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"
70 #include "gdbsupport/selftest.h"
71 #include "scoped-mock-context.h"
72 #include "test-target.h"
73 #include "gdbsupport/common-debug.h"
75 /* Prototypes for local functions */
77 static void sig_print_info (enum gdb_signal
);
79 static void sig_print_header (void);
81 static void follow_inferior_reset_breakpoints (void);
83 static bool currently_stepping (struct thread_info
*tp
);
85 static void insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*);
87 static void insert_step_resume_breakpoint_at_caller (struct frame_info
*);
89 static void insert_longjmp_resume_breakpoint (struct gdbarch
*, CORE_ADDR
);
91 static bool maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
);
93 static void resume (gdb_signal sig
);
95 static void wait_for_inferior (inferior
*inf
);
97 /* Asynchronous signal handler registered as event loop source for
98 when we have pending events ready to be passed to the core. */
99 static struct async_event_handler
*infrun_async_inferior_event_token
;
101 /* Stores whether infrun_async was previously enabled or disabled.
102 Starts off as -1, indicating "never enabled/disabled". */
103 static int infrun_is_async
= -1;
108 infrun_async (int enable
)
110 if (infrun_is_async
!= enable
)
112 infrun_is_async
= enable
;
114 infrun_debug_printf ("enable=%d", enable
);
117 mark_async_event_handler (infrun_async_inferior_event_token
);
119 clear_async_event_handler (infrun_async_inferior_event_token
);
126 mark_infrun_async_event_handler (void)
128 mark_async_event_handler (infrun_async_inferior_event_token
);
131 /* When set, stop the 'step' command if we enter a function which has
132 no line number information. The normal behavior is that we step
133 over such function. */
134 bool step_stop_if_no_debug
= false;
136 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
137 struct cmd_list_element
*c
, const char *value
)
139 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
142 /* proceed and normal_stop use this to notify the user when the
143 inferior stopped in a different thread than it had been running
146 static ptid_t previous_inferior_ptid
;
148 /* If set (default for legacy reasons), when following a fork, GDB
149 will detach from one of the fork branches, child or parent.
150 Exactly which branch is detached depends on 'set follow-fork-mode'
153 static bool detach_fork
= true;
155 bool debug_displaced
= false;
157 show_debug_displaced (struct ui_file
*file
, int from_tty
,
158 struct cmd_list_element
*c
, const char *value
)
160 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
163 unsigned int debug_infrun
= 0;
165 show_debug_infrun (struct ui_file
*file
, int from_tty
,
166 struct cmd_list_element
*c
, const char *value
)
168 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 /* True after stop if current stack frame should be printed. */
373 static bool 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
)
904 infrun_debug_printf ("resuming vfork parent thread %s",
905 target_pid_to_str (thread
->ptid
).c_str ());
907 switch_to_thread (thread
);
908 clear_proceed_status (0);
909 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
915 /* Called whenever we notice an exec or exit event, to handle
916 detaching or resuming a vfork parent. */
919 handle_vfork_child_exec_or_exit (int exec
)
921 struct inferior
*inf
= current_inferior ();
923 if (inf
->vfork_parent
)
925 int resume_parent
= -1;
927 /* This exec or exit marks the end of the shared memory region
928 between the parent and the child. Break the bonds. */
929 inferior
*vfork_parent
= inf
->vfork_parent
;
930 inf
->vfork_parent
->vfork_child
= NULL
;
931 inf
->vfork_parent
= NULL
;
933 /* If the user wanted to detach from the parent, now is the
935 if (vfork_parent
->pending_detach
)
937 struct program_space
*pspace
;
938 struct address_space
*aspace
;
940 /* follow-fork child, detach-on-fork on. */
942 vfork_parent
->pending_detach
= 0;
944 scoped_restore_current_pspace_and_thread restore_thread
;
946 /* We're letting loose of the parent. */
947 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
948 switch_to_thread (tp
);
950 /* We're about to detach from the parent, which implicitly
951 removes breakpoints from its address space. There's a
952 catch here: we want to reuse the spaces for the child,
953 but, parent/child are still sharing the pspace at this
954 point, although the exec in reality makes the kernel give
955 the child a fresh set of new pages. The problem here is
956 that the breakpoints module being unaware of this, would
957 likely chose the child process to write to the parent
958 address space. Swapping the child temporarily away from
959 the spaces has the desired effect. Yes, this is "sort
962 pspace
= inf
->pspace
;
963 aspace
= inf
->aspace
;
967 if (print_inferior_events
)
970 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
972 target_terminal::ours_for_output ();
976 fprintf_filtered (gdb_stdlog
,
977 _("[Detaching vfork parent %s "
978 "after child exec]\n"), pidstr
.c_str ());
982 fprintf_filtered (gdb_stdlog
,
983 _("[Detaching vfork parent %s "
984 "after child exit]\n"), pidstr
.c_str ());
988 target_detach (vfork_parent
, 0);
991 inf
->pspace
= pspace
;
992 inf
->aspace
= aspace
;
996 /* We're staying attached to the parent, so, really give the
997 child a new address space. */
998 inf
->pspace
= new program_space (maybe_new_address_space ());
999 inf
->aspace
= inf
->pspace
->aspace
;
1001 set_current_program_space (inf
->pspace
);
1003 resume_parent
= vfork_parent
->pid
;
1007 /* If this is a vfork child exiting, then the pspace and
1008 aspaces were shared with the parent. Since we're
1009 reporting the process exit, we'll be mourning all that is
1010 found in the address space, and switching to null_ptid,
1011 preparing to start a new inferior. But, since we don't
1012 want to clobber the parent's address/program spaces, we
1013 go ahead and create a new one for this exiting
1016 /* Switch to no-thread while running clone_program_space, so
1017 that clone_program_space doesn't want to read the
1018 selected frame of a dead process. */
1019 scoped_restore_current_thread restore_thread
;
1020 switch_to_no_thread ();
1022 inf
->pspace
= new program_space (maybe_new_address_space ());
1023 inf
->aspace
= inf
->pspace
->aspace
;
1024 set_current_program_space (inf
->pspace
);
1026 inf
->symfile_flags
= SYMFILE_NO_READ
;
1027 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1029 resume_parent
= vfork_parent
->pid
;
1032 gdb_assert (current_program_space
== inf
->pspace
);
1034 if (non_stop
&& resume_parent
!= -1)
1036 /* If the user wanted the parent to be running, let it go
1038 scoped_restore_current_thread restore_thread
;
1040 infrun_debug_printf ("resuming vfork parent process %d",
1043 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1048 /* Enum strings for "set|show follow-exec-mode". */
1050 static const char follow_exec_mode_new
[] = "new";
1051 static const char follow_exec_mode_same
[] = "same";
1052 static const char *const follow_exec_mode_names
[] =
1054 follow_exec_mode_new
,
1055 follow_exec_mode_same
,
1059 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1061 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1062 struct cmd_list_element
*c
, const char *value
)
1064 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1067 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1070 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1072 struct inferior
*inf
= current_inferior ();
1073 int pid
= ptid
.pid ();
1074 ptid_t process_ptid
;
1076 /* Switch terminal for any messages produced e.g. by
1077 breakpoint_re_set. */
1078 target_terminal::ours_for_output ();
1080 /* This is an exec event that we actually wish to pay attention to.
1081 Refresh our symbol table to the newly exec'd program, remove any
1082 momentary bp's, etc.
1084 If there are breakpoints, they aren't really inserted now,
1085 since the exec() transformed our inferior into a fresh set
1088 We want to preserve symbolic breakpoints on the list, since
1089 we have hopes that they can be reset after the new a.out's
1090 symbol table is read.
1092 However, any "raw" breakpoints must be removed from the list
1093 (e.g., the solib bp's), since their address is probably invalid
1096 And, we DON'T want to call delete_breakpoints() here, since
1097 that may write the bp's "shadow contents" (the instruction
1098 value that was overwritten with a TRAP instruction). Since
1099 we now have a new a.out, those shadow contents aren't valid. */
1101 mark_breakpoints_out ();
1103 /* The target reports the exec event to the main thread, even if
1104 some other thread does the exec, and even if the main thread was
1105 stopped or already gone. We may still have non-leader threads of
1106 the process on our list. E.g., on targets that don't have thread
1107 exit events (like remote); or on native Linux in non-stop mode if
1108 there were only two threads in the inferior and the non-leader
1109 one is the one that execs (and nothing forces an update of the
1110 thread list up to here). When debugging remotely, it's best to
1111 avoid extra traffic, when possible, so avoid syncing the thread
1112 list with the target, and instead go ahead and delete all threads
1113 of the process but one that reported the event. Note this must
1114 be done before calling update_breakpoints_after_exec, as
1115 otherwise clearing the threads' resources would reference stale
1116 thread breakpoints -- it may have been one of these threads that
1117 stepped across the exec. We could just clear their stepping
1118 states, but as long as we're iterating, might as well delete
1119 them. Deleting them now rather than at the next user-visible
1120 stop provides a nicer sequence of events for user and MI
1122 for (thread_info
*th
: all_threads_safe ())
1123 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1126 /* We also need to clear any left over stale state for the
1127 leader/event thread. E.g., if there was any step-resume
1128 breakpoint or similar, it's gone now. We cannot truly
1129 step-to-next statement through an exec(). */
1130 thread_info
*th
= inferior_thread ();
1131 th
->control
.step_resume_breakpoint
= NULL
;
1132 th
->control
.exception_resume_breakpoint
= NULL
;
1133 th
->control
.single_step_breakpoints
= NULL
;
1134 th
->control
.step_range_start
= 0;
1135 th
->control
.step_range_end
= 0;
1137 /* The user may have had the main thread held stopped in the
1138 previous image (e.g., schedlock on, or non-stop). Release
1140 th
->stop_requested
= 0;
1142 update_breakpoints_after_exec ();
1144 /* What is this a.out's name? */
1145 process_ptid
= ptid_t (pid
);
1146 printf_unfiltered (_("%s is executing new program: %s\n"),
1147 target_pid_to_str (process_ptid
).c_str (),
1150 /* We've followed the inferior through an exec. Therefore, the
1151 inferior has essentially been killed & reborn. */
1153 breakpoint_init_inferior (inf_execd
);
1155 gdb::unique_xmalloc_ptr
<char> exec_file_host
1156 = exec_file_find (exec_file_target
, NULL
);
1158 /* If we were unable to map the executable target pathname onto a host
1159 pathname, tell the user that. Otherwise GDB's subsequent behavior
1160 is confusing. Maybe it would even be better to stop at this point
1161 so that the user can specify a file manually before continuing. */
1162 if (exec_file_host
== NULL
)
1163 warning (_("Could not load symbols for executable %s.\n"
1164 "Do you need \"set sysroot\"?"),
1167 /* Reset the shared library package. This ensures that we get a
1168 shlib event when the child reaches "_start", at which point the
1169 dld will have had a chance to initialize the child. */
1170 /* Also, loading a symbol file below may trigger symbol lookups, and
1171 we don't want those to be satisfied by the libraries of the
1172 previous incarnation of this process. */
1173 no_shared_libraries (NULL
, 0);
1175 if (follow_exec_mode_string
== follow_exec_mode_new
)
1177 /* The user wants to keep the old inferior and program spaces
1178 around. Create a new fresh one, and switch to it. */
1180 /* Do exit processing for the original inferior before setting the new
1181 inferior's pid. Having two inferiors with the same pid would confuse
1182 find_inferior_p(t)id. Transfer the terminal state and info from the
1183 old to the new inferior. */
1184 inf
= add_inferior_with_spaces ();
1185 swap_terminal_info (inf
, current_inferior ());
1186 exit_inferior_silent (current_inferior ());
1189 target_follow_exec (inf
, exec_file_target
);
1191 inferior
*org_inferior
= current_inferior ();
1192 switch_to_inferior_no_thread (inf
);
1193 push_target (org_inferior
->process_target ());
1194 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1195 switch_to_thread (thr
);
1199 /* The old description may no longer be fit for the new image.
1200 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1201 old description; we'll read a new one below. No need to do
1202 this on "follow-exec-mode new", as the old inferior stays
1203 around (its description is later cleared/refetched on
1205 target_clear_description ();
1208 gdb_assert (current_program_space
== inf
->pspace
);
1210 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1211 because the proper displacement for a PIE (Position Independent
1212 Executable) main symbol file will only be computed by
1213 solib_create_inferior_hook below. breakpoint_re_set would fail
1214 to insert the breakpoints with the zero displacement. */
1215 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1217 /* If the target can specify a description, read it. Must do this
1218 after flipping to the new executable (because the target supplied
1219 description must be compatible with the executable's
1220 architecture, and the old executable may e.g., be 32-bit, while
1221 the new one 64-bit), and before anything involving memory or
1223 target_find_description ();
1225 gdb::observers::inferior_execd
.notify (inf
);
1227 breakpoint_re_set ();
1229 /* Reinsert all breakpoints. (Those which were symbolic have
1230 been reset to the proper address in the new a.out, thanks
1231 to symbol_file_command...). */
1232 insert_breakpoints ();
1234 /* The next resume of this inferior should bring it to the shlib
1235 startup breakpoints. (If the user had also set bp's on
1236 "main" from the old (parent) process, then they'll auto-
1237 matically get reset there in the new process.). */
1240 /* The chain of threads that need to do a step-over operation to get
1241 past e.g., a breakpoint. What technique is used to step over the
1242 breakpoint/watchpoint does not matter -- all threads end up in the
1243 same queue, to maintain rough temporal order of execution, in order
1244 to avoid starvation, otherwise, we could e.g., find ourselves
1245 constantly stepping the same couple threads past their breakpoints
1246 over and over, if the single-step finish fast enough. */
1247 struct thread_info
*global_thread_step_over_chain_head
;
1249 /* Bit flags indicating what the thread needs to step over. */
1251 enum step_over_what_flag
1253 /* Step over a breakpoint. */
1254 STEP_OVER_BREAKPOINT
= 1,
1256 /* Step past a non-continuable watchpoint, in order to let the
1257 instruction execute so we can evaluate the watchpoint
1259 STEP_OVER_WATCHPOINT
= 2
1261 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1263 /* Info about an instruction that is being stepped over. */
1265 struct step_over_info
1267 /* If we're stepping past a breakpoint, this is the address space
1268 and address of the instruction the breakpoint is set at. We'll
1269 skip inserting all breakpoints here. Valid iff ASPACE is
1271 const address_space
*aspace
;
1274 /* The instruction being stepped over triggers a nonsteppable
1275 watchpoint. If true, we'll skip inserting watchpoints. */
1276 int nonsteppable_watchpoint_p
;
1278 /* The thread's global number. */
1282 /* The step-over info of the location that is being stepped over.
1284 Note that with async/breakpoint always-inserted mode, a user might
1285 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1286 being stepped over. As setting a new breakpoint inserts all
1287 breakpoints, we need to make sure the breakpoint being stepped over
1288 isn't inserted then. We do that by only clearing the step-over
1289 info when the step-over is actually finished (or aborted).
1291 Presently GDB can only step over one breakpoint at any given time.
1292 Given threads that can't run code in the same address space as the
1293 breakpoint's can't really miss the breakpoint, GDB could be taught
1294 to step-over at most one breakpoint per address space (so this info
1295 could move to the address space object if/when GDB is extended).
1296 The set of breakpoints being stepped over will normally be much
1297 smaller than the set of all breakpoints, so a flag in the
1298 breakpoint location structure would be wasteful. A separate list
1299 also saves complexity and run-time, as otherwise we'd have to go
1300 through all breakpoint locations clearing their flag whenever we
1301 start a new sequence. Similar considerations weigh against storing
1302 this info in the thread object. Plus, not all step overs actually
1303 have breakpoint locations -- e.g., stepping past a single-step
1304 breakpoint, or stepping to complete a non-continuable
1306 static struct step_over_info step_over_info
;
1308 /* Record the address of the breakpoint/instruction we're currently
1310 N.B. We record the aspace and address now, instead of say just the thread,
1311 because when we need the info later the thread may be running. */
1314 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1315 int nonsteppable_watchpoint_p
,
1318 step_over_info
.aspace
= aspace
;
1319 step_over_info
.address
= address
;
1320 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1321 step_over_info
.thread
= thread
;
1324 /* Called when we're not longer stepping over a breakpoint / an
1325 instruction, so all breakpoints are free to be (re)inserted. */
1328 clear_step_over_info (void)
1330 infrun_debug_printf ("clearing step over info");
1331 step_over_info
.aspace
= NULL
;
1332 step_over_info
.address
= 0;
1333 step_over_info
.nonsteppable_watchpoint_p
= 0;
1334 step_over_info
.thread
= -1;
1340 stepping_past_instruction_at (struct address_space
*aspace
,
1343 return (step_over_info
.aspace
!= NULL
1344 && breakpoint_address_match (aspace
, address
,
1345 step_over_info
.aspace
,
1346 step_over_info
.address
));
1352 thread_is_stepping_over_breakpoint (int thread
)
1354 return (step_over_info
.thread
!= -1
1355 && thread
== step_over_info
.thread
);
1361 stepping_past_nonsteppable_watchpoint (void)
1363 return step_over_info
.nonsteppable_watchpoint_p
;
1366 /* Returns true if step-over info is valid. */
1369 step_over_info_valid_p (void)
1371 return (step_over_info
.aspace
!= NULL
1372 || stepping_past_nonsteppable_watchpoint ());
1376 /* Displaced stepping. */
1378 /* In non-stop debugging mode, we must take special care to manage
1379 breakpoints properly; in particular, the traditional strategy for
1380 stepping a thread past a breakpoint it has hit is unsuitable.
1381 'Displaced stepping' is a tactic for stepping one thread past a
1382 breakpoint it has hit while ensuring that other threads running
1383 concurrently will hit the breakpoint as they should.
1385 The traditional way to step a thread T off a breakpoint in a
1386 multi-threaded program in all-stop mode is as follows:
1388 a0) Initially, all threads are stopped, and breakpoints are not
1390 a1) We single-step T, leaving breakpoints uninserted.
1391 a2) We insert breakpoints, and resume all threads.
1393 In non-stop debugging, however, this strategy is unsuitable: we
1394 don't want to have to stop all threads in the system in order to
1395 continue or step T past a breakpoint. Instead, we use displaced
1398 n0) Initially, T is stopped, other threads are running, and
1399 breakpoints are inserted.
1400 n1) We copy the instruction "under" the breakpoint to a separate
1401 location, outside the main code stream, making any adjustments
1402 to the instruction, register, and memory state as directed by
1404 n2) We single-step T over the instruction at its new location.
1405 n3) We adjust the resulting register and memory state as directed
1406 by T's architecture. This includes resetting T's PC to point
1407 back into the main instruction stream.
1410 This approach depends on the following gdbarch methods:
1412 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1413 indicate where to copy the instruction, and how much space must
1414 be reserved there. We use these in step n1.
1416 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1417 address, and makes any necessary adjustments to the instruction,
1418 register contents, and memory. We use this in step n1.
1420 - gdbarch_displaced_step_fixup adjusts registers and memory after
1421 we have successfully single-stepped the instruction, to yield the
1422 same effect the instruction would have had if we had executed it
1423 at its original address. We use this in step n3.
1425 The gdbarch_displaced_step_copy_insn and
1426 gdbarch_displaced_step_fixup functions must be written so that
1427 copying an instruction with gdbarch_displaced_step_copy_insn,
1428 single-stepping across the copied instruction, and then applying
1429 gdbarch_displaced_insn_fixup should have the same effects on the
1430 thread's memory and registers as stepping the instruction in place
1431 would have. Exactly which responsibilities fall to the copy and
1432 which fall to the fixup is up to the author of those functions.
1434 See the comments in gdbarch.sh for details.
1436 Note that displaced stepping and software single-step cannot
1437 currently be used in combination, although with some care I think
1438 they could be made to. Software single-step works by placing
1439 breakpoints on all possible subsequent instructions; if the
1440 displaced instruction is a PC-relative jump, those breakpoints
1441 could fall in very strange places --- on pages that aren't
1442 executable, or at addresses that are not proper instruction
1443 boundaries. (We do generally let other threads run while we wait
1444 to hit the software single-step breakpoint, and they might
1445 encounter such a corrupted instruction.) One way to work around
1446 this would be to have gdbarch_displaced_step_copy_insn fully
1447 simulate the effect of PC-relative instructions (and return NULL)
1448 on architectures that use software single-stepping.
1450 In non-stop mode, we can have independent and simultaneous step
1451 requests, so more than one thread may need to simultaneously step
1452 over a breakpoint. The current implementation assumes there is
1453 only one scratch space per process. In this case, we have to
1454 serialize access to the scratch space. If thread A wants to step
1455 over a breakpoint, but we are currently waiting for some other
1456 thread to complete a displaced step, we leave thread A stopped and
1457 place it in the displaced_step_request_queue. Whenever a displaced
1458 step finishes, we pick the next thread in the queue and start a new
1459 displaced step operation on it. See displaced_step_prepare and
1460 displaced_step_fixup for details. */
1462 /* Default destructor for displaced_step_copy_insn_closure. */
1464 displaced_step_copy_insn_closure::~displaced_step_copy_insn_closure ()
1467 /* Returns true if any inferior has a thread doing a displaced
1471 displaced_step_in_progress_any_inferior ()
1473 for (inferior
*i
: all_inferiors ())
1475 if (i
->displaced_step_state
.step_thread
!= nullptr)
1482 /* Return true if THREAD is doing a displaced step. */
1485 displaced_step_in_progress_thread (thread_info
*thread
)
1487 gdb_assert (thread
!= NULL
);
1489 return thread
->inf
->displaced_step_state
.step_thread
== thread
;
1492 /* Return true if INF has a thread doing a displaced step. */
1495 displaced_step_in_progress (inferior
*inf
)
1497 return inf
->displaced_step_state
.step_thread
!= nullptr;
1500 /* If inferior is in displaced stepping, and ADDR equals to starting address
1501 of copy area, return corresponding displaced_step_copy_insn_closure.
1502 Otherwise, return NULL. */
1504 displaced_step_copy_insn_closure
*
1505 get_displaced_step_copy_insn_closure_by_addr (CORE_ADDR addr
)
1507 displaced_step_inferior_state
&displaced
1508 = current_inferior ()->displaced_step_state
;
1510 /* If checking the mode of displaced instruction in copy area. */
1511 if (displaced
.step_thread
!= nullptr
1512 && displaced
.step_copy
== addr
)
1513 return displaced
.step_closure
.get ();
1519 infrun_inferior_exit (struct inferior
*inf
)
1521 inf
->displaced_step_state
.reset ();
1525 infrun_inferior_execd (inferior
*inf
)
1527 /* If a thread was doing a displaced step in this inferior at the moment of
1528 the exec, it no longer exists. Even if the exec'ing thread was the one
1529 doing a displaced step, we don't want to to any fixup nor restore displaced
1530 stepping buffer bytes. */
1531 inf
->displaced_step_state
.reset ();
1533 /* Since an in-line step is done with everything else stopped, if there was
1534 one in progress at the time of the exec, it must have been the exec'ing
1536 clear_step_over_info ();
1539 /* If ON, and the architecture supports it, GDB will use displaced
1540 stepping to step over breakpoints. If OFF, or if the architecture
1541 doesn't support it, GDB will instead use the traditional
1542 hold-and-step approach. If AUTO (which is the default), GDB will
1543 decide which technique to use to step over breakpoints depending on
1544 whether the target works in a non-stop way (see use_displaced_stepping). */
1546 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1549 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1550 struct cmd_list_element
*c
,
1553 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1554 fprintf_filtered (file
,
1555 _("Debugger's willingness to use displaced stepping "
1556 "to step over breakpoints is %s (currently %s).\n"),
1557 value
, target_is_non_stop_p () ? "on" : "off");
1559 fprintf_filtered (file
,
1560 _("Debugger's willingness to use displaced stepping "
1561 "to step over breakpoints is %s.\n"), value
);
1564 /* Return true if the gdbarch implements the required methods to use
1565 displaced stepping. */
1568 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1570 /* Only check for the presence of step_copy_insn. Other required methods
1571 are checked by the gdbarch validation. */
1572 return gdbarch_displaced_step_copy_insn_p (arch
);
1575 /* Return non-zero if displaced stepping can/should be used to step
1576 over breakpoints of thread TP. */
1579 use_displaced_stepping (thread_info
*tp
)
1581 /* If the user disabled it explicitly, don't use displaced stepping. */
1582 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1585 /* If "auto", only use displaced stepping if the target operates in a non-stop
1587 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1588 && !target_is_non_stop_p ())
1591 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1593 /* If the architecture doesn't implement displaced stepping, don't use
1595 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1598 /* If recording, don't use displaced stepping. */
1599 if (find_record_target () != nullptr)
1602 /* If displaced stepping failed before for this inferior, don't bother trying
1604 if (tp
->inf
->displaced_step_state
.failed_before
)
1610 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1613 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1615 displaced
->reset ();
1618 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1619 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1621 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1626 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1630 for (size_t i
= 0; i
< len
; i
++)
1633 ret
+= string_printf ("%02x", buf
[i
]);
1635 ret
+= string_printf (" %02x", buf
[i
]);
1641 /* Prepare to single-step, using displaced stepping.
1643 Note that we cannot use displaced stepping when we have a signal to
1644 deliver. If we have a signal to deliver and an instruction to step
1645 over, then after the step, there will be no indication from the
1646 target whether the thread entered a signal handler or ignored the
1647 signal and stepped over the instruction successfully --- both cases
1648 result in a simple SIGTRAP. In the first case we mustn't do a
1649 fixup, and in the second case we must --- but we can't tell which.
1650 Comments in the code for 'random signals' in handle_inferior_event
1651 explain how we handle this case instead.
1653 Returns 1 if preparing was successful -- this thread is going to be
1654 stepped now; 0 if displaced stepping this thread got queued; or -1
1655 if this instruction can't be displaced stepped. */
1658 displaced_step_prepare_throw (thread_info
*tp
)
1660 regcache
*regcache
= get_thread_regcache (tp
);
1661 struct gdbarch
*gdbarch
= regcache
->arch ();
1662 const address_space
*aspace
= regcache
->aspace ();
1663 CORE_ADDR original
, copy
;
1667 /* We should never reach this function if the architecture does not
1668 support displaced stepping. */
1669 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1671 /* Nor if the thread isn't meant to step over a breakpoint. */
1672 gdb_assert (tp
->control
.trap_expected
);
1674 /* Disable range stepping while executing in the scratch pad. We
1675 want a single-step even if executing the displaced instruction in
1676 the scratch buffer lands within the stepping range (e.g., a
1678 tp
->control
.may_range_step
= 0;
1680 /* We have to displaced step one thread at a time, as we only have
1681 access to a single scratch space per inferior. */
1683 displaced_step_inferior_state
*displaced
= &tp
->inf
->displaced_step_state
;
1685 if (displaced
->step_thread
!= nullptr)
1687 /* Already waiting for a displaced step to finish. Defer this
1688 request and place in queue. */
1690 displaced_debug_printf ("deferring step of %s",
1691 target_pid_to_str (tp
->ptid
).c_str ());
1693 global_thread_step_over_chain_enqueue (tp
);
1697 displaced_debug_printf ("stepping %s now",
1698 target_pid_to_str (tp
->ptid
).c_str ());
1700 displaced_step_reset (displaced
);
1702 scoped_restore_current_thread restore_thread
;
1704 switch_to_thread (tp
);
1706 original
= regcache_read_pc (regcache
);
1708 copy
= gdbarch_displaced_step_location (gdbarch
);
1709 len
= gdbarch_max_insn_length (gdbarch
);
1711 if (breakpoint_in_range_p (aspace
, copy
, len
))
1713 /* There's a breakpoint set in the scratch pad location range
1714 (which is usually around the entry point). We'd either
1715 install it before resuming, which would overwrite/corrupt the
1716 scratch pad, or if it was already inserted, this displaced
1717 step would overwrite it. The latter is OK in the sense that
1718 we already assume that no thread is going to execute the code
1719 in the scratch pad range (after initial startup) anyway, but
1720 the former is unacceptable. Simply punt and fallback to
1721 stepping over this breakpoint in-line. */
1722 displaced_debug_printf ("breakpoint set in scratch pad. "
1723 "Stepping over breakpoint in-line instead.");
1728 /* Save the original contents of the copy area. */
1729 displaced
->step_saved_copy
.resize (len
);
1730 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1732 throw_error (MEMORY_ERROR
,
1733 _("Error accessing memory address %s (%s) for "
1734 "displaced-stepping scratch space."),
1735 paddress (gdbarch
, copy
), safe_strerror (status
));
1737 displaced_debug_printf ("saved %s: %s",
1738 paddress (gdbarch
, copy
),
1739 displaced_step_dump_bytes
1740 (displaced
->step_saved_copy
.data (), len
).c_str ());
1742 displaced
->step_closure
1743 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1744 if (displaced
->step_closure
== NULL
)
1746 /* The architecture doesn't know how or want to displaced step
1747 this instruction or instruction sequence. Fallback to
1748 stepping over the breakpoint in-line. */
1752 /* Save the information we need to fix things up if the step
1754 displaced
->step_thread
= tp
;
1755 displaced
->step_gdbarch
= gdbarch
;
1756 displaced
->step_original
= original
;
1757 displaced
->step_copy
= copy
;
1760 displaced_step_reset_cleanup
cleanup (displaced
);
1762 /* Resume execution at the copy. */
1763 regcache_write_pc (regcache
, copy
);
1768 displaced_debug_printf ("displaced pc to %s", paddress (gdbarch
, copy
));
1773 /* Wrapper for displaced_step_prepare_throw that disabled further
1774 attempts at displaced stepping if we get a memory error. */
1777 displaced_step_prepare (thread_info
*thread
)
1783 prepared
= displaced_step_prepare_throw (thread
);
1785 catch (const gdb_exception_error
&ex
)
1787 if (ex
.error
!= MEMORY_ERROR
1788 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1791 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1794 /* Be verbose if "set displaced-stepping" is "on", silent if
1796 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1798 warning (_("disabling displaced stepping: %s"),
1802 /* Disable further displaced stepping attempts. */
1803 thread
->inf
->displaced_step_state
.failed_before
= 1;
1810 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1811 const gdb_byte
*myaddr
, int len
)
1813 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1815 inferior_ptid
= ptid
;
1816 write_memory (memaddr
, myaddr
, len
);
1819 /* Restore the contents of the copy area for thread PTID. */
1822 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1825 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1827 write_memory_ptid (ptid
, displaced
->step_copy
,
1828 displaced
->step_saved_copy
.data (), len
);
1830 displaced_debug_printf ("restored %s %s",
1831 target_pid_to_str (ptid
).c_str (),
1832 paddress (displaced
->step_gdbarch
,
1833 displaced
->step_copy
));
1836 /* If we displaced stepped an instruction successfully, adjust
1837 registers and memory to yield the same effect the instruction would
1838 have had if we had executed it at its original address, and return
1839 1. If the instruction didn't complete, relocate the PC and return
1840 -1. If the thread wasn't displaced stepping, return 0. */
1843 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1845 displaced_step_inferior_state
*displaced
1846 = &event_thread
->inf
->displaced_step_state
;
1849 /* Was this event for the thread we displaced? */
1850 if (displaced
->step_thread
!= event_thread
)
1853 /* Fixup may need to read memory/registers. Switch to the thread
1854 that we're fixing up. Also, target_stopped_by_watchpoint checks
1855 the current thread, and displaced_step_restore performs ptid-dependent
1856 memory accesses using current_inferior() and current_top_target(). */
1857 switch_to_thread (event_thread
);
1859 displaced_step_reset_cleanup
cleanup (displaced
);
1861 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1863 /* Did the instruction complete successfully? */
1864 if (signal
== GDB_SIGNAL_TRAP
1865 && !(target_stopped_by_watchpoint ()
1866 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1867 || target_have_steppable_watchpoint ())))
1869 /* Fix up the resulting state. */
1870 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1871 displaced
->step_closure
.get (),
1872 displaced
->step_original
,
1873 displaced
->step_copy
,
1874 get_thread_regcache (displaced
->step_thread
));
1879 /* Since the instruction didn't complete, all we can do is
1881 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1882 CORE_ADDR pc
= regcache_read_pc (regcache
);
1884 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1885 regcache_write_pc (regcache
, pc
);
1892 /* Data to be passed around while handling an event. This data is
1893 discarded between events. */
1894 struct execution_control_state
1896 process_stratum_target
*target
;
1898 /* The thread that got the event, if this was a thread event; NULL
1900 struct thread_info
*event_thread
;
1902 struct target_waitstatus ws
;
1903 int stop_func_filled_in
;
1904 CORE_ADDR stop_func_start
;
1905 CORE_ADDR stop_func_end
;
1906 const char *stop_func_name
;
1909 /* True if the event thread hit the single-step breakpoint of
1910 another thread. Thus the event doesn't cause a stop, the thread
1911 needs to be single-stepped past the single-step breakpoint before
1912 we can switch back to the original stepping thread. */
1913 int hit_singlestep_breakpoint
;
1916 /* Clear ECS and set it to point at TP. */
1919 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1921 memset (ecs
, 0, sizeof (*ecs
));
1922 ecs
->event_thread
= tp
;
1923 ecs
->ptid
= tp
->ptid
;
1926 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1927 static void prepare_to_wait (struct execution_control_state
*ecs
);
1928 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1929 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1931 /* Are there any pending step-over requests? If so, run all we can
1932 now and return true. Otherwise, return false. */
1935 start_step_over (void)
1937 struct thread_info
*tp
, *next
;
1939 /* Don't start a new step-over if we already have an in-line
1940 step-over operation ongoing. */
1941 if (step_over_info_valid_p ())
1944 for (tp
= global_thread_step_over_chain_head
; tp
!= NULL
; tp
= next
)
1946 struct execution_control_state ecss
;
1947 struct execution_control_state
*ecs
= &ecss
;
1948 step_over_what step_what
;
1949 int must_be_in_line
;
1951 gdb_assert (!tp
->stop_requested
);
1953 next
= global_thread_step_over_chain_next (tp
);
1955 /* If this inferior already has a displaced step in process,
1956 don't start a new one. */
1957 if (displaced_step_in_progress (tp
->inf
))
1960 step_what
= thread_still_needs_step_over (tp
);
1961 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1962 || ((step_what
& STEP_OVER_BREAKPOINT
)
1963 && !use_displaced_stepping (tp
)));
1965 /* We currently stop all threads of all processes to step-over
1966 in-line. If we need to start a new in-line step-over, let
1967 any pending displaced steps finish first. */
1968 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1971 global_thread_step_over_chain_remove (tp
);
1973 if (global_thread_step_over_chain_head
== NULL
)
1974 infrun_debug_printf ("step-over queue now empty");
1976 if (tp
->control
.trap_expected
1980 internal_error (__FILE__
, __LINE__
,
1981 "[%s] has inconsistent state: "
1982 "trap_expected=%d, resumed=%d, executing=%d\n",
1983 target_pid_to_str (tp
->ptid
).c_str (),
1984 tp
->control
.trap_expected
,
1989 infrun_debug_printf ("resuming [%s] for step-over",
1990 target_pid_to_str (tp
->ptid
).c_str ());
1992 /* keep_going_pass_signal skips the step-over if the breakpoint
1993 is no longer inserted. In all-stop, we want to keep looking
1994 for a thread that needs a step-over instead of resuming TP,
1995 because we wouldn't be able to resume anything else until the
1996 target stops again. In non-stop, the resume always resumes
1997 only TP, so it's OK to let the thread resume freely. */
1998 if (!target_is_non_stop_p () && !step_what
)
2001 switch_to_thread (tp
);
2002 reset_ecs (ecs
, tp
);
2003 keep_going_pass_signal (ecs
);
2005 if (!ecs
->wait_some_more
)
2006 error (_("Command aborted."));
2008 gdb_assert (tp
->resumed
);
2010 /* If we started a new in-line step-over, we're done. */
2011 if (step_over_info_valid_p ())
2013 gdb_assert (tp
->control
.trap_expected
);
2017 if (!target_is_non_stop_p ())
2019 /* On all-stop, shouldn't have resumed unless we needed a
2021 gdb_assert (tp
->control
.trap_expected
2022 || tp
->step_after_step_resume_breakpoint
);
2024 /* With remote targets (at least), in all-stop, we can't
2025 issue any further remote commands until the program stops
2030 /* Either the thread no longer needed a step-over, or a new
2031 displaced stepping sequence started. Even in the latter
2032 case, continue looking. Maybe we can also start another
2033 displaced step on a thread of other process. */
2039 /* Update global variables holding ptids to hold NEW_PTID if they were
2040 holding OLD_PTID. */
2042 infrun_thread_ptid_changed (process_stratum_target
*target
,
2043 ptid_t old_ptid
, ptid_t new_ptid
)
2045 if (inferior_ptid
== old_ptid
2046 && current_inferior ()->process_target () == target
)
2047 inferior_ptid
= new_ptid
;
2052 static const char schedlock_off
[] = "off";
2053 static const char schedlock_on
[] = "on";
2054 static const char schedlock_step
[] = "step";
2055 static const char schedlock_replay
[] = "replay";
2056 static const char *const scheduler_enums
[] = {
2063 static const char *scheduler_mode
= schedlock_replay
;
2065 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2066 struct cmd_list_element
*c
, const char *value
)
2068 fprintf_filtered (file
,
2069 _("Mode for locking scheduler "
2070 "during execution is \"%s\".\n"),
2075 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2077 if (!target_can_lock_scheduler ())
2079 scheduler_mode
= schedlock_off
;
2080 error (_("Target '%s' cannot support this command."), target_shortname
);
2084 /* True if execution commands resume all threads of all processes by
2085 default; otherwise, resume only threads of the current inferior
2087 bool sched_multi
= false;
2089 /* Try to setup for software single stepping over the specified location.
2090 Return true if target_resume() should use hardware single step.
2092 GDBARCH the current gdbarch.
2093 PC the location to step over. */
2096 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2098 bool hw_step
= true;
2100 if (execution_direction
== EXEC_FORWARD
2101 && gdbarch_software_single_step_p (gdbarch
))
2102 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2110 user_visible_resume_ptid (int step
)
2116 /* With non-stop mode on, threads are always handled
2118 resume_ptid
= inferior_ptid
;
2120 else if ((scheduler_mode
== schedlock_on
)
2121 || (scheduler_mode
== schedlock_step
&& step
))
2123 /* User-settable 'scheduler' mode requires solo thread
2125 resume_ptid
= inferior_ptid
;
2127 else if ((scheduler_mode
== schedlock_replay
)
2128 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2130 /* User-settable 'scheduler' mode requires solo thread resume in replay
2132 resume_ptid
= inferior_ptid
;
2134 else if (!sched_multi
&& target_supports_multi_process ())
2136 /* Resume all threads of the current process (and none of other
2138 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2142 /* Resume all threads of all processes. */
2143 resume_ptid
= RESUME_ALL
;
2151 process_stratum_target
*
2152 user_visible_resume_target (ptid_t resume_ptid
)
2154 return (resume_ptid
== minus_one_ptid
&& sched_multi
2156 : current_inferior ()->process_target ());
2159 /* Return a ptid representing the set of threads that we will resume,
2160 in the perspective of the target, assuming run control handling
2161 does not require leaving some threads stopped (e.g., stepping past
2162 breakpoint). USER_STEP indicates whether we're about to start the
2163 target for a stepping command. */
2166 internal_resume_ptid (int user_step
)
2168 /* In non-stop, we always control threads individually. Note that
2169 the target may always work in non-stop mode even with "set
2170 non-stop off", in which case user_visible_resume_ptid could
2171 return a wildcard ptid. */
2172 if (target_is_non_stop_p ())
2173 return inferior_ptid
;
2175 return user_visible_resume_ptid (user_step
);
2178 /* Wrapper for target_resume, that handles infrun-specific
2182 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2184 struct thread_info
*tp
= inferior_thread ();
2186 gdb_assert (!tp
->stop_requested
);
2188 /* Install inferior's terminal modes. */
2189 target_terminal::inferior ();
2191 /* Avoid confusing the next resume, if the next stop/resume
2192 happens to apply to another thread. */
2193 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2195 /* Advise target which signals may be handled silently.
2197 If we have removed breakpoints because we are stepping over one
2198 in-line (in any thread), we need to receive all signals to avoid
2199 accidentally skipping a breakpoint during execution of a signal
2202 Likewise if we're displaced stepping, otherwise a trap for a
2203 breakpoint in a signal handler might be confused with the
2204 displaced step finishing. We don't make the displaced_step_fixup
2205 step distinguish the cases instead, because:
2207 - a backtrace while stopped in the signal handler would show the
2208 scratch pad as frame older than the signal handler, instead of
2209 the real mainline code.
2211 - when the thread is later resumed, the signal handler would
2212 return to the scratch pad area, which would no longer be
2214 if (step_over_info_valid_p ()
2215 || displaced_step_in_progress (tp
->inf
))
2216 target_pass_signals ({});
2218 target_pass_signals (signal_pass
);
2220 target_resume (resume_ptid
, step
, sig
);
2222 target_commit_resume ();
2224 if (target_can_async_p ())
2228 /* Resume the inferior. SIG is the signal to give the inferior
2229 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2230 call 'resume', which handles exceptions. */
2233 resume_1 (enum gdb_signal sig
)
2235 struct regcache
*regcache
= get_current_regcache ();
2236 struct gdbarch
*gdbarch
= regcache
->arch ();
2237 struct thread_info
*tp
= inferior_thread ();
2238 const address_space
*aspace
= regcache
->aspace ();
2240 /* This represents the user's step vs continue request. When
2241 deciding whether "set scheduler-locking step" applies, it's the
2242 user's intention that counts. */
2243 const int user_step
= tp
->control
.stepping_command
;
2244 /* This represents what we'll actually request the target to do.
2245 This can decay from a step to a continue, if e.g., we need to
2246 implement single-stepping with breakpoints (software
2250 gdb_assert (!tp
->stop_requested
);
2251 gdb_assert (!thread_is_in_step_over_chain (tp
));
2253 if (tp
->suspend
.waitstatus_pending_p
)
2256 ("thread %s has pending wait "
2257 "status %s (currently_stepping=%d).",
2258 target_pid_to_str (tp
->ptid
).c_str (),
2259 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2260 currently_stepping (tp
));
2262 tp
->inf
->process_target ()->threads_executing
= true;
2265 /* FIXME: What should we do if we are supposed to resume this
2266 thread with a signal? Maybe we should maintain a queue of
2267 pending signals to deliver. */
2268 if (sig
!= GDB_SIGNAL_0
)
2270 warning (_("Couldn't deliver signal %s to %s."),
2271 gdb_signal_to_name (sig
),
2272 target_pid_to_str (tp
->ptid
).c_str ());
2275 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2277 if (target_can_async_p ())
2280 /* Tell the event loop we have an event to process. */
2281 mark_async_event_handler (infrun_async_inferior_event_token
);
2286 tp
->stepped_breakpoint
= 0;
2288 /* Depends on stepped_breakpoint. */
2289 step
= currently_stepping (tp
);
2291 if (current_inferior ()->waiting_for_vfork_done
)
2293 /* Don't try to single-step a vfork parent that is waiting for
2294 the child to get out of the shared memory region (by exec'ing
2295 or exiting). This is particularly important on software
2296 single-step archs, as the child process would trip on the
2297 software single step breakpoint inserted for the parent
2298 process. Since the parent will not actually execute any
2299 instruction until the child is out of the shared region (such
2300 are vfork's semantics), it is safe to simply continue it.
2301 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2302 the parent, and tell it to `keep_going', which automatically
2303 re-sets it stepping. */
2304 infrun_debug_printf ("resume : clear step");
2308 CORE_ADDR pc
= regcache_read_pc (regcache
);
2310 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2311 "current thread [%s] at %s",
2312 step
, gdb_signal_to_symbol_string (sig
),
2313 tp
->control
.trap_expected
,
2314 target_pid_to_str (inferior_ptid
).c_str (),
2315 paddress (gdbarch
, pc
));
2317 /* Normally, by the time we reach `resume', the breakpoints are either
2318 removed or inserted, as appropriate. The exception is if we're sitting
2319 at a permanent breakpoint; we need to step over it, but permanent
2320 breakpoints can't be removed. So we have to test for it here. */
2321 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2323 if (sig
!= GDB_SIGNAL_0
)
2325 /* We have a signal to pass to the inferior. The resume
2326 may, or may not take us to the signal handler. If this
2327 is a step, we'll need to stop in the signal handler, if
2328 there's one, (if the target supports stepping into
2329 handlers), or in the next mainline instruction, if
2330 there's no handler. If this is a continue, we need to be
2331 sure to run the handler with all breakpoints inserted.
2332 In all cases, set a breakpoint at the current address
2333 (where the handler returns to), and once that breakpoint
2334 is hit, resume skipping the permanent breakpoint. If
2335 that breakpoint isn't hit, then we've stepped into the
2336 signal handler (or hit some other event). We'll delete
2337 the step-resume breakpoint then. */
2339 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2340 "deliver signal first");
2342 clear_step_over_info ();
2343 tp
->control
.trap_expected
= 0;
2345 if (tp
->control
.step_resume_breakpoint
== NULL
)
2347 /* Set a "high-priority" step-resume, as we don't want
2348 user breakpoints at PC to trigger (again) when this
2350 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2351 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2353 tp
->step_after_step_resume_breakpoint
= step
;
2356 insert_breakpoints ();
2360 /* There's no signal to pass, we can go ahead and skip the
2361 permanent breakpoint manually. */
2362 infrun_debug_printf ("skipping permanent breakpoint");
2363 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2364 /* Update pc to reflect the new address from which we will
2365 execute instructions. */
2366 pc
= regcache_read_pc (regcache
);
2370 /* We've already advanced the PC, so the stepping part
2371 is done. Now we need to arrange for a trap to be
2372 reported to handle_inferior_event. Set a breakpoint
2373 at the current PC, and run to it. Don't update
2374 prev_pc, because if we end in
2375 switch_back_to_stepped_thread, we want the "expected
2376 thread advanced also" branch to be taken. IOW, we
2377 don't want this thread to step further from PC
2379 gdb_assert (!step_over_info_valid_p ());
2380 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2381 insert_breakpoints ();
2383 resume_ptid
= internal_resume_ptid (user_step
);
2384 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2391 /* If we have a breakpoint to step over, make sure to do a single
2392 step only. Same if we have software watchpoints. */
2393 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2394 tp
->control
.may_range_step
= 0;
2396 /* If displaced stepping is enabled, step over breakpoints by executing a
2397 copy of the instruction at a different address.
2399 We can't use displaced stepping when we have a signal to deliver;
2400 the comments for displaced_step_prepare explain why. The
2401 comments in the handle_inferior event for dealing with 'random
2402 signals' explain what we do instead.
2404 We can't use displaced stepping when we are waiting for vfork_done
2405 event, displaced stepping breaks the vfork child similarly as single
2406 step software breakpoint. */
2407 if (tp
->control
.trap_expected
2408 && use_displaced_stepping (tp
)
2409 && !step_over_info_valid_p ()
2410 && sig
== GDB_SIGNAL_0
2411 && !current_inferior ()->waiting_for_vfork_done
)
2413 int prepared
= displaced_step_prepare (tp
);
2417 infrun_debug_printf ("Got placed in step-over queue");
2419 tp
->control
.trap_expected
= 0;
2422 else if (prepared
< 0)
2424 /* Fallback to stepping over the breakpoint in-line. */
2426 if (target_is_non_stop_p ())
2427 stop_all_threads ();
2429 set_step_over_info (regcache
->aspace (),
2430 regcache_read_pc (regcache
), 0, tp
->global_num
);
2432 step
= maybe_software_singlestep (gdbarch
, pc
);
2434 insert_breakpoints ();
2436 else if (prepared
> 0)
2438 /* Update pc to reflect the new address from which we will
2439 execute instructions due to displaced stepping. */
2440 pc
= regcache_read_pc (get_thread_regcache (tp
));
2442 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2446 /* Do we need to do it the hard way, w/temp breakpoints? */
2448 step
= maybe_software_singlestep (gdbarch
, pc
);
2450 /* Currently, our software single-step implementation leads to different
2451 results than hardware single-stepping in one situation: when stepping
2452 into delivering a signal which has an associated signal handler,
2453 hardware single-step will stop at the first instruction of the handler,
2454 while software single-step will simply skip execution of the handler.
2456 For now, this difference in behavior is accepted since there is no
2457 easy way to actually implement single-stepping into a signal handler
2458 without kernel support.
2460 However, there is one scenario where this difference leads to follow-on
2461 problems: if we're stepping off a breakpoint by removing all breakpoints
2462 and then single-stepping. In this case, the software single-step
2463 behavior means that even if there is a *breakpoint* in the signal
2464 handler, GDB still would not stop.
2466 Fortunately, we can at least fix this particular issue. We detect
2467 here the case where we are about to deliver a signal while software
2468 single-stepping with breakpoints removed. In this situation, we
2469 revert the decisions to remove all breakpoints and insert single-
2470 step breakpoints, and instead we install a step-resume breakpoint
2471 at the current address, deliver the signal without stepping, and
2472 once we arrive back at the step-resume breakpoint, actually step
2473 over the breakpoint we originally wanted to step over. */
2474 if (thread_has_single_step_breakpoints_set (tp
)
2475 && sig
!= GDB_SIGNAL_0
2476 && step_over_info_valid_p ())
2478 /* If we have nested signals or a pending signal is delivered
2479 immediately after a handler returns, might already have
2480 a step-resume breakpoint set on the earlier handler. We cannot
2481 set another step-resume breakpoint; just continue on until the
2482 original breakpoint is hit. */
2483 if (tp
->control
.step_resume_breakpoint
== NULL
)
2485 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2486 tp
->step_after_step_resume_breakpoint
= 1;
2489 delete_single_step_breakpoints (tp
);
2491 clear_step_over_info ();
2492 tp
->control
.trap_expected
= 0;
2494 insert_breakpoints ();
2497 /* If STEP is set, it's a request to use hardware stepping
2498 facilities. But in that case, we should never
2499 use singlestep breakpoint. */
2500 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2502 /* Decide the set of threads to ask the target to resume. */
2503 if (tp
->control
.trap_expected
)
2505 /* We're allowing a thread to run past a breakpoint it has
2506 hit, either by single-stepping the thread with the breakpoint
2507 removed, or by displaced stepping, with the breakpoint inserted.
2508 In the former case, we need to single-step only this thread,
2509 and keep others stopped, as they can miss this breakpoint if
2510 allowed to run. That's not really a problem for displaced
2511 stepping, but, we still keep other threads stopped, in case
2512 another thread is also stopped for a breakpoint waiting for
2513 its turn in the displaced stepping queue. */
2514 resume_ptid
= inferior_ptid
;
2517 resume_ptid
= internal_resume_ptid (user_step
);
2519 if (execution_direction
!= EXEC_REVERSE
2520 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2522 /* There are two cases where we currently need to step a
2523 breakpoint instruction when we have a signal to deliver:
2525 - See handle_signal_stop where we handle random signals that
2526 could take out us out of the stepping range. Normally, in
2527 that case we end up continuing (instead of stepping) over the
2528 signal handler with a breakpoint at PC, but there are cases
2529 where we should _always_ single-step, even if we have a
2530 step-resume breakpoint, like when a software watchpoint is
2531 set. Assuming single-stepping and delivering a signal at the
2532 same time would takes us to the signal handler, then we could
2533 have removed the breakpoint at PC to step over it. However,
2534 some hardware step targets (like e.g., Mac OS) can't step
2535 into signal handlers, and for those, we need to leave the
2536 breakpoint at PC inserted, as otherwise if the handler
2537 recurses and executes PC again, it'll miss the breakpoint.
2538 So we leave the breakpoint inserted anyway, but we need to
2539 record that we tried to step a breakpoint instruction, so
2540 that adjust_pc_after_break doesn't end up confused.
2542 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2543 in one thread after another thread that was stepping had been
2544 momentarily paused for a step-over. When we re-resume the
2545 stepping thread, it may be resumed from that address with a
2546 breakpoint that hasn't trapped yet. Seen with
2547 gdb.threads/non-stop-fair-events.exp, on targets that don't
2548 do displaced stepping. */
2550 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2551 target_pid_to_str (tp
->ptid
).c_str ());
2553 tp
->stepped_breakpoint
= 1;
2555 /* Most targets can step a breakpoint instruction, thus
2556 executing it normally. But if this one cannot, just
2557 continue and we will hit it anyway. */
2558 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2563 && tp
->control
.trap_expected
2564 && use_displaced_stepping (tp
)
2565 && !step_over_info_valid_p ())
2567 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2568 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2569 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2572 read_memory (actual_pc
, buf
, sizeof (buf
));
2573 displaced_debug_printf ("run %s: %s",
2574 paddress (resume_gdbarch
, actual_pc
),
2575 displaced_step_dump_bytes
2576 (buf
, sizeof (buf
)).c_str ());
2579 if (tp
->control
.may_range_step
)
2581 /* If we're resuming a thread with the PC out of the step
2582 range, then we're doing some nested/finer run control
2583 operation, like stepping the thread out of the dynamic
2584 linker or the displaced stepping scratch pad. We
2585 shouldn't have allowed a range step then. */
2586 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2589 do_target_resume (resume_ptid
, step
, sig
);
2593 /* Resume the inferior. SIG is the signal to give the inferior
2594 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2595 rolls back state on error. */
2598 resume (gdb_signal sig
)
2604 catch (const gdb_exception
&ex
)
2606 /* If resuming is being aborted for any reason, delete any
2607 single-step breakpoint resume_1 may have created, to avoid
2608 confusing the following resumption, and to avoid leaving
2609 single-step breakpoints perturbing other threads, in case
2610 we're running in non-stop mode. */
2611 if (inferior_ptid
!= null_ptid
)
2612 delete_single_step_breakpoints (inferior_thread ());
2622 /* Counter that tracks number of user visible stops. This can be used
2623 to tell whether a command has proceeded the inferior past the
2624 current location. This allows e.g., inferior function calls in
2625 breakpoint commands to not interrupt the command list. When the
2626 call finishes successfully, the inferior is standing at the same
2627 breakpoint as if nothing happened (and so we don't call
2629 static ULONGEST current_stop_id
;
2636 return current_stop_id
;
2639 /* Called when we report a user visible stop. */
2647 /* Clear out all variables saying what to do when inferior is continued.
2648 First do this, then set the ones you want, then call `proceed'. */
2651 clear_proceed_status_thread (struct thread_info
*tp
)
2653 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2655 /* If we're starting a new sequence, then the previous finished
2656 single-step is no longer relevant. */
2657 if (tp
->suspend
.waitstatus_pending_p
)
2659 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2661 infrun_debug_printf ("pending event of %s was a finished step. "
2663 target_pid_to_str (tp
->ptid
).c_str ());
2665 tp
->suspend
.waitstatus_pending_p
= 0;
2666 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2671 ("thread %s has pending wait status %s (currently_stepping=%d).",
2672 target_pid_to_str (tp
->ptid
).c_str (),
2673 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2674 currently_stepping (tp
));
2678 /* If this signal should not be seen by program, give it zero.
2679 Used for debugging signals. */
2680 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2681 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2683 delete tp
->thread_fsm
;
2684 tp
->thread_fsm
= NULL
;
2686 tp
->control
.trap_expected
= 0;
2687 tp
->control
.step_range_start
= 0;
2688 tp
->control
.step_range_end
= 0;
2689 tp
->control
.may_range_step
= 0;
2690 tp
->control
.step_frame_id
= null_frame_id
;
2691 tp
->control
.step_stack_frame_id
= null_frame_id
;
2692 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2693 tp
->control
.step_start_function
= NULL
;
2694 tp
->stop_requested
= 0;
2696 tp
->control
.stop_step
= 0;
2698 tp
->control
.proceed_to_finish
= 0;
2700 tp
->control
.stepping_command
= 0;
2702 /* Discard any remaining commands or status from previous stop. */
2703 bpstat_clear (&tp
->control
.stop_bpstat
);
2707 clear_proceed_status (int step
)
2709 /* With scheduler-locking replay, stop replaying other threads if we're
2710 not replaying the user-visible resume ptid.
2712 This is a convenience feature to not require the user to explicitly
2713 stop replaying the other threads. We're assuming that the user's
2714 intent is to resume tracing the recorded process. */
2715 if (!non_stop
&& scheduler_mode
== schedlock_replay
2716 && target_record_is_replaying (minus_one_ptid
)
2717 && !target_record_will_replay (user_visible_resume_ptid (step
),
2718 execution_direction
))
2719 target_record_stop_replaying ();
2721 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2723 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2724 process_stratum_target
*resume_target
2725 = user_visible_resume_target (resume_ptid
);
2727 /* In all-stop mode, delete the per-thread status of all threads
2728 we're about to resume, implicitly and explicitly. */
2729 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2730 clear_proceed_status_thread (tp
);
2733 if (inferior_ptid
!= null_ptid
)
2735 struct inferior
*inferior
;
2739 /* If in non-stop mode, only delete the per-thread status of
2740 the current thread. */
2741 clear_proceed_status_thread (inferior_thread ());
2744 inferior
= current_inferior ();
2745 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2748 gdb::observers::about_to_proceed
.notify ();
2751 /* Returns true if TP is still stopped at a breakpoint that needs
2752 stepping-over in order to make progress. If the breakpoint is gone
2753 meanwhile, we can skip the whole step-over dance. */
2756 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2758 if (tp
->stepping_over_breakpoint
)
2760 struct regcache
*regcache
= get_thread_regcache (tp
);
2762 if (breakpoint_here_p (regcache
->aspace (),
2763 regcache_read_pc (regcache
))
2764 == ordinary_breakpoint_here
)
2767 tp
->stepping_over_breakpoint
= 0;
2773 /* Check whether thread TP still needs to start a step-over in order
2774 to make progress when resumed. Returns an bitwise or of enum
2775 step_over_what bits, indicating what needs to be stepped over. */
2777 static step_over_what
2778 thread_still_needs_step_over (struct thread_info
*tp
)
2780 step_over_what what
= 0;
2782 if (thread_still_needs_step_over_bp (tp
))
2783 what
|= STEP_OVER_BREAKPOINT
;
2785 if (tp
->stepping_over_watchpoint
2786 && !target_have_steppable_watchpoint ())
2787 what
|= STEP_OVER_WATCHPOINT
;
2792 /* Returns true if scheduler locking applies. STEP indicates whether
2793 we're about to do a step/next-like command to a thread. */
2796 schedlock_applies (struct thread_info
*tp
)
2798 return (scheduler_mode
== schedlock_on
2799 || (scheduler_mode
== schedlock_step
2800 && tp
->control
.stepping_command
)
2801 || (scheduler_mode
== schedlock_replay
2802 && target_record_will_replay (minus_one_ptid
,
2803 execution_direction
)));
2806 /* Calls target_commit_resume on all targets. */
2809 commit_resume_all_targets ()
2811 scoped_restore_current_thread restore_thread
;
2813 /* Map between process_target and a representative inferior. This
2814 is to avoid committing a resume in the same target more than
2815 once. Resumptions must be idempotent, so this is an
2817 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2819 for (inferior
*inf
: all_non_exited_inferiors ())
2820 if (inf
->has_execution ())
2821 conn_inf
[inf
->process_target ()] = inf
;
2823 for (const auto &ci
: conn_inf
)
2825 inferior
*inf
= ci
.second
;
2826 switch_to_inferior_no_thread (inf
);
2827 target_commit_resume ();
2831 /* Check that all the targets we're about to resume are in non-stop
2832 mode. Ideally, we'd only care whether all targets support
2833 target-async, but we're not there yet. E.g., stop_all_threads
2834 doesn't know how to handle all-stop targets. Also, the remote
2835 protocol in all-stop mode is synchronous, irrespective of
2836 target-async, which means that things like a breakpoint re-set
2837 triggered by one target would try to read memory from all targets
2841 check_multi_target_resumption (process_stratum_target
*resume_target
)
2843 if (!non_stop
&& resume_target
== nullptr)
2845 scoped_restore_current_thread restore_thread
;
2847 /* This is used to track whether we're resuming more than one
2849 process_stratum_target
*first_connection
= nullptr;
2851 /* The first inferior we see with a target that does not work in
2852 always-non-stop mode. */
2853 inferior
*first_not_non_stop
= nullptr;
2855 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2857 switch_to_inferior_no_thread (inf
);
2859 if (!target_has_execution ())
2862 process_stratum_target
*proc_target
2863 = current_inferior ()->process_target();
2865 if (!target_is_non_stop_p ())
2866 first_not_non_stop
= inf
;
2868 if (first_connection
== nullptr)
2869 first_connection
= proc_target
;
2870 else if (first_connection
!= proc_target
2871 && first_not_non_stop
!= nullptr)
2873 switch_to_inferior_no_thread (first_not_non_stop
);
2875 proc_target
= current_inferior ()->process_target();
2877 error (_("Connection %d (%s) does not support "
2878 "multi-target resumption."),
2879 proc_target
->connection_number
,
2880 make_target_connection_string (proc_target
).c_str ());
2886 /* Basic routine for continuing the program in various fashions.
2888 ADDR is the address to resume at, or -1 for resume where stopped.
2889 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2890 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2892 You should call clear_proceed_status before calling proceed. */
2895 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2897 struct regcache
*regcache
;
2898 struct gdbarch
*gdbarch
;
2900 struct execution_control_state ecss
;
2901 struct execution_control_state
*ecs
= &ecss
;
2904 /* If we're stopped at a fork/vfork, follow the branch set by the
2905 "set follow-fork-mode" command; otherwise, we'll just proceed
2906 resuming the current thread. */
2907 if (!follow_fork ())
2909 /* The target for some reason decided not to resume. */
2911 if (target_can_async_p ())
2912 inferior_event_handler (INF_EXEC_COMPLETE
);
2916 /* We'll update this if & when we switch to a new thread. */
2917 previous_inferior_ptid
= inferior_ptid
;
2919 regcache
= get_current_regcache ();
2920 gdbarch
= regcache
->arch ();
2921 const address_space
*aspace
= regcache
->aspace ();
2923 pc
= regcache_read_pc_protected (regcache
);
2925 thread_info
*cur_thr
= inferior_thread ();
2927 /* Fill in with reasonable starting values. */
2928 init_thread_stepping_state (cur_thr
);
2930 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2933 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2934 process_stratum_target
*resume_target
2935 = user_visible_resume_target (resume_ptid
);
2937 check_multi_target_resumption (resume_target
);
2939 if (addr
== (CORE_ADDR
) -1)
2941 if (pc
== cur_thr
->suspend
.stop_pc
2942 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2943 && execution_direction
!= EXEC_REVERSE
)
2944 /* There is a breakpoint at the address we will resume at,
2945 step one instruction before inserting breakpoints so that
2946 we do not stop right away (and report a second hit at this
2949 Note, we don't do this in reverse, because we won't
2950 actually be executing the breakpoint insn anyway.
2951 We'll be (un-)executing the previous instruction. */
2952 cur_thr
->stepping_over_breakpoint
= 1;
2953 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2954 && gdbarch_single_step_through_delay (gdbarch
,
2955 get_current_frame ()))
2956 /* We stepped onto an instruction that needs to be stepped
2957 again before re-inserting the breakpoint, do so. */
2958 cur_thr
->stepping_over_breakpoint
= 1;
2962 regcache_write_pc (regcache
, addr
);
2965 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2966 cur_thr
->suspend
.stop_signal
= siggnal
;
2968 /* If an exception is thrown from this point on, make sure to
2969 propagate GDB's knowledge of the executing state to the
2970 frontend/user running state. */
2971 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2973 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2974 threads (e.g., we might need to set threads stepping over
2975 breakpoints first), from the user/frontend's point of view, all
2976 threads in RESUME_PTID are now running. Unless we're calling an
2977 inferior function, as in that case we pretend the inferior
2978 doesn't run at all. */
2979 if (!cur_thr
->control
.in_infcall
)
2980 set_running (resume_target
, resume_ptid
, true);
2982 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
2983 gdb_signal_to_symbol_string (siggnal
));
2985 annotate_starting ();
2987 /* Make sure that output from GDB appears before output from the
2989 gdb_flush (gdb_stdout
);
2991 /* Since we've marked the inferior running, give it the terminal. A
2992 QUIT/Ctrl-C from here on is forwarded to the target (which can
2993 still detect attempts to unblock a stuck connection with repeated
2994 Ctrl-C from within target_pass_ctrlc). */
2995 target_terminal::inferior ();
2997 /* In a multi-threaded task we may select another thread and
2998 then continue or step.
3000 But if a thread that we're resuming had stopped at a breakpoint,
3001 it will immediately cause another breakpoint stop without any
3002 execution (i.e. it will report a breakpoint hit incorrectly). So
3003 we must step over it first.
3005 Look for threads other than the current (TP) that reported a
3006 breakpoint hit and haven't been resumed yet since. */
3008 /* If scheduler locking applies, we can avoid iterating over all
3010 if (!non_stop
&& !schedlock_applies (cur_thr
))
3012 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3015 switch_to_thread_no_regs (tp
);
3017 /* Ignore the current thread here. It's handled
3022 if (!thread_still_needs_step_over (tp
))
3025 gdb_assert (!thread_is_in_step_over_chain (tp
));
3027 infrun_debug_printf ("need to step-over [%s] first",
3028 target_pid_to_str (tp
->ptid
).c_str ());
3030 global_thread_step_over_chain_enqueue (tp
);
3033 switch_to_thread (cur_thr
);
3036 /* Enqueue the current thread last, so that we move all other
3037 threads over their breakpoints first. */
3038 if (cur_thr
->stepping_over_breakpoint
)
3039 global_thread_step_over_chain_enqueue (cur_thr
);
3041 /* If the thread isn't started, we'll still need to set its prev_pc,
3042 so that switch_back_to_stepped_thread knows the thread hasn't
3043 advanced. Must do this before resuming any thread, as in
3044 all-stop/remote, once we resume we can't send any other packet
3045 until the target stops again. */
3046 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3049 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3051 started
= start_step_over ();
3053 if (step_over_info_valid_p ())
3055 /* Either this thread started a new in-line step over, or some
3056 other thread was already doing one. In either case, don't
3057 resume anything else until the step-over is finished. */
3059 else if (started
&& !target_is_non_stop_p ())
3061 /* A new displaced stepping sequence was started. In all-stop,
3062 we can't talk to the target anymore until it next stops. */
3064 else if (!non_stop
&& target_is_non_stop_p ())
3066 /* In all-stop, but the target is always in non-stop mode.
3067 Start all other threads that are implicitly resumed too. */
3068 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3071 switch_to_thread_no_regs (tp
);
3073 if (!tp
->inf
->has_execution ())
3075 infrun_debug_printf ("[%s] target has no execution",
3076 target_pid_to_str (tp
->ptid
).c_str ());
3082 infrun_debug_printf ("[%s] resumed",
3083 target_pid_to_str (tp
->ptid
).c_str ());
3084 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3088 if (thread_is_in_step_over_chain (tp
))
3090 infrun_debug_printf ("[%s] needs step-over",
3091 target_pid_to_str (tp
->ptid
).c_str ());
3095 infrun_debug_printf ("resuming %s",
3096 target_pid_to_str (tp
->ptid
).c_str ());
3098 reset_ecs (ecs
, tp
);
3099 switch_to_thread (tp
);
3100 keep_going_pass_signal (ecs
);
3101 if (!ecs
->wait_some_more
)
3102 error (_("Command aborted."));
3105 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3107 /* The thread wasn't started, and isn't queued, run it now. */
3108 reset_ecs (ecs
, cur_thr
);
3109 switch_to_thread (cur_thr
);
3110 keep_going_pass_signal (ecs
);
3111 if (!ecs
->wait_some_more
)
3112 error (_("Command aborted."));
3116 commit_resume_all_targets ();
3118 finish_state
.release ();
3120 /* If we've switched threads above, switch back to the previously
3121 current thread. We don't want the user to see a different
3123 switch_to_thread (cur_thr
);
3125 /* Tell the event loop to wait for it to stop. If the target
3126 supports asynchronous execution, it'll do this from within
3128 if (!target_can_async_p ())
3129 mark_async_event_handler (infrun_async_inferior_event_token
);
3133 /* Start remote-debugging of a machine over a serial link. */
3136 start_remote (int from_tty
)
3138 inferior
*inf
= current_inferior ();
3139 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3141 /* Always go on waiting for the target, regardless of the mode. */
3142 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3143 indicate to wait_for_inferior that a target should timeout if
3144 nothing is returned (instead of just blocking). Because of this,
3145 targets expecting an immediate response need to, internally, set
3146 things up so that the target_wait() is forced to eventually
3148 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3149 differentiate to its caller what the state of the target is after
3150 the initial open has been performed. Here we're assuming that
3151 the target has stopped. It should be possible to eventually have
3152 target_open() return to the caller an indication that the target
3153 is currently running and GDB state should be set to the same as
3154 for an async run. */
3155 wait_for_inferior (inf
);
3157 /* Now that the inferior has stopped, do any bookkeeping like
3158 loading shared libraries. We want to do this before normal_stop,
3159 so that the displayed frame is up to date. */
3160 post_create_inferior (from_tty
);
3165 /* Initialize static vars when a new inferior begins. */
3168 init_wait_for_inferior (void)
3170 /* These are meaningless until the first time through wait_for_inferior. */
3172 breakpoint_init_inferior (inf_starting
);
3174 clear_proceed_status (0);
3176 nullify_last_target_wait_ptid ();
3178 previous_inferior_ptid
= inferior_ptid
;
3183 static void handle_inferior_event (struct execution_control_state
*ecs
);
3185 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3186 struct execution_control_state
*ecs
);
3187 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3188 struct execution_control_state
*ecs
);
3189 static void handle_signal_stop (struct execution_control_state
*ecs
);
3190 static void check_exception_resume (struct execution_control_state
*,
3191 struct frame_info
*);
3193 static void end_stepping_range (struct execution_control_state
*ecs
);
3194 static void stop_waiting (struct execution_control_state
*ecs
);
3195 static void keep_going (struct execution_control_state
*ecs
);
3196 static void process_event_stop_test (struct execution_control_state
*ecs
);
3197 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3199 /* This function is attached as a "thread_stop_requested" observer.
3200 Cleanup local state that assumed the PTID was to be resumed, and
3201 report the stop to the frontend. */
3204 infrun_thread_stop_requested (ptid_t ptid
)
3206 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3208 /* PTID was requested to stop. If the thread was already stopped,
3209 but the user/frontend doesn't know about that yet (e.g., the
3210 thread had been temporarily paused for some step-over), set up
3211 for reporting the stop now. */
3212 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3214 if (tp
->state
!= THREAD_RUNNING
)
3219 /* Remove matching threads from the step-over queue, so
3220 start_step_over doesn't try to resume them
3222 if (thread_is_in_step_over_chain (tp
))
3223 global_thread_step_over_chain_remove (tp
);
3225 /* If the thread is stopped, but the user/frontend doesn't
3226 know about that yet, queue a pending event, as if the
3227 thread had just stopped now. Unless the thread already had
3229 if (!tp
->suspend
.waitstatus_pending_p
)
3231 tp
->suspend
.waitstatus_pending_p
= 1;
3232 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3233 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3236 /* Clear the inline-frame state, since we're re-processing the
3238 clear_inline_frame_state (tp
);
3240 /* If this thread was paused because some other thread was
3241 doing an inline-step over, let that finish first. Once
3242 that happens, we'll restart all threads and consume pending
3243 stop events then. */
3244 if (step_over_info_valid_p ())
3247 /* Otherwise we can process the (new) pending event now. Set
3248 it so this pending event is considered by
3255 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3257 if (target_last_proc_target
== tp
->inf
->process_target ()
3258 && target_last_wait_ptid
== tp
->ptid
)
3259 nullify_last_target_wait_ptid ();
3262 /* Delete the step resume, single-step and longjmp/exception resume
3263 breakpoints of TP. */
3266 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3268 delete_step_resume_breakpoint (tp
);
3269 delete_exception_resume_breakpoint (tp
);
3270 delete_single_step_breakpoints (tp
);
3273 /* If the target still has execution, call FUNC for each thread that
3274 just stopped. In all-stop, that's all the non-exited threads; in
3275 non-stop, that's the current thread, only. */
3277 typedef void (*for_each_just_stopped_thread_callback_func
)
3278 (struct thread_info
*tp
);
3281 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3283 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3286 if (target_is_non_stop_p ())
3288 /* If in non-stop mode, only the current thread stopped. */
3289 func (inferior_thread ());
3293 /* In all-stop mode, all threads have stopped. */
3294 for (thread_info
*tp
: all_non_exited_threads ())
3299 /* Delete the step resume and longjmp/exception resume breakpoints of
3300 the threads that just stopped. */
3303 delete_just_stopped_threads_infrun_breakpoints (void)
3305 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3308 /* Delete the single-step breakpoints of the threads that just
3312 delete_just_stopped_threads_single_step_breakpoints (void)
3314 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3320 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3321 const struct target_waitstatus
*ws
)
3323 std::string status_string
= target_waitstatus_to_string (ws
);
3326 /* The text is split over several lines because it was getting too long.
3327 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3328 output as a unit; we want only one timestamp printed if debug_timestamp
3331 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3334 waiton_ptid
.tid ());
3335 if (waiton_ptid
.pid () != -1)
3336 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3337 stb
.printf (", status) =\n");
3338 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3342 target_pid_to_str (result_ptid
).c_str ());
3343 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3345 /* This uses %s in part to handle %'s in the text, but also to avoid
3346 a gcc error: the format attribute requires a string literal. */
3347 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3350 /* Select a thread at random, out of those which are resumed and have
3353 static struct thread_info
*
3354 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3358 auto has_event
= [&] (thread_info
*tp
)
3360 return (tp
->ptid
.matches (waiton_ptid
)
3362 && tp
->suspend
.waitstatus_pending_p
);
3365 /* First see how many events we have. Count only resumed threads
3366 that have an event pending. */
3367 for (thread_info
*tp
: inf
->non_exited_threads ())
3371 if (num_events
== 0)
3374 /* Now randomly pick a thread out of those that have had events. */
3375 int random_selector
= (int) ((num_events
* (double) rand ())
3376 / (RAND_MAX
+ 1.0));
3379 infrun_debug_printf ("Found %d events, selecting #%d",
3380 num_events
, random_selector
);
3382 /* Select the Nth thread that has had an event. */
3383 for (thread_info
*tp
: inf
->non_exited_threads ())
3385 if (random_selector
-- == 0)
3388 gdb_assert_not_reached ("event thread not found");
3391 /* Wrapper for target_wait that first checks whether threads have
3392 pending statuses to report before actually asking the target for
3393 more events. INF is the inferior we're using to call target_wait
3397 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3398 target_waitstatus
*status
, target_wait_flags options
)
3401 struct thread_info
*tp
;
3403 /* We know that we are looking for an event in the target of inferior
3404 INF, but we don't know which thread the event might come from. As
3405 such we want to make sure that INFERIOR_PTID is reset so that none of
3406 the wait code relies on it - doing so is always a mistake. */
3407 switch_to_inferior_no_thread (inf
);
3409 /* First check if there is a resumed thread with a wait status
3411 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3413 tp
= random_pending_event_thread (inf
, ptid
);
3417 infrun_debug_printf ("Waiting for specific thread %s.",
3418 target_pid_to_str (ptid
).c_str ());
3420 /* We have a specific thread to check. */
3421 tp
= find_thread_ptid (inf
, ptid
);
3422 gdb_assert (tp
!= NULL
);
3423 if (!tp
->suspend
.waitstatus_pending_p
)
3428 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3429 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3431 struct regcache
*regcache
= get_thread_regcache (tp
);
3432 struct gdbarch
*gdbarch
= regcache
->arch ();
3436 pc
= regcache_read_pc (regcache
);
3438 if (pc
!= tp
->suspend
.stop_pc
)
3440 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3441 target_pid_to_str (tp
->ptid
).c_str (),
3442 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3443 paddress (gdbarch
, pc
));
3446 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3448 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3449 target_pid_to_str (tp
->ptid
).c_str (),
3450 paddress (gdbarch
, pc
));
3457 infrun_debug_printf ("pending event of %s cancelled.",
3458 target_pid_to_str (tp
->ptid
).c_str ());
3460 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3461 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3467 infrun_debug_printf ("Using pending wait status %s for %s.",
3468 target_waitstatus_to_string
3469 (&tp
->suspend
.waitstatus
).c_str (),
3470 target_pid_to_str (tp
->ptid
).c_str ());
3472 /* Now that we've selected our final event LWP, un-adjust its PC
3473 if it was a software breakpoint (and the target doesn't
3474 always adjust the PC itself). */
3475 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3476 && !target_supports_stopped_by_sw_breakpoint ())
3478 struct regcache
*regcache
;
3479 struct gdbarch
*gdbarch
;
3482 regcache
= get_thread_regcache (tp
);
3483 gdbarch
= regcache
->arch ();
3485 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3490 pc
= regcache_read_pc (regcache
);
3491 regcache_write_pc (regcache
, pc
+ decr_pc
);
3495 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3496 *status
= tp
->suspend
.waitstatus
;
3497 tp
->suspend
.waitstatus_pending_p
= 0;
3499 /* Wake up the event loop again, until all pending events are
3501 if (target_is_async_p ())
3502 mark_async_event_handler (infrun_async_inferior_event_token
);
3506 /* But if we don't find one, we'll have to wait. */
3508 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3510 if (!target_can_async_p ())
3511 options
&= ~TARGET_WNOHANG
;
3513 if (deprecated_target_wait_hook
)
3514 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3516 event_ptid
= target_wait (ptid
, status
, options
);
3521 /* Wrapper for target_wait that first checks whether threads have
3522 pending statuses to report before actually asking the target for
3523 more events. Polls for events from all inferiors/targets. */
3526 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3527 target_wait_flags options
)
3529 int num_inferiors
= 0;
3530 int random_selector
;
3532 /* For fairness, we pick the first inferior/target to poll at random
3533 out of all inferiors that may report events, and then continue
3534 polling the rest of the inferior list starting from that one in a
3535 circular fashion until the whole list is polled once. */
3537 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3539 return (inf
->process_target () != NULL
3540 && ptid_t (inf
->pid
).matches (wait_ptid
));
3543 /* First see how many matching inferiors we have. */
3544 for (inferior
*inf
: all_inferiors ())
3545 if (inferior_matches (inf
))
3548 if (num_inferiors
== 0)
3550 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3554 /* Now randomly pick an inferior out of those that matched. */
3555 random_selector
= (int)
3556 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3558 if (num_inferiors
> 1)
3559 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3560 num_inferiors
, random_selector
);
3562 /* Select the Nth inferior that matched. */
3564 inferior
*selected
= nullptr;
3566 for (inferior
*inf
: all_inferiors ())
3567 if (inferior_matches (inf
))
3568 if (random_selector
-- == 0)
3574 /* Now poll for events out of each of the matching inferior's
3575 targets, starting from the selected one. */
3577 auto do_wait
= [&] (inferior
*inf
)
3579 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3580 ecs
->target
= inf
->process_target ();
3581 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3584 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3585 here spuriously after the target is all stopped and we've already
3586 reported the stop to the user, polling for events. */
3587 scoped_restore_current_thread restore_thread
;
3589 int inf_num
= selected
->num
;
3590 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3591 if (inferior_matches (inf
))
3595 for (inferior
*inf
= inferior_list
;
3596 inf
!= NULL
&& inf
->num
< inf_num
;
3598 if (inferior_matches (inf
))
3602 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3606 /* Prepare and stabilize the inferior for detaching it. E.g.,
3607 detaching while a thread is displaced stepping is a recipe for
3608 crashing it, as nothing would readjust the PC out of the scratch
3612 prepare_for_detach (void)
3614 struct inferior
*inf
= current_inferior ();
3615 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3617 displaced_step_inferior_state
*displaced
= &inf
->displaced_step_state
;
3619 /* Is any thread of this process displaced stepping? If not,
3620 there's nothing else to do. */
3621 if (displaced
->step_thread
== nullptr)
3624 infrun_debug_printf ("displaced-stepping in-process while detaching");
3626 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3628 while (displaced
->step_thread
!= nullptr)
3630 struct execution_control_state ecss
;
3631 struct execution_control_state
*ecs
;
3634 memset (ecs
, 0, sizeof (*ecs
));
3636 overlay_cache_invalid
= 1;
3637 /* Flush target cache before starting to handle each event.
3638 Target was running and cache could be stale. This is just a
3639 heuristic. Running threads may modify target memory, but we
3640 don't get any event. */
3641 target_dcache_invalidate ();
3643 do_target_wait (pid_ptid
, ecs
, 0);
3646 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3648 /* If an error happens while handling the event, propagate GDB's
3649 knowledge of the executing state to the frontend/user running
3651 scoped_finish_thread_state
finish_state (inf
->process_target (),
3654 /* Now figure out what to do with the result of the result. */
3655 handle_inferior_event (ecs
);
3657 /* No error, don't finish the state yet. */
3658 finish_state
.release ();
3660 /* Breakpoints and watchpoints are not installed on the target
3661 at this point, and signals are passed directly to the
3662 inferior, so this must mean the process is gone. */
3663 if (!ecs
->wait_some_more
)
3665 restore_detaching
.release ();
3666 error (_("Program exited while detaching"));
3670 restore_detaching
.release ();
3673 /* Wait for control to return from inferior to debugger.
3675 If inferior gets a signal, we may decide to start it up again
3676 instead of returning. That is why there is a loop in this function.
3677 When this function actually returns it means the inferior
3678 should be left stopped and GDB should read more commands. */
3681 wait_for_inferior (inferior
*inf
)
3683 infrun_debug_printf ("wait_for_inferior ()");
3685 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3687 /* If an error happens while handling the event, propagate GDB's
3688 knowledge of the executing state to the frontend/user running
3690 scoped_finish_thread_state finish_state
3691 (inf
->process_target (), minus_one_ptid
);
3695 struct execution_control_state ecss
;
3696 struct execution_control_state
*ecs
= &ecss
;
3698 memset (ecs
, 0, sizeof (*ecs
));
3700 overlay_cache_invalid
= 1;
3702 /* Flush target cache before starting to handle each event.
3703 Target was running and cache could be stale. This is just a
3704 heuristic. Running threads may modify target memory, but we
3705 don't get any event. */
3706 target_dcache_invalidate ();
3708 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3709 ecs
->target
= inf
->process_target ();
3712 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3714 /* Now figure out what to do with the result of the result. */
3715 handle_inferior_event (ecs
);
3717 if (!ecs
->wait_some_more
)
3721 /* No error, don't finish the state yet. */
3722 finish_state
.release ();
3725 /* Cleanup that reinstalls the readline callback handler, if the
3726 target is running in the background. If while handling the target
3727 event something triggered a secondary prompt, like e.g., a
3728 pagination prompt, we'll have removed the callback handler (see
3729 gdb_readline_wrapper_line). Need to do this as we go back to the
3730 event loop, ready to process further input. Note this has no
3731 effect if the handler hasn't actually been removed, because calling
3732 rl_callback_handler_install resets the line buffer, thus losing
3736 reinstall_readline_callback_handler_cleanup ()
3738 struct ui
*ui
= current_ui
;
3742 /* We're not going back to the top level event loop yet. Don't
3743 install the readline callback, as it'd prep the terminal,
3744 readline-style (raw, noecho) (e.g., --batch). We'll install
3745 it the next time the prompt is displayed, when we're ready
3750 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3751 gdb_rl_callback_handler_reinstall ();
3754 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3755 that's just the event thread. In all-stop, that's all threads. */
3758 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3760 if (ecs
->event_thread
!= NULL
3761 && ecs
->event_thread
->thread_fsm
!= NULL
)
3762 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3766 for (thread_info
*thr
: all_non_exited_threads ())
3768 if (thr
->thread_fsm
== NULL
)
3770 if (thr
== ecs
->event_thread
)
3773 switch_to_thread (thr
);
3774 thr
->thread_fsm
->clean_up (thr
);
3777 if (ecs
->event_thread
!= NULL
)
3778 switch_to_thread (ecs
->event_thread
);
3782 /* Helper for all_uis_check_sync_execution_done that works on the
3786 check_curr_ui_sync_execution_done (void)
3788 struct ui
*ui
= current_ui
;
3790 if (ui
->prompt_state
== PROMPT_NEEDED
3792 && !gdb_in_secondary_prompt_p (ui
))
3794 target_terminal::ours ();
3795 gdb::observers::sync_execution_done
.notify ();
3796 ui_register_input_event_handler (ui
);
3803 all_uis_check_sync_execution_done (void)
3805 SWITCH_THRU_ALL_UIS ()
3807 check_curr_ui_sync_execution_done ();
3814 all_uis_on_sync_execution_starting (void)
3816 SWITCH_THRU_ALL_UIS ()
3818 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3819 async_disable_stdin ();
3823 /* Asynchronous version of wait_for_inferior. It is called by the
3824 event loop whenever a change of state is detected on the file
3825 descriptor corresponding to the target. It can be called more than
3826 once to complete a single execution command. In such cases we need
3827 to keep the state in a global variable ECSS. If it is the last time
3828 that this function is called for a single execution command, then
3829 report to the user that the inferior has stopped, and do the
3830 necessary cleanups. */
3833 fetch_inferior_event ()
3835 struct execution_control_state ecss
;
3836 struct execution_control_state
*ecs
= &ecss
;
3839 memset (ecs
, 0, sizeof (*ecs
));
3841 /* Events are always processed with the main UI as current UI. This
3842 way, warnings, debug output, etc. are always consistently sent to
3843 the main console. */
3844 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3846 /* Temporarily disable pagination. Otherwise, the user would be
3847 given an option to press 'q' to quit, which would cause an early
3848 exit and could leave GDB in a half-baked state. */
3849 scoped_restore save_pagination
3850 = make_scoped_restore (&pagination_enabled
, false);
3852 /* End up with readline processing input, if necessary. */
3854 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3856 /* We're handling a live event, so make sure we're doing live
3857 debugging. If we're looking at traceframes while the target is
3858 running, we're going to need to get back to that mode after
3859 handling the event. */
3860 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3863 maybe_restore_traceframe
.emplace ();
3864 set_current_traceframe (-1);
3867 /* The user/frontend should not notice a thread switch due to
3868 internal events. Make sure we revert to the user selected
3869 thread and frame after handling the event and running any
3870 breakpoint commands. */
3871 scoped_restore_current_thread restore_thread
;
3873 overlay_cache_invalid
= 1;
3874 /* Flush target cache before starting to handle each event. Target
3875 was running and cache could be stale. This is just a heuristic.
3876 Running threads may modify target memory, but we don't get any
3878 target_dcache_invalidate ();
3880 scoped_restore save_exec_dir
3881 = make_scoped_restore (&execution_direction
,
3882 target_execution_direction ());
3884 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3887 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3889 /* Switch to the target that generated the event, so we can do
3891 switch_to_target_no_thread (ecs
->target
);
3894 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3896 /* If an error happens while handling the event, propagate GDB's
3897 knowledge of the executing state to the frontend/user running
3899 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3900 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3902 /* Get executed before scoped_restore_current_thread above to apply
3903 still for the thread which has thrown the exception. */
3904 auto defer_bpstat_clear
3905 = make_scope_exit (bpstat_clear_actions
);
3906 auto defer_delete_threads
3907 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3909 /* Now figure out what to do with the result of the result. */
3910 handle_inferior_event (ecs
);
3912 if (!ecs
->wait_some_more
)
3914 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3915 bool should_stop
= true;
3916 struct thread_info
*thr
= ecs
->event_thread
;
3918 delete_just_stopped_threads_infrun_breakpoints ();
3922 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3924 if (thread_fsm
!= NULL
)
3925 should_stop
= thread_fsm
->should_stop (thr
);
3934 bool should_notify_stop
= true;
3937 clean_up_just_stopped_threads_fsms (ecs
);
3939 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3940 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3942 if (should_notify_stop
)
3944 /* We may not find an inferior if this was a process exit. */
3945 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3946 proceeded
= normal_stop ();
3951 inferior_event_handler (INF_EXEC_COMPLETE
);
3955 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3956 previously selected thread is gone. We have two
3957 choices - switch to no thread selected, or restore the
3958 previously selected thread (now exited). We chose the
3959 later, just because that's what GDB used to do. After
3960 this, "info threads" says "The current thread <Thread
3961 ID 2> has terminated." instead of "No thread
3965 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3966 restore_thread
.dont_restore ();
3970 defer_delete_threads
.release ();
3971 defer_bpstat_clear
.release ();
3973 /* No error, don't finish the thread states yet. */
3974 finish_state
.release ();
3976 /* This scope is used to ensure that readline callbacks are
3977 reinstalled here. */
3980 /* If a UI was in sync execution mode, and now isn't, restore its
3981 prompt (a synchronous execution command has finished, and we're
3982 ready for input). */
3983 all_uis_check_sync_execution_done ();
3986 && exec_done_display_p
3987 && (inferior_ptid
== null_ptid
3988 || inferior_thread ()->state
!= THREAD_RUNNING
))
3989 printf_unfiltered (_("completed.\n"));
3995 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
3996 struct symtab_and_line sal
)
3998 /* This can be removed once this function no longer implicitly relies on the
3999 inferior_ptid value. */
4000 gdb_assert (inferior_ptid
== tp
->ptid
);
4002 tp
->control
.step_frame_id
= get_frame_id (frame
);
4003 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4005 tp
->current_symtab
= sal
.symtab
;
4006 tp
->current_line
= sal
.line
;
4009 /* Clear context switchable stepping state. */
4012 init_thread_stepping_state (struct thread_info
*tss
)
4014 tss
->stepped_breakpoint
= 0;
4015 tss
->stepping_over_breakpoint
= 0;
4016 tss
->stepping_over_watchpoint
= 0;
4017 tss
->step_after_step_resume_breakpoint
= 0;
4023 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4024 target_waitstatus status
)
4026 target_last_proc_target
= target
;
4027 target_last_wait_ptid
= ptid
;
4028 target_last_waitstatus
= status
;
4034 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4035 target_waitstatus
*status
)
4037 if (target
!= nullptr)
4038 *target
= target_last_proc_target
;
4039 if (ptid
!= nullptr)
4040 *ptid
= target_last_wait_ptid
;
4041 if (status
!= nullptr)
4042 *status
= target_last_waitstatus
;
4048 nullify_last_target_wait_ptid (void)
4050 target_last_proc_target
= nullptr;
4051 target_last_wait_ptid
= minus_one_ptid
;
4052 target_last_waitstatus
= {};
4055 /* Switch thread contexts. */
4058 context_switch (execution_control_state
*ecs
)
4060 if (ecs
->ptid
!= inferior_ptid
4061 && (inferior_ptid
== null_ptid
4062 || ecs
->event_thread
!= inferior_thread ()))
4064 infrun_debug_printf ("Switching context from %s to %s",
4065 target_pid_to_str (inferior_ptid
).c_str (),
4066 target_pid_to_str (ecs
->ptid
).c_str ());
4069 switch_to_thread (ecs
->event_thread
);
4072 /* If the target can't tell whether we've hit breakpoints
4073 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4074 check whether that could have been caused by a breakpoint. If so,
4075 adjust the PC, per gdbarch_decr_pc_after_break. */
4078 adjust_pc_after_break (struct thread_info
*thread
,
4079 struct target_waitstatus
*ws
)
4081 struct regcache
*regcache
;
4082 struct gdbarch
*gdbarch
;
4083 CORE_ADDR breakpoint_pc
, decr_pc
;
4085 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4086 we aren't, just return.
4088 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4089 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4090 implemented by software breakpoints should be handled through the normal
4093 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4094 different signals (SIGILL or SIGEMT for instance), but it is less
4095 clear where the PC is pointing afterwards. It may not match
4096 gdbarch_decr_pc_after_break. I don't know any specific target that
4097 generates these signals at breakpoints (the code has been in GDB since at
4098 least 1992) so I can not guess how to handle them here.
4100 In earlier versions of GDB, a target with
4101 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4102 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4103 target with both of these set in GDB history, and it seems unlikely to be
4104 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4106 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4109 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4112 /* In reverse execution, when a breakpoint is hit, the instruction
4113 under it has already been de-executed. The reported PC always
4114 points at the breakpoint address, so adjusting it further would
4115 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4118 B1 0x08000000 : INSN1
4119 B2 0x08000001 : INSN2
4121 PC -> 0x08000003 : INSN4
4123 Say you're stopped at 0x08000003 as above. Reverse continuing
4124 from that point should hit B2 as below. Reading the PC when the
4125 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4126 been de-executed already.
4128 B1 0x08000000 : INSN1
4129 B2 PC -> 0x08000001 : INSN2
4133 We can't apply the same logic as for forward execution, because
4134 we would wrongly adjust the PC to 0x08000000, since there's a
4135 breakpoint at PC - 1. We'd then report a hit on B1, although
4136 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4138 if (execution_direction
== EXEC_REVERSE
)
4141 /* If the target can tell whether the thread hit a SW breakpoint,
4142 trust it. Targets that can tell also adjust the PC
4144 if (target_supports_stopped_by_sw_breakpoint ())
4147 /* Note that relying on whether a breakpoint is planted in memory to
4148 determine this can fail. E.g,. the breakpoint could have been
4149 removed since. Or the thread could have been told to step an
4150 instruction the size of a breakpoint instruction, and only
4151 _after_ was a breakpoint inserted at its address. */
4153 /* If this target does not decrement the PC after breakpoints, then
4154 we have nothing to do. */
4155 regcache
= get_thread_regcache (thread
);
4156 gdbarch
= regcache
->arch ();
4158 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4162 const address_space
*aspace
= regcache
->aspace ();
4164 /* Find the location where (if we've hit a breakpoint) the
4165 breakpoint would be. */
4166 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4168 /* If the target can't tell whether a software breakpoint triggered,
4169 fallback to figuring it out based on breakpoints we think were
4170 inserted in the target, and on whether the thread was stepped or
4173 /* Check whether there actually is a software breakpoint inserted at
4176 If in non-stop mode, a race condition is possible where we've
4177 removed a breakpoint, but stop events for that breakpoint were
4178 already queued and arrive later. To suppress those spurious
4179 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4180 and retire them after a number of stop events are reported. Note
4181 this is an heuristic and can thus get confused. The real fix is
4182 to get the "stopped by SW BP and needs adjustment" info out of
4183 the target/kernel (and thus never reach here; see above). */
4184 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4185 || (target_is_non_stop_p ()
4186 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4188 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4190 if (record_full_is_used ())
4191 restore_operation_disable
.emplace
4192 (record_full_gdb_operation_disable_set ());
4194 /* When using hardware single-step, a SIGTRAP is reported for both
4195 a completed single-step and a software breakpoint. Need to
4196 differentiate between the two, as the latter needs adjusting
4197 but the former does not.
4199 The SIGTRAP can be due to a completed hardware single-step only if
4200 - we didn't insert software single-step breakpoints
4201 - this thread is currently being stepped
4203 If any of these events did not occur, we must have stopped due
4204 to hitting a software breakpoint, and have to back up to the
4207 As a special case, we could have hardware single-stepped a
4208 software breakpoint. In this case (prev_pc == breakpoint_pc),
4209 we also need to back up to the breakpoint address. */
4211 if (thread_has_single_step_breakpoints_set (thread
)
4212 || !currently_stepping (thread
)
4213 || (thread
->stepped_breakpoint
4214 && thread
->prev_pc
== breakpoint_pc
))
4215 regcache_write_pc (regcache
, breakpoint_pc
);
4220 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4222 for (frame
= get_prev_frame (frame
);
4224 frame
= get_prev_frame (frame
))
4226 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4229 if (get_frame_type (frame
) != INLINE_FRAME
)
4236 /* Look for an inline frame that is marked for skip.
4237 If PREV_FRAME is TRUE start at the previous frame,
4238 otherwise start at the current frame. Stop at the
4239 first non-inline frame, or at the frame where the
4243 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4245 struct frame_info
*frame
= get_current_frame ();
4248 frame
= get_prev_frame (frame
);
4250 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4252 const char *fn
= NULL
;
4253 symtab_and_line sal
;
4256 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4258 if (get_frame_type (frame
) != INLINE_FRAME
)
4261 sal
= find_frame_sal (frame
);
4262 sym
= get_frame_function (frame
);
4265 fn
= sym
->print_name ();
4268 && function_name_is_marked_for_skip (fn
, sal
))
4275 /* If the event thread has the stop requested flag set, pretend it
4276 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4280 handle_stop_requested (struct execution_control_state
*ecs
)
4282 if (ecs
->event_thread
->stop_requested
)
4284 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4285 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4286 handle_signal_stop (ecs
);
4292 /* Auxiliary function that handles syscall entry/return events.
4293 It returns true if the inferior should keep going (and GDB
4294 should ignore the event), or false if the event deserves to be
4298 handle_syscall_event (struct execution_control_state
*ecs
)
4300 struct regcache
*regcache
;
4303 context_switch (ecs
);
4305 regcache
= get_thread_regcache (ecs
->event_thread
);
4306 syscall_number
= ecs
->ws
.value
.syscall_number
;
4307 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4309 if (catch_syscall_enabled () > 0
4310 && catching_syscall_number (syscall_number
) > 0)
4312 infrun_debug_printf ("syscall number=%d", syscall_number
);
4314 ecs
->event_thread
->control
.stop_bpstat
4315 = bpstat_stop_status (regcache
->aspace (),
4316 ecs
->event_thread
->suspend
.stop_pc
,
4317 ecs
->event_thread
, &ecs
->ws
);
4319 if (handle_stop_requested (ecs
))
4322 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4324 /* Catchpoint hit. */
4329 if (handle_stop_requested (ecs
))
4332 /* If no catchpoint triggered for this, then keep going. */
4338 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4341 fill_in_stop_func (struct gdbarch
*gdbarch
,
4342 struct execution_control_state
*ecs
)
4344 if (!ecs
->stop_func_filled_in
)
4347 const general_symbol_info
*gsi
;
4349 /* Don't care about return value; stop_func_start and stop_func_name
4350 will both be 0 if it doesn't work. */
4351 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4353 &ecs
->stop_func_start
,
4354 &ecs
->stop_func_end
,
4356 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4358 /* The call to find_pc_partial_function, above, will set
4359 stop_func_start and stop_func_end to the start and end
4360 of the range containing the stop pc. If this range
4361 contains the entry pc for the block (which is always the
4362 case for contiguous blocks), advance stop_func_start past
4363 the function's start offset and entrypoint. Note that
4364 stop_func_start is NOT advanced when in a range of a
4365 non-contiguous block that does not contain the entry pc. */
4366 if (block
!= nullptr
4367 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4368 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4370 ecs
->stop_func_start
4371 += gdbarch_deprecated_function_start_offset (gdbarch
);
4373 if (gdbarch_skip_entrypoint_p (gdbarch
))
4374 ecs
->stop_func_start
4375 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4378 ecs
->stop_func_filled_in
= 1;
4383 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4385 static enum stop_kind
4386 get_inferior_stop_soon (execution_control_state
*ecs
)
4388 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4390 gdb_assert (inf
!= NULL
);
4391 return inf
->control
.stop_soon
;
4394 /* Poll for one event out of the current target. Store the resulting
4395 waitstatus in WS, and return the event ptid. Does not block. */
4398 poll_one_curr_target (struct target_waitstatus
*ws
)
4402 overlay_cache_invalid
= 1;
4404 /* Flush target cache before starting to handle each event.
4405 Target was running and cache could be stale. This is just a
4406 heuristic. Running threads may modify target memory, but we
4407 don't get any event. */
4408 target_dcache_invalidate ();
4410 if (deprecated_target_wait_hook
)
4411 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4413 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4416 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4421 /* An event reported by wait_one. */
4423 struct wait_one_event
4425 /* The target the event came out of. */
4426 process_stratum_target
*target
;
4428 /* The PTID the event was for. */
4431 /* The waitstatus. */
4432 target_waitstatus ws
;
4435 /* Wait for one event out of any target. */
4437 static wait_one_event
4442 for (inferior
*inf
: all_inferiors ())
4444 process_stratum_target
*target
= inf
->process_target ();
4446 || !target
->is_async_p ()
4447 || !target
->threads_executing
)
4450 switch_to_inferior_no_thread (inf
);
4452 wait_one_event event
;
4453 event
.target
= target
;
4454 event
.ptid
= poll_one_curr_target (&event
.ws
);
4456 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4458 /* If nothing is resumed, remove the target from the
4462 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4466 /* Block waiting for some event. */
4473 for (inferior
*inf
: all_inferiors ())
4475 process_stratum_target
*target
= inf
->process_target ();
4477 || !target
->is_async_p ()
4478 || !target
->threads_executing
)
4481 int fd
= target
->async_wait_fd ();
4482 FD_SET (fd
, &readfds
);
4489 /* No waitable targets left. All must be stopped. */
4490 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4495 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4501 perror_with_name ("interruptible_select");
4506 /* Save the thread's event and stop reason to process it later. */
4509 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4511 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4512 target_waitstatus_to_string (ws
).c_str (),
4517 /* Record for later. */
4518 tp
->suspend
.waitstatus
= *ws
;
4519 tp
->suspend
.waitstatus_pending_p
= 1;
4521 struct regcache
*regcache
= get_thread_regcache (tp
);
4522 const address_space
*aspace
= regcache
->aspace ();
4524 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4525 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4527 CORE_ADDR pc
= regcache_read_pc (regcache
);
4529 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4531 scoped_restore_current_thread restore_thread
;
4532 switch_to_thread (tp
);
4534 if (target_stopped_by_watchpoint ())
4536 tp
->suspend
.stop_reason
4537 = TARGET_STOPPED_BY_WATCHPOINT
;
4539 else if (target_supports_stopped_by_sw_breakpoint ()
4540 && target_stopped_by_sw_breakpoint ())
4542 tp
->suspend
.stop_reason
4543 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4545 else if (target_supports_stopped_by_hw_breakpoint ()
4546 && target_stopped_by_hw_breakpoint ())
4548 tp
->suspend
.stop_reason
4549 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4551 else if (!target_supports_stopped_by_hw_breakpoint ()
4552 && hardware_breakpoint_inserted_here_p (aspace
,
4555 tp
->suspend
.stop_reason
4556 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4558 else if (!target_supports_stopped_by_sw_breakpoint ()
4559 && software_breakpoint_inserted_here_p (aspace
,
4562 tp
->suspend
.stop_reason
4563 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4565 else if (!thread_has_single_step_breakpoints_set (tp
)
4566 && currently_stepping (tp
))
4568 tp
->suspend
.stop_reason
4569 = TARGET_STOPPED_BY_SINGLE_STEP
;
4574 /* Mark the non-executing threads accordingly. In all-stop, all
4575 threads of all processes are stopped when we get any event
4576 reported. In non-stop mode, only the event thread stops. */
4579 mark_non_executing_threads (process_stratum_target
*target
,
4581 struct target_waitstatus ws
)
4585 if (!target_is_non_stop_p ())
4586 mark_ptid
= minus_one_ptid
;
4587 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4588 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4590 /* If we're handling a process exit in non-stop mode, even
4591 though threads haven't been deleted yet, one would think
4592 that there is nothing to do, as threads of the dead process
4593 will be soon deleted, and threads of any other process were
4594 left running. However, on some targets, threads survive a
4595 process exit event. E.g., for the "checkpoint" command,
4596 when the current checkpoint/fork exits, linux-fork.c
4597 automatically switches to another fork from within
4598 target_mourn_inferior, by associating the same
4599 inferior/thread to another fork. We haven't mourned yet at
4600 this point, but we must mark any threads left in the
4601 process as not-executing so that finish_thread_state marks
4602 them stopped (in the user's perspective) if/when we present
4603 the stop to the user. */
4604 mark_ptid
= ptid_t (event_ptid
.pid ());
4607 mark_ptid
= event_ptid
;
4609 set_executing (target
, mark_ptid
, false);
4611 /* Likewise the resumed flag. */
4612 set_resumed (target
, mark_ptid
, false);
4618 stop_all_threads (void)
4620 /* We may need multiple passes to discover all threads. */
4624 gdb_assert (exists_non_stop_target ());
4626 infrun_debug_printf ("starting");
4628 scoped_restore_current_thread restore_thread
;
4630 /* Enable thread events of all targets. */
4631 for (auto *target
: all_non_exited_process_targets ())
4633 switch_to_target_no_thread (target
);
4634 target_thread_events (true);
4639 /* Disable thread events of all targets. */
4640 for (auto *target
: all_non_exited_process_targets ())
4642 switch_to_target_no_thread (target
);
4643 target_thread_events (false);
4646 /* Use debug_prefixed_printf directly to get a meaningful function
4649 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
4652 /* Request threads to stop, and then wait for the stops. Because
4653 threads we already know about can spawn more threads while we're
4654 trying to stop them, and we only learn about new threads when we
4655 update the thread list, do this in a loop, and keep iterating
4656 until two passes find no threads that need to be stopped. */
4657 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4659 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4662 int waits_needed
= 0;
4664 for (auto *target
: all_non_exited_process_targets ())
4666 switch_to_target_no_thread (target
);
4667 update_thread_list ();
4670 /* Go through all threads looking for threads that we need
4671 to tell the target to stop. */
4672 for (thread_info
*t
: all_non_exited_threads ())
4674 /* For a single-target setting with an all-stop target,
4675 we would not even arrive here. For a multi-target
4676 setting, until GDB is able to handle a mixture of
4677 all-stop and non-stop targets, simply skip all-stop
4678 targets' threads. This should be fine due to the
4679 protection of 'check_multi_target_resumption'. */
4681 switch_to_thread_no_regs (t
);
4682 if (!target_is_non_stop_p ())
4687 /* If already stopping, don't request a stop again.
4688 We just haven't seen the notification yet. */
4689 if (!t
->stop_requested
)
4691 infrun_debug_printf (" %s executing, need stop",
4692 target_pid_to_str (t
->ptid
).c_str ());
4693 target_stop (t
->ptid
);
4694 t
->stop_requested
= 1;
4698 infrun_debug_printf (" %s executing, already stopping",
4699 target_pid_to_str (t
->ptid
).c_str ());
4702 if (t
->stop_requested
)
4707 infrun_debug_printf (" %s not executing",
4708 target_pid_to_str (t
->ptid
).c_str ());
4710 /* The thread may be not executing, but still be
4711 resumed with a pending status to process. */
4716 if (waits_needed
== 0)
4719 /* If we find new threads on the second iteration, restart
4720 over. We want to see two iterations in a row with all
4725 for (int i
= 0; i
< waits_needed
; i
++)
4727 wait_one_event event
= wait_one ();
4730 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4731 target_pid_to_str (event
.ptid
).c_str ());
4733 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4735 /* All resumed threads exited. */
4738 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4739 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4740 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4742 /* One thread/process exited/signalled. */
4744 thread_info
*t
= nullptr;
4746 /* The target may have reported just a pid. If so, try
4747 the first non-exited thread. */
4748 if (event
.ptid
.is_pid ())
4750 int pid
= event
.ptid
.pid ();
4751 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4752 for (thread_info
*tp
: inf
->non_exited_threads ())
4758 /* If there is no available thread, the event would
4759 have to be appended to a per-inferior event list,
4760 which does not exist (and if it did, we'd have
4761 to adjust run control command to be able to
4762 resume such an inferior). We assert here instead
4763 of going into an infinite loop. */
4764 gdb_assert (t
!= nullptr);
4767 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4771 t
= find_thread_ptid (event
.target
, event
.ptid
);
4772 /* Check if this is the first time we see this thread.
4773 Don't bother adding if it individually exited. */
4775 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4776 t
= add_thread (event
.target
, event
.ptid
);
4781 /* Set the threads as non-executing to avoid
4782 another stop attempt on them. */
4783 switch_to_thread_no_regs (t
);
4784 mark_non_executing_threads (event
.target
, event
.ptid
,
4786 save_waitstatus (t
, &event
.ws
);
4787 t
->stop_requested
= false;
4792 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4794 t
= add_thread (event
.target
, event
.ptid
);
4796 t
->stop_requested
= 0;
4799 t
->control
.may_range_step
= 0;
4801 /* This may be the first time we see the inferior report
4803 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4804 if (inf
->needs_setup
)
4806 switch_to_thread_no_regs (t
);
4810 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4811 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4813 /* We caught the event that we intended to catch, so
4814 there's no event pending. */
4815 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4816 t
->suspend
.waitstatus_pending_p
= 0;
4818 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4820 /* Add it back to the step-over queue. */
4822 ("displaced-step of %s canceled: adding back to "
4823 "the step-over queue",
4824 target_pid_to_str (t
->ptid
).c_str ());
4826 t
->control
.trap_expected
= 0;
4827 global_thread_step_over_chain_enqueue (t
);
4832 enum gdb_signal sig
;
4833 struct regcache
*regcache
;
4836 ("target_wait %s, saving status for %d.%ld.%ld",
4837 target_waitstatus_to_string (&event
.ws
).c_str (),
4838 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4840 /* Record for later. */
4841 save_waitstatus (t
, &event
.ws
);
4843 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4844 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4846 if (displaced_step_fixup (t
, sig
) < 0)
4848 /* Add it back to the step-over queue. */
4849 t
->control
.trap_expected
= 0;
4850 global_thread_step_over_chain_enqueue (t
);
4853 regcache
= get_thread_regcache (t
);
4854 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4856 infrun_debug_printf ("saved stop_pc=%s for %s "
4857 "(currently_stepping=%d)",
4858 paddress (target_gdbarch (),
4859 t
->suspend
.stop_pc
),
4860 target_pid_to_str (t
->ptid
).c_str (),
4861 currently_stepping (t
));
4869 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4872 handle_no_resumed (struct execution_control_state
*ecs
)
4874 if (target_can_async_p ())
4876 bool any_sync
= false;
4878 for (ui
*ui
: all_uis ())
4880 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4888 /* There were no unwaited-for children left in the target, but,
4889 we're not synchronously waiting for events either. Just
4892 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4893 prepare_to_wait (ecs
);
4898 /* Otherwise, if we were running a synchronous execution command, we
4899 may need to cancel it and give the user back the terminal.
4901 In non-stop mode, the target can't tell whether we've already
4902 consumed previous stop events, so it can end up sending us a
4903 no-resumed event like so:
4905 #0 - thread 1 is left stopped
4907 #1 - thread 2 is resumed and hits breakpoint
4908 -> TARGET_WAITKIND_STOPPED
4910 #2 - thread 3 is resumed and exits
4911 this is the last resumed thread, so
4912 -> TARGET_WAITKIND_NO_RESUMED
4914 #3 - gdb processes stop for thread 2 and decides to re-resume
4917 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4918 thread 2 is now resumed, so the event should be ignored.
4920 IOW, if the stop for thread 2 doesn't end a foreground command,
4921 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4922 event. But it could be that the event meant that thread 2 itself
4923 (or whatever other thread was the last resumed thread) exited.
4925 To address this we refresh the thread list and check whether we
4926 have resumed threads _now_. In the example above, this removes
4927 thread 3 from the thread list. If thread 2 was re-resumed, we
4928 ignore this event. If we find no thread resumed, then we cancel
4929 the synchronous command and show "no unwaited-for " to the
4932 inferior
*curr_inf
= current_inferior ();
4934 scoped_restore_current_thread restore_thread
;
4936 for (auto *target
: all_non_exited_process_targets ())
4938 switch_to_target_no_thread (target
);
4939 update_thread_list ();
4944 - the current target has no thread executing, and
4945 - the current inferior is native, and
4946 - the current inferior is the one which has the terminal, and
4949 then a Ctrl-C from this point on would remain stuck in the
4950 kernel, until a thread resumes and dequeues it. That would
4951 result in the GDB CLI not reacting to Ctrl-C, not able to
4952 interrupt the program. To address this, if the current inferior
4953 no longer has any thread executing, we give the terminal to some
4954 other inferior that has at least one thread executing. */
4955 bool swap_terminal
= true;
4957 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4958 whether to report it to the user. */
4959 bool ignore_event
= false;
4961 for (thread_info
*thread
: all_non_exited_threads ())
4963 if (swap_terminal
&& thread
->executing
)
4965 if (thread
->inf
!= curr_inf
)
4967 target_terminal::ours ();
4969 switch_to_thread (thread
);
4970 target_terminal::inferior ();
4972 swap_terminal
= false;
4976 && (thread
->executing
4977 || thread
->suspend
.waitstatus_pending_p
))
4979 /* Either there were no unwaited-for children left in the
4980 target at some point, but there are now, or some target
4981 other than the eventing one has unwaited-for children
4982 left. Just ignore. */
4983 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
4984 "(ignoring: found resumed)");
4986 ignore_event
= true;
4989 if (ignore_event
&& !swap_terminal
)
4995 switch_to_inferior_no_thread (curr_inf
);
4996 prepare_to_wait (ecs
);
5000 /* Go ahead and report the event. */
5004 /* Given an execution control state that has been freshly filled in by
5005 an event from the inferior, figure out what it means and take
5008 The alternatives are:
5010 1) stop_waiting and return; to really stop and return to the
5013 2) keep_going and return; to wait for the next event (set
5014 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5018 handle_inferior_event (struct execution_control_state
*ecs
)
5020 /* Make sure that all temporary struct value objects that were
5021 created during the handling of the event get deleted at the
5023 scoped_value_mark free_values
;
5025 enum stop_kind stop_soon
;
5027 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5029 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5031 /* We had an event in the inferior, but we are not interested in
5032 handling it at this level. The lower layers have already
5033 done what needs to be done, if anything.
5035 One of the possible circumstances for this is when the
5036 inferior produces output for the console. The inferior has
5037 not stopped, and we are ignoring the event. Another possible
5038 circumstance is any event which the lower level knows will be
5039 reported multiple times without an intervening resume. */
5040 prepare_to_wait (ecs
);
5044 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5046 prepare_to_wait (ecs
);
5050 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5051 && handle_no_resumed (ecs
))
5054 /* Cache the last target/ptid/waitstatus. */
5055 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5057 /* Always clear state belonging to the previous time we stopped. */
5058 stop_stack_dummy
= STOP_NONE
;
5060 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5062 /* No unwaited-for children left. IOW, all resumed children
5064 stop_print_frame
= false;
5069 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5070 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5072 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5073 /* If it's a new thread, add it to the thread database. */
5074 if (ecs
->event_thread
== NULL
)
5075 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5077 /* Disable range stepping. If the next step request could use a
5078 range, this will be end up re-enabled then. */
5079 ecs
->event_thread
->control
.may_range_step
= 0;
5082 /* Dependent on valid ECS->EVENT_THREAD. */
5083 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5085 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5086 reinit_frame_cache ();
5088 breakpoint_retire_moribund ();
5090 /* First, distinguish signals caused by the debugger from signals
5091 that have to do with the program's own actions. Note that
5092 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5093 on the operating system version. Here we detect when a SIGILL or
5094 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5095 something similar for SIGSEGV, since a SIGSEGV will be generated
5096 when we're trying to execute a breakpoint instruction on a
5097 non-executable stack. This happens for call dummy breakpoints
5098 for architectures like SPARC that place call dummies on the
5100 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5101 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5102 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5103 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5105 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5107 if (breakpoint_inserted_here_p (regcache
->aspace (),
5108 regcache_read_pc (regcache
)))
5110 infrun_debug_printf ("Treating signal as SIGTRAP");
5111 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5115 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5117 switch (ecs
->ws
.kind
)
5119 case TARGET_WAITKIND_LOADED
:
5120 context_switch (ecs
);
5121 /* Ignore gracefully during startup of the inferior, as it might
5122 be the shell which has just loaded some objects, otherwise
5123 add the symbols for the newly loaded objects. Also ignore at
5124 the beginning of an attach or remote session; we will query
5125 the full list of libraries once the connection is
5128 stop_soon
= get_inferior_stop_soon (ecs
);
5129 if (stop_soon
== NO_STOP_QUIETLY
)
5131 struct regcache
*regcache
;
5133 regcache
= get_thread_regcache (ecs
->event_thread
);
5135 handle_solib_event ();
5137 ecs
->event_thread
->control
.stop_bpstat
5138 = bpstat_stop_status (regcache
->aspace (),
5139 ecs
->event_thread
->suspend
.stop_pc
,
5140 ecs
->event_thread
, &ecs
->ws
);
5142 if (handle_stop_requested (ecs
))
5145 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5147 /* A catchpoint triggered. */
5148 process_event_stop_test (ecs
);
5152 /* If requested, stop when the dynamic linker notifies
5153 gdb of events. This allows the user to get control
5154 and place breakpoints in initializer routines for
5155 dynamically loaded objects (among other things). */
5156 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5157 if (stop_on_solib_events
)
5159 /* Make sure we print "Stopped due to solib-event" in
5161 stop_print_frame
= true;
5168 /* If we are skipping through a shell, or through shared library
5169 loading that we aren't interested in, resume the program. If
5170 we're running the program normally, also resume. */
5171 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5173 /* Loading of shared libraries might have changed breakpoint
5174 addresses. Make sure new breakpoints are inserted. */
5175 if (stop_soon
== NO_STOP_QUIETLY
)
5176 insert_breakpoints ();
5177 resume (GDB_SIGNAL_0
);
5178 prepare_to_wait (ecs
);
5182 /* But stop if we're attaching or setting up a remote
5184 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5185 || stop_soon
== STOP_QUIETLY_REMOTE
)
5187 infrun_debug_printf ("quietly stopped");
5192 internal_error (__FILE__
, __LINE__
,
5193 _("unhandled stop_soon: %d"), (int) stop_soon
);
5195 case TARGET_WAITKIND_SPURIOUS
:
5196 if (handle_stop_requested (ecs
))
5198 context_switch (ecs
);
5199 resume (GDB_SIGNAL_0
);
5200 prepare_to_wait (ecs
);
5203 case TARGET_WAITKIND_THREAD_CREATED
:
5204 if (handle_stop_requested (ecs
))
5206 context_switch (ecs
);
5207 if (!switch_back_to_stepped_thread (ecs
))
5211 case TARGET_WAITKIND_EXITED
:
5212 case TARGET_WAITKIND_SIGNALLED
:
5214 /* Depending on the system, ecs->ptid may point to a thread or
5215 to a process. On some targets, target_mourn_inferior may
5216 need to have access to the just-exited thread. That is the
5217 case of GNU/Linux's "checkpoint" support, for example.
5218 Call the switch_to_xxx routine as appropriate. */
5219 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5221 switch_to_thread (thr
);
5224 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5225 switch_to_inferior_no_thread (inf
);
5228 handle_vfork_child_exec_or_exit (0);
5229 target_terminal::ours (); /* Must do this before mourn anyway. */
5231 /* Clearing any previous state of convenience variables. */
5232 clear_exit_convenience_vars ();
5234 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5236 /* Record the exit code in the convenience variable $_exitcode, so
5237 that the user can inspect this again later. */
5238 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5239 (LONGEST
) ecs
->ws
.value
.integer
);
5241 /* Also record this in the inferior itself. */
5242 current_inferior ()->has_exit_code
= 1;
5243 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5245 /* Support the --return-child-result option. */
5246 return_child_result_value
= ecs
->ws
.value
.integer
;
5248 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5252 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5254 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5256 /* Set the value of the internal variable $_exitsignal,
5257 which holds the signal uncaught by the inferior. */
5258 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5259 gdbarch_gdb_signal_to_target (gdbarch
,
5260 ecs
->ws
.value
.sig
));
5264 /* We don't have access to the target's method used for
5265 converting between signal numbers (GDB's internal
5266 representation <-> target's representation).
5267 Therefore, we cannot do a good job at displaying this
5268 information to the user. It's better to just warn
5269 her about it (if infrun debugging is enabled), and
5271 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5275 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5278 gdb_flush (gdb_stdout
);
5279 target_mourn_inferior (inferior_ptid
);
5280 stop_print_frame
= false;
5284 case TARGET_WAITKIND_FORKED
:
5285 case TARGET_WAITKIND_VFORKED
:
5286 /* Check whether the inferior is displaced stepping. */
5288 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5289 struct gdbarch
*gdbarch
= regcache
->arch ();
5290 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5292 /* If this is a fork (child gets its own address space copy) and the
5293 displaced step buffer was in use at the time of the fork, restore
5294 displaced step buffer bytes in the child process. */
5295 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5297 displaced_step_inferior_state
*displaced
5298 = &parent_inf
->displaced_step_state
;
5300 if (displaced
->step_thread
!= nullptr)
5301 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5304 /* If displaced stepping is supported, and thread ecs->ptid is
5305 displaced stepping. */
5306 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5308 struct regcache
*child_regcache
;
5309 CORE_ADDR parent_pc
;
5311 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5312 indicating that the displaced stepping of syscall instruction
5313 has been done. Perform cleanup for parent process here. Note
5314 that this operation also cleans up the child process for vfork,
5315 because their pages are shared. */
5316 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5317 /* Start a new step-over in another thread if there's one
5321 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5322 the child's PC is also within the scratchpad. Set the child's PC
5323 to the parent's PC value, which has already been fixed up.
5324 FIXME: we use the parent's aspace here, although we're touching
5325 the child, because the child hasn't been added to the inferior
5326 list yet at this point. */
5329 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5330 ecs
->ws
.value
.related_pid
,
5332 parent_inf
->aspace
);
5333 /* Read PC value of parent process. */
5334 parent_pc
= regcache_read_pc (regcache
);
5336 displaced_debug_printf ("write child pc from %s to %s",
5338 regcache_read_pc (child_regcache
)),
5339 paddress (gdbarch
, parent_pc
));
5341 regcache_write_pc (child_regcache
, parent_pc
);
5345 context_switch (ecs
);
5347 /* Immediately detach breakpoints from the child before there's
5348 any chance of letting the user delete breakpoints from the
5349 breakpoint lists. If we don't do this early, it's easy to
5350 leave left over traps in the child, vis: "break foo; catch
5351 fork; c; <fork>; del; c; <child calls foo>". We only follow
5352 the fork on the last `continue', and by that time the
5353 breakpoint at "foo" is long gone from the breakpoint table.
5354 If we vforked, then we don't need to unpatch here, since both
5355 parent and child are sharing the same memory pages; we'll
5356 need to unpatch at follow/detach time instead to be certain
5357 that new breakpoints added between catchpoint hit time and
5358 vfork follow are detached. */
5359 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5361 /* This won't actually modify the breakpoint list, but will
5362 physically remove the breakpoints from the child. */
5363 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5366 delete_just_stopped_threads_single_step_breakpoints ();
5368 /* In case the event is caught by a catchpoint, remember that
5369 the event is to be followed at the next resume of the thread,
5370 and not immediately. */
5371 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5373 ecs
->event_thread
->suspend
.stop_pc
5374 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5376 ecs
->event_thread
->control
.stop_bpstat
5377 = bpstat_stop_status (get_current_regcache ()->aspace (),
5378 ecs
->event_thread
->suspend
.stop_pc
,
5379 ecs
->event_thread
, &ecs
->ws
);
5381 if (handle_stop_requested (ecs
))
5384 /* If no catchpoint triggered for this, then keep going. Note
5385 that we're interested in knowing the bpstat actually causes a
5386 stop, not just if it may explain the signal. Software
5387 watchpoints, for example, always appear in the bpstat. */
5388 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5391 = (follow_fork_mode_string
== follow_fork_mode_child
);
5393 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5395 process_stratum_target
*targ
5396 = ecs
->event_thread
->inf
->process_target ();
5398 bool should_resume
= follow_fork ();
5400 /* Note that one of these may be an invalid pointer,
5401 depending on detach_fork. */
5402 thread_info
*parent
= ecs
->event_thread
;
5404 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5406 /* At this point, the parent is marked running, and the
5407 child is marked stopped. */
5409 /* If not resuming the parent, mark it stopped. */
5410 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5411 parent
->set_running (false);
5413 /* If resuming the child, mark it running. */
5414 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5415 child
->set_running (true);
5417 /* In non-stop mode, also resume the other branch. */
5418 if (!detach_fork
&& (non_stop
5419 || (sched_multi
&& target_is_non_stop_p ())))
5422 switch_to_thread (parent
);
5424 switch_to_thread (child
);
5426 ecs
->event_thread
= inferior_thread ();
5427 ecs
->ptid
= inferior_ptid
;
5432 switch_to_thread (child
);
5434 switch_to_thread (parent
);
5436 ecs
->event_thread
= inferior_thread ();
5437 ecs
->ptid
= inferior_ptid
;
5445 process_event_stop_test (ecs
);
5448 case TARGET_WAITKIND_VFORK_DONE
:
5449 /* Done with the shared memory region. Re-insert breakpoints in
5450 the parent, and keep going. */
5452 context_switch (ecs
);
5454 current_inferior ()->waiting_for_vfork_done
= 0;
5455 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5457 if (handle_stop_requested (ecs
))
5460 /* This also takes care of reinserting breakpoints in the
5461 previously locked inferior. */
5465 case TARGET_WAITKIND_EXECD
:
5467 /* Note we can't read registers yet (the stop_pc), because we
5468 don't yet know the inferior's post-exec architecture.
5469 'stop_pc' is explicitly read below instead. */
5470 switch_to_thread_no_regs (ecs
->event_thread
);
5472 /* Do whatever is necessary to the parent branch of the vfork. */
5473 handle_vfork_child_exec_or_exit (1);
5475 /* This causes the eventpoints and symbol table to be reset.
5476 Must do this now, before trying to determine whether to
5478 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5480 /* In follow_exec we may have deleted the original thread and
5481 created a new one. Make sure that the event thread is the
5482 execd thread for that case (this is a nop otherwise). */
5483 ecs
->event_thread
= inferior_thread ();
5485 ecs
->event_thread
->suspend
.stop_pc
5486 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5488 ecs
->event_thread
->control
.stop_bpstat
5489 = bpstat_stop_status (get_current_regcache ()->aspace (),
5490 ecs
->event_thread
->suspend
.stop_pc
,
5491 ecs
->event_thread
, &ecs
->ws
);
5493 /* Note that this may be referenced from inside
5494 bpstat_stop_status above, through inferior_has_execd. */
5495 xfree (ecs
->ws
.value
.execd_pathname
);
5496 ecs
->ws
.value
.execd_pathname
= NULL
;
5498 if (handle_stop_requested (ecs
))
5501 /* If no catchpoint triggered for this, then keep going. */
5502 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5504 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5508 process_event_stop_test (ecs
);
5511 /* Be careful not to try to gather much state about a thread
5512 that's in a syscall. It's frequently a losing proposition. */
5513 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5514 /* Getting the current syscall number. */
5515 if (handle_syscall_event (ecs
) == 0)
5516 process_event_stop_test (ecs
);
5519 /* Before examining the threads further, step this thread to
5520 get it entirely out of the syscall. (We get notice of the
5521 event when the thread is just on the verge of exiting a
5522 syscall. Stepping one instruction seems to get it back
5524 case TARGET_WAITKIND_SYSCALL_RETURN
:
5525 if (handle_syscall_event (ecs
) == 0)
5526 process_event_stop_test (ecs
);
5529 case TARGET_WAITKIND_STOPPED
:
5530 handle_signal_stop (ecs
);
5533 case TARGET_WAITKIND_NO_HISTORY
:
5534 /* Reverse execution: target ran out of history info. */
5536 /* Switch to the stopped thread. */
5537 context_switch (ecs
);
5538 infrun_debug_printf ("stopped");
5540 delete_just_stopped_threads_single_step_breakpoints ();
5541 ecs
->event_thread
->suspend
.stop_pc
5542 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5544 if (handle_stop_requested (ecs
))
5547 gdb::observers::no_history
.notify ();
5553 /* Restart threads back to what they were trying to do back when we
5554 paused them for an in-line step-over. The EVENT_THREAD thread is
5558 restart_threads (struct thread_info
*event_thread
)
5560 /* In case the instruction just stepped spawned a new thread. */
5561 update_thread_list ();
5563 for (thread_info
*tp
: all_non_exited_threads ())
5565 switch_to_thread_no_regs (tp
);
5567 if (tp
== event_thread
)
5569 infrun_debug_printf ("restart threads: [%s] is event thread",
5570 target_pid_to_str (tp
->ptid
).c_str ());
5574 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5576 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5577 target_pid_to_str (tp
->ptid
).c_str ());
5583 infrun_debug_printf ("restart threads: [%s] resumed",
5584 target_pid_to_str (tp
->ptid
).c_str ());
5585 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5589 if (thread_is_in_step_over_chain (tp
))
5591 infrun_debug_printf ("restart threads: [%s] needs step-over",
5592 target_pid_to_str (tp
->ptid
).c_str ());
5593 gdb_assert (!tp
->resumed
);
5598 if (tp
->suspend
.waitstatus_pending_p
)
5600 infrun_debug_printf ("restart threads: [%s] has pending status",
5601 target_pid_to_str (tp
->ptid
).c_str ());
5606 gdb_assert (!tp
->stop_requested
);
5608 /* If some thread needs to start a step-over at this point, it
5609 should still be in the step-over queue, and thus skipped
5611 if (thread_still_needs_step_over (tp
))
5613 internal_error (__FILE__
, __LINE__
,
5614 "thread [%s] needs a step-over, but not in "
5615 "step-over queue\n",
5616 target_pid_to_str (tp
->ptid
).c_str ());
5619 if (currently_stepping (tp
))
5621 infrun_debug_printf ("restart threads: [%s] was stepping",
5622 target_pid_to_str (tp
->ptid
).c_str ());
5623 keep_going_stepped_thread (tp
);
5627 struct execution_control_state ecss
;
5628 struct execution_control_state
*ecs
= &ecss
;
5630 infrun_debug_printf ("restart threads: [%s] continuing",
5631 target_pid_to_str (tp
->ptid
).c_str ());
5632 reset_ecs (ecs
, tp
);
5633 switch_to_thread (tp
);
5634 keep_going_pass_signal (ecs
);
5639 /* Callback for iterate_over_threads. Find a resumed thread that has
5640 a pending waitstatus. */
5643 resumed_thread_with_pending_status (struct thread_info
*tp
,
5647 && tp
->suspend
.waitstatus_pending_p
);
5650 /* Called when we get an event that may finish an in-line or
5651 out-of-line (displaced stepping) step-over started previously.
5652 Return true if the event is processed and we should go back to the
5653 event loop; false if the caller should continue processing the
5657 finish_step_over (struct execution_control_state
*ecs
)
5659 displaced_step_fixup (ecs
->event_thread
,
5660 ecs
->event_thread
->suspend
.stop_signal
);
5662 bool had_step_over_info
= step_over_info_valid_p ();
5664 if (had_step_over_info
)
5666 /* If we're stepping over a breakpoint with all threads locked,
5667 then only the thread that was stepped should be reporting
5669 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5671 clear_step_over_info ();
5674 if (!target_is_non_stop_p ())
5677 /* Start a new step-over in another thread if there's one that
5681 /* If we were stepping over a breakpoint before, and haven't started
5682 a new in-line step-over sequence, then restart all other threads
5683 (except the event thread). We can't do this in all-stop, as then
5684 e.g., we wouldn't be able to issue any other remote packet until
5685 these other threads stop. */
5686 if (had_step_over_info
&& !step_over_info_valid_p ())
5688 struct thread_info
*pending
;
5690 /* If we only have threads with pending statuses, the restart
5691 below won't restart any thread and so nothing re-inserts the
5692 breakpoint we just stepped over. But we need it inserted
5693 when we later process the pending events, otherwise if
5694 another thread has a pending event for this breakpoint too,
5695 we'd discard its event (because the breakpoint that
5696 originally caused the event was no longer inserted). */
5697 context_switch (ecs
);
5698 insert_breakpoints ();
5700 restart_threads (ecs
->event_thread
);
5702 /* If we have events pending, go through handle_inferior_event
5703 again, picking up a pending event at random. This avoids
5704 thread starvation. */
5706 /* But not if we just stepped over a watchpoint in order to let
5707 the instruction execute so we can evaluate its expression.
5708 The set of watchpoints that triggered is recorded in the
5709 breakpoint objects themselves (see bp->watchpoint_triggered).
5710 If we processed another event first, that other event could
5711 clobber this info. */
5712 if (ecs
->event_thread
->stepping_over_watchpoint
)
5715 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5717 if (pending
!= NULL
)
5719 struct thread_info
*tp
= ecs
->event_thread
;
5720 struct regcache
*regcache
;
5722 infrun_debug_printf ("found resumed threads with "
5723 "pending events, saving status");
5725 gdb_assert (pending
!= tp
);
5727 /* Record the event thread's event for later. */
5728 save_waitstatus (tp
, &ecs
->ws
);
5729 /* This was cleared early, by handle_inferior_event. Set it
5730 so this pending event is considered by
5734 gdb_assert (!tp
->executing
);
5736 regcache
= get_thread_regcache (tp
);
5737 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5739 infrun_debug_printf ("saved stop_pc=%s for %s "
5740 "(currently_stepping=%d)",
5741 paddress (target_gdbarch (),
5742 tp
->suspend
.stop_pc
),
5743 target_pid_to_str (tp
->ptid
).c_str (),
5744 currently_stepping (tp
));
5746 /* This in-line step-over finished; clear this so we won't
5747 start a new one. This is what handle_signal_stop would
5748 do, if we returned false. */
5749 tp
->stepping_over_breakpoint
= 0;
5751 /* Wake up the event loop again. */
5752 mark_async_event_handler (infrun_async_inferior_event_token
);
5754 prepare_to_wait (ecs
);
5762 /* Come here when the program has stopped with a signal. */
5765 handle_signal_stop (struct execution_control_state
*ecs
)
5767 struct frame_info
*frame
;
5768 struct gdbarch
*gdbarch
;
5769 int stopped_by_watchpoint
;
5770 enum stop_kind stop_soon
;
5773 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5775 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5777 /* Do we need to clean up the state of a thread that has
5778 completed a displaced single-step? (Doing so usually affects
5779 the PC, so do it here, before we set stop_pc.) */
5780 if (finish_step_over (ecs
))
5783 /* If we either finished a single-step or hit a breakpoint, but
5784 the user wanted this thread to be stopped, pretend we got a
5785 SIG0 (generic unsignaled stop). */
5786 if (ecs
->event_thread
->stop_requested
5787 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5788 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5790 ecs
->event_thread
->suspend
.stop_pc
5791 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5795 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5796 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5798 switch_to_thread (ecs
->event_thread
);
5800 infrun_debug_printf ("stop_pc=%s",
5801 paddress (reg_gdbarch
,
5802 ecs
->event_thread
->suspend
.stop_pc
));
5803 if (target_stopped_by_watchpoint ())
5807 infrun_debug_printf ("stopped by watchpoint");
5809 if (target_stopped_data_address (current_top_target (), &addr
))
5810 infrun_debug_printf ("stopped data address=%s",
5811 paddress (reg_gdbarch
, addr
));
5813 infrun_debug_printf ("(no data address available)");
5817 /* This is originated from start_remote(), start_inferior() and
5818 shared libraries hook functions. */
5819 stop_soon
= get_inferior_stop_soon (ecs
);
5820 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5822 context_switch (ecs
);
5823 infrun_debug_printf ("quietly stopped");
5824 stop_print_frame
= true;
5829 /* This originates from attach_command(). We need to overwrite
5830 the stop_signal here, because some kernels don't ignore a
5831 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5832 See more comments in inferior.h. On the other hand, if we
5833 get a non-SIGSTOP, report it to the user - assume the backend
5834 will handle the SIGSTOP if it should show up later.
5836 Also consider that the attach is complete when we see a
5837 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5838 target extended-remote report it instead of a SIGSTOP
5839 (e.g. gdbserver). We already rely on SIGTRAP being our
5840 signal, so this is no exception.
5842 Also consider that the attach is complete when we see a
5843 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5844 the target to stop all threads of the inferior, in case the
5845 low level attach operation doesn't stop them implicitly. If
5846 they weren't stopped implicitly, then the stub will report a
5847 GDB_SIGNAL_0, meaning: stopped for no particular reason
5848 other than GDB's request. */
5849 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5850 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5851 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5852 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5854 stop_print_frame
= true;
5856 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5860 /* See if something interesting happened to the non-current thread. If
5861 so, then switch to that thread. */
5862 if (ecs
->ptid
!= inferior_ptid
)
5864 infrun_debug_printf ("context switch");
5866 context_switch (ecs
);
5868 if (deprecated_context_hook
)
5869 deprecated_context_hook (ecs
->event_thread
->global_num
);
5872 /* At this point, get hold of the now-current thread's frame. */
5873 frame
= get_current_frame ();
5874 gdbarch
= get_frame_arch (frame
);
5876 /* Pull the single step breakpoints out of the target. */
5877 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5879 struct regcache
*regcache
;
5882 regcache
= get_thread_regcache (ecs
->event_thread
);
5883 const address_space
*aspace
= regcache
->aspace ();
5885 pc
= regcache_read_pc (regcache
);
5887 /* However, before doing so, if this single-step breakpoint was
5888 actually for another thread, set this thread up for moving
5890 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5893 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5895 infrun_debug_printf ("[%s] hit another thread's single-step "
5897 target_pid_to_str (ecs
->ptid
).c_str ());
5898 ecs
->hit_singlestep_breakpoint
= 1;
5903 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5904 target_pid_to_str (ecs
->ptid
).c_str ());
5907 delete_just_stopped_threads_single_step_breakpoints ();
5909 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5910 && ecs
->event_thread
->control
.trap_expected
5911 && ecs
->event_thread
->stepping_over_watchpoint
)
5912 stopped_by_watchpoint
= 0;
5914 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5916 /* If necessary, step over this watchpoint. We'll be back to display
5918 if (stopped_by_watchpoint
5919 && (target_have_steppable_watchpoint ()
5920 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5922 /* At this point, we are stopped at an instruction which has
5923 attempted to write to a piece of memory under control of
5924 a watchpoint. The instruction hasn't actually executed
5925 yet. If we were to evaluate the watchpoint expression
5926 now, we would get the old value, and therefore no change
5927 would seem to have occurred.
5929 In order to make watchpoints work `right', we really need
5930 to complete the memory write, and then evaluate the
5931 watchpoint expression. We do this by single-stepping the
5934 It may not be necessary to disable the watchpoint to step over
5935 it. For example, the PA can (with some kernel cooperation)
5936 single step over a watchpoint without disabling the watchpoint.
5938 It is far more common to need to disable a watchpoint to step
5939 the inferior over it. If we have non-steppable watchpoints,
5940 we must disable the current watchpoint; it's simplest to
5941 disable all watchpoints.
5943 Any breakpoint at PC must also be stepped over -- if there's
5944 one, it will have already triggered before the watchpoint
5945 triggered, and we either already reported it to the user, or
5946 it didn't cause a stop and we called keep_going. In either
5947 case, if there was a breakpoint at PC, we must be trying to
5949 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5954 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5955 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5956 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5957 ecs
->event_thread
->control
.stop_step
= 0;
5958 stop_print_frame
= true;
5959 stopped_by_random_signal
= 0;
5960 bpstat stop_chain
= NULL
;
5962 /* Hide inlined functions starting here, unless we just performed stepi or
5963 nexti. After stepi and nexti, always show the innermost frame (not any
5964 inline function call sites). */
5965 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5967 const address_space
*aspace
5968 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5970 /* skip_inline_frames is expensive, so we avoid it if we can
5971 determine that the address is one where functions cannot have
5972 been inlined. This improves performance with inferiors that
5973 load a lot of shared libraries, because the solib event
5974 breakpoint is defined as the address of a function (i.e. not
5975 inline). Note that we have to check the previous PC as well
5976 as the current one to catch cases when we have just
5977 single-stepped off a breakpoint prior to reinstating it.
5978 Note that we're assuming that the code we single-step to is
5979 not inline, but that's not definitive: there's nothing
5980 preventing the event breakpoint function from containing
5981 inlined code, and the single-step ending up there. If the
5982 user had set a breakpoint on that inlined code, the missing
5983 skip_inline_frames call would break things. Fortunately
5984 that's an extremely unlikely scenario. */
5985 if (!pc_at_non_inline_function (aspace
,
5986 ecs
->event_thread
->suspend
.stop_pc
,
5988 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5989 && ecs
->event_thread
->control
.trap_expected
5990 && pc_at_non_inline_function (aspace
,
5991 ecs
->event_thread
->prev_pc
,
5994 stop_chain
= build_bpstat_chain (aspace
,
5995 ecs
->event_thread
->suspend
.stop_pc
,
5997 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5999 /* Re-fetch current thread's frame in case that invalidated
6001 frame
= get_current_frame ();
6002 gdbarch
= get_frame_arch (frame
);
6006 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6007 && ecs
->event_thread
->control
.trap_expected
6008 && gdbarch_single_step_through_delay_p (gdbarch
)
6009 && currently_stepping (ecs
->event_thread
))
6011 /* We're trying to step off a breakpoint. Turns out that we're
6012 also on an instruction that needs to be stepped multiple
6013 times before it's been fully executing. E.g., architectures
6014 with a delay slot. It needs to be stepped twice, once for
6015 the instruction and once for the delay slot. */
6016 int step_through_delay
6017 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6019 if (step_through_delay
)
6020 infrun_debug_printf ("step through delay");
6022 if (ecs
->event_thread
->control
.step_range_end
== 0
6023 && step_through_delay
)
6025 /* The user issued a continue when stopped at a breakpoint.
6026 Set up for another trap and get out of here. */
6027 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6031 else if (step_through_delay
)
6033 /* The user issued a step when stopped at a breakpoint.
6034 Maybe we should stop, maybe we should not - the delay
6035 slot *might* correspond to a line of source. In any
6036 case, don't decide that here, just set
6037 ecs->stepping_over_breakpoint, making sure we
6038 single-step again before breakpoints are re-inserted. */
6039 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6043 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6044 handles this event. */
6045 ecs
->event_thread
->control
.stop_bpstat
6046 = bpstat_stop_status (get_current_regcache ()->aspace (),
6047 ecs
->event_thread
->suspend
.stop_pc
,
6048 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6050 /* Following in case break condition called a
6052 stop_print_frame
= true;
6054 /* This is where we handle "moribund" watchpoints. Unlike
6055 software breakpoints traps, hardware watchpoint traps are
6056 always distinguishable from random traps. If no high-level
6057 watchpoint is associated with the reported stop data address
6058 anymore, then the bpstat does not explain the signal ---
6059 simply make sure to ignore it if `stopped_by_watchpoint' is
6062 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6063 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6065 && stopped_by_watchpoint
)
6067 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6071 /* NOTE: cagney/2003-03-29: These checks for a random signal
6072 at one stage in the past included checks for an inferior
6073 function call's call dummy's return breakpoint. The original
6074 comment, that went with the test, read:
6076 ``End of a stack dummy. Some systems (e.g. Sony news) give
6077 another signal besides SIGTRAP, so check here as well as
6080 If someone ever tries to get call dummys on a
6081 non-executable stack to work (where the target would stop
6082 with something like a SIGSEGV), then those tests might need
6083 to be re-instated. Given, however, that the tests were only
6084 enabled when momentary breakpoints were not being used, I
6085 suspect that it won't be the case.
6087 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6088 be necessary for call dummies on a non-executable stack on
6091 /* See if the breakpoints module can explain the signal. */
6093 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6094 ecs
->event_thread
->suspend
.stop_signal
);
6096 /* Maybe this was a trap for a software breakpoint that has since
6098 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6100 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6101 ecs
->event_thread
->suspend
.stop_pc
))
6103 struct regcache
*regcache
;
6106 /* Re-adjust PC to what the program would see if GDB was not
6108 regcache
= get_thread_regcache (ecs
->event_thread
);
6109 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6112 gdb::optional
<scoped_restore_tmpl
<int>>
6113 restore_operation_disable
;
6115 if (record_full_is_used ())
6116 restore_operation_disable
.emplace
6117 (record_full_gdb_operation_disable_set ());
6119 regcache_write_pc (regcache
,
6120 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6125 /* A delayed software breakpoint event. Ignore the trap. */
6126 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6131 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6132 has since been removed. */
6133 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6135 /* A delayed hardware breakpoint event. Ignore the trap. */
6136 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6141 /* If not, perhaps stepping/nexting can. */
6143 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6144 && currently_stepping (ecs
->event_thread
));
6146 /* Perhaps the thread hit a single-step breakpoint of _another_
6147 thread. Single-step breakpoints are transparent to the
6148 breakpoints module. */
6150 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6152 /* No? Perhaps we got a moribund watchpoint. */
6154 random_signal
= !stopped_by_watchpoint
;
6156 /* Always stop if the user explicitly requested this thread to
6158 if (ecs
->event_thread
->stop_requested
)
6161 infrun_debug_printf ("user-requested stop");
6164 /* For the program's own signals, act according to
6165 the signal handling tables. */
6169 /* Signal not for debugging purposes. */
6170 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6171 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6173 infrun_debug_printf ("random signal (%s)",
6174 gdb_signal_to_symbol_string (stop_signal
));
6176 stopped_by_random_signal
= 1;
6178 /* Always stop on signals if we're either just gaining control
6179 of the program, or the user explicitly requested this thread
6180 to remain stopped. */
6181 if (stop_soon
!= NO_STOP_QUIETLY
6182 || ecs
->event_thread
->stop_requested
6184 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6190 /* Notify observers the signal has "handle print" set. Note we
6191 returned early above if stopping; normal_stop handles the
6192 printing in that case. */
6193 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6195 /* The signal table tells us to print about this signal. */
6196 target_terminal::ours_for_output ();
6197 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6198 target_terminal::inferior ();
6201 /* Clear the signal if it should not be passed. */
6202 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6203 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6205 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6206 && ecs
->event_thread
->control
.trap_expected
6207 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6209 /* We were just starting a new sequence, attempting to
6210 single-step off of a breakpoint and expecting a SIGTRAP.
6211 Instead this signal arrives. This signal will take us out
6212 of the stepping range so GDB needs to remember to, when
6213 the signal handler returns, resume stepping off that
6215 /* To simplify things, "continue" is forced to use the same
6216 code paths as single-step - set a breakpoint at the
6217 signal return address and then, once hit, step off that
6219 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6221 insert_hp_step_resume_breakpoint_at_frame (frame
);
6222 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6223 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6224 ecs
->event_thread
->control
.trap_expected
= 0;
6226 /* If we were nexting/stepping some other thread, switch to
6227 it, so that we don't continue it, losing control. */
6228 if (!switch_back_to_stepped_thread (ecs
))
6233 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6234 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6236 || ecs
->event_thread
->control
.step_range_end
== 1)
6237 && frame_id_eq (get_stack_frame_id (frame
),
6238 ecs
->event_thread
->control
.step_stack_frame_id
)
6239 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6241 /* The inferior is about to take a signal that will take it
6242 out of the single step range. Set a breakpoint at the
6243 current PC (which is presumably where the signal handler
6244 will eventually return) and then allow the inferior to
6247 Note that this is only needed for a signal delivered
6248 while in the single-step range. Nested signals aren't a
6249 problem as they eventually all return. */
6250 infrun_debug_printf ("signal may take us out of single-step range");
6252 clear_step_over_info ();
6253 insert_hp_step_resume_breakpoint_at_frame (frame
);
6254 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6255 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6256 ecs
->event_thread
->control
.trap_expected
= 0;
6261 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6262 when either there's a nested signal, or when there's a
6263 pending signal enabled just as the signal handler returns
6264 (leaving the inferior at the step-resume-breakpoint without
6265 actually executing it). Either way continue until the
6266 breakpoint is really hit. */
6268 if (!switch_back_to_stepped_thread (ecs
))
6270 infrun_debug_printf ("random signal, keep going");
6277 process_event_stop_test (ecs
);
6280 /* Come here when we've got some debug event / signal we can explain
6281 (IOW, not a random signal), and test whether it should cause a
6282 stop, or whether we should resume the inferior (transparently).
6283 E.g., could be a breakpoint whose condition evaluates false; we
6284 could be still stepping within the line; etc. */
6287 process_event_stop_test (struct execution_control_state
*ecs
)
6289 struct symtab_and_line stop_pc_sal
;
6290 struct frame_info
*frame
;
6291 struct gdbarch
*gdbarch
;
6292 CORE_ADDR jmp_buf_pc
;
6293 struct bpstat_what what
;
6295 /* Handle cases caused by hitting a breakpoint. */
6297 frame
= get_current_frame ();
6298 gdbarch
= get_frame_arch (frame
);
6300 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6302 if (what
.call_dummy
)
6304 stop_stack_dummy
= what
.call_dummy
;
6307 /* A few breakpoint types have callbacks associated (e.g.,
6308 bp_jit_event). Run them now. */
6309 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6311 /* If we hit an internal event that triggers symbol changes, the
6312 current frame will be invalidated within bpstat_what (e.g., if we
6313 hit an internal solib event). Re-fetch it. */
6314 frame
= get_current_frame ();
6315 gdbarch
= get_frame_arch (frame
);
6317 switch (what
.main_action
)
6319 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6320 /* If we hit the breakpoint at longjmp while stepping, we
6321 install a momentary breakpoint at the target of the
6324 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6326 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6328 if (what
.is_longjmp
)
6330 struct value
*arg_value
;
6332 /* If we set the longjmp breakpoint via a SystemTap probe,
6333 then use it to extract the arguments. The destination PC
6334 is the third argument to the probe. */
6335 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6338 jmp_buf_pc
= value_as_address (arg_value
);
6339 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6341 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6342 || !gdbarch_get_longjmp_target (gdbarch
,
6343 frame
, &jmp_buf_pc
))
6345 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6346 "(!gdbarch_get_longjmp_target)");
6351 /* Insert a breakpoint at resume address. */
6352 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6355 check_exception_resume (ecs
, frame
);
6359 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6361 struct frame_info
*init_frame
;
6363 /* There are several cases to consider.
6365 1. The initiating frame no longer exists. In this case we
6366 must stop, because the exception or longjmp has gone too
6369 2. The initiating frame exists, and is the same as the
6370 current frame. We stop, because the exception or longjmp
6373 3. The initiating frame exists and is different from the
6374 current frame. This means the exception or longjmp has
6375 been caught beneath the initiating frame, so keep going.
6377 4. longjmp breakpoint has been placed just to protect
6378 against stale dummy frames and user is not interested in
6379 stopping around longjmps. */
6381 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6383 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6385 delete_exception_resume_breakpoint (ecs
->event_thread
);
6387 if (what
.is_longjmp
)
6389 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6391 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6399 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6403 struct frame_id current_id
6404 = get_frame_id (get_current_frame ());
6405 if (frame_id_eq (current_id
,
6406 ecs
->event_thread
->initiating_frame
))
6408 /* Case 2. Fall through. */
6418 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6420 delete_step_resume_breakpoint (ecs
->event_thread
);
6422 end_stepping_range (ecs
);
6426 case BPSTAT_WHAT_SINGLE
:
6427 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6428 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6429 /* Still need to check other stuff, at least the case where we
6430 are stepping and step out of the right range. */
6433 case BPSTAT_WHAT_STEP_RESUME
:
6434 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6436 delete_step_resume_breakpoint (ecs
->event_thread
);
6437 if (ecs
->event_thread
->control
.proceed_to_finish
6438 && execution_direction
== EXEC_REVERSE
)
6440 struct thread_info
*tp
= ecs
->event_thread
;
6442 /* We are finishing a function in reverse, and just hit the
6443 step-resume breakpoint at the start address of the
6444 function, and we're almost there -- just need to back up
6445 by one more single-step, which should take us back to the
6447 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6451 fill_in_stop_func (gdbarch
, ecs
);
6452 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6453 && execution_direction
== EXEC_REVERSE
)
6455 /* We are stepping over a function call in reverse, and just
6456 hit the step-resume breakpoint at the start address of
6457 the function. Go back to single-stepping, which should
6458 take us back to the function call. */
6459 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6465 case BPSTAT_WHAT_STOP_NOISY
:
6466 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6467 stop_print_frame
= true;
6469 /* Assume the thread stopped for a breakpoint. We'll still check
6470 whether a/the breakpoint is there when the thread is next
6472 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6477 case BPSTAT_WHAT_STOP_SILENT
:
6478 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6479 stop_print_frame
= false;
6481 /* Assume the thread stopped for a breakpoint. We'll still check
6482 whether a/the breakpoint is there when the thread is next
6484 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6488 case BPSTAT_WHAT_HP_STEP_RESUME
:
6489 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6491 delete_step_resume_breakpoint (ecs
->event_thread
);
6492 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6494 /* Back when the step-resume breakpoint was inserted, we
6495 were trying to single-step off a breakpoint. Go back to
6497 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6498 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6504 case BPSTAT_WHAT_KEEP_CHECKING
:
6508 /* If we stepped a permanent breakpoint and we had a high priority
6509 step-resume breakpoint for the address we stepped, but we didn't
6510 hit it, then we must have stepped into the signal handler. The
6511 step-resume was only necessary to catch the case of _not_
6512 stepping into the handler, so delete it, and fall through to
6513 checking whether the step finished. */
6514 if (ecs
->event_thread
->stepped_breakpoint
)
6516 struct breakpoint
*sr_bp
6517 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6520 && sr_bp
->loc
->permanent
6521 && sr_bp
->type
== bp_hp_step_resume
6522 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6524 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6525 delete_step_resume_breakpoint (ecs
->event_thread
);
6526 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6530 /* We come here if we hit a breakpoint but should not stop for it.
6531 Possibly we also were stepping and should stop for that. So fall
6532 through and test for stepping. But, if not stepping, do not
6535 /* In all-stop mode, if we're currently stepping but have stopped in
6536 some other thread, we need to switch back to the stepped thread. */
6537 if (switch_back_to_stepped_thread (ecs
))
6540 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6542 infrun_debug_printf ("step-resume breakpoint is inserted");
6544 /* Having a step-resume breakpoint overrides anything
6545 else having to do with stepping commands until
6546 that breakpoint is reached. */
6551 if (ecs
->event_thread
->control
.step_range_end
== 0)
6553 infrun_debug_printf ("no stepping, continue");
6554 /* Likewise if we aren't even stepping. */
6559 /* Re-fetch current thread's frame in case the code above caused
6560 the frame cache to be re-initialized, making our FRAME variable
6561 a dangling pointer. */
6562 frame
= get_current_frame ();
6563 gdbarch
= get_frame_arch (frame
);
6564 fill_in_stop_func (gdbarch
, ecs
);
6566 /* If stepping through a line, keep going if still within it.
6568 Note that step_range_end is the address of the first instruction
6569 beyond the step range, and NOT the address of the last instruction
6572 Note also that during reverse execution, we may be stepping
6573 through a function epilogue and therefore must detect when
6574 the current-frame changes in the middle of a line. */
6576 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6578 && (execution_direction
!= EXEC_REVERSE
6579 || frame_id_eq (get_frame_id (frame
),
6580 ecs
->event_thread
->control
.step_frame_id
)))
6583 ("stepping inside range [%s-%s]",
6584 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6585 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6587 /* Tentatively re-enable range stepping; `resume' disables it if
6588 necessary (e.g., if we're stepping over a breakpoint or we
6589 have software watchpoints). */
6590 ecs
->event_thread
->control
.may_range_step
= 1;
6592 /* When stepping backward, stop at beginning of line range
6593 (unless it's the function entry point, in which case
6594 keep going back to the call point). */
6595 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6596 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6597 && stop_pc
!= ecs
->stop_func_start
6598 && execution_direction
== EXEC_REVERSE
)
6599 end_stepping_range (ecs
);
6606 /* We stepped out of the stepping range. */
6608 /* If we are stepping at the source level and entered the runtime
6609 loader dynamic symbol resolution code...
6611 EXEC_FORWARD: we keep on single stepping until we exit the run
6612 time loader code and reach the callee's address.
6614 EXEC_REVERSE: we've already executed the callee (backward), and
6615 the runtime loader code is handled just like any other
6616 undebuggable function call. Now we need only keep stepping
6617 backward through the trampoline code, and that's handled further
6618 down, so there is nothing for us to do here. */
6620 if (execution_direction
!= EXEC_REVERSE
6621 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6622 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6624 CORE_ADDR pc_after_resolver
=
6625 gdbarch_skip_solib_resolver (gdbarch
,
6626 ecs
->event_thread
->suspend
.stop_pc
);
6628 infrun_debug_printf ("stepped into dynsym resolve code");
6630 if (pc_after_resolver
)
6632 /* Set up a step-resume breakpoint at the address
6633 indicated by SKIP_SOLIB_RESOLVER. */
6634 symtab_and_line sr_sal
;
6635 sr_sal
.pc
= pc_after_resolver
;
6636 sr_sal
.pspace
= get_frame_program_space (frame
);
6638 insert_step_resume_breakpoint_at_sal (gdbarch
,
6639 sr_sal
, null_frame_id
);
6646 /* Step through an indirect branch thunk. */
6647 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6648 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6649 ecs
->event_thread
->suspend
.stop_pc
))
6651 infrun_debug_printf ("stepped into indirect branch thunk");
6656 if (ecs
->event_thread
->control
.step_range_end
!= 1
6657 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6658 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6659 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6661 infrun_debug_printf ("stepped into signal trampoline");
6662 /* The inferior, while doing a "step" or "next", has ended up in
6663 a signal trampoline (either by a signal being delivered or by
6664 the signal handler returning). Just single-step until the
6665 inferior leaves the trampoline (either by calling the handler
6671 /* If we're in the return path from a shared library trampoline,
6672 we want to proceed through the trampoline when stepping. */
6673 /* macro/2012-04-25: This needs to come before the subroutine
6674 call check below as on some targets return trampolines look
6675 like subroutine calls (MIPS16 return thunks). */
6676 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6677 ecs
->event_thread
->suspend
.stop_pc
,
6678 ecs
->stop_func_name
)
6679 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6681 /* Determine where this trampoline returns. */
6682 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6683 CORE_ADDR real_stop_pc
6684 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6686 infrun_debug_printf ("stepped into solib return tramp");
6688 /* Only proceed through if we know where it's going. */
6691 /* And put the step-breakpoint there and go until there. */
6692 symtab_and_line sr_sal
;
6693 sr_sal
.pc
= real_stop_pc
;
6694 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6695 sr_sal
.pspace
= get_frame_program_space (frame
);
6697 /* Do not specify what the fp should be when we stop since
6698 on some machines the prologue is where the new fp value
6700 insert_step_resume_breakpoint_at_sal (gdbarch
,
6701 sr_sal
, null_frame_id
);
6703 /* Restart without fiddling with the step ranges or
6710 /* Check for subroutine calls. The check for the current frame
6711 equalling the step ID is not necessary - the check of the
6712 previous frame's ID is sufficient - but it is a common case and
6713 cheaper than checking the previous frame's ID.
6715 NOTE: frame_id_eq will never report two invalid frame IDs as
6716 being equal, so to get into this block, both the current and
6717 previous frame must have valid frame IDs. */
6718 /* The outer_frame_id check is a heuristic to detect stepping
6719 through startup code. If we step over an instruction which
6720 sets the stack pointer from an invalid value to a valid value,
6721 we may detect that as a subroutine call from the mythical
6722 "outermost" function. This could be fixed by marking
6723 outermost frames as !stack_p,code_p,special_p. Then the
6724 initial outermost frame, before sp was valid, would
6725 have code_addr == &_start. See the comment in frame_id_eq
6727 if (!frame_id_eq (get_stack_frame_id (frame
),
6728 ecs
->event_thread
->control
.step_stack_frame_id
)
6729 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6730 ecs
->event_thread
->control
.step_stack_frame_id
)
6731 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6733 || (ecs
->event_thread
->control
.step_start_function
6734 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6736 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6737 CORE_ADDR real_stop_pc
;
6739 infrun_debug_printf ("stepped into subroutine");
6741 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6743 /* I presume that step_over_calls is only 0 when we're
6744 supposed to be stepping at the assembly language level
6745 ("stepi"). Just stop. */
6746 /* And this works the same backward as frontward. MVS */
6747 end_stepping_range (ecs
);
6751 /* Reverse stepping through solib trampolines. */
6753 if (execution_direction
== EXEC_REVERSE
6754 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6755 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6756 || (ecs
->stop_func_start
== 0
6757 && in_solib_dynsym_resolve_code (stop_pc
))))
6759 /* Any solib trampoline code can be handled in reverse
6760 by simply continuing to single-step. We have already
6761 executed the solib function (backwards), and a few
6762 steps will take us back through the trampoline to the
6768 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6770 /* We're doing a "next".
6772 Normal (forward) execution: set a breakpoint at the
6773 callee's return address (the address at which the caller
6776 Reverse (backward) execution. set the step-resume
6777 breakpoint at the start of the function that we just
6778 stepped into (backwards), and continue to there. When we
6779 get there, we'll need to single-step back to the caller. */
6781 if (execution_direction
== EXEC_REVERSE
)
6783 /* If we're already at the start of the function, we've either
6784 just stepped backward into a single instruction function,
6785 or stepped back out of a signal handler to the first instruction
6786 of the function. Just keep going, which will single-step back
6788 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6790 /* Normal function call return (static or dynamic). */
6791 symtab_and_line sr_sal
;
6792 sr_sal
.pc
= ecs
->stop_func_start
;
6793 sr_sal
.pspace
= get_frame_program_space (frame
);
6794 insert_step_resume_breakpoint_at_sal (gdbarch
,
6795 sr_sal
, null_frame_id
);
6799 insert_step_resume_breakpoint_at_caller (frame
);
6805 /* If we are in a function call trampoline (a stub between the
6806 calling routine and the real function), locate the real
6807 function. That's what tells us (a) whether we want to step
6808 into it at all, and (b) what prologue we want to run to the
6809 end of, if we do step into it. */
6810 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6811 if (real_stop_pc
== 0)
6812 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6813 if (real_stop_pc
!= 0)
6814 ecs
->stop_func_start
= real_stop_pc
;
6816 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6818 symtab_and_line sr_sal
;
6819 sr_sal
.pc
= ecs
->stop_func_start
;
6820 sr_sal
.pspace
= get_frame_program_space (frame
);
6822 insert_step_resume_breakpoint_at_sal (gdbarch
,
6823 sr_sal
, null_frame_id
);
6828 /* If we have line number information for the function we are
6829 thinking of stepping into and the function isn't on the skip
6832 If there are several symtabs at that PC (e.g. with include
6833 files), just want to know whether *any* of them have line
6834 numbers. find_pc_line handles this. */
6836 struct symtab_and_line tmp_sal
;
6838 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6839 if (tmp_sal
.line
!= 0
6840 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6842 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6844 if (execution_direction
== EXEC_REVERSE
)
6845 handle_step_into_function_backward (gdbarch
, ecs
);
6847 handle_step_into_function (gdbarch
, ecs
);
6852 /* If we have no line number and the step-stop-if-no-debug is
6853 set, we stop the step so that the user has a chance to switch
6854 in assembly mode. */
6855 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6856 && step_stop_if_no_debug
)
6858 end_stepping_range (ecs
);
6862 if (execution_direction
== EXEC_REVERSE
)
6864 /* If we're already at the start of the function, we've either just
6865 stepped backward into a single instruction function without line
6866 number info, or stepped back out of a signal handler to the first
6867 instruction of the function without line number info. Just keep
6868 going, which will single-step back to the caller. */
6869 if (ecs
->stop_func_start
!= stop_pc
)
6871 /* Set a breakpoint at callee's start address.
6872 From there we can step once and be back in the caller. */
6873 symtab_and_line sr_sal
;
6874 sr_sal
.pc
= ecs
->stop_func_start
;
6875 sr_sal
.pspace
= get_frame_program_space (frame
);
6876 insert_step_resume_breakpoint_at_sal (gdbarch
,
6877 sr_sal
, null_frame_id
);
6881 /* Set a breakpoint at callee's return address (the address
6882 at which the caller will resume). */
6883 insert_step_resume_breakpoint_at_caller (frame
);
6889 /* Reverse stepping through solib trampolines. */
6891 if (execution_direction
== EXEC_REVERSE
6892 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6894 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6896 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6897 || (ecs
->stop_func_start
== 0
6898 && in_solib_dynsym_resolve_code (stop_pc
)))
6900 /* Any solib trampoline code can be handled in reverse
6901 by simply continuing to single-step. We have already
6902 executed the solib function (backwards), and a few
6903 steps will take us back through the trampoline to the
6908 else if (in_solib_dynsym_resolve_code (stop_pc
))
6910 /* Stepped backward into the solib dynsym resolver.
6911 Set a breakpoint at its start and continue, then
6912 one more step will take us out. */
6913 symtab_and_line sr_sal
;
6914 sr_sal
.pc
= ecs
->stop_func_start
;
6915 sr_sal
.pspace
= get_frame_program_space (frame
);
6916 insert_step_resume_breakpoint_at_sal (gdbarch
,
6917 sr_sal
, null_frame_id
);
6923 /* This always returns the sal for the inner-most frame when we are in a
6924 stack of inlined frames, even if GDB actually believes that it is in a
6925 more outer frame. This is checked for below by calls to
6926 inline_skipped_frames. */
6927 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6929 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6930 the trampoline processing logic, however, there are some trampolines
6931 that have no names, so we should do trampoline handling first. */
6932 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6933 && ecs
->stop_func_name
== NULL
6934 && stop_pc_sal
.line
== 0)
6936 infrun_debug_printf ("stepped into undebuggable function");
6938 /* The inferior just stepped into, or returned to, an
6939 undebuggable function (where there is no debugging information
6940 and no line number corresponding to the address where the
6941 inferior stopped). Since we want to skip this kind of code,
6942 we keep going until the inferior returns from this
6943 function - unless the user has asked us not to (via
6944 set step-mode) or we no longer know how to get back
6945 to the call site. */
6946 if (step_stop_if_no_debug
6947 || !frame_id_p (frame_unwind_caller_id (frame
)))
6949 /* If we have no line number and the step-stop-if-no-debug
6950 is set, we stop the step so that the user has a chance to
6951 switch in assembly mode. */
6952 end_stepping_range (ecs
);
6957 /* Set a breakpoint at callee's return address (the address
6958 at which the caller will resume). */
6959 insert_step_resume_breakpoint_at_caller (frame
);
6965 if (ecs
->event_thread
->control
.step_range_end
== 1)
6967 /* It is stepi or nexti. We always want to stop stepping after
6969 infrun_debug_printf ("stepi/nexti");
6970 end_stepping_range (ecs
);
6974 if (stop_pc_sal
.line
== 0)
6976 /* We have no line number information. That means to stop
6977 stepping (does this always happen right after one instruction,
6978 when we do "s" in a function with no line numbers,
6979 or can this happen as a result of a return or longjmp?). */
6980 infrun_debug_printf ("line number info");
6981 end_stepping_range (ecs
);
6985 /* Look for "calls" to inlined functions, part one. If the inline
6986 frame machinery detected some skipped call sites, we have entered
6987 a new inline function. */
6989 if (frame_id_eq (get_frame_id (get_current_frame ()),
6990 ecs
->event_thread
->control
.step_frame_id
)
6991 && inline_skipped_frames (ecs
->event_thread
))
6993 infrun_debug_printf ("stepped into inlined function");
6995 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6997 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6999 /* For "step", we're going to stop. But if the call site
7000 for this inlined function is on the same source line as
7001 we were previously stepping, go down into the function
7002 first. Otherwise stop at the call site. */
7004 if (call_sal
.line
== ecs
->event_thread
->current_line
7005 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7007 step_into_inline_frame (ecs
->event_thread
);
7008 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7015 end_stepping_range (ecs
);
7020 /* For "next", we should stop at the call site if it is on a
7021 different source line. Otherwise continue through the
7022 inlined function. */
7023 if (call_sal
.line
== ecs
->event_thread
->current_line
7024 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7027 end_stepping_range (ecs
);
7032 /* Look for "calls" to inlined functions, part two. If we are still
7033 in the same real function we were stepping through, but we have
7034 to go further up to find the exact frame ID, we are stepping
7035 through a more inlined call beyond its call site. */
7037 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7038 && !frame_id_eq (get_frame_id (get_current_frame ()),
7039 ecs
->event_thread
->control
.step_frame_id
)
7040 && stepped_in_from (get_current_frame (),
7041 ecs
->event_thread
->control
.step_frame_id
))
7043 infrun_debug_printf ("stepping through inlined function");
7045 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7046 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7049 end_stepping_range (ecs
);
7053 bool refresh_step_info
= true;
7054 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7055 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7056 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7058 if (stop_pc_sal
.is_stmt
)
7060 /* We are at the start of a different line. So stop. Note that
7061 we don't stop if we step into the middle of a different line.
7062 That is said to make things like for (;;) statements work
7064 infrun_debug_printf ("stepped to a different line");
7065 end_stepping_range (ecs
);
7068 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7069 ecs
->event_thread
->control
.step_frame_id
))
7071 /* We are at the start of a different line, however, this line is
7072 not marked as a statement, and we have not changed frame. We
7073 ignore this line table entry, and continue stepping forward,
7074 looking for a better place to stop. */
7075 refresh_step_info
= false;
7076 infrun_debug_printf ("stepped to a different line, but "
7077 "it's not the start of a statement");
7081 /* We aren't done stepping.
7083 Optimize by setting the stepping range to the line.
7084 (We might not be in the original line, but if we entered a
7085 new line in mid-statement, we continue stepping. This makes
7086 things like for(;;) statements work better.)
7088 If we entered a SAL that indicates a non-statement line table entry,
7089 then we update the stepping range, but we don't update the step info,
7090 which includes things like the line number we are stepping away from.
7091 This means we will stop when we find a line table entry that is marked
7092 as is-statement, even if it matches the non-statement one we just
7095 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7096 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7097 ecs
->event_thread
->control
.may_range_step
= 1;
7098 if (refresh_step_info
)
7099 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7101 infrun_debug_printf ("keep going");
7105 /* In all-stop mode, if we're currently stepping but have stopped in
7106 some other thread, we may need to switch back to the stepped
7107 thread. Returns true we set the inferior running, false if we left
7108 it stopped (and the event needs further processing). */
7111 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7113 if (!target_is_non_stop_p ())
7115 struct thread_info
*stepping_thread
;
7117 /* If any thread is blocked on some internal breakpoint, and we
7118 simply need to step over that breakpoint to get it going
7119 again, do that first. */
7121 /* However, if we see an event for the stepping thread, then we
7122 know all other threads have been moved past their breakpoints
7123 already. Let the caller check whether the step is finished,
7124 etc., before deciding to move it past a breakpoint. */
7125 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7128 /* Check if the current thread is blocked on an incomplete
7129 step-over, interrupted by a random signal. */
7130 if (ecs
->event_thread
->control
.trap_expected
7131 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7134 ("need to finish step-over of [%s]",
7135 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7140 /* Check if the current thread is blocked by a single-step
7141 breakpoint of another thread. */
7142 if (ecs
->hit_singlestep_breakpoint
)
7144 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7145 target_pid_to_str (ecs
->ptid
).c_str ());
7150 /* If this thread needs yet another step-over (e.g., stepping
7151 through a delay slot), do it first before moving on to
7153 if (thread_still_needs_step_over (ecs
->event_thread
))
7156 ("thread [%s] still needs step-over",
7157 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7162 /* If scheduler locking applies even if not stepping, there's no
7163 need to walk over threads. Above we've checked whether the
7164 current thread is stepping. If some other thread not the
7165 event thread is stepping, then it must be that scheduler
7166 locking is not in effect. */
7167 if (schedlock_applies (ecs
->event_thread
))
7170 /* Otherwise, we no longer expect a trap in the current thread.
7171 Clear the trap_expected flag before switching back -- this is
7172 what keep_going does as well, if we call it. */
7173 ecs
->event_thread
->control
.trap_expected
= 0;
7175 /* Likewise, clear the signal if it should not be passed. */
7176 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7177 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7179 /* Do all pending step-overs before actually proceeding with
7181 if (start_step_over ())
7183 prepare_to_wait (ecs
);
7187 /* Look for the stepping/nexting thread. */
7188 stepping_thread
= NULL
;
7190 for (thread_info
*tp
: all_non_exited_threads ())
7192 switch_to_thread_no_regs (tp
);
7194 /* Ignore threads of processes the caller is not
7197 && (tp
->inf
->process_target () != ecs
->target
7198 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7201 /* When stepping over a breakpoint, we lock all threads
7202 except the one that needs to move past the breakpoint.
7203 If a non-event thread has this set, the "incomplete
7204 step-over" check above should have caught it earlier. */
7205 if (tp
->control
.trap_expected
)
7207 internal_error (__FILE__
, __LINE__
,
7208 "[%s] has inconsistent state: "
7209 "trap_expected=%d\n",
7210 target_pid_to_str (tp
->ptid
).c_str (),
7211 tp
->control
.trap_expected
);
7214 /* Did we find the stepping thread? */
7215 if (tp
->control
.step_range_end
)
7217 /* Yep. There should only one though. */
7218 gdb_assert (stepping_thread
== NULL
);
7220 /* The event thread is handled at the top, before we
7222 gdb_assert (tp
!= ecs
->event_thread
);
7224 /* If some thread other than the event thread is
7225 stepping, then scheduler locking can't be in effect,
7226 otherwise we wouldn't have resumed the current event
7227 thread in the first place. */
7228 gdb_assert (!schedlock_applies (tp
));
7230 stepping_thread
= tp
;
7234 if (stepping_thread
!= NULL
)
7236 infrun_debug_printf ("switching back to stepped thread");
7238 if (keep_going_stepped_thread (stepping_thread
))
7240 prepare_to_wait (ecs
);
7245 switch_to_thread (ecs
->event_thread
);
7251 /* Set a previously stepped thread back to stepping. Returns true on
7252 success, false if the resume is not possible (e.g., the thread
7256 keep_going_stepped_thread (struct thread_info
*tp
)
7258 struct frame_info
*frame
;
7259 struct execution_control_state ecss
;
7260 struct execution_control_state
*ecs
= &ecss
;
7262 /* If the stepping thread exited, then don't try to switch back and
7263 resume it, which could fail in several different ways depending
7264 on the target. Instead, just keep going.
7266 We can find a stepping dead thread in the thread list in two
7269 - The target supports thread exit events, and when the target
7270 tries to delete the thread from the thread list, inferior_ptid
7271 pointed at the exiting thread. In such case, calling
7272 delete_thread does not really remove the thread from the list;
7273 instead, the thread is left listed, with 'exited' state.
7275 - The target's debug interface does not support thread exit
7276 events, and so we have no idea whatsoever if the previously
7277 stepping thread is still alive. For that reason, we need to
7278 synchronously query the target now. */
7280 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7282 infrun_debug_printf ("not resuming previously stepped thread, it has "
7289 infrun_debug_printf ("resuming previously stepped thread");
7291 reset_ecs (ecs
, tp
);
7292 switch_to_thread (tp
);
7294 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7295 frame
= get_current_frame ();
7297 /* If the PC of the thread we were trying to single-step has
7298 changed, then that thread has trapped or been signaled, but the
7299 event has not been reported to GDB yet. Re-poll the target
7300 looking for this particular thread's event (i.e. temporarily
7301 enable schedlock) by:
7303 - setting a break at the current PC
7304 - resuming that particular thread, only (by setting trap
7307 This prevents us continuously moving the single-step breakpoint
7308 forward, one instruction at a time, overstepping. */
7310 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7314 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7315 paddress (target_gdbarch (), tp
->prev_pc
),
7316 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7318 /* Clear the info of the previous step-over, as it's no longer
7319 valid (if the thread was trying to step over a breakpoint, it
7320 has already succeeded). It's what keep_going would do too,
7321 if we called it. Do this before trying to insert the sss
7322 breakpoint, otherwise if we were previously trying to step
7323 over this exact address in another thread, the breakpoint is
7325 clear_step_over_info ();
7326 tp
->control
.trap_expected
= 0;
7328 insert_single_step_breakpoint (get_frame_arch (frame
),
7329 get_frame_address_space (frame
),
7330 tp
->suspend
.stop_pc
);
7333 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7334 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7338 infrun_debug_printf ("expected thread still hasn't advanced");
7340 keep_going_pass_signal (ecs
);
7346 /* Is thread TP in the middle of (software or hardware)
7347 single-stepping? (Note the result of this function must never be
7348 passed directly as target_resume's STEP parameter.) */
7351 currently_stepping (struct thread_info
*tp
)
7353 return ((tp
->control
.step_range_end
7354 && tp
->control
.step_resume_breakpoint
== NULL
)
7355 || tp
->control
.trap_expected
7356 || tp
->stepped_breakpoint
7357 || bpstat_should_step ());
7360 /* Inferior has stepped into a subroutine call with source code that
7361 we should not step over. Do step to the first line of code in
7365 handle_step_into_function (struct gdbarch
*gdbarch
,
7366 struct execution_control_state
*ecs
)
7368 fill_in_stop_func (gdbarch
, ecs
);
7370 compunit_symtab
*cust
7371 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7372 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7373 ecs
->stop_func_start
7374 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7376 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7377 /* Use the step_resume_break to step until the end of the prologue,
7378 even if that involves jumps (as it seems to on the vax under
7380 /* If the prologue ends in the middle of a source line, continue to
7381 the end of that source line (if it is still within the function).
7382 Otherwise, just go to end of prologue. */
7383 if (stop_func_sal
.end
7384 && stop_func_sal
.pc
!= ecs
->stop_func_start
7385 && stop_func_sal
.end
< ecs
->stop_func_end
)
7386 ecs
->stop_func_start
= stop_func_sal
.end
;
7388 /* Architectures which require breakpoint adjustment might not be able
7389 to place a breakpoint at the computed address. If so, the test
7390 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7391 ecs->stop_func_start to an address at which a breakpoint may be
7392 legitimately placed.
7394 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7395 made, GDB will enter an infinite loop when stepping through
7396 optimized code consisting of VLIW instructions which contain
7397 subinstructions corresponding to different source lines. On
7398 FR-V, it's not permitted to place a breakpoint on any but the
7399 first subinstruction of a VLIW instruction. When a breakpoint is
7400 set, GDB will adjust the breakpoint address to the beginning of
7401 the VLIW instruction. Thus, we need to make the corresponding
7402 adjustment here when computing the stop address. */
7404 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7406 ecs
->stop_func_start
7407 = gdbarch_adjust_breakpoint_address (gdbarch
,
7408 ecs
->stop_func_start
);
7411 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7413 /* We are already there: stop now. */
7414 end_stepping_range (ecs
);
7419 /* Put the step-breakpoint there and go until there. */
7420 symtab_and_line sr_sal
;
7421 sr_sal
.pc
= ecs
->stop_func_start
;
7422 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7423 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7425 /* Do not specify what the fp should be when we stop since on
7426 some machines the prologue is where the new fp value is
7428 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7430 /* And make sure stepping stops right away then. */
7431 ecs
->event_thread
->control
.step_range_end
7432 = ecs
->event_thread
->control
.step_range_start
;
7437 /* Inferior has stepped backward into a subroutine call with source
7438 code that we should not step over. Do step to the beginning of the
7439 last line of code in it. */
7442 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7443 struct execution_control_state
*ecs
)
7445 struct compunit_symtab
*cust
;
7446 struct symtab_and_line stop_func_sal
;
7448 fill_in_stop_func (gdbarch
, ecs
);
7450 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7451 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7452 ecs
->stop_func_start
7453 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7455 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7457 /* OK, we're just going to keep stepping here. */
7458 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7460 /* We're there already. Just stop stepping now. */
7461 end_stepping_range (ecs
);
7465 /* Else just reset the step range and keep going.
7466 No step-resume breakpoint, they don't work for
7467 epilogues, which can have multiple entry paths. */
7468 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7469 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7475 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7476 This is used to both functions and to skip over code. */
7479 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7480 struct symtab_and_line sr_sal
,
7481 struct frame_id sr_id
,
7482 enum bptype sr_type
)
7484 /* There should never be more than one step-resume or longjmp-resume
7485 breakpoint per thread, so we should never be setting a new
7486 step_resume_breakpoint when one is already active. */
7487 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7488 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7490 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7491 paddress (gdbarch
, sr_sal
.pc
));
7493 inferior_thread ()->control
.step_resume_breakpoint
7494 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7498 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7499 struct symtab_and_line sr_sal
,
7500 struct frame_id sr_id
)
7502 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7507 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7508 This is used to skip a potential signal handler.
7510 This is called with the interrupted function's frame. The signal
7511 handler, when it returns, will resume the interrupted function at
7515 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7517 gdb_assert (return_frame
!= NULL
);
7519 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7521 symtab_and_line sr_sal
;
7522 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7523 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7524 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7526 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7527 get_stack_frame_id (return_frame
),
7531 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7532 is used to skip a function after stepping into it (for "next" or if
7533 the called function has no debugging information).
7535 The current function has almost always been reached by single
7536 stepping a call or return instruction. NEXT_FRAME belongs to the
7537 current function, and the breakpoint will be set at the caller's
7540 This is a separate function rather than reusing
7541 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7542 get_prev_frame, which may stop prematurely (see the implementation
7543 of frame_unwind_caller_id for an example). */
7546 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7548 /* We shouldn't have gotten here if we don't know where the call site
7550 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7552 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7554 symtab_and_line sr_sal
;
7555 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7556 frame_unwind_caller_pc (next_frame
));
7557 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7558 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7560 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7561 frame_unwind_caller_id (next_frame
));
7564 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7565 new breakpoint at the target of a jmp_buf. The handling of
7566 longjmp-resume uses the same mechanisms used for handling
7567 "step-resume" breakpoints. */
7570 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7572 /* There should never be more than one longjmp-resume breakpoint per
7573 thread, so we should never be setting a new
7574 longjmp_resume_breakpoint when one is already active. */
7575 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7577 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7578 paddress (gdbarch
, pc
));
7580 inferior_thread ()->control
.exception_resume_breakpoint
=
7581 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7584 /* Insert an exception resume breakpoint. TP is the thread throwing
7585 the exception. The block B is the block of the unwinder debug hook
7586 function. FRAME is the frame corresponding to the call to this
7587 function. SYM is the symbol of the function argument holding the
7588 target PC of the exception. */
7591 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7592 const struct block
*b
,
7593 struct frame_info
*frame
,
7598 struct block_symbol vsym
;
7599 struct value
*value
;
7601 struct breakpoint
*bp
;
7603 vsym
= lookup_symbol_search_name (sym
->search_name (),
7605 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7606 /* If the value was optimized out, revert to the old behavior. */
7607 if (! value_optimized_out (value
))
7609 handler
= value_as_address (value
);
7611 infrun_debug_printf ("exception resume at %lx",
7612 (unsigned long) handler
);
7614 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7616 bp_exception_resume
).release ();
7618 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7621 bp
->thread
= tp
->global_num
;
7622 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7625 catch (const gdb_exception_error
&e
)
7627 /* We want to ignore errors here. */
7631 /* A helper for check_exception_resume that sets an
7632 exception-breakpoint based on a SystemTap probe. */
7635 insert_exception_resume_from_probe (struct thread_info
*tp
,
7636 const struct bound_probe
*probe
,
7637 struct frame_info
*frame
)
7639 struct value
*arg_value
;
7641 struct breakpoint
*bp
;
7643 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7647 handler
= value_as_address (arg_value
);
7649 infrun_debug_printf ("exception resume at %s",
7650 paddress (probe
->objfile
->arch (), handler
));
7652 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7653 handler
, bp_exception_resume
).release ();
7654 bp
->thread
= tp
->global_num
;
7655 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7658 /* This is called when an exception has been intercepted. Check to
7659 see whether the exception's destination is of interest, and if so,
7660 set an exception resume breakpoint there. */
7663 check_exception_resume (struct execution_control_state
*ecs
,
7664 struct frame_info
*frame
)
7666 struct bound_probe probe
;
7667 struct symbol
*func
;
7669 /* First see if this exception unwinding breakpoint was set via a
7670 SystemTap probe point. If so, the probe has two arguments: the
7671 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7672 set a breakpoint there. */
7673 probe
= find_probe_by_pc (get_frame_pc (frame
));
7676 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7680 func
= get_frame_function (frame
);
7686 const struct block
*b
;
7687 struct block_iterator iter
;
7691 /* The exception breakpoint is a thread-specific breakpoint on
7692 the unwinder's debug hook, declared as:
7694 void _Unwind_DebugHook (void *cfa, void *handler);
7696 The CFA argument indicates the frame to which control is
7697 about to be transferred. HANDLER is the destination PC.
7699 We ignore the CFA and set a temporary breakpoint at HANDLER.
7700 This is not extremely efficient but it avoids issues in gdb
7701 with computing the DWARF CFA, and it also works even in weird
7702 cases such as throwing an exception from inside a signal
7705 b
= SYMBOL_BLOCK_VALUE (func
);
7706 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7708 if (!SYMBOL_IS_ARGUMENT (sym
))
7715 insert_exception_resume_breakpoint (ecs
->event_thread
,
7721 catch (const gdb_exception_error
&e
)
7727 stop_waiting (struct execution_control_state
*ecs
)
7729 infrun_debug_printf ("stop_waiting");
7731 /* Let callers know we don't want to wait for the inferior anymore. */
7732 ecs
->wait_some_more
= 0;
7734 /* If all-stop, but there exists a non-stop target, stop all
7735 threads now that we're presenting the stop to the user. */
7736 if (!non_stop
&& exists_non_stop_target ())
7737 stop_all_threads ();
7740 /* Like keep_going, but passes the signal to the inferior, even if the
7741 signal is set to nopass. */
7744 keep_going_pass_signal (struct execution_control_state
*ecs
)
7746 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7747 gdb_assert (!ecs
->event_thread
->resumed
);
7749 /* Save the pc before execution, to compare with pc after stop. */
7750 ecs
->event_thread
->prev_pc
7751 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7753 if (ecs
->event_thread
->control
.trap_expected
)
7755 struct thread_info
*tp
= ecs
->event_thread
;
7757 infrun_debug_printf ("%s has trap_expected set, "
7758 "resuming to collect trap",
7759 target_pid_to_str (tp
->ptid
).c_str ());
7761 /* We haven't yet gotten our trap, and either: intercepted a
7762 non-signal event (e.g., a fork); or took a signal which we
7763 are supposed to pass through to the inferior. Simply
7765 resume (ecs
->event_thread
->suspend
.stop_signal
);
7767 else if (step_over_info_valid_p ())
7769 /* Another thread is stepping over a breakpoint in-line. If
7770 this thread needs a step-over too, queue the request. In
7771 either case, this resume must be deferred for later. */
7772 struct thread_info
*tp
= ecs
->event_thread
;
7774 if (ecs
->hit_singlestep_breakpoint
7775 || thread_still_needs_step_over (tp
))
7777 infrun_debug_printf ("step-over already in progress: "
7778 "step-over for %s deferred",
7779 target_pid_to_str (tp
->ptid
).c_str ());
7780 global_thread_step_over_chain_enqueue (tp
);
7784 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7785 target_pid_to_str (tp
->ptid
).c_str ());
7790 struct regcache
*regcache
= get_current_regcache ();
7793 step_over_what step_what
;
7795 /* Either the trap was not expected, but we are continuing
7796 anyway (if we got a signal, the user asked it be passed to
7799 We got our expected trap, but decided we should resume from
7802 We're going to run this baby now!
7804 Note that insert_breakpoints won't try to re-insert
7805 already inserted breakpoints. Therefore, we don't
7806 care if breakpoints were already inserted, or not. */
7808 /* If we need to step over a breakpoint, and we're not using
7809 displaced stepping to do so, insert all breakpoints
7810 (watchpoints, etc.) but the one we're stepping over, step one
7811 instruction, and then re-insert the breakpoint when that step
7814 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7816 remove_bp
= (ecs
->hit_singlestep_breakpoint
7817 || (step_what
& STEP_OVER_BREAKPOINT
));
7818 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7820 /* We can't use displaced stepping if we need to step past a
7821 watchpoint. The instruction copied to the scratch pad would
7822 still trigger the watchpoint. */
7824 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7826 set_step_over_info (regcache
->aspace (),
7827 regcache_read_pc (regcache
), remove_wps
,
7828 ecs
->event_thread
->global_num
);
7830 else if (remove_wps
)
7831 set_step_over_info (NULL
, 0, remove_wps
, -1);
7833 /* If we now need to do an in-line step-over, we need to stop
7834 all other threads. Note this must be done before
7835 insert_breakpoints below, because that removes the breakpoint
7836 we're about to step over, otherwise other threads could miss
7838 if (step_over_info_valid_p () && target_is_non_stop_p ())
7839 stop_all_threads ();
7841 /* Stop stepping if inserting breakpoints fails. */
7844 insert_breakpoints ();
7846 catch (const gdb_exception_error
&e
)
7848 exception_print (gdb_stderr
, e
);
7850 clear_step_over_info ();
7854 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7856 resume (ecs
->event_thread
->suspend
.stop_signal
);
7859 prepare_to_wait (ecs
);
7862 /* Called when we should continue running the inferior, because the
7863 current event doesn't cause a user visible stop. This does the
7864 resuming part; waiting for the next event is done elsewhere. */
7867 keep_going (struct execution_control_state
*ecs
)
7869 if (ecs
->event_thread
->control
.trap_expected
7870 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7871 ecs
->event_thread
->control
.trap_expected
= 0;
7873 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7874 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7875 keep_going_pass_signal (ecs
);
7878 /* This function normally comes after a resume, before
7879 handle_inferior_event exits. It takes care of any last bits of
7880 housekeeping, and sets the all-important wait_some_more flag. */
7883 prepare_to_wait (struct execution_control_state
*ecs
)
7885 infrun_debug_printf ("prepare_to_wait");
7887 ecs
->wait_some_more
= 1;
7889 /* If the target can't async, emulate it by marking the infrun event
7890 handler such that as soon as we get back to the event-loop, we
7891 immediately end up in fetch_inferior_event again calling
7893 if (!target_can_async_p ())
7894 mark_infrun_async_event_handler ();
7897 /* We are done with the step range of a step/next/si/ni command.
7898 Called once for each n of a "step n" operation. */
7901 end_stepping_range (struct execution_control_state
*ecs
)
7903 ecs
->event_thread
->control
.stop_step
= 1;
7907 /* Several print_*_reason functions to print why the inferior has stopped.
7908 We always print something when the inferior exits, or receives a signal.
7909 The rest of the cases are dealt with later on in normal_stop and
7910 print_it_typical. Ideally there should be a call to one of these
7911 print_*_reason functions functions from handle_inferior_event each time
7912 stop_waiting is called.
7914 Note that we don't call these directly, instead we delegate that to
7915 the interpreters, through observers. Interpreters then call these
7916 with whatever uiout is right. */
7919 print_end_stepping_range_reason (struct ui_out
*uiout
)
7921 /* For CLI-like interpreters, print nothing. */
7923 if (uiout
->is_mi_like_p ())
7925 uiout
->field_string ("reason",
7926 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7931 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7933 annotate_signalled ();
7934 if (uiout
->is_mi_like_p ())
7936 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7937 uiout
->text ("\nProgram terminated with signal ");
7938 annotate_signal_name ();
7939 uiout
->field_string ("signal-name",
7940 gdb_signal_to_name (siggnal
));
7941 annotate_signal_name_end ();
7943 annotate_signal_string ();
7944 uiout
->field_string ("signal-meaning",
7945 gdb_signal_to_string (siggnal
));
7946 annotate_signal_string_end ();
7947 uiout
->text (".\n");
7948 uiout
->text ("The program no longer exists.\n");
7952 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7954 struct inferior
*inf
= current_inferior ();
7955 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7957 annotate_exited (exitstatus
);
7960 if (uiout
->is_mi_like_p ())
7961 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7962 std::string exit_code_str
7963 = string_printf ("0%o", (unsigned int) exitstatus
);
7964 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7965 plongest (inf
->num
), pidstr
.c_str (),
7966 string_field ("exit-code", exit_code_str
.c_str ()));
7970 if (uiout
->is_mi_like_p ())
7972 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7973 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7974 plongest (inf
->num
), pidstr
.c_str ());
7979 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7981 struct thread_info
*thr
= inferior_thread ();
7985 if (uiout
->is_mi_like_p ())
7987 else if (show_thread_that_caused_stop ())
7991 uiout
->text ("\nThread ");
7992 uiout
->field_string ("thread-id", print_thread_id (thr
));
7994 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7997 uiout
->text (" \"");
7998 uiout
->field_string ("name", name
);
8003 uiout
->text ("\nProgram");
8005 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8006 uiout
->text (" stopped");
8009 uiout
->text (" received signal ");
8010 annotate_signal_name ();
8011 if (uiout
->is_mi_like_p ())
8013 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8014 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8015 annotate_signal_name_end ();
8017 annotate_signal_string ();
8018 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8020 struct regcache
*regcache
= get_current_regcache ();
8021 struct gdbarch
*gdbarch
= regcache
->arch ();
8022 if (gdbarch_report_signal_info_p (gdbarch
))
8023 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8025 annotate_signal_string_end ();
8027 uiout
->text (".\n");
8031 print_no_history_reason (struct ui_out
*uiout
)
8033 uiout
->text ("\nNo more reverse-execution history.\n");
8036 /* Print current location without a level number, if we have changed
8037 functions or hit a breakpoint. Print source line if we have one.
8038 bpstat_print contains the logic deciding in detail what to print,
8039 based on the event(s) that just occurred. */
8042 print_stop_location (struct target_waitstatus
*ws
)
8045 enum print_what source_flag
;
8046 int do_frame_printing
= 1;
8047 struct thread_info
*tp
= inferior_thread ();
8049 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8053 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8054 should) carry around the function and does (or should) use
8055 that when doing a frame comparison. */
8056 if (tp
->control
.stop_step
8057 && frame_id_eq (tp
->control
.step_frame_id
,
8058 get_frame_id (get_current_frame ()))
8059 && (tp
->control
.step_start_function
8060 == find_pc_function (tp
->suspend
.stop_pc
)))
8062 /* Finished step, just print source line. */
8063 source_flag
= SRC_LINE
;
8067 /* Print location and source line. */
8068 source_flag
= SRC_AND_LOC
;
8071 case PRINT_SRC_AND_LOC
:
8072 /* Print location and source line. */
8073 source_flag
= SRC_AND_LOC
;
8075 case PRINT_SRC_ONLY
:
8076 source_flag
= SRC_LINE
;
8079 /* Something bogus. */
8080 source_flag
= SRC_LINE
;
8081 do_frame_printing
= 0;
8084 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8087 /* The behavior of this routine with respect to the source
8089 SRC_LINE: Print only source line
8090 LOCATION: Print only location
8091 SRC_AND_LOC: Print location and source line. */
8092 if (do_frame_printing
)
8093 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8099 print_stop_event (struct ui_out
*uiout
, bool displays
)
8101 struct target_waitstatus last
;
8102 struct thread_info
*tp
;
8104 get_last_target_status (nullptr, nullptr, &last
);
8107 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8109 print_stop_location (&last
);
8111 /* Display the auto-display expressions. */
8116 tp
= inferior_thread ();
8117 if (tp
->thread_fsm
!= NULL
8118 && tp
->thread_fsm
->finished_p ())
8120 struct return_value_info
*rv
;
8122 rv
= tp
->thread_fsm
->return_value ();
8124 print_return_value (uiout
, rv
);
8131 maybe_remove_breakpoints (void)
8133 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8135 if (remove_breakpoints ())
8137 target_terminal::ours_for_output ();
8138 printf_filtered (_("Cannot remove breakpoints because "
8139 "program is no longer writable.\nFurther "
8140 "execution is probably impossible.\n"));
8145 /* The execution context that just caused a normal stop. */
8152 DISABLE_COPY_AND_ASSIGN (stop_context
);
8154 bool changed () const;
8159 /* The event PTID. */
8163 /* If stopp for a thread event, this is the thread that caused the
8165 struct thread_info
*thread
;
8167 /* The inferior that caused the stop. */
8171 /* Initializes a new stop context. If stopped for a thread event, this
8172 takes a strong reference to the thread. */
8174 stop_context::stop_context ()
8176 stop_id
= get_stop_id ();
8177 ptid
= inferior_ptid
;
8178 inf_num
= current_inferior ()->num
;
8180 if (inferior_ptid
!= null_ptid
)
8182 /* Take a strong reference so that the thread can't be deleted
8184 thread
= inferior_thread ();
8191 /* Release a stop context previously created with save_stop_context.
8192 Releases the strong reference to the thread as well. */
8194 stop_context::~stop_context ()
8200 /* Return true if the current context no longer matches the saved stop
8204 stop_context::changed () const
8206 if (ptid
!= inferior_ptid
)
8208 if (inf_num
!= current_inferior ()->num
)
8210 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8212 if (get_stop_id () != stop_id
)
8222 struct target_waitstatus last
;
8224 get_last_target_status (nullptr, nullptr, &last
);
8228 /* If an exception is thrown from this point on, make sure to
8229 propagate GDB's knowledge of the executing state to the
8230 frontend/user running state. A QUIT is an easy exception to see
8231 here, so do this before any filtered output. */
8233 ptid_t finish_ptid
= null_ptid
;
8236 finish_ptid
= minus_one_ptid
;
8237 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8238 || last
.kind
== TARGET_WAITKIND_EXITED
)
8240 /* On some targets, we may still have live threads in the
8241 inferior when we get a process exit event. E.g., for
8242 "checkpoint", when the current checkpoint/fork exits,
8243 linux-fork.c automatically switches to another fork from
8244 within target_mourn_inferior. */
8245 if (inferior_ptid
!= null_ptid
)
8246 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8248 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8249 finish_ptid
= inferior_ptid
;
8251 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8252 if (finish_ptid
!= null_ptid
)
8254 maybe_finish_thread_state
.emplace
8255 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8258 /* As we're presenting a stop, and potentially removing breakpoints,
8259 update the thread list so we can tell whether there are threads
8260 running on the target. With target remote, for example, we can
8261 only learn about new threads when we explicitly update the thread
8262 list. Do this before notifying the interpreters about signal
8263 stops, end of stepping ranges, etc., so that the "new thread"
8264 output is emitted before e.g., "Program received signal FOO",
8265 instead of after. */
8266 update_thread_list ();
8268 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8269 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8271 /* As with the notification of thread events, we want to delay
8272 notifying the user that we've switched thread context until
8273 the inferior actually stops.
8275 There's no point in saying anything if the inferior has exited.
8276 Note that SIGNALLED here means "exited with a signal", not
8277 "received a signal".
8279 Also skip saying anything in non-stop mode. In that mode, as we
8280 don't want GDB to switch threads behind the user's back, to avoid
8281 races where the user is typing a command to apply to thread x,
8282 but GDB switches to thread y before the user finishes entering
8283 the command, fetch_inferior_event installs a cleanup to restore
8284 the current thread back to the thread the user had selected right
8285 after this event is handled, so we're not really switching, only
8286 informing of a stop. */
8288 && previous_inferior_ptid
!= inferior_ptid
8289 && target_has_execution ()
8290 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8291 && last
.kind
!= TARGET_WAITKIND_EXITED
8292 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8294 SWITCH_THRU_ALL_UIS ()
8296 target_terminal::ours_for_output ();
8297 printf_filtered (_("[Switching to %s]\n"),
8298 target_pid_to_str (inferior_ptid
).c_str ());
8299 annotate_thread_changed ();
8301 previous_inferior_ptid
= inferior_ptid
;
8304 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8306 SWITCH_THRU_ALL_UIS ()
8307 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8309 target_terminal::ours_for_output ();
8310 printf_filtered (_("No unwaited-for children left.\n"));
8314 /* Note: this depends on the update_thread_list call above. */
8315 maybe_remove_breakpoints ();
8317 /* If an auto-display called a function and that got a signal,
8318 delete that auto-display to avoid an infinite recursion. */
8320 if (stopped_by_random_signal
)
8321 disable_current_display ();
8323 SWITCH_THRU_ALL_UIS ()
8325 async_enable_stdin ();
8328 /* Let the user/frontend see the threads as stopped. */
8329 maybe_finish_thread_state
.reset ();
8331 /* Select innermost stack frame - i.e., current frame is frame 0,
8332 and current location is based on that. Handle the case where the
8333 dummy call is returning after being stopped. E.g. the dummy call
8334 previously hit a breakpoint. (If the dummy call returns
8335 normally, we won't reach here.) Do this before the stop hook is
8336 run, so that it doesn't get to see the temporary dummy frame,
8337 which is not where we'll present the stop. */
8338 if (has_stack_frames ())
8340 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8342 /* Pop the empty frame that contains the stack dummy. This
8343 also restores inferior state prior to the call (struct
8344 infcall_suspend_state). */
8345 struct frame_info
*frame
= get_current_frame ();
8347 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8349 /* frame_pop calls reinit_frame_cache as the last thing it
8350 does which means there's now no selected frame. */
8353 select_frame (get_current_frame ());
8355 /* Set the current source location. */
8356 set_current_sal_from_frame (get_current_frame ());
8359 /* Look up the hook_stop and run it (CLI internally handles problem
8360 of stop_command's pre-hook not existing). */
8361 if (stop_command
!= NULL
)
8363 stop_context saved_context
;
8367 execute_cmd_pre_hook (stop_command
);
8369 catch (const gdb_exception
&ex
)
8371 exception_fprintf (gdb_stderr
, ex
,
8372 "Error while running hook_stop:\n");
8375 /* If the stop hook resumes the target, then there's no point in
8376 trying to notify about the previous stop; its context is
8377 gone. Likewise if the command switches thread or inferior --
8378 the observers would print a stop for the wrong
8380 if (saved_context
.changed ())
8384 /* Notify observers about the stop. This is where the interpreters
8385 print the stop event. */
8386 if (inferior_ptid
!= null_ptid
)
8387 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8390 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8392 annotate_stopped ();
8394 if (target_has_execution ())
8396 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8397 && last
.kind
!= TARGET_WAITKIND_EXITED
8398 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8399 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8400 Delete any breakpoint that is to be deleted at the next stop. */
8401 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8404 /* Try to get rid of automatically added inferiors that are no
8405 longer needed. Keeping those around slows down things linearly.
8406 Note that this never removes the current inferior. */
8413 signal_stop_state (int signo
)
8415 return signal_stop
[signo
];
8419 signal_print_state (int signo
)
8421 return signal_print
[signo
];
8425 signal_pass_state (int signo
)
8427 return signal_program
[signo
];
8431 signal_cache_update (int signo
)
8435 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8436 signal_cache_update (signo
);
8441 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8442 && signal_print
[signo
] == 0
8443 && signal_program
[signo
] == 1
8444 && signal_catch
[signo
] == 0);
8448 signal_stop_update (int signo
, int state
)
8450 int ret
= signal_stop
[signo
];
8452 signal_stop
[signo
] = state
;
8453 signal_cache_update (signo
);
8458 signal_print_update (int signo
, int state
)
8460 int ret
= signal_print
[signo
];
8462 signal_print
[signo
] = state
;
8463 signal_cache_update (signo
);
8468 signal_pass_update (int signo
, int state
)
8470 int ret
= signal_program
[signo
];
8472 signal_program
[signo
] = state
;
8473 signal_cache_update (signo
);
8477 /* Update the global 'signal_catch' from INFO and notify the
8481 signal_catch_update (const unsigned int *info
)
8485 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8486 signal_catch
[i
] = info
[i
] > 0;
8487 signal_cache_update (-1);
8488 target_pass_signals (signal_pass
);
8492 sig_print_header (void)
8494 printf_filtered (_("Signal Stop\tPrint\tPass "
8495 "to program\tDescription\n"));
8499 sig_print_info (enum gdb_signal oursig
)
8501 const char *name
= gdb_signal_to_name (oursig
);
8502 int name_padding
= 13 - strlen (name
);
8504 if (name_padding
<= 0)
8507 printf_filtered ("%s", name
);
8508 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8509 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8510 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8511 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8512 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8515 /* Specify how various signals in the inferior should be handled. */
8518 handle_command (const char *args
, int from_tty
)
8520 int digits
, wordlen
;
8521 int sigfirst
, siglast
;
8522 enum gdb_signal oursig
;
8527 error_no_arg (_("signal to handle"));
8530 /* Allocate and zero an array of flags for which signals to handle. */
8532 const size_t nsigs
= GDB_SIGNAL_LAST
;
8533 unsigned char sigs
[nsigs
] {};
8535 /* Break the command line up into args. */
8537 gdb_argv
built_argv (args
);
8539 /* Walk through the args, looking for signal oursigs, signal names, and
8540 actions. Signal numbers and signal names may be interspersed with
8541 actions, with the actions being performed for all signals cumulatively
8542 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8544 for (char *arg
: built_argv
)
8546 wordlen
= strlen (arg
);
8547 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8551 sigfirst
= siglast
= -1;
8553 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8555 /* Apply action to all signals except those used by the
8556 debugger. Silently skip those. */
8559 siglast
= nsigs
- 1;
8561 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8563 SET_SIGS (nsigs
, sigs
, signal_stop
);
8564 SET_SIGS (nsigs
, sigs
, signal_print
);
8566 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8568 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8570 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8572 SET_SIGS (nsigs
, sigs
, signal_print
);
8574 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8576 SET_SIGS (nsigs
, sigs
, signal_program
);
8578 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8580 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8582 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8584 SET_SIGS (nsigs
, sigs
, signal_program
);
8586 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8588 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8589 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8591 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8593 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8595 else if (digits
> 0)
8597 /* It is numeric. The numeric signal refers to our own
8598 internal signal numbering from target.h, not to host/target
8599 signal number. This is a feature; users really should be
8600 using symbolic names anyway, and the common ones like
8601 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8603 sigfirst
= siglast
= (int)
8604 gdb_signal_from_command (atoi (arg
));
8605 if (arg
[digits
] == '-')
8608 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8610 if (sigfirst
> siglast
)
8612 /* Bet he didn't figure we'd think of this case... */
8613 std::swap (sigfirst
, siglast
);
8618 oursig
= gdb_signal_from_name (arg
);
8619 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8621 sigfirst
= siglast
= (int) oursig
;
8625 /* Not a number and not a recognized flag word => complain. */
8626 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8630 /* If any signal numbers or symbol names were found, set flags for
8631 which signals to apply actions to. */
8633 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8635 switch ((enum gdb_signal
) signum
)
8637 case GDB_SIGNAL_TRAP
:
8638 case GDB_SIGNAL_INT
:
8639 if (!allsigs
&& !sigs
[signum
])
8641 if (query (_("%s is used by the debugger.\n\
8642 Are you sure you want to change it? "),
8643 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8648 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8652 case GDB_SIGNAL_DEFAULT
:
8653 case GDB_SIGNAL_UNKNOWN
:
8654 /* Make sure that "all" doesn't print these. */
8663 for (int signum
= 0; signum
< nsigs
; signum
++)
8666 signal_cache_update (-1);
8667 target_pass_signals (signal_pass
);
8668 target_program_signals (signal_program
);
8672 /* Show the results. */
8673 sig_print_header ();
8674 for (; signum
< nsigs
; signum
++)
8676 sig_print_info ((enum gdb_signal
) signum
);
8683 /* Complete the "handle" command. */
8686 handle_completer (struct cmd_list_element
*ignore
,
8687 completion_tracker
&tracker
,
8688 const char *text
, const char *word
)
8690 static const char * const keywords
[] =
8704 signal_completer (ignore
, tracker
, text
, word
);
8705 complete_on_enum (tracker
, keywords
, word
, word
);
8709 gdb_signal_from_command (int num
)
8711 if (num
>= 1 && num
<= 15)
8712 return (enum gdb_signal
) num
;
8713 error (_("Only signals 1-15 are valid as numeric signals.\n\
8714 Use \"info signals\" for a list of symbolic signals."));
8717 /* Print current contents of the tables set by the handle command.
8718 It is possible we should just be printing signals actually used
8719 by the current target (but for things to work right when switching
8720 targets, all signals should be in the signal tables). */
8723 info_signals_command (const char *signum_exp
, int from_tty
)
8725 enum gdb_signal oursig
;
8727 sig_print_header ();
8731 /* First see if this is a symbol name. */
8732 oursig
= gdb_signal_from_name (signum_exp
);
8733 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8735 /* No, try numeric. */
8737 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8739 sig_print_info (oursig
);
8743 printf_filtered ("\n");
8744 /* These ugly casts brought to you by the native VAX compiler. */
8745 for (oursig
= GDB_SIGNAL_FIRST
;
8746 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8747 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8751 if (oursig
!= GDB_SIGNAL_UNKNOWN
8752 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8753 sig_print_info (oursig
);
8756 printf_filtered (_("\nUse the \"handle\" command "
8757 "to change these tables.\n"));
8760 /* The $_siginfo convenience variable is a bit special. We don't know
8761 for sure the type of the value until we actually have a chance to
8762 fetch the data. The type can change depending on gdbarch, so it is
8763 also dependent on which thread you have selected.
8765 1. making $_siginfo be an internalvar that creates a new value on
8768 2. making the value of $_siginfo be an lval_computed value. */
8770 /* This function implements the lval_computed support for reading a
8774 siginfo_value_read (struct value
*v
)
8776 LONGEST transferred
;
8778 /* If we can access registers, so can we access $_siginfo. Likewise
8780 validate_registers_access ();
8783 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8785 value_contents_all_raw (v
),
8787 TYPE_LENGTH (value_type (v
)));
8789 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8790 error (_("Unable to read siginfo"));
8793 /* This function implements the lval_computed support for writing a
8797 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8799 LONGEST transferred
;
8801 /* If we can access registers, so can we access $_siginfo. Likewise
8803 validate_registers_access ();
8805 transferred
= target_write (current_top_target (),
8806 TARGET_OBJECT_SIGNAL_INFO
,
8808 value_contents_all_raw (fromval
),
8810 TYPE_LENGTH (value_type (fromval
)));
8812 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8813 error (_("Unable to write siginfo"));
8816 static const struct lval_funcs siginfo_value_funcs
=
8822 /* Return a new value with the correct type for the siginfo object of
8823 the current thread using architecture GDBARCH. Return a void value
8824 if there's no object available. */
8826 static struct value
*
8827 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8830 if (target_has_stack ()
8831 && inferior_ptid
!= null_ptid
8832 && gdbarch_get_siginfo_type_p (gdbarch
))
8834 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8836 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8839 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8843 /* infcall_suspend_state contains state about the program itself like its
8844 registers and any signal it received when it last stopped.
8845 This state must be restored regardless of how the inferior function call
8846 ends (either successfully, or after it hits a breakpoint or signal)
8847 if the program is to properly continue where it left off. */
8849 class infcall_suspend_state
8852 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8853 once the inferior function call has finished. */
8854 infcall_suspend_state (struct gdbarch
*gdbarch
,
8855 const struct thread_info
*tp
,
8856 struct regcache
*regcache
)
8857 : m_thread_suspend (tp
->suspend
),
8858 m_registers (new readonly_detached_regcache (*regcache
))
8860 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8862 if (gdbarch_get_siginfo_type_p (gdbarch
))
8864 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8865 size_t len
= TYPE_LENGTH (type
);
8867 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8869 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8870 siginfo_data
.get (), 0, len
) != len
)
8872 /* Errors ignored. */
8873 siginfo_data
.reset (nullptr);
8879 m_siginfo_gdbarch
= gdbarch
;
8880 m_siginfo_data
= std::move (siginfo_data
);
8884 /* Return a pointer to the stored register state. */
8886 readonly_detached_regcache
*registers () const
8888 return m_registers
.get ();
8891 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8893 void restore (struct gdbarch
*gdbarch
,
8894 struct thread_info
*tp
,
8895 struct regcache
*regcache
) const
8897 tp
->suspend
= m_thread_suspend
;
8899 if (m_siginfo_gdbarch
== gdbarch
)
8901 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8903 /* Errors ignored. */
8904 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8905 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8908 /* The inferior can be gone if the user types "print exit(0)"
8909 (and perhaps other times). */
8910 if (target_has_execution ())
8911 /* NB: The register write goes through to the target. */
8912 regcache
->restore (registers ());
8916 /* How the current thread stopped before the inferior function call was
8918 struct thread_suspend_state m_thread_suspend
;
8920 /* The registers before the inferior function call was executed. */
8921 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8923 /* Format of SIGINFO_DATA or NULL if it is not present. */
8924 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8926 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8927 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8928 content would be invalid. */
8929 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8932 infcall_suspend_state_up
8933 save_infcall_suspend_state ()
8935 struct thread_info
*tp
= inferior_thread ();
8936 struct regcache
*regcache
= get_current_regcache ();
8937 struct gdbarch
*gdbarch
= regcache
->arch ();
8939 infcall_suspend_state_up inf_state
8940 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8942 /* Having saved the current state, adjust the thread state, discarding
8943 any stop signal information. The stop signal is not useful when
8944 starting an inferior function call, and run_inferior_call will not use
8945 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8946 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8951 /* Restore inferior session state to INF_STATE. */
8954 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8956 struct thread_info
*tp
= inferior_thread ();
8957 struct regcache
*regcache
= get_current_regcache ();
8958 struct gdbarch
*gdbarch
= regcache
->arch ();
8960 inf_state
->restore (gdbarch
, tp
, regcache
);
8961 discard_infcall_suspend_state (inf_state
);
8965 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8970 readonly_detached_regcache
*
8971 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8973 return inf_state
->registers ();
8976 /* infcall_control_state contains state regarding gdb's control of the
8977 inferior itself like stepping control. It also contains session state like
8978 the user's currently selected frame. */
8980 struct infcall_control_state
8982 struct thread_control_state thread_control
;
8983 struct inferior_control_state inferior_control
;
8986 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8987 int stopped_by_random_signal
= 0;
8989 /* ID and level of the selected frame when the inferior function
8991 struct frame_id selected_frame_id
{};
8992 int selected_frame_level
= -1;
8995 /* Save all of the information associated with the inferior<==>gdb
8998 infcall_control_state_up
8999 save_infcall_control_state ()
9001 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9002 struct thread_info
*tp
= inferior_thread ();
9003 struct inferior
*inf
= current_inferior ();
9005 inf_status
->thread_control
= tp
->control
;
9006 inf_status
->inferior_control
= inf
->control
;
9008 tp
->control
.step_resume_breakpoint
= NULL
;
9009 tp
->control
.exception_resume_breakpoint
= NULL
;
9011 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9012 chain. If caller's caller is walking the chain, they'll be happier if we
9013 hand them back the original chain when restore_infcall_control_state is
9015 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9018 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9019 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9021 save_selected_frame (&inf_status
->selected_frame_id
,
9022 &inf_status
->selected_frame_level
);
9027 /* Restore inferior session state to INF_STATUS. */
9030 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9032 struct thread_info
*tp
= inferior_thread ();
9033 struct inferior
*inf
= current_inferior ();
9035 if (tp
->control
.step_resume_breakpoint
)
9036 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9038 if (tp
->control
.exception_resume_breakpoint
)
9039 tp
->control
.exception_resume_breakpoint
->disposition
9040 = disp_del_at_next_stop
;
9042 /* Handle the bpstat_copy of the chain. */
9043 bpstat_clear (&tp
->control
.stop_bpstat
);
9045 tp
->control
= inf_status
->thread_control
;
9046 inf
->control
= inf_status
->inferior_control
;
9049 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9050 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9052 if (target_has_stack ())
9054 restore_selected_frame (inf_status
->selected_frame_id
,
9055 inf_status
->selected_frame_level
);
9062 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9064 if (inf_status
->thread_control
.step_resume_breakpoint
)
9065 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9066 = disp_del_at_next_stop
;
9068 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9069 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9070 = disp_del_at_next_stop
;
9072 /* See save_infcall_control_state for info on stop_bpstat. */
9073 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9081 clear_exit_convenience_vars (void)
9083 clear_internalvar (lookup_internalvar ("_exitsignal"));
9084 clear_internalvar (lookup_internalvar ("_exitcode"));
9088 /* User interface for reverse debugging:
9089 Set exec-direction / show exec-direction commands
9090 (returns error unless target implements to_set_exec_direction method). */
9092 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9093 static const char exec_forward
[] = "forward";
9094 static const char exec_reverse
[] = "reverse";
9095 static const char *exec_direction
= exec_forward
;
9096 static const char *const exec_direction_names
[] = {
9103 set_exec_direction_func (const char *args
, int from_tty
,
9104 struct cmd_list_element
*cmd
)
9106 if (target_can_execute_reverse ())
9108 if (!strcmp (exec_direction
, exec_forward
))
9109 execution_direction
= EXEC_FORWARD
;
9110 else if (!strcmp (exec_direction
, exec_reverse
))
9111 execution_direction
= EXEC_REVERSE
;
9115 exec_direction
= exec_forward
;
9116 error (_("Target does not support this operation."));
9121 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9122 struct cmd_list_element
*cmd
, const char *value
)
9124 switch (execution_direction
) {
9126 fprintf_filtered (out
, _("Forward.\n"));
9129 fprintf_filtered (out
, _("Reverse.\n"));
9132 internal_error (__FILE__
, __LINE__
,
9133 _("bogus execution_direction value: %d"),
9134 (int) execution_direction
);
9139 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9140 struct cmd_list_element
*c
, const char *value
)
9142 fprintf_filtered (file
, _("Resuming the execution of threads "
9143 "of all processes is %s.\n"), value
);
9146 /* Implementation of `siginfo' variable. */
9148 static const struct internalvar_funcs siginfo_funcs
=
9155 /* Callback for infrun's target events source. This is marked when a
9156 thread has a pending status to process. */
9159 infrun_async_inferior_event_handler (gdb_client_data data
)
9161 inferior_event_handler (INF_REG_EVENT
);
9168 /* Verify that when two threads with the same ptid exist (from two different
9169 targets) and one of them changes ptid, we only update inferior_ptid if
9170 it is appropriate. */
9173 infrun_thread_ptid_changed ()
9175 gdbarch
*arch
= current_inferior ()->gdbarch
;
9177 /* The thread which inferior_ptid represents changes ptid. */
9179 scoped_restore_current_pspace_and_thread restore
;
9181 scoped_mock_context
<test_target_ops
> target1 (arch
);
9182 scoped_mock_context
<test_target_ops
> target2 (arch
);
9183 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9185 ptid_t
old_ptid (111, 222);
9186 ptid_t
new_ptid (111, 333);
9188 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9189 target1
.mock_thread
.ptid
= old_ptid
;
9190 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9191 target2
.mock_thread
.ptid
= old_ptid
;
9193 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9194 set_current_inferior (&target1
.mock_inferior
);
9196 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9198 gdb_assert (inferior_ptid
== new_ptid
);
9201 /* A thread with the same ptid as inferior_ptid, but from another target,
9204 scoped_restore_current_pspace_and_thread restore
;
9206 scoped_mock_context
<test_target_ops
> target1 (arch
);
9207 scoped_mock_context
<test_target_ops
> target2 (arch
);
9208 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9210 ptid_t
old_ptid (111, 222);
9211 ptid_t
new_ptid (111, 333);
9213 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9214 target1
.mock_thread
.ptid
= old_ptid
;
9215 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9216 target2
.mock_thread
.ptid
= old_ptid
;
9218 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9219 set_current_inferior (&target2
.mock_inferior
);
9221 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9223 gdb_assert (inferior_ptid
== old_ptid
);
9227 } /* namespace selftests */
9229 #endif /* GDB_SELF_TEST */
9231 void _initialize_infrun ();
9233 _initialize_infrun ()
9235 struct cmd_list_element
*c
;
9237 /* Register extra event sources in the event loop. */
9238 infrun_async_inferior_event_token
9239 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9242 add_info ("signals", info_signals_command
, _("\
9243 What debugger does when program gets various signals.\n\
9244 Specify a signal as argument to print info on that signal only."));
9245 add_info_alias ("handle", "signals", 0);
9247 c
= add_com ("handle", class_run
, handle_command
, _("\
9248 Specify how to handle signals.\n\
9249 Usage: handle SIGNAL [ACTIONS]\n\
9250 Args are signals and actions to apply to those signals.\n\
9251 If no actions are specified, the current settings for the specified signals\n\
9252 will be displayed instead.\n\
9254 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9255 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9256 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9257 The special arg \"all\" is recognized to mean all signals except those\n\
9258 used by the debugger, typically SIGTRAP and SIGINT.\n\
9260 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9261 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9262 Stop means reenter debugger if this signal happens (implies print).\n\
9263 Print means print a message if this signal happens.\n\
9264 Pass means let program see this signal; otherwise program doesn't know.\n\
9265 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9266 Pass and Stop may be combined.\n\
9268 Multiple signals may be specified. Signal numbers and signal names\n\
9269 may be interspersed with actions, with the actions being performed for\n\
9270 all signals cumulatively specified."));
9271 set_cmd_completer (c
, handle_completer
);
9274 stop_command
= add_cmd ("stop", class_obscure
,
9275 not_just_help_class_command
, _("\
9276 There is no `stop' command, but you can set a hook on `stop'.\n\
9277 This allows you to set a list of commands to be run each time execution\n\
9278 of the program stops."), &cmdlist
);
9280 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9281 Set inferior debugging."), _("\
9282 Show inferior debugging."), _("\
9283 When non-zero, inferior specific debugging is enabled."),
9286 &setdebuglist
, &showdebuglist
);
9288 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9289 &debug_displaced
, _("\
9290 Set displaced stepping debugging."), _("\
9291 Show displaced stepping debugging."), _("\
9292 When non-zero, displaced stepping specific debugging is enabled."),
9294 show_debug_displaced
,
9295 &setdebuglist
, &showdebuglist
);
9297 add_setshow_boolean_cmd ("non-stop", no_class
,
9299 Set whether gdb controls the inferior in non-stop mode."), _("\
9300 Show whether gdb controls the inferior in non-stop mode."), _("\
9301 When debugging a multi-threaded program and this setting is\n\
9302 off (the default, also called all-stop mode), when one thread stops\n\
9303 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9304 all other threads in the program while you interact with the thread of\n\
9305 interest. When you continue or step a thread, you can allow the other\n\
9306 threads to run, or have them remain stopped, but while you inspect any\n\
9307 thread's state, all threads stop.\n\
9309 In non-stop mode, when one thread stops, other threads can continue\n\
9310 to run freely. You'll be able to step each thread independently,\n\
9311 leave it stopped or free to run as needed."),
9317 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9320 signal_print
[i
] = 1;
9321 signal_program
[i
] = 1;
9322 signal_catch
[i
] = 0;
9325 /* Signals caused by debugger's own actions should not be given to
9326 the program afterwards.
9328 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9329 explicitly specifies that it should be delivered to the target
9330 program. Typically, that would occur when a user is debugging a
9331 target monitor on a simulator: the target monitor sets a
9332 breakpoint; the simulator encounters this breakpoint and halts
9333 the simulation handing control to GDB; GDB, noting that the stop
9334 address doesn't map to any known breakpoint, returns control back
9335 to the simulator; the simulator then delivers the hardware
9336 equivalent of a GDB_SIGNAL_TRAP to the program being
9338 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9339 signal_program
[GDB_SIGNAL_INT
] = 0;
9341 /* Signals that are not errors should not normally enter the debugger. */
9342 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9343 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9344 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9345 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9346 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9347 signal_print
[GDB_SIGNAL_PROF
] = 0;
9348 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9349 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9350 signal_stop
[GDB_SIGNAL_IO
] = 0;
9351 signal_print
[GDB_SIGNAL_IO
] = 0;
9352 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9353 signal_print
[GDB_SIGNAL_POLL
] = 0;
9354 signal_stop
[GDB_SIGNAL_URG
] = 0;
9355 signal_print
[GDB_SIGNAL_URG
] = 0;
9356 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9357 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9358 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9359 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9361 /* These signals are used internally by user-level thread
9362 implementations. (See signal(5) on Solaris.) Like the above
9363 signals, a healthy program receives and handles them as part of
9364 its normal operation. */
9365 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9366 signal_print
[GDB_SIGNAL_LWP
] = 0;
9367 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9368 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9369 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9370 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9371 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9372 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9374 /* Update cached state. */
9375 signal_cache_update (-1);
9377 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9378 &stop_on_solib_events
, _("\
9379 Set stopping for shared library events."), _("\
9380 Show stopping for shared library events."), _("\
9381 If nonzero, gdb will give control to the user when the dynamic linker\n\
9382 notifies gdb of shared library events. The most common event of interest\n\
9383 to the user would be loading/unloading of a new library."),
9384 set_stop_on_solib_events
,
9385 show_stop_on_solib_events
,
9386 &setlist
, &showlist
);
9388 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9389 follow_fork_mode_kind_names
,
9390 &follow_fork_mode_string
, _("\
9391 Set debugger response to a program call of fork or vfork."), _("\
9392 Show debugger response to a program call of fork or vfork."), _("\
9393 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9394 parent - the original process is debugged after a fork\n\
9395 child - the new process is debugged after a fork\n\
9396 The unfollowed process will continue to run.\n\
9397 By default, the debugger will follow the parent process."),
9399 show_follow_fork_mode_string
,
9400 &setlist
, &showlist
);
9402 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9403 follow_exec_mode_names
,
9404 &follow_exec_mode_string
, _("\
9405 Set debugger response to a program call of exec."), _("\
9406 Show debugger response to a program call of exec."), _("\
9407 An exec call replaces the program image of a process.\n\
9409 follow-exec-mode can be:\n\
9411 new - the debugger creates a new inferior and rebinds the process\n\
9412 to this new inferior. The program the process was running before\n\
9413 the exec call can be restarted afterwards by restarting the original\n\
9416 same - the debugger keeps the process bound to the same inferior.\n\
9417 The new executable image replaces the previous executable loaded in\n\
9418 the inferior. Restarting the inferior after the exec call restarts\n\
9419 the executable the process was running after the exec call.\n\
9421 By default, the debugger will use the same inferior."),
9423 show_follow_exec_mode_string
,
9424 &setlist
, &showlist
);
9426 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9427 scheduler_enums
, &scheduler_mode
, _("\
9428 Set mode for locking scheduler during execution."), _("\
9429 Show mode for locking scheduler during execution."), _("\
9430 off == no locking (threads may preempt at any time)\n\
9431 on == full locking (no thread except the current thread may run)\n\
9432 This applies to both normal execution and replay mode.\n\
9433 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9434 In this mode, other threads may run during other commands.\n\
9435 This applies to both normal execution and replay mode.\n\
9436 replay == scheduler locked in replay mode and unlocked during normal execution."),
9437 set_schedlock_func
, /* traps on target vector */
9438 show_scheduler_mode
,
9439 &setlist
, &showlist
);
9441 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9442 Set mode for resuming threads of all processes."), _("\
9443 Show mode for resuming threads of all processes."), _("\
9444 When on, execution commands (such as 'continue' or 'next') resume all\n\
9445 threads of all processes. When off (which is the default), execution\n\
9446 commands only resume the threads of the current process. The set of\n\
9447 threads that are resumed is further refined by the scheduler-locking\n\
9448 mode (see help set scheduler-locking)."),
9450 show_schedule_multiple
,
9451 &setlist
, &showlist
);
9453 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9454 Set mode of the step operation."), _("\
9455 Show mode of the step operation."), _("\
9456 When set, doing a step over a function without debug line information\n\
9457 will stop at the first instruction of that function. Otherwise, the\n\
9458 function is skipped and the step command stops at a different source line."),
9460 show_step_stop_if_no_debug
,
9461 &setlist
, &showlist
);
9463 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9464 &can_use_displaced_stepping
, _("\
9465 Set debugger's willingness to use displaced stepping."), _("\
9466 Show debugger's willingness to use displaced stepping."), _("\
9467 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9468 supported by the target architecture. If off, gdb will not use displaced\n\
9469 stepping to step over breakpoints, even if such is supported by the target\n\
9470 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9471 if the target architecture supports it and non-stop mode is active, but will not\n\
9472 use it in all-stop mode (see help set non-stop)."),
9474 show_can_use_displaced_stepping
,
9475 &setlist
, &showlist
);
9477 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9478 &exec_direction
, _("Set direction of execution.\n\
9479 Options are 'forward' or 'reverse'."),
9480 _("Show direction of execution (forward/reverse)."),
9481 _("Tells gdb whether to execute forward or backward."),
9482 set_exec_direction_func
, show_exec_direction_func
,
9483 &setlist
, &showlist
);
9485 /* Set/show detach-on-fork: user-settable mode. */
9487 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9488 Set whether gdb will detach the child of a fork."), _("\
9489 Show whether gdb will detach the child of a fork."), _("\
9490 Tells gdb whether to detach the child of a fork."),
9491 NULL
, NULL
, &setlist
, &showlist
);
9493 /* Set/show disable address space randomization mode. */
9495 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9496 &disable_randomization
, _("\
9497 Set disabling of debuggee's virtual address space randomization."), _("\
9498 Show disabling of debuggee's virtual address space randomization."), _("\
9499 When this mode is on (which is the default), randomization of the virtual\n\
9500 address space is disabled. Standalone programs run with the randomization\n\
9501 enabled by default on some platforms."),
9502 &set_disable_randomization
,
9503 &show_disable_randomization
,
9504 &setlist
, &showlist
);
9506 /* ptid initializations */
9507 inferior_ptid
= null_ptid
;
9508 target_last_wait_ptid
= minus_one_ptid
;
9510 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9511 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9512 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9513 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9514 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
);
9516 /* Explicitly create without lookup, since that tries to create a
9517 value with a void typed value, and when we get here, gdbarch
9518 isn't initialized yet. At this point, we're quite sure there
9519 isn't another convenience variable of the same name. */
9520 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9522 add_setshow_boolean_cmd ("observer", no_class
,
9523 &observer_mode_1
, _("\
9524 Set whether gdb controls the inferior in observer mode."), _("\
9525 Show whether gdb controls the inferior in observer mode."), _("\
9526 In observer mode, GDB can get data from the inferior, but not\n\
9527 affect its execution. Registers and memory may not be changed,\n\
9528 breakpoints may not be set, and the program cannot be interrupted\n\
9536 selftests::register_test ("infrun_thread_ptid_changed",
9537 selftests::infrun_thread_ptid_changed
);