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 /* Returns true if any inferior has a thread doing a displaced
1470 displaced_step_in_progress_any_inferior ()
1472 for (inferior
*i
: all_inferiors ())
1474 if (i
->displaced_step_state
.step_thread
!= nullptr)
1481 /* Return true if THREAD is doing a displaced step. */
1484 displaced_step_in_progress_thread (thread_info
*thread
)
1486 gdb_assert (thread
!= NULL
);
1488 return thread
->inf
->displaced_step_state
.step_thread
== thread
;
1491 /* Return true if INF has a thread doing a displaced step. */
1494 displaced_step_in_progress (inferior
*inf
)
1496 return inf
->displaced_step_state
.step_thread
!= nullptr;
1499 /* If inferior is in displaced stepping, and ADDR equals to starting address
1500 of copy area, return corresponding displaced_step_closure. Otherwise,
1503 struct displaced_step_closure
*
1504 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1506 displaced_step_inferior_state
&displaced
1507 = current_inferior ()->displaced_step_state
;
1509 /* If checking the mode of displaced instruction in copy area. */
1510 if (displaced
.step_thread
!= nullptr
1511 && displaced
.step_copy
== addr
)
1512 return displaced
.step_closure
.get ();
1518 infrun_inferior_exit (struct inferior
*inf
)
1520 inf
->displaced_step_state
.reset ();
1524 infrun_inferior_execd (inferior
*inf
)
1526 /* If a thread was doing a displaced step in this inferior at the moment of
1527 the exec, it no longer exists. Even if the exec'ing thread was the one
1528 doing a displaced step, we don't want to to any fixup nor restore displaced
1529 stepping buffer bytes. */
1530 inf
->displaced_step_state
.reset ();
1532 /* Since an in-line step is done with everything else stopped, if there was
1533 one in progress at the time of the exec, it must have been the exec'ing
1535 clear_step_over_info ();
1538 /* If ON, and the architecture supports it, GDB will use displaced
1539 stepping to step over breakpoints. If OFF, or if the architecture
1540 doesn't support it, GDB will instead use the traditional
1541 hold-and-step approach. If AUTO (which is the default), GDB will
1542 decide which technique to use to step over breakpoints depending on
1543 whether the target works in a non-stop way (see use_displaced_stepping). */
1545 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1548 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1549 struct cmd_list_element
*c
,
1552 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1553 fprintf_filtered (file
,
1554 _("Debugger's willingness to use displaced stepping "
1555 "to step over breakpoints is %s (currently %s).\n"),
1556 value
, target_is_non_stop_p () ? "on" : "off");
1558 fprintf_filtered (file
,
1559 _("Debugger's willingness to use displaced stepping "
1560 "to step over breakpoints is %s.\n"), value
);
1563 /* Return true if the gdbarch implements the required methods to use
1564 displaced stepping. */
1567 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1569 /* Only check for the presence of step_copy_insn. Other required methods
1570 are checked by the gdbarch validation. */
1571 return gdbarch_displaced_step_copy_insn_p (arch
);
1574 /* Return non-zero if displaced stepping can/should be used to step
1575 over breakpoints of thread TP. */
1578 use_displaced_stepping (thread_info
*tp
)
1580 /* If the user disabled it explicitly, don't use displaced stepping. */
1581 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1584 /* If "auto", only use displaced stepping if the target operates in a non-stop
1586 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1587 && !target_is_non_stop_p ())
1590 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1592 /* If the architecture doesn't implement displaced stepping, don't use
1594 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1597 /* If recording, don't use displaced stepping. */
1598 if (find_record_target () != nullptr)
1601 /* If displaced stepping failed before for this inferior, don't bother trying
1603 if (tp
->inf
->displaced_step_state
.failed_before
)
1609 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1612 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1614 displaced
->reset ();
1617 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1618 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1620 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1625 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1629 for (size_t i
= 0; i
< len
; i
++)
1632 ret
+= string_printf ("%02x", buf
[i
]);
1634 ret
+= string_printf (" %02x", buf
[i
]);
1640 /* Prepare to single-step, using displaced stepping.
1642 Note that we cannot use displaced stepping when we have a signal to
1643 deliver. If we have a signal to deliver and an instruction to step
1644 over, then after the step, there will be no indication from the
1645 target whether the thread entered a signal handler or ignored the
1646 signal and stepped over the instruction successfully --- both cases
1647 result in a simple SIGTRAP. In the first case we mustn't do a
1648 fixup, and in the second case we must --- but we can't tell which.
1649 Comments in the code for 'random signals' in handle_inferior_event
1650 explain how we handle this case instead.
1652 Returns 1 if preparing was successful -- this thread is going to be
1653 stepped now; 0 if displaced stepping this thread got queued; or -1
1654 if this instruction can't be displaced stepped. */
1657 displaced_step_prepare_throw (thread_info
*tp
)
1659 regcache
*regcache
= get_thread_regcache (tp
);
1660 struct gdbarch
*gdbarch
= regcache
->arch ();
1661 const address_space
*aspace
= regcache
->aspace ();
1662 CORE_ADDR original
, copy
;
1666 /* We should never reach this function if the architecture does not
1667 support displaced stepping. */
1668 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1670 /* Nor if the thread isn't meant to step over a breakpoint. */
1671 gdb_assert (tp
->control
.trap_expected
);
1673 /* Disable range stepping while executing in the scratch pad. We
1674 want a single-step even if executing the displaced instruction in
1675 the scratch buffer lands within the stepping range (e.g., a
1677 tp
->control
.may_range_step
= 0;
1679 /* We have to displaced step one thread at a time, as we only have
1680 access to a single scratch space per inferior. */
1682 displaced_step_inferior_state
*displaced
= &tp
->inf
->displaced_step_state
;
1684 if (displaced
->step_thread
!= nullptr)
1686 /* Already waiting for a displaced step to finish. Defer this
1687 request and place in queue. */
1689 displaced_debug_printf ("deferring step of %s",
1690 target_pid_to_str (tp
->ptid
).c_str ());
1692 thread_step_over_chain_enqueue (tp
);
1696 displaced_debug_printf ("stepping %s now",
1697 target_pid_to_str (tp
->ptid
).c_str ());
1699 displaced_step_reset (displaced
);
1701 scoped_restore_current_thread restore_thread
;
1703 switch_to_thread (tp
);
1705 original
= regcache_read_pc (regcache
);
1707 copy
= gdbarch_displaced_step_location (gdbarch
);
1708 len
= gdbarch_max_insn_length (gdbarch
);
1710 if (breakpoint_in_range_p (aspace
, copy
, len
))
1712 /* There's a breakpoint set in the scratch pad location range
1713 (which is usually around the entry point). We'd either
1714 install it before resuming, which would overwrite/corrupt the
1715 scratch pad, or if it was already inserted, this displaced
1716 step would overwrite it. The latter is OK in the sense that
1717 we already assume that no thread is going to execute the code
1718 in the scratch pad range (after initial startup) anyway, but
1719 the former is unacceptable. Simply punt and fallback to
1720 stepping over this breakpoint in-line. */
1721 displaced_debug_printf ("breakpoint set in scratch pad. "
1722 "Stepping over breakpoint in-line instead.");
1727 /* Save the original contents of the copy area. */
1728 displaced
->step_saved_copy
.resize (len
);
1729 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1731 throw_error (MEMORY_ERROR
,
1732 _("Error accessing memory address %s (%s) for "
1733 "displaced-stepping scratch space."),
1734 paddress (gdbarch
, copy
), safe_strerror (status
));
1736 displaced_debug_printf ("saved %s: %s",
1737 paddress (gdbarch
, copy
),
1738 displaced_step_dump_bytes
1739 (displaced
->step_saved_copy
.data (), len
).c_str ());
1741 displaced
->step_closure
1742 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1743 if (displaced
->step_closure
== NULL
)
1745 /* The architecture doesn't know how or want to displaced step
1746 this instruction or instruction sequence. Fallback to
1747 stepping over the breakpoint in-line. */
1751 /* Save the information we need to fix things up if the step
1753 displaced
->step_thread
= tp
;
1754 displaced
->step_gdbarch
= gdbarch
;
1755 displaced
->step_original
= original
;
1756 displaced
->step_copy
= copy
;
1759 displaced_step_reset_cleanup
cleanup (displaced
);
1761 /* Resume execution at the copy. */
1762 regcache_write_pc (regcache
, copy
);
1767 displaced_debug_printf ("displaced pc to %s", paddress (gdbarch
, copy
));
1772 /* Wrapper for displaced_step_prepare_throw that disabled further
1773 attempts at displaced stepping if we get a memory error. */
1776 displaced_step_prepare (thread_info
*thread
)
1782 prepared
= displaced_step_prepare_throw (thread
);
1784 catch (const gdb_exception_error
&ex
)
1786 if (ex
.error
!= MEMORY_ERROR
1787 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1790 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1793 /* Be verbose if "set displaced-stepping" is "on", silent if
1795 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1797 warning (_("disabling displaced stepping: %s"),
1801 /* Disable further displaced stepping attempts. */
1802 thread
->inf
->displaced_step_state
.failed_before
= 1;
1809 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1810 const gdb_byte
*myaddr
, int len
)
1812 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1814 inferior_ptid
= ptid
;
1815 write_memory (memaddr
, myaddr
, len
);
1818 /* Restore the contents of the copy area for thread PTID. */
1821 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1824 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1826 write_memory_ptid (ptid
, displaced
->step_copy
,
1827 displaced
->step_saved_copy
.data (), len
);
1829 displaced_debug_printf ("restored %s %s",
1830 target_pid_to_str (ptid
).c_str (),
1831 paddress (displaced
->step_gdbarch
,
1832 displaced
->step_copy
));
1835 /* If we displaced stepped an instruction successfully, adjust
1836 registers and memory to yield the same effect the instruction would
1837 have had if we had executed it at its original address, and return
1838 1. If the instruction didn't complete, relocate the PC and return
1839 -1. If the thread wasn't displaced stepping, return 0. */
1842 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1844 displaced_step_inferior_state
*displaced
1845 = &event_thread
->inf
->displaced_step_state
;
1848 /* Was this event for the thread we displaced? */
1849 if (displaced
->step_thread
!= event_thread
)
1852 /* Fixup may need to read memory/registers. Switch to the thread
1853 that we're fixing up. Also, target_stopped_by_watchpoint checks
1854 the current thread, and displaced_step_restore performs ptid-dependent
1855 memory accesses using current_inferior() and current_top_target(). */
1856 switch_to_thread (event_thread
);
1858 displaced_step_reset_cleanup
cleanup (displaced
);
1860 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1862 /* Did the instruction complete successfully? */
1863 if (signal
== GDB_SIGNAL_TRAP
1864 && !(target_stopped_by_watchpoint ()
1865 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1866 || target_have_steppable_watchpoint ())))
1868 /* Fix up the resulting state. */
1869 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1870 displaced
->step_closure
.get (),
1871 displaced
->step_original
,
1872 displaced
->step_copy
,
1873 get_thread_regcache (displaced
->step_thread
));
1878 /* Since the instruction didn't complete, all we can do is
1880 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1881 CORE_ADDR pc
= regcache_read_pc (regcache
);
1883 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1884 regcache_write_pc (regcache
, pc
);
1891 /* Data to be passed around while handling an event. This data is
1892 discarded between events. */
1893 struct execution_control_state
1895 process_stratum_target
*target
;
1897 /* The thread that got the event, if this was a thread event; NULL
1899 struct thread_info
*event_thread
;
1901 struct target_waitstatus ws
;
1902 int stop_func_filled_in
;
1903 CORE_ADDR stop_func_start
;
1904 CORE_ADDR stop_func_end
;
1905 const char *stop_func_name
;
1908 /* True if the event thread hit the single-step breakpoint of
1909 another thread. Thus the event doesn't cause a stop, the thread
1910 needs to be single-stepped past the single-step breakpoint before
1911 we can switch back to the original stepping thread. */
1912 int hit_singlestep_breakpoint
;
1915 /* Clear ECS and set it to point at TP. */
1918 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1920 memset (ecs
, 0, sizeof (*ecs
));
1921 ecs
->event_thread
= tp
;
1922 ecs
->ptid
= tp
->ptid
;
1925 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1926 static void prepare_to_wait (struct execution_control_state
*ecs
);
1927 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1928 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1930 /* Are there any pending step-over requests? If so, run all we can
1931 now and return true. Otherwise, return false. */
1934 start_step_over (void)
1936 struct thread_info
*tp
, *next
;
1938 /* Don't start a new step-over if we already have an in-line
1939 step-over operation ongoing. */
1940 if (step_over_info_valid_p ())
1943 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1945 struct execution_control_state ecss
;
1946 struct execution_control_state
*ecs
= &ecss
;
1947 step_over_what step_what
;
1948 int must_be_in_line
;
1950 gdb_assert (!tp
->stop_requested
);
1952 next
= thread_step_over_chain_next (tp
);
1954 /* If this inferior already has a displaced step in process,
1955 don't start a new one. */
1956 if (displaced_step_in_progress (tp
->inf
))
1959 step_what
= thread_still_needs_step_over (tp
);
1960 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1961 || ((step_what
& STEP_OVER_BREAKPOINT
)
1962 && !use_displaced_stepping (tp
)));
1964 /* We currently stop all threads of all processes to step-over
1965 in-line. If we need to start a new in-line step-over, let
1966 any pending displaced steps finish first. */
1967 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1970 thread_step_over_chain_remove (tp
);
1972 if (step_over_queue_head
== NULL
)
1973 infrun_debug_printf ("step-over queue now empty");
1975 if (tp
->control
.trap_expected
1979 internal_error (__FILE__
, __LINE__
,
1980 "[%s] has inconsistent state: "
1981 "trap_expected=%d, resumed=%d, executing=%d\n",
1982 target_pid_to_str (tp
->ptid
).c_str (),
1983 tp
->control
.trap_expected
,
1988 infrun_debug_printf ("resuming [%s] for step-over",
1989 target_pid_to_str (tp
->ptid
).c_str ());
1991 /* keep_going_pass_signal skips the step-over if the breakpoint
1992 is no longer inserted. In all-stop, we want to keep looking
1993 for a thread that needs a step-over instead of resuming TP,
1994 because we wouldn't be able to resume anything else until the
1995 target stops again. In non-stop, the resume always resumes
1996 only TP, so it's OK to let the thread resume freely. */
1997 if (!target_is_non_stop_p () && !step_what
)
2000 switch_to_thread (tp
);
2001 reset_ecs (ecs
, tp
);
2002 keep_going_pass_signal (ecs
);
2004 if (!ecs
->wait_some_more
)
2005 error (_("Command aborted."));
2007 gdb_assert (tp
->resumed
);
2009 /* If we started a new in-line step-over, we're done. */
2010 if (step_over_info_valid_p ())
2012 gdb_assert (tp
->control
.trap_expected
);
2016 if (!target_is_non_stop_p ())
2018 /* On all-stop, shouldn't have resumed unless we needed a
2020 gdb_assert (tp
->control
.trap_expected
2021 || tp
->step_after_step_resume_breakpoint
);
2023 /* With remote targets (at least), in all-stop, we can't
2024 issue any further remote commands until the program stops
2029 /* Either the thread no longer needed a step-over, or a new
2030 displaced stepping sequence started. Even in the latter
2031 case, continue looking. Maybe we can also start another
2032 displaced step on a thread of other process. */
2038 /* Update global variables holding ptids to hold NEW_PTID if they were
2039 holding OLD_PTID. */
2041 infrun_thread_ptid_changed (process_stratum_target
*target
,
2042 ptid_t old_ptid
, ptid_t new_ptid
)
2044 if (inferior_ptid
== old_ptid
2045 && current_inferior ()->process_target () == target
)
2046 inferior_ptid
= new_ptid
;
2051 static const char schedlock_off
[] = "off";
2052 static const char schedlock_on
[] = "on";
2053 static const char schedlock_step
[] = "step";
2054 static const char schedlock_replay
[] = "replay";
2055 static const char *const scheduler_enums
[] = {
2062 static const char *scheduler_mode
= schedlock_replay
;
2064 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2065 struct cmd_list_element
*c
, const char *value
)
2067 fprintf_filtered (file
,
2068 _("Mode for locking scheduler "
2069 "during execution is \"%s\".\n"),
2074 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2076 if (!target_can_lock_scheduler ())
2078 scheduler_mode
= schedlock_off
;
2079 error (_("Target '%s' cannot support this command."), target_shortname
);
2083 /* True if execution commands resume all threads of all processes by
2084 default; otherwise, resume only threads of the current inferior
2086 bool sched_multi
= false;
2088 /* Try to setup for software single stepping over the specified location.
2089 Return true if target_resume() should use hardware single step.
2091 GDBARCH the current gdbarch.
2092 PC the location to step over. */
2095 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2097 bool hw_step
= true;
2099 if (execution_direction
== EXEC_FORWARD
2100 && gdbarch_software_single_step_p (gdbarch
))
2101 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2109 user_visible_resume_ptid (int step
)
2115 /* With non-stop mode on, threads are always handled
2117 resume_ptid
= inferior_ptid
;
2119 else if ((scheduler_mode
== schedlock_on
)
2120 || (scheduler_mode
== schedlock_step
&& step
))
2122 /* User-settable 'scheduler' mode requires solo thread
2124 resume_ptid
= inferior_ptid
;
2126 else if ((scheduler_mode
== schedlock_replay
)
2127 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2129 /* User-settable 'scheduler' mode requires solo thread resume in replay
2131 resume_ptid
= inferior_ptid
;
2133 else if (!sched_multi
&& target_supports_multi_process ())
2135 /* Resume all threads of the current process (and none of other
2137 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2141 /* Resume all threads of all processes. */
2142 resume_ptid
= RESUME_ALL
;
2150 process_stratum_target
*
2151 user_visible_resume_target (ptid_t resume_ptid
)
2153 return (resume_ptid
== minus_one_ptid
&& sched_multi
2155 : current_inferior ()->process_target ());
2158 /* Return a ptid representing the set of threads that we will resume,
2159 in the perspective of the target, assuming run control handling
2160 does not require leaving some threads stopped (e.g., stepping past
2161 breakpoint). USER_STEP indicates whether we're about to start the
2162 target for a stepping command. */
2165 internal_resume_ptid (int user_step
)
2167 /* In non-stop, we always control threads individually. Note that
2168 the target may always work in non-stop mode even with "set
2169 non-stop off", in which case user_visible_resume_ptid could
2170 return a wildcard ptid. */
2171 if (target_is_non_stop_p ())
2172 return inferior_ptid
;
2174 return user_visible_resume_ptid (user_step
);
2177 /* Wrapper for target_resume, that handles infrun-specific
2181 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2183 struct thread_info
*tp
= inferior_thread ();
2185 gdb_assert (!tp
->stop_requested
);
2187 /* Install inferior's terminal modes. */
2188 target_terminal::inferior ();
2190 /* Avoid confusing the next resume, if the next stop/resume
2191 happens to apply to another thread. */
2192 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2194 /* Advise target which signals may be handled silently.
2196 If we have removed breakpoints because we are stepping over one
2197 in-line (in any thread), we need to receive all signals to avoid
2198 accidentally skipping a breakpoint during execution of a signal
2201 Likewise if we're displaced stepping, otherwise a trap for a
2202 breakpoint in a signal handler might be confused with the
2203 displaced step finishing. We don't make the displaced_step_fixup
2204 step distinguish the cases instead, because:
2206 - a backtrace while stopped in the signal handler would show the
2207 scratch pad as frame older than the signal handler, instead of
2208 the real mainline code.
2210 - when the thread is later resumed, the signal handler would
2211 return to the scratch pad area, which would no longer be
2213 if (step_over_info_valid_p ()
2214 || displaced_step_in_progress (tp
->inf
))
2215 target_pass_signals ({});
2217 target_pass_signals (signal_pass
);
2219 target_resume (resume_ptid
, step
, sig
);
2221 target_commit_resume ();
2223 if (target_can_async_p ())
2227 /* Resume the inferior. SIG is the signal to give the inferior
2228 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2229 call 'resume', which handles exceptions. */
2232 resume_1 (enum gdb_signal sig
)
2234 struct regcache
*regcache
= get_current_regcache ();
2235 struct gdbarch
*gdbarch
= regcache
->arch ();
2236 struct thread_info
*tp
= inferior_thread ();
2237 const address_space
*aspace
= regcache
->aspace ();
2239 /* This represents the user's step vs continue request. When
2240 deciding whether "set scheduler-locking step" applies, it's the
2241 user's intention that counts. */
2242 const int user_step
= tp
->control
.stepping_command
;
2243 /* This represents what we'll actually request the target to do.
2244 This can decay from a step to a continue, if e.g., we need to
2245 implement single-stepping with breakpoints (software
2249 gdb_assert (!tp
->stop_requested
);
2250 gdb_assert (!thread_is_in_step_over_chain (tp
));
2252 if (tp
->suspend
.waitstatus_pending_p
)
2255 ("thread %s has pending wait "
2256 "status %s (currently_stepping=%d).",
2257 target_pid_to_str (tp
->ptid
).c_str (),
2258 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2259 currently_stepping (tp
));
2261 tp
->inf
->process_target ()->threads_executing
= true;
2264 /* FIXME: What should we do if we are supposed to resume this
2265 thread with a signal? Maybe we should maintain a queue of
2266 pending signals to deliver. */
2267 if (sig
!= GDB_SIGNAL_0
)
2269 warning (_("Couldn't deliver signal %s to %s."),
2270 gdb_signal_to_name (sig
),
2271 target_pid_to_str (tp
->ptid
).c_str ());
2274 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2276 if (target_can_async_p ())
2279 /* Tell the event loop we have an event to process. */
2280 mark_async_event_handler (infrun_async_inferior_event_token
);
2285 tp
->stepped_breakpoint
= 0;
2287 /* Depends on stepped_breakpoint. */
2288 step
= currently_stepping (tp
);
2290 if (current_inferior ()->waiting_for_vfork_done
)
2292 /* Don't try to single-step a vfork parent that is waiting for
2293 the child to get out of the shared memory region (by exec'ing
2294 or exiting). This is particularly important on software
2295 single-step archs, as the child process would trip on the
2296 software single step breakpoint inserted for the parent
2297 process. Since the parent will not actually execute any
2298 instruction until the child is out of the shared region (such
2299 are vfork's semantics), it is safe to simply continue it.
2300 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2301 the parent, and tell it to `keep_going', which automatically
2302 re-sets it stepping. */
2303 infrun_debug_printf ("resume : clear step");
2307 CORE_ADDR pc
= regcache_read_pc (regcache
);
2309 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2310 "current thread [%s] at %s",
2311 step
, gdb_signal_to_symbol_string (sig
),
2312 tp
->control
.trap_expected
,
2313 target_pid_to_str (inferior_ptid
).c_str (),
2314 paddress (gdbarch
, pc
));
2316 /* Normally, by the time we reach `resume', the breakpoints are either
2317 removed or inserted, as appropriate. The exception is if we're sitting
2318 at a permanent breakpoint; we need to step over it, but permanent
2319 breakpoints can't be removed. So we have to test for it here. */
2320 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2322 if (sig
!= GDB_SIGNAL_0
)
2324 /* We have a signal to pass to the inferior. The resume
2325 may, or may not take us to the signal handler. If this
2326 is a step, we'll need to stop in the signal handler, if
2327 there's one, (if the target supports stepping into
2328 handlers), or in the next mainline instruction, if
2329 there's no handler. If this is a continue, we need to be
2330 sure to run the handler with all breakpoints inserted.
2331 In all cases, set a breakpoint at the current address
2332 (where the handler returns to), and once that breakpoint
2333 is hit, resume skipping the permanent breakpoint. If
2334 that breakpoint isn't hit, then we've stepped into the
2335 signal handler (or hit some other event). We'll delete
2336 the step-resume breakpoint then. */
2338 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2339 "deliver signal first");
2341 clear_step_over_info ();
2342 tp
->control
.trap_expected
= 0;
2344 if (tp
->control
.step_resume_breakpoint
== NULL
)
2346 /* Set a "high-priority" step-resume, as we don't want
2347 user breakpoints at PC to trigger (again) when this
2349 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2350 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2352 tp
->step_after_step_resume_breakpoint
= step
;
2355 insert_breakpoints ();
2359 /* There's no signal to pass, we can go ahead and skip the
2360 permanent breakpoint manually. */
2361 infrun_debug_printf ("skipping permanent breakpoint");
2362 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2363 /* Update pc to reflect the new address from which we will
2364 execute instructions. */
2365 pc
= regcache_read_pc (regcache
);
2369 /* We've already advanced the PC, so the stepping part
2370 is done. Now we need to arrange for a trap to be
2371 reported to handle_inferior_event. Set a breakpoint
2372 at the current PC, and run to it. Don't update
2373 prev_pc, because if we end in
2374 switch_back_to_stepped_thread, we want the "expected
2375 thread advanced also" branch to be taken. IOW, we
2376 don't want this thread to step further from PC
2378 gdb_assert (!step_over_info_valid_p ());
2379 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2380 insert_breakpoints ();
2382 resume_ptid
= internal_resume_ptid (user_step
);
2383 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2390 /* If we have a breakpoint to step over, make sure to do a single
2391 step only. Same if we have software watchpoints. */
2392 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2393 tp
->control
.may_range_step
= 0;
2395 /* If displaced stepping is enabled, step over breakpoints by executing a
2396 copy of the instruction at a different address.
2398 We can't use displaced stepping when we have a signal to deliver;
2399 the comments for displaced_step_prepare explain why. The
2400 comments in the handle_inferior event for dealing with 'random
2401 signals' explain what we do instead.
2403 We can't use displaced stepping when we are waiting for vfork_done
2404 event, displaced stepping breaks the vfork child similarly as single
2405 step software breakpoint. */
2406 if (tp
->control
.trap_expected
2407 && use_displaced_stepping (tp
)
2408 && !step_over_info_valid_p ()
2409 && sig
== GDB_SIGNAL_0
2410 && !current_inferior ()->waiting_for_vfork_done
)
2412 int prepared
= displaced_step_prepare (tp
);
2416 infrun_debug_printf ("Got placed in step-over queue");
2418 tp
->control
.trap_expected
= 0;
2421 else if (prepared
< 0)
2423 /* Fallback to stepping over the breakpoint in-line. */
2425 if (target_is_non_stop_p ())
2426 stop_all_threads ();
2428 set_step_over_info (regcache
->aspace (),
2429 regcache_read_pc (regcache
), 0, tp
->global_num
);
2431 step
= maybe_software_singlestep (gdbarch
, pc
);
2433 insert_breakpoints ();
2435 else if (prepared
> 0)
2437 /* Update pc to reflect the new address from which we will
2438 execute instructions due to displaced stepping. */
2439 pc
= regcache_read_pc (get_thread_regcache (tp
));
2441 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2445 /* Do we need to do it the hard way, w/temp breakpoints? */
2447 step
= maybe_software_singlestep (gdbarch
, pc
);
2449 /* Currently, our software single-step implementation leads to different
2450 results than hardware single-stepping in one situation: when stepping
2451 into delivering a signal which has an associated signal handler,
2452 hardware single-step will stop at the first instruction of the handler,
2453 while software single-step will simply skip execution of the handler.
2455 For now, this difference in behavior is accepted since there is no
2456 easy way to actually implement single-stepping into a signal handler
2457 without kernel support.
2459 However, there is one scenario where this difference leads to follow-on
2460 problems: if we're stepping off a breakpoint by removing all breakpoints
2461 and then single-stepping. In this case, the software single-step
2462 behavior means that even if there is a *breakpoint* in the signal
2463 handler, GDB still would not stop.
2465 Fortunately, we can at least fix this particular issue. We detect
2466 here the case where we are about to deliver a signal while software
2467 single-stepping with breakpoints removed. In this situation, we
2468 revert the decisions to remove all breakpoints and insert single-
2469 step breakpoints, and instead we install a step-resume breakpoint
2470 at the current address, deliver the signal without stepping, and
2471 once we arrive back at the step-resume breakpoint, actually step
2472 over the breakpoint we originally wanted to step over. */
2473 if (thread_has_single_step_breakpoints_set (tp
)
2474 && sig
!= GDB_SIGNAL_0
2475 && step_over_info_valid_p ())
2477 /* If we have nested signals or a pending signal is delivered
2478 immediately after a handler returns, might already have
2479 a step-resume breakpoint set on the earlier handler. We cannot
2480 set another step-resume breakpoint; just continue on until the
2481 original breakpoint is hit. */
2482 if (tp
->control
.step_resume_breakpoint
== NULL
)
2484 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2485 tp
->step_after_step_resume_breakpoint
= 1;
2488 delete_single_step_breakpoints (tp
);
2490 clear_step_over_info ();
2491 tp
->control
.trap_expected
= 0;
2493 insert_breakpoints ();
2496 /* If STEP is set, it's a request to use hardware stepping
2497 facilities. But in that case, we should never
2498 use singlestep breakpoint. */
2499 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2501 /* Decide the set of threads to ask the target to resume. */
2502 if (tp
->control
.trap_expected
)
2504 /* We're allowing a thread to run past a breakpoint it has
2505 hit, either by single-stepping the thread with the breakpoint
2506 removed, or by displaced stepping, with the breakpoint inserted.
2507 In the former case, we need to single-step only this thread,
2508 and keep others stopped, as they can miss this breakpoint if
2509 allowed to run. That's not really a problem for displaced
2510 stepping, but, we still keep other threads stopped, in case
2511 another thread is also stopped for a breakpoint waiting for
2512 its turn in the displaced stepping queue. */
2513 resume_ptid
= inferior_ptid
;
2516 resume_ptid
= internal_resume_ptid (user_step
);
2518 if (execution_direction
!= EXEC_REVERSE
2519 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2521 /* There are two cases where we currently need to step a
2522 breakpoint instruction when we have a signal to deliver:
2524 - See handle_signal_stop where we handle random signals that
2525 could take out us out of the stepping range. Normally, in
2526 that case we end up continuing (instead of stepping) over the
2527 signal handler with a breakpoint at PC, but there are cases
2528 where we should _always_ single-step, even if we have a
2529 step-resume breakpoint, like when a software watchpoint is
2530 set. Assuming single-stepping and delivering a signal at the
2531 same time would takes us to the signal handler, then we could
2532 have removed the breakpoint at PC to step over it. However,
2533 some hardware step targets (like e.g., Mac OS) can't step
2534 into signal handlers, and for those, we need to leave the
2535 breakpoint at PC inserted, as otherwise if the handler
2536 recurses and executes PC again, it'll miss the breakpoint.
2537 So we leave the breakpoint inserted anyway, but we need to
2538 record that we tried to step a breakpoint instruction, so
2539 that adjust_pc_after_break doesn't end up confused.
2541 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2542 in one thread after another thread that was stepping had been
2543 momentarily paused for a step-over. When we re-resume the
2544 stepping thread, it may be resumed from that address with a
2545 breakpoint that hasn't trapped yet. Seen with
2546 gdb.threads/non-stop-fair-events.exp, on targets that don't
2547 do displaced stepping. */
2549 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2550 target_pid_to_str (tp
->ptid
).c_str ());
2552 tp
->stepped_breakpoint
= 1;
2554 /* Most targets can step a breakpoint instruction, thus
2555 executing it normally. But if this one cannot, just
2556 continue and we will hit it anyway. */
2557 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2562 && tp
->control
.trap_expected
2563 && use_displaced_stepping (tp
)
2564 && !step_over_info_valid_p ())
2566 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2567 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2568 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2571 read_memory (actual_pc
, buf
, sizeof (buf
));
2572 displaced_debug_printf ("run %s: %s",
2573 paddress (resume_gdbarch
, actual_pc
),
2574 displaced_step_dump_bytes
2575 (buf
, sizeof (buf
)).c_str ());
2578 if (tp
->control
.may_range_step
)
2580 /* If we're resuming a thread with the PC out of the step
2581 range, then we're doing some nested/finer run control
2582 operation, like stepping the thread out of the dynamic
2583 linker or the displaced stepping scratch pad. We
2584 shouldn't have allowed a range step then. */
2585 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2588 do_target_resume (resume_ptid
, step
, sig
);
2592 /* Resume the inferior. SIG is the signal to give the inferior
2593 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2594 rolls back state on error. */
2597 resume (gdb_signal sig
)
2603 catch (const gdb_exception
&ex
)
2605 /* If resuming is being aborted for any reason, delete any
2606 single-step breakpoint resume_1 may have created, to avoid
2607 confusing the following resumption, and to avoid leaving
2608 single-step breakpoints perturbing other threads, in case
2609 we're running in non-stop mode. */
2610 if (inferior_ptid
!= null_ptid
)
2611 delete_single_step_breakpoints (inferior_thread ());
2621 /* Counter that tracks number of user visible stops. This can be used
2622 to tell whether a command has proceeded the inferior past the
2623 current location. This allows e.g., inferior function calls in
2624 breakpoint commands to not interrupt the command list. When the
2625 call finishes successfully, the inferior is standing at the same
2626 breakpoint as if nothing happened (and so we don't call
2628 static ULONGEST current_stop_id
;
2635 return current_stop_id
;
2638 /* Called when we report a user visible stop. */
2646 /* Clear out all variables saying what to do when inferior is continued.
2647 First do this, then set the ones you want, then call `proceed'. */
2650 clear_proceed_status_thread (struct thread_info
*tp
)
2652 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2654 /* If we're starting a new sequence, then the previous finished
2655 single-step is no longer relevant. */
2656 if (tp
->suspend
.waitstatus_pending_p
)
2658 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2660 infrun_debug_printf ("pending event of %s was a finished step. "
2662 target_pid_to_str (tp
->ptid
).c_str ());
2664 tp
->suspend
.waitstatus_pending_p
= 0;
2665 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2670 ("thread %s has pending wait status %s (currently_stepping=%d).",
2671 target_pid_to_str (tp
->ptid
).c_str (),
2672 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2673 currently_stepping (tp
));
2677 /* If this signal should not be seen by program, give it zero.
2678 Used for debugging signals. */
2679 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2680 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2682 delete tp
->thread_fsm
;
2683 tp
->thread_fsm
= NULL
;
2685 tp
->control
.trap_expected
= 0;
2686 tp
->control
.step_range_start
= 0;
2687 tp
->control
.step_range_end
= 0;
2688 tp
->control
.may_range_step
= 0;
2689 tp
->control
.step_frame_id
= null_frame_id
;
2690 tp
->control
.step_stack_frame_id
= null_frame_id
;
2691 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2692 tp
->control
.step_start_function
= NULL
;
2693 tp
->stop_requested
= 0;
2695 tp
->control
.stop_step
= 0;
2697 tp
->control
.proceed_to_finish
= 0;
2699 tp
->control
.stepping_command
= 0;
2701 /* Discard any remaining commands or status from previous stop. */
2702 bpstat_clear (&tp
->control
.stop_bpstat
);
2706 clear_proceed_status (int step
)
2708 /* With scheduler-locking replay, stop replaying other threads if we're
2709 not replaying the user-visible resume ptid.
2711 This is a convenience feature to not require the user to explicitly
2712 stop replaying the other threads. We're assuming that the user's
2713 intent is to resume tracing the recorded process. */
2714 if (!non_stop
&& scheduler_mode
== schedlock_replay
2715 && target_record_is_replaying (minus_one_ptid
)
2716 && !target_record_will_replay (user_visible_resume_ptid (step
),
2717 execution_direction
))
2718 target_record_stop_replaying ();
2720 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2722 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2723 process_stratum_target
*resume_target
2724 = user_visible_resume_target (resume_ptid
);
2726 /* In all-stop mode, delete the per-thread status of all threads
2727 we're about to resume, implicitly and explicitly. */
2728 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2729 clear_proceed_status_thread (tp
);
2732 if (inferior_ptid
!= null_ptid
)
2734 struct inferior
*inferior
;
2738 /* If in non-stop mode, only delete the per-thread status of
2739 the current thread. */
2740 clear_proceed_status_thread (inferior_thread ());
2743 inferior
= current_inferior ();
2744 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2747 gdb::observers::about_to_proceed
.notify ();
2750 /* Returns true if TP is still stopped at a breakpoint that needs
2751 stepping-over in order to make progress. If the breakpoint is gone
2752 meanwhile, we can skip the whole step-over dance. */
2755 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2757 if (tp
->stepping_over_breakpoint
)
2759 struct regcache
*regcache
= get_thread_regcache (tp
);
2761 if (breakpoint_here_p (regcache
->aspace (),
2762 regcache_read_pc (regcache
))
2763 == ordinary_breakpoint_here
)
2766 tp
->stepping_over_breakpoint
= 0;
2772 /* Check whether thread TP still needs to start a step-over in order
2773 to make progress when resumed. Returns an bitwise or of enum
2774 step_over_what bits, indicating what needs to be stepped over. */
2776 static step_over_what
2777 thread_still_needs_step_over (struct thread_info
*tp
)
2779 step_over_what what
= 0;
2781 if (thread_still_needs_step_over_bp (tp
))
2782 what
|= STEP_OVER_BREAKPOINT
;
2784 if (tp
->stepping_over_watchpoint
2785 && !target_have_steppable_watchpoint ())
2786 what
|= STEP_OVER_WATCHPOINT
;
2791 /* Returns true if scheduler locking applies. STEP indicates whether
2792 we're about to do a step/next-like command to a thread. */
2795 schedlock_applies (struct thread_info
*tp
)
2797 return (scheduler_mode
== schedlock_on
2798 || (scheduler_mode
== schedlock_step
2799 && tp
->control
.stepping_command
)
2800 || (scheduler_mode
== schedlock_replay
2801 && target_record_will_replay (minus_one_ptid
,
2802 execution_direction
)));
2805 /* Calls target_commit_resume on all targets. */
2808 commit_resume_all_targets ()
2810 scoped_restore_current_thread restore_thread
;
2812 /* Map between process_target and a representative inferior. This
2813 is to avoid committing a resume in the same target more than
2814 once. Resumptions must be idempotent, so this is an
2816 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2818 for (inferior
*inf
: all_non_exited_inferiors ())
2819 if (inf
->has_execution ())
2820 conn_inf
[inf
->process_target ()] = inf
;
2822 for (const auto &ci
: conn_inf
)
2824 inferior
*inf
= ci
.second
;
2825 switch_to_inferior_no_thread (inf
);
2826 target_commit_resume ();
2830 /* Check that all the targets we're about to resume are in non-stop
2831 mode. Ideally, we'd only care whether all targets support
2832 target-async, but we're not there yet. E.g., stop_all_threads
2833 doesn't know how to handle all-stop targets. Also, the remote
2834 protocol in all-stop mode is synchronous, irrespective of
2835 target-async, which means that things like a breakpoint re-set
2836 triggered by one target would try to read memory from all targets
2840 check_multi_target_resumption (process_stratum_target
*resume_target
)
2842 if (!non_stop
&& resume_target
== nullptr)
2844 scoped_restore_current_thread restore_thread
;
2846 /* This is used to track whether we're resuming more than one
2848 process_stratum_target
*first_connection
= nullptr;
2850 /* The first inferior we see with a target that does not work in
2851 always-non-stop mode. */
2852 inferior
*first_not_non_stop
= nullptr;
2854 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2856 switch_to_inferior_no_thread (inf
);
2858 if (!target_has_execution ())
2861 process_stratum_target
*proc_target
2862 = current_inferior ()->process_target();
2864 if (!target_is_non_stop_p ())
2865 first_not_non_stop
= inf
;
2867 if (first_connection
== nullptr)
2868 first_connection
= proc_target
;
2869 else if (first_connection
!= proc_target
2870 && first_not_non_stop
!= nullptr)
2872 switch_to_inferior_no_thread (first_not_non_stop
);
2874 proc_target
= current_inferior ()->process_target();
2876 error (_("Connection %d (%s) does not support "
2877 "multi-target resumption."),
2878 proc_target
->connection_number
,
2879 make_target_connection_string (proc_target
).c_str ());
2885 /* Basic routine for continuing the program in various fashions.
2887 ADDR is the address to resume at, or -1 for resume where stopped.
2888 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2889 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2891 You should call clear_proceed_status before calling proceed. */
2894 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2896 struct regcache
*regcache
;
2897 struct gdbarch
*gdbarch
;
2899 struct execution_control_state ecss
;
2900 struct execution_control_state
*ecs
= &ecss
;
2903 /* If we're stopped at a fork/vfork, follow the branch set by the
2904 "set follow-fork-mode" command; otherwise, we'll just proceed
2905 resuming the current thread. */
2906 if (!follow_fork ())
2908 /* The target for some reason decided not to resume. */
2910 if (target_can_async_p ())
2911 inferior_event_handler (INF_EXEC_COMPLETE
);
2915 /* We'll update this if & when we switch to a new thread. */
2916 previous_inferior_ptid
= inferior_ptid
;
2918 regcache
= get_current_regcache ();
2919 gdbarch
= regcache
->arch ();
2920 const address_space
*aspace
= regcache
->aspace ();
2922 pc
= regcache_read_pc_protected (regcache
);
2924 thread_info
*cur_thr
= inferior_thread ();
2926 /* Fill in with reasonable starting values. */
2927 init_thread_stepping_state (cur_thr
);
2929 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2932 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2933 process_stratum_target
*resume_target
2934 = user_visible_resume_target (resume_ptid
);
2936 check_multi_target_resumption (resume_target
);
2938 if (addr
== (CORE_ADDR
) -1)
2940 if (pc
== cur_thr
->suspend
.stop_pc
2941 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2942 && execution_direction
!= EXEC_REVERSE
)
2943 /* There is a breakpoint at the address we will resume at,
2944 step one instruction before inserting breakpoints so that
2945 we do not stop right away (and report a second hit at this
2948 Note, we don't do this in reverse, because we won't
2949 actually be executing the breakpoint insn anyway.
2950 We'll be (un-)executing the previous instruction. */
2951 cur_thr
->stepping_over_breakpoint
= 1;
2952 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2953 && gdbarch_single_step_through_delay (gdbarch
,
2954 get_current_frame ()))
2955 /* We stepped onto an instruction that needs to be stepped
2956 again before re-inserting the breakpoint, do so. */
2957 cur_thr
->stepping_over_breakpoint
= 1;
2961 regcache_write_pc (regcache
, addr
);
2964 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2965 cur_thr
->suspend
.stop_signal
= siggnal
;
2967 /* If an exception is thrown from this point on, make sure to
2968 propagate GDB's knowledge of the executing state to the
2969 frontend/user running state. */
2970 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2972 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2973 threads (e.g., we might need to set threads stepping over
2974 breakpoints first), from the user/frontend's point of view, all
2975 threads in RESUME_PTID are now running. Unless we're calling an
2976 inferior function, as in that case we pretend the inferior
2977 doesn't run at all. */
2978 if (!cur_thr
->control
.in_infcall
)
2979 set_running (resume_target
, resume_ptid
, true);
2981 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
2982 gdb_signal_to_symbol_string (siggnal
));
2984 annotate_starting ();
2986 /* Make sure that output from GDB appears before output from the
2988 gdb_flush (gdb_stdout
);
2990 /* Since we've marked the inferior running, give it the terminal. A
2991 QUIT/Ctrl-C from here on is forwarded to the target (which can
2992 still detect attempts to unblock a stuck connection with repeated
2993 Ctrl-C from within target_pass_ctrlc). */
2994 target_terminal::inferior ();
2996 /* In a multi-threaded task we may select another thread and
2997 then continue or step.
2999 But if a thread that we're resuming had stopped at a breakpoint,
3000 it will immediately cause another breakpoint stop without any
3001 execution (i.e. it will report a breakpoint hit incorrectly). So
3002 we must step over it first.
3004 Look for threads other than the current (TP) that reported a
3005 breakpoint hit and haven't been resumed yet since. */
3007 /* If scheduler locking applies, we can avoid iterating over all
3009 if (!non_stop
&& !schedlock_applies (cur_thr
))
3011 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3014 switch_to_thread_no_regs (tp
);
3016 /* Ignore the current thread here. It's handled
3021 if (!thread_still_needs_step_over (tp
))
3024 gdb_assert (!thread_is_in_step_over_chain (tp
));
3026 infrun_debug_printf ("need to step-over [%s] first",
3027 target_pid_to_str (tp
->ptid
).c_str ());
3029 thread_step_over_chain_enqueue (tp
);
3032 switch_to_thread (cur_thr
);
3035 /* Enqueue the current thread last, so that we move all other
3036 threads over their breakpoints first. */
3037 if (cur_thr
->stepping_over_breakpoint
)
3038 thread_step_over_chain_enqueue (cur_thr
);
3040 /* If the thread isn't started, we'll still need to set its prev_pc,
3041 so that switch_back_to_stepped_thread knows the thread hasn't
3042 advanced. Must do this before resuming any thread, as in
3043 all-stop/remote, once we resume we can't send any other packet
3044 until the target stops again. */
3045 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3048 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3050 started
= start_step_over ();
3052 if (step_over_info_valid_p ())
3054 /* Either this thread started a new in-line step over, or some
3055 other thread was already doing one. In either case, don't
3056 resume anything else until the step-over is finished. */
3058 else if (started
&& !target_is_non_stop_p ())
3060 /* A new displaced stepping sequence was started. In all-stop,
3061 we can't talk to the target anymore until it next stops. */
3063 else if (!non_stop
&& target_is_non_stop_p ())
3065 /* In all-stop, but the target is always in non-stop mode.
3066 Start all other threads that are implicitly resumed too. */
3067 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3070 switch_to_thread_no_regs (tp
);
3072 if (!tp
->inf
->has_execution ())
3074 infrun_debug_printf ("[%s] target has no execution",
3075 target_pid_to_str (tp
->ptid
).c_str ());
3081 infrun_debug_printf ("[%s] resumed",
3082 target_pid_to_str (tp
->ptid
).c_str ());
3083 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3087 if (thread_is_in_step_over_chain (tp
))
3089 infrun_debug_printf ("[%s] needs step-over",
3090 target_pid_to_str (tp
->ptid
).c_str ());
3094 infrun_debug_printf ("resuming %s",
3095 target_pid_to_str (tp
->ptid
).c_str ());
3097 reset_ecs (ecs
, tp
);
3098 switch_to_thread (tp
);
3099 keep_going_pass_signal (ecs
);
3100 if (!ecs
->wait_some_more
)
3101 error (_("Command aborted."));
3104 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3106 /* The thread wasn't started, and isn't queued, run it now. */
3107 reset_ecs (ecs
, cur_thr
);
3108 switch_to_thread (cur_thr
);
3109 keep_going_pass_signal (ecs
);
3110 if (!ecs
->wait_some_more
)
3111 error (_("Command aborted."));
3115 commit_resume_all_targets ();
3117 finish_state
.release ();
3119 /* If we've switched threads above, switch back to the previously
3120 current thread. We don't want the user to see a different
3122 switch_to_thread (cur_thr
);
3124 /* Tell the event loop to wait for it to stop. If the target
3125 supports asynchronous execution, it'll do this from within
3127 if (!target_can_async_p ())
3128 mark_async_event_handler (infrun_async_inferior_event_token
);
3132 /* Start remote-debugging of a machine over a serial link. */
3135 start_remote (int from_tty
)
3137 inferior
*inf
= current_inferior ();
3138 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3140 /* Always go on waiting for the target, regardless of the mode. */
3141 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3142 indicate to wait_for_inferior that a target should timeout if
3143 nothing is returned (instead of just blocking). Because of this,
3144 targets expecting an immediate response need to, internally, set
3145 things up so that the target_wait() is forced to eventually
3147 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3148 differentiate to its caller what the state of the target is after
3149 the initial open has been performed. Here we're assuming that
3150 the target has stopped. It should be possible to eventually have
3151 target_open() return to the caller an indication that the target
3152 is currently running and GDB state should be set to the same as
3153 for an async run. */
3154 wait_for_inferior (inf
);
3156 /* Now that the inferior has stopped, do any bookkeeping like
3157 loading shared libraries. We want to do this before normal_stop,
3158 so that the displayed frame is up to date. */
3159 post_create_inferior (from_tty
);
3164 /* Initialize static vars when a new inferior begins. */
3167 init_wait_for_inferior (void)
3169 /* These are meaningless until the first time through wait_for_inferior. */
3171 breakpoint_init_inferior (inf_starting
);
3173 clear_proceed_status (0);
3175 nullify_last_target_wait_ptid ();
3177 previous_inferior_ptid
= inferior_ptid
;
3182 static void handle_inferior_event (struct execution_control_state
*ecs
);
3184 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3185 struct execution_control_state
*ecs
);
3186 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3187 struct execution_control_state
*ecs
);
3188 static void handle_signal_stop (struct execution_control_state
*ecs
);
3189 static void check_exception_resume (struct execution_control_state
*,
3190 struct frame_info
*);
3192 static void end_stepping_range (struct execution_control_state
*ecs
);
3193 static void stop_waiting (struct execution_control_state
*ecs
);
3194 static void keep_going (struct execution_control_state
*ecs
);
3195 static void process_event_stop_test (struct execution_control_state
*ecs
);
3196 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3198 /* This function is attached as a "thread_stop_requested" observer.
3199 Cleanup local state that assumed the PTID was to be resumed, and
3200 report the stop to the frontend. */
3203 infrun_thread_stop_requested (ptid_t ptid
)
3205 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3207 /* PTID was requested to stop. If the thread was already stopped,
3208 but the user/frontend doesn't know about that yet (e.g., the
3209 thread had been temporarily paused for some step-over), set up
3210 for reporting the stop now. */
3211 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3213 if (tp
->state
!= THREAD_RUNNING
)
3218 /* Remove matching threads from the step-over queue, so
3219 start_step_over doesn't try to resume them
3221 if (thread_is_in_step_over_chain (tp
))
3222 thread_step_over_chain_remove (tp
);
3224 /* If the thread is stopped, but the user/frontend doesn't
3225 know about that yet, queue a pending event, as if the
3226 thread had just stopped now. Unless the thread already had
3228 if (!tp
->suspend
.waitstatus_pending_p
)
3230 tp
->suspend
.waitstatus_pending_p
= 1;
3231 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3232 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3235 /* Clear the inline-frame state, since we're re-processing the
3237 clear_inline_frame_state (tp
);
3239 /* If this thread was paused because some other thread was
3240 doing an inline-step over, let that finish first. Once
3241 that happens, we'll restart all threads and consume pending
3242 stop events then. */
3243 if (step_over_info_valid_p ())
3246 /* Otherwise we can process the (new) pending event now. Set
3247 it so this pending event is considered by
3254 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3256 if (target_last_proc_target
== tp
->inf
->process_target ()
3257 && target_last_wait_ptid
== tp
->ptid
)
3258 nullify_last_target_wait_ptid ();
3261 /* Delete the step resume, single-step and longjmp/exception resume
3262 breakpoints of TP. */
3265 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3267 delete_step_resume_breakpoint (tp
);
3268 delete_exception_resume_breakpoint (tp
);
3269 delete_single_step_breakpoints (tp
);
3272 /* If the target still has execution, call FUNC for each thread that
3273 just stopped. In all-stop, that's all the non-exited threads; in
3274 non-stop, that's the current thread, only. */
3276 typedef void (*for_each_just_stopped_thread_callback_func
)
3277 (struct thread_info
*tp
);
3280 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3282 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3285 if (target_is_non_stop_p ())
3287 /* If in non-stop mode, only the current thread stopped. */
3288 func (inferior_thread ());
3292 /* In all-stop mode, all threads have stopped. */
3293 for (thread_info
*tp
: all_non_exited_threads ())
3298 /* Delete the step resume and longjmp/exception resume breakpoints of
3299 the threads that just stopped. */
3302 delete_just_stopped_threads_infrun_breakpoints (void)
3304 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3307 /* Delete the single-step breakpoints of the threads that just
3311 delete_just_stopped_threads_single_step_breakpoints (void)
3313 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3319 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3320 const struct target_waitstatus
*ws
)
3322 std::string status_string
= target_waitstatus_to_string (ws
);
3325 /* The text is split over several lines because it was getting too long.
3326 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3327 output as a unit; we want only one timestamp printed if debug_timestamp
3330 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3333 waiton_ptid
.tid ());
3334 if (waiton_ptid
.pid () != -1)
3335 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3336 stb
.printf (", status) =\n");
3337 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3341 target_pid_to_str (result_ptid
).c_str ());
3342 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3344 /* This uses %s in part to handle %'s in the text, but also to avoid
3345 a gcc error: the format attribute requires a string literal. */
3346 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3349 /* Select a thread at random, out of those which are resumed and have
3352 static struct thread_info
*
3353 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3357 auto has_event
= [&] (thread_info
*tp
)
3359 return (tp
->ptid
.matches (waiton_ptid
)
3361 && tp
->suspend
.waitstatus_pending_p
);
3364 /* First see how many events we have. Count only resumed threads
3365 that have an event pending. */
3366 for (thread_info
*tp
: inf
->non_exited_threads ())
3370 if (num_events
== 0)
3373 /* Now randomly pick a thread out of those that have had events. */
3374 int random_selector
= (int) ((num_events
* (double) rand ())
3375 / (RAND_MAX
+ 1.0));
3378 infrun_debug_printf ("Found %d events, selecting #%d",
3379 num_events
, random_selector
);
3381 /* Select the Nth thread that has had an event. */
3382 for (thread_info
*tp
: inf
->non_exited_threads ())
3384 if (random_selector
-- == 0)
3387 gdb_assert_not_reached ("event thread not found");
3390 /* Wrapper for target_wait that first checks whether threads have
3391 pending statuses to report before actually asking the target for
3392 more events. INF is the inferior we're using to call target_wait
3396 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3397 target_waitstatus
*status
, target_wait_flags options
)
3400 struct thread_info
*tp
;
3402 /* We know that we are looking for an event in the target of inferior
3403 INF, but we don't know which thread the event might come from. As
3404 such we want to make sure that INFERIOR_PTID is reset so that none of
3405 the wait code relies on it - doing so is always a mistake. */
3406 switch_to_inferior_no_thread (inf
);
3408 /* First check if there is a resumed thread with a wait status
3410 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3412 tp
= random_pending_event_thread (inf
, ptid
);
3416 infrun_debug_printf ("Waiting for specific thread %s.",
3417 target_pid_to_str (ptid
).c_str ());
3419 /* We have a specific thread to check. */
3420 tp
= find_thread_ptid (inf
, ptid
);
3421 gdb_assert (tp
!= NULL
);
3422 if (!tp
->suspend
.waitstatus_pending_p
)
3427 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3428 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3430 struct regcache
*regcache
= get_thread_regcache (tp
);
3431 struct gdbarch
*gdbarch
= regcache
->arch ();
3435 pc
= regcache_read_pc (regcache
);
3437 if (pc
!= tp
->suspend
.stop_pc
)
3439 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3440 target_pid_to_str (tp
->ptid
).c_str (),
3441 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3442 paddress (gdbarch
, pc
));
3445 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3447 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3448 target_pid_to_str (tp
->ptid
).c_str (),
3449 paddress (gdbarch
, pc
));
3456 infrun_debug_printf ("pending event of %s cancelled.",
3457 target_pid_to_str (tp
->ptid
).c_str ());
3459 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3460 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3466 infrun_debug_printf ("Using pending wait status %s for %s.",
3467 target_waitstatus_to_string
3468 (&tp
->suspend
.waitstatus
).c_str (),
3469 target_pid_to_str (tp
->ptid
).c_str ());
3471 /* Now that we've selected our final event LWP, un-adjust its PC
3472 if it was a software breakpoint (and the target doesn't
3473 always adjust the PC itself). */
3474 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3475 && !target_supports_stopped_by_sw_breakpoint ())
3477 struct regcache
*regcache
;
3478 struct gdbarch
*gdbarch
;
3481 regcache
= get_thread_regcache (tp
);
3482 gdbarch
= regcache
->arch ();
3484 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3489 pc
= regcache_read_pc (regcache
);
3490 regcache_write_pc (regcache
, pc
+ decr_pc
);
3494 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3495 *status
= tp
->suspend
.waitstatus
;
3496 tp
->suspend
.waitstatus_pending_p
= 0;
3498 /* Wake up the event loop again, until all pending events are
3500 if (target_is_async_p ())
3501 mark_async_event_handler (infrun_async_inferior_event_token
);
3505 /* But if we don't find one, we'll have to wait. */
3507 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3509 if (!target_can_async_p ())
3510 options
&= ~TARGET_WNOHANG
;
3512 if (deprecated_target_wait_hook
)
3513 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3515 event_ptid
= target_wait (ptid
, status
, options
);
3520 /* Wrapper for target_wait that first checks whether threads have
3521 pending statuses to report before actually asking the target for
3522 more events. Polls for events from all inferiors/targets. */
3525 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3526 target_wait_flags options
)
3528 int num_inferiors
= 0;
3529 int random_selector
;
3531 /* For fairness, we pick the first inferior/target to poll at random
3532 out of all inferiors that may report events, and then continue
3533 polling the rest of the inferior list starting from that one in a
3534 circular fashion until the whole list is polled once. */
3536 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3538 return (inf
->process_target () != NULL
3539 && ptid_t (inf
->pid
).matches (wait_ptid
));
3542 /* First see how many matching inferiors we have. */
3543 for (inferior
*inf
: all_inferiors ())
3544 if (inferior_matches (inf
))
3547 if (num_inferiors
== 0)
3549 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3553 /* Now randomly pick an inferior out of those that matched. */
3554 random_selector
= (int)
3555 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3557 if (num_inferiors
> 1)
3558 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3559 num_inferiors
, random_selector
);
3561 /* Select the Nth inferior that matched. */
3563 inferior
*selected
= nullptr;
3565 for (inferior
*inf
: all_inferiors ())
3566 if (inferior_matches (inf
))
3567 if (random_selector
-- == 0)
3573 /* Now poll for events out of each of the matching inferior's
3574 targets, starting from the selected one. */
3576 auto do_wait
= [&] (inferior
*inf
)
3578 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3579 ecs
->target
= inf
->process_target ();
3580 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3583 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3584 here spuriously after the target is all stopped and we've already
3585 reported the stop to the user, polling for events. */
3586 scoped_restore_current_thread restore_thread
;
3588 int inf_num
= selected
->num
;
3589 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3590 if (inferior_matches (inf
))
3594 for (inferior
*inf
= inferior_list
;
3595 inf
!= NULL
&& inf
->num
< inf_num
;
3597 if (inferior_matches (inf
))
3601 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3605 /* Prepare and stabilize the inferior for detaching it. E.g.,
3606 detaching while a thread is displaced stepping is a recipe for
3607 crashing it, as nothing would readjust the PC out of the scratch
3611 prepare_for_detach (void)
3613 struct inferior
*inf
= current_inferior ();
3614 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3616 displaced_step_inferior_state
*displaced
= &inf
->displaced_step_state
;
3618 /* Is any thread of this process displaced stepping? If not,
3619 there's nothing else to do. */
3620 if (displaced
->step_thread
== nullptr)
3623 infrun_debug_printf ("displaced-stepping in-process while detaching");
3625 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3627 while (displaced
->step_thread
!= nullptr)
3629 struct execution_control_state ecss
;
3630 struct execution_control_state
*ecs
;
3633 memset (ecs
, 0, sizeof (*ecs
));
3635 overlay_cache_invalid
= 1;
3636 /* Flush target cache before starting to handle each event.
3637 Target was running and cache could be stale. This is just a
3638 heuristic. Running threads may modify target memory, but we
3639 don't get any event. */
3640 target_dcache_invalidate ();
3642 do_target_wait (pid_ptid
, ecs
, 0);
3645 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3647 /* If an error happens while handling the event, propagate GDB's
3648 knowledge of the executing state to the frontend/user running
3650 scoped_finish_thread_state
finish_state (inf
->process_target (),
3653 /* Now figure out what to do with the result of the result. */
3654 handle_inferior_event (ecs
);
3656 /* No error, don't finish the state yet. */
3657 finish_state
.release ();
3659 /* Breakpoints and watchpoints are not installed on the target
3660 at this point, and signals are passed directly to the
3661 inferior, so this must mean the process is gone. */
3662 if (!ecs
->wait_some_more
)
3664 restore_detaching
.release ();
3665 error (_("Program exited while detaching"));
3669 restore_detaching
.release ();
3672 /* Wait for control to return from inferior to debugger.
3674 If inferior gets a signal, we may decide to start it up again
3675 instead of returning. That is why there is a loop in this function.
3676 When this function actually returns it means the inferior
3677 should be left stopped and GDB should read more commands. */
3680 wait_for_inferior (inferior
*inf
)
3682 infrun_debug_printf ("wait_for_inferior ()");
3684 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3686 /* If an error happens while handling the event, propagate GDB's
3687 knowledge of the executing state to the frontend/user running
3689 scoped_finish_thread_state finish_state
3690 (inf
->process_target (), minus_one_ptid
);
3694 struct execution_control_state ecss
;
3695 struct execution_control_state
*ecs
= &ecss
;
3697 memset (ecs
, 0, sizeof (*ecs
));
3699 overlay_cache_invalid
= 1;
3701 /* Flush target cache before starting to handle each event.
3702 Target was running and cache could be stale. This is just a
3703 heuristic. Running threads may modify target memory, but we
3704 don't get any event. */
3705 target_dcache_invalidate ();
3707 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3708 ecs
->target
= inf
->process_target ();
3711 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3713 /* Now figure out what to do with the result of the result. */
3714 handle_inferior_event (ecs
);
3716 if (!ecs
->wait_some_more
)
3720 /* No error, don't finish the state yet. */
3721 finish_state
.release ();
3724 /* Cleanup that reinstalls the readline callback handler, if the
3725 target is running in the background. If while handling the target
3726 event something triggered a secondary prompt, like e.g., a
3727 pagination prompt, we'll have removed the callback handler (see
3728 gdb_readline_wrapper_line). Need to do this as we go back to the
3729 event loop, ready to process further input. Note this has no
3730 effect if the handler hasn't actually been removed, because calling
3731 rl_callback_handler_install resets the line buffer, thus losing
3735 reinstall_readline_callback_handler_cleanup ()
3737 struct ui
*ui
= current_ui
;
3741 /* We're not going back to the top level event loop yet. Don't
3742 install the readline callback, as it'd prep the terminal,
3743 readline-style (raw, noecho) (e.g., --batch). We'll install
3744 it the next time the prompt is displayed, when we're ready
3749 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3750 gdb_rl_callback_handler_reinstall ();
3753 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3754 that's just the event thread. In all-stop, that's all threads. */
3757 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3759 if (ecs
->event_thread
!= NULL
3760 && ecs
->event_thread
->thread_fsm
!= NULL
)
3761 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3765 for (thread_info
*thr
: all_non_exited_threads ())
3767 if (thr
->thread_fsm
== NULL
)
3769 if (thr
== ecs
->event_thread
)
3772 switch_to_thread (thr
);
3773 thr
->thread_fsm
->clean_up (thr
);
3776 if (ecs
->event_thread
!= NULL
)
3777 switch_to_thread (ecs
->event_thread
);
3781 /* Helper for all_uis_check_sync_execution_done that works on the
3785 check_curr_ui_sync_execution_done (void)
3787 struct ui
*ui
= current_ui
;
3789 if (ui
->prompt_state
== PROMPT_NEEDED
3791 && !gdb_in_secondary_prompt_p (ui
))
3793 target_terminal::ours ();
3794 gdb::observers::sync_execution_done
.notify ();
3795 ui_register_input_event_handler (ui
);
3802 all_uis_check_sync_execution_done (void)
3804 SWITCH_THRU_ALL_UIS ()
3806 check_curr_ui_sync_execution_done ();
3813 all_uis_on_sync_execution_starting (void)
3815 SWITCH_THRU_ALL_UIS ()
3817 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3818 async_disable_stdin ();
3822 /* Asynchronous version of wait_for_inferior. It is called by the
3823 event loop whenever a change of state is detected on the file
3824 descriptor corresponding to the target. It can be called more than
3825 once to complete a single execution command. In such cases we need
3826 to keep the state in a global variable ECSS. If it is the last time
3827 that this function is called for a single execution command, then
3828 report to the user that the inferior has stopped, and do the
3829 necessary cleanups. */
3832 fetch_inferior_event ()
3834 struct execution_control_state ecss
;
3835 struct execution_control_state
*ecs
= &ecss
;
3838 memset (ecs
, 0, sizeof (*ecs
));
3840 /* Events are always processed with the main UI as current UI. This
3841 way, warnings, debug output, etc. are always consistently sent to
3842 the main console. */
3843 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3845 /* Temporarily disable pagination. Otherwise, the user would be
3846 given an option to press 'q' to quit, which would cause an early
3847 exit and could leave GDB in a half-baked state. */
3848 scoped_restore save_pagination
3849 = make_scoped_restore (&pagination_enabled
, false);
3851 /* End up with readline processing input, if necessary. */
3853 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3855 /* We're handling a live event, so make sure we're doing live
3856 debugging. If we're looking at traceframes while the target is
3857 running, we're going to need to get back to that mode after
3858 handling the event. */
3859 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3862 maybe_restore_traceframe
.emplace ();
3863 set_current_traceframe (-1);
3866 /* The user/frontend should not notice a thread switch due to
3867 internal events. Make sure we revert to the user selected
3868 thread and frame after handling the event and running any
3869 breakpoint commands. */
3870 scoped_restore_current_thread restore_thread
;
3872 overlay_cache_invalid
= 1;
3873 /* Flush target cache before starting to handle each event. Target
3874 was running and cache could be stale. This is just a heuristic.
3875 Running threads may modify target memory, but we don't get any
3877 target_dcache_invalidate ();
3879 scoped_restore save_exec_dir
3880 = make_scoped_restore (&execution_direction
,
3881 target_execution_direction ());
3883 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3886 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3888 /* Switch to the target that generated the event, so we can do
3890 switch_to_target_no_thread (ecs
->target
);
3893 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3895 /* If an error happens while handling the event, propagate GDB's
3896 knowledge of the executing state to the frontend/user running
3898 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3899 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3901 /* Get executed before scoped_restore_current_thread above to apply
3902 still for the thread which has thrown the exception. */
3903 auto defer_bpstat_clear
3904 = make_scope_exit (bpstat_clear_actions
);
3905 auto defer_delete_threads
3906 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3908 /* Now figure out what to do with the result of the result. */
3909 handle_inferior_event (ecs
);
3911 if (!ecs
->wait_some_more
)
3913 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3914 bool should_stop
= true;
3915 struct thread_info
*thr
= ecs
->event_thread
;
3917 delete_just_stopped_threads_infrun_breakpoints ();
3921 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3923 if (thread_fsm
!= NULL
)
3924 should_stop
= thread_fsm
->should_stop (thr
);
3933 bool should_notify_stop
= true;
3936 clean_up_just_stopped_threads_fsms (ecs
);
3938 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3939 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3941 if (should_notify_stop
)
3943 /* We may not find an inferior if this was a process exit. */
3944 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3945 proceeded
= normal_stop ();
3950 inferior_event_handler (INF_EXEC_COMPLETE
);
3954 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3955 previously selected thread is gone. We have two
3956 choices - switch to no thread selected, or restore the
3957 previously selected thread (now exited). We chose the
3958 later, just because that's what GDB used to do. After
3959 this, "info threads" says "The current thread <Thread
3960 ID 2> has terminated." instead of "No thread
3964 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3965 restore_thread
.dont_restore ();
3969 defer_delete_threads
.release ();
3970 defer_bpstat_clear
.release ();
3972 /* No error, don't finish the thread states yet. */
3973 finish_state
.release ();
3975 /* This scope is used to ensure that readline callbacks are
3976 reinstalled here. */
3979 /* If a UI was in sync execution mode, and now isn't, restore its
3980 prompt (a synchronous execution command has finished, and we're
3981 ready for input). */
3982 all_uis_check_sync_execution_done ();
3985 && exec_done_display_p
3986 && (inferior_ptid
== null_ptid
3987 || inferior_thread ()->state
!= THREAD_RUNNING
))
3988 printf_unfiltered (_("completed.\n"));
3994 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
3995 struct symtab_and_line sal
)
3997 /* This can be removed once this function no longer implicitly relies on the
3998 inferior_ptid value. */
3999 gdb_assert (inferior_ptid
== tp
->ptid
);
4001 tp
->control
.step_frame_id
= get_frame_id (frame
);
4002 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4004 tp
->current_symtab
= sal
.symtab
;
4005 tp
->current_line
= sal
.line
;
4008 /* Clear context switchable stepping state. */
4011 init_thread_stepping_state (struct thread_info
*tss
)
4013 tss
->stepped_breakpoint
= 0;
4014 tss
->stepping_over_breakpoint
= 0;
4015 tss
->stepping_over_watchpoint
= 0;
4016 tss
->step_after_step_resume_breakpoint
= 0;
4022 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4023 target_waitstatus status
)
4025 target_last_proc_target
= target
;
4026 target_last_wait_ptid
= ptid
;
4027 target_last_waitstatus
= status
;
4033 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4034 target_waitstatus
*status
)
4036 if (target
!= nullptr)
4037 *target
= target_last_proc_target
;
4038 if (ptid
!= nullptr)
4039 *ptid
= target_last_wait_ptid
;
4040 if (status
!= nullptr)
4041 *status
= target_last_waitstatus
;
4047 nullify_last_target_wait_ptid (void)
4049 target_last_proc_target
= nullptr;
4050 target_last_wait_ptid
= minus_one_ptid
;
4051 target_last_waitstatus
= {};
4054 /* Switch thread contexts. */
4057 context_switch (execution_control_state
*ecs
)
4059 if (ecs
->ptid
!= inferior_ptid
4060 && (inferior_ptid
== null_ptid
4061 || ecs
->event_thread
!= inferior_thread ()))
4063 infrun_debug_printf ("Switching context from %s to %s",
4064 target_pid_to_str (inferior_ptid
).c_str (),
4065 target_pid_to_str (ecs
->ptid
).c_str ());
4068 switch_to_thread (ecs
->event_thread
);
4071 /* If the target can't tell whether we've hit breakpoints
4072 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4073 check whether that could have been caused by a breakpoint. If so,
4074 adjust the PC, per gdbarch_decr_pc_after_break. */
4077 adjust_pc_after_break (struct thread_info
*thread
,
4078 struct target_waitstatus
*ws
)
4080 struct regcache
*regcache
;
4081 struct gdbarch
*gdbarch
;
4082 CORE_ADDR breakpoint_pc
, decr_pc
;
4084 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4085 we aren't, just return.
4087 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4088 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4089 implemented by software breakpoints should be handled through the normal
4092 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4093 different signals (SIGILL or SIGEMT for instance), but it is less
4094 clear where the PC is pointing afterwards. It may not match
4095 gdbarch_decr_pc_after_break. I don't know any specific target that
4096 generates these signals at breakpoints (the code has been in GDB since at
4097 least 1992) so I can not guess how to handle them here.
4099 In earlier versions of GDB, a target with
4100 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4101 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4102 target with both of these set in GDB history, and it seems unlikely to be
4103 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4105 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4108 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4111 /* In reverse execution, when a breakpoint is hit, the instruction
4112 under it has already been de-executed. The reported PC always
4113 points at the breakpoint address, so adjusting it further would
4114 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4117 B1 0x08000000 : INSN1
4118 B2 0x08000001 : INSN2
4120 PC -> 0x08000003 : INSN4
4122 Say you're stopped at 0x08000003 as above. Reverse continuing
4123 from that point should hit B2 as below. Reading the PC when the
4124 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4125 been de-executed already.
4127 B1 0x08000000 : INSN1
4128 B2 PC -> 0x08000001 : INSN2
4132 We can't apply the same logic as for forward execution, because
4133 we would wrongly adjust the PC to 0x08000000, since there's a
4134 breakpoint at PC - 1. We'd then report a hit on B1, although
4135 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4137 if (execution_direction
== EXEC_REVERSE
)
4140 /* If the target can tell whether the thread hit a SW breakpoint,
4141 trust it. Targets that can tell also adjust the PC
4143 if (target_supports_stopped_by_sw_breakpoint ())
4146 /* Note that relying on whether a breakpoint is planted in memory to
4147 determine this can fail. E.g,. the breakpoint could have been
4148 removed since. Or the thread could have been told to step an
4149 instruction the size of a breakpoint instruction, and only
4150 _after_ was a breakpoint inserted at its address. */
4152 /* If this target does not decrement the PC after breakpoints, then
4153 we have nothing to do. */
4154 regcache
= get_thread_regcache (thread
);
4155 gdbarch
= regcache
->arch ();
4157 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4161 const address_space
*aspace
= regcache
->aspace ();
4163 /* Find the location where (if we've hit a breakpoint) the
4164 breakpoint would be. */
4165 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4167 /* If the target can't tell whether a software breakpoint triggered,
4168 fallback to figuring it out based on breakpoints we think were
4169 inserted in the target, and on whether the thread was stepped or
4172 /* Check whether there actually is a software breakpoint inserted at
4175 If in non-stop mode, a race condition is possible where we've
4176 removed a breakpoint, but stop events for that breakpoint were
4177 already queued and arrive later. To suppress those spurious
4178 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4179 and retire them after a number of stop events are reported. Note
4180 this is an heuristic and can thus get confused. The real fix is
4181 to get the "stopped by SW BP and needs adjustment" info out of
4182 the target/kernel (and thus never reach here; see above). */
4183 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4184 || (target_is_non_stop_p ()
4185 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4187 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4189 if (record_full_is_used ())
4190 restore_operation_disable
.emplace
4191 (record_full_gdb_operation_disable_set ());
4193 /* When using hardware single-step, a SIGTRAP is reported for both
4194 a completed single-step and a software breakpoint. Need to
4195 differentiate between the two, as the latter needs adjusting
4196 but the former does not.
4198 The SIGTRAP can be due to a completed hardware single-step only if
4199 - we didn't insert software single-step breakpoints
4200 - this thread is currently being stepped
4202 If any of these events did not occur, we must have stopped due
4203 to hitting a software breakpoint, and have to back up to the
4206 As a special case, we could have hardware single-stepped a
4207 software breakpoint. In this case (prev_pc == breakpoint_pc),
4208 we also need to back up to the breakpoint address. */
4210 if (thread_has_single_step_breakpoints_set (thread
)
4211 || !currently_stepping (thread
)
4212 || (thread
->stepped_breakpoint
4213 && thread
->prev_pc
== breakpoint_pc
))
4214 regcache_write_pc (regcache
, breakpoint_pc
);
4219 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4221 for (frame
= get_prev_frame (frame
);
4223 frame
= get_prev_frame (frame
))
4225 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4228 if (get_frame_type (frame
) != INLINE_FRAME
)
4235 /* Look for an inline frame that is marked for skip.
4236 If PREV_FRAME is TRUE start at the previous frame,
4237 otherwise start at the current frame. Stop at the
4238 first non-inline frame, or at the frame where the
4242 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4244 struct frame_info
*frame
= get_current_frame ();
4247 frame
= get_prev_frame (frame
);
4249 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4251 const char *fn
= NULL
;
4252 symtab_and_line sal
;
4255 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4257 if (get_frame_type (frame
) != INLINE_FRAME
)
4260 sal
= find_frame_sal (frame
);
4261 sym
= get_frame_function (frame
);
4264 fn
= sym
->print_name ();
4267 && function_name_is_marked_for_skip (fn
, sal
))
4274 /* If the event thread has the stop requested flag set, pretend it
4275 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4279 handle_stop_requested (struct execution_control_state
*ecs
)
4281 if (ecs
->event_thread
->stop_requested
)
4283 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4284 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4285 handle_signal_stop (ecs
);
4291 /* Auxiliary function that handles syscall entry/return events.
4292 It returns true if the inferior should keep going (and GDB
4293 should ignore the event), or false if the event deserves to be
4297 handle_syscall_event (struct execution_control_state
*ecs
)
4299 struct regcache
*regcache
;
4302 context_switch (ecs
);
4304 regcache
= get_thread_regcache (ecs
->event_thread
);
4305 syscall_number
= ecs
->ws
.value
.syscall_number
;
4306 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4308 if (catch_syscall_enabled () > 0
4309 && catching_syscall_number (syscall_number
) > 0)
4311 infrun_debug_printf ("syscall number=%d", syscall_number
);
4313 ecs
->event_thread
->control
.stop_bpstat
4314 = bpstat_stop_status (regcache
->aspace (),
4315 ecs
->event_thread
->suspend
.stop_pc
,
4316 ecs
->event_thread
, &ecs
->ws
);
4318 if (handle_stop_requested (ecs
))
4321 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4323 /* Catchpoint hit. */
4328 if (handle_stop_requested (ecs
))
4331 /* If no catchpoint triggered for this, then keep going. */
4337 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4340 fill_in_stop_func (struct gdbarch
*gdbarch
,
4341 struct execution_control_state
*ecs
)
4343 if (!ecs
->stop_func_filled_in
)
4346 const general_symbol_info
*gsi
;
4348 /* Don't care about return value; stop_func_start and stop_func_name
4349 will both be 0 if it doesn't work. */
4350 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4352 &ecs
->stop_func_start
,
4353 &ecs
->stop_func_end
,
4355 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4357 /* The call to find_pc_partial_function, above, will set
4358 stop_func_start and stop_func_end to the start and end
4359 of the range containing the stop pc. If this range
4360 contains the entry pc for the block (which is always the
4361 case for contiguous blocks), advance stop_func_start past
4362 the function's start offset and entrypoint. Note that
4363 stop_func_start is NOT advanced when in a range of a
4364 non-contiguous block that does not contain the entry pc. */
4365 if (block
!= nullptr
4366 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4367 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4369 ecs
->stop_func_start
4370 += gdbarch_deprecated_function_start_offset (gdbarch
);
4372 if (gdbarch_skip_entrypoint_p (gdbarch
))
4373 ecs
->stop_func_start
4374 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4377 ecs
->stop_func_filled_in
= 1;
4382 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4384 static enum stop_kind
4385 get_inferior_stop_soon (execution_control_state
*ecs
)
4387 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4389 gdb_assert (inf
!= NULL
);
4390 return inf
->control
.stop_soon
;
4393 /* Poll for one event out of the current target. Store the resulting
4394 waitstatus in WS, and return the event ptid. Does not block. */
4397 poll_one_curr_target (struct target_waitstatus
*ws
)
4401 overlay_cache_invalid
= 1;
4403 /* Flush target cache before starting to handle each event.
4404 Target was running and cache could be stale. This is just a
4405 heuristic. Running threads may modify target memory, but we
4406 don't get any event. */
4407 target_dcache_invalidate ();
4409 if (deprecated_target_wait_hook
)
4410 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4412 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4415 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4420 /* An event reported by wait_one. */
4422 struct wait_one_event
4424 /* The target the event came out of. */
4425 process_stratum_target
*target
;
4427 /* The PTID the event was for. */
4430 /* The waitstatus. */
4431 target_waitstatus ws
;
4434 /* Wait for one event out of any target. */
4436 static wait_one_event
4441 for (inferior
*inf
: all_inferiors ())
4443 process_stratum_target
*target
= inf
->process_target ();
4445 || !target
->is_async_p ()
4446 || !target
->threads_executing
)
4449 switch_to_inferior_no_thread (inf
);
4451 wait_one_event event
;
4452 event
.target
= target
;
4453 event
.ptid
= poll_one_curr_target (&event
.ws
);
4455 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4457 /* If nothing is resumed, remove the target from the
4461 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4465 /* Block waiting for some event. */
4472 for (inferior
*inf
: all_inferiors ())
4474 process_stratum_target
*target
= inf
->process_target ();
4476 || !target
->is_async_p ()
4477 || !target
->threads_executing
)
4480 int fd
= target
->async_wait_fd ();
4481 FD_SET (fd
, &readfds
);
4488 /* No waitable targets left. All must be stopped. */
4489 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4494 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4500 perror_with_name ("interruptible_select");
4505 /* Save the thread's event and stop reason to process it later. */
4508 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4510 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4511 target_waitstatus_to_string (ws
).c_str (),
4516 /* Record for later. */
4517 tp
->suspend
.waitstatus
= *ws
;
4518 tp
->suspend
.waitstatus_pending_p
= 1;
4520 struct regcache
*regcache
= get_thread_regcache (tp
);
4521 const address_space
*aspace
= regcache
->aspace ();
4523 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4524 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4526 CORE_ADDR pc
= regcache_read_pc (regcache
);
4528 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4530 scoped_restore_current_thread restore_thread
;
4531 switch_to_thread (tp
);
4533 if (target_stopped_by_watchpoint ())
4535 tp
->suspend
.stop_reason
4536 = TARGET_STOPPED_BY_WATCHPOINT
;
4538 else if (target_supports_stopped_by_sw_breakpoint ()
4539 && target_stopped_by_sw_breakpoint ())
4541 tp
->suspend
.stop_reason
4542 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4544 else if (target_supports_stopped_by_hw_breakpoint ()
4545 && target_stopped_by_hw_breakpoint ())
4547 tp
->suspend
.stop_reason
4548 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4550 else if (!target_supports_stopped_by_hw_breakpoint ()
4551 && hardware_breakpoint_inserted_here_p (aspace
,
4554 tp
->suspend
.stop_reason
4555 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4557 else if (!target_supports_stopped_by_sw_breakpoint ()
4558 && software_breakpoint_inserted_here_p (aspace
,
4561 tp
->suspend
.stop_reason
4562 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4564 else if (!thread_has_single_step_breakpoints_set (tp
)
4565 && currently_stepping (tp
))
4567 tp
->suspend
.stop_reason
4568 = TARGET_STOPPED_BY_SINGLE_STEP
;
4573 /* Mark the non-executing threads accordingly. In all-stop, all
4574 threads of all processes are stopped when we get any event
4575 reported. In non-stop mode, only the event thread stops. */
4578 mark_non_executing_threads (process_stratum_target
*target
,
4580 struct target_waitstatus ws
)
4584 if (!target_is_non_stop_p ())
4585 mark_ptid
= minus_one_ptid
;
4586 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4587 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4589 /* If we're handling a process exit in non-stop mode, even
4590 though threads haven't been deleted yet, one would think
4591 that there is nothing to do, as threads of the dead process
4592 will be soon deleted, and threads of any other process were
4593 left running. However, on some targets, threads survive a
4594 process exit event. E.g., for the "checkpoint" command,
4595 when the current checkpoint/fork exits, linux-fork.c
4596 automatically switches to another fork from within
4597 target_mourn_inferior, by associating the same
4598 inferior/thread to another fork. We haven't mourned yet at
4599 this point, but we must mark any threads left in the
4600 process as not-executing so that finish_thread_state marks
4601 them stopped (in the user's perspective) if/when we present
4602 the stop to the user. */
4603 mark_ptid
= ptid_t (event_ptid
.pid ());
4606 mark_ptid
= event_ptid
;
4608 set_executing (target
, mark_ptid
, false);
4610 /* Likewise the resumed flag. */
4611 set_resumed (target
, mark_ptid
, false);
4617 stop_all_threads (void)
4619 /* We may need multiple passes to discover all threads. */
4623 gdb_assert (exists_non_stop_target ());
4625 infrun_debug_printf ("starting");
4627 scoped_restore_current_thread restore_thread
;
4629 /* Enable thread events of all targets. */
4630 for (auto *target
: all_non_exited_process_targets ())
4632 switch_to_target_no_thread (target
);
4633 target_thread_events (true);
4638 /* Disable thread events of all targets. */
4639 for (auto *target
: all_non_exited_process_targets ())
4641 switch_to_target_no_thread (target
);
4642 target_thread_events (false);
4645 /* Use debug_prefixed_printf directly to get a meaningful function
4648 debug_prefixed_printf ("infrun", "stop_all_threads", "done");
4651 /* Request threads to stop, and then wait for the stops. Because
4652 threads we already know about can spawn more threads while we're
4653 trying to stop them, and we only learn about new threads when we
4654 update the thread list, do this in a loop, and keep iterating
4655 until two passes find no threads that need to be stopped. */
4656 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4658 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4661 int waits_needed
= 0;
4663 for (auto *target
: all_non_exited_process_targets ())
4665 switch_to_target_no_thread (target
);
4666 update_thread_list ();
4669 /* Go through all threads looking for threads that we need
4670 to tell the target to stop. */
4671 for (thread_info
*t
: all_non_exited_threads ())
4673 /* For a single-target setting with an all-stop target,
4674 we would not even arrive here. For a multi-target
4675 setting, until GDB is able to handle a mixture of
4676 all-stop and non-stop targets, simply skip all-stop
4677 targets' threads. This should be fine due to the
4678 protection of 'check_multi_target_resumption'. */
4680 switch_to_thread_no_regs (t
);
4681 if (!target_is_non_stop_p ())
4686 /* If already stopping, don't request a stop again.
4687 We just haven't seen the notification yet. */
4688 if (!t
->stop_requested
)
4690 infrun_debug_printf (" %s executing, need stop",
4691 target_pid_to_str (t
->ptid
).c_str ());
4692 target_stop (t
->ptid
);
4693 t
->stop_requested
= 1;
4697 infrun_debug_printf (" %s executing, already stopping",
4698 target_pid_to_str (t
->ptid
).c_str ());
4701 if (t
->stop_requested
)
4706 infrun_debug_printf (" %s not executing",
4707 target_pid_to_str (t
->ptid
).c_str ());
4709 /* The thread may be not executing, but still be
4710 resumed with a pending status to process. */
4715 if (waits_needed
== 0)
4718 /* If we find new threads on the second iteration, restart
4719 over. We want to see two iterations in a row with all
4724 for (int i
= 0; i
< waits_needed
; i
++)
4726 wait_one_event event
= wait_one ();
4729 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4730 target_pid_to_str (event
.ptid
).c_str ());
4732 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4734 /* All resumed threads exited. */
4737 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4738 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4739 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4741 /* One thread/process exited/signalled. */
4743 thread_info
*t
= nullptr;
4745 /* The target may have reported just a pid. If so, try
4746 the first non-exited thread. */
4747 if (event
.ptid
.is_pid ())
4749 int pid
= event
.ptid
.pid ();
4750 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4751 for (thread_info
*tp
: inf
->non_exited_threads ())
4757 /* If there is no available thread, the event would
4758 have to be appended to a per-inferior event list,
4759 which does not exist (and if it did, we'd have
4760 to adjust run control command to be able to
4761 resume such an inferior). We assert here instead
4762 of going into an infinite loop. */
4763 gdb_assert (t
!= nullptr);
4766 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4770 t
= find_thread_ptid (event
.target
, event
.ptid
);
4771 /* Check if this is the first time we see this thread.
4772 Don't bother adding if it individually exited. */
4774 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4775 t
= add_thread (event
.target
, event
.ptid
);
4780 /* Set the threads as non-executing to avoid
4781 another stop attempt on them. */
4782 switch_to_thread_no_regs (t
);
4783 mark_non_executing_threads (event
.target
, event
.ptid
,
4785 save_waitstatus (t
, &event
.ws
);
4786 t
->stop_requested
= false;
4791 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4793 t
= add_thread (event
.target
, event
.ptid
);
4795 t
->stop_requested
= 0;
4798 t
->control
.may_range_step
= 0;
4800 /* This may be the first time we see the inferior report
4802 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4803 if (inf
->needs_setup
)
4805 switch_to_thread_no_regs (t
);
4809 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4810 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4812 /* We caught the event that we intended to catch, so
4813 there's no event pending. */
4814 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4815 t
->suspend
.waitstatus_pending_p
= 0;
4817 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4819 /* Add it back to the step-over queue. */
4821 ("displaced-step of %s canceled: adding back to "
4822 "the step-over queue",
4823 target_pid_to_str (t
->ptid
).c_str ());
4825 t
->control
.trap_expected
= 0;
4826 thread_step_over_chain_enqueue (t
);
4831 enum gdb_signal sig
;
4832 struct regcache
*regcache
;
4835 ("target_wait %s, saving status for %d.%ld.%ld",
4836 target_waitstatus_to_string (&event
.ws
).c_str (),
4837 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4839 /* Record for later. */
4840 save_waitstatus (t
, &event
.ws
);
4842 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4843 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4845 if (displaced_step_fixup (t
, sig
) < 0)
4847 /* Add it back to the step-over queue. */
4848 t
->control
.trap_expected
= 0;
4849 thread_step_over_chain_enqueue (t
);
4852 regcache
= get_thread_regcache (t
);
4853 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4855 infrun_debug_printf ("saved stop_pc=%s for %s "
4856 "(currently_stepping=%d)",
4857 paddress (target_gdbarch (),
4858 t
->suspend
.stop_pc
),
4859 target_pid_to_str (t
->ptid
).c_str (),
4860 currently_stepping (t
));
4868 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4871 handle_no_resumed (struct execution_control_state
*ecs
)
4873 if (target_can_async_p ())
4875 bool any_sync
= false;
4877 for (ui
*ui
: all_uis ())
4879 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4887 /* There were no unwaited-for children left in the target, but,
4888 we're not synchronously waiting for events either. Just
4891 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4892 prepare_to_wait (ecs
);
4897 /* Otherwise, if we were running a synchronous execution command, we
4898 may need to cancel it and give the user back the terminal.
4900 In non-stop mode, the target can't tell whether we've already
4901 consumed previous stop events, so it can end up sending us a
4902 no-resumed event like so:
4904 #0 - thread 1 is left stopped
4906 #1 - thread 2 is resumed and hits breakpoint
4907 -> TARGET_WAITKIND_STOPPED
4909 #2 - thread 3 is resumed and exits
4910 this is the last resumed thread, so
4911 -> TARGET_WAITKIND_NO_RESUMED
4913 #3 - gdb processes stop for thread 2 and decides to re-resume
4916 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4917 thread 2 is now resumed, so the event should be ignored.
4919 IOW, if the stop for thread 2 doesn't end a foreground command,
4920 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4921 event. But it could be that the event meant that thread 2 itself
4922 (or whatever other thread was the last resumed thread) exited.
4924 To address this we refresh the thread list and check whether we
4925 have resumed threads _now_. In the example above, this removes
4926 thread 3 from the thread list. If thread 2 was re-resumed, we
4927 ignore this event. If we find no thread resumed, then we cancel
4928 the synchronous command and show "no unwaited-for " to the
4931 inferior
*curr_inf
= current_inferior ();
4933 scoped_restore_current_thread restore_thread
;
4935 for (auto *target
: all_non_exited_process_targets ())
4937 switch_to_target_no_thread (target
);
4938 update_thread_list ();
4943 - the current target has no thread executing, and
4944 - the current inferior is native, and
4945 - the current inferior is the one which has the terminal, and
4948 then a Ctrl-C from this point on would remain stuck in the
4949 kernel, until a thread resumes and dequeues it. That would
4950 result in the GDB CLI not reacting to Ctrl-C, not able to
4951 interrupt the program. To address this, if the current inferior
4952 no longer has any thread executing, we give the terminal to some
4953 other inferior that has at least one thread executing. */
4954 bool swap_terminal
= true;
4956 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4957 whether to report it to the user. */
4958 bool ignore_event
= false;
4960 for (thread_info
*thread
: all_non_exited_threads ())
4962 if (swap_terminal
&& thread
->executing
)
4964 if (thread
->inf
!= curr_inf
)
4966 target_terminal::ours ();
4968 switch_to_thread (thread
);
4969 target_terminal::inferior ();
4971 swap_terminal
= false;
4975 && (thread
->executing
4976 || thread
->suspend
.waitstatus_pending_p
))
4978 /* Either there were no unwaited-for children left in the
4979 target at some point, but there are now, or some target
4980 other than the eventing one has unwaited-for children
4981 left. Just ignore. */
4982 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
4983 "(ignoring: found resumed)");
4985 ignore_event
= true;
4988 if (ignore_event
&& !swap_terminal
)
4994 switch_to_inferior_no_thread (curr_inf
);
4995 prepare_to_wait (ecs
);
4999 /* Go ahead and report the event. */
5003 /* Given an execution control state that has been freshly filled in by
5004 an event from the inferior, figure out what it means and take
5007 The alternatives are:
5009 1) stop_waiting and return; to really stop and return to the
5012 2) keep_going and return; to wait for the next event (set
5013 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5017 handle_inferior_event (struct execution_control_state
*ecs
)
5019 /* Make sure that all temporary struct value objects that were
5020 created during the handling of the event get deleted at the
5022 scoped_value_mark free_values
;
5024 enum stop_kind stop_soon
;
5026 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5028 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5030 /* We had an event in the inferior, but we are not interested in
5031 handling it at this level. The lower layers have already
5032 done what needs to be done, if anything.
5034 One of the possible circumstances for this is when the
5035 inferior produces output for the console. The inferior has
5036 not stopped, and we are ignoring the event. Another possible
5037 circumstance is any event which the lower level knows will be
5038 reported multiple times without an intervening resume. */
5039 prepare_to_wait (ecs
);
5043 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5045 prepare_to_wait (ecs
);
5049 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5050 && handle_no_resumed (ecs
))
5053 /* Cache the last target/ptid/waitstatus. */
5054 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5056 /* Always clear state belonging to the previous time we stopped. */
5057 stop_stack_dummy
= STOP_NONE
;
5059 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5061 /* No unwaited-for children left. IOW, all resumed children
5063 stop_print_frame
= false;
5068 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5069 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5071 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5072 /* If it's a new thread, add it to the thread database. */
5073 if (ecs
->event_thread
== NULL
)
5074 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5076 /* Disable range stepping. If the next step request could use a
5077 range, this will be end up re-enabled then. */
5078 ecs
->event_thread
->control
.may_range_step
= 0;
5081 /* Dependent on valid ECS->EVENT_THREAD. */
5082 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5084 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5085 reinit_frame_cache ();
5087 breakpoint_retire_moribund ();
5089 /* First, distinguish signals caused by the debugger from signals
5090 that have to do with the program's own actions. Note that
5091 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5092 on the operating system version. Here we detect when a SIGILL or
5093 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5094 something similar for SIGSEGV, since a SIGSEGV will be generated
5095 when we're trying to execute a breakpoint instruction on a
5096 non-executable stack. This happens for call dummy breakpoints
5097 for architectures like SPARC that place call dummies on the
5099 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5100 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5101 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5102 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5104 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5106 if (breakpoint_inserted_here_p (regcache
->aspace (),
5107 regcache_read_pc (regcache
)))
5109 infrun_debug_printf ("Treating signal as SIGTRAP");
5110 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5114 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5116 switch (ecs
->ws
.kind
)
5118 case TARGET_WAITKIND_LOADED
:
5119 context_switch (ecs
);
5120 /* Ignore gracefully during startup of the inferior, as it might
5121 be the shell which has just loaded some objects, otherwise
5122 add the symbols for the newly loaded objects. Also ignore at
5123 the beginning of an attach or remote session; we will query
5124 the full list of libraries once the connection is
5127 stop_soon
= get_inferior_stop_soon (ecs
);
5128 if (stop_soon
== NO_STOP_QUIETLY
)
5130 struct regcache
*regcache
;
5132 regcache
= get_thread_regcache (ecs
->event_thread
);
5134 handle_solib_event ();
5136 ecs
->event_thread
->control
.stop_bpstat
5137 = bpstat_stop_status (regcache
->aspace (),
5138 ecs
->event_thread
->suspend
.stop_pc
,
5139 ecs
->event_thread
, &ecs
->ws
);
5141 if (handle_stop_requested (ecs
))
5144 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5146 /* A catchpoint triggered. */
5147 process_event_stop_test (ecs
);
5151 /* If requested, stop when the dynamic linker notifies
5152 gdb of events. This allows the user to get control
5153 and place breakpoints in initializer routines for
5154 dynamically loaded objects (among other things). */
5155 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5156 if (stop_on_solib_events
)
5158 /* Make sure we print "Stopped due to solib-event" in
5160 stop_print_frame
= true;
5167 /* If we are skipping through a shell, or through shared library
5168 loading that we aren't interested in, resume the program. If
5169 we're running the program normally, also resume. */
5170 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5172 /* Loading of shared libraries might have changed breakpoint
5173 addresses. Make sure new breakpoints are inserted. */
5174 if (stop_soon
== NO_STOP_QUIETLY
)
5175 insert_breakpoints ();
5176 resume (GDB_SIGNAL_0
);
5177 prepare_to_wait (ecs
);
5181 /* But stop if we're attaching or setting up a remote
5183 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5184 || stop_soon
== STOP_QUIETLY_REMOTE
)
5186 infrun_debug_printf ("quietly stopped");
5191 internal_error (__FILE__
, __LINE__
,
5192 _("unhandled stop_soon: %d"), (int) stop_soon
);
5194 case TARGET_WAITKIND_SPURIOUS
:
5195 if (handle_stop_requested (ecs
))
5197 context_switch (ecs
);
5198 resume (GDB_SIGNAL_0
);
5199 prepare_to_wait (ecs
);
5202 case TARGET_WAITKIND_THREAD_CREATED
:
5203 if (handle_stop_requested (ecs
))
5205 context_switch (ecs
);
5206 if (!switch_back_to_stepped_thread (ecs
))
5210 case TARGET_WAITKIND_EXITED
:
5211 case TARGET_WAITKIND_SIGNALLED
:
5213 /* Depending on the system, ecs->ptid may point to a thread or
5214 to a process. On some targets, target_mourn_inferior may
5215 need to have access to the just-exited thread. That is the
5216 case of GNU/Linux's "checkpoint" support, for example.
5217 Call the switch_to_xxx routine as appropriate. */
5218 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5220 switch_to_thread (thr
);
5223 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5224 switch_to_inferior_no_thread (inf
);
5227 handle_vfork_child_exec_or_exit (0);
5228 target_terminal::ours (); /* Must do this before mourn anyway. */
5230 /* Clearing any previous state of convenience variables. */
5231 clear_exit_convenience_vars ();
5233 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5235 /* Record the exit code in the convenience variable $_exitcode, so
5236 that the user can inspect this again later. */
5237 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5238 (LONGEST
) ecs
->ws
.value
.integer
);
5240 /* Also record this in the inferior itself. */
5241 current_inferior ()->has_exit_code
= 1;
5242 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5244 /* Support the --return-child-result option. */
5245 return_child_result_value
= ecs
->ws
.value
.integer
;
5247 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5251 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5253 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5255 /* Set the value of the internal variable $_exitsignal,
5256 which holds the signal uncaught by the inferior. */
5257 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5258 gdbarch_gdb_signal_to_target (gdbarch
,
5259 ecs
->ws
.value
.sig
));
5263 /* We don't have access to the target's method used for
5264 converting between signal numbers (GDB's internal
5265 representation <-> target's representation).
5266 Therefore, we cannot do a good job at displaying this
5267 information to the user. It's better to just warn
5268 her about it (if infrun debugging is enabled), and
5270 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5274 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5277 gdb_flush (gdb_stdout
);
5278 target_mourn_inferior (inferior_ptid
);
5279 stop_print_frame
= false;
5283 case TARGET_WAITKIND_FORKED
:
5284 case TARGET_WAITKIND_VFORKED
:
5285 /* Check whether the inferior is displaced stepping. */
5287 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5288 struct gdbarch
*gdbarch
= regcache
->arch ();
5289 inferior
*parent_inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5291 /* If this is a fork (child gets its own address space copy) and the
5292 displaced step buffer was in use at the time of the fork, restore
5293 displaced step buffer bytes in the child process. */
5294 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5296 displaced_step_inferior_state
*displaced
5297 = &parent_inf
->displaced_step_state
;
5299 if (displaced
->step_thread
!= nullptr)
5300 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5303 /* If displaced stepping is supported, and thread ecs->ptid is
5304 displaced stepping. */
5305 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5307 struct regcache
*child_regcache
;
5308 CORE_ADDR parent_pc
;
5310 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5311 indicating that the displaced stepping of syscall instruction
5312 has been done. Perform cleanup for parent process here. Note
5313 that this operation also cleans up the child process for vfork,
5314 because their pages are shared. */
5315 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5316 /* Start a new step-over in another thread if there's one
5320 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5321 the child's PC is also within the scratchpad. Set the child's PC
5322 to the parent's PC value, which has already been fixed up.
5323 FIXME: we use the parent's aspace here, although we're touching
5324 the child, because the child hasn't been added to the inferior
5325 list yet at this point. */
5328 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5329 ecs
->ws
.value
.related_pid
,
5331 parent_inf
->aspace
);
5332 /* Read PC value of parent process. */
5333 parent_pc
= regcache_read_pc (regcache
);
5335 displaced_debug_printf ("write child pc from %s to %s",
5337 regcache_read_pc (child_regcache
)),
5338 paddress (gdbarch
, parent_pc
));
5340 regcache_write_pc (child_regcache
, parent_pc
);
5344 context_switch (ecs
);
5346 /* Immediately detach breakpoints from the child before there's
5347 any chance of letting the user delete breakpoints from the
5348 breakpoint lists. If we don't do this early, it's easy to
5349 leave left over traps in the child, vis: "break foo; catch
5350 fork; c; <fork>; del; c; <child calls foo>". We only follow
5351 the fork on the last `continue', and by that time the
5352 breakpoint at "foo" is long gone from the breakpoint table.
5353 If we vforked, then we don't need to unpatch here, since both
5354 parent and child are sharing the same memory pages; we'll
5355 need to unpatch at follow/detach time instead to be certain
5356 that new breakpoints added between catchpoint hit time and
5357 vfork follow are detached. */
5358 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5360 /* This won't actually modify the breakpoint list, but will
5361 physically remove the breakpoints from the child. */
5362 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5365 delete_just_stopped_threads_single_step_breakpoints ();
5367 /* In case the event is caught by a catchpoint, remember that
5368 the event is to be followed at the next resume of the thread,
5369 and not immediately. */
5370 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5372 ecs
->event_thread
->suspend
.stop_pc
5373 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5375 ecs
->event_thread
->control
.stop_bpstat
5376 = bpstat_stop_status (get_current_regcache ()->aspace (),
5377 ecs
->event_thread
->suspend
.stop_pc
,
5378 ecs
->event_thread
, &ecs
->ws
);
5380 if (handle_stop_requested (ecs
))
5383 /* If no catchpoint triggered for this, then keep going. Note
5384 that we're interested in knowing the bpstat actually causes a
5385 stop, not just if it may explain the signal. Software
5386 watchpoints, for example, always appear in the bpstat. */
5387 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5390 = (follow_fork_mode_string
== follow_fork_mode_child
);
5392 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5394 process_stratum_target
*targ
5395 = ecs
->event_thread
->inf
->process_target ();
5397 bool should_resume
= follow_fork ();
5399 /* Note that one of these may be an invalid pointer,
5400 depending on detach_fork. */
5401 thread_info
*parent
= ecs
->event_thread
;
5403 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5405 /* At this point, the parent is marked running, and the
5406 child is marked stopped. */
5408 /* If not resuming the parent, mark it stopped. */
5409 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5410 parent
->set_running (false);
5412 /* If resuming the child, mark it running. */
5413 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5414 child
->set_running (true);
5416 /* In non-stop mode, also resume the other branch. */
5417 if (!detach_fork
&& (non_stop
5418 || (sched_multi
&& target_is_non_stop_p ())))
5421 switch_to_thread (parent
);
5423 switch_to_thread (child
);
5425 ecs
->event_thread
= inferior_thread ();
5426 ecs
->ptid
= inferior_ptid
;
5431 switch_to_thread (child
);
5433 switch_to_thread (parent
);
5435 ecs
->event_thread
= inferior_thread ();
5436 ecs
->ptid
= inferior_ptid
;
5444 process_event_stop_test (ecs
);
5447 case TARGET_WAITKIND_VFORK_DONE
:
5448 /* Done with the shared memory region. Re-insert breakpoints in
5449 the parent, and keep going. */
5451 context_switch (ecs
);
5453 current_inferior ()->waiting_for_vfork_done
= 0;
5454 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5456 if (handle_stop_requested (ecs
))
5459 /* This also takes care of reinserting breakpoints in the
5460 previously locked inferior. */
5464 case TARGET_WAITKIND_EXECD
:
5466 /* Note we can't read registers yet (the stop_pc), because we
5467 don't yet know the inferior's post-exec architecture.
5468 'stop_pc' is explicitly read below instead. */
5469 switch_to_thread_no_regs (ecs
->event_thread
);
5471 /* Do whatever is necessary to the parent branch of the vfork. */
5472 handle_vfork_child_exec_or_exit (1);
5474 /* This causes the eventpoints and symbol table to be reset.
5475 Must do this now, before trying to determine whether to
5477 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5479 /* In follow_exec we may have deleted the original thread and
5480 created a new one. Make sure that the event thread is the
5481 execd thread for that case (this is a nop otherwise). */
5482 ecs
->event_thread
= inferior_thread ();
5484 ecs
->event_thread
->suspend
.stop_pc
5485 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5487 ecs
->event_thread
->control
.stop_bpstat
5488 = bpstat_stop_status (get_current_regcache ()->aspace (),
5489 ecs
->event_thread
->suspend
.stop_pc
,
5490 ecs
->event_thread
, &ecs
->ws
);
5492 /* Note that this may be referenced from inside
5493 bpstat_stop_status above, through inferior_has_execd. */
5494 xfree (ecs
->ws
.value
.execd_pathname
);
5495 ecs
->ws
.value
.execd_pathname
= NULL
;
5497 if (handle_stop_requested (ecs
))
5500 /* If no catchpoint triggered for this, then keep going. */
5501 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5503 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5507 process_event_stop_test (ecs
);
5510 /* Be careful not to try to gather much state about a thread
5511 that's in a syscall. It's frequently a losing proposition. */
5512 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5513 /* Getting the current syscall number. */
5514 if (handle_syscall_event (ecs
) == 0)
5515 process_event_stop_test (ecs
);
5518 /* Before examining the threads further, step this thread to
5519 get it entirely out of the syscall. (We get notice of the
5520 event when the thread is just on the verge of exiting a
5521 syscall. Stepping one instruction seems to get it back
5523 case TARGET_WAITKIND_SYSCALL_RETURN
:
5524 if (handle_syscall_event (ecs
) == 0)
5525 process_event_stop_test (ecs
);
5528 case TARGET_WAITKIND_STOPPED
:
5529 handle_signal_stop (ecs
);
5532 case TARGET_WAITKIND_NO_HISTORY
:
5533 /* Reverse execution: target ran out of history info. */
5535 /* Switch to the stopped thread. */
5536 context_switch (ecs
);
5537 infrun_debug_printf ("stopped");
5539 delete_just_stopped_threads_single_step_breakpoints ();
5540 ecs
->event_thread
->suspend
.stop_pc
5541 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5543 if (handle_stop_requested (ecs
))
5546 gdb::observers::no_history
.notify ();
5552 /* Restart threads back to what they were trying to do back when we
5553 paused them for an in-line step-over. The EVENT_THREAD thread is
5557 restart_threads (struct thread_info
*event_thread
)
5559 /* In case the instruction just stepped spawned a new thread. */
5560 update_thread_list ();
5562 for (thread_info
*tp
: all_non_exited_threads ())
5564 switch_to_thread_no_regs (tp
);
5566 if (tp
== event_thread
)
5568 infrun_debug_printf ("restart threads: [%s] is event thread",
5569 target_pid_to_str (tp
->ptid
).c_str ());
5573 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5575 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5576 target_pid_to_str (tp
->ptid
).c_str ());
5582 infrun_debug_printf ("restart threads: [%s] resumed",
5583 target_pid_to_str (tp
->ptid
).c_str ());
5584 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5588 if (thread_is_in_step_over_chain (tp
))
5590 infrun_debug_printf ("restart threads: [%s] needs step-over",
5591 target_pid_to_str (tp
->ptid
).c_str ());
5592 gdb_assert (!tp
->resumed
);
5597 if (tp
->suspend
.waitstatus_pending_p
)
5599 infrun_debug_printf ("restart threads: [%s] has pending status",
5600 target_pid_to_str (tp
->ptid
).c_str ());
5605 gdb_assert (!tp
->stop_requested
);
5607 /* If some thread needs to start a step-over at this point, it
5608 should still be in the step-over queue, and thus skipped
5610 if (thread_still_needs_step_over (tp
))
5612 internal_error (__FILE__
, __LINE__
,
5613 "thread [%s] needs a step-over, but not in "
5614 "step-over queue\n",
5615 target_pid_to_str (tp
->ptid
).c_str ());
5618 if (currently_stepping (tp
))
5620 infrun_debug_printf ("restart threads: [%s] was stepping",
5621 target_pid_to_str (tp
->ptid
).c_str ());
5622 keep_going_stepped_thread (tp
);
5626 struct execution_control_state ecss
;
5627 struct execution_control_state
*ecs
= &ecss
;
5629 infrun_debug_printf ("restart threads: [%s] continuing",
5630 target_pid_to_str (tp
->ptid
).c_str ());
5631 reset_ecs (ecs
, tp
);
5632 switch_to_thread (tp
);
5633 keep_going_pass_signal (ecs
);
5638 /* Callback for iterate_over_threads. Find a resumed thread that has
5639 a pending waitstatus. */
5642 resumed_thread_with_pending_status (struct thread_info
*tp
,
5646 && tp
->suspend
.waitstatus_pending_p
);
5649 /* Called when we get an event that may finish an in-line or
5650 out-of-line (displaced stepping) step-over started previously.
5651 Return true if the event is processed and we should go back to the
5652 event loop; false if the caller should continue processing the
5656 finish_step_over (struct execution_control_state
*ecs
)
5658 displaced_step_fixup (ecs
->event_thread
,
5659 ecs
->event_thread
->suspend
.stop_signal
);
5661 bool had_step_over_info
= step_over_info_valid_p ();
5663 if (had_step_over_info
)
5665 /* If we're stepping over a breakpoint with all threads locked,
5666 then only the thread that was stepped should be reporting
5668 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5670 clear_step_over_info ();
5673 if (!target_is_non_stop_p ())
5676 /* Start a new step-over in another thread if there's one that
5680 /* If we were stepping over a breakpoint before, and haven't started
5681 a new in-line step-over sequence, then restart all other threads
5682 (except the event thread). We can't do this in all-stop, as then
5683 e.g., we wouldn't be able to issue any other remote packet until
5684 these other threads stop. */
5685 if (had_step_over_info
&& !step_over_info_valid_p ())
5687 struct thread_info
*pending
;
5689 /* If we only have threads with pending statuses, the restart
5690 below won't restart any thread and so nothing re-inserts the
5691 breakpoint we just stepped over. But we need it inserted
5692 when we later process the pending events, otherwise if
5693 another thread has a pending event for this breakpoint too,
5694 we'd discard its event (because the breakpoint that
5695 originally caused the event was no longer inserted). */
5696 context_switch (ecs
);
5697 insert_breakpoints ();
5699 restart_threads (ecs
->event_thread
);
5701 /* If we have events pending, go through handle_inferior_event
5702 again, picking up a pending event at random. This avoids
5703 thread starvation. */
5705 /* But not if we just stepped over a watchpoint in order to let
5706 the instruction execute so we can evaluate its expression.
5707 The set of watchpoints that triggered is recorded in the
5708 breakpoint objects themselves (see bp->watchpoint_triggered).
5709 If we processed another event first, that other event could
5710 clobber this info. */
5711 if (ecs
->event_thread
->stepping_over_watchpoint
)
5714 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5716 if (pending
!= NULL
)
5718 struct thread_info
*tp
= ecs
->event_thread
;
5719 struct regcache
*regcache
;
5721 infrun_debug_printf ("found resumed threads with "
5722 "pending events, saving status");
5724 gdb_assert (pending
!= tp
);
5726 /* Record the event thread's event for later. */
5727 save_waitstatus (tp
, &ecs
->ws
);
5728 /* This was cleared early, by handle_inferior_event. Set it
5729 so this pending event is considered by
5733 gdb_assert (!tp
->executing
);
5735 regcache
= get_thread_regcache (tp
);
5736 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5738 infrun_debug_printf ("saved stop_pc=%s for %s "
5739 "(currently_stepping=%d)",
5740 paddress (target_gdbarch (),
5741 tp
->suspend
.stop_pc
),
5742 target_pid_to_str (tp
->ptid
).c_str (),
5743 currently_stepping (tp
));
5745 /* This in-line step-over finished; clear this so we won't
5746 start a new one. This is what handle_signal_stop would
5747 do, if we returned false. */
5748 tp
->stepping_over_breakpoint
= 0;
5750 /* Wake up the event loop again. */
5751 mark_async_event_handler (infrun_async_inferior_event_token
);
5753 prepare_to_wait (ecs
);
5761 /* Come here when the program has stopped with a signal. */
5764 handle_signal_stop (struct execution_control_state
*ecs
)
5766 struct frame_info
*frame
;
5767 struct gdbarch
*gdbarch
;
5768 int stopped_by_watchpoint
;
5769 enum stop_kind stop_soon
;
5772 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5774 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5776 /* Do we need to clean up the state of a thread that has
5777 completed a displaced single-step? (Doing so usually affects
5778 the PC, so do it here, before we set stop_pc.) */
5779 if (finish_step_over (ecs
))
5782 /* If we either finished a single-step or hit a breakpoint, but
5783 the user wanted this thread to be stopped, pretend we got a
5784 SIG0 (generic unsignaled stop). */
5785 if (ecs
->event_thread
->stop_requested
5786 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5787 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5789 ecs
->event_thread
->suspend
.stop_pc
5790 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5794 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5795 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5797 switch_to_thread (ecs
->event_thread
);
5799 infrun_debug_printf ("stop_pc=%s",
5800 paddress (reg_gdbarch
,
5801 ecs
->event_thread
->suspend
.stop_pc
));
5802 if (target_stopped_by_watchpoint ())
5806 infrun_debug_printf ("stopped by watchpoint");
5808 if (target_stopped_data_address (current_top_target (), &addr
))
5809 infrun_debug_printf ("stopped data address=%s",
5810 paddress (reg_gdbarch
, addr
));
5812 infrun_debug_printf ("(no data address available)");
5816 /* This is originated from start_remote(), start_inferior() and
5817 shared libraries hook functions. */
5818 stop_soon
= get_inferior_stop_soon (ecs
);
5819 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5821 context_switch (ecs
);
5822 infrun_debug_printf ("quietly stopped");
5823 stop_print_frame
= true;
5828 /* This originates from attach_command(). We need to overwrite
5829 the stop_signal here, because some kernels don't ignore a
5830 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5831 See more comments in inferior.h. On the other hand, if we
5832 get a non-SIGSTOP, report it to the user - assume the backend
5833 will handle the SIGSTOP if it should show up later.
5835 Also consider that the attach is complete when we see a
5836 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5837 target extended-remote report it instead of a SIGSTOP
5838 (e.g. gdbserver). We already rely on SIGTRAP being our
5839 signal, so this is no exception.
5841 Also consider that the attach is complete when we see a
5842 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5843 the target to stop all threads of the inferior, in case the
5844 low level attach operation doesn't stop them implicitly. If
5845 they weren't stopped implicitly, then the stub will report a
5846 GDB_SIGNAL_0, meaning: stopped for no particular reason
5847 other than GDB's request. */
5848 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5849 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5850 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5851 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5853 stop_print_frame
= true;
5855 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5859 /* See if something interesting happened to the non-current thread. If
5860 so, then switch to that thread. */
5861 if (ecs
->ptid
!= inferior_ptid
)
5863 infrun_debug_printf ("context switch");
5865 context_switch (ecs
);
5867 if (deprecated_context_hook
)
5868 deprecated_context_hook (ecs
->event_thread
->global_num
);
5871 /* At this point, get hold of the now-current thread's frame. */
5872 frame
= get_current_frame ();
5873 gdbarch
= get_frame_arch (frame
);
5875 /* Pull the single step breakpoints out of the target. */
5876 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5878 struct regcache
*regcache
;
5881 regcache
= get_thread_regcache (ecs
->event_thread
);
5882 const address_space
*aspace
= regcache
->aspace ();
5884 pc
= regcache_read_pc (regcache
);
5886 /* However, before doing so, if this single-step breakpoint was
5887 actually for another thread, set this thread up for moving
5889 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5892 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5894 infrun_debug_printf ("[%s] hit another thread's single-step "
5896 target_pid_to_str (ecs
->ptid
).c_str ());
5897 ecs
->hit_singlestep_breakpoint
= 1;
5902 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5903 target_pid_to_str (ecs
->ptid
).c_str ());
5906 delete_just_stopped_threads_single_step_breakpoints ();
5908 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5909 && ecs
->event_thread
->control
.trap_expected
5910 && ecs
->event_thread
->stepping_over_watchpoint
)
5911 stopped_by_watchpoint
= 0;
5913 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5915 /* If necessary, step over this watchpoint. We'll be back to display
5917 if (stopped_by_watchpoint
5918 && (target_have_steppable_watchpoint ()
5919 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5921 /* At this point, we are stopped at an instruction which has
5922 attempted to write to a piece of memory under control of
5923 a watchpoint. The instruction hasn't actually executed
5924 yet. If we were to evaluate the watchpoint expression
5925 now, we would get the old value, and therefore no change
5926 would seem to have occurred.
5928 In order to make watchpoints work `right', we really need
5929 to complete the memory write, and then evaluate the
5930 watchpoint expression. We do this by single-stepping the
5933 It may not be necessary to disable the watchpoint to step over
5934 it. For example, the PA can (with some kernel cooperation)
5935 single step over a watchpoint without disabling the watchpoint.
5937 It is far more common to need to disable a watchpoint to step
5938 the inferior over it. If we have non-steppable watchpoints,
5939 we must disable the current watchpoint; it's simplest to
5940 disable all watchpoints.
5942 Any breakpoint at PC must also be stepped over -- if there's
5943 one, it will have already triggered before the watchpoint
5944 triggered, and we either already reported it to the user, or
5945 it didn't cause a stop and we called keep_going. In either
5946 case, if there was a breakpoint at PC, we must be trying to
5948 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5953 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5954 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5955 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5956 ecs
->event_thread
->control
.stop_step
= 0;
5957 stop_print_frame
= true;
5958 stopped_by_random_signal
= 0;
5959 bpstat stop_chain
= NULL
;
5961 /* Hide inlined functions starting here, unless we just performed stepi or
5962 nexti. After stepi and nexti, always show the innermost frame (not any
5963 inline function call sites). */
5964 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5966 const address_space
*aspace
5967 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5969 /* skip_inline_frames is expensive, so we avoid it if we can
5970 determine that the address is one where functions cannot have
5971 been inlined. This improves performance with inferiors that
5972 load a lot of shared libraries, because the solib event
5973 breakpoint is defined as the address of a function (i.e. not
5974 inline). Note that we have to check the previous PC as well
5975 as the current one to catch cases when we have just
5976 single-stepped off a breakpoint prior to reinstating it.
5977 Note that we're assuming that the code we single-step to is
5978 not inline, but that's not definitive: there's nothing
5979 preventing the event breakpoint function from containing
5980 inlined code, and the single-step ending up there. If the
5981 user had set a breakpoint on that inlined code, the missing
5982 skip_inline_frames call would break things. Fortunately
5983 that's an extremely unlikely scenario. */
5984 if (!pc_at_non_inline_function (aspace
,
5985 ecs
->event_thread
->suspend
.stop_pc
,
5987 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5988 && ecs
->event_thread
->control
.trap_expected
5989 && pc_at_non_inline_function (aspace
,
5990 ecs
->event_thread
->prev_pc
,
5993 stop_chain
= build_bpstat_chain (aspace
,
5994 ecs
->event_thread
->suspend
.stop_pc
,
5996 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5998 /* Re-fetch current thread's frame in case that invalidated
6000 frame
= get_current_frame ();
6001 gdbarch
= get_frame_arch (frame
);
6005 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6006 && ecs
->event_thread
->control
.trap_expected
6007 && gdbarch_single_step_through_delay_p (gdbarch
)
6008 && currently_stepping (ecs
->event_thread
))
6010 /* We're trying to step off a breakpoint. Turns out that we're
6011 also on an instruction that needs to be stepped multiple
6012 times before it's been fully executing. E.g., architectures
6013 with a delay slot. It needs to be stepped twice, once for
6014 the instruction and once for the delay slot. */
6015 int step_through_delay
6016 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6018 if (step_through_delay
)
6019 infrun_debug_printf ("step through delay");
6021 if (ecs
->event_thread
->control
.step_range_end
== 0
6022 && step_through_delay
)
6024 /* The user issued a continue when stopped at a breakpoint.
6025 Set up for another trap and get out of here. */
6026 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6030 else if (step_through_delay
)
6032 /* The user issued a step when stopped at a breakpoint.
6033 Maybe we should stop, maybe we should not - the delay
6034 slot *might* correspond to a line of source. In any
6035 case, don't decide that here, just set
6036 ecs->stepping_over_breakpoint, making sure we
6037 single-step again before breakpoints are re-inserted. */
6038 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6042 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6043 handles this event. */
6044 ecs
->event_thread
->control
.stop_bpstat
6045 = bpstat_stop_status (get_current_regcache ()->aspace (),
6046 ecs
->event_thread
->suspend
.stop_pc
,
6047 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6049 /* Following in case break condition called a
6051 stop_print_frame
= true;
6053 /* This is where we handle "moribund" watchpoints. Unlike
6054 software breakpoints traps, hardware watchpoint traps are
6055 always distinguishable from random traps. If no high-level
6056 watchpoint is associated with the reported stop data address
6057 anymore, then the bpstat does not explain the signal ---
6058 simply make sure to ignore it if `stopped_by_watchpoint' is
6061 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6062 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6064 && stopped_by_watchpoint
)
6066 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6070 /* NOTE: cagney/2003-03-29: These checks for a random signal
6071 at one stage in the past included checks for an inferior
6072 function call's call dummy's return breakpoint. The original
6073 comment, that went with the test, read:
6075 ``End of a stack dummy. Some systems (e.g. Sony news) give
6076 another signal besides SIGTRAP, so check here as well as
6079 If someone ever tries to get call dummys on a
6080 non-executable stack to work (where the target would stop
6081 with something like a SIGSEGV), then those tests might need
6082 to be re-instated. Given, however, that the tests were only
6083 enabled when momentary breakpoints were not being used, I
6084 suspect that it won't be the case.
6086 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6087 be necessary for call dummies on a non-executable stack on
6090 /* See if the breakpoints module can explain the signal. */
6092 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6093 ecs
->event_thread
->suspend
.stop_signal
);
6095 /* Maybe this was a trap for a software breakpoint that has since
6097 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6099 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6100 ecs
->event_thread
->suspend
.stop_pc
))
6102 struct regcache
*regcache
;
6105 /* Re-adjust PC to what the program would see if GDB was not
6107 regcache
= get_thread_regcache (ecs
->event_thread
);
6108 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6111 gdb::optional
<scoped_restore_tmpl
<int>>
6112 restore_operation_disable
;
6114 if (record_full_is_used ())
6115 restore_operation_disable
.emplace
6116 (record_full_gdb_operation_disable_set ());
6118 regcache_write_pc (regcache
,
6119 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6124 /* A delayed software breakpoint event. Ignore the trap. */
6125 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6130 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6131 has since been removed. */
6132 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6134 /* A delayed hardware breakpoint event. Ignore the trap. */
6135 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6140 /* If not, perhaps stepping/nexting can. */
6142 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6143 && currently_stepping (ecs
->event_thread
));
6145 /* Perhaps the thread hit a single-step breakpoint of _another_
6146 thread. Single-step breakpoints are transparent to the
6147 breakpoints module. */
6149 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6151 /* No? Perhaps we got a moribund watchpoint. */
6153 random_signal
= !stopped_by_watchpoint
;
6155 /* Always stop if the user explicitly requested this thread to
6157 if (ecs
->event_thread
->stop_requested
)
6160 infrun_debug_printf ("user-requested stop");
6163 /* For the program's own signals, act according to
6164 the signal handling tables. */
6168 /* Signal not for debugging purposes. */
6169 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6170 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6172 infrun_debug_printf ("random signal (%s)",
6173 gdb_signal_to_symbol_string (stop_signal
));
6175 stopped_by_random_signal
= 1;
6177 /* Always stop on signals if we're either just gaining control
6178 of the program, or the user explicitly requested this thread
6179 to remain stopped. */
6180 if (stop_soon
!= NO_STOP_QUIETLY
6181 || ecs
->event_thread
->stop_requested
6183 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6189 /* Notify observers the signal has "handle print" set. Note we
6190 returned early above if stopping; normal_stop handles the
6191 printing in that case. */
6192 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6194 /* The signal table tells us to print about this signal. */
6195 target_terminal::ours_for_output ();
6196 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6197 target_terminal::inferior ();
6200 /* Clear the signal if it should not be passed. */
6201 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6202 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6204 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6205 && ecs
->event_thread
->control
.trap_expected
6206 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6208 /* We were just starting a new sequence, attempting to
6209 single-step off of a breakpoint and expecting a SIGTRAP.
6210 Instead this signal arrives. This signal will take us out
6211 of the stepping range so GDB needs to remember to, when
6212 the signal handler returns, resume stepping off that
6214 /* To simplify things, "continue" is forced to use the same
6215 code paths as single-step - set a breakpoint at the
6216 signal return address and then, once hit, step off that
6218 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6220 insert_hp_step_resume_breakpoint_at_frame (frame
);
6221 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6222 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6223 ecs
->event_thread
->control
.trap_expected
= 0;
6225 /* If we were nexting/stepping some other thread, switch to
6226 it, so that we don't continue it, losing control. */
6227 if (!switch_back_to_stepped_thread (ecs
))
6232 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6233 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6235 || ecs
->event_thread
->control
.step_range_end
== 1)
6236 && frame_id_eq (get_stack_frame_id (frame
),
6237 ecs
->event_thread
->control
.step_stack_frame_id
)
6238 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6240 /* The inferior is about to take a signal that will take it
6241 out of the single step range. Set a breakpoint at the
6242 current PC (which is presumably where the signal handler
6243 will eventually return) and then allow the inferior to
6246 Note that this is only needed for a signal delivered
6247 while in the single-step range. Nested signals aren't a
6248 problem as they eventually all return. */
6249 infrun_debug_printf ("signal may take us out of single-step range");
6251 clear_step_over_info ();
6252 insert_hp_step_resume_breakpoint_at_frame (frame
);
6253 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6254 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6255 ecs
->event_thread
->control
.trap_expected
= 0;
6260 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6261 when either there's a nested signal, or when there's a
6262 pending signal enabled just as the signal handler returns
6263 (leaving the inferior at the step-resume-breakpoint without
6264 actually executing it). Either way continue until the
6265 breakpoint is really hit. */
6267 if (!switch_back_to_stepped_thread (ecs
))
6269 infrun_debug_printf ("random signal, keep going");
6276 process_event_stop_test (ecs
);
6279 /* Come here when we've got some debug event / signal we can explain
6280 (IOW, not a random signal), and test whether it should cause a
6281 stop, or whether we should resume the inferior (transparently).
6282 E.g., could be a breakpoint whose condition evaluates false; we
6283 could be still stepping within the line; etc. */
6286 process_event_stop_test (struct execution_control_state
*ecs
)
6288 struct symtab_and_line stop_pc_sal
;
6289 struct frame_info
*frame
;
6290 struct gdbarch
*gdbarch
;
6291 CORE_ADDR jmp_buf_pc
;
6292 struct bpstat_what what
;
6294 /* Handle cases caused by hitting a breakpoint. */
6296 frame
= get_current_frame ();
6297 gdbarch
= get_frame_arch (frame
);
6299 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6301 if (what
.call_dummy
)
6303 stop_stack_dummy
= what
.call_dummy
;
6306 /* A few breakpoint types have callbacks associated (e.g.,
6307 bp_jit_event). Run them now. */
6308 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6310 /* If we hit an internal event that triggers symbol changes, the
6311 current frame will be invalidated within bpstat_what (e.g., if we
6312 hit an internal solib event). Re-fetch it. */
6313 frame
= get_current_frame ();
6314 gdbarch
= get_frame_arch (frame
);
6316 switch (what
.main_action
)
6318 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6319 /* If we hit the breakpoint at longjmp while stepping, we
6320 install a momentary breakpoint at the target of the
6323 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6325 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6327 if (what
.is_longjmp
)
6329 struct value
*arg_value
;
6331 /* If we set the longjmp breakpoint via a SystemTap probe,
6332 then use it to extract the arguments. The destination PC
6333 is the third argument to the probe. */
6334 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6337 jmp_buf_pc
= value_as_address (arg_value
);
6338 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6340 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6341 || !gdbarch_get_longjmp_target (gdbarch
,
6342 frame
, &jmp_buf_pc
))
6344 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6345 "(!gdbarch_get_longjmp_target)");
6350 /* Insert a breakpoint at resume address. */
6351 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6354 check_exception_resume (ecs
, frame
);
6358 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6360 struct frame_info
*init_frame
;
6362 /* There are several cases to consider.
6364 1. The initiating frame no longer exists. In this case we
6365 must stop, because the exception or longjmp has gone too
6368 2. The initiating frame exists, and is the same as the
6369 current frame. We stop, because the exception or longjmp
6372 3. The initiating frame exists and is different from the
6373 current frame. This means the exception or longjmp has
6374 been caught beneath the initiating frame, so keep going.
6376 4. longjmp breakpoint has been placed just to protect
6377 against stale dummy frames and user is not interested in
6378 stopping around longjmps. */
6380 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6382 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6384 delete_exception_resume_breakpoint (ecs
->event_thread
);
6386 if (what
.is_longjmp
)
6388 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6390 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6398 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6402 struct frame_id current_id
6403 = get_frame_id (get_current_frame ());
6404 if (frame_id_eq (current_id
,
6405 ecs
->event_thread
->initiating_frame
))
6407 /* Case 2. Fall through. */
6417 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6419 delete_step_resume_breakpoint (ecs
->event_thread
);
6421 end_stepping_range (ecs
);
6425 case BPSTAT_WHAT_SINGLE
:
6426 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6427 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6428 /* Still need to check other stuff, at least the case where we
6429 are stepping and step out of the right range. */
6432 case BPSTAT_WHAT_STEP_RESUME
:
6433 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6435 delete_step_resume_breakpoint (ecs
->event_thread
);
6436 if (ecs
->event_thread
->control
.proceed_to_finish
6437 && execution_direction
== EXEC_REVERSE
)
6439 struct thread_info
*tp
= ecs
->event_thread
;
6441 /* We are finishing a function in reverse, and just hit the
6442 step-resume breakpoint at the start address of the
6443 function, and we're almost there -- just need to back up
6444 by one more single-step, which should take us back to the
6446 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6450 fill_in_stop_func (gdbarch
, ecs
);
6451 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6452 && execution_direction
== EXEC_REVERSE
)
6454 /* We are stepping over a function call in reverse, and just
6455 hit the step-resume breakpoint at the start address of
6456 the function. Go back to single-stepping, which should
6457 take us back to the function call. */
6458 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6464 case BPSTAT_WHAT_STOP_NOISY
:
6465 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6466 stop_print_frame
= true;
6468 /* Assume the thread stopped for a breakpoint. We'll still check
6469 whether a/the breakpoint is there when the thread is next
6471 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6476 case BPSTAT_WHAT_STOP_SILENT
:
6477 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6478 stop_print_frame
= false;
6480 /* Assume the thread stopped for a breakpoint. We'll still check
6481 whether a/the breakpoint is there when the thread is next
6483 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6487 case BPSTAT_WHAT_HP_STEP_RESUME
:
6488 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6490 delete_step_resume_breakpoint (ecs
->event_thread
);
6491 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6493 /* Back when the step-resume breakpoint was inserted, we
6494 were trying to single-step off a breakpoint. Go back to
6496 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6497 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6503 case BPSTAT_WHAT_KEEP_CHECKING
:
6507 /* If we stepped a permanent breakpoint and we had a high priority
6508 step-resume breakpoint for the address we stepped, but we didn't
6509 hit it, then we must have stepped into the signal handler. The
6510 step-resume was only necessary to catch the case of _not_
6511 stepping into the handler, so delete it, and fall through to
6512 checking whether the step finished. */
6513 if (ecs
->event_thread
->stepped_breakpoint
)
6515 struct breakpoint
*sr_bp
6516 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6519 && sr_bp
->loc
->permanent
6520 && sr_bp
->type
== bp_hp_step_resume
6521 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6523 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6524 delete_step_resume_breakpoint (ecs
->event_thread
);
6525 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6529 /* We come here if we hit a breakpoint but should not stop for it.
6530 Possibly we also were stepping and should stop for that. So fall
6531 through and test for stepping. But, if not stepping, do not
6534 /* In all-stop mode, if we're currently stepping but have stopped in
6535 some other thread, we need to switch back to the stepped thread. */
6536 if (switch_back_to_stepped_thread (ecs
))
6539 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6541 infrun_debug_printf ("step-resume breakpoint is inserted");
6543 /* Having a step-resume breakpoint overrides anything
6544 else having to do with stepping commands until
6545 that breakpoint is reached. */
6550 if (ecs
->event_thread
->control
.step_range_end
== 0)
6552 infrun_debug_printf ("no stepping, continue");
6553 /* Likewise if we aren't even stepping. */
6558 /* Re-fetch current thread's frame in case the code above caused
6559 the frame cache to be re-initialized, making our FRAME variable
6560 a dangling pointer. */
6561 frame
= get_current_frame ();
6562 gdbarch
= get_frame_arch (frame
);
6563 fill_in_stop_func (gdbarch
, ecs
);
6565 /* If stepping through a line, keep going if still within it.
6567 Note that step_range_end is the address of the first instruction
6568 beyond the step range, and NOT the address of the last instruction
6571 Note also that during reverse execution, we may be stepping
6572 through a function epilogue and therefore must detect when
6573 the current-frame changes in the middle of a line. */
6575 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6577 && (execution_direction
!= EXEC_REVERSE
6578 || frame_id_eq (get_frame_id (frame
),
6579 ecs
->event_thread
->control
.step_frame_id
)))
6582 ("stepping inside range [%s-%s]",
6583 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6584 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6586 /* Tentatively re-enable range stepping; `resume' disables it if
6587 necessary (e.g., if we're stepping over a breakpoint or we
6588 have software watchpoints). */
6589 ecs
->event_thread
->control
.may_range_step
= 1;
6591 /* When stepping backward, stop at beginning of line range
6592 (unless it's the function entry point, in which case
6593 keep going back to the call point). */
6594 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6595 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6596 && stop_pc
!= ecs
->stop_func_start
6597 && execution_direction
== EXEC_REVERSE
)
6598 end_stepping_range (ecs
);
6605 /* We stepped out of the stepping range. */
6607 /* If we are stepping at the source level and entered the runtime
6608 loader dynamic symbol resolution code...
6610 EXEC_FORWARD: we keep on single stepping until we exit the run
6611 time loader code and reach the callee's address.
6613 EXEC_REVERSE: we've already executed the callee (backward), and
6614 the runtime loader code is handled just like any other
6615 undebuggable function call. Now we need only keep stepping
6616 backward through the trampoline code, and that's handled further
6617 down, so there is nothing for us to do here. */
6619 if (execution_direction
!= EXEC_REVERSE
6620 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6621 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6623 CORE_ADDR pc_after_resolver
=
6624 gdbarch_skip_solib_resolver (gdbarch
,
6625 ecs
->event_thread
->suspend
.stop_pc
);
6627 infrun_debug_printf ("stepped into dynsym resolve code");
6629 if (pc_after_resolver
)
6631 /* Set up a step-resume breakpoint at the address
6632 indicated by SKIP_SOLIB_RESOLVER. */
6633 symtab_and_line sr_sal
;
6634 sr_sal
.pc
= pc_after_resolver
;
6635 sr_sal
.pspace
= get_frame_program_space (frame
);
6637 insert_step_resume_breakpoint_at_sal (gdbarch
,
6638 sr_sal
, null_frame_id
);
6645 /* Step through an indirect branch thunk. */
6646 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6647 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6648 ecs
->event_thread
->suspend
.stop_pc
))
6650 infrun_debug_printf ("stepped into indirect branch thunk");
6655 if (ecs
->event_thread
->control
.step_range_end
!= 1
6656 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6657 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6658 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6660 infrun_debug_printf ("stepped into signal trampoline");
6661 /* The inferior, while doing a "step" or "next", has ended up in
6662 a signal trampoline (either by a signal being delivered or by
6663 the signal handler returning). Just single-step until the
6664 inferior leaves the trampoline (either by calling the handler
6670 /* If we're in the return path from a shared library trampoline,
6671 we want to proceed through the trampoline when stepping. */
6672 /* macro/2012-04-25: This needs to come before the subroutine
6673 call check below as on some targets return trampolines look
6674 like subroutine calls (MIPS16 return thunks). */
6675 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6676 ecs
->event_thread
->suspend
.stop_pc
,
6677 ecs
->stop_func_name
)
6678 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6680 /* Determine where this trampoline returns. */
6681 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6682 CORE_ADDR real_stop_pc
6683 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6685 infrun_debug_printf ("stepped into solib return tramp");
6687 /* Only proceed through if we know where it's going. */
6690 /* And put the step-breakpoint there and go until there. */
6691 symtab_and_line sr_sal
;
6692 sr_sal
.pc
= real_stop_pc
;
6693 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6694 sr_sal
.pspace
= get_frame_program_space (frame
);
6696 /* Do not specify what the fp should be when we stop since
6697 on some machines the prologue is where the new fp value
6699 insert_step_resume_breakpoint_at_sal (gdbarch
,
6700 sr_sal
, null_frame_id
);
6702 /* Restart without fiddling with the step ranges or
6709 /* Check for subroutine calls. The check for the current frame
6710 equalling the step ID is not necessary - the check of the
6711 previous frame's ID is sufficient - but it is a common case and
6712 cheaper than checking the previous frame's ID.
6714 NOTE: frame_id_eq will never report two invalid frame IDs as
6715 being equal, so to get into this block, both the current and
6716 previous frame must have valid frame IDs. */
6717 /* The outer_frame_id check is a heuristic to detect stepping
6718 through startup code. If we step over an instruction which
6719 sets the stack pointer from an invalid value to a valid value,
6720 we may detect that as a subroutine call from the mythical
6721 "outermost" function. This could be fixed by marking
6722 outermost frames as !stack_p,code_p,special_p. Then the
6723 initial outermost frame, before sp was valid, would
6724 have code_addr == &_start. See the comment in frame_id_eq
6726 if (!frame_id_eq (get_stack_frame_id (frame
),
6727 ecs
->event_thread
->control
.step_stack_frame_id
)
6728 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6729 ecs
->event_thread
->control
.step_stack_frame_id
)
6730 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6732 || (ecs
->event_thread
->control
.step_start_function
6733 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6735 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6736 CORE_ADDR real_stop_pc
;
6738 infrun_debug_printf ("stepped into subroutine");
6740 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6742 /* I presume that step_over_calls is only 0 when we're
6743 supposed to be stepping at the assembly language level
6744 ("stepi"). Just stop. */
6745 /* And this works the same backward as frontward. MVS */
6746 end_stepping_range (ecs
);
6750 /* Reverse stepping through solib trampolines. */
6752 if (execution_direction
== EXEC_REVERSE
6753 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6754 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6755 || (ecs
->stop_func_start
== 0
6756 && in_solib_dynsym_resolve_code (stop_pc
))))
6758 /* Any solib trampoline code can be handled in reverse
6759 by simply continuing to single-step. We have already
6760 executed the solib function (backwards), and a few
6761 steps will take us back through the trampoline to the
6767 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6769 /* We're doing a "next".
6771 Normal (forward) execution: set a breakpoint at the
6772 callee's return address (the address at which the caller
6775 Reverse (backward) execution. set the step-resume
6776 breakpoint at the start of the function that we just
6777 stepped into (backwards), and continue to there. When we
6778 get there, we'll need to single-step back to the caller. */
6780 if (execution_direction
== EXEC_REVERSE
)
6782 /* If we're already at the start of the function, we've either
6783 just stepped backward into a single instruction function,
6784 or stepped back out of a signal handler to the first instruction
6785 of the function. Just keep going, which will single-step back
6787 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6789 /* Normal function call return (static or dynamic). */
6790 symtab_and_line sr_sal
;
6791 sr_sal
.pc
= ecs
->stop_func_start
;
6792 sr_sal
.pspace
= get_frame_program_space (frame
);
6793 insert_step_resume_breakpoint_at_sal (gdbarch
,
6794 sr_sal
, null_frame_id
);
6798 insert_step_resume_breakpoint_at_caller (frame
);
6804 /* If we are in a function call trampoline (a stub between the
6805 calling routine and the real function), locate the real
6806 function. That's what tells us (a) whether we want to step
6807 into it at all, and (b) what prologue we want to run to the
6808 end of, if we do step into it. */
6809 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6810 if (real_stop_pc
== 0)
6811 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6812 if (real_stop_pc
!= 0)
6813 ecs
->stop_func_start
= real_stop_pc
;
6815 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6817 symtab_and_line sr_sal
;
6818 sr_sal
.pc
= ecs
->stop_func_start
;
6819 sr_sal
.pspace
= get_frame_program_space (frame
);
6821 insert_step_resume_breakpoint_at_sal (gdbarch
,
6822 sr_sal
, null_frame_id
);
6827 /* If we have line number information for the function we are
6828 thinking of stepping into and the function isn't on the skip
6831 If there are several symtabs at that PC (e.g. with include
6832 files), just want to know whether *any* of them have line
6833 numbers. find_pc_line handles this. */
6835 struct symtab_and_line tmp_sal
;
6837 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6838 if (tmp_sal
.line
!= 0
6839 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6841 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6843 if (execution_direction
== EXEC_REVERSE
)
6844 handle_step_into_function_backward (gdbarch
, ecs
);
6846 handle_step_into_function (gdbarch
, ecs
);
6851 /* If we have no line number and the step-stop-if-no-debug is
6852 set, we stop the step so that the user has a chance to switch
6853 in assembly mode. */
6854 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6855 && step_stop_if_no_debug
)
6857 end_stepping_range (ecs
);
6861 if (execution_direction
== EXEC_REVERSE
)
6863 /* If we're already at the start of the function, we've either just
6864 stepped backward into a single instruction function without line
6865 number info, or stepped back out of a signal handler to the first
6866 instruction of the function without line number info. Just keep
6867 going, which will single-step back to the caller. */
6868 if (ecs
->stop_func_start
!= stop_pc
)
6870 /* Set a breakpoint at callee's start address.
6871 From there we can step once and be back in the caller. */
6872 symtab_and_line sr_sal
;
6873 sr_sal
.pc
= ecs
->stop_func_start
;
6874 sr_sal
.pspace
= get_frame_program_space (frame
);
6875 insert_step_resume_breakpoint_at_sal (gdbarch
,
6876 sr_sal
, null_frame_id
);
6880 /* Set a breakpoint at callee's return address (the address
6881 at which the caller will resume). */
6882 insert_step_resume_breakpoint_at_caller (frame
);
6888 /* Reverse stepping through solib trampolines. */
6890 if (execution_direction
== EXEC_REVERSE
6891 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6893 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6895 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6896 || (ecs
->stop_func_start
== 0
6897 && in_solib_dynsym_resolve_code (stop_pc
)))
6899 /* Any solib trampoline code can be handled in reverse
6900 by simply continuing to single-step. We have already
6901 executed the solib function (backwards), and a few
6902 steps will take us back through the trampoline to the
6907 else if (in_solib_dynsym_resolve_code (stop_pc
))
6909 /* Stepped backward into the solib dynsym resolver.
6910 Set a breakpoint at its start and continue, then
6911 one more step will take us out. */
6912 symtab_and_line sr_sal
;
6913 sr_sal
.pc
= ecs
->stop_func_start
;
6914 sr_sal
.pspace
= get_frame_program_space (frame
);
6915 insert_step_resume_breakpoint_at_sal (gdbarch
,
6916 sr_sal
, null_frame_id
);
6922 /* This always returns the sal for the inner-most frame when we are in a
6923 stack of inlined frames, even if GDB actually believes that it is in a
6924 more outer frame. This is checked for below by calls to
6925 inline_skipped_frames. */
6926 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6928 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6929 the trampoline processing logic, however, there are some trampolines
6930 that have no names, so we should do trampoline handling first. */
6931 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6932 && ecs
->stop_func_name
== NULL
6933 && stop_pc_sal
.line
== 0)
6935 infrun_debug_printf ("stepped into undebuggable function");
6937 /* The inferior just stepped into, or returned to, an
6938 undebuggable function (where there is no debugging information
6939 and no line number corresponding to the address where the
6940 inferior stopped). Since we want to skip this kind of code,
6941 we keep going until the inferior returns from this
6942 function - unless the user has asked us not to (via
6943 set step-mode) or we no longer know how to get back
6944 to the call site. */
6945 if (step_stop_if_no_debug
6946 || !frame_id_p (frame_unwind_caller_id (frame
)))
6948 /* If we have no line number and the step-stop-if-no-debug
6949 is set, we stop the step so that the user has a chance to
6950 switch in assembly mode. */
6951 end_stepping_range (ecs
);
6956 /* Set a breakpoint at callee's return address (the address
6957 at which the caller will resume). */
6958 insert_step_resume_breakpoint_at_caller (frame
);
6964 if (ecs
->event_thread
->control
.step_range_end
== 1)
6966 /* It is stepi or nexti. We always want to stop stepping after
6968 infrun_debug_printf ("stepi/nexti");
6969 end_stepping_range (ecs
);
6973 if (stop_pc_sal
.line
== 0)
6975 /* We have no line number information. That means to stop
6976 stepping (does this always happen right after one instruction,
6977 when we do "s" in a function with no line numbers,
6978 or can this happen as a result of a return or longjmp?). */
6979 infrun_debug_printf ("line number info");
6980 end_stepping_range (ecs
);
6984 /* Look for "calls" to inlined functions, part one. If the inline
6985 frame machinery detected some skipped call sites, we have entered
6986 a new inline function. */
6988 if (frame_id_eq (get_frame_id (get_current_frame ()),
6989 ecs
->event_thread
->control
.step_frame_id
)
6990 && inline_skipped_frames (ecs
->event_thread
))
6992 infrun_debug_printf ("stepped into inlined function");
6994 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6996 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6998 /* For "step", we're going to stop. But if the call site
6999 for this inlined function is on the same source line as
7000 we were previously stepping, go down into the function
7001 first. Otherwise stop at the call site. */
7003 if (call_sal
.line
== ecs
->event_thread
->current_line
7004 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7006 step_into_inline_frame (ecs
->event_thread
);
7007 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7014 end_stepping_range (ecs
);
7019 /* For "next", we should stop at the call site if it is on a
7020 different source line. Otherwise continue through the
7021 inlined function. */
7022 if (call_sal
.line
== ecs
->event_thread
->current_line
7023 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7026 end_stepping_range (ecs
);
7031 /* Look for "calls" to inlined functions, part two. If we are still
7032 in the same real function we were stepping through, but we have
7033 to go further up to find the exact frame ID, we are stepping
7034 through a more inlined call beyond its call site. */
7036 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7037 && !frame_id_eq (get_frame_id (get_current_frame ()),
7038 ecs
->event_thread
->control
.step_frame_id
)
7039 && stepped_in_from (get_current_frame (),
7040 ecs
->event_thread
->control
.step_frame_id
))
7042 infrun_debug_printf ("stepping through inlined function");
7044 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7045 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7048 end_stepping_range (ecs
);
7052 bool refresh_step_info
= true;
7053 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7054 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7055 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7057 if (stop_pc_sal
.is_stmt
)
7059 /* We are at the start of a different line. So stop. Note that
7060 we don't stop if we step into the middle of a different line.
7061 That is said to make things like for (;;) statements work
7063 infrun_debug_printf ("stepped to a different line");
7064 end_stepping_range (ecs
);
7067 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7068 ecs
->event_thread
->control
.step_frame_id
))
7070 /* We are at the start of a different line, however, this line is
7071 not marked as a statement, and we have not changed frame. We
7072 ignore this line table entry, and continue stepping forward,
7073 looking for a better place to stop. */
7074 refresh_step_info
= false;
7075 infrun_debug_printf ("stepped to a different line, but "
7076 "it's not the start of a statement");
7080 /* We aren't done stepping.
7082 Optimize by setting the stepping range to the line.
7083 (We might not be in the original line, but if we entered a
7084 new line in mid-statement, we continue stepping. This makes
7085 things like for(;;) statements work better.)
7087 If we entered a SAL that indicates a non-statement line table entry,
7088 then we update the stepping range, but we don't update the step info,
7089 which includes things like the line number we are stepping away from.
7090 This means we will stop when we find a line table entry that is marked
7091 as is-statement, even if it matches the non-statement one we just
7094 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7095 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7096 ecs
->event_thread
->control
.may_range_step
= 1;
7097 if (refresh_step_info
)
7098 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7100 infrun_debug_printf ("keep going");
7104 /* In all-stop mode, if we're currently stepping but have stopped in
7105 some other thread, we may need to switch back to the stepped
7106 thread. Returns true we set the inferior running, false if we left
7107 it stopped (and the event needs further processing). */
7110 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7112 if (!target_is_non_stop_p ())
7114 struct thread_info
*stepping_thread
;
7116 /* If any thread is blocked on some internal breakpoint, and we
7117 simply need to step over that breakpoint to get it going
7118 again, do that first. */
7120 /* However, if we see an event for the stepping thread, then we
7121 know all other threads have been moved past their breakpoints
7122 already. Let the caller check whether the step is finished,
7123 etc., before deciding to move it past a breakpoint. */
7124 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7127 /* Check if the current thread is blocked on an incomplete
7128 step-over, interrupted by a random signal. */
7129 if (ecs
->event_thread
->control
.trap_expected
7130 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7133 ("need to finish step-over of [%s]",
7134 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7139 /* Check if the current thread is blocked by a single-step
7140 breakpoint of another thread. */
7141 if (ecs
->hit_singlestep_breakpoint
)
7143 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7144 target_pid_to_str (ecs
->ptid
).c_str ());
7149 /* If this thread needs yet another step-over (e.g., stepping
7150 through a delay slot), do it first before moving on to
7152 if (thread_still_needs_step_over (ecs
->event_thread
))
7155 ("thread [%s] still needs step-over",
7156 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7161 /* If scheduler locking applies even if not stepping, there's no
7162 need to walk over threads. Above we've checked whether the
7163 current thread is stepping. If some other thread not the
7164 event thread is stepping, then it must be that scheduler
7165 locking is not in effect. */
7166 if (schedlock_applies (ecs
->event_thread
))
7169 /* Otherwise, we no longer expect a trap in the current thread.
7170 Clear the trap_expected flag before switching back -- this is
7171 what keep_going does as well, if we call it. */
7172 ecs
->event_thread
->control
.trap_expected
= 0;
7174 /* Likewise, clear the signal if it should not be passed. */
7175 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7176 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7178 /* Do all pending step-overs before actually proceeding with
7180 if (start_step_over ())
7182 prepare_to_wait (ecs
);
7186 /* Look for the stepping/nexting thread. */
7187 stepping_thread
= NULL
;
7189 for (thread_info
*tp
: all_non_exited_threads ())
7191 switch_to_thread_no_regs (tp
);
7193 /* Ignore threads of processes the caller is not
7196 && (tp
->inf
->process_target () != ecs
->target
7197 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7200 /* When stepping over a breakpoint, we lock all threads
7201 except the one that needs to move past the breakpoint.
7202 If a non-event thread has this set, the "incomplete
7203 step-over" check above should have caught it earlier. */
7204 if (tp
->control
.trap_expected
)
7206 internal_error (__FILE__
, __LINE__
,
7207 "[%s] has inconsistent state: "
7208 "trap_expected=%d\n",
7209 target_pid_to_str (tp
->ptid
).c_str (),
7210 tp
->control
.trap_expected
);
7213 /* Did we find the stepping thread? */
7214 if (tp
->control
.step_range_end
)
7216 /* Yep. There should only one though. */
7217 gdb_assert (stepping_thread
== NULL
);
7219 /* The event thread is handled at the top, before we
7221 gdb_assert (tp
!= ecs
->event_thread
);
7223 /* If some thread other than the event thread is
7224 stepping, then scheduler locking can't be in effect,
7225 otherwise we wouldn't have resumed the current event
7226 thread in the first place. */
7227 gdb_assert (!schedlock_applies (tp
));
7229 stepping_thread
= tp
;
7233 if (stepping_thread
!= NULL
)
7235 infrun_debug_printf ("switching back to stepped thread");
7237 if (keep_going_stepped_thread (stepping_thread
))
7239 prepare_to_wait (ecs
);
7244 switch_to_thread (ecs
->event_thread
);
7250 /* Set a previously stepped thread back to stepping. Returns true on
7251 success, false if the resume is not possible (e.g., the thread
7255 keep_going_stepped_thread (struct thread_info
*tp
)
7257 struct frame_info
*frame
;
7258 struct execution_control_state ecss
;
7259 struct execution_control_state
*ecs
= &ecss
;
7261 /* If the stepping thread exited, then don't try to switch back and
7262 resume it, which could fail in several different ways depending
7263 on the target. Instead, just keep going.
7265 We can find a stepping dead thread in the thread list in two
7268 - The target supports thread exit events, and when the target
7269 tries to delete the thread from the thread list, inferior_ptid
7270 pointed at the exiting thread. In such case, calling
7271 delete_thread does not really remove the thread from the list;
7272 instead, the thread is left listed, with 'exited' state.
7274 - The target's debug interface does not support thread exit
7275 events, and so we have no idea whatsoever if the previously
7276 stepping thread is still alive. For that reason, we need to
7277 synchronously query the target now. */
7279 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7281 infrun_debug_printf ("not resuming previously stepped thread, it has "
7288 infrun_debug_printf ("resuming previously stepped thread");
7290 reset_ecs (ecs
, tp
);
7291 switch_to_thread (tp
);
7293 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7294 frame
= get_current_frame ();
7296 /* If the PC of the thread we were trying to single-step has
7297 changed, then that thread has trapped or been signaled, but the
7298 event has not been reported to GDB yet. Re-poll the target
7299 looking for this particular thread's event (i.e. temporarily
7300 enable schedlock) by:
7302 - setting a break at the current PC
7303 - resuming that particular thread, only (by setting trap
7306 This prevents us continuously moving the single-step breakpoint
7307 forward, one instruction at a time, overstepping. */
7309 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7313 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7314 paddress (target_gdbarch (), tp
->prev_pc
),
7315 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7317 /* Clear the info of the previous step-over, as it's no longer
7318 valid (if the thread was trying to step over a breakpoint, it
7319 has already succeeded). It's what keep_going would do too,
7320 if we called it. Do this before trying to insert the sss
7321 breakpoint, otherwise if we were previously trying to step
7322 over this exact address in another thread, the breakpoint is
7324 clear_step_over_info ();
7325 tp
->control
.trap_expected
= 0;
7327 insert_single_step_breakpoint (get_frame_arch (frame
),
7328 get_frame_address_space (frame
),
7329 tp
->suspend
.stop_pc
);
7332 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7333 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7337 infrun_debug_printf ("expected thread still hasn't advanced");
7339 keep_going_pass_signal (ecs
);
7345 /* Is thread TP in the middle of (software or hardware)
7346 single-stepping? (Note the result of this function must never be
7347 passed directly as target_resume's STEP parameter.) */
7350 currently_stepping (struct thread_info
*tp
)
7352 return ((tp
->control
.step_range_end
7353 && tp
->control
.step_resume_breakpoint
== NULL
)
7354 || tp
->control
.trap_expected
7355 || tp
->stepped_breakpoint
7356 || bpstat_should_step ());
7359 /* Inferior has stepped into a subroutine call with source code that
7360 we should not step over. Do step to the first line of code in
7364 handle_step_into_function (struct gdbarch
*gdbarch
,
7365 struct execution_control_state
*ecs
)
7367 fill_in_stop_func (gdbarch
, ecs
);
7369 compunit_symtab
*cust
7370 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7371 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7372 ecs
->stop_func_start
7373 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7375 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7376 /* Use the step_resume_break to step until the end of the prologue,
7377 even if that involves jumps (as it seems to on the vax under
7379 /* If the prologue ends in the middle of a source line, continue to
7380 the end of that source line (if it is still within the function).
7381 Otherwise, just go to end of prologue. */
7382 if (stop_func_sal
.end
7383 && stop_func_sal
.pc
!= ecs
->stop_func_start
7384 && stop_func_sal
.end
< ecs
->stop_func_end
)
7385 ecs
->stop_func_start
= stop_func_sal
.end
;
7387 /* Architectures which require breakpoint adjustment might not be able
7388 to place a breakpoint at the computed address. If so, the test
7389 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7390 ecs->stop_func_start to an address at which a breakpoint may be
7391 legitimately placed.
7393 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7394 made, GDB will enter an infinite loop when stepping through
7395 optimized code consisting of VLIW instructions which contain
7396 subinstructions corresponding to different source lines. On
7397 FR-V, it's not permitted to place a breakpoint on any but the
7398 first subinstruction of a VLIW instruction. When a breakpoint is
7399 set, GDB will adjust the breakpoint address to the beginning of
7400 the VLIW instruction. Thus, we need to make the corresponding
7401 adjustment here when computing the stop address. */
7403 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7405 ecs
->stop_func_start
7406 = gdbarch_adjust_breakpoint_address (gdbarch
,
7407 ecs
->stop_func_start
);
7410 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7412 /* We are already there: stop now. */
7413 end_stepping_range (ecs
);
7418 /* Put the step-breakpoint there and go until there. */
7419 symtab_and_line sr_sal
;
7420 sr_sal
.pc
= ecs
->stop_func_start
;
7421 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7422 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7424 /* Do not specify what the fp should be when we stop since on
7425 some machines the prologue is where the new fp value is
7427 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7429 /* And make sure stepping stops right away then. */
7430 ecs
->event_thread
->control
.step_range_end
7431 = ecs
->event_thread
->control
.step_range_start
;
7436 /* Inferior has stepped backward into a subroutine call with source
7437 code that we should not step over. Do step to the beginning of the
7438 last line of code in it. */
7441 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7442 struct execution_control_state
*ecs
)
7444 struct compunit_symtab
*cust
;
7445 struct symtab_and_line stop_func_sal
;
7447 fill_in_stop_func (gdbarch
, ecs
);
7449 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7450 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7451 ecs
->stop_func_start
7452 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7454 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7456 /* OK, we're just going to keep stepping here. */
7457 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7459 /* We're there already. Just stop stepping now. */
7460 end_stepping_range (ecs
);
7464 /* Else just reset the step range and keep going.
7465 No step-resume breakpoint, they don't work for
7466 epilogues, which can have multiple entry paths. */
7467 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7468 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7474 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7475 This is used to both functions and to skip over code. */
7478 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7479 struct symtab_and_line sr_sal
,
7480 struct frame_id sr_id
,
7481 enum bptype sr_type
)
7483 /* There should never be more than one step-resume or longjmp-resume
7484 breakpoint per thread, so we should never be setting a new
7485 step_resume_breakpoint when one is already active. */
7486 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7487 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7489 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7490 paddress (gdbarch
, sr_sal
.pc
));
7492 inferior_thread ()->control
.step_resume_breakpoint
7493 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7497 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7498 struct symtab_and_line sr_sal
,
7499 struct frame_id sr_id
)
7501 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7506 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7507 This is used to skip a potential signal handler.
7509 This is called with the interrupted function's frame. The signal
7510 handler, when it returns, will resume the interrupted function at
7514 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7516 gdb_assert (return_frame
!= NULL
);
7518 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7520 symtab_and_line sr_sal
;
7521 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7522 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7523 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7525 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7526 get_stack_frame_id (return_frame
),
7530 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7531 is used to skip a function after stepping into it (for "next" or if
7532 the called function has no debugging information).
7534 The current function has almost always been reached by single
7535 stepping a call or return instruction. NEXT_FRAME belongs to the
7536 current function, and the breakpoint will be set at the caller's
7539 This is a separate function rather than reusing
7540 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7541 get_prev_frame, which may stop prematurely (see the implementation
7542 of frame_unwind_caller_id for an example). */
7545 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7547 /* We shouldn't have gotten here if we don't know where the call site
7549 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7551 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7553 symtab_and_line sr_sal
;
7554 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7555 frame_unwind_caller_pc (next_frame
));
7556 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7557 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7559 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7560 frame_unwind_caller_id (next_frame
));
7563 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7564 new breakpoint at the target of a jmp_buf. The handling of
7565 longjmp-resume uses the same mechanisms used for handling
7566 "step-resume" breakpoints. */
7569 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7571 /* There should never be more than one longjmp-resume breakpoint per
7572 thread, so we should never be setting a new
7573 longjmp_resume_breakpoint when one is already active. */
7574 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7576 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7577 paddress (gdbarch
, pc
));
7579 inferior_thread ()->control
.exception_resume_breakpoint
=
7580 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7583 /* Insert an exception resume breakpoint. TP is the thread throwing
7584 the exception. The block B is the block of the unwinder debug hook
7585 function. FRAME is the frame corresponding to the call to this
7586 function. SYM is the symbol of the function argument holding the
7587 target PC of the exception. */
7590 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7591 const struct block
*b
,
7592 struct frame_info
*frame
,
7597 struct block_symbol vsym
;
7598 struct value
*value
;
7600 struct breakpoint
*bp
;
7602 vsym
= lookup_symbol_search_name (sym
->search_name (),
7604 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7605 /* If the value was optimized out, revert to the old behavior. */
7606 if (! value_optimized_out (value
))
7608 handler
= value_as_address (value
);
7610 infrun_debug_printf ("exception resume at %lx",
7611 (unsigned long) handler
);
7613 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7615 bp_exception_resume
).release ();
7617 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7620 bp
->thread
= tp
->global_num
;
7621 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7624 catch (const gdb_exception_error
&e
)
7626 /* We want to ignore errors here. */
7630 /* A helper for check_exception_resume that sets an
7631 exception-breakpoint based on a SystemTap probe. */
7634 insert_exception_resume_from_probe (struct thread_info
*tp
,
7635 const struct bound_probe
*probe
,
7636 struct frame_info
*frame
)
7638 struct value
*arg_value
;
7640 struct breakpoint
*bp
;
7642 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7646 handler
= value_as_address (arg_value
);
7648 infrun_debug_printf ("exception resume at %s",
7649 paddress (probe
->objfile
->arch (), handler
));
7651 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7652 handler
, bp_exception_resume
).release ();
7653 bp
->thread
= tp
->global_num
;
7654 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7657 /* This is called when an exception has been intercepted. Check to
7658 see whether the exception's destination is of interest, and if so,
7659 set an exception resume breakpoint there. */
7662 check_exception_resume (struct execution_control_state
*ecs
,
7663 struct frame_info
*frame
)
7665 struct bound_probe probe
;
7666 struct symbol
*func
;
7668 /* First see if this exception unwinding breakpoint was set via a
7669 SystemTap probe point. If so, the probe has two arguments: the
7670 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7671 set a breakpoint there. */
7672 probe
= find_probe_by_pc (get_frame_pc (frame
));
7675 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7679 func
= get_frame_function (frame
);
7685 const struct block
*b
;
7686 struct block_iterator iter
;
7690 /* The exception breakpoint is a thread-specific breakpoint on
7691 the unwinder's debug hook, declared as:
7693 void _Unwind_DebugHook (void *cfa, void *handler);
7695 The CFA argument indicates the frame to which control is
7696 about to be transferred. HANDLER is the destination PC.
7698 We ignore the CFA and set a temporary breakpoint at HANDLER.
7699 This is not extremely efficient but it avoids issues in gdb
7700 with computing the DWARF CFA, and it also works even in weird
7701 cases such as throwing an exception from inside a signal
7704 b
= SYMBOL_BLOCK_VALUE (func
);
7705 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7707 if (!SYMBOL_IS_ARGUMENT (sym
))
7714 insert_exception_resume_breakpoint (ecs
->event_thread
,
7720 catch (const gdb_exception_error
&e
)
7726 stop_waiting (struct execution_control_state
*ecs
)
7728 infrun_debug_printf ("stop_waiting");
7730 /* Let callers know we don't want to wait for the inferior anymore. */
7731 ecs
->wait_some_more
= 0;
7733 /* If all-stop, but there exists a non-stop target, stop all
7734 threads now that we're presenting the stop to the user. */
7735 if (!non_stop
&& exists_non_stop_target ())
7736 stop_all_threads ();
7739 /* Like keep_going, but passes the signal to the inferior, even if the
7740 signal is set to nopass. */
7743 keep_going_pass_signal (struct execution_control_state
*ecs
)
7745 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7746 gdb_assert (!ecs
->event_thread
->resumed
);
7748 /* Save the pc before execution, to compare with pc after stop. */
7749 ecs
->event_thread
->prev_pc
7750 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7752 if (ecs
->event_thread
->control
.trap_expected
)
7754 struct thread_info
*tp
= ecs
->event_thread
;
7756 infrun_debug_printf ("%s has trap_expected set, "
7757 "resuming to collect trap",
7758 target_pid_to_str (tp
->ptid
).c_str ());
7760 /* We haven't yet gotten our trap, and either: intercepted a
7761 non-signal event (e.g., a fork); or took a signal which we
7762 are supposed to pass through to the inferior. Simply
7764 resume (ecs
->event_thread
->suspend
.stop_signal
);
7766 else if (step_over_info_valid_p ())
7768 /* Another thread is stepping over a breakpoint in-line. If
7769 this thread needs a step-over too, queue the request. In
7770 either case, this resume must be deferred for later. */
7771 struct thread_info
*tp
= ecs
->event_thread
;
7773 if (ecs
->hit_singlestep_breakpoint
7774 || thread_still_needs_step_over (tp
))
7776 infrun_debug_printf ("step-over already in progress: "
7777 "step-over for %s deferred",
7778 target_pid_to_str (tp
->ptid
).c_str ());
7779 thread_step_over_chain_enqueue (tp
);
7783 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7784 target_pid_to_str (tp
->ptid
).c_str ());
7789 struct regcache
*regcache
= get_current_regcache ();
7792 step_over_what step_what
;
7794 /* Either the trap was not expected, but we are continuing
7795 anyway (if we got a signal, the user asked it be passed to
7798 We got our expected trap, but decided we should resume from
7801 We're going to run this baby now!
7803 Note that insert_breakpoints won't try to re-insert
7804 already inserted breakpoints. Therefore, we don't
7805 care if breakpoints were already inserted, or not. */
7807 /* If we need to step over a breakpoint, and we're not using
7808 displaced stepping to do so, insert all breakpoints
7809 (watchpoints, etc.) but the one we're stepping over, step one
7810 instruction, and then re-insert the breakpoint when that step
7813 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7815 remove_bp
= (ecs
->hit_singlestep_breakpoint
7816 || (step_what
& STEP_OVER_BREAKPOINT
));
7817 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7819 /* We can't use displaced stepping if we need to step past a
7820 watchpoint. The instruction copied to the scratch pad would
7821 still trigger the watchpoint. */
7823 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7825 set_step_over_info (regcache
->aspace (),
7826 regcache_read_pc (regcache
), remove_wps
,
7827 ecs
->event_thread
->global_num
);
7829 else if (remove_wps
)
7830 set_step_over_info (NULL
, 0, remove_wps
, -1);
7832 /* If we now need to do an in-line step-over, we need to stop
7833 all other threads. Note this must be done before
7834 insert_breakpoints below, because that removes the breakpoint
7835 we're about to step over, otherwise other threads could miss
7837 if (step_over_info_valid_p () && target_is_non_stop_p ())
7838 stop_all_threads ();
7840 /* Stop stepping if inserting breakpoints fails. */
7843 insert_breakpoints ();
7845 catch (const gdb_exception_error
&e
)
7847 exception_print (gdb_stderr
, e
);
7849 clear_step_over_info ();
7853 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7855 resume (ecs
->event_thread
->suspend
.stop_signal
);
7858 prepare_to_wait (ecs
);
7861 /* Called when we should continue running the inferior, because the
7862 current event doesn't cause a user visible stop. This does the
7863 resuming part; waiting for the next event is done elsewhere. */
7866 keep_going (struct execution_control_state
*ecs
)
7868 if (ecs
->event_thread
->control
.trap_expected
7869 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7870 ecs
->event_thread
->control
.trap_expected
= 0;
7872 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7873 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7874 keep_going_pass_signal (ecs
);
7877 /* This function normally comes after a resume, before
7878 handle_inferior_event exits. It takes care of any last bits of
7879 housekeeping, and sets the all-important wait_some_more flag. */
7882 prepare_to_wait (struct execution_control_state
*ecs
)
7884 infrun_debug_printf ("prepare_to_wait");
7886 ecs
->wait_some_more
= 1;
7888 /* If the target can't async, emulate it by marking the infrun event
7889 handler such that as soon as we get back to the event-loop, we
7890 immediately end up in fetch_inferior_event again calling
7892 if (!target_can_async_p ())
7893 mark_infrun_async_event_handler ();
7896 /* We are done with the step range of a step/next/si/ni command.
7897 Called once for each n of a "step n" operation. */
7900 end_stepping_range (struct execution_control_state
*ecs
)
7902 ecs
->event_thread
->control
.stop_step
= 1;
7906 /* Several print_*_reason functions to print why the inferior has stopped.
7907 We always print something when the inferior exits, or receives a signal.
7908 The rest of the cases are dealt with later on in normal_stop and
7909 print_it_typical. Ideally there should be a call to one of these
7910 print_*_reason functions functions from handle_inferior_event each time
7911 stop_waiting is called.
7913 Note that we don't call these directly, instead we delegate that to
7914 the interpreters, through observers. Interpreters then call these
7915 with whatever uiout is right. */
7918 print_end_stepping_range_reason (struct ui_out
*uiout
)
7920 /* For CLI-like interpreters, print nothing. */
7922 if (uiout
->is_mi_like_p ())
7924 uiout
->field_string ("reason",
7925 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7930 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7932 annotate_signalled ();
7933 if (uiout
->is_mi_like_p ())
7935 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7936 uiout
->text ("\nProgram terminated with signal ");
7937 annotate_signal_name ();
7938 uiout
->field_string ("signal-name",
7939 gdb_signal_to_name (siggnal
));
7940 annotate_signal_name_end ();
7942 annotate_signal_string ();
7943 uiout
->field_string ("signal-meaning",
7944 gdb_signal_to_string (siggnal
));
7945 annotate_signal_string_end ();
7946 uiout
->text (".\n");
7947 uiout
->text ("The program no longer exists.\n");
7951 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7953 struct inferior
*inf
= current_inferior ();
7954 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7956 annotate_exited (exitstatus
);
7959 if (uiout
->is_mi_like_p ())
7960 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7961 std::string exit_code_str
7962 = string_printf ("0%o", (unsigned int) exitstatus
);
7963 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7964 plongest (inf
->num
), pidstr
.c_str (),
7965 string_field ("exit-code", exit_code_str
.c_str ()));
7969 if (uiout
->is_mi_like_p ())
7971 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7972 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7973 plongest (inf
->num
), pidstr
.c_str ());
7978 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7980 struct thread_info
*thr
= inferior_thread ();
7984 if (uiout
->is_mi_like_p ())
7986 else if (show_thread_that_caused_stop ())
7990 uiout
->text ("\nThread ");
7991 uiout
->field_string ("thread-id", print_thread_id (thr
));
7993 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7996 uiout
->text (" \"");
7997 uiout
->field_string ("name", name
);
8002 uiout
->text ("\nProgram");
8004 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8005 uiout
->text (" stopped");
8008 uiout
->text (" received signal ");
8009 annotate_signal_name ();
8010 if (uiout
->is_mi_like_p ())
8012 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8013 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8014 annotate_signal_name_end ();
8016 annotate_signal_string ();
8017 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8019 struct regcache
*regcache
= get_current_regcache ();
8020 struct gdbarch
*gdbarch
= regcache
->arch ();
8021 if (gdbarch_report_signal_info_p (gdbarch
))
8022 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8024 annotate_signal_string_end ();
8026 uiout
->text (".\n");
8030 print_no_history_reason (struct ui_out
*uiout
)
8032 uiout
->text ("\nNo more reverse-execution history.\n");
8035 /* Print current location without a level number, if we have changed
8036 functions or hit a breakpoint. Print source line if we have one.
8037 bpstat_print contains the logic deciding in detail what to print,
8038 based on the event(s) that just occurred. */
8041 print_stop_location (struct target_waitstatus
*ws
)
8044 enum print_what source_flag
;
8045 int do_frame_printing
= 1;
8046 struct thread_info
*tp
= inferior_thread ();
8048 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8052 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8053 should) carry around the function and does (or should) use
8054 that when doing a frame comparison. */
8055 if (tp
->control
.stop_step
8056 && frame_id_eq (tp
->control
.step_frame_id
,
8057 get_frame_id (get_current_frame ()))
8058 && (tp
->control
.step_start_function
8059 == find_pc_function (tp
->suspend
.stop_pc
)))
8061 /* Finished step, just print source line. */
8062 source_flag
= SRC_LINE
;
8066 /* Print location and source line. */
8067 source_flag
= SRC_AND_LOC
;
8070 case PRINT_SRC_AND_LOC
:
8071 /* Print location and source line. */
8072 source_flag
= SRC_AND_LOC
;
8074 case PRINT_SRC_ONLY
:
8075 source_flag
= SRC_LINE
;
8078 /* Something bogus. */
8079 source_flag
= SRC_LINE
;
8080 do_frame_printing
= 0;
8083 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8086 /* The behavior of this routine with respect to the source
8088 SRC_LINE: Print only source line
8089 LOCATION: Print only location
8090 SRC_AND_LOC: Print location and source line. */
8091 if (do_frame_printing
)
8092 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8098 print_stop_event (struct ui_out
*uiout
, bool displays
)
8100 struct target_waitstatus last
;
8101 struct thread_info
*tp
;
8103 get_last_target_status (nullptr, nullptr, &last
);
8106 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8108 print_stop_location (&last
);
8110 /* Display the auto-display expressions. */
8115 tp
= inferior_thread ();
8116 if (tp
->thread_fsm
!= NULL
8117 && tp
->thread_fsm
->finished_p ())
8119 struct return_value_info
*rv
;
8121 rv
= tp
->thread_fsm
->return_value ();
8123 print_return_value (uiout
, rv
);
8130 maybe_remove_breakpoints (void)
8132 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8134 if (remove_breakpoints ())
8136 target_terminal::ours_for_output ();
8137 printf_filtered (_("Cannot remove breakpoints because "
8138 "program is no longer writable.\nFurther "
8139 "execution is probably impossible.\n"));
8144 /* The execution context that just caused a normal stop. */
8151 DISABLE_COPY_AND_ASSIGN (stop_context
);
8153 bool changed () const;
8158 /* The event PTID. */
8162 /* If stopp for a thread event, this is the thread that caused the
8164 struct thread_info
*thread
;
8166 /* The inferior that caused the stop. */
8170 /* Initializes a new stop context. If stopped for a thread event, this
8171 takes a strong reference to the thread. */
8173 stop_context::stop_context ()
8175 stop_id
= get_stop_id ();
8176 ptid
= inferior_ptid
;
8177 inf_num
= current_inferior ()->num
;
8179 if (inferior_ptid
!= null_ptid
)
8181 /* Take a strong reference so that the thread can't be deleted
8183 thread
= inferior_thread ();
8190 /* Release a stop context previously created with save_stop_context.
8191 Releases the strong reference to the thread as well. */
8193 stop_context::~stop_context ()
8199 /* Return true if the current context no longer matches the saved stop
8203 stop_context::changed () const
8205 if (ptid
!= inferior_ptid
)
8207 if (inf_num
!= current_inferior ()->num
)
8209 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8211 if (get_stop_id () != stop_id
)
8221 struct target_waitstatus last
;
8223 get_last_target_status (nullptr, nullptr, &last
);
8227 /* If an exception is thrown from this point on, make sure to
8228 propagate GDB's knowledge of the executing state to the
8229 frontend/user running state. A QUIT is an easy exception to see
8230 here, so do this before any filtered output. */
8232 ptid_t finish_ptid
= null_ptid
;
8235 finish_ptid
= minus_one_ptid
;
8236 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8237 || last
.kind
== TARGET_WAITKIND_EXITED
)
8239 /* On some targets, we may still have live threads in the
8240 inferior when we get a process exit event. E.g., for
8241 "checkpoint", when the current checkpoint/fork exits,
8242 linux-fork.c automatically switches to another fork from
8243 within target_mourn_inferior. */
8244 if (inferior_ptid
!= null_ptid
)
8245 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8247 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8248 finish_ptid
= inferior_ptid
;
8250 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8251 if (finish_ptid
!= null_ptid
)
8253 maybe_finish_thread_state
.emplace
8254 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8257 /* As we're presenting a stop, and potentially removing breakpoints,
8258 update the thread list so we can tell whether there are threads
8259 running on the target. With target remote, for example, we can
8260 only learn about new threads when we explicitly update the thread
8261 list. Do this before notifying the interpreters about signal
8262 stops, end of stepping ranges, etc., so that the "new thread"
8263 output is emitted before e.g., "Program received signal FOO",
8264 instead of after. */
8265 update_thread_list ();
8267 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8268 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8270 /* As with the notification of thread events, we want to delay
8271 notifying the user that we've switched thread context until
8272 the inferior actually stops.
8274 There's no point in saying anything if the inferior has exited.
8275 Note that SIGNALLED here means "exited with a signal", not
8276 "received a signal".
8278 Also skip saying anything in non-stop mode. In that mode, as we
8279 don't want GDB to switch threads behind the user's back, to avoid
8280 races where the user is typing a command to apply to thread x,
8281 but GDB switches to thread y before the user finishes entering
8282 the command, fetch_inferior_event installs a cleanup to restore
8283 the current thread back to the thread the user had selected right
8284 after this event is handled, so we're not really switching, only
8285 informing of a stop. */
8287 && previous_inferior_ptid
!= inferior_ptid
8288 && target_has_execution ()
8289 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8290 && last
.kind
!= TARGET_WAITKIND_EXITED
8291 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8293 SWITCH_THRU_ALL_UIS ()
8295 target_terminal::ours_for_output ();
8296 printf_filtered (_("[Switching to %s]\n"),
8297 target_pid_to_str (inferior_ptid
).c_str ());
8298 annotate_thread_changed ();
8300 previous_inferior_ptid
= inferior_ptid
;
8303 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8305 SWITCH_THRU_ALL_UIS ()
8306 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8308 target_terminal::ours_for_output ();
8309 printf_filtered (_("No unwaited-for children left.\n"));
8313 /* Note: this depends on the update_thread_list call above. */
8314 maybe_remove_breakpoints ();
8316 /* If an auto-display called a function and that got a signal,
8317 delete that auto-display to avoid an infinite recursion. */
8319 if (stopped_by_random_signal
)
8320 disable_current_display ();
8322 SWITCH_THRU_ALL_UIS ()
8324 async_enable_stdin ();
8327 /* Let the user/frontend see the threads as stopped. */
8328 maybe_finish_thread_state
.reset ();
8330 /* Select innermost stack frame - i.e., current frame is frame 0,
8331 and current location is based on that. Handle the case where the
8332 dummy call is returning after being stopped. E.g. the dummy call
8333 previously hit a breakpoint. (If the dummy call returns
8334 normally, we won't reach here.) Do this before the stop hook is
8335 run, so that it doesn't get to see the temporary dummy frame,
8336 which is not where we'll present the stop. */
8337 if (has_stack_frames ())
8339 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8341 /* Pop the empty frame that contains the stack dummy. This
8342 also restores inferior state prior to the call (struct
8343 infcall_suspend_state). */
8344 struct frame_info
*frame
= get_current_frame ();
8346 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8348 /* frame_pop calls reinit_frame_cache as the last thing it
8349 does which means there's now no selected frame. */
8352 select_frame (get_current_frame ());
8354 /* Set the current source location. */
8355 set_current_sal_from_frame (get_current_frame ());
8358 /* Look up the hook_stop and run it (CLI internally handles problem
8359 of stop_command's pre-hook not existing). */
8360 if (stop_command
!= NULL
)
8362 stop_context saved_context
;
8366 execute_cmd_pre_hook (stop_command
);
8368 catch (const gdb_exception
&ex
)
8370 exception_fprintf (gdb_stderr
, ex
,
8371 "Error while running hook_stop:\n");
8374 /* If the stop hook resumes the target, then there's no point in
8375 trying to notify about the previous stop; its context is
8376 gone. Likewise if the command switches thread or inferior --
8377 the observers would print a stop for the wrong
8379 if (saved_context
.changed ())
8383 /* Notify observers about the stop. This is where the interpreters
8384 print the stop event. */
8385 if (inferior_ptid
!= null_ptid
)
8386 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8389 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8391 annotate_stopped ();
8393 if (target_has_execution ())
8395 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8396 && last
.kind
!= TARGET_WAITKIND_EXITED
8397 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8398 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8399 Delete any breakpoint that is to be deleted at the next stop. */
8400 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8403 /* Try to get rid of automatically added inferiors that are no
8404 longer needed. Keeping those around slows down things linearly.
8405 Note that this never removes the current inferior. */
8412 signal_stop_state (int signo
)
8414 return signal_stop
[signo
];
8418 signal_print_state (int signo
)
8420 return signal_print
[signo
];
8424 signal_pass_state (int signo
)
8426 return signal_program
[signo
];
8430 signal_cache_update (int signo
)
8434 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8435 signal_cache_update (signo
);
8440 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8441 && signal_print
[signo
] == 0
8442 && signal_program
[signo
] == 1
8443 && signal_catch
[signo
] == 0);
8447 signal_stop_update (int signo
, int state
)
8449 int ret
= signal_stop
[signo
];
8451 signal_stop
[signo
] = state
;
8452 signal_cache_update (signo
);
8457 signal_print_update (int signo
, int state
)
8459 int ret
= signal_print
[signo
];
8461 signal_print
[signo
] = state
;
8462 signal_cache_update (signo
);
8467 signal_pass_update (int signo
, int state
)
8469 int ret
= signal_program
[signo
];
8471 signal_program
[signo
] = state
;
8472 signal_cache_update (signo
);
8476 /* Update the global 'signal_catch' from INFO and notify the
8480 signal_catch_update (const unsigned int *info
)
8484 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8485 signal_catch
[i
] = info
[i
] > 0;
8486 signal_cache_update (-1);
8487 target_pass_signals (signal_pass
);
8491 sig_print_header (void)
8493 printf_filtered (_("Signal Stop\tPrint\tPass "
8494 "to program\tDescription\n"));
8498 sig_print_info (enum gdb_signal oursig
)
8500 const char *name
= gdb_signal_to_name (oursig
);
8501 int name_padding
= 13 - strlen (name
);
8503 if (name_padding
<= 0)
8506 printf_filtered ("%s", name
);
8507 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8508 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8509 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8510 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8511 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8514 /* Specify how various signals in the inferior should be handled. */
8517 handle_command (const char *args
, int from_tty
)
8519 int digits
, wordlen
;
8520 int sigfirst
, siglast
;
8521 enum gdb_signal oursig
;
8526 error_no_arg (_("signal to handle"));
8529 /* Allocate and zero an array of flags for which signals to handle. */
8531 const size_t nsigs
= GDB_SIGNAL_LAST
;
8532 unsigned char sigs
[nsigs
] {};
8534 /* Break the command line up into args. */
8536 gdb_argv
built_argv (args
);
8538 /* Walk through the args, looking for signal oursigs, signal names, and
8539 actions. Signal numbers and signal names may be interspersed with
8540 actions, with the actions being performed for all signals cumulatively
8541 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8543 for (char *arg
: built_argv
)
8545 wordlen
= strlen (arg
);
8546 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8550 sigfirst
= siglast
= -1;
8552 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8554 /* Apply action to all signals except those used by the
8555 debugger. Silently skip those. */
8558 siglast
= nsigs
- 1;
8560 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8562 SET_SIGS (nsigs
, sigs
, signal_stop
);
8563 SET_SIGS (nsigs
, sigs
, signal_print
);
8565 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8567 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8569 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8571 SET_SIGS (nsigs
, sigs
, signal_print
);
8573 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8575 SET_SIGS (nsigs
, sigs
, signal_program
);
8577 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8579 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8581 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8583 SET_SIGS (nsigs
, sigs
, signal_program
);
8585 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8587 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8588 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8590 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8592 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8594 else if (digits
> 0)
8596 /* It is numeric. The numeric signal refers to our own
8597 internal signal numbering from target.h, not to host/target
8598 signal number. This is a feature; users really should be
8599 using symbolic names anyway, and the common ones like
8600 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8602 sigfirst
= siglast
= (int)
8603 gdb_signal_from_command (atoi (arg
));
8604 if (arg
[digits
] == '-')
8607 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8609 if (sigfirst
> siglast
)
8611 /* Bet he didn't figure we'd think of this case... */
8612 std::swap (sigfirst
, siglast
);
8617 oursig
= gdb_signal_from_name (arg
);
8618 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8620 sigfirst
= siglast
= (int) oursig
;
8624 /* Not a number and not a recognized flag word => complain. */
8625 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8629 /* If any signal numbers or symbol names were found, set flags for
8630 which signals to apply actions to. */
8632 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8634 switch ((enum gdb_signal
) signum
)
8636 case GDB_SIGNAL_TRAP
:
8637 case GDB_SIGNAL_INT
:
8638 if (!allsigs
&& !sigs
[signum
])
8640 if (query (_("%s is used by the debugger.\n\
8641 Are you sure you want to change it? "),
8642 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8647 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8651 case GDB_SIGNAL_DEFAULT
:
8652 case GDB_SIGNAL_UNKNOWN
:
8653 /* Make sure that "all" doesn't print these. */
8662 for (int signum
= 0; signum
< nsigs
; signum
++)
8665 signal_cache_update (-1);
8666 target_pass_signals (signal_pass
);
8667 target_program_signals (signal_program
);
8671 /* Show the results. */
8672 sig_print_header ();
8673 for (; signum
< nsigs
; signum
++)
8675 sig_print_info ((enum gdb_signal
) signum
);
8682 /* Complete the "handle" command. */
8685 handle_completer (struct cmd_list_element
*ignore
,
8686 completion_tracker
&tracker
,
8687 const char *text
, const char *word
)
8689 static const char * const keywords
[] =
8703 signal_completer (ignore
, tracker
, text
, word
);
8704 complete_on_enum (tracker
, keywords
, word
, word
);
8708 gdb_signal_from_command (int num
)
8710 if (num
>= 1 && num
<= 15)
8711 return (enum gdb_signal
) num
;
8712 error (_("Only signals 1-15 are valid as numeric signals.\n\
8713 Use \"info signals\" for a list of symbolic signals."));
8716 /* Print current contents of the tables set by the handle command.
8717 It is possible we should just be printing signals actually used
8718 by the current target (but for things to work right when switching
8719 targets, all signals should be in the signal tables). */
8722 info_signals_command (const char *signum_exp
, int from_tty
)
8724 enum gdb_signal oursig
;
8726 sig_print_header ();
8730 /* First see if this is a symbol name. */
8731 oursig
= gdb_signal_from_name (signum_exp
);
8732 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8734 /* No, try numeric. */
8736 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8738 sig_print_info (oursig
);
8742 printf_filtered ("\n");
8743 /* These ugly casts brought to you by the native VAX compiler. */
8744 for (oursig
= GDB_SIGNAL_FIRST
;
8745 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8746 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8750 if (oursig
!= GDB_SIGNAL_UNKNOWN
8751 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8752 sig_print_info (oursig
);
8755 printf_filtered (_("\nUse the \"handle\" command "
8756 "to change these tables.\n"));
8759 /* The $_siginfo convenience variable is a bit special. We don't know
8760 for sure the type of the value until we actually have a chance to
8761 fetch the data. The type can change depending on gdbarch, so it is
8762 also dependent on which thread you have selected.
8764 1. making $_siginfo be an internalvar that creates a new value on
8767 2. making the value of $_siginfo be an lval_computed value. */
8769 /* This function implements the lval_computed support for reading a
8773 siginfo_value_read (struct value
*v
)
8775 LONGEST transferred
;
8777 /* If we can access registers, so can we access $_siginfo. Likewise
8779 validate_registers_access ();
8782 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8784 value_contents_all_raw (v
),
8786 TYPE_LENGTH (value_type (v
)));
8788 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8789 error (_("Unable to read siginfo"));
8792 /* This function implements the lval_computed support for writing a
8796 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8798 LONGEST transferred
;
8800 /* If we can access registers, so can we access $_siginfo. Likewise
8802 validate_registers_access ();
8804 transferred
= target_write (current_top_target (),
8805 TARGET_OBJECT_SIGNAL_INFO
,
8807 value_contents_all_raw (fromval
),
8809 TYPE_LENGTH (value_type (fromval
)));
8811 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8812 error (_("Unable to write siginfo"));
8815 static const struct lval_funcs siginfo_value_funcs
=
8821 /* Return a new value with the correct type for the siginfo object of
8822 the current thread using architecture GDBARCH. Return a void value
8823 if there's no object available. */
8825 static struct value
*
8826 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8829 if (target_has_stack ()
8830 && inferior_ptid
!= null_ptid
8831 && gdbarch_get_siginfo_type_p (gdbarch
))
8833 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8835 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8838 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8842 /* infcall_suspend_state contains state about the program itself like its
8843 registers and any signal it received when it last stopped.
8844 This state must be restored regardless of how the inferior function call
8845 ends (either successfully, or after it hits a breakpoint or signal)
8846 if the program is to properly continue where it left off. */
8848 class infcall_suspend_state
8851 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8852 once the inferior function call has finished. */
8853 infcall_suspend_state (struct gdbarch
*gdbarch
,
8854 const struct thread_info
*tp
,
8855 struct regcache
*regcache
)
8856 : m_thread_suspend (tp
->suspend
),
8857 m_registers (new readonly_detached_regcache (*regcache
))
8859 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8861 if (gdbarch_get_siginfo_type_p (gdbarch
))
8863 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8864 size_t len
= TYPE_LENGTH (type
);
8866 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8868 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8869 siginfo_data
.get (), 0, len
) != len
)
8871 /* Errors ignored. */
8872 siginfo_data
.reset (nullptr);
8878 m_siginfo_gdbarch
= gdbarch
;
8879 m_siginfo_data
= std::move (siginfo_data
);
8883 /* Return a pointer to the stored register state. */
8885 readonly_detached_regcache
*registers () const
8887 return m_registers
.get ();
8890 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8892 void restore (struct gdbarch
*gdbarch
,
8893 struct thread_info
*tp
,
8894 struct regcache
*regcache
) const
8896 tp
->suspend
= m_thread_suspend
;
8898 if (m_siginfo_gdbarch
== gdbarch
)
8900 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8902 /* Errors ignored. */
8903 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8904 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8907 /* The inferior can be gone if the user types "print exit(0)"
8908 (and perhaps other times). */
8909 if (target_has_execution ())
8910 /* NB: The register write goes through to the target. */
8911 regcache
->restore (registers ());
8915 /* How the current thread stopped before the inferior function call was
8917 struct thread_suspend_state m_thread_suspend
;
8919 /* The registers before the inferior function call was executed. */
8920 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8922 /* Format of SIGINFO_DATA or NULL if it is not present. */
8923 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8925 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8926 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8927 content would be invalid. */
8928 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8931 infcall_suspend_state_up
8932 save_infcall_suspend_state ()
8934 struct thread_info
*tp
= inferior_thread ();
8935 struct regcache
*regcache
= get_current_regcache ();
8936 struct gdbarch
*gdbarch
= regcache
->arch ();
8938 infcall_suspend_state_up inf_state
8939 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8941 /* Having saved the current state, adjust the thread state, discarding
8942 any stop signal information. The stop signal is not useful when
8943 starting an inferior function call, and run_inferior_call will not use
8944 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8945 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8950 /* Restore inferior session state to INF_STATE. */
8953 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8955 struct thread_info
*tp
= inferior_thread ();
8956 struct regcache
*regcache
= get_current_regcache ();
8957 struct gdbarch
*gdbarch
= regcache
->arch ();
8959 inf_state
->restore (gdbarch
, tp
, regcache
);
8960 discard_infcall_suspend_state (inf_state
);
8964 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8969 readonly_detached_regcache
*
8970 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8972 return inf_state
->registers ();
8975 /* infcall_control_state contains state regarding gdb's control of the
8976 inferior itself like stepping control. It also contains session state like
8977 the user's currently selected frame. */
8979 struct infcall_control_state
8981 struct thread_control_state thread_control
;
8982 struct inferior_control_state inferior_control
;
8985 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8986 int stopped_by_random_signal
= 0;
8988 /* ID and level of the selected frame when the inferior function
8990 struct frame_id selected_frame_id
{};
8991 int selected_frame_level
= -1;
8994 /* Save all of the information associated with the inferior<==>gdb
8997 infcall_control_state_up
8998 save_infcall_control_state ()
9000 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9001 struct thread_info
*tp
= inferior_thread ();
9002 struct inferior
*inf
= current_inferior ();
9004 inf_status
->thread_control
= tp
->control
;
9005 inf_status
->inferior_control
= inf
->control
;
9007 tp
->control
.step_resume_breakpoint
= NULL
;
9008 tp
->control
.exception_resume_breakpoint
= NULL
;
9010 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9011 chain. If caller's caller is walking the chain, they'll be happier if we
9012 hand them back the original chain when restore_infcall_control_state is
9014 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9017 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9018 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9020 save_selected_frame (&inf_status
->selected_frame_id
,
9021 &inf_status
->selected_frame_level
);
9026 /* Restore inferior session state to INF_STATUS. */
9029 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9031 struct thread_info
*tp
= inferior_thread ();
9032 struct inferior
*inf
= current_inferior ();
9034 if (tp
->control
.step_resume_breakpoint
)
9035 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9037 if (tp
->control
.exception_resume_breakpoint
)
9038 tp
->control
.exception_resume_breakpoint
->disposition
9039 = disp_del_at_next_stop
;
9041 /* Handle the bpstat_copy of the chain. */
9042 bpstat_clear (&tp
->control
.stop_bpstat
);
9044 tp
->control
= inf_status
->thread_control
;
9045 inf
->control
= inf_status
->inferior_control
;
9048 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9049 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9051 if (target_has_stack ())
9053 restore_selected_frame (inf_status
->selected_frame_id
,
9054 inf_status
->selected_frame_level
);
9061 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9063 if (inf_status
->thread_control
.step_resume_breakpoint
)
9064 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9065 = disp_del_at_next_stop
;
9067 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9068 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9069 = disp_del_at_next_stop
;
9071 /* See save_infcall_control_state for info on stop_bpstat. */
9072 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9080 clear_exit_convenience_vars (void)
9082 clear_internalvar (lookup_internalvar ("_exitsignal"));
9083 clear_internalvar (lookup_internalvar ("_exitcode"));
9087 /* User interface for reverse debugging:
9088 Set exec-direction / show exec-direction commands
9089 (returns error unless target implements to_set_exec_direction method). */
9091 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9092 static const char exec_forward
[] = "forward";
9093 static const char exec_reverse
[] = "reverse";
9094 static const char *exec_direction
= exec_forward
;
9095 static const char *const exec_direction_names
[] = {
9102 set_exec_direction_func (const char *args
, int from_tty
,
9103 struct cmd_list_element
*cmd
)
9105 if (target_can_execute_reverse ())
9107 if (!strcmp (exec_direction
, exec_forward
))
9108 execution_direction
= EXEC_FORWARD
;
9109 else if (!strcmp (exec_direction
, exec_reverse
))
9110 execution_direction
= EXEC_REVERSE
;
9114 exec_direction
= exec_forward
;
9115 error (_("Target does not support this operation."));
9120 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9121 struct cmd_list_element
*cmd
, const char *value
)
9123 switch (execution_direction
) {
9125 fprintf_filtered (out
, _("Forward.\n"));
9128 fprintf_filtered (out
, _("Reverse.\n"));
9131 internal_error (__FILE__
, __LINE__
,
9132 _("bogus execution_direction value: %d"),
9133 (int) execution_direction
);
9138 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9139 struct cmd_list_element
*c
, const char *value
)
9141 fprintf_filtered (file
, _("Resuming the execution of threads "
9142 "of all processes is %s.\n"), value
);
9145 /* Implementation of `siginfo' variable. */
9147 static const struct internalvar_funcs siginfo_funcs
=
9154 /* Callback for infrun's target events source. This is marked when a
9155 thread has a pending status to process. */
9158 infrun_async_inferior_event_handler (gdb_client_data data
)
9160 inferior_event_handler (INF_REG_EVENT
);
9167 /* Verify that when two threads with the same ptid exist (from two different
9168 targets) and one of them changes ptid, we only update inferior_ptid if
9169 it is appropriate. */
9172 infrun_thread_ptid_changed ()
9174 gdbarch
*arch
= current_inferior ()->gdbarch
;
9176 /* The thread which inferior_ptid represents changes ptid. */
9178 scoped_restore_current_pspace_and_thread restore
;
9180 scoped_mock_context
<test_target_ops
> target1 (arch
);
9181 scoped_mock_context
<test_target_ops
> target2 (arch
);
9182 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9184 ptid_t
old_ptid (111, 222);
9185 ptid_t
new_ptid (111, 333);
9187 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9188 target1
.mock_thread
.ptid
= old_ptid
;
9189 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9190 target2
.mock_thread
.ptid
= old_ptid
;
9192 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9193 set_current_inferior (&target1
.mock_inferior
);
9195 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9197 gdb_assert (inferior_ptid
== new_ptid
);
9200 /* A thread with the same ptid as inferior_ptid, but from another target,
9203 scoped_restore_current_pspace_and_thread restore
;
9205 scoped_mock_context
<test_target_ops
> target1 (arch
);
9206 scoped_mock_context
<test_target_ops
> target2 (arch
);
9207 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9209 ptid_t
old_ptid (111, 222);
9210 ptid_t
new_ptid (111, 333);
9212 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9213 target1
.mock_thread
.ptid
= old_ptid
;
9214 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9215 target2
.mock_thread
.ptid
= old_ptid
;
9217 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9218 set_current_inferior (&target2
.mock_inferior
);
9220 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9222 gdb_assert (inferior_ptid
== old_ptid
);
9226 } /* namespace selftests */
9228 #endif /* GDB_SELF_TEST */
9230 void _initialize_infrun ();
9232 _initialize_infrun ()
9234 struct cmd_list_element
*c
;
9236 /* Register extra event sources in the event loop. */
9237 infrun_async_inferior_event_token
9238 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9241 add_info ("signals", info_signals_command
, _("\
9242 What debugger does when program gets various signals.\n\
9243 Specify a signal as argument to print info on that signal only."));
9244 add_info_alias ("handle", "signals", 0);
9246 c
= add_com ("handle", class_run
, handle_command
, _("\
9247 Specify how to handle signals.\n\
9248 Usage: handle SIGNAL [ACTIONS]\n\
9249 Args are signals and actions to apply to those signals.\n\
9250 If no actions are specified, the current settings for the specified signals\n\
9251 will be displayed instead.\n\
9253 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9254 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9255 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9256 The special arg \"all\" is recognized to mean all signals except those\n\
9257 used by the debugger, typically SIGTRAP and SIGINT.\n\
9259 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9260 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9261 Stop means reenter debugger if this signal happens (implies print).\n\
9262 Print means print a message if this signal happens.\n\
9263 Pass means let program see this signal; otherwise program doesn't know.\n\
9264 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9265 Pass and Stop may be combined.\n\
9267 Multiple signals may be specified. Signal numbers and signal names\n\
9268 may be interspersed with actions, with the actions being performed for\n\
9269 all signals cumulatively specified."));
9270 set_cmd_completer (c
, handle_completer
);
9273 stop_command
= add_cmd ("stop", class_obscure
,
9274 not_just_help_class_command
, _("\
9275 There is no `stop' command, but you can set a hook on `stop'.\n\
9276 This allows you to set a list of commands to be run each time execution\n\
9277 of the program stops."), &cmdlist
);
9279 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9280 Set inferior debugging."), _("\
9281 Show inferior debugging."), _("\
9282 When non-zero, inferior specific debugging is enabled."),
9285 &setdebuglist
, &showdebuglist
);
9287 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9288 &debug_displaced
, _("\
9289 Set displaced stepping debugging."), _("\
9290 Show displaced stepping debugging."), _("\
9291 When non-zero, displaced stepping specific debugging is enabled."),
9293 show_debug_displaced
,
9294 &setdebuglist
, &showdebuglist
);
9296 add_setshow_boolean_cmd ("non-stop", no_class
,
9298 Set whether gdb controls the inferior in non-stop mode."), _("\
9299 Show whether gdb controls the inferior in non-stop mode."), _("\
9300 When debugging a multi-threaded program and this setting is\n\
9301 off (the default, also called all-stop mode), when one thread stops\n\
9302 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9303 all other threads in the program while you interact with the thread of\n\
9304 interest. When you continue or step a thread, you can allow the other\n\
9305 threads to run, or have them remain stopped, but while you inspect any\n\
9306 thread's state, all threads stop.\n\
9308 In non-stop mode, when one thread stops, other threads can continue\n\
9309 to run freely. You'll be able to step each thread independently,\n\
9310 leave it stopped or free to run as needed."),
9316 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9319 signal_print
[i
] = 1;
9320 signal_program
[i
] = 1;
9321 signal_catch
[i
] = 0;
9324 /* Signals caused by debugger's own actions should not be given to
9325 the program afterwards.
9327 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9328 explicitly specifies that it should be delivered to the target
9329 program. Typically, that would occur when a user is debugging a
9330 target monitor on a simulator: the target monitor sets a
9331 breakpoint; the simulator encounters this breakpoint and halts
9332 the simulation handing control to GDB; GDB, noting that the stop
9333 address doesn't map to any known breakpoint, returns control back
9334 to the simulator; the simulator then delivers the hardware
9335 equivalent of a GDB_SIGNAL_TRAP to the program being
9337 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9338 signal_program
[GDB_SIGNAL_INT
] = 0;
9340 /* Signals that are not errors should not normally enter the debugger. */
9341 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9342 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9343 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9344 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9345 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9346 signal_print
[GDB_SIGNAL_PROF
] = 0;
9347 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9348 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9349 signal_stop
[GDB_SIGNAL_IO
] = 0;
9350 signal_print
[GDB_SIGNAL_IO
] = 0;
9351 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9352 signal_print
[GDB_SIGNAL_POLL
] = 0;
9353 signal_stop
[GDB_SIGNAL_URG
] = 0;
9354 signal_print
[GDB_SIGNAL_URG
] = 0;
9355 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9356 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9357 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9358 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9360 /* These signals are used internally by user-level thread
9361 implementations. (See signal(5) on Solaris.) Like the above
9362 signals, a healthy program receives and handles them as part of
9363 its normal operation. */
9364 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9365 signal_print
[GDB_SIGNAL_LWP
] = 0;
9366 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9367 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9368 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9369 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9370 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9371 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9373 /* Update cached state. */
9374 signal_cache_update (-1);
9376 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9377 &stop_on_solib_events
, _("\
9378 Set stopping for shared library events."), _("\
9379 Show stopping for shared library events."), _("\
9380 If nonzero, gdb will give control to the user when the dynamic linker\n\
9381 notifies gdb of shared library events. The most common event of interest\n\
9382 to the user would be loading/unloading of a new library."),
9383 set_stop_on_solib_events
,
9384 show_stop_on_solib_events
,
9385 &setlist
, &showlist
);
9387 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9388 follow_fork_mode_kind_names
,
9389 &follow_fork_mode_string
, _("\
9390 Set debugger response to a program call of fork or vfork."), _("\
9391 Show debugger response to a program call of fork or vfork."), _("\
9392 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9393 parent - the original process is debugged after a fork\n\
9394 child - the new process is debugged after a fork\n\
9395 The unfollowed process will continue to run.\n\
9396 By default, the debugger will follow the parent process."),
9398 show_follow_fork_mode_string
,
9399 &setlist
, &showlist
);
9401 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9402 follow_exec_mode_names
,
9403 &follow_exec_mode_string
, _("\
9404 Set debugger response to a program call of exec."), _("\
9405 Show debugger response to a program call of exec."), _("\
9406 An exec call replaces the program image of a process.\n\
9408 follow-exec-mode can be:\n\
9410 new - the debugger creates a new inferior and rebinds the process\n\
9411 to this new inferior. The program the process was running before\n\
9412 the exec call can be restarted afterwards by restarting the original\n\
9415 same - the debugger keeps the process bound to the same inferior.\n\
9416 The new executable image replaces the previous executable loaded in\n\
9417 the inferior. Restarting the inferior after the exec call restarts\n\
9418 the executable the process was running after the exec call.\n\
9420 By default, the debugger will use the same inferior."),
9422 show_follow_exec_mode_string
,
9423 &setlist
, &showlist
);
9425 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9426 scheduler_enums
, &scheduler_mode
, _("\
9427 Set mode for locking scheduler during execution."), _("\
9428 Show mode for locking scheduler during execution."), _("\
9429 off == no locking (threads may preempt at any time)\n\
9430 on == full locking (no thread except the current thread may run)\n\
9431 This applies to both normal execution and replay mode.\n\
9432 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9433 In this mode, other threads may run during other commands.\n\
9434 This applies to both normal execution and replay mode.\n\
9435 replay == scheduler locked in replay mode and unlocked during normal execution."),
9436 set_schedlock_func
, /* traps on target vector */
9437 show_scheduler_mode
,
9438 &setlist
, &showlist
);
9440 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9441 Set mode for resuming threads of all processes."), _("\
9442 Show mode for resuming threads of all processes."), _("\
9443 When on, execution commands (such as 'continue' or 'next') resume all\n\
9444 threads of all processes. When off (which is the default), execution\n\
9445 commands only resume the threads of the current process. The set of\n\
9446 threads that are resumed is further refined by the scheduler-locking\n\
9447 mode (see help set scheduler-locking)."),
9449 show_schedule_multiple
,
9450 &setlist
, &showlist
);
9452 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9453 Set mode of the step operation."), _("\
9454 Show mode of the step operation."), _("\
9455 When set, doing a step over a function without debug line information\n\
9456 will stop at the first instruction of that function. Otherwise, the\n\
9457 function is skipped and the step command stops at a different source line."),
9459 show_step_stop_if_no_debug
,
9460 &setlist
, &showlist
);
9462 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9463 &can_use_displaced_stepping
, _("\
9464 Set debugger's willingness to use displaced stepping."), _("\
9465 Show debugger's willingness to use displaced stepping."), _("\
9466 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9467 supported by the target architecture. If off, gdb will not use displaced\n\
9468 stepping to step over breakpoints, even if such is supported by the target\n\
9469 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9470 if the target architecture supports it and non-stop mode is active, but will not\n\
9471 use it in all-stop mode (see help set non-stop)."),
9473 show_can_use_displaced_stepping
,
9474 &setlist
, &showlist
);
9476 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9477 &exec_direction
, _("Set direction of execution.\n\
9478 Options are 'forward' or 'reverse'."),
9479 _("Show direction of execution (forward/reverse)."),
9480 _("Tells gdb whether to execute forward or backward."),
9481 set_exec_direction_func
, show_exec_direction_func
,
9482 &setlist
, &showlist
);
9484 /* Set/show detach-on-fork: user-settable mode. */
9486 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9487 Set whether gdb will detach the child of a fork."), _("\
9488 Show whether gdb will detach the child of a fork."), _("\
9489 Tells gdb whether to detach the child of a fork."),
9490 NULL
, NULL
, &setlist
, &showlist
);
9492 /* Set/show disable address space randomization mode. */
9494 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9495 &disable_randomization
, _("\
9496 Set disabling of debuggee's virtual address space randomization."), _("\
9497 Show disabling of debuggee's virtual address space randomization."), _("\
9498 When this mode is on (which is the default), randomization of the virtual\n\
9499 address space is disabled. Standalone programs run with the randomization\n\
9500 enabled by default on some platforms."),
9501 &set_disable_randomization
,
9502 &show_disable_randomization
,
9503 &setlist
, &showlist
);
9505 /* ptid initializations */
9506 inferior_ptid
= null_ptid
;
9507 target_last_wait_ptid
= minus_one_ptid
;
9509 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9510 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9511 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9512 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9513 gdb::observers::inferior_execd
.attach (infrun_inferior_execd
);
9515 /* Explicitly create without lookup, since that tries to create a
9516 value with a void typed value, and when we get here, gdbarch
9517 isn't initialized yet. At this point, we're quite sure there
9518 isn't another convenience variable of the same name. */
9519 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9521 add_setshow_boolean_cmd ("observer", no_class
,
9522 &observer_mode_1
, _("\
9523 Set whether gdb controls the inferior in observer mode."), _("\
9524 Show whether gdb controls the inferior in observer mode."), _("\
9525 In observer mode, GDB can get data from the inferior, but not\n\
9526 affect its execution. Registers and memory may not be changed,\n\
9527 breakpoints may not be set, and the program cannot be interrupted\n\
9535 selftests::register_test ("infrun_thread_ptid_changed",
9536 selftests::infrun_thread_ptid_changed
);