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_debug_printf_1 (const char *func_name
, const char *fmt
, ...)
112 debug_prefixed_vprintf ("infrun", func_name
, fmt
, ap
);
119 infrun_async (int enable
)
121 if (infrun_is_async
!= enable
)
123 infrun_is_async
= enable
;
125 infrun_debug_printf ("enable=%d", enable
);
128 mark_async_event_handler (infrun_async_inferior_event_token
);
130 clear_async_event_handler (infrun_async_inferior_event_token
);
137 mark_infrun_async_event_handler (void)
139 mark_async_event_handler (infrun_async_inferior_event_token
);
142 /* When set, stop the 'step' command if we enter a function which has
143 no line number information. The normal behavior is that we step
144 over such function. */
145 bool step_stop_if_no_debug
= false;
147 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
148 struct cmd_list_element
*c
, const char *value
)
150 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
153 /* proceed and normal_stop use this to notify the user when the
154 inferior stopped in a different thread than it had been running
157 static ptid_t previous_inferior_ptid
;
159 /* If set (default for legacy reasons), when following a fork, GDB
160 will detach from one of the fork branches, child or parent.
161 Exactly which branch is detached depends on 'set follow-fork-mode'
164 static bool detach_fork
= true;
166 bool debug_displaced
= false;
168 show_debug_displaced (struct ui_file
*file
, int from_tty
,
169 struct cmd_list_element
*c
, const char *value
)
171 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
174 unsigned int debug_infrun
= 0;
176 show_debug_infrun (struct ui_file
*file
, int from_tty
,
177 struct cmd_list_element
*c
, const char *value
)
179 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
185 displaced_debug_printf_1 (const char *func_name
, const char *fmt
, ...)
189 debug_prefixed_vprintf ("displaced", func_name
, fmt
, ap
);
193 /* Support for disabling address space randomization. */
195 bool disable_randomization
= true;
198 show_disable_randomization (struct ui_file
*file
, int from_tty
,
199 struct cmd_list_element
*c
, const char *value
)
201 if (target_supports_disable_randomization ())
202 fprintf_filtered (file
,
203 _("Disabling randomization of debuggee's "
204 "virtual address space is %s.\n"),
207 fputs_filtered (_("Disabling randomization of debuggee's "
208 "virtual address space is unsupported on\n"
209 "this platform.\n"), file
);
213 set_disable_randomization (const char *args
, int from_tty
,
214 struct cmd_list_element
*c
)
216 if (!target_supports_disable_randomization ())
217 error (_("Disabling randomization of debuggee's "
218 "virtual address space is unsupported on\n"
222 /* User interface for non-stop mode. */
224 bool non_stop
= false;
225 static bool non_stop_1
= false;
228 set_non_stop (const char *args
, int from_tty
,
229 struct cmd_list_element
*c
)
231 if (target_has_execution ())
233 non_stop_1
= non_stop
;
234 error (_("Cannot change this setting while the inferior is running."));
237 non_stop
= non_stop_1
;
241 show_non_stop (struct ui_file
*file
, int from_tty
,
242 struct cmd_list_element
*c
, const char *value
)
244 fprintf_filtered (file
,
245 _("Controlling the inferior in non-stop mode is %s.\n"),
249 /* "Observer mode" is somewhat like a more extreme version of
250 non-stop, in which all GDB operations that might affect the
251 target's execution have been disabled. */
253 bool observer_mode
= false;
254 static bool observer_mode_1
= false;
257 set_observer_mode (const char *args
, int from_tty
,
258 struct cmd_list_element
*c
)
260 if (target_has_execution ())
262 observer_mode_1
= observer_mode
;
263 error (_("Cannot change this setting while the inferior is running."));
266 observer_mode
= observer_mode_1
;
268 may_write_registers
= !observer_mode
;
269 may_write_memory
= !observer_mode
;
270 may_insert_breakpoints
= !observer_mode
;
271 may_insert_tracepoints
= !observer_mode
;
272 /* We can insert fast tracepoints in or out of observer mode,
273 but enable them if we're going into this mode. */
275 may_insert_fast_tracepoints
= true;
276 may_stop
= !observer_mode
;
277 update_target_permissions ();
279 /* Going *into* observer mode we must force non-stop, then
280 going out we leave it that way. */
283 pagination_enabled
= 0;
284 non_stop
= non_stop_1
= true;
288 printf_filtered (_("Observer mode is now %s.\n"),
289 (observer_mode
? "on" : "off"));
293 show_observer_mode (struct ui_file
*file
, int from_tty
,
294 struct cmd_list_element
*c
, const char *value
)
296 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
299 /* This updates the value of observer mode based on changes in
300 permissions. Note that we are deliberately ignoring the values of
301 may-write-registers and may-write-memory, since the user may have
302 reason to enable these during a session, for instance to turn on a
303 debugging-related global. */
306 update_observer_mode (void)
308 bool newval
= (!may_insert_breakpoints
309 && !may_insert_tracepoints
310 && may_insert_fast_tracepoints
314 /* Let the user know if things change. */
315 if (newval
!= observer_mode
)
316 printf_filtered (_("Observer mode is now %s.\n"),
317 (newval
? "on" : "off"));
319 observer_mode
= observer_mode_1
= newval
;
322 /* Tables of how to react to signals; the user sets them. */
324 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
325 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
326 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
328 /* Table of signals that are registered with "catch signal". A
329 non-zero entry indicates that the signal is caught by some "catch
331 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
333 /* Table of signals that the target may silently handle.
334 This is automatically determined from the flags above,
335 and simply cached here. */
336 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
338 #define SET_SIGS(nsigs,sigs,flags) \
340 int signum = (nsigs); \
341 while (signum-- > 0) \
342 if ((sigs)[signum]) \
343 (flags)[signum] = 1; \
346 #define UNSET_SIGS(nsigs,sigs,flags) \
348 int signum = (nsigs); \
349 while (signum-- > 0) \
350 if ((sigs)[signum]) \
351 (flags)[signum] = 0; \
354 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
355 this function is to avoid exporting `signal_program'. */
358 update_signals_program_target (void)
360 target_program_signals (signal_program
);
363 /* Value to pass to target_resume() to cause all threads to resume. */
365 #define RESUME_ALL minus_one_ptid
367 /* Command list pointer for the "stop" placeholder. */
369 static struct cmd_list_element
*stop_command
;
371 /* Nonzero if we want to give control to the user when we're notified
372 of shared library events by the dynamic linker. */
373 int stop_on_solib_events
;
375 /* Enable or disable optional shared library event breakpoints
376 as appropriate when the above flag is changed. */
379 set_stop_on_solib_events (const char *args
,
380 int from_tty
, struct cmd_list_element
*c
)
382 update_solib_breakpoints ();
386 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
387 struct cmd_list_element
*c
, const char *value
)
389 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
393 /* True after stop if current stack frame should be printed. */
395 static bool stop_print_frame
;
397 /* This is a cached copy of the target/ptid/waitstatus of the last
398 event returned by target_wait()/deprecated_target_wait_hook().
399 This information is returned by get_last_target_status(). */
400 static process_stratum_target
*target_last_proc_target
;
401 static ptid_t target_last_wait_ptid
;
402 static struct target_waitstatus target_last_waitstatus
;
404 void init_thread_stepping_state (struct thread_info
*tss
);
406 static const char follow_fork_mode_child
[] = "child";
407 static const char follow_fork_mode_parent
[] = "parent";
409 static const char *const follow_fork_mode_kind_names
[] = {
410 follow_fork_mode_child
,
411 follow_fork_mode_parent
,
415 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
417 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
418 struct cmd_list_element
*c
, const char *value
)
420 fprintf_filtered (file
,
421 _("Debugger response to a program "
422 "call of fork or vfork is \"%s\".\n"),
427 /* Handle changes to the inferior list based on the type of fork,
428 which process is being followed, and whether the other process
429 should be detached. On entry inferior_ptid must be the ptid of
430 the fork parent. At return inferior_ptid is the ptid of the
431 followed inferior. */
434 follow_fork_inferior (bool follow_child
, bool detach_fork
)
437 ptid_t parent_ptid
, child_ptid
;
439 has_vforked
= (inferior_thread ()->pending_follow
.kind
440 == TARGET_WAITKIND_VFORKED
);
441 parent_ptid
= inferior_ptid
;
442 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
445 && !non_stop
/* Non-stop always resumes both branches. */
446 && current_ui
->prompt_state
== PROMPT_BLOCKED
447 && !(follow_child
|| detach_fork
|| sched_multi
))
449 /* The parent stays blocked inside the vfork syscall until the
450 child execs or exits. If we don't let the child run, then
451 the parent stays blocked. If we're telling the parent to run
452 in the foreground, the user will not be able to ctrl-c to get
453 back the terminal, effectively hanging the debug session. */
454 fprintf_filtered (gdb_stderr
, _("\
455 Can not resume the parent process over vfork in the foreground while\n\
456 holding the child stopped. Try \"set detach-on-fork\" or \
457 \"set schedule-multiple\".\n"));
463 /* Detach new forked process? */
466 /* Before detaching from the child, remove all breakpoints
467 from it. If we forked, then this has already been taken
468 care of by infrun.c. If we vforked however, any
469 breakpoint inserted in the parent is visible in the
470 child, even those added while stopped in a vfork
471 catchpoint. This will remove the breakpoints from the
472 parent also, but they'll be reinserted below. */
475 /* Keep breakpoints list in sync. */
476 remove_breakpoints_inf (current_inferior ());
479 if (print_inferior_events
)
481 /* Ensure that we have a process ptid. */
482 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
484 target_terminal::ours_for_output ();
485 fprintf_filtered (gdb_stdlog
,
486 _("[Detaching after %s from child %s]\n"),
487 has_vforked
? "vfork" : "fork",
488 target_pid_to_str (process_ptid
).c_str ());
493 struct inferior
*parent_inf
, *child_inf
;
495 /* Add process to GDB's tables. */
496 child_inf
= add_inferior (child_ptid
.pid ());
498 parent_inf
= current_inferior ();
499 child_inf
->attach_flag
= parent_inf
->attach_flag
;
500 copy_terminal_info (child_inf
, parent_inf
);
501 child_inf
->gdbarch
= parent_inf
->gdbarch
;
502 copy_inferior_target_desc_info (child_inf
, parent_inf
);
504 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
506 set_current_inferior (child_inf
);
507 switch_to_no_thread ();
508 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
509 push_target (parent_inf
->process_target ());
510 thread_info
*child_thr
511 = add_thread_silent (child_inf
->process_target (), child_ptid
);
513 /* If this is a vfork child, then the address-space is
514 shared with the parent. */
517 child_inf
->pspace
= parent_inf
->pspace
;
518 child_inf
->aspace
= parent_inf
->aspace
;
522 /* The parent will be frozen until the child is done
523 with the shared region. Keep track of the
525 child_inf
->vfork_parent
= parent_inf
;
526 child_inf
->pending_detach
= 0;
527 parent_inf
->vfork_child
= child_inf
;
528 parent_inf
->pending_detach
= 0;
530 /* Now that the inferiors and program spaces are all
531 wired up, we can switch to the child thread (which
532 switches inferior and program space too). */
533 switch_to_thread (child_thr
);
537 child_inf
->aspace
= new_address_space ();
538 child_inf
->pspace
= new program_space (child_inf
->aspace
);
539 child_inf
->removable
= 1;
540 set_current_program_space (child_inf
->pspace
);
541 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
543 /* solib_create_inferior_hook relies on the current
545 switch_to_thread (child_thr
);
547 /* Let the shared library layer (e.g., solib-svr4) learn
548 about this new process, relocate the cloned exec, pull
549 in shared libraries, and install the solib event
550 breakpoint. If a "cloned-VM" event was propagated
551 better throughout the core, this wouldn't be
553 solib_create_inferior_hook (0);
559 struct inferior
*parent_inf
;
561 parent_inf
= current_inferior ();
563 /* If we detached from the child, then we have to be careful
564 to not insert breakpoints in the parent until the child
565 is done with the shared memory region. However, if we're
566 staying attached to the child, then we can and should
567 insert breakpoints, so that we can debug it. A
568 subsequent child exec or exit is enough to know when does
569 the child stops using the parent's address space. */
570 parent_inf
->waiting_for_vfork_done
= detach_fork
;
571 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
576 /* Follow the child. */
577 struct inferior
*parent_inf
, *child_inf
;
578 struct program_space
*parent_pspace
;
580 if (print_inferior_events
)
582 std::string parent_pid
= target_pid_to_str (parent_ptid
);
583 std::string child_pid
= target_pid_to_str (child_ptid
);
585 target_terminal::ours_for_output ();
586 fprintf_filtered (gdb_stdlog
,
587 _("[Attaching after %s %s to child %s]\n"),
589 has_vforked
? "vfork" : "fork",
593 /* Add the new inferior first, so that the target_detach below
594 doesn't unpush the target. */
596 child_inf
= add_inferior (child_ptid
.pid ());
598 parent_inf
= current_inferior ();
599 child_inf
->attach_flag
= parent_inf
->attach_flag
;
600 copy_terminal_info (child_inf
, parent_inf
);
601 child_inf
->gdbarch
= parent_inf
->gdbarch
;
602 copy_inferior_target_desc_info (child_inf
, parent_inf
);
604 parent_pspace
= parent_inf
->pspace
;
606 process_stratum_target
*target
= parent_inf
->process_target ();
609 /* Hold a strong reference to the target while (maybe)
610 detaching the parent. Otherwise detaching could close the
612 auto target_ref
= target_ops_ref::new_reference (target
);
614 /* If we're vforking, we want to hold on to the parent until
615 the child exits or execs. At child exec or exit time we
616 can remove the old breakpoints from the parent and detach
617 or resume debugging it. Otherwise, detach the parent now;
618 we'll want to reuse it's program/address spaces, but we
619 can't set them to the child before removing breakpoints
620 from the parent, otherwise, the breakpoints module could
621 decide to remove breakpoints from the wrong process (since
622 they'd be assigned to the same address space). */
626 gdb_assert (child_inf
->vfork_parent
== NULL
);
627 gdb_assert (parent_inf
->vfork_child
== NULL
);
628 child_inf
->vfork_parent
= parent_inf
;
629 child_inf
->pending_detach
= 0;
630 parent_inf
->vfork_child
= child_inf
;
631 parent_inf
->pending_detach
= detach_fork
;
632 parent_inf
->waiting_for_vfork_done
= 0;
634 else if (detach_fork
)
636 if (print_inferior_events
)
638 /* Ensure that we have a process ptid. */
639 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
641 target_terminal::ours_for_output ();
642 fprintf_filtered (gdb_stdlog
,
643 _("[Detaching after fork from "
645 target_pid_to_str (process_ptid
).c_str ());
648 target_detach (parent_inf
, 0);
652 /* Note that the detach above makes PARENT_INF dangling. */
654 /* Add the child thread to the appropriate lists, and switch
655 to this new thread, before cloning the program space, and
656 informing the solib layer about this new process. */
658 set_current_inferior (child_inf
);
659 push_target (target
);
662 thread_info
*child_thr
= add_thread_silent (target
, child_ptid
);
664 /* If this is a vfork child, then the address-space is shared
665 with the parent. If we detached from the parent, then we can
666 reuse the parent's program/address spaces. */
667 if (has_vforked
|| detach_fork
)
669 child_inf
->pspace
= parent_pspace
;
670 child_inf
->aspace
= child_inf
->pspace
->aspace
;
676 child_inf
->aspace
= new_address_space ();
677 child_inf
->pspace
= new program_space (child_inf
->aspace
);
678 child_inf
->removable
= 1;
679 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
680 set_current_program_space (child_inf
->pspace
);
681 clone_program_space (child_inf
->pspace
, parent_pspace
);
683 /* Let the shared library layer (e.g., solib-svr4) learn
684 about this new process, relocate the cloned exec, pull in
685 shared libraries, and install the solib event breakpoint.
686 If a "cloned-VM" event was propagated better throughout
687 the core, this wouldn't be required. */
688 solib_create_inferior_hook (0);
691 switch_to_thread (child_thr
);
694 return target_follow_fork (follow_child
, detach_fork
);
697 /* Tell the target to follow the fork we're stopped at. Returns true
698 if the inferior should be resumed; false, if the target for some
699 reason decided it's best not to resume. */
704 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
705 bool should_resume
= true;
706 struct thread_info
*tp
;
708 /* Copy user stepping state to the new inferior thread. FIXME: the
709 followed fork child thread should have a copy of most of the
710 parent thread structure's run control related fields, not just these.
711 Initialized to avoid "may be used uninitialized" warnings from gcc. */
712 struct breakpoint
*step_resume_breakpoint
= NULL
;
713 struct breakpoint
*exception_resume_breakpoint
= NULL
;
714 CORE_ADDR step_range_start
= 0;
715 CORE_ADDR step_range_end
= 0;
716 int current_line
= 0;
717 symtab
*current_symtab
= NULL
;
718 struct frame_id step_frame_id
= { 0 };
719 struct thread_fsm
*thread_fsm
= NULL
;
723 process_stratum_target
*wait_target
;
725 struct target_waitstatus wait_status
;
727 /* Get the last target status returned by target_wait(). */
728 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
730 /* If not stopped at a fork event, then there's nothing else to
732 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
733 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
736 /* Check if we switched over from WAIT_PTID, since the event was
738 if (wait_ptid
!= minus_one_ptid
739 && (current_inferior ()->process_target () != wait_target
740 || inferior_ptid
!= wait_ptid
))
742 /* We did. Switch back to WAIT_PTID thread, to tell the
743 target to follow it (in either direction). We'll
744 afterwards refuse to resume, and inform the user what
746 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
747 switch_to_thread (wait_thread
);
748 should_resume
= false;
752 tp
= inferior_thread ();
754 /* If there were any forks/vforks that were caught and are now to be
755 followed, then do so now. */
756 switch (tp
->pending_follow
.kind
)
758 case TARGET_WAITKIND_FORKED
:
759 case TARGET_WAITKIND_VFORKED
:
761 ptid_t parent
, child
;
763 /* If the user did a next/step, etc, over a fork call,
764 preserve the stepping state in the fork child. */
765 if (follow_child
&& should_resume
)
767 step_resume_breakpoint
= clone_momentary_breakpoint
768 (tp
->control
.step_resume_breakpoint
);
769 step_range_start
= tp
->control
.step_range_start
;
770 step_range_end
= tp
->control
.step_range_end
;
771 current_line
= tp
->current_line
;
772 current_symtab
= tp
->current_symtab
;
773 step_frame_id
= tp
->control
.step_frame_id
;
774 exception_resume_breakpoint
775 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
776 thread_fsm
= tp
->thread_fsm
;
778 /* For now, delete the parent's sr breakpoint, otherwise,
779 parent/child sr breakpoints are considered duplicates,
780 and the child version will not be installed. Remove
781 this when the breakpoints module becomes aware of
782 inferiors and address spaces. */
783 delete_step_resume_breakpoint (tp
);
784 tp
->control
.step_range_start
= 0;
785 tp
->control
.step_range_end
= 0;
786 tp
->control
.step_frame_id
= null_frame_id
;
787 delete_exception_resume_breakpoint (tp
);
788 tp
->thread_fsm
= NULL
;
791 parent
= inferior_ptid
;
792 child
= tp
->pending_follow
.value
.related_pid
;
794 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
795 /* Set up inferior(s) as specified by the caller, and tell the
796 target to do whatever is necessary to follow either parent
798 if (follow_fork_inferior (follow_child
, detach_fork
))
800 /* Target refused to follow, or there's some other reason
801 we shouldn't resume. */
806 /* This pending follow fork event is now handled, one way
807 or another. The previous selected thread may be gone
808 from the lists by now, but if it is still around, need
809 to clear the pending follow request. */
810 tp
= find_thread_ptid (parent_targ
, parent
);
812 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
814 /* This makes sure we don't try to apply the "Switched
815 over from WAIT_PID" logic above. */
816 nullify_last_target_wait_ptid ();
818 /* If we followed the child, switch to it... */
821 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
822 switch_to_thread (child_thr
);
824 /* ... and preserve the stepping state, in case the
825 user was stepping over the fork call. */
828 tp
= inferior_thread ();
829 tp
->control
.step_resume_breakpoint
830 = step_resume_breakpoint
;
831 tp
->control
.step_range_start
= step_range_start
;
832 tp
->control
.step_range_end
= step_range_end
;
833 tp
->current_line
= current_line
;
834 tp
->current_symtab
= current_symtab
;
835 tp
->control
.step_frame_id
= step_frame_id
;
836 tp
->control
.exception_resume_breakpoint
837 = exception_resume_breakpoint
;
838 tp
->thread_fsm
= thread_fsm
;
842 /* If we get here, it was because we're trying to
843 resume from a fork catchpoint, but, the user
844 has switched threads away from the thread that
845 forked. In that case, the resume command
846 issued is most likely not applicable to the
847 child, so just warn, and refuse to resume. */
848 warning (_("Not resuming: switched threads "
849 "before following fork child."));
852 /* Reset breakpoints in the child as appropriate. */
853 follow_inferior_reset_breakpoints ();
858 case TARGET_WAITKIND_SPURIOUS
:
859 /* Nothing to follow. */
862 internal_error (__FILE__
, __LINE__
,
863 "Unexpected pending_follow.kind %d\n",
864 tp
->pending_follow
.kind
);
868 return should_resume
;
872 follow_inferior_reset_breakpoints (void)
874 struct thread_info
*tp
= inferior_thread ();
876 /* Was there a step_resume breakpoint? (There was if the user
877 did a "next" at the fork() call.) If so, explicitly reset its
878 thread number. Cloned step_resume breakpoints are disabled on
879 creation, so enable it here now that it is associated with the
882 step_resumes are a form of bp that are made to be per-thread.
883 Since we created the step_resume bp when the parent process
884 was being debugged, and now are switching to the child process,
885 from the breakpoint package's viewpoint, that's a switch of
886 "threads". We must update the bp's notion of which thread
887 it is for, or it'll be ignored when it triggers. */
889 if (tp
->control
.step_resume_breakpoint
)
891 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
892 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
895 /* Treat exception_resume breakpoints like step_resume breakpoints. */
896 if (tp
->control
.exception_resume_breakpoint
)
898 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
899 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
902 /* Reinsert all breakpoints in the child. The user may have set
903 breakpoints after catching the fork, in which case those
904 were never set in the child, but only in the parent. This makes
905 sure the inserted breakpoints match the breakpoint list. */
907 breakpoint_re_set ();
908 insert_breakpoints ();
911 /* The child has exited or execed: resume threads of the parent the
912 user wanted to be executing. */
915 proceed_after_vfork_done (struct thread_info
*thread
,
918 int pid
= * (int *) arg
;
920 if (thread
->ptid
.pid () == pid
921 && thread
->state
== THREAD_RUNNING
922 && !thread
->executing
923 && !thread
->stop_requested
924 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
926 infrun_debug_printf ("resuming vfork parent thread %s",
927 target_pid_to_str (thread
->ptid
).c_str ());
929 switch_to_thread (thread
);
930 clear_proceed_status (0);
931 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
937 /* Called whenever we notice an exec or exit event, to handle
938 detaching or resuming a vfork parent. */
941 handle_vfork_child_exec_or_exit (int exec
)
943 struct inferior
*inf
= current_inferior ();
945 if (inf
->vfork_parent
)
947 int resume_parent
= -1;
949 /* This exec or exit marks the end of the shared memory region
950 between the parent and the child. Break the bonds. */
951 inferior
*vfork_parent
= inf
->vfork_parent
;
952 inf
->vfork_parent
->vfork_child
= NULL
;
953 inf
->vfork_parent
= NULL
;
955 /* If the user wanted to detach from the parent, now is the
957 if (vfork_parent
->pending_detach
)
959 struct program_space
*pspace
;
960 struct address_space
*aspace
;
962 /* follow-fork child, detach-on-fork on. */
964 vfork_parent
->pending_detach
= 0;
966 scoped_restore_current_pspace_and_thread restore_thread
;
968 /* We're letting loose of the parent. */
969 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
970 switch_to_thread (tp
);
972 /* We're about to detach from the parent, which implicitly
973 removes breakpoints from its address space. There's a
974 catch here: we want to reuse the spaces for the child,
975 but, parent/child are still sharing the pspace at this
976 point, although the exec in reality makes the kernel give
977 the child a fresh set of new pages. The problem here is
978 that the breakpoints module being unaware of this, would
979 likely chose the child process to write to the parent
980 address space. Swapping the child temporarily away from
981 the spaces has the desired effect. Yes, this is "sort
984 pspace
= inf
->pspace
;
985 aspace
= inf
->aspace
;
989 if (print_inferior_events
)
992 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
994 target_terminal::ours_for_output ();
998 fprintf_filtered (gdb_stdlog
,
999 _("[Detaching vfork parent %s "
1000 "after child exec]\n"), pidstr
.c_str ());
1004 fprintf_filtered (gdb_stdlog
,
1005 _("[Detaching vfork parent %s "
1006 "after child exit]\n"), pidstr
.c_str ());
1010 target_detach (vfork_parent
, 0);
1013 inf
->pspace
= pspace
;
1014 inf
->aspace
= aspace
;
1018 /* We're staying attached to the parent, so, really give the
1019 child a new address space. */
1020 inf
->pspace
= new program_space (maybe_new_address_space ());
1021 inf
->aspace
= inf
->pspace
->aspace
;
1023 set_current_program_space (inf
->pspace
);
1025 resume_parent
= vfork_parent
->pid
;
1029 /* If this is a vfork child exiting, then the pspace and
1030 aspaces were shared with the parent. Since we're
1031 reporting the process exit, we'll be mourning all that is
1032 found in the address space, and switching to null_ptid,
1033 preparing to start a new inferior. But, since we don't
1034 want to clobber the parent's address/program spaces, we
1035 go ahead and create a new one for this exiting
1038 /* Switch to no-thread while running clone_program_space, so
1039 that clone_program_space doesn't want to read the
1040 selected frame of a dead process. */
1041 scoped_restore_current_thread restore_thread
;
1042 switch_to_no_thread ();
1044 inf
->pspace
= new program_space (maybe_new_address_space ());
1045 inf
->aspace
= inf
->pspace
->aspace
;
1046 set_current_program_space (inf
->pspace
);
1048 inf
->symfile_flags
= SYMFILE_NO_READ
;
1049 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1051 resume_parent
= vfork_parent
->pid
;
1054 gdb_assert (current_program_space
== inf
->pspace
);
1056 if (non_stop
&& resume_parent
!= -1)
1058 /* If the user wanted the parent to be running, let it go
1060 scoped_restore_current_thread restore_thread
;
1062 infrun_debug_printf ("resuming vfork parent process %d",
1065 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1070 /* Enum strings for "set|show follow-exec-mode". */
1072 static const char follow_exec_mode_new
[] = "new";
1073 static const char follow_exec_mode_same
[] = "same";
1074 static const char *const follow_exec_mode_names
[] =
1076 follow_exec_mode_new
,
1077 follow_exec_mode_same
,
1081 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1083 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1084 struct cmd_list_element
*c
, const char *value
)
1086 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1089 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1092 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1094 struct inferior
*inf
= current_inferior ();
1095 int pid
= ptid
.pid ();
1096 ptid_t process_ptid
;
1098 /* Switch terminal for any messages produced e.g. by
1099 breakpoint_re_set. */
1100 target_terminal::ours_for_output ();
1102 /* This is an exec event that we actually wish to pay attention to.
1103 Refresh our symbol table to the newly exec'd program, remove any
1104 momentary bp's, etc.
1106 If there are breakpoints, they aren't really inserted now,
1107 since the exec() transformed our inferior into a fresh set
1110 We want to preserve symbolic breakpoints on the list, since
1111 we have hopes that they can be reset after the new a.out's
1112 symbol table is read.
1114 However, any "raw" breakpoints must be removed from the list
1115 (e.g., the solib bp's), since their address is probably invalid
1118 And, we DON'T want to call delete_breakpoints() here, since
1119 that may write the bp's "shadow contents" (the instruction
1120 value that was overwritten with a TRAP instruction). Since
1121 we now have a new a.out, those shadow contents aren't valid. */
1123 mark_breakpoints_out ();
1125 /* The target reports the exec event to the main thread, even if
1126 some other thread does the exec, and even if the main thread was
1127 stopped or already gone. We may still have non-leader threads of
1128 the process on our list. E.g., on targets that don't have thread
1129 exit events (like remote); or on native Linux in non-stop mode if
1130 there were only two threads in the inferior and the non-leader
1131 one is the one that execs (and nothing forces an update of the
1132 thread list up to here). When debugging remotely, it's best to
1133 avoid extra traffic, when possible, so avoid syncing the thread
1134 list with the target, and instead go ahead and delete all threads
1135 of the process but one that reported the event. Note this must
1136 be done before calling update_breakpoints_after_exec, as
1137 otherwise clearing the threads' resources would reference stale
1138 thread breakpoints -- it may have been one of these threads that
1139 stepped across the exec. We could just clear their stepping
1140 states, but as long as we're iterating, might as well delete
1141 them. Deleting them now rather than at the next user-visible
1142 stop provides a nicer sequence of events for user and MI
1144 for (thread_info
*th
: all_threads_safe ())
1145 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1148 /* We also need to clear any left over stale state for the
1149 leader/event thread. E.g., if there was any step-resume
1150 breakpoint or similar, it's gone now. We cannot truly
1151 step-to-next statement through an exec(). */
1152 thread_info
*th
= inferior_thread ();
1153 th
->control
.step_resume_breakpoint
= NULL
;
1154 th
->control
.exception_resume_breakpoint
= NULL
;
1155 th
->control
.single_step_breakpoints
= NULL
;
1156 th
->control
.step_range_start
= 0;
1157 th
->control
.step_range_end
= 0;
1159 /* The user may have had the main thread held stopped in the
1160 previous image (e.g., schedlock on, or non-stop). Release
1162 th
->stop_requested
= 0;
1164 update_breakpoints_after_exec ();
1166 /* What is this a.out's name? */
1167 process_ptid
= ptid_t (pid
);
1168 printf_unfiltered (_("%s is executing new program: %s\n"),
1169 target_pid_to_str (process_ptid
).c_str (),
1172 /* We've followed the inferior through an exec. Therefore, the
1173 inferior has essentially been killed & reborn. */
1175 breakpoint_init_inferior (inf_execd
);
1177 gdb::unique_xmalloc_ptr
<char> exec_file_host
1178 = exec_file_find (exec_file_target
, NULL
);
1180 /* If we were unable to map the executable target pathname onto a host
1181 pathname, tell the user that. Otherwise GDB's subsequent behavior
1182 is confusing. Maybe it would even be better to stop at this point
1183 so that the user can specify a file manually before continuing. */
1184 if (exec_file_host
== NULL
)
1185 warning (_("Could not load symbols for executable %s.\n"
1186 "Do you need \"set sysroot\"?"),
1189 /* Reset the shared library package. This ensures that we get a
1190 shlib event when the child reaches "_start", at which point the
1191 dld will have had a chance to initialize the child. */
1192 /* Also, loading a symbol file below may trigger symbol lookups, and
1193 we don't want those to be satisfied by the libraries of the
1194 previous incarnation of this process. */
1195 no_shared_libraries (NULL
, 0);
1197 if (follow_exec_mode_string
== follow_exec_mode_new
)
1199 /* The user wants to keep the old inferior and program spaces
1200 around. Create a new fresh one, and switch to it. */
1202 /* Do exit processing for the original inferior before setting the new
1203 inferior's pid. Having two inferiors with the same pid would confuse
1204 find_inferior_p(t)id. Transfer the terminal state and info from the
1205 old to the new inferior. */
1206 inf
= add_inferior_with_spaces ();
1207 swap_terminal_info (inf
, current_inferior ());
1208 exit_inferior_silent (current_inferior ());
1211 target_follow_exec (inf
, exec_file_target
);
1213 inferior
*org_inferior
= current_inferior ();
1214 switch_to_inferior_no_thread (inf
);
1215 push_target (org_inferior
->process_target ());
1216 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1217 switch_to_thread (thr
);
1221 /* The old description may no longer be fit for the new image.
1222 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1223 old description; we'll read a new one below. No need to do
1224 this on "follow-exec-mode new", as the old inferior stays
1225 around (its description is later cleared/refetched on
1227 target_clear_description ();
1230 gdb_assert (current_program_space
== inf
->pspace
);
1232 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1233 because the proper displacement for a PIE (Position Independent
1234 Executable) main symbol file will only be computed by
1235 solib_create_inferior_hook below. breakpoint_re_set would fail
1236 to insert the breakpoints with the zero displacement. */
1237 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1239 /* If the target can specify a description, read it. Must do this
1240 after flipping to the new executable (because the target supplied
1241 description must be compatible with the executable's
1242 architecture, and the old executable may e.g., be 32-bit, while
1243 the new one 64-bit), and before anything involving memory or
1245 target_find_description ();
1247 solib_create_inferior_hook (0);
1249 jit_inferior_created_hook (inf
);
1251 breakpoint_re_set ();
1253 /* Reinsert all breakpoints. (Those which were symbolic have
1254 been reset to the proper address in the new a.out, thanks
1255 to symbol_file_command...). */
1256 insert_breakpoints ();
1258 /* The next resume of this inferior should bring it to the shlib
1259 startup breakpoints. (If the user had also set bp's on
1260 "main" from the old (parent) process, then they'll auto-
1261 matically get reset there in the new process.). */
1264 /* The queue of threads that need to do a step-over operation to get
1265 past e.g., a breakpoint. What technique is used to step over the
1266 breakpoint/watchpoint does not matter -- all threads end up in the
1267 same queue, to maintain rough temporal order of execution, in order
1268 to avoid starvation, otherwise, we could e.g., find ourselves
1269 constantly stepping the same couple threads past their breakpoints
1270 over and over, if the single-step finish fast enough. */
1271 struct thread_info
*step_over_queue_head
;
1273 /* Bit flags indicating what the thread needs to step over. */
1275 enum step_over_what_flag
1277 /* Step over a breakpoint. */
1278 STEP_OVER_BREAKPOINT
= 1,
1280 /* Step past a non-continuable watchpoint, in order to let the
1281 instruction execute so we can evaluate the watchpoint
1283 STEP_OVER_WATCHPOINT
= 2
1285 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1287 /* Info about an instruction that is being stepped over. */
1289 struct step_over_info
1291 /* If we're stepping past a breakpoint, this is the address space
1292 and address of the instruction the breakpoint is set at. We'll
1293 skip inserting all breakpoints here. Valid iff ASPACE is
1295 const address_space
*aspace
;
1298 /* The instruction being stepped over triggers a nonsteppable
1299 watchpoint. If true, we'll skip inserting watchpoints. */
1300 int nonsteppable_watchpoint_p
;
1302 /* The thread's global number. */
1306 /* The step-over info of the location that is being stepped over.
1308 Note that with async/breakpoint always-inserted mode, a user might
1309 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1310 being stepped over. As setting a new breakpoint inserts all
1311 breakpoints, we need to make sure the breakpoint being stepped over
1312 isn't inserted then. We do that by only clearing the step-over
1313 info when the step-over is actually finished (or aborted).
1315 Presently GDB can only step over one breakpoint at any given time.
1316 Given threads that can't run code in the same address space as the
1317 breakpoint's can't really miss the breakpoint, GDB could be taught
1318 to step-over at most one breakpoint per address space (so this info
1319 could move to the address space object if/when GDB is extended).
1320 The set of breakpoints being stepped over will normally be much
1321 smaller than the set of all breakpoints, so a flag in the
1322 breakpoint location structure would be wasteful. A separate list
1323 also saves complexity and run-time, as otherwise we'd have to go
1324 through all breakpoint locations clearing their flag whenever we
1325 start a new sequence. Similar considerations weigh against storing
1326 this info in the thread object. Plus, not all step overs actually
1327 have breakpoint locations -- e.g., stepping past a single-step
1328 breakpoint, or stepping to complete a non-continuable
1330 static struct step_over_info step_over_info
;
1332 /* Record the address of the breakpoint/instruction we're currently
1334 N.B. We record the aspace and address now, instead of say just the thread,
1335 because when we need the info later the thread may be running. */
1338 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1339 int nonsteppable_watchpoint_p
,
1342 step_over_info
.aspace
= aspace
;
1343 step_over_info
.address
= address
;
1344 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1345 step_over_info
.thread
= thread
;
1348 /* Called when we're not longer stepping over a breakpoint / an
1349 instruction, so all breakpoints are free to be (re)inserted. */
1352 clear_step_over_info (void)
1354 infrun_debug_printf ("clearing step over info");
1355 step_over_info
.aspace
= NULL
;
1356 step_over_info
.address
= 0;
1357 step_over_info
.nonsteppable_watchpoint_p
= 0;
1358 step_over_info
.thread
= -1;
1364 stepping_past_instruction_at (struct address_space
*aspace
,
1367 return (step_over_info
.aspace
!= NULL
1368 && breakpoint_address_match (aspace
, address
,
1369 step_over_info
.aspace
,
1370 step_over_info
.address
));
1376 thread_is_stepping_over_breakpoint (int thread
)
1378 return (step_over_info
.thread
!= -1
1379 && thread
== step_over_info
.thread
);
1385 stepping_past_nonsteppable_watchpoint (void)
1387 return step_over_info
.nonsteppable_watchpoint_p
;
1390 /* Returns true if step-over info is valid. */
1393 step_over_info_valid_p (void)
1395 return (step_over_info
.aspace
!= NULL
1396 || stepping_past_nonsteppable_watchpoint ());
1400 /* Displaced stepping. */
1402 /* In non-stop debugging mode, we must take special care to manage
1403 breakpoints properly; in particular, the traditional strategy for
1404 stepping a thread past a breakpoint it has hit is unsuitable.
1405 'Displaced stepping' is a tactic for stepping one thread past a
1406 breakpoint it has hit while ensuring that other threads running
1407 concurrently will hit the breakpoint as they should.
1409 The traditional way to step a thread T off a breakpoint in a
1410 multi-threaded program in all-stop mode is as follows:
1412 a0) Initially, all threads are stopped, and breakpoints are not
1414 a1) We single-step T, leaving breakpoints uninserted.
1415 a2) We insert breakpoints, and resume all threads.
1417 In non-stop debugging, however, this strategy is unsuitable: we
1418 don't want to have to stop all threads in the system in order to
1419 continue or step T past a breakpoint. Instead, we use displaced
1422 n0) Initially, T is stopped, other threads are running, and
1423 breakpoints are inserted.
1424 n1) We copy the instruction "under" the breakpoint to a separate
1425 location, outside the main code stream, making any adjustments
1426 to the instruction, register, and memory state as directed by
1428 n2) We single-step T over the instruction at its new location.
1429 n3) We adjust the resulting register and memory state as directed
1430 by T's architecture. This includes resetting T's PC to point
1431 back into the main instruction stream.
1434 This approach depends on the following gdbarch methods:
1436 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1437 indicate where to copy the instruction, and how much space must
1438 be reserved there. We use these in step n1.
1440 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1441 address, and makes any necessary adjustments to the instruction,
1442 register contents, and memory. We use this in step n1.
1444 - gdbarch_displaced_step_fixup adjusts registers and memory after
1445 we have successfully single-stepped the instruction, to yield the
1446 same effect the instruction would have had if we had executed it
1447 at its original address. We use this in step n3.
1449 The gdbarch_displaced_step_copy_insn and
1450 gdbarch_displaced_step_fixup functions must be written so that
1451 copying an instruction with gdbarch_displaced_step_copy_insn,
1452 single-stepping across the copied instruction, and then applying
1453 gdbarch_displaced_insn_fixup should have the same effects on the
1454 thread's memory and registers as stepping the instruction in place
1455 would have. Exactly which responsibilities fall to the copy and
1456 which fall to the fixup is up to the author of those functions.
1458 See the comments in gdbarch.sh for details.
1460 Note that displaced stepping and software single-step cannot
1461 currently be used in combination, although with some care I think
1462 they could be made to. Software single-step works by placing
1463 breakpoints on all possible subsequent instructions; if the
1464 displaced instruction is a PC-relative jump, those breakpoints
1465 could fall in very strange places --- on pages that aren't
1466 executable, or at addresses that are not proper instruction
1467 boundaries. (We do generally let other threads run while we wait
1468 to hit the software single-step breakpoint, and they might
1469 encounter such a corrupted instruction.) One way to work around
1470 this would be to have gdbarch_displaced_step_copy_insn fully
1471 simulate the effect of PC-relative instructions (and return NULL)
1472 on architectures that use software single-stepping.
1474 In non-stop mode, we can have independent and simultaneous step
1475 requests, so more than one thread may need to simultaneously step
1476 over a breakpoint. The current implementation assumes there is
1477 only one scratch space per process. In this case, we have to
1478 serialize access to the scratch space. If thread A wants to step
1479 over a breakpoint, but we are currently waiting for some other
1480 thread to complete a displaced step, we leave thread A stopped and
1481 place it in the displaced_step_request_queue. Whenever a displaced
1482 step finishes, we pick the next thread in the queue and start a new
1483 displaced step operation on it. See displaced_step_prepare and
1484 displaced_step_fixup for details. */
1486 /* Default destructor for displaced_step_closure. */
1488 displaced_step_closure::~displaced_step_closure () = default;
1490 /* Get the displaced stepping state of inferior INF. */
1492 static displaced_step_inferior_state
*
1493 get_displaced_stepping_state (inferior
*inf
)
1495 return &inf
->displaced_step_state
;
1498 /* Returns true if any inferior has a thread doing a displaced
1502 displaced_step_in_progress_any_inferior ()
1504 for (inferior
*i
: all_inferiors ())
1506 if (i
->displaced_step_state
.step_thread
!= nullptr)
1513 /* Return true if THREAD is doing a displaced step. */
1516 displaced_step_in_progress_thread (thread_info
*thread
)
1518 gdb_assert (thread
!= NULL
);
1520 return get_displaced_stepping_state (thread
->inf
)->step_thread
== thread
;
1523 /* Return true if INF has a thread doing a displaced step. */
1526 displaced_step_in_progress (inferior
*inf
)
1528 return get_displaced_stepping_state (inf
)->step_thread
!= nullptr;
1531 /* If inferior is in displaced stepping, and ADDR equals to starting address
1532 of copy area, return corresponding displaced_step_closure. Otherwise,
1535 struct displaced_step_closure
*
1536 get_displaced_step_closure_by_addr (CORE_ADDR addr
)
1538 displaced_step_inferior_state
*displaced
1539 = get_displaced_stepping_state (current_inferior ());
1541 /* If checking the mode of displaced instruction in copy area. */
1542 if (displaced
->step_thread
!= nullptr
1543 && displaced
->step_copy
== addr
)
1544 return displaced
->step_closure
.get ();
1550 infrun_inferior_exit (struct inferior
*inf
)
1552 inf
->displaced_step_state
.reset ();
1555 /* If ON, and the architecture supports it, GDB will use displaced
1556 stepping to step over breakpoints. If OFF, or if the architecture
1557 doesn't support it, GDB will instead use the traditional
1558 hold-and-step approach. If AUTO (which is the default), GDB will
1559 decide which technique to use to step over breakpoints depending on
1560 whether the target works in a non-stop way (see use_displaced_stepping). */
1562 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1565 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1566 struct cmd_list_element
*c
,
1569 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1570 fprintf_filtered (file
,
1571 _("Debugger's willingness to use displaced stepping "
1572 "to step over breakpoints is %s (currently %s).\n"),
1573 value
, target_is_non_stop_p () ? "on" : "off");
1575 fprintf_filtered (file
,
1576 _("Debugger's willingness to use displaced stepping "
1577 "to step over breakpoints is %s.\n"), value
);
1580 /* Return true if the gdbarch implements the required methods to use
1581 displaced stepping. */
1584 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1586 /* Only check for the presence of step_copy_insn. Other required methods
1587 are checked by the gdbarch validation. */
1588 return gdbarch_displaced_step_copy_insn_p (arch
);
1591 /* Return non-zero if displaced stepping can/should be used to step
1592 over breakpoints of thread TP. */
1595 use_displaced_stepping (thread_info
*tp
)
1597 /* If the user disabled it explicitly, don't use displaced stepping. */
1598 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1601 /* If "auto", only use displaced stepping if the target operates in a non-stop
1603 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1604 && !target_is_non_stop_p ())
1607 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1609 /* If the architecture doesn't implement displaced stepping, don't use
1611 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1614 /* If recording, don't use displaced stepping. */
1615 if (find_record_target () != nullptr)
1618 displaced_step_inferior_state
*displaced_state
1619 = get_displaced_stepping_state (tp
->inf
);
1621 /* If displaced stepping failed before for this inferior, don't bother trying
1623 if (displaced_state
->failed_before
)
1629 /* Simple function wrapper around displaced_step_inferior_state::reset. */
1632 displaced_step_reset (displaced_step_inferior_state
*displaced
)
1634 displaced
->reset ();
1637 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1638 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1640 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1645 displaced_step_dump_bytes (const gdb_byte
*buf
, size_t len
)
1649 for (size_t i
= 0; i
< len
; i
++)
1652 ret
+= string_printf ("%02x", buf
[i
]);
1654 ret
+= string_printf (" %02x", buf
[i
]);
1660 /* Prepare to single-step, using displaced stepping.
1662 Note that we cannot use displaced stepping when we have a signal to
1663 deliver. If we have a signal to deliver and an instruction to step
1664 over, then after the step, there will be no indication from the
1665 target whether the thread entered a signal handler or ignored the
1666 signal and stepped over the instruction successfully --- both cases
1667 result in a simple SIGTRAP. In the first case we mustn't do a
1668 fixup, and in the second case we must --- but we can't tell which.
1669 Comments in the code for 'random signals' in handle_inferior_event
1670 explain how we handle this case instead.
1672 Returns 1 if preparing was successful -- this thread is going to be
1673 stepped now; 0 if displaced stepping this thread got queued; or -1
1674 if this instruction can't be displaced stepped. */
1677 displaced_step_prepare_throw (thread_info
*tp
)
1679 regcache
*regcache
= get_thread_regcache (tp
);
1680 struct gdbarch
*gdbarch
= regcache
->arch ();
1681 const address_space
*aspace
= regcache
->aspace ();
1682 CORE_ADDR original
, copy
;
1686 /* We should never reach this function if the architecture does not
1687 support displaced stepping. */
1688 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1690 /* Nor if the thread isn't meant to step over a breakpoint. */
1691 gdb_assert (tp
->control
.trap_expected
);
1693 /* Disable range stepping while executing in the scratch pad. We
1694 want a single-step even if executing the displaced instruction in
1695 the scratch buffer lands within the stepping range (e.g., a
1697 tp
->control
.may_range_step
= 0;
1699 /* We have to displaced step one thread at a time, as we only have
1700 access to a single scratch space per inferior. */
1702 displaced_step_inferior_state
*displaced
1703 = get_displaced_stepping_state (tp
->inf
);
1705 if (displaced
->step_thread
!= nullptr)
1707 /* Already waiting for a displaced step to finish. Defer this
1708 request and place in queue. */
1710 displaced_debug_printf ("deferring step of %s",
1711 target_pid_to_str (tp
->ptid
).c_str ());
1713 thread_step_over_chain_enqueue (tp
);
1717 displaced_debug_printf ("stepping %s now",
1718 target_pid_to_str (tp
->ptid
).c_str ());
1720 displaced_step_reset (displaced
);
1722 scoped_restore_current_thread restore_thread
;
1724 switch_to_thread (tp
);
1726 original
= regcache_read_pc (regcache
);
1728 copy
= gdbarch_displaced_step_location (gdbarch
);
1729 len
= gdbarch_max_insn_length (gdbarch
);
1731 if (breakpoint_in_range_p (aspace
, copy
, len
))
1733 /* There's a breakpoint set in the scratch pad location range
1734 (which is usually around the entry point). We'd either
1735 install it before resuming, which would overwrite/corrupt the
1736 scratch pad, or if it was already inserted, this displaced
1737 step would overwrite it. The latter is OK in the sense that
1738 we already assume that no thread is going to execute the code
1739 in the scratch pad range (after initial startup) anyway, but
1740 the former is unacceptable. Simply punt and fallback to
1741 stepping over this breakpoint in-line. */
1742 displaced_debug_printf ("breakpoint set in scratch pad. "
1743 "Stepping over breakpoint in-line instead.");
1748 /* Save the original contents of the copy area. */
1749 displaced
->step_saved_copy
.resize (len
);
1750 status
= target_read_memory (copy
, displaced
->step_saved_copy
.data (), len
);
1752 throw_error (MEMORY_ERROR
,
1753 _("Error accessing memory address %s (%s) for "
1754 "displaced-stepping scratch space."),
1755 paddress (gdbarch
, copy
), safe_strerror (status
));
1757 displaced_debug_printf ("saved %s: %s",
1758 paddress (gdbarch
, copy
),
1759 displaced_step_dump_bytes
1760 (displaced
->step_saved_copy
.data (), len
).c_str ());
1762 displaced
->step_closure
1763 = gdbarch_displaced_step_copy_insn (gdbarch
, original
, copy
, regcache
);
1764 if (displaced
->step_closure
== NULL
)
1766 /* The architecture doesn't know how or want to displaced step
1767 this instruction or instruction sequence. Fallback to
1768 stepping over the breakpoint in-line. */
1772 /* Save the information we need to fix things up if the step
1774 displaced
->step_thread
= tp
;
1775 displaced
->step_gdbarch
= gdbarch
;
1776 displaced
->step_original
= original
;
1777 displaced
->step_copy
= copy
;
1780 displaced_step_reset_cleanup
cleanup (displaced
);
1782 /* Resume execution at the copy. */
1783 regcache_write_pc (regcache
, copy
);
1788 displaced_debug_printf ("displaced pc to %s", paddress (gdbarch
, copy
));
1793 /* Wrapper for displaced_step_prepare_throw that disabled further
1794 attempts at displaced stepping if we get a memory error. */
1797 displaced_step_prepare (thread_info
*thread
)
1803 prepared
= displaced_step_prepare_throw (thread
);
1805 catch (const gdb_exception_error
&ex
)
1807 struct displaced_step_inferior_state
*displaced_state
;
1809 if (ex
.error
!= MEMORY_ERROR
1810 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1813 infrun_debug_printf ("caught exception, disabling displaced stepping: %s",
1816 /* Be verbose if "set displaced-stepping" is "on", silent if
1818 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1820 warning (_("disabling displaced stepping: %s"),
1824 /* Disable further displaced stepping attempts. */
1826 = get_displaced_stepping_state (thread
->inf
);
1827 displaced_state
->failed_before
= 1;
1834 write_memory_ptid (ptid_t ptid
, CORE_ADDR memaddr
,
1835 const gdb_byte
*myaddr
, int len
)
1837 scoped_restore save_inferior_ptid
= make_scoped_restore (&inferior_ptid
);
1839 inferior_ptid
= ptid
;
1840 write_memory (memaddr
, myaddr
, len
);
1843 /* Restore the contents of the copy area for thread PTID. */
1846 displaced_step_restore (struct displaced_step_inferior_state
*displaced
,
1849 ULONGEST len
= gdbarch_max_insn_length (displaced
->step_gdbarch
);
1851 write_memory_ptid (ptid
, displaced
->step_copy
,
1852 displaced
->step_saved_copy
.data (), len
);
1854 displaced_debug_printf ("restored %s %s",
1855 target_pid_to_str (ptid
).c_str (),
1856 paddress (displaced
->step_gdbarch
,
1857 displaced
->step_copy
));
1860 /* If we displaced stepped an instruction successfully, adjust
1861 registers and memory to yield the same effect the instruction would
1862 have had if we had executed it at its original address, and return
1863 1. If the instruction didn't complete, relocate the PC and return
1864 -1. If the thread wasn't displaced stepping, return 0. */
1867 displaced_step_fixup (thread_info
*event_thread
, enum gdb_signal signal
)
1869 struct displaced_step_inferior_state
*displaced
1870 = get_displaced_stepping_state (event_thread
->inf
);
1873 /* Was this event for the thread we displaced? */
1874 if (displaced
->step_thread
!= event_thread
)
1877 /* Fixup may need to read memory/registers. Switch to the thread
1878 that we're fixing up. Also, target_stopped_by_watchpoint checks
1879 the current thread, and displaced_step_restore performs ptid-dependent
1880 memory accesses using current_inferior() and current_top_target(). */
1881 switch_to_thread (event_thread
);
1883 displaced_step_reset_cleanup
cleanup (displaced
);
1885 displaced_step_restore (displaced
, displaced
->step_thread
->ptid
);
1887 /* Did the instruction complete successfully? */
1888 if (signal
== GDB_SIGNAL_TRAP
1889 && !(target_stopped_by_watchpoint ()
1890 && (gdbarch_have_nonsteppable_watchpoint (displaced
->step_gdbarch
)
1891 || target_have_steppable_watchpoint ())))
1893 /* Fix up the resulting state. */
1894 gdbarch_displaced_step_fixup (displaced
->step_gdbarch
,
1895 displaced
->step_closure
.get (),
1896 displaced
->step_original
,
1897 displaced
->step_copy
,
1898 get_thread_regcache (displaced
->step_thread
));
1903 /* Since the instruction didn't complete, all we can do is
1905 struct regcache
*regcache
= get_thread_regcache (event_thread
);
1906 CORE_ADDR pc
= regcache_read_pc (regcache
);
1908 pc
= displaced
->step_original
+ (pc
- displaced
->step_copy
);
1909 regcache_write_pc (regcache
, pc
);
1916 /* Data to be passed around while handling an event. This data is
1917 discarded between events. */
1918 struct execution_control_state
1920 process_stratum_target
*target
;
1922 /* The thread that got the event, if this was a thread event; NULL
1924 struct thread_info
*event_thread
;
1926 struct target_waitstatus ws
;
1927 int stop_func_filled_in
;
1928 CORE_ADDR stop_func_start
;
1929 CORE_ADDR stop_func_end
;
1930 const char *stop_func_name
;
1933 /* True if the event thread hit the single-step breakpoint of
1934 another thread. Thus the event doesn't cause a stop, the thread
1935 needs to be single-stepped past the single-step breakpoint before
1936 we can switch back to the original stepping thread. */
1937 int hit_singlestep_breakpoint
;
1940 /* Clear ECS and set it to point at TP. */
1943 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1945 memset (ecs
, 0, sizeof (*ecs
));
1946 ecs
->event_thread
= tp
;
1947 ecs
->ptid
= tp
->ptid
;
1950 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1951 static void prepare_to_wait (struct execution_control_state
*ecs
);
1952 static bool keep_going_stepped_thread (struct thread_info
*tp
);
1953 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1955 /* Are there any pending step-over requests? If so, run all we can
1956 now and return true. Otherwise, return false. */
1959 start_step_over (void)
1961 struct thread_info
*tp
, *next
;
1963 /* Don't start a new step-over if we already have an in-line
1964 step-over operation ongoing. */
1965 if (step_over_info_valid_p ())
1968 for (tp
= step_over_queue_head
; tp
!= NULL
; tp
= next
)
1970 struct execution_control_state ecss
;
1971 struct execution_control_state
*ecs
= &ecss
;
1972 step_over_what step_what
;
1973 int must_be_in_line
;
1975 gdb_assert (!tp
->stop_requested
);
1977 next
= thread_step_over_chain_next (tp
);
1979 /* If this inferior already has a displaced step in process,
1980 don't start a new one. */
1981 if (displaced_step_in_progress (tp
->inf
))
1984 step_what
= thread_still_needs_step_over (tp
);
1985 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1986 || ((step_what
& STEP_OVER_BREAKPOINT
)
1987 && !use_displaced_stepping (tp
)));
1989 /* We currently stop all threads of all processes to step-over
1990 in-line. If we need to start a new in-line step-over, let
1991 any pending displaced steps finish first. */
1992 if (must_be_in_line
&& displaced_step_in_progress_any_inferior ())
1995 thread_step_over_chain_remove (tp
);
1997 if (step_over_queue_head
== NULL
)
1998 infrun_debug_printf ("step-over queue now empty");
2000 if (tp
->control
.trap_expected
2004 internal_error (__FILE__
, __LINE__
,
2005 "[%s] has inconsistent state: "
2006 "trap_expected=%d, resumed=%d, executing=%d\n",
2007 target_pid_to_str (tp
->ptid
).c_str (),
2008 tp
->control
.trap_expected
,
2013 infrun_debug_printf ("resuming [%s] for step-over",
2014 target_pid_to_str (tp
->ptid
).c_str ());
2016 /* keep_going_pass_signal skips the step-over if the breakpoint
2017 is no longer inserted. In all-stop, we want to keep looking
2018 for a thread that needs a step-over instead of resuming TP,
2019 because we wouldn't be able to resume anything else until the
2020 target stops again. In non-stop, the resume always resumes
2021 only TP, so it's OK to let the thread resume freely. */
2022 if (!target_is_non_stop_p () && !step_what
)
2025 switch_to_thread (tp
);
2026 reset_ecs (ecs
, tp
);
2027 keep_going_pass_signal (ecs
);
2029 if (!ecs
->wait_some_more
)
2030 error (_("Command aborted."));
2032 gdb_assert (tp
->resumed
);
2034 /* If we started a new in-line step-over, we're done. */
2035 if (step_over_info_valid_p ())
2037 gdb_assert (tp
->control
.trap_expected
);
2041 if (!target_is_non_stop_p ())
2043 /* On all-stop, shouldn't have resumed unless we needed a
2045 gdb_assert (tp
->control
.trap_expected
2046 || tp
->step_after_step_resume_breakpoint
);
2048 /* With remote targets (at least), in all-stop, we can't
2049 issue any further remote commands until the program stops
2054 /* Either the thread no longer needed a step-over, or a new
2055 displaced stepping sequence started. Even in the latter
2056 case, continue looking. Maybe we can also start another
2057 displaced step on a thread of other process. */
2063 /* Update global variables holding ptids to hold NEW_PTID if they were
2064 holding OLD_PTID. */
2066 infrun_thread_ptid_changed (process_stratum_target
*target
,
2067 ptid_t old_ptid
, ptid_t new_ptid
)
2069 if (inferior_ptid
== old_ptid
2070 && current_inferior ()->process_target () == target
)
2071 inferior_ptid
= new_ptid
;
2076 static const char schedlock_off
[] = "off";
2077 static const char schedlock_on
[] = "on";
2078 static const char schedlock_step
[] = "step";
2079 static const char schedlock_replay
[] = "replay";
2080 static const char *const scheduler_enums
[] = {
2087 static const char *scheduler_mode
= schedlock_replay
;
2089 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2090 struct cmd_list_element
*c
, const char *value
)
2092 fprintf_filtered (file
,
2093 _("Mode for locking scheduler "
2094 "during execution is \"%s\".\n"),
2099 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2101 if (!target_can_lock_scheduler ())
2103 scheduler_mode
= schedlock_off
;
2104 error (_("Target '%s' cannot support this command."), target_shortname
);
2108 /* True if execution commands resume all threads of all processes by
2109 default; otherwise, resume only threads of the current inferior
2111 bool sched_multi
= false;
2113 /* Try to setup for software single stepping over the specified location.
2114 Return true if target_resume() should use hardware single step.
2116 GDBARCH the current gdbarch.
2117 PC the location to step over. */
2120 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2122 bool hw_step
= true;
2124 if (execution_direction
== EXEC_FORWARD
2125 && gdbarch_software_single_step_p (gdbarch
))
2126 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2134 user_visible_resume_ptid (int step
)
2140 /* With non-stop mode on, threads are always handled
2142 resume_ptid
= inferior_ptid
;
2144 else if ((scheduler_mode
== schedlock_on
)
2145 || (scheduler_mode
== schedlock_step
&& step
))
2147 /* User-settable 'scheduler' mode requires solo thread
2149 resume_ptid
= inferior_ptid
;
2151 else if ((scheduler_mode
== schedlock_replay
)
2152 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2154 /* User-settable 'scheduler' mode requires solo thread resume in replay
2156 resume_ptid
= inferior_ptid
;
2158 else if (!sched_multi
&& target_supports_multi_process ())
2160 /* Resume all threads of the current process (and none of other
2162 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2166 /* Resume all threads of all processes. */
2167 resume_ptid
= RESUME_ALL
;
2175 process_stratum_target
*
2176 user_visible_resume_target (ptid_t resume_ptid
)
2178 return (resume_ptid
== minus_one_ptid
&& sched_multi
2180 : current_inferior ()->process_target ());
2183 /* Return a ptid representing the set of threads that we will resume,
2184 in the perspective of the target, assuming run control handling
2185 does not require leaving some threads stopped (e.g., stepping past
2186 breakpoint). USER_STEP indicates whether we're about to start the
2187 target for a stepping command. */
2190 internal_resume_ptid (int user_step
)
2192 /* In non-stop, we always control threads individually. Note that
2193 the target may always work in non-stop mode even with "set
2194 non-stop off", in which case user_visible_resume_ptid could
2195 return a wildcard ptid. */
2196 if (target_is_non_stop_p ())
2197 return inferior_ptid
;
2199 return user_visible_resume_ptid (user_step
);
2202 /* Wrapper for target_resume, that handles infrun-specific
2206 do_target_resume (ptid_t resume_ptid
, bool step
, enum gdb_signal sig
)
2208 struct thread_info
*tp
= inferior_thread ();
2210 gdb_assert (!tp
->stop_requested
);
2212 /* Install inferior's terminal modes. */
2213 target_terminal::inferior ();
2215 /* Avoid confusing the next resume, if the next stop/resume
2216 happens to apply to another thread. */
2217 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2219 /* Advise target which signals may be handled silently.
2221 If we have removed breakpoints because we are stepping over one
2222 in-line (in any thread), we need to receive all signals to avoid
2223 accidentally skipping a breakpoint during execution of a signal
2226 Likewise if we're displaced stepping, otherwise a trap for a
2227 breakpoint in a signal handler might be confused with the
2228 displaced step finishing. We don't make the displaced_step_fixup
2229 step distinguish the cases instead, because:
2231 - a backtrace while stopped in the signal handler would show the
2232 scratch pad as frame older than the signal handler, instead of
2233 the real mainline code.
2235 - when the thread is later resumed, the signal handler would
2236 return to the scratch pad area, which would no longer be
2238 if (step_over_info_valid_p ()
2239 || displaced_step_in_progress (tp
->inf
))
2240 target_pass_signals ({});
2242 target_pass_signals (signal_pass
);
2244 target_resume (resume_ptid
, step
, sig
);
2246 target_commit_resume ();
2248 if (target_can_async_p ())
2252 /* Resume the inferior. SIG is the signal to give the inferior
2253 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2254 call 'resume', which handles exceptions. */
2257 resume_1 (enum gdb_signal sig
)
2259 struct regcache
*regcache
= get_current_regcache ();
2260 struct gdbarch
*gdbarch
= regcache
->arch ();
2261 struct thread_info
*tp
= inferior_thread ();
2262 const address_space
*aspace
= regcache
->aspace ();
2264 /* This represents the user's step vs continue request. When
2265 deciding whether "set scheduler-locking step" applies, it's the
2266 user's intention that counts. */
2267 const int user_step
= tp
->control
.stepping_command
;
2268 /* This represents what we'll actually request the target to do.
2269 This can decay from a step to a continue, if e.g., we need to
2270 implement single-stepping with breakpoints (software
2274 gdb_assert (!tp
->stop_requested
);
2275 gdb_assert (!thread_is_in_step_over_chain (tp
));
2277 if (tp
->suspend
.waitstatus_pending_p
)
2280 ("thread %s has pending wait "
2281 "status %s (currently_stepping=%d).",
2282 target_pid_to_str (tp
->ptid
).c_str (),
2283 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2284 currently_stepping (tp
));
2286 tp
->inf
->process_target ()->threads_executing
= true;
2289 /* FIXME: What should we do if we are supposed to resume this
2290 thread with a signal? Maybe we should maintain a queue of
2291 pending signals to deliver. */
2292 if (sig
!= GDB_SIGNAL_0
)
2294 warning (_("Couldn't deliver signal %s to %s."),
2295 gdb_signal_to_name (sig
),
2296 target_pid_to_str (tp
->ptid
).c_str ());
2299 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2301 if (target_can_async_p ())
2304 /* Tell the event loop we have an event to process. */
2305 mark_async_event_handler (infrun_async_inferior_event_token
);
2310 tp
->stepped_breakpoint
= 0;
2312 /* Depends on stepped_breakpoint. */
2313 step
= currently_stepping (tp
);
2315 if (current_inferior ()->waiting_for_vfork_done
)
2317 /* Don't try to single-step a vfork parent that is waiting for
2318 the child to get out of the shared memory region (by exec'ing
2319 or exiting). This is particularly important on software
2320 single-step archs, as the child process would trip on the
2321 software single step breakpoint inserted for the parent
2322 process. Since the parent will not actually execute any
2323 instruction until the child is out of the shared region (such
2324 are vfork's semantics), it is safe to simply continue it.
2325 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2326 the parent, and tell it to `keep_going', which automatically
2327 re-sets it stepping. */
2328 infrun_debug_printf ("resume : clear step");
2332 CORE_ADDR pc
= regcache_read_pc (regcache
);
2334 infrun_debug_printf ("step=%d, signal=%s, trap_expected=%d, "
2335 "current thread [%s] at %s",
2336 step
, gdb_signal_to_symbol_string (sig
),
2337 tp
->control
.trap_expected
,
2338 target_pid_to_str (inferior_ptid
).c_str (),
2339 paddress (gdbarch
, pc
));
2341 /* Normally, by the time we reach `resume', the breakpoints are either
2342 removed or inserted, as appropriate. The exception is if we're sitting
2343 at a permanent breakpoint; we need to step over it, but permanent
2344 breakpoints can't be removed. So we have to test for it here. */
2345 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2347 if (sig
!= GDB_SIGNAL_0
)
2349 /* We have a signal to pass to the inferior. The resume
2350 may, or may not take us to the signal handler. If this
2351 is a step, we'll need to stop in the signal handler, if
2352 there's one, (if the target supports stepping into
2353 handlers), or in the next mainline instruction, if
2354 there's no handler. If this is a continue, we need to be
2355 sure to run the handler with all breakpoints inserted.
2356 In all cases, set a breakpoint at the current address
2357 (where the handler returns to), and once that breakpoint
2358 is hit, resume skipping the permanent breakpoint. If
2359 that breakpoint isn't hit, then we've stepped into the
2360 signal handler (or hit some other event). We'll delete
2361 the step-resume breakpoint then. */
2363 infrun_debug_printf ("resume: skipping permanent breakpoint, "
2364 "deliver signal first");
2366 clear_step_over_info ();
2367 tp
->control
.trap_expected
= 0;
2369 if (tp
->control
.step_resume_breakpoint
== NULL
)
2371 /* Set a "high-priority" step-resume, as we don't want
2372 user breakpoints at PC to trigger (again) when this
2374 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2375 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2377 tp
->step_after_step_resume_breakpoint
= step
;
2380 insert_breakpoints ();
2384 /* There's no signal to pass, we can go ahead and skip the
2385 permanent breakpoint manually. */
2386 infrun_debug_printf ("skipping permanent breakpoint");
2387 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2388 /* Update pc to reflect the new address from which we will
2389 execute instructions. */
2390 pc
= regcache_read_pc (regcache
);
2394 /* We've already advanced the PC, so the stepping part
2395 is done. Now we need to arrange for a trap to be
2396 reported to handle_inferior_event. Set a breakpoint
2397 at the current PC, and run to it. Don't update
2398 prev_pc, because if we end in
2399 switch_back_to_stepped_thread, we want the "expected
2400 thread advanced also" branch to be taken. IOW, we
2401 don't want this thread to step further from PC
2403 gdb_assert (!step_over_info_valid_p ());
2404 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2405 insert_breakpoints ();
2407 resume_ptid
= internal_resume_ptid (user_step
);
2408 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
2415 /* If we have a breakpoint to step over, make sure to do a single
2416 step only. Same if we have software watchpoints. */
2417 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2418 tp
->control
.may_range_step
= 0;
2420 /* If displaced stepping is enabled, step over breakpoints by executing a
2421 copy of the instruction at a different address.
2423 We can't use displaced stepping when we have a signal to deliver;
2424 the comments for displaced_step_prepare explain why. The
2425 comments in the handle_inferior event for dealing with 'random
2426 signals' explain what we do instead.
2428 We can't use displaced stepping when we are waiting for vfork_done
2429 event, displaced stepping breaks the vfork child similarly as single
2430 step software breakpoint. */
2431 if (tp
->control
.trap_expected
2432 && use_displaced_stepping (tp
)
2433 && !step_over_info_valid_p ()
2434 && sig
== GDB_SIGNAL_0
2435 && !current_inferior ()->waiting_for_vfork_done
)
2437 int prepared
= displaced_step_prepare (tp
);
2441 infrun_debug_printf ("Got placed in step-over queue");
2443 tp
->control
.trap_expected
= 0;
2446 else if (prepared
< 0)
2448 /* Fallback to stepping over the breakpoint in-line. */
2450 if (target_is_non_stop_p ())
2451 stop_all_threads ();
2453 set_step_over_info (regcache
->aspace (),
2454 regcache_read_pc (regcache
), 0, tp
->global_num
);
2456 step
= maybe_software_singlestep (gdbarch
, pc
);
2458 insert_breakpoints ();
2460 else if (prepared
> 0)
2462 /* Update pc to reflect the new address from which we will
2463 execute instructions due to displaced stepping. */
2464 pc
= regcache_read_pc (get_thread_regcache (tp
));
2466 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
);
2470 /* Do we need to do it the hard way, w/temp breakpoints? */
2472 step
= maybe_software_singlestep (gdbarch
, pc
);
2474 /* Currently, our software single-step implementation leads to different
2475 results than hardware single-stepping in one situation: when stepping
2476 into delivering a signal which has an associated signal handler,
2477 hardware single-step will stop at the first instruction of the handler,
2478 while software single-step will simply skip execution of the handler.
2480 For now, this difference in behavior is accepted since there is no
2481 easy way to actually implement single-stepping into a signal handler
2482 without kernel support.
2484 However, there is one scenario where this difference leads to follow-on
2485 problems: if we're stepping off a breakpoint by removing all breakpoints
2486 and then single-stepping. In this case, the software single-step
2487 behavior means that even if there is a *breakpoint* in the signal
2488 handler, GDB still would not stop.
2490 Fortunately, we can at least fix this particular issue. We detect
2491 here the case where we are about to deliver a signal while software
2492 single-stepping with breakpoints removed. In this situation, we
2493 revert the decisions to remove all breakpoints and insert single-
2494 step breakpoints, and instead we install a step-resume breakpoint
2495 at the current address, deliver the signal without stepping, and
2496 once we arrive back at the step-resume breakpoint, actually step
2497 over the breakpoint we originally wanted to step over. */
2498 if (thread_has_single_step_breakpoints_set (tp
)
2499 && sig
!= GDB_SIGNAL_0
2500 && step_over_info_valid_p ())
2502 /* If we have nested signals or a pending signal is delivered
2503 immediately after a handler returns, might already have
2504 a step-resume breakpoint set on the earlier handler. We cannot
2505 set another step-resume breakpoint; just continue on until the
2506 original breakpoint is hit. */
2507 if (tp
->control
.step_resume_breakpoint
== NULL
)
2509 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2510 tp
->step_after_step_resume_breakpoint
= 1;
2513 delete_single_step_breakpoints (tp
);
2515 clear_step_over_info ();
2516 tp
->control
.trap_expected
= 0;
2518 insert_breakpoints ();
2521 /* If STEP is set, it's a request to use hardware stepping
2522 facilities. But in that case, we should never
2523 use singlestep breakpoint. */
2524 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2526 /* Decide the set of threads to ask the target to resume. */
2527 if (tp
->control
.trap_expected
)
2529 /* We're allowing a thread to run past a breakpoint it has
2530 hit, either by single-stepping the thread with the breakpoint
2531 removed, or by displaced stepping, with the breakpoint inserted.
2532 In the former case, we need to single-step only this thread,
2533 and keep others stopped, as they can miss this breakpoint if
2534 allowed to run. That's not really a problem for displaced
2535 stepping, but, we still keep other threads stopped, in case
2536 another thread is also stopped for a breakpoint waiting for
2537 its turn in the displaced stepping queue. */
2538 resume_ptid
= inferior_ptid
;
2541 resume_ptid
= internal_resume_ptid (user_step
);
2543 if (execution_direction
!= EXEC_REVERSE
2544 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2546 /* There are two cases where we currently need to step a
2547 breakpoint instruction when we have a signal to deliver:
2549 - See handle_signal_stop where we handle random signals that
2550 could take out us out of the stepping range. Normally, in
2551 that case we end up continuing (instead of stepping) over the
2552 signal handler with a breakpoint at PC, but there are cases
2553 where we should _always_ single-step, even if we have a
2554 step-resume breakpoint, like when a software watchpoint is
2555 set. Assuming single-stepping and delivering a signal at the
2556 same time would takes us to the signal handler, then we could
2557 have removed the breakpoint at PC to step over it. However,
2558 some hardware step targets (like e.g., Mac OS) can't step
2559 into signal handlers, and for those, we need to leave the
2560 breakpoint at PC inserted, as otherwise if the handler
2561 recurses and executes PC again, it'll miss the breakpoint.
2562 So we leave the breakpoint inserted anyway, but we need to
2563 record that we tried to step a breakpoint instruction, so
2564 that adjust_pc_after_break doesn't end up confused.
2566 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2567 in one thread after another thread that was stepping had been
2568 momentarily paused for a step-over. When we re-resume the
2569 stepping thread, it may be resumed from that address with a
2570 breakpoint that hasn't trapped yet. Seen with
2571 gdb.threads/non-stop-fair-events.exp, on targets that don't
2572 do displaced stepping. */
2574 infrun_debug_printf ("resume: [%s] stepped breakpoint",
2575 target_pid_to_str (tp
->ptid
).c_str ());
2577 tp
->stepped_breakpoint
= 1;
2579 /* Most targets can step a breakpoint instruction, thus
2580 executing it normally. But if this one cannot, just
2581 continue and we will hit it anyway. */
2582 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2587 && tp
->control
.trap_expected
2588 && use_displaced_stepping (tp
)
2589 && !step_over_info_valid_p ())
2591 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2592 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2593 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2596 read_memory (actual_pc
, buf
, sizeof (buf
));
2597 displaced_debug_printf ("run %s: %s",
2598 paddress (resume_gdbarch
, actual_pc
),
2599 displaced_step_dump_bytes
2600 (buf
, sizeof (buf
)).c_str ());
2603 if (tp
->control
.may_range_step
)
2605 /* If we're resuming a thread with the PC out of the step
2606 range, then we're doing some nested/finer run control
2607 operation, like stepping the thread out of the dynamic
2608 linker or the displaced stepping scratch pad. We
2609 shouldn't have allowed a range step then. */
2610 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2613 do_target_resume (resume_ptid
, step
, sig
);
2617 /* Resume the inferior. SIG is the signal to give the inferior
2618 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2619 rolls back state on error. */
2622 resume (gdb_signal sig
)
2628 catch (const gdb_exception
&ex
)
2630 /* If resuming is being aborted for any reason, delete any
2631 single-step breakpoint resume_1 may have created, to avoid
2632 confusing the following resumption, and to avoid leaving
2633 single-step breakpoints perturbing other threads, in case
2634 we're running in non-stop mode. */
2635 if (inferior_ptid
!= null_ptid
)
2636 delete_single_step_breakpoints (inferior_thread ());
2646 /* Counter that tracks number of user visible stops. This can be used
2647 to tell whether a command has proceeded the inferior past the
2648 current location. This allows e.g., inferior function calls in
2649 breakpoint commands to not interrupt the command list. When the
2650 call finishes successfully, the inferior is standing at the same
2651 breakpoint as if nothing happened (and so we don't call
2653 static ULONGEST current_stop_id
;
2660 return current_stop_id
;
2663 /* Called when we report a user visible stop. */
2671 /* Clear out all variables saying what to do when inferior is continued.
2672 First do this, then set the ones you want, then call `proceed'. */
2675 clear_proceed_status_thread (struct thread_info
*tp
)
2677 infrun_debug_printf ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2679 /* If we're starting a new sequence, then the previous finished
2680 single-step is no longer relevant. */
2681 if (tp
->suspend
.waitstatus_pending_p
)
2683 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2685 infrun_debug_printf ("pending event of %s was a finished step. "
2687 target_pid_to_str (tp
->ptid
).c_str ());
2689 tp
->suspend
.waitstatus_pending_p
= 0;
2690 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2695 ("thread %s has pending wait status %s (currently_stepping=%d).",
2696 target_pid_to_str (tp
->ptid
).c_str (),
2697 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2698 currently_stepping (tp
));
2702 /* If this signal should not be seen by program, give it zero.
2703 Used for debugging signals. */
2704 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2705 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2707 delete tp
->thread_fsm
;
2708 tp
->thread_fsm
= NULL
;
2710 tp
->control
.trap_expected
= 0;
2711 tp
->control
.step_range_start
= 0;
2712 tp
->control
.step_range_end
= 0;
2713 tp
->control
.may_range_step
= 0;
2714 tp
->control
.step_frame_id
= null_frame_id
;
2715 tp
->control
.step_stack_frame_id
= null_frame_id
;
2716 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2717 tp
->control
.step_start_function
= NULL
;
2718 tp
->stop_requested
= 0;
2720 tp
->control
.stop_step
= 0;
2722 tp
->control
.proceed_to_finish
= 0;
2724 tp
->control
.stepping_command
= 0;
2726 /* Discard any remaining commands or status from previous stop. */
2727 bpstat_clear (&tp
->control
.stop_bpstat
);
2731 clear_proceed_status (int step
)
2733 /* With scheduler-locking replay, stop replaying other threads if we're
2734 not replaying the user-visible resume ptid.
2736 This is a convenience feature to not require the user to explicitly
2737 stop replaying the other threads. We're assuming that the user's
2738 intent is to resume tracing the recorded process. */
2739 if (!non_stop
&& scheduler_mode
== schedlock_replay
2740 && target_record_is_replaying (minus_one_ptid
)
2741 && !target_record_will_replay (user_visible_resume_ptid (step
),
2742 execution_direction
))
2743 target_record_stop_replaying ();
2745 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2747 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2748 process_stratum_target
*resume_target
2749 = user_visible_resume_target (resume_ptid
);
2751 /* In all-stop mode, delete the per-thread status of all threads
2752 we're about to resume, implicitly and explicitly. */
2753 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2754 clear_proceed_status_thread (tp
);
2757 if (inferior_ptid
!= null_ptid
)
2759 struct inferior
*inferior
;
2763 /* If in non-stop mode, only delete the per-thread status of
2764 the current thread. */
2765 clear_proceed_status_thread (inferior_thread ());
2768 inferior
= current_inferior ();
2769 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2772 gdb::observers::about_to_proceed
.notify ();
2775 /* Returns true if TP is still stopped at a breakpoint that needs
2776 stepping-over in order to make progress. If the breakpoint is gone
2777 meanwhile, we can skip the whole step-over dance. */
2780 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2782 if (tp
->stepping_over_breakpoint
)
2784 struct regcache
*regcache
= get_thread_regcache (tp
);
2786 if (breakpoint_here_p (regcache
->aspace (),
2787 regcache_read_pc (regcache
))
2788 == ordinary_breakpoint_here
)
2791 tp
->stepping_over_breakpoint
= 0;
2797 /* Check whether thread TP still needs to start a step-over in order
2798 to make progress when resumed. Returns an bitwise or of enum
2799 step_over_what bits, indicating what needs to be stepped over. */
2801 static step_over_what
2802 thread_still_needs_step_over (struct thread_info
*tp
)
2804 step_over_what what
= 0;
2806 if (thread_still_needs_step_over_bp (tp
))
2807 what
|= STEP_OVER_BREAKPOINT
;
2809 if (tp
->stepping_over_watchpoint
2810 && !target_have_steppable_watchpoint ())
2811 what
|= STEP_OVER_WATCHPOINT
;
2816 /* Returns true if scheduler locking applies. STEP indicates whether
2817 we're about to do a step/next-like command to a thread. */
2820 schedlock_applies (struct thread_info
*tp
)
2822 return (scheduler_mode
== schedlock_on
2823 || (scheduler_mode
== schedlock_step
2824 && tp
->control
.stepping_command
)
2825 || (scheduler_mode
== schedlock_replay
2826 && target_record_will_replay (minus_one_ptid
,
2827 execution_direction
)));
2830 /* Calls target_commit_resume on all targets. */
2833 commit_resume_all_targets ()
2835 scoped_restore_current_thread restore_thread
;
2837 /* Map between process_target and a representative inferior. This
2838 is to avoid committing a resume in the same target more than
2839 once. Resumptions must be idempotent, so this is an
2841 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2843 for (inferior
*inf
: all_non_exited_inferiors ())
2844 if (inf
->has_execution ())
2845 conn_inf
[inf
->process_target ()] = inf
;
2847 for (const auto &ci
: conn_inf
)
2849 inferior
*inf
= ci
.second
;
2850 switch_to_inferior_no_thread (inf
);
2851 target_commit_resume ();
2855 /* Check that all the targets we're about to resume are in non-stop
2856 mode. Ideally, we'd only care whether all targets support
2857 target-async, but we're not there yet. E.g., stop_all_threads
2858 doesn't know how to handle all-stop targets. Also, the remote
2859 protocol in all-stop mode is synchronous, irrespective of
2860 target-async, which means that things like a breakpoint re-set
2861 triggered by one target would try to read memory from all targets
2865 check_multi_target_resumption (process_stratum_target
*resume_target
)
2867 if (!non_stop
&& resume_target
== nullptr)
2869 scoped_restore_current_thread restore_thread
;
2871 /* This is used to track whether we're resuming more than one
2873 process_stratum_target
*first_connection
= nullptr;
2875 /* The first inferior we see with a target that does not work in
2876 always-non-stop mode. */
2877 inferior
*first_not_non_stop
= nullptr;
2879 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2881 switch_to_inferior_no_thread (inf
);
2883 if (!target_has_execution ())
2886 process_stratum_target
*proc_target
2887 = current_inferior ()->process_target();
2889 if (!target_is_non_stop_p ())
2890 first_not_non_stop
= inf
;
2892 if (first_connection
== nullptr)
2893 first_connection
= proc_target
;
2894 else if (first_connection
!= proc_target
2895 && first_not_non_stop
!= nullptr)
2897 switch_to_inferior_no_thread (first_not_non_stop
);
2899 proc_target
= current_inferior ()->process_target();
2901 error (_("Connection %d (%s) does not support "
2902 "multi-target resumption."),
2903 proc_target
->connection_number
,
2904 make_target_connection_string (proc_target
).c_str ());
2910 /* Basic routine for continuing the program in various fashions.
2912 ADDR is the address to resume at, or -1 for resume where stopped.
2913 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2914 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2916 You should call clear_proceed_status before calling proceed. */
2919 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2921 struct regcache
*regcache
;
2922 struct gdbarch
*gdbarch
;
2924 struct execution_control_state ecss
;
2925 struct execution_control_state
*ecs
= &ecss
;
2928 /* If we're stopped at a fork/vfork, follow the branch set by the
2929 "set follow-fork-mode" command; otherwise, we'll just proceed
2930 resuming the current thread. */
2931 if (!follow_fork ())
2933 /* The target for some reason decided not to resume. */
2935 if (target_can_async_p ())
2936 inferior_event_handler (INF_EXEC_COMPLETE
);
2940 /* We'll update this if & when we switch to a new thread. */
2941 previous_inferior_ptid
= inferior_ptid
;
2943 regcache
= get_current_regcache ();
2944 gdbarch
= regcache
->arch ();
2945 const address_space
*aspace
= regcache
->aspace ();
2947 pc
= regcache_read_pc_protected (regcache
);
2949 thread_info
*cur_thr
= inferior_thread ();
2951 /* Fill in with reasonable starting values. */
2952 init_thread_stepping_state (cur_thr
);
2954 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2957 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2958 process_stratum_target
*resume_target
2959 = user_visible_resume_target (resume_ptid
);
2961 check_multi_target_resumption (resume_target
);
2963 if (addr
== (CORE_ADDR
) -1)
2965 if (pc
== cur_thr
->suspend
.stop_pc
2966 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2967 && execution_direction
!= EXEC_REVERSE
)
2968 /* There is a breakpoint at the address we will resume at,
2969 step one instruction before inserting breakpoints so that
2970 we do not stop right away (and report a second hit at this
2973 Note, we don't do this in reverse, because we won't
2974 actually be executing the breakpoint insn anyway.
2975 We'll be (un-)executing the previous instruction. */
2976 cur_thr
->stepping_over_breakpoint
= 1;
2977 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2978 && gdbarch_single_step_through_delay (gdbarch
,
2979 get_current_frame ()))
2980 /* We stepped onto an instruction that needs to be stepped
2981 again before re-inserting the breakpoint, do so. */
2982 cur_thr
->stepping_over_breakpoint
= 1;
2986 regcache_write_pc (regcache
, addr
);
2989 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2990 cur_thr
->suspend
.stop_signal
= siggnal
;
2992 /* If an exception is thrown from this point on, make sure to
2993 propagate GDB's knowledge of the executing state to the
2994 frontend/user running state. */
2995 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2997 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2998 threads (e.g., we might need to set threads stepping over
2999 breakpoints first), from the user/frontend's point of view, all
3000 threads in RESUME_PTID are now running. Unless we're calling an
3001 inferior function, as in that case we pretend the inferior
3002 doesn't run at all. */
3003 if (!cur_thr
->control
.in_infcall
)
3004 set_running (resume_target
, resume_ptid
, true);
3006 infrun_debug_printf ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3007 gdb_signal_to_symbol_string (siggnal
));
3009 annotate_starting ();
3011 /* Make sure that output from GDB appears before output from the
3013 gdb_flush (gdb_stdout
);
3015 /* Since we've marked the inferior running, give it the terminal. A
3016 QUIT/Ctrl-C from here on is forwarded to the target (which can
3017 still detect attempts to unblock a stuck connection with repeated
3018 Ctrl-C from within target_pass_ctrlc). */
3019 target_terminal::inferior ();
3021 /* In a multi-threaded task we may select another thread and
3022 then continue or step.
3024 But if a thread that we're resuming had stopped at a breakpoint,
3025 it will immediately cause another breakpoint stop without any
3026 execution (i.e. it will report a breakpoint hit incorrectly). So
3027 we must step over it first.
3029 Look for threads other than the current (TP) that reported a
3030 breakpoint hit and haven't been resumed yet since. */
3032 /* If scheduler locking applies, we can avoid iterating over all
3034 if (!non_stop
&& !schedlock_applies (cur_thr
))
3036 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3039 switch_to_thread_no_regs (tp
);
3041 /* Ignore the current thread here. It's handled
3046 if (!thread_still_needs_step_over (tp
))
3049 gdb_assert (!thread_is_in_step_over_chain (tp
));
3051 infrun_debug_printf ("need to step-over [%s] first",
3052 target_pid_to_str (tp
->ptid
).c_str ());
3054 thread_step_over_chain_enqueue (tp
);
3057 switch_to_thread (cur_thr
);
3060 /* Enqueue the current thread last, so that we move all other
3061 threads over their breakpoints first. */
3062 if (cur_thr
->stepping_over_breakpoint
)
3063 thread_step_over_chain_enqueue (cur_thr
);
3065 /* If the thread isn't started, we'll still need to set its prev_pc,
3066 so that switch_back_to_stepped_thread knows the thread hasn't
3067 advanced. Must do this before resuming any thread, as in
3068 all-stop/remote, once we resume we can't send any other packet
3069 until the target stops again. */
3070 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3073 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3075 started
= start_step_over ();
3077 if (step_over_info_valid_p ())
3079 /* Either this thread started a new in-line step over, or some
3080 other thread was already doing one. In either case, don't
3081 resume anything else until the step-over is finished. */
3083 else if (started
&& !target_is_non_stop_p ())
3085 /* A new displaced stepping sequence was started. In all-stop,
3086 we can't talk to the target anymore until it next stops. */
3088 else if (!non_stop
&& target_is_non_stop_p ())
3090 /* In all-stop, but the target is always in non-stop mode.
3091 Start all other threads that are implicitly resumed too. */
3092 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3095 switch_to_thread_no_regs (tp
);
3097 if (!tp
->inf
->has_execution ())
3099 infrun_debug_printf ("[%s] target has no execution",
3100 target_pid_to_str (tp
->ptid
).c_str ());
3106 infrun_debug_printf ("[%s] resumed",
3107 target_pid_to_str (tp
->ptid
).c_str ());
3108 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3112 if (thread_is_in_step_over_chain (tp
))
3114 infrun_debug_printf ("[%s] needs step-over",
3115 target_pid_to_str (tp
->ptid
).c_str ());
3119 infrun_debug_printf ("resuming %s",
3120 target_pid_to_str (tp
->ptid
).c_str ());
3122 reset_ecs (ecs
, tp
);
3123 switch_to_thread (tp
);
3124 keep_going_pass_signal (ecs
);
3125 if (!ecs
->wait_some_more
)
3126 error (_("Command aborted."));
3129 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3131 /* The thread wasn't started, and isn't queued, run it now. */
3132 reset_ecs (ecs
, cur_thr
);
3133 switch_to_thread (cur_thr
);
3134 keep_going_pass_signal (ecs
);
3135 if (!ecs
->wait_some_more
)
3136 error (_("Command aborted."));
3140 commit_resume_all_targets ();
3142 finish_state
.release ();
3144 /* If we've switched threads above, switch back to the previously
3145 current thread. We don't want the user to see a different
3147 switch_to_thread (cur_thr
);
3149 /* Tell the event loop to wait for it to stop. If the target
3150 supports asynchronous execution, it'll do this from within
3152 if (!target_can_async_p ())
3153 mark_async_event_handler (infrun_async_inferior_event_token
);
3157 /* Start remote-debugging of a machine over a serial link. */
3160 start_remote (int from_tty
)
3162 inferior
*inf
= current_inferior ();
3163 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3165 /* Always go on waiting for the target, regardless of the mode. */
3166 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3167 indicate to wait_for_inferior that a target should timeout if
3168 nothing is returned (instead of just blocking). Because of this,
3169 targets expecting an immediate response need to, internally, set
3170 things up so that the target_wait() is forced to eventually
3172 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3173 differentiate to its caller what the state of the target is after
3174 the initial open has been performed. Here we're assuming that
3175 the target has stopped. It should be possible to eventually have
3176 target_open() return to the caller an indication that the target
3177 is currently running and GDB state should be set to the same as
3178 for an async run. */
3179 wait_for_inferior (inf
);
3181 /* Now that the inferior has stopped, do any bookkeeping like
3182 loading shared libraries. We want to do this before normal_stop,
3183 so that the displayed frame is up to date. */
3184 post_create_inferior (from_tty
);
3189 /* Initialize static vars when a new inferior begins. */
3192 init_wait_for_inferior (void)
3194 /* These are meaningless until the first time through wait_for_inferior. */
3196 breakpoint_init_inferior (inf_starting
);
3198 clear_proceed_status (0);
3200 nullify_last_target_wait_ptid ();
3202 previous_inferior_ptid
= inferior_ptid
;
3207 static void handle_inferior_event (struct execution_control_state
*ecs
);
3209 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3210 struct execution_control_state
*ecs
);
3211 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3212 struct execution_control_state
*ecs
);
3213 static void handle_signal_stop (struct execution_control_state
*ecs
);
3214 static void check_exception_resume (struct execution_control_state
*,
3215 struct frame_info
*);
3217 static void end_stepping_range (struct execution_control_state
*ecs
);
3218 static void stop_waiting (struct execution_control_state
*ecs
);
3219 static void keep_going (struct execution_control_state
*ecs
);
3220 static void process_event_stop_test (struct execution_control_state
*ecs
);
3221 static bool switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3223 /* This function is attached as a "thread_stop_requested" observer.
3224 Cleanup local state that assumed the PTID was to be resumed, and
3225 report the stop to the frontend. */
3228 infrun_thread_stop_requested (ptid_t ptid
)
3230 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3232 /* PTID was requested to stop. If the thread was already stopped,
3233 but the user/frontend doesn't know about that yet (e.g., the
3234 thread had been temporarily paused for some step-over), set up
3235 for reporting the stop now. */
3236 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3238 if (tp
->state
!= THREAD_RUNNING
)
3243 /* Remove matching threads from the step-over queue, so
3244 start_step_over doesn't try to resume them
3246 if (thread_is_in_step_over_chain (tp
))
3247 thread_step_over_chain_remove (tp
);
3249 /* If the thread is stopped, but the user/frontend doesn't
3250 know about that yet, queue a pending event, as if the
3251 thread had just stopped now. Unless the thread already had
3253 if (!tp
->suspend
.waitstatus_pending_p
)
3255 tp
->suspend
.waitstatus_pending_p
= 1;
3256 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3257 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3260 /* Clear the inline-frame state, since we're re-processing the
3262 clear_inline_frame_state (tp
);
3264 /* If this thread was paused because some other thread was
3265 doing an inline-step over, let that finish first. Once
3266 that happens, we'll restart all threads and consume pending
3267 stop events then. */
3268 if (step_over_info_valid_p ())
3271 /* Otherwise we can process the (new) pending event now. Set
3272 it so this pending event is considered by
3279 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3281 if (target_last_proc_target
== tp
->inf
->process_target ()
3282 && target_last_wait_ptid
== tp
->ptid
)
3283 nullify_last_target_wait_ptid ();
3286 /* Delete the step resume, single-step and longjmp/exception resume
3287 breakpoints of TP. */
3290 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3292 delete_step_resume_breakpoint (tp
);
3293 delete_exception_resume_breakpoint (tp
);
3294 delete_single_step_breakpoints (tp
);
3297 /* If the target still has execution, call FUNC for each thread that
3298 just stopped. In all-stop, that's all the non-exited threads; in
3299 non-stop, that's the current thread, only. */
3301 typedef void (*for_each_just_stopped_thread_callback_func
)
3302 (struct thread_info
*tp
);
3305 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3307 if (!target_has_execution () || inferior_ptid
== null_ptid
)
3310 if (target_is_non_stop_p ())
3312 /* If in non-stop mode, only the current thread stopped. */
3313 func (inferior_thread ());
3317 /* In all-stop mode, all threads have stopped. */
3318 for (thread_info
*tp
: all_non_exited_threads ())
3323 /* Delete the step resume and longjmp/exception resume breakpoints of
3324 the threads that just stopped. */
3327 delete_just_stopped_threads_infrun_breakpoints (void)
3329 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3332 /* Delete the single-step breakpoints of the threads that just
3336 delete_just_stopped_threads_single_step_breakpoints (void)
3338 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3344 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3345 const struct target_waitstatus
*ws
)
3347 std::string status_string
= target_waitstatus_to_string (ws
);
3350 /* The text is split over several lines because it was getting too long.
3351 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3352 output as a unit; we want only one timestamp printed if debug_timestamp
3355 stb
.printf ("[infrun] target_wait (%d.%ld.%ld",
3358 waiton_ptid
.tid ());
3359 if (waiton_ptid
.pid () != -1)
3360 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3361 stb
.printf (", status) =\n");
3362 stb
.printf ("[infrun] %d.%ld.%ld [%s],\n",
3366 target_pid_to_str (result_ptid
).c_str ());
3367 stb
.printf ("[infrun] %s\n", status_string
.c_str ());
3369 /* This uses %s in part to handle %'s in the text, but also to avoid
3370 a gcc error: the format attribute requires a string literal. */
3371 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3374 /* Select a thread at random, out of those which are resumed and have
3377 static struct thread_info
*
3378 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3382 auto has_event
= [&] (thread_info
*tp
)
3384 return (tp
->ptid
.matches (waiton_ptid
)
3386 && tp
->suspend
.waitstatus_pending_p
);
3389 /* First see how many events we have. Count only resumed threads
3390 that have an event pending. */
3391 for (thread_info
*tp
: inf
->non_exited_threads ())
3395 if (num_events
== 0)
3398 /* Now randomly pick a thread out of those that have had events. */
3399 int random_selector
= (int) ((num_events
* (double) rand ())
3400 / (RAND_MAX
+ 1.0));
3403 infrun_debug_printf ("Found %d events, selecting #%d",
3404 num_events
, random_selector
);
3406 /* Select the Nth thread that has had an event. */
3407 for (thread_info
*tp
: inf
->non_exited_threads ())
3409 if (random_selector
-- == 0)
3412 gdb_assert_not_reached ("event thread not found");
3415 /* Wrapper for target_wait that first checks whether threads have
3416 pending statuses to report before actually asking the target for
3417 more events. INF is the inferior we're using to call target_wait
3421 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3422 target_waitstatus
*status
, target_wait_flags options
)
3425 struct thread_info
*tp
;
3427 /* We know that we are looking for an event in the target of inferior
3428 INF, but we don't know which thread the event might come from. As
3429 such we want to make sure that INFERIOR_PTID is reset so that none of
3430 the wait code relies on it - doing so is always a mistake. */
3431 switch_to_inferior_no_thread (inf
);
3433 /* First check if there is a resumed thread with a wait status
3435 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3437 tp
= random_pending_event_thread (inf
, ptid
);
3441 infrun_debug_printf ("Waiting for specific thread %s.",
3442 target_pid_to_str (ptid
).c_str ());
3444 /* We have a specific thread to check. */
3445 tp
= find_thread_ptid (inf
, ptid
);
3446 gdb_assert (tp
!= NULL
);
3447 if (!tp
->suspend
.waitstatus_pending_p
)
3452 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3453 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3455 struct regcache
*regcache
= get_thread_regcache (tp
);
3456 struct gdbarch
*gdbarch
= regcache
->arch ();
3460 pc
= regcache_read_pc (regcache
);
3462 if (pc
!= tp
->suspend
.stop_pc
)
3464 infrun_debug_printf ("PC of %s changed. was=%s, now=%s",
3465 target_pid_to_str (tp
->ptid
).c_str (),
3466 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3467 paddress (gdbarch
, pc
));
3470 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3472 infrun_debug_printf ("previous breakpoint of %s, at %s gone",
3473 target_pid_to_str (tp
->ptid
).c_str (),
3474 paddress (gdbarch
, pc
));
3481 infrun_debug_printf ("pending event of %s cancelled.",
3482 target_pid_to_str (tp
->ptid
).c_str ());
3484 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3485 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3491 infrun_debug_printf ("Using pending wait status %s for %s.",
3492 target_waitstatus_to_string
3493 (&tp
->suspend
.waitstatus
).c_str (),
3494 target_pid_to_str (tp
->ptid
).c_str ());
3496 /* Now that we've selected our final event LWP, un-adjust its PC
3497 if it was a software breakpoint (and the target doesn't
3498 always adjust the PC itself). */
3499 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3500 && !target_supports_stopped_by_sw_breakpoint ())
3502 struct regcache
*regcache
;
3503 struct gdbarch
*gdbarch
;
3506 regcache
= get_thread_regcache (tp
);
3507 gdbarch
= regcache
->arch ();
3509 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3514 pc
= regcache_read_pc (regcache
);
3515 regcache_write_pc (regcache
, pc
+ decr_pc
);
3519 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3520 *status
= tp
->suspend
.waitstatus
;
3521 tp
->suspend
.waitstatus_pending_p
= 0;
3523 /* Wake up the event loop again, until all pending events are
3525 if (target_is_async_p ())
3526 mark_async_event_handler (infrun_async_inferior_event_token
);
3530 /* But if we don't find one, we'll have to wait. */
3532 /* We can't ask a non-async target to do a non-blocking wait, so this will be
3534 if (!target_can_async_p ())
3535 options
&= ~TARGET_WNOHANG
;
3537 if (deprecated_target_wait_hook
)
3538 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3540 event_ptid
= target_wait (ptid
, status
, options
);
3545 /* Wrapper for target_wait that first checks whether threads have
3546 pending statuses to report before actually asking the target for
3547 more events. Polls for events from all inferiors/targets. */
3550 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
,
3551 target_wait_flags options
)
3553 int num_inferiors
= 0;
3554 int random_selector
;
3556 /* For fairness, we pick the first inferior/target to poll at random
3557 out of all inferiors that may report events, and then continue
3558 polling the rest of the inferior list starting from that one in a
3559 circular fashion until the whole list is polled once. */
3561 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3563 return (inf
->process_target () != NULL
3564 && ptid_t (inf
->pid
).matches (wait_ptid
));
3567 /* First see how many matching inferiors we have. */
3568 for (inferior
*inf
: all_inferiors ())
3569 if (inferior_matches (inf
))
3572 if (num_inferiors
== 0)
3574 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3578 /* Now randomly pick an inferior out of those that matched. */
3579 random_selector
= (int)
3580 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3582 if (num_inferiors
> 1)
3583 infrun_debug_printf ("Found %d inferiors, starting at #%d",
3584 num_inferiors
, random_selector
);
3586 /* Select the Nth inferior that matched. */
3588 inferior
*selected
= nullptr;
3590 for (inferior
*inf
: all_inferiors ())
3591 if (inferior_matches (inf
))
3592 if (random_selector
-- == 0)
3598 /* Now poll for events out of each of the matching inferior's
3599 targets, starting from the selected one. */
3601 auto do_wait
= [&] (inferior
*inf
)
3603 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3604 ecs
->target
= inf
->process_target ();
3605 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3608 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3609 here spuriously after the target is all stopped and we've already
3610 reported the stop to the user, polling for events. */
3611 scoped_restore_current_thread restore_thread
;
3613 int inf_num
= selected
->num
;
3614 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3615 if (inferior_matches (inf
))
3619 for (inferior
*inf
= inferior_list
;
3620 inf
!= NULL
&& inf
->num
< inf_num
;
3622 if (inferior_matches (inf
))
3626 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3630 /* Prepare and stabilize the inferior for detaching it. E.g.,
3631 detaching while a thread is displaced stepping is a recipe for
3632 crashing it, as nothing would readjust the PC out of the scratch
3636 prepare_for_detach (void)
3638 struct inferior
*inf
= current_inferior ();
3639 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3641 displaced_step_inferior_state
*displaced
= get_displaced_stepping_state (inf
);
3643 /* Is any thread of this process displaced stepping? If not,
3644 there's nothing else to do. */
3645 if (displaced
->step_thread
== nullptr)
3648 infrun_debug_printf ("displaced-stepping in-process while detaching");
3650 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3652 while (displaced
->step_thread
!= nullptr)
3654 struct execution_control_state ecss
;
3655 struct execution_control_state
*ecs
;
3658 memset (ecs
, 0, sizeof (*ecs
));
3660 overlay_cache_invalid
= 1;
3661 /* Flush target cache before starting to handle each event.
3662 Target was running and cache could be stale. This is just a
3663 heuristic. Running threads may modify target memory, but we
3664 don't get any event. */
3665 target_dcache_invalidate ();
3667 do_target_wait (pid_ptid
, ecs
, 0);
3670 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3672 /* If an error happens while handling the event, propagate GDB's
3673 knowledge of the executing state to the frontend/user running
3675 scoped_finish_thread_state
finish_state (inf
->process_target (),
3678 /* Now figure out what to do with the result of the result. */
3679 handle_inferior_event (ecs
);
3681 /* No error, don't finish the state yet. */
3682 finish_state
.release ();
3684 /* Breakpoints and watchpoints are not installed on the target
3685 at this point, and signals are passed directly to the
3686 inferior, so this must mean the process is gone. */
3687 if (!ecs
->wait_some_more
)
3689 restore_detaching
.release ();
3690 error (_("Program exited while detaching"));
3694 restore_detaching
.release ();
3697 /* Wait for control to return from inferior to debugger.
3699 If inferior gets a signal, we may decide to start it up again
3700 instead of returning. That is why there is a loop in this function.
3701 When this function actually returns it means the inferior
3702 should be left stopped and GDB should read more commands. */
3705 wait_for_inferior (inferior
*inf
)
3707 infrun_debug_printf ("wait_for_inferior ()");
3709 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3711 /* If an error happens while handling the event, propagate GDB's
3712 knowledge of the executing state to the frontend/user running
3714 scoped_finish_thread_state finish_state
3715 (inf
->process_target (), minus_one_ptid
);
3719 struct execution_control_state ecss
;
3720 struct execution_control_state
*ecs
= &ecss
;
3722 memset (ecs
, 0, sizeof (*ecs
));
3724 overlay_cache_invalid
= 1;
3726 /* Flush target cache before starting to handle each event.
3727 Target was running and cache could be stale. This is just a
3728 heuristic. Running threads may modify target memory, but we
3729 don't get any event. */
3730 target_dcache_invalidate ();
3732 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3733 ecs
->target
= inf
->process_target ();
3736 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3738 /* Now figure out what to do with the result of the result. */
3739 handle_inferior_event (ecs
);
3741 if (!ecs
->wait_some_more
)
3745 /* No error, don't finish the state yet. */
3746 finish_state
.release ();
3749 /* Cleanup that reinstalls the readline callback handler, if the
3750 target is running in the background. If while handling the target
3751 event something triggered a secondary prompt, like e.g., a
3752 pagination prompt, we'll have removed the callback handler (see
3753 gdb_readline_wrapper_line). Need to do this as we go back to the
3754 event loop, ready to process further input. Note this has no
3755 effect if the handler hasn't actually been removed, because calling
3756 rl_callback_handler_install resets the line buffer, thus losing
3760 reinstall_readline_callback_handler_cleanup ()
3762 struct ui
*ui
= current_ui
;
3766 /* We're not going back to the top level event loop yet. Don't
3767 install the readline callback, as it'd prep the terminal,
3768 readline-style (raw, noecho) (e.g., --batch). We'll install
3769 it the next time the prompt is displayed, when we're ready
3774 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3775 gdb_rl_callback_handler_reinstall ();
3778 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3779 that's just the event thread. In all-stop, that's all threads. */
3782 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3784 if (ecs
->event_thread
!= NULL
3785 && ecs
->event_thread
->thread_fsm
!= NULL
)
3786 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3790 for (thread_info
*thr
: all_non_exited_threads ())
3792 if (thr
->thread_fsm
== NULL
)
3794 if (thr
== ecs
->event_thread
)
3797 switch_to_thread (thr
);
3798 thr
->thread_fsm
->clean_up (thr
);
3801 if (ecs
->event_thread
!= NULL
)
3802 switch_to_thread (ecs
->event_thread
);
3806 /* Helper for all_uis_check_sync_execution_done that works on the
3810 check_curr_ui_sync_execution_done (void)
3812 struct ui
*ui
= current_ui
;
3814 if (ui
->prompt_state
== PROMPT_NEEDED
3816 && !gdb_in_secondary_prompt_p (ui
))
3818 target_terminal::ours ();
3819 gdb::observers::sync_execution_done
.notify ();
3820 ui_register_input_event_handler (ui
);
3827 all_uis_check_sync_execution_done (void)
3829 SWITCH_THRU_ALL_UIS ()
3831 check_curr_ui_sync_execution_done ();
3838 all_uis_on_sync_execution_starting (void)
3840 SWITCH_THRU_ALL_UIS ()
3842 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3843 async_disable_stdin ();
3847 /* Asynchronous version of wait_for_inferior. It is called by the
3848 event loop whenever a change of state is detected on the file
3849 descriptor corresponding to the target. It can be called more than
3850 once to complete a single execution command. In such cases we need
3851 to keep the state in a global variable ECSS. If it is the last time
3852 that this function is called for a single execution command, then
3853 report to the user that the inferior has stopped, and do the
3854 necessary cleanups. */
3857 fetch_inferior_event ()
3859 struct execution_control_state ecss
;
3860 struct execution_control_state
*ecs
= &ecss
;
3863 memset (ecs
, 0, sizeof (*ecs
));
3865 /* Events are always processed with the main UI as current UI. This
3866 way, warnings, debug output, etc. are always consistently sent to
3867 the main console. */
3868 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3870 /* Temporarily disable pagination. Otherwise, the user would be
3871 given an option to press 'q' to quit, which would cause an early
3872 exit and could leave GDB in a half-baked state. */
3873 scoped_restore save_pagination
3874 = make_scoped_restore (&pagination_enabled
, false);
3876 /* End up with readline processing input, if necessary. */
3878 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3880 /* We're handling a live event, so make sure we're doing live
3881 debugging. If we're looking at traceframes while the target is
3882 running, we're going to need to get back to that mode after
3883 handling the event. */
3884 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3887 maybe_restore_traceframe
.emplace ();
3888 set_current_traceframe (-1);
3891 /* The user/frontend should not notice a thread switch due to
3892 internal events. Make sure we revert to the user selected
3893 thread and frame after handling the event and running any
3894 breakpoint commands. */
3895 scoped_restore_current_thread restore_thread
;
3897 overlay_cache_invalid
= 1;
3898 /* Flush target cache before starting to handle each event. Target
3899 was running and cache could be stale. This is just a heuristic.
3900 Running threads may modify target memory, but we don't get any
3902 target_dcache_invalidate ();
3904 scoped_restore save_exec_dir
3905 = make_scoped_restore (&execution_direction
,
3906 target_execution_direction ());
3908 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3911 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3913 /* Switch to the target that generated the event, so we can do
3915 switch_to_target_no_thread (ecs
->target
);
3918 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3920 /* If an error happens while handling the event, propagate GDB's
3921 knowledge of the executing state to the frontend/user running
3923 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3924 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3926 /* Get executed before scoped_restore_current_thread above to apply
3927 still for the thread which has thrown the exception. */
3928 auto defer_bpstat_clear
3929 = make_scope_exit (bpstat_clear_actions
);
3930 auto defer_delete_threads
3931 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3933 /* Now figure out what to do with the result of the result. */
3934 handle_inferior_event (ecs
);
3936 if (!ecs
->wait_some_more
)
3938 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3939 int should_stop
= 1;
3940 struct thread_info
*thr
= ecs
->event_thread
;
3942 delete_just_stopped_threads_infrun_breakpoints ();
3946 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3948 if (thread_fsm
!= NULL
)
3949 should_stop
= thread_fsm
->should_stop (thr
);
3958 bool should_notify_stop
= true;
3961 clean_up_just_stopped_threads_fsms (ecs
);
3963 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3964 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3966 if (should_notify_stop
)
3968 /* We may not find an inferior if this was a process exit. */
3969 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3970 proceeded
= normal_stop ();
3975 inferior_event_handler (INF_EXEC_COMPLETE
);
3979 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3980 previously selected thread is gone. We have two
3981 choices - switch to no thread selected, or restore the
3982 previously selected thread (now exited). We chose the
3983 later, just because that's what GDB used to do. After
3984 this, "info threads" says "The current thread <Thread
3985 ID 2> has terminated." instead of "No thread
3989 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3990 restore_thread
.dont_restore ();
3994 defer_delete_threads
.release ();
3995 defer_bpstat_clear
.release ();
3997 /* No error, don't finish the thread states yet. */
3998 finish_state
.release ();
4000 /* This scope is used to ensure that readline callbacks are
4001 reinstalled here. */
4004 /* If a UI was in sync execution mode, and now isn't, restore its
4005 prompt (a synchronous execution command has finished, and we're
4006 ready for input). */
4007 all_uis_check_sync_execution_done ();
4010 && exec_done_display_p
4011 && (inferior_ptid
== null_ptid
4012 || inferior_thread ()->state
!= THREAD_RUNNING
))
4013 printf_unfiltered (_("completed.\n"));
4019 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4020 struct symtab_and_line sal
)
4022 /* This can be removed once this function no longer implicitly relies on the
4023 inferior_ptid value. */
4024 gdb_assert (inferior_ptid
== tp
->ptid
);
4026 tp
->control
.step_frame_id
= get_frame_id (frame
);
4027 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4029 tp
->current_symtab
= sal
.symtab
;
4030 tp
->current_line
= sal
.line
;
4033 /* Clear context switchable stepping state. */
4036 init_thread_stepping_state (struct thread_info
*tss
)
4038 tss
->stepped_breakpoint
= 0;
4039 tss
->stepping_over_breakpoint
= 0;
4040 tss
->stepping_over_watchpoint
= 0;
4041 tss
->step_after_step_resume_breakpoint
= 0;
4047 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4048 target_waitstatus status
)
4050 target_last_proc_target
= target
;
4051 target_last_wait_ptid
= ptid
;
4052 target_last_waitstatus
= status
;
4058 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4059 target_waitstatus
*status
)
4061 if (target
!= nullptr)
4062 *target
= target_last_proc_target
;
4063 if (ptid
!= nullptr)
4064 *ptid
= target_last_wait_ptid
;
4065 if (status
!= nullptr)
4066 *status
= target_last_waitstatus
;
4072 nullify_last_target_wait_ptid (void)
4074 target_last_proc_target
= nullptr;
4075 target_last_wait_ptid
= minus_one_ptid
;
4076 target_last_waitstatus
= {};
4079 /* Switch thread contexts. */
4082 context_switch (execution_control_state
*ecs
)
4084 if (ecs
->ptid
!= inferior_ptid
4085 && (inferior_ptid
== null_ptid
4086 || ecs
->event_thread
!= inferior_thread ()))
4088 infrun_debug_printf ("Switching context from %s to %s",
4089 target_pid_to_str (inferior_ptid
).c_str (),
4090 target_pid_to_str (ecs
->ptid
).c_str ());
4093 switch_to_thread (ecs
->event_thread
);
4096 /* If the target can't tell whether we've hit breakpoints
4097 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4098 check whether that could have been caused by a breakpoint. If so,
4099 adjust the PC, per gdbarch_decr_pc_after_break. */
4102 adjust_pc_after_break (struct thread_info
*thread
,
4103 struct target_waitstatus
*ws
)
4105 struct regcache
*regcache
;
4106 struct gdbarch
*gdbarch
;
4107 CORE_ADDR breakpoint_pc
, decr_pc
;
4109 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4110 we aren't, just return.
4112 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4113 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4114 implemented by software breakpoints should be handled through the normal
4117 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4118 different signals (SIGILL or SIGEMT for instance), but it is less
4119 clear where the PC is pointing afterwards. It may not match
4120 gdbarch_decr_pc_after_break. I don't know any specific target that
4121 generates these signals at breakpoints (the code has been in GDB since at
4122 least 1992) so I can not guess how to handle them here.
4124 In earlier versions of GDB, a target with
4125 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4126 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4127 target with both of these set in GDB history, and it seems unlikely to be
4128 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4130 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4133 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4136 /* In reverse execution, when a breakpoint is hit, the instruction
4137 under it has already been de-executed. The reported PC always
4138 points at the breakpoint address, so adjusting it further would
4139 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4142 B1 0x08000000 : INSN1
4143 B2 0x08000001 : INSN2
4145 PC -> 0x08000003 : INSN4
4147 Say you're stopped at 0x08000003 as above. Reverse continuing
4148 from that point should hit B2 as below. Reading the PC when the
4149 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4150 been de-executed already.
4152 B1 0x08000000 : INSN1
4153 B2 PC -> 0x08000001 : INSN2
4157 We can't apply the same logic as for forward execution, because
4158 we would wrongly adjust the PC to 0x08000000, since there's a
4159 breakpoint at PC - 1. We'd then report a hit on B1, although
4160 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4162 if (execution_direction
== EXEC_REVERSE
)
4165 /* If the target can tell whether the thread hit a SW breakpoint,
4166 trust it. Targets that can tell also adjust the PC
4168 if (target_supports_stopped_by_sw_breakpoint ())
4171 /* Note that relying on whether a breakpoint is planted in memory to
4172 determine this can fail. E.g,. the breakpoint could have been
4173 removed since. Or the thread could have been told to step an
4174 instruction the size of a breakpoint instruction, and only
4175 _after_ was a breakpoint inserted at its address. */
4177 /* If this target does not decrement the PC after breakpoints, then
4178 we have nothing to do. */
4179 regcache
= get_thread_regcache (thread
);
4180 gdbarch
= regcache
->arch ();
4182 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4186 const address_space
*aspace
= regcache
->aspace ();
4188 /* Find the location where (if we've hit a breakpoint) the
4189 breakpoint would be. */
4190 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4192 /* If the target can't tell whether a software breakpoint triggered,
4193 fallback to figuring it out based on breakpoints we think were
4194 inserted in the target, and on whether the thread was stepped or
4197 /* Check whether there actually is a software breakpoint inserted at
4200 If in non-stop mode, a race condition is possible where we've
4201 removed a breakpoint, but stop events for that breakpoint were
4202 already queued and arrive later. To suppress those spurious
4203 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4204 and retire them after a number of stop events are reported. Note
4205 this is an heuristic and can thus get confused. The real fix is
4206 to get the "stopped by SW BP and needs adjustment" info out of
4207 the target/kernel (and thus never reach here; see above). */
4208 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4209 || (target_is_non_stop_p ()
4210 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4212 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4214 if (record_full_is_used ())
4215 restore_operation_disable
.emplace
4216 (record_full_gdb_operation_disable_set ());
4218 /* When using hardware single-step, a SIGTRAP is reported for both
4219 a completed single-step and a software breakpoint. Need to
4220 differentiate between the two, as the latter needs adjusting
4221 but the former does not.
4223 The SIGTRAP can be due to a completed hardware single-step only if
4224 - we didn't insert software single-step breakpoints
4225 - this thread is currently being stepped
4227 If any of these events did not occur, we must have stopped due
4228 to hitting a software breakpoint, and have to back up to the
4231 As a special case, we could have hardware single-stepped a
4232 software breakpoint. In this case (prev_pc == breakpoint_pc),
4233 we also need to back up to the breakpoint address. */
4235 if (thread_has_single_step_breakpoints_set (thread
)
4236 || !currently_stepping (thread
)
4237 || (thread
->stepped_breakpoint
4238 && thread
->prev_pc
== breakpoint_pc
))
4239 regcache_write_pc (regcache
, breakpoint_pc
);
4244 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4246 for (frame
= get_prev_frame (frame
);
4248 frame
= get_prev_frame (frame
))
4250 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4253 if (get_frame_type (frame
) != INLINE_FRAME
)
4260 /* Look for an inline frame that is marked for skip.
4261 If PREV_FRAME is TRUE start at the previous frame,
4262 otherwise start at the current frame. Stop at the
4263 first non-inline frame, or at the frame where the
4267 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4269 struct frame_info
*frame
= get_current_frame ();
4272 frame
= get_prev_frame (frame
);
4274 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4276 const char *fn
= NULL
;
4277 symtab_and_line sal
;
4280 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4282 if (get_frame_type (frame
) != INLINE_FRAME
)
4285 sal
= find_frame_sal (frame
);
4286 sym
= get_frame_function (frame
);
4289 fn
= sym
->print_name ();
4292 && function_name_is_marked_for_skip (fn
, sal
))
4299 /* If the event thread has the stop requested flag set, pretend it
4300 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4304 handle_stop_requested (struct execution_control_state
*ecs
)
4306 if (ecs
->event_thread
->stop_requested
)
4308 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4309 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4310 handle_signal_stop (ecs
);
4316 /* Auxiliary function that handles syscall entry/return events.
4317 It returns true if the inferior should keep going (and GDB
4318 should ignore the event), or false if the event deserves to be
4322 handle_syscall_event (struct execution_control_state
*ecs
)
4324 struct regcache
*regcache
;
4327 context_switch (ecs
);
4329 regcache
= get_thread_regcache (ecs
->event_thread
);
4330 syscall_number
= ecs
->ws
.value
.syscall_number
;
4331 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4333 if (catch_syscall_enabled () > 0
4334 && catching_syscall_number (syscall_number
) > 0)
4336 infrun_debug_printf ("syscall number=%d", syscall_number
);
4338 ecs
->event_thread
->control
.stop_bpstat
4339 = bpstat_stop_status (regcache
->aspace (),
4340 ecs
->event_thread
->suspend
.stop_pc
,
4341 ecs
->event_thread
, &ecs
->ws
);
4343 if (handle_stop_requested (ecs
))
4346 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4348 /* Catchpoint hit. */
4353 if (handle_stop_requested (ecs
))
4356 /* If no catchpoint triggered for this, then keep going. */
4362 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4365 fill_in_stop_func (struct gdbarch
*gdbarch
,
4366 struct execution_control_state
*ecs
)
4368 if (!ecs
->stop_func_filled_in
)
4371 const general_symbol_info
*gsi
;
4373 /* Don't care about return value; stop_func_start and stop_func_name
4374 will both be 0 if it doesn't work. */
4375 find_pc_partial_function_sym (ecs
->event_thread
->suspend
.stop_pc
,
4377 &ecs
->stop_func_start
,
4378 &ecs
->stop_func_end
,
4380 ecs
->stop_func_name
= gsi
== nullptr ? nullptr : gsi
->print_name ();
4382 /* The call to find_pc_partial_function, above, will set
4383 stop_func_start and stop_func_end to the start and end
4384 of the range containing the stop pc. If this range
4385 contains the entry pc for the block (which is always the
4386 case for contiguous blocks), advance stop_func_start past
4387 the function's start offset and entrypoint. Note that
4388 stop_func_start is NOT advanced when in a range of a
4389 non-contiguous block that does not contain the entry pc. */
4390 if (block
!= nullptr
4391 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4392 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4394 ecs
->stop_func_start
4395 += gdbarch_deprecated_function_start_offset (gdbarch
);
4397 if (gdbarch_skip_entrypoint_p (gdbarch
))
4398 ecs
->stop_func_start
4399 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4402 ecs
->stop_func_filled_in
= 1;
4407 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4409 static enum stop_kind
4410 get_inferior_stop_soon (execution_control_state
*ecs
)
4412 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4414 gdb_assert (inf
!= NULL
);
4415 return inf
->control
.stop_soon
;
4418 /* Poll for one event out of the current target. Store the resulting
4419 waitstatus in WS, and return the event ptid. Does not block. */
4422 poll_one_curr_target (struct target_waitstatus
*ws
)
4426 overlay_cache_invalid
= 1;
4428 /* Flush target cache before starting to handle each event.
4429 Target was running and cache could be stale. This is just a
4430 heuristic. Running threads may modify target memory, but we
4431 don't get any event. */
4432 target_dcache_invalidate ();
4434 if (deprecated_target_wait_hook
)
4435 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4437 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4440 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4445 /* An event reported by wait_one. */
4447 struct wait_one_event
4449 /* The target the event came out of. */
4450 process_stratum_target
*target
;
4452 /* The PTID the event was for. */
4455 /* The waitstatus. */
4456 target_waitstatus ws
;
4459 /* Wait for one event out of any target. */
4461 static wait_one_event
4466 for (inferior
*inf
: all_inferiors ())
4468 process_stratum_target
*target
= inf
->process_target ();
4470 || !target
->is_async_p ()
4471 || !target
->threads_executing
)
4474 switch_to_inferior_no_thread (inf
);
4476 wait_one_event event
;
4477 event
.target
= target
;
4478 event
.ptid
= poll_one_curr_target (&event
.ws
);
4480 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4482 /* If nothing is resumed, remove the target from the
4486 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4490 /* Block waiting for some event. */
4497 for (inferior
*inf
: all_inferiors ())
4499 process_stratum_target
*target
= inf
->process_target ();
4501 || !target
->is_async_p ()
4502 || !target
->threads_executing
)
4505 int fd
= target
->async_wait_fd ();
4506 FD_SET (fd
, &readfds
);
4513 /* No waitable targets left. All must be stopped. */
4514 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4519 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4525 perror_with_name ("interruptible_select");
4530 /* Save the thread's event and stop reason to process it later. */
4533 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4535 infrun_debug_printf ("saving status %s for %d.%ld.%ld",
4536 target_waitstatus_to_string (ws
).c_str (),
4541 /* Record for later. */
4542 tp
->suspend
.waitstatus
= *ws
;
4543 tp
->suspend
.waitstatus_pending_p
= 1;
4545 struct regcache
*regcache
= get_thread_regcache (tp
);
4546 const address_space
*aspace
= regcache
->aspace ();
4548 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4549 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4551 CORE_ADDR pc
= regcache_read_pc (regcache
);
4553 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4555 scoped_restore_current_thread restore_thread
;
4556 switch_to_thread (tp
);
4558 if (target_stopped_by_watchpoint ())
4560 tp
->suspend
.stop_reason
4561 = TARGET_STOPPED_BY_WATCHPOINT
;
4563 else if (target_supports_stopped_by_sw_breakpoint ()
4564 && target_stopped_by_sw_breakpoint ())
4566 tp
->suspend
.stop_reason
4567 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4569 else if (target_supports_stopped_by_hw_breakpoint ()
4570 && target_stopped_by_hw_breakpoint ())
4572 tp
->suspend
.stop_reason
4573 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4575 else if (!target_supports_stopped_by_hw_breakpoint ()
4576 && hardware_breakpoint_inserted_here_p (aspace
,
4579 tp
->suspend
.stop_reason
4580 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4582 else if (!target_supports_stopped_by_sw_breakpoint ()
4583 && software_breakpoint_inserted_here_p (aspace
,
4586 tp
->suspend
.stop_reason
4587 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4589 else if (!thread_has_single_step_breakpoints_set (tp
)
4590 && currently_stepping (tp
))
4592 tp
->suspend
.stop_reason
4593 = TARGET_STOPPED_BY_SINGLE_STEP
;
4598 /* Mark the non-executing threads accordingly. In all-stop, all
4599 threads of all processes are stopped when we get any event
4600 reported. In non-stop mode, only the event thread stops. */
4603 mark_non_executing_threads (process_stratum_target
*target
,
4605 struct target_waitstatus ws
)
4609 if (!target_is_non_stop_p ())
4610 mark_ptid
= minus_one_ptid
;
4611 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4612 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4614 /* If we're handling a process exit in non-stop mode, even
4615 though threads haven't been deleted yet, one would think
4616 that there is nothing to do, as threads of the dead process
4617 will be soon deleted, and threads of any other process were
4618 left running. However, on some targets, threads survive a
4619 process exit event. E.g., for the "checkpoint" command,
4620 when the current checkpoint/fork exits, linux-fork.c
4621 automatically switches to another fork from within
4622 target_mourn_inferior, by associating the same
4623 inferior/thread to another fork. We haven't mourned yet at
4624 this point, but we must mark any threads left in the
4625 process as not-executing so that finish_thread_state marks
4626 them stopped (in the user's perspective) if/when we present
4627 the stop to the user. */
4628 mark_ptid
= ptid_t (event_ptid
.pid ());
4631 mark_ptid
= event_ptid
;
4633 set_executing (target
, mark_ptid
, false);
4635 /* Likewise the resumed flag. */
4636 set_resumed (target
, mark_ptid
, false);
4642 stop_all_threads (void)
4644 /* We may need multiple passes to discover all threads. */
4648 gdb_assert (exists_non_stop_target ());
4650 infrun_debug_printf ("starting");
4652 scoped_restore_current_thread restore_thread
;
4654 /* Enable thread events of all targets. */
4655 for (auto *target
: all_non_exited_process_targets ())
4657 switch_to_target_no_thread (target
);
4658 target_thread_events (true);
4663 /* Disable thread events of all targets. */
4664 for (auto *target
: all_non_exited_process_targets ())
4666 switch_to_target_no_thread (target
);
4667 target_thread_events (false);
4670 /* Use infrun_debug_printf_1 directly to get a meaningful function
4673 infrun_debug_printf_1 ("stop_all_threads", "done");
4676 /* Request threads to stop, and then wait for the stops. Because
4677 threads we already know about can spawn more threads while we're
4678 trying to stop them, and we only learn about new threads when we
4679 update the thread list, do this in a loop, and keep iterating
4680 until two passes find no threads that need to be stopped. */
4681 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4683 infrun_debug_printf ("pass=%d, iterations=%d", pass
, iterations
);
4686 int waits_needed
= 0;
4688 for (auto *target
: all_non_exited_process_targets ())
4690 switch_to_target_no_thread (target
);
4691 update_thread_list ();
4694 /* Go through all threads looking for threads that we need
4695 to tell the target to stop. */
4696 for (thread_info
*t
: all_non_exited_threads ())
4698 /* For a single-target setting with an all-stop target,
4699 we would not even arrive here. For a multi-target
4700 setting, until GDB is able to handle a mixture of
4701 all-stop and non-stop targets, simply skip all-stop
4702 targets' threads. This should be fine due to the
4703 protection of 'check_multi_target_resumption'. */
4705 switch_to_thread_no_regs (t
);
4706 if (!target_is_non_stop_p ())
4711 /* If already stopping, don't request a stop again.
4712 We just haven't seen the notification yet. */
4713 if (!t
->stop_requested
)
4715 infrun_debug_printf (" %s executing, need stop",
4716 target_pid_to_str (t
->ptid
).c_str ());
4717 target_stop (t
->ptid
);
4718 t
->stop_requested
= 1;
4722 infrun_debug_printf (" %s executing, already stopping",
4723 target_pid_to_str (t
->ptid
).c_str ());
4726 if (t
->stop_requested
)
4731 infrun_debug_printf (" %s not executing",
4732 target_pid_to_str (t
->ptid
).c_str ());
4734 /* The thread may be not executing, but still be
4735 resumed with a pending status to process. */
4740 if (waits_needed
== 0)
4743 /* If we find new threads on the second iteration, restart
4744 over. We want to see two iterations in a row with all
4749 for (int i
= 0; i
< waits_needed
; i
++)
4751 wait_one_event event
= wait_one ();
4754 ("%s %s", target_waitstatus_to_string (&event
.ws
).c_str (),
4755 target_pid_to_str (event
.ptid
).c_str ());
4757 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4759 /* All resumed threads exited. */
4762 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4763 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4764 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4766 /* One thread/process exited/signalled. */
4768 thread_info
*t
= nullptr;
4770 /* The target may have reported just a pid. If so, try
4771 the first non-exited thread. */
4772 if (event
.ptid
.is_pid ())
4774 int pid
= event
.ptid
.pid ();
4775 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4776 for (thread_info
*tp
: inf
->non_exited_threads ())
4782 /* If there is no available thread, the event would
4783 have to be appended to a per-inferior event list,
4784 which does not exist (and if it did, we'd have
4785 to adjust run control command to be able to
4786 resume such an inferior). We assert here instead
4787 of going into an infinite loop. */
4788 gdb_assert (t
!= nullptr);
4791 ("using %s", target_pid_to_str (t
->ptid
).c_str ());
4795 t
= find_thread_ptid (event
.target
, event
.ptid
);
4796 /* Check if this is the first time we see this thread.
4797 Don't bother adding if it individually exited. */
4799 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4800 t
= add_thread (event
.target
, event
.ptid
);
4805 /* Set the threads as non-executing to avoid
4806 another stop attempt on them. */
4807 switch_to_thread_no_regs (t
);
4808 mark_non_executing_threads (event
.target
, event
.ptid
,
4810 save_waitstatus (t
, &event
.ws
);
4811 t
->stop_requested
= false;
4816 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4818 t
= add_thread (event
.target
, event
.ptid
);
4820 t
->stop_requested
= 0;
4823 t
->control
.may_range_step
= 0;
4825 /* This may be the first time we see the inferior report
4827 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4828 if (inf
->needs_setup
)
4830 switch_to_thread_no_regs (t
);
4834 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4835 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4837 /* We caught the event that we intended to catch, so
4838 there's no event pending. */
4839 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4840 t
->suspend
.waitstatus_pending_p
= 0;
4842 if (displaced_step_fixup (t
, GDB_SIGNAL_0
) < 0)
4844 /* Add it back to the step-over queue. */
4846 ("displaced-step of %s canceled: adding back to "
4847 "the step-over queue",
4848 target_pid_to_str (t
->ptid
).c_str ());
4850 t
->control
.trap_expected
= 0;
4851 thread_step_over_chain_enqueue (t
);
4856 enum gdb_signal sig
;
4857 struct regcache
*regcache
;
4860 ("target_wait %s, saving status for %d.%ld.%ld",
4861 target_waitstatus_to_string (&event
.ws
).c_str (),
4862 t
->ptid
.pid (), t
->ptid
.lwp (), t
->ptid
.tid ());
4864 /* Record for later. */
4865 save_waitstatus (t
, &event
.ws
);
4867 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4868 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4870 if (displaced_step_fixup (t
, sig
) < 0)
4872 /* Add it back to the step-over queue. */
4873 t
->control
.trap_expected
= 0;
4874 thread_step_over_chain_enqueue (t
);
4877 regcache
= get_thread_regcache (t
);
4878 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4880 infrun_debug_printf ("saved stop_pc=%s for %s "
4881 "(currently_stepping=%d)",
4882 paddress (target_gdbarch (),
4883 t
->suspend
.stop_pc
),
4884 target_pid_to_str (t
->ptid
).c_str (),
4885 currently_stepping (t
));
4893 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4896 handle_no_resumed (struct execution_control_state
*ecs
)
4898 if (target_can_async_p ())
4900 bool any_sync
= false;
4902 for (ui
*ui
: all_uis ())
4904 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4912 /* There were no unwaited-for children left in the target, but,
4913 we're not synchronously waiting for events either. Just
4916 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4917 prepare_to_wait (ecs
);
4922 /* Otherwise, if we were running a synchronous execution command, we
4923 may need to cancel it and give the user back the terminal.
4925 In non-stop mode, the target can't tell whether we've already
4926 consumed previous stop events, so it can end up sending us a
4927 no-resumed event like so:
4929 #0 - thread 1 is left stopped
4931 #1 - thread 2 is resumed and hits breakpoint
4932 -> TARGET_WAITKIND_STOPPED
4934 #2 - thread 3 is resumed and exits
4935 this is the last resumed thread, so
4936 -> TARGET_WAITKIND_NO_RESUMED
4938 #3 - gdb processes stop for thread 2 and decides to re-resume
4941 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4942 thread 2 is now resumed, so the event should be ignored.
4944 IOW, if the stop for thread 2 doesn't end a foreground command,
4945 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4946 event. But it could be that the event meant that thread 2 itself
4947 (or whatever other thread was the last resumed thread) exited.
4949 To address this we refresh the thread list and check whether we
4950 have resumed threads _now_. In the example above, this removes
4951 thread 3 from the thread list. If thread 2 was re-resumed, we
4952 ignore this event. If we find no thread resumed, then we cancel
4953 the synchronous command and show "no unwaited-for " to the
4956 inferior
*curr_inf
= current_inferior ();
4958 scoped_restore_current_thread restore_thread
;
4960 for (auto *target
: all_non_exited_process_targets ())
4962 switch_to_target_no_thread (target
);
4963 update_thread_list ();
4968 - the current target has no thread executing, and
4969 - the current inferior is native, and
4970 - the current inferior is the one which has the terminal, and
4973 then a Ctrl-C from this point on would remain stuck in the
4974 kernel, until a thread resumes and dequeues it. That would
4975 result in the GDB CLI not reacting to Ctrl-C, not able to
4976 interrupt the program. To address this, if the current inferior
4977 no longer has any thread executing, we give the terminal to some
4978 other inferior that has at least one thread executing. */
4979 bool swap_terminal
= true;
4981 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4982 whether to report it to the user. */
4983 bool ignore_event
= false;
4985 for (thread_info
*thread
: all_non_exited_threads ())
4987 if (swap_terminal
&& thread
->executing
)
4989 if (thread
->inf
!= curr_inf
)
4991 target_terminal::ours ();
4993 switch_to_thread (thread
);
4994 target_terminal::inferior ();
4996 swap_terminal
= false;
5000 && (thread
->executing
5001 || thread
->suspend
.waitstatus_pending_p
))
5003 /* Either there were no unwaited-for children left in the
5004 target at some point, but there are now, or some target
5005 other than the eventing one has unwaited-for children
5006 left. Just ignore. */
5007 infrun_debug_printf ("TARGET_WAITKIND_NO_RESUMED "
5008 "(ignoring: found resumed)");
5010 ignore_event
= true;
5013 if (ignore_event
&& !swap_terminal
)
5019 switch_to_inferior_no_thread (curr_inf
);
5020 prepare_to_wait (ecs
);
5024 /* Go ahead and report the event. */
5028 /* Given an execution control state that has been freshly filled in by
5029 an event from the inferior, figure out what it means and take
5032 The alternatives are:
5034 1) stop_waiting and return; to really stop and return to the
5037 2) keep_going and return; to wait for the next event (set
5038 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5042 handle_inferior_event (struct execution_control_state
*ecs
)
5044 /* Make sure that all temporary struct value objects that were
5045 created during the handling of the event get deleted at the
5047 scoped_value_mark free_values
;
5049 enum stop_kind stop_soon
;
5051 infrun_debug_printf ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5053 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5055 /* We had an event in the inferior, but we are not interested in
5056 handling it at this level. The lower layers have already
5057 done what needs to be done, if anything.
5059 One of the possible circumstances for this is when the
5060 inferior produces output for the console. The inferior has
5061 not stopped, and we are ignoring the event. Another possible
5062 circumstance is any event which the lower level knows will be
5063 reported multiple times without an intervening resume. */
5064 prepare_to_wait (ecs
);
5068 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5070 prepare_to_wait (ecs
);
5074 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5075 && handle_no_resumed (ecs
))
5078 /* Cache the last target/ptid/waitstatus. */
5079 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5081 /* Always clear state belonging to the previous time we stopped. */
5082 stop_stack_dummy
= STOP_NONE
;
5084 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5086 /* No unwaited-for children left. IOW, all resumed children
5088 stop_print_frame
= false;
5093 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5094 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5096 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5097 /* If it's a new thread, add it to the thread database. */
5098 if (ecs
->event_thread
== NULL
)
5099 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5101 /* Disable range stepping. If the next step request could use a
5102 range, this will be end up re-enabled then. */
5103 ecs
->event_thread
->control
.may_range_step
= 0;
5106 /* Dependent on valid ECS->EVENT_THREAD. */
5107 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5109 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5110 reinit_frame_cache ();
5112 breakpoint_retire_moribund ();
5114 /* First, distinguish signals caused by the debugger from signals
5115 that have to do with the program's own actions. Note that
5116 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5117 on the operating system version. Here we detect when a SIGILL or
5118 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5119 something similar for SIGSEGV, since a SIGSEGV will be generated
5120 when we're trying to execute a breakpoint instruction on a
5121 non-executable stack. This happens for call dummy breakpoints
5122 for architectures like SPARC that place call dummies on the
5124 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5125 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5126 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5127 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5129 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5131 if (breakpoint_inserted_here_p (regcache
->aspace (),
5132 regcache_read_pc (regcache
)))
5134 infrun_debug_printf ("Treating signal as SIGTRAP");
5135 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5139 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5141 switch (ecs
->ws
.kind
)
5143 case TARGET_WAITKIND_LOADED
:
5144 context_switch (ecs
);
5145 /* Ignore gracefully during startup of the inferior, as it might
5146 be the shell which has just loaded some objects, otherwise
5147 add the symbols for the newly loaded objects. Also ignore at
5148 the beginning of an attach or remote session; we will query
5149 the full list of libraries once the connection is
5152 stop_soon
= get_inferior_stop_soon (ecs
);
5153 if (stop_soon
== NO_STOP_QUIETLY
)
5155 struct regcache
*regcache
;
5157 regcache
= get_thread_regcache (ecs
->event_thread
);
5159 handle_solib_event ();
5161 ecs
->event_thread
->control
.stop_bpstat
5162 = bpstat_stop_status (regcache
->aspace (),
5163 ecs
->event_thread
->suspend
.stop_pc
,
5164 ecs
->event_thread
, &ecs
->ws
);
5166 if (handle_stop_requested (ecs
))
5169 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5171 /* A catchpoint triggered. */
5172 process_event_stop_test (ecs
);
5176 /* If requested, stop when the dynamic linker notifies
5177 gdb of events. This allows the user to get control
5178 and place breakpoints in initializer routines for
5179 dynamically loaded objects (among other things). */
5180 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5181 if (stop_on_solib_events
)
5183 /* Make sure we print "Stopped due to solib-event" in
5185 stop_print_frame
= true;
5192 /* If we are skipping through a shell, or through shared library
5193 loading that we aren't interested in, resume the program. If
5194 we're running the program normally, also resume. */
5195 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5197 /* Loading of shared libraries might have changed breakpoint
5198 addresses. Make sure new breakpoints are inserted. */
5199 if (stop_soon
== NO_STOP_QUIETLY
)
5200 insert_breakpoints ();
5201 resume (GDB_SIGNAL_0
);
5202 prepare_to_wait (ecs
);
5206 /* But stop if we're attaching or setting up a remote
5208 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5209 || stop_soon
== STOP_QUIETLY_REMOTE
)
5211 infrun_debug_printf ("quietly stopped");
5216 internal_error (__FILE__
, __LINE__
,
5217 _("unhandled stop_soon: %d"), (int) stop_soon
);
5219 case TARGET_WAITKIND_SPURIOUS
:
5220 if (handle_stop_requested (ecs
))
5222 context_switch (ecs
);
5223 resume (GDB_SIGNAL_0
);
5224 prepare_to_wait (ecs
);
5227 case TARGET_WAITKIND_THREAD_CREATED
:
5228 if (handle_stop_requested (ecs
))
5230 context_switch (ecs
);
5231 if (!switch_back_to_stepped_thread (ecs
))
5235 case TARGET_WAITKIND_EXITED
:
5236 case TARGET_WAITKIND_SIGNALLED
:
5238 /* Depending on the system, ecs->ptid may point to a thread or
5239 to a process. On some targets, target_mourn_inferior may
5240 need to have access to the just-exited thread. That is the
5241 case of GNU/Linux's "checkpoint" support, for example.
5242 Call the switch_to_xxx routine as appropriate. */
5243 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5245 switch_to_thread (thr
);
5248 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5249 switch_to_inferior_no_thread (inf
);
5252 handle_vfork_child_exec_or_exit (0);
5253 target_terminal::ours (); /* Must do this before mourn anyway. */
5255 /* Clearing any previous state of convenience variables. */
5256 clear_exit_convenience_vars ();
5258 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5260 /* Record the exit code in the convenience variable $_exitcode, so
5261 that the user can inspect this again later. */
5262 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5263 (LONGEST
) ecs
->ws
.value
.integer
);
5265 /* Also record this in the inferior itself. */
5266 current_inferior ()->has_exit_code
= 1;
5267 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5269 /* Support the --return-child-result option. */
5270 return_child_result_value
= ecs
->ws
.value
.integer
;
5272 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5276 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5278 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5280 /* Set the value of the internal variable $_exitsignal,
5281 which holds the signal uncaught by the inferior. */
5282 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5283 gdbarch_gdb_signal_to_target (gdbarch
,
5284 ecs
->ws
.value
.sig
));
5288 /* We don't have access to the target's method used for
5289 converting between signal numbers (GDB's internal
5290 representation <-> target's representation).
5291 Therefore, we cannot do a good job at displaying this
5292 information to the user. It's better to just warn
5293 her about it (if infrun debugging is enabled), and
5295 infrun_debug_printf ("Cannot fill $_exitsignal with the correct "
5299 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5302 gdb_flush (gdb_stdout
);
5303 target_mourn_inferior (inferior_ptid
);
5304 stop_print_frame
= false;
5308 case TARGET_WAITKIND_FORKED
:
5309 case TARGET_WAITKIND_VFORKED
:
5310 /* Check whether the inferior is displaced stepping. */
5312 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5313 struct gdbarch
*gdbarch
= regcache
->arch ();
5315 /* If checking displaced stepping is supported, and thread
5316 ecs->ptid is displaced stepping. */
5317 if (displaced_step_in_progress_thread (ecs
->event_thread
))
5319 struct inferior
*parent_inf
5320 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5321 struct regcache
*child_regcache
;
5322 CORE_ADDR parent_pc
;
5324 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5326 struct displaced_step_inferior_state
*displaced
5327 = get_displaced_stepping_state (parent_inf
);
5329 /* Restore scratch pad for child process. */
5330 displaced_step_restore (displaced
, ecs
->ws
.value
.related_pid
);
5333 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5334 indicating that the displaced stepping of syscall instruction
5335 has been done. Perform cleanup for parent process here. Note
5336 that this operation also cleans up the child process for vfork,
5337 because their pages are shared. */
5338 displaced_step_fixup (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5339 /* Start a new step-over in another thread if there's one
5343 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5344 the child's PC is also within the scratchpad. Set the child's PC
5345 to the parent's PC value, which has already been fixed up.
5346 FIXME: we use the parent's aspace here, although we're touching
5347 the child, because the child hasn't been added to the inferior
5348 list yet at this point. */
5351 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5352 ecs
->ws
.value
.related_pid
,
5354 parent_inf
->aspace
);
5355 /* Read PC value of parent process. */
5356 parent_pc
= regcache_read_pc (regcache
);
5358 displaced_debug_printf ("write child pc from %s to %s",
5360 regcache_read_pc (child_regcache
)),
5361 paddress (gdbarch
, parent_pc
));
5363 regcache_write_pc (child_regcache
, parent_pc
);
5367 context_switch (ecs
);
5369 /* Immediately detach breakpoints from the child before there's
5370 any chance of letting the user delete breakpoints from the
5371 breakpoint lists. If we don't do this early, it's easy to
5372 leave left over traps in the child, vis: "break foo; catch
5373 fork; c; <fork>; del; c; <child calls foo>". We only follow
5374 the fork on the last `continue', and by that time the
5375 breakpoint at "foo" is long gone from the breakpoint table.
5376 If we vforked, then we don't need to unpatch here, since both
5377 parent and child are sharing the same memory pages; we'll
5378 need to unpatch at follow/detach time instead to be certain
5379 that new breakpoints added between catchpoint hit time and
5380 vfork follow are detached. */
5381 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5383 /* This won't actually modify the breakpoint list, but will
5384 physically remove the breakpoints from the child. */
5385 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5388 delete_just_stopped_threads_single_step_breakpoints ();
5390 /* In case the event is caught by a catchpoint, remember that
5391 the event is to be followed at the next resume of the thread,
5392 and not immediately. */
5393 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5395 ecs
->event_thread
->suspend
.stop_pc
5396 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5398 ecs
->event_thread
->control
.stop_bpstat
5399 = bpstat_stop_status (get_current_regcache ()->aspace (),
5400 ecs
->event_thread
->suspend
.stop_pc
,
5401 ecs
->event_thread
, &ecs
->ws
);
5403 if (handle_stop_requested (ecs
))
5406 /* If no catchpoint triggered for this, then keep going. Note
5407 that we're interested in knowing the bpstat actually causes a
5408 stop, not just if it may explain the signal. Software
5409 watchpoints, for example, always appear in the bpstat. */
5410 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5413 = (follow_fork_mode_string
== follow_fork_mode_child
);
5415 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5417 process_stratum_target
*targ
5418 = ecs
->event_thread
->inf
->process_target ();
5420 bool should_resume
= follow_fork ();
5422 /* Note that one of these may be an invalid pointer,
5423 depending on detach_fork. */
5424 thread_info
*parent
= ecs
->event_thread
;
5426 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5428 /* At this point, the parent is marked running, and the
5429 child is marked stopped. */
5431 /* If not resuming the parent, mark it stopped. */
5432 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5433 parent
->set_running (false);
5435 /* If resuming the child, mark it running. */
5436 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5437 child
->set_running (true);
5439 /* In non-stop mode, also resume the other branch. */
5440 if (!detach_fork
&& (non_stop
5441 || (sched_multi
&& target_is_non_stop_p ())))
5444 switch_to_thread (parent
);
5446 switch_to_thread (child
);
5448 ecs
->event_thread
= inferior_thread ();
5449 ecs
->ptid
= inferior_ptid
;
5454 switch_to_thread (child
);
5456 switch_to_thread (parent
);
5458 ecs
->event_thread
= inferior_thread ();
5459 ecs
->ptid
= inferior_ptid
;
5467 process_event_stop_test (ecs
);
5470 case TARGET_WAITKIND_VFORK_DONE
:
5471 /* Done with the shared memory region. Re-insert breakpoints in
5472 the parent, and keep going. */
5474 context_switch (ecs
);
5476 current_inferior ()->waiting_for_vfork_done
= 0;
5477 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5479 if (handle_stop_requested (ecs
))
5482 /* This also takes care of reinserting breakpoints in the
5483 previously locked inferior. */
5487 case TARGET_WAITKIND_EXECD
:
5489 /* Note we can't read registers yet (the stop_pc), because we
5490 don't yet know the inferior's post-exec architecture.
5491 'stop_pc' is explicitly read below instead. */
5492 switch_to_thread_no_regs (ecs
->event_thread
);
5494 /* Do whatever is necessary to the parent branch of the vfork. */
5495 handle_vfork_child_exec_or_exit (1);
5497 /* This causes the eventpoints and symbol table to be reset.
5498 Must do this now, before trying to determine whether to
5500 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5502 /* In follow_exec we may have deleted the original thread and
5503 created a new one. Make sure that the event thread is the
5504 execd thread for that case (this is a nop otherwise). */
5505 ecs
->event_thread
= inferior_thread ();
5507 ecs
->event_thread
->suspend
.stop_pc
5508 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5510 ecs
->event_thread
->control
.stop_bpstat
5511 = bpstat_stop_status (get_current_regcache ()->aspace (),
5512 ecs
->event_thread
->suspend
.stop_pc
,
5513 ecs
->event_thread
, &ecs
->ws
);
5515 /* Note that this may be referenced from inside
5516 bpstat_stop_status above, through inferior_has_execd. */
5517 xfree (ecs
->ws
.value
.execd_pathname
);
5518 ecs
->ws
.value
.execd_pathname
= NULL
;
5520 if (handle_stop_requested (ecs
))
5523 /* If no catchpoint triggered for this, then keep going. */
5524 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5526 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5530 process_event_stop_test (ecs
);
5533 /* Be careful not to try to gather much state about a thread
5534 that's in a syscall. It's frequently a losing proposition. */
5535 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5536 /* Getting the current syscall number. */
5537 if (handle_syscall_event (ecs
) == 0)
5538 process_event_stop_test (ecs
);
5541 /* Before examining the threads further, step this thread to
5542 get it entirely out of the syscall. (We get notice of the
5543 event when the thread is just on the verge of exiting a
5544 syscall. Stepping one instruction seems to get it back
5546 case TARGET_WAITKIND_SYSCALL_RETURN
:
5547 if (handle_syscall_event (ecs
) == 0)
5548 process_event_stop_test (ecs
);
5551 case TARGET_WAITKIND_STOPPED
:
5552 handle_signal_stop (ecs
);
5555 case TARGET_WAITKIND_NO_HISTORY
:
5556 /* Reverse execution: target ran out of history info. */
5558 /* Switch to the stopped thread. */
5559 context_switch (ecs
);
5560 infrun_debug_printf ("stopped");
5562 delete_just_stopped_threads_single_step_breakpoints ();
5563 ecs
->event_thread
->suspend
.stop_pc
5564 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5566 if (handle_stop_requested (ecs
))
5569 gdb::observers::no_history
.notify ();
5575 /* Restart threads back to what they were trying to do back when we
5576 paused them for an in-line step-over. The EVENT_THREAD thread is
5580 restart_threads (struct thread_info
*event_thread
)
5582 /* In case the instruction just stepped spawned a new thread. */
5583 update_thread_list ();
5585 for (thread_info
*tp
: all_non_exited_threads ())
5587 switch_to_thread_no_regs (tp
);
5589 if (tp
== event_thread
)
5591 infrun_debug_printf ("restart threads: [%s] is event thread",
5592 target_pid_to_str (tp
->ptid
).c_str ());
5596 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5598 infrun_debug_printf ("restart threads: [%s] not meant to be running",
5599 target_pid_to_str (tp
->ptid
).c_str ());
5605 infrun_debug_printf ("restart threads: [%s] resumed",
5606 target_pid_to_str (tp
->ptid
).c_str ());
5607 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5611 if (thread_is_in_step_over_chain (tp
))
5613 infrun_debug_printf ("restart threads: [%s] needs step-over",
5614 target_pid_to_str (tp
->ptid
).c_str ());
5615 gdb_assert (!tp
->resumed
);
5620 if (tp
->suspend
.waitstatus_pending_p
)
5622 infrun_debug_printf ("restart threads: [%s] has pending status",
5623 target_pid_to_str (tp
->ptid
).c_str ());
5628 gdb_assert (!tp
->stop_requested
);
5630 /* If some thread needs to start a step-over at this point, it
5631 should still be in the step-over queue, and thus skipped
5633 if (thread_still_needs_step_over (tp
))
5635 internal_error (__FILE__
, __LINE__
,
5636 "thread [%s] needs a step-over, but not in "
5637 "step-over queue\n",
5638 target_pid_to_str (tp
->ptid
).c_str ());
5641 if (currently_stepping (tp
))
5643 infrun_debug_printf ("restart threads: [%s] was stepping",
5644 target_pid_to_str (tp
->ptid
).c_str ());
5645 keep_going_stepped_thread (tp
);
5649 struct execution_control_state ecss
;
5650 struct execution_control_state
*ecs
= &ecss
;
5652 infrun_debug_printf ("restart threads: [%s] continuing",
5653 target_pid_to_str (tp
->ptid
).c_str ());
5654 reset_ecs (ecs
, tp
);
5655 switch_to_thread (tp
);
5656 keep_going_pass_signal (ecs
);
5661 /* Callback for iterate_over_threads. Find a resumed thread that has
5662 a pending waitstatus. */
5665 resumed_thread_with_pending_status (struct thread_info
*tp
,
5669 && tp
->suspend
.waitstatus_pending_p
);
5672 /* Called when we get an event that may finish an in-line or
5673 out-of-line (displaced stepping) step-over started previously.
5674 Return true if the event is processed and we should go back to the
5675 event loop; false if the caller should continue processing the
5679 finish_step_over (struct execution_control_state
*ecs
)
5681 displaced_step_fixup (ecs
->event_thread
,
5682 ecs
->event_thread
->suspend
.stop_signal
);
5684 bool had_step_over_info
= step_over_info_valid_p ();
5686 if (had_step_over_info
)
5688 /* If we're stepping over a breakpoint with all threads locked,
5689 then only the thread that was stepped should be reporting
5691 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5693 clear_step_over_info ();
5696 if (!target_is_non_stop_p ())
5699 /* Start a new step-over in another thread if there's one that
5703 /* If we were stepping over a breakpoint before, and haven't started
5704 a new in-line step-over sequence, then restart all other threads
5705 (except the event thread). We can't do this in all-stop, as then
5706 e.g., we wouldn't be able to issue any other remote packet until
5707 these other threads stop. */
5708 if (had_step_over_info
&& !step_over_info_valid_p ())
5710 struct thread_info
*pending
;
5712 /* If we only have threads with pending statuses, the restart
5713 below won't restart any thread and so nothing re-inserts the
5714 breakpoint we just stepped over. But we need it inserted
5715 when we later process the pending events, otherwise if
5716 another thread has a pending event for this breakpoint too,
5717 we'd discard its event (because the breakpoint that
5718 originally caused the event was no longer inserted). */
5719 context_switch (ecs
);
5720 insert_breakpoints ();
5722 restart_threads (ecs
->event_thread
);
5724 /* If we have events pending, go through handle_inferior_event
5725 again, picking up a pending event at random. This avoids
5726 thread starvation. */
5728 /* But not if we just stepped over a watchpoint in order to let
5729 the instruction execute so we can evaluate its expression.
5730 The set of watchpoints that triggered is recorded in the
5731 breakpoint objects themselves (see bp->watchpoint_triggered).
5732 If we processed another event first, that other event could
5733 clobber this info. */
5734 if (ecs
->event_thread
->stepping_over_watchpoint
)
5737 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5739 if (pending
!= NULL
)
5741 struct thread_info
*tp
= ecs
->event_thread
;
5742 struct regcache
*regcache
;
5744 infrun_debug_printf ("found resumed threads with "
5745 "pending events, saving status");
5747 gdb_assert (pending
!= tp
);
5749 /* Record the event thread's event for later. */
5750 save_waitstatus (tp
, &ecs
->ws
);
5751 /* This was cleared early, by handle_inferior_event. Set it
5752 so this pending event is considered by
5756 gdb_assert (!tp
->executing
);
5758 regcache
= get_thread_regcache (tp
);
5759 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5761 infrun_debug_printf ("saved stop_pc=%s for %s "
5762 "(currently_stepping=%d)",
5763 paddress (target_gdbarch (),
5764 tp
->suspend
.stop_pc
),
5765 target_pid_to_str (tp
->ptid
).c_str (),
5766 currently_stepping (tp
));
5768 /* This in-line step-over finished; clear this so we won't
5769 start a new one. This is what handle_signal_stop would
5770 do, if we returned false. */
5771 tp
->stepping_over_breakpoint
= 0;
5773 /* Wake up the event loop again. */
5774 mark_async_event_handler (infrun_async_inferior_event_token
);
5776 prepare_to_wait (ecs
);
5784 /* Come here when the program has stopped with a signal. */
5787 handle_signal_stop (struct execution_control_state
*ecs
)
5789 struct frame_info
*frame
;
5790 struct gdbarch
*gdbarch
;
5791 int stopped_by_watchpoint
;
5792 enum stop_kind stop_soon
;
5795 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5797 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5799 /* Do we need to clean up the state of a thread that has
5800 completed a displaced single-step? (Doing so usually affects
5801 the PC, so do it here, before we set stop_pc.) */
5802 if (finish_step_over (ecs
))
5805 /* If we either finished a single-step or hit a breakpoint, but
5806 the user wanted this thread to be stopped, pretend we got a
5807 SIG0 (generic unsignaled stop). */
5808 if (ecs
->event_thread
->stop_requested
5809 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5810 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5812 ecs
->event_thread
->suspend
.stop_pc
5813 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5817 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5818 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5820 switch_to_thread (ecs
->event_thread
);
5822 infrun_debug_printf ("stop_pc=%s",
5823 paddress (reg_gdbarch
,
5824 ecs
->event_thread
->suspend
.stop_pc
));
5825 if (target_stopped_by_watchpoint ())
5829 infrun_debug_printf ("stopped by watchpoint");
5831 if (target_stopped_data_address (current_top_target (), &addr
))
5832 infrun_debug_printf ("stopped data address=%s",
5833 paddress (reg_gdbarch
, addr
));
5835 infrun_debug_printf ("(no data address available)");
5839 /* This is originated from start_remote(), start_inferior() and
5840 shared libraries hook functions. */
5841 stop_soon
= get_inferior_stop_soon (ecs
);
5842 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5844 context_switch (ecs
);
5845 infrun_debug_printf ("quietly stopped");
5846 stop_print_frame
= true;
5851 /* This originates from attach_command(). We need to overwrite
5852 the stop_signal here, because some kernels don't ignore a
5853 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5854 See more comments in inferior.h. On the other hand, if we
5855 get a non-SIGSTOP, report it to the user - assume the backend
5856 will handle the SIGSTOP if it should show up later.
5858 Also consider that the attach is complete when we see a
5859 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5860 target extended-remote report it instead of a SIGSTOP
5861 (e.g. gdbserver). We already rely on SIGTRAP being our
5862 signal, so this is no exception.
5864 Also consider that the attach is complete when we see a
5865 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5866 the target to stop all threads of the inferior, in case the
5867 low level attach operation doesn't stop them implicitly. If
5868 they weren't stopped implicitly, then the stub will report a
5869 GDB_SIGNAL_0, meaning: stopped for no particular reason
5870 other than GDB's request. */
5871 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5872 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5873 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5874 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5876 stop_print_frame
= true;
5878 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5882 /* See if something interesting happened to the non-current thread. If
5883 so, then switch to that thread. */
5884 if (ecs
->ptid
!= inferior_ptid
)
5886 infrun_debug_printf ("context switch");
5888 context_switch (ecs
);
5890 if (deprecated_context_hook
)
5891 deprecated_context_hook (ecs
->event_thread
->global_num
);
5894 /* At this point, get hold of the now-current thread's frame. */
5895 frame
= get_current_frame ();
5896 gdbarch
= get_frame_arch (frame
);
5898 /* Pull the single step breakpoints out of the target. */
5899 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5901 struct regcache
*regcache
;
5904 regcache
= get_thread_regcache (ecs
->event_thread
);
5905 const address_space
*aspace
= regcache
->aspace ();
5907 pc
= regcache_read_pc (regcache
);
5909 /* However, before doing so, if this single-step breakpoint was
5910 actually for another thread, set this thread up for moving
5912 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5915 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5917 infrun_debug_printf ("[%s] hit another thread's single-step "
5919 target_pid_to_str (ecs
->ptid
).c_str ());
5920 ecs
->hit_singlestep_breakpoint
= 1;
5925 infrun_debug_printf ("[%s] hit its single-step breakpoint",
5926 target_pid_to_str (ecs
->ptid
).c_str ());
5929 delete_just_stopped_threads_single_step_breakpoints ();
5931 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5932 && ecs
->event_thread
->control
.trap_expected
5933 && ecs
->event_thread
->stepping_over_watchpoint
)
5934 stopped_by_watchpoint
= 0;
5936 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5938 /* If necessary, step over this watchpoint. We'll be back to display
5940 if (stopped_by_watchpoint
5941 && (target_have_steppable_watchpoint ()
5942 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5944 /* At this point, we are stopped at an instruction which has
5945 attempted to write to a piece of memory under control of
5946 a watchpoint. The instruction hasn't actually executed
5947 yet. If we were to evaluate the watchpoint expression
5948 now, we would get the old value, and therefore no change
5949 would seem to have occurred.
5951 In order to make watchpoints work `right', we really need
5952 to complete the memory write, and then evaluate the
5953 watchpoint expression. We do this by single-stepping the
5956 It may not be necessary to disable the watchpoint to step over
5957 it. For example, the PA can (with some kernel cooperation)
5958 single step over a watchpoint without disabling the watchpoint.
5960 It is far more common to need to disable a watchpoint to step
5961 the inferior over it. If we have non-steppable watchpoints,
5962 we must disable the current watchpoint; it's simplest to
5963 disable all watchpoints.
5965 Any breakpoint at PC must also be stepped over -- if there's
5966 one, it will have already triggered before the watchpoint
5967 triggered, and we either already reported it to the user, or
5968 it didn't cause a stop and we called keep_going. In either
5969 case, if there was a breakpoint at PC, we must be trying to
5971 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5976 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5977 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5978 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5979 ecs
->event_thread
->control
.stop_step
= 0;
5980 stop_print_frame
= true;
5981 stopped_by_random_signal
= 0;
5982 bpstat stop_chain
= NULL
;
5984 /* Hide inlined functions starting here, unless we just performed stepi or
5985 nexti. After stepi and nexti, always show the innermost frame (not any
5986 inline function call sites). */
5987 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5989 const address_space
*aspace
5990 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5992 /* skip_inline_frames is expensive, so we avoid it if we can
5993 determine that the address is one where functions cannot have
5994 been inlined. This improves performance with inferiors that
5995 load a lot of shared libraries, because the solib event
5996 breakpoint is defined as the address of a function (i.e. not
5997 inline). Note that we have to check the previous PC as well
5998 as the current one to catch cases when we have just
5999 single-stepped off a breakpoint prior to reinstating it.
6000 Note that we're assuming that the code we single-step to is
6001 not inline, but that's not definitive: there's nothing
6002 preventing the event breakpoint function from containing
6003 inlined code, and the single-step ending up there. If the
6004 user had set a breakpoint on that inlined code, the missing
6005 skip_inline_frames call would break things. Fortunately
6006 that's an extremely unlikely scenario. */
6007 if (!pc_at_non_inline_function (aspace
,
6008 ecs
->event_thread
->suspend
.stop_pc
,
6010 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6011 && ecs
->event_thread
->control
.trap_expected
6012 && pc_at_non_inline_function (aspace
,
6013 ecs
->event_thread
->prev_pc
,
6016 stop_chain
= build_bpstat_chain (aspace
,
6017 ecs
->event_thread
->suspend
.stop_pc
,
6019 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6021 /* Re-fetch current thread's frame in case that invalidated
6023 frame
= get_current_frame ();
6024 gdbarch
= get_frame_arch (frame
);
6028 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6029 && ecs
->event_thread
->control
.trap_expected
6030 && gdbarch_single_step_through_delay_p (gdbarch
)
6031 && currently_stepping (ecs
->event_thread
))
6033 /* We're trying to step off a breakpoint. Turns out that we're
6034 also on an instruction that needs to be stepped multiple
6035 times before it's been fully executing. E.g., architectures
6036 with a delay slot. It needs to be stepped twice, once for
6037 the instruction and once for the delay slot. */
6038 int step_through_delay
6039 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6041 if (step_through_delay
)
6042 infrun_debug_printf ("step through delay");
6044 if (ecs
->event_thread
->control
.step_range_end
== 0
6045 && step_through_delay
)
6047 /* The user issued a continue when stopped at a breakpoint.
6048 Set up for another trap and get out of here. */
6049 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6053 else if (step_through_delay
)
6055 /* The user issued a step when stopped at a breakpoint.
6056 Maybe we should stop, maybe we should not - the delay
6057 slot *might* correspond to a line of source. In any
6058 case, don't decide that here, just set
6059 ecs->stepping_over_breakpoint, making sure we
6060 single-step again before breakpoints are re-inserted. */
6061 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6065 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6066 handles this event. */
6067 ecs
->event_thread
->control
.stop_bpstat
6068 = bpstat_stop_status (get_current_regcache ()->aspace (),
6069 ecs
->event_thread
->suspend
.stop_pc
,
6070 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6072 /* Following in case break condition called a
6074 stop_print_frame
= true;
6076 /* This is where we handle "moribund" watchpoints. Unlike
6077 software breakpoints traps, hardware watchpoint traps are
6078 always distinguishable from random traps. If no high-level
6079 watchpoint is associated with the reported stop data address
6080 anymore, then the bpstat does not explain the signal ---
6081 simply make sure to ignore it if `stopped_by_watchpoint' is
6084 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6085 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6087 && stopped_by_watchpoint
)
6089 infrun_debug_printf ("no user watchpoint explains watchpoint SIGTRAP, "
6093 /* NOTE: cagney/2003-03-29: These checks for a random signal
6094 at one stage in the past included checks for an inferior
6095 function call's call dummy's return breakpoint. The original
6096 comment, that went with the test, read:
6098 ``End of a stack dummy. Some systems (e.g. Sony news) give
6099 another signal besides SIGTRAP, so check here as well as
6102 If someone ever tries to get call dummys on a
6103 non-executable stack to work (where the target would stop
6104 with something like a SIGSEGV), then those tests might need
6105 to be re-instated. Given, however, that the tests were only
6106 enabled when momentary breakpoints were not being used, I
6107 suspect that it won't be the case.
6109 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6110 be necessary for call dummies on a non-executable stack on
6113 /* See if the breakpoints module can explain the signal. */
6115 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6116 ecs
->event_thread
->suspend
.stop_signal
);
6118 /* Maybe this was a trap for a software breakpoint that has since
6120 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6122 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6123 ecs
->event_thread
->suspend
.stop_pc
))
6125 struct regcache
*regcache
;
6128 /* Re-adjust PC to what the program would see if GDB was not
6130 regcache
= get_thread_regcache (ecs
->event_thread
);
6131 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6134 gdb::optional
<scoped_restore_tmpl
<int>>
6135 restore_operation_disable
;
6137 if (record_full_is_used ())
6138 restore_operation_disable
.emplace
6139 (record_full_gdb_operation_disable_set ());
6141 regcache_write_pc (regcache
,
6142 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6147 /* A delayed software breakpoint event. Ignore the trap. */
6148 infrun_debug_printf ("delayed software breakpoint trap, ignoring");
6153 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6154 has since been removed. */
6155 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6157 /* A delayed hardware breakpoint event. Ignore the trap. */
6158 infrun_debug_printf ("delayed hardware breakpoint/watchpoint "
6163 /* If not, perhaps stepping/nexting can. */
6165 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6166 && currently_stepping (ecs
->event_thread
));
6168 /* Perhaps the thread hit a single-step breakpoint of _another_
6169 thread. Single-step breakpoints are transparent to the
6170 breakpoints module. */
6172 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6174 /* No? Perhaps we got a moribund watchpoint. */
6176 random_signal
= !stopped_by_watchpoint
;
6178 /* Always stop if the user explicitly requested this thread to
6180 if (ecs
->event_thread
->stop_requested
)
6183 infrun_debug_printf ("user-requested stop");
6186 /* For the program's own signals, act according to
6187 the signal handling tables. */
6191 /* Signal not for debugging purposes. */
6192 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6193 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6195 infrun_debug_printf ("random signal (%s)",
6196 gdb_signal_to_symbol_string (stop_signal
));
6198 stopped_by_random_signal
= 1;
6200 /* Always stop on signals if we're either just gaining control
6201 of the program, or the user explicitly requested this thread
6202 to remain stopped. */
6203 if (stop_soon
!= NO_STOP_QUIETLY
6204 || ecs
->event_thread
->stop_requested
6206 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6212 /* Notify observers the signal has "handle print" set. Note we
6213 returned early above if stopping; normal_stop handles the
6214 printing in that case. */
6215 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6217 /* The signal table tells us to print about this signal. */
6218 target_terminal::ours_for_output ();
6219 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6220 target_terminal::inferior ();
6223 /* Clear the signal if it should not be passed. */
6224 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6225 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6227 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6228 && ecs
->event_thread
->control
.trap_expected
6229 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6231 /* We were just starting a new sequence, attempting to
6232 single-step off of a breakpoint and expecting a SIGTRAP.
6233 Instead this signal arrives. This signal will take us out
6234 of the stepping range so GDB needs to remember to, when
6235 the signal handler returns, resume stepping off that
6237 /* To simplify things, "continue" is forced to use the same
6238 code paths as single-step - set a breakpoint at the
6239 signal return address and then, once hit, step off that
6241 infrun_debug_printf ("signal arrived while stepping over breakpoint");
6243 insert_hp_step_resume_breakpoint_at_frame (frame
);
6244 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6245 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6246 ecs
->event_thread
->control
.trap_expected
= 0;
6248 /* If we were nexting/stepping some other thread, switch to
6249 it, so that we don't continue it, losing control. */
6250 if (!switch_back_to_stepped_thread (ecs
))
6255 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6256 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6258 || ecs
->event_thread
->control
.step_range_end
== 1)
6259 && frame_id_eq (get_stack_frame_id (frame
),
6260 ecs
->event_thread
->control
.step_stack_frame_id
)
6261 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6263 /* The inferior is about to take a signal that will take it
6264 out of the single step range. Set a breakpoint at the
6265 current PC (which is presumably where the signal handler
6266 will eventually return) and then allow the inferior to
6269 Note that this is only needed for a signal delivered
6270 while in the single-step range. Nested signals aren't a
6271 problem as they eventually all return. */
6272 infrun_debug_printf ("signal may take us out of single-step range");
6274 clear_step_over_info ();
6275 insert_hp_step_resume_breakpoint_at_frame (frame
);
6276 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6277 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6278 ecs
->event_thread
->control
.trap_expected
= 0;
6283 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6284 when either there's a nested signal, or when there's a
6285 pending signal enabled just as the signal handler returns
6286 (leaving the inferior at the step-resume-breakpoint without
6287 actually executing it). Either way continue until the
6288 breakpoint is really hit. */
6290 if (!switch_back_to_stepped_thread (ecs
))
6292 infrun_debug_printf ("random signal, keep going");
6299 process_event_stop_test (ecs
);
6302 /* Come here when we've got some debug event / signal we can explain
6303 (IOW, not a random signal), and test whether it should cause a
6304 stop, or whether we should resume the inferior (transparently).
6305 E.g., could be a breakpoint whose condition evaluates false; we
6306 could be still stepping within the line; etc. */
6309 process_event_stop_test (struct execution_control_state
*ecs
)
6311 struct symtab_and_line stop_pc_sal
;
6312 struct frame_info
*frame
;
6313 struct gdbarch
*gdbarch
;
6314 CORE_ADDR jmp_buf_pc
;
6315 struct bpstat_what what
;
6317 /* Handle cases caused by hitting a breakpoint. */
6319 frame
= get_current_frame ();
6320 gdbarch
= get_frame_arch (frame
);
6322 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6324 if (what
.call_dummy
)
6326 stop_stack_dummy
= what
.call_dummy
;
6329 /* A few breakpoint types have callbacks associated (e.g.,
6330 bp_jit_event). Run them now. */
6331 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6333 /* If we hit an internal event that triggers symbol changes, the
6334 current frame will be invalidated within bpstat_what (e.g., if we
6335 hit an internal solib event). Re-fetch it. */
6336 frame
= get_current_frame ();
6337 gdbarch
= get_frame_arch (frame
);
6339 switch (what
.main_action
)
6341 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6342 /* If we hit the breakpoint at longjmp while stepping, we
6343 install a momentary breakpoint at the target of the
6346 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6348 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6350 if (what
.is_longjmp
)
6352 struct value
*arg_value
;
6354 /* If we set the longjmp breakpoint via a SystemTap probe,
6355 then use it to extract the arguments. The destination PC
6356 is the third argument to the probe. */
6357 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6360 jmp_buf_pc
= value_as_address (arg_value
);
6361 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6363 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6364 || !gdbarch_get_longjmp_target (gdbarch
,
6365 frame
, &jmp_buf_pc
))
6367 infrun_debug_printf ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6368 "(!gdbarch_get_longjmp_target)");
6373 /* Insert a breakpoint at resume address. */
6374 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6377 check_exception_resume (ecs
, frame
);
6381 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6383 struct frame_info
*init_frame
;
6385 /* There are several cases to consider.
6387 1. The initiating frame no longer exists. In this case we
6388 must stop, because the exception or longjmp has gone too
6391 2. The initiating frame exists, and is the same as the
6392 current frame. We stop, because the exception or longjmp
6395 3. The initiating frame exists and is different from the
6396 current frame. This means the exception or longjmp has
6397 been caught beneath the initiating frame, so keep going.
6399 4. longjmp breakpoint has been placed just to protect
6400 against stale dummy frames and user is not interested in
6401 stopping around longjmps. */
6403 infrun_debug_printf ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6405 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6407 delete_exception_resume_breakpoint (ecs
->event_thread
);
6409 if (what
.is_longjmp
)
6411 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6413 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6421 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6425 struct frame_id current_id
6426 = get_frame_id (get_current_frame ());
6427 if (frame_id_eq (current_id
,
6428 ecs
->event_thread
->initiating_frame
))
6430 /* Case 2. Fall through. */
6440 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6442 delete_step_resume_breakpoint (ecs
->event_thread
);
6444 end_stepping_range (ecs
);
6448 case BPSTAT_WHAT_SINGLE
:
6449 infrun_debug_printf ("BPSTAT_WHAT_SINGLE");
6450 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6451 /* Still need to check other stuff, at least the case where we
6452 are stepping and step out of the right range. */
6455 case BPSTAT_WHAT_STEP_RESUME
:
6456 infrun_debug_printf ("BPSTAT_WHAT_STEP_RESUME");
6458 delete_step_resume_breakpoint (ecs
->event_thread
);
6459 if (ecs
->event_thread
->control
.proceed_to_finish
6460 && execution_direction
== EXEC_REVERSE
)
6462 struct thread_info
*tp
= ecs
->event_thread
;
6464 /* We are finishing a function in reverse, and just hit the
6465 step-resume breakpoint at the start address of the
6466 function, and we're almost there -- just need to back up
6467 by one more single-step, which should take us back to the
6469 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6473 fill_in_stop_func (gdbarch
, ecs
);
6474 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6475 && execution_direction
== EXEC_REVERSE
)
6477 /* We are stepping over a function call in reverse, and just
6478 hit the step-resume breakpoint at the start address of
6479 the function. Go back to single-stepping, which should
6480 take us back to the function call. */
6481 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6487 case BPSTAT_WHAT_STOP_NOISY
:
6488 infrun_debug_printf ("BPSTAT_WHAT_STOP_NOISY");
6489 stop_print_frame
= true;
6491 /* Assume the thread stopped for a breakpoint. We'll still check
6492 whether a/the breakpoint is there when the thread is next
6494 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6499 case BPSTAT_WHAT_STOP_SILENT
:
6500 infrun_debug_printf ("BPSTAT_WHAT_STOP_SILENT");
6501 stop_print_frame
= false;
6503 /* Assume the thread stopped for a breakpoint. We'll still check
6504 whether a/the breakpoint is there when the thread is next
6506 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6510 case BPSTAT_WHAT_HP_STEP_RESUME
:
6511 infrun_debug_printf ("BPSTAT_WHAT_HP_STEP_RESUME");
6513 delete_step_resume_breakpoint (ecs
->event_thread
);
6514 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6516 /* Back when the step-resume breakpoint was inserted, we
6517 were trying to single-step off a breakpoint. Go back to
6519 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6520 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6526 case BPSTAT_WHAT_KEEP_CHECKING
:
6530 /* If we stepped a permanent breakpoint and we had a high priority
6531 step-resume breakpoint for the address we stepped, but we didn't
6532 hit it, then we must have stepped into the signal handler. The
6533 step-resume was only necessary to catch the case of _not_
6534 stepping into the handler, so delete it, and fall through to
6535 checking whether the step finished. */
6536 if (ecs
->event_thread
->stepped_breakpoint
)
6538 struct breakpoint
*sr_bp
6539 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6542 && sr_bp
->loc
->permanent
6543 && sr_bp
->type
== bp_hp_step_resume
6544 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6546 infrun_debug_printf ("stepped permanent breakpoint, stopped in handler");
6547 delete_step_resume_breakpoint (ecs
->event_thread
);
6548 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6552 /* We come here if we hit a breakpoint but should not stop for it.
6553 Possibly we also were stepping and should stop for that. So fall
6554 through and test for stepping. But, if not stepping, do not
6557 /* In all-stop mode, if we're currently stepping but have stopped in
6558 some other thread, we need to switch back to the stepped thread. */
6559 if (switch_back_to_stepped_thread (ecs
))
6562 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6564 infrun_debug_printf ("step-resume breakpoint is inserted");
6566 /* Having a step-resume breakpoint overrides anything
6567 else having to do with stepping commands until
6568 that breakpoint is reached. */
6573 if (ecs
->event_thread
->control
.step_range_end
== 0)
6575 infrun_debug_printf ("no stepping, continue");
6576 /* Likewise if we aren't even stepping. */
6581 /* Re-fetch current thread's frame in case the code above caused
6582 the frame cache to be re-initialized, making our FRAME variable
6583 a dangling pointer. */
6584 frame
= get_current_frame ();
6585 gdbarch
= get_frame_arch (frame
);
6586 fill_in_stop_func (gdbarch
, ecs
);
6588 /* If stepping through a line, keep going if still within it.
6590 Note that step_range_end is the address of the first instruction
6591 beyond the step range, and NOT the address of the last instruction
6594 Note also that during reverse execution, we may be stepping
6595 through a function epilogue and therefore must detect when
6596 the current-frame changes in the middle of a line. */
6598 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6600 && (execution_direction
!= EXEC_REVERSE
6601 || frame_id_eq (get_frame_id (frame
),
6602 ecs
->event_thread
->control
.step_frame_id
)))
6605 ("stepping inside range [%s-%s]",
6606 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6607 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6609 /* Tentatively re-enable range stepping; `resume' disables it if
6610 necessary (e.g., if we're stepping over a breakpoint or we
6611 have software watchpoints). */
6612 ecs
->event_thread
->control
.may_range_step
= 1;
6614 /* When stepping backward, stop at beginning of line range
6615 (unless it's the function entry point, in which case
6616 keep going back to the call point). */
6617 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6618 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6619 && stop_pc
!= ecs
->stop_func_start
6620 && execution_direction
== EXEC_REVERSE
)
6621 end_stepping_range (ecs
);
6628 /* We stepped out of the stepping range. */
6630 /* If we are stepping at the source level and entered the runtime
6631 loader dynamic symbol resolution code...
6633 EXEC_FORWARD: we keep on single stepping until we exit the run
6634 time loader code and reach the callee's address.
6636 EXEC_REVERSE: we've already executed the callee (backward), and
6637 the runtime loader code is handled just like any other
6638 undebuggable function call. Now we need only keep stepping
6639 backward through the trampoline code, and that's handled further
6640 down, so there is nothing for us to do here. */
6642 if (execution_direction
!= EXEC_REVERSE
6643 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6644 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6646 CORE_ADDR pc_after_resolver
=
6647 gdbarch_skip_solib_resolver (gdbarch
,
6648 ecs
->event_thread
->suspend
.stop_pc
);
6650 infrun_debug_printf ("stepped into dynsym resolve code");
6652 if (pc_after_resolver
)
6654 /* Set up a step-resume breakpoint at the address
6655 indicated by SKIP_SOLIB_RESOLVER. */
6656 symtab_and_line sr_sal
;
6657 sr_sal
.pc
= pc_after_resolver
;
6658 sr_sal
.pspace
= get_frame_program_space (frame
);
6660 insert_step_resume_breakpoint_at_sal (gdbarch
,
6661 sr_sal
, null_frame_id
);
6668 /* Step through an indirect branch thunk. */
6669 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6670 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6671 ecs
->event_thread
->suspend
.stop_pc
))
6673 infrun_debug_printf ("stepped into indirect branch thunk");
6678 if (ecs
->event_thread
->control
.step_range_end
!= 1
6679 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6680 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6681 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6683 infrun_debug_printf ("stepped into signal trampoline");
6684 /* The inferior, while doing a "step" or "next", has ended up in
6685 a signal trampoline (either by a signal being delivered or by
6686 the signal handler returning). Just single-step until the
6687 inferior leaves the trampoline (either by calling the handler
6693 /* If we're in the return path from a shared library trampoline,
6694 we want to proceed through the trampoline when stepping. */
6695 /* macro/2012-04-25: This needs to come before the subroutine
6696 call check below as on some targets return trampolines look
6697 like subroutine calls (MIPS16 return thunks). */
6698 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6699 ecs
->event_thread
->suspend
.stop_pc
,
6700 ecs
->stop_func_name
)
6701 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6703 /* Determine where this trampoline returns. */
6704 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6705 CORE_ADDR real_stop_pc
6706 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6708 infrun_debug_printf ("stepped into solib return tramp");
6710 /* Only proceed through if we know where it's going. */
6713 /* And put the step-breakpoint there and go until there. */
6714 symtab_and_line sr_sal
;
6715 sr_sal
.pc
= real_stop_pc
;
6716 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6717 sr_sal
.pspace
= get_frame_program_space (frame
);
6719 /* Do not specify what the fp should be when we stop since
6720 on some machines the prologue is where the new fp value
6722 insert_step_resume_breakpoint_at_sal (gdbarch
,
6723 sr_sal
, null_frame_id
);
6725 /* Restart without fiddling with the step ranges or
6732 /* Check for subroutine calls. The check for the current frame
6733 equalling the step ID is not necessary - the check of the
6734 previous frame's ID is sufficient - but it is a common case and
6735 cheaper than checking the previous frame's ID.
6737 NOTE: frame_id_eq will never report two invalid frame IDs as
6738 being equal, so to get into this block, both the current and
6739 previous frame must have valid frame IDs. */
6740 /* The outer_frame_id check is a heuristic to detect stepping
6741 through startup code. If we step over an instruction which
6742 sets the stack pointer from an invalid value to a valid value,
6743 we may detect that as a subroutine call from the mythical
6744 "outermost" function. This could be fixed by marking
6745 outermost frames as !stack_p,code_p,special_p. Then the
6746 initial outermost frame, before sp was valid, would
6747 have code_addr == &_start. See the comment in frame_id_eq
6749 if (!frame_id_eq (get_stack_frame_id (frame
),
6750 ecs
->event_thread
->control
.step_stack_frame_id
)
6751 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6752 ecs
->event_thread
->control
.step_stack_frame_id
)
6753 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6755 || (ecs
->event_thread
->control
.step_start_function
6756 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6758 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6759 CORE_ADDR real_stop_pc
;
6761 infrun_debug_printf ("stepped into subroutine");
6763 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6765 /* I presume that step_over_calls is only 0 when we're
6766 supposed to be stepping at the assembly language level
6767 ("stepi"). Just stop. */
6768 /* And this works the same backward as frontward. MVS */
6769 end_stepping_range (ecs
);
6773 /* Reverse stepping through solib trampolines. */
6775 if (execution_direction
== EXEC_REVERSE
6776 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6777 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6778 || (ecs
->stop_func_start
== 0
6779 && in_solib_dynsym_resolve_code (stop_pc
))))
6781 /* Any solib trampoline code can be handled in reverse
6782 by simply continuing to single-step. We have already
6783 executed the solib function (backwards), and a few
6784 steps will take us back through the trampoline to the
6790 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6792 /* We're doing a "next".
6794 Normal (forward) execution: set a breakpoint at the
6795 callee's return address (the address at which the caller
6798 Reverse (backward) execution. set the step-resume
6799 breakpoint at the start of the function that we just
6800 stepped into (backwards), and continue to there. When we
6801 get there, we'll need to single-step back to the caller. */
6803 if (execution_direction
== EXEC_REVERSE
)
6805 /* If we're already at the start of the function, we've either
6806 just stepped backward into a single instruction function,
6807 or stepped back out of a signal handler to the first instruction
6808 of the function. Just keep going, which will single-step back
6810 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6812 /* Normal function call return (static or dynamic). */
6813 symtab_and_line sr_sal
;
6814 sr_sal
.pc
= ecs
->stop_func_start
;
6815 sr_sal
.pspace
= get_frame_program_space (frame
);
6816 insert_step_resume_breakpoint_at_sal (gdbarch
,
6817 sr_sal
, null_frame_id
);
6821 insert_step_resume_breakpoint_at_caller (frame
);
6827 /* If we are in a function call trampoline (a stub between the
6828 calling routine and the real function), locate the real
6829 function. That's what tells us (a) whether we want to step
6830 into it at all, and (b) what prologue we want to run to the
6831 end of, if we do step into it. */
6832 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6833 if (real_stop_pc
== 0)
6834 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6835 if (real_stop_pc
!= 0)
6836 ecs
->stop_func_start
= real_stop_pc
;
6838 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6840 symtab_and_line sr_sal
;
6841 sr_sal
.pc
= ecs
->stop_func_start
;
6842 sr_sal
.pspace
= get_frame_program_space (frame
);
6844 insert_step_resume_breakpoint_at_sal (gdbarch
,
6845 sr_sal
, null_frame_id
);
6850 /* If we have line number information for the function we are
6851 thinking of stepping into and the function isn't on the skip
6854 If there are several symtabs at that PC (e.g. with include
6855 files), just want to know whether *any* of them have line
6856 numbers. find_pc_line handles this. */
6858 struct symtab_and_line tmp_sal
;
6860 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6861 if (tmp_sal
.line
!= 0
6862 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6864 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6866 if (execution_direction
== EXEC_REVERSE
)
6867 handle_step_into_function_backward (gdbarch
, ecs
);
6869 handle_step_into_function (gdbarch
, ecs
);
6874 /* If we have no line number and the step-stop-if-no-debug is
6875 set, we stop the step so that the user has a chance to switch
6876 in assembly mode. */
6877 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6878 && step_stop_if_no_debug
)
6880 end_stepping_range (ecs
);
6884 if (execution_direction
== EXEC_REVERSE
)
6886 /* If we're already at the start of the function, we've either just
6887 stepped backward into a single instruction function without line
6888 number info, or stepped back out of a signal handler to the first
6889 instruction of the function without line number info. Just keep
6890 going, which will single-step back to the caller. */
6891 if (ecs
->stop_func_start
!= stop_pc
)
6893 /* Set a breakpoint at callee's start address.
6894 From there we can step once and be back in the caller. */
6895 symtab_and_line sr_sal
;
6896 sr_sal
.pc
= ecs
->stop_func_start
;
6897 sr_sal
.pspace
= get_frame_program_space (frame
);
6898 insert_step_resume_breakpoint_at_sal (gdbarch
,
6899 sr_sal
, null_frame_id
);
6903 /* Set a breakpoint at callee's return address (the address
6904 at which the caller will resume). */
6905 insert_step_resume_breakpoint_at_caller (frame
);
6911 /* Reverse stepping through solib trampolines. */
6913 if (execution_direction
== EXEC_REVERSE
6914 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6916 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6918 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6919 || (ecs
->stop_func_start
== 0
6920 && in_solib_dynsym_resolve_code (stop_pc
)))
6922 /* Any solib trampoline code can be handled in reverse
6923 by simply continuing to single-step. We have already
6924 executed the solib function (backwards), and a few
6925 steps will take us back through the trampoline to the
6930 else if (in_solib_dynsym_resolve_code (stop_pc
))
6932 /* Stepped backward into the solib dynsym resolver.
6933 Set a breakpoint at its start and continue, then
6934 one more step will take us out. */
6935 symtab_and_line sr_sal
;
6936 sr_sal
.pc
= ecs
->stop_func_start
;
6937 sr_sal
.pspace
= get_frame_program_space (frame
);
6938 insert_step_resume_breakpoint_at_sal (gdbarch
,
6939 sr_sal
, null_frame_id
);
6945 /* This always returns the sal for the inner-most frame when we are in a
6946 stack of inlined frames, even if GDB actually believes that it is in a
6947 more outer frame. This is checked for below by calls to
6948 inline_skipped_frames. */
6949 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6951 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6952 the trampoline processing logic, however, there are some trampolines
6953 that have no names, so we should do trampoline handling first. */
6954 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6955 && ecs
->stop_func_name
== NULL
6956 && stop_pc_sal
.line
== 0)
6958 infrun_debug_printf ("stepped into undebuggable function");
6960 /* The inferior just stepped into, or returned to, an
6961 undebuggable function (where there is no debugging information
6962 and no line number corresponding to the address where the
6963 inferior stopped). Since we want to skip this kind of code,
6964 we keep going until the inferior returns from this
6965 function - unless the user has asked us not to (via
6966 set step-mode) or we no longer know how to get back
6967 to the call site. */
6968 if (step_stop_if_no_debug
6969 || !frame_id_p (frame_unwind_caller_id (frame
)))
6971 /* If we have no line number and the step-stop-if-no-debug
6972 is set, we stop the step so that the user has a chance to
6973 switch in assembly mode. */
6974 end_stepping_range (ecs
);
6979 /* Set a breakpoint at callee's return address (the address
6980 at which the caller will resume). */
6981 insert_step_resume_breakpoint_at_caller (frame
);
6987 if (ecs
->event_thread
->control
.step_range_end
== 1)
6989 /* It is stepi or nexti. We always want to stop stepping after
6991 infrun_debug_printf ("stepi/nexti");
6992 end_stepping_range (ecs
);
6996 if (stop_pc_sal
.line
== 0)
6998 /* We have no line number information. That means to stop
6999 stepping (does this always happen right after one instruction,
7000 when we do "s" in a function with no line numbers,
7001 or can this happen as a result of a return or longjmp?). */
7002 infrun_debug_printf ("line number info");
7003 end_stepping_range (ecs
);
7007 /* Look for "calls" to inlined functions, part one. If the inline
7008 frame machinery detected some skipped call sites, we have entered
7009 a new inline function. */
7011 if (frame_id_eq (get_frame_id (get_current_frame ()),
7012 ecs
->event_thread
->control
.step_frame_id
)
7013 && inline_skipped_frames (ecs
->event_thread
))
7015 infrun_debug_printf ("stepped into inlined function");
7017 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7019 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7021 /* For "step", we're going to stop. But if the call site
7022 for this inlined function is on the same source line as
7023 we were previously stepping, go down into the function
7024 first. Otherwise stop at the call site. */
7026 if (call_sal
.line
== ecs
->event_thread
->current_line
7027 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7029 step_into_inline_frame (ecs
->event_thread
);
7030 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7037 end_stepping_range (ecs
);
7042 /* For "next", we should stop at the call site if it is on a
7043 different source line. Otherwise continue through the
7044 inlined function. */
7045 if (call_sal
.line
== ecs
->event_thread
->current_line
7046 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7049 end_stepping_range (ecs
);
7054 /* Look for "calls" to inlined functions, part two. If we are still
7055 in the same real function we were stepping through, but we have
7056 to go further up to find the exact frame ID, we are stepping
7057 through a more inlined call beyond its call site. */
7059 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7060 && !frame_id_eq (get_frame_id (get_current_frame ()),
7061 ecs
->event_thread
->control
.step_frame_id
)
7062 && stepped_in_from (get_current_frame (),
7063 ecs
->event_thread
->control
.step_frame_id
))
7065 infrun_debug_printf ("stepping through inlined function");
7067 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7068 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7071 end_stepping_range (ecs
);
7075 bool refresh_step_info
= true;
7076 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7077 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7078 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7080 if (stop_pc_sal
.is_stmt
)
7082 /* We are at the start of a different line. So stop. Note that
7083 we don't stop if we step into the middle of a different line.
7084 That is said to make things like for (;;) statements work
7086 infrun_debug_printf ("stepped to a different line");
7087 end_stepping_range (ecs
);
7090 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7091 ecs
->event_thread
->control
.step_frame_id
))
7093 /* We are at the start of a different line, however, this line is
7094 not marked as a statement, and we have not changed frame. We
7095 ignore this line table entry, and continue stepping forward,
7096 looking for a better place to stop. */
7097 refresh_step_info
= false;
7098 infrun_debug_printf ("stepped to a different line, but "
7099 "it's not the start of a statement");
7103 /* We aren't done stepping.
7105 Optimize by setting the stepping range to the line.
7106 (We might not be in the original line, but if we entered a
7107 new line in mid-statement, we continue stepping. This makes
7108 things like for(;;) statements work better.)
7110 If we entered a SAL that indicates a non-statement line table entry,
7111 then we update the stepping range, but we don't update the step info,
7112 which includes things like the line number we are stepping away from.
7113 This means we will stop when we find a line table entry that is marked
7114 as is-statement, even if it matches the non-statement one we just
7117 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7118 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7119 ecs
->event_thread
->control
.may_range_step
= 1;
7120 if (refresh_step_info
)
7121 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7123 infrun_debug_printf ("keep going");
7127 /* In all-stop mode, if we're currently stepping but have stopped in
7128 some other thread, we may need to switch back to the stepped
7129 thread. Returns true we set the inferior running, false if we left
7130 it stopped (and the event needs further processing). */
7133 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7135 if (!target_is_non_stop_p ())
7137 struct thread_info
*stepping_thread
;
7139 /* If any thread is blocked on some internal breakpoint, and we
7140 simply need to step over that breakpoint to get it going
7141 again, do that first. */
7143 /* However, if we see an event for the stepping thread, then we
7144 know all other threads have been moved past their breakpoints
7145 already. Let the caller check whether the step is finished,
7146 etc., before deciding to move it past a breakpoint. */
7147 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7150 /* Check if the current thread is blocked on an incomplete
7151 step-over, interrupted by a random signal. */
7152 if (ecs
->event_thread
->control
.trap_expected
7153 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7156 ("need to finish step-over of [%s]",
7157 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7162 /* Check if the current thread is blocked by a single-step
7163 breakpoint of another thread. */
7164 if (ecs
->hit_singlestep_breakpoint
)
7166 infrun_debug_printf ("need to step [%s] over single-step breakpoint",
7167 target_pid_to_str (ecs
->ptid
).c_str ());
7172 /* If this thread needs yet another step-over (e.g., stepping
7173 through a delay slot), do it first before moving on to
7175 if (thread_still_needs_step_over (ecs
->event_thread
))
7178 ("thread [%s] still needs step-over",
7179 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7184 /* If scheduler locking applies even if not stepping, there's no
7185 need to walk over threads. Above we've checked whether the
7186 current thread is stepping. If some other thread not the
7187 event thread is stepping, then it must be that scheduler
7188 locking is not in effect. */
7189 if (schedlock_applies (ecs
->event_thread
))
7192 /* Otherwise, we no longer expect a trap in the current thread.
7193 Clear the trap_expected flag before switching back -- this is
7194 what keep_going does as well, if we call it. */
7195 ecs
->event_thread
->control
.trap_expected
= 0;
7197 /* Likewise, clear the signal if it should not be passed. */
7198 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7199 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7201 /* Do all pending step-overs before actually proceeding with
7203 if (start_step_over ())
7205 prepare_to_wait (ecs
);
7209 /* Look for the stepping/nexting thread. */
7210 stepping_thread
= NULL
;
7212 for (thread_info
*tp
: all_non_exited_threads ())
7214 switch_to_thread_no_regs (tp
);
7216 /* Ignore threads of processes the caller is not
7219 && (tp
->inf
->process_target () != ecs
->target
7220 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7223 /* When stepping over a breakpoint, we lock all threads
7224 except the one that needs to move past the breakpoint.
7225 If a non-event thread has this set, the "incomplete
7226 step-over" check above should have caught it earlier. */
7227 if (tp
->control
.trap_expected
)
7229 internal_error (__FILE__
, __LINE__
,
7230 "[%s] has inconsistent state: "
7231 "trap_expected=%d\n",
7232 target_pid_to_str (tp
->ptid
).c_str (),
7233 tp
->control
.trap_expected
);
7236 /* Did we find the stepping thread? */
7237 if (tp
->control
.step_range_end
)
7239 /* Yep. There should only one though. */
7240 gdb_assert (stepping_thread
== NULL
);
7242 /* The event thread is handled at the top, before we
7244 gdb_assert (tp
!= ecs
->event_thread
);
7246 /* If some thread other than the event thread is
7247 stepping, then scheduler locking can't be in effect,
7248 otherwise we wouldn't have resumed the current event
7249 thread in the first place. */
7250 gdb_assert (!schedlock_applies (tp
));
7252 stepping_thread
= tp
;
7256 if (stepping_thread
!= NULL
)
7258 infrun_debug_printf ("switching back to stepped thread");
7260 if (keep_going_stepped_thread (stepping_thread
))
7262 prepare_to_wait (ecs
);
7267 switch_to_thread (ecs
->event_thread
);
7273 /* Set a previously stepped thread back to stepping. Returns true on
7274 success, false if the resume is not possible (e.g., the thread
7278 keep_going_stepped_thread (struct thread_info
*tp
)
7280 struct frame_info
*frame
;
7281 struct execution_control_state ecss
;
7282 struct execution_control_state
*ecs
= &ecss
;
7284 /* If the stepping thread exited, then don't try to switch back and
7285 resume it, which could fail in several different ways depending
7286 on the target. Instead, just keep going.
7288 We can find a stepping dead thread in the thread list in two
7291 - The target supports thread exit events, and when the target
7292 tries to delete the thread from the thread list, inferior_ptid
7293 pointed at the exiting thread. In such case, calling
7294 delete_thread does not really remove the thread from the list;
7295 instead, the thread is left listed, with 'exited' state.
7297 - The target's debug interface does not support thread exit
7298 events, and so we have no idea whatsoever if the previously
7299 stepping thread is still alive. For that reason, we need to
7300 synchronously query the target now. */
7302 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7304 infrun_debug_printf ("not resuming previously stepped thread, it has "
7311 infrun_debug_printf ("resuming previously stepped thread");
7313 reset_ecs (ecs
, tp
);
7314 switch_to_thread (tp
);
7316 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7317 frame
= get_current_frame ();
7319 /* If the PC of the thread we were trying to single-step has
7320 changed, then that thread has trapped or been signaled, but the
7321 event has not been reported to GDB yet. Re-poll the target
7322 looking for this particular thread's event (i.e. temporarily
7323 enable schedlock) by:
7325 - setting a break at the current PC
7326 - resuming that particular thread, only (by setting trap
7329 This prevents us continuously moving the single-step breakpoint
7330 forward, one instruction at a time, overstepping. */
7332 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7336 infrun_debug_printf ("expected thread advanced also (%s -> %s)",
7337 paddress (target_gdbarch (), tp
->prev_pc
),
7338 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7340 /* Clear the info of the previous step-over, as it's no longer
7341 valid (if the thread was trying to step over a breakpoint, it
7342 has already succeeded). It's what keep_going would do too,
7343 if we called it. Do this before trying to insert the sss
7344 breakpoint, otherwise if we were previously trying to step
7345 over this exact address in another thread, the breakpoint is
7347 clear_step_over_info ();
7348 tp
->control
.trap_expected
= 0;
7350 insert_single_step_breakpoint (get_frame_arch (frame
),
7351 get_frame_address_space (frame
),
7352 tp
->suspend
.stop_pc
);
7355 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7356 do_target_resume (resume_ptid
, false, GDB_SIGNAL_0
);
7360 infrun_debug_printf ("expected thread still hasn't advanced");
7362 keep_going_pass_signal (ecs
);
7368 /* Is thread TP in the middle of (software or hardware)
7369 single-stepping? (Note the result of this function must never be
7370 passed directly as target_resume's STEP parameter.) */
7373 currently_stepping (struct thread_info
*tp
)
7375 return ((tp
->control
.step_range_end
7376 && tp
->control
.step_resume_breakpoint
== NULL
)
7377 || tp
->control
.trap_expected
7378 || tp
->stepped_breakpoint
7379 || bpstat_should_step ());
7382 /* Inferior has stepped into a subroutine call with source code that
7383 we should not step over. Do step to the first line of code in
7387 handle_step_into_function (struct gdbarch
*gdbarch
,
7388 struct execution_control_state
*ecs
)
7390 fill_in_stop_func (gdbarch
, ecs
);
7392 compunit_symtab
*cust
7393 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7394 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7395 ecs
->stop_func_start
7396 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7398 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7399 /* Use the step_resume_break to step until the end of the prologue,
7400 even if that involves jumps (as it seems to on the vax under
7402 /* If the prologue ends in the middle of a source line, continue to
7403 the end of that source line (if it is still within the function).
7404 Otherwise, just go to end of prologue. */
7405 if (stop_func_sal
.end
7406 && stop_func_sal
.pc
!= ecs
->stop_func_start
7407 && stop_func_sal
.end
< ecs
->stop_func_end
)
7408 ecs
->stop_func_start
= stop_func_sal
.end
;
7410 /* Architectures which require breakpoint adjustment might not be able
7411 to place a breakpoint at the computed address. If so, the test
7412 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7413 ecs->stop_func_start to an address at which a breakpoint may be
7414 legitimately placed.
7416 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7417 made, GDB will enter an infinite loop when stepping through
7418 optimized code consisting of VLIW instructions which contain
7419 subinstructions corresponding to different source lines. On
7420 FR-V, it's not permitted to place a breakpoint on any but the
7421 first subinstruction of a VLIW instruction. When a breakpoint is
7422 set, GDB will adjust the breakpoint address to the beginning of
7423 the VLIW instruction. Thus, we need to make the corresponding
7424 adjustment here when computing the stop address. */
7426 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7428 ecs
->stop_func_start
7429 = gdbarch_adjust_breakpoint_address (gdbarch
,
7430 ecs
->stop_func_start
);
7433 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7435 /* We are already there: stop now. */
7436 end_stepping_range (ecs
);
7441 /* Put the step-breakpoint there and go until there. */
7442 symtab_and_line sr_sal
;
7443 sr_sal
.pc
= ecs
->stop_func_start
;
7444 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7445 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7447 /* Do not specify what the fp should be when we stop since on
7448 some machines the prologue is where the new fp value is
7450 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7452 /* And make sure stepping stops right away then. */
7453 ecs
->event_thread
->control
.step_range_end
7454 = ecs
->event_thread
->control
.step_range_start
;
7459 /* Inferior has stepped backward into a subroutine call with source
7460 code that we should not step over. Do step to the beginning of the
7461 last line of code in it. */
7464 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7465 struct execution_control_state
*ecs
)
7467 struct compunit_symtab
*cust
;
7468 struct symtab_and_line stop_func_sal
;
7470 fill_in_stop_func (gdbarch
, ecs
);
7472 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7473 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7474 ecs
->stop_func_start
7475 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7477 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7479 /* OK, we're just going to keep stepping here. */
7480 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7482 /* We're there already. Just stop stepping now. */
7483 end_stepping_range (ecs
);
7487 /* Else just reset the step range and keep going.
7488 No step-resume breakpoint, they don't work for
7489 epilogues, which can have multiple entry paths. */
7490 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7491 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7497 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7498 This is used to both functions and to skip over code. */
7501 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7502 struct symtab_and_line sr_sal
,
7503 struct frame_id sr_id
,
7504 enum bptype sr_type
)
7506 /* There should never be more than one step-resume or longjmp-resume
7507 breakpoint per thread, so we should never be setting a new
7508 step_resume_breakpoint when one is already active. */
7509 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7510 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7512 infrun_debug_printf ("inserting step-resume breakpoint at %s",
7513 paddress (gdbarch
, sr_sal
.pc
));
7515 inferior_thread ()->control
.step_resume_breakpoint
7516 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7520 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7521 struct symtab_and_line sr_sal
,
7522 struct frame_id sr_id
)
7524 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7529 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7530 This is used to skip a potential signal handler.
7532 This is called with the interrupted function's frame. The signal
7533 handler, when it returns, will resume the interrupted function at
7537 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7539 gdb_assert (return_frame
!= NULL
);
7541 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7543 symtab_and_line sr_sal
;
7544 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7545 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7546 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7548 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7549 get_stack_frame_id (return_frame
),
7553 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7554 is used to skip a function after stepping into it (for "next" or if
7555 the called function has no debugging information).
7557 The current function has almost always been reached by single
7558 stepping a call or return instruction. NEXT_FRAME belongs to the
7559 current function, and the breakpoint will be set at the caller's
7562 This is a separate function rather than reusing
7563 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7564 get_prev_frame, which may stop prematurely (see the implementation
7565 of frame_unwind_caller_id for an example). */
7568 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7570 /* We shouldn't have gotten here if we don't know where the call site
7572 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7574 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7576 symtab_and_line sr_sal
;
7577 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7578 frame_unwind_caller_pc (next_frame
));
7579 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7580 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7582 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7583 frame_unwind_caller_id (next_frame
));
7586 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7587 new breakpoint at the target of a jmp_buf. The handling of
7588 longjmp-resume uses the same mechanisms used for handling
7589 "step-resume" breakpoints. */
7592 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7594 /* There should never be more than one longjmp-resume breakpoint per
7595 thread, so we should never be setting a new
7596 longjmp_resume_breakpoint when one is already active. */
7597 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7599 infrun_debug_printf ("inserting longjmp-resume breakpoint at %s",
7600 paddress (gdbarch
, pc
));
7602 inferior_thread ()->control
.exception_resume_breakpoint
=
7603 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7606 /* Insert an exception resume breakpoint. TP is the thread throwing
7607 the exception. The block B is the block of the unwinder debug hook
7608 function. FRAME is the frame corresponding to the call to this
7609 function. SYM is the symbol of the function argument holding the
7610 target PC of the exception. */
7613 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7614 const struct block
*b
,
7615 struct frame_info
*frame
,
7620 struct block_symbol vsym
;
7621 struct value
*value
;
7623 struct breakpoint
*bp
;
7625 vsym
= lookup_symbol_search_name (sym
->search_name (),
7627 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7628 /* If the value was optimized out, revert to the old behavior. */
7629 if (! value_optimized_out (value
))
7631 handler
= value_as_address (value
);
7633 infrun_debug_printf ("exception resume at %lx",
7634 (unsigned long) handler
);
7636 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7638 bp_exception_resume
).release ();
7640 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7643 bp
->thread
= tp
->global_num
;
7644 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7647 catch (const gdb_exception_error
&e
)
7649 /* We want to ignore errors here. */
7653 /* A helper for check_exception_resume that sets an
7654 exception-breakpoint based on a SystemTap probe. */
7657 insert_exception_resume_from_probe (struct thread_info
*tp
,
7658 const struct bound_probe
*probe
,
7659 struct frame_info
*frame
)
7661 struct value
*arg_value
;
7663 struct breakpoint
*bp
;
7665 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7669 handler
= value_as_address (arg_value
);
7671 infrun_debug_printf ("exception resume at %s",
7672 paddress (probe
->objfile
->arch (), handler
));
7674 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7675 handler
, bp_exception_resume
).release ();
7676 bp
->thread
= tp
->global_num
;
7677 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7680 /* This is called when an exception has been intercepted. Check to
7681 see whether the exception's destination is of interest, and if so,
7682 set an exception resume breakpoint there. */
7685 check_exception_resume (struct execution_control_state
*ecs
,
7686 struct frame_info
*frame
)
7688 struct bound_probe probe
;
7689 struct symbol
*func
;
7691 /* First see if this exception unwinding breakpoint was set via a
7692 SystemTap probe point. If so, the probe has two arguments: the
7693 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7694 set a breakpoint there. */
7695 probe
= find_probe_by_pc (get_frame_pc (frame
));
7698 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7702 func
= get_frame_function (frame
);
7708 const struct block
*b
;
7709 struct block_iterator iter
;
7713 /* The exception breakpoint is a thread-specific breakpoint on
7714 the unwinder's debug hook, declared as:
7716 void _Unwind_DebugHook (void *cfa, void *handler);
7718 The CFA argument indicates the frame to which control is
7719 about to be transferred. HANDLER is the destination PC.
7721 We ignore the CFA and set a temporary breakpoint at HANDLER.
7722 This is not extremely efficient but it avoids issues in gdb
7723 with computing the DWARF CFA, and it also works even in weird
7724 cases such as throwing an exception from inside a signal
7727 b
= SYMBOL_BLOCK_VALUE (func
);
7728 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7730 if (!SYMBOL_IS_ARGUMENT (sym
))
7737 insert_exception_resume_breakpoint (ecs
->event_thread
,
7743 catch (const gdb_exception_error
&e
)
7749 stop_waiting (struct execution_control_state
*ecs
)
7751 infrun_debug_printf ("stop_waiting");
7753 /* Let callers know we don't want to wait for the inferior anymore. */
7754 ecs
->wait_some_more
= 0;
7756 /* If all-stop, but there exists a non-stop target, stop all
7757 threads now that we're presenting the stop to the user. */
7758 if (!non_stop
&& exists_non_stop_target ())
7759 stop_all_threads ();
7762 /* Like keep_going, but passes the signal to the inferior, even if the
7763 signal is set to nopass. */
7766 keep_going_pass_signal (struct execution_control_state
*ecs
)
7768 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7769 gdb_assert (!ecs
->event_thread
->resumed
);
7771 /* Save the pc before execution, to compare with pc after stop. */
7772 ecs
->event_thread
->prev_pc
7773 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7775 if (ecs
->event_thread
->control
.trap_expected
)
7777 struct thread_info
*tp
= ecs
->event_thread
;
7779 infrun_debug_printf ("%s has trap_expected set, "
7780 "resuming to collect trap",
7781 target_pid_to_str (tp
->ptid
).c_str ());
7783 /* We haven't yet gotten our trap, and either: intercepted a
7784 non-signal event (e.g., a fork); or took a signal which we
7785 are supposed to pass through to the inferior. Simply
7787 resume (ecs
->event_thread
->suspend
.stop_signal
);
7789 else if (step_over_info_valid_p ())
7791 /* Another thread is stepping over a breakpoint in-line. If
7792 this thread needs a step-over too, queue the request. In
7793 either case, this resume must be deferred for later. */
7794 struct thread_info
*tp
= ecs
->event_thread
;
7796 if (ecs
->hit_singlestep_breakpoint
7797 || thread_still_needs_step_over (tp
))
7799 infrun_debug_printf ("step-over already in progress: "
7800 "step-over for %s deferred",
7801 target_pid_to_str (tp
->ptid
).c_str ());
7802 thread_step_over_chain_enqueue (tp
);
7806 infrun_debug_printf ("step-over in progress: resume of %s deferred",
7807 target_pid_to_str (tp
->ptid
).c_str ());
7812 struct regcache
*regcache
= get_current_regcache ();
7815 step_over_what step_what
;
7817 /* Either the trap was not expected, but we are continuing
7818 anyway (if we got a signal, the user asked it be passed to
7821 We got our expected trap, but decided we should resume from
7824 We're going to run this baby now!
7826 Note that insert_breakpoints won't try to re-insert
7827 already inserted breakpoints. Therefore, we don't
7828 care if breakpoints were already inserted, or not. */
7830 /* If we need to step over a breakpoint, and we're not using
7831 displaced stepping to do so, insert all breakpoints
7832 (watchpoints, etc.) but the one we're stepping over, step one
7833 instruction, and then re-insert the breakpoint when that step
7836 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7838 remove_bp
= (ecs
->hit_singlestep_breakpoint
7839 || (step_what
& STEP_OVER_BREAKPOINT
));
7840 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7842 /* We can't use displaced stepping if we need to step past a
7843 watchpoint. The instruction copied to the scratch pad would
7844 still trigger the watchpoint. */
7846 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7848 set_step_over_info (regcache
->aspace (),
7849 regcache_read_pc (regcache
), remove_wps
,
7850 ecs
->event_thread
->global_num
);
7852 else if (remove_wps
)
7853 set_step_over_info (NULL
, 0, remove_wps
, -1);
7855 /* If we now need to do an in-line step-over, we need to stop
7856 all other threads. Note this must be done before
7857 insert_breakpoints below, because that removes the breakpoint
7858 we're about to step over, otherwise other threads could miss
7860 if (step_over_info_valid_p () && target_is_non_stop_p ())
7861 stop_all_threads ();
7863 /* Stop stepping if inserting breakpoints fails. */
7866 insert_breakpoints ();
7868 catch (const gdb_exception_error
&e
)
7870 exception_print (gdb_stderr
, e
);
7872 clear_step_over_info ();
7876 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7878 resume (ecs
->event_thread
->suspend
.stop_signal
);
7881 prepare_to_wait (ecs
);
7884 /* Called when we should continue running the inferior, because the
7885 current event doesn't cause a user visible stop. This does the
7886 resuming part; waiting for the next event is done elsewhere. */
7889 keep_going (struct execution_control_state
*ecs
)
7891 if (ecs
->event_thread
->control
.trap_expected
7892 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7893 ecs
->event_thread
->control
.trap_expected
= 0;
7895 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7896 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7897 keep_going_pass_signal (ecs
);
7900 /* This function normally comes after a resume, before
7901 handle_inferior_event exits. It takes care of any last bits of
7902 housekeeping, and sets the all-important wait_some_more flag. */
7905 prepare_to_wait (struct execution_control_state
*ecs
)
7907 infrun_debug_printf ("prepare_to_wait");
7909 ecs
->wait_some_more
= 1;
7911 /* If the target can't async, emulate it by marking the infrun event
7912 handler such that as soon as we get back to the event-loop, we
7913 immediately end up in fetch_inferior_event again calling
7915 if (!target_can_async_p ())
7916 mark_infrun_async_event_handler ();
7919 /* We are done with the step range of a step/next/si/ni command.
7920 Called once for each n of a "step n" operation. */
7923 end_stepping_range (struct execution_control_state
*ecs
)
7925 ecs
->event_thread
->control
.stop_step
= 1;
7929 /* Several print_*_reason functions to print why the inferior has stopped.
7930 We always print something when the inferior exits, or receives a signal.
7931 The rest of the cases are dealt with later on in normal_stop and
7932 print_it_typical. Ideally there should be a call to one of these
7933 print_*_reason functions functions from handle_inferior_event each time
7934 stop_waiting is called.
7936 Note that we don't call these directly, instead we delegate that to
7937 the interpreters, through observers. Interpreters then call these
7938 with whatever uiout is right. */
7941 print_end_stepping_range_reason (struct ui_out
*uiout
)
7943 /* For CLI-like interpreters, print nothing. */
7945 if (uiout
->is_mi_like_p ())
7947 uiout
->field_string ("reason",
7948 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7953 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7955 annotate_signalled ();
7956 if (uiout
->is_mi_like_p ())
7958 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7959 uiout
->text ("\nProgram terminated with signal ");
7960 annotate_signal_name ();
7961 uiout
->field_string ("signal-name",
7962 gdb_signal_to_name (siggnal
));
7963 annotate_signal_name_end ();
7965 annotate_signal_string ();
7966 uiout
->field_string ("signal-meaning",
7967 gdb_signal_to_string (siggnal
));
7968 annotate_signal_string_end ();
7969 uiout
->text (".\n");
7970 uiout
->text ("The program no longer exists.\n");
7974 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7976 struct inferior
*inf
= current_inferior ();
7977 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7979 annotate_exited (exitstatus
);
7982 if (uiout
->is_mi_like_p ())
7983 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7984 std::string exit_code_str
7985 = string_printf ("0%o", (unsigned int) exitstatus
);
7986 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7987 plongest (inf
->num
), pidstr
.c_str (),
7988 string_field ("exit-code", exit_code_str
.c_str ()));
7992 if (uiout
->is_mi_like_p ())
7994 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7995 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7996 plongest (inf
->num
), pidstr
.c_str ());
8001 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8003 struct thread_info
*thr
= inferior_thread ();
8007 if (uiout
->is_mi_like_p ())
8009 else if (show_thread_that_caused_stop ())
8013 uiout
->text ("\nThread ");
8014 uiout
->field_string ("thread-id", print_thread_id (thr
));
8016 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8019 uiout
->text (" \"");
8020 uiout
->field_string ("name", name
);
8025 uiout
->text ("\nProgram");
8027 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8028 uiout
->text (" stopped");
8031 uiout
->text (" received signal ");
8032 annotate_signal_name ();
8033 if (uiout
->is_mi_like_p ())
8035 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8036 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8037 annotate_signal_name_end ();
8039 annotate_signal_string ();
8040 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8042 struct regcache
*regcache
= get_current_regcache ();
8043 struct gdbarch
*gdbarch
= regcache
->arch ();
8044 if (gdbarch_report_signal_info_p (gdbarch
))
8045 gdbarch_report_signal_info (gdbarch
, uiout
, siggnal
);
8047 annotate_signal_string_end ();
8049 uiout
->text (".\n");
8053 print_no_history_reason (struct ui_out
*uiout
)
8055 uiout
->text ("\nNo more reverse-execution history.\n");
8058 /* Print current location without a level number, if we have changed
8059 functions or hit a breakpoint. Print source line if we have one.
8060 bpstat_print contains the logic deciding in detail what to print,
8061 based on the event(s) that just occurred. */
8064 print_stop_location (struct target_waitstatus
*ws
)
8067 enum print_what source_flag
;
8068 int do_frame_printing
= 1;
8069 struct thread_info
*tp
= inferior_thread ();
8071 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8075 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8076 should) carry around the function and does (or should) use
8077 that when doing a frame comparison. */
8078 if (tp
->control
.stop_step
8079 && frame_id_eq (tp
->control
.step_frame_id
,
8080 get_frame_id (get_current_frame ()))
8081 && (tp
->control
.step_start_function
8082 == find_pc_function (tp
->suspend
.stop_pc
)))
8084 /* Finished step, just print source line. */
8085 source_flag
= SRC_LINE
;
8089 /* Print location and source line. */
8090 source_flag
= SRC_AND_LOC
;
8093 case PRINT_SRC_AND_LOC
:
8094 /* Print location and source line. */
8095 source_flag
= SRC_AND_LOC
;
8097 case PRINT_SRC_ONLY
:
8098 source_flag
= SRC_LINE
;
8101 /* Something bogus. */
8102 source_flag
= SRC_LINE
;
8103 do_frame_printing
= 0;
8106 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8109 /* The behavior of this routine with respect to the source
8111 SRC_LINE: Print only source line
8112 LOCATION: Print only location
8113 SRC_AND_LOC: Print location and source line. */
8114 if (do_frame_printing
)
8115 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8121 print_stop_event (struct ui_out
*uiout
, bool displays
)
8123 struct target_waitstatus last
;
8124 struct thread_info
*tp
;
8126 get_last_target_status (nullptr, nullptr, &last
);
8129 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8131 print_stop_location (&last
);
8133 /* Display the auto-display expressions. */
8138 tp
= inferior_thread ();
8139 if (tp
->thread_fsm
!= NULL
8140 && tp
->thread_fsm
->finished_p ())
8142 struct return_value_info
*rv
;
8144 rv
= tp
->thread_fsm
->return_value ();
8146 print_return_value (uiout
, rv
);
8153 maybe_remove_breakpoints (void)
8155 if (!breakpoints_should_be_inserted_now () && target_has_execution ())
8157 if (remove_breakpoints ())
8159 target_terminal::ours_for_output ();
8160 printf_filtered (_("Cannot remove breakpoints because "
8161 "program is no longer writable.\nFurther "
8162 "execution is probably impossible.\n"));
8167 /* The execution context that just caused a normal stop. */
8174 DISABLE_COPY_AND_ASSIGN (stop_context
);
8176 bool changed () const;
8181 /* The event PTID. */
8185 /* If stopp for a thread event, this is the thread that caused the
8187 struct thread_info
*thread
;
8189 /* The inferior that caused the stop. */
8193 /* Initializes a new stop context. If stopped for a thread event, this
8194 takes a strong reference to the thread. */
8196 stop_context::stop_context ()
8198 stop_id
= get_stop_id ();
8199 ptid
= inferior_ptid
;
8200 inf_num
= current_inferior ()->num
;
8202 if (inferior_ptid
!= null_ptid
)
8204 /* Take a strong reference so that the thread can't be deleted
8206 thread
= inferior_thread ();
8213 /* Release a stop context previously created with save_stop_context.
8214 Releases the strong reference to the thread as well. */
8216 stop_context::~stop_context ()
8222 /* Return true if the current context no longer matches the saved stop
8226 stop_context::changed () const
8228 if (ptid
!= inferior_ptid
)
8230 if (inf_num
!= current_inferior ()->num
)
8232 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8234 if (get_stop_id () != stop_id
)
8244 struct target_waitstatus last
;
8246 get_last_target_status (nullptr, nullptr, &last
);
8250 /* If an exception is thrown from this point on, make sure to
8251 propagate GDB's knowledge of the executing state to the
8252 frontend/user running state. A QUIT is an easy exception to see
8253 here, so do this before any filtered output. */
8255 ptid_t finish_ptid
= null_ptid
;
8258 finish_ptid
= minus_one_ptid
;
8259 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8260 || last
.kind
== TARGET_WAITKIND_EXITED
)
8262 /* On some targets, we may still have live threads in the
8263 inferior when we get a process exit event. E.g., for
8264 "checkpoint", when the current checkpoint/fork exits,
8265 linux-fork.c automatically switches to another fork from
8266 within target_mourn_inferior. */
8267 if (inferior_ptid
!= null_ptid
)
8268 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8270 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8271 finish_ptid
= inferior_ptid
;
8273 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8274 if (finish_ptid
!= null_ptid
)
8276 maybe_finish_thread_state
.emplace
8277 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8280 /* As we're presenting a stop, and potentially removing breakpoints,
8281 update the thread list so we can tell whether there are threads
8282 running on the target. With target remote, for example, we can
8283 only learn about new threads when we explicitly update the thread
8284 list. Do this before notifying the interpreters about signal
8285 stops, end of stepping ranges, etc., so that the "new thread"
8286 output is emitted before e.g., "Program received signal FOO",
8287 instead of after. */
8288 update_thread_list ();
8290 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8291 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8293 /* As with the notification of thread events, we want to delay
8294 notifying the user that we've switched thread context until
8295 the inferior actually stops.
8297 There's no point in saying anything if the inferior has exited.
8298 Note that SIGNALLED here means "exited with a signal", not
8299 "received a signal".
8301 Also skip saying anything in non-stop mode. In that mode, as we
8302 don't want GDB to switch threads behind the user's back, to avoid
8303 races where the user is typing a command to apply to thread x,
8304 but GDB switches to thread y before the user finishes entering
8305 the command, fetch_inferior_event installs a cleanup to restore
8306 the current thread back to the thread the user had selected right
8307 after this event is handled, so we're not really switching, only
8308 informing of a stop. */
8310 && previous_inferior_ptid
!= inferior_ptid
8311 && target_has_execution ()
8312 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8313 && last
.kind
!= TARGET_WAITKIND_EXITED
8314 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8316 SWITCH_THRU_ALL_UIS ()
8318 target_terminal::ours_for_output ();
8319 printf_filtered (_("[Switching to %s]\n"),
8320 target_pid_to_str (inferior_ptid
).c_str ());
8321 annotate_thread_changed ();
8323 previous_inferior_ptid
= inferior_ptid
;
8326 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8328 SWITCH_THRU_ALL_UIS ()
8329 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8331 target_terminal::ours_for_output ();
8332 printf_filtered (_("No unwaited-for children left.\n"));
8336 /* Note: this depends on the update_thread_list call above. */
8337 maybe_remove_breakpoints ();
8339 /* If an auto-display called a function and that got a signal,
8340 delete that auto-display to avoid an infinite recursion. */
8342 if (stopped_by_random_signal
)
8343 disable_current_display ();
8345 SWITCH_THRU_ALL_UIS ()
8347 async_enable_stdin ();
8350 /* Let the user/frontend see the threads as stopped. */
8351 maybe_finish_thread_state
.reset ();
8353 /* Select innermost stack frame - i.e., current frame is frame 0,
8354 and current location is based on that. Handle the case where the
8355 dummy call is returning after being stopped. E.g. the dummy call
8356 previously hit a breakpoint. (If the dummy call returns
8357 normally, we won't reach here.) Do this before the stop hook is
8358 run, so that it doesn't get to see the temporary dummy frame,
8359 which is not where we'll present the stop. */
8360 if (has_stack_frames ())
8362 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8364 /* Pop the empty frame that contains the stack dummy. This
8365 also restores inferior state prior to the call (struct
8366 infcall_suspend_state). */
8367 struct frame_info
*frame
= get_current_frame ();
8369 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8371 /* frame_pop calls reinit_frame_cache as the last thing it
8372 does which means there's now no selected frame. */
8375 select_frame (get_current_frame ());
8377 /* Set the current source location. */
8378 set_current_sal_from_frame (get_current_frame ());
8381 /* Look up the hook_stop and run it (CLI internally handles problem
8382 of stop_command's pre-hook not existing). */
8383 if (stop_command
!= NULL
)
8385 stop_context saved_context
;
8389 execute_cmd_pre_hook (stop_command
);
8391 catch (const gdb_exception
&ex
)
8393 exception_fprintf (gdb_stderr
, ex
,
8394 "Error while running hook_stop:\n");
8397 /* If the stop hook resumes the target, then there's no point in
8398 trying to notify about the previous stop; its context is
8399 gone. Likewise if the command switches thread or inferior --
8400 the observers would print a stop for the wrong
8402 if (saved_context
.changed ())
8406 /* Notify observers about the stop. This is where the interpreters
8407 print the stop event. */
8408 if (inferior_ptid
!= null_ptid
)
8409 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8412 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8414 annotate_stopped ();
8416 if (target_has_execution ())
8418 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8419 && last
.kind
!= TARGET_WAITKIND_EXITED
8420 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8421 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8422 Delete any breakpoint that is to be deleted at the next stop. */
8423 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8426 /* Try to get rid of automatically added inferiors that are no
8427 longer needed. Keeping those around slows down things linearly.
8428 Note that this never removes the current inferior. */
8435 signal_stop_state (int signo
)
8437 return signal_stop
[signo
];
8441 signal_print_state (int signo
)
8443 return signal_print
[signo
];
8447 signal_pass_state (int signo
)
8449 return signal_program
[signo
];
8453 signal_cache_update (int signo
)
8457 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8458 signal_cache_update (signo
);
8463 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8464 && signal_print
[signo
] == 0
8465 && signal_program
[signo
] == 1
8466 && signal_catch
[signo
] == 0);
8470 signal_stop_update (int signo
, int state
)
8472 int ret
= signal_stop
[signo
];
8474 signal_stop
[signo
] = state
;
8475 signal_cache_update (signo
);
8480 signal_print_update (int signo
, int state
)
8482 int ret
= signal_print
[signo
];
8484 signal_print
[signo
] = state
;
8485 signal_cache_update (signo
);
8490 signal_pass_update (int signo
, int state
)
8492 int ret
= signal_program
[signo
];
8494 signal_program
[signo
] = state
;
8495 signal_cache_update (signo
);
8499 /* Update the global 'signal_catch' from INFO and notify the
8503 signal_catch_update (const unsigned int *info
)
8507 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8508 signal_catch
[i
] = info
[i
] > 0;
8509 signal_cache_update (-1);
8510 target_pass_signals (signal_pass
);
8514 sig_print_header (void)
8516 printf_filtered (_("Signal Stop\tPrint\tPass "
8517 "to program\tDescription\n"));
8521 sig_print_info (enum gdb_signal oursig
)
8523 const char *name
= gdb_signal_to_name (oursig
);
8524 int name_padding
= 13 - strlen (name
);
8526 if (name_padding
<= 0)
8529 printf_filtered ("%s", name
);
8530 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8531 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8532 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8533 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8534 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8537 /* Specify how various signals in the inferior should be handled. */
8540 handle_command (const char *args
, int from_tty
)
8542 int digits
, wordlen
;
8543 int sigfirst
, siglast
;
8544 enum gdb_signal oursig
;
8549 error_no_arg (_("signal to handle"));
8552 /* Allocate and zero an array of flags for which signals to handle. */
8554 const size_t nsigs
= GDB_SIGNAL_LAST
;
8555 unsigned char sigs
[nsigs
] {};
8557 /* Break the command line up into args. */
8559 gdb_argv
built_argv (args
);
8561 /* Walk through the args, looking for signal oursigs, signal names, and
8562 actions. Signal numbers and signal names may be interspersed with
8563 actions, with the actions being performed for all signals cumulatively
8564 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8566 for (char *arg
: built_argv
)
8568 wordlen
= strlen (arg
);
8569 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8573 sigfirst
= siglast
= -1;
8575 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8577 /* Apply action to all signals except those used by the
8578 debugger. Silently skip those. */
8581 siglast
= nsigs
- 1;
8583 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8585 SET_SIGS (nsigs
, sigs
, signal_stop
);
8586 SET_SIGS (nsigs
, sigs
, signal_print
);
8588 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8590 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8592 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8594 SET_SIGS (nsigs
, sigs
, signal_print
);
8596 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8598 SET_SIGS (nsigs
, sigs
, signal_program
);
8600 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8602 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8604 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8606 SET_SIGS (nsigs
, sigs
, signal_program
);
8608 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8610 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8611 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8613 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8615 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8617 else if (digits
> 0)
8619 /* It is numeric. The numeric signal refers to our own
8620 internal signal numbering from target.h, not to host/target
8621 signal number. This is a feature; users really should be
8622 using symbolic names anyway, and the common ones like
8623 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8625 sigfirst
= siglast
= (int)
8626 gdb_signal_from_command (atoi (arg
));
8627 if (arg
[digits
] == '-')
8630 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8632 if (sigfirst
> siglast
)
8634 /* Bet he didn't figure we'd think of this case... */
8635 std::swap (sigfirst
, siglast
);
8640 oursig
= gdb_signal_from_name (arg
);
8641 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8643 sigfirst
= siglast
= (int) oursig
;
8647 /* Not a number and not a recognized flag word => complain. */
8648 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8652 /* If any signal numbers or symbol names were found, set flags for
8653 which signals to apply actions to. */
8655 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8657 switch ((enum gdb_signal
) signum
)
8659 case GDB_SIGNAL_TRAP
:
8660 case GDB_SIGNAL_INT
:
8661 if (!allsigs
&& !sigs
[signum
])
8663 if (query (_("%s is used by the debugger.\n\
8664 Are you sure you want to change it? "),
8665 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8670 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8674 case GDB_SIGNAL_DEFAULT
:
8675 case GDB_SIGNAL_UNKNOWN
:
8676 /* Make sure that "all" doesn't print these. */
8685 for (int signum
= 0; signum
< nsigs
; signum
++)
8688 signal_cache_update (-1);
8689 target_pass_signals (signal_pass
);
8690 target_program_signals (signal_program
);
8694 /* Show the results. */
8695 sig_print_header ();
8696 for (; signum
< nsigs
; signum
++)
8698 sig_print_info ((enum gdb_signal
) signum
);
8705 /* Complete the "handle" command. */
8708 handle_completer (struct cmd_list_element
*ignore
,
8709 completion_tracker
&tracker
,
8710 const char *text
, const char *word
)
8712 static const char * const keywords
[] =
8726 signal_completer (ignore
, tracker
, text
, word
);
8727 complete_on_enum (tracker
, keywords
, word
, word
);
8731 gdb_signal_from_command (int num
)
8733 if (num
>= 1 && num
<= 15)
8734 return (enum gdb_signal
) num
;
8735 error (_("Only signals 1-15 are valid as numeric signals.\n\
8736 Use \"info signals\" for a list of symbolic signals."));
8739 /* Print current contents of the tables set by the handle command.
8740 It is possible we should just be printing signals actually used
8741 by the current target (but for things to work right when switching
8742 targets, all signals should be in the signal tables). */
8745 info_signals_command (const char *signum_exp
, int from_tty
)
8747 enum gdb_signal oursig
;
8749 sig_print_header ();
8753 /* First see if this is a symbol name. */
8754 oursig
= gdb_signal_from_name (signum_exp
);
8755 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8757 /* No, try numeric. */
8759 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8761 sig_print_info (oursig
);
8765 printf_filtered ("\n");
8766 /* These ugly casts brought to you by the native VAX compiler. */
8767 for (oursig
= GDB_SIGNAL_FIRST
;
8768 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8769 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8773 if (oursig
!= GDB_SIGNAL_UNKNOWN
8774 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8775 sig_print_info (oursig
);
8778 printf_filtered (_("\nUse the \"handle\" command "
8779 "to change these tables.\n"));
8782 /* The $_siginfo convenience variable is a bit special. We don't know
8783 for sure the type of the value until we actually have a chance to
8784 fetch the data. The type can change depending on gdbarch, so it is
8785 also dependent on which thread you have selected.
8787 1. making $_siginfo be an internalvar that creates a new value on
8790 2. making the value of $_siginfo be an lval_computed value. */
8792 /* This function implements the lval_computed support for reading a
8796 siginfo_value_read (struct value
*v
)
8798 LONGEST transferred
;
8800 /* If we can access registers, so can we access $_siginfo. Likewise
8802 validate_registers_access ();
8805 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8807 value_contents_all_raw (v
),
8809 TYPE_LENGTH (value_type (v
)));
8811 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8812 error (_("Unable to read siginfo"));
8815 /* This function implements the lval_computed support for writing a
8819 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8821 LONGEST transferred
;
8823 /* If we can access registers, so can we access $_siginfo. Likewise
8825 validate_registers_access ();
8827 transferred
= target_write (current_top_target (),
8828 TARGET_OBJECT_SIGNAL_INFO
,
8830 value_contents_all_raw (fromval
),
8832 TYPE_LENGTH (value_type (fromval
)));
8834 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8835 error (_("Unable to write siginfo"));
8838 static const struct lval_funcs siginfo_value_funcs
=
8844 /* Return a new value with the correct type for the siginfo object of
8845 the current thread using architecture GDBARCH. Return a void value
8846 if there's no object available. */
8848 static struct value
*
8849 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8852 if (target_has_stack ()
8853 && inferior_ptid
!= null_ptid
8854 && gdbarch_get_siginfo_type_p (gdbarch
))
8856 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8858 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8861 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8865 /* infcall_suspend_state contains state about the program itself like its
8866 registers and any signal it received when it last stopped.
8867 This state must be restored regardless of how the inferior function call
8868 ends (either successfully, or after it hits a breakpoint or signal)
8869 if the program is to properly continue where it left off. */
8871 class infcall_suspend_state
8874 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8875 once the inferior function call has finished. */
8876 infcall_suspend_state (struct gdbarch
*gdbarch
,
8877 const struct thread_info
*tp
,
8878 struct regcache
*regcache
)
8879 : m_thread_suspend (tp
->suspend
),
8880 m_registers (new readonly_detached_regcache (*regcache
))
8882 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8884 if (gdbarch_get_siginfo_type_p (gdbarch
))
8886 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8887 size_t len
= TYPE_LENGTH (type
);
8889 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8891 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8892 siginfo_data
.get (), 0, len
) != len
)
8894 /* Errors ignored. */
8895 siginfo_data
.reset (nullptr);
8901 m_siginfo_gdbarch
= gdbarch
;
8902 m_siginfo_data
= std::move (siginfo_data
);
8906 /* Return a pointer to the stored register state. */
8908 readonly_detached_regcache
*registers () const
8910 return m_registers
.get ();
8913 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8915 void restore (struct gdbarch
*gdbarch
,
8916 struct thread_info
*tp
,
8917 struct regcache
*regcache
) const
8919 tp
->suspend
= m_thread_suspend
;
8921 if (m_siginfo_gdbarch
== gdbarch
)
8923 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8925 /* Errors ignored. */
8926 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8927 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8930 /* The inferior can be gone if the user types "print exit(0)"
8931 (and perhaps other times). */
8932 if (target_has_execution ())
8933 /* NB: The register write goes through to the target. */
8934 regcache
->restore (registers ());
8938 /* How the current thread stopped before the inferior function call was
8940 struct thread_suspend_state m_thread_suspend
;
8942 /* The registers before the inferior function call was executed. */
8943 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8945 /* Format of SIGINFO_DATA or NULL if it is not present. */
8946 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8948 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8949 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8950 content would be invalid. */
8951 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8954 infcall_suspend_state_up
8955 save_infcall_suspend_state ()
8957 struct thread_info
*tp
= inferior_thread ();
8958 struct regcache
*regcache
= get_current_regcache ();
8959 struct gdbarch
*gdbarch
= regcache
->arch ();
8961 infcall_suspend_state_up inf_state
8962 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8964 /* Having saved the current state, adjust the thread state, discarding
8965 any stop signal information. The stop signal is not useful when
8966 starting an inferior function call, and run_inferior_call will not use
8967 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8968 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8973 /* Restore inferior session state to INF_STATE. */
8976 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8978 struct thread_info
*tp
= inferior_thread ();
8979 struct regcache
*regcache
= get_current_regcache ();
8980 struct gdbarch
*gdbarch
= regcache
->arch ();
8982 inf_state
->restore (gdbarch
, tp
, regcache
);
8983 discard_infcall_suspend_state (inf_state
);
8987 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8992 readonly_detached_regcache
*
8993 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8995 return inf_state
->registers ();
8998 /* infcall_control_state contains state regarding gdb's control of the
8999 inferior itself like stepping control. It also contains session state like
9000 the user's currently selected frame. */
9002 struct infcall_control_state
9004 struct thread_control_state thread_control
;
9005 struct inferior_control_state inferior_control
;
9008 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9009 int stopped_by_random_signal
= 0;
9011 /* ID and level of the selected frame when the inferior function
9013 struct frame_id selected_frame_id
{};
9014 int selected_frame_level
= -1;
9017 /* Save all of the information associated with the inferior<==>gdb
9020 infcall_control_state_up
9021 save_infcall_control_state ()
9023 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9024 struct thread_info
*tp
= inferior_thread ();
9025 struct inferior
*inf
= current_inferior ();
9027 inf_status
->thread_control
= tp
->control
;
9028 inf_status
->inferior_control
= inf
->control
;
9030 tp
->control
.step_resume_breakpoint
= NULL
;
9031 tp
->control
.exception_resume_breakpoint
= NULL
;
9033 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9034 chain. If caller's caller is walking the chain, they'll be happier if we
9035 hand them back the original chain when restore_infcall_control_state is
9037 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9040 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9041 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9043 save_selected_frame (&inf_status
->selected_frame_id
,
9044 &inf_status
->selected_frame_level
);
9049 /* Restore inferior session state to INF_STATUS. */
9052 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9054 struct thread_info
*tp
= inferior_thread ();
9055 struct inferior
*inf
= current_inferior ();
9057 if (tp
->control
.step_resume_breakpoint
)
9058 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9060 if (tp
->control
.exception_resume_breakpoint
)
9061 tp
->control
.exception_resume_breakpoint
->disposition
9062 = disp_del_at_next_stop
;
9064 /* Handle the bpstat_copy of the chain. */
9065 bpstat_clear (&tp
->control
.stop_bpstat
);
9067 tp
->control
= inf_status
->thread_control
;
9068 inf
->control
= inf_status
->inferior_control
;
9071 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9072 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9074 if (target_has_stack ())
9076 restore_selected_frame (inf_status
->selected_frame_id
,
9077 inf_status
->selected_frame_level
);
9084 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9086 if (inf_status
->thread_control
.step_resume_breakpoint
)
9087 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9088 = disp_del_at_next_stop
;
9090 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9091 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9092 = disp_del_at_next_stop
;
9094 /* See save_infcall_control_state for info on stop_bpstat. */
9095 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9103 clear_exit_convenience_vars (void)
9105 clear_internalvar (lookup_internalvar ("_exitsignal"));
9106 clear_internalvar (lookup_internalvar ("_exitcode"));
9110 /* User interface for reverse debugging:
9111 Set exec-direction / show exec-direction commands
9112 (returns error unless target implements to_set_exec_direction method). */
9114 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9115 static const char exec_forward
[] = "forward";
9116 static const char exec_reverse
[] = "reverse";
9117 static const char *exec_direction
= exec_forward
;
9118 static const char *const exec_direction_names
[] = {
9125 set_exec_direction_func (const char *args
, int from_tty
,
9126 struct cmd_list_element
*cmd
)
9128 if (target_can_execute_reverse ())
9130 if (!strcmp (exec_direction
, exec_forward
))
9131 execution_direction
= EXEC_FORWARD
;
9132 else if (!strcmp (exec_direction
, exec_reverse
))
9133 execution_direction
= EXEC_REVERSE
;
9137 exec_direction
= exec_forward
;
9138 error (_("Target does not support this operation."));
9143 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9144 struct cmd_list_element
*cmd
, const char *value
)
9146 switch (execution_direction
) {
9148 fprintf_filtered (out
, _("Forward.\n"));
9151 fprintf_filtered (out
, _("Reverse.\n"));
9154 internal_error (__FILE__
, __LINE__
,
9155 _("bogus execution_direction value: %d"),
9156 (int) execution_direction
);
9161 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9162 struct cmd_list_element
*c
, const char *value
)
9164 fprintf_filtered (file
, _("Resuming the execution of threads "
9165 "of all processes is %s.\n"), value
);
9168 /* Implementation of `siginfo' variable. */
9170 static const struct internalvar_funcs siginfo_funcs
=
9177 /* Callback for infrun's target events source. This is marked when a
9178 thread has a pending status to process. */
9181 infrun_async_inferior_event_handler (gdb_client_data data
)
9183 inferior_event_handler (INF_REG_EVENT
);
9190 /* Verify that when two threads with the same ptid exist (from two different
9191 targets) and one of them changes ptid, we only update inferior_ptid if
9192 it is appropriate. */
9195 infrun_thread_ptid_changed ()
9197 gdbarch
*arch
= current_inferior ()->gdbarch
;
9199 /* The thread which inferior_ptid represents changes ptid. */
9201 scoped_restore_current_pspace_and_thread restore
;
9203 scoped_mock_context
<test_target_ops
> target1 (arch
);
9204 scoped_mock_context
<test_target_ops
> target2 (arch
);
9205 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9207 ptid_t
old_ptid (111, 222);
9208 ptid_t
new_ptid (111, 333);
9210 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9211 target1
.mock_thread
.ptid
= old_ptid
;
9212 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9213 target2
.mock_thread
.ptid
= old_ptid
;
9215 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9216 set_current_inferior (&target1
.mock_inferior
);
9218 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9220 gdb_assert (inferior_ptid
== new_ptid
);
9223 /* A thread with the same ptid as inferior_ptid, but from another target,
9226 scoped_restore_current_pspace_and_thread restore
;
9228 scoped_mock_context
<test_target_ops
> target1 (arch
);
9229 scoped_mock_context
<test_target_ops
> target2 (arch
);
9230 target2
.mock_inferior
.next
= &target1
.mock_inferior
;
9232 ptid_t
old_ptid (111, 222);
9233 ptid_t
new_ptid (111, 333);
9235 target1
.mock_inferior
.pid
= old_ptid
.pid ();
9236 target1
.mock_thread
.ptid
= old_ptid
;
9237 target2
.mock_inferior
.pid
= old_ptid
.pid ();
9238 target2
.mock_thread
.ptid
= old_ptid
;
9240 auto restore_inferior_ptid
= make_scoped_restore (&inferior_ptid
, old_ptid
);
9241 set_current_inferior (&target2
.mock_inferior
);
9243 thread_change_ptid (&target1
.mock_target
, old_ptid
, new_ptid
);
9245 gdb_assert (inferior_ptid
== old_ptid
);
9249 } /* namespace selftests */
9251 #endif /* GDB_SELF_TEST */
9253 void _initialize_infrun ();
9255 _initialize_infrun ()
9257 struct cmd_list_element
*c
;
9259 /* Register extra event sources in the event loop. */
9260 infrun_async_inferior_event_token
9261 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
,
9264 add_info ("signals", info_signals_command
, _("\
9265 What debugger does when program gets various signals.\n\
9266 Specify a signal as argument to print info on that signal only."));
9267 add_info_alias ("handle", "signals", 0);
9269 c
= add_com ("handle", class_run
, handle_command
, _("\
9270 Specify how to handle signals.\n\
9271 Usage: handle SIGNAL [ACTIONS]\n\
9272 Args are signals and actions to apply to those signals.\n\
9273 If no actions are specified, the current settings for the specified signals\n\
9274 will be displayed instead.\n\
9276 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9277 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9278 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9279 The special arg \"all\" is recognized to mean all signals except those\n\
9280 used by the debugger, typically SIGTRAP and SIGINT.\n\
9282 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9283 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9284 Stop means reenter debugger if this signal happens (implies print).\n\
9285 Print means print a message if this signal happens.\n\
9286 Pass means let program see this signal; otherwise program doesn't know.\n\
9287 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9288 Pass and Stop may be combined.\n\
9290 Multiple signals may be specified. Signal numbers and signal names\n\
9291 may be interspersed with actions, with the actions being performed for\n\
9292 all signals cumulatively specified."));
9293 set_cmd_completer (c
, handle_completer
);
9296 stop_command
= add_cmd ("stop", class_obscure
,
9297 not_just_help_class_command
, _("\
9298 There is no `stop' command, but you can set a hook on `stop'.\n\
9299 This allows you to set a list of commands to be run each time execution\n\
9300 of the program stops."), &cmdlist
);
9302 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9303 Set inferior debugging."), _("\
9304 Show inferior debugging."), _("\
9305 When non-zero, inferior specific debugging is enabled."),
9308 &setdebuglist
, &showdebuglist
);
9310 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9311 &debug_displaced
, _("\
9312 Set displaced stepping debugging."), _("\
9313 Show displaced stepping debugging."), _("\
9314 When non-zero, displaced stepping specific debugging is enabled."),
9316 show_debug_displaced
,
9317 &setdebuglist
, &showdebuglist
);
9319 add_setshow_boolean_cmd ("non-stop", no_class
,
9321 Set whether gdb controls the inferior in non-stop mode."), _("\
9322 Show whether gdb controls the inferior in non-stop mode."), _("\
9323 When debugging a multi-threaded program and this setting is\n\
9324 off (the default, also called all-stop mode), when one thread stops\n\
9325 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9326 all other threads in the program while you interact with the thread of\n\
9327 interest. When you continue or step a thread, you can allow the other\n\
9328 threads to run, or have them remain stopped, but while you inspect any\n\
9329 thread's state, all threads stop.\n\
9331 In non-stop mode, when one thread stops, other threads can continue\n\
9332 to run freely. You'll be able to step each thread independently,\n\
9333 leave it stopped or free to run as needed."),
9339 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9342 signal_print
[i
] = 1;
9343 signal_program
[i
] = 1;
9344 signal_catch
[i
] = 0;
9347 /* Signals caused by debugger's own actions should not be given to
9348 the program afterwards.
9350 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9351 explicitly specifies that it should be delivered to the target
9352 program. Typically, that would occur when a user is debugging a
9353 target monitor on a simulator: the target monitor sets a
9354 breakpoint; the simulator encounters this breakpoint and halts
9355 the simulation handing control to GDB; GDB, noting that the stop
9356 address doesn't map to any known breakpoint, returns control back
9357 to the simulator; the simulator then delivers the hardware
9358 equivalent of a GDB_SIGNAL_TRAP to the program being
9360 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9361 signal_program
[GDB_SIGNAL_INT
] = 0;
9363 /* Signals that are not errors should not normally enter the debugger. */
9364 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9365 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9366 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9367 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9368 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9369 signal_print
[GDB_SIGNAL_PROF
] = 0;
9370 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9371 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9372 signal_stop
[GDB_SIGNAL_IO
] = 0;
9373 signal_print
[GDB_SIGNAL_IO
] = 0;
9374 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9375 signal_print
[GDB_SIGNAL_POLL
] = 0;
9376 signal_stop
[GDB_SIGNAL_URG
] = 0;
9377 signal_print
[GDB_SIGNAL_URG
] = 0;
9378 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9379 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9380 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9381 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9383 /* These signals are used internally by user-level thread
9384 implementations. (See signal(5) on Solaris.) Like the above
9385 signals, a healthy program receives and handles them as part of
9386 its normal operation. */
9387 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9388 signal_print
[GDB_SIGNAL_LWP
] = 0;
9389 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9390 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9391 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9392 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9393 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9394 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9396 /* Update cached state. */
9397 signal_cache_update (-1);
9399 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9400 &stop_on_solib_events
, _("\
9401 Set stopping for shared library events."), _("\
9402 Show stopping for shared library events."), _("\
9403 If nonzero, gdb will give control to the user when the dynamic linker\n\
9404 notifies gdb of shared library events. The most common event of interest\n\
9405 to the user would be loading/unloading of a new library."),
9406 set_stop_on_solib_events
,
9407 show_stop_on_solib_events
,
9408 &setlist
, &showlist
);
9410 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9411 follow_fork_mode_kind_names
,
9412 &follow_fork_mode_string
, _("\
9413 Set debugger response to a program call of fork or vfork."), _("\
9414 Show debugger response to a program call of fork or vfork."), _("\
9415 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9416 parent - the original process is debugged after a fork\n\
9417 child - the new process is debugged after a fork\n\
9418 The unfollowed process will continue to run.\n\
9419 By default, the debugger will follow the parent process."),
9421 show_follow_fork_mode_string
,
9422 &setlist
, &showlist
);
9424 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9425 follow_exec_mode_names
,
9426 &follow_exec_mode_string
, _("\
9427 Set debugger response to a program call of exec."), _("\
9428 Show debugger response to a program call of exec."), _("\
9429 An exec call replaces the program image of a process.\n\
9431 follow-exec-mode can be:\n\
9433 new - the debugger creates a new inferior and rebinds the process\n\
9434 to this new inferior. The program the process was running before\n\
9435 the exec call can be restarted afterwards by restarting the original\n\
9438 same - the debugger keeps the process bound to the same inferior.\n\
9439 The new executable image replaces the previous executable loaded in\n\
9440 the inferior. Restarting the inferior after the exec call restarts\n\
9441 the executable the process was running after the exec call.\n\
9443 By default, the debugger will use the same inferior."),
9445 show_follow_exec_mode_string
,
9446 &setlist
, &showlist
);
9448 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9449 scheduler_enums
, &scheduler_mode
, _("\
9450 Set mode for locking scheduler during execution."), _("\
9451 Show mode for locking scheduler during execution."), _("\
9452 off == no locking (threads may preempt at any time)\n\
9453 on == full locking (no thread except the current thread may run)\n\
9454 This applies to both normal execution and replay mode.\n\
9455 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9456 In this mode, other threads may run during other commands.\n\
9457 This applies to both normal execution and replay mode.\n\
9458 replay == scheduler locked in replay mode and unlocked during normal execution."),
9459 set_schedlock_func
, /* traps on target vector */
9460 show_scheduler_mode
,
9461 &setlist
, &showlist
);
9463 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9464 Set mode for resuming threads of all processes."), _("\
9465 Show mode for resuming threads of all processes."), _("\
9466 When on, execution commands (such as 'continue' or 'next') resume all\n\
9467 threads of all processes. When off (which is the default), execution\n\
9468 commands only resume the threads of the current process. The set of\n\
9469 threads that are resumed is further refined by the scheduler-locking\n\
9470 mode (see help set scheduler-locking)."),
9472 show_schedule_multiple
,
9473 &setlist
, &showlist
);
9475 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9476 Set mode of the step operation."), _("\
9477 Show mode of the step operation."), _("\
9478 When set, doing a step over a function without debug line information\n\
9479 will stop at the first instruction of that function. Otherwise, the\n\
9480 function is skipped and the step command stops at a different source line."),
9482 show_step_stop_if_no_debug
,
9483 &setlist
, &showlist
);
9485 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9486 &can_use_displaced_stepping
, _("\
9487 Set debugger's willingness to use displaced stepping."), _("\
9488 Show debugger's willingness to use displaced stepping."), _("\
9489 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9490 supported by the target architecture. If off, gdb will not use displaced\n\
9491 stepping to step over breakpoints, even if such is supported by the target\n\
9492 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9493 if the target architecture supports it and non-stop mode is active, but will not\n\
9494 use it in all-stop mode (see help set non-stop)."),
9496 show_can_use_displaced_stepping
,
9497 &setlist
, &showlist
);
9499 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9500 &exec_direction
, _("Set direction of execution.\n\
9501 Options are 'forward' or 'reverse'."),
9502 _("Show direction of execution (forward/reverse)."),
9503 _("Tells gdb whether to execute forward or backward."),
9504 set_exec_direction_func
, show_exec_direction_func
,
9505 &setlist
, &showlist
);
9507 /* Set/show detach-on-fork: user-settable mode. */
9509 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9510 Set whether gdb will detach the child of a fork."), _("\
9511 Show whether gdb will detach the child of a fork."), _("\
9512 Tells gdb whether to detach the child of a fork."),
9513 NULL
, NULL
, &setlist
, &showlist
);
9515 /* Set/show disable address space randomization mode. */
9517 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9518 &disable_randomization
, _("\
9519 Set disabling of debuggee's virtual address space randomization."), _("\
9520 Show disabling of debuggee's virtual address space randomization."), _("\
9521 When this mode is on (which is the default), randomization of the virtual\n\
9522 address space is disabled. Standalone programs run with the randomization\n\
9523 enabled by default on some platforms."),
9524 &set_disable_randomization
,
9525 &show_disable_randomization
,
9526 &setlist
, &showlist
);
9528 /* ptid initializations */
9529 inferior_ptid
= null_ptid
;
9530 target_last_wait_ptid
= minus_one_ptid
;
9532 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9533 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9534 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9535 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9537 /* Explicitly create without lookup, since that tries to create a
9538 value with a void typed value, and when we get here, gdbarch
9539 isn't initialized yet. At this point, we're quite sure there
9540 isn't another convenience variable of the same name. */
9541 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9543 add_setshow_boolean_cmd ("observer", no_class
,
9544 &observer_mode_1
, _("\
9545 Set whether gdb controls the inferior in observer mode."), _("\
9546 Show whether gdb controls the inferior in observer mode."), _("\
9547 In observer mode, GDB can get data from the inferior, but not\n\
9548 affect its execution. Registers and memory may not be changed,\n\
9549 breakpoints may not be set, and the program cannot be interrupted\n\
9557 selftests::register_test ("infrun_thread_ptid_changed",
9558 selftests::infrun_thread_ptid_changed
);