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 queue 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
*step_over_queue_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_closure. */
1464 displaced_step_closure::~displaced_step_closure () = default;
1466 /* Get the displaced stepping state of inferior INF. */
1468 static displaced_step_inferior_state
*
1469 get_displaced_stepping_state (inferior
*inf
)
1471 return &inf
->displaced_step_state
;
1474 /* Returns true if any inferior has a thread doing a displaced
1478 displaced_step_in_progress_any_inferior ()
1480 for (inferior
*i
: all_inferiors ())
1482 if (i
->displaced_step_state
.step_thread
!= nullptr)
1489 /* Return true if THREAD is doing a displaced step. */
1492 displaced_step_in_progress_thread (thread_info
*thread
)
1494 gdb_assert (thread
!= NULL
);
1496 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1499 /* Return true if INF has a thread doing a displaced step. */
1502 displaced_step_in_progress (inferior
*inf
)
1504 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1507 /* If inferior is in displaced stepping, and ADDR equals to starting address
1508 of copy area, return corresponding displaced_step_closure. Otherwise,
1511 struct displaced_step_closure
*
1512 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1514 displaced_step_inferior_state
*displaced
1515 = get_displaced_stepping_state (current_inferior ());
1517 /* If checking the mode of displaced instruction in copy area. */
1518 if (displaced
->step_thread
!= nullptr
1519 && displaced
->step_copy
== addr
)
1520 return displaced
->step_closure
.get ();
1526 infrun_inferior_exit (struct inferior
*inf
)
1528 inf
->displaced_step_state
.reset ();
1531 /* If ON, and the architecture supports it, GDB will use displaced
1532 stepping to step over breakpoints. If OFF, or if the architecture
1533 doesn't support it, GDB will instead use the traditional
1534 hold-and-step approach. If AUTO (which is the default), GDB will
1535 decide which technique to use to step over breakpoints depending on
1536 whether the target works in a non-stop way (see use_displaced_stepping). */
1538 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1541 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1542 struct cmd_list_element
*c
,
1545 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1546 fprintf_filtered (file
,
1547 _("Debugger's willingness to use displaced stepping "
1548 "to step over breakpoints is %s (currently %s).\n"),
1549 value
, target_is_non_stop_p () ? "on" : "off");
1551 fprintf_filtered (file
,
1552 _("Debugger's willingness to use displaced stepping "
1553 "to step over breakpoints is %s.\n"), value
);
1556 /* Return true if the gdbarch implements the required methods to use
1557 displaced stepping. */
1560 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1562 /* Only check for the presence of step_copy_insn. Other required methods
1563 are checked by the gdbarch validation. */
1564 return gdbarch_displaced_step_copy_insn_p (arch
);
1567 /* Return non-zero if displaced stepping can/should be used to step
1568 over breakpoints of thread TP. */
1571 use_displaced_stepping (thread_info
*tp
)
1573 /* If the user disabled it explicitly, don't use displaced stepping. */
1574 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1577 /* If "auto", only use displaced stepping if the target operates in a non-stop
1579 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1580 && !target_is_non_stop_p ())
1583 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1585 /* If the architecture doesn't implement displaced stepping, don't use
1587 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1590 /* If recording, don't use displaced stepping. */
1591 if (find_record_target () != nullptr)
1594 displaced_step_inferior_state
*displaced_state
1595 = get_displaced_stepping_state (tp
->inf
);
1597 /* If displaced stepping failed before for this inferior, don't bother trying
1599 if (displaced_state
->failed_before
)
1605 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1608 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1610 displaced
->reset ();
1613 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1614 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1616 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1621 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1625 for (size_t i
= 0; i
< len
; i
++)
1628 ret
+= string_printf ("%02x", buf
[i
]);
1630 ret
+= string_printf (" %02x", buf
[i
]);
1636 /* Prepare to single-step, using displaced stepping.
1638 Note that we cannot use displaced stepping when we have a signal to
1639 deliver. If we have a signal to deliver and an instruction to step
1640 over, then after the step, there will be no indication from the
1641 target whether the thread entered a signal handler or ignored the
1642 signal and stepped over the instruction successfully --- both cases
1643 result in a simple SIGTRAP. In the first case we mustn't do a
1644 fixup, and in the second case we must --- but we can't tell which.
1645 Comments in the code for 'random signals' in handle_inferior_event
1646 explain how we handle this case instead.
1648 Returns 1 if preparing was successful -- this thread is going to be
1649 stepped now; 0 if displaced stepping this thread got queued; or -1
1650 if this instruction can't be displaced stepped. */
1653 displaced_step_prepare_throw (thread_info
*tp
)
1655 regcache
*regcache
= get_thread_regcache (tp
);
1656 struct gdbarch
*gdbarch
= regcache
->arch ();
1657 const address_space
*aspace
= regcache
->aspace ();
1658 CORE_ADDR original
, copy
;
1662 /* We should never reach this function if the architecture does not
1663 support displaced stepping. */
1664 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1666 /* Nor if the thread isn't meant to step over a breakpoint. */
1667 gdb_assert (tp
->control
.trap_expected
);
1669 /* Disable range stepping while executing in the scratch pad. We
1670 want a single-step even if executing the displaced instruction in
1671 the scratch buffer lands within the stepping range (e.g., a
1673 tp
->control
.may_range_step
= 0;
1675 /* We have to displaced step one thread at a time, as we only have
1676 access to a single scratch space per inferior. */
1678 displaced_step_inferior_state
*displaced
1679 = get_displaced_stepping_state (tp
->inf
);
1681 if (displaced
->step_thread
!= nullptr)
1683 /* Already waiting for a displaced step to finish. Defer this
1684 request and place in queue. */
1686 displaced_debug_printf ("deferring step of %s",
1687 target_pid_to_str (tp
->ptid
).c_str ());
1689 thread_step_over_chain_enqueue (tp
);
1693 displaced_debug_printf ("stepping %s now",
1694 target_pid_to_str (tp
->ptid
).c_str ());
1696 displaced_step_reset (displaced
);
1698 scoped_restore_current_thread restore_thread
;
1700 switch_to_thread (tp
);
1702 original
= regcache_read_pc (regcache
);
1704 copy
= gdbarch_displaced_step_location (gdbarch
);
1705 len
= gdbarch_max_insn_length (gdbarch
);
1707 if (breakpoint_in_range_p (aspace
, copy
, len
))
1709 /* There's a breakpoint set in the scratch pad location range
1710 (which is usually around the entry point). We'd either
1711 install it before resuming, which would overwrite/corrupt the
1712 scratch pad, or if it was already inserted, this displaced
1713 step would overwrite it. The latter is OK in the sense that
1714 we already assume that no thread is going to execute the code
1715 in the scratch pad range (after initial startup) anyway, but
1716 the former is unacceptable. Simply punt and fallback to
1717 stepping over this breakpoint in-line. */
1718 displaced_debug_printf ("breakpoint set in scratch pad. "
1719 "Stepping over breakpoint in-line instead.");
1724 /* Save the original contents of the copy area. */
1725 displaced
->step_saved_copy
.resize (len
);
1726 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1728 throw_error (MEMORY_ERROR
,
1729 _("Error accessing memory address %s (%s) for "
1730 "displaced-stepping scratch space."),
1731 paddress (gdbarch
, copy
), safe_strerror (status
));
1733 displaced_debug_printf ("saved %s: %s",
1734 paddress (gdbarch
, copy
),
1735 displaced_step_dump_bytes
1736 (displaced
->step_saved_copy
.data (), len
).c_str ());
1738 displaced
->step_closure
1739 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1740 if (displaced
->step_closure
== NULL
)
1742 /* The architecture doesn't know how or want to displaced step
1743 this instruction or instruction sequence. Fallback to
1744 stepping over the breakpoint in-line. */
1748 /* Save the information we need to fix things up if the step
1750 displaced
->step_thread
= tp
;
1751 displaced
->step_gdbarch
= gdbarch
;
1752 displaced
->step_original
= original
;
1753 displaced
->step_copy
= copy
;
1756 displaced_step_reset_cleanup
cleanup (displaced
);
1758 /* Resume execution at the copy. */
1759 regcache_write_pc (regcache
, copy
);
1764 displaced_debug_printf ("displaced pc to %s", paddress (gdbarch
, copy
));
1769 /* Wrapper for displaced_step_prepare_throw that disabled further
1770 attempts at displaced stepping if we get a memory error. */
1773 displaced_step_prepare (thread_info
*thread
)
1779 prepared
= displaced_step_prepare_throw (thread
);
1781 catch (const gdb_exception_error
&ex
)
1783 struct displaced_step_inferior_state
*displaced_state
;
1785 if (ex
.error
!= MEMORY_ERROR
1786 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1789 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1792 /* Be verbose if "set displaced-stepping" is "on", silent if
1794 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1796 warning (_("disabling displaced stepping: %s"),
1800 /* Disable further displaced stepping attempts. */
1802 = get_displaced_stepping_state (thread
->inf
);
1803 displaced_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 struct displaced_step_inferior_state
*displaced
1846 = get_displaced_stepping_state (event_thread
->inf
);
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
= step_over_queue_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
= 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 thread_step_over_chain_remove (tp
);
1973 if (step_over_queue_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 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 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 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
= get_displaced_stepping_state (inf
);
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 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 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 ();
5291 /* If checking displaced stepping is supported, and thread
5292 ecs->ptid is displaced stepping. */
5293 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5295 struct inferior
*parent_inf
5296 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5297 struct regcache
*child_regcache
;
5298 CORE_ADDR parent_pc
;
5300 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5302 struct displaced_step_inferior_state
*displaced
5303 = get_displaced_stepping_state (parent_inf
);
5305 /* Restore scratch pad for child process. */
5306 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5309 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5310 indicating that the displaced stepping of syscall instruction
5311 has been done. Perform cleanup for parent process here. Note
5312 that this operation also cleans up the child process for vfork,
5313 because their pages are shared. */
5314 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5315 /* Start a new step-over in another thread if there's one
5319 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5320 the child's PC is also within the scratchpad. Set the child's PC
5321 to the parent's PC value, which has already been fixed up.
5322 FIXME: we use the parent's aspace here, although we're touching
5323 the child, because the child hasn't been added to the inferior
5324 list yet at this point. */
5327 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5328 ecs
->ws
.value
.related_pid
,
5330 parent_inf
->aspace
);
5331 /* Read PC value of parent process. */
5332 parent_pc
= regcache_read_pc (regcache
);
5334 displaced_debug_printf ("write child pc from %s to %s",
5336 regcache_read_pc (child_regcache
)),
5337 paddress (gdbarch
, parent_pc
));
5339 regcache_write_pc (child_regcache
, parent_pc
);
5343 context_switch (ecs
);
5345 /* Immediately detach breakpoints from the child before there's
5346 any chance of letting the user delete breakpoints from the
5347 breakpoint lists. If we don't do this early, it's easy to
5348 leave left over traps in the child, vis: "break foo; catch
5349 fork; c; <fork>; del; c; <child calls foo>". We only follow
5350 the fork on the last `continue', and by that time the
5351 breakpoint at "foo" is long gone from the breakpoint table.
5352 If we vforked, then we don't need to unpatch here, since both
5353 parent and child are sharing the same memory pages; we'll
5354 need to unpatch at follow/detach time instead to be certain
5355 that new breakpoints added between catchpoint hit time and
5356 vfork follow are detached. */
5357 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5359 /* This won't actually modify the breakpoint list, but will
5360 physically remove the breakpoints from the child. */
5361 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5364 delete_just_stopped_threads_single_step_breakpoints ();
5366 /* In case the event is caught by a catchpoint, remember that
5367 the event is to be followed at the next resume of the thread,
5368 and not immediately. */
5369 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5371 ecs
->event_thread
->suspend
.stop_pc
5372 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5374 ecs
->event_thread
->control
.stop_bpstat
5375 = bpstat_stop_status (get_current_regcache ()->aspace (),
5376 ecs
->event_thread
->suspend
.stop_pc
,
5377 ecs
->event_thread
, &ecs
->ws
);
5379 if (handle_stop_requested (ecs
))
5382 /* If no catchpoint triggered for this, then keep going. Note
5383 that we're interested in knowing the bpstat actually causes a
5384 stop, not just if it may explain the signal. Software
5385 watchpoints, for example, always appear in the bpstat. */
5386 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5389 = (follow_fork_mode_string
== follow_fork_mode_child
);
5391 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5393 process_stratum_target
*targ
5394 = ecs
->event_thread
->inf
->process_target ();
5396 bool should_resume
= follow_fork ();
5398 /* Note that one of these may be an invalid pointer,
5399 depending on detach_fork. */
5400 thread_info
*parent
= ecs
->event_thread
;
5402 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5404 /* At this point, the parent is marked running, and the
5405 child is marked stopped. */
5407 /* If not resuming the parent, mark it stopped. */
5408 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5409 parent
->set_running (false);
5411 /* If resuming the child, mark it running. */
5412 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5413 child
->set_running (true);
5415 /* In non-stop mode, also resume the other branch. */
5416 if (!detach_fork
&& (non_stop
5417 || (sched_multi
&& target_is_non_stop_p ())))
5420 switch_to_thread (parent
);
5422 switch_to_thread (child
);
5424 ecs
->event_thread
= inferior_thread ();
5425 ecs
->ptid
= inferior_ptid
;
5430 switch_to_thread (child
);
5432 switch_to_thread (parent
);
5434 ecs
->event_thread
= inferior_thread ();
5435 ecs
->ptid
= inferior_ptid
;
5443 process_event_stop_test (ecs
);
5446 case TARGET_WAITKIND_VFORK_DONE
:
5447 /* Done with the shared memory region. Re-insert breakpoints in
5448 the parent, and keep going. */
5450 context_switch (ecs
);
5452 current_inferior ()->waiting_for_vfork_done
= 0;
5453 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5455 if (handle_stop_requested (ecs
))
5458 /* This also takes care of reinserting breakpoints in the
5459 previously locked inferior. */
5463 case TARGET_WAITKIND_EXECD
:
5465 /* Note we can't read registers yet (the stop_pc), because we
5466 don't yet know the inferior's post-exec architecture.
5467 'stop_pc' is explicitly read below instead. */
5468 switch_to_thread_no_regs (ecs
->event_thread
);
5470 /* Do whatever is necessary to the parent branch of the vfork. */
5471 handle_vfork_child_exec_or_exit (1);
5473 /* This causes the eventpoints and symbol table to be reset.
5474 Must do this now, before trying to determine whether to
5476 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5478 /* In follow_exec we may have deleted the original thread and
5479 created a new one. Make sure that the event thread is the
5480 execd thread for that case (this is a nop otherwise). */
5481 ecs
->event_thread
= inferior_thread ();
5483 ecs
->event_thread
->suspend
.stop_pc
5484 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5486 ecs
->event_thread
->control
.stop_bpstat
5487 = bpstat_stop_status (get_current_regcache ()->aspace (),
5488 ecs
->event_thread
->suspend
.stop_pc
,
5489 ecs
->event_thread
, &ecs
->ws
);
5491 /* Note that this may be referenced from inside
5492 bpstat_stop_status above, through inferior_has_execd. */
5493 xfree (ecs
->ws
.value
.execd_pathname
);
5494 ecs
->ws
.value
.execd_pathname
= NULL
;
5496 if (handle_stop_requested (ecs
))
5499 /* If no catchpoint triggered for this, then keep going. */
5500 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5502 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5506 process_event_stop_test (ecs
);
5509 /* Be careful not to try to gather much state about a thread
5510 that's in a syscall. It's frequently a losing proposition. */
5511 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5512 /* Getting the current syscall number. */
5513 if (handle_syscall_event (ecs
) == 0)
5514 process_event_stop_test (ecs
);
5517 /* Before examining the threads further, step this thread to
5518 get it entirely out of the syscall. (We get notice of the
5519 event when the thread is just on the verge of exiting a
5520 syscall. Stepping one instruction seems to get it back
5522 case TARGET_WAITKIND_SYSCALL_RETURN
:
5523 if (handle_syscall_event (ecs
) == 0)
5524 process_event_stop_test (ecs
);
5527 case TARGET_WAITKIND_STOPPED
:
5528 handle_signal_stop (ecs
);
5531 case TARGET_WAITKIND_NO_HISTORY
:
5532 /* Reverse execution: target ran out of history info. */
5534 /* Switch to the stopped thread. */
5535 context_switch (ecs
);
5536 infrun_debug_printf ("stopped");
5538 delete_just_stopped_threads_single_step_breakpoints ();
5539 ecs
->event_thread
->suspend
.stop_pc
5540 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5542 if (handle_stop_requested (ecs
))
5545 gdb::observers::no_history
.notify ();
5551 /* Restart threads back to what they were trying to do back when we
5552 paused them for an in-line step-over. The EVENT_THREAD thread is
5556 restart_threads (struct thread_info
*event_thread
)
5558 /* In case the instruction just stepped spawned a new thread. */
5559 update_thread_list ();
5561 for (thread_info
*tp
: all_non_exited_threads ())
5563 switch_to_thread_no_regs (tp
);
5565 if (tp
== event_thread
)
5567 infrun_debug_printf ("restart threads: [%s] is event thread",
5568 target_pid_to_str (tp
->ptid
).c_str ());
5572 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5574 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5575 target_pid_to_str (tp
->ptid
).c_str ());
5581 infrun_debug_printf ("restart threads: [%s] resumed",
5582 target_pid_to_str (tp
->ptid
).c_str ());
5583 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5587 if (thread_is_in_step_over_chain (tp
))
5589 infrun_debug_printf ("restart threads: [%s] needs step-over",
5590 target_pid_to_str (tp
->ptid
).c_str ());
5591 gdb_assert (!tp
->resumed
);
5596 if (tp
->suspend
.waitstatus_pending_p
)
5598 infrun_debug_printf ("restart threads: [%s] has pending status",
5599 target_pid_to_str (tp
->ptid
).c_str ());
5604 gdb_assert (!tp
->stop_requested
);
5606 /* If some thread needs to start a step-over at this point, it
5607 should still be in the step-over queue, and thus skipped
5609 if (thread_still_needs_step_over (tp
))
5611 internal_error (__FILE__
, __LINE__
,
5612 "thread [%s] needs a step-over, but not in "
5613 "step-over queue\n",
5614 target_pid_to_str (tp
->ptid
).c_str ());
5617 if (currently_stepping (tp
))
5619 infrun_debug_printf ("restart threads: [%s] was stepping",
5620 target_pid_to_str (tp
->ptid
).c_str ());
5621 keep_going_stepped_thread (tp
);
5625 struct execution_control_state ecss
;
5626 struct execution_control_state
*ecs
= &ecss
;
5628 infrun_debug_printf ("restart threads: [%s] continuing",
5629 target_pid_to_str (tp
->ptid
).c_str ());
5630 reset_ecs (ecs
, tp
);
5631 switch_to_thread (tp
);
5632 keep_going_pass_signal (ecs
);
5637 /* Callback for iterate_over_threads. Find a resumed thread that has
5638 a pending waitstatus. */
5641 resumed_thread_with_pending_status (struct thread_info
*tp
,
5645 && tp
->suspend
.waitstatus_pending_p
);
5648 /* Called when we get an event that may finish an in-line or
5649 out-of-line (displaced stepping) step-over started previously.
5650 Return true if the event is processed and we should go back to the
5651 event loop; false if the caller should continue processing the
5655 finish_step_over (struct execution_control_state
*ecs
)
5657 displaced_step_fixup (ecs
->event_thread
,
5658 ecs
->event_thread
->suspend
.stop_signal
);
5660 bool had_step_over_info
= step_over_info_valid_p ();
5662 if (had_step_over_info
)
5664 /* If we're stepping over a breakpoint with all threads locked,
5665 then only the thread that was stepped should be reporting
5667 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5669 clear_step_over_info ();
5672 if (!target_is_non_stop_p ())
5675 /* Start a new step-over in another thread if there's one that
5679 /* If we were stepping over a breakpoint before, and haven't started
5680 a new in-line step-over sequence, then restart all other threads
5681 (except the event thread). We can't do this in all-stop, as then
5682 e.g., we wouldn't be able to issue any other remote packet until
5683 these other threads stop. */
5684 if (had_step_over_info
&& !step_over_info_valid_p ())
5686 struct thread_info
*pending
;
5688 /* If we only have threads with pending statuses, the restart
5689 below won't restart any thread and so nothing re-inserts the
5690 breakpoint we just stepped over. But we need it inserted
5691 when we later process the pending events, otherwise if
5692 another thread has a pending event for this breakpoint too,
5693 we'd discard its event (because the breakpoint that
5694 originally caused the event was no longer inserted). */
5695 context_switch (ecs
);
5696 insert_breakpoints ();
5698 restart_threads (ecs
->event_thread
);
5700 /* If we have events pending, go through handle_inferior_event
5701 again, picking up a pending event at random. This avoids
5702 thread starvation. */
5704 /* But not if we just stepped over a watchpoint in order to let
5705 the instruction execute so we can evaluate its expression.
5706 The set of watchpoints that triggered is recorded in the
5707 breakpoint objects themselves (see bp->watchpoint_triggered).
5708 If we processed another event first, that other event could
5709 clobber this info. */
5710 if (ecs
->event_thread
->stepping_over_watchpoint
)
5713 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5715 if (pending
!= NULL
)
5717 struct thread_info
*tp
= ecs
->event_thread
;
5718 struct regcache
*regcache
;
5720 infrun_debug_printf ("found resumed threads with "
5721 "pending events, saving status");
5723 gdb_assert (pending
!= tp
);
5725 /* Record the event thread's event for later. */
5726 save_waitstatus (tp
, &ecs
->ws
);
5727 /* This was cleared early, by handle_inferior_event. Set it
5728 so this pending event is considered by
5732 gdb_assert (!tp
->executing
);
5734 regcache
= get_thread_regcache (tp
);
5735 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5737 infrun_debug_printf ("saved stop_pc=%s for %s "
5738 "(currently_stepping=%d)",
5739 paddress (target_gdbarch (),
5740 tp
->suspend
.stop_pc
),
5741 target_pid_to_str (tp
->ptid
).c_str (),
5742 currently_stepping (tp
));
5744 /* This in-line step-over finished; clear this so we won't
5745 start a new one. This is what handle_signal_stop would
5746 do, if we returned false. */
5747 tp
->stepping_over_breakpoint
= 0;
5749 /* Wake up the event loop again. */
5750 mark_async_event_handler (infrun_async_inferior_event_token
);
5752 prepare_to_wait (ecs
);
5760 /* Come here when the program has stopped with a signal. */
5763 handle_signal_stop (struct execution_control_state
*ecs
)
5765 struct frame_info
*frame
;
5766 struct gdbarch
*gdbarch
;
5767 int stopped_by_watchpoint
;
5768 enum stop_kind stop_soon
;
5771 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5773 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5775 /* Do we need to clean up the state of a thread that has
5776 completed a displaced single-step? (Doing so usually affects
5777 the PC, so do it here, before we set stop_pc.) */
5778 if (finish_step_over (ecs
))
5781 /* If we either finished a single-step or hit a breakpoint, but
5782 the user wanted this thread to be stopped, pretend we got a
5783 SIG0 (generic unsignaled stop). */
5784 if (ecs
->event_thread
->stop_requested
5785 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5786 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5788 ecs
->event_thread
->suspend
.stop_pc
5789 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5793 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5794 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5796 switch_to_thread (ecs
->event_thread
);
5798 infrun_debug_printf ("stop_pc=%s",
5799 paddress (reg_gdbarch
,
5800 ecs
->event_thread
->suspend
.stop_pc
));
5801 if (target_stopped_by_watchpoint ())
5805 infrun_debug_printf ("stopped by watchpoint");
5807 if (target_stopped_data_address (current_top_target (), &addr
))
5808 infrun_debug_printf ("stopped data address=%s",
5809 paddress (reg_gdbarch
, addr
));
5811 infrun_debug_printf ("(no data address available)");
5815 /* This is originated from start_remote(), start_inferior() and
5816 shared libraries hook functions. */
5817 stop_soon
= get_inferior_stop_soon (ecs
);
5818 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5820 context_switch (ecs
);
5821 infrun_debug_printf ("quietly stopped");
5822 stop_print_frame
= true;
5827 /* This originates from attach_command(). We need to overwrite
5828 the stop_signal here, because some kernels don't ignore a
5829 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5830 See more comments in inferior.h. On the other hand, if we
5831 get a non-SIGSTOP, report it to the user - assume the backend
5832 will handle the SIGSTOP if it should show up later.
5834 Also consider that the attach is complete when we see a
5835 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5836 target extended-remote report it instead of a SIGSTOP
5837 (e.g. gdbserver). We already rely on SIGTRAP being our
5838 signal, so this is no exception.
5840 Also consider that the attach is complete when we see a
5841 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5842 the target to stop all threads of the inferior, in case the
5843 low level attach operation doesn't stop them implicitly. If
5844 they weren't stopped implicitly, then the stub will report a
5845 GDB_SIGNAL_0, meaning: stopped for no particular reason
5846 other than GDB's request. */
5847 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5848 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5849 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5850 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5852 stop_print_frame
= true;
5854 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5858 /* See if something interesting happened to the non-current thread. If
5859 so, then switch to that thread. */
5860 if (ecs
->ptid
!= inferior_ptid
)
5862 infrun_debug_printf ("context switch");
5864 context_switch (ecs
);
5866 if (deprecated_context_hook
)
5867 deprecated_context_hook (ecs
->event_thread
->global_num
);
5870 /* At this point, get hold of the now-current thread's frame. */
5871 frame
= get_current_frame ();
5872 gdbarch
= get_frame_arch (frame
);
5874 /* Pull the single step breakpoints out of the target. */
5875 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5877 struct regcache
*regcache
;
5880 regcache
= get_thread_regcache (ecs
->event_thread
);
5881 const address_space
*aspace
= regcache
->aspace ();
5883 pc
= regcache_read_pc (regcache
);
5885 /* However, before doing so, if this single-step breakpoint was
5886 actually for another thread, set this thread up for moving
5888 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5891 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5893 infrun_debug_printf ("[%s] hit another thread's single-step "
5895 target_pid_to_str (ecs
->ptid
).c_str ());
5896 ecs
->hit_singlestep_breakpoint
= 1;
5901 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5902 target_pid_to_str (ecs
->ptid
).c_str ());
5905 delete_just_stopped_threads_single_step_breakpoints ();
5907 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5908 && ecs
->event_thread
->control
.trap_expected
5909 && ecs
->event_thread
->stepping_over_watchpoint
)
5910 stopped_by_watchpoint
= 0;
5912 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5914 /* If necessary, step over this watchpoint. We'll be back to display
5916 if (stopped_by_watchpoint
5917 && (target_have_steppable_watchpoint ()
5918 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5920 /* At this point, we are stopped at an instruction which has
5921 attempted to write to a piece of memory under control of
5922 a watchpoint. The instruction hasn't actually executed
5923 yet. If we were to evaluate the watchpoint expression
5924 now, we would get the old value, and therefore no change
5925 would seem to have occurred.
5927 In order to make watchpoints work `right', we really need
5928 to complete the memory write, and then evaluate the
5929 watchpoint expression. We do this by single-stepping the
5932 It may not be necessary to disable the watchpoint to step over
5933 it. For example, the PA can (with some kernel cooperation)
5934 single step over a watchpoint without disabling the watchpoint.
5936 It is far more common to need to disable a watchpoint to step
5937 the inferior over it. If we have non-steppable watchpoints,
5938 we must disable the current watchpoint; it's simplest to
5939 disable all watchpoints.
5941 Any breakpoint at PC must also be stepped over -- if there's
5942 one, it will have already triggered before the watchpoint
5943 triggered, and we either already reported it to the user, or
5944 it didn't cause a stop and we called keep_going. In either
5945 case, if there was a breakpoint at PC, we must be trying to
5947 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5952 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5953 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5954 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5955 ecs
->event_thread
->control
.stop_step
= 0;
5956 stop_print_frame
= true;
5957 stopped_by_random_signal
= 0;
5958 bpstat stop_chain
= NULL
;
5960 /* Hide inlined functions starting here, unless we just performed stepi or
5961 nexti. After stepi and nexti, always show the innermost frame (not any
5962 inline function call sites). */
5963 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5965 const address_space
*aspace
5966 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5968 /* skip_inline_frames is expensive, so we avoid it if we can
5969 determine that the address is one where functions cannot have
5970 been inlined. This improves performance with inferiors that
5971 load a lot of shared libraries, because the solib event
5972 breakpoint is defined as the address of a function (i.e. not
5973 inline). Note that we have to check the previous PC as well
5974 as the current one to catch cases when we have just
5975 single-stepped off a breakpoint prior to reinstating it.
5976 Note that we're assuming that the code we single-step to is
5977 not inline, but that's not definitive: there's nothing
5978 preventing the event breakpoint function from containing
5979 inlined code, and the single-step ending up there. If the
5980 user had set a breakpoint on that inlined code, the missing
5981 skip_inline_frames call would break things. Fortunately
5982 that's an extremely unlikely scenario. */
5983 if (!pc_at_non_inline_function (aspace
,
5984 ecs
->event_thread
->suspend
.stop_pc
,
5986 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5987 && ecs
->event_thread
->control
.trap_expected
5988 && pc_at_non_inline_function (aspace
,
5989 ecs
->event_thread
->prev_pc
,
5992 stop_chain
= build_bpstat_chain (aspace
,
5993 ecs
->event_thread
->suspend
.stop_pc
,
5995 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5997 /* Re-fetch current thread's frame in case that invalidated
5999 frame
= get_current_frame ();
6000 gdbarch
= get_frame_arch (frame
);
6004 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6005 && ecs
->event_thread
->control
.trap_expected
6006 && gdbarch_single_step_through_delay_p (gdbarch
)
6007 && currently_stepping (ecs
->event_thread
))
6009 /* We're trying to step off a breakpoint. Turns out that we're
6010 also on an instruction that needs to be stepped multiple
6011 times before it's been fully executing. E.g., architectures
6012 with a delay slot. It needs to be stepped twice, once for
6013 the instruction and once for the delay slot. */
6014 int step_through_delay
6015 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6017 if (step_through_delay
)
6018 infrun_debug_printf ("step through delay");
6020 if (ecs
->event_thread
->control
.step_range_end
== 0
6021 && step_through_delay
)
6023 /* The user issued a continue when stopped at a breakpoint.
6024 Set up for another trap and get out of here. */
6025 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6029 else if (step_through_delay
)
6031 /* The user issued a step when stopped at a breakpoint.
6032 Maybe we should stop, maybe we should not - the delay
6033 slot *might* correspond to a line of source. In any
6034 case, don't decide that here, just set
6035 ecs->stepping_over_breakpoint, making sure we
6036 single-step again before breakpoints are re-inserted. */
6037 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6041 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6042 handles this event. */
6043 ecs
->event_thread
->control
.stop_bpstat
6044 = bpstat_stop_status (get_current_regcache ()->aspace (),
6045 ecs
->event_thread
->suspend
.stop_pc
,
6046 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6048 /* Following in case break condition called a
6050 stop_print_frame
= true;
6052 /* This is where we handle "moribund" watchpoints. Unlike
6053 software breakpoints traps, hardware watchpoint traps are
6054 always distinguishable from random traps. If no high-level
6055 watchpoint is associated with the reported stop data address
6056 anymore, then the bpstat does not explain the signal ---
6057 simply make sure to ignore it if `stopped_by_watchpoint' is
6060 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6061 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6063 && stopped_by_watchpoint
)
6065 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6069 /* NOTE: cagney/2003-03-29: These checks for a random signal
6070 at one stage in the past included checks for an inferior
6071 function call's call dummy's return breakpoint. The original
6072 comment, that went with the test, read:
6074 ``End of a stack dummy. Some systems (e.g. Sony news) give
6075 another signal besides SIGTRAP, so check here as well as
6078 If someone ever tries to get call dummys on a
6079 non-executable stack to work (where the target would stop
6080 with something like a SIGSEGV), then those tests might need
6081 to be re-instated. Given, however, that the tests were only
6082 enabled when momentary breakpoints were not being used, I
6083 suspect that it won't be the case.
6085 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6086 be necessary for call dummies on a non-executable stack on
6089 /* See if the breakpoints module can explain the signal. */
6091 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6092 ecs
->event_thread
->suspend
.stop_signal
);
6094 /* Maybe this was a trap for a software breakpoint that has since
6096 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6098 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6099 ecs
->event_thread
->suspend
.stop_pc
))
6101 struct regcache
*regcache
;
6104 /* Re-adjust PC to what the program would see if GDB was not
6106 regcache
= get_thread_regcache (ecs
->event_thread
);
6107 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6110 gdb::optional
<scoped_restore_tmpl
<int>>
6111 restore_operation_disable
;
6113 if (record_full_is_used ())
6114 restore_operation_disable
.emplace
6115 (record_full_gdb_operation_disable_set ());
6117 regcache_write_pc (regcache
,
6118 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6123 /* A delayed software breakpoint event. Ignore the trap. */
6124 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6129 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6130 has since been removed. */
6131 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6133 /* A delayed hardware breakpoint event. Ignore the trap. */
6134 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6139 /* If not, perhaps stepping/nexting can. */
6141 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6142 && currently_stepping (ecs
->event_thread
));
6144 /* Perhaps the thread hit a single-step breakpoint of _another_
6145 thread. Single-step breakpoints are transparent to the
6146 breakpoints module. */
6148 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6150 /* No? Perhaps we got a moribund watchpoint. */
6152 random_signal
= !stopped_by_watchpoint
;
6154 /* Always stop if the user explicitly requested this thread to
6156 if (ecs
->event_thread
->stop_requested
)
6159 infrun_debug_printf ("user-requested stop");
6162 /* For the program's own signals, act according to
6163 the signal handling tables. */
6167 /* Signal not for debugging purposes. */
6168 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6169 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6171 infrun_debug_printf ("random signal (%s)",
6172 gdb_signal_to_symbol_string (stop_signal
));
6174 stopped_by_random_signal
= 1;
6176 /* Always stop on signals if we're either just gaining control
6177 of the program, or the user explicitly requested this thread
6178 to remain stopped. */
6179 if (stop_soon
!= NO_STOP_QUIETLY
6180 || ecs
->event_thread
->stop_requested
6182 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6188 /* Notify observers the signal has "handle print" set. Note we
6189 returned early above if stopping; normal_stop handles the
6190 printing in that case. */
6191 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6193 /* The signal table tells us to print about this signal. */
6194 target_terminal::ours_for_output ();
6195 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6196 target_terminal::inferior ();
6199 /* Clear the signal if it should not be passed. */
6200 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6201 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6203 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6204 && ecs
->event_thread
->control
.trap_expected
6205 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6207 /* We were just starting a new sequence, attempting to
6208 single-step off of a breakpoint and expecting a SIGTRAP.
6209 Instead this signal arrives. This signal will take us out
6210 of the stepping range so GDB needs to remember to, when
6211 the signal handler returns, resume stepping off that
6213 /* To simplify things, "continue" is forced to use the same
6214 code paths as single-step - set a breakpoint at the
6215 signal return address and then, once hit, step off that
6217 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6219 insert_hp_step_resume_breakpoint_at_frame (frame
);
6220 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6221 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6222 ecs
->event_thread
->control
.trap_expected
= 0;
6224 /* If we were nexting/stepping some other thread, switch to
6225 it, so that we don't continue it, losing control. */
6226 if (!switch_back_to_stepped_thread (ecs
))
6231 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6232 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6234 || ecs
->event_thread
->control
.step_range_end
== 1)
6235 && frame_id_eq (get_stack_frame_id (frame
),
6236 ecs
->event_thread
->control
.step_stack_frame_id
)
6237 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6239 /* The inferior is about to take a signal that will take it
6240 out of the single step range. Set a breakpoint at the
6241 current PC (which is presumably where the signal handler
6242 will eventually return) and then allow the inferior to
6245 Note that this is only needed for a signal delivered
6246 while in the single-step range. Nested signals aren't a
6247 problem as they eventually all return. */
6248 infrun_debug_printf ("signal may take us out of single-step range");
6250 clear_step_over_info ();
6251 insert_hp_step_resume_breakpoint_at_frame (frame
);
6252 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6253 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6254 ecs
->event_thread
->control
.trap_expected
= 0;
6259 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6260 when either there's a nested signal, or when there's a
6261 pending signal enabled just as the signal handler returns
6262 (leaving the inferior at the step-resume-breakpoint without
6263 actually executing it). Either way continue until the
6264 breakpoint is really hit. */
6266 if (!switch_back_to_stepped_thread (ecs
))
6268 infrun_debug_printf ("random signal, keep going");
6275 process_event_stop_test (ecs
);
6278 /* Come here when we've got some debug event / signal we can explain
6279 (IOW, not a random signal), and test whether it should cause a
6280 stop, or whether we should resume the inferior (transparently).
6281 E.g., could be a breakpoint whose condition evaluates false; we
6282 could be still stepping within the line; etc. */
6285 process_event_stop_test (struct execution_control_state
*ecs
)
6287 struct symtab_and_line stop_pc_sal
;
6288 struct frame_info
*frame
;
6289 struct gdbarch
*gdbarch
;
6290 CORE_ADDR jmp_buf_pc
;
6291 struct bpstat_what what
;
6293 /* Handle cases caused by hitting a breakpoint. */
6295 frame
= get_current_frame ();
6296 gdbarch
= get_frame_arch (frame
);
6298 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6300 if (what
.call_dummy
)
6302 stop_stack_dummy
= what
.call_dummy
;
6305 /* A few breakpoint types have callbacks associated (e.g.,
6306 bp_jit_event). Run them now. */
6307 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6309 /* If we hit an internal event that triggers symbol changes, the
6310 current frame will be invalidated within bpstat_what (e.g., if we
6311 hit an internal solib event). Re-fetch it. */
6312 frame
= get_current_frame ();
6313 gdbarch
= get_frame_arch (frame
);
6315 switch (what
.main_action
)
6317 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6318 /* If we hit the breakpoint at longjmp while stepping, we
6319 install a momentary breakpoint at the target of the
6322 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6324 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6326 if (what
.is_longjmp
)
6328 struct value
*arg_value
;
6330 /* If we set the longjmp breakpoint via a SystemTap probe,
6331 then use it to extract the arguments. The destination PC
6332 is the third argument to the probe. */
6333 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6336 jmp_buf_pc
= value_as_address (arg_value
);
6337 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6339 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6340 || !gdbarch_get_longjmp_target (gdbarch
,
6341 frame
, &jmp_buf_pc
))
6343 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6344 "(!gdbarch_get_longjmp_target)");
6349 /* Insert a breakpoint at resume address. */
6350 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6353 check_exception_resume (ecs
, frame
);
6357 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6359 struct frame_info
*init_frame
;
6361 /* There are several cases to consider.
6363 1. The initiating frame no longer exists. In this case we
6364 must stop, because the exception or longjmp has gone too
6367 2. The initiating frame exists, and is the same as the
6368 current frame. We stop, because the exception or longjmp
6371 3. The initiating frame exists and is different from the
6372 current frame. This means the exception or longjmp has
6373 been caught beneath the initiating frame, so keep going.
6375 4. longjmp breakpoint has been placed just to protect
6376 against stale dummy frames and user is not interested in
6377 stopping around longjmps. */
6379 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6381 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6383 delete_exception_resume_breakpoint (ecs
->event_thread
);
6385 if (what
.is_longjmp
)
6387 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6389 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6397 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6401 struct frame_id current_id
6402 = get_frame_id (get_current_frame ());
6403 if (frame_id_eq (current_id
,
6404 ecs
->event_thread
->initiating_frame
))
6406 /* Case 2. Fall through. */
6416 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6418 delete_step_resume_breakpoint (ecs
->event_thread
);
6420 end_stepping_range (ecs
);
6424 case BPSTAT_WHAT_SINGLE
:
6425 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6426 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6427 /* Still need to check other stuff, at least the case where we
6428 are stepping and step out of the right range. */
6431 case BPSTAT_WHAT_STEP_RESUME
:
6432 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6434 delete_step_resume_breakpoint (ecs
->event_thread
);
6435 if (ecs
->event_thread
->control
.proceed_to_finish
6436 && execution_direction
== EXEC_REVERSE
)
6438 struct thread_info
*tp
= ecs
->event_thread
;
6440 /* We are finishing a function in reverse, and just hit the
6441 step-resume breakpoint at the start address of the
6442 function, and we're almost there -- just need to back up
6443 by one more single-step, which should take us back to the
6445 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6449 fill_in_stop_func (gdbarch
, ecs
);
6450 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6451 && execution_direction
== EXEC_REVERSE
)
6453 /* We are stepping over a function call in reverse, and just
6454 hit the step-resume breakpoint at the start address of
6455 the function. Go back to single-stepping, which should
6456 take us back to the function call. */
6457 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6463 case BPSTAT_WHAT_STOP_NOISY
:
6464 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6465 stop_print_frame
= true;
6467 /* Assume the thread stopped for a breakpoint. We'll still check
6468 whether a/the breakpoint is there when the thread is next
6470 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6475 case BPSTAT_WHAT_STOP_SILENT
:
6476 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6477 stop_print_frame
= false;
6479 /* Assume the thread stopped for a breakpoint. We'll still check
6480 whether a/the breakpoint is there when the thread is next
6482 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6486 case BPSTAT_WHAT_HP_STEP_RESUME
:
6487 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6489 delete_step_resume_breakpoint (ecs
->event_thread
);
6490 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6492 /* Back when the step-resume breakpoint was inserted, we
6493 were trying to single-step off a breakpoint. Go back to
6495 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6496 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6502 case BPSTAT_WHAT_KEEP_CHECKING
:
6506 /* If we stepped a permanent breakpoint and we had a high priority
6507 step-resume breakpoint for the address we stepped, but we didn't
6508 hit it, then we must have stepped into the signal handler. The
6509 step-resume was only necessary to catch the case of _not_
6510 stepping into the handler, so delete it, and fall through to
6511 checking whether the step finished. */
6512 if (ecs
->event_thread
->stepped_breakpoint
)
6514 struct breakpoint
*sr_bp
6515 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6518 && sr_bp
->loc
->permanent
6519 && sr_bp
->type
== bp_hp_step_resume
6520 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6522 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6523 delete_step_resume_breakpoint (ecs
->event_thread
);
6524 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6528 /* We come here if we hit a breakpoint but should not stop for it.
6529 Possibly we also were stepping and should stop for that. So fall
6530 through and test for stepping. But, if not stepping, do not
6533 /* In all-stop mode, if we're currently stepping but have stopped in
6534 some other thread, we need to switch back to the stepped thread. */
6535 if (switch_back_to_stepped_thread (ecs
))
6538 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6540 infrun_debug_printf ("step-resume breakpoint is inserted");
6542 /* Having a step-resume breakpoint overrides anything
6543 else having to do with stepping commands until
6544 that breakpoint is reached. */
6549 if (ecs
->event_thread
->control
.step_range_end
== 0)
6551 infrun_debug_printf ("no stepping, continue");
6552 /* Likewise if we aren't even stepping. */
6557 /* Re-fetch current thread's frame in case the code above caused
6558 the frame cache to be re-initialized, making our FRAME variable
6559 a dangling pointer. */
6560 frame
= get_current_frame ();
6561 gdbarch
= get_frame_arch (frame
);
6562 fill_in_stop_func (gdbarch
, ecs
);
6564 /* If stepping through a line, keep going if still within it.
6566 Note that step_range_end is the address of the first instruction
6567 beyond the step range, and NOT the address of the last instruction
6570 Note also that during reverse execution, we may be stepping
6571 through a function epilogue and therefore must detect when
6572 the current-frame changes in the middle of a line. */
6574 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6576 && (execution_direction
!= EXEC_REVERSE
6577 || frame_id_eq (get_frame_id (frame
),
6578 ecs
->event_thread
->control
.step_frame_id
)))
6581 ("stepping inside range [%s-%s]",
6582 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6583 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6585 /* Tentatively re-enable range stepping; `resume' disables it if
6586 necessary (e.g., if we're stepping over a breakpoint or we
6587 have software watchpoints). */
6588 ecs
->event_thread
->control
.may_range_step
= 1;
6590 /* When stepping backward, stop at beginning of line range
6591 (unless it's the function entry point, in which case
6592 keep going back to the call point). */
6593 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6594 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6595 && stop_pc
!= ecs
->stop_func_start
6596 && execution_direction
== EXEC_REVERSE
)
6597 end_stepping_range (ecs
);
6604 /* We stepped out of the stepping range. */
6606 /* If we are stepping at the source level and entered the runtime
6607 loader dynamic symbol resolution code...
6609 EXEC_FORWARD: we keep on single stepping until we exit the run
6610 time loader code and reach the callee's address.
6612 EXEC_REVERSE: we've already executed the callee (backward), and
6613 the runtime loader code is handled just like any other
6614 undebuggable function call. Now we need only keep stepping
6615 backward through the trampoline code, and that's handled further
6616 down, so there is nothing for us to do here. */
6618 if (execution_direction
!= EXEC_REVERSE
6619 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6620 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6622 CORE_ADDR pc_after_resolver
=
6623 gdbarch_skip_solib_resolver (gdbarch
,
6624 ecs
->event_thread
->suspend
.stop_pc
);
6626 infrun_debug_printf ("stepped into dynsym resolve code");
6628 if (pc_after_resolver
)
6630 /* Set up a step-resume breakpoint at the address
6631 indicated by SKIP_SOLIB_RESOLVER. */
6632 symtab_and_line sr_sal
;
6633 sr_sal
.pc
= pc_after_resolver
;
6634 sr_sal
.pspace
= get_frame_program_space (frame
);
6636 insert_step_resume_breakpoint_at_sal (gdbarch
,
6637 sr_sal
, null_frame_id
);
6644 /* Step through an indirect branch thunk. */
6645 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6646 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6647 ecs
->event_thread
->suspend
.stop_pc
))
6649 infrun_debug_printf ("stepped into indirect branch thunk");
6654 if (ecs
->event_thread
->control
.step_range_end
!= 1
6655 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6656 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6657 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6659 infrun_debug_printf ("stepped into signal trampoline");
6660 /* The inferior, while doing a "step" or "next", has ended up in
6661 a signal trampoline (either by a signal being delivered or by
6662 the signal handler returning). Just single-step until the
6663 inferior leaves the trampoline (either by calling the handler
6669 /* If we're in the return path from a shared library trampoline,
6670 we want to proceed through the trampoline when stepping. */
6671 /* macro/2012-04-25: This needs to come before the subroutine
6672 call check below as on some targets return trampolines look
6673 like subroutine calls (MIPS16 return thunks). */
6674 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6675 ecs
->event_thread
->suspend
.stop_pc
,
6676 ecs
->stop_func_name
)
6677 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6679 /* Determine where this trampoline returns. */
6680 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6681 CORE_ADDR real_stop_pc
6682 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6684 infrun_debug_printf ("stepped into solib return tramp");
6686 /* Only proceed through if we know where it's going. */
6689 /* And put the step-breakpoint there and go until there. */
6690 symtab_and_line sr_sal
;
6691 sr_sal
.pc
= real_stop_pc
;
6692 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6693 sr_sal
.pspace
= get_frame_program_space (frame
);
6695 /* Do not specify what the fp should be when we stop since
6696 on some machines the prologue is where the new fp value
6698 insert_step_resume_breakpoint_at_sal (gdbarch
,
6699 sr_sal
, null_frame_id
);
6701 /* Restart without fiddling with the step ranges or
6708 /* Check for subroutine calls. The check for the current frame
6709 equalling the step ID is not necessary - the check of the
6710 previous frame's ID is sufficient - but it is a common case and
6711 cheaper than checking the previous frame's ID.
6713 NOTE: frame_id_eq will never report two invalid frame IDs as
6714 being equal, so to get into this block, both the current and
6715 previous frame must have valid frame IDs. */
6716 /* The outer_frame_id check is a heuristic to detect stepping
6717 through startup code. If we step over an instruction which
6718 sets the stack pointer from an invalid value to a valid value,
6719 we may detect that as a subroutine call from the mythical
6720 "outermost" function. This could be fixed by marking
6721 outermost frames as !stack_p,code_p,special_p. Then the
6722 initial outermost frame, before sp was valid, would
6723 have code_addr == &_start. See the comment in frame_id_eq
6725 if (!frame_id_eq (get_stack_frame_id (frame
),
6726 ecs
->event_thread
->control
.step_stack_frame_id
)
6727 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6728 ecs
->event_thread
->control
.step_stack_frame_id
)
6729 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6731 || (ecs
->event_thread
->control
.step_start_function
6732 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6734 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6735 CORE_ADDR real_stop_pc
;
6737 infrun_debug_printf ("stepped into subroutine");
6739 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6741 /* I presume that step_over_calls is only 0 when we're
6742 supposed to be stepping at the assembly language level
6743 ("stepi"). Just stop. */
6744 /* And this works the same backward as frontward. MVS */
6745 end_stepping_range (ecs
);
6749 /* Reverse stepping through solib trampolines. */
6751 if (execution_direction
== EXEC_REVERSE
6752 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6753 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6754 || (ecs
->stop_func_start
== 0
6755 && in_solib_dynsym_resolve_code (stop_pc
))))
6757 /* Any solib trampoline code can be handled in reverse
6758 by simply continuing to single-step. We have already
6759 executed the solib function (backwards), and a few
6760 steps will take us back through the trampoline to the
6766 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6768 /* We're doing a "next".
6770 Normal (forward) execution: set a breakpoint at the
6771 callee's return address (the address at which the caller
6774 Reverse (backward) execution. set the step-resume
6775 breakpoint at the start of the function that we just
6776 stepped into (backwards), and continue to there. When we
6777 get there, we'll need to single-step back to the caller. */
6779 if (execution_direction
== EXEC_REVERSE
)
6781 /* If we're already at the start of the function, we've either
6782 just stepped backward into a single instruction function,
6783 or stepped back out of a signal handler to the first instruction
6784 of the function. Just keep going, which will single-step back
6786 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6788 /* Normal function call return (static or dynamic). */
6789 symtab_and_line sr_sal
;
6790 sr_sal
.pc
= ecs
->stop_func_start
;
6791 sr_sal
.pspace
= get_frame_program_space (frame
);
6792 insert_step_resume_breakpoint_at_sal (gdbarch
,
6793 sr_sal
, null_frame_id
);
6797 insert_step_resume_breakpoint_at_caller (frame
);
6803 /* If we are in a function call trampoline (a stub between the
6804 calling routine and the real function), locate the real
6805 function. That's what tells us (a) whether we want to step
6806 into it at all, and (b) what prologue we want to run to the
6807 end of, if we do step into it. */
6808 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6809 if (real_stop_pc
== 0)
6810 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6811 if (real_stop_pc
!= 0)
6812 ecs
->stop_func_start
= real_stop_pc
;
6814 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6816 symtab_and_line sr_sal
;
6817 sr_sal
.pc
= ecs
->stop_func_start
;
6818 sr_sal
.pspace
= get_frame_program_space (frame
);
6820 insert_step_resume_breakpoint_at_sal (gdbarch
,
6821 sr_sal
, null_frame_id
);
6826 /* If we have line number information for the function we are
6827 thinking of stepping into and the function isn't on the skip
6830 If there are several symtabs at that PC (e.g. with include
6831 files), just want to know whether *any* of them have line
6832 numbers. find_pc_line handles this. */
6834 struct symtab_and_line tmp_sal
;
6836 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6837 if (tmp_sal
.line
!= 0
6838 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6840 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6842 if (execution_direction
== EXEC_REVERSE
)
6843 handle_step_into_function_backward (gdbarch
, ecs
);
6845 handle_step_into_function (gdbarch
, ecs
);
6850 /* If we have no line number and the step-stop-if-no-debug is
6851 set, we stop the step so that the user has a chance to switch
6852 in assembly mode. */
6853 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6854 && step_stop_if_no_debug
)
6856 end_stepping_range (ecs
);
6860 if (execution_direction
== EXEC_REVERSE
)
6862 /* If we're already at the start of the function, we've either just
6863 stepped backward into a single instruction function without line
6864 number info, or stepped back out of a signal handler to the first
6865 instruction of the function without line number info. Just keep
6866 going, which will single-step back to the caller. */
6867 if (ecs
->stop_func_start
!= stop_pc
)
6869 /* Set a breakpoint at callee's start address.
6870 From there we can step once and be back in the caller. */
6871 symtab_and_line sr_sal
;
6872 sr_sal
.pc
= ecs
->stop_func_start
;
6873 sr_sal
.pspace
= get_frame_program_space (frame
);
6874 insert_step_resume_breakpoint_at_sal (gdbarch
,
6875 sr_sal
, null_frame_id
);
6879 /* Set a breakpoint at callee's return address (the address
6880 at which the caller will resume). */
6881 insert_step_resume_breakpoint_at_caller (frame
);
6887 /* Reverse stepping through solib trampolines. */
6889 if (execution_direction
== EXEC_REVERSE
6890 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6892 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6894 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6895 || (ecs
->stop_func_start
== 0
6896 && in_solib_dynsym_resolve_code (stop_pc
)))
6898 /* Any solib trampoline code can be handled in reverse
6899 by simply continuing to single-step. We have already
6900 executed the solib function (backwards), and a few
6901 steps will take us back through the trampoline to the
6906 else if (in_solib_dynsym_resolve_code (stop_pc
))
6908 /* Stepped backward into the solib dynsym resolver.
6909 Set a breakpoint at its start and continue, then
6910 one more step will take us out. */
6911 symtab_and_line sr_sal
;
6912 sr_sal
.pc
= ecs
->stop_func_start
;
6913 sr_sal
.pspace
= get_frame_program_space (frame
);
6914 insert_step_resume_breakpoint_at_sal (gdbarch
,
6915 sr_sal
, null_frame_id
);
6921 /* This always returns the sal for the inner-most frame when we are in a
6922 stack of inlined frames, even if GDB actually believes that it is in a
6923 more outer frame. This is checked for below by calls to
6924 inline_skipped_frames. */
6925 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6927 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6928 the trampoline processing logic, however, there are some trampolines
6929 that have no names, so we should do trampoline handling first. */
6930 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6931 && ecs
->stop_func_name
== NULL
6932 && stop_pc_sal
.line
== 0)
6934 infrun_debug_printf ("stepped into undebuggable function");
6936 /* The inferior just stepped into, or returned to, an
6937 undebuggable function (where there is no debugging information
6938 and no line number corresponding to the address where the
6939 inferior stopped). Since we want to skip this kind of code,
6940 we keep going until the inferior returns from this
6941 function - unless the user has asked us not to (via
6942 set step-mode) or we no longer know how to get back
6943 to the call site. */
6944 if (step_stop_if_no_debug
6945 || !frame_id_p (frame_unwind_caller_id (frame
)))
6947 /* If we have no line number and the step-stop-if-no-debug
6948 is set, we stop the step so that the user has a chance to
6949 switch in assembly mode. */
6950 end_stepping_range (ecs
);
6955 /* Set a breakpoint at callee's return address (the address
6956 at which the caller will resume). */
6957 insert_step_resume_breakpoint_at_caller (frame
);
6963 if (ecs
->event_thread
->control
.step_range_end
== 1)
6965 /* It is stepi or nexti. We always want to stop stepping after
6967 infrun_debug_printf ("stepi/nexti");
6968 end_stepping_range (ecs
);
6972 if (stop_pc_sal
.line
== 0)
6974 /* We have no line number information. That means to stop
6975 stepping (does this always happen right after one instruction,
6976 when we do "s" in a function with no line numbers,
6977 or can this happen as a result of a return or longjmp?). */
6978 infrun_debug_printf ("line number info");
6979 end_stepping_range (ecs
);
6983 /* Look for "calls" to inlined functions, part one. If the inline
6984 frame machinery detected some skipped call sites, we have entered
6985 a new inline function. */
6987 if (frame_id_eq (get_frame_id (get_current_frame ()),
6988 ecs
->event_thread
->control
.step_frame_id
)
6989 && inline_skipped_frames (ecs
->event_thread
))
6991 infrun_debug_printf ("stepped into inlined function");
6993 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6995 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6997 /* For "step", we're going to stop. But if the call site
6998 for this inlined function is on the same source line as
6999 we were previously stepping, go down into the function
7000 first. Otherwise stop at the call site. */
7002 if (call_sal
.line
== ecs
->event_thread
->current_line
7003 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7005 step_into_inline_frame (ecs
->event_thread
);
7006 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7013 end_stepping_range (ecs
);
7018 /* For "next", we should stop at the call site if it is on a
7019 different source line. Otherwise continue through the
7020 inlined function. */
7021 if (call_sal
.line
== ecs
->event_thread
->current_line
7022 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7025 end_stepping_range (ecs
);
7030 /* Look for "calls" to inlined functions, part two. If we are still
7031 in the same real function we were stepping through, but we have
7032 to go further up to find the exact frame ID, we are stepping
7033 through a more inlined call beyond its call site. */
7035 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7036 && !frame_id_eq (get_frame_id (get_current_frame ()),
7037 ecs
->event_thread
->control
.step_frame_id
)
7038 && stepped_in_from (get_current_frame (),
7039 ecs
->event_thread
->control
.step_frame_id
))
7041 infrun_debug_printf ("stepping through inlined function");
7043 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7044 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7047 end_stepping_range (ecs
);
7051 bool refresh_step_info
= true;
7052 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7053 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7054 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7056 if (stop_pc_sal
.is_stmt
)
7058 /* We are at the start of a different line. So stop. Note that
7059 we don't stop if we step into the middle of a different line.
7060 That is said to make things like for (;;) statements work
7062 infrun_debug_printf ("stepped to a different line");
7063 end_stepping_range (ecs
);
7066 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7067 ecs
->event_thread
->control
.step_frame_id
))
7069 /* We are at the start of a different line, however, this line is
7070 not marked as a statement, and we have not changed frame. We
7071 ignore this line table entry, and continue stepping forward,
7072 looking for a better place to stop. */
7073 refresh_step_info
= false;
7074 infrun_debug_printf ("stepped to a different line, but "
7075 "it's not the start of a statement");
7079 /* We aren't done stepping.
7081 Optimize by setting the stepping range to the line.
7082 (We might not be in the original line, but if we entered a
7083 new line in mid-statement, we continue stepping. This makes
7084 things like for(;;) statements work better.)
7086 If we entered a SAL that indicates a non-statement line table entry,
7087 then we update the stepping range, but we don't update the step info,
7088 which includes things like the line number we are stepping away from.
7089 This means we will stop when we find a line table entry that is marked
7090 as is-statement, even if it matches the non-statement one we just
7093 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7094 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7095 ecs
->event_thread
->control
.may_range_step
= 1;
7096 if (refresh_step_info
)
7097 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7099 infrun_debug_printf ("keep going");
7103 /* In all-stop mode, if we're currently stepping but have stopped in
7104 some other thread, we may need to switch back to the stepped
7105 thread. Returns true we set the inferior running, false if we left
7106 it stopped (and the event needs further processing). */
7109 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7111 if (!target_is_non_stop_p ())
7113 struct thread_info
*stepping_thread
;
7115 /* If any thread is blocked on some internal breakpoint, and we
7116 simply need to step over that breakpoint to get it going
7117 again, do that first. */
7119 /* However, if we see an event for the stepping thread, then we
7120 know all other threads have been moved past their breakpoints
7121 already. Let the caller check whether the step is finished,
7122 etc., before deciding to move it past a breakpoint. */
7123 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7126 /* Check if the current thread is blocked on an incomplete
7127 step-over, interrupted by a random signal. */
7128 if (ecs
->event_thread
->control
.trap_expected
7129 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7132 ("need to finish step-over of [%s]",
7133 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7138 /* Check if the current thread is blocked by a single-step
7139 breakpoint of another thread. */
7140 if (ecs
->hit_singlestep_breakpoint
)
7142 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7143 target_pid_to_str (ecs
->ptid
).c_str ());
7148 /* If this thread needs yet another step-over (e.g., stepping
7149 through a delay slot), do it first before moving on to
7151 if (thread_still_needs_step_over (ecs
->event_thread
))
7154 ("thread [%s] still needs step-over",
7155 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7160 /* If scheduler locking applies even if not stepping, there's no
7161 need to walk over threads. Above we've checked whether the
7162 current thread is stepping. If some other thread not the
7163 event thread is stepping, then it must be that scheduler
7164 locking is not in effect. */
7165 if (schedlock_applies (ecs
->event_thread
))
7168 /* Otherwise, we no longer expect a trap in the current thread.
7169 Clear the trap_expected flag before switching back -- this is
7170 what keep_going does as well, if we call it. */
7171 ecs
->event_thread
->control
.trap_expected
= 0;
7173 /* Likewise, clear the signal if it should not be passed. */
7174 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7175 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7177 /* Do all pending step-overs before actually proceeding with
7179 if (start_step_over ())
7181 prepare_to_wait (ecs
);
7185 /* Look for the stepping/nexting thread. */
7186 stepping_thread
= NULL
;
7188 for (thread_info
*tp
: all_non_exited_threads ())
7190 switch_to_thread_no_regs (tp
);
7192 /* Ignore threads of processes the caller is not
7195 && (tp
->inf
->process_target () != ecs
->target
7196 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7199 /* When stepping over a breakpoint, we lock all threads
7200 except the one that needs to move past the breakpoint.
7201 If a non-event thread has this set, the "incomplete
7202 step-over" check above should have caught it earlier. */
7203 if (tp
->control
.trap_expected
)
7205 internal_error (__FILE__
, __LINE__
,
7206 "[%s] has inconsistent state: "
7207 "trap_expected=%d\n",
7208 target_pid_to_str (tp
->ptid
).c_str (),
7209 tp
->control
.trap_expected
);
7212 /* Did we find the stepping thread? */
7213 if (tp
->control
.step_range_end
)
7215 /* Yep. There should only one though. */
7216 gdb_assert (stepping_thread
== NULL
);
7218 /* The event thread is handled at the top, before we
7220 gdb_assert (tp
!= ecs
->event_thread
);
7222 /* If some thread other than the event thread is
7223 stepping, then scheduler locking can't be in effect,
7224 otherwise we wouldn't have resumed the current event
7225 thread in the first place. */
7226 gdb_assert (!schedlock_applies (tp
));
7228 stepping_thread
= tp
;
7232 if (stepping_thread
!= NULL
)
7234 infrun_debug_printf ("switching back to stepped thread");
7236 if (keep_going_stepped_thread (stepping_thread
))
7238 prepare_to_wait (ecs
);
7243 switch_to_thread (ecs
->event_thread
);
7249 /* Set a previously stepped thread back to stepping. Returns true on
7250 success, false if the resume is not possible (e.g., the thread
7254 keep_going_stepped_thread (struct thread_info
*tp
)
7256 struct frame_info
*frame
;
7257 struct execution_control_state ecss
;
7258 struct execution_control_state
*ecs
= &ecss
;
7260 /* If the stepping thread exited, then don't try to switch back and
7261 resume it, which could fail in several different ways depending
7262 on the target. Instead, just keep going.
7264 We can find a stepping dead thread in the thread list in two
7267 - The target supports thread exit events, and when the target
7268 tries to delete the thread from the thread list, inferior_ptid
7269 pointed at the exiting thread. In such case, calling
7270 delete_thread does not really remove the thread from the list;
7271 instead, the thread is left listed, with 'exited' state.
7273 - The target's debug interface does not support thread exit
7274 events, and so we have no idea whatsoever if the previously
7275 stepping thread is still alive. For that reason, we need to
7276 synchronously query the target now. */
7278 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7280 infrun_debug_printf ("not resuming previously stepped thread, it has "
7287 infrun_debug_printf ("resuming previously stepped thread");
7289 reset_ecs (ecs
, tp
);
7290 switch_to_thread (tp
);
7292 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7293 frame
= get_current_frame ();
7295 /* If the PC of the thread we were trying to single-step has
7296 changed, then that thread has trapped or been signaled, but the
7297 event has not been reported to GDB yet. Re-poll the target
7298 looking for this particular thread's event (i.e. temporarily
7299 enable schedlock) by:
7301 - setting a break at the current PC
7302 - resuming that particular thread, only (by setting trap
7305 This prevents us continuously moving the single-step breakpoint
7306 forward, one instruction at a time, overstepping. */
7308 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7312 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7313 paddress (target_gdbarch (), tp
->prev_pc
),
7314 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7316 /* Clear the info of the previous step-over, as it's no longer
7317 valid (if the thread was trying to step over a breakpoint, it
7318 has already succeeded). It's what keep_going would do too,
7319 if we called it. Do this before trying to insert the sss
7320 breakpoint, otherwise if we were previously trying to step
7321 over this exact address in another thread, the breakpoint is
7323 clear_step_over_info ();
7324 tp
->control
.trap_expected
= 0;
7326 insert_single_step_breakpoint (get_frame_arch (frame
),
7327 get_frame_address_space (frame
),
7328 tp
->suspend
.stop_pc
);
7331 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7332 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7336 infrun_debug_printf ("expected thread still hasn't advanced");
7338 keep_going_pass_signal (ecs
);
7344 /* Is thread TP in the middle of (software or hardware)
7345 single-stepping? (Note the result of this function must never be
7346 passed directly as target_resume's STEP parameter.) */
7349 currently_stepping (struct thread_info
*tp
)
7351 return ((tp
->control
.step_range_end
7352 && tp
->control
.step_resume_breakpoint
== NULL
)
7353 || tp
->control
.trap_expected
7354 || tp
->stepped_breakpoint
7355 || bpstat_should_step ());
7358 /* Inferior has stepped into a subroutine call with source code that
7359 we should not step over. Do step to the first line of code in
7363 handle_step_into_function (struct gdbarch
*gdbarch
,
7364 struct execution_control_state
*ecs
)
7366 fill_in_stop_func (gdbarch
, ecs
);
7368 compunit_symtab
*cust
7369 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7370 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7371 ecs
->stop_func_start
7372 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7374 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7375 /* Use the step_resume_break to step until the end of the prologue,
7376 even if that involves jumps (as it seems to on the vax under
7378 /* If the prologue ends in the middle of a source line, continue to
7379 the end of that source line (if it is still within the function).
7380 Otherwise, just go to end of prologue. */
7381 if (stop_func_sal
.end
7382 && stop_func_sal
.pc
!= ecs
->stop_func_start
7383 && stop_func_sal
.end
< ecs
->stop_func_end
)
7384 ecs
->stop_func_start
= stop_func_sal
.end
;
7386 /* Architectures which require breakpoint adjustment might not be able
7387 to place a breakpoint at the computed address. If so, the test
7388 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7389 ecs->stop_func_start to an address at which a breakpoint may be
7390 legitimately placed.
7392 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7393 made, GDB will enter an infinite loop when stepping through
7394 optimized code consisting of VLIW instructions which contain
7395 subinstructions corresponding to different source lines. On
7396 FR-V, it's not permitted to place a breakpoint on any but the
7397 first subinstruction of a VLIW instruction. When a breakpoint is
7398 set, GDB will adjust the breakpoint address to the beginning of
7399 the VLIW instruction. Thus, we need to make the corresponding
7400 adjustment here when computing the stop address. */
7402 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7404 ecs
->stop_func_start
7405 = gdbarch_adjust_breakpoint_address (gdbarch
,
7406 ecs
->stop_func_start
);
7409 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7411 /* We are already there: stop now. */
7412 end_stepping_range (ecs
);
7417 /* Put the step-breakpoint there and go until there. */
7418 symtab_and_line sr_sal
;
7419 sr_sal
.pc
= ecs
->stop_func_start
;
7420 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7421 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7423 /* Do not specify what the fp should be when we stop since on
7424 some machines the prologue is where the new fp value is
7426 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7428 /* And make sure stepping stops right away then. */
7429 ecs
->event_thread
->control
.step_range_end
7430 = ecs
->event_thread
->control
.step_range_start
;
7435 /* Inferior has stepped backward into a subroutine call with source
7436 code that we should not step over. Do step to the beginning of the
7437 last line of code in it. */
7440 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7441 struct execution_control_state
*ecs
)
7443 struct compunit_symtab
*cust
;
7444 struct symtab_and_line stop_func_sal
;
7446 fill_in_stop_func (gdbarch
, ecs
);
7448 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7449 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7450 ecs
->stop_func_start
7451 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7453 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7455 /* OK, we're just going to keep stepping here. */
7456 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7458 /* We're there already. Just stop stepping now. */
7459 end_stepping_range (ecs
);
7463 /* Else just reset the step range and keep going.
7464 No step-resume breakpoint, they don't work for
7465 epilogues, which can have multiple entry paths. */
7466 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7467 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7473 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7474 This is used to both functions and to skip over code. */
7477 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7478 struct symtab_and_line sr_sal
,
7479 struct frame_id sr_id
,
7480 enum bptype sr_type
)
7482 /* There should never be more than one step-resume or longjmp-resume
7483 breakpoint per thread, so we should never be setting a new
7484 step_resume_breakpoint when one is already active. */
7485 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7486 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7488 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7489 paddress (gdbarch
, sr_sal
.pc
));
7491 inferior_thread ()->control
.step_resume_breakpoint
7492 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7496 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7497 struct symtab_and_line sr_sal
,
7498 struct frame_id sr_id
)
7500 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7505 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7506 This is used to skip a potential signal handler.
7508 This is called with the interrupted function's frame. The signal
7509 handler, when it returns, will resume the interrupted function at
7513 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7515 gdb_assert (return_frame
!= NULL
);
7517 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7519 symtab_and_line sr_sal
;
7520 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7521 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7522 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7524 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7525 get_stack_frame_id (return_frame
),
7529 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7530 is used to skip a function after stepping into it (for "next" or if
7531 the called function has no debugging information).
7533 The current function has almost always been reached by single
7534 stepping a call or return instruction. NEXT_FRAME belongs to the
7535 current function, and the breakpoint will be set at the caller's
7538 This is a separate function rather than reusing
7539 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7540 get_prev_frame, which may stop prematurely (see the implementation
7541 of frame_unwind_caller_id for an example). */
7544 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7546 /* We shouldn't have gotten here if we don't know where the call site
7548 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7550 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7552 symtab_and_line sr_sal
;
7553 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7554 frame_unwind_caller_pc (next_frame
));
7555 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7556 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7558 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7559 frame_unwind_caller_id (next_frame
));
7562 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7563 new breakpoint at the target of a jmp_buf. The handling of
7564 longjmp-resume uses the same mechanisms used for handling
7565 "step-resume" breakpoints. */
7568 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7570 /* There should never be more than one longjmp-resume breakpoint per
7571 thread, so we should never be setting a new
7572 longjmp_resume_breakpoint when one is already active. */
7573 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7575 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7576 paddress (gdbarch
, pc
));
7578 inferior_thread ()->control
.exception_resume_breakpoint
=
7579 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7582 /* Insert an exception resume breakpoint. TP is the thread throwing
7583 the exception. The block B is the block of the unwinder debug hook
7584 function. FRAME is the frame corresponding to the call to this
7585 function. SYM is the symbol of the function argument holding the
7586 target PC of the exception. */
7589 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7590 const struct block
*b
,
7591 struct frame_info
*frame
,
7596 struct block_symbol vsym
;
7597 struct value
*value
;
7599 struct breakpoint
*bp
;
7601 vsym
= lookup_symbol_search_name (sym
->search_name (),
7603 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7604 /* If the value was optimized out, revert to the old behavior. */
7605 if (! value_optimized_out (value
))
7607 handler
= value_as_address (value
);
7609 infrun_debug_printf ("exception resume at %lx",
7610 (unsigned long) handler
);
7612 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7614 bp_exception_resume
).release ();
7616 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7619 bp
->thread
= tp
->global_num
;
7620 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7623 catch (const gdb_exception_error
&e
)
7625 /* We want to ignore errors here. */
7629 /* A helper for check_exception_resume that sets an
7630 exception-breakpoint based on a SystemTap probe. */
7633 insert_exception_resume_from_probe (struct thread_info
*tp
,
7634 const struct bound_probe
*probe
,
7635 struct frame_info
*frame
)
7637 struct value
*arg_value
;
7639 struct breakpoint
*bp
;
7641 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7645 handler
= value_as_address (arg_value
);
7647 infrun_debug_printf ("exception resume at %s",
7648 paddress (probe
->objfile
->arch (), handler
));
7650 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7651 handler
, bp_exception_resume
).release ();
7652 bp
->thread
= tp
->global_num
;
7653 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7656 /* This is called when an exception has been intercepted. Check to
7657 see whether the exception's destination is of interest, and if so,
7658 set an exception resume breakpoint there. */
7661 check_exception_resume (struct execution_control_state
*ecs
,
7662 struct frame_info
*frame
)
7664 struct bound_probe probe
;
7665 struct symbol
*func
;
7667 /* First see if this exception unwinding breakpoint was set via a
7668 SystemTap probe point. If so, the probe has two arguments: the
7669 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7670 set a breakpoint there. */
7671 probe
= find_probe_by_pc (get_frame_pc (frame
));
7674 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7678 func
= get_frame_function (frame
);
7684 const struct block
*b
;
7685 struct block_iterator iter
;
7689 /* The exception breakpoint is a thread-specific breakpoint on
7690 the unwinder's debug hook, declared as:
7692 void _Unwind_DebugHook (void *cfa, void *handler);
7694 The CFA argument indicates the frame to which control is
7695 about to be transferred. HANDLER is the destination PC.
7697 We ignore the CFA and set a temporary breakpoint at HANDLER.
7698 This is not extremely efficient but it avoids issues in gdb
7699 with computing the DWARF CFA, and it also works even in weird
7700 cases such as throwing an exception from inside a signal
7703 b
= SYMBOL_BLOCK_VALUE (func
);
7704 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7706 if (!SYMBOL_IS_ARGUMENT (sym
))
7713 insert_exception_resume_breakpoint (ecs
->event_thread
,
7719 catch (const gdb_exception_error
&e
)
7725 stop_waiting (struct execution_control_state
*ecs
)
7727 infrun_debug_printf ("stop_waiting");
7729 /* Let callers know we don't want to wait for the inferior anymore. */
7730 ecs
->wait_some_more
= 0;
7732 /* If all-stop, but there exists a non-stop target, stop all
7733 threads now that we're presenting the stop to the user. */
7734 if (!non_stop
&& exists_non_stop_target ())
7735 stop_all_threads ();
7738 /* Like keep_going, but passes the signal to the inferior, even if the
7739 signal is set to nopass. */
7742 keep_going_pass_signal (struct execution_control_state
*ecs
)
7744 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7745 gdb_assert (!ecs
->event_thread
->resumed
);
7747 /* Save the pc before execution, to compare with pc after stop. */
7748 ecs
->event_thread
->prev_pc
7749 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7751 if (ecs
->event_thread
->control
.trap_expected
)
7753 struct thread_info
*tp
= ecs
->event_thread
;
7755 infrun_debug_printf ("%s has trap_expected set, "
7756 "resuming to collect trap",
7757 target_pid_to_str (tp
->ptid
).c_str ());
7759 /* We haven't yet gotten our trap, and either: intercepted a
7760 non-signal event (e.g., a fork); or took a signal which we
7761 are supposed to pass through to the inferior. Simply
7763 resume (ecs
->event_thread
->suspend
.stop_signal
);
7765 else if (step_over_info_valid_p ())
7767 /* Another thread is stepping over a breakpoint in-line. If
7768 this thread needs a step-over too, queue the request. In
7769 either case, this resume must be deferred for later. */
7770 struct thread_info
*tp
= ecs
->event_thread
;
7772 if (ecs
->hit_singlestep_breakpoint
7773 || thread_still_needs_step_over (tp
))
7775 infrun_debug_printf ("step-over already in progress: "
7776 "step-over for %s deferred",
7777 target_pid_to_str (tp
->ptid
).c_str ());
7778 thread_step_over_chain_enqueue (tp
);
7782 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7783 target_pid_to_str (tp
->ptid
).c_str ());
7788 struct regcache
*regcache
= get_current_regcache ();
7791 step_over_what step_what
;
7793 /* Either the trap was not expected, but we are continuing
7794 anyway (if we got a signal, the user asked it be passed to
7797 We got our expected trap, but decided we should resume from
7800 We're going to run this baby now!
7802 Note that insert_breakpoints won't try to re-insert
7803 already inserted breakpoints. Therefore, we don't
7804 care if breakpoints were already inserted, or not. */
7806 /* If we need to step over a breakpoint, and we're not using
7807 displaced stepping to do so, insert all breakpoints
7808 (watchpoints, etc.) but the one we're stepping over, step one
7809 instruction, and then re-insert the breakpoint when that step
7812 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7814 remove_bp
= (ecs
->hit_singlestep_breakpoint
7815 || (step_what
& STEP_OVER_BREAKPOINT
));
7816 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7818 /* We can't use displaced stepping if we need to step past a
7819 watchpoint. The instruction copied to the scratch pad would
7820 still trigger the watchpoint. */
7822 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7824 set_step_over_info (regcache
->aspace (),
7825 regcache_read_pc (regcache
), remove_wps
,
7826 ecs
->event_thread
->global_num
);
7828 else if (remove_wps
)
7829 set_step_over_info (NULL
, 0, remove_wps
, -1);
7831 /* If we now need to do an in-line step-over, we need to stop
7832 all other threads. Note this must be done before
7833 insert_breakpoints below, because that removes the breakpoint
7834 we're about to step over, otherwise other threads could miss
7836 if (step_over_info_valid_p () && target_is_non_stop_p ())
7837 stop_all_threads ();
7839 /* Stop stepping if inserting breakpoints fails. */
7842 insert_breakpoints ();
7844 catch (const gdb_exception_error
&e
)
7846 exception_print (gdb_stderr
, e
);
7848 clear_step_over_info ();
7852 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7854 resume (ecs
->event_thread
->suspend
.stop_signal
);
7857 prepare_to_wait (ecs
);
7860 /* Called when we should continue running the inferior, because the
7861 current event doesn't cause a user visible stop. This does the
7862 resuming part; waiting for the next event is done elsewhere. */
7865 keep_going (struct execution_control_state
*ecs
)
7867 if (ecs
->event_thread
->control
.trap_expected
7868 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7869 ecs
->event_thread
->control
.trap_expected
= 0;
7871 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7872 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7873 keep_going_pass_signal (ecs
);
7876 /* This function normally comes after a resume, before
7877 handle_inferior_event exits. It takes care of any last bits of
7878 housekeeping, and sets the all-important wait_some_more flag. */
7881 prepare_to_wait (struct execution_control_state
*ecs
)
7883 infrun_debug_printf ("prepare_to_wait");
7885 ecs
->wait_some_more
= 1;
7887 /* If the target can't async, emulate it by marking the infrun event
7888 handler such that as soon as we get back to the event-loop, we
7889 immediately end up in fetch_inferior_event again calling
7891 if (!target_can_async_p ())
7892 mark_infrun_async_event_handler ();
7895 /* We are done with the step range of a step/next/si/ni command.
7896 Called once for each n of a "step n" operation. */
7899 end_stepping_range (struct execution_control_state
*ecs
)
7901 ecs
->event_thread
->control
.stop_step
= 1;
7905 /* Several print_*_reason functions to print why the inferior has stopped.
7906 We always print something when the inferior exits, or receives a signal.
7907 The rest of the cases are dealt with later on in normal_stop and
7908 print_it_typical. Ideally there should be a call to one of these
7909 print_*_reason functions functions from handle_inferior_event each time
7910 stop_waiting is called.
7912 Note that we don't call these directly, instead we delegate that to
7913 the interpreters, through observers. Interpreters then call these
7914 with whatever uiout is right. */
7917 print_end_stepping_range_reason (struct ui_out
*uiout
)
7919 /* For CLI-like interpreters, print nothing. */
7921 if (uiout
->is_mi_like_p ())
7923 uiout
->field_string ("reason",
7924 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7929 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7931 annotate_signalled ();
7932 if (uiout
->is_mi_like_p ())
7934 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7935 uiout
->text ("\nProgram terminated with signal ");
7936 annotate_signal_name ();
7937 uiout
->field_string ("signal-name",
7938 gdb_signal_to_name (siggnal
));
7939 annotate_signal_name_end ();
7941 annotate_signal_string ();
7942 uiout
->field_string ("signal-meaning",
7943 gdb_signal_to_string (siggnal
));
7944 annotate_signal_string_end ();
7945 uiout
->text (".\n");
7946 uiout
->text ("The program no longer exists.\n");
7950 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7952 struct inferior
*inf
= current_inferior ();
7953 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7955 annotate_exited (exitstatus
);
7958 if (uiout
->is_mi_like_p ())
7959 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7960 std::string exit_code_str
7961 = string_printf ("0%o", (unsigned int) exitstatus
);
7962 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7963 plongest (inf
->num
), pidstr
.c_str (),
7964 string_field ("exit-code", exit_code_str
.c_str ()));
7968 if (uiout
->is_mi_like_p ())
7970 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7971 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7972 plongest (inf
->num
), pidstr
.c_str ());
7977 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7979 struct thread_info
*thr
= inferior_thread ();
7983 if (uiout
->is_mi_like_p ())
7985 else if (show_thread_that_caused_stop ())
7989 uiout
->text ("\nThread ");
7990 uiout
->field_string ("thread-id", print_thread_id (thr
));
7992 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7995 uiout
->text (" \"");
7996 uiout
->field_string ("name", name
);
8001 uiout
->text ("\nProgram");
8003 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8004 uiout
->text (" stopped");
8007 uiout
->text (" received signal ");
8008 annotate_signal_name ();
8009 if (uiout
->is_mi_like_p ())
8011 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8012 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8013 annotate_signal_name_end ();
8015 annotate_signal_string ();
8016 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8018 struct regcache
*regcache
= get_current_regcache ();
8019 struct gdbarch
*gdbarch
= regcache
->arch ();
8020 if (gdbarch_report_signal_info_p (gdbarch
))
8021 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8023 annotate_signal_string_end ();
8025 uiout
->text (".\n");
8029 print_no_history_reason (struct ui_out
*uiout
)
8031 uiout
->text ("\nNo more reverse-execution history.\n");
8034 /* Print current location without a level number, if we have changed
8035 functions or hit a breakpoint. Print source line if we have one.
8036 bpstat_print contains the logic deciding in detail what to print,
8037 based on the event(s) that just occurred. */
8040 print_stop_location (struct target_waitstatus
*ws
)
8043 enum print_what source_flag
;
8044 int do_frame_printing
= 1;
8045 struct thread_info
*tp
= inferior_thread ();
8047 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8051 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8052 should) carry around the function and does (or should) use
8053 that when doing a frame comparison. */
8054 if (tp
->control
.stop_step
8055 && frame_id_eq (tp
->control
.step_frame_id
,
8056 get_frame_id (get_current_frame ()))
8057 && (tp
->control
.step_start_function
8058 == find_pc_function (tp
->suspend
.stop_pc
)))
8060 /* Finished step, just print source line. */
8061 source_flag
= SRC_LINE
;
8065 /* Print location and source line. */
8066 source_flag
= SRC_AND_LOC
;
8069 case PRINT_SRC_AND_LOC
:
8070 /* Print location and source line. */
8071 source_flag
= SRC_AND_LOC
;
8073 case PRINT_SRC_ONLY
:
8074 source_flag
= SRC_LINE
;
8077 /* Something bogus. */
8078 source_flag
= SRC_LINE
;
8079 do_frame_printing
= 0;
8082 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8085 /* The behavior of this routine with respect to the source
8087 SRC_LINE: Print only source line
8088 LOCATION: Print only location
8089 SRC_AND_LOC: Print location and source line. */
8090 if (do_frame_printing
)
8091 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8097 print_stop_event (struct ui_out
*uiout
, bool displays
)
8099 struct target_waitstatus last
;
8100 struct thread_info
*tp
;
8102 get_last_target_status (nullptr, nullptr, &last
);
8105 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8107 print_stop_location (&last
);
8109 /* Display the auto-display expressions. */
8114 tp
= inferior_thread ();
8115 if (tp
->thread_fsm
!= NULL
8116 && tp
->thread_fsm
->finished_p ())
8118 struct return_value_info
*rv
;
8120 rv
= tp
->thread_fsm
->return_value ();
8122 print_return_value (uiout
, rv
);
8129 maybe_remove_breakpoints (void)
8131 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8133 if (remove_breakpoints ())
8135 target_terminal::ours_for_output ();
8136 printf_filtered (_("Cannot remove breakpoints because "
8137 "program is no longer writable.\nFurther "
8138 "execution is probably impossible.\n"));
8143 /* The execution context that just caused a normal stop. */
8150 DISABLE_COPY_AND_ASSIGN (stop_context
);
8152 bool changed () const;
8157 /* The event PTID. */
8161 /* If stopp for a thread event, this is the thread that caused the
8163 struct thread_info
*thread
;
8165 /* The inferior that caused the stop. */
8169 /* Initializes a new stop context. If stopped for a thread event, this
8170 takes a strong reference to the thread. */
8172 stop_context::stop_context ()
8174 stop_id
= get_stop_id ();
8175 ptid
= inferior_ptid
;
8176 inf_num
= current_inferior ()->num
;
8178 if (inferior_ptid
!= null_ptid
)
8180 /* Take a strong reference so that the thread can't be deleted
8182 thread
= inferior_thread ();
8189 /* Release a stop context previously created with save_stop_context.
8190 Releases the strong reference to the thread as well. */
8192 stop_context::~stop_context ()
8198 /* Return true if the current context no longer matches the saved stop
8202 stop_context::changed () const
8204 if (ptid
!= inferior_ptid
)
8206 if (inf_num
!= current_inferior ()->num
)
8208 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8210 if (get_stop_id () != stop_id
)
8220 struct target_waitstatus last
;
8222 get_last_target_status (nullptr, nullptr, &last
);
8226 /* If an exception is thrown from this point on, make sure to
8227 propagate GDB's knowledge of the executing state to the
8228 frontend/user running state. A QUIT is an easy exception to see
8229 here, so do this before any filtered output. */
8231 ptid_t finish_ptid
= null_ptid
;
8234 finish_ptid
= minus_one_ptid
;
8235 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8236 || last
.kind
== TARGET_WAITKIND_EXITED
)
8238 /* On some targets, we may still have live threads in the
8239 inferior when we get a process exit event. E.g., for
8240 "checkpoint", when the current checkpoint/fork exits,
8241 linux-fork.c automatically switches to another fork from
8242 within target_mourn_inferior. */
8243 if (inferior_ptid
!= null_ptid
)
8244 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8246 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8247 finish_ptid
= inferior_ptid
;
8249 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8250 if (finish_ptid
!= null_ptid
)
8252 maybe_finish_thread_state
.emplace
8253 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8256 /* As we're presenting a stop, and potentially removing breakpoints,
8257 update the thread list so we can tell whether there are threads
8258 running on the target. With target remote, for example, we can
8259 only learn about new threads when we explicitly update the thread
8260 list. Do this before notifying the interpreters about signal
8261 stops, end of stepping ranges, etc., so that the "new thread"
8262 output is emitted before e.g., "Program received signal FOO",
8263 instead of after. */
8264 update_thread_list ();
8266 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8267 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8269 /* As with the notification of thread events, we want to delay
8270 notifying the user that we've switched thread context until
8271 the inferior actually stops.
8273 There's no point in saying anything if the inferior has exited.
8274 Note that SIGNALLED here means "exited with a signal", not
8275 "received a signal".
8277 Also skip saying anything in non-stop mode. In that mode, as we
8278 don't want GDB to switch threads behind the user's back, to avoid
8279 races where the user is typing a command to apply to thread x,
8280 but GDB switches to thread y before the user finishes entering
8281 the command, fetch_inferior_event installs a cleanup to restore
8282 the current thread back to the thread the user had selected right
8283 after this event is handled, so we're not really switching, only
8284 informing of a stop. */
8286 && previous_inferior_ptid
!= inferior_ptid
8287 && target_has_execution ()
8288 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8289 && last
.kind
!= TARGET_WAITKIND_EXITED
8290 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8292 SWITCH_THRU_ALL_UIS ()
8294 target_terminal::ours_for_output ();
8295 printf_filtered (_("[Switching to %s]\n"),
8296 target_pid_to_str (inferior_ptid
).c_str ());
8297 annotate_thread_changed ();
8299 previous_inferior_ptid
= inferior_ptid
;
8302 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8304 SWITCH_THRU_ALL_UIS ()
8305 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8307 target_terminal::ours_for_output ();
8308 printf_filtered (_("No unwaited-for children left.\n"));
8312 /* Note: this depends on the update_thread_list call above. */
8313 maybe_remove_breakpoints ();
8315 /* If an auto-display called a function and that got a signal,
8316 delete that auto-display to avoid an infinite recursion. */
8318 if (stopped_by_random_signal
)
8319 disable_current_display ();
8321 SWITCH_THRU_ALL_UIS ()
8323 async_enable_stdin ();
8326 /* Let the user/frontend see the threads as stopped. */
8327 maybe_finish_thread_state
.reset ();
8329 /* Select innermost stack frame - i.e., current frame is frame 0,
8330 and current location is based on that. Handle the case where the
8331 dummy call is returning after being stopped. E.g. the dummy call
8332 previously hit a breakpoint. (If the dummy call returns
8333 normally, we won't reach here.) Do this before the stop hook is
8334 run, so that it doesn't get to see the temporary dummy frame,
8335 which is not where we'll present the stop. */
8336 if (has_stack_frames ())
8338 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8340 /* Pop the empty frame that contains the stack dummy. This
8341 also restores inferior state prior to the call (struct
8342 infcall_suspend_state). */
8343 struct frame_info
*frame
= get_current_frame ();
8345 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8347 /* frame_pop calls reinit_frame_cache as the last thing it
8348 does which means there's now no selected frame. */
8351 select_frame (get_current_frame ());
8353 /* Set the current source location. */
8354 set_current_sal_from_frame (get_current_frame ());
8357 /* Look up the hook_stop and run it (CLI internally handles problem
8358 of stop_command's pre-hook not existing). */
8359 if (stop_command
!= NULL
)
8361 stop_context saved_context
;
8365 execute_cmd_pre_hook (stop_command
);
8367 catch (const gdb_exception
&ex
)
8369 exception_fprintf (gdb_stderr
, ex
,
8370 "Error while running hook_stop:\n");
8373 /* If the stop hook resumes the target, then there's no point in
8374 trying to notify about the previous stop; its context is
8375 gone. Likewise if the command switches thread or inferior --
8376 the observers would print a stop for the wrong
8378 if (saved_context
.changed ())
8382 /* Notify observers about the stop. This is where the interpreters
8383 print the stop event. */
8384 if (inferior_ptid
!= null_ptid
)
8385 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8388 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8390 annotate_stopped ();
8392 if (target_has_execution ())
8394 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8395 && last
.kind
!= TARGET_WAITKIND_EXITED
8396 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8397 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8398 Delete any breakpoint that is to be deleted at the next stop. */
8399 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8402 /* Try to get rid of automatically added inferiors that are no
8403 longer needed. Keeping those around slows down things linearly.
8404 Note that this never removes the current inferior. */
8411 signal_stop_state (int signo
)
8413 return signal_stop
[signo
];
8417 signal_print_state (int signo
)
8419 return signal_print
[signo
];
8423 signal_pass_state (int signo
)
8425 return signal_program
[signo
];
8429 signal_cache_update (int signo
)
8433 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8434 signal_cache_update (signo
);
8439 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8440 && signal_print
[signo
] == 0
8441 && signal_program
[signo
] == 1
8442 && signal_catch
[signo
] == 0);
8446 signal_stop_update (int signo
, int state
)
8448 int ret
= signal_stop
[signo
];
8450 signal_stop
[signo
] = state
;
8451 signal_cache_update (signo
);
8456 signal_print_update (int signo
, int state
)
8458 int ret
= signal_print
[signo
];
8460 signal_print
[signo
] = state
;
8461 signal_cache_update (signo
);
8466 signal_pass_update (int signo
, int state
)
8468 int ret
= signal_program
[signo
];
8470 signal_program
[signo
] = state
;
8471 signal_cache_update (signo
);
8475 /* Update the global 'signal_catch' from INFO and notify the
8479 signal_catch_update (const unsigned int *info
)
8483 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8484 signal_catch
[i
] = info
[i
] > 0;
8485 signal_cache_update (-1);
8486 target_pass_signals (signal_pass
);
8490 sig_print_header (void)
8492 printf_filtered (_("Signal Stop\tPrint\tPass "
8493 "to program\tDescription\n"));
8497 sig_print_info (enum gdb_signal oursig
)
8499 const char *name
= gdb_signal_to_name (oursig
);
8500 int name_padding
= 13 - strlen (name
);
8502 if (name_padding
<= 0)
8505 printf_filtered ("%s", name
);
8506 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8507 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8508 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8509 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8510 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8513 /* Specify how various signals in the inferior should be handled. */
8516 handle_command (const char *args
, int from_tty
)
8518 int digits
, wordlen
;
8519 int sigfirst
, siglast
;
8520 enum gdb_signal oursig
;
8525 error_no_arg (_("signal to handle"));
8528 /* Allocate and zero an array of flags for which signals to handle. */
8530 const size_t nsigs
= GDB_SIGNAL_LAST
;
8531 unsigned char sigs
[nsigs
] {};
8533 /* Break the command line up into args. */
8535 gdb_argv
built_argv (args
);
8537 /* Walk through the args, looking for signal oursigs, signal names, and
8538 actions. Signal numbers and signal names may be interspersed with
8539 actions, with the actions being performed for all signals cumulatively
8540 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8542 for (char *arg
: built_argv
)
8544 wordlen
= strlen (arg
);
8545 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8549 sigfirst
= siglast
= -1;
8551 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8553 /* Apply action to all signals except those used by the
8554 debugger. Silently skip those. */
8557 siglast
= nsigs
- 1;
8559 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8561 SET_SIGS (nsigs
, sigs
, signal_stop
);
8562 SET_SIGS (nsigs
, sigs
, signal_print
);
8564 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8566 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8568 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8570 SET_SIGS (nsigs
, sigs
, signal_print
);
8572 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8574 SET_SIGS (nsigs
, sigs
, signal_program
);
8576 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8578 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8580 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8582 SET_SIGS (nsigs
, sigs
, signal_program
);
8584 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8586 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8587 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8589 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8591 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8593 else if (digits
> 0)
8595 /* It is numeric. The numeric signal refers to our own
8596 internal signal numbering from target.h, not to host/target
8597 signal number. This is a feature; users really should be
8598 using symbolic names anyway, and the common ones like
8599 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8601 sigfirst
= siglast
= (int)
8602 gdb_signal_from_command (atoi (arg
));
8603 if (arg
[digits
] == '-')
8606 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8608 if (sigfirst
> siglast
)
8610 /* Bet he didn't figure we'd think of this case... */
8611 std::swap (sigfirst
, siglast
);
8616 oursig
= gdb_signal_from_name (arg
);
8617 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8619 sigfirst
= siglast
= (int) oursig
;
8623 /* Not a number and not a recognized flag word => complain. */
8624 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8628 /* If any signal numbers or symbol names were found, set flags for
8629 which signals to apply actions to. */
8631 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8633 switch ((enum gdb_signal
) signum
)
8635 case GDB_SIGNAL_TRAP
:
8636 case GDB_SIGNAL_INT
:
8637 if (!allsigs
&& !sigs
[signum
])
8639 if (query (_("%s is used by the debugger.\n\
8640 Are you sure you want to change it? "),
8641 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8646 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8650 case GDB_SIGNAL_DEFAULT
:
8651 case GDB_SIGNAL_UNKNOWN
:
8652 /* Make sure that "all" doesn't print these. */
8661 for (int signum
= 0; signum
< nsigs
; signum
++)
8664 signal_cache_update (-1);
8665 target_pass_signals (signal_pass
);
8666 target_program_signals (signal_program
);
8670 /* Show the results. */
8671 sig_print_header ();
8672 for (; signum
< nsigs
; signum
++)
8674 sig_print_info ((enum gdb_signal
) signum
);
8681 /* Complete the "handle" command. */
8684 handle_completer (struct cmd_list_element
*ignore
,
8685 completion_tracker
&tracker
,
8686 const char *text
, const char *word
)
8688 static const char * const keywords
[] =
8702 signal_completer (ignore
, tracker
, text
, word
);
8703 complete_on_enum (tracker
, keywords
, word
, word
);
8707 gdb_signal_from_command (int num
)
8709 if (num
>= 1 && num
<= 15)
8710 return (enum gdb_signal
) num
;
8711 error (_("Only signals 1-15 are valid as numeric signals.\n\
8712 Use \"info signals\" for a list of symbolic signals."));
8715 /* Print current contents of the tables set by the handle command.
8716 It is possible we should just be printing signals actually used
8717 by the current target (but for things to work right when switching
8718 targets, all signals should be in the signal tables). */
8721 info_signals_command (const char *signum_exp
, int from_tty
)
8723 enum gdb_signal oursig
;
8725 sig_print_header ();
8729 /* First see if this is a symbol name. */
8730 oursig
= gdb_signal_from_name (signum_exp
);
8731 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8733 /* No, try numeric. */
8735 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8737 sig_print_info (oursig
);
8741 printf_filtered ("\n");
8742 /* These ugly casts brought to you by the native VAX compiler. */
8743 for (oursig
= GDB_SIGNAL_FIRST
;
8744 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8745 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8749 if (oursig
!= GDB_SIGNAL_UNKNOWN
8750 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8751 sig_print_info (oursig
);
8754 printf_filtered (_("\nUse the \"handle\" command "
8755 "to change these tables.\n"));
8758 /* The $_siginfo convenience variable is a bit special. We don't know
8759 for sure the type of the value until we actually have a chance to
8760 fetch the data. The type can change depending on gdbarch, so it is
8761 also dependent on which thread you have selected.
8763 1. making $_siginfo be an internalvar that creates a new value on
8766 2. making the value of $_siginfo be an lval_computed value. */
8768 /* This function implements the lval_computed support for reading a
8772 siginfo_value_read (struct value
*v
)
8774 LONGEST transferred
;
8776 /* If we can access registers, so can we access $_siginfo. Likewise
8778 validate_registers_access ();
8781 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8783 value_contents_all_raw (v
),
8785 TYPE_LENGTH (value_type (v
)));
8787 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8788 error (_("Unable to read siginfo"));
8791 /* This function implements the lval_computed support for writing a
8795 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8797 LONGEST transferred
;
8799 /* If we can access registers, so can we access $_siginfo. Likewise
8801 validate_registers_access ();
8803 transferred
= target_write (current_top_target (),
8804 TARGET_OBJECT_SIGNAL_INFO
,
8806 value_contents_all_raw (fromval
),
8808 TYPE_LENGTH (value_type (fromval
)));
8810 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8811 error (_("Unable to write siginfo"));
8814 static const struct lval_funcs siginfo_value_funcs
=
8820 /* Return a new value with the correct type for the siginfo object of
8821 the current thread using architecture GDBARCH. Return a void value
8822 if there's no object available. */
8824 static struct value
*
8825 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8828 if (target_has_stack ()
8829 && inferior_ptid
!= null_ptid
8830 && gdbarch_get_siginfo_type_p (gdbarch
))
8832 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8834 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8837 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8841 /* infcall_suspend_state contains state about the program itself like its
8842 registers and any signal it received when it last stopped.
8843 This state must be restored regardless of how the inferior function call
8844 ends (either successfully, or after it hits a breakpoint or signal)
8845 if the program is to properly continue where it left off. */
8847 class infcall_suspend_state
8850 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8851 once the inferior function call has finished. */
8852 infcall_suspend_state (struct gdbarch
*gdbarch
,
8853 const struct thread_info
*tp
,
8854 struct regcache
*regcache
)
8855 : m_thread_suspend (tp
->suspend
),
8856 m_registers (new readonly_detached_regcache (*regcache
))
8858 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8860 if (gdbarch_get_siginfo_type_p (gdbarch
))
8862 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8863 size_t len
= TYPE_LENGTH (type
);
8865 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8867 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8868 siginfo_data
.get (), 0, len
) != len
)
8870 /* Errors ignored. */
8871 siginfo_data
.reset (nullptr);
8877 m_siginfo_gdbarch
= gdbarch
;
8878 m_siginfo_data
= std::move (siginfo_data
);
8882 /* Return a pointer to the stored register state. */
8884 readonly_detached_regcache
*registers () const
8886 return m_registers
.get ();
8889 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8891 void restore (struct gdbarch
*gdbarch
,
8892 struct thread_info
*tp
,
8893 struct regcache
*regcache
) const
8895 tp
->suspend
= m_thread_suspend
;
8897 if (m_siginfo_gdbarch
== gdbarch
)
8899 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8901 /* Errors ignored. */
8902 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8903 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8906 /* The inferior can be gone if the user types "print exit(0)"
8907 (and perhaps other times). */
8908 if (target_has_execution ())
8909 /* NB: The register write goes through to the target. */
8910 regcache
->restore (registers ());
8914 /* How the current thread stopped before the inferior function call was
8916 struct thread_suspend_state m_thread_suspend
;
8918 /* The registers before the inferior function call was executed. */
8919 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8921 /* Format of SIGINFO_DATA or NULL if it is not present. */
8922 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8924 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8925 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8926 content would be invalid. */
8927 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8930 infcall_suspend_state_up
8931 save_infcall_suspend_state ()
8933 struct thread_info
*tp
= inferior_thread ();
8934 struct regcache
*regcache
= get_current_regcache ();
8935 struct gdbarch
*gdbarch
= regcache
->arch ();
8937 infcall_suspend_state_up inf_state
8938 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8940 /* Having saved the current state, adjust the thread state, discarding
8941 any stop signal information. The stop signal is not useful when
8942 starting an inferior function call, and run_inferior_call will not use
8943 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8944 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8949 /* Restore inferior session state to INF_STATE. */
8952 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8954 struct thread_info
*tp
= inferior_thread ();
8955 struct regcache
*regcache
= get_current_regcache ();
8956 struct gdbarch
*gdbarch
= regcache
->arch ();
8958 inf_state
->restore (gdbarch
, tp
, regcache
);
8959 discard_infcall_suspend_state (inf_state
);
8963 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8968 readonly_detached_regcache
*
8969 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8971 return inf_state
->registers ();
8974 /* infcall_control_state contains state regarding gdb's control of the
8975 inferior itself like stepping control. It also contains session state like
8976 the user's currently selected frame. */
8978 struct infcall_control_state
8980 struct thread_control_state thread_control
;
8981 struct inferior_control_state inferior_control
;
8984 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8985 int stopped_by_random_signal
= 0;
8987 /* ID and level of the selected frame when the inferior function
8989 struct frame_id selected_frame_id
{};
8990 int selected_frame_level
= -1;
8993 /* Save all of the information associated with the inferior<==>gdb
8996 infcall_control_state_up
8997 save_infcall_control_state ()
8999 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9000 struct thread_info
*tp
= inferior_thread ();
9001 struct inferior
*inf
= current_inferior ();
9003 inf_status
->thread_control
= tp
->control
;
9004 inf_status
->inferior_control
= inf
->control
;
9006 tp
->control
.step_resume_breakpoint
= NULL
;
9007 tp
->control
.exception_resume_breakpoint
= NULL
;
9009 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9010 chain. If caller's caller is walking the chain, they'll be happier if we
9011 hand them back the original chain when restore_infcall_control_state is
9013 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9016 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9017 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9019 save_selected_frame (&inf_status
->selected_frame_id
,
9020 &inf_status
->selected_frame_level
);
9025 /* Restore inferior session state to INF_STATUS. */
9028 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9030 struct thread_info
*tp
= inferior_thread ();
9031 struct inferior
*inf
= current_inferior ();
9033 if (tp
->control
.step_resume_breakpoint
)
9034 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9036 if (tp
->control
.exception_resume_breakpoint
)
9037 tp
->control
.exception_resume_breakpoint
->disposition
9038 = disp_del_at_next_stop
;
9040 /* Handle the bpstat_copy of the chain. */
9041 bpstat_clear (&tp
->control
.stop_bpstat
);
9043 tp
->control
= inf_status
->thread_control
;
9044 inf
->control
= inf_status
->inferior_control
;
9047 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9048 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9050 if (target_has_stack ())
9052 restore_selected_frame (inf_status
->selected_frame_id
,
9053 inf_status
->selected_frame_level
);
9060 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9062 if (inf_status
->thread_control
.step_resume_breakpoint
)
9063 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9064 = disp_del_at_next_stop
;
9066 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9067 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9068 = disp_del_at_next_stop
;
9070 /* See save_infcall_control_state for info on stop_bpstat. */
9071 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9079 clear_exit_convenience_vars (void)
9081 clear_internalvar (lookup_internalvar ("_exitsignal"));
9082 clear_internalvar (lookup_internalvar ("_exitcode"));
9086 /* User interface for reverse debugging:
9087 Set exec-direction / show exec-direction commands
9088 (returns error unless target implements to_set_exec_direction method). */
9090 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9091 static const char exec_forward
[] = "forward";
9092 static const char exec_reverse
[] = "reverse";
9093 static const char *exec_direction
= exec_forward
;
9094 static const char *const exec_direction_names
[] = {
9101 set_exec_direction_func (const char *args
, int from_tty
,
9102 struct cmd_list_element
*cmd
)
9104 if (target_can_execute_reverse ())
9106 if (!strcmp (exec_direction
, exec_forward
))
9107 execution_direction
= EXEC_FORWARD
;
9108 else if (!strcmp (exec_direction
, exec_reverse
))
9109 execution_direction
= EXEC_REVERSE
;
9113 exec_direction
= exec_forward
;
9114 error (_("Target does not support this operation."));
9119 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9120 struct cmd_list_element
*cmd
, const char *value
)
9122 switch (execution_direction
) {
9124 fprintf_filtered (out
, _("Forward.\n"));
9127 fprintf_filtered (out
, _("Reverse.\n"));
9130 internal_error (__FILE__
, __LINE__
,
9131 _("bogus execution_direction value: %d"),
9132 (int) execution_direction
);
9137 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9138 struct cmd_list_element
*c
, const char *value
)
9140 fprintf_filtered (file
, _("Resuming the execution of threads "
9141 "of all processes is %s.\n"), value
);
9144 /* Implementation of `siginfo' variable. */
9146 static const struct internalvar_funcs siginfo_funcs
=
9153 /* Callback for infrun's target events source. This is marked when a
9154 thread has a pending status to process. */
9157 infrun_async_inferior_event_handler (gdb_client_data data
)
9159 inferior_event_handler (INF_REG_EVENT
);
9166 /* Verify that when two threads with the same ptid exist (from two different
9167 targets) and one of them changes ptid, we only update inferior_ptid if
9168 it is appropriate. */
9171 infrun_thread_ptid_changed ()
9173 gdbarch
*arch
= current_inferior ()->gdbarch
;
9175 /* The thread which inferior_ptid represents changes ptid. */
9177 scoped_restore_current_pspace_and_thread restore
;
9179 scoped_mock_context
<test_target_ops
> target1 (arch
);
9180 scoped_mock_context
<test_target_ops
> target2 (arch
);
9181 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9183 ptid_t
old_ptid (111, 222);
9184 ptid_t
new_ptid (111, 333);
9186 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9187 target1
.mock_thread
.ptid
= old_ptid
;
9188 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9189 target2
.mock_thread
.ptid
= old_ptid
;
9191 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9192 set_current_inferior (&target1
.mock_inferior
);
9194 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9196 gdb_assert (inferior_ptid
== new_ptid
);
9199 /* A thread with the same ptid as inferior_ptid, but from another target,
9202 scoped_restore_current_pspace_and_thread restore
;
9204 scoped_mock_context
<test_target_ops
> target1 (arch
);
9205 scoped_mock_context
<test_target_ops
> target2 (arch
);
9206 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9208 ptid_t
old_ptid (111, 222);
9209 ptid_t
new_ptid (111, 333);
9211 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9212 target1
.mock_thread
.ptid
= old_ptid
;
9213 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9214 target2
.mock_thread
.ptid
= old_ptid
;
9216 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9217 set_current_inferior (&target2
.mock_inferior
);
9219 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9221 gdb_assert (inferior_ptid
== old_ptid
);
9225 } /* namespace selftests */
9227 #endif /* GDB_SELF_TEST */
9229 void _initialize_infrun ();
9231 _initialize_infrun ()
9233 struct cmd_list_element
*c
;
9235 /* Register extra event sources in the event loop. */
9236 infrun_async_inferior_event_token
9237 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9240 add_info ("signals", info_signals_command
, _("\
9241 What debugger does when program gets various signals.\n\
9242 Specify a signal as argument to print info on that signal only."));
9243 add_info_alias ("handle", "signals", 0);
9245 c
= add_com ("handle", class_run
, handle_command
, _("\
9246 Specify how to handle signals.\n\
9247 Usage: handle SIGNAL [ACTIONS]\n\
9248 Args are signals and actions to apply to those signals.\n\
9249 If no actions are specified, the current settings for the specified signals\n\
9250 will be displayed instead.\n\
9252 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9253 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9254 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9255 The special arg \"all\" is recognized to mean all signals except those\n\
9256 used by the debugger, typically SIGTRAP and SIGINT.\n\
9258 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9259 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9260 Stop means reenter debugger if this signal happens (implies print).\n\
9261 Print means print a message if this signal happens.\n\
9262 Pass means let program see this signal; otherwise program doesn't know.\n\
9263 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9264 Pass and Stop may be combined.\n\
9266 Multiple signals may be specified. Signal numbers and signal names\n\
9267 may be interspersed with actions, with the actions being performed for\n\
9268 all signals cumulatively specified."));
9269 set_cmd_completer (c
, handle_completer
);
9272 stop_command
= add_cmd ("stop", class_obscure
,
9273 not_just_help_class_command
, _("\
9274 There is no `stop' command, but you can set a hook on `stop'.\n\
9275 This allows you to set a list of commands to be run each time execution\n\
9276 of the program stops."), &cmdlist
);
9278 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9279 Set inferior debugging."), _("\
9280 Show inferior debugging."), _("\
9281 When non-zero, inferior specific debugging is enabled."),
9284 &setdebuglist
, &showdebuglist
);
9286 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9287 &debug_displaced
, _("\
9288 Set displaced stepping debugging."), _("\
9289 Show displaced stepping debugging."), _("\
9290 When non-zero, displaced stepping specific debugging is enabled."),
9292 show_debug_displaced
,
9293 &setdebuglist
, &showdebuglist
);
9295 add_setshow_boolean_cmd ("non-stop", no_class
,
9297 Set whether gdb controls the inferior in non-stop mode."), _("\
9298 Show whether gdb controls the inferior in non-stop mode."), _("\
9299 When debugging a multi-threaded program and this setting is\n\
9300 off (the default, also called all-stop mode), when one thread stops\n\
9301 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9302 all other threads in the program while you interact with the thread of\n\
9303 interest. When you continue or step a thread, you can allow the other\n\
9304 threads to run, or have them remain stopped, but while you inspect any\n\
9305 thread's state, all threads stop.\n\
9307 In non-stop mode, when one thread stops, other threads can continue\n\
9308 to run freely. You'll be able to step each thread independently,\n\
9309 leave it stopped or free to run as needed."),
9315 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9318 signal_print
[i
] = 1;
9319 signal_program
[i
] = 1;
9320 signal_catch
[i
] = 0;
9323 /* Signals caused by debugger's own actions should not be given to
9324 the program afterwards.
9326 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9327 explicitly specifies that it should be delivered to the target
9328 program. Typically, that would occur when a user is debugging a
9329 target monitor on a simulator: the target monitor sets a
9330 breakpoint; the simulator encounters this breakpoint and halts
9331 the simulation handing control to GDB; GDB, noting that the stop
9332 address doesn't map to any known breakpoint, returns control back
9333 to the simulator; the simulator then delivers the hardware
9334 equivalent of a GDB_SIGNAL_TRAP to the program being
9336 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9337 signal_program
[GDB_SIGNAL_INT
] = 0;
9339 /* Signals that are not errors should not normally enter the debugger. */
9340 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9341 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9342 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9343 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9344 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9345 signal_print
[GDB_SIGNAL_PROF
] = 0;
9346 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9347 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9348 signal_stop
[GDB_SIGNAL_IO
] = 0;
9349 signal_print
[GDB_SIGNAL_IO
] = 0;
9350 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9351 signal_print
[GDB_SIGNAL_POLL
] = 0;
9352 signal_stop
[GDB_SIGNAL_URG
] = 0;
9353 signal_print
[GDB_SIGNAL_URG
] = 0;
9354 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9355 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9356 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9357 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9359 /* These signals are used internally by user-level thread
9360 implementations. (See signal(5) on Solaris.) Like the above
9361 signals, a healthy program receives and handles them as part of
9362 its normal operation. */
9363 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9364 signal_print
[GDB_SIGNAL_LWP
] = 0;
9365 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9366 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9367 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9368 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9369 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9370 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9372 /* Update cached state. */
9373 signal_cache_update (-1);
9375 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9376 &stop_on_solib_events
, _("\
9377 Set stopping for shared library events."), _("\
9378 Show stopping for shared library events."), _("\
9379 If nonzero, gdb will give control to the user when the dynamic linker\n\
9380 notifies gdb of shared library events. The most common event of interest\n\
9381 to the user would be loading/unloading of a new library."),
9382 set_stop_on_solib_events
,
9383 show_stop_on_solib_events
,
9384 &setlist
, &showlist
);
9386 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9387 follow_fork_mode_kind_names
,
9388 &follow_fork_mode_string
, _("\
9389 Set debugger response to a program call of fork or vfork."), _("\
9390 Show debugger response to a program call of fork or vfork."), _("\
9391 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9392 parent - the original process is debugged after a fork\n\
9393 child - the new process is debugged after a fork\n\
9394 The unfollowed process will continue to run.\n\
9395 By default, the debugger will follow the parent process."),
9397 show_follow_fork_mode_string
,
9398 &setlist
, &showlist
);
9400 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9401 follow_exec_mode_names
,
9402 &follow_exec_mode_string
, _("\
9403 Set debugger response to a program call of exec."), _("\
9404 Show debugger response to a program call of exec."), _("\
9405 An exec call replaces the program image of a process.\n\
9407 follow-exec-mode can be:\n\
9409 new - the debugger creates a new inferior and rebinds the process\n\
9410 to this new inferior. The program the process was running before\n\
9411 the exec call can be restarted afterwards by restarting the original\n\
9414 same - the debugger keeps the process bound to the same inferior.\n\
9415 The new executable image replaces the previous executable loaded in\n\
9416 the inferior. Restarting the inferior after the exec call restarts\n\
9417 the executable the process was running after the exec call.\n\
9419 By default, the debugger will use the same inferior."),
9421 show_follow_exec_mode_string
,
9422 &setlist
, &showlist
);
9424 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9425 scheduler_enums
, &scheduler_mode
, _("\
9426 Set mode for locking scheduler during execution."), _("\
9427 Show mode for locking scheduler during execution."), _("\
9428 off == no locking (threads may preempt at any time)\n\
9429 on == full locking (no thread except the current thread may run)\n\
9430 This applies to both normal execution and replay mode.\n\
9431 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9432 In this mode, other threads may run during other commands.\n\
9433 This applies to both normal execution and replay mode.\n\
9434 replay == scheduler locked in replay mode and unlocked during normal execution."),
9435 set_schedlock_func
, /* traps on target vector */
9436 show_scheduler_mode
,
9437 &setlist
, &showlist
);
9439 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9440 Set mode for resuming threads of all processes."), _("\
9441 Show mode for resuming threads of all processes."), _("\
9442 When on, execution commands (such as 'continue' or 'next') resume all\n\
9443 threads of all processes. When off (which is the default), execution\n\
9444 commands only resume the threads of the current process. The set of\n\
9445 threads that are resumed is further refined by the scheduler-locking\n\
9446 mode (see help set scheduler-locking)."),
9448 show_schedule_multiple
,
9449 &setlist
, &showlist
);
9451 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9452 Set mode of the step operation."), _("\
9453 Show mode of the step operation."), _("\
9454 When set, doing a step over a function without debug line information\n\
9455 will stop at the first instruction of that function. Otherwise, the\n\
9456 function is skipped and the step command stops at a different source line."),
9458 show_step_stop_if_no_debug
,
9459 &setlist
, &showlist
);
9461 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9462 &can_use_displaced_stepping
, _("\
9463 Set debugger's willingness to use displaced stepping."), _("\
9464 Show debugger's willingness to use displaced stepping."), _("\
9465 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9466 supported by the target architecture. If off, gdb will not use displaced\n\
9467 stepping to step over breakpoints, even if such is supported by the target\n\
9468 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9469 if the target architecture supports it and non-stop mode is active, but will not\n\
9470 use it in all-stop mode (see help set non-stop)."),
9472 show_can_use_displaced_stepping
,
9473 &setlist
, &showlist
);
9475 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9476 &exec_direction
, _("Set direction of execution.\n\
9477 Options are 'forward' or 'reverse'."),
9478 _("Show direction of execution (forward/reverse)."),
9479 _("Tells gdb whether to execute forward or backward."),
9480 set_exec_direction_func
, show_exec_direction_func
,
9481 &setlist
, &showlist
);
9483 /* Set/show detach-on-fork: user-settable mode. */
9485 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9486 Set whether gdb will detach the child of a fork."), _("\
9487 Show whether gdb will detach the child of a fork."), _("\
9488 Tells gdb whether to detach the child of a fork."),
9489 NULL
, NULL
, &setlist
, &showlist
);
9491 /* Set/show disable address space randomization mode. */
9493 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9494 &disable_randomization
, _("\
9495 Set disabling of debuggee's virtual address space randomization."), _("\
9496 Show disabling of debuggee's virtual address space randomization."), _("\
9497 When this mode is on (which is the default), randomization of the virtual\n\
9498 address space is disabled. Standalone programs run with the randomization\n\
9499 enabled by default on some platforms."),
9500 &set_disable_randomization
,
9501 &show_disable_randomization
,
9502 &setlist
, &showlist
);
9504 /* ptid initializations */
9505 inferior_ptid
= null_ptid
;
9506 target_last_wait_ptid
= minus_one_ptid
;
9508 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9509 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9510 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9511 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9513 /* Explicitly create without lookup, since that tries to create a
9514 value with a void typed value, and when we get here, gdbarch
9515 isn't initialized yet. At this point, we're quite sure there
9516 isn't another convenience variable of the same name. */
9517 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9519 add_setshow_boolean_cmd ("observer", no_class
,
9520 &observer_mode_1
, _("\
9521 Set whether gdb controls the inferior in observer mode."), _("\
9522 Show whether gdb controls the inferior in observer mode."), _("\
9523 In observer mode, GDB can get data from the inferior, but not\n\
9524 affect its execution. Registers and memory may not be changed,\n\
9525 breakpoints may not be set, and the program cannot be interrupted\n\
9533 selftests::register_test ("infrun_thread_ptid_changed",
9534 selftests::infrun_thread_ptid_changed
);