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/>. */
22 #include "displaced-stepping.h"
23 #include "gdbsupport/common-defs.h"
24 #include "gdbsupport/common-utils.h"
30 #include "breakpoint.h"
34 #include "target-connection.h"
35 #include "gdbthread.h"
43 #include "observable.h"
48 #include "mi/mi-common.h"
49 #include "event-top.h"
51 #include "record-full.h"
52 #include "inline-frame.h"
54 #include "tracepoint.h"
58 #include "completer.h"
59 #include "target-descriptions.h"
60 #include "target-dcache.h"
63 #include "gdbsupport/event-loop.h"
64 #include "thread-fsm.h"
65 #include "gdbsupport/enum-flags.h"
66 #include "progspace-and-thread.h"
67 #include "gdbsupport/gdb_optional.h"
68 #include "arch-utils.h"
69 #include "gdbsupport/scope-exit.h"
70 #include "gdbsupport/forward-scope-exit.h"
71 #include "gdbsupport/gdb_select.h"
72 #include <unordered_map>
73 #include "async-event.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 int 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 int 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;
105 #define infrun_log_debug(fmt, args...) \
106 infrun_log_debug_1 (__LINE__, __func__, fmt, ##args)
108 static void ATTRIBUTE_PRINTF(3, 4)
109 infrun_log_debug_1 (int line
, const char *func
,
110 const char *fmt
, ...)
115 va_start (args
, fmt
);
116 std::string msg
= string_vprintf (fmt
, args
);
119 fprintf_unfiltered (gdb_stdout
, "infrun: %s: %s\n", func
, msg
.c_str ());
126 infrun_async (int enable
)
128 if (infrun_is_async
!= enable
)
130 infrun_is_async
= enable
;
132 infrun_log_debug ("enable=%d", enable
);
135 mark_async_event_handler (infrun_async_inferior_event_token
);
137 clear_async_event_handler (infrun_async_inferior_event_token
);
144 mark_infrun_async_event_handler (void)
146 mark_async_event_handler (infrun_async_inferior_event_token
);
149 /* When set, stop the 'step' command if we enter a function which has
150 no line number information. The normal behavior is that we step
151 over such function. */
152 bool step_stop_if_no_debug
= false;
154 show_step_stop_if_no_debug (struct ui_file
*file
, int from_tty
,
155 struct cmd_list_element
*c
, const char *value
)
157 fprintf_filtered (file
, _("Mode of the step operation is %s.\n"), value
);
160 /* proceed and normal_stop use this to notify the user when the
161 inferior stopped in a different thread than it had been running
164 static ptid_t previous_inferior_ptid
;
166 /* If set (default for legacy reasons), when following a fork, GDB
167 will detach from one of the fork branches, child or parent.
168 Exactly which branch is detached depends on 'set follow-fork-mode'
171 static bool detach_fork
= true;
173 bool debug_displaced
= false;
175 show_debug_displaced (struct ui_file
*file
, int from_tty
,
176 struct cmd_list_element
*c
, const char *value
)
178 fprintf_filtered (file
, _("Displace stepping debugging is %s.\n"), value
);
181 unsigned int debug_infrun
= 0;
183 show_debug_infrun (struct ui_file
*file
, int from_tty
,
184 struct cmd_list_element
*c
, const char *value
)
186 fprintf_filtered (file
, _("Inferior debugging is %s.\n"), value
);
190 /* Support for disabling address space randomization. */
192 bool disable_randomization
= true;
195 show_disable_randomization (struct ui_file
*file
, int from_tty
,
196 struct cmd_list_element
*c
, const char *value
)
198 if (target_supports_disable_randomization ())
199 fprintf_filtered (file
,
200 _("Disabling randomization of debuggee's "
201 "virtual address space is %s.\n"),
204 fputs_filtered (_("Disabling randomization of debuggee's "
205 "virtual address space is unsupported on\n"
206 "this platform.\n"), file
);
210 set_disable_randomization (const char *args
, int from_tty
,
211 struct cmd_list_element
*c
)
213 if (!target_supports_disable_randomization ())
214 error (_("Disabling randomization of debuggee's "
215 "virtual address space is unsupported on\n"
219 /* User interface for non-stop mode. */
221 bool non_stop
= false;
222 static bool non_stop_1
= false;
225 set_non_stop (const char *args
, int from_tty
,
226 struct cmd_list_element
*c
)
228 if (target_has_execution
)
230 non_stop_1
= non_stop
;
231 error (_("Cannot change this setting while the inferior is running."));
234 non_stop
= non_stop_1
;
238 show_non_stop (struct ui_file
*file
, int from_tty
,
239 struct cmd_list_element
*c
, const char *value
)
241 fprintf_filtered (file
,
242 _("Controlling the inferior in non-stop mode is %s.\n"),
246 /* "Observer mode" is somewhat like a more extreme version of
247 non-stop, in which all GDB operations that might affect the
248 target's execution have been disabled. */
250 bool observer_mode
= false;
251 static bool observer_mode_1
= false;
254 set_observer_mode (const char *args
, int from_tty
,
255 struct cmd_list_element
*c
)
257 if (target_has_execution
)
259 observer_mode_1
= observer_mode
;
260 error (_("Cannot change this setting while the inferior is running."));
263 observer_mode
= observer_mode_1
;
265 may_write_registers
= !observer_mode
;
266 may_write_memory
= !observer_mode
;
267 may_insert_breakpoints
= !observer_mode
;
268 may_insert_tracepoints
= !observer_mode
;
269 /* We can insert fast tracepoints in or out of observer mode,
270 but enable them if we're going into this mode. */
272 may_insert_fast_tracepoints
= true;
273 may_stop
= !observer_mode
;
274 update_target_permissions ();
276 /* Going *into* observer mode we must force non-stop, then
277 going out we leave it that way. */
280 pagination_enabled
= 0;
281 non_stop
= non_stop_1
= true;
285 printf_filtered (_("Observer mode is now %s.\n"),
286 (observer_mode
? "on" : "off"));
290 show_observer_mode (struct ui_file
*file
, int from_tty
,
291 struct cmd_list_element
*c
, const char *value
)
293 fprintf_filtered (file
, _("Observer mode is %s.\n"), value
);
296 /* This updates the value of observer mode based on changes in
297 permissions. Note that we are deliberately ignoring the values of
298 may-write-registers and may-write-memory, since the user may have
299 reason to enable these during a session, for instance to turn on a
300 debugging-related global. */
303 update_observer_mode (void)
305 bool newval
= (!may_insert_breakpoints
306 && !may_insert_tracepoints
307 && may_insert_fast_tracepoints
311 /* Let the user know if things change. */
312 if (newval
!= observer_mode
)
313 printf_filtered (_("Observer mode is now %s.\n"),
314 (newval
? "on" : "off"));
316 observer_mode
= observer_mode_1
= newval
;
319 /* Tables of how to react to signals; the user sets them. */
321 static unsigned char signal_stop
[GDB_SIGNAL_LAST
];
322 static unsigned char signal_print
[GDB_SIGNAL_LAST
];
323 static unsigned char signal_program
[GDB_SIGNAL_LAST
];
325 /* Table of signals that are registered with "catch signal". A
326 non-zero entry indicates that the signal is caught by some "catch
328 static unsigned char signal_catch
[GDB_SIGNAL_LAST
];
330 /* Table of signals that the target may silently handle.
331 This is automatically determined from the flags above,
332 and simply cached here. */
333 static unsigned char signal_pass
[GDB_SIGNAL_LAST
];
335 #define SET_SIGS(nsigs,sigs,flags) \
337 int signum = (nsigs); \
338 while (signum-- > 0) \
339 if ((sigs)[signum]) \
340 (flags)[signum] = 1; \
343 #define UNSET_SIGS(nsigs,sigs,flags) \
345 int signum = (nsigs); \
346 while (signum-- > 0) \
347 if ((sigs)[signum]) \
348 (flags)[signum] = 0; \
351 /* Update the target's copy of SIGNAL_PROGRAM. The sole purpose of
352 this function is to avoid exporting `signal_program'. */
355 update_signals_program_target (void)
357 target_program_signals (signal_program
);
360 /* Value to pass to target_resume() to cause all threads to resume. */
362 #define RESUME_ALL minus_one_ptid
364 /* Command list pointer for the "stop" placeholder. */
366 static struct cmd_list_element
*stop_command
;
368 /* Nonzero if we want to give control to the user when we're notified
369 of shared library events by the dynamic linker. */
370 int stop_on_solib_events
;
372 /* Enable or disable optional shared library event breakpoints
373 as appropriate when the above flag is changed. */
376 set_stop_on_solib_events (const char *args
,
377 int from_tty
, struct cmd_list_element
*c
)
379 update_solib_breakpoints ();
383 show_stop_on_solib_events (struct ui_file
*file
, int from_tty
,
384 struct cmd_list_element
*c
, const char *value
)
386 fprintf_filtered (file
, _("Stopping for shared library events is %s.\n"),
390 /* Nonzero after stop if current stack frame should be printed. */
392 static int stop_print_frame
;
394 /* This is a cached copy of the target/ptid/waitstatus of the last
395 event returned by target_wait()/deprecated_target_wait_hook().
396 This information is returned by get_last_target_status(). */
397 static process_stratum_target
*target_last_proc_target
;
398 static ptid_t target_last_wait_ptid
;
399 static struct target_waitstatus target_last_waitstatus
;
401 void init_thread_stepping_state (struct thread_info
*tss
);
403 static const char follow_fork_mode_child
[] = "child";
404 static const char follow_fork_mode_parent
[] = "parent";
406 static const char *const follow_fork_mode_kind_names
[] = {
407 follow_fork_mode_child
,
408 follow_fork_mode_parent
,
412 static const char *follow_fork_mode_string
= follow_fork_mode_parent
;
414 show_follow_fork_mode_string (struct ui_file
*file
, int from_tty
,
415 struct cmd_list_element
*c
, const char *value
)
417 fprintf_filtered (file
,
418 _("Debugger response to a program "
419 "call of fork or vfork is \"%s\".\n"),
424 /* Handle changes to the inferior list based on the type of fork,
425 which process is being followed, and whether the other process
426 should be detached. On entry inferior_ptid must be the ptid of
427 the fork parent. At return inferior_ptid is the ptid of the
428 followed inferior. */
431 follow_fork_inferior (bool follow_child
, bool detach_fork
)
434 ptid_t parent_ptid
, child_ptid
;
436 has_vforked
= (inferior_thread ()->pending_follow
.kind
437 == TARGET_WAITKIND_VFORKED
);
438 parent_ptid
= inferior_ptid
;
439 child_ptid
= inferior_thread ()->pending_follow
.value
.related_pid
;
442 && !non_stop
/* Non-stop always resumes both branches. */
443 && current_ui
->prompt_state
== PROMPT_BLOCKED
444 && !(follow_child
|| detach_fork
|| sched_multi
))
446 /* The parent stays blocked inside the vfork syscall until the
447 child execs or exits. If we don't let the child run, then
448 the parent stays blocked. If we're telling the parent to run
449 in the foreground, the user will not be able to ctrl-c to get
450 back the terminal, effectively hanging the debug session. */
451 fprintf_filtered (gdb_stderr
, _("\
452 Can not resume the parent process over vfork in the foreground while\n\
453 holding the child stopped. Try \"set detach-on-fork\" or \
454 \"set schedule-multiple\".\n"));
460 /* Detach new forked process? */
463 /* Before detaching from the child, remove all breakpoints
464 from it. If we forked, then this has already been taken
465 care of by infrun.c. If we vforked however, any
466 breakpoint inserted in the parent is visible in the
467 child, even those added while stopped in a vfork
468 catchpoint. This will remove the breakpoints from the
469 parent also, but they'll be reinserted below. */
472 /* Keep breakpoints list in sync. */
473 remove_breakpoints_inf (current_inferior ());
476 if (print_inferior_events
)
478 /* Ensure that we have a process ptid. */
479 ptid_t process_ptid
= ptid_t (child_ptid
.pid ());
481 target_terminal::ours_for_output ();
482 fprintf_filtered (gdb_stdlog
,
483 _("[Detaching after %s from child %s]\n"),
484 has_vforked
? "vfork" : "fork",
485 target_pid_to_str (process_ptid
).c_str ());
490 struct inferior
*parent_inf
, *child_inf
;
492 /* Add process to GDB's tables. */
493 child_inf
= add_inferior (child_ptid
.pid ());
495 parent_inf
= current_inferior ();
496 child_inf
->attach_flag
= parent_inf
->attach_flag
;
497 copy_terminal_info (child_inf
, parent_inf
);
498 child_inf
->gdbarch
= parent_inf
->gdbarch
;
499 copy_inferior_target_desc_info (child_inf
, parent_inf
);
501 scoped_restore_current_pspace_and_thread restore_pspace_thread
;
503 set_current_inferior (child_inf
);
504 switch_to_no_thread ();
505 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
506 push_target (parent_inf
->process_target ());
507 add_thread_silent (child_inf
->process_target (), child_ptid
);
508 inferior_ptid
= child_ptid
;
510 /* If this is a vfork child, then the address-space is
511 shared with the parent. */
514 child_inf
->pspace
= parent_inf
->pspace
;
515 child_inf
->aspace
= parent_inf
->aspace
;
519 /* The parent will be frozen until the child is done
520 with the shared region. Keep track of the
522 child_inf
->vfork_parent
= parent_inf
;
523 child_inf
->pending_detach
= 0;
524 parent_inf
->vfork_child
= child_inf
;
525 parent_inf
->pending_detach
= 0;
529 child_inf
->aspace
= new_address_space ();
530 child_inf
->pspace
= new program_space (child_inf
->aspace
);
531 child_inf
->removable
= 1;
532 set_current_program_space (child_inf
->pspace
);
533 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
535 /* Let the shared library layer (e.g., solib-svr4) learn
536 about this new process, relocate the cloned exec, pull
537 in shared libraries, and install the solib event
538 breakpoint. If a "cloned-VM" event was propagated
539 better throughout the core, this wouldn't be
541 solib_create_inferior_hook (0);
547 struct inferior
*parent_inf
;
549 parent_inf
= current_inferior ();
551 /* If we detached from the child, then we have to be careful
552 to not insert breakpoints in the parent until the child
553 is done with the shared memory region. However, if we're
554 staying attached to the child, then we can and should
555 insert breakpoints, so that we can debug it. A
556 subsequent child exec or exit is enough to know when does
557 the child stops using the parent's address space. */
558 parent_inf
->waiting_for_vfork_done
= detach_fork
;
559 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
564 /* Follow the child. */
565 struct inferior
*parent_inf
, *child_inf
;
566 struct program_space
*parent_pspace
;
568 if (print_inferior_events
)
570 std::string parent_pid
= target_pid_to_str (parent_ptid
);
571 std::string child_pid
= target_pid_to_str (child_ptid
);
573 target_terminal::ours_for_output ();
574 fprintf_filtered (gdb_stdlog
,
575 _("[Attaching after %s %s to child %s]\n"),
577 has_vforked
? "vfork" : "fork",
581 /* Add the new inferior first, so that the target_detach below
582 doesn't unpush the target. */
584 child_inf
= add_inferior (child_ptid
.pid ());
586 parent_inf
= current_inferior ();
587 child_inf
->attach_flag
= parent_inf
->attach_flag
;
588 copy_terminal_info (child_inf
, parent_inf
);
589 child_inf
->gdbarch
= parent_inf
->gdbarch
;
590 copy_inferior_target_desc_info (child_inf
, parent_inf
);
592 parent_pspace
= parent_inf
->pspace
;
594 process_stratum_target
*target
= parent_inf
->process_target ();
597 /* Hold a strong reference to the target while (maybe)
598 detaching the parent. Otherwise detaching could close the
600 auto target_ref
= target_ops_ref::new_reference (target
);
602 /* If we're vforking, we want to hold on to the parent until
603 the child exits or execs. At child exec or exit time we
604 can remove the old breakpoints from the parent and detach
605 or resume debugging it. Otherwise, detach the parent now;
606 we'll want to reuse it's program/address spaces, but we
607 can't set them to the child before removing breakpoints
608 from the parent, otherwise, the breakpoints module could
609 decide to remove breakpoints from the wrong process (since
610 they'd be assigned to the same address space). */
614 gdb_assert (child_inf
->vfork_parent
== NULL
);
615 gdb_assert (parent_inf
->vfork_child
== NULL
);
616 child_inf
->vfork_parent
= parent_inf
;
617 child_inf
->pending_detach
= 0;
618 parent_inf
->vfork_child
= child_inf
;
619 parent_inf
->pending_detach
= detach_fork
;
620 parent_inf
->waiting_for_vfork_done
= 0;
622 else if (detach_fork
)
624 if (print_inferior_events
)
626 /* Ensure that we have a process ptid. */
627 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
629 target_terminal::ours_for_output ();
630 fprintf_filtered (gdb_stdlog
,
631 _("[Detaching after fork from "
633 target_pid_to_str (process_ptid
).c_str ());
636 target_detach (parent_inf
, 0);
640 /* Note that the detach above makes PARENT_INF dangling. */
642 /* Add the child thread to the appropriate lists, and switch
643 to this new thread, before cloning the program space, and
644 informing the solib layer about this new process. */
646 set_current_inferior (child_inf
);
647 push_target (target
);
650 add_thread_silent (target
, child_ptid
);
651 inferior_ptid
= child_ptid
;
653 /* If this is a vfork child, then the address-space is shared
654 with the parent. If we detached from the parent, then we can
655 reuse the parent's program/address spaces. */
656 if (has_vforked
|| detach_fork
)
658 child_inf
->pspace
= parent_pspace
;
659 child_inf
->aspace
= child_inf
->pspace
->aspace
;
665 child_inf
->aspace
= new_address_space ();
666 child_inf
->pspace
= new program_space (child_inf
->aspace
);
667 child_inf
->removable
= 1;
668 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
669 set_current_program_space (child_inf
->pspace
);
670 clone_program_space (child_inf
->pspace
, parent_pspace
);
672 /* Let the shared library layer (e.g., solib-svr4) learn
673 about this new process, relocate the cloned exec, pull in
674 shared libraries, and install the solib event breakpoint.
675 If a "cloned-VM" event was propagated better throughout
676 the core, this wouldn't be required. */
677 solib_create_inferior_hook (0);
681 return target_follow_fork (follow_child
, detach_fork
);
684 /* Tell the target to follow the fork we're stopped at. Returns true
685 if the inferior should be resumed; false, if the target for some
686 reason decided it's best not to resume. */
691 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
692 bool should_resume
= true;
693 struct thread_info
*tp
;
695 /* Copy user stepping state to the new inferior thread. FIXME: the
696 followed fork child thread should have a copy of most of the
697 parent thread structure's run control related fields, not just these.
698 Initialized to avoid "may be used uninitialized" warnings from gcc. */
699 struct breakpoint
*step_resume_breakpoint
= NULL
;
700 struct breakpoint
*exception_resume_breakpoint
= NULL
;
701 CORE_ADDR step_range_start
= 0;
702 CORE_ADDR step_range_end
= 0;
703 int current_line
= 0;
704 symtab
*current_symtab
= NULL
;
705 struct frame_id step_frame_id
= { 0 };
706 struct thread_fsm
*thread_fsm
= NULL
;
710 process_stratum_target
*wait_target
;
712 struct target_waitstatus wait_status
;
714 /* Get the last target status returned by target_wait(). */
715 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
717 /* If not stopped at a fork event, then there's nothing else to
719 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
720 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
723 /* Check if we switched over from WAIT_PTID, since the event was
725 if (wait_ptid
!= minus_one_ptid
726 && (current_inferior ()->process_target () != wait_target
727 || inferior_ptid
!= wait_ptid
))
729 /* We did. Switch back to WAIT_PTID thread, to tell the
730 target to follow it (in either direction). We'll
731 afterwards refuse to resume, and inform the user what
733 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
734 switch_to_thread (wait_thread
);
735 should_resume
= false;
739 tp
= inferior_thread ();
741 /* If there were any forks/vforks that were caught and are now to be
742 followed, then do so now. */
743 switch (tp
->pending_follow
.kind
)
745 case TARGET_WAITKIND_FORKED
:
746 case TARGET_WAITKIND_VFORKED
:
748 ptid_t parent
, child
;
750 /* If the user did a next/step, etc, over a fork call,
751 preserve the stepping state in the fork child. */
752 if (follow_child
&& should_resume
)
754 step_resume_breakpoint
= clone_momentary_breakpoint
755 (tp
->control
.step_resume_breakpoint
);
756 step_range_start
= tp
->control
.step_range_start
;
757 step_range_end
= tp
->control
.step_range_end
;
758 current_line
= tp
->current_line
;
759 current_symtab
= tp
->current_symtab
;
760 step_frame_id
= tp
->control
.step_frame_id
;
761 exception_resume_breakpoint
762 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
763 thread_fsm
= tp
->thread_fsm
;
765 /* For now, delete the parent's sr breakpoint, otherwise,
766 parent/child sr breakpoints are considered duplicates,
767 and the child version will not be installed. Remove
768 this when the breakpoints module becomes aware of
769 inferiors and address spaces. */
770 delete_step_resume_breakpoint (tp
);
771 tp
->control
.step_range_start
= 0;
772 tp
->control
.step_range_end
= 0;
773 tp
->control
.step_frame_id
= null_frame_id
;
774 delete_exception_resume_breakpoint (tp
);
775 tp
->thread_fsm
= NULL
;
778 parent
= inferior_ptid
;
779 child
= tp
->pending_follow
.value
.related_pid
;
781 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
782 /* Set up inferior(s) as specified by the caller, and tell the
783 target to do whatever is necessary to follow either parent
785 if (follow_fork_inferior (follow_child
, detach_fork
))
787 /* Target refused to follow, or there's some other reason
788 we shouldn't resume. */
793 /* This pending follow fork event is now handled, one way
794 or another. The previous selected thread may be gone
795 from the lists by now, but if it is still around, need
796 to clear the pending follow request. */
797 tp
= find_thread_ptid (parent_targ
, parent
);
799 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
801 /* This makes sure we don't try to apply the "Switched
802 over from WAIT_PID" logic above. */
803 nullify_last_target_wait_ptid ();
805 /* If we followed the child, switch to it... */
808 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
809 switch_to_thread (child_thr
);
811 /* ... and preserve the stepping state, in case the
812 user was stepping over the fork call. */
815 tp
= inferior_thread ();
816 tp
->control
.step_resume_breakpoint
817 = step_resume_breakpoint
;
818 tp
->control
.step_range_start
= step_range_start
;
819 tp
->control
.step_range_end
= step_range_end
;
820 tp
->current_line
= current_line
;
821 tp
->current_symtab
= current_symtab
;
822 tp
->control
.step_frame_id
= step_frame_id
;
823 tp
->control
.exception_resume_breakpoint
824 = exception_resume_breakpoint
;
825 tp
->thread_fsm
= thread_fsm
;
829 /* If we get here, it was because we're trying to
830 resume from a fork catchpoint, but, the user
831 has switched threads away from the thread that
832 forked. In that case, the resume command
833 issued is most likely not applicable to the
834 child, so just warn, and refuse to resume. */
835 warning (_("Not resuming: switched threads "
836 "before following fork child."));
839 /* Reset breakpoints in the child as appropriate. */
840 follow_inferior_reset_breakpoints ();
845 case TARGET_WAITKIND_SPURIOUS
:
846 /* Nothing to follow. */
849 internal_error (__FILE__
, __LINE__
,
850 "Unexpected pending_follow.kind %d\n",
851 tp
->pending_follow
.kind
);
855 return should_resume
;
859 follow_inferior_reset_breakpoints (void)
861 struct thread_info
*tp
= inferior_thread ();
863 /* Was there a step_resume breakpoint? (There was if the user
864 did a "next" at the fork() call.) If so, explicitly reset its
865 thread number. Cloned step_resume breakpoints are disabled on
866 creation, so enable it here now that it is associated with the
869 step_resumes are a form of bp that are made to be per-thread.
870 Since we created the step_resume bp when the parent process
871 was being debugged, and now are switching to the child process,
872 from the breakpoint package's viewpoint, that's a switch of
873 "threads". We must update the bp's notion of which thread
874 it is for, or it'll be ignored when it triggers. */
876 if (tp
->control
.step_resume_breakpoint
)
878 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
879 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
882 /* Treat exception_resume breakpoints like step_resume breakpoints. */
883 if (tp
->control
.exception_resume_breakpoint
)
885 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
886 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
889 /* Reinsert all breakpoints in the child. The user may have set
890 breakpoints after catching the fork, in which case those
891 were never set in the child, but only in the parent. This makes
892 sure the inserted breakpoints match the breakpoint list. */
894 breakpoint_re_set ();
895 insert_breakpoints ();
898 /* The child has exited or execed: resume threads of the parent the
899 user wanted to be executing. */
902 proceed_after_vfork_done (struct thread_info
*thread
,
905 int pid
= * (int *) arg
;
907 if (thread
->ptid
.pid () == pid
908 && thread
->state
== THREAD_RUNNING
909 && !thread
->executing
910 && !thread
->stop_requested
911 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
913 infrun_log_debug ("resuming vfork parent thread %s",
914 target_pid_to_str (thread
->ptid
).c_str ());
916 switch_to_thread (thread
);
917 clear_proceed_status (0);
918 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
924 /* Save/restore inferior_ptid, current program space and current
925 inferior. Only use this if the current context points at an exited
926 inferior (and therefore there's no current thread to save). */
927 class scoped_restore_exited_inferior
930 scoped_restore_exited_inferior ()
931 : m_saved_ptid (&inferior_ptid
)
935 scoped_restore_tmpl
<ptid_t
> m_saved_ptid
;
936 scoped_restore_current_program_space m_pspace
;
937 scoped_restore_current_inferior m_inferior
;
940 /* Called whenever we notice an exec or exit event, to handle
941 detaching or resuming a vfork parent. */
944 handle_vfork_child_exec_or_exit (int exec
)
946 struct inferior
*inf
= current_inferior ();
948 if (inf
->vfork_parent
)
950 int resume_parent
= -1;
952 /* This exec or exit marks the end of the shared memory region
953 between the parent and the child. Break the bonds. */
954 inferior
*vfork_parent
= inf
->vfork_parent
;
955 inf
->vfork_parent
->vfork_child
= NULL
;
956 inf
->vfork_parent
= NULL
;
958 /* If the user wanted to detach from the parent, now is the
960 if (vfork_parent
->pending_detach
)
962 struct thread_info
*tp
;
963 struct program_space
*pspace
;
964 struct address_space
*aspace
;
966 /* follow-fork child, detach-on-fork on. */
968 vfork_parent
->pending_detach
= 0;
970 gdb::optional
<scoped_restore_exited_inferior
>
971 maybe_restore_inferior
;
972 gdb::optional
<scoped_restore_current_pspace_and_thread
>
973 maybe_restore_thread
;
975 /* If we're handling a child exit, then inferior_ptid points
976 at the inferior's pid, not to a thread. */
978 maybe_restore_inferior
.emplace ();
980 maybe_restore_thread
.emplace ();
982 /* We're letting loose of the parent. */
983 tp
= any_live_thread_of_inferior (vfork_parent
);
984 switch_to_thread (tp
);
986 /* We're about to detach from the parent, which implicitly
987 removes breakpoints from its address space. There's a
988 catch here: we want to reuse the spaces for the child,
989 but, parent/child are still sharing the pspace at this
990 point, although the exec in reality makes the kernel give
991 the child a fresh set of new pages. The problem here is
992 that the breakpoints module being unaware of this, would
993 likely chose the child process to write to the parent
994 address space. Swapping the child temporarily away from
995 the spaces has the desired effect. Yes, this is "sort
998 pspace
= inf
->pspace
;
999 aspace
= inf
->aspace
;
1003 if (print_inferior_events
)
1006 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
1008 target_terminal::ours_for_output ();
1012 fprintf_filtered (gdb_stdlog
,
1013 _("[Detaching vfork parent %s "
1014 "after child exec]\n"), pidstr
.c_str ());
1018 fprintf_filtered (gdb_stdlog
,
1019 _("[Detaching vfork parent %s "
1020 "after child exit]\n"), pidstr
.c_str ());
1024 target_detach (vfork_parent
, 0);
1027 inf
->pspace
= pspace
;
1028 inf
->aspace
= aspace
;
1032 /* We're staying attached to the parent, so, really give the
1033 child a new address space. */
1034 inf
->pspace
= new program_space (maybe_new_address_space ());
1035 inf
->aspace
= inf
->pspace
->aspace
;
1037 set_current_program_space (inf
->pspace
);
1039 resume_parent
= vfork_parent
->pid
;
1043 /* If this is a vfork child exiting, then the pspace and
1044 aspaces were shared with the parent. Since we're
1045 reporting the process exit, we'll be mourning all that is
1046 found in the address space, and switching to null_ptid,
1047 preparing to start a new inferior. But, since we don't
1048 want to clobber the parent's address/program spaces, we
1049 go ahead and create a new one for this exiting
1052 /* Switch to null_ptid while running clone_program_space, so
1053 that clone_program_space doesn't want to read the
1054 selected frame of a dead process. */
1055 scoped_restore restore_ptid
1056 = make_scoped_restore (&inferior_ptid
, null_ptid
);
1058 inf
->pspace
= new program_space (maybe_new_address_space ());
1059 inf
->aspace
= inf
->pspace
->aspace
;
1060 set_current_program_space (inf
->pspace
);
1062 inf
->symfile_flags
= SYMFILE_NO_READ
;
1063 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1065 resume_parent
= vfork_parent
->pid
;
1068 gdb_assert (current_program_space
== inf
->pspace
);
1070 if (non_stop
&& resume_parent
!= -1)
1072 /* If the user wanted the parent to be running, let it go
1074 scoped_restore_current_thread restore_thread
;
1076 infrun_log_debug ("resuming vfork parent process %d",
1079 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1084 /* Enum strings for "set|show follow-exec-mode". */
1086 static const char follow_exec_mode_new
[] = "new";
1087 static const char follow_exec_mode_same
[] = "same";
1088 static const char *const follow_exec_mode_names
[] =
1090 follow_exec_mode_new
,
1091 follow_exec_mode_same
,
1095 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1097 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1098 struct cmd_list_element
*c
, const char *value
)
1100 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1103 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1106 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1108 struct inferior
*inf
= current_inferior ();
1109 int pid
= ptid
.pid ();
1110 ptid_t process_ptid
;
1112 /* Switch terminal for any messages produced e.g. by
1113 breakpoint_re_set. */
1114 target_terminal::ours_for_output ();
1116 /* This is an exec event that we actually wish to pay attention to.
1117 Refresh our symbol table to the newly exec'd program, remove any
1118 momentary bp's, etc.
1120 If there are breakpoints, they aren't really inserted now,
1121 since the exec() transformed our inferior into a fresh set
1124 We want to preserve symbolic breakpoints on the list, since
1125 we have hopes that they can be reset after the new a.out's
1126 symbol table is read.
1128 However, any "raw" breakpoints must be removed from the list
1129 (e.g., the solib bp's), since their address is probably invalid
1132 And, we DON'T want to call delete_breakpoints() here, since
1133 that may write the bp's "shadow contents" (the instruction
1134 value that was overwritten with a TRAP instruction). Since
1135 we now have a new a.out, those shadow contents aren't valid. */
1137 mark_breakpoints_out ();
1139 /* The target reports the exec event to the main thread, even if
1140 some other thread does the exec, and even if the main thread was
1141 stopped or already gone. We may still have non-leader threads of
1142 the process on our list. E.g., on targets that don't have thread
1143 exit events (like remote); or on native Linux in non-stop mode if
1144 there were only two threads in the inferior and the non-leader
1145 one is the one that execs (and nothing forces an update of the
1146 thread list up to here). When debugging remotely, it's best to
1147 avoid extra traffic, when possible, so avoid syncing the thread
1148 list with the target, and instead go ahead and delete all threads
1149 of the process but one that reported the event. Note this must
1150 be done before calling update_breakpoints_after_exec, as
1151 otherwise clearing the threads' resources would reference stale
1152 thread breakpoints -- it may have been one of these threads that
1153 stepped across the exec. We could just clear their stepping
1154 states, but as long as we're iterating, might as well delete
1155 them. Deleting them now rather than at the next user-visible
1156 stop provides a nicer sequence of events for user and MI
1158 for (thread_info
*th
: all_threads_safe ())
1159 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1162 /* We also need to clear any left over stale state for the
1163 leader/event thread. E.g., if there was any step-resume
1164 breakpoint or similar, it's gone now. We cannot truly
1165 step-to-next statement through an exec(). */
1166 thread_info
*th
= inferior_thread ();
1167 th
->control
.step_resume_breakpoint
= NULL
;
1168 th
->control
.exception_resume_breakpoint
= NULL
;
1169 th
->control
.single_step_breakpoints
= NULL
;
1170 th
->control
.step_range_start
= 0;
1171 th
->control
.step_range_end
= 0;
1173 /* The user may have had the main thread held stopped in the
1174 previous image (e.g., schedlock on, or non-stop). Release
1176 th
->stop_requested
= 0;
1178 update_breakpoints_after_exec ();
1180 /* What is this a.out's name? */
1181 process_ptid
= ptid_t (pid
);
1182 printf_unfiltered (_("%s is executing new program: %s\n"),
1183 target_pid_to_str (process_ptid
).c_str (),
1186 /* We've followed the inferior through an exec. Therefore, the
1187 inferior has essentially been killed & reborn. */
1189 breakpoint_init_inferior (inf_execd
);
1191 gdb::unique_xmalloc_ptr
<char> exec_file_host
1192 = exec_file_find (exec_file_target
, NULL
);
1194 /* If we were unable to map the executable target pathname onto a host
1195 pathname, tell the user that. Otherwise GDB's subsequent behavior
1196 is confusing. Maybe it would even be better to stop at this point
1197 so that the user can specify a file manually before continuing. */
1198 if (exec_file_host
== NULL
)
1199 warning (_("Could not load symbols for executable %s.\n"
1200 "Do you need \"set sysroot\"?"),
1203 /* Reset the shared library package. This ensures that we get a
1204 shlib event when the child reaches "_start", at which point the
1205 dld will have had a chance to initialize the child. */
1206 /* Also, loading a symbol file below may trigger symbol lookups, and
1207 we don't want those to be satisfied by the libraries of the
1208 previous incarnation of this process. */
1209 no_shared_libraries (NULL
, 0);
1211 if (follow_exec_mode_string
== follow_exec_mode_new
)
1213 /* The user wants to keep the old inferior and program spaces
1214 around. Create a new fresh one, and switch to it. */
1216 /* Do exit processing for the original inferior before setting the new
1217 inferior's pid. Having two inferiors with the same pid would confuse
1218 find_inferior_p(t)id. Transfer the terminal state and info from the
1219 old to the new inferior. */
1220 inf
= add_inferior_with_spaces ();
1221 swap_terminal_info (inf
, current_inferior ());
1222 exit_inferior_silent (current_inferior ());
1225 target_follow_exec (inf
, exec_file_target
);
1227 inferior
*org_inferior
= current_inferior ();
1228 switch_to_inferior_no_thread (inf
);
1229 push_target (org_inferior
->process_target ());
1230 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1231 switch_to_thread (thr
);
1235 /* The old description may no longer be fit for the new image.
1236 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1237 old description; we'll read a new one below. No need to do
1238 this on "follow-exec-mode new", as the old inferior stays
1239 around (its description is later cleared/refetched on
1241 target_clear_description ();
1244 gdb_assert (current_program_space
== inf
->pspace
);
1246 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1247 because the proper displacement for a PIE (Position Independent
1248 Executable) main symbol file will only be computed by
1249 solib_create_inferior_hook below. breakpoint_re_set would fail
1250 to insert the breakpoints with the zero displacement. */
1251 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1253 /* If the target can specify a description, read it. Must do this
1254 after flipping to the new executable (because the target supplied
1255 description must be compatible with the executable's
1256 architecture, and the old executable may e.g., be 32-bit, while
1257 the new one 64-bit), and before anything involving memory or
1259 target_find_description ();
1261 solib_create_inferior_hook (0);
1263 jit_inferior_created_hook ();
1265 breakpoint_re_set ();
1267 /* Reinsert all breakpoints. (Those which were symbolic have
1268 been reset to the proper address in the new a.out, thanks
1269 to symbol_file_command...). */
1270 insert_breakpoints ();
1272 gdb::observers::inferior_execd
.notify (inf
);
1274 /* The next resume of this inferior should bring it to the shlib
1275 startup breakpoints. (If the user had also set bp's on
1276 "main" from the old (parent) process, then they'll auto-
1277 matically get reset there in the new process.). */
1280 /* The queue of threads that need to do a step-over operation to get
1281 past e.g., a breakpoint. What technique is used to step over the
1282 breakpoint/watchpoint does not matter -- all threads end up in the
1283 same queue, to maintain rough temporal order of execution, in order
1284 to avoid starvation, otherwise, we could e.g., find ourselves
1285 constantly stepping the same couple threads past their breakpoints
1286 over and over, if the single-step finish fast enough. */
1287 struct thread_info
*global_thread_step_over_chain_head
;
1289 /* Bit flags indicating what the thread needs to step over. */
1291 enum step_over_what_flag
1293 /* Step over a breakpoint. */
1294 STEP_OVER_BREAKPOINT
= 1,
1296 /* Step past a non-continuable watchpoint, in order to let the
1297 instruction execute so we can evaluate the watchpoint
1299 STEP_OVER_WATCHPOINT
= 2
1301 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1303 /* Info about an instruction that is being stepped over. */
1305 struct step_over_info
1307 /* If we're stepping past a breakpoint, this is the address space
1308 and address of the instruction the breakpoint is set at. We'll
1309 skip inserting all breakpoints here. Valid iff ASPACE is
1311 const address_space
*aspace
;
1314 /* The instruction being stepped over triggers a nonsteppable
1315 watchpoint. If true, we'll skip inserting watchpoints. */
1316 int nonsteppable_watchpoint_p
;
1318 /* The thread's global number. */
1322 /* The step-over info of the location that is being stepped over.
1324 Note that with async/breakpoint always-inserted mode, a user might
1325 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1326 being stepped over. As setting a new breakpoint inserts all
1327 breakpoints, we need to make sure the breakpoint being stepped over
1328 isn't inserted then. We do that by only clearing the step-over
1329 info when the step-over is actually finished (or aborted).
1331 Presently GDB can only step over one breakpoint at any given time.
1332 Given threads that can't run code in the same address space as the
1333 breakpoint's can't really miss the breakpoint, GDB could be taught
1334 to step-over at most one breakpoint per address space (so this info
1335 could move to the address space object if/when GDB is extended).
1336 The set of breakpoints being stepped over will normally be much
1337 smaller than the set of all breakpoints, so a flag in the
1338 breakpoint location structure would be wasteful. A separate list
1339 also saves complexity and run-time, as otherwise we'd have to go
1340 through all breakpoint locations clearing their flag whenever we
1341 start a new sequence. Similar considerations weigh against storing
1342 this info in the thread object. Plus, not all step overs actually
1343 have breakpoint locations -- e.g., stepping past a single-step
1344 breakpoint, or stepping to complete a non-continuable
1346 static struct step_over_info step_over_info
;
1348 /* Record the address of the breakpoint/instruction we're currently
1350 N.B. We record the aspace and address now, instead of say just the thread,
1351 because when we need the info later the thread may be running. */
1354 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1355 int nonsteppable_watchpoint_p
,
1358 step_over_info
.aspace
= aspace
;
1359 step_over_info
.address
= address
;
1360 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1361 step_over_info
.thread
= thread
;
1364 /* Called when we're not longer stepping over a breakpoint / an
1365 instruction, so all breakpoints are free to be (re)inserted. */
1368 clear_step_over_info (void)
1370 infrun_log_debug ("clearing step over info");
1371 step_over_info
.aspace
= NULL
;
1372 step_over_info
.address
= 0;
1373 step_over_info
.nonsteppable_watchpoint_p
= 0;
1374 step_over_info
.thread
= -1;
1380 stepping_past_instruction_at (struct address_space
*aspace
,
1383 return (step_over_info
.aspace
!= NULL
1384 && breakpoint_address_match (aspace
, address
,
1385 step_over_info
.aspace
,
1386 step_over_info
.address
));
1392 thread_is_stepping_over_breakpoint (int thread
)
1394 return (step_over_info
.thread
!= -1
1395 && thread
== step_over_info
.thread
);
1401 stepping_past_nonsteppable_watchpoint (void)
1403 return step_over_info
.nonsteppable_watchpoint_p
;
1406 /* Returns true if step-over info is valid. */
1409 step_over_info_valid_p (void)
1411 return (step_over_info
.aspace
!= NULL
1412 || stepping_past_nonsteppable_watchpoint ());
1416 /* Displaced stepping. */
1418 /* In non-stop debugging mode, we must take special care to manage
1419 breakpoints properly; in particular, the traditional strategy for
1420 stepping a thread past a breakpoint it has hit is unsuitable.
1421 'Displaced stepping' is a tactic for stepping one thread past a
1422 breakpoint it has hit while ensuring that other threads running
1423 concurrently will hit the breakpoint as they should.
1425 The traditional way to step a thread T off a breakpoint in a
1426 multi-threaded program in all-stop mode is as follows:
1428 a0) Initially, all threads are stopped, and breakpoints are not
1430 a1) We single-step T, leaving breakpoints uninserted.
1431 a2) We insert breakpoints, and resume all threads.
1433 In non-stop debugging, however, this strategy is unsuitable: we
1434 don't want to have to stop all threads in the system in order to
1435 continue or step T past a breakpoint. Instead, we use displaced
1438 n0) Initially, T is stopped, other threads are running, and
1439 breakpoints are inserted.
1440 n1) We copy the instruction "under" the breakpoint to a separate
1441 location, outside the main code stream, making any adjustments
1442 to the instruction, register, and memory state as directed by
1444 n2) We single-step T over the instruction at its new location.
1445 n3) We adjust the resulting register and memory state as directed
1446 by T's architecture. This includes resetting T's PC to point
1447 back into the main instruction stream.
1450 This approach depends on the following gdbarch methods:
1452 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1453 indicate where to copy the instruction, and how much space must
1454 be reserved there. We use these in step n1.
1456 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1457 address, and makes any necessary adjustments to the instruction,
1458 register contents, and memory. We use this in step n1.
1460 - gdbarch_displaced_step_fixup adjusts registers and memory after
1461 we have successfully single-stepped the instruction, to yield the
1462 same effect the instruction would have had if we had executed it
1463 at its original address. We use this in step n3.
1465 The gdbarch_displaced_step_copy_insn and
1466 gdbarch_displaced_step_fixup functions must be written so that
1467 copying an instruction with gdbarch_displaced_step_copy_insn,
1468 single-stepping across the copied instruction, and then applying
1469 gdbarch_displaced_insn_fixup should have the same effects on the
1470 thread's memory and registers as stepping the instruction in place
1471 would have. Exactly which responsibilities fall to the copy and
1472 which fall to the fixup is up to the author of those functions.
1474 See the comments in gdbarch.sh for details.
1476 Note that displaced stepping and software single-step cannot
1477 currently be used in combination, although with some care I think
1478 they could be made to. Software single-step works by placing
1479 breakpoints on all possible subsequent instructions; if the
1480 displaced instruction is a PC-relative jump, those breakpoints
1481 could fall in very strange places --- on pages that aren't
1482 executable, or at addresses that are not proper instruction
1483 boundaries. (We do generally let other threads run while we wait
1484 to hit the software single-step breakpoint, and they might
1485 encounter such a corrupted instruction.) One way to work around
1486 this would be to have gdbarch_displaced_step_copy_insn fully
1487 simulate the effect of PC-relative instructions (and return NULL)
1488 on architectures that use software single-stepping.
1490 In non-stop mode, we can have independent and simultaneous step
1491 requests, so more than one thread may need to simultaneously step
1492 over a breakpoint. The current implementation assumes there is
1493 only one scratch space per process. In this case, we have to
1494 serialize access to the scratch space. If thread A wants to step
1495 over a breakpoint, but we are currently waiting for some other
1496 thread to complete a displaced step, we leave thread A stopped and
1497 place it in the displaced_step_request_queue. Whenever a displaced
1498 step finishes, we pick the next thread in the queue and start a new
1499 displaced step operation on it. See displaced_step_prepare and
1500 displaced_step_fixup for details. */
1502 /* Get the displaced stepping state of inferior INF. */
1504 static displaced_step_inferior_state
*
1505 get_displaced_stepping_state (inferior
*inf
)
1507 return &inf
->displaced_step_state
;
1510 /* Get the displaced stepping state of thread THREAD. */
1512 static displaced_step_thread_state
*
1513 get_displaced_stepping_state (thread_info
*thread
)
1515 return &thread
->displaced_step_state
;
1518 /* Return true if the given thread is doing a displaced step. */
1521 displaced_step_in_progress (thread_info
*thread
)
1523 gdb_assert (thread
!= NULL
);
1525 return get_displaced_stepping_state (thread
)->in_progress ();
1528 /* Return true if any thread of this inferior is doing a displaced step. */
1531 displaced_step_in_progress (inferior
*inf
)
1533 for (thread_info
*thread
: inf
->non_exited_threads ())
1535 if (displaced_step_in_progress (thread
))
1542 /* Return true if any thread is doing a displaced step. */
1545 displaced_step_in_progress_any_thread ()
1547 for (thread_info
*thread
: all_non_exited_threads ())
1549 if (displaced_step_in_progress (thread
))
1556 /* If inferior is in displaced stepping, and ADDR equals to starting address
1557 of copy area, return corresponding displaced_step_copy_insn_closure. Otherwise,
1560 struct displaced_step_copy_insn_closure
*
1561 get_displaced_step_copy_insn_closure_by_addr (CORE_ADDR addr
)
1563 // FIXME: implement me (only needed on ARM).
1564 // displaced_step_inferior_state *displaced
1565 // = get_displaced_stepping_state (current_inferior ());
1567 // /* If checking the mode of displaced instruction in copy area. */
1568 // if (displaced->step_thread != nullptr
1569 // && displaced->step_copy == addr)
1570 // return displaced->step_closure.get ();
1576 infrun_inferior_exit (struct inferior
*inf
)
1578 inf
->displaced_step_state
.reset ();
1581 /* If ON, and the architecture supports it, GDB will use displaced
1582 stepping to step over breakpoints. If OFF, or if the architecture
1583 doesn't support it, GDB will instead use the traditional
1584 hold-and-step approach. If AUTO (which is the default), GDB will
1585 decide which technique to use to step over breakpoints depending on
1586 whether the target works in a non-stop way (see use_displaced_stepping). */
1588 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1591 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1592 struct cmd_list_element
*c
,
1595 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1596 fprintf_filtered (file
,
1597 _("Debugger's willingness to use displaced stepping "
1598 "to step over breakpoints is %s (currently %s).\n"),
1599 value
, target_is_non_stop_p () ? "on" : "off");
1601 fprintf_filtered (file
,
1602 _("Debugger's willingness to use displaced stepping "
1603 "to step over breakpoints is %s.\n"), value
);
1606 /* Return true if the target behing THREAD supports displaced stepping. */
1609 target_supports_displaced_stepping (thread_info
*thread
)
1611 inferior
*inf
= thread
->inf
;
1612 target_ops
*target
= inf
->top_target ();
1614 return target
->supports_displaced_step (thread
);
1617 /* Return non-zero if displaced stepping can/should be used to step
1618 over breakpoints of thread TP. */
1621 use_displaced_stepping (thread_info
*tp
)
1623 /* If the user disabled it explicitly, don't use displaced stepping. */
1624 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1627 /* If "auto", only use displaced stepping if the target operates in a non-stop
1629 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1630 && !target_is_non_stop_p ())
1633 /* If the target doesn't support displaced stepping, don't use it. */
1634 if (!target_supports_displaced_stepping (tp
))
1637 /* If recording, don't use displaced stepping. */
1638 if (find_record_target () != nullptr)
1641 displaced_step_inferior_state
*displaced_state
1642 = get_displaced_stepping_state (tp
->inf
);
1644 /* If displaced stepping failed before for this inferior, don't bother trying
1646 if (displaced_state
->failed_before
)
1652 /* Simple function wrapper around displaced_step_thread_state::reset. */
1655 displaced_step_reset (displaced_step_thread_state
*displaced
)
1657 displaced
->reset ();
1660 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1661 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1663 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1665 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1667 displaced_step_dump_bytes (struct ui_file
*file
,
1668 const gdb_byte
*buf
,
1673 for (i
= 0; i
< len
; i
++)
1674 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1675 fputs_unfiltered ("\n", file
);
1678 /* Prepare to single-step, using displaced stepping.
1680 Note that we cannot use displaced stepping when we have a signal to
1681 deliver. If we have a signal to deliver and an instruction to step
1682 over, then after the step, there will be no indication from the
1683 target whether the thread entered a signal handler or ignored the
1684 signal and stepped over the instruction successfully --- both cases
1685 result in a simple SIGTRAP. In the first case we mustn't do a
1686 fixup, and in the second case we must --- but we can't tell which.
1687 Comments in the code for 'random signals' in handle_inferior_event
1688 explain how we handle this case instead.
1690 Returns 1 if preparing was successful -- this thread is going to be
1691 stepped now; 0 if displaced stepping this thread got queued; or -1
1692 if this instruction can't be displaced stepped. */
1694 static displaced_step_prepare_status
1695 displaced_step_prepare_throw (thread_info
*tp
)
1697 regcache
*regcache
= get_thread_regcache (tp
);
1698 struct gdbarch
*gdbarch
= regcache
->arch ();
1699 displaced_step_thread_state
*thread_disp_step_state
1700 = get_displaced_stepping_state (tp
);
1702 /* We should never reach this function if the target does not
1703 support displaced stepping. */
1704 gdb_assert (target_supports_displaced_stepping (tp
));
1706 /* Nor if the thread isn't meant to step over a breakpoint. */
1707 gdb_assert (tp
->control
.trap_expected
);
1709 /* Disable range stepping while executing in the scratch pad. We
1710 want a single-step even if executing the displaced instruction in
1711 the scratch buffer lands within the stepping range (e.g., a
1713 tp
->control
.may_range_step
= 0;
1715 /* We are about to start a displaced step for this thread, if one is already
1716 in progress, we goofed up somewhere. */
1717 gdb_assert (!thread_disp_step_state
->in_progress ());
1719 scoped_restore_current_thread restore_thread
;
1721 switch_to_thread (tp
);
1723 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1725 displaced_step_prepare_status status
=
1726 tp
->inf
->top_target ()->displaced_step_prepare (tp
);
1728 if (status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
1730 if (debug_displaced
)
1731 fprintf_unfiltered (gdb_stdlog
,
1732 "displaced: failed to prepare (%s)",
1733 target_pid_to_str (tp
->ptid
).c_str ());
1735 return DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1737 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1739 /* Not enough displaced stepping resources available, defer this
1740 request by placing it the queue. */
1742 if (debug_displaced
)
1743 fprintf_unfiltered (gdb_stdlog
,
1744 "displaced: not enough resources available, "
1745 "deferring step of %s\n",
1746 target_pid_to_str (tp
->ptid
).c_str ());
1748 global_thread_step_over_chain_enqueue (tp
);
1749 tp
->inf
->displaced_step_state
.unavailable
= true;
1751 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1754 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1756 // FIXME: Should probably replicated in the arch implementation now.
1758 // if (breakpoint_in_range_p (aspace, copy, len))
1760 // /* There's a breakpoint set in the scratch pad location range
1761 // (which is usually around the entry point). We'd either
1762 // install it before resuming, which would overwrite/corrupt the
1763 // scratch pad, or if it was already inserted, this displaced
1764 // step would overwrite it. The latter is OK in the sense that
1765 // we already assume that no thread is going to execute the code
1766 // in the scratch pad range (after initial startup) anyway, but
1767 // the former is unacceptable. Simply punt and fallback to
1768 // stepping over this breakpoint in-line. */
1769 // if (debug_displaced)
1771 // fprintf_unfiltered (gdb_stdlog,
1772 // "displaced: breakpoint set in scratch pad. "
1773 // "Stepping over breakpoint in-line instead.\n");
1776 // gdb_assert (false);
1777 // gdbarch_displaced_step_release_location (gdbarch, copy);
1782 /* Save the information we need to fix things up if the step
1784 thread_disp_step_state
->set (gdbarch
);
1786 // FIXME: get it from _prepare?
1787 CORE_ADDR displaced_pc
= 0;
1789 if (debug_displaced
)
1790 fprintf_unfiltered (gdb_stdlog
,
1791 "displaced: prepared successfully thread=%s, "
1792 "original_pc=%s, displaced_pc=%s\n",
1793 target_pid_to_str (tp
->ptid
).c_str (),
1794 paddress (gdbarch
, original_pc
),
1795 paddress (gdbarch
, displaced_pc
));
1797 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1800 /* Wrapper for displaced_step_prepare_throw that disabled further
1801 attempts at displaced stepping if we get a memory error. */
1803 static displaced_step_prepare_status
1804 displaced_step_prepare (thread_info
*thread
)
1806 displaced_step_prepare_status status
1807 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1811 status
= displaced_step_prepare_throw (thread
);
1813 catch (const gdb_exception_error
&ex
)
1815 struct displaced_step_inferior_state
*displaced_state
;
1817 if (ex
.error
!= MEMORY_ERROR
1818 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1821 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1824 /* Be verbose if "set displaced-stepping" is "on", silent if
1826 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1828 warning (_("disabling displaced stepping: %s"),
1832 /* Disable further displaced stepping attempts. */
1834 = get_displaced_stepping_state (thread
->inf
);
1835 displaced_state
->failed_before
= 1;
1841 /* If we displaced stepped an instruction successfully, adjust
1842 registers and memory to yield the same effect the instruction would
1843 have had if we had executed it at its original address, and return
1844 1. If the instruction didn't complete, relocate the PC and return
1845 -1. If the thread wasn't displaced stepping, return 0. */
1848 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1850 displaced_step_thread_state
*displaced
1851 = get_displaced_stepping_state (event_thread
);
1853 /* Was this thread performing a displaced step? */
1854 if (!displaced
->in_progress ())
1857 displaced_step_reset_cleanup
cleanup (displaced
);
1859 /* Fixup may need to read memory/registers. Switch to the thread
1860 that we're fixing up. Also, target_stopped_by_watchpoint checks
1861 the current thread, and displaced_step_restore performs ptid-dependent
1862 memory accesses using current_inferior() and current_top_target(). */
1863 switch_to_thread (event_thread
);
1865 /* Do the fixup, and release the resources acquired to do the displaced
1867 displaced_step_finish_status finish_status
=
1868 event_thread
->inf
->top_target ()->displaced_step_finish (event_thread
,
1871 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1877 /* Data to be passed around while handling an event. This data is
1878 discarded between events. */
1879 struct execution_control_state
1881 process_stratum_target
*target
;
1883 /* The thread that got the event, if this was a thread event; NULL
1885 struct thread_info
*event_thread
;
1887 struct target_waitstatus ws
;
1888 int stop_func_filled_in
;
1889 CORE_ADDR stop_func_start
;
1890 CORE_ADDR stop_func_end
;
1891 const char *stop_func_name
;
1894 /* True if the event thread hit the single-step breakpoint of
1895 another thread. Thus the event doesn't cause a stop, the thread
1896 needs to be single-stepped past the single-step breakpoint before
1897 we can switch back to the original stepping thread. */
1898 int hit_singlestep_breakpoint
;
1901 /* Clear ECS and set it to point at TP. */
1904 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1906 memset (ecs
, 0, sizeof (*ecs
));
1907 ecs
->event_thread
= tp
;
1908 ecs
->ptid
= tp
->ptid
;
1911 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1912 static void prepare_to_wait (struct execution_control_state
*ecs
);
1913 static int keep_going_stepped_thread (struct thread_info
*tp
);
1914 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1916 /* Are there any pending step-over requests? If so, run all we can
1917 now and return true. Otherwise, return false. */
1920 start_step_over (void)
1922 struct thread_info
*tp
, *next
;
1925 /* Don't start a new step-over if we already have an in-line
1926 step-over operation ongoing. */
1927 if (step_over_info_valid_p ())
1930 /* Steal the global thread step over chain. */
1931 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1932 global_thread_step_over_chain_head
= NULL
;
1935 fprintf_unfiltered (gdb_stdlog
,
1936 "infrun: stealing list of %d threads to step from global queue\n",
1937 thread_step_over_chain_length (threads_to_step
));
1939 for (inferior
*inf
: all_inferiors ())
1940 inf
->displaced_step_state
.unavailable
= false;
1942 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1944 struct execution_control_state ecss
;
1945 struct execution_control_state
*ecs
= &ecss
;
1946 step_over_what step_what
;
1947 int must_be_in_line
;
1949 gdb_assert (!tp
->stop_requested
);
1951 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1953 step_what
= thread_still_needs_step_over (tp
);
1954 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1955 || ((step_what
& STEP_OVER_BREAKPOINT
)
1956 && !use_displaced_stepping (tp
)));
1958 /* We currently stop all threads of all processes to step-over
1959 in-line. If we need to start a new in-line step-over, let
1960 any pending displaced steps finish first. */
1961 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1964 thread_step_over_chain_remove (&threads_to_step
, tp
);
1966 if (tp
->control
.trap_expected
1970 internal_error (__FILE__
, __LINE__
,
1971 "[%s] has inconsistent state: "
1972 "trap_expected=%d, resumed=%d, executing=%d\n",
1973 target_pid_to_str (tp
->ptid
).c_str (),
1974 tp
->control
.trap_expected
,
1979 infrun_log_debug ("resuming [%s] for step-over",
1980 target_pid_to_str (tp
->ptid
).c_str ());
1982 /* keep_going_pass_signal skips the step-over if the breakpoint
1983 is no longer inserted. In all-stop, we want to keep looking
1984 for a thread that needs a step-over instead of resuming TP,
1985 because we wouldn't be able to resume anything else until the
1986 target stops again. In non-stop, the resume always resumes
1987 only TP, so it's OK to let the thread resume freely. */
1988 if (!target_is_non_stop_p () && !step_what
)
1991 if (tp
->inf
->displaced_step_state
.unavailable
)
1993 global_thread_step_over_chain_enqueue (tp
);
1997 switch_to_thread (tp
);
1998 reset_ecs (ecs
, tp
);
1999 keep_going_pass_signal (ecs
);
2001 if (!ecs
->wait_some_more
)
2002 error (_("Command aborted."));
2004 /* If the thread's step over could not be initiated, it was re-added
2005 to the global step over chain. */
2008 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
2009 target_pid_to_str (tp
->ptid
).c_str ());
2010 gdb_assert (!thread_is_in_step_over_chain (tp
));
2014 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
2015 target_pid_to_str (tp
->ptid
).c_str ());
2016 gdb_assert (thread_is_in_step_over_chain (tp
));
2020 /* If we started a new in-line step-over, we're done. */
2021 if (step_over_info_valid_p ())
2023 gdb_assert (tp
->control
.trap_expected
);
2028 if (!target_is_non_stop_p ())
2030 /* On all-stop, shouldn't have resumed unless we needed a
2032 gdb_assert (tp
->control
.trap_expected
2033 || tp
->step_after_step_resume_breakpoint
);
2035 /* With remote targets (at least), in all-stop, we can't
2036 issue any further remote commands until the program stops
2042 /* Either the thread no longer needed a step-over, or a new
2043 displaced stepping sequence started. Even in the latter
2044 case, continue looking. Maybe we can also start another
2045 displaced step on a thread of other process. */
2048 /* If there are threads left in the THREADS_TO_STEP list, but we have
2049 detected that we can't start anything more, put back these threads
2050 in the global list. */
2051 if (threads_to_step
== NULL
)
2054 fprintf_unfiltered (gdb_stdlog
,
2055 "infrun: step-over queue now empty\n");
2060 fprintf_unfiltered (gdb_stdlog
,
2061 "infrun: putting back %d threads to step in global queue\n",
2062 thread_step_over_chain_length (threads_to_step
));
2063 while (threads_to_step
!= nullptr)
2065 thread_info
*thread
= threads_to_step
;
2067 /* Remove from that list. */
2068 thread_step_over_chain_remove (&threads_to_step
, thread
);
2070 /* Add to global list. */
2071 global_thread_step_over_chain_enqueue (thread
);
2079 /* Update global variables holding ptids to hold NEW_PTID if they were
2080 holding OLD_PTID. */
2082 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2084 if (inferior_ptid
== old_ptid
)
2085 inferior_ptid
= new_ptid
;
2090 static const char schedlock_off
[] = "off";
2091 static const char schedlock_on
[] = "on";
2092 static const char schedlock_step
[] = "step";
2093 static const char schedlock_replay
[] = "replay";
2094 static const char *const scheduler_enums
[] = {
2101 static const char *scheduler_mode
= schedlock_replay
;
2103 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2104 struct cmd_list_element
*c
, const char *value
)
2106 fprintf_filtered (file
,
2107 _("Mode for locking scheduler "
2108 "during execution is \"%s\".\n"),
2113 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2115 if (!target_can_lock_scheduler
)
2117 scheduler_mode
= schedlock_off
;
2118 error (_("Target '%s' cannot support this command."), target_shortname
);
2122 /* True if execution commands resume all threads of all processes by
2123 default; otherwise, resume only threads of the current inferior
2125 bool sched_multi
= false;
2127 /* Try to setup for software single stepping over the specified location.
2128 Return 1 if target_resume() should use hardware single step.
2130 GDBARCH the current gdbarch.
2131 PC the location to step over. */
2134 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2138 if (execution_direction
== EXEC_FORWARD
2139 && gdbarch_software_single_step_p (gdbarch
))
2140 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2148 user_visible_resume_ptid (int step
)
2154 /* With non-stop mode on, threads are always handled
2156 resume_ptid
= inferior_ptid
;
2158 else if ((scheduler_mode
== schedlock_on
)
2159 || (scheduler_mode
== schedlock_step
&& step
))
2161 /* User-settable 'scheduler' mode requires solo thread
2163 resume_ptid
= inferior_ptid
;
2165 else if ((scheduler_mode
== schedlock_replay
)
2166 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2168 /* User-settable 'scheduler' mode requires solo thread resume in replay
2170 resume_ptid
= inferior_ptid
;
2172 else if (!sched_multi
&& target_supports_multi_process ())
2174 /* Resume all threads of the current process (and none of other
2176 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2180 /* Resume all threads of all processes. */
2181 resume_ptid
= RESUME_ALL
;
2189 process_stratum_target
*
2190 user_visible_resume_target (ptid_t resume_ptid
)
2192 return (resume_ptid
== minus_one_ptid
&& sched_multi
2194 : current_inferior ()->process_target ());
2197 /* Return a ptid representing the set of threads that we will resume,
2198 in the perspective of the target, assuming run control handling
2199 does not require leaving some threads stopped (e.g., stepping past
2200 breakpoint). USER_STEP indicates whether we're about to start the
2201 target for a stepping command. */
2204 internal_resume_ptid (int user_step
)
2206 /* In non-stop, we always control threads individually. Note that
2207 the target may always work in non-stop mode even with "set
2208 non-stop off", in which case user_visible_resume_ptid could
2209 return a wildcard ptid. */
2210 if (target_is_non_stop_p ())
2211 return inferior_ptid
;
2213 return user_visible_resume_ptid (user_step
);
2216 /* Wrapper for target_resume, that handles infrun-specific
2220 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2222 struct thread_info
*tp
= inferior_thread ();
2224 gdb_assert (!tp
->stop_requested
);
2226 /* Install inferior's terminal modes. */
2227 target_terminal::inferior ();
2229 /* Avoid confusing the next resume, if the next stop/resume
2230 happens to apply to another thread. */
2231 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2233 /* Advise target which signals may be handled silently.
2235 If we have removed breakpoints because we are stepping over one
2236 in-line (in any thread), we need to receive all signals to avoid
2237 accidentally skipping a breakpoint during execution of a signal
2240 Likewise if we're displaced stepping, otherwise a trap for a
2241 breakpoint in a signal handler might be confused with the
2242 displaced step finishing. We don't make the displaced_step_fixup
2243 step distinguish the cases instead, because:
2245 - a backtrace while stopped in the signal handler would show the
2246 scratch pad as frame older than the signal handler, instead of
2247 the real mainline code.
2249 - when the thread is later resumed, the signal handler would
2250 return to the scratch pad area, which would no longer be
2252 if (step_over_info_valid_p ()
2253 || displaced_step_in_progress (tp
->inf
))
2254 target_pass_signals ({});
2256 target_pass_signals (signal_pass
);
2258 target_resume (resume_ptid
, step
, sig
);
2260 target_commit_resume ();
2262 if (target_can_async_p ())
2266 /* Resume the inferior. SIG is the signal to give the inferior
2267 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2268 call 'resume', which handles exceptions. */
2271 resume_1 (enum gdb_signal sig
)
2273 struct regcache
*regcache
= get_current_regcache ();
2274 struct gdbarch
*gdbarch
= regcache
->arch ();
2275 struct thread_info
*tp
= inferior_thread ();
2276 const address_space
*aspace
= regcache
->aspace ();
2278 /* This represents the user's step vs continue request. When
2279 deciding whether "set scheduler-locking step" applies, it's the
2280 user's intention that counts. */
2281 const int user_step
= tp
->control
.stepping_command
;
2282 /* This represents what we'll actually request the target to do.
2283 This can decay from a step to a continue, if e.g., we need to
2284 implement single-stepping with breakpoints (software
2288 gdb_assert (!tp
->stop_requested
);
2289 gdb_assert (!thread_is_in_step_over_chain (tp
));
2291 if (tp
->suspend
.waitstatus_pending_p
)
2294 ("thread %s has pending wait "
2295 "status %s (currently_stepping=%d).",
2296 target_pid_to_str (tp
->ptid
).c_str (),
2297 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2298 currently_stepping (tp
));
2300 tp
->inf
->process_target ()->threads_executing
= true;
2303 /* FIXME: What should we do if we are supposed to resume this
2304 thread with a signal? Maybe we should maintain a queue of
2305 pending signals to deliver. */
2306 if (sig
!= GDB_SIGNAL_0
)
2308 warning (_("Couldn't deliver signal %s to %s."),
2309 gdb_signal_to_name (sig
),
2310 target_pid_to_str (tp
->ptid
).c_str ());
2313 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2315 if (target_can_async_p ())
2318 /* Tell the event loop we have an event to process. */
2319 mark_async_event_handler (infrun_async_inferior_event_token
);
2324 tp
->stepped_breakpoint
= 0;
2326 /* Depends on stepped_breakpoint. */
2327 step
= currently_stepping (tp
);
2329 if (current_inferior ()->waiting_for_vfork_done
)
2331 /* Don't try to single-step a vfork parent that is waiting for
2332 the child to get out of the shared memory region (by exec'ing
2333 or exiting). This is particularly important on software
2334 single-step archs, as the child process would trip on the
2335 software single step breakpoint inserted for the parent
2336 process. Since the parent will not actually execute any
2337 instruction until the child is out of the shared region (such
2338 are vfork's semantics), it is safe to simply continue it.
2339 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2340 the parent, and tell it to `keep_going', which automatically
2341 re-sets it stepping. */
2342 infrun_log_debug ("resume : clear step");
2346 CORE_ADDR pc
= regcache_read_pc (regcache
);
2348 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2349 "current thread [%s] at %s",
2350 step
, gdb_signal_to_symbol_string (sig
),
2351 tp
->control
.trap_expected
,
2352 target_pid_to_str (inferior_ptid
).c_str (),
2353 paddress (gdbarch
, pc
));
2355 /* Normally, by the time we reach `resume', the breakpoints are either
2356 removed or inserted, as appropriate. The exception is if we're sitting
2357 at a permanent breakpoint; we need to step over it, but permanent
2358 breakpoints can't be removed. So we have to test for it here. */
2359 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2361 if (sig
!= GDB_SIGNAL_0
)
2363 /* We have a signal to pass to the inferior. The resume
2364 may, or may not take us to the signal handler. If this
2365 is a step, we'll need to stop in the signal handler, if
2366 there's one, (if the target supports stepping into
2367 handlers), or in the next mainline instruction, if
2368 there's no handler. If this is a continue, we need to be
2369 sure to run the handler with all breakpoints inserted.
2370 In all cases, set a breakpoint at the current address
2371 (where the handler returns to), and once that breakpoint
2372 is hit, resume skipping the permanent breakpoint. If
2373 that breakpoint isn't hit, then we've stepped into the
2374 signal handler (or hit some other event). We'll delete
2375 the step-resume breakpoint then. */
2377 infrun_log_debug ("resume: skipping permanent breakpoint, "
2378 "deliver signal first");
2380 clear_step_over_info ();
2381 tp
->control
.trap_expected
= 0;
2383 if (tp
->control
.step_resume_breakpoint
== NULL
)
2385 /* Set a "high-priority" step-resume, as we don't want
2386 user breakpoints at PC to trigger (again) when this
2388 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2389 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2391 tp
->step_after_step_resume_breakpoint
= step
;
2394 insert_breakpoints ();
2398 /* There's no signal to pass, we can go ahead and skip the
2399 permanent breakpoint manually. */
2400 infrun_log_debug ("skipping permanent breakpoint");
2401 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2402 /* Update pc to reflect the new address from which we will
2403 execute instructions. */
2404 pc
= regcache_read_pc (regcache
);
2408 /* We've already advanced the PC, so the stepping part
2409 is done. Now we need to arrange for a trap to be
2410 reported to handle_inferior_event. Set a breakpoint
2411 at the current PC, and run to it. Don't update
2412 prev_pc, because if we end in
2413 switch_back_to_stepped_thread, we want the "expected
2414 thread advanced also" branch to be taken. IOW, we
2415 don't want this thread to step further from PC
2417 gdb_assert (!step_over_info_valid_p ());
2418 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2419 insert_breakpoints ();
2421 resume_ptid
= internal_resume_ptid (user_step
);
2422 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2429 /* If we have a breakpoint to step over, make sure to do a single
2430 step only. Same if we have software watchpoints. */
2431 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2432 tp
->control
.may_range_step
= 0;
2434 /* If displaced stepping is enabled, step over breakpoints by executing a
2435 copy of the instruction at a different address.
2437 We can't use displaced stepping when we have a signal to deliver;
2438 the comments for displaced_step_prepare explain why. The
2439 comments in the handle_inferior event for dealing with 'random
2440 signals' explain what we do instead.
2442 We can't use displaced stepping when we are waiting for vfork_done
2443 event, displaced stepping breaks the vfork child similarly as single
2444 step software breakpoint. */
2445 if (tp
->control
.trap_expected
2446 && use_displaced_stepping (tp
)
2447 && !step_over_info_valid_p ()
2448 && sig
== GDB_SIGNAL_0
2449 && !current_inferior ()->waiting_for_vfork_done
)
2451 displaced_step_prepare_status prepare_status
2452 = displaced_step_prepare (tp
);
2454 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2456 infrun_log_debug ("Got placed in step-over queue");
2458 tp
->control
.trap_expected
= 0;
2461 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2463 /* Fallback to stepping over the breakpoint in-line. */
2465 if (target_is_non_stop_p ())
2466 stop_all_threads ();
2468 set_step_over_info (regcache
->aspace (),
2469 regcache_read_pc (regcache
), 0, tp
->global_num
);
2471 step
= maybe_software_singlestep (gdbarch
, pc
);
2473 insert_breakpoints ();
2475 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2477 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2480 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2483 /* Do we need to do it the hard way, w/temp breakpoints? */
2485 step
= maybe_software_singlestep (gdbarch
, pc
);
2487 /* Currently, our software single-step implementation leads to different
2488 results than hardware single-stepping in one situation: when stepping
2489 into delivering a signal which has an associated signal handler,
2490 hardware single-step will stop at the first instruction of the handler,
2491 while software single-step will simply skip execution of the handler.
2493 For now, this difference in behavior is accepted since there is no
2494 easy way to actually implement single-stepping into a signal handler
2495 without kernel support.
2497 However, there is one scenario where this difference leads to follow-on
2498 problems: if we're stepping off a breakpoint by removing all breakpoints
2499 and then single-stepping. In this case, the software single-step
2500 behavior means that even if there is a *breakpoint* in the signal
2501 handler, GDB still would not stop.
2503 Fortunately, we can at least fix this particular issue. We detect
2504 here the case where we are about to deliver a signal while software
2505 single-stepping with breakpoints removed. In this situation, we
2506 revert the decisions to remove all breakpoints and insert single-
2507 step breakpoints, and instead we install a step-resume breakpoint
2508 at the current address, deliver the signal without stepping, and
2509 once we arrive back at the step-resume breakpoint, actually step
2510 over the breakpoint we originally wanted to step over. */
2511 if (thread_has_single_step_breakpoints_set (tp
)
2512 && sig
!= GDB_SIGNAL_0
2513 && step_over_info_valid_p ())
2515 /* If we have nested signals or a pending signal is delivered
2516 immediately after a handler returns, might already have
2517 a step-resume breakpoint set on the earlier handler. We cannot
2518 set another step-resume breakpoint; just continue on until the
2519 original breakpoint is hit. */
2520 if (tp
->control
.step_resume_breakpoint
== NULL
)
2522 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2523 tp
->step_after_step_resume_breakpoint
= 1;
2526 delete_single_step_breakpoints (tp
);
2528 clear_step_over_info ();
2529 tp
->control
.trap_expected
= 0;
2531 insert_breakpoints ();
2534 /* If STEP is set, it's a request to use hardware stepping
2535 facilities. But in that case, we should never
2536 use singlestep breakpoint. */
2537 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2539 /* Decide the set of threads to ask the target to resume. */
2540 if (tp
->control
.trap_expected
)
2542 /* We're allowing a thread to run past a breakpoint it has
2543 hit, either by single-stepping the thread with the breakpoint
2544 removed, or by displaced stepping, with the breakpoint inserted.
2545 In the former case, we need to single-step only this thread,
2546 and keep others stopped, as they can miss this breakpoint if
2547 allowed to run. That's not really a problem for displaced
2548 stepping, but, we still keep other threads stopped, in case
2549 another thread is also stopped for a breakpoint waiting for
2550 its turn in the displaced stepping queue. */
2551 resume_ptid
= inferior_ptid
;
2554 resume_ptid
= internal_resume_ptid (user_step
);
2556 if (execution_direction
!= EXEC_REVERSE
2557 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2559 /* There are two cases where we currently need to step a
2560 breakpoint instruction when we have a signal to deliver:
2562 - See handle_signal_stop where we handle random signals that
2563 could take out us out of the stepping range. Normally, in
2564 that case we end up continuing (instead of stepping) over the
2565 signal handler with a breakpoint at PC, but there are cases
2566 where we should _always_ single-step, even if we have a
2567 step-resume breakpoint, like when a software watchpoint is
2568 set. Assuming single-stepping and delivering a signal at the
2569 same time would takes us to the signal handler, then we could
2570 have removed the breakpoint at PC to step over it. However,
2571 some hardware step targets (like e.g., Mac OS) can't step
2572 into signal handlers, and for those, we need to leave the
2573 breakpoint at PC inserted, as otherwise if the handler
2574 recurses and executes PC again, it'll miss the breakpoint.
2575 So we leave the breakpoint inserted anyway, but we need to
2576 record that we tried to step a breakpoint instruction, so
2577 that adjust_pc_after_break doesn't end up confused.
2579 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2580 in one thread after another thread that was stepping had been
2581 momentarily paused for a step-over. When we re-resume the
2582 stepping thread, it may be resumed from that address with a
2583 breakpoint that hasn't trapped yet. Seen with
2584 gdb.threads/non-stop-fair-events.exp, on targets that don't
2585 do displaced stepping. */
2587 infrun_log_debug ("resume: [%s] stepped breakpoint",
2588 target_pid_to_str (tp
->ptid
).c_str ());
2590 tp
->stepped_breakpoint
= 1;
2592 /* Most targets can step a breakpoint instruction, thus
2593 executing it normally. But if this one cannot, just
2594 continue and we will hit it anyway. */
2595 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2600 && tp
->control
.trap_expected
2601 && use_displaced_stepping (tp
)
2602 && !step_over_info_valid_p ())
2604 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2605 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2606 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2609 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2610 paddress (resume_gdbarch
, actual_pc
));
2611 read_memory (actual_pc
, buf
, sizeof (buf
));
2612 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2615 if (tp
->control
.may_range_step
)
2617 /* If we're resuming a thread with the PC out of the step
2618 range, then we're doing some nested/finer run control
2619 operation, like stepping the thread out of the dynamic
2620 linker or the displaced stepping scratch pad. We
2621 shouldn't have allowed a range step then. */
2622 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2625 do_target_resume (resume_ptid
, step
, sig
);
2629 /* Resume the inferior. SIG is the signal to give the inferior
2630 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2631 rolls back state on error. */
2634 resume (gdb_signal sig
)
2640 catch (const gdb_exception
&ex
)
2642 /* If resuming is being aborted for any reason, delete any
2643 single-step breakpoint resume_1 may have created, to avoid
2644 confusing the following resumption, and to avoid leaving
2645 single-step breakpoints perturbing other threads, in case
2646 we're running in non-stop mode. */
2647 if (inferior_ptid
!= null_ptid
)
2648 delete_single_step_breakpoints (inferior_thread ());
2658 /* Counter that tracks number of user visible stops. This can be used
2659 to tell whether a command has proceeded the inferior past the
2660 current location. This allows e.g., inferior function calls in
2661 breakpoint commands to not interrupt the command list. When the
2662 call finishes successfully, the inferior is standing at the same
2663 breakpoint as if nothing happened (and so we don't call
2665 static ULONGEST current_stop_id
;
2672 return current_stop_id
;
2675 /* Called when we report a user visible stop. */
2683 /* Clear out all variables saying what to do when inferior is continued.
2684 First do this, then set the ones you want, then call `proceed'. */
2687 clear_proceed_status_thread (struct thread_info
*tp
)
2689 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2691 /* If we're starting a new sequence, then the previous finished
2692 single-step is no longer relevant. */
2693 if (tp
->suspend
.waitstatus_pending_p
)
2695 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2697 infrun_log_debug ("pending event of %s was a finished step. "
2699 target_pid_to_str (tp
->ptid
).c_str ());
2701 tp
->suspend
.waitstatus_pending_p
= 0;
2702 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2707 ("thread %s has pending wait status %s (currently_stepping=%d).",
2708 target_pid_to_str (tp
->ptid
).c_str (),
2709 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2710 currently_stepping (tp
));
2714 /* If this signal should not be seen by program, give it zero.
2715 Used for debugging signals. */
2716 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2717 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2719 delete tp
->thread_fsm
;
2720 tp
->thread_fsm
= NULL
;
2722 tp
->control
.trap_expected
= 0;
2723 tp
->control
.step_range_start
= 0;
2724 tp
->control
.step_range_end
= 0;
2725 tp
->control
.may_range_step
= 0;
2726 tp
->control
.step_frame_id
= null_frame_id
;
2727 tp
->control
.step_stack_frame_id
= null_frame_id
;
2728 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2729 tp
->control
.step_start_function
= NULL
;
2730 tp
->stop_requested
= 0;
2732 tp
->control
.stop_step
= 0;
2734 tp
->control
.proceed_to_finish
= 0;
2736 tp
->control
.stepping_command
= 0;
2738 /* Discard any remaining commands or status from previous stop. */
2739 bpstat_clear (&tp
->control
.stop_bpstat
);
2743 clear_proceed_status (int step
)
2745 /* With scheduler-locking replay, stop replaying other threads if we're
2746 not replaying the user-visible resume ptid.
2748 This is a convenience feature to not require the user to explicitly
2749 stop replaying the other threads. We're assuming that the user's
2750 intent is to resume tracing the recorded process. */
2751 if (!non_stop
&& scheduler_mode
== schedlock_replay
2752 && target_record_is_replaying (minus_one_ptid
)
2753 && !target_record_will_replay (user_visible_resume_ptid (step
),
2754 execution_direction
))
2755 target_record_stop_replaying ();
2757 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2759 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2760 process_stratum_target
*resume_target
2761 = user_visible_resume_target (resume_ptid
);
2763 /* In all-stop mode, delete the per-thread status of all threads
2764 we're about to resume, implicitly and explicitly. */
2765 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2766 clear_proceed_status_thread (tp
);
2769 if (inferior_ptid
!= null_ptid
)
2771 struct inferior
*inferior
;
2775 /* If in non-stop mode, only delete the per-thread status of
2776 the current thread. */
2777 clear_proceed_status_thread (inferior_thread ());
2780 inferior
= current_inferior ();
2781 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2784 gdb::observers::about_to_proceed
.notify ();
2787 /* Returns true if TP is still stopped at a breakpoint that needs
2788 stepping-over in order to make progress. If the breakpoint is gone
2789 meanwhile, we can skip the whole step-over dance. */
2792 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2794 if (tp
->stepping_over_breakpoint
)
2796 struct regcache
*regcache
= get_thread_regcache (tp
);
2798 if (breakpoint_here_p (regcache
->aspace (),
2799 regcache_read_pc (regcache
))
2800 == ordinary_breakpoint_here
)
2803 tp
->stepping_over_breakpoint
= 0;
2809 /* Check whether thread TP still needs to start a step-over in order
2810 to make progress when resumed. Returns an bitwise or of enum
2811 step_over_what bits, indicating what needs to be stepped over. */
2813 static step_over_what
2814 thread_still_needs_step_over (struct thread_info
*tp
)
2816 step_over_what what
= 0;
2818 if (thread_still_needs_step_over_bp (tp
))
2819 what
|= STEP_OVER_BREAKPOINT
;
2821 if (tp
->stepping_over_watchpoint
2822 && !target_have_steppable_watchpoint
)
2823 what
|= STEP_OVER_WATCHPOINT
;
2828 /* Returns true if scheduler locking applies. STEP indicates whether
2829 we're about to do a step/next-like command to a thread. */
2832 schedlock_applies (struct thread_info
*tp
)
2834 return (scheduler_mode
== schedlock_on
2835 || (scheduler_mode
== schedlock_step
2836 && tp
->control
.stepping_command
)
2837 || (scheduler_mode
== schedlock_replay
2838 && target_record_will_replay (minus_one_ptid
,
2839 execution_direction
)));
2842 /* Calls target_commit_resume on all targets. */
2845 commit_resume_all_targets ()
2847 scoped_restore_current_thread restore_thread
;
2849 /* Map between process_target and a representative inferior. This
2850 is to avoid committing a resume in the same target more than
2851 once. Resumptions must be idempotent, so this is an
2853 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2855 for (inferior
*inf
: all_non_exited_inferiors ())
2856 if (inf
->has_execution ())
2857 conn_inf
[inf
->process_target ()] = inf
;
2859 for (const auto &ci
: conn_inf
)
2861 inferior
*inf
= ci
.second
;
2862 switch_to_inferior_no_thread (inf
);
2863 target_commit_resume ();
2867 /* Check that all the targets we're about to resume are in non-stop
2868 mode. Ideally, we'd only care whether all targets support
2869 target-async, but we're not there yet. E.g., stop_all_threads
2870 doesn't know how to handle all-stop targets. Also, the remote
2871 protocol in all-stop mode is synchronous, irrespective of
2872 target-async, which means that things like a breakpoint re-set
2873 triggered by one target would try to read memory from all targets
2877 check_multi_target_resumption (process_stratum_target
*resume_target
)
2879 if (!non_stop
&& resume_target
== nullptr)
2881 scoped_restore_current_thread restore_thread
;
2883 /* This is used to track whether we're resuming more than one
2885 process_stratum_target
*first_connection
= nullptr;
2887 /* The first inferior we see with a target that does not work in
2888 always-non-stop mode. */
2889 inferior
*first_not_non_stop
= nullptr;
2891 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2893 switch_to_inferior_no_thread (inf
);
2895 if (!target_has_execution
)
2898 process_stratum_target
*proc_target
2899 = current_inferior ()->process_target();
2901 if (!target_is_non_stop_p ())
2902 first_not_non_stop
= inf
;
2904 if (first_connection
== nullptr)
2905 first_connection
= proc_target
;
2906 else if (first_connection
!= proc_target
2907 && first_not_non_stop
!= nullptr)
2909 switch_to_inferior_no_thread (first_not_non_stop
);
2911 proc_target
= current_inferior ()->process_target();
2913 error (_("Connection %d (%s) does not support "
2914 "multi-target resumption."),
2915 proc_target
->connection_number
,
2916 make_target_connection_string (proc_target
).c_str ());
2922 /* Basic routine for continuing the program in various fashions.
2924 ADDR is the address to resume at, or -1 for resume where stopped.
2925 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2926 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2928 You should call clear_proceed_status before calling proceed. */
2931 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2933 struct regcache
*regcache
;
2934 struct gdbarch
*gdbarch
;
2936 struct execution_control_state ecss
;
2937 struct execution_control_state
*ecs
= &ecss
;
2940 /* If we're stopped at a fork/vfork, follow the branch set by the
2941 "set follow-fork-mode" command; otherwise, we'll just proceed
2942 resuming the current thread. */
2943 if (!follow_fork ())
2945 /* The target for some reason decided not to resume. */
2947 if (target_can_async_p ())
2948 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2952 /* We'll update this if & when we switch to a new thread. */
2953 previous_inferior_ptid
= inferior_ptid
;
2955 regcache
= get_current_regcache ();
2956 gdbarch
= regcache
->arch ();
2957 const address_space
*aspace
= regcache
->aspace ();
2959 pc
= regcache_read_pc_protected (regcache
);
2961 thread_info
*cur_thr
= inferior_thread ();
2963 /* Fill in with reasonable starting values. */
2964 init_thread_stepping_state (cur_thr
);
2966 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2969 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2970 process_stratum_target
*resume_target
2971 = user_visible_resume_target (resume_ptid
);
2973 check_multi_target_resumption (resume_target
);
2975 if (addr
== (CORE_ADDR
) -1)
2977 if (pc
== cur_thr
->suspend
.stop_pc
2978 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2979 && execution_direction
!= EXEC_REVERSE
)
2980 /* There is a breakpoint at the address we will resume at,
2981 step one instruction before inserting breakpoints so that
2982 we do not stop right away (and report a second hit at this
2985 Note, we don't do this in reverse, because we won't
2986 actually be executing the breakpoint insn anyway.
2987 We'll be (un-)executing the previous instruction. */
2988 cur_thr
->stepping_over_breakpoint
= 1;
2989 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2990 && gdbarch_single_step_through_delay (gdbarch
,
2991 get_current_frame ()))
2992 /* We stepped onto an instruction that needs to be stepped
2993 again before re-inserting the breakpoint, do so. */
2994 cur_thr
->stepping_over_breakpoint
= 1;
2998 regcache_write_pc (regcache
, addr
);
3001 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3002 cur_thr
->suspend
.stop_signal
= siggnal
;
3004 /* If an exception is thrown from this point on, make sure to
3005 propagate GDB's knowledge of the executing state to the
3006 frontend/user running state. */
3007 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3009 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3010 threads (e.g., we might need to set threads stepping over
3011 breakpoints first), from the user/frontend's point of view, all
3012 threads in RESUME_PTID are now running. Unless we're calling an
3013 inferior function, as in that case we pretend the inferior
3014 doesn't run at all. */
3015 if (!cur_thr
->control
.in_infcall
)
3016 set_running (resume_target
, resume_ptid
, true);
3018 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3019 gdb_signal_to_symbol_string (siggnal
));
3021 annotate_starting ();
3023 /* Make sure that output from GDB appears before output from the
3025 gdb_flush (gdb_stdout
);
3027 /* Since we've marked the inferior running, give it the terminal. A
3028 QUIT/Ctrl-C from here on is forwarded to the target (which can
3029 still detect attempts to unblock a stuck connection with repeated
3030 Ctrl-C from within target_pass_ctrlc). */
3031 target_terminal::inferior ();
3033 /* In a multi-threaded task we may select another thread and
3034 then continue or step.
3036 But if a thread that we're resuming had stopped at a breakpoint,
3037 it will immediately cause another breakpoint stop without any
3038 execution (i.e. it will report a breakpoint hit incorrectly). So
3039 we must step over it first.
3041 Look for threads other than the current (TP) that reported a
3042 breakpoint hit and haven't been resumed yet since. */
3044 /* If scheduler locking applies, we can avoid iterating over all
3046 if (!non_stop
&& !schedlock_applies (cur_thr
))
3048 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3051 switch_to_thread_no_regs (tp
);
3053 /* Ignore the current thread here. It's handled
3058 if (!thread_still_needs_step_over (tp
))
3061 gdb_assert (!thread_is_in_step_over_chain (tp
));
3063 infrun_log_debug ("need to step-over [%s] first",
3064 target_pid_to_str (tp
->ptid
).c_str ());
3066 global_thread_step_over_chain_enqueue (tp
);
3069 switch_to_thread (cur_thr
);
3072 /* Enqueue the current thread last, so that we move all other
3073 threads over their breakpoints first. */
3074 if (cur_thr
->stepping_over_breakpoint
)
3075 global_thread_step_over_chain_enqueue (cur_thr
);
3077 /* If the thread isn't started, we'll still need to set its prev_pc,
3078 so that switch_back_to_stepped_thread knows the thread hasn't
3079 advanced. Must do this before resuming any thread, as in
3080 all-stop/remote, once we resume we can't send any other packet
3081 until the target stops again. */
3082 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3085 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3087 started
= start_step_over ();
3089 if (step_over_info_valid_p ())
3091 /* Either this thread started a new in-line step over, or some
3092 other thread was already doing one. In either case, don't
3093 resume anything else until the step-over is finished. */
3095 else if (started
&& !target_is_non_stop_p ())
3097 /* A new displaced stepping sequence was started. In all-stop,
3098 we can't talk to the target anymore until it next stops. */
3100 else if (!non_stop
&& target_is_non_stop_p ())
3102 /* In all-stop, but the target is always in non-stop mode.
3103 Start all other threads that are implicitly resumed too. */
3104 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3107 switch_to_thread_no_regs (tp
);
3109 if (!tp
->inf
->has_execution ())
3111 infrun_log_debug ("[%s] target has no execution",
3112 target_pid_to_str (tp
->ptid
).c_str ());
3118 infrun_log_debug ("[%s] resumed",
3119 target_pid_to_str (tp
->ptid
).c_str ());
3120 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3124 if (thread_is_in_step_over_chain (tp
))
3126 infrun_log_debug ("[%s] needs step-over",
3127 target_pid_to_str (tp
->ptid
).c_str ());
3131 infrun_log_debug ("resuming %s",
3132 target_pid_to_str (tp
->ptid
).c_str ());
3134 reset_ecs (ecs
, tp
);
3135 switch_to_thread (tp
);
3136 keep_going_pass_signal (ecs
);
3137 if (!ecs
->wait_some_more
)
3138 error (_("Command aborted."));
3141 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3143 /* The thread wasn't started, and isn't queued, run it now. */
3144 reset_ecs (ecs
, cur_thr
);
3145 switch_to_thread (cur_thr
);
3146 keep_going_pass_signal (ecs
);
3147 if (!ecs
->wait_some_more
)
3148 error (_("Command aborted."));
3152 commit_resume_all_targets ();
3154 finish_state
.release ();
3156 /* If we've switched threads above, switch back to the previously
3157 current thread. We don't want the user to see a different
3159 switch_to_thread (cur_thr
);
3161 /* Tell the event loop to wait for it to stop. If the target
3162 supports asynchronous execution, it'll do this from within
3164 if (!target_can_async_p ())
3165 mark_async_event_handler (infrun_async_inferior_event_token
);
3169 /* Start remote-debugging of a machine over a serial link. */
3172 start_remote (int from_tty
)
3174 inferior
*inf
= current_inferior ();
3175 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3177 /* Always go on waiting for the target, regardless of the mode. */
3178 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3179 indicate to wait_for_inferior that a target should timeout if
3180 nothing is returned (instead of just blocking). Because of this,
3181 targets expecting an immediate response need to, internally, set
3182 things up so that the target_wait() is forced to eventually
3184 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3185 differentiate to its caller what the state of the target is after
3186 the initial open has been performed. Here we're assuming that
3187 the target has stopped. It should be possible to eventually have
3188 target_open() return to the caller an indication that the target
3189 is currently running and GDB state should be set to the same as
3190 for an async run. */
3191 wait_for_inferior (inf
);
3193 /* Now that the inferior has stopped, do any bookkeeping like
3194 loading shared libraries. We want to do this before normal_stop,
3195 so that the displayed frame is up to date. */
3196 post_create_inferior (current_top_target (), from_tty
);
3201 /* Initialize static vars when a new inferior begins. */
3204 init_wait_for_inferior (void)
3206 /* These are meaningless until the first time through wait_for_inferior. */
3208 breakpoint_init_inferior (inf_starting
);
3210 clear_proceed_status (0);
3212 nullify_last_target_wait_ptid ();
3214 previous_inferior_ptid
= inferior_ptid
;
3219 static void handle_inferior_event (struct execution_control_state
*ecs
);
3221 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3222 struct execution_control_state
*ecs
);
3223 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3224 struct execution_control_state
*ecs
);
3225 static void handle_signal_stop (struct execution_control_state
*ecs
);
3226 static void check_exception_resume (struct execution_control_state
*,
3227 struct frame_info
*);
3229 static void end_stepping_range (struct execution_control_state
*ecs
);
3230 static void stop_waiting (struct execution_control_state
*ecs
);
3231 static void keep_going (struct execution_control_state
*ecs
);
3232 static void process_event_stop_test (struct execution_control_state
*ecs
);
3233 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3235 /* This function is attached as a "thread_stop_requested" observer.
3236 Cleanup local state that assumed the PTID was to be resumed, and
3237 report the stop to the frontend. */
3240 infrun_thread_stop_requested (ptid_t ptid
)
3242 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3244 /* PTID was requested to stop. If the thread was already stopped,
3245 but the user/frontend doesn't know about that yet (e.g., the
3246 thread had been temporarily paused for some step-over), set up
3247 for reporting the stop now. */
3248 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3250 if (tp
->state
!= THREAD_RUNNING
)
3255 /* Remove matching threads from the step-over queue, so
3256 start_step_over doesn't try to resume them
3258 if (thread_is_in_step_over_chain (tp
))
3259 global_thread_step_over_chain_remove (tp
);
3261 /* If the thread is stopped, but the user/frontend doesn't
3262 know about that yet, queue a pending event, as if the
3263 thread had just stopped now. Unless the thread already had
3265 if (!tp
->suspend
.waitstatus_pending_p
)
3267 tp
->suspend
.waitstatus_pending_p
= 1;
3268 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3269 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3272 /* Clear the inline-frame state, since we're re-processing the
3274 clear_inline_frame_state (tp
);
3276 /* If this thread was paused because some other thread was
3277 doing an inline-step over, let that finish first. Once
3278 that happens, we'll restart all threads and consume pending
3279 stop events then. */
3280 if (step_over_info_valid_p ())
3283 /* Otherwise we can process the (new) pending event now. Set
3284 it so this pending event is considered by
3291 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3293 if (target_last_proc_target
== tp
->inf
->process_target ()
3294 && target_last_wait_ptid
== tp
->ptid
)
3295 nullify_last_target_wait_ptid ();
3298 /* Delete the step resume, single-step and longjmp/exception resume
3299 breakpoints of TP. */
3302 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3304 delete_step_resume_breakpoint (tp
);
3305 delete_exception_resume_breakpoint (tp
);
3306 delete_single_step_breakpoints (tp
);
3309 /* If the target still has execution, call FUNC for each thread that
3310 just stopped. In all-stop, that's all the non-exited threads; in
3311 non-stop, that's the current thread, only. */
3313 typedef void (*for_each_just_stopped_thread_callback_func
)
3314 (struct thread_info
*tp
);
3317 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3319 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3322 if (target_is_non_stop_p ())
3324 /* If in non-stop mode, only the current thread stopped. */
3325 func (inferior_thread ());
3329 /* In all-stop mode, all threads have stopped. */
3330 for (thread_info
*tp
: all_non_exited_threads ())
3335 /* Delete the step resume and longjmp/exception resume breakpoints of
3336 the threads that just stopped. */
3339 delete_just_stopped_threads_infrun_breakpoints (void)
3341 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3344 /* Delete the single-step breakpoints of the threads that just
3348 delete_just_stopped_threads_single_step_breakpoints (void)
3350 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3356 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3357 const struct target_waitstatus
*ws
)
3359 std::string status_string
= target_waitstatus_to_string (ws
);
3362 /* The text is split over several lines because it was getting too long.
3363 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3364 output as a unit; we want only one timestamp printed if debug_timestamp
3367 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3370 waiton_ptid
.tid ());
3371 if (waiton_ptid
.pid () != -1)
3372 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3373 stb
.printf (", status) =\n");
3374 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3378 target_pid_to_str (result_ptid
).c_str ());
3379 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3381 /* This uses %s in part to handle %'s in the text, but also to avoid
3382 a gcc error: the format attribute requires a string literal. */
3383 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3386 /* Select a thread at random, out of those which are resumed and have
3389 static struct thread_info
*
3390 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3394 auto has_event
= [&] (thread_info
*tp
)
3396 return (tp
->ptid
.matches (waiton_ptid
)
3398 && tp
->suspend
.waitstatus_pending_p
);
3401 /* First see how many events we have. Count only resumed threads
3402 that have an event pending. */
3403 for (thread_info
*tp
: inf
->non_exited_threads ())
3407 if (num_events
== 0)
3410 /* Now randomly pick a thread out of those that have had events. */
3411 int random_selector
= (int) ((num_events
* (double) rand ())
3412 / (RAND_MAX
+ 1.0));
3415 infrun_log_debug ("Found %d events, selecting #%d",
3416 num_events
, random_selector
);
3418 /* Select the Nth thread that has had an event. */
3419 for (thread_info
*tp
: inf
->non_exited_threads ())
3421 if (random_selector
-- == 0)
3424 gdb_assert_not_reached ("event thread not found");
3427 /* Wrapper for target_wait that first checks whether threads have
3428 pending statuses to report before actually asking the target for
3429 more events. INF is the inferior we're using to call target_wait
3433 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3434 target_waitstatus
*status
, int options
)
3437 struct thread_info
*tp
;
3439 /* We know that we are looking for an event in the target of inferior
3440 INF, but we don't know which thread the event might come from. As
3441 such we want to make sure that INFERIOR_PTID is reset so that none of
3442 the wait code relies on it - doing so is always a mistake. */
3443 switch_to_inferior_no_thread (inf
);
3445 /* First check if there is a resumed thread with a wait status
3447 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3449 tp
= random_pending_event_thread (inf
, ptid
);
3453 infrun_log_debug ("Waiting for specific thread %s.",
3454 target_pid_to_str (ptid
).c_str ());
3456 /* We have a specific thread to check. */
3457 tp
= find_thread_ptid (inf
, ptid
);
3458 gdb_assert (tp
!= NULL
);
3459 if (!tp
->suspend
.waitstatus_pending_p
)
3464 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3465 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3467 struct regcache
*regcache
= get_thread_regcache (tp
);
3468 struct gdbarch
*gdbarch
= regcache
->arch ();
3472 pc
= regcache_read_pc (regcache
);
3474 if (pc
!= tp
->suspend
.stop_pc
)
3476 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3477 target_pid_to_str (tp
->ptid
).c_str (),
3478 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3479 paddress (gdbarch
, pc
));
3482 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3484 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3485 target_pid_to_str (tp
->ptid
).c_str (),
3486 paddress (gdbarch
, pc
));
3493 infrun_log_debug ("pending event of %s cancelled.",
3494 target_pid_to_str (tp
->ptid
).c_str ());
3496 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3497 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3503 infrun_log_debug ("Using pending wait status %s for %s.",
3504 target_waitstatus_to_string
3505 (&tp
->suspend
.waitstatus
).c_str (),
3506 target_pid_to_str (tp
->ptid
).c_str ());
3508 /* Now that we've selected our final event LWP, un-adjust its PC
3509 if it was a software breakpoint (and the target doesn't
3510 always adjust the PC itself). */
3511 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3512 && !target_supports_stopped_by_sw_breakpoint ())
3514 struct regcache
*regcache
;
3515 struct gdbarch
*gdbarch
;
3518 regcache
= get_thread_regcache (tp
);
3519 gdbarch
= regcache
->arch ();
3521 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3526 pc
= regcache_read_pc (regcache
);
3527 regcache_write_pc (regcache
, pc
+ decr_pc
);
3531 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3532 *status
= tp
->suspend
.waitstatus
;
3533 tp
->suspend
.waitstatus_pending_p
= 0;
3535 /* Wake up the event loop again, until all pending events are
3537 if (target_is_async_p ())
3538 mark_async_event_handler (infrun_async_inferior_event_token
);
3542 /* But if we don't find one, we'll have to wait. */
3544 if (deprecated_target_wait_hook
)
3545 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3547 event_ptid
= target_wait (ptid
, status
, options
);
3552 /* Returns true if INF has any resumed thread with a status
3556 threads_are_resumed_pending_p (inferior
*inf
)
3558 for (thread_info
*tp
: inf
->non_exited_threads ())
3560 && tp
->suspend
.waitstatus_pending_p
)
3566 /* Wrapper for target_wait that first checks whether threads have
3567 pending statuses to report before actually asking the target for
3568 more events. Polls for events from all inferiors/targets. */
3571 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3573 int num_inferiors
= 0;
3574 int random_selector
;
3576 /* For fairness, we pick the first inferior/target to poll at
3577 random, and then continue polling the rest of the inferior list
3578 starting from that one in a circular fashion until the whole list
3581 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3583 return (inf
->process_target () != NULL
3584 && (threads_are_executing (inf
->process_target ())
3585 || threads_are_resumed_pending_p (inf
))
3586 && ptid_t (inf
->pid
).matches (wait_ptid
));
3589 /* First see how many resumed inferiors we have. */
3590 for (inferior
*inf
: all_inferiors ())
3591 if (inferior_matches (inf
))
3594 if (num_inferiors
== 0)
3596 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3600 /* Now randomly pick an inferior out of those that were resumed. */
3601 random_selector
= (int)
3602 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3604 if (num_inferiors
> 1)
3605 infrun_log_debug ("Found %d inferiors, starting at #%d",
3606 num_inferiors
, random_selector
);
3608 /* Select the Nth inferior that was resumed. */
3610 inferior
*selected
= nullptr;
3612 for (inferior
*inf
: all_inferiors ())
3613 if (inferior_matches (inf
))
3614 if (random_selector
-- == 0)
3620 /* Now poll for events out of each of the resumed inferior's
3621 targets, starting from the selected one. */
3623 auto do_wait
= [&] (inferior
*inf
)
3625 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3626 ecs
->target
= inf
->process_target ();
3627 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3630 /* Needed in all-stop+target-non-stop mode, because we end up here
3631 spuriously after the target is all stopped and we've already
3632 reported the stop to the user, polling for events. */
3633 scoped_restore_current_thread restore_thread
;
3635 int inf_num
= selected
->num
;
3636 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3637 if (inferior_matches (inf
))
3641 for (inferior
*inf
= inferior_list
;
3642 inf
!= NULL
&& inf
->num
< inf_num
;
3644 if (inferior_matches (inf
))
3648 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3652 /* Prepare and stabilize the inferior for detaching it. E.g.,
3653 detaching while a thread is displaced stepping is a recipe for
3654 crashing it, as nothing would readjust the PC out of the scratch
3658 prepare_for_detach (void)
3660 struct inferior
*inf
= current_inferior ();
3661 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3663 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3665 /* Is any thread of this process displaced stepping? If not,
3666 there's nothing else to do. */
3667 if (displaced_step_in_progress (inf
))
3670 infrun_log_debug ("displaced-stepping in-process while detaching");
3672 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3677 struct execution_control_state ecss
;
3678 struct execution_control_state
*ecs
;
3681 memset (ecs
, 0, sizeof (*ecs
));
3683 overlay_cache_invalid
= 1;
3684 /* Flush target cache before starting to handle each event.
3685 Target was running and cache could be stale. This is just a
3686 heuristic. Running threads may modify target memory, but we
3687 don't get any event. */
3688 target_dcache_invalidate ();
3690 do_target_wait (pid_ptid
, ecs
, 0);
3693 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3695 /* If an error happens while handling the event, propagate GDB's
3696 knowledge of the executing state to the frontend/user running
3698 scoped_finish_thread_state
finish_state (inf
->process_target (),
3701 /* Now figure out what to do with the result of the result. */
3702 handle_inferior_event (ecs
);
3704 /* No error, don't finish the state yet. */
3705 finish_state
.release ();
3707 /* Breakpoints and watchpoints are not installed on the target
3708 at this point, and signals are passed directly to the
3709 inferior, so this must mean the process is gone. */
3710 if (!ecs
->wait_some_more
)
3712 restore_detaching
.release ();
3713 error (_("Program exited while detaching"));
3717 restore_detaching
.release ();
3720 /* Wait for control to return from inferior to debugger.
3722 If inferior gets a signal, we may decide to start it up again
3723 instead of returning. That is why there is a loop in this function.
3724 When this function actually returns it means the inferior
3725 should be left stopped and GDB should read more commands. */
3728 wait_for_inferior (inferior
*inf
)
3730 infrun_log_debug ("wait_for_inferior ()");
3732 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3734 /* If an error happens while handling the event, propagate GDB's
3735 knowledge of the executing state to the frontend/user running
3737 scoped_finish_thread_state finish_state
3738 (inf
->process_target (), minus_one_ptid
);
3742 struct execution_control_state ecss
;
3743 struct execution_control_state
*ecs
= &ecss
;
3745 memset (ecs
, 0, sizeof (*ecs
));
3747 overlay_cache_invalid
= 1;
3749 /* Flush target cache before starting to handle each event.
3750 Target was running and cache could be stale. This is just a
3751 heuristic. Running threads may modify target memory, but we
3752 don't get any event. */
3753 target_dcache_invalidate ();
3755 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3756 ecs
->target
= inf
->process_target ();
3759 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3761 /* Now figure out what to do with the result of the result. */
3762 handle_inferior_event (ecs
);
3764 if (!ecs
->wait_some_more
)
3768 /* No error, don't finish the state yet. */
3769 finish_state
.release ();
3772 /* Cleanup that reinstalls the readline callback handler, if the
3773 target is running in the background. If while handling the target
3774 event something triggered a secondary prompt, like e.g., a
3775 pagination prompt, we'll have removed the callback handler (see
3776 gdb_readline_wrapper_line). Need to do this as we go back to the
3777 event loop, ready to process further input. Note this has no
3778 effect if the handler hasn't actually been removed, because calling
3779 rl_callback_handler_install resets the line buffer, thus losing
3783 reinstall_readline_callback_handler_cleanup ()
3785 struct ui
*ui
= current_ui
;
3789 /* We're not going back to the top level event loop yet. Don't
3790 install the readline callback, as it'd prep the terminal,
3791 readline-style (raw, noecho) (e.g., --batch). We'll install
3792 it the next time the prompt is displayed, when we're ready
3797 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3798 gdb_rl_callback_handler_reinstall ();
3801 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3802 that's just the event thread. In all-stop, that's all threads. */
3805 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3807 if (ecs
->event_thread
!= NULL
3808 && ecs
->event_thread
->thread_fsm
!= NULL
)
3809 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3813 for (thread_info
*thr
: all_non_exited_threads ())
3815 if (thr
->thread_fsm
== NULL
)
3817 if (thr
== ecs
->event_thread
)
3820 switch_to_thread (thr
);
3821 thr
->thread_fsm
->clean_up (thr
);
3824 if (ecs
->event_thread
!= NULL
)
3825 switch_to_thread (ecs
->event_thread
);
3829 /* Helper for all_uis_check_sync_execution_done that works on the
3833 check_curr_ui_sync_execution_done (void)
3835 struct ui
*ui
= current_ui
;
3837 if (ui
->prompt_state
== PROMPT_NEEDED
3839 && !gdb_in_secondary_prompt_p (ui
))
3841 target_terminal::ours ();
3842 gdb::observers::sync_execution_done
.notify ();
3843 ui_register_input_event_handler (ui
);
3850 all_uis_check_sync_execution_done (void)
3852 SWITCH_THRU_ALL_UIS ()
3854 check_curr_ui_sync_execution_done ();
3861 all_uis_on_sync_execution_starting (void)
3863 SWITCH_THRU_ALL_UIS ()
3865 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3866 async_disable_stdin ();
3870 /* Asynchronous version of wait_for_inferior. It is called by the
3871 event loop whenever a change of state is detected on the file
3872 descriptor corresponding to the target. It can be called more than
3873 once to complete a single execution command. In such cases we need
3874 to keep the state in a global variable ECSS. If it is the last time
3875 that this function is called for a single execution command, then
3876 report to the user that the inferior has stopped, and do the
3877 necessary cleanups. */
3880 fetch_inferior_event (void *client_data
)
3882 struct execution_control_state ecss
;
3883 struct execution_control_state
*ecs
= &ecss
;
3886 memset (ecs
, 0, sizeof (*ecs
));
3888 /* Events are always processed with the main UI as current UI. This
3889 way, warnings, debug output, etc. are always consistently sent to
3890 the main console. */
3891 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3893 /* End up with readline processing input, if necessary. */
3895 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3897 /* We're handling a live event, so make sure we're doing live
3898 debugging. If we're looking at traceframes while the target is
3899 running, we're going to need to get back to that mode after
3900 handling the event. */
3901 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3904 maybe_restore_traceframe
.emplace ();
3905 set_current_traceframe (-1);
3908 /* The user/frontend should not notice a thread switch due to
3909 internal events. Make sure we revert to the user selected
3910 thread and frame after handling the event and running any
3911 breakpoint commands. */
3912 scoped_restore_current_thread restore_thread
;
3914 overlay_cache_invalid
= 1;
3915 /* Flush target cache before starting to handle each event. Target
3916 was running and cache could be stale. This is just a heuristic.
3917 Running threads may modify target memory, but we don't get any
3919 target_dcache_invalidate ();
3921 scoped_restore save_exec_dir
3922 = make_scoped_restore (&execution_direction
,
3923 target_execution_direction ());
3925 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3928 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3930 /* Switch to the target that generated the event, so we can do
3931 target calls. Any inferior bound to the target will do, so we
3932 just switch to the first we find. */
3933 for (inferior
*inf
: all_inferiors (ecs
->target
))
3935 switch_to_inferior_no_thread (inf
);
3940 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3942 /* If an error happens while handling the event, propagate GDB's
3943 knowledge of the executing state to the frontend/user running
3945 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3946 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3948 /* Get executed before scoped_restore_current_thread above to apply
3949 still for the thread which has thrown the exception. */
3950 auto defer_bpstat_clear
3951 = make_scope_exit (bpstat_clear_actions
);
3952 auto defer_delete_threads
3953 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3955 /* Now figure out what to do with the result of the result. */
3956 handle_inferior_event (ecs
);
3958 if (!ecs
->wait_some_more
)
3960 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3961 int should_stop
= 1;
3962 struct thread_info
*thr
= ecs
->event_thread
;
3964 delete_just_stopped_threads_infrun_breakpoints ();
3968 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3970 if (thread_fsm
!= NULL
)
3971 should_stop
= thread_fsm
->should_stop (thr
);
3980 bool should_notify_stop
= true;
3983 clean_up_just_stopped_threads_fsms (ecs
);
3985 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3986 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3988 if (should_notify_stop
)
3990 /* We may not find an inferior if this was a process exit. */
3991 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3992 proceeded
= normal_stop ();
3997 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4001 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4002 previously selected thread is gone. We have two
4003 choices - switch to no thread selected, or restore the
4004 previously selected thread (now exited). We chose the
4005 later, just because that's what GDB used to do. After
4006 this, "info threads" says "The current thread <Thread
4007 ID 2> has terminated." instead of "No thread
4011 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4012 restore_thread
.dont_restore ();
4016 defer_delete_threads
.release ();
4017 defer_bpstat_clear
.release ();
4019 /* No error, don't finish the thread states yet. */
4020 finish_state
.release ();
4022 /* This scope is used to ensure that readline callbacks are
4023 reinstalled here. */
4026 /* If a UI was in sync execution mode, and now isn't, restore its
4027 prompt (a synchronous execution command has finished, and we're
4028 ready for input). */
4029 all_uis_check_sync_execution_done ();
4032 && exec_done_display_p
4033 && (inferior_ptid
== null_ptid
4034 || inferior_thread ()->state
!= THREAD_RUNNING
))
4035 printf_unfiltered (_("completed.\n"));
4041 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4042 struct symtab_and_line sal
)
4044 /* This can be removed once this function no longer implicitly relies on the
4045 inferior_ptid value. */
4046 gdb_assert (inferior_ptid
== tp
->ptid
);
4048 tp
->control
.step_frame_id
= get_frame_id (frame
);
4049 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4051 tp
->current_symtab
= sal
.symtab
;
4052 tp
->current_line
= sal
.line
;
4055 /* Clear context switchable stepping state. */
4058 init_thread_stepping_state (struct thread_info
*tss
)
4060 tss
->stepped_breakpoint
= 0;
4061 tss
->stepping_over_breakpoint
= 0;
4062 tss
->stepping_over_watchpoint
= 0;
4063 tss
->step_after_step_resume_breakpoint
= 0;
4069 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4070 target_waitstatus status
)
4072 target_last_proc_target
= target
;
4073 target_last_wait_ptid
= ptid
;
4074 target_last_waitstatus
= status
;
4080 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4081 target_waitstatus
*status
)
4083 if (target
!= nullptr)
4084 *target
= target_last_proc_target
;
4085 if (ptid
!= nullptr)
4086 *ptid
= target_last_wait_ptid
;
4087 if (status
!= nullptr)
4088 *status
= target_last_waitstatus
;
4094 nullify_last_target_wait_ptid (void)
4096 target_last_proc_target
= nullptr;
4097 target_last_wait_ptid
= minus_one_ptid
;
4098 target_last_waitstatus
= {};
4101 /* Switch thread contexts. */
4104 context_switch (execution_control_state
*ecs
)
4106 if (ecs
->ptid
!= inferior_ptid
4107 && (inferior_ptid
== null_ptid
4108 || ecs
->event_thread
!= inferior_thread ()))
4110 infrun_log_debug ("Switching context from %s to %s",
4111 target_pid_to_str (inferior_ptid
).c_str (),
4112 target_pid_to_str (ecs
->ptid
).c_str ());
4115 switch_to_thread (ecs
->event_thread
);
4118 /* If the target can't tell whether we've hit breakpoints
4119 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4120 check whether that could have been caused by a breakpoint. If so,
4121 adjust the PC, per gdbarch_decr_pc_after_break. */
4124 adjust_pc_after_break (struct thread_info
*thread
,
4125 struct target_waitstatus
*ws
)
4127 struct regcache
*regcache
;
4128 struct gdbarch
*gdbarch
;
4129 CORE_ADDR breakpoint_pc
, decr_pc
;
4131 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4132 we aren't, just return.
4134 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4135 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4136 implemented by software breakpoints should be handled through the normal
4139 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4140 different signals (SIGILL or SIGEMT for instance), but it is less
4141 clear where the PC is pointing afterwards. It may not match
4142 gdbarch_decr_pc_after_break. I don't know any specific target that
4143 generates these signals at breakpoints (the code has been in GDB since at
4144 least 1992) so I can not guess how to handle them here.
4146 In earlier versions of GDB, a target with
4147 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4148 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4149 target with both of these set in GDB history, and it seems unlikely to be
4150 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4152 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4155 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4158 /* In reverse execution, when a breakpoint is hit, the instruction
4159 under it has already been de-executed. The reported PC always
4160 points at the breakpoint address, so adjusting it further would
4161 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4164 B1 0x08000000 : INSN1
4165 B2 0x08000001 : INSN2
4167 PC -> 0x08000003 : INSN4
4169 Say you're stopped at 0x08000003 as above. Reverse continuing
4170 from that point should hit B2 as below. Reading the PC when the
4171 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4172 been de-executed already.
4174 B1 0x08000000 : INSN1
4175 B2 PC -> 0x08000001 : INSN2
4179 We can't apply the same logic as for forward execution, because
4180 we would wrongly adjust the PC to 0x08000000, since there's a
4181 breakpoint at PC - 1. We'd then report a hit on B1, although
4182 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4184 if (execution_direction
== EXEC_REVERSE
)
4187 /* If the target can tell whether the thread hit a SW breakpoint,
4188 trust it. Targets that can tell also adjust the PC
4190 if (target_supports_stopped_by_sw_breakpoint ())
4193 /* Note that relying on whether a breakpoint is planted in memory to
4194 determine this can fail. E.g,. the breakpoint could have been
4195 removed since. Or the thread could have been told to step an
4196 instruction the size of a breakpoint instruction, and only
4197 _after_ was a breakpoint inserted at its address. */
4199 /* If this target does not decrement the PC after breakpoints, then
4200 we have nothing to do. */
4201 regcache
= get_thread_regcache (thread
);
4202 gdbarch
= regcache
->arch ();
4204 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4208 const address_space
*aspace
= regcache
->aspace ();
4210 /* Find the location where (if we've hit a breakpoint) the
4211 breakpoint would be. */
4212 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4214 /* If the target can't tell whether a software breakpoint triggered,
4215 fallback to figuring it out based on breakpoints we think were
4216 inserted in the target, and on whether the thread was stepped or
4219 /* Check whether there actually is a software breakpoint inserted at
4222 If in non-stop mode, a race condition is possible where we've
4223 removed a breakpoint, but stop events for that breakpoint were
4224 already queued and arrive later. To suppress those spurious
4225 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4226 and retire them after a number of stop events are reported. Note
4227 this is an heuristic and can thus get confused. The real fix is
4228 to get the "stopped by SW BP and needs adjustment" info out of
4229 the target/kernel (and thus never reach here; see above). */
4230 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4231 || (target_is_non_stop_p ()
4232 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4234 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4236 if (record_full_is_used ())
4237 restore_operation_disable
.emplace
4238 (record_full_gdb_operation_disable_set ());
4240 /* When using hardware single-step, a SIGTRAP is reported for both
4241 a completed single-step and a software breakpoint. Need to
4242 differentiate between the two, as the latter needs adjusting
4243 but the former does not.
4245 The SIGTRAP can be due to a completed hardware single-step only if
4246 - we didn't insert software single-step breakpoints
4247 - this thread is currently being stepped
4249 If any of these events did not occur, we must have stopped due
4250 to hitting a software breakpoint, and have to back up to the
4253 As a special case, we could have hardware single-stepped a
4254 software breakpoint. In this case (prev_pc == breakpoint_pc),
4255 we also need to back up to the breakpoint address. */
4257 if (thread_has_single_step_breakpoints_set (thread
)
4258 || !currently_stepping (thread
)
4259 || (thread
->stepped_breakpoint
4260 && thread
->prev_pc
== breakpoint_pc
))
4261 regcache_write_pc (regcache
, breakpoint_pc
);
4266 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4268 for (frame
= get_prev_frame (frame
);
4270 frame
= get_prev_frame (frame
))
4272 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4274 if (get_frame_type (frame
) != INLINE_FRAME
)
4281 /* Look for an inline frame that is marked for skip.
4282 If PREV_FRAME is TRUE start at the previous frame,
4283 otherwise start at the current frame. Stop at the
4284 first non-inline frame, or at the frame where the
4288 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4290 struct frame_info
*frame
= get_current_frame ();
4293 frame
= get_prev_frame (frame
);
4295 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4297 const char *fn
= NULL
;
4298 symtab_and_line sal
;
4301 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4303 if (get_frame_type (frame
) != INLINE_FRAME
)
4306 sal
= find_frame_sal (frame
);
4307 sym
= get_frame_function (frame
);
4310 fn
= sym
->print_name ();
4313 && function_name_is_marked_for_skip (fn
, sal
))
4320 /* If the event thread has the stop requested flag set, pretend it
4321 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4325 handle_stop_requested (struct execution_control_state
*ecs
)
4327 if (ecs
->event_thread
->stop_requested
)
4329 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4330 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4331 handle_signal_stop (ecs
);
4337 /* Auxiliary function that handles syscall entry/return events.
4338 It returns 1 if the inferior should keep going (and GDB
4339 should ignore the event), or 0 if the event deserves to be
4343 handle_syscall_event (struct execution_control_state
*ecs
)
4345 struct regcache
*regcache
;
4348 context_switch (ecs
);
4350 regcache
= get_thread_regcache (ecs
->event_thread
);
4351 syscall_number
= ecs
->ws
.value
.syscall_number
;
4352 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4354 if (catch_syscall_enabled () > 0
4355 && catching_syscall_number (syscall_number
) > 0)
4357 infrun_log_debug ("syscall number=%d", syscall_number
);
4359 ecs
->event_thread
->control
.stop_bpstat
4360 = bpstat_stop_status (regcache
->aspace (),
4361 ecs
->event_thread
->suspend
.stop_pc
,
4362 ecs
->event_thread
, &ecs
->ws
);
4364 if (handle_stop_requested (ecs
))
4367 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4369 /* Catchpoint hit. */
4374 if (handle_stop_requested (ecs
))
4377 /* If no catchpoint triggered for this, then keep going. */
4382 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4385 fill_in_stop_func (struct gdbarch
*gdbarch
,
4386 struct execution_control_state
*ecs
)
4388 if (!ecs
->stop_func_filled_in
)
4392 /* Don't care about return value; stop_func_start and stop_func_name
4393 will both be 0 if it doesn't work. */
4394 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4395 &ecs
->stop_func_name
,
4396 &ecs
->stop_func_start
,
4397 &ecs
->stop_func_end
,
4400 /* The call to find_pc_partial_function, above, will set
4401 stop_func_start and stop_func_end to the start and end
4402 of the range containing the stop pc. If this range
4403 contains the entry pc for the block (which is always the
4404 case for contiguous blocks), advance stop_func_start past
4405 the function's start offset and entrypoint. Note that
4406 stop_func_start is NOT advanced when in a range of a
4407 non-contiguous block that does not contain the entry pc. */
4408 if (block
!= nullptr
4409 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4410 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4412 ecs
->stop_func_start
4413 += gdbarch_deprecated_function_start_offset (gdbarch
);
4415 if (gdbarch_skip_entrypoint_p (gdbarch
))
4416 ecs
->stop_func_start
4417 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4420 ecs
->stop_func_filled_in
= 1;
4425 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4427 static enum stop_kind
4428 get_inferior_stop_soon (execution_control_state
*ecs
)
4430 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4432 gdb_assert (inf
!= NULL
);
4433 return inf
->control
.stop_soon
;
4436 /* Poll for one event out of the current target. Store the resulting
4437 waitstatus in WS, and return the event ptid. Does not block. */
4440 poll_one_curr_target (struct target_waitstatus
*ws
)
4444 overlay_cache_invalid
= 1;
4446 /* Flush target cache before starting to handle each event.
4447 Target was running and cache could be stale. This is just a
4448 heuristic. Running threads may modify target memory, but we
4449 don't get any event. */
4450 target_dcache_invalidate ();
4452 if (deprecated_target_wait_hook
)
4453 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4455 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4458 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4463 /* An event reported by wait_one. */
4465 struct wait_one_event
4467 /* The target the event came out of. */
4468 process_stratum_target
*target
;
4470 /* The PTID the event was for. */
4473 /* The waitstatus. */
4474 target_waitstatus ws
;
4477 /* Wait for one event out of any target. */
4479 static wait_one_event
4484 for (inferior
*inf
: all_inferiors ())
4486 process_stratum_target
*target
= inf
->process_target ();
4488 || !target
->is_async_p ()
4489 || !target
->threads_executing
)
4492 switch_to_inferior_no_thread (inf
);
4494 wait_one_event event
;
4495 event
.target
= target
;
4496 event
.ptid
= poll_one_curr_target (&event
.ws
);
4498 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4500 /* If nothing is resumed, remove the target from the
4504 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4508 /* Block waiting for some event. */
4515 for (inferior
*inf
: all_inferiors ())
4517 process_stratum_target
*target
= inf
->process_target ();
4519 || !target
->is_async_p ()
4520 || !target
->threads_executing
)
4523 int fd
= target
->async_wait_fd ();
4524 FD_SET (fd
, &readfds
);
4531 /* No waitable targets left. All must be stopped. */
4532 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4537 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4543 perror_with_name ("interruptible_select");
4548 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4549 instead of the current thread. */
4550 #define THREAD_STOPPED_BY(REASON) \
4552 thread_stopped_by_ ## REASON (ptid_t ptid) \
4554 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4555 inferior_ptid = ptid; \
4557 return target_stopped_by_ ## REASON (); \
4560 /* Generate thread_stopped_by_watchpoint. */
4561 THREAD_STOPPED_BY (watchpoint
)
4562 /* Generate thread_stopped_by_sw_breakpoint. */
4563 THREAD_STOPPED_BY (sw_breakpoint
)
4564 /* Generate thread_stopped_by_hw_breakpoint. */
4565 THREAD_STOPPED_BY (hw_breakpoint
)
4567 /* Save the thread's event and stop reason to process it later. */
4570 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4572 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4573 target_waitstatus_to_string (ws
).c_str (),
4578 /* Record for later. */
4579 tp
->suspend
.waitstatus
= *ws
;
4580 tp
->suspend
.waitstatus_pending_p
= 1;
4582 struct regcache
*regcache
= get_thread_regcache (tp
);
4583 const address_space
*aspace
= regcache
->aspace ();
4585 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4586 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4588 CORE_ADDR pc
= regcache_read_pc (regcache
);
4590 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4592 if (thread_stopped_by_watchpoint (tp
->ptid
))
4594 tp
->suspend
.stop_reason
4595 = TARGET_STOPPED_BY_WATCHPOINT
;
4597 else if (target_supports_stopped_by_sw_breakpoint ()
4598 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4600 tp
->suspend
.stop_reason
4601 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4603 else if (target_supports_stopped_by_hw_breakpoint ()
4604 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4606 tp
->suspend
.stop_reason
4607 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4609 else if (!target_supports_stopped_by_hw_breakpoint ()
4610 && hardware_breakpoint_inserted_here_p (aspace
,
4613 tp
->suspend
.stop_reason
4614 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4616 else if (!target_supports_stopped_by_sw_breakpoint ()
4617 && software_breakpoint_inserted_here_p (aspace
,
4620 tp
->suspend
.stop_reason
4621 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4623 else if (!thread_has_single_step_breakpoints_set (tp
)
4624 && currently_stepping (tp
))
4626 tp
->suspend
.stop_reason
4627 = TARGET_STOPPED_BY_SINGLE_STEP
;
4632 /* Mark the non-executing threads accordingly. In all-stop, all
4633 threads of all processes are stopped when we get any event
4634 reported. In non-stop mode, only the event thread stops. */
4637 mark_non_executing_threads (process_stratum_target
*target
,
4639 struct target_waitstatus ws
)
4643 if (!target_is_non_stop_p ())
4644 mark_ptid
= minus_one_ptid
;
4645 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4646 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4648 /* If we're handling a process exit in non-stop mode, even
4649 though threads haven't been deleted yet, one would think
4650 that there is nothing to do, as threads of the dead process
4651 will be soon deleted, and threads of any other process were
4652 left running. However, on some targets, threads survive a
4653 process exit event. E.g., for the "checkpoint" command,
4654 when the current checkpoint/fork exits, linux-fork.c
4655 automatically switches to another fork from within
4656 target_mourn_inferior, by associating the same
4657 inferior/thread to another fork. We haven't mourned yet at
4658 this point, but we must mark any threads left in the
4659 process as not-executing so that finish_thread_state marks
4660 them stopped (in the user's perspective) if/when we present
4661 the stop to the user. */
4662 mark_ptid
= ptid_t (event_ptid
.pid ());
4665 mark_ptid
= event_ptid
;
4667 set_executing (target
, mark_ptid
, false);
4669 /* Likewise the resumed flag. */
4670 set_resumed (target
, mark_ptid
, false);
4676 stop_all_threads (void)
4678 /* We may need multiple passes to discover all threads. */
4682 gdb_assert (exists_non_stop_target ());
4684 infrun_log_debug ("stop_all_threads");
4686 scoped_restore_current_thread restore_thread
;
4688 /* Enable thread events of all targets. */
4689 for (auto *target
: all_non_exited_process_targets ())
4691 switch_to_target_no_thread (target
);
4692 target_thread_events (true);
4697 /* Disable thread events of all targets. */
4698 for (auto *target
: all_non_exited_process_targets ())
4700 switch_to_target_no_thread (target
);
4701 target_thread_events (false);
4705 infrun_log_debug ("stop_all_threads done");
4708 /* Request threads to stop, and then wait for the stops. Because
4709 threads we already know about can spawn more threads while we're
4710 trying to stop them, and we only learn about new threads when we
4711 update the thread list, do this in a loop, and keep iterating
4712 until two passes find no threads that need to be stopped. */
4713 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4715 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4719 int waits_needed
= 0;
4721 for (auto *target
: all_non_exited_process_targets ())
4723 switch_to_target_no_thread (target
);
4724 update_thread_list ();
4727 /* Go through all threads looking for threads that we need
4728 to tell the target to stop. */
4729 for (thread_info
*t
: all_non_exited_threads ())
4731 /* For a single-target setting with an all-stop target,
4732 we would not even arrive here. For a multi-target
4733 setting, until GDB is able to handle a mixture of
4734 all-stop and non-stop targets, simply skip all-stop
4735 targets' threads. This should be fine due to the
4736 protection of 'check_multi_target_resumption'. */
4738 switch_to_thread_no_regs (t
);
4739 if (!target_is_non_stop_p ())
4744 /* If already stopping, don't request a stop again.
4745 We just haven't seen the notification yet. */
4746 if (!t
->stop_requested
)
4748 infrun_log_debug (" %s executing, need stop",
4749 target_pid_to_str (t
->ptid
).c_str ());
4750 target_stop (t
->ptid
);
4751 t
->stop_requested
= 1;
4755 infrun_log_debug (" %s executing, already stopping",
4756 target_pid_to_str (t
->ptid
).c_str ());
4759 if (t
->stop_requested
)
4764 infrun_log_debug (" %s not executing",
4765 target_pid_to_str (t
->ptid
).c_str ());
4767 /* The thread may be not executing, but still be
4768 resumed with a pending status to process. */
4773 if (waits_needed
== 0)
4776 /* If we find new threads on the second iteration, restart
4777 over. We want to see two iterations in a row with all
4782 for (int i
= 0; i
< waits_needed
; i
++)
4784 wait_one_event event
= wait_one ();
4786 infrun_log_debug ("%s %s\n",
4787 target_waitstatus_to_string (&event
.ws
).c_str (),
4788 target_pid_to_str (event
.ptid
).c_str ());
4790 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4792 /* All resumed threads exited. */
4795 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4796 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4797 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4799 /* One thread/process exited/signalled. */
4801 thread_info
*t
= nullptr;
4803 /* The target may have reported just a pid. If so, try
4804 the first non-exited thread. */
4805 if (event
.ptid
.is_pid ())
4807 int pid
= event
.ptid
.pid ();
4808 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4809 for (thread_info
*tp
: inf
->non_exited_threads ())
4815 /* If there is no available thread, the event would
4816 have to be appended to a per-inferior event list,
4817 which does not exist (and if it did, we'd have
4818 to adjust run control command to be able to
4819 resume such an inferior). We assert here instead
4820 of going into an infinite loop. */
4821 gdb_assert (t
!= nullptr);
4823 infrun_log_debug ("using %s\n",
4824 target_pid_to_str (t
->ptid
).c_str ());
4828 t
= find_thread_ptid (event
.target
, event
.ptid
);
4829 /* Check if this is the first time we see this thread.
4830 Don't bother adding if it individually exited. */
4832 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4833 t
= add_thread (event
.target
, event
.ptid
);
4838 /* Set the threads as non-executing to avoid
4839 another stop attempt on them. */
4840 switch_to_thread_no_regs (t
);
4841 mark_non_executing_threads (event
.target
, event
.ptid
,
4843 save_waitstatus (t
, &event
.ws
);
4844 t
->stop_requested
= false;
4849 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4851 t
= add_thread (event
.target
, event
.ptid
);
4853 t
->stop_requested
= 0;
4856 t
->control
.may_range_step
= 0;
4858 /* This may be the first time we see the inferior report
4860 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4861 if (inf
->needs_setup
)
4863 switch_to_thread_no_regs (t
);
4867 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4868 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4870 /* We caught the event that we intended to catch, so
4871 there's no event pending. */
4872 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4873 t
->suspend
.waitstatus_pending_p
= 0;
4875 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4877 /* Add it back to the step-over queue. */
4878 infrun_log_debug ("displaced-step of %s "
4879 "canceled: adding back to the "
4880 "step-over queue\n",
4881 target_pid_to_str (t
->ptid
).c_str ());
4883 t
->control
.trap_expected
= 0;
4884 global_thread_step_over_chain_enqueue (t
);
4889 enum gdb_signal sig
;
4890 struct regcache
*regcache
;
4894 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4896 infrun_log_debug ("target_wait %s, saving "
4897 "status for %d.%ld.%ld\n",
4904 /* Record for later. */
4905 save_waitstatus (t
, &event
.ws
);
4907 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4908 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4910 if (displaced_step_finish (t
, sig
) < 0)
4912 /* Add it back to the step-over queue. */
4913 t
->control
.trap_expected
= 0;
4914 global_thread_step_over_chain_enqueue (t
);
4917 regcache
= get_thread_regcache (t
);
4918 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4920 infrun_log_debug ("saved stop_pc=%s for %s "
4921 "(currently_stepping=%d)\n",
4922 paddress (target_gdbarch (),
4923 t
->suspend
.stop_pc
),
4924 target_pid_to_str (t
->ptid
).c_str (),
4925 currently_stepping (t
));
4933 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4936 handle_no_resumed (struct execution_control_state
*ecs
)
4938 if (target_can_async_p ())
4942 for (ui
*ui
: all_uis ())
4944 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4952 /* There were no unwaited-for children left in the target, but,
4953 we're not synchronously waiting for events either. Just
4956 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4957 prepare_to_wait (ecs
);
4962 /* Otherwise, if we were running a synchronous execution command, we
4963 may need to cancel it and give the user back the terminal.
4965 In non-stop mode, the target can't tell whether we've already
4966 consumed previous stop events, so it can end up sending us a
4967 no-resumed event like so:
4969 #0 - thread 1 is left stopped
4971 #1 - thread 2 is resumed and hits breakpoint
4972 -> TARGET_WAITKIND_STOPPED
4974 #2 - thread 3 is resumed and exits
4975 this is the last resumed thread, so
4976 -> TARGET_WAITKIND_NO_RESUMED
4978 #3 - gdb processes stop for thread 2 and decides to re-resume
4981 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4982 thread 2 is now resumed, so the event should be ignored.
4984 IOW, if the stop for thread 2 doesn't end a foreground command,
4985 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4986 event. But it could be that the event meant that thread 2 itself
4987 (or whatever other thread was the last resumed thread) exited.
4989 To address this we refresh the thread list and check whether we
4990 have resumed threads _now_. In the example above, this removes
4991 thread 3 from the thread list. If thread 2 was re-resumed, we
4992 ignore this event. If we find no thread resumed, then we cancel
4993 the synchronous command show "no unwaited-for " to the user. */
4994 update_thread_list ();
4996 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4998 if (thread
->executing
4999 || thread
->suspend
.waitstatus_pending_p
)
5001 /* There were no unwaited-for children left in the target at
5002 some point, but there are now. Just ignore. */
5003 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
5004 "(ignoring: found resumed)");
5005 prepare_to_wait (ecs
);
5010 /* Go ahead and report the event. */
5014 /* Given an execution control state that has been freshly filled in by
5015 an event from the inferior, figure out what it means and take
5018 The alternatives are:
5020 1) stop_waiting and return; to really stop and return to the
5023 2) keep_going and return; to wait for the next event (set
5024 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5028 handle_inferior_event (struct execution_control_state
*ecs
)
5030 /* Make sure that all temporary struct value objects that were
5031 created during the handling of the event get deleted at the
5033 scoped_value_mark free_values
;
5035 enum stop_kind stop_soon
;
5037 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5039 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5041 /* We had an event in the inferior, but we are not interested in
5042 handling it at this level. The lower layers have already
5043 done what needs to be done, if anything.
5045 One of the possible circumstances for this is when the
5046 inferior produces output for the console. The inferior has
5047 not stopped, and we are ignoring the event. Another possible
5048 circumstance is any event which the lower level knows will be
5049 reported multiple times without an intervening resume. */
5050 prepare_to_wait (ecs
);
5054 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5056 prepare_to_wait (ecs
);
5060 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5061 && handle_no_resumed (ecs
))
5064 /* Cache the last target/ptid/waitstatus. */
5065 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5067 /* Always clear state belonging to the previous time we stopped. */
5068 stop_stack_dummy
= STOP_NONE
;
5070 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5072 /* No unwaited-for children left. IOW, all resumed children
5074 stop_print_frame
= 0;
5079 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5080 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5082 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5083 /* If it's a new thread, add it to the thread database. */
5084 if (ecs
->event_thread
== NULL
)
5085 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5087 /* Disable range stepping. If the next step request could use a
5088 range, this will be end up re-enabled then. */
5089 ecs
->event_thread
->control
.may_range_step
= 0;
5092 /* Dependent on valid ECS->EVENT_THREAD. */
5093 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5095 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5096 reinit_frame_cache ();
5098 breakpoint_retire_moribund ();
5100 /* First, distinguish signals caused by the debugger from signals
5101 that have to do with the program's own actions. Note that
5102 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5103 on the operating system version. Here we detect when a SIGILL or
5104 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5105 something similar for SIGSEGV, since a SIGSEGV will be generated
5106 when we're trying to execute a breakpoint instruction on a
5107 non-executable stack. This happens for call dummy breakpoints
5108 for architectures like SPARC that place call dummies on the
5110 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5111 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5112 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5113 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5115 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5117 if (breakpoint_inserted_here_p (regcache
->aspace (),
5118 regcache_read_pc (regcache
)))
5120 infrun_log_debug ("Treating signal as SIGTRAP");
5121 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5125 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5127 switch (ecs
->ws
.kind
)
5129 case TARGET_WAITKIND_LOADED
:
5130 context_switch (ecs
);
5131 /* Ignore gracefully during startup of the inferior, as it might
5132 be the shell which has just loaded some objects, otherwise
5133 add the symbols for the newly loaded objects. Also ignore at
5134 the beginning of an attach or remote session; we will query
5135 the full list of libraries once the connection is
5138 stop_soon
= get_inferior_stop_soon (ecs
);
5139 if (stop_soon
== NO_STOP_QUIETLY
)
5141 struct regcache
*regcache
;
5143 regcache
= get_thread_regcache (ecs
->event_thread
);
5145 handle_solib_event ();
5147 ecs
->event_thread
->control
.stop_bpstat
5148 = bpstat_stop_status (regcache
->aspace (),
5149 ecs
->event_thread
->suspend
.stop_pc
,
5150 ecs
->event_thread
, &ecs
->ws
);
5152 if (handle_stop_requested (ecs
))
5155 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5157 /* A catchpoint triggered. */
5158 process_event_stop_test (ecs
);
5162 /* If requested, stop when the dynamic linker notifies
5163 gdb of events. This allows the user to get control
5164 and place breakpoints in initializer routines for
5165 dynamically loaded objects (among other things). */
5166 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5167 if (stop_on_solib_events
)
5169 /* Make sure we print "Stopped due to solib-event" in
5171 stop_print_frame
= 1;
5178 /* If we are skipping through a shell, or through shared library
5179 loading that we aren't interested in, resume the program. If
5180 we're running the program normally, also resume. */
5181 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5183 /* Loading of shared libraries might have changed breakpoint
5184 addresses. Make sure new breakpoints are inserted. */
5185 if (stop_soon
== NO_STOP_QUIETLY
)
5186 insert_breakpoints ();
5187 resume (GDB_SIGNAL_0
);
5188 prepare_to_wait (ecs
);
5192 /* But stop if we're attaching or setting up a remote
5194 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5195 || stop_soon
== STOP_QUIETLY_REMOTE
)
5197 infrun_log_debug ("quietly stopped");
5202 internal_error (__FILE__
, __LINE__
,
5203 _("unhandled stop_soon: %d"), (int) stop_soon
);
5205 case TARGET_WAITKIND_SPURIOUS
:
5206 if (handle_stop_requested (ecs
))
5208 context_switch (ecs
);
5209 resume (GDB_SIGNAL_0
);
5210 prepare_to_wait (ecs
);
5213 case TARGET_WAITKIND_THREAD_CREATED
:
5214 if (handle_stop_requested (ecs
))
5216 context_switch (ecs
);
5217 if (!switch_back_to_stepped_thread (ecs
))
5221 case TARGET_WAITKIND_EXITED
:
5222 case TARGET_WAITKIND_SIGNALLED
:
5223 inferior_ptid
= ecs
->ptid
;
5224 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5225 set_current_program_space (current_inferior ()->pspace
);
5226 handle_vfork_child_exec_or_exit (0);
5227 target_terminal::ours (); /* Must do this before mourn anyway. */
5229 /* Clearing any previous state of convenience variables. */
5230 clear_exit_convenience_vars ();
5232 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5234 /* Record the exit code in the convenience variable $_exitcode, so
5235 that the user can inspect this again later. */
5236 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5237 (LONGEST
) ecs
->ws
.value
.integer
);
5239 /* Also record this in the inferior itself. */
5240 current_inferior ()->has_exit_code
= 1;
5241 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5243 /* Support the --return-child-result option. */
5244 return_child_result_value
= ecs
->ws
.value
.integer
;
5246 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5250 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5252 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5254 /* Set the value of the internal variable $_exitsignal,
5255 which holds the signal uncaught by the inferior. */
5256 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5257 gdbarch_gdb_signal_to_target (gdbarch
,
5258 ecs
->ws
.value
.sig
));
5262 /* We don't have access to the target's method used for
5263 converting between signal numbers (GDB's internal
5264 representation <-> target's representation).
5265 Therefore, we cannot do a good job at displaying this
5266 information to the user. It's better to just warn
5267 her about it (if infrun debugging is enabled), and
5269 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5273 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5276 gdb_flush (gdb_stdout
);
5277 target_mourn_inferior (inferior_ptid
);
5278 stop_print_frame
= 0;
5282 case TARGET_WAITKIND_FORKED
:
5283 case TARGET_WAITKIND_VFORKED
:
5284 /* Check whether the inferior is displaced stepping. */
5286 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5287 struct gdbarch
*gdbarch
= regcache
->arch ();
5289 /* If checking displaced stepping is supported, and thread
5290 ecs->ptid is displaced stepping. */
5291 if (displaced_step_in_progress (ecs
->event_thread
))
5293 struct inferior
*parent_inf
5294 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5295 struct regcache
*child_regcache
;
5296 CORE_ADDR parent_pc
;
5298 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5300 // struct displaced_step_inferior_state *displaced
5301 // = get_displaced_stepping_state (parent_inf);
5303 /* Restore scratch pad for child process. */
5304 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5305 // FIXME: we should restore all the buffers that were currently in use
5308 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5309 indicating that the displaced stepping of syscall instruction
5310 has been done. Perform cleanup for parent process here. Note
5311 that this operation also cleans up the child process for vfork,
5312 because their pages are shared. */
5313 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5314 /* Start a new step-over in another thread if there's one
5318 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5319 the child's PC is also within the scratchpad. Set the child's PC
5320 to the parent's PC value, which has already been fixed up.
5321 FIXME: we use the parent's aspace here, although we're touching
5322 the child, because the child hasn't been added to the inferior
5323 list yet at this point. */
5326 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5327 ecs
->ws
.value
.related_pid
,
5329 parent_inf
->aspace
);
5330 /* Read PC value of parent process. */
5331 parent_pc
= regcache_read_pc (regcache
);
5333 if (debug_displaced
)
5334 fprintf_unfiltered (gdb_stdlog
,
5335 "displaced: write child pc from %s to %s\n",
5337 regcache_read_pc (child_regcache
)),
5338 paddress (gdbarch
, parent_pc
));
5340 regcache_write_pc (child_regcache
, parent_pc
);
5344 context_switch (ecs
);
5346 /* Immediately detach breakpoints from the child before there's
5347 any chance of letting the user delete breakpoints from the
5348 breakpoint lists. If we don't do this early, it's easy to
5349 leave left over traps in the child, vis: "break foo; catch
5350 fork; c; <fork>; del; c; <child calls foo>". We only follow
5351 the fork on the last `continue', and by that time the
5352 breakpoint at "foo" is long gone from the breakpoint table.
5353 If we vforked, then we don't need to unpatch here, since both
5354 parent and child are sharing the same memory pages; we'll
5355 need to unpatch at follow/detach time instead to be certain
5356 that new breakpoints added between catchpoint hit time and
5357 vfork follow are detached. */
5358 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5360 /* This won't actually modify the breakpoint list, but will
5361 physically remove the breakpoints from the child. */
5362 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5365 delete_just_stopped_threads_single_step_breakpoints ();
5367 /* In case the event is caught by a catchpoint, remember that
5368 the event is to be followed at the next resume of the thread,
5369 and not immediately. */
5370 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5372 ecs
->event_thread
->suspend
.stop_pc
5373 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5375 ecs
->event_thread
->control
.stop_bpstat
5376 = bpstat_stop_status (get_current_regcache ()->aspace (),
5377 ecs
->event_thread
->suspend
.stop_pc
,
5378 ecs
->event_thread
, &ecs
->ws
);
5380 if (handle_stop_requested (ecs
))
5383 /* If no catchpoint triggered for this, then keep going. Note
5384 that we're interested in knowing the bpstat actually causes a
5385 stop, not just if it may explain the signal. Software
5386 watchpoints, for example, always appear in the bpstat. */
5387 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5390 = (follow_fork_mode_string
== follow_fork_mode_child
);
5392 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5394 process_stratum_target
*targ
5395 = ecs
->event_thread
->inf
->process_target ();
5397 bool should_resume
= follow_fork ();
5399 /* Note that one of these may be an invalid pointer,
5400 depending on detach_fork. */
5401 thread_info
*parent
= ecs
->event_thread
;
5403 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5405 /* At this point, the parent is marked running, and the
5406 child is marked stopped. */
5408 /* If not resuming the parent, mark it stopped. */
5409 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5410 parent
->set_running (false);
5412 /* If resuming the child, mark it running. */
5413 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5414 child
->set_running (true);
5416 /* In non-stop mode, also resume the other branch. */
5417 if (!detach_fork
&& (non_stop
5418 || (sched_multi
&& target_is_non_stop_p ())))
5421 switch_to_thread (parent
);
5423 switch_to_thread (child
);
5425 ecs
->event_thread
= inferior_thread ();
5426 ecs
->ptid
= inferior_ptid
;
5431 switch_to_thread (child
);
5433 switch_to_thread (parent
);
5435 ecs
->event_thread
= inferior_thread ();
5436 ecs
->ptid
= inferior_ptid
;
5444 process_event_stop_test (ecs
);
5447 case TARGET_WAITKIND_VFORK_DONE
:
5448 /* Done with the shared memory region. Re-insert breakpoints in
5449 the parent, and keep going. */
5451 context_switch (ecs
);
5453 current_inferior ()->waiting_for_vfork_done
= 0;
5454 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5456 if (handle_stop_requested (ecs
))
5459 /* This also takes care of reinserting breakpoints in the
5460 previously locked inferior. */
5464 case TARGET_WAITKIND_EXECD
:
5466 /* Note we can't read registers yet (the stop_pc), because we
5467 don't yet know the inferior's post-exec architecture.
5468 'stop_pc' is explicitly read below instead. */
5469 switch_to_thread_no_regs (ecs
->event_thread
);
5471 /* Do whatever is necessary to the parent branch of the vfork. */
5472 handle_vfork_child_exec_or_exit (1);
5474 /* This causes the eventpoints and symbol table to be reset.
5475 Must do this now, before trying to determine whether to
5477 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5479 /* In follow_exec we may have deleted the original thread and
5480 created a new one. Make sure that the event thread is the
5481 execd thread for that case (this is a nop otherwise). */
5482 ecs
->event_thread
= inferior_thread ();
5484 ecs
->event_thread
->suspend
.stop_pc
5485 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5487 ecs
->event_thread
->control
.stop_bpstat
5488 = bpstat_stop_status (get_current_regcache ()->aspace (),
5489 ecs
->event_thread
->suspend
.stop_pc
,
5490 ecs
->event_thread
, &ecs
->ws
);
5492 /* Note that this may be referenced from inside
5493 bpstat_stop_status above, through inferior_has_execd. */
5494 xfree (ecs
->ws
.value
.execd_pathname
);
5495 ecs
->ws
.value
.execd_pathname
= NULL
;
5497 if (handle_stop_requested (ecs
))
5500 /* If no catchpoint triggered for this, then keep going. */
5501 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5503 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5507 process_event_stop_test (ecs
);
5510 /* Be careful not to try to gather much state about a thread
5511 that's in a syscall. It's frequently a losing proposition. */
5512 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5513 /* Getting the current syscall number. */
5514 if (handle_syscall_event (ecs
) == 0)
5515 process_event_stop_test (ecs
);
5518 /* Before examining the threads further, step this thread to
5519 get it entirely out of the syscall. (We get notice of the
5520 event when the thread is just on the verge of exiting a
5521 syscall. Stepping one instruction seems to get it back
5523 case TARGET_WAITKIND_SYSCALL_RETURN
:
5524 if (handle_syscall_event (ecs
) == 0)
5525 process_event_stop_test (ecs
);
5528 case TARGET_WAITKIND_STOPPED
:
5529 handle_signal_stop (ecs
);
5532 case TARGET_WAITKIND_NO_HISTORY
:
5533 /* Reverse execution: target ran out of history info. */
5535 /* Switch to the stopped thread. */
5536 context_switch (ecs
);
5537 infrun_log_debug ("stopped");
5539 delete_just_stopped_threads_single_step_breakpoints ();
5540 ecs
->event_thread
->suspend
.stop_pc
5541 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5543 if (handle_stop_requested (ecs
))
5546 gdb::observers::no_history
.notify ();
5552 /* Restart threads back to what they were trying to do back when we
5553 paused them for an in-line step-over. The EVENT_THREAD thread is
5557 restart_threads (struct thread_info
*event_thread
)
5559 /* In case the instruction just stepped spawned a new thread. */
5560 update_thread_list ();
5562 for (thread_info
*tp
: all_non_exited_threads ())
5564 switch_to_thread_no_regs (tp
);
5566 if (tp
== event_thread
)
5568 infrun_log_debug ("restart threads: [%s] is event thread",
5569 target_pid_to_str (tp
->ptid
).c_str ());
5573 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5575 infrun_log_debug ("restart threads: [%s] not meant to be running",
5576 target_pid_to_str (tp
->ptid
).c_str ());
5582 infrun_log_debug ("restart threads: [%s] resumed",
5583 target_pid_to_str (tp
->ptid
).c_str ());
5584 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5588 if (thread_is_in_step_over_chain (tp
))
5590 infrun_log_debug ("restart threads: [%s] needs step-over",
5591 target_pid_to_str (tp
->ptid
).c_str ());
5592 gdb_assert (!tp
->resumed
);
5597 if (tp
->suspend
.waitstatus_pending_p
)
5599 infrun_log_debug ("restart threads: [%s] has pending status",
5600 target_pid_to_str (tp
->ptid
).c_str ());
5605 gdb_assert (!tp
->stop_requested
);
5607 /* If some thread needs to start a step-over at this point, it
5608 should still be in the step-over queue, and thus skipped
5610 if (thread_still_needs_step_over (tp
))
5612 internal_error (__FILE__
, __LINE__
,
5613 "thread [%s] needs a step-over, but not in "
5614 "step-over queue\n",
5615 target_pid_to_str (tp
->ptid
).c_str ());
5618 if (currently_stepping (tp
))
5620 infrun_log_debug ("restart threads: [%s] was stepping",
5621 target_pid_to_str (tp
->ptid
).c_str ());
5622 keep_going_stepped_thread (tp
);
5626 struct execution_control_state ecss
;
5627 struct execution_control_state
*ecs
= &ecss
;
5629 infrun_log_debug ("restart threads: [%s] continuing",
5630 target_pid_to_str (tp
->ptid
).c_str ());
5631 reset_ecs (ecs
, tp
);
5632 switch_to_thread (tp
);
5633 keep_going_pass_signal (ecs
);
5638 /* Callback for iterate_over_threads. Find a resumed thread that has
5639 a pending waitstatus. */
5642 resumed_thread_with_pending_status (struct thread_info
*tp
,
5646 && tp
->suspend
.waitstatus_pending_p
);
5649 /* Called when we get an event that may finish an in-line or
5650 out-of-line (displaced stepping) step-over started previously.
5651 Return true if the event is processed and we should go back to the
5652 event loop; false if the caller should continue processing the
5656 finish_step_over (struct execution_control_state
*ecs
)
5658 int had_step_over_info
;
5660 displaced_step_finish (ecs
->event_thread
,
5661 ecs
->event_thread
->suspend
.stop_signal
);
5663 had_step_over_info
= step_over_info_valid_p ();
5665 if (had_step_over_info
)
5667 /* If we're stepping over a breakpoint with all threads locked,
5668 then only the thread that was stepped should be reporting
5670 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5672 clear_step_over_info ();
5675 if (!target_is_non_stop_p ())
5678 /* Start a new step-over in another thread if there's one that
5682 /* If we were stepping over a breakpoint before, and haven't started
5683 a new in-line step-over sequence, then restart all other threads
5684 (except the event thread). We can't do this in all-stop, as then
5685 e.g., we wouldn't be able to issue any other remote packet until
5686 these other threads stop. */
5687 if (had_step_over_info
&& !step_over_info_valid_p ())
5689 struct thread_info
*pending
;
5691 /* If we only have threads with pending statuses, the restart
5692 below won't restart any thread and so nothing re-inserts the
5693 breakpoint we just stepped over. But we need it inserted
5694 when we later process the pending events, otherwise if
5695 another thread has a pending event for this breakpoint too,
5696 we'd discard its event (because the breakpoint that
5697 originally caused the event was no longer inserted). */
5698 context_switch (ecs
);
5699 insert_breakpoints ();
5701 restart_threads (ecs
->event_thread
);
5703 /* If we have events pending, go through handle_inferior_event
5704 again, picking up a pending event at random. This avoids
5705 thread starvation. */
5707 /* But not if we just stepped over a watchpoint in order to let
5708 the instruction execute so we can evaluate its expression.
5709 The set of watchpoints that triggered is recorded in the
5710 breakpoint objects themselves (see bp->watchpoint_triggered).
5711 If we processed another event first, that other event could
5712 clobber this info. */
5713 if (ecs
->event_thread
->stepping_over_watchpoint
)
5716 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5718 if (pending
!= NULL
)
5720 struct thread_info
*tp
= ecs
->event_thread
;
5721 struct regcache
*regcache
;
5723 infrun_log_debug ("found resumed threads with "
5724 "pending events, saving status");
5726 gdb_assert (pending
!= tp
);
5728 /* Record the event thread's event for later. */
5729 save_waitstatus (tp
, &ecs
->ws
);
5730 /* This was cleared early, by handle_inferior_event. Set it
5731 so this pending event is considered by
5735 gdb_assert (!tp
->executing
);
5737 regcache
= get_thread_regcache (tp
);
5738 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5740 infrun_log_debug ("saved stop_pc=%s for %s "
5741 "(currently_stepping=%d)\n",
5742 paddress (target_gdbarch (),
5743 tp
->suspend
.stop_pc
),
5744 target_pid_to_str (tp
->ptid
).c_str (),
5745 currently_stepping (tp
));
5747 /* This in-line step-over finished; clear this so we won't
5748 start a new one. This is what handle_signal_stop would
5749 do, if we returned false. */
5750 tp
->stepping_over_breakpoint
= 0;
5752 /* Wake up the event loop again. */
5753 mark_async_event_handler (infrun_async_inferior_event_token
);
5755 prepare_to_wait (ecs
);
5763 /* Come here when the program has stopped with a signal. */
5766 handle_signal_stop (struct execution_control_state
*ecs
)
5768 struct frame_info
*frame
;
5769 struct gdbarch
*gdbarch
;
5770 int stopped_by_watchpoint
;
5771 enum stop_kind stop_soon
;
5774 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5776 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5778 /* Do we need to clean up the state of a thread that has
5779 completed a displaced single-step? (Doing so usually affects
5780 the PC, so do it here, before we set stop_pc.) */
5781 if (finish_step_over (ecs
))
5784 /* If we either finished a single-step or hit a breakpoint, but
5785 the user wanted this thread to be stopped, pretend we got a
5786 SIG0 (generic unsignaled stop). */
5787 if (ecs
->event_thread
->stop_requested
5788 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5789 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5791 ecs
->event_thread
->suspend
.stop_pc
5792 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5796 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5797 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5799 switch_to_thread (ecs
->event_thread
);
5801 infrun_log_debug ("stop_pc=%s",
5802 paddress (reg_gdbarch
,
5803 ecs
->event_thread
->suspend
.stop_pc
));
5804 if (target_stopped_by_watchpoint ())
5808 infrun_log_debug ("stopped by watchpoint");
5810 if (target_stopped_data_address (current_top_target (), &addr
))
5811 infrun_log_debug ("stopped data address=%s",
5812 paddress (reg_gdbarch
, addr
));
5814 infrun_log_debug ("(no data address available)");
5818 /* This is originated from start_remote(), start_inferior() and
5819 shared libraries hook functions. */
5820 stop_soon
= get_inferior_stop_soon (ecs
);
5821 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5823 context_switch (ecs
);
5824 infrun_log_debug ("quietly stopped");
5825 stop_print_frame
= 1;
5830 /* This originates from attach_command(). We need to overwrite
5831 the stop_signal here, because some kernels don't ignore a
5832 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5833 See more comments in inferior.h. On the other hand, if we
5834 get a non-SIGSTOP, report it to the user - assume the backend
5835 will handle the SIGSTOP if it should show up later.
5837 Also consider that the attach is complete when we see a
5838 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5839 target extended-remote report it instead of a SIGSTOP
5840 (e.g. gdbserver). We already rely on SIGTRAP being our
5841 signal, so this is no exception.
5843 Also consider that the attach is complete when we see a
5844 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5845 the target to stop all threads of the inferior, in case the
5846 low level attach operation doesn't stop them implicitly. If
5847 they weren't stopped implicitly, then the stub will report a
5848 GDB_SIGNAL_0, meaning: stopped for no particular reason
5849 other than GDB's request. */
5850 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5851 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5852 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5853 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5855 stop_print_frame
= 1;
5857 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5861 /* See if something interesting happened to the non-current thread. If
5862 so, then switch to that thread. */
5863 if (ecs
->ptid
!= inferior_ptid
)
5865 infrun_log_debug ("context switch");
5867 context_switch (ecs
);
5869 if (deprecated_context_hook
)
5870 deprecated_context_hook (ecs
->event_thread
->global_num
);
5873 /* At this point, get hold of the now-current thread's frame. */
5874 frame
= get_current_frame ();
5875 gdbarch
= get_frame_arch (frame
);
5877 /* Pull the single step breakpoints out of the target. */
5878 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5880 struct regcache
*regcache
;
5883 regcache
= get_thread_regcache (ecs
->event_thread
);
5884 const address_space
*aspace
= regcache
->aspace ();
5886 pc
= regcache_read_pc (regcache
);
5888 /* However, before doing so, if this single-step breakpoint was
5889 actually for another thread, set this thread up for moving
5891 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5894 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5896 infrun_log_debug ("[%s] hit another thread's single-step "
5898 target_pid_to_str (ecs
->ptid
).c_str ());
5899 ecs
->hit_singlestep_breakpoint
= 1;
5904 infrun_log_debug ("[%s] hit its single-step breakpoint",
5905 target_pid_to_str (ecs
->ptid
).c_str ());
5908 delete_just_stopped_threads_single_step_breakpoints ();
5910 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5911 && ecs
->event_thread
->control
.trap_expected
5912 && ecs
->event_thread
->stepping_over_watchpoint
)
5913 stopped_by_watchpoint
= 0;
5915 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5917 /* If necessary, step over this watchpoint. We'll be back to display
5919 if (stopped_by_watchpoint
5920 && (target_have_steppable_watchpoint
5921 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5923 /* At this point, we are stopped at an instruction which has
5924 attempted to write to a piece of memory under control of
5925 a watchpoint. The instruction hasn't actually executed
5926 yet. If we were to evaluate the watchpoint expression
5927 now, we would get the old value, and therefore no change
5928 would seem to have occurred.
5930 In order to make watchpoints work `right', we really need
5931 to complete the memory write, and then evaluate the
5932 watchpoint expression. We do this by single-stepping the
5935 It may not be necessary to disable the watchpoint to step over
5936 it. For example, the PA can (with some kernel cooperation)
5937 single step over a watchpoint without disabling the watchpoint.
5939 It is far more common to need to disable a watchpoint to step
5940 the inferior over it. If we have non-steppable watchpoints,
5941 we must disable the current watchpoint; it's simplest to
5942 disable all watchpoints.
5944 Any breakpoint at PC must also be stepped over -- if there's
5945 one, it will have already triggered before the watchpoint
5946 triggered, and we either already reported it to the user, or
5947 it didn't cause a stop and we called keep_going. In either
5948 case, if there was a breakpoint at PC, we must be trying to
5950 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5955 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5956 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5957 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5958 ecs
->event_thread
->control
.stop_step
= 0;
5959 stop_print_frame
= 1;
5960 stopped_by_random_signal
= 0;
5961 bpstat stop_chain
= NULL
;
5963 /* Hide inlined functions starting here, unless we just performed stepi or
5964 nexti. After stepi and nexti, always show the innermost frame (not any
5965 inline function call sites). */
5966 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5968 const address_space
*aspace
5969 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5971 /* skip_inline_frames is expensive, so we avoid it if we can
5972 determine that the address is one where functions cannot have
5973 been inlined. This improves performance with inferiors that
5974 load a lot of shared libraries, because the solib event
5975 breakpoint is defined as the address of a function (i.e. not
5976 inline). Note that we have to check the previous PC as well
5977 as the current one to catch cases when we have just
5978 single-stepped off a breakpoint prior to reinstating it.
5979 Note that we're assuming that the code we single-step to is
5980 not inline, but that's not definitive: there's nothing
5981 preventing the event breakpoint function from containing
5982 inlined code, and the single-step ending up there. If the
5983 user had set a breakpoint on that inlined code, the missing
5984 skip_inline_frames call would break things. Fortunately
5985 that's an extremely unlikely scenario. */
5986 if (!pc_at_non_inline_function (aspace
,
5987 ecs
->event_thread
->suspend
.stop_pc
,
5989 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5990 && ecs
->event_thread
->control
.trap_expected
5991 && pc_at_non_inline_function (aspace
,
5992 ecs
->event_thread
->prev_pc
,
5995 stop_chain
= build_bpstat_chain (aspace
,
5996 ecs
->event_thread
->suspend
.stop_pc
,
5998 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6000 /* Re-fetch current thread's frame in case that invalidated
6002 frame
= get_current_frame ();
6003 gdbarch
= get_frame_arch (frame
);
6007 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6008 && ecs
->event_thread
->control
.trap_expected
6009 && gdbarch_single_step_through_delay_p (gdbarch
)
6010 && currently_stepping (ecs
->event_thread
))
6012 /* We're trying to step off a breakpoint. Turns out that we're
6013 also on an instruction that needs to be stepped multiple
6014 times before it's been fully executing. E.g., architectures
6015 with a delay slot. It needs to be stepped twice, once for
6016 the instruction and once for the delay slot. */
6017 int step_through_delay
6018 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6020 if (step_through_delay
)
6021 infrun_log_debug ("step through delay");
6023 if (ecs
->event_thread
->control
.step_range_end
== 0
6024 && step_through_delay
)
6026 /* The user issued a continue when stopped at a breakpoint.
6027 Set up for another trap and get out of here. */
6028 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6032 else if (step_through_delay
)
6034 /* The user issued a step when stopped at a breakpoint.
6035 Maybe we should stop, maybe we should not - the delay
6036 slot *might* correspond to a line of source. In any
6037 case, don't decide that here, just set
6038 ecs->stepping_over_breakpoint, making sure we
6039 single-step again before breakpoints are re-inserted. */
6040 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6044 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6045 handles this event. */
6046 ecs
->event_thread
->control
.stop_bpstat
6047 = bpstat_stop_status (get_current_regcache ()->aspace (),
6048 ecs
->event_thread
->suspend
.stop_pc
,
6049 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6051 /* Following in case break condition called a
6053 stop_print_frame
= 1;
6055 /* This is where we handle "moribund" watchpoints. Unlike
6056 software breakpoints traps, hardware watchpoint traps are
6057 always distinguishable from random traps. If no high-level
6058 watchpoint is associated with the reported stop data address
6059 anymore, then the bpstat does not explain the signal ---
6060 simply make sure to ignore it if `stopped_by_watchpoint' is
6063 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6064 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6066 && stopped_by_watchpoint
)
6068 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6072 /* NOTE: cagney/2003-03-29: These checks for a random signal
6073 at one stage in the past included checks for an inferior
6074 function call's call dummy's return breakpoint. The original
6075 comment, that went with the test, read:
6077 ``End of a stack dummy. Some systems (e.g. Sony news) give
6078 another signal besides SIGTRAP, so check here as well as
6081 If someone ever tries to get call dummys on a
6082 non-executable stack to work (where the target would stop
6083 with something like a SIGSEGV), then those tests might need
6084 to be re-instated. Given, however, that the tests were only
6085 enabled when momentary breakpoints were not being used, I
6086 suspect that it won't be the case.
6088 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6089 be necessary for call dummies on a non-executable stack on
6092 /* See if the breakpoints module can explain the signal. */
6094 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6095 ecs
->event_thread
->suspend
.stop_signal
);
6097 /* Maybe this was a trap for a software breakpoint that has since
6099 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6101 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6102 ecs
->event_thread
->suspend
.stop_pc
))
6104 struct regcache
*regcache
;
6107 /* Re-adjust PC to what the program would see if GDB was not
6109 regcache
= get_thread_regcache (ecs
->event_thread
);
6110 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6113 gdb::optional
<scoped_restore_tmpl
<int>>
6114 restore_operation_disable
;
6116 if (record_full_is_used ())
6117 restore_operation_disable
.emplace
6118 (record_full_gdb_operation_disable_set ());
6120 regcache_write_pc (regcache
,
6121 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6126 /* A delayed software breakpoint event. Ignore the trap. */
6127 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6132 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6133 has since been removed. */
6134 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6136 /* A delayed hardware breakpoint event. Ignore the trap. */
6137 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6142 /* If not, perhaps stepping/nexting can. */
6144 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6145 && currently_stepping (ecs
->event_thread
));
6147 /* Perhaps the thread hit a single-step breakpoint of _another_
6148 thread. Single-step breakpoints are transparent to the
6149 breakpoints module. */
6151 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6153 /* No? Perhaps we got a moribund watchpoint. */
6155 random_signal
= !stopped_by_watchpoint
;
6157 /* Always stop if the user explicitly requested this thread to
6159 if (ecs
->event_thread
->stop_requested
)
6162 infrun_log_debug ("user-requested stop");
6165 /* For the program's own signals, act according to
6166 the signal handling tables. */
6170 /* Signal not for debugging purposes. */
6171 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6172 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6174 infrun_log_debug ("random signal (%s)",
6175 gdb_signal_to_symbol_string (stop_signal
));
6177 stopped_by_random_signal
= 1;
6179 /* Always stop on signals if we're either just gaining control
6180 of the program, or the user explicitly requested this thread
6181 to remain stopped. */
6182 if (stop_soon
!= NO_STOP_QUIETLY
6183 || ecs
->event_thread
->stop_requested
6185 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6191 /* Notify observers the signal has "handle print" set. Note we
6192 returned early above if stopping; normal_stop handles the
6193 printing in that case. */
6194 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6196 /* The signal table tells us to print about this signal. */
6197 target_terminal::ours_for_output ();
6198 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6199 target_terminal::inferior ();
6202 /* Clear the signal if it should not be passed. */
6203 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6204 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6206 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6207 && ecs
->event_thread
->control
.trap_expected
6208 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6210 /* We were just starting a new sequence, attempting to
6211 single-step off of a breakpoint and expecting a SIGTRAP.
6212 Instead this signal arrives. This signal will take us out
6213 of the stepping range so GDB needs to remember to, when
6214 the signal handler returns, resume stepping off that
6216 /* To simplify things, "continue" is forced to use the same
6217 code paths as single-step - set a breakpoint at the
6218 signal return address and then, once hit, step off that
6220 infrun_log_debug ("signal arrived while stepping over breakpoint");
6222 insert_hp_step_resume_breakpoint_at_frame (frame
);
6223 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6224 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6225 ecs
->event_thread
->control
.trap_expected
= 0;
6227 /* If we were nexting/stepping some other thread, switch to
6228 it, so that we don't continue it, losing control. */
6229 if (!switch_back_to_stepped_thread (ecs
))
6234 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6235 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6237 || ecs
->event_thread
->control
.step_range_end
== 1)
6238 && frame_id_eq (get_stack_frame_id (frame
),
6239 ecs
->event_thread
->control
.step_stack_frame_id
)
6240 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6242 /* The inferior is about to take a signal that will take it
6243 out of the single step range. Set a breakpoint at the
6244 current PC (which is presumably where the signal handler
6245 will eventually return) and then allow the inferior to
6248 Note that this is only needed for a signal delivered
6249 while in the single-step range. Nested signals aren't a
6250 problem as they eventually all return. */
6251 infrun_log_debug ("signal may take us out of single-step range");
6253 clear_step_over_info ();
6254 insert_hp_step_resume_breakpoint_at_frame (frame
);
6255 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6256 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6257 ecs
->event_thread
->control
.trap_expected
= 0;
6262 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6263 when either there's a nested signal, or when there's a
6264 pending signal enabled just as the signal handler returns
6265 (leaving the inferior at the step-resume-breakpoint without
6266 actually executing it). Either way continue until the
6267 breakpoint is really hit. */
6269 if (!switch_back_to_stepped_thread (ecs
))
6271 infrun_log_debug ("random signal, keep going");
6278 process_event_stop_test (ecs
);
6281 /* Come here when we've got some debug event / signal we can explain
6282 (IOW, not a random signal), and test whether it should cause a
6283 stop, or whether we should resume the inferior (transparently).
6284 E.g., could be a breakpoint whose condition evaluates false; we
6285 could be still stepping within the line; etc. */
6288 process_event_stop_test (struct execution_control_state
*ecs
)
6290 struct symtab_and_line stop_pc_sal
;
6291 struct frame_info
*frame
;
6292 struct gdbarch
*gdbarch
;
6293 CORE_ADDR jmp_buf_pc
;
6294 struct bpstat_what what
;
6296 /* Handle cases caused by hitting a breakpoint. */
6298 frame
= get_current_frame ();
6299 gdbarch
= get_frame_arch (frame
);
6301 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6303 if (what
.call_dummy
)
6305 stop_stack_dummy
= what
.call_dummy
;
6308 /* A few breakpoint types have callbacks associated (e.g.,
6309 bp_jit_event). Run them now. */
6310 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6312 /* If we hit an internal event that triggers symbol changes, the
6313 current frame will be invalidated within bpstat_what (e.g., if we
6314 hit an internal solib event). Re-fetch it. */
6315 frame
= get_current_frame ();
6316 gdbarch
= get_frame_arch (frame
);
6318 switch (what
.main_action
)
6320 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6321 /* If we hit the breakpoint at longjmp while stepping, we
6322 install a momentary breakpoint at the target of the
6325 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6327 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6329 if (what
.is_longjmp
)
6331 struct value
*arg_value
;
6333 /* If we set the longjmp breakpoint via a SystemTap probe,
6334 then use it to extract the arguments. The destination PC
6335 is the third argument to the probe. */
6336 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6339 jmp_buf_pc
= value_as_address (arg_value
);
6340 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6342 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6343 || !gdbarch_get_longjmp_target (gdbarch
,
6344 frame
, &jmp_buf_pc
))
6346 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6347 "(!gdbarch_get_longjmp_target)");
6352 /* Insert a breakpoint at resume address. */
6353 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6356 check_exception_resume (ecs
, frame
);
6360 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6362 struct frame_info
*init_frame
;
6364 /* There are several cases to consider.
6366 1. The initiating frame no longer exists. In this case we
6367 must stop, because the exception or longjmp has gone too
6370 2. The initiating frame exists, and is the same as the
6371 current frame. We stop, because the exception or longjmp
6374 3. The initiating frame exists and is different from the
6375 current frame. This means the exception or longjmp has
6376 been caught beneath the initiating frame, so keep going.
6378 4. longjmp breakpoint has been placed just to protect
6379 against stale dummy frames and user is not interested in
6380 stopping around longjmps. */
6382 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6384 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6386 delete_exception_resume_breakpoint (ecs
->event_thread
);
6388 if (what
.is_longjmp
)
6390 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6392 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6400 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6404 struct frame_id current_id
6405 = get_frame_id (get_current_frame ());
6406 if (frame_id_eq (current_id
,
6407 ecs
->event_thread
->initiating_frame
))
6409 /* Case 2. Fall through. */
6419 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6421 delete_step_resume_breakpoint (ecs
->event_thread
);
6423 end_stepping_range (ecs
);
6427 case BPSTAT_WHAT_SINGLE
:
6428 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6429 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6430 /* Still need to check other stuff, at least the case where we
6431 are stepping and step out of the right range. */
6434 case BPSTAT_WHAT_STEP_RESUME
:
6435 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6437 delete_step_resume_breakpoint (ecs
->event_thread
);
6438 if (ecs
->event_thread
->control
.proceed_to_finish
6439 && execution_direction
== EXEC_REVERSE
)
6441 struct thread_info
*tp
= ecs
->event_thread
;
6443 /* We are finishing a function in reverse, and just hit the
6444 step-resume breakpoint at the start address of the
6445 function, and we're almost there -- just need to back up
6446 by one more single-step, which should take us back to the
6448 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6452 fill_in_stop_func (gdbarch
, ecs
);
6453 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6454 && execution_direction
== EXEC_REVERSE
)
6456 /* We are stepping over a function call in reverse, and just
6457 hit the step-resume breakpoint at the start address of
6458 the function. Go back to single-stepping, which should
6459 take us back to the function call. */
6460 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6466 case BPSTAT_WHAT_STOP_NOISY
:
6467 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6468 stop_print_frame
= 1;
6470 /* Assume the thread stopped for a breapoint. We'll still check
6471 whether a/the breakpoint is there when the thread is next
6473 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6478 case BPSTAT_WHAT_STOP_SILENT
:
6479 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6480 stop_print_frame
= 0;
6482 /* Assume the thread stopped for a breapoint. We'll still check
6483 whether a/the breakpoint is there when the thread is next
6485 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6489 case BPSTAT_WHAT_HP_STEP_RESUME
:
6490 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6492 delete_step_resume_breakpoint (ecs
->event_thread
);
6493 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6495 /* Back when the step-resume breakpoint was inserted, we
6496 were trying to single-step off a breakpoint. Go back to
6498 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6499 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6505 case BPSTAT_WHAT_KEEP_CHECKING
:
6509 /* If we stepped a permanent breakpoint and we had a high priority
6510 step-resume breakpoint for the address we stepped, but we didn't
6511 hit it, then we must have stepped into the signal handler. The
6512 step-resume was only necessary to catch the case of _not_
6513 stepping into the handler, so delete it, and fall through to
6514 checking whether the step finished. */
6515 if (ecs
->event_thread
->stepped_breakpoint
)
6517 struct breakpoint
*sr_bp
6518 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6521 && sr_bp
->loc
->permanent
6522 && sr_bp
->type
== bp_hp_step_resume
6523 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6525 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6526 delete_step_resume_breakpoint (ecs
->event_thread
);
6527 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6531 /* We come here if we hit a breakpoint but should not stop for it.
6532 Possibly we also were stepping and should stop for that. So fall
6533 through and test for stepping. But, if not stepping, do not
6536 /* In all-stop mode, if we're currently stepping but have stopped in
6537 some other thread, we need to switch back to the stepped thread. */
6538 if (switch_back_to_stepped_thread (ecs
))
6541 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6543 infrun_log_debug ("step-resume breakpoint is inserted");
6545 /* Having a step-resume breakpoint overrides anything
6546 else having to do with stepping commands until
6547 that breakpoint is reached. */
6552 if (ecs
->event_thread
->control
.step_range_end
== 0)
6554 infrun_log_debug ("no stepping, continue");
6555 /* Likewise if we aren't even stepping. */
6560 /* Re-fetch current thread's frame in case the code above caused
6561 the frame cache to be re-initialized, making our FRAME variable
6562 a dangling pointer. */
6563 frame
= get_current_frame ();
6564 gdbarch
= get_frame_arch (frame
);
6565 fill_in_stop_func (gdbarch
, ecs
);
6567 /* If stepping through a line, keep going if still within it.
6569 Note that step_range_end is the address of the first instruction
6570 beyond the step range, and NOT the address of the last instruction
6573 Note also that during reverse execution, we may be stepping
6574 through a function epilogue and therefore must detect when
6575 the current-frame changes in the middle of a line. */
6577 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6579 && (execution_direction
!= EXEC_REVERSE
6580 || frame_id_eq (get_frame_id (frame
),
6581 ecs
->event_thread
->control
.step_frame_id
)))
6584 ("stepping inside range [%s-%s]",
6585 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6586 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6588 /* Tentatively re-enable range stepping; `resume' disables it if
6589 necessary (e.g., if we're stepping over a breakpoint or we
6590 have software watchpoints). */
6591 ecs
->event_thread
->control
.may_range_step
= 1;
6593 /* When stepping backward, stop at beginning of line range
6594 (unless it's the function entry point, in which case
6595 keep going back to the call point). */
6596 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6597 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6598 && stop_pc
!= ecs
->stop_func_start
6599 && execution_direction
== EXEC_REVERSE
)
6600 end_stepping_range (ecs
);
6607 /* We stepped out of the stepping range. */
6609 /* If we are stepping at the source level and entered the runtime
6610 loader dynamic symbol resolution code...
6612 EXEC_FORWARD: we keep on single stepping until we exit the run
6613 time loader code and reach the callee's address.
6615 EXEC_REVERSE: we've already executed the callee (backward), and
6616 the runtime loader code is handled just like any other
6617 undebuggable function call. Now we need only keep stepping
6618 backward through the trampoline code, and that's handled further
6619 down, so there is nothing for us to do here. */
6621 if (execution_direction
!= EXEC_REVERSE
6622 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6623 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6625 CORE_ADDR pc_after_resolver
=
6626 gdbarch_skip_solib_resolver (gdbarch
,
6627 ecs
->event_thread
->suspend
.stop_pc
);
6629 infrun_log_debug ("stepped into dynsym resolve code");
6631 if (pc_after_resolver
)
6633 /* Set up a step-resume breakpoint at the address
6634 indicated by SKIP_SOLIB_RESOLVER. */
6635 symtab_and_line sr_sal
;
6636 sr_sal
.pc
= pc_after_resolver
;
6637 sr_sal
.pspace
= get_frame_program_space (frame
);
6639 insert_step_resume_breakpoint_at_sal (gdbarch
,
6640 sr_sal
, null_frame_id
);
6647 /* Step through an indirect branch thunk. */
6648 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6649 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6650 ecs
->event_thread
->suspend
.stop_pc
))
6652 infrun_log_debug ("stepped into indirect branch thunk");
6657 if (ecs
->event_thread
->control
.step_range_end
!= 1
6658 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6659 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6660 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6662 infrun_log_debug ("stepped into signal trampoline");
6663 /* The inferior, while doing a "step" or "next", has ended up in
6664 a signal trampoline (either by a signal being delivered or by
6665 the signal handler returning). Just single-step until the
6666 inferior leaves the trampoline (either by calling the handler
6672 /* If we're in the return path from a shared library trampoline,
6673 we want to proceed through the trampoline when stepping. */
6674 /* macro/2012-04-25: This needs to come before the subroutine
6675 call check below as on some targets return trampolines look
6676 like subroutine calls (MIPS16 return thunks). */
6677 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6678 ecs
->event_thread
->suspend
.stop_pc
,
6679 ecs
->stop_func_name
)
6680 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6682 /* Determine where this trampoline returns. */
6683 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6684 CORE_ADDR real_stop_pc
6685 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6687 infrun_log_debug ("stepped into solib return tramp");
6689 /* Only proceed through if we know where it's going. */
6692 /* And put the step-breakpoint there and go until there. */
6693 symtab_and_line sr_sal
;
6694 sr_sal
.pc
= real_stop_pc
;
6695 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6696 sr_sal
.pspace
= get_frame_program_space (frame
);
6698 /* Do not specify what the fp should be when we stop since
6699 on some machines the prologue is where the new fp value
6701 insert_step_resume_breakpoint_at_sal (gdbarch
,
6702 sr_sal
, null_frame_id
);
6704 /* Restart without fiddling with the step ranges or
6711 /* Check for subroutine calls. The check for the current frame
6712 equalling the step ID is not necessary - the check of the
6713 previous frame's ID is sufficient - but it is a common case and
6714 cheaper than checking the previous frame's ID.
6716 NOTE: frame_id_eq will never report two invalid frame IDs as
6717 being equal, so to get into this block, both the current and
6718 previous frame must have valid frame IDs. */
6719 /* The outer_frame_id check is a heuristic to detect stepping
6720 through startup code. If we step over an instruction which
6721 sets the stack pointer from an invalid value to a valid value,
6722 we may detect that as a subroutine call from the mythical
6723 "outermost" function. This could be fixed by marking
6724 outermost frames as !stack_p,code_p,special_p. Then the
6725 initial outermost frame, before sp was valid, would
6726 have code_addr == &_start. See the comment in frame_id_eq
6728 if (!frame_id_eq (get_stack_frame_id (frame
),
6729 ecs
->event_thread
->control
.step_stack_frame_id
)
6730 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6731 ecs
->event_thread
->control
.step_stack_frame_id
)
6732 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6734 || (ecs
->event_thread
->control
.step_start_function
6735 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6737 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6738 CORE_ADDR real_stop_pc
;
6740 infrun_log_debug ("stepped into subroutine");
6742 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6744 /* I presume that step_over_calls is only 0 when we're
6745 supposed to be stepping at the assembly language level
6746 ("stepi"). Just stop. */
6747 /* And this works the same backward as frontward. MVS */
6748 end_stepping_range (ecs
);
6752 /* Reverse stepping through solib trampolines. */
6754 if (execution_direction
== EXEC_REVERSE
6755 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6756 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6757 || (ecs
->stop_func_start
== 0
6758 && in_solib_dynsym_resolve_code (stop_pc
))))
6760 /* Any solib trampoline code can be handled in reverse
6761 by simply continuing to single-step. We have already
6762 executed the solib function (backwards), and a few
6763 steps will take us back through the trampoline to the
6769 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6771 /* We're doing a "next".
6773 Normal (forward) execution: set a breakpoint at the
6774 callee's return address (the address at which the caller
6777 Reverse (backward) execution. set the step-resume
6778 breakpoint at the start of the function that we just
6779 stepped into (backwards), and continue to there. When we
6780 get there, we'll need to single-step back to the caller. */
6782 if (execution_direction
== EXEC_REVERSE
)
6784 /* If we're already at the start of the function, we've either
6785 just stepped backward into a single instruction function,
6786 or stepped back out of a signal handler to the first instruction
6787 of the function. Just keep going, which will single-step back
6789 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6791 /* Normal function call return (static or dynamic). */
6792 symtab_and_line sr_sal
;
6793 sr_sal
.pc
= ecs
->stop_func_start
;
6794 sr_sal
.pspace
= get_frame_program_space (frame
);
6795 insert_step_resume_breakpoint_at_sal (gdbarch
,
6796 sr_sal
, null_frame_id
);
6800 insert_step_resume_breakpoint_at_caller (frame
);
6806 /* If we are in a function call trampoline (a stub between the
6807 calling routine and the real function), locate the real
6808 function. That's what tells us (a) whether we want to step
6809 into it at all, and (b) what prologue we want to run to the
6810 end of, if we do step into it. */
6811 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6812 if (real_stop_pc
== 0)
6813 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6814 if (real_stop_pc
!= 0)
6815 ecs
->stop_func_start
= real_stop_pc
;
6817 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6819 symtab_and_line sr_sal
;
6820 sr_sal
.pc
= ecs
->stop_func_start
;
6821 sr_sal
.pspace
= get_frame_program_space (frame
);
6823 insert_step_resume_breakpoint_at_sal (gdbarch
,
6824 sr_sal
, null_frame_id
);
6829 /* If we have line number information for the function we are
6830 thinking of stepping into and the function isn't on the skip
6833 If there are several symtabs at that PC (e.g. with include
6834 files), just want to know whether *any* of them have line
6835 numbers. find_pc_line handles this. */
6837 struct symtab_and_line tmp_sal
;
6839 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6840 if (tmp_sal
.line
!= 0
6841 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6843 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6845 if (execution_direction
== EXEC_REVERSE
)
6846 handle_step_into_function_backward (gdbarch
, ecs
);
6848 handle_step_into_function (gdbarch
, ecs
);
6853 /* If we have no line number and the step-stop-if-no-debug is
6854 set, we stop the step so that the user has a chance to switch
6855 in assembly mode. */
6856 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6857 && step_stop_if_no_debug
)
6859 end_stepping_range (ecs
);
6863 if (execution_direction
== EXEC_REVERSE
)
6865 /* If we're already at the start of the function, we've either just
6866 stepped backward into a single instruction function without line
6867 number info, or stepped back out of a signal handler to the first
6868 instruction of the function without line number info. Just keep
6869 going, which will single-step back to the caller. */
6870 if (ecs
->stop_func_start
!= stop_pc
)
6872 /* Set a breakpoint at callee's start address.
6873 From there we can step once and be back in the caller. */
6874 symtab_and_line sr_sal
;
6875 sr_sal
.pc
= ecs
->stop_func_start
;
6876 sr_sal
.pspace
= get_frame_program_space (frame
);
6877 insert_step_resume_breakpoint_at_sal (gdbarch
,
6878 sr_sal
, null_frame_id
);
6882 /* Set a breakpoint at callee's return address (the address
6883 at which the caller will resume). */
6884 insert_step_resume_breakpoint_at_caller (frame
);
6890 /* Reverse stepping through solib trampolines. */
6892 if (execution_direction
== EXEC_REVERSE
6893 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6895 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6897 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6898 || (ecs
->stop_func_start
== 0
6899 && in_solib_dynsym_resolve_code (stop_pc
)))
6901 /* Any solib trampoline code can be handled in reverse
6902 by simply continuing to single-step. We have already
6903 executed the solib function (backwards), and a few
6904 steps will take us back through the trampoline to the
6909 else if (in_solib_dynsym_resolve_code (stop_pc
))
6911 /* Stepped backward into the solib dynsym resolver.
6912 Set a breakpoint at its start and continue, then
6913 one more step will take us out. */
6914 symtab_and_line sr_sal
;
6915 sr_sal
.pc
= ecs
->stop_func_start
;
6916 sr_sal
.pspace
= get_frame_program_space (frame
);
6917 insert_step_resume_breakpoint_at_sal (gdbarch
,
6918 sr_sal
, null_frame_id
);
6924 /* This always returns the sal for the inner-most frame when we are in a
6925 stack of inlined frames, even if GDB actually believes that it is in a
6926 more outer frame. This is checked for below by calls to
6927 inline_skipped_frames. */
6928 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6930 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6931 the trampoline processing logic, however, there are some trampolines
6932 that have no names, so we should do trampoline handling first. */
6933 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6934 && ecs
->stop_func_name
== NULL
6935 && stop_pc_sal
.line
== 0)
6937 infrun_log_debug ("stepped into undebuggable function");
6939 /* The inferior just stepped into, or returned to, an
6940 undebuggable function (where there is no debugging information
6941 and no line number corresponding to the address where the
6942 inferior stopped). Since we want to skip this kind of code,
6943 we keep going until the inferior returns from this
6944 function - unless the user has asked us not to (via
6945 set step-mode) or we no longer know how to get back
6946 to the call site. */
6947 if (step_stop_if_no_debug
6948 || !frame_id_p (frame_unwind_caller_id (frame
)))
6950 /* If we have no line number and the step-stop-if-no-debug
6951 is set, we stop the step so that the user has a chance to
6952 switch in assembly mode. */
6953 end_stepping_range (ecs
);
6958 /* Set a breakpoint at callee's return address (the address
6959 at which the caller will resume). */
6960 insert_step_resume_breakpoint_at_caller (frame
);
6966 if (ecs
->event_thread
->control
.step_range_end
== 1)
6968 /* It is stepi or nexti. We always want to stop stepping after
6970 infrun_log_debug ("stepi/nexti");
6971 end_stepping_range (ecs
);
6975 if (stop_pc_sal
.line
== 0)
6977 /* We have no line number information. That means to stop
6978 stepping (does this always happen right after one instruction,
6979 when we do "s" in a function with no line numbers,
6980 or can this happen as a result of a return or longjmp?). */
6981 infrun_log_debug ("line number info");
6982 end_stepping_range (ecs
);
6986 /* Look for "calls" to inlined functions, part one. If the inline
6987 frame machinery detected some skipped call sites, we have entered
6988 a new inline function. */
6990 if (frame_id_eq (get_frame_id (get_current_frame ()),
6991 ecs
->event_thread
->control
.step_frame_id
)
6992 && inline_skipped_frames (ecs
->event_thread
))
6994 infrun_log_debug ("stepped into inlined function");
6996 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6998 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7000 /* For "step", we're going to stop. But if the call site
7001 for this inlined function is on the same source line as
7002 we were previously stepping, go down into the function
7003 first. Otherwise stop at the call site. */
7005 if (call_sal
.line
== ecs
->event_thread
->current_line
7006 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7008 step_into_inline_frame (ecs
->event_thread
);
7009 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7016 end_stepping_range (ecs
);
7021 /* For "next", we should stop at the call site if it is on a
7022 different source line. Otherwise continue through the
7023 inlined function. */
7024 if (call_sal
.line
== ecs
->event_thread
->current_line
7025 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7028 end_stepping_range (ecs
);
7033 /* Look for "calls" to inlined functions, part two. If we are still
7034 in the same real function we were stepping through, but we have
7035 to go further up to find the exact frame ID, we are stepping
7036 through a more inlined call beyond its call site. */
7038 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7039 && !frame_id_eq (get_frame_id (get_current_frame ()),
7040 ecs
->event_thread
->control
.step_frame_id
)
7041 && stepped_in_from (get_current_frame (),
7042 ecs
->event_thread
->control
.step_frame_id
))
7044 infrun_log_debug ("stepping through inlined function");
7046 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7047 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7050 end_stepping_range (ecs
);
7054 bool refresh_step_info
= true;
7055 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7056 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7057 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7059 if (stop_pc_sal
.is_stmt
)
7061 /* We are at the start of a different line. So stop. Note that
7062 we don't stop if we step into the middle of a different line.
7063 That is said to make things like for (;;) statements work
7065 infrun_log_debug ("infrun: stepped to a different line\n");
7066 end_stepping_range (ecs
);
7069 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7070 ecs
->event_thread
->control
.step_frame_id
))
7072 /* We are at the start of a different line, however, this line is
7073 not marked as a statement, and we have not changed frame. We
7074 ignore this line table entry, and continue stepping forward,
7075 looking for a better place to stop. */
7076 refresh_step_info
= false;
7077 infrun_log_debug ("infrun: stepped to a different line, but "
7078 "it's not the start of a statement\n");
7082 /* We aren't done stepping.
7084 Optimize by setting the stepping range to the line.
7085 (We might not be in the original line, but if we entered a
7086 new line in mid-statement, we continue stepping. This makes
7087 things like for(;;) statements work better.)
7089 If we entered a SAL that indicates a non-statement line table entry,
7090 then we update the stepping range, but we don't update the step info,
7091 which includes things like the line number we are stepping away from.
7092 This means we will stop when we find a line table entry that is marked
7093 as is-statement, even if it matches the non-statement one we just
7096 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7097 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7098 ecs
->event_thread
->control
.may_range_step
= 1;
7099 if (refresh_step_info
)
7100 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7102 infrun_log_debug ("keep going");
7106 /* In all-stop mode, if we're currently stepping but have stopped in
7107 some other thread, we may need to switch back to the stepped
7108 thread. Returns true we set the inferior running, false if we left
7109 it stopped (and the event needs further processing). */
7112 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7114 if (!target_is_non_stop_p ())
7116 struct thread_info
*stepping_thread
;
7118 /* If any thread is blocked on some internal breakpoint, and we
7119 simply need to step over that breakpoint to get it going
7120 again, do that first. */
7122 /* However, if we see an event for the stepping thread, then we
7123 know all other threads have been moved past their breakpoints
7124 already. Let the caller check whether the step is finished,
7125 etc., before deciding to move it past a breakpoint. */
7126 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7129 /* Check if the current thread is blocked on an incomplete
7130 step-over, interrupted by a random signal. */
7131 if (ecs
->event_thread
->control
.trap_expected
7132 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7134 infrun_log_debug ("need to finish step-over of [%s]",
7135 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7140 /* Check if the current thread is blocked by a single-step
7141 breakpoint of another thread. */
7142 if (ecs
->hit_singlestep_breakpoint
)
7144 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7145 target_pid_to_str (ecs
->ptid
).c_str ());
7150 /* If this thread needs yet another step-over (e.g., stepping
7151 through a delay slot), do it first before moving on to
7153 if (thread_still_needs_step_over (ecs
->event_thread
))
7156 ("thread [%s] still needs step-over",
7157 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7162 /* If scheduler locking applies even if not stepping, there's no
7163 need to walk over threads. Above we've checked whether the
7164 current thread is stepping. If some other thread not the
7165 event thread is stepping, then it must be that scheduler
7166 locking is not in effect. */
7167 if (schedlock_applies (ecs
->event_thread
))
7170 /* Otherwise, we no longer expect a trap in the current thread.
7171 Clear the trap_expected flag before switching back -- this is
7172 what keep_going does as well, if we call it. */
7173 ecs
->event_thread
->control
.trap_expected
= 0;
7175 /* Likewise, clear the signal if it should not be passed. */
7176 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7177 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7179 /* Do all pending step-overs before actually proceeding with
7181 if (start_step_over ())
7183 prepare_to_wait (ecs
);
7187 /* Look for the stepping/nexting thread. */
7188 stepping_thread
= NULL
;
7190 for (thread_info
*tp
: all_non_exited_threads ())
7192 switch_to_thread_no_regs (tp
);
7194 /* Ignore threads of processes the caller is not
7197 && (tp
->inf
->process_target () != ecs
->target
7198 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7201 /* When stepping over a breakpoint, we lock all threads
7202 except the one that needs to move past the breakpoint.
7203 If a non-event thread has this set, the "incomplete
7204 step-over" check above should have caught it earlier. */
7205 if (tp
->control
.trap_expected
)
7207 internal_error (__FILE__
, __LINE__
,
7208 "[%s] has inconsistent state: "
7209 "trap_expected=%d\n",
7210 target_pid_to_str (tp
->ptid
).c_str (),
7211 tp
->control
.trap_expected
);
7214 /* Did we find the stepping thread? */
7215 if (tp
->control
.step_range_end
)
7217 /* Yep. There should only one though. */
7218 gdb_assert (stepping_thread
== NULL
);
7220 /* The event thread is handled at the top, before we
7222 gdb_assert (tp
!= ecs
->event_thread
);
7224 /* If some thread other than the event thread is
7225 stepping, then scheduler locking can't be in effect,
7226 otherwise we wouldn't have resumed the current event
7227 thread in the first place. */
7228 gdb_assert (!schedlock_applies (tp
));
7230 stepping_thread
= tp
;
7234 if (stepping_thread
!= NULL
)
7236 infrun_log_debug ("switching back to stepped thread");
7238 if (keep_going_stepped_thread (stepping_thread
))
7240 prepare_to_wait (ecs
);
7245 switch_to_thread (ecs
->event_thread
);
7251 /* Set a previously stepped thread back to stepping. Returns true on
7252 success, false if the resume is not possible (e.g., the thread
7256 keep_going_stepped_thread (struct thread_info
*tp
)
7258 struct frame_info
*frame
;
7259 struct execution_control_state ecss
;
7260 struct execution_control_state
*ecs
= &ecss
;
7262 /* If the stepping thread exited, then don't try to switch back and
7263 resume it, which could fail in several different ways depending
7264 on the target. Instead, just keep going.
7266 We can find a stepping dead thread in the thread list in two
7269 - The target supports thread exit events, and when the target
7270 tries to delete the thread from the thread list, inferior_ptid
7271 pointed at the exiting thread. In such case, calling
7272 delete_thread does not really remove the thread from the list;
7273 instead, the thread is left listed, with 'exited' state.
7275 - The target's debug interface does not support thread exit
7276 events, and so we have no idea whatsoever if the previously
7277 stepping thread is still alive. For that reason, we need to
7278 synchronously query the target now. */
7280 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7282 infrun_log_debug ("not resuming previously stepped thread, it has "
7289 infrun_log_debug ("resuming previously stepped thread");
7291 reset_ecs (ecs
, tp
);
7292 switch_to_thread (tp
);
7294 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7295 frame
= get_current_frame ();
7297 /* If the PC of the thread we were trying to single-step has
7298 changed, then that thread has trapped or been signaled, but the
7299 event has not been reported to GDB yet. Re-poll the target
7300 looking for this particular thread's event (i.e. temporarily
7301 enable schedlock) by:
7303 - setting a break at the current PC
7304 - resuming that particular thread, only (by setting trap
7307 This prevents us continuously moving the single-step breakpoint
7308 forward, one instruction at a time, overstepping. */
7310 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7314 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7315 paddress (target_gdbarch (), tp
->prev_pc
),
7316 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7318 /* Clear the info of the previous step-over, as it's no longer
7319 valid (if the thread was trying to step over a breakpoint, it
7320 has already succeeded). It's what keep_going would do too,
7321 if we called it. Do this before trying to insert the sss
7322 breakpoint, otherwise if we were previously trying to step
7323 over this exact address in another thread, the breakpoint is
7325 clear_step_over_info ();
7326 tp
->control
.trap_expected
= 0;
7328 insert_single_step_breakpoint (get_frame_arch (frame
),
7329 get_frame_address_space (frame
),
7330 tp
->suspend
.stop_pc
);
7333 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7334 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7338 infrun_log_debug ("expected thread still hasn't advanced");
7340 keep_going_pass_signal (ecs
);
7345 /* Is thread TP in the middle of (software or hardware)
7346 single-stepping? (Note the result of this function must never be
7347 passed directly as target_resume's STEP parameter.) */
7350 currently_stepping (struct thread_info
*tp
)
7352 return ((tp
->control
.step_range_end
7353 && tp
->control
.step_resume_breakpoint
== NULL
)
7354 || tp
->control
.trap_expected
7355 || tp
->stepped_breakpoint
7356 || bpstat_should_step ());
7359 /* Inferior has stepped into a subroutine call with source code that
7360 we should not step over. Do step to the first line of code in
7364 handle_step_into_function (struct gdbarch
*gdbarch
,
7365 struct execution_control_state
*ecs
)
7367 fill_in_stop_func (gdbarch
, ecs
);
7369 compunit_symtab
*cust
7370 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7371 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7372 ecs
->stop_func_start
7373 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7375 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7376 /* Use the step_resume_break to step until the end of the prologue,
7377 even if that involves jumps (as it seems to on the vax under
7379 /* If the prologue ends in the middle of a source line, continue to
7380 the end of that source line (if it is still within the function).
7381 Otherwise, just go to end of prologue. */
7382 if (stop_func_sal
.end
7383 && stop_func_sal
.pc
!= ecs
->stop_func_start
7384 && stop_func_sal
.end
< ecs
->stop_func_end
)
7385 ecs
->stop_func_start
= stop_func_sal
.end
;
7387 /* Architectures which require breakpoint adjustment might not be able
7388 to place a breakpoint at the computed address. If so, the test
7389 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7390 ecs->stop_func_start to an address at which a breakpoint may be
7391 legitimately placed.
7393 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7394 made, GDB will enter an infinite loop when stepping through
7395 optimized code consisting of VLIW instructions which contain
7396 subinstructions corresponding to different source lines. On
7397 FR-V, it's not permitted to place a breakpoint on any but the
7398 first subinstruction of a VLIW instruction. When a breakpoint is
7399 set, GDB will adjust the breakpoint address to the beginning of
7400 the VLIW instruction. Thus, we need to make the corresponding
7401 adjustment here when computing the stop address. */
7403 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7405 ecs
->stop_func_start
7406 = gdbarch_adjust_breakpoint_address (gdbarch
,
7407 ecs
->stop_func_start
);
7410 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7412 /* We are already there: stop now. */
7413 end_stepping_range (ecs
);
7418 /* Put the step-breakpoint there and go until there. */
7419 symtab_and_line sr_sal
;
7420 sr_sal
.pc
= ecs
->stop_func_start
;
7421 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7422 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7424 /* Do not specify what the fp should be when we stop since on
7425 some machines the prologue is where the new fp value is
7427 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7429 /* And make sure stepping stops right away then. */
7430 ecs
->event_thread
->control
.step_range_end
7431 = ecs
->event_thread
->control
.step_range_start
;
7436 /* Inferior has stepped backward into a subroutine call with source
7437 code that we should not step over. Do step to the beginning of the
7438 last line of code in it. */
7441 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7442 struct execution_control_state
*ecs
)
7444 struct compunit_symtab
*cust
;
7445 struct symtab_and_line stop_func_sal
;
7447 fill_in_stop_func (gdbarch
, ecs
);
7449 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7450 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7451 ecs
->stop_func_start
7452 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7454 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7456 /* OK, we're just going to keep stepping here. */
7457 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7459 /* We're there already. Just stop stepping now. */
7460 end_stepping_range (ecs
);
7464 /* Else just reset the step range and keep going.
7465 No step-resume breakpoint, they don't work for
7466 epilogues, which can have multiple entry paths. */
7467 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7468 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7474 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7475 This is used to both functions and to skip over code. */
7478 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7479 struct symtab_and_line sr_sal
,
7480 struct frame_id sr_id
,
7481 enum bptype sr_type
)
7483 /* There should never be more than one step-resume or longjmp-resume
7484 breakpoint per thread, so we should never be setting a new
7485 step_resume_breakpoint when one is already active. */
7486 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7487 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7489 infrun_log_debug ("inserting step-resume breakpoint at %s",
7490 paddress (gdbarch
, sr_sal
.pc
));
7492 inferior_thread ()->control
.step_resume_breakpoint
7493 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7497 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7498 struct symtab_and_line sr_sal
,
7499 struct frame_id sr_id
)
7501 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7506 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7507 This is used to skip a potential signal handler.
7509 This is called with the interrupted function's frame. The signal
7510 handler, when it returns, will resume the interrupted function at
7514 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7516 gdb_assert (return_frame
!= NULL
);
7518 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7520 symtab_and_line sr_sal
;
7521 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7522 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7523 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7525 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7526 get_stack_frame_id (return_frame
),
7530 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7531 is used to skip a function after stepping into it (for "next" or if
7532 the called function has no debugging information).
7534 The current function has almost always been reached by single
7535 stepping a call or return instruction. NEXT_FRAME belongs to the
7536 current function, and the breakpoint will be set at the caller's
7539 This is a separate function rather than reusing
7540 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7541 get_prev_frame, which may stop prematurely (see the implementation
7542 of frame_unwind_caller_id for an example). */
7545 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7547 /* We shouldn't have gotten here if we don't know where the call site
7549 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7551 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7553 symtab_and_line sr_sal
;
7554 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7555 frame_unwind_caller_pc (next_frame
));
7556 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7557 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7559 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7560 frame_unwind_caller_id (next_frame
));
7563 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7564 new breakpoint at the target of a jmp_buf. The handling of
7565 longjmp-resume uses the same mechanisms used for handling
7566 "step-resume" breakpoints. */
7569 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7571 /* There should never be more than one longjmp-resume breakpoint per
7572 thread, so we should never be setting a new
7573 longjmp_resume_breakpoint when one is already active. */
7574 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7576 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7577 paddress (gdbarch
, pc
));
7579 inferior_thread ()->control
.exception_resume_breakpoint
=
7580 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7583 /* Insert an exception resume breakpoint. TP is the thread throwing
7584 the exception. The block B is the block of the unwinder debug hook
7585 function. FRAME is the frame corresponding to the call to this
7586 function. SYM is the symbol of the function argument holding the
7587 target PC of the exception. */
7590 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7591 const struct block
*b
,
7592 struct frame_info
*frame
,
7597 struct block_symbol vsym
;
7598 struct value
*value
;
7600 struct breakpoint
*bp
;
7602 vsym
= lookup_symbol_search_name (sym
->search_name (),
7604 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7605 /* If the value was optimized out, revert to the old behavior. */
7606 if (! value_optimized_out (value
))
7608 handler
= value_as_address (value
);
7610 infrun_log_debug ("exception resume at %lx",
7611 (unsigned long) handler
);
7613 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7615 bp_exception_resume
).release ();
7617 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7620 bp
->thread
= tp
->global_num
;
7621 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7624 catch (const gdb_exception_error
&e
)
7626 /* We want to ignore errors here. */
7630 /* A helper for check_exception_resume that sets an
7631 exception-breakpoint based on a SystemTap probe. */
7634 insert_exception_resume_from_probe (struct thread_info
*tp
,
7635 const struct bound_probe
*probe
,
7636 struct frame_info
*frame
)
7638 struct value
*arg_value
;
7640 struct breakpoint
*bp
;
7642 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7646 handler
= value_as_address (arg_value
);
7648 infrun_log_debug ("exception resume at %s",
7649 paddress (probe
->objfile
->arch (), handler
));
7651 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7652 handler
, bp_exception_resume
).release ();
7653 bp
->thread
= tp
->global_num
;
7654 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7657 /* This is called when an exception has been intercepted. Check to
7658 see whether the exception's destination is of interest, and if so,
7659 set an exception resume breakpoint there. */
7662 check_exception_resume (struct execution_control_state
*ecs
,
7663 struct frame_info
*frame
)
7665 struct bound_probe probe
;
7666 struct symbol
*func
;
7668 /* First see if this exception unwinding breakpoint was set via a
7669 SystemTap probe point. If so, the probe has two arguments: the
7670 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7671 set a breakpoint there. */
7672 probe
= find_probe_by_pc (get_frame_pc (frame
));
7675 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7679 func
= get_frame_function (frame
);
7685 const struct block
*b
;
7686 struct block_iterator iter
;
7690 /* The exception breakpoint is a thread-specific breakpoint on
7691 the unwinder's debug hook, declared as:
7693 void _Unwind_DebugHook (void *cfa, void *handler);
7695 The CFA argument indicates the frame to which control is
7696 about to be transferred. HANDLER is the destination PC.
7698 We ignore the CFA and set a temporary breakpoint at HANDLER.
7699 This is not extremely efficient but it avoids issues in gdb
7700 with computing the DWARF CFA, and it also works even in weird
7701 cases such as throwing an exception from inside a signal
7704 b
= SYMBOL_BLOCK_VALUE (func
);
7705 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7707 if (!SYMBOL_IS_ARGUMENT (sym
))
7714 insert_exception_resume_breakpoint (ecs
->event_thread
,
7720 catch (const gdb_exception_error
&e
)
7726 stop_waiting (struct execution_control_state
*ecs
)
7728 infrun_log_debug ("stop_waiting");
7730 /* Let callers know we don't want to wait for the inferior anymore. */
7731 ecs
->wait_some_more
= 0;
7733 /* If all-stop, but there exists a non-stop target, stop all
7734 threads now that we're presenting the stop to the user. */
7735 if (!non_stop
&& exists_non_stop_target ())
7736 stop_all_threads ();
7739 /* Like keep_going, but passes the signal to the inferior, even if the
7740 signal is set to nopass. */
7743 keep_going_pass_signal (struct execution_control_state
*ecs
)
7745 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7746 gdb_assert (!ecs
->event_thread
->resumed
);
7748 /* Save the pc before execution, to compare with pc after stop. */
7749 ecs
->event_thread
->prev_pc
7750 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7752 if (ecs
->event_thread
->control
.trap_expected
)
7754 struct thread_info
*tp
= ecs
->event_thread
;
7756 infrun_log_debug ("%s has trap_expected set, "
7757 "resuming to collect trap",
7758 target_pid_to_str (tp
->ptid
).c_str ());
7760 /* We haven't yet gotten our trap, and either: intercepted a
7761 non-signal event (e.g., a fork); or took a signal which we
7762 are supposed to pass through to the inferior. Simply
7764 resume (ecs
->event_thread
->suspend
.stop_signal
);
7766 else if (step_over_info_valid_p ())
7768 /* Another thread is stepping over a breakpoint in-line. If
7769 this thread needs a step-over too, queue the request. In
7770 either case, this resume must be deferred for later. */
7771 struct thread_info
*tp
= ecs
->event_thread
;
7773 if (ecs
->hit_singlestep_breakpoint
7774 || thread_still_needs_step_over (tp
))
7776 infrun_log_debug ("step-over already in progress: "
7777 "step-over for %s deferred",
7778 target_pid_to_str (tp
->ptid
).c_str ());
7779 global_thread_step_over_chain_enqueue (tp
);
7783 infrun_log_debug ("step-over in progress: resume of %s deferred",
7784 target_pid_to_str (tp
->ptid
).c_str ());
7789 struct regcache
*regcache
= get_current_regcache ();
7792 step_over_what step_what
;
7794 /* Either the trap was not expected, but we are continuing
7795 anyway (if we got a signal, the user asked it be passed to
7798 We got our expected trap, but decided we should resume from
7801 We're going to run this baby now!
7803 Note that insert_breakpoints won't try to re-insert
7804 already inserted breakpoints. Therefore, we don't
7805 care if breakpoints were already inserted, or not. */
7807 /* If we need to step over a breakpoint, and we're not using
7808 displaced stepping to do so, insert all breakpoints
7809 (watchpoints, etc.) but the one we're stepping over, step one
7810 instruction, and then re-insert the breakpoint when that step
7813 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7815 remove_bp
= (ecs
->hit_singlestep_breakpoint
7816 || (step_what
& STEP_OVER_BREAKPOINT
));
7817 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7819 /* We can't use displaced stepping if we need to step past a
7820 watchpoint. The instruction copied to the scratch pad would
7821 still trigger the watchpoint. */
7823 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7825 set_step_over_info (regcache
->aspace (),
7826 regcache_read_pc (regcache
), remove_wps
,
7827 ecs
->event_thread
->global_num
);
7829 else if (remove_wps
)
7830 set_step_over_info (NULL
, 0, remove_wps
, -1);
7832 /* If we now need to do an in-line step-over, we need to stop
7833 all other threads. Note this must be done before
7834 insert_breakpoints below, because that removes the breakpoint
7835 we're about to step over, otherwise other threads could miss
7837 if (step_over_info_valid_p () && target_is_non_stop_p ())
7838 stop_all_threads ();
7840 /* Stop stepping if inserting breakpoints fails. */
7843 insert_breakpoints ();
7845 catch (const gdb_exception_error
&e
)
7847 exception_print (gdb_stderr
, e
);
7849 clear_step_over_info ();
7853 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7855 resume (ecs
->event_thread
->suspend
.stop_signal
);
7858 prepare_to_wait (ecs
);
7861 /* Called when we should continue running the inferior, because the
7862 current event doesn't cause a user visible stop. This does the
7863 resuming part; waiting for the next event is done elsewhere. */
7866 keep_going (struct execution_control_state
*ecs
)
7868 if (ecs
->event_thread
->control
.trap_expected
7869 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7870 ecs
->event_thread
->control
.trap_expected
= 0;
7872 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7873 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7874 keep_going_pass_signal (ecs
);
7877 /* This function normally comes after a resume, before
7878 handle_inferior_event exits. It takes care of any last bits of
7879 housekeeping, and sets the all-important wait_some_more flag. */
7882 prepare_to_wait (struct execution_control_state
*ecs
)
7884 infrun_log_debug ("prepare_to_wait");
7886 ecs
->wait_some_more
= 1;
7888 if (!target_is_async_p ())
7889 mark_infrun_async_event_handler ();
7892 /* We are done with the step range of a step/next/si/ni command.
7893 Called once for each n of a "step n" operation. */
7896 end_stepping_range (struct execution_control_state
*ecs
)
7898 ecs
->event_thread
->control
.stop_step
= 1;
7902 /* Several print_*_reason functions to print why the inferior has stopped.
7903 We always print something when the inferior exits, or receives a signal.
7904 The rest of the cases are dealt with later on in normal_stop and
7905 print_it_typical. Ideally there should be a call to one of these
7906 print_*_reason functions functions from handle_inferior_event each time
7907 stop_waiting is called.
7909 Note that we don't call these directly, instead we delegate that to
7910 the interpreters, through observers. Interpreters then call these
7911 with whatever uiout is right. */
7914 print_end_stepping_range_reason (struct ui_out
*uiout
)
7916 /* For CLI-like interpreters, print nothing. */
7918 if (uiout
->is_mi_like_p ())
7920 uiout
->field_string ("reason",
7921 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7926 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7928 annotate_signalled ();
7929 if (uiout
->is_mi_like_p ())
7931 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7932 uiout
->text ("\nProgram terminated with signal ");
7933 annotate_signal_name ();
7934 uiout
->field_string ("signal-name",
7935 gdb_signal_to_name (siggnal
));
7936 annotate_signal_name_end ();
7938 annotate_signal_string ();
7939 uiout
->field_string ("signal-meaning",
7940 gdb_signal_to_string (siggnal
));
7941 annotate_signal_string_end ();
7942 uiout
->text (".\n");
7943 uiout
->text ("The program no longer exists.\n");
7947 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7949 struct inferior
*inf
= current_inferior ();
7950 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7952 annotate_exited (exitstatus
);
7955 if (uiout
->is_mi_like_p ())
7956 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7957 std::string exit_code_str
7958 = string_printf ("0%o", (unsigned int) exitstatus
);
7959 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7960 plongest (inf
->num
), pidstr
.c_str (),
7961 string_field ("exit-code", exit_code_str
.c_str ()));
7965 if (uiout
->is_mi_like_p ())
7967 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7968 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7969 plongest (inf
->num
), pidstr
.c_str ());
7973 /* Some targets/architectures can do extra processing/display of
7974 segmentation faults. E.g., Intel MPX boundary faults.
7975 Call the architecture dependent function to handle the fault. */
7978 handle_segmentation_fault (struct ui_out
*uiout
)
7980 struct regcache
*regcache
= get_current_regcache ();
7981 struct gdbarch
*gdbarch
= regcache
->arch ();
7983 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7984 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7988 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7990 struct thread_info
*thr
= inferior_thread ();
7994 if (uiout
->is_mi_like_p ())
7996 else if (show_thread_that_caused_stop ())
8000 uiout
->text ("\nThread ");
8001 uiout
->field_string ("thread-id", print_thread_id (thr
));
8003 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8006 uiout
->text (" \"");
8007 uiout
->field_string ("name", name
);
8012 uiout
->text ("\nProgram");
8014 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8015 uiout
->text (" stopped");
8018 uiout
->text (" received signal ");
8019 annotate_signal_name ();
8020 if (uiout
->is_mi_like_p ())
8022 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8023 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8024 annotate_signal_name_end ();
8026 annotate_signal_string ();
8027 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8029 if (siggnal
== GDB_SIGNAL_SEGV
)
8030 handle_segmentation_fault (uiout
);
8032 annotate_signal_string_end ();
8034 uiout
->text (".\n");
8038 print_no_history_reason (struct ui_out
*uiout
)
8040 uiout
->text ("\nNo more reverse-execution history.\n");
8043 /* Print current location without a level number, if we have changed
8044 functions or hit a breakpoint. Print source line if we have one.
8045 bpstat_print contains the logic deciding in detail what to print,
8046 based on the event(s) that just occurred. */
8049 print_stop_location (struct target_waitstatus
*ws
)
8052 enum print_what source_flag
;
8053 int do_frame_printing
= 1;
8054 struct thread_info
*tp
= inferior_thread ();
8056 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8060 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8061 should) carry around the function and does (or should) use
8062 that when doing a frame comparison. */
8063 if (tp
->control
.stop_step
8064 && frame_id_eq (tp
->control
.step_frame_id
,
8065 get_frame_id (get_current_frame ()))
8066 && (tp
->control
.step_start_function
8067 == find_pc_function (tp
->suspend
.stop_pc
)))
8069 /* Finished step, just print source line. */
8070 source_flag
= SRC_LINE
;
8074 /* Print location and source line. */
8075 source_flag
= SRC_AND_LOC
;
8078 case PRINT_SRC_AND_LOC
:
8079 /* Print location and source line. */
8080 source_flag
= SRC_AND_LOC
;
8082 case PRINT_SRC_ONLY
:
8083 source_flag
= SRC_LINE
;
8086 /* Something bogus. */
8087 source_flag
= SRC_LINE
;
8088 do_frame_printing
= 0;
8091 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8094 /* The behavior of this routine with respect to the source
8096 SRC_LINE: Print only source line
8097 LOCATION: Print only location
8098 SRC_AND_LOC: Print location and source line. */
8099 if (do_frame_printing
)
8100 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8106 print_stop_event (struct ui_out
*uiout
, bool displays
)
8108 struct target_waitstatus last
;
8109 struct thread_info
*tp
;
8111 get_last_target_status (nullptr, nullptr, &last
);
8114 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8116 print_stop_location (&last
);
8118 /* Display the auto-display expressions. */
8123 tp
= inferior_thread ();
8124 if (tp
->thread_fsm
!= NULL
8125 && tp
->thread_fsm
->finished_p ())
8127 struct return_value_info
*rv
;
8129 rv
= tp
->thread_fsm
->return_value ();
8131 print_return_value (uiout
, rv
);
8138 maybe_remove_breakpoints (void)
8140 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8142 if (remove_breakpoints ())
8144 target_terminal::ours_for_output ();
8145 printf_filtered (_("Cannot remove breakpoints because "
8146 "program is no longer writable.\nFurther "
8147 "execution is probably impossible.\n"));
8152 /* The execution context that just caused a normal stop. */
8159 DISABLE_COPY_AND_ASSIGN (stop_context
);
8161 bool changed () const;
8166 /* The event PTID. */
8170 /* If stopp for a thread event, this is the thread that caused the
8172 struct thread_info
*thread
;
8174 /* The inferior that caused the stop. */
8178 /* Initializes a new stop context. If stopped for a thread event, this
8179 takes a strong reference to the thread. */
8181 stop_context::stop_context ()
8183 stop_id
= get_stop_id ();
8184 ptid
= inferior_ptid
;
8185 inf_num
= current_inferior ()->num
;
8187 if (inferior_ptid
!= null_ptid
)
8189 /* Take a strong reference so that the thread can't be deleted
8191 thread
= inferior_thread ();
8198 /* Release a stop context previously created with save_stop_context.
8199 Releases the strong reference to the thread as well. */
8201 stop_context::~stop_context ()
8207 /* Return true if the current context no longer matches the saved stop
8211 stop_context::changed () const
8213 if (ptid
!= inferior_ptid
)
8215 if (inf_num
!= current_inferior ()->num
)
8217 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8219 if (get_stop_id () != stop_id
)
8229 struct target_waitstatus last
;
8231 get_last_target_status (nullptr, nullptr, &last
);
8235 /* If an exception is thrown from this point on, make sure to
8236 propagate GDB's knowledge of the executing state to the
8237 frontend/user running state. A QUIT is an easy exception to see
8238 here, so do this before any filtered output. */
8240 ptid_t finish_ptid
= null_ptid
;
8243 finish_ptid
= minus_one_ptid
;
8244 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8245 || last
.kind
== TARGET_WAITKIND_EXITED
)
8247 /* On some targets, we may still have live threads in the
8248 inferior when we get a process exit event. E.g., for
8249 "checkpoint", when the current checkpoint/fork exits,
8250 linux-fork.c automatically switches to another fork from
8251 within target_mourn_inferior. */
8252 if (inferior_ptid
!= null_ptid
)
8253 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8255 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8256 finish_ptid
= inferior_ptid
;
8258 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8259 if (finish_ptid
!= null_ptid
)
8261 maybe_finish_thread_state
.emplace
8262 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8265 /* As we're presenting a stop, and potentially removing breakpoints,
8266 update the thread list so we can tell whether there are threads
8267 running on the target. With target remote, for example, we can
8268 only learn about new threads when we explicitly update the thread
8269 list. Do this before notifying the interpreters about signal
8270 stops, end of stepping ranges, etc., so that the "new thread"
8271 output is emitted before e.g., "Program received signal FOO",
8272 instead of after. */
8273 update_thread_list ();
8275 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8276 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8278 /* As with the notification of thread events, we want to delay
8279 notifying the user that we've switched thread context until
8280 the inferior actually stops.
8282 There's no point in saying anything if the inferior has exited.
8283 Note that SIGNALLED here means "exited with a signal", not
8284 "received a signal".
8286 Also skip saying anything in non-stop mode. In that mode, as we
8287 don't want GDB to switch threads behind the user's back, to avoid
8288 races where the user is typing a command to apply to thread x,
8289 but GDB switches to thread y before the user finishes entering
8290 the command, fetch_inferior_event installs a cleanup to restore
8291 the current thread back to the thread the user had selected right
8292 after this event is handled, so we're not really switching, only
8293 informing of a stop. */
8295 && previous_inferior_ptid
!= inferior_ptid
8296 && target_has_execution
8297 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8298 && last
.kind
!= TARGET_WAITKIND_EXITED
8299 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8301 SWITCH_THRU_ALL_UIS ()
8303 target_terminal::ours_for_output ();
8304 printf_filtered (_("[Switching to %s]\n"),
8305 target_pid_to_str (inferior_ptid
).c_str ());
8306 annotate_thread_changed ();
8308 previous_inferior_ptid
= inferior_ptid
;
8311 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8313 SWITCH_THRU_ALL_UIS ()
8314 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8316 target_terminal::ours_for_output ();
8317 printf_filtered (_("No unwaited-for children left.\n"));
8321 /* Note: this depends on the update_thread_list call above. */
8322 maybe_remove_breakpoints ();
8324 /* If an auto-display called a function and that got a signal,
8325 delete that auto-display to avoid an infinite recursion. */
8327 if (stopped_by_random_signal
)
8328 disable_current_display ();
8330 SWITCH_THRU_ALL_UIS ()
8332 async_enable_stdin ();
8335 /* Let the user/frontend see the threads as stopped. */
8336 maybe_finish_thread_state
.reset ();
8338 /* Select innermost stack frame - i.e., current frame is frame 0,
8339 and current location is based on that. Handle the case where the
8340 dummy call is returning after being stopped. E.g. the dummy call
8341 previously hit a breakpoint. (If the dummy call returns
8342 normally, we won't reach here.) Do this before the stop hook is
8343 run, so that it doesn't get to see the temporary dummy frame,
8344 which is not where we'll present the stop. */
8345 if (has_stack_frames ())
8347 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8349 /* Pop the empty frame that contains the stack dummy. This
8350 also restores inferior state prior to the call (struct
8351 infcall_suspend_state). */
8352 struct frame_info
*frame
= get_current_frame ();
8354 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8356 /* frame_pop calls reinit_frame_cache as the last thing it
8357 does which means there's now no selected frame. */
8360 select_frame (get_current_frame ());
8362 /* Set the current source location. */
8363 set_current_sal_from_frame (get_current_frame ());
8366 /* Look up the hook_stop and run it (CLI internally handles problem
8367 of stop_command's pre-hook not existing). */
8368 if (stop_command
!= NULL
)
8370 stop_context saved_context
;
8374 execute_cmd_pre_hook (stop_command
);
8376 catch (const gdb_exception
&ex
)
8378 exception_fprintf (gdb_stderr
, ex
,
8379 "Error while running hook_stop:\n");
8382 /* If the stop hook resumes the target, then there's no point in
8383 trying to notify about the previous stop; its context is
8384 gone. Likewise if the command switches thread or inferior --
8385 the observers would print a stop for the wrong
8387 if (saved_context
.changed ())
8391 /* Notify observers about the stop. This is where the interpreters
8392 print the stop event. */
8393 if (inferior_ptid
!= null_ptid
)
8394 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8397 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8399 annotate_stopped ();
8401 if (target_has_execution
)
8403 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8404 && last
.kind
!= TARGET_WAITKIND_EXITED
8405 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8406 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8407 Delete any breakpoint that is to be deleted at the next stop. */
8408 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8411 /* Try to get rid of automatically added inferiors that are no
8412 longer needed. Keeping those around slows down things linearly.
8413 Note that this never removes the current inferior. */
8420 signal_stop_state (int signo
)
8422 return signal_stop
[signo
];
8426 signal_print_state (int signo
)
8428 return signal_print
[signo
];
8432 signal_pass_state (int signo
)
8434 return signal_program
[signo
];
8438 signal_cache_update (int signo
)
8442 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8443 signal_cache_update (signo
);
8448 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8449 && signal_print
[signo
] == 0
8450 && signal_program
[signo
] == 1
8451 && signal_catch
[signo
] == 0);
8455 signal_stop_update (int signo
, int state
)
8457 int ret
= signal_stop
[signo
];
8459 signal_stop
[signo
] = state
;
8460 signal_cache_update (signo
);
8465 signal_print_update (int signo
, int state
)
8467 int ret
= signal_print
[signo
];
8469 signal_print
[signo
] = state
;
8470 signal_cache_update (signo
);
8475 signal_pass_update (int signo
, int state
)
8477 int ret
= signal_program
[signo
];
8479 signal_program
[signo
] = state
;
8480 signal_cache_update (signo
);
8484 /* Update the global 'signal_catch' from INFO and notify the
8488 signal_catch_update (const unsigned int *info
)
8492 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8493 signal_catch
[i
] = info
[i
] > 0;
8494 signal_cache_update (-1);
8495 target_pass_signals (signal_pass
);
8499 sig_print_header (void)
8501 printf_filtered (_("Signal Stop\tPrint\tPass "
8502 "to program\tDescription\n"));
8506 sig_print_info (enum gdb_signal oursig
)
8508 const char *name
= gdb_signal_to_name (oursig
);
8509 int name_padding
= 13 - strlen (name
);
8511 if (name_padding
<= 0)
8514 printf_filtered ("%s", name
);
8515 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8516 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8517 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8518 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8519 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8522 /* Specify how various signals in the inferior should be handled. */
8525 handle_command (const char *args
, int from_tty
)
8527 int digits
, wordlen
;
8528 int sigfirst
, siglast
;
8529 enum gdb_signal oursig
;
8534 error_no_arg (_("signal to handle"));
8537 /* Allocate and zero an array of flags for which signals to handle. */
8539 const size_t nsigs
= GDB_SIGNAL_LAST
;
8540 unsigned char sigs
[nsigs
] {};
8542 /* Break the command line up into args. */
8544 gdb_argv
built_argv (args
);
8546 /* Walk through the args, looking for signal oursigs, signal names, and
8547 actions. Signal numbers and signal names may be interspersed with
8548 actions, with the actions being performed for all signals cumulatively
8549 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8551 for (char *arg
: built_argv
)
8553 wordlen
= strlen (arg
);
8554 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8558 sigfirst
= siglast
= -1;
8560 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8562 /* Apply action to all signals except those used by the
8563 debugger. Silently skip those. */
8566 siglast
= nsigs
- 1;
8568 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8570 SET_SIGS (nsigs
, sigs
, signal_stop
);
8571 SET_SIGS (nsigs
, sigs
, signal_print
);
8573 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8575 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8577 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8579 SET_SIGS (nsigs
, sigs
, signal_print
);
8581 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8583 SET_SIGS (nsigs
, sigs
, signal_program
);
8585 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8587 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8589 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8591 SET_SIGS (nsigs
, sigs
, signal_program
);
8593 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8595 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8596 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8598 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8600 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8602 else if (digits
> 0)
8604 /* It is numeric. The numeric signal refers to our own
8605 internal signal numbering from target.h, not to host/target
8606 signal number. This is a feature; users really should be
8607 using symbolic names anyway, and the common ones like
8608 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8610 sigfirst
= siglast
= (int)
8611 gdb_signal_from_command (atoi (arg
));
8612 if (arg
[digits
] == '-')
8615 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8617 if (sigfirst
> siglast
)
8619 /* Bet he didn't figure we'd think of this case... */
8620 std::swap (sigfirst
, siglast
);
8625 oursig
= gdb_signal_from_name (arg
);
8626 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8628 sigfirst
= siglast
= (int) oursig
;
8632 /* Not a number and not a recognized flag word => complain. */
8633 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8637 /* If any signal numbers or symbol names were found, set flags for
8638 which signals to apply actions to. */
8640 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8642 switch ((enum gdb_signal
) signum
)
8644 case GDB_SIGNAL_TRAP
:
8645 case GDB_SIGNAL_INT
:
8646 if (!allsigs
&& !sigs
[signum
])
8648 if (query (_("%s is used by the debugger.\n\
8649 Are you sure you want to change it? "),
8650 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8655 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8659 case GDB_SIGNAL_DEFAULT
:
8660 case GDB_SIGNAL_UNKNOWN
:
8661 /* Make sure that "all" doesn't print these. */
8670 for (int signum
= 0; signum
< nsigs
; signum
++)
8673 signal_cache_update (-1);
8674 target_pass_signals (signal_pass
);
8675 target_program_signals (signal_program
);
8679 /* Show the results. */
8680 sig_print_header ();
8681 for (; signum
< nsigs
; signum
++)
8683 sig_print_info ((enum gdb_signal
) signum
);
8690 /* Complete the "handle" command. */
8693 handle_completer (struct cmd_list_element
*ignore
,
8694 completion_tracker
&tracker
,
8695 const char *text
, const char *word
)
8697 static const char * const keywords
[] =
8711 signal_completer (ignore
, tracker
, text
, word
);
8712 complete_on_enum (tracker
, keywords
, word
, word
);
8716 gdb_signal_from_command (int num
)
8718 if (num
>= 1 && num
<= 15)
8719 return (enum gdb_signal
) num
;
8720 error (_("Only signals 1-15 are valid as numeric signals.\n\
8721 Use \"info signals\" for a list of symbolic signals."));
8724 /* Print current contents of the tables set by the handle command.
8725 It is possible we should just be printing signals actually used
8726 by the current target (but for things to work right when switching
8727 targets, all signals should be in the signal tables). */
8730 info_signals_command (const char *signum_exp
, int from_tty
)
8732 enum gdb_signal oursig
;
8734 sig_print_header ();
8738 /* First see if this is a symbol name. */
8739 oursig
= gdb_signal_from_name (signum_exp
);
8740 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8742 /* No, try numeric. */
8744 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8746 sig_print_info (oursig
);
8750 printf_filtered ("\n");
8751 /* These ugly casts brought to you by the native VAX compiler. */
8752 for (oursig
= GDB_SIGNAL_FIRST
;
8753 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8754 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8758 if (oursig
!= GDB_SIGNAL_UNKNOWN
8759 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8760 sig_print_info (oursig
);
8763 printf_filtered (_("\nUse the \"handle\" command "
8764 "to change these tables.\n"));
8767 /* The $_siginfo convenience variable is a bit special. We don't know
8768 for sure the type of the value until we actually have a chance to
8769 fetch the data. The type can change depending on gdbarch, so it is
8770 also dependent on which thread you have selected.
8772 1. making $_siginfo be an internalvar that creates a new value on
8775 2. making the value of $_siginfo be an lval_computed value. */
8777 /* This function implements the lval_computed support for reading a
8781 siginfo_value_read (struct value
*v
)
8783 LONGEST transferred
;
8785 /* If we can access registers, so can we access $_siginfo. Likewise
8787 validate_registers_access ();
8790 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8792 value_contents_all_raw (v
),
8794 TYPE_LENGTH (value_type (v
)));
8796 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8797 error (_("Unable to read siginfo"));
8800 /* This function implements the lval_computed support for writing a
8804 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8806 LONGEST transferred
;
8808 /* If we can access registers, so can we access $_siginfo. Likewise
8810 validate_registers_access ();
8812 transferred
= target_write (current_top_target (),
8813 TARGET_OBJECT_SIGNAL_INFO
,
8815 value_contents_all_raw (fromval
),
8817 TYPE_LENGTH (value_type (fromval
)));
8819 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8820 error (_("Unable to write siginfo"));
8823 static const struct lval_funcs siginfo_value_funcs
=
8829 /* Return a new value with the correct type for the siginfo object of
8830 the current thread using architecture GDBARCH. Return a void value
8831 if there's no object available. */
8833 static struct value
*
8834 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8837 if (target_has_stack
8838 && inferior_ptid
!= null_ptid
8839 && gdbarch_get_siginfo_type_p (gdbarch
))
8841 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8843 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8846 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8850 /* infcall_suspend_state contains state about the program itself like its
8851 registers and any signal it received when it last stopped.
8852 This state must be restored regardless of how the inferior function call
8853 ends (either successfully, or after it hits a breakpoint or signal)
8854 if the program is to properly continue where it left off. */
8856 class infcall_suspend_state
8859 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8860 once the inferior function call has finished. */
8861 infcall_suspend_state (struct gdbarch
*gdbarch
,
8862 const struct thread_info
*tp
,
8863 struct regcache
*regcache
)
8864 : m_thread_suspend (tp
->suspend
),
8865 m_registers (new readonly_detached_regcache (*regcache
))
8867 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8869 if (gdbarch_get_siginfo_type_p (gdbarch
))
8871 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8872 size_t len
= TYPE_LENGTH (type
);
8874 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8876 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8877 siginfo_data
.get (), 0, len
) != len
)
8879 /* Errors ignored. */
8880 siginfo_data
.reset (nullptr);
8886 m_siginfo_gdbarch
= gdbarch
;
8887 m_siginfo_data
= std::move (siginfo_data
);
8891 /* Return a pointer to the stored register state. */
8893 readonly_detached_regcache
*registers () const
8895 return m_registers
.get ();
8898 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8900 void restore (struct gdbarch
*gdbarch
,
8901 struct thread_info
*tp
,
8902 struct regcache
*regcache
) const
8904 tp
->suspend
= m_thread_suspend
;
8906 if (m_siginfo_gdbarch
== gdbarch
)
8908 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8910 /* Errors ignored. */
8911 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8912 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8915 /* The inferior can be gone if the user types "print exit(0)"
8916 (and perhaps other times). */
8917 if (target_has_execution
)
8918 /* NB: The register write goes through to the target. */
8919 regcache
->restore (registers ());
8923 /* How the current thread stopped before the inferior function call was
8925 struct thread_suspend_state m_thread_suspend
;
8927 /* The registers before the inferior function call was executed. */
8928 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8930 /* Format of SIGINFO_DATA or NULL if it is not present. */
8931 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8933 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8934 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8935 content would be invalid. */
8936 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8939 infcall_suspend_state_up
8940 save_infcall_suspend_state ()
8942 struct thread_info
*tp
= inferior_thread ();
8943 struct regcache
*regcache
= get_current_regcache ();
8944 struct gdbarch
*gdbarch
= regcache
->arch ();
8946 infcall_suspend_state_up inf_state
8947 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8949 /* Having saved the current state, adjust the thread state, discarding
8950 any stop signal information. The stop signal is not useful when
8951 starting an inferior function call, and run_inferior_call will not use
8952 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8953 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8958 /* Restore inferior session state to INF_STATE. */
8961 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8963 struct thread_info
*tp
= inferior_thread ();
8964 struct regcache
*regcache
= get_current_regcache ();
8965 struct gdbarch
*gdbarch
= regcache
->arch ();
8967 inf_state
->restore (gdbarch
, tp
, regcache
);
8968 discard_infcall_suspend_state (inf_state
);
8972 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8977 readonly_detached_regcache
*
8978 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8980 return inf_state
->registers ();
8983 /* infcall_control_state contains state regarding gdb's control of the
8984 inferior itself like stepping control. It also contains session state like
8985 the user's currently selected frame. */
8987 struct infcall_control_state
8989 struct thread_control_state thread_control
;
8990 struct inferior_control_state inferior_control
;
8993 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8994 int stopped_by_random_signal
= 0;
8996 /* ID if the selected frame when the inferior function call was made. */
8997 struct frame_id selected_frame_id
{};
9000 /* Save all of the information associated with the inferior<==>gdb
9003 infcall_control_state_up
9004 save_infcall_control_state ()
9006 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9007 struct thread_info
*tp
= inferior_thread ();
9008 struct inferior
*inf
= current_inferior ();
9010 inf_status
->thread_control
= tp
->control
;
9011 inf_status
->inferior_control
= inf
->control
;
9013 tp
->control
.step_resume_breakpoint
= NULL
;
9014 tp
->control
.exception_resume_breakpoint
= NULL
;
9016 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9017 chain. If caller's caller is walking the chain, they'll be happier if we
9018 hand them back the original chain when restore_infcall_control_state is
9020 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9023 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9024 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9026 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9032 restore_selected_frame (const frame_id
&fid
)
9034 frame_info
*frame
= frame_find_by_id (fid
);
9036 /* If inf_status->selected_frame_id is NULL, there was no previously
9040 warning (_("Unable to restore previously selected frame."));
9044 select_frame (frame
);
9047 /* Restore inferior session state to INF_STATUS. */
9050 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9052 struct thread_info
*tp
= inferior_thread ();
9053 struct inferior
*inf
= current_inferior ();
9055 if (tp
->control
.step_resume_breakpoint
)
9056 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9058 if (tp
->control
.exception_resume_breakpoint
)
9059 tp
->control
.exception_resume_breakpoint
->disposition
9060 = disp_del_at_next_stop
;
9062 /* Handle the bpstat_copy of the chain. */
9063 bpstat_clear (&tp
->control
.stop_bpstat
);
9065 tp
->control
= inf_status
->thread_control
;
9066 inf
->control
= inf_status
->inferior_control
;
9069 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9070 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9072 if (target_has_stack
)
9074 /* The point of the try/catch is that if the stack is clobbered,
9075 walking the stack might encounter a garbage pointer and
9076 error() trying to dereference it. */
9079 restore_selected_frame (inf_status
->selected_frame_id
);
9081 catch (const gdb_exception_error
&ex
)
9083 exception_fprintf (gdb_stderr
, ex
,
9084 "Unable to restore previously selected frame:\n");
9085 /* Error in restoring the selected frame. Select the
9087 select_frame (get_current_frame ());
9095 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9097 if (inf_status
->thread_control
.step_resume_breakpoint
)
9098 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9099 = disp_del_at_next_stop
;
9101 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9102 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9103 = disp_del_at_next_stop
;
9105 /* See save_infcall_control_state for info on stop_bpstat. */
9106 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9114 clear_exit_convenience_vars (void)
9116 clear_internalvar (lookup_internalvar ("_exitsignal"));
9117 clear_internalvar (lookup_internalvar ("_exitcode"));
9121 /* User interface for reverse debugging:
9122 Set exec-direction / show exec-direction commands
9123 (returns error unless target implements to_set_exec_direction method). */
9125 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9126 static const char exec_forward
[] = "forward";
9127 static const char exec_reverse
[] = "reverse";
9128 static const char *exec_direction
= exec_forward
;
9129 static const char *const exec_direction_names
[] = {
9136 set_exec_direction_func (const char *args
, int from_tty
,
9137 struct cmd_list_element
*cmd
)
9139 if (target_can_execute_reverse
)
9141 if (!strcmp (exec_direction
, exec_forward
))
9142 execution_direction
= EXEC_FORWARD
;
9143 else if (!strcmp (exec_direction
, exec_reverse
))
9144 execution_direction
= EXEC_REVERSE
;
9148 exec_direction
= exec_forward
;
9149 error (_("Target does not support this operation."));
9154 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9155 struct cmd_list_element
*cmd
, const char *value
)
9157 switch (execution_direction
) {
9159 fprintf_filtered (out
, _("Forward.\n"));
9162 fprintf_filtered (out
, _("Reverse.\n"));
9165 internal_error (__FILE__
, __LINE__
,
9166 _("bogus execution_direction value: %d"),
9167 (int) execution_direction
);
9172 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9173 struct cmd_list_element
*c
, const char *value
)
9175 fprintf_filtered (file
, _("Resuming the execution of threads "
9176 "of all processes is %s.\n"), value
);
9179 /* Implementation of `siginfo' variable. */
9181 static const struct internalvar_funcs siginfo_funcs
=
9188 /* Callback for infrun's target events source. This is marked when a
9189 thread has a pending status to process. */
9192 infrun_async_inferior_event_handler (gdb_client_data data
)
9194 inferior_event_handler (INF_REG_EVENT
, NULL
);
9197 void _initialize_infrun ();
9199 _initialize_infrun ()
9201 struct cmd_list_element
*c
;
9203 /* Register extra event sources in the event loop. */
9204 infrun_async_inferior_event_token
9205 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9207 add_info ("signals", info_signals_command
, _("\
9208 What debugger does when program gets various signals.\n\
9209 Specify a signal as argument to print info on that signal only."));
9210 add_info_alias ("handle", "signals", 0);
9212 c
= add_com ("handle", class_run
, handle_command
, _("\
9213 Specify how to handle signals.\n\
9214 Usage: handle SIGNAL [ACTIONS]\n\
9215 Args are signals and actions to apply to those signals.\n\
9216 If no actions are specified, the current settings for the specified signals\n\
9217 will be displayed instead.\n\
9219 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9220 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9221 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9222 The special arg \"all\" is recognized to mean all signals except those\n\
9223 used by the debugger, typically SIGTRAP and SIGINT.\n\
9225 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9226 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9227 Stop means reenter debugger if this signal happens (implies print).\n\
9228 Print means print a message if this signal happens.\n\
9229 Pass means let program see this signal; otherwise program doesn't know.\n\
9230 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9231 Pass and Stop may be combined.\n\
9233 Multiple signals may be specified. Signal numbers and signal names\n\
9234 may be interspersed with actions, with the actions being performed for\n\
9235 all signals cumulatively specified."));
9236 set_cmd_completer (c
, handle_completer
);
9239 stop_command
= add_cmd ("stop", class_obscure
,
9240 not_just_help_class_command
, _("\
9241 There is no `stop' command, but you can set a hook on `stop'.\n\
9242 This allows you to set a list of commands to be run each time execution\n\
9243 of the program stops."), &cmdlist
);
9245 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9246 Set inferior debugging."), _("\
9247 Show inferior debugging."), _("\
9248 When non-zero, inferior specific debugging is enabled."),
9251 &setdebuglist
, &showdebuglist
);
9253 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9254 &debug_displaced
, _("\
9255 Set displaced stepping debugging."), _("\
9256 Show displaced stepping debugging."), _("\
9257 When non-zero, displaced stepping specific debugging is enabled."),
9259 show_debug_displaced
,
9260 &setdebuglist
, &showdebuglist
);
9262 add_setshow_boolean_cmd ("non-stop", no_class
,
9264 Set whether gdb controls the inferior in non-stop mode."), _("\
9265 Show whether gdb controls the inferior in non-stop mode."), _("\
9266 When debugging a multi-threaded program and this setting is\n\
9267 off (the default, also called all-stop mode), when one thread stops\n\
9268 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9269 all other threads in the program while you interact with the thread of\n\
9270 interest. When you continue or step a thread, you can allow the other\n\
9271 threads to run, or have them remain stopped, but while you inspect any\n\
9272 thread's state, all threads stop.\n\
9274 In non-stop mode, when one thread stops, other threads can continue\n\
9275 to run freely. You'll be able to step each thread independently,\n\
9276 leave it stopped or free to run as needed."),
9282 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9285 signal_print
[i
] = 1;
9286 signal_program
[i
] = 1;
9287 signal_catch
[i
] = 0;
9290 /* Signals caused by debugger's own actions should not be given to
9291 the program afterwards.
9293 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9294 explicitly specifies that it should be delivered to the target
9295 program. Typically, that would occur when a user is debugging a
9296 target monitor on a simulator: the target monitor sets a
9297 breakpoint; the simulator encounters this breakpoint and halts
9298 the simulation handing control to GDB; GDB, noting that the stop
9299 address doesn't map to any known breakpoint, returns control back
9300 to the simulator; the simulator then delivers the hardware
9301 equivalent of a GDB_SIGNAL_TRAP to the program being
9303 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9304 signal_program
[GDB_SIGNAL_INT
] = 0;
9306 /* Signals that are not errors should not normally enter the debugger. */
9307 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9308 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9309 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9310 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9311 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9312 signal_print
[GDB_SIGNAL_PROF
] = 0;
9313 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9314 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9315 signal_stop
[GDB_SIGNAL_IO
] = 0;
9316 signal_print
[GDB_SIGNAL_IO
] = 0;
9317 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9318 signal_print
[GDB_SIGNAL_POLL
] = 0;
9319 signal_stop
[GDB_SIGNAL_URG
] = 0;
9320 signal_print
[GDB_SIGNAL_URG
] = 0;
9321 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9322 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9323 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9324 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9326 /* These signals are used internally by user-level thread
9327 implementations. (See signal(5) on Solaris.) Like the above
9328 signals, a healthy program receives and handles them as part of
9329 its normal operation. */
9330 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9331 signal_print
[GDB_SIGNAL_LWP
] = 0;
9332 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9333 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9334 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9335 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9336 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9337 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9339 /* Update cached state. */
9340 signal_cache_update (-1);
9342 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9343 &stop_on_solib_events
, _("\
9344 Set stopping for shared library events."), _("\
9345 Show stopping for shared library events."), _("\
9346 If nonzero, gdb will give control to the user when the dynamic linker\n\
9347 notifies gdb of shared library events. The most common event of interest\n\
9348 to the user would be loading/unloading of a new library."),
9349 set_stop_on_solib_events
,
9350 show_stop_on_solib_events
,
9351 &setlist
, &showlist
);
9353 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9354 follow_fork_mode_kind_names
,
9355 &follow_fork_mode_string
, _("\
9356 Set debugger response to a program call of fork or vfork."), _("\
9357 Show debugger response to a program call of fork or vfork."), _("\
9358 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9359 parent - the original process is debugged after a fork\n\
9360 child - the new process is debugged after a fork\n\
9361 The unfollowed process will continue to run.\n\
9362 By default, the debugger will follow the parent process."),
9364 show_follow_fork_mode_string
,
9365 &setlist
, &showlist
);
9367 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9368 follow_exec_mode_names
,
9369 &follow_exec_mode_string
, _("\
9370 Set debugger response to a program call of exec."), _("\
9371 Show debugger response to a program call of exec."), _("\
9372 An exec call replaces the program image of a process.\n\
9374 follow-exec-mode can be:\n\
9376 new - the debugger creates a new inferior and rebinds the process\n\
9377 to this new inferior. The program the process was running before\n\
9378 the exec call can be restarted afterwards by restarting the original\n\
9381 same - the debugger keeps the process bound to the same inferior.\n\
9382 The new executable image replaces the previous executable loaded in\n\
9383 the inferior. Restarting the inferior after the exec call restarts\n\
9384 the executable the process was running after the exec call.\n\
9386 By default, the debugger will use the same inferior."),
9388 show_follow_exec_mode_string
,
9389 &setlist
, &showlist
);
9391 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9392 scheduler_enums
, &scheduler_mode
, _("\
9393 Set mode for locking scheduler during execution."), _("\
9394 Show mode for locking scheduler during execution."), _("\
9395 off == no locking (threads may preempt at any time)\n\
9396 on == full locking (no thread except the current thread may run)\n\
9397 This applies to both normal execution and replay mode.\n\
9398 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9399 In this mode, other threads may run during other commands.\n\
9400 This applies to both normal execution and replay mode.\n\
9401 replay == scheduler locked in replay mode and unlocked during normal execution."),
9402 set_schedlock_func
, /* traps on target vector */
9403 show_scheduler_mode
,
9404 &setlist
, &showlist
);
9406 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9407 Set mode for resuming threads of all processes."), _("\
9408 Show mode for resuming threads of all processes."), _("\
9409 When on, execution commands (such as 'continue' or 'next') resume all\n\
9410 threads of all processes. When off (which is the default), execution\n\
9411 commands only resume the threads of the current process. The set of\n\
9412 threads that are resumed is further refined by the scheduler-locking\n\
9413 mode (see help set scheduler-locking)."),
9415 show_schedule_multiple
,
9416 &setlist
, &showlist
);
9418 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9419 Set mode of the step operation."), _("\
9420 Show mode of the step operation."), _("\
9421 When set, doing a step over a function without debug line information\n\
9422 will stop at the first instruction of that function. Otherwise, the\n\
9423 function is skipped and the step command stops at a different source line."),
9425 show_step_stop_if_no_debug
,
9426 &setlist
, &showlist
);
9428 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9429 &can_use_displaced_stepping
, _("\
9430 Set debugger's willingness to use displaced stepping."), _("\
9431 Show debugger's willingness to use displaced stepping."), _("\
9432 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9433 supported by the target architecture. If off, gdb will not use displaced\n\
9434 stepping to step over breakpoints, even if such is supported by the target\n\
9435 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9436 if the target architecture supports it and non-stop mode is active, but will not\n\
9437 use it in all-stop mode (see help set non-stop)."),
9439 show_can_use_displaced_stepping
,
9440 &setlist
, &showlist
);
9442 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9443 &exec_direction
, _("Set direction of execution.\n\
9444 Options are 'forward' or 'reverse'."),
9445 _("Show direction of execution (forward/reverse)."),
9446 _("Tells gdb whether to execute forward or backward."),
9447 set_exec_direction_func
, show_exec_direction_func
,
9448 &setlist
, &showlist
);
9450 /* Set/show detach-on-fork: user-settable mode. */
9452 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9453 Set whether gdb will detach the child of a fork."), _("\
9454 Show whether gdb will detach the child of a fork."), _("\
9455 Tells gdb whether to detach the child of a fork."),
9456 NULL
, NULL
, &setlist
, &showlist
);
9458 /* Set/show disable address space randomization mode. */
9460 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9461 &disable_randomization
, _("\
9462 Set disabling of debuggee's virtual address space randomization."), _("\
9463 Show disabling of debuggee's virtual address space randomization."), _("\
9464 When this mode is on (which is the default), randomization of the virtual\n\
9465 address space is disabled. Standalone programs run with the randomization\n\
9466 enabled by default on some platforms."),
9467 &set_disable_randomization
,
9468 &show_disable_randomization
,
9469 &setlist
, &showlist
);
9471 /* ptid initializations */
9472 inferior_ptid
= null_ptid
;
9473 target_last_wait_ptid
= minus_one_ptid
;
9475 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9476 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9477 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9478 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9480 /* Explicitly create without lookup, since that tries to create a
9481 value with a void typed value, and when we get here, gdbarch
9482 isn't initialized yet. At this point, we're quite sure there
9483 isn't another convenience variable of the same name. */
9484 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9486 add_setshow_boolean_cmd ("observer", no_class
,
9487 &observer_mode_1
, _("\
9488 Set whether gdb controls the inferior in observer mode."), _("\
9489 Show whether gdb controls the inferior in observer mode."), _("\
9490 In observer mode, GDB can get data from the inferior, but not\n\
9491 affect its execution. Registers and memory may not be changed,\n\
9492 breakpoints may not be set, and the program cannot be interrupted\n\