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
, NULL
);
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 (void *client_data
)
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
, NULL
);
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 show "no unwaited-for " to the user. */
5072 update_thread_list ();
5074 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
5076 if (thread
->executing
5077 || thread
->suspend
.waitstatus_pending_p
)
5079 /* There were no unwaited-for children left in the target at
5080 some point, but there are now. Just ignore. */
5082 fprintf_unfiltered (gdb_stdlog
,
5083 "infrun: TARGET_WAITKIND_NO_RESUMED "
5084 "(ignoring: found resumed)\n");
5085 prepare_to_wait (ecs
);
5090 /* Go ahead and report the event. */
5094 /* Given an execution control state that has been freshly filled in by
5095 an event from the inferior, figure out what it means and take
5098 The alternatives are:
5100 1) stop_waiting and return; to really stop and return to the
5103 2) keep_going and return; to wait for the next event (set
5104 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5108 handle_inferior_event (struct execution_control_state
*ecs
)
5110 /* Make sure that all temporary struct value objects that were
5111 created during the handling of the event get deleted at the
5113 scoped_value_mark free_values
;
5115 enum stop_kind stop_soon
;
5118 fprintf_unfiltered (gdb_stdlog
, "infrun: handle_inferior_event %s\n",
5119 target_waitstatus_to_string (&ecs
->ws
).c_str ());
5121 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5123 /* We had an event in the inferior, but we are not interested in
5124 handling it at this level. The lower layers have already
5125 done what needs to be done, if anything.
5127 One of the possible circumstances for this is when the
5128 inferior produces output for the console. The inferior has
5129 not stopped, and we are ignoring the event. Another possible
5130 circumstance is any event which the lower level knows will be
5131 reported multiple times without an intervening resume. */
5132 prepare_to_wait (ecs
);
5136 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5138 prepare_to_wait (ecs
);
5142 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5143 && handle_no_resumed (ecs
))
5146 /* Cache the last target/ptid/waitstatus. */
5147 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5149 /* Always clear state belonging to the previous time we stopped. */
5150 stop_stack_dummy
= STOP_NONE
;
5152 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5154 /* No unwaited-for children left. IOW, all resumed children
5156 stop_print_frame
= 0;
5161 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5162 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5164 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5165 /* If it's a new thread, add it to the thread database. */
5166 if (ecs
->event_thread
== NULL
)
5167 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5169 /* Disable range stepping. If the next step request could use a
5170 range, this will be end up re-enabled then. */
5171 ecs
->event_thread
->control
.may_range_step
= 0;
5174 /* Dependent on valid ECS->EVENT_THREAD. */
5175 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5177 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5178 reinit_frame_cache ();
5180 breakpoint_retire_moribund ();
5182 /* First, distinguish signals caused by the debugger from signals
5183 that have to do with the program's own actions. Note that
5184 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5185 on the operating system version. Here we detect when a SIGILL or
5186 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5187 something similar for SIGSEGV, since a SIGSEGV will be generated
5188 when we're trying to execute a breakpoint instruction on a
5189 non-executable stack. This happens for call dummy breakpoints
5190 for architectures like SPARC that place call dummies on the
5192 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5193 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5194 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5195 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5197 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5199 if (breakpoint_inserted_here_p (regcache
->aspace (),
5200 regcache_read_pc (regcache
)))
5203 fprintf_unfiltered (gdb_stdlog
,
5204 "infrun: Treating signal as SIGTRAP\n");
5205 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5209 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5211 switch (ecs
->ws
.kind
)
5213 case TARGET_WAITKIND_LOADED
:
5214 context_switch (ecs
);
5215 /* Ignore gracefully during startup of the inferior, as it might
5216 be the shell which has just loaded some objects, otherwise
5217 add the symbols for the newly loaded objects. Also ignore at
5218 the beginning of an attach or remote session; we will query
5219 the full list of libraries once the connection is
5222 stop_soon
= get_inferior_stop_soon (ecs
);
5223 if (stop_soon
== NO_STOP_QUIETLY
)
5225 struct regcache
*regcache
;
5227 regcache
= get_thread_regcache (ecs
->event_thread
);
5229 handle_solib_event ();
5231 ecs
->event_thread
->control
.stop_bpstat
5232 = bpstat_stop_status (regcache
->aspace (),
5233 ecs
->event_thread
->suspend
.stop_pc
,
5234 ecs
->event_thread
, &ecs
->ws
);
5236 if (handle_stop_requested (ecs
))
5239 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5241 /* A catchpoint triggered. */
5242 process_event_stop_test (ecs
);
5246 /* If requested, stop when the dynamic linker notifies
5247 gdb of events. This allows the user to get control
5248 and place breakpoints in initializer routines for
5249 dynamically loaded objects (among other things). */
5250 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5251 if (stop_on_solib_events
)
5253 /* Make sure we print "Stopped due to solib-event" in
5255 stop_print_frame
= 1;
5262 /* If we are skipping through a shell, or through shared library
5263 loading that we aren't interested in, resume the program. If
5264 we're running the program normally, also resume. */
5265 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5267 /* Loading of shared libraries might have changed breakpoint
5268 addresses. Make sure new breakpoints are inserted. */
5269 if (stop_soon
== NO_STOP_QUIETLY
)
5270 insert_breakpoints ();
5271 resume (GDB_SIGNAL_0
);
5272 prepare_to_wait (ecs
);
5276 /* But stop if we're attaching or setting up a remote
5278 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5279 || stop_soon
== STOP_QUIETLY_REMOTE
)
5282 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5287 internal_error (__FILE__
, __LINE__
,
5288 _("unhandled stop_soon: %d"), (int) stop_soon
);
5290 case TARGET_WAITKIND_SPURIOUS
:
5291 if (handle_stop_requested (ecs
))
5293 context_switch (ecs
);
5294 resume (GDB_SIGNAL_0
);
5295 prepare_to_wait (ecs
);
5298 case TARGET_WAITKIND_THREAD_CREATED
:
5299 if (handle_stop_requested (ecs
))
5301 context_switch (ecs
);
5302 if (!switch_back_to_stepped_thread (ecs
))
5306 case TARGET_WAITKIND_EXITED
:
5307 case TARGET_WAITKIND_SIGNALLED
:
5309 /* Depending on the system, ecs->ptid may point to a thread or
5310 to a process. On some targets, target_mourn_inferior may
5311 need to have access to the just-exited thread. That is the
5312 case of GNU/Linux's "checkpoint" support, for example.
5313 Call the switch_to_xxx routine as appropriate. */
5314 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5316 switch_to_thread (thr
);
5319 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5320 switch_to_inferior_no_thread (inf
);
5323 handle_vfork_child_exec_or_exit (0);
5324 target_terminal::ours (); /* Must do this before mourn anyway. */
5326 /* Clearing any previous state of convenience variables. */
5327 clear_exit_convenience_vars ();
5329 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5331 /* Record the exit code in the convenience variable $_exitcode, so
5332 that the user can inspect this again later. */
5333 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5334 (LONGEST
) ecs
->ws
.value
.integer
);
5336 /* Also record this in the inferior itself. */
5337 current_inferior ()->has_exit_code
= 1;
5338 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5340 /* Support the --return-child-result option. */
5341 return_child_result_value
= ecs
->ws
.value
.integer
;
5343 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5347 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5349 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5351 /* Set the value of the internal variable $_exitsignal,
5352 which holds the signal uncaught by the inferior. */
5353 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5354 gdbarch_gdb_signal_to_target (gdbarch
,
5355 ecs
->ws
.value
.sig
));
5359 /* We don't have access to the target's method used for
5360 converting between signal numbers (GDB's internal
5361 representation <-> target's representation).
5362 Therefore, we cannot do a good job at displaying this
5363 information to the user. It's better to just warn
5364 her about it (if infrun debugging is enabled), and
5367 fprintf_filtered (gdb_stdlog
, _("\
5368 Cannot fill $_exitsignal with the correct signal number.\n"));
5371 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5374 gdb_flush (gdb_stdout
);
5375 target_mourn_inferior (inferior_ptid
);
5376 stop_print_frame
= 0;
5380 case TARGET_WAITKIND_FORKED
:
5381 case TARGET_WAITKIND_VFORKED
:
5382 /* Check whether the inferior is displaced stepping. */
5384 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5385 struct gdbarch
*gdbarch
= regcache
->arch ();
5387 /* If checking displaced stepping is supported, and thread
5388 ecs->ptid is displaced stepping. */
5389 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5391 struct inferior
*parent_inf
5392 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5393 struct regcache
*child_regcache
;
5394 CORE_ADDR parent_pc
;
5396 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5398 struct displaced_step_inferior_state
*displaced
5399 = get_displaced_stepping_state (parent_inf
);
5401 /* Restore scratch pad for child process. */
5402 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5405 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5406 indicating that the displaced stepping of syscall instruction
5407 has been done. Perform cleanup for parent process here. Note
5408 that this operation also cleans up the child process for vfork,
5409 because their pages are shared. */
5410 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5411 /* Start a new step-over in another thread if there's one
5415 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5416 the child's PC is also within the scratchpad. Set the child's PC
5417 to the parent's PC value, which has already been fixed up.
5418 FIXME: we use the parent's aspace here, although we're touching
5419 the child, because the child hasn't been added to the inferior
5420 list yet at this point. */
5423 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5424 ecs
->ws
.value
.related_pid
,
5426 parent_inf
->aspace
);
5427 /* Read PC value of parent process. */
5428 parent_pc
= regcache_read_pc (regcache
);
5430 if (debug_displaced
)
5431 fprintf_unfiltered (gdb_stdlog
,
5432 "displaced: write child pc from %s to %s\n",
5434 regcache_read_pc (child_regcache
)),
5435 paddress (gdbarch
, parent_pc
));
5437 regcache_write_pc (child_regcache
, parent_pc
);
5441 context_switch (ecs
);
5443 /* Immediately detach breakpoints from the child before there's
5444 any chance of letting the user delete breakpoints from the
5445 breakpoint lists. If we don't do this early, it's easy to
5446 leave left over traps in the child, vis: "break foo; catch
5447 fork; c; <fork>; del; c; <child calls foo>". We only follow
5448 the fork on the last `continue', and by that time the
5449 breakpoint at "foo" is long gone from the breakpoint table.
5450 If we vforked, then we don't need to unpatch here, since both
5451 parent and child are sharing the same memory pages; we'll
5452 need to unpatch at follow/detach time instead to be certain
5453 that new breakpoints added between catchpoint hit time and
5454 vfork follow are detached. */
5455 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5457 /* This won't actually modify the breakpoint list, but will
5458 physically remove the breakpoints from the child. */
5459 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5462 delete_just_stopped_threads_single_step_breakpoints ();
5464 /* In case the event is caught by a catchpoint, remember that
5465 the event is to be followed at the next resume of the thread,
5466 and not immediately. */
5467 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5469 ecs
->event_thread
->suspend
.stop_pc
5470 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5472 ecs
->event_thread
->control
.stop_bpstat
5473 = bpstat_stop_status (get_current_regcache ()->aspace (),
5474 ecs
->event_thread
->suspend
.stop_pc
,
5475 ecs
->event_thread
, &ecs
->ws
);
5477 if (handle_stop_requested (ecs
))
5480 /* If no catchpoint triggered for this, then keep going. Note
5481 that we're interested in knowing the bpstat actually causes a
5482 stop, not just if it may explain the signal. Software
5483 watchpoints, for example, always appear in the bpstat. */
5484 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5487 = (follow_fork_mode_string
== follow_fork_mode_child
);
5489 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5491 process_stratum_target
*targ
5492 = ecs
->event_thread
->inf
->process_target ();
5494 bool should_resume
= follow_fork ();
5496 /* Note that one of these may be an invalid pointer,
5497 depending on detach_fork. */
5498 thread_info
*parent
= ecs
->event_thread
;
5500 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5502 /* At this point, the parent is marked running, and the
5503 child is marked stopped. */
5505 /* If not resuming the parent, mark it stopped. */
5506 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5507 parent
->set_running (false);
5509 /* If resuming the child, mark it running. */
5510 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5511 child
->set_running (true);
5513 /* In non-stop mode, also resume the other branch. */
5514 if (!detach_fork
&& (non_stop
5515 || (sched_multi
&& target_is_non_stop_p ())))
5518 switch_to_thread (parent
);
5520 switch_to_thread (child
);
5522 ecs
->event_thread
= inferior_thread ();
5523 ecs
->ptid
= inferior_ptid
;
5528 switch_to_thread (child
);
5530 switch_to_thread (parent
);
5532 ecs
->event_thread
= inferior_thread ();
5533 ecs
->ptid
= inferior_ptid
;
5541 process_event_stop_test (ecs
);
5544 case TARGET_WAITKIND_VFORK_DONE
:
5545 /* Done with the shared memory region. Re-insert breakpoints in
5546 the parent, and keep going. */
5548 context_switch (ecs
);
5550 current_inferior ()->waiting_for_vfork_done
= 0;
5551 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5553 if (handle_stop_requested (ecs
))
5556 /* This also takes care of reinserting breakpoints in the
5557 previously locked inferior. */
5561 case TARGET_WAITKIND_EXECD
:
5563 /* Note we can't read registers yet (the stop_pc), because we
5564 don't yet know the inferior's post-exec architecture.
5565 'stop_pc' is explicitly read below instead. */
5566 switch_to_thread_no_regs (ecs
->event_thread
);
5568 /* Do whatever is necessary to the parent branch of the vfork. */
5569 handle_vfork_child_exec_or_exit (1);
5571 /* This causes the eventpoints and symbol table to be reset.
5572 Must do this now, before trying to determine whether to
5574 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5576 /* In follow_exec we may have deleted the original thread and
5577 created a new one. Make sure that the event thread is the
5578 execd thread for that case (this is a nop otherwise). */
5579 ecs
->event_thread
= inferior_thread ();
5581 ecs
->event_thread
->suspend
.stop_pc
5582 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5584 ecs
->event_thread
->control
.stop_bpstat
5585 = bpstat_stop_status (get_current_regcache ()->aspace (),
5586 ecs
->event_thread
->suspend
.stop_pc
,
5587 ecs
->event_thread
, &ecs
->ws
);
5589 /* Note that this may be referenced from inside
5590 bpstat_stop_status above, through inferior_has_execd. */
5591 xfree (ecs
->ws
.value
.execd_pathname
);
5592 ecs
->ws
.value
.execd_pathname
= NULL
;
5594 if (handle_stop_requested (ecs
))
5597 /* If no catchpoint triggered for this, then keep going. */
5598 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5600 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5604 process_event_stop_test (ecs
);
5607 /* Be careful not to try to gather much state about a thread
5608 that's in a syscall. It's frequently a losing proposition. */
5609 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5610 /* Getting the current syscall number. */
5611 if (handle_syscall_event (ecs
) == 0)
5612 process_event_stop_test (ecs
);
5615 /* Before examining the threads further, step this thread to
5616 get it entirely out of the syscall. (We get notice of the
5617 event when the thread is just on the verge of exiting a
5618 syscall. Stepping one instruction seems to get it back
5620 case TARGET_WAITKIND_SYSCALL_RETURN
:
5621 if (handle_syscall_event (ecs
) == 0)
5622 process_event_stop_test (ecs
);
5625 case TARGET_WAITKIND_STOPPED
:
5626 handle_signal_stop (ecs
);
5629 case TARGET_WAITKIND_NO_HISTORY
:
5630 /* Reverse execution: target ran out of history info. */
5632 /* Switch to the stopped thread. */
5633 context_switch (ecs
);
5635 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped\n");
5637 delete_just_stopped_threads_single_step_breakpoints ();
5638 ecs
->event_thread
->suspend
.stop_pc
5639 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5641 if (handle_stop_requested (ecs
))
5644 gdb::observers::no_history
.notify ();
5650 /* Restart threads back to what they were trying to do back when we
5651 paused them for an in-line step-over. The EVENT_THREAD thread is
5655 restart_threads (struct thread_info
*event_thread
)
5657 /* In case the instruction just stepped spawned a new thread. */
5658 update_thread_list ();
5660 for (thread_info
*tp
: all_non_exited_threads ())
5662 switch_to_thread_no_regs (tp
);
5664 if (tp
== event_thread
)
5667 fprintf_unfiltered (gdb_stdlog
,
5668 "infrun: restart threads: "
5669 "[%s] is event thread\n",
5670 target_pid_to_str (tp
->ptid
).c_str ());
5674 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5677 fprintf_unfiltered (gdb_stdlog
,
5678 "infrun: restart threads: "
5679 "[%s] not meant to be running\n",
5680 target_pid_to_str (tp
->ptid
).c_str ());
5687 fprintf_unfiltered (gdb_stdlog
,
5688 "infrun: restart threads: [%s] resumed\n",
5689 target_pid_to_str (tp
->ptid
).c_str ());
5690 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5694 if (thread_is_in_step_over_chain (tp
))
5697 fprintf_unfiltered (gdb_stdlog
,
5698 "infrun: restart threads: "
5699 "[%s] needs step-over\n",
5700 target_pid_to_str (tp
->ptid
).c_str ());
5701 gdb_assert (!tp
->resumed
);
5706 if (tp
->suspend
.waitstatus_pending_p
)
5709 fprintf_unfiltered (gdb_stdlog
,
5710 "infrun: restart threads: "
5711 "[%s] has pending status\n",
5712 target_pid_to_str (tp
->ptid
).c_str ());
5717 gdb_assert (!tp
->stop_requested
);
5719 /* If some thread needs to start a step-over at this point, it
5720 should still be in the step-over queue, and thus skipped
5722 if (thread_still_needs_step_over (tp
))
5724 internal_error (__FILE__
, __LINE__
,
5725 "thread [%s] needs a step-over, but not in "
5726 "step-over queue\n",
5727 target_pid_to_str (tp
->ptid
).c_str ());
5730 if (currently_stepping (tp
))
5733 fprintf_unfiltered (gdb_stdlog
,
5734 "infrun: restart threads: [%s] was stepping\n",
5735 target_pid_to_str (tp
->ptid
).c_str ());
5736 keep_going_stepped_thread (tp
);
5740 struct execution_control_state ecss
;
5741 struct execution_control_state
*ecs
= &ecss
;
5744 fprintf_unfiltered (gdb_stdlog
,
5745 "infrun: restart threads: [%s] continuing\n",
5746 target_pid_to_str (tp
->ptid
).c_str ());
5747 reset_ecs (ecs
, tp
);
5748 switch_to_thread (tp
);
5749 keep_going_pass_signal (ecs
);
5754 /* Callback for iterate_over_threads. Find a resumed thread that has
5755 a pending waitstatus. */
5758 resumed_thread_with_pending_status (struct thread_info
*tp
,
5762 && tp
->suspend
.waitstatus_pending_p
);
5765 /* Called when we get an event that may finish an in-line or
5766 out-of-line (displaced stepping) step-over started previously.
5767 Return true if the event is processed and we should go back to the
5768 event loop; false if the caller should continue processing the
5772 finish_step_over (struct execution_control_state
*ecs
)
5774 int had_step_over_info
;
5776 displaced_step_fixup (ecs
->event_thread
,
5777 ecs
->event_thread
->suspend
.stop_signal
);
5779 had_step_over_info
= step_over_info_valid_p ();
5781 if (had_step_over_info
)
5783 /* If we're stepping over a breakpoint with all threads locked,
5784 then only the thread that was stepped should be reporting
5786 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5788 clear_step_over_info ();
5791 if (!target_is_non_stop_p ())
5794 /* Start a new step-over in another thread if there's one that
5798 /* If we were stepping over a breakpoint before, and haven't started
5799 a new in-line step-over sequence, then restart all other threads
5800 (except the event thread). We can't do this in all-stop, as then
5801 e.g., we wouldn't be able to issue any other remote packet until
5802 these other threads stop. */
5803 if (had_step_over_info
&& !step_over_info_valid_p ())
5805 struct thread_info
*pending
;
5807 /* If we only have threads with pending statuses, the restart
5808 below won't restart any thread and so nothing re-inserts the
5809 breakpoint we just stepped over. But we need it inserted
5810 when we later process the pending events, otherwise if
5811 another thread has a pending event for this breakpoint too,
5812 we'd discard its event (because the breakpoint that
5813 originally caused the event was no longer inserted). */
5814 context_switch (ecs
);
5815 insert_breakpoints ();
5817 restart_threads (ecs
->event_thread
);
5819 /* If we have events pending, go through handle_inferior_event
5820 again, picking up a pending event at random. This avoids
5821 thread starvation. */
5823 /* But not if we just stepped over a watchpoint in order to let
5824 the instruction execute so we can evaluate its expression.
5825 The set of watchpoints that triggered is recorded in the
5826 breakpoint objects themselves (see bp->watchpoint_triggered).
5827 If we processed another event first, that other event could
5828 clobber this info. */
5829 if (ecs
->event_thread
->stepping_over_watchpoint
)
5832 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5834 if (pending
!= NULL
)
5836 struct thread_info
*tp
= ecs
->event_thread
;
5837 struct regcache
*regcache
;
5841 fprintf_unfiltered (gdb_stdlog
,
5842 "infrun: found resumed threads with "
5843 "pending events, saving status\n");
5846 gdb_assert (pending
!= tp
);
5848 /* Record the event thread's event for later. */
5849 save_waitstatus (tp
, &ecs
->ws
);
5850 /* This was cleared early, by handle_inferior_event. Set it
5851 so this pending event is considered by
5855 gdb_assert (!tp
->executing
);
5857 regcache
= get_thread_regcache (tp
);
5858 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5862 fprintf_unfiltered (gdb_stdlog
,
5863 "infrun: saved stop_pc=%s for %s "
5864 "(currently_stepping=%d)\n",
5865 paddress (target_gdbarch (),
5866 tp
->suspend
.stop_pc
),
5867 target_pid_to_str (tp
->ptid
).c_str (),
5868 currently_stepping (tp
));
5871 /* This in-line step-over finished; clear this so we won't
5872 start a new one. This is what handle_signal_stop would
5873 do, if we returned false. */
5874 tp
->stepping_over_breakpoint
= 0;
5876 /* Wake up the event loop again. */
5877 mark_async_event_handler (infrun_async_inferior_event_token
);
5879 prepare_to_wait (ecs
);
5887 /* Come here when the program has stopped with a signal. */
5890 handle_signal_stop (struct execution_control_state
*ecs
)
5892 struct frame_info
*frame
;
5893 struct gdbarch
*gdbarch
;
5894 int stopped_by_watchpoint
;
5895 enum stop_kind stop_soon
;
5898 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5900 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5902 /* Do we need to clean up the state of a thread that has
5903 completed a displaced single-step? (Doing so usually affects
5904 the PC, so do it here, before we set stop_pc.) */
5905 if (finish_step_over (ecs
))
5908 /* If we either finished a single-step or hit a breakpoint, but
5909 the user wanted this thread to be stopped, pretend we got a
5910 SIG0 (generic unsignaled stop). */
5911 if (ecs
->event_thread
->stop_requested
5912 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5913 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5915 ecs
->event_thread
->suspend
.stop_pc
5916 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5920 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5921 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5923 switch_to_thread (ecs
->event_thread
);
5925 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_pc = %s\n",
5926 paddress (reg_gdbarch
,
5927 ecs
->event_thread
->suspend
.stop_pc
));
5928 if (target_stopped_by_watchpoint ())
5932 fprintf_unfiltered (gdb_stdlog
, "infrun: stopped by watchpoint\n");
5934 if (target_stopped_data_address (current_top_target (), &addr
))
5935 fprintf_unfiltered (gdb_stdlog
,
5936 "infrun: stopped data address = %s\n",
5937 paddress (reg_gdbarch
, addr
));
5939 fprintf_unfiltered (gdb_stdlog
,
5940 "infrun: (no data address available)\n");
5944 /* This is originated from start_remote(), start_inferior() and
5945 shared libraries hook functions. */
5946 stop_soon
= get_inferior_stop_soon (ecs
);
5947 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5949 context_switch (ecs
);
5951 fprintf_unfiltered (gdb_stdlog
, "infrun: quietly stopped\n");
5952 stop_print_frame
= 1;
5957 /* This originates from attach_command(). We need to overwrite
5958 the stop_signal here, because some kernels don't ignore a
5959 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5960 See more comments in inferior.h. On the other hand, if we
5961 get a non-SIGSTOP, report it to the user - assume the backend
5962 will handle the SIGSTOP if it should show up later.
5964 Also consider that the attach is complete when we see a
5965 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5966 target extended-remote report it instead of a SIGSTOP
5967 (e.g. gdbserver). We already rely on SIGTRAP being our
5968 signal, so this is no exception.
5970 Also consider that the attach is complete when we see a
5971 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5972 the target to stop all threads of the inferior, in case the
5973 low level attach operation doesn't stop them implicitly. If
5974 they weren't stopped implicitly, then the stub will report a
5975 GDB_SIGNAL_0, meaning: stopped for no particular reason
5976 other than GDB's request. */
5977 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5978 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5979 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5980 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5982 stop_print_frame
= 1;
5984 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5988 /* See if something interesting happened to the non-current thread. If
5989 so, then switch to that thread. */
5990 if (ecs
->ptid
!= inferior_ptid
)
5993 fprintf_unfiltered (gdb_stdlog
, "infrun: context switch\n");
5995 context_switch (ecs
);
5997 if (deprecated_context_hook
)
5998 deprecated_context_hook (ecs
->event_thread
->global_num
);
6001 /* At this point, get hold of the now-current thread's frame. */
6002 frame
= get_current_frame ();
6003 gdbarch
= get_frame_arch (frame
);
6005 /* Pull the single step breakpoints out of the target. */
6006 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
6008 struct regcache
*regcache
;
6011 regcache
= get_thread_regcache (ecs
->event_thread
);
6012 const address_space
*aspace
= regcache
->aspace ();
6014 pc
= regcache_read_pc (regcache
);
6016 /* However, before doing so, if this single-step breakpoint was
6017 actually for another thread, set this thread up for moving
6019 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
6022 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
6026 fprintf_unfiltered (gdb_stdlog
,
6027 "infrun: [%s] hit another thread's "
6028 "single-step breakpoint\n",
6029 target_pid_to_str (ecs
->ptid
).c_str ());
6031 ecs
->hit_singlestep_breakpoint
= 1;
6038 fprintf_unfiltered (gdb_stdlog
,
6039 "infrun: [%s] hit its "
6040 "single-step breakpoint\n",
6041 target_pid_to_str (ecs
->ptid
).c_str ());
6045 delete_just_stopped_threads_single_step_breakpoints ();
6047 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6048 && ecs
->event_thread
->control
.trap_expected
6049 && ecs
->event_thread
->stepping_over_watchpoint
)
6050 stopped_by_watchpoint
= 0;
6052 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
6054 /* If necessary, step over this watchpoint. We'll be back to display
6056 if (stopped_by_watchpoint
6057 && (target_have_steppable_watchpoint
6058 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
6060 /* At this point, we are stopped at an instruction which has
6061 attempted to write to a piece of memory under control of
6062 a watchpoint. The instruction hasn't actually executed
6063 yet. If we were to evaluate the watchpoint expression
6064 now, we would get the old value, and therefore no change
6065 would seem to have occurred.
6067 In order to make watchpoints work `right', we really need
6068 to complete the memory write, and then evaluate the
6069 watchpoint expression. We do this by single-stepping the
6072 It may not be necessary to disable the watchpoint to step over
6073 it. For example, the PA can (with some kernel cooperation)
6074 single step over a watchpoint without disabling the watchpoint.
6076 It is far more common to need to disable a watchpoint to step
6077 the inferior over it. If we have non-steppable watchpoints,
6078 we must disable the current watchpoint; it's simplest to
6079 disable all watchpoints.
6081 Any breakpoint at PC must also be stepped over -- if there's
6082 one, it will have already triggered before the watchpoint
6083 triggered, and we either already reported it to the user, or
6084 it didn't cause a stop and we called keep_going. In either
6085 case, if there was a breakpoint at PC, we must be trying to
6087 ecs
->event_thread
->stepping_over_watchpoint
= 1;
6092 ecs
->event_thread
->stepping_over_breakpoint
= 0;
6093 ecs
->event_thread
->stepping_over_watchpoint
= 0;
6094 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
6095 ecs
->event_thread
->control
.stop_step
= 0;
6096 stop_print_frame
= 1;
6097 stopped_by_random_signal
= 0;
6098 bpstat stop_chain
= NULL
;
6100 /* Hide inlined functions starting here, unless we just performed stepi or
6101 nexti. After stepi and nexti, always show the innermost frame (not any
6102 inline function call sites). */
6103 if (ecs
->event_thread
->control
.step_range_end
!= 1)
6105 const address_space
*aspace
6106 = get_thread_regcache (ecs
->event_thread
)->aspace ();
6108 /* skip_inline_frames is expensive, so we avoid it if we can
6109 determine that the address is one where functions cannot have
6110 been inlined. This improves performance with inferiors that
6111 load a lot of shared libraries, because the solib event
6112 breakpoint is defined as the address of a function (i.e. not
6113 inline). Note that we have to check the previous PC as well
6114 as the current one to catch cases when we have just
6115 single-stepped off a breakpoint prior to reinstating it.
6116 Note that we're assuming that the code we single-step to is
6117 not inline, but that's not definitive: there's nothing
6118 preventing the event breakpoint function from containing
6119 inlined code, and the single-step ending up there. If the
6120 user had set a breakpoint on that inlined code, the missing
6121 skip_inline_frames call would break things. Fortunately
6122 that's an extremely unlikely scenario. */
6123 if (!pc_at_non_inline_function (aspace
,
6124 ecs
->event_thread
->suspend
.stop_pc
,
6126 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6127 && ecs
->event_thread
->control
.trap_expected
6128 && pc_at_non_inline_function (aspace
,
6129 ecs
->event_thread
->prev_pc
,
6132 stop_chain
= build_bpstat_chain (aspace
,
6133 ecs
->event_thread
->suspend
.stop_pc
,
6135 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6137 /* Re-fetch current thread's frame in case that invalidated
6139 frame
= get_current_frame ();
6140 gdbarch
= get_frame_arch (frame
);
6144 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6145 && ecs
->event_thread
->control
.trap_expected
6146 && gdbarch_single_step_through_delay_p (gdbarch
)
6147 && currently_stepping (ecs
->event_thread
))
6149 /* We're trying to step off a breakpoint. Turns out that we're
6150 also on an instruction that needs to be stepped multiple
6151 times before it's been fully executing. E.g., architectures
6152 with a delay slot. It needs to be stepped twice, once for
6153 the instruction and once for the delay slot. */
6154 int step_through_delay
6155 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6157 if (debug_infrun
&& step_through_delay
)
6158 fprintf_unfiltered (gdb_stdlog
, "infrun: step through delay\n");
6159 if (ecs
->event_thread
->control
.step_range_end
== 0
6160 && step_through_delay
)
6162 /* The user issued a continue when stopped at a breakpoint.
6163 Set up for another trap and get out of here. */
6164 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6168 else if (step_through_delay
)
6170 /* The user issued a step when stopped at a breakpoint.
6171 Maybe we should stop, maybe we should not - the delay
6172 slot *might* correspond to a line of source. In any
6173 case, don't decide that here, just set
6174 ecs->stepping_over_breakpoint, making sure we
6175 single-step again before breakpoints are re-inserted. */
6176 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6180 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6181 handles this event. */
6182 ecs
->event_thread
->control
.stop_bpstat
6183 = bpstat_stop_status (get_current_regcache ()->aspace (),
6184 ecs
->event_thread
->suspend
.stop_pc
,
6185 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6187 /* Following in case break condition called a
6189 stop_print_frame
= 1;
6191 /* This is where we handle "moribund" watchpoints. Unlike
6192 software breakpoints traps, hardware watchpoint traps are
6193 always distinguishable from random traps. If no high-level
6194 watchpoint is associated with the reported stop data address
6195 anymore, then the bpstat does not explain the signal ---
6196 simply make sure to ignore it if `stopped_by_watchpoint' is
6200 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6201 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6203 && stopped_by_watchpoint
)
6204 fprintf_unfiltered (gdb_stdlog
,
6205 "infrun: no user watchpoint explains "
6206 "watchpoint SIGTRAP, ignoring\n");
6208 /* NOTE: cagney/2003-03-29: These checks for a random signal
6209 at one stage in the past included checks for an inferior
6210 function call's call dummy's return breakpoint. The original
6211 comment, that went with the test, read:
6213 ``End of a stack dummy. Some systems (e.g. Sony news) give
6214 another signal besides SIGTRAP, so check here as well as
6217 If someone ever tries to get call dummys on a
6218 non-executable stack to work (where the target would stop
6219 with something like a SIGSEGV), then those tests might need
6220 to be re-instated. Given, however, that the tests were only
6221 enabled when momentary breakpoints were not being used, I
6222 suspect that it won't be the case.
6224 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6225 be necessary for call dummies on a non-executable stack on
6228 /* See if the breakpoints module can explain the signal. */
6230 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6231 ecs
->event_thread
->suspend
.stop_signal
);
6233 /* Maybe this was a trap for a software breakpoint that has since
6235 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6237 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6238 ecs
->event_thread
->suspend
.stop_pc
))
6240 struct regcache
*regcache
;
6243 /* Re-adjust PC to what the program would see if GDB was not
6245 regcache
= get_thread_regcache (ecs
->event_thread
);
6246 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6249 gdb::optional
<scoped_restore_tmpl
<int>>
6250 restore_operation_disable
;
6252 if (record_full_is_used ())
6253 restore_operation_disable
.emplace
6254 (record_full_gdb_operation_disable_set ());
6256 regcache_write_pc (regcache
,
6257 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6262 /* A delayed software breakpoint event. Ignore the trap. */
6264 fprintf_unfiltered (gdb_stdlog
,
6265 "infrun: delayed software breakpoint "
6266 "trap, ignoring\n");
6271 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6272 has since been removed. */
6273 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6275 /* A delayed hardware breakpoint event. Ignore the trap. */
6277 fprintf_unfiltered (gdb_stdlog
,
6278 "infrun: delayed hardware breakpoint/watchpoint "
6279 "trap, ignoring\n");
6283 /* If not, perhaps stepping/nexting can. */
6285 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6286 && currently_stepping (ecs
->event_thread
));
6288 /* Perhaps the thread hit a single-step breakpoint of _another_
6289 thread. Single-step breakpoints are transparent to the
6290 breakpoints module. */
6292 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6294 /* No? Perhaps we got a moribund watchpoint. */
6296 random_signal
= !stopped_by_watchpoint
;
6298 /* Always stop if the user explicitly requested this thread to
6300 if (ecs
->event_thread
->stop_requested
)
6304 fprintf_unfiltered (gdb_stdlog
, "infrun: user-requested stop\n");
6307 /* For the program's own signals, act according to
6308 the signal handling tables. */
6312 /* Signal not for debugging purposes. */
6313 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6314 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6317 fprintf_unfiltered (gdb_stdlog
, "infrun: random signal (%s)\n",
6318 gdb_signal_to_symbol_string (stop_signal
));
6320 stopped_by_random_signal
= 1;
6322 /* Always stop on signals if we're either just gaining control
6323 of the program, or the user explicitly requested this thread
6324 to remain stopped. */
6325 if (stop_soon
!= NO_STOP_QUIETLY
6326 || ecs
->event_thread
->stop_requested
6328 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6334 /* Notify observers the signal has "handle print" set. Note we
6335 returned early above if stopping; normal_stop handles the
6336 printing in that case. */
6337 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6339 /* The signal table tells us to print about this signal. */
6340 target_terminal::ours_for_output ();
6341 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6342 target_terminal::inferior ();
6345 /* Clear the signal if it should not be passed. */
6346 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6347 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6349 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6350 && ecs
->event_thread
->control
.trap_expected
6351 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6353 /* We were just starting a new sequence, attempting to
6354 single-step off of a breakpoint and expecting a SIGTRAP.
6355 Instead this signal arrives. This signal will take us out
6356 of the stepping range so GDB needs to remember to, when
6357 the signal handler returns, resume stepping off that
6359 /* To simplify things, "continue" is forced to use the same
6360 code paths as single-step - set a breakpoint at the
6361 signal return address and then, once hit, step off that
6364 fprintf_unfiltered (gdb_stdlog
,
6365 "infrun: signal arrived while stepping over "
6368 insert_hp_step_resume_breakpoint_at_frame (frame
);
6369 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6370 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6371 ecs
->event_thread
->control
.trap_expected
= 0;
6373 /* If we were nexting/stepping some other thread, switch to
6374 it, so that we don't continue it, losing control. */
6375 if (!switch_back_to_stepped_thread (ecs
))
6380 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6381 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6383 || ecs
->event_thread
->control
.step_range_end
== 1)
6384 && frame_id_eq (get_stack_frame_id (frame
),
6385 ecs
->event_thread
->control
.step_stack_frame_id
)
6386 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6388 /* The inferior is about to take a signal that will take it
6389 out of the single step range. Set a breakpoint at the
6390 current PC (which is presumably where the signal handler
6391 will eventually return) and then allow the inferior to
6394 Note that this is only needed for a signal delivered
6395 while in the single-step range. Nested signals aren't a
6396 problem as they eventually all return. */
6398 fprintf_unfiltered (gdb_stdlog
,
6399 "infrun: signal may take us out of "
6400 "single-step range\n");
6402 clear_step_over_info ();
6403 insert_hp_step_resume_breakpoint_at_frame (frame
);
6404 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6405 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6406 ecs
->event_thread
->control
.trap_expected
= 0;
6411 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6412 when either there's a nested signal, or when there's a
6413 pending signal enabled just as the signal handler returns
6414 (leaving the inferior at the step-resume-breakpoint without
6415 actually executing it). Either way continue until the
6416 breakpoint is really hit. */
6418 if (!switch_back_to_stepped_thread (ecs
))
6421 fprintf_unfiltered (gdb_stdlog
,
6422 "infrun: random signal, keep going\n");
6429 process_event_stop_test (ecs
);
6432 /* Come here when we've got some debug event / signal we can explain
6433 (IOW, not a random signal), and test whether it should cause a
6434 stop, or whether we should resume the inferior (transparently).
6435 E.g., could be a breakpoint whose condition evaluates false; we
6436 could be still stepping within the line; etc. */
6439 process_event_stop_test (struct execution_control_state
*ecs
)
6441 struct symtab_and_line stop_pc_sal
;
6442 struct frame_info
*frame
;
6443 struct gdbarch
*gdbarch
;
6444 CORE_ADDR jmp_buf_pc
;
6445 struct bpstat_what what
;
6447 /* Handle cases caused by hitting a breakpoint. */
6449 frame
= get_current_frame ();
6450 gdbarch
= get_frame_arch (frame
);
6452 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6454 if (what
.call_dummy
)
6456 stop_stack_dummy
= what
.call_dummy
;
6459 /* A few breakpoint types have callbacks associated (e.g.,
6460 bp_jit_event). Run them now. */
6461 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6463 /* If we hit an internal event that triggers symbol changes, the
6464 current frame will be invalidated within bpstat_what (e.g., if we
6465 hit an internal solib event). Re-fetch it. */
6466 frame
= get_current_frame ();
6467 gdbarch
= get_frame_arch (frame
);
6469 switch (what
.main_action
)
6471 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6472 /* If we hit the breakpoint at longjmp while stepping, we
6473 install a momentary breakpoint at the target of the
6477 fprintf_unfiltered (gdb_stdlog
,
6478 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME\n");
6480 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6482 if (what
.is_longjmp
)
6484 struct value
*arg_value
;
6486 /* If we set the longjmp breakpoint via a SystemTap probe,
6487 then use it to extract the arguments. The destination PC
6488 is the third argument to the probe. */
6489 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6492 jmp_buf_pc
= value_as_address (arg_value
);
6493 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6495 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6496 || !gdbarch_get_longjmp_target (gdbarch
,
6497 frame
, &jmp_buf_pc
))
6500 fprintf_unfiltered (gdb_stdlog
,
6501 "infrun: BPSTAT_WHAT_SET_LONGJMP_RESUME "
6502 "(!gdbarch_get_longjmp_target)\n");
6507 /* Insert a breakpoint at resume address. */
6508 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6511 check_exception_resume (ecs
, frame
);
6515 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6517 struct frame_info
*init_frame
;
6519 /* There are several cases to consider.
6521 1. The initiating frame no longer exists. In this case we
6522 must stop, because the exception or longjmp has gone too
6525 2. The initiating frame exists, and is the same as the
6526 current frame. We stop, because the exception or longjmp
6529 3. The initiating frame exists and is different from the
6530 current frame. This means the exception or longjmp has
6531 been caught beneath the initiating frame, so keep going.
6533 4. longjmp breakpoint has been placed just to protect
6534 against stale dummy frames and user is not interested in
6535 stopping around longjmps. */
6538 fprintf_unfiltered (gdb_stdlog
,
6539 "infrun: BPSTAT_WHAT_CLEAR_LONGJMP_RESUME\n");
6541 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6543 delete_exception_resume_breakpoint (ecs
->event_thread
);
6545 if (what
.is_longjmp
)
6547 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6549 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6557 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6561 struct frame_id current_id
6562 = get_frame_id (get_current_frame ());
6563 if (frame_id_eq (current_id
,
6564 ecs
->event_thread
->initiating_frame
))
6566 /* Case 2. Fall through. */
6576 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6578 delete_step_resume_breakpoint (ecs
->event_thread
);
6580 end_stepping_range (ecs
);
6584 case BPSTAT_WHAT_SINGLE
:
6586 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_SINGLE\n");
6587 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6588 /* Still need to check other stuff, at least the case where we
6589 are stepping and step out of the right range. */
6592 case BPSTAT_WHAT_STEP_RESUME
:
6594 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STEP_RESUME\n");
6596 delete_step_resume_breakpoint (ecs
->event_thread
);
6597 if (ecs
->event_thread
->control
.proceed_to_finish
6598 && execution_direction
== EXEC_REVERSE
)
6600 struct thread_info
*tp
= ecs
->event_thread
;
6602 /* We are finishing a function in reverse, and just hit the
6603 step-resume breakpoint at the start address of the
6604 function, and we're almost there -- just need to back up
6605 by one more single-step, which should take us back to the
6607 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6611 fill_in_stop_func (gdbarch
, ecs
);
6612 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6613 && execution_direction
== EXEC_REVERSE
)
6615 /* We are stepping over a function call in reverse, and just
6616 hit the step-resume breakpoint at the start address of
6617 the function. Go back to single-stepping, which should
6618 take us back to the function call. */
6619 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6625 case BPSTAT_WHAT_STOP_NOISY
:
6627 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_NOISY\n");
6628 stop_print_frame
= 1;
6630 /* Assume the thread stopped for a breapoint. We'll still check
6631 whether a/the breakpoint is there when the thread is next
6633 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6638 case BPSTAT_WHAT_STOP_SILENT
:
6640 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_STOP_SILENT\n");
6641 stop_print_frame
= 0;
6643 /* Assume the thread stopped for a breapoint. We'll still check
6644 whether a/the breakpoint is there when the thread is next
6646 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6650 case BPSTAT_WHAT_HP_STEP_RESUME
:
6652 fprintf_unfiltered (gdb_stdlog
, "infrun: BPSTAT_WHAT_HP_STEP_RESUME\n");
6654 delete_step_resume_breakpoint (ecs
->event_thread
);
6655 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6657 /* Back when the step-resume breakpoint was inserted, we
6658 were trying to single-step off a breakpoint. Go back to
6660 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6661 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6667 case BPSTAT_WHAT_KEEP_CHECKING
:
6671 /* If we stepped a permanent breakpoint and we had a high priority
6672 step-resume breakpoint for the address we stepped, but we didn't
6673 hit it, then we must have stepped into the signal handler. The
6674 step-resume was only necessary to catch the case of _not_
6675 stepping into the handler, so delete it, and fall through to
6676 checking whether the step finished. */
6677 if (ecs
->event_thread
->stepped_breakpoint
)
6679 struct breakpoint
*sr_bp
6680 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6683 && sr_bp
->loc
->permanent
6684 && sr_bp
->type
== bp_hp_step_resume
6685 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6688 fprintf_unfiltered (gdb_stdlog
,
6689 "infrun: stepped permanent breakpoint, stopped in "
6691 delete_step_resume_breakpoint (ecs
->event_thread
);
6692 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6696 /* We come here if we hit a breakpoint but should not stop for it.
6697 Possibly we also were stepping and should stop for that. So fall
6698 through and test for stepping. But, if not stepping, do not
6701 /* In all-stop mode, if we're currently stepping but have stopped in
6702 some other thread, we need to switch back to the stepped thread. */
6703 if (switch_back_to_stepped_thread (ecs
))
6706 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6709 fprintf_unfiltered (gdb_stdlog
,
6710 "infrun: step-resume breakpoint is inserted\n");
6712 /* Having a step-resume breakpoint overrides anything
6713 else having to do with stepping commands until
6714 that breakpoint is reached. */
6719 if (ecs
->event_thread
->control
.step_range_end
== 0)
6722 fprintf_unfiltered (gdb_stdlog
, "infrun: no stepping, continue\n");
6723 /* Likewise if we aren't even stepping. */
6728 /* Re-fetch current thread's frame in case the code above caused
6729 the frame cache to be re-initialized, making our FRAME variable
6730 a dangling pointer. */
6731 frame
= get_current_frame ();
6732 gdbarch
= get_frame_arch (frame
);
6733 fill_in_stop_func (gdbarch
, ecs
);
6735 /* If stepping through a line, keep going if still within it.
6737 Note that step_range_end is the address of the first instruction
6738 beyond the step range, and NOT the address of the last instruction
6741 Note also that during reverse execution, we may be stepping
6742 through a function epilogue and therefore must detect when
6743 the current-frame changes in the middle of a line. */
6745 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6747 && (execution_direction
!= EXEC_REVERSE
6748 || frame_id_eq (get_frame_id (frame
),
6749 ecs
->event_thread
->control
.step_frame_id
)))
6753 (gdb_stdlog
, "infrun: stepping inside range [%s-%s]\n",
6754 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6755 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6757 /* Tentatively re-enable range stepping; `resume' disables it if
6758 necessary (e.g., if we're stepping over a breakpoint or we
6759 have software watchpoints). */
6760 ecs
->event_thread
->control
.may_range_step
= 1;
6762 /* When stepping backward, stop at beginning of line range
6763 (unless it's the function entry point, in which case
6764 keep going back to the call point). */
6765 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6766 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6767 && stop_pc
!= ecs
->stop_func_start
6768 && execution_direction
== EXEC_REVERSE
)
6769 end_stepping_range (ecs
);
6776 /* We stepped out of the stepping range. */
6778 /* If we are stepping at the source level and entered the runtime
6779 loader dynamic symbol resolution code...
6781 EXEC_FORWARD: we keep on single stepping until we exit the run
6782 time loader code and reach the callee's address.
6784 EXEC_REVERSE: we've already executed the callee (backward), and
6785 the runtime loader code is handled just like any other
6786 undebuggable function call. Now we need only keep stepping
6787 backward through the trampoline code, and that's handled further
6788 down, so there is nothing for us to do here. */
6790 if (execution_direction
!= EXEC_REVERSE
6791 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6792 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6794 CORE_ADDR pc_after_resolver
=
6795 gdbarch_skip_solib_resolver (gdbarch
,
6796 ecs
->event_thread
->suspend
.stop_pc
);
6799 fprintf_unfiltered (gdb_stdlog
,
6800 "infrun: stepped into dynsym resolve code\n");
6802 if (pc_after_resolver
)
6804 /* Set up a step-resume breakpoint at the address
6805 indicated by SKIP_SOLIB_RESOLVER. */
6806 symtab_and_line sr_sal
;
6807 sr_sal
.pc
= pc_after_resolver
;
6808 sr_sal
.pspace
= get_frame_program_space (frame
);
6810 insert_step_resume_breakpoint_at_sal (gdbarch
,
6811 sr_sal
, null_frame_id
);
6818 /* Step through an indirect branch thunk. */
6819 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6820 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6821 ecs
->event_thread
->suspend
.stop_pc
))
6824 fprintf_unfiltered (gdb_stdlog
,
6825 "infrun: stepped into indirect branch thunk\n");
6830 if (ecs
->event_thread
->control
.step_range_end
!= 1
6831 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6832 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6833 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6836 fprintf_unfiltered (gdb_stdlog
,
6837 "infrun: stepped into signal trampoline\n");
6838 /* The inferior, while doing a "step" or "next", has ended up in
6839 a signal trampoline (either by a signal being delivered or by
6840 the signal handler returning). Just single-step until the
6841 inferior leaves the trampoline (either by calling the handler
6847 /* If we're in the return path from a shared library trampoline,
6848 we want to proceed through the trampoline when stepping. */
6849 /* macro/2012-04-25: This needs to come before the subroutine
6850 call check below as on some targets return trampolines look
6851 like subroutine calls (MIPS16 return thunks). */
6852 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6853 ecs
->event_thread
->suspend
.stop_pc
,
6854 ecs
->stop_func_name
)
6855 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6857 /* Determine where this trampoline returns. */
6858 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6859 CORE_ADDR real_stop_pc
6860 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6863 fprintf_unfiltered (gdb_stdlog
,
6864 "infrun: stepped into solib return tramp\n");
6866 /* Only proceed through if we know where it's going. */
6869 /* And put the step-breakpoint there and go until there. */
6870 symtab_and_line sr_sal
;
6871 sr_sal
.pc
= real_stop_pc
;
6872 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6873 sr_sal
.pspace
= get_frame_program_space (frame
);
6875 /* Do not specify what the fp should be when we stop since
6876 on some machines the prologue is where the new fp value
6878 insert_step_resume_breakpoint_at_sal (gdbarch
,
6879 sr_sal
, null_frame_id
);
6881 /* Restart without fiddling with the step ranges or
6888 /* Check for subroutine calls. The check for the current frame
6889 equalling the step ID is not necessary - the check of the
6890 previous frame's ID is sufficient - but it is a common case and
6891 cheaper than checking the previous frame's ID.
6893 NOTE: frame_id_eq will never report two invalid frame IDs as
6894 being equal, so to get into this block, both the current and
6895 previous frame must have valid frame IDs. */
6896 /* The outer_frame_id check is a heuristic to detect stepping
6897 through startup code. If we step over an instruction which
6898 sets the stack pointer from an invalid value to a valid value,
6899 we may detect that as a subroutine call from the mythical
6900 "outermost" function. This could be fixed by marking
6901 outermost frames as !stack_p,code_p,special_p. Then the
6902 initial outermost frame, before sp was valid, would
6903 have code_addr == &_start. See the comment in frame_id_eq
6905 if (!frame_id_eq (get_stack_frame_id (frame
),
6906 ecs
->event_thread
->control
.step_stack_frame_id
)
6907 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6908 ecs
->event_thread
->control
.step_stack_frame_id
)
6909 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6911 || (ecs
->event_thread
->control
.step_start_function
6912 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6914 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6915 CORE_ADDR real_stop_pc
;
6918 fprintf_unfiltered (gdb_stdlog
, "infrun: stepped into subroutine\n");
6920 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6922 /* I presume that step_over_calls is only 0 when we're
6923 supposed to be stepping at the assembly language level
6924 ("stepi"). Just stop. */
6925 /* And this works the same backward as frontward. MVS */
6926 end_stepping_range (ecs
);
6930 /* Reverse stepping through solib trampolines. */
6932 if (execution_direction
== EXEC_REVERSE
6933 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6934 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6935 || (ecs
->stop_func_start
== 0
6936 && in_solib_dynsym_resolve_code (stop_pc
))))
6938 /* Any solib trampoline code can be handled in reverse
6939 by simply continuing to single-step. We have already
6940 executed the solib function (backwards), and a few
6941 steps will take us back through the trampoline to the
6947 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6949 /* We're doing a "next".
6951 Normal (forward) execution: set a breakpoint at the
6952 callee's return address (the address at which the caller
6955 Reverse (backward) execution. set the step-resume
6956 breakpoint at the start of the function that we just
6957 stepped into (backwards), and continue to there. When we
6958 get there, we'll need to single-step back to the caller. */
6960 if (execution_direction
== EXEC_REVERSE
)
6962 /* If we're already at the start of the function, we've either
6963 just stepped backward into a single instruction function,
6964 or stepped back out of a signal handler to the first instruction
6965 of the function. Just keep going, which will single-step back
6967 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6969 /* Normal function call return (static or dynamic). */
6970 symtab_and_line sr_sal
;
6971 sr_sal
.pc
= ecs
->stop_func_start
;
6972 sr_sal
.pspace
= get_frame_program_space (frame
);
6973 insert_step_resume_breakpoint_at_sal (gdbarch
,
6974 sr_sal
, null_frame_id
);
6978 insert_step_resume_breakpoint_at_caller (frame
);
6984 /* If we are in a function call trampoline (a stub between the
6985 calling routine and the real function), locate the real
6986 function. That's what tells us (a) whether we want to step
6987 into it at all, and (b) what prologue we want to run to the
6988 end of, if we do step into it. */
6989 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6990 if (real_stop_pc
== 0)
6991 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6992 if (real_stop_pc
!= 0)
6993 ecs
->stop_func_start
= real_stop_pc
;
6995 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6997 symtab_and_line sr_sal
;
6998 sr_sal
.pc
= ecs
->stop_func_start
;
6999 sr_sal
.pspace
= get_frame_program_space (frame
);
7001 insert_step_resume_breakpoint_at_sal (gdbarch
,
7002 sr_sal
, null_frame_id
);
7007 /* If we have line number information for the function we are
7008 thinking of stepping into and the function isn't on the skip
7011 If there are several symtabs at that PC (e.g. with include
7012 files), just want to know whether *any* of them have line
7013 numbers. find_pc_line handles this. */
7015 struct symtab_and_line tmp_sal
;
7017 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7018 if (tmp_sal
.line
!= 0
7019 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
7021 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
7023 if (execution_direction
== EXEC_REVERSE
)
7024 handle_step_into_function_backward (gdbarch
, ecs
);
7026 handle_step_into_function (gdbarch
, ecs
);
7031 /* If we have no line number and the step-stop-if-no-debug is
7032 set, we stop the step so that the user has a chance to switch
7033 in assembly mode. */
7034 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7035 && step_stop_if_no_debug
)
7037 end_stepping_range (ecs
);
7041 if (execution_direction
== EXEC_REVERSE
)
7043 /* If we're already at the start of the function, we've either just
7044 stepped backward into a single instruction function without line
7045 number info, or stepped back out of a signal handler to the first
7046 instruction of the function without line number info. Just keep
7047 going, which will single-step back to the caller. */
7048 if (ecs
->stop_func_start
!= stop_pc
)
7050 /* Set a breakpoint at callee's start address.
7051 From there we can step once and be back in the caller. */
7052 symtab_and_line sr_sal
;
7053 sr_sal
.pc
= ecs
->stop_func_start
;
7054 sr_sal
.pspace
= get_frame_program_space (frame
);
7055 insert_step_resume_breakpoint_at_sal (gdbarch
,
7056 sr_sal
, null_frame_id
);
7060 /* Set a breakpoint at callee's return address (the address
7061 at which the caller will resume). */
7062 insert_step_resume_breakpoint_at_caller (frame
);
7068 /* Reverse stepping through solib trampolines. */
7070 if (execution_direction
== EXEC_REVERSE
7071 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
7073 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
7075 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
7076 || (ecs
->stop_func_start
== 0
7077 && in_solib_dynsym_resolve_code (stop_pc
)))
7079 /* Any solib trampoline code can be handled in reverse
7080 by simply continuing to single-step. We have already
7081 executed the solib function (backwards), and a few
7082 steps will take us back through the trampoline to the
7087 else if (in_solib_dynsym_resolve_code (stop_pc
))
7089 /* Stepped backward into the solib dynsym resolver.
7090 Set a breakpoint at its start and continue, then
7091 one more step will take us out. */
7092 symtab_and_line sr_sal
;
7093 sr_sal
.pc
= ecs
->stop_func_start
;
7094 sr_sal
.pspace
= get_frame_program_space (frame
);
7095 insert_step_resume_breakpoint_at_sal (gdbarch
,
7096 sr_sal
, null_frame_id
);
7102 /* This always returns the sal for the inner-most frame when we are in a
7103 stack of inlined frames, even if GDB actually believes that it is in a
7104 more outer frame. This is checked for below by calls to
7105 inline_skipped_frames. */
7106 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7108 /* NOTE: tausq/2004-05-24: This if block used to be done before all
7109 the trampoline processing logic, however, there are some trampolines
7110 that have no names, so we should do trampoline handling first. */
7111 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
7112 && ecs
->stop_func_name
== NULL
7113 && stop_pc_sal
.line
== 0)
7116 fprintf_unfiltered (gdb_stdlog
,
7117 "infrun: stepped into undebuggable function\n");
7119 /* The inferior just stepped into, or returned to, an
7120 undebuggable function (where there is no debugging information
7121 and no line number corresponding to the address where the
7122 inferior stopped). Since we want to skip this kind of code,
7123 we keep going until the inferior returns from this
7124 function - unless the user has asked us not to (via
7125 set step-mode) or we no longer know how to get back
7126 to the call site. */
7127 if (step_stop_if_no_debug
7128 || !frame_id_p (frame_unwind_caller_id (frame
)))
7130 /* If we have no line number and the step-stop-if-no-debug
7131 is set, we stop the step so that the user has a chance to
7132 switch in assembly mode. */
7133 end_stepping_range (ecs
);
7138 /* Set a breakpoint at callee's return address (the address
7139 at which the caller will resume). */
7140 insert_step_resume_breakpoint_at_caller (frame
);
7146 if (ecs
->event_thread
->control
.step_range_end
== 1)
7148 /* It is stepi or nexti. We always want to stop stepping after
7151 fprintf_unfiltered (gdb_stdlog
, "infrun: stepi/nexti\n");
7152 end_stepping_range (ecs
);
7156 if (stop_pc_sal
.line
== 0)
7158 /* We have no line number information. That means to stop
7159 stepping (does this always happen right after one instruction,
7160 when we do "s" in a function with no line numbers,
7161 or can this happen as a result of a return or longjmp?). */
7163 fprintf_unfiltered (gdb_stdlog
, "infrun: no line number info\n");
7164 end_stepping_range (ecs
);
7168 /* Look for "calls" to inlined functions, part one. If the inline
7169 frame machinery detected some skipped call sites, we have entered
7170 a new inline function. */
7172 if (frame_id_eq (get_frame_id (get_current_frame ()),
7173 ecs
->event_thread
->control
.step_frame_id
)
7174 && inline_skipped_frames (ecs
->event_thread
))
7177 fprintf_unfiltered (gdb_stdlog
,
7178 "infrun: stepped into inlined function\n");
7180 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7182 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7184 /* For "step", we're going to stop. But if the call site
7185 for this inlined function is on the same source line as
7186 we were previously stepping, go down into the function
7187 first. Otherwise stop at the call site. */
7189 if (call_sal
.line
== ecs
->event_thread
->current_line
7190 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7192 step_into_inline_frame (ecs
->event_thread
);
7193 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7200 end_stepping_range (ecs
);
7205 /* For "next", we should stop at the call site if it is on a
7206 different source line. Otherwise continue through the
7207 inlined function. */
7208 if (call_sal
.line
== ecs
->event_thread
->current_line
7209 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7212 end_stepping_range (ecs
);
7217 /* Look for "calls" to inlined functions, part two. If we are still
7218 in the same real function we were stepping through, but we have
7219 to go further up to find the exact frame ID, we are stepping
7220 through a more inlined call beyond its call site. */
7222 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7223 && !frame_id_eq (get_frame_id (get_current_frame ()),
7224 ecs
->event_thread
->control
.step_frame_id
)
7225 && stepped_in_from (get_current_frame (),
7226 ecs
->event_thread
->control
.step_frame_id
))
7229 fprintf_unfiltered (gdb_stdlog
,
7230 "infrun: stepping through inlined function\n");
7232 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7233 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7236 end_stepping_range (ecs
);
7240 bool refresh_step_info
= true;
7241 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7242 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7243 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7245 if (stop_pc_sal
.is_stmt
)
7247 /* We are at the start of a different line. So stop. Note that
7248 we don't stop if we step into the middle of a different line.
7249 That is said to make things like for (;;) statements work
7252 fprintf_unfiltered (gdb_stdlog
,
7253 "infrun: stepped to a different line\n");
7254 end_stepping_range (ecs
);
7257 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7258 ecs
->event_thread
->control
.step_frame_id
))
7260 /* We are at the start of a different line, however, this line is
7261 not marked as a statement, and we have not changed frame. We
7262 ignore this line table entry, and continue stepping forward,
7263 looking for a better place to stop. */
7264 refresh_step_info
= false;
7266 fprintf_unfiltered (gdb_stdlog
,
7267 "infrun: stepped to a different line, but "
7268 "it's not the start of a statement\n");
7272 /* We aren't done stepping.
7274 Optimize by setting the stepping range to the line.
7275 (We might not be in the original line, but if we entered a
7276 new line in mid-statement, we continue stepping. This makes
7277 things like for(;;) statements work better.)
7279 If we entered a SAL that indicates a non-statement line table entry,
7280 then we update the stepping range, but we don't update the step info,
7281 which includes things like the line number we are stepping away from.
7282 This means we will stop when we find a line table entry that is marked
7283 as is-statement, even if it matches the non-statement one we just
7286 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7287 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7288 ecs
->event_thread
->control
.may_range_step
= 1;
7289 if (refresh_step_info
)
7290 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7293 fprintf_unfiltered (gdb_stdlog
, "infrun: keep going\n");
7297 /* In all-stop mode, if we're currently stepping but have stopped in
7298 some other thread, we may need to switch back to the stepped
7299 thread. Returns true we set the inferior running, false if we left
7300 it stopped (and the event needs further processing). */
7303 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7305 if (!target_is_non_stop_p ())
7307 struct thread_info
*stepping_thread
;
7309 /* If any thread is blocked on some internal breakpoint, and we
7310 simply need to step over that breakpoint to get it going
7311 again, do that first. */
7313 /* However, if we see an event for the stepping thread, then we
7314 know all other threads have been moved past their breakpoints
7315 already. Let the caller check whether the step is finished,
7316 etc., before deciding to move it past a breakpoint. */
7317 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7320 /* Check if the current thread is blocked on an incomplete
7321 step-over, interrupted by a random signal. */
7322 if (ecs
->event_thread
->control
.trap_expected
7323 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7327 fprintf_unfiltered (gdb_stdlog
,
7328 "infrun: need to finish step-over of [%s]\n",
7329 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7335 /* Check if the current thread is blocked by a single-step
7336 breakpoint of another thread. */
7337 if (ecs
->hit_singlestep_breakpoint
)
7341 fprintf_unfiltered (gdb_stdlog
,
7342 "infrun: need to step [%s] over single-step "
7344 target_pid_to_str (ecs
->ptid
).c_str ());
7350 /* If this thread needs yet another step-over (e.g., stepping
7351 through a delay slot), do it first before moving on to
7353 if (thread_still_needs_step_over (ecs
->event_thread
))
7357 fprintf_unfiltered (gdb_stdlog
,
7358 "infrun: thread [%s] still needs step-over\n",
7359 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7365 /* If scheduler locking applies even if not stepping, there's no
7366 need to walk over threads. Above we've checked whether the
7367 current thread is stepping. If some other thread not the
7368 event thread is stepping, then it must be that scheduler
7369 locking is not in effect. */
7370 if (schedlock_applies (ecs
->event_thread
))
7373 /* Otherwise, we no longer expect a trap in the current thread.
7374 Clear the trap_expected flag before switching back -- this is
7375 what keep_going does as well, if we call it. */
7376 ecs
->event_thread
->control
.trap_expected
= 0;
7378 /* Likewise, clear the signal if it should not be passed. */
7379 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7380 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7382 /* Do all pending step-overs before actually proceeding with
7384 if (start_step_over ())
7386 prepare_to_wait (ecs
);
7390 /* Look for the stepping/nexting thread. */
7391 stepping_thread
= NULL
;
7393 for (thread_info
*tp
: all_non_exited_threads ())
7395 switch_to_thread_no_regs (tp
);
7397 /* Ignore threads of processes the caller is not
7400 && (tp
->inf
->process_target () != ecs
->target
7401 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7404 /* When stepping over a breakpoint, we lock all threads
7405 except the one that needs to move past the breakpoint.
7406 If a non-event thread has this set, the "incomplete
7407 step-over" check above should have caught it earlier. */
7408 if (tp
->control
.trap_expected
)
7410 internal_error (__FILE__
, __LINE__
,
7411 "[%s] has inconsistent state: "
7412 "trap_expected=%d\n",
7413 target_pid_to_str (tp
->ptid
).c_str (),
7414 tp
->control
.trap_expected
);
7417 /* Did we find the stepping thread? */
7418 if (tp
->control
.step_range_end
)
7420 /* Yep. There should only one though. */
7421 gdb_assert (stepping_thread
== NULL
);
7423 /* The event thread is handled at the top, before we
7425 gdb_assert (tp
!= ecs
->event_thread
);
7427 /* If some thread other than the event thread is
7428 stepping, then scheduler locking can't be in effect,
7429 otherwise we wouldn't have resumed the current event
7430 thread in the first place. */
7431 gdb_assert (!schedlock_applies (tp
));
7433 stepping_thread
= tp
;
7437 if (stepping_thread
!= NULL
)
7440 fprintf_unfiltered (gdb_stdlog
,
7441 "infrun: switching back to stepped thread\n");
7443 if (keep_going_stepped_thread (stepping_thread
))
7445 prepare_to_wait (ecs
);
7450 switch_to_thread (ecs
->event_thread
);
7456 /* Set a previously stepped thread back to stepping. Returns true on
7457 success, false if the resume is not possible (e.g., the thread
7461 keep_going_stepped_thread (struct thread_info
*tp
)
7463 struct frame_info
*frame
;
7464 struct execution_control_state ecss
;
7465 struct execution_control_state
*ecs
= &ecss
;
7467 /* If the stepping thread exited, then don't try to switch back and
7468 resume it, which could fail in several different ways depending
7469 on the target. Instead, just keep going.
7471 We can find a stepping dead thread in the thread list in two
7474 - The target supports thread exit events, and when the target
7475 tries to delete the thread from the thread list, inferior_ptid
7476 pointed at the exiting thread. In such case, calling
7477 delete_thread does not really remove the thread from the list;
7478 instead, the thread is left listed, with 'exited' state.
7480 - The target's debug interface does not support thread exit
7481 events, and so we have no idea whatsoever if the previously
7482 stepping thread is still alive. For that reason, we need to
7483 synchronously query the target now. */
7485 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7488 fprintf_unfiltered (gdb_stdlog
,
7489 "infrun: not resuming previously "
7490 "stepped thread, it has vanished\n");
7497 fprintf_unfiltered (gdb_stdlog
,
7498 "infrun: resuming previously stepped thread\n");
7500 reset_ecs (ecs
, tp
);
7501 switch_to_thread (tp
);
7503 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7504 frame
= get_current_frame ();
7506 /* If the PC of the thread we were trying to single-step has
7507 changed, then that thread has trapped or been signaled, but the
7508 event has not been reported to GDB yet. Re-poll the target
7509 looking for this particular thread's event (i.e. temporarily
7510 enable schedlock) by:
7512 - setting a break at the current PC
7513 - resuming that particular thread, only (by setting trap
7516 This prevents us continuously moving the single-step breakpoint
7517 forward, one instruction at a time, overstepping. */
7519 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7524 fprintf_unfiltered (gdb_stdlog
,
7525 "infrun: expected thread advanced also (%s -> %s)\n",
7526 paddress (target_gdbarch (), tp
->prev_pc
),
7527 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7529 /* Clear the info of the previous step-over, as it's no longer
7530 valid (if the thread was trying to step over a breakpoint, it
7531 has already succeeded). It's what keep_going would do too,
7532 if we called it. Do this before trying to insert the sss
7533 breakpoint, otherwise if we were previously trying to step
7534 over this exact address in another thread, the breakpoint is
7536 clear_step_over_info ();
7537 tp
->control
.trap_expected
= 0;
7539 insert_single_step_breakpoint (get_frame_arch (frame
),
7540 get_frame_address_space (frame
),
7541 tp
->suspend
.stop_pc
);
7544 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7545 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7550 fprintf_unfiltered (gdb_stdlog
,
7551 "infrun: expected thread still hasn't advanced\n");
7553 keep_going_pass_signal (ecs
);
7558 /* Is thread TP in the middle of (software or hardware)
7559 single-stepping? (Note the result of this function must never be
7560 passed directly as target_resume's STEP parameter.) */
7563 currently_stepping (struct thread_info
*tp
)
7565 return ((tp
->control
.step_range_end
7566 && tp
->control
.step_resume_breakpoint
== NULL
)
7567 || tp
->control
.trap_expected
7568 || tp
->stepped_breakpoint
7569 || bpstat_should_step ());
7572 /* Inferior has stepped into a subroutine call with source code that
7573 we should not step over. Do step to the first line of code in
7577 handle_step_into_function (struct gdbarch
*gdbarch
,
7578 struct execution_control_state
*ecs
)
7580 fill_in_stop_func (gdbarch
, ecs
);
7582 compunit_symtab
*cust
7583 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7584 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7585 ecs
->stop_func_start
7586 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7588 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7589 /* Use the step_resume_break to step until the end of the prologue,
7590 even if that involves jumps (as it seems to on the vax under
7592 /* If the prologue ends in the middle of a source line, continue to
7593 the end of that source line (if it is still within the function).
7594 Otherwise, just go to end of prologue. */
7595 if (stop_func_sal
.end
7596 && stop_func_sal
.pc
!= ecs
->stop_func_start
7597 && stop_func_sal
.end
< ecs
->stop_func_end
)
7598 ecs
->stop_func_start
= stop_func_sal
.end
;
7600 /* Architectures which require breakpoint adjustment might not be able
7601 to place a breakpoint at the computed address. If so, the test
7602 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7603 ecs->stop_func_start to an address at which a breakpoint may be
7604 legitimately placed.
7606 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7607 made, GDB will enter an infinite loop when stepping through
7608 optimized code consisting of VLIW instructions which contain
7609 subinstructions corresponding to different source lines. On
7610 FR-V, it's not permitted to place a breakpoint on any but the
7611 first subinstruction of a VLIW instruction. When a breakpoint is
7612 set, GDB will adjust the breakpoint address to the beginning of
7613 the VLIW instruction. Thus, we need to make the corresponding
7614 adjustment here when computing the stop address. */
7616 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7618 ecs
->stop_func_start
7619 = gdbarch_adjust_breakpoint_address (gdbarch
,
7620 ecs
->stop_func_start
);
7623 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7625 /* We are already there: stop now. */
7626 end_stepping_range (ecs
);
7631 /* Put the step-breakpoint there and go until there. */
7632 symtab_and_line sr_sal
;
7633 sr_sal
.pc
= ecs
->stop_func_start
;
7634 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7635 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7637 /* Do not specify what the fp should be when we stop since on
7638 some machines the prologue is where the new fp value is
7640 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7642 /* And make sure stepping stops right away then. */
7643 ecs
->event_thread
->control
.step_range_end
7644 = ecs
->event_thread
->control
.step_range_start
;
7649 /* Inferior has stepped backward into a subroutine call with source
7650 code that we should not step over. Do step to the beginning of the
7651 last line of code in it. */
7654 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7655 struct execution_control_state
*ecs
)
7657 struct compunit_symtab
*cust
;
7658 struct symtab_and_line stop_func_sal
;
7660 fill_in_stop_func (gdbarch
, ecs
);
7662 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7663 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7664 ecs
->stop_func_start
7665 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7667 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7669 /* OK, we're just going to keep stepping here. */
7670 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7672 /* We're there already. Just stop stepping now. */
7673 end_stepping_range (ecs
);
7677 /* Else just reset the step range and keep going.
7678 No step-resume breakpoint, they don't work for
7679 epilogues, which can have multiple entry paths. */
7680 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7681 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7687 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7688 This is used to both functions and to skip over code. */
7691 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7692 struct symtab_and_line sr_sal
,
7693 struct frame_id sr_id
,
7694 enum bptype sr_type
)
7696 /* There should never be more than one step-resume or longjmp-resume
7697 breakpoint per thread, so we should never be setting a new
7698 step_resume_breakpoint when one is already active. */
7699 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7700 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7703 fprintf_unfiltered (gdb_stdlog
,
7704 "infrun: inserting step-resume breakpoint at %s\n",
7705 paddress (gdbarch
, sr_sal
.pc
));
7707 inferior_thread ()->control
.step_resume_breakpoint
7708 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7712 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7713 struct symtab_and_line sr_sal
,
7714 struct frame_id sr_id
)
7716 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7721 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7722 This is used to skip a potential signal handler.
7724 This is called with the interrupted function's frame. The signal
7725 handler, when it returns, will resume the interrupted function at
7729 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7731 gdb_assert (return_frame
!= NULL
);
7733 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7735 symtab_and_line sr_sal
;
7736 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7737 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7738 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7740 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7741 get_stack_frame_id (return_frame
),
7745 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7746 is used to skip a function after stepping into it (for "next" or if
7747 the called function has no debugging information).
7749 The current function has almost always been reached by single
7750 stepping a call or return instruction. NEXT_FRAME belongs to the
7751 current function, and the breakpoint will be set at the caller's
7754 This is a separate function rather than reusing
7755 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7756 get_prev_frame, which may stop prematurely (see the implementation
7757 of frame_unwind_caller_id for an example). */
7760 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7762 /* We shouldn't have gotten here if we don't know where the call site
7764 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7766 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7768 symtab_and_line sr_sal
;
7769 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7770 frame_unwind_caller_pc (next_frame
));
7771 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7772 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7774 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7775 frame_unwind_caller_id (next_frame
));
7778 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7779 new breakpoint at the target of a jmp_buf. The handling of
7780 longjmp-resume uses the same mechanisms used for handling
7781 "step-resume" breakpoints. */
7784 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7786 /* There should never be more than one longjmp-resume breakpoint per
7787 thread, so we should never be setting a new
7788 longjmp_resume_breakpoint when one is already active. */
7789 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7792 fprintf_unfiltered (gdb_stdlog
,
7793 "infrun: inserting longjmp-resume breakpoint at %s\n",
7794 paddress (gdbarch
, pc
));
7796 inferior_thread ()->control
.exception_resume_breakpoint
=
7797 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7800 /* Insert an exception resume breakpoint. TP is the thread throwing
7801 the exception. The block B is the block of the unwinder debug hook
7802 function. FRAME is the frame corresponding to the call to this
7803 function. SYM is the symbol of the function argument holding the
7804 target PC of the exception. */
7807 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7808 const struct block
*b
,
7809 struct frame_info
*frame
,
7814 struct block_symbol vsym
;
7815 struct value
*value
;
7817 struct breakpoint
*bp
;
7819 vsym
= lookup_symbol_search_name (sym
->search_name (),
7821 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7822 /* If the value was optimized out, revert to the old behavior. */
7823 if (! value_optimized_out (value
))
7825 handler
= value_as_address (value
);
7828 fprintf_unfiltered (gdb_stdlog
,
7829 "infrun: exception resume at %lx\n",
7830 (unsigned long) handler
);
7832 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7834 bp_exception_resume
).release ();
7836 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7839 bp
->thread
= tp
->global_num
;
7840 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7843 catch (const gdb_exception_error
&e
)
7845 /* We want to ignore errors here. */
7849 /* A helper for check_exception_resume that sets an
7850 exception-breakpoint based on a SystemTap probe. */
7853 insert_exception_resume_from_probe (struct thread_info
*tp
,
7854 const struct bound_probe
*probe
,
7855 struct frame_info
*frame
)
7857 struct value
*arg_value
;
7859 struct breakpoint
*bp
;
7861 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7865 handler
= value_as_address (arg_value
);
7868 fprintf_unfiltered (gdb_stdlog
,
7869 "infrun: exception resume at %s\n",
7870 paddress (probe
->objfile
->arch (),
7873 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7874 handler
, bp_exception_resume
).release ();
7875 bp
->thread
= tp
->global_num
;
7876 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7879 /* This is called when an exception has been intercepted. Check to
7880 see whether the exception's destination is of interest, and if so,
7881 set an exception resume breakpoint there. */
7884 check_exception_resume (struct execution_control_state
*ecs
,
7885 struct frame_info
*frame
)
7887 struct bound_probe probe
;
7888 struct symbol
*func
;
7890 /* First see if this exception unwinding breakpoint was set via a
7891 SystemTap probe point. If so, the probe has two arguments: the
7892 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7893 set a breakpoint there. */
7894 probe
= find_probe_by_pc (get_frame_pc (frame
));
7897 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7901 func
= get_frame_function (frame
);
7907 const struct block
*b
;
7908 struct block_iterator iter
;
7912 /* The exception breakpoint is a thread-specific breakpoint on
7913 the unwinder's debug hook, declared as:
7915 void _Unwind_DebugHook (void *cfa, void *handler);
7917 The CFA argument indicates the frame to which control is
7918 about to be transferred. HANDLER is the destination PC.
7920 We ignore the CFA and set a temporary breakpoint at HANDLER.
7921 This is not extremely efficient but it avoids issues in gdb
7922 with computing the DWARF CFA, and it also works even in weird
7923 cases such as throwing an exception from inside a signal
7926 b
= SYMBOL_BLOCK_VALUE (func
);
7927 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7929 if (!SYMBOL_IS_ARGUMENT (sym
))
7936 insert_exception_resume_breakpoint (ecs
->event_thread
,
7942 catch (const gdb_exception_error
&e
)
7948 stop_waiting (struct execution_control_state
*ecs
)
7951 fprintf_unfiltered (gdb_stdlog
, "infrun: stop_waiting\n");
7953 /* Let callers know we don't want to wait for the inferior anymore. */
7954 ecs
->wait_some_more
= 0;
7956 /* If all-stop, but there exists a non-stop target, stop all
7957 threads now that we're presenting the stop to the user. */
7958 if (!non_stop
&& exists_non_stop_target ())
7959 stop_all_threads ();
7962 /* Like keep_going, but passes the signal to the inferior, even if the
7963 signal is set to nopass. */
7966 keep_going_pass_signal (struct execution_control_state
*ecs
)
7968 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7969 gdb_assert (!ecs
->event_thread
->resumed
);
7971 /* Save the pc before execution, to compare with pc after stop. */
7972 ecs
->event_thread
->prev_pc
7973 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7975 if (ecs
->event_thread
->control
.trap_expected
)
7977 struct thread_info
*tp
= ecs
->event_thread
;
7980 fprintf_unfiltered (gdb_stdlog
,
7981 "infrun: %s has trap_expected set, "
7982 "resuming to collect trap\n",
7983 target_pid_to_str (tp
->ptid
).c_str ());
7985 /* We haven't yet gotten our trap, and either: intercepted a
7986 non-signal event (e.g., a fork); or took a signal which we
7987 are supposed to pass through to the inferior. Simply
7989 resume (ecs
->event_thread
->suspend
.stop_signal
);
7991 else if (step_over_info_valid_p ())
7993 /* Another thread is stepping over a breakpoint in-line. If
7994 this thread needs a step-over too, queue the request. In
7995 either case, this resume must be deferred for later. */
7996 struct thread_info
*tp
= ecs
->event_thread
;
7998 if (ecs
->hit_singlestep_breakpoint
7999 || thread_still_needs_step_over (tp
))
8002 fprintf_unfiltered (gdb_stdlog
,
8003 "infrun: step-over already in progress: "
8004 "step-over for %s deferred\n",
8005 target_pid_to_str (tp
->ptid
).c_str ());
8006 thread_step_over_chain_enqueue (tp
);
8011 fprintf_unfiltered (gdb_stdlog
,
8012 "infrun: step-over in progress: "
8013 "resume of %s deferred\n",
8014 target_pid_to_str (tp
->ptid
).c_str ());
8019 struct regcache
*regcache
= get_current_regcache ();
8022 step_over_what step_what
;
8024 /* Either the trap was not expected, but we are continuing
8025 anyway (if we got a signal, the user asked it be passed to
8028 We got our expected trap, but decided we should resume from
8031 We're going to run this baby now!
8033 Note that insert_breakpoints won't try to re-insert
8034 already inserted breakpoints. Therefore, we don't
8035 care if breakpoints were already inserted, or not. */
8037 /* If we need to step over a breakpoint, and we're not using
8038 displaced stepping to do so, insert all breakpoints
8039 (watchpoints, etc.) but the one we're stepping over, step one
8040 instruction, and then re-insert the breakpoint when that step
8043 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
8045 remove_bp
= (ecs
->hit_singlestep_breakpoint
8046 || (step_what
& STEP_OVER_BREAKPOINT
));
8047 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
8049 /* We can't use displaced stepping if we need to step past a
8050 watchpoint. The instruction copied to the scratch pad would
8051 still trigger the watchpoint. */
8053 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
8055 set_step_over_info (regcache
->aspace (),
8056 regcache_read_pc (regcache
), remove_wps
,
8057 ecs
->event_thread
->global_num
);
8059 else if (remove_wps
)
8060 set_step_over_info (NULL
, 0, remove_wps
, -1);
8062 /* If we now need to do an in-line step-over, we need to stop
8063 all other threads. Note this must be done before
8064 insert_breakpoints below, because that removes the breakpoint
8065 we're about to step over, otherwise other threads could miss
8067 if (step_over_info_valid_p () && target_is_non_stop_p ())
8068 stop_all_threads ();
8070 /* Stop stepping if inserting breakpoints fails. */
8073 insert_breakpoints ();
8075 catch (const gdb_exception_error
&e
)
8077 exception_print (gdb_stderr
, e
);
8079 clear_step_over_info ();
8083 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
8085 resume (ecs
->event_thread
->suspend
.stop_signal
);
8088 prepare_to_wait (ecs
);
8091 /* Called when we should continue running the inferior, because the
8092 current event doesn't cause a user visible stop. This does the
8093 resuming part; waiting for the next event is done elsewhere. */
8096 keep_going (struct execution_control_state
*ecs
)
8098 if (ecs
->event_thread
->control
.trap_expected
8099 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
8100 ecs
->event_thread
->control
.trap_expected
= 0;
8102 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
8103 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8104 keep_going_pass_signal (ecs
);
8107 /* This function normally comes after a resume, before
8108 handle_inferior_event exits. It takes care of any last bits of
8109 housekeeping, and sets the all-important wait_some_more flag. */
8112 prepare_to_wait (struct execution_control_state
*ecs
)
8115 fprintf_unfiltered (gdb_stdlog
, "infrun: prepare_to_wait\n");
8117 ecs
->wait_some_more
= 1;
8119 if (!target_is_async_p ())
8120 mark_infrun_async_event_handler ();
8123 /* We are done with the step range of a step/next/si/ni command.
8124 Called once for each n of a "step n" operation. */
8127 end_stepping_range (struct execution_control_state
*ecs
)
8129 ecs
->event_thread
->control
.stop_step
= 1;
8133 /* Several print_*_reason functions to print why the inferior has stopped.
8134 We always print something when the inferior exits, or receives a signal.
8135 The rest of the cases are dealt with later on in normal_stop and
8136 print_it_typical. Ideally there should be a call to one of these
8137 print_*_reason functions functions from handle_inferior_event each time
8138 stop_waiting is called.
8140 Note that we don't call these directly, instead we delegate that to
8141 the interpreters, through observers. Interpreters then call these
8142 with whatever uiout is right. */
8145 print_end_stepping_range_reason (struct ui_out
*uiout
)
8147 /* For CLI-like interpreters, print nothing. */
8149 if (uiout
->is_mi_like_p ())
8151 uiout
->field_string ("reason",
8152 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
8157 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8159 annotate_signalled ();
8160 if (uiout
->is_mi_like_p ())
8162 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
8163 uiout
->text ("\nProgram terminated with signal ");
8164 annotate_signal_name ();
8165 uiout
->field_string ("signal-name",
8166 gdb_signal_to_name (siggnal
));
8167 annotate_signal_name_end ();
8169 annotate_signal_string ();
8170 uiout
->field_string ("signal-meaning",
8171 gdb_signal_to_string (siggnal
));
8172 annotate_signal_string_end ();
8173 uiout
->text (".\n");
8174 uiout
->text ("The program no longer exists.\n");
8178 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
8180 struct inferior
*inf
= current_inferior ();
8181 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
8183 annotate_exited (exitstatus
);
8186 if (uiout
->is_mi_like_p ())
8187 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
8188 std::string exit_code_str
8189 = string_printf ("0%o", (unsigned int) exitstatus
);
8190 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
8191 plongest (inf
->num
), pidstr
.c_str (),
8192 string_field ("exit-code", exit_code_str
.c_str ()));
8196 if (uiout
->is_mi_like_p ())
8198 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
8199 uiout
->message ("[Inferior %s (%s) exited normally]\n",
8200 plongest (inf
->num
), pidstr
.c_str ());
8204 /* Some targets/architectures can do extra processing/display of
8205 segmentation faults. E.g., Intel MPX boundary faults.
8206 Call the architecture dependent function to handle the fault. */
8209 handle_segmentation_fault (struct ui_out
*uiout
)
8211 struct regcache
*regcache
= get_current_regcache ();
8212 struct gdbarch
*gdbarch
= regcache
->arch ();
8214 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8215 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8219 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8221 struct thread_info
*thr
= inferior_thread ();
8225 if (uiout
->is_mi_like_p ())
8227 else if (show_thread_that_caused_stop ())
8231 uiout
->text ("\nThread ");
8232 uiout
->field_string ("thread-id", print_thread_id (thr
));
8234 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8237 uiout
->text (" \"");
8238 uiout
->field_string ("name", name
);
8243 uiout
->text ("\nProgram");
8245 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8246 uiout
->text (" stopped");
8249 uiout
->text (" received signal ");
8250 annotate_signal_name ();
8251 if (uiout
->is_mi_like_p ())
8253 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8254 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8255 annotate_signal_name_end ();
8257 annotate_signal_string ();
8258 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8260 if (siggnal
== GDB_SIGNAL_SEGV
)
8261 handle_segmentation_fault (uiout
);
8263 annotate_signal_string_end ();
8265 uiout
->text (".\n");
8269 print_no_history_reason (struct ui_out
*uiout
)
8271 uiout
->text ("\nNo more reverse-execution history.\n");
8274 /* Print current location without a level number, if we have changed
8275 functions or hit a breakpoint. Print source line if we have one.
8276 bpstat_print contains the logic deciding in detail what to print,
8277 based on the event(s) that just occurred. */
8280 print_stop_location (struct target_waitstatus
*ws
)
8283 enum print_what source_flag
;
8284 int do_frame_printing
= 1;
8285 struct thread_info
*tp
= inferior_thread ();
8287 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8291 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8292 should) carry around the function and does (or should) use
8293 that when doing a frame comparison. */
8294 if (tp
->control
.stop_step
8295 && frame_id_eq (tp
->control
.step_frame_id
,
8296 get_frame_id (get_current_frame ()))
8297 && (tp
->control
.step_start_function
8298 == find_pc_function (tp
->suspend
.stop_pc
)))
8300 /* Finished step, just print source line. */
8301 source_flag
= SRC_LINE
;
8305 /* Print location and source line. */
8306 source_flag
= SRC_AND_LOC
;
8309 case PRINT_SRC_AND_LOC
:
8310 /* Print location and source line. */
8311 source_flag
= SRC_AND_LOC
;
8313 case PRINT_SRC_ONLY
:
8314 source_flag
= SRC_LINE
;
8317 /* Something bogus. */
8318 source_flag
= SRC_LINE
;
8319 do_frame_printing
= 0;
8322 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8325 /* The behavior of this routine with respect to the source
8327 SRC_LINE: Print only source line
8328 LOCATION: Print only location
8329 SRC_AND_LOC: Print location and source line. */
8330 if (do_frame_printing
)
8331 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8337 print_stop_event (struct ui_out
*uiout
, bool displays
)
8339 struct target_waitstatus last
;
8340 struct thread_info
*tp
;
8342 get_last_target_status (nullptr, nullptr, &last
);
8345 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8347 print_stop_location (&last
);
8349 /* Display the auto-display expressions. */
8354 tp
= inferior_thread ();
8355 if (tp
->thread_fsm
!= NULL
8356 && tp
->thread_fsm
->finished_p ())
8358 struct return_value_info
*rv
;
8360 rv
= tp
->thread_fsm
->return_value ();
8362 print_return_value (uiout
, rv
);
8369 maybe_remove_breakpoints (void)
8371 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8373 if (remove_breakpoints ())
8375 target_terminal::ours_for_output ();
8376 printf_filtered (_("Cannot remove breakpoints because "
8377 "program is no longer writable.\nFurther "
8378 "execution is probably impossible.\n"));
8383 /* The execution context that just caused a normal stop. */
8390 DISABLE_COPY_AND_ASSIGN (stop_context
);
8392 bool changed () const;
8397 /* The event PTID. */
8401 /* If stopp for a thread event, this is the thread that caused the
8403 struct thread_info
*thread
;
8405 /* The inferior that caused the stop. */
8409 /* Initializes a new stop context. If stopped for a thread event, this
8410 takes a strong reference to the thread. */
8412 stop_context::stop_context ()
8414 stop_id
= get_stop_id ();
8415 ptid
= inferior_ptid
;
8416 inf_num
= current_inferior ()->num
;
8418 if (inferior_ptid
!= null_ptid
)
8420 /* Take a strong reference so that the thread can't be deleted
8422 thread
= inferior_thread ();
8429 /* Release a stop context previously created with save_stop_context.
8430 Releases the strong reference to the thread as well. */
8432 stop_context::~stop_context ()
8438 /* Return true if the current context no longer matches the saved stop
8442 stop_context::changed () const
8444 if (ptid
!= inferior_ptid
)
8446 if (inf_num
!= current_inferior ()->num
)
8448 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8450 if (get_stop_id () != stop_id
)
8460 struct target_waitstatus last
;
8462 get_last_target_status (nullptr, nullptr, &last
);
8466 /* If an exception is thrown from this point on, make sure to
8467 propagate GDB's knowledge of the executing state to the
8468 frontend/user running state. A QUIT is an easy exception to see
8469 here, so do this before any filtered output. */
8471 ptid_t finish_ptid
= null_ptid
;
8474 finish_ptid
= minus_one_ptid
;
8475 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8476 || last
.kind
== TARGET_WAITKIND_EXITED
)
8478 /* On some targets, we may still have live threads in the
8479 inferior when we get a process exit event. E.g., for
8480 "checkpoint", when the current checkpoint/fork exits,
8481 linux-fork.c automatically switches to another fork from
8482 within target_mourn_inferior. */
8483 if (inferior_ptid
!= null_ptid
)
8484 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8486 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8487 finish_ptid
= inferior_ptid
;
8489 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8490 if (finish_ptid
!= null_ptid
)
8492 maybe_finish_thread_state
.emplace
8493 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8496 /* As we're presenting a stop, and potentially removing breakpoints,
8497 update the thread list so we can tell whether there are threads
8498 running on the target. With target remote, for example, we can
8499 only learn about new threads when we explicitly update the thread
8500 list. Do this before notifying the interpreters about signal
8501 stops, end of stepping ranges, etc., so that the "new thread"
8502 output is emitted before e.g., "Program received signal FOO",
8503 instead of after. */
8504 update_thread_list ();
8506 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8507 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8509 /* As with the notification of thread events, we want to delay
8510 notifying the user that we've switched thread context until
8511 the inferior actually stops.
8513 There's no point in saying anything if the inferior has exited.
8514 Note that SIGNALLED here means "exited with a signal", not
8515 "received a signal".
8517 Also skip saying anything in non-stop mode. In that mode, as we
8518 don't want GDB to switch threads behind the user's back, to avoid
8519 races where the user is typing a command to apply to thread x,
8520 but GDB switches to thread y before the user finishes entering
8521 the command, fetch_inferior_event installs a cleanup to restore
8522 the current thread back to the thread the user had selected right
8523 after this event is handled, so we're not really switching, only
8524 informing of a stop. */
8526 && previous_inferior_ptid
!= inferior_ptid
8527 && target_has_execution
8528 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8529 && last
.kind
!= TARGET_WAITKIND_EXITED
8530 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8532 SWITCH_THRU_ALL_UIS ()
8534 target_terminal::ours_for_output ();
8535 printf_filtered (_("[Switching to %s]\n"),
8536 target_pid_to_str (inferior_ptid
).c_str ());
8537 annotate_thread_changed ();
8539 previous_inferior_ptid
= inferior_ptid
;
8542 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8544 SWITCH_THRU_ALL_UIS ()
8545 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8547 target_terminal::ours_for_output ();
8548 printf_filtered (_("No unwaited-for children left.\n"));
8552 /* Note: this depends on the update_thread_list call above. */
8553 maybe_remove_breakpoints ();
8555 /* If an auto-display called a function and that got a signal,
8556 delete that auto-display to avoid an infinite recursion. */
8558 if (stopped_by_random_signal
)
8559 disable_current_display ();
8561 SWITCH_THRU_ALL_UIS ()
8563 async_enable_stdin ();
8566 /* Let the user/frontend see the threads as stopped. */
8567 maybe_finish_thread_state
.reset ();
8569 /* Select innermost stack frame - i.e., current frame is frame 0,
8570 and current location is based on that. Handle the case where the
8571 dummy call is returning after being stopped. E.g. the dummy call
8572 previously hit a breakpoint. (If the dummy call returns
8573 normally, we won't reach here.) Do this before the stop hook is
8574 run, so that it doesn't get to see the temporary dummy frame,
8575 which is not where we'll present the stop. */
8576 if (has_stack_frames ())
8578 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8580 /* Pop the empty frame that contains the stack dummy. This
8581 also restores inferior state prior to the call (struct
8582 infcall_suspend_state). */
8583 struct frame_info
*frame
= get_current_frame ();
8585 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8587 /* frame_pop calls reinit_frame_cache as the last thing it
8588 does which means there's now no selected frame. */
8591 select_frame (get_current_frame ());
8593 /* Set the current source location. */
8594 set_current_sal_from_frame (get_current_frame ());
8597 /* Look up the hook_stop and run it (CLI internally handles problem
8598 of stop_command's pre-hook not existing). */
8599 if (stop_command
!= NULL
)
8601 stop_context saved_context
;
8605 execute_cmd_pre_hook (stop_command
);
8607 catch (const gdb_exception
&ex
)
8609 exception_fprintf (gdb_stderr
, ex
,
8610 "Error while running hook_stop:\n");
8613 /* If the stop hook resumes the target, then there's no point in
8614 trying to notify about the previous stop; its context is
8615 gone. Likewise if the command switches thread or inferior --
8616 the observers would print a stop for the wrong
8618 if (saved_context
.changed ())
8622 /* Notify observers about the stop. This is where the interpreters
8623 print the stop event. */
8624 if (inferior_ptid
!= null_ptid
)
8625 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8628 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8630 annotate_stopped ();
8632 if (target_has_execution
)
8634 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8635 && last
.kind
!= TARGET_WAITKIND_EXITED
8636 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8637 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8638 Delete any breakpoint that is to be deleted at the next stop. */
8639 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8642 /* Try to get rid of automatically added inferiors that are no
8643 longer needed. Keeping those around slows down things linearly.
8644 Note that this never removes the current inferior. */
8651 signal_stop_state (int signo
)
8653 return signal_stop
[signo
];
8657 signal_print_state (int signo
)
8659 return signal_print
[signo
];
8663 signal_pass_state (int signo
)
8665 return signal_program
[signo
];
8669 signal_cache_update (int signo
)
8673 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8674 signal_cache_update (signo
);
8679 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8680 && signal_print
[signo
] == 0
8681 && signal_program
[signo
] == 1
8682 && signal_catch
[signo
] == 0);
8686 signal_stop_update (int signo
, int state
)
8688 int ret
= signal_stop
[signo
];
8690 signal_stop
[signo
] = state
;
8691 signal_cache_update (signo
);
8696 signal_print_update (int signo
, int state
)
8698 int ret
= signal_print
[signo
];
8700 signal_print
[signo
] = state
;
8701 signal_cache_update (signo
);
8706 signal_pass_update (int signo
, int state
)
8708 int ret
= signal_program
[signo
];
8710 signal_program
[signo
] = state
;
8711 signal_cache_update (signo
);
8715 /* Update the global 'signal_catch' from INFO and notify the
8719 signal_catch_update (const unsigned int *info
)
8723 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8724 signal_catch
[i
] = info
[i
] > 0;
8725 signal_cache_update (-1);
8726 target_pass_signals (signal_pass
);
8730 sig_print_header (void)
8732 printf_filtered (_("Signal Stop\tPrint\tPass "
8733 "to program\tDescription\n"));
8737 sig_print_info (enum gdb_signal oursig
)
8739 const char *name
= gdb_signal_to_name (oursig
);
8740 int name_padding
= 13 - strlen (name
);
8742 if (name_padding
<= 0)
8745 printf_filtered ("%s", name
);
8746 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8747 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8748 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8749 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8750 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8753 /* Specify how various signals in the inferior should be handled. */
8756 handle_command (const char *args
, int from_tty
)
8758 int digits
, wordlen
;
8759 int sigfirst
, siglast
;
8760 enum gdb_signal oursig
;
8765 error_no_arg (_("signal to handle"));
8768 /* Allocate and zero an array of flags for which signals to handle. */
8770 const size_t nsigs
= GDB_SIGNAL_LAST
;
8771 unsigned char sigs
[nsigs
] {};
8773 /* Break the command line up into args. */
8775 gdb_argv
built_argv (args
);
8777 /* Walk through the args, looking for signal oursigs, signal names, and
8778 actions. Signal numbers and signal names may be interspersed with
8779 actions, with the actions being performed for all signals cumulatively
8780 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8782 for (char *arg
: built_argv
)
8784 wordlen
= strlen (arg
);
8785 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8789 sigfirst
= siglast
= -1;
8791 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8793 /* Apply action to all signals except those used by the
8794 debugger. Silently skip those. */
8797 siglast
= nsigs
- 1;
8799 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8801 SET_SIGS (nsigs
, sigs
, signal_stop
);
8802 SET_SIGS (nsigs
, sigs
, signal_print
);
8804 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8806 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8808 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8810 SET_SIGS (nsigs
, sigs
, signal_print
);
8812 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8814 SET_SIGS (nsigs
, sigs
, signal_program
);
8816 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8818 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8820 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8822 SET_SIGS (nsigs
, sigs
, signal_program
);
8824 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8826 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8827 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8829 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8831 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8833 else if (digits
> 0)
8835 /* It is numeric. The numeric signal refers to our own
8836 internal signal numbering from target.h, not to host/target
8837 signal number. This is a feature; users really should be
8838 using symbolic names anyway, and the common ones like
8839 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8841 sigfirst
= siglast
= (int)
8842 gdb_signal_from_command (atoi (arg
));
8843 if (arg
[digits
] == '-')
8846 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8848 if (sigfirst
> siglast
)
8850 /* Bet he didn't figure we'd think of this case... */
8851 std::swap (sigfirst
, siglast
);
8856 oursig
= gdb_signal_from_name (arg
);
8857 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8859 sigfirst
= siglast
= (int) oursig
;
8863 /* Not a number and not a recognized flag word => complain. */
8864 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8868 /* If any signal numbers or symbol names were found, set flags for
8869 which signals to apply actions to. */
8871 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8873 switch ((enum gdb_signal
) signum
)
8875 case GDB_SIGNAL_TRAP
:
8876 case GDB_SIGNAL_INT
:
8877 if (!allsigs
&& !sigs
[signum
])
8879 if (query (_("%s is used by the debugger.\n\
8880 Are you sure you want to change it? "),
8881 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8886 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8890 case GDB_SIGNAL_DEFAULT
:
8891 case GDB_SIGNAL_UNKNOWN
:
8892 /* Make sure that "all" doesn't print these. */
8901 for (int signum
= 0; signum
< nsigs
; signum
++)
8904 signal_cache_update (-1);
8905 target_pass_signals (signal_pass
);
8906 target_program_signals (signal_program
);
8910 /* Show the results. */
8911 sig_print_header ();
8912 for (; signum
< nsigs
; signum
++)
8914 sig_print_info ((enum gdb_signal
) signum
);
8921 /* Complete the "handle" command. */
8924 handle_completer (struct cmd_list_element
*ignore
,
8925 completion_tracker
&tracker
,
8926 const char *text
, const char *word
)
8928 static const char * const keywords
[] =
8942 signal_completer (ignore
, tracker
, text
, word
);
8943 complete_on_enum (tracker
, keywords
, word
, word
);
8947 gdb_signal_from_command (int num
)
8949 if (num
>= 1 && num
<= 15)
8950 return (enum gdb_signal
) num
;
8951 error (_("Only signals 1-15 are valid as numeric signals.\n\
8952 Use \"info signals\" for a list of symbolic signals."));
8955 /* Print current contents of the tables set by the handle command.
8956 It is possible we should just be printing signals actually used
8957 by the current target (but for things to work right when switching
8958 targets, all signals should be in the signal tables). */
8961 info_signals_command (const char *signum_exp
, int from_tty
)
8963 enum gdb_signal oursig
;
8965 sig_print_header ();
8969 /* First see if this is a symbol name. */
8970 oursig
= gdb_signal_from_name (signum_exp
);
8971 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8973 /* No, try numeric. */
8975 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8977 sig_print_info (oursig
);
8981 printf_filtered ("\n");
8982 /* These ugly casts brought to you by the native VAX compiler. */
8983 for (oursig
= GDB_SIGNAL_FIRST
;
8984 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8985 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8989 if (oursig
!= GDB_SIGNAL_UNKNOWN
8990 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8991 sig_print_info (oursig
);
8994 printf_filtered (_("\nUse the \"handle\" command "
8995 "to change these tables.\n"));
8998 /* The $_siginfo convenience variable is a bit special. We don't know
8999 for sure the type of the value until we actually have a chance to
9000 fetch the data. The type can change depending on gdbarch, so it is
9001 also dependent on which thread you have selected.
9003 1. making $_siginfo be an internalvar that creates a new value on
9006 2. making the value of $_siginfo be an lval_computed value. */
9008 /* This function implements the lval_computed support for reading a
9012 siginfo_value_read (struct value
*v
)
9014 LONGEST transferred
;
9016 /* If we can access registers, so can we access $_siginfo. Likewise
9018 validate_registers_access ();
9021 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
9023 value_contents_all_raw (v
),
9025 TYPE_LENGTH (value_type (v
)));
9027 if (transferred
!= TYPE_LENGTH (value_type (v
)))
9028 error (_("Unable to read siginfo"));
9031 /* This function implements the lval_computed support for writing a
9035 siginfo_value_write (struct value
*v
, struct value
*fromval
)
9037 LONGEST transferred
;
9039 /* If we can access registers, so can we access $_siginfo. Likewise
9041 validate_registers_access ();
9043 transferred
= target_write (current_top_target (),
9044 TARGET_OBJECT_SIGNAL_INFO
,
9046 value_contents_all_raw (fromval
),
9048 TYPE_LENGTH (value_type (fromval
)));
9050 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
9051 error (_("Unable to write siginfo"));
9054 static const struct lval_funcs siginfo_value_funcs
=
9060 /* Return a new value with the correct type for the siginfo object of
9061 the current thread using architecture GDBARCH. Return a void value
9062 if there's no object available. */
9064 static struct value
*
9065 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
9068 if (target_has_stack
9069 && inferior_ptid
!= null_ptid
9070 && gdbarch_get_siginfo_type_p (gdbarch
))
9072 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9074 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
9077 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
9081 /* infcall_suspend_state contains state about the program itself like its
9082 registers and any signal it received when it last stopped.
9083 This state must be restored regardless of how the inferior function call
9084 ends (either successfully, or after it hits a breakpoint or signal)
9085 if the program is to properly continue where it left off. */
9087 class infcall_suspend_state
9090 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
9091 once the inferior function call has finished. */
9092 infcall_suspend_state (struct gdbarch
*gdbarch
,
9093 const struct thread_info
*tp
,
9094 struct regcache
*regcache
)
9095 : m_thread_suspend (tp
->suspend
),
9096 m_registers (new readonly_detached_regcache (*regcache
))
9098 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
9100 if (gdbarch_get_siginfo_type_p (gdbarch
))
9102 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9103 size_t len
= TYPE_LENGTH (type
);
9105 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
9107 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9108 siginfo_data
.get (), 0, len
) != len
)
9110 /* Errors ignored. */
9111 siginfo_data
.reset (nullptr);
9117 m_siginfo_gdbarch
= gdbarch
;
9118 m_siginfo_data
= std::move (siginfo_data
);
9122 /* Return a pointer to the stored register state. */
9124 readonly_detached_regcache
*registers () const
9126 return m_registers
.get ();
9129 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
9131 void restore (struct gdbarch
*gdbarch
,
9132 struct thread_info
*tp
,
9133 struct regcache
*regcache
) const
9135 tp
->suspend
= m_thread_suspend
;
9137 if (m_siginfo_gdbarch
== gdbarch
)
9139 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
9141 /* Errors ignored. */
9142 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
9143 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
9146 /* The inferior can be gone if the user types "print exit(0)"
9147 (and perhaps other times). */
9148 if (target_has_execution
)
9149 /* NB: The register write goes through to the target. */
9150 regcache
->restore (registers ());
9154 /* How the current thread stopped before the inferior function call was
9156 struct thread_suspend_state m_thread_suspend
;
9158 /* The registers before the inferior function call was executed. */
9159 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
9161 /* Format of SIGINFO_DATA or NULL if it is not present. */
9162 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
9164 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
9165 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
9166 content would be invalid. */
9167 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
9170 infcall_suspend_state_up
9171 save_infcall_suspend_state ()
9173 struct thread_info
*tp
= inferior_thread ();
9174 struct regcache
*regcache
= get_current_regcache ();
9175 struct gdbarch
*gdbarch
= regcache
->arch ();
9177 infcall_suspend_state_up inf_state
9178 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
9180 /* Having saved the current state, adjust the thread state, discarding
9181 any stop signal information. The stop signal is not useful when
9182 starting an inferior function call, and run_inferior_call will not use
9183 the signal due to its `proceed' call with GDB_SIGNAL_0. */
9184 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
9189 /* Restore inferior session state to INF_STATE. */
9192 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9194 struct thread_info
*tp
= inferior_thread ();
9195 struct regcache
*regcache
= get_current_regcache ();
9196 struct gdbarch
*gdbarch
= regcache
->arch ();
9198 inf_state
->restore (gdbarch
, tp
, regcache
);
9199 discard_infcall_suspend_state (inf_state
);
9203 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9208 readonly_detached_regcache
*
9209 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9211 return inf_state
->registers ();
9214 /* infcall_control_state contains state regarding gdb's control of the
9215 inferior itself like stepping control. It also contains session state like
9216 the user's currently selected frame. */
9218 struct infcall_control_state
9220 struct thread_control_state thread_control
;
9221 struct inferior_control_state inferior_control
;
9224 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9225 int stopped_by_random_signal
= 0;
9227 /* ID if the selected frame when the inferior function call was made. */
9228 struct frame_id selected_frame_id
{};
9231 /* Save all of the information associated with the inferior<==>gdb
9234 infcall_control_state_up
9235 save_infcall_control_state ()
9237 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9238 struct thread_info
*tp
= inferior_thread ();
9239 struct inferior
*inf
= current_inferior ();
9241 inf_status
->thread_control
= tp
->control
;
9242 inf_status
->inferior_control
= inf
->control
;
9244 tp
->control
.step_resume_breakpoint
= NULL
;
9245 tp
->control
.exception_resume_breakpoint
= NULL
;
9247 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9248 chain. If caller's caller is walking the chain, they'll be happier if we
9249 hand them back the original chain when restore_infcall_control_state is
9251 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9254 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9255 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9257 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9263 restore_selected_frame (const frame_id
&fid
)
9265 frame_info
*frame
= frame_find_by_id (fid
);
9267 /* If inf_status->selected_frame_id is NULL, there was no previously
9271 warning (_("Unable to restore previously selected frame."));
9275 select_frame (frame
);
9278 /* Restore inferior session state to INF_STATUS. */
9281 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9283 struct thread_info
*tp
= inferior_thread ();
9284 struct inferior
*inf
= current_inferior ();
9286 if (tp
->control
.step_resume_breakpoint
)
9287 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9289 if (tp
->control
.exception_resume_breakpoint
)
9290 tp
->control
.exception_resume_breakpoint
->disposition
9291 = disp_del_at_next_stop
;
9293 /* Handle the bpstat_copy of the chain. */
9294 bpstat_clear (&tp
->control
.stop_bpstat
);
9296 tp
->control
= inf_status
->thread_control
;
9297 inf
->control
= inf_status
->inferior_control
;
9300 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9301 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9303 if (target_has_stack
)
9305 /* The point of the try/catch is that if the stack is clobbered,
9306 walking the stack might encounter a garbage pointer and
9307 error() trying to dereference it. */
9310 restore_selected_frame (inf_status
->selected_frame_id
);
9312 catch (const gdb_exception_error
&ex
)
9314 exception_fprintf (gdb_stderr
, ex
,
9315 "Unable to restore previously selected frame:\n");
9316 /* Error in restoring the selected frame. Select the
9318 select_frame (get_current_frame ());
9326 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9328 if (inf_status
->thread_control
.step_resume_breakpoint
)
9329 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9330 = disp_del_at_next_stop
;
9332 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9333 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9334 = disp_del_at_next_stop
;
9336 /* See save_infcall_control_state for info on stop_bpstat. */
9337 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9345 clear_exit_convenience_vars (void)
9347 clear_internalvar (lookup_internalvar ("_exitsignal"));
9348 clear_internalvar (lookup_internalvar ("_exitcode"));
9352 /* User interface for reverse debugging:
9353 Set exec-direction / show exec-direction commands
9354 (returns error unless target implements to_set_exec_direction method). */
9356 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9357 static const char exec_forward
[] = "forward";
9358 static const char exec_reverse
[] = "reverse";
9359 static const char *exec_direction
= exec_forward
;
9360 static const char *const exec_direction_names
[] = {
9367 set_exec_direction_func (const char *args
, int from_tty
,
9368 struct cmd_list_element
*cmd
)
9370 if (target_can_execute_reverse
)
9372 if (!strcmp (exec_direction
, exec_forward
))
9373 execution_direction
= EXEC_FORWARD
;
9374 else if (!strcmp (exec_direction
, exec_reverse
))
9375 execution_direction
= EXEC_REVERSE
;
9379 exec_direction
= exec_forward
;
9380 error (_("Target does not support this operation."));
9385 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9386 struct cmd_list_element
*cmd
, const char *value
)
9388 switch (execution_direction
) {
9390 fprintf_filtered (out
, _("Forward.\n"));
9393 fprintf_filtered (out
, _("Reverse.\n"));
9396 internal_error (__FILE__
, __LINE__
,
9397 _("bogus execution_direction value: %d"),
9398 (int) execution_direction
);
9403 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9404 struct cmd_list_element
*c
, const char *value
)
9406 fprintf_filtered (file
, _("Resuming the execution of threads "
9407 "of all processes is %s.\n"), value
);
9410 /* Implementation of `siginfo' variable. */
9412 static const struct internalvar_funcs siginfo_funcs
=
9419 /* Callback for infrun's target events source. This is marked when a
9420 thread has a pending status to process. */
9423 infrun_async_inferior_event_handler (gdb_client_data data
)
9425 inferior_event_handler (INF_REG_EVENT
, NULL
);
9428 void _initialize_infrun ();
9430 _initialize_infrun ()
9432 struct cmd_list_element
*c
;
9434 /* Register extra event sources in the event loop. */
9435 infrun_async_inferior_event_token
9436 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9438 add_info ("signals", info_signals_command
, _("\
9439 What debugger does when program gets various signals.\n\
9440 Specify a signal as argument to print info on that signal only."));
9441 add_info_alias ("handle", "signals", 0);
9443 c
= add_com ("handle", class_run
, handle_command
, _("\
9444 Specify how to handle signals.\n\
9445 Usage: handle SIGNAL [ACTIONS]\n\
9446 Args are signals and actions to apply to those signals.\n\
9447 If no actions are specified, the current settings for the specified signals\n\
9448 will be displayed instead.\n\
9450 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9451 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9452 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9453 The special arg \"all\" is recognized to mean all signals except those\n\
9454 used by the debugger, typically SIGTRAP and SIGINT.\n\
9456 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9457 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9458 Stop means reenter debugger if this signal happens (implies print).\n\
9459 Print means print a message if this signal happens.\n\
9460 Pass means let program see this signal; otherwise program doesn't know.\n\
9461 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9462 Pass and Stop may be combined.\n\
9464 Multiple signals may be specified. Signal numbers and signal names\n\
9465 may be interspersed with actions, with the actions being performed for\n\
9466 all signals cumulatively specified."));
9467 set_cmd_completer (c
, handle_completer
);
9470 stop_command
= add_cmd ("stop", class_obscure
,
9471 not_just_help_class_command
, _("\
9472 There is no `stop' command, but you can set a hook on `stop'.\n\
9473 This allows you to set a list of commands to be run each time execution\n\
9474 of the program stops."), &cmdlist
);
9476 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9477 Set inferior debugging."), _("\
9478 Show inferior debugging."), _("\
9479 When non-zero, inferior specific debugging is enabled."),
9482 &setdebuglist
, &showdebuglist
);
9484 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9485 &debug_displaced
, _("\
9486 Set displaced stepping debugging."), _("\
9487 Show displaced stepping debugging."), _("\
9488 When non-zero, displaced stepping specific debugging is enabled."),
9490 show_debug_displaced
,
9491 &setdebuglist
, &showdebuglist
);
9493 add_setshow_boolean_cmd ("non-stop", no_class
,
9495 Set whether gdb controls the inferior in non-stop mode."), _("\
9496 Show whether gdb controls the inferior in non-stop mode."), _("\
9497 When debugging a multi-threaded program and this setting is\n\
9498 off (the default, also called all-stop mode), when one thread stops\n\
9499 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9500 all other threads in the program while you interact with the thread of\n\
9501 interest. When you continue or step a thread, you can allow the other\n\
9502 threads to run, or have them remain stopped, but while you inspect any\n\
9503 thread's state, all threads stop.\n\
9505 In non-stop mode, when one thread stops, other threads can continue\n\
9506 to run freely. You'll be able to step each thread independently,\n\
9507 leave it stopped or free to run as needed."),
9513 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9516 signal_print
[i
] = 1;
9517 signal_program
[i
] = 1;
9518 signal_catch
[i
] = 0;
9521 /* Signals caused by debugger's own actions should not be given to
9522 the program afterwards.
9524 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9525 explicitly specifies that it should be delivered to the target
9526 program. Typically, that would occur when a user is debugging a
9527 target monitor on a simulator: the target monitor sets a
9528 breakpoint; the simulator encounters this breakpoint and halts
9529 the simulation handing control to GDB; GDB, noting that the stop
9530 address doesn't map to any known breakpoint, returns control back
9531 to the simulator; the simulator then delivers the hardware
9532 equivalent of a GDB_SIGNAL_TRAP to the program being
9534 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9535 signal_program
[GDB_SIGNAL_INT
] = 0;
9537 /* Signals that are not errors should not normally enter the debugger. */
9538 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9539 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9540 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9541 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9542 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9543 signal_print
[GDB_SIGNAL_PROF
] = 0;
9544 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9545 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9546 signal_stop
[GDB_SIGNAL_IO
] = 0;
9547 signal_print
[GDB_SIGNAL_IO
] = 0;
9548 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9549 signal_print
[GDB_SIGNAL_POLL
] = 0;
9550 signal_stop
[GDB_SIGNAL_URG
] = 0;
9551 signal_print
[GDB_SIGNAL_URG
] = 0;
9552 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9553 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9554 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9555 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9557 /* These signals are used internally by user-level thread
9558 implementations. (See signal(5) on Solaris.) Like the above
9559 signals, a healthy program receives and handles them as part of
9560 its normal operation. */
9561 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9562 signal_print
[GDB_SIGNAL_LWP
] = 0;
9563 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9564 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9565 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9566 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9567 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9568 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9570 /* Update cached state. */
9571 signal_cache_update (-1);
9573 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9574 &stop_on_solib_events
, _("\
9575 Set stopping for shared library events."), _("\
9576 Show stopping for shared library events."), _("\
9577 If nonzero, gdb will give control to the user when the dynamic linker\n\
9578 notifies gdb of shared library events. The most common event of interest\n\
9579 to the user would be loading/unloading of a new library."),
9580 set_stop_on_solib_events
,
9581 show_stop_on_solib_events
,
9582 &setlist
, &showlist
);
9584 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9585 follow_fork_mode_kind_names
,
9586 &follow_fork_mode_string
, _("\
9587 Set debugger response to a program call of fork or vfork."), _("\
9588 Show debugger response to a program call of fork or vfork."), _("\
9589 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9590 parent - the original process is debugged after a fork\n\
9591 child - the new process is debugged after a fork\n\
9592 The unfollowed process will continue to run.\n\
9593 By default, the debugger will follow the parent process."),
9595 show_follow_fork_mode_string
,
9596 &setlist
, &showlist
);
9598 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9599 follow_exec_mode_names
,
9600 &follow_exec_mode_string
, _("\
9601 Set debugger response to a program call of exec."), _("\
9602 Show debugger response to a program call of exec."), _("\
9603 An exec call replaces the program image of a process.\n\
9605 follow-exec-mode can be:\n\
9607 new - the debugger creates a new inferior and rebinds the process\n\
9608 to this new inferior. The program the process was running before\n\
9609 the exec call can be restarted afterwards by restarting the original\n\
9612 same - the debugger keeps the process bound to the same inferior.\n\
9613 The new executable image replaces the previous executable loaded in\n\
9614 the inferior. Restarting the inferior after the exec call restarts\n\
9615 the executable the process was running after the exec call.\n\
9617 By default, the debugger will use the same inferior."),
9619 show_follow_exec_mode_string
,
9620 &setlist
, &showlist
);
9622 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9623 scheduler_enums
, &scheduler_mode
, _("\
9624 Set mode for locking scheduler during execution."), _("\
9625 Show mode for locking scheduler during execution."), _("\
9626 off == no locking (threads may preempt at any time)\n\
9627 on == full locking (no thread except the current thread may run)\n\
9628 This applies to both normal execution and replay mode.\n\
9629 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9630 In this mode, other threads may run during other commands.\n\
9631 This applies to both normal execution and replay mode.\n\
9632 replay == scheduler locked in replay mode and unlocked during normal execution."),
9633 set_schedlock_func
, /* traps on target vector */
9634 show_scheduler_mode
,
9635 &setlist
, &showlist
);
9637 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9638 Set mode for resuming threads of all processes."), _("\
9639 Show mode for resuming threads of all processes."), _("\
9640 When on, execution commands (such as 'continue' or 'next') resume all\n\
9641 threads of all processes. When off (which is the default), execution\n\
9642 commands only resume the threads of the current process. The set of\n\
9643 threads that are resumed is further refined by the scheduler-locking\n\
9644 mode (see help set scheduler-locking)."),
9646 show_schedule_multiple
,
9647 &setlist
, &showlist
);
9649 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9650 Set mode of the step operation."), _("\
9651 Show mode of the step operation."), _("\
9652 When set, doing a step over a function without debug line information\n\
9653 will stop at the first instruction of that function. Otherwise, the\n\
9654 function is skipped and the step command stops at a different source line."),
9656 show_step_stop_if_no_debug
,
9657 &setlist
, &showlist
);
9659 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9660 &can_use_displaced_stepping
, _("\
9661 Set debugger's willingness to use displaced stepping."), _("\
9662 Show debugger's willingness to use displaced stepping."), _("\
9663 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9664 supported by the target architecture. If off, gdb will not use displaced\n\
9665 stepping to step over breakpoints, even if such is supported by the target\n\
9666 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9667 if the target architecture supports it and non-stop mode is active, but will not\n\
9668 use it in all-stop mode (see help set non-stop)."),
9670 show_can_use_displaced_stepping
,
9671 &setlist
, &showlist
);
9673 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9674 &exec_direction
, _("Set direction of execution.\n\
9675 Options are 'forward' or 'reverse'."),
9676 _("Show direction of execution (forward/reverse)."),
9677 _("Tells gdb whether to execute forward or backward."),
9678 set_exec_direction_func
, show_exec_direction_func
,
9679 &setlist
, &showlist
);
9681 /* Set/show detach-on-fork: user-settable mode. */
9683 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9684 Set whether gdb will detach the child of a fork."), _("\
9685 Show whether gdb will detach the child of a fork."), _("\
9686 Tells gdb whether to detach the child of a fork."),
9687 NULL
, NULL
, &setlist
, &showlist
);
9689 /* Set/show disable address space randomization mode. */
9691 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9692 &disable_randomization
, _("\
9693 Set disabling of debuggee's virtual address space randomization."), _("\
9694 Show disabling of debuggee's virtual address space randomization."), _("\
9695 When this mode is on (which is the default), randomization of the virtual\n\
9696 address space is disabled. Standalone programs run with the randomization\n\
9697 enabled by default on some platforms."),
9698 &set_disable_randomization
,
9699 &show_disable_randomization
,
9700 &setlist
, &showlist
);
9702 /* ptid initializations */
9703 inferior_ptid
= null_ptid
;
9704 target_last_wait_ptid
= minus_one_ptid
;
9706 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9707 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9708 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9709 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9711 /* Explicitly create without lookup, since that tries to create a
9712 value with a void typed value, and when we get here, gdbarch
9713 isn't initialized yet. At this point, we're quite sure there
9714 isn't another convenience variable of the same name. */
9715 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9717 add_setshow_boolean_cmd ("observer", no_class
,
9718 &observer_mode_1
, _("\
9719 Set whether gdb controls the inferior in observer mode."), _("\
9720 Show whether gdb controls the inferior in observer mode."), _("\
9721 In observer mode, GDB can get data from the inferior, but not\n\
9722 affect its execution. Registers and memory may not be changed,\n\
9723 breakpoints may not be set, and the program cannot be interrupted\n\