
->event_thread
->suspend
.stop_signal
);
8003 else if (step_over_info_valid_p ())
8005 /* Another thread is stepping over a breakpoint in-line. If
8006 this thread needs a step-over too, queue the request. In
8007 either case, this resume must be deferred for later. */
8008 struct thread_info
*tp
= ecs
->event_thread
;
8010 if (ecs
->hit_singlestep_breakpoint
8011 || thread_still_needs_step_over (tp
))
8014 fprintf_unfiltered (gdb_stdlog
,
8015 "infrun: step-over already in progress: "
8016 "step-over for %s deferred\n",
8017 target_pid_to_str (tp
->ptid
).c_str ());
8018 thread_step_over_chain_enqueue (tp
);
8023 fprintf_unfiltered (gdb_stdlog
,
8024 "infrun: step-over in progress: "
8025 "resume of %s deferred\n",
8026 target_pid_to_str (tp
->ptid
).c_str ());
8031 struct regcache
*regcache
= get_current_regcache ();
8034 step_over_what step_what
;
8036 /* Either the trap was not expected, but we are continuing
8037 anyway (if we got a signal, the user asked it be passed to
8040 We got our expected trap, but decided we should resume from
8043 We're going to run this baby now!
8045 Note that insert_breakpoints won't try to re-insert
8046 already inserted breakpoints. Therefore, we don't
8047 care if breakpoints were already inserted, or not. */
8049 /* If we need to step over a breakpoint, and we're not using
8050 displaced stepping to do so, insert all breakpoints
8051 (watchpoints, etc.) but the one we're stepping over, step one
8052 instruction, and then re-insert the breakpoint when that step
8055 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
8057 remove_bp
= (ecs
->hit_singlestep_breakpoint
8058 || (step_what
& STEP_OVER_BREAKPOINT
));
8059 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
8061 /* We can't use displaced stepping if we need to step past a
8062 watchpoint. The instruction copied to the scratch pad would
8063 still trigger the watchpoint. */
8065 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
8067 set_step_over_info (regcache
->aspace (),
8068 regcache_read_pc (regcache
), remove_wps
,
8069 ecs
->event_thread
->global_num
);
8071 else if (remove_wps
)
8072 set_step_over_info (NULL
, 0, remove_wps
, -1);
8074 /* If we now need to do an in-line step-over, we need to stop
8075 all other threads. Note this must be done before
8076 insert_breakpoints below, because that removes the breakpoint
8077 we're about to step over, otherwise other threads could miss
8079 if (step_over_info_valid_p () && target_is_non_stop_p ())
8080 stop_all_threads ();
8082 /* Stop stepping if inserting breakpoints fails. */
8085 insert_breakpoints ();
8087 catch (const gdb_exception_error
&e
)
8089 exception_print (gdb_stderr
, e
);
8091 clear_step_over_info ();
8095 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8097 resume (ecs
->event_thread
->suspend
.stop_signal
);
8100 prepare_to_wait (ecs
);
8103 /* Called when we should continue running the inferior, because the
8104 current event doesn't cause a user visible stop. This does the
8105 resuming part; waiting for the next event is done elsewhere. */
8108 keep_going (struct execution_control_state
*ecs
)
8110 if (ecs
->event_thread
->control
.trap_expected
8111 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
8112 ecs
->event_thread
->control
.trap_expected
= 0;
8114 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
8115 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8116 keep_going_pass_signal (ecs
);
8119 /* This function normally comes after a resume, before
8120 handle_inferior_event exits. It takes care of any last bits of
8121 housekeeping, and sets the all-important wait_some_more flag. */
8124 prepare_to_wait (struct execution_control_state
*ecs
)
8127 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
8129 ecs
->wait_some_more
= 1;
8131 /* If the target can't async, emulate it by marking the infrun event
8132 handler such that as soon as we get back to the event-loop, we
8133 immediately end up in fetch_inferior_event again calling
8135 if (!target_can_async_p ())
8136 mark_infrun_async_event_handler ();
8139 /* We are done with the step range of a step/next/si/ni command.
8140 Called once for each n of a "step n" operation. */
8143 end_stepping_range (struct execution_control_state
*ecs
)
8145 ecs
->event_thread
->control
.stop_step
= 1;
8149 /* Several print_*_reason functions to print why the inferior has stopped.
8150 We always print something when the inferior exits, or receives a signal.
8151 The rest of the cases are dealt with later on in normal_stop and
8152 print_it_typical. Ideally there should be a call to one of these
8153 print_*_reason functions functions from handle_inferior_event each time
8154 stop_waiting is called.
8156 Note that we don't call these directly, instead we delegate that to
8157 the interpreters, through observers. Interpreters then call these
8158 with whatever uiout is right. */
8161 print_end_stepping_range_reason (struct ui_out
*uiout
)
8163 /* For CLI-like interpreters, print nothing. */
8165 if (uiout
->is_mi_like_p ())
8167 uiout
->field_string ("reason",
8168 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8173 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8175 annotate_signalled ();
8176 if (uiout
->is_mi_like_p ())
8178 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8179 uiout
->text ("\nProgram terminated with signal ");
8180 annotate_signal_name ();
8181 uiout
->field_string ("signal-name",
8182 gdb_signal_to_name (siggnal
));
8183 annotate_signal_name_end ();
8185 annotate_signal_string ();
8186 uiout
->field_string ("signal-meaning",
8187 gdb_signal_to_string (siggnal
));
8188 annotate_signal_string_end ();
8189 uiout
->text (".\n");
8190 uiout
->text ("The program no longer exists.\n");
8194 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8196 struct inferior
*inf
= current_inferior ();
8197 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8199 annotate_exited (exitstatus
);
8202 if (uiout
->is_mi_like_p ())
8203 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8204 std::string exit_code_str
8205 = string_printf ("0%o", (unsigned int) exitstatus
);
8206 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8207 plongest (inf
->num
), pidstr
.c_str (),
8208 string_field ("exit-code", exit_code_str
.c_str ()));
8212 if (uiout
->is_mi_like_p ())
8214 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8215 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8216 plongest (inf
->num
), pidstr
.c_str ());
8220 /* Some targets/architectures can do extra processing/display of
8221 segmentation faults. E.g., Intel MPX boundary faults.
8222 Call the architecture dependent function to handle the fault. */
8225 handle_segmentation_fault (struct ui_out
*uiout
)
8227 struct regcache
*regcache
= get_current_regcache ();
8228 struct gdbarch
*gdbarch
= regcache
->arch ();
8230 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8231 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8235 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8237 struct thread_info
*thr
= inferior_thread ();
8241 if (uiout
->is_mi_like_p ())
8243 else if (show_thread_that_caused_stop ())
8247 uiout
->text ("\nThread ");
8248 uiout
->field_string ("thread-id", print_thread_id (thr
));
8250 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8253 uiout
->text (" \"");
8254 uiout
->field_string ("name", name
);
8259 uiout
->text ("\nProgram");
8261 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8262 uiout
->text (" stopped");
8265 uiout
->text (" received signal ");
8266 annotate_signal_name ();
8267 if (uiout
->is_mi_like_p ())
8269 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8270 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8271 annotate_signal_name_end ();
8273 annotate_signal_string ();
8274 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8276 if (siggnal
== GDB_SIGNAL_SEGV
)
8277 handle_segmentation_fault (uiout
);
8279 annotate_signal_string_end ();
8281 uiout
->text (".\n");
8285 print_no_history_reason (struct ui_out
*uiout
)
8287 uiout
->text ("\nNo more reverse-execution history.\n");
8290 /* Print current location without a level number, if we have changed
8291 functions or hit a breakpoint. Print source line if we have one.
8292 bpstat_print contains the logic deciding in detail what to print,
8293 based on the event(s) that just occurred. */
8296 print_stop_location (struct target_waitstatus
*ws
)
8299 enum print_what source_flag
;
8300 int do_frame_printing
= 1;
8301 struct thread_info
*tp
= inferior_thread ();
8303 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8307 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8308 should) carry around the function and does (or should) use
8309 that when doing a frame comparison. */
8310 if (tp
->control
.stop_step
8311 && frame_id_eq (tp
->control
.step_frame_id
,
8312 get_frame_id (get_current_frame ()))
8313 && (tp
->control
.step_start_function
8314 == find_pc_function (tp
->suspend
.stop_pc
)))
8316 /* Finished step, just print source line. */
8317 source_flag
= SRC_LINE
;
8321 /* Print location and source line. */
8322 source_flag
= SRC_AND_LOC
;
8325 case PRINT_SRC_AND_LOC
:
8326 /* Print location and source line. */
8327 source_flag
= SRC_AND_LOC
;
8329 case PRINT_SRC_ONLY
:
8330 source_flag
= SRC_LINE
;
8333 /* Something bogus. */
8334 source_flag
= SRC_LINE
;
8335 do_frame_printing
= 0;
8338 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8341 /* The behavior of this routine with respect to the source
8343 SRC_LINE: Print only source line
8344 LOCATION: Print only location
8345 SRC_AND_LOC: Print location and source line. */
8346 if (do_frame_printing
)
8347 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8353 print_stop_event (struct ui_out
*uiout
, bool displays
)
8355 struct target_waitstatus last
;
8356 struct thread_info
*tp
;
8358 get_last_target_status (nullptr, nullptr, &last
);
8361 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8363 print_stop_location (&last
);
8365 /* Display the auto-display expressions. */
8370 tp
= inferior_thread ();
8371 if (tp
->thread_fsm
!= NULL
8372 && tp
->thread_fsm
->finished_p ())
8374 struct return_value_info
*rv
;
8376 rv
= tp
->thread_fsm
->return_value ();
8378 print_return_value (uiout
, rv
);
8385 maybe_remove_breakpoints (void)
8387 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8389 if (remove_breakpoints ())
8391 target_terminal::ours_for_output ();
8392 printf_filtered (_("Cannot remove breakpoints because "
8393 "program is no longer writable.\nFurther "
8394 "execution is probably impossible.\n"));
8399 /* The execution context that just caused a normal stop. */
8406 DISABLE_COPY_AND_ASSIGN (stop_context
);
8408 bool changed () const;
8413 /* The event PTID. */
8417 /* If stopp for a thread event, this is the thread that caused the
8419 struct thread_info
*thread
;
8421 /* The inferior that caused the stop. */
8425 /* Initializes a new stop context. If stopped for a thread event, this
8426 takes a strong reference to the thread. */
8428 stop_context::stop_context ()
8430 stop_id
= get_stop_id ();
8431 ptid
= inferior_ptid
;
8432 inf_num
= current_inferior ()->num
;
8434 if (inferior_ptid
!= null_ptid
)
8436 /* Take a strong reference so that the thread can't be deleted
8438 thread
= inferior_thread ();
8445 /* Release a stop context previously created with save_stop_context.
8446 Releases the strong reference to the thread as well. */
8448 stop_context::~stop_context ()
8454 /* Return true if the current context no longer matches the saved stop
8458 stop_context::changed () const
8460 if (ptid
!= inferior_ptid
)
8462 if (inf_num
!= current_inferior ()->num
)
8464 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8466 if (get_stop_id () != stop_id
)
8476 struct target_waitstatus last
;
8478 get_last_target_status (nullptr, nullptr, &last
);
8482 /* If an exception is thrown from this point on, make sure to
8483 propagate GDB's knowledge of the executing state to the
8484 frontend/user running state. A QUIT is an easy exception to see
8485 here, so do this before any filtered output. */
8487 ptid_t finish_ptid
= null_ptid
;
8490 finish_ptid
= minus_one_ptid
;
8491 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8492 || last
.kind
== TARGET_WAITKIND_EXITED
)
8494 /* On some targets, we may still have live threads in the
8495 inferior when we get a process exit event. E.g., for
8496 "checkpoint", when the current checkpoint/fork exits,
8497 linux-fork.c automatically switches to another fork from
8498 within target_mourn_inferior. */
8499 if (inferior_ptid
!= null_ptid
)
8500 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8502 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8503 finish_ptid
= inferior_ptid
;
8505 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8506 if (finish_ptid
!= null_ptid
)
8508 maybe_finish_thread_state
.emplace
8509 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8512 /* As we're presenting a stop, and potentially removing breakpoints,
8513 update the thread list so we can tell whether there are threads
8514 running on the target. With target remote, for example, we can
8515 only learn about new threads when we explicitly update the thread
8516 list. Do this before notifying the interpreters about signal
8517 stops, end of stepping ranges, etc., so that the "new thread"
8518 output is emitted before e.g., "Program received signal FOO",
8519 instead of after. */
8520 update_thread_list ();
8522 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8523 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8525 /* As with the notification of thread events, we want to delay
8526 notifying the user that we've switched thread context until
8527 the inferior actually stops.
8529 There's no point in saying anything if the inferior has exited.
8530 Note that SIGNALLED here means "exited with a signal", not
8531 "received a signal".
8533 Also skip saying anything in non-stop mode. In that mode, as we
8534 don't want GDB to switch threads behind the user's back, to avoid
8535 races where the user is typing a command to apply to thread x,
8536 but GDB switches to thread y before the user finishes entering
8537 the command, fetch_inferior_event installs a cleanup to restore
8538 the current thread back to the thread the user had selected right
8539 after this event is handled, so we're not really switching, only
8540 informing of a stop. */
8542 && previous_inferior_ptid
!= inferior_ptid
8543 && target_has_execution
8544 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8545 && last
.kind
!= TARGET_WAITKIND_EXITED
8546 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8548 SWITCH_THRU_ALL_UIS ()
8550 target_terminal::ours_for_output ();
8551 printf_filtered (_("[Switching to %s]\n"),
8552 target_pid_to_str (inferior_ptid
).c_str ());
8553 annotate_thread_changed ();
8555 previous_inferior_ptid
= inferior_ptid
;
8558 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8560 SWITCH_THRU_ALL_UIS ()
8561 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8563 target_terminal::ours_for_output ();
8564 printf_filtered (_("No unwaited-for children left.\n"));
8568 /* Note: this depends on the update_thread_list call above. */
8569 maybe_remove_breakpoints ();
8571 /* If an auto-display called a function and that got a signal,
8572 delete that auto-display to avoid an infinite recursion. */
8574 if (stopped_by_random_signal
)
8575 disable_current_display ();
8577 SWITCH_THRU_ALL_UIS ()
8579 async_enable_stdin ();
8582 /* Let the user/frontend see the threads as stopped. */
8583 maybe_finish_thread_state
.reset ();
8585 /* Select innermost stack frame - i.e., current frame is frame 0,
8586 and current location is based on that. Handle the case where the
8587 dummy call is returning after being stopped. E.g. the dummy call
8588 previously hit a breakpoint. (If the dummy call returns
8589 normally, we won't reach here.) Do this before the stop hook is
8590 run, so that it doesn't get to see the temporary dummy frame,
8591 which is not where we'll present the stop. */
8592 if (has_stack_frames ())
8594 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8596 /* Pop the empty frame that contains the stack dummy. This
8597 also restores inferior state prior to the call (struct
8598 infcall_suspend_state). */
8599 struct frame_info
*frame
= get_current_frame ();
8601 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8603 /* frame_pop calls reinit_frame_cache as the last thing it
8604 does which means there's now no selected frame. */
8607 select_frame (get_current_frame ());
8609 /* Set the current source location. */
8610 set_current_sal_from_frame (get_current_frame ());
8613 /* Look up the hook_stop and run it (CLI internally handles problem
8614 of stop_command's pre-hook not existing). */
8615 if (stop_command
!= NULL
)
8617 stop_context saved_context
;
8621 execute_cmd_pre_hook (stop_command
);
8623 catch (const gdb_exception
&ex
)
8625 exception_fprintf (gdb_stderr
, ex
,
8626 "Error while running hook_stop:\n");
8629 /* If the stop hook resumes the target, then there's no point in
8630 trying to notify about the previous stop; its context is
8631 gone. Likewise if the command switches thread or inferior --
8632 the observers would print a stop for the wrong
8634 if (saved_context
.changed ())
8638 /* Notify observers about the stop. This is where the interpreters
8639 print the stop event. */
8640 if (inferior_ptid
!= null_ptid
)
8641 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8644 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8646 annotate_stopped ();
8648 if (target_has_execution
)
8650 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8651 && last
.kind
!= TARGET_WAITKIND_EXITED
8652 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8653 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8654 Delete any breakpoint that is to be deleted at the next stop. */
8655 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8658 /* Try to get rid of automatically added inferiors that are no
8659 longer needed. Keeping those around slows down things linearly.
8660 Note that this never removes the current inferior. */
8667 signal_stop_state (int signo
)
8669 return signal_stop
[signo
];
8673 signal_print_state (int signo
)
8675 return signal_print
[signo
];
8679 signal_pass_state (int signo
)
8681 return signal_program
[signo
];
8685 signal_cache_update (int signo
)
8689 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8690 signal_cache_update (signo
);
8695 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8696 && signal_print
[signo
] == 0
8697 && signal_program
[signo
] == 1
8698 && signal_catch
[signo
] == 0);
8702 signal_stop_update (int signo
, int state
)
8704 int ret
= signal_stop
[signo
];
8706 signal_stop
[signo
] = state
;
8707 signal_cache_update (signo
);
8712 signal_print_update (int signo
, int state
)
8714 int ret
= signal_print
[signo
];
8716 signal_print
[signo
] = state
;
8717 signal_cache_update (signo
);
8722 signal_pass_update (int signo
, int state
)
8724 int ret
= signal_program
[signo
];
8726 signal_program
[signo
] = state
;
8727 signal_cache_update (signo
);
8731 /* Update the global 'signal_catch' from INFO and notify the
8735 signal_catch_update (const unsigned int *info
)
8739 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8740 signal_catch
[i
] = info
[i
] > 0;
8741 signal_cache_update (-1);
8742 target_pass_signals (signal_pass
);
8746 sig_print_header (void)
8748 printf_filtered (_("Signal Stop\tPrint\tPass "
8749 "to program\tDescription\n"));
8753 sig_print_info (enum gdb_signal oursig
)
8755 const char *name
= gdb_signal_to_name (oursig
);
8756 int name_padding
= 13 - strlen (name
);
8758 if (name_padding
<= 0)
8761 printf_filtered ("%s", name
);
8762 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8763 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8764 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8765 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8766 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8769 /* Specify how various signals in the inferior should be handled. */
8772 handle_command (const char *args
, int from_tty
)
8774 int digits
, wordlen
;
8775 int sigfirst
, siglast
;
8776 enum gdb_signal oursig
;
8781 error_no_arg (_("signal to handle"));
8784 /* Allocate and zero an array of flags for which signals to handle. */
8786 const size_t nsigs
= GDB_SIGNAL_LAST
;
8787 unsigned char sigs
[nsigs
] {};
8789 /* Break the command line up into args. */
8791 gdb_argv
built_argv (args
);
8793 /* Walk through the args, looking for signal oursigs, signal names, and
8794 actions. Signal numbers and signal names may be interspersed with
8795 actions, with the actions being performed for all signals cumulatively
8796 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8798 for (char *arg
: built_argv
)
8800 wordlen
= strlen (arg
);
8801 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8805 sigfirst
= siglast
= -1;
8807 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8809 /* Apply action to all signals except those used by the
8810 debugger. Silently skip those. */
8813 siglast
= nsigs
- 1;
8815 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8817 SET_SIGS (nsigs
, sigs
, signal_stop
);
8818 SET_SIGS (nsigs
, sigs
, signal_print
);
8820 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8822 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8824 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8826 SET_SIGS (nsigs
, sigs
, signal_print
);
8828 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8830 SET_SIGS (nsigs
, sigs
, signal_program
);
8832 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8834 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8836 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8838 SET_SIGS (nsigs
, sigs
, signal_program
);
8840 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8842 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8843 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8845 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8847 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8849 else if (digits
> 0)
8851 /* It is numeric. The numeric signal refers to our own
8852 internal signal numbering from target.h, not to host/target
8853 signal number. This is a feature; users really should be
8854 using symbolic names anyway, and the common ones like
8855 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8857 sigfirst
= siglast
= (int)
8858 gdb_signal_from_command (atoi (arg
));
8859 if (arg
[digits
] == '-')
8862 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8864 if (sigfirst
> siglast
)
8866 /* Bet he didn't figure we'd think of this case... */
8867 std::swap (sigfirst
, siglast
);
8872 oursig
= gdb_signal_from_name (arg
);
8873 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8875 sigfirst
= siglast
= (int) oursig
;
8879 /* Not a number and not a recognized flag word => complain. */
8880 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8884 /* If any signal numbers or symbol names were found, set flags for
8885 which signals to apply actions to. */
8887 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8889 switch ((enum gdb_signal
) signum
)
8891 case GDB_SIGNAL_TRAP
:
8892 case GDB_SIGNAL_INT
:
8893 if (!allsigs
&& !sigs
[signum
])
8895 if (query (_("%s is used by the debugger.\n\
8896 Are you sure you want to change it? "),
8897 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8902 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8906 case GDB_SIGNAL_DEFAULT
:
8907 case GDB_SIGNAL_UNKNOWN
:
8908 /* Make sure that "all" doesn't print these. */
8917 for (int signum
= 0; signum
< nsigs
; signum
++)
8920 signal_cache_update (-1);
8921 target_pass_signals (signal_pass
);
8922 target_program_signals (signal_program
);
8926 /* Show the results. */
8927 sig_print_header ();
8928 for (; signum
< nsigs
; signum
++)
8930 sig_print_info ((enum gdb_signal
) signum
);
8937 /* Complete the "handle" command. */
8940 handle_completer (struct cmd_list_element
*ignore
,
8941 completion_tracker
&tracker
,
8942 const char *text
, const char *word
)
8944 static const char * const keywords
[] =
8958 signal_completer (ignore
, tracker
, text
, word
);
8959 complete_on_enum (tracker
, keywords
, word
, word
);
8963 gdb_signal_from_command (int num
)
8965 if (num
>= 1 && num
<= 15)
8966 return (enum gdb_signal
) num
;
8967 error (_("Only signals 1-15 are valid as numeric signals.\n\
8968 Use \"info signals\" for a list of symbolic signals."));
8971 /* Print current contents of the tables set by the handle command.
8972 It is possible we should just be printing signals actually used
8973 by the current target (but for things to work right when switching
8974 targets, all signals should be in the signal tables). */
8977 info_signals_command (const char *signum_exp
, int from_tty
)
8979 enum gdb_signal oursig
;
8981 sig_print_header ();
8985 /* First see if this is a symbol name. */
8986 oursig
= gdb_signal_from_name (signum_exp
);
8987 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8989 /* No, try numeric. */
8991 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8993 sig_print_info (oursig
);
8997 printf_filtered ("\n");
8998 /* These ugly casts brought to you by the native VAX compiler. */
8999 for (oursig
= GDB_SIGNAL_FIRST
;
9000 (int) oursig
< (int) GDB_SIGNAL_LAST
;
9001 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
9005 if (oursig
!= GDB_SIGNAL_UNKNOWN
9006 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
9007 sig_print_info (oursig
);
9010 printf_filtered (_("\nUse the \"handle\" command "
9011 "to change these tables.\n"));
9014 /* The $_siginfo convenience variable is a bit special. We don't know
9015 for sure the type of the value until we actually have a chance to
9016 fetch the data. The type can change depending on gdbarch, so it is
9017 also dependent on which thread you have selected.
9019 1. making $_siginfo be an internalvar that creates a new value on
9022 2. making the value of $_siginfo be an lval_computed value. */
9024 /* This function implements the lval_computed support for reading a
9028 siginfo_value_read (struct value
*v
)
9030 LONGEST transferred
;
9032 /* If we can access registers, so can we access $_siginfo. Likewise
9034 validate_registers_access ();
9037 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
9039 value_contents_all_raw (v
),
9041 TYPE_LENGTH (value_type (v
)));
9043 if (transferred
!= TYPE_LENGTH (value_type (v
)))
9044 error (_("Unable to read siginfo"));
9047 /* This function implements the lval_computed support for writing a
9051 siginfo_value_write (struct value
*v
, struct value
*fromval
)
9053 LONGEST transferred
;
9055 /* If we can access registers, so can we access $_siginfo. Likewise
9057 validate_registers_access ();
9059 transferred
= target_write (current_top_target (),
9060 TARGET_OBJECT_SIGNAL_INFO
,
9062 value_contents_all_raw (fromval
),
9064 TYPE_LENGTH (value_type (fromval
)));
9066 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
9067 error (_("Unable to write siginfo"));
9070 static const struct lval_funcs siginfo_value_funcs
=
9076 /* Return a new value with the correct type for the siginfo object of
9077 the current thread using architecture GDBARCH. Return a void value
9078 if there's no object available. */
9080 static struct value
*
9081 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9084 if (target_has_stack
9085 && inferior_ptid
!= null_ptid
9086 && gdbarch_get_siginfo_type_p (gdbarch
))
9088 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9090 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
9093 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
9097 /* infcall_suspend_state contains state about the program itself like its
9098 registers and any signal it received when it last stopped.
9099 This state must be restored regardless of how the inferior function call
9100 ends (either successfully, or after it hits a breakpoint or signal)
9101 if the program is to properly continue where it left off. */
9103 class infcall_suspend_state
9106 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9107 once the inferior function call has finished. */
9108 infcall_suspend_state (struct gdbarch
*gdbarch
,
9109 const struct thread_info
*tp
,
9110 struct regcache
*regcache
)
9111 : m_thread_suspend (tp
->suspend
),
9112 m_registers (new readonly_detached_regcache (*regcache
))
9114 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9116 if (gdbarch_get_siginfo_type_p (gdbarch
))
9118 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9119 size_t len
= TYPE_LENGTH (type
);
9121 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9123 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9124 siginfo_data
.get (), 0, len
) != len
)
9126 /* Errors ignored. */
9127 siginfo_data
.reset (nullptr);
9133 m_siginfo_gdbarch
= gdbarch
;
9134 m_siginfo_data
= std::move (siginfo_data
);
9138 /* Return a pointer to the stored register state. */
9140 readonly_detached_regcache
*registers () const
9142 return m_registers
.get ();
9145 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9147 void restore (struct gdbarch
*gdbarch
,
9148 struct thread_info
*tp
,
9149 struct regcache
*regcache
) const
9151 tp
->suspend
= m_thread_suspend
;
9153 if (m_siginfo_gdbarch
== gdbarch
)
9155 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9157 /* Errors ignored. */
9158 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9159 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9162 /* The inferior can be gone if the user types "print exit(0)"
9163 (and perhaps other times). */
9164 if (target_has_execution
)
9165 /* NB: The register write goes through to the target. */
9166 regcache
->restore (registers ());
9170 /* How the current thread stopped before the inferior function call was
9172 struct thread_suspend_state m_thread_suspend
;
9174 /* The registers before the inferior function call was executed. */
9175 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9177 /* Format of SIGINFO_DATA or NULL if it is not present. */
9178 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9180 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9181 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9182 content would be invalid. */
9183 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9186 infcall_suspend_state_up
9187 save_infcall_suspend_state ()
9189 struct thread_info
*tp
= inferior_thread ();
9190 struct regcache
*regcache
= get_current_regcache ();
9191 struct gdbarch
*gdbarch
= regcache
->arch ();
9193 infcall_suspend_state_up inf_state
9194 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9196 /* Having saved the current state, adjust the thread state, discarding
9197 any stop signal information. The stop signal is not useful when
9198 starting an inferior function call, and run_inferior_call will not use
9199 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9200 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9205 /* Restore inferior session state to INF_STATE. */
9208 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9210 struct thread_info
*tp
= inferior_thread ();
9211 struct regcache
*regcache
= get_current_regcache ();
9212 struct gdbarch
*gdbarch
= regcache
->arch ();
9214 inf_state
->restore (gdbarch
, tp
, regcache
);
9215 discard_infcall_suspend_state (inf_state
);
9219 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9224 readonly_detached_regcache
*
9225 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9227 return inf_state
->registers ();
9230 /* infcall_control_state contains state regarding gdb's control of the
9231 inferior itself like stepping control. It also contains session state like
9232 the user's currently selected frame. */
9234 struct infcall_control_state
9236 struct thread_control_state thread_control
;
9237 struct inferior_control_state inferior_control
;
9240 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9241 int stopped_by_random_signal
= 0;
9243 /* ID if the selected frame when the inferior function call was made. */
9244 struct frame_id selected_frame_id
{};
9247 /* Save all of the information associated with the inferior<==>gdb
9250 infcall_control_state_up
9251 save_infcall_control_state ()
9253 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9254 struct thread_info
*tp
= inferior_thread ();
9255 struct inferior
*inf
= current_inferior ();
9257 inf_status
->thread_control
= tp
->control
;
9258 inf_status
->inferior_control
= inf
->control
;
9260 tp
->control
.step_resume_breakpoint
= NULL
;
9261 tp
->control
.exception_resume_breakpoint
= NULL
;
9263 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9264 chain. If caller's caller is walking the chain, they'll be happier if we
9265 hand them back the original chain when restore_infcall_control_state is
9267 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9270 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9271 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9273 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9279 restore_selected_frame (const frame_id
&fid
)
9281 frame_info
*frame
= frame_find_by_id (fid
);
9283 /* If inf_status->selected_frame_id is NULL, there was no previously
9287 warning (_("Unable to restore previously selected frame."));
9291 select_frame (frame
);
9294 /* Restore inferior session state to INF_STATUS. */
9297 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9299 struct thread_info
*tp
= inferior_thread ();
9300 struct inferior
*inf
= current_inferior ();
9302 if (tp
->control
.step_resume_breakpoint
)
9303 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9305 if (tp
->control
.exception_resume_breakpoint
)
9306 tp
->control
.exception_resume_breakpoint
->disposition
9307 = disp_del_at_next_stop
;
9309 /* Handle the bpstat_copy of the chain. */
9310 bpstat_clear (&tp
->control
.stop_bpstat
);
9312 tp
->control
= inf_status
->thread_control
;
9313 inf
->control
= inf_status
->inferior_control
;
9316 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9317 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9319 if (target_has_stack
)
9321 /* The point of the try/catch is that if the stack is clobbered,
9322 walking the stack might encounter a garbage pointer and
9323 error() trying to dereference it. */
9326 restore_selected_frame (inf_status
->selected_frame_id
);
9328 catch (const gdb_exception_error
&ex
)
9330 exception_fprintf (gdb_stderr
, ex
,
9331 "Unable to restore previously selected frame:\n");
9332 /* Error in restoring the selected frame. Select the
9334 select_frame (get_current_frame ());
9342 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9344 if (inf_status
->thread_control
.step_resume_breakpoint
)
9345 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9346 = disp_del_at_next_stop
;
9348 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9349 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9350 = disp_del_at_next_stop
;
9352 /* See save_infcall_control_state for info on stop_bpstat. */
9353 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9361 clear_exit_convenience_vars (void)
9363 clear_internalvar (lookup_internalvar ("_exitsignal"));
9364 clear_internalvar (lookup_internalvar ("_exitcode"));
9368 /* User interface for reverse debugging:
9369 Set exec-direction / show exec-direction commands
9370 (returns error unless target implements to_set_exec_direction method). */
9372 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9373 static const char exec_forward
[] = "forward";
9374 static const char exec_reverse
[] = "reverse";
9375 static const char *exec_direction
= exec_forward
;
9376 static const char *const exec_direction_names
[] = {
9383 set_exec_direction_func (const char *args
, int from_tty
,
9384 struct cmd_list_element
*cmd
)
9386 if (target_can_execute_reverse
)
9388 if (!strcmp (exec_direction
, exec_forward
))
9389 execution_direction
= EXEC_FORWARD
;
9390 else if (!strcmp (exec_direction
, exec_reverse
))
9391 execution_direction
= EXEC_REVERSE
;
9395 exec_direction
= exec_forward
;
9396 error (_("Target does not support this operation."));
9401 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9402 struct cmd_list_element
*cmd
, const char *value
)
9404 switch (execution_direction
) {
9406 fprintf_filtered (out
, _("Forward.\n"));
9409 fprintf_filtered (out
, _("Reverse.\n"));
9412 internal_error (__FILE__
, __LINE__
,
9413 _("bogus execution_direction value: %d"),
9414 (int) execution_direction
);
9419 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9420 struct cmd_list_element
*c
, const char *value
)
9422 fprintf_filtered (file
, _("Resuming the execution of threads "
9423 "of all processes is %s.\n"), value
);
9426 /* Implementation of `siginfo' variable. */
9428 static const struct internalvar_funcs siginfo_funcs
=
9435 /* Callback for infrun's target events source. This is marked when a
9436 thread has a pending status to process. */
9439 infrun_async_inferior_event_handler (gdb_client_data data
)
9441 inferior_event_handler (INF_REG_EVENT
);
9444 void _initialize_infrun ();
9446 _initialize_infrun ()
9448 struct cmd_list_element
*c
;
9450 /* Register extra event sources in the event loop. */
9451 infrun_async_inferior_event_token
9452 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9454 add_info ("signals", info_signals_command
, _("\
9455 What debugger does when program gets various signals.\n\
9456 Specify a signal as argument to print info on that signal only."));
9457 add_info_alias ("handle", "signals", 0);
9459 c
= add_com ("handle", class_run
, handle_command
, _("\
9460 Specify how to handle signals.\n\
9461 Usage: handle SIGNAL [ACTIONS]\n\
9462 Args are signals and actions to apply to those signals.\n\
9463 If no actions are specified, the current settings for the specified signals\n\
9464 will be displayed instead.\n\
9466 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9467 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9468 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9469 The special arg \"all\" is recognized to mean all signals except those\n\
9470 used by the debugger, typically SIGTRAP and SIGINT.\n\
9472 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9473 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9474 Stop means reenter debugger if this signal happens (implies print).\n\
9475 Print means print a message if this signal happens.\n\
9476 Pass means let program see this signal; otherwise program doesn't know.\n\
9477 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9478 Pass and Stop may be combined.\n\
9480 Multiple signals may be specified. Signal numbers and signal names\n\
9481 may be interspersed with actions, with the actions being performed for\n\
9482 all signals cumulatively specified."));
9483 set_cmd_completer (c
, handle_completer
);
9486 stop_command
= add_cmd ("stop", class_obscure
,
9487 not_just_help_class_command
, _("\
9488 There is no `stop' command, but you can set a hook on `stop'.\n\
9489 This allows you to set a list of commands to be run each time execution\n\
9490 of the program stops."), &cmdlist
);
9492 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9493 Set inferior debugging."), _("\
9494 Show inferior debugging."), _("\
9495 When non-zero, inferior specific debugging is enabled."),
9498 &setdebuglist
, &showdebuglist
);
9500 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9501 &debug_displaced
, _("\
9502 Set displaced stepping debugging."), _("\
9503 Show displaced stepping debugging."), _("\
9504 When non-zero, displaced stepping specific debugging is enabled."),
9506 show_debug_displaced
,
9507 &setdebuglist
, &showdebuglist
);
9509 add_setshow_boolean_cmd ("non-stop", no_class
,
9511 Set whether gdb controls the inferior in non-stop mode."), _("\
9512 Show whether gdb controls the inferior in non-stop mode."), _("\
9513 When debugging a multi-threaded program and this setting is\n\
9514 off (the default, also called all-stop mode), when one thread stops\n\
9515 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9516 all other threads in the program while you interact with the thread of\n\
9517 interest. When you continue or step a thread, you can allow the other\n\
9518 threads to run, or have them remain stopped, but while you inspect any\n\
9519 thread's state, all threads stop.\n\
9521 In non-stop mode, when one thread stops, other threads can continue\n\
9522 to run freely. You'll be able to step each thread independently,\n\
9523 leave it stopped or free to run as needed."),
9529 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9532 signal_print
[i
] = 1;
9533 signal_program
[i
] = 1;
9534 signal_catch
[i
] = 0;
9537 /* Signals caused by debugger's own actions should not be given to
9538 the program afterwards.
9540 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9541 explicitly specifies that it should be delivered to the target
9542 program. Typically, that would occur when a user is debugging a
9543 target monitor on a simulator: the target monitor sets a
9544 breakpoint; the simulator encounters this breakpoint and halts
9545 the simulation handing control to GDB; GDB, noting that the stop
9546 address doesn't map to any known breakpoint, returns control back
9547 to the simulator; the simulator then delivers the hardware
9548 equivalent of a GDB_SIGNAL_TRAP to the program being
9550 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9551 signal_program
[GDB_SIGNAL_INT
] = 0;
9553 /* Signals that are not errors should not normally enter the debugger. */
9554 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9555 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9556 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9557 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9558 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9559 signal_print
[GDB_SIGNAL_PROF
] = 0;
9560 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9561 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9562 signal_stop
[GDB_SIGNAL_IO
] = 0;
9563 signal_print
[GDB_SIGNAL_IO
] = 0;
9564 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9565 signal_print
[GDB_SIGNAL_POLL
] = 0;
9566 signal_stop
[GDB_SIGNAL_URG
] = 0;
9567 signal_print
[GDB_SIGNAL_URG
] = 0;
9568 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9569 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9570 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9571 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9573 /* These signals are used internally by user-level thread
9574 implementations. (See signal(5) on Solaris.) Like the above
9575 signals, a healthy program receives and handles them as part of
9576 its normal operation. */
9577 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9578 signal_print
[GDB_SIGNAL_LWP
] = 0;
9579 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9580 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9581 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9582 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9583 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9584 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9586 /* Update cached state. */
9587 signal_cache_update (-1);
9589 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9590 &stop_on_solib_events
, _("\
9591 Set stopping for shared library events."), _("\
9592 Show stopping for shared library events."), _("\
9593 If nonzero, gdb will give control to the user when the dynamic linker\n\
9594 notifies gdb of shared library events. The most common event of interest\n\
9595 to the user would be loading/unloading of a new library."),
9596 set_stop_on_solib_events
,
9597 show_stop_on_solib_events
,
9598 &setlist
, &showlist
);
9600 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9601 follow_fork_mode_kind_names
,
9602 &follow_fork_mode_string
, _("\
9603 Set debugger response to a program call of fork or vfork."), _("\
9604 Show debugger response to a program call of fork or vfork."), _("\
9605 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9606 parent - the original process is debugged after a fork\n\
9607 child - the new process is debugged after a fork\n\
9608 The unfollowed process will continue to run.\n\
9609 By default, the debugger will follow the parent process."),
9611 show_follow_fork_mode_string
,
9612 &setlist
, &showlist
);
9614 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9615 follow_exec_mode_names
,
9616 &follow_exec_mode_string
, _("\
9617 Set debugger response to a program call of exec."), _("\
9618 Show debugger response to a program call of exec."), _("\
9619 An exec call replaces the program image of a process.\n\
9621 follow-exec-mode can be:\n\
9623 new - the debugger creates a new inferior and rebinds the process\n\
9624 to this new inferior. The program the process was running before\n\
9625 the exec call can be restarted afterwards by restarting the original\n\
9628 same - the debugger keeps the process bound to the same inferior.\n\
9629 The new executable image replaces the previous executable loaded in\n\
9630 the inferior. Restarting the inferior after the exec call restarts\n\
9631 the executable the process was running after the exec call.\n\
9633 By default, the debugger will use the same inferior."),
9635 show_follow_exec_mode_string
,
9636 &setlist
, &showlist
);
9638 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9639 scheduler_enums
, &scheduler_mode
, _("\
9640 Set mode for locking scheduler during execution."), _("\
9641 Show mode for locking scheduler during execution."), _("\
9642 off == no locking (threads may preempt at any time)\n\
9643 on == full locking (no thread except the current thread may run)\n\
9644 This applies to both normal execution and replay mode.\n\
9645 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9646 In this mode, other threads may run during other commands.\n\
9647 This applies to both normal execution and replay mode.\n\
9648 replay == scheduler locked in replay mode and unlocked during normal execution."),
9649 set_schedlock_func
, /* traps on target vector */
9650 show_scheduler_mode
,
9651 &setlist
, &showlist
);
9653 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9654 Set mode for resuming threads of all processes."), _("\
9655 Show mode for resuming threads of all processes."), _("\
9656 When on, execution commands (such as 'continue' or 'next') resume all\n\
9657 threads of all processes. When off (which is the default), execution\n\
9658 commands only resume the threads of the current process. The set of\n\
9659 threads that are resumed is further refined by the scheduler-locking\n\
9660 mode (see help set scheduler-locking)."),
9662 show_schedule_multiple
,
9663 &setlist
, &showlist
);
9665 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9666 Set mode of the step operation."), _("\
9667 Show mode of the step operation."), _("\
9668 When set, doing a step over a function without debug line information\n\
9669 will stop at the first instruction of that function. Otherwise, the\n\
9670 function is skipped and the step command stops at a different source line."),
9672 show_step_stop_if_no_debug
,
9673 &setlist
, &showlist
);
9675 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9676 &can_use_displaced_stepping
, _("\
9677 Set debugger's willingness to use displaced stepping."), _("\
9678 Show debugger's willingness to use displaced stepping."), _("\
9679 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9680 supported by the target architecture. If off, gdb will not use displaced\n\
9681 stepping to step over breakpoints, even if such is supported by the target\n\
9682 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9683 if the target architecture supports it and non-stop mode is active, but will not\n\
9684 use it in all-stop mode (see help set non-stop)."),
9686 show_can_use_displaced_stepping
,
9687 &setlist
, &showlist
);
9689 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9690 &exec_direction
, _("Set direction of execution.\n\
9691 Options are 'forward' or 'reverse'."),
9692 _("Show direction of execution (forward/reverse)."),
9693 _("Tells gdb whether to execute forward or backward."),
9694 set_exec_direction_func
, show_exec_direction_func
,
9695 &setlist
, &showlist
);
9697 /* Set/show detach-on-fork: user-settable mode. */
9699 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9700 Set whether gdb will detach the child of a fork."), _("\
9701 Show whether gdb will detach the child of a fork."), _("\
9702 Tells gdb whether to detach the child of a fork."),
9703 NULL
, NULL
, &setlist
, &showlist
);
9705 /* Set/show disable address space randomization mode. */
9707 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9708 &disable_randomization
, _("\
9709 Set disabling of debuggee's virtual address space randomization."), _("\
9710 Show disabling of debuggee's virtual address space randomization."), _("\
9711 When this mode is on (which is the default), randomization of the virtual\n\
9712 address space is disabled. Standalone programs run with the randomization\n\
9713 enabled by default on some platforms."),
9714 &set_disable_randomization
,
9715 &show_disable_randomization
,
9716 &setlist
, &showlist
);
9718 /* ptid initializations */
9719 inferior_ptid
= null_ptid
;
9720 target_last_wait_ptid
= minus_one_ptid
;
9722 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9723 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9724 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9725 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9727 /* Explicitly create without lookup, since that tries to create a
9728 value with a void typed value, and when we get here, gdbarch
9729 isn't initialized yet. At this point, we're quite sure there
9730 isn't another convenience variable of the same name. */
9731 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9733 add_setshow_boolean_cmd ("observer", no_class
,
9734 &observer_mode_1
, _("\
9735 Set whether gdb controls the inferior in observer mode."), _("\
9736 Show whether gdb controls the inferior in observer mode."), _("\
9737 In observer mode, GDB can get data from the inferior, but not\n\
9738 affect its execution. Registers and memory may not be changed,\n\
9739 breakpoints may not be set, and the program cannot be interrupted\n\