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 gdbarch implements the required methods to use
1607 displaced stepping. */
1610 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1612 /* Only check for the presence of `prepare`. `finish` is required by the
1613 gdbarch verification to be provided if `prepare` is provided. */
1614 return gdbarch_displaced_step_prepare_p (arch
);
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 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1635 /* If the architecture doesn't implement displaced stepping, don't use
1637 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1640 /* If recording, don't use displaced stepping. */
1641 if (find_record_target () != nullptr)
1644 displaced_step_inferior_state
*displaced_state
1645 = get_displaced_stepping_state (tp
->inf
);
1647 /* If displaced stepping failed before for this inferior, don't bother trying
1649 if (displaced_state
->failed_before
)
1655 /* Simple function wrapper around displaced_step_thread_state::reset. */
1658 displaced_step_reset (displaced_step_thread_state
*displaced
)
1660 displaced
->reset ();
1663 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1664 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1666 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1668 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1670 displaced_step_dump_bytes (struct ui_file
*file
,
1671 const gdb_byte
*buf
,
1676 for (i
= 0; i
< len
; i
++)
1677 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1678 fputs_unfiltered ("\n", file
);
1681 /* Prepare to single-step, using displaced stepping.
1683 Note that we cannot use displaced stepping when we have a signal to
1684 deliver. If we have a signal to deliver and an instruction to step
1685 over, then after the step, there will be no indication from the
1686 target whether the thread entered a signal handler or ignored the
1687 signal and stepped over the instruction successfully --- both cases
1688 result in a simple SIGTRAP. In the first case we mustn't do a
1689 fixup, and in the second case we must --- but we can't tell which.
1690 Comments in the code for 'random signals' in handle_inferior_event
1691 explain how we handle this case instead.
1693 Returns 1 if preparing was successful -- this thread is going to be
1694 stepped now; 0 if displaced stepping this thread got queued; or -1
1695 if this instruction can't be displaced stepped. */
1697 static displaced_step_prepare_status
1698 displaced_step_prepare_throw (thread_info
*tp
)
1700 regcache
*regcache
= get_thread_regcache (tp
);
1701 struct gdbarch
*gdbarch
= regcache
->arch ();
1702 displaced_step_thread_state
*thread_disp_step_state
1703 = get_displaced_stepping_state (tp
);
1705 /* We should never reach this function if the architecture does not
1706 support displaced stepping. */
1707 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1709 /* Nor if the thread isn't meant to step over a breakpoint. */
1710 gdb_assert (tp
->control
.trap_expected
);
1712 /* Disable range stepping while executing in the scratch pad. We
1713 want a single-step even if executing the displaced instruction in
1714 the scratch buffer lands within the stepping range (e.g., a
1716 tp
->control
.may_range_step
= 0;
1718 /* We are about to start a displaced step for this thread, if one is already
1719 in progress, we goofed up somewhere. */
1720 gdb_assert (!thread_disp_step_state
->in_progress ());
1722 scoped_restore_current_thread restore_thread
;
1724 switch_to_thread (tp
);
1726 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1728 displaced_step_prepare_status status
=
1729 tp
->inf
->top_target ()->displaced_step_prepare (tp
);
1731 if (status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
1733 if (debug_displaced
)
1734 fprintf_unfiltered (gdb_stdlog
,
1735 "displaced: failed to prepare (%s)",
1736 target_pid_to_str (tp
->ptid
).c_str ());
1738 return DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1740 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1742 /* Not enough displaced stepping resources available, defer this
1743 request by placing it the queue. */
1745 if (debug_displaced
)
1746 fprintf_unfiltered (gdb_stdlog
,
1747 "displaced: not enough resources available, "
1748 "deferring step of %s\n",
1749 target_pid_to_str (tp
->ptid
).c_str ());
1751 global_thread_step_over_chain_enqueue (tp
);
1752 tp
->inf
->displaced_step_state
.unavailable
= true;
1754 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1757 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1759 // FIXME: Should probably replicated in the arch implementation now.
1761 // if (breakpoint_in_range_p (aspace, copy, len))
1763 // /* There's a breakpoint set in the scratch pad location range
1764 // (which is usually around the entry point). We'd either
1765 // install it before resuming, which would overwrite/corrupt the
1766 // scratch pad, or if it was already inserted, this displaced
1767 // step would overwrite it. The latter is OK in the sense that
1768 // we already assume that no thread is going to execute the code
1769 // in the scratch pad range (after initial startup) anyway, but
1770 // the former is unacceptable. Simply punt and fallback to
1771 // stepping over this breakpoint in-line. */
1772 // if (debug_displaced)
1774 // fprintf_unfiltered (gdb_stdlog,
1775 // "displaced: breakpoint set in scratch pad. "
1776 // "Stepping over breakpoint in-line instead.\n");
1779 // gdb_assert (false);
1780 // gdbarch_displaced_step_release_location (gdbarch, copy);
1785 /* Save the information we need to fix things up if the step
1787 thread_disp_step_state
->set (gdbarch
);
1789 // FIXME: get it from _prepare?
1790 CORE_ADDR displaced_pc
= 0;
1792 if (debug_displaced
)
1793 fprintf_unfiltered (gdb_stdlog
,
1794 "displaced: prepared successfully thread=%s, "
1795 "original_pc=%s, displaced_pc=%s\n",
1796 target_pid_to_str (tp
->ptid
).c_str (),
1797 paddress (gdbarch
, original_pc
),
1798 paddress (gdbarch
, displaced_pc
));
1800 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1803 /* Wrapper for displaced_step_prepare_throw that disabled further
1804 attempts at displaced stepping if we get a memory error. */
1806 static displaced_step_prepare_status
1807 displaced_step_prepare (thread_info
*thread
)
1809 displaced_step_prepare_status status
1810 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1814 status
= displaced_step_prepare_throw (thread
);
1816 catch (const gdb_exception_error
&ex
)
1818 struct displaced_step_inferior_state
*displaced_state
;
1820 if (ex
.error
!= MEMORY_ERROR
1821 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1824 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1827 /* Be verbose if "set displaced-stepping" is "on", silent if
1829 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1831 warning (_("disabling displaced stepping: %s"),
1835 /* Disable further displaced stepping attempts. */
1837 = get_displaced_stepping_state (thread
->inf
);
1838 displaced_state
->failed_before
= 1;
1844 /* If we displaced stepped an instruction successfully, adjust
1845 registers and memory to yield the same effect the instruction would
1846 have had if we had executed it at its original address, and return
1847 1. If the instruction didn't complete, relocate the PC and return
1848 -1. If the thread wasn't displaced stepping, return 0. */
1851 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1853 displaced_step_thread_state
*displaced
1854 = get_displaced_stepping_state (event_thread
);
1856 /* Was this thread performing a displaced step? */
1857 if (!displaced
->in_progress ())
1860 displaced_step_reset_cleanup
cleanup (displaced
);
1862 /* Fixup may need to read memory/registers. Switch to the thread
1863 that we're fixing up. Also, target_stopped_by_watchpoint checks
1864 the current thread, and displaced_step_restore performs ptid-dependent
1865 memory accesses using current_inferior() and current_top_target(). */
1866 switch_to_thread (event_thread
);
1868 /* Do the fixup, and release the resources acquired to do the displaced
1870 displaced_step_finish_status finish_status
=
1871 event_thread
->inf
->top_target ()->displaced_step_finish (event_thread
,
1874 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1880 /* Data to be passed around while handling an event. This data is
1881 discarded between events. */
1882 struct execution_control_state
1884 process_stratum_target
*target
;
1886 /* The thread that got the event, if this was a thread event; NULL
1888 struct thread_info
*event_thread
;
1890 struct target_waitstatus ws
;
1891 int stop_func_filled_in
;
1892 CORE_ADDR stop_func_start
;
1893 CORE_ADDR stop_func_end
;
1894 const char *stop_func_name
;
1897 /* True if the event thread hit the single-step breakpoint of
1898 another thread. Thus the event doesn't cause a stop, the thread
1899 needs to be single-stepped past the single-step breakpoint before
1900 we can switch back to the original stepping thread. */
1901 int hit_singlestep_breakpoint
;
1904 /* Clear ECS and set it to point at TP. */
1907 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1909 memset (ecs
, 0, sizeof (*ecs
));
1910 ecs
->event_thread
= tp
;
1911 ecs
->ptid
= tp
->ptid
;
1914 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1915 static void prepare_to_wait (struct execution_control_state
*ecs
);
1916 static int keep_going_stepped_thread (struct thread_info
*tp
);
1917 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1919 /* Are there any pending step-over requests? If so, run all we can
1920 now and return true. Otherwise, return false. */
1923 start_step_over (void)
1925 struct thread_info
*tp
, *next
;
1928 /* Don't start a new step-over if we already have an in-line
1929 step-over operation ongoing. */
1930 if (step_over_info_valid_p ())
1933 /* Steal the global thread step over chain. */
1934 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1935 global_thread_step_over_chain_head
= NULL
;
1938 fprintf_unfiltered (gdb_stdlog
,
1939 "infrun: stealing list of %d threads to step from global queue\n",
1940 thread_step_over_chain_length (threads_to_step
));
1942 for (inferior
*inf
: all_inferiors ())
1943 inf
->displaced_step_state
.unavailable
= false;
1945 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1947 struct execution_control_state ecss
;
1948 struct execution_control_state
*ecs
= &ecss
;
1949 step_over_what step_what
;
1950 int must_be_in_line
;
1952 gdb_assert (!tp
->stop_requested
);
1954 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1956 step_what
= thread_still_needs_step_over (tp
);
1957 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1958 || ((step_what
& STEP_OVER_BREAKPOINT
)
1959 && !use_displaced_stepping (tp
)));
1961 /* We currently stop all threads of all processes to step-over
1962 in-line. If we need to start a new in-line step-over, let
1963 any pending displaced steps finish first. */
1964 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1967 thread_step_over_chain_remove (&threads_to_step
, tp
);
1969 if (tp
->control
.trap_expected
1973 internal_error (__FILE__
, __LINE__
,
1974 "[%s] has inconsistent state: "
1975 "trap_expected=%d, resumed=%d, executing=%d\n",
1976 target_pid_to_str (tp
->ptid
).c_str (),
1977 tp
->control
.trap_expected
,
1982 infrun_log_debug ("resuming [%s] for step-over",
1983 target_pid_to_str (tp
->ptid
).c_str ());
1985 /* keep_going_pass_signal skips the step-over if the breakpoint
1986 is no longer inserted. In all-stop, we want to keep looking
1987 for a thread that needs a step-over instead of resuming TP,
1988 because we wouldn't be able to resume anything else until the
1989 target stops again. In non-stop, the resume always resumes
1990 only TP, so it's OK to let the thread resume freely. */
1991 if (!target_is_non_stop_p () && !step_what
)
1994 if (tp
->inf
->displaced_step_state
.unavailable
)
1996 global_thread_step_over_chain_enqueue (tp
);
2000 switch_to_thread (tp
);
2001 reset_ecs (ecs
, tp
);
2002 keep_going_pass_signal (ecs
);
2004 if (!ecs
->wait_some_more
)
2005 error (_("Command aborted."));
2007 /* If the thread's step over could not be initiated, it was re-added
2008 to the global step over chain. */
2011 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
2012 target_pid_to_str (tp
->ptid
).c_str ());
2013 gdb_assert (!thread_is_in_step_over_chain (tp
));
2017 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
2018 target_pid_to_str (tp
->ptid
).c_str ());
2019 gdb_assert (thread_is_in_step_over_chain (tp
));
2023 /* If we started a new in-line step-over, we're done. */
2024 if (step_over_info_valid_p ())
2026 gdb_assert (tp
->control
.trap_expected
);
2031 if (!target_is_non_stop_p ())
2033 /* On all-stop, shouldn't have resumed unless we needed a
2035 gdb_assert (tp
->control
.trap_expected
2036 || tp
->step_after_step_resume_breakpoint
);
2038 /* With remote targets (at least), in all-stop, we can't
2039 issue any further remote commands until the program stops
2045 /* Either the thread no longer needed a step-over, or a new
2046 displaced stepping sequence started. Even in the latter
2047 case, continue looking. Maybe we can also start another
2048 displaced step on a thread of other process. */
2051 /* If there are threads left in the THREADS_TO_STEP list, but we have
2052 detected that we can't start anything more, put back these threads
2053 in the global list. */
2054 if (threads_to_step
== NULL
)
2057 fprintf_unfiltered (gdb_stdlog
,
2058 "infrun: step-over queue now empty\n");
2063 fprintf_unfiltered (gdb_stdlog
,
2064 "infrun: putting back %d threads to step in global queue\n",
2065 thread_step_over_chain_length (threads_to_step
));
2066 while (threads_to_step
!= nullptr)
2068 thread_info
*thread
= threads_to_step
;
2070 /* Remove from that list. */
2071 thread_step_over_chain_remove (&threads_to_step
, thread
);
2073 /* Add to global list. */
2074 global_thread_step_over_chain_enqueue (thread
);
2082 /* Update global variables holding ptids to hold NEW_PTID if they were
2083 holding OLD_PTID. */
2085 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2087 if (inferior_ptid
== old_ptid
)
2088 inferior_ptid
= new_ptid
;
2093 static const char schedlock_off
[] = "off";
2094 static const char schedlock_on
[] = "on";
2095 static const char schedlock_step
[] = "step";
2096 static const char schedlock_replay
[] = "replay";
2097 static const char *const scheduler_enums
[] = {
2104 static const char *scheduler_mode
= schedlock_replay
;
2106 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2107 struct cmd_list_element
*c
, const char *value
)
2109 fprintf_filtered (file
,
2110 _("Mode for locking scheduler "
2111 "during execution is \"%s\".\n"),
2116 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2118 if (!target_can_lock_scheduler
)
2120 scheduler_mode
= schedlock_off
;
2121 error (_("Target '%s' cannot support this command."), target_shortname
);
2125 /* True if execution commands resume all threads of all processes by
2126 default; otherwise, resume only threads of the current inferior
2128 bool sched_multi
= false;
2130 /* Try to setup for software single stepping over the specified location.
2131 Return 1 if target_resume() should use hardware single step.
2133 GDBARCH the current gdbarch.
2134 PC the location to step over. */
2137 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2141 if (execution_direction
== EXEC_FORWARD
2142 && gdbarch_software_single_step_p (gdbarch
))
2143 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2151 user_visible_resume_ptid (int step
)
2157 /* With non-stop mode on, threads are always handled
2159 resume_ptid
= inferior_ptid
;
2161 else if ((scheduler_mode
== schedlock_on
)
2162 || (scheduler_mode
== schedlock_step
&& step
))
2164 /* User-settable 'scheduler' mode requires solo thread
2166 resume_ptid
= inferior_ptid
;
2168 else if ((scheduler_mode
== schedlock_replay
)
2169 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2171 /* User-settable 'scheduler' mode requires solo thread resume in replay
2173 resume_ptid
= inferior_ptid
;
2175 else if (!sched_multi
&& target_supports_multi_process ())
2177 /* Resume all threads of the current process (and none of other
2179 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2183 /* Resume all threads of all processes. */
2184 resume_ptid
= RESUME_ALL
;
2192 process_stratum_target
*
2193 user_visible_resume_target (ptid_t resume_ptid
)
2195 return (resume_ptid
== minus_one_ptid
&& sched_multi
2197 : current_inferior ()->process_target ());
2200 /* Return a ptid representing the set of threads that we will resume,
2201 in the perspective of the target, assuming run control handling
2202 does not require leaving some threads stopped (e.g., stepping past
2203 breakpoint). USER_STEP indicates whether we're about to start the
2204 target for a stepping command. */
2207 internal_resume_ptid (int user_step
)
2209 /* In non-stop, we always control threads individually. Note that
2210 the target may always work in non-stop mode even with "set
2211 non-stop off", in which case user_visible_resume_ptid could
2212 return a wildcard ptid. */
2213 if (target_is_non_stop_p ())
2214 return inferior_ptid
;
2216 return user_visible_resume_ptid (user_step
);
2219 /* Wrapper for target_resume, that handles infrun-specific
2223 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2225 struct thread_info
*tp
= inferior_thread ();
2227 gdb_assert (!tp
->stop_requested
);
2229 /* Install inferior's terminal modes. */
2230 target_terminal::inferior ();
2232 /* Avoid confusing the next resume, if the next stop/resume
2233 happens to apply to another thread. */
2234 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2236 /* Advise target which signals may be handled silently.
2238 If we have removed breakpoints because we are stepping over one
2239 in-line (in any thread), we need to receive all signals to avoid
2240 accidentally skipping a breakpoint during execution of a signal
2243 Likewise if we're displaced stepping, otherwise a trap for a
2244 breakpoint in a signal handler might be confused with the
2245 displaced step finishing. We don't make the displaced_step_fixup
2246 step distinguish the cases instead, because:
2248 - a backtrace while stopped in the signal handler would show the
2249 scratch pad as frame older than the signal handler, instead of
2250 the real mainline code.
2252 - when the thread is later resumed, the signal handler would
2253 return to the scratch pad area, which would no longer be
2255 if (step_over_info_valid_p ()
2256 || displaced_step_in_progress (tp
->inf
))
2257 target_pass_signals ({});
2259 target_pass_signals (signal_pass
);
2261 target_resume (resume_ptid
, step
, sig
);
2263 target_commit_resume ();
2265 if (target_can_async_p ())
2269 /* Resume the inferior. SIG is the signal to give the inferior
2270 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2271 call 'resume', which handles exceptions. */
2274 resume_1 (enum gdb_signal sig
)
2276 struct regcache
*regcache
= get_current_regcache ();
2277 struct gdbarch
*gdbarch
= regcache
->arch ();
2278 struct thread_info
*tp
= inferior_thread ();
2279 const address_space
*aspace
= regcache
->aspace ();
2281 /* This represents the user's step vs continue request. When
2282 deciding whether "set scheduler-locking step" applies, it's the
2283 user's intention that counts. */
2284 const int user_step
= tp
->control
.stepping_command
;
2285 /* This represents what we'll actually request the target to do.
2286 This can decay from a step to a continue, if e.g., we need to
2287 implement single-stepping with breakpoints (software
2291 gdb_assert (!tp
->stop_requested
);
2292 gdb_assert (!thread_is_in_step_over_chain (tp
));
2294 if (tp
->suspend
.waitstatus_pending_p
)
2297 ("thread %s has pending wait "
2298 "status %s (currently_stepping=%d).",
2299 target_pid_to_str (tp
->ptid
).c_str (),
2300 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2301 currently_stepping (tp
));
2303 tp
->inf
->process_target ()->threads_executing
= true;
2306 /* FIXME: What should we do if we are supposed to resume this
2307 thread with a signal? Maybe we should maintain a queue of
2308 pending signals to deliver. */
2309 if (sig
!= GDB_SIGNAL_0
)
2311 warning (_("Couldn't deliver signal %s to %s."),
2312 gdb_signal_to_name (sig
),
2313 target_pid_to_str (tp
->ptid
).c_str ());
2316 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2318 if (target_can_async_p ())
2321 /* Tell the event loop we have an event to process. */
2322 mark_async_event_handler (infrun_async_inferior_event_token
);
2327 tp
->stepped_breakpoint
= 0;
2329 /* Depends on stepped_breakpoint. */
2330 step
= currently_stepping (tp
);
2332 if (current_inferior ()->waiting_for_vfork_done
)
2334 /* Don't try to single-step a vfork parent that is waiting for
2335 the child to get out of the shared memory region (by exec'ing
2336 or exiting). This is particularly important on software
2337 single-step archs, as the child process would trip on the
2338 software single step breakpoint inserted for the parent
2339 process. Since the parent will not actually execute any
2340 instruction until the child is out of the shared region (such
2341 are vfork's semantics), it is safe to simply continue it.
2342 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2343 the parent, and tell it to `keep_going', which automatically
2344 re-sets it stepping. */
2345 infrun_log_debug ("resume : clear step");
2349 CORE_ADDR pc
= regcache_read_pc (regcache
);
2351 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2352 "current thread [%s] at %s",
2353 step
, gdb_signal_to_symbol_string (sig
),
2354 tp
->control
.trap_expected
,
2355 target_pid_to_str (inferior_ptid
).c_str (),
2356 paddress (gdbarch
, pc
));
2358 /* Normally, by the time we reach `resume', the breakpoints are either
2359 removed or inserted, as appropriate. The exception is if we're sitting
2360 at a permanent breakpoint; we need to step over it, but permanent
2361 breakpoints can't be removed. So we have to test for it here. */
2362 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2364 if (sig
!= GDB_SIGNAL_0
)
2366 /* We have a signal to pass to the inferior. The resume
2367 may, or may not take us to the signal handler. If this
2368 is a step, we'll need to stop in the signal handler, if
2369 there's one, (if the target supports stepping into
2370 handlers), or in the next mainline instruction, if
2371 there's no handler. If this is a continue, we need to be
2372 sure to run the handler with all breakpoints inserted.
2373 In all cases, set a breakpoint at the current address
2374 (where the handler returns to), and once that breakpoint
2375 is hit, resume skipping the permanent breakpoint. If
2376 that breakpoint isn't hit, then we've stepped into the
2377 signal handler (or hit some other event). We'll delete
2378 the step-resume breakpoint then. */
2380 infrun_log_debug ("resume: skipping permanent breakpoint, "
2381 "deliver signal first");
2383 clear_step_over_info ();
2384 tp
->control
.trap_expected
= 0;
2386 if (tp
->control
.step_resume_breakpoint
== NULL
)
2388 /* Set a "high-priority" step-resume, as we don't want
2389 user breakpoints at PC to trigger (again) when this
2391 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2392 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2394 tp
->step_after_step_resume_breakpoint
= step
;
2397 insert_breakpoints ();
2401 /* There's no signal to pass, we can go ahead and skip the
2402 permanent breakpoint manually. */
2403 infrun_log_debug ("skipping permanent breakpoint");
2404 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2405 /* Update pc to reflect the new address from which we will
2406 execute instructions. */
2407 pc
= regcache_read_pc (regcache
);
2411 /* We've already advanced the PC, so the stepping part
2412 is done. Now we need to arrange for a trap to be
2413 reported to handle_inferior_event. Set a breakpoint
2414 at the current PC, and run to it. Don't update
2415 prev_pc, because if we end in
2416 switch_back_to_stepped_thread, we want the "expected
2417 thread advanced also" branch to be taken. IOW, we
2418 don't want this thread to step further from PC
2420 gdb_assert (!step_over_info_valid_p ());
2421 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2422 insert_breakpoints ();
2424 resume_ptid
= internal_resume_ptid (user_step
);
2425 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2432 /* If we have a breakpoint to step over, make sure to do a single
2433 step only. Same if we have software watchpoints. */
2434 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2435 tp
->control
.may_range_step
= 0;
2437 /* If displaced stepping is enabled, step over breakpoints by executing a
2438 copy of the instruction at a different address.
2440 We can't use displaced stepping when we have a signal to deliver;
2441 the comments for displaced_step_prepare explain why. The
2442 comments in the handle_inferior event for dealing with 'random
2443 signals' explain what we do instead.
2445 We can't use displaced stepping when we are waiting for vfork_done
2446 event, displaced stepping breaks the vfork child similarly as single
2447 step software breakpoint. */
2448 if (tp
->control
.trap_expected
2449 && use_displaced_stepping (tp
)
2450 && !step_over_info_valid_p ()
2451 && sig
== GDB_SIGNAL_0
2452 && !current_inferior ()->waiting_for_vfork_done
)
2454 displaced_step_prepare_status prepare_status
2455 = displaced_step_prepare (tp
);
2457 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2459 infrun_log_debug ("Got placed in step-over queue");
2461 tp
->control
.trap_expected
= 0;
2464 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2466 /* Fallback to stepping over the breakpoint in-line. */
2468 if (target_is_non_stop_p ())
2469 stop_all_threads ();
2471 set_step_over_info (regcache
->aspace (),
2472 regcache_read_pc (regcache
), 0, tp
->global_num
);
2474 step
= maybe_software_singlestep (gdbarch
, pc
);
2476 insert_breakpoints ();
2478 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2480 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2483 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2486 /* Do we need to do it the hard way, w/temp breakpoints? */
2488 step
= maybe_software_singlestep (gdbarch
, pc
);
2490 /* Currently, our software single-step implementation leads to different
2491 results than hardware single-stepping in one situation: when stepping
2492 into delivering a signal which has an associated signal handler,
2493 hardware single-step will stop at the first instruction of the handler,
2494 while software single-step will simply skip execution of the handler.
2496 For now, this difference in behavior is accepted since there is no
2497 easy way to actually implement single-stepping into a signal handler
2498 without kernel support.
2500 However, there is one scenario where this difference leads to follow-on
2501 problems: if we're stepping off a breakpoint by removing all breakpoints
2502 and then single-stepping. In this case, the software single-step
2503 behavior means that even if there is a *breakpoint* in the signal
2504 handler, GDB still would not stop.
2506 Fortunately, we can at least fix this particular issue. We detect
2507 here the case where we are about to deliver a signal while software
2508 single-stepping with breakpoints removed. In this situation, we
2509 revert the decisions to remove all breakpoints and insert single-
2510 step breakpoints, and instead we install a step-resume breakpoint
2511 at the current address, deliver the signal without stepping, and
2512 once we arrive back at the step-resume breakpoint, actually step
2513 over the breakpoint we originally wanted to step over. */
2514 if (thread_has_single_step_breakpoints_set (tp
)
2515 && sig
!= GDB_SIGNAL_0
2516 && step_over_info_valid_p ())
2518 /* If we have nested signals or a pending signal is delivered
2519 immediately after a handler returns, might already have
2520 a step-resume breakpoint set on the earlier handler. We cannot
2521 set another step-resume breakpoint; just continue on until the
2522 original breakpoint is hit. */
2523 if (tp
->control
.step_resume_breakpoint
== NULL
)
2525 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2526 tp
->step_after_step_resume_breakpoint
= 1;
2529 delete_single_step_breakpoints (tp
);
2531 clear_step_over_info ();
2532 tp
->control
.trap_expected
= 0;
2534 insert_breakpoints ();
2537 /* If STEP is set, it's a request to use hardware stepping
2538 facilities. But in that case, we should never
2539 use singlestep breakpoint. */
2540 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2542 /* Decide the set of threads to ask the target to resume. */
2543 if (tp
->control
.trap_expected
)
2545 /* We're allowing a thread to run past a breakpoint it has
2546 hit, either by single-stepping the thread with the breakpoint
2547 removed, or by displaced stepping, with the breakpoint inserted.
2548 In the former case, we need to single-step only this thread,
2549 and keep others stopped, as they can miss this breakpoint if
2550 allowed to run. That's not really a problem for displaced
2551 stepping, but, we still keep other threads stopped, in case
2552 another thread is also stopped for a breakpoint waiting for
2553 its turn in the displaced stepping queue. */
2554 resume_ptid
= inferior_ptid
;
2557 resume_ptid
= internal_resume_ptid (user_step
);
2559 if (execution_direction
!= EXEC_REVERSE
2560 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2562 /* There are two cases where we currently need to step a
2563 breakpoint instruction when we have a signal to deliver:
2565 - See handle_signal_stop where we handle random signals that
2566 could take out us out of the stepping range. Normally, in
2567 that case we end up continuing (instead of stepping) over the
2568 signal handler with a breakpoint at PC, but there are cases
2569 where we should _always_ single-step, even if we have a
2570 step-resume breakpoint, like when a software watchpoint is
2571 set. Assuming single-stepping and delivering a signal at the
2572 same time would takes us to the signal handler, then we could
2573 have removed the breakpoint at PC to step over it. However,
2574 some hardware step targets (like e.g., Mac OS) can't step
2575 into signal handlers, and for those, we need to leave the
2576 breakpoint at PC inserted, as otherwise if the handler
2577 recurses and executes PC again, it'll miss the breakpoint.
2578 So we leave the breakpoint inserted anyway, but we need to
2579 record that we tried to step a breakpoint instruction, so
2580 that adjust_pc_after_break doesn't end up confused.
2582 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2583 in one thread after another thread that was stepping had been
2584 momentarily paused for a step-over. When we re-resume the
2585 stepping thread, it may be resumed from that address with a
2586 breakpoint that hasn't trapped yet. Seen with
2587 gdb.threads/non-stop-fair-events.exp, on targets that don't
2588 do displaced stepping. */
2590 infrun_log_debug ("resume: [%s] stepped breakpoint",
2591 target_pid_to_str (tp
->ptid
).c_str ());
2593 tp
->stepped_breakpoint
= 1;
2595 /* Most targets can step a breakpoint instruction, thus
2596 executing it normally. But if this one cannot, just
2597 continue and we will hit it anyway. */
2598 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2603 && tp
->control
.trap_expected
2604 && use_displaced_stepping (tp
)
2605 && !step_over_info_valid_p ())
2607 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2608 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2609 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2612 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2613 paddress (resume_gdbarch
, actual_pc
));
2614 read_memory (actual_pc
, buf
, sizeof (buf
));
2615 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2618 if (tp
->control
.may_range_step
)
2620 /* If we're resuming a thread with the PC out of the step
2621 range, then we're doing some nested/finer run control
2622 operation, like stepping the thread out of the dynamic
2623 linker or the displaced stepping scratch pad. We
2624 shouldn't have allowed a range step then. */
2625 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2628 do_target_resume (resume_ptid
, step
, sig
);
2632 /* Resume the inferior. SIG is the signal to give the inferior
2633 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2634 rolls back state on error. */
2637 resume (gdb_signal sig
)
2643 catch (const gdb_exception
&ex
)
2645 /* If resuming is being aborted for any reason, delete any
2646 single-step breakpoint resume_1 may have created, to avoid
2647 confusing the following resumption, and to avoid leaving
2648 single-step breakpoints perturbing other threads, in case
2649 we're running in non-stop mode. */
2650 if (inferior_ptid
!= null_ptid
)
2651 delete_single_step_breakpoints (inferior_thread ());
2661 /* Counter that tracks number of user visible stops. This can be used
2662 to tell whether a command has proceeded the inferior past the
2663 current location. This allows e.g., inferior function calls in
2664 breakpoint commands to not interrupt the command list. When the
2665 call finishes successfully, the inferior is standing at the same
2666 breakpoint as if nothing happened (and so we don't call
2668 static ULONGEST current_stop_id
;
2675 return current_stop_id
;
2678 /* Called when we report a user visible stop. */
2686 /* Clear out all variables saying what to do when inferior is continued.
2687 First do this, then set the ones you want, then call `proceed'. */
2690 clear_proceed_status_thread (struct thread_info
*tp
)
2692 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2694 /* If we're starting a new sequence, then the previous finished
2695 single-step is no longer relevant. */
2696 if (tp
->suspend
.waitstatus_pending_p
)
2698 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2700 infrun_log_debug ("pending event of %s was a finished step. "
2702 target_pid_to_str (tp
->ptid
).c_str ());
2704 tp
->suspend
.waitstatus_pending_p
= 0;
2705 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2710 ("thread %s has pending wait status %s (currently_stepping=%d).",
2711 target_pid_to_str (tp
->ptid
).c_str (),
2712 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2713 currently_stepping (tp
));
2717 /* If this signal should not be seen by program, give it zero.
2718 Used for debugging signals. */
2719 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2720 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2722 delete tp
->thread_fsm
;
2723 tp
->thread_fsm
= NULL
;
2725 tp
->control
.trap_expected
= 0;
2726 tp
->control
.step_range_start
= 0;
2727 tp
->control
.step_range_end
= 0;
2728 tp
->control
.may_range_step
= 0;
2729 tp
->control
.step_frame_id
= null_frame_id
;
2730 tp
->control
.step_stack_frame_id
= null_frame_id
;
2731 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2732 tp
->control
.step_start_function
= NULL
;
2733 tp
->stop_requested
= 0;
2735 tp
->control
.stop_step
= 0;
2737 tp
->control
.proceed_to_finish
= 0;
2739 tp
->control
.stepping_command
= 0;
2741 /* Discard any remaining commands or status from previous stop. */
2742 bpstat_clear (&tp
->control
.stop_bpstat
);
2746 clear_proceed_status (int step
)
2748 /* With scheduler-locking replay, stop replaying other threads if we're
2749 not replaying the user-visible resume ptid.
2751 This is a convenience feature to not require the user to explicitly
2752 stop replaying the other threads. We're assuming that the user's
2753 intent is to resume tracing the recorded process. */
2754 if (!non_stop
&& scheduler_mode
== schedlock_replay
2755 && target_record_is_replaying (minus_one_ptid
)
2756 && !target_record_will_replay (user_visible_resume_ptid (step
),
2757 execution_direction
))
2758 target_record_stop_replaying ();
2760 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2762 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2763 process_stratum_target
*resume_target
2764 = user_visible_resume_target (resume_ptid
);
2766 /* In all-stop mode, delete the per-thread status of all threads
2767 we're about to resume, implicitly and explicitly. */
2768 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2769 clear_proceed_status_thread (tp
);
2772 if (inferior_ptid
!= null_ptid
)
2774 struct inferior
*inferior
;
2778 /* If in non-stop mode, only delete the per-thread status of
2779 the current thread. */
2780 clear_proceed_status_thread (inferior_thread ());
2783 inferior
= current_inferior ();
2784 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2787 gdb::observers::about_to_proceed
.notify ();
2790 /* Returns true if TP is still stopped at a breakpoint that needs
2791 stepping-over in order to make progress. If the breakpoint is gone
2792 meanwhile, we can skip the whole step-over dance. */
2795 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2797 if (tp
->stepping_over_breakpoint
)
2799 struct regcache
*regcache
= get_thread_regcache (tp
);
2801 if (breakpoint_here_p (regcache
->aspace (),
2802 regcache_read_pc (regcache
))
2803 == ordinary_breakpoint_here
)
2806 tp
->stepping_over_breakpoint
= 0;
2812 /* Check whether thread TP still needs to start a step-over in order
2813 to make progress when resumed. Returns an bitwise or of enum
2814 step_over_what bits, indicating what needs to be stepped over. */
2816 static step_over_what
2817 thread_still_needs_step_over (struct thread_info
*tp
)
2819 step_over_what what
= 0;
2821 if (thread_still_needs_step_over_bp (tp
))
2822 what
|= STEP_OVER_BREAKPOINT
;
2824 if (tp
->stepping_over_watchpoint
2825 && !target_have_steppable_watchpoint
)
2826 what
|= STEP_OVER_WATCHPOINT
;
2831 /* Returns true if scheduler locking applies. STEP indicates whether
2832 we're about to do a step/next-like command to a thread. */
2835 schedlock_applies (struct thread_info
*tp
)
2837 return (scheduler_mode
== schedlock_on
2838 || (scheduler_mode
== schedlock_step
2839 && tp
->control
.stepping_command
)
2840 || (scheduler_mode
== schedlock_replay
2841 && target_record_will_replay (minus_one_ptid
,
2842 execution_direction
)));
2845 /* Calls target_commit_resume on all targets. */
2848 commit_resume_all_targets ()
2850 scoped_restore_current_thread restore_thread
;
2852 /* Map between process_target and a representative inferior. This
2853 is to avoid committing a resume in the same target more than
2854 once. Resumptions must be idempotent, so this is an
2856 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2858 for (inferior
*inf
: all_non_exited_inferiors ())
2859 if (inf
->has_execution ())
2860 conn_inf
[inf
->process_target ()] = inf
;
2862 for (const auto &ci
: conn_inf
)
2864 inferior
*inf
= ci
.second
;
2865 switch_to_inferior_no_thread (inf
);
2866 target_commit_resume ();
2870 /* Check that all the targets we're about to resume are in non-stop
2871 mode. Ideally, we'd only care whether all targets support
2872 target-async, but we're not there yet. E.g., stop_all_threads
2873 doesn't know how to handle all-stop targets. Also, the remote
2874 protocol in all-stop mode is synchronous, irrespective of
2875 target-async, which means that things like a breakpoint re-set
2876 triggered by one target would try to read memory from all targets
2880 check_multi_target_resumption (process_stratum_target
*resume_target
)
2882 if (!non_stop
&& resume_target
== nullptr)
2884 scoped_restore_current_thread restore_thread
;
2886 /* This is used to track whether we're resuming more than one
2888 process_stratum_target
*first_connection
= nullptr;
2890 /* The first inferior we see with a target that does not work in
2891 always-non-stop mode. */
2892 inferior
*first_not_non_stop
= nullptr;
2894 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2896 switch_to_inferior_no_thread (inf
);
2898 if (!target_has_execution
)
2901 process_stratum_target
*proc_target
2902 = current_inferior ()->process_target();
2904 if (!target_is_non_stop_p ())
2905 first_not_non_stop
= inf
;
2907 if (first_connection
== nullptr)
2908 first_connection
= proc_target
;
2909 else if (first_connection
!= proc_target
2910 && first_not_non_stop
!= nullptr)
2912 switch_to_inferior_no_thread (first_not_non_stop
);
2914 proc_target
= current_inferior ()->process_target();
2916 error (_("Connection %d (%s) does not support "
2917 "multi-target resumption."),
2918 proc_target
->connection_number
,
2919 make_target_connection_string (proc_target
).c_str ());
2925 /* Basic routine for continuing the program in various fashions.
2927 ADDR is the address to resume at, or -1 for resume where stopped.
2928 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2929 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2931 You should call clear_proceed_status before calling proceed. */
2934 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2936 struct regcache
*regcache
;
2937 struct gdbarch
*gdbarch
;
2939 struct execution_control_state ecss
;
2940 struct execution_control_state
*ecs
= &ecss
;
2943 /* If we're stopped at a fork/vfork, follow the branch set by the
2944 "set follow-fork-mode" command; otherwise, we'll just proceed
2945 resuming the current thread. */
2946 if (!follow_fork ())
2948 /* The target for some reason decided not to resume. */
2950 if (target_can_async_p ())
2951 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2955 /* We'll update this if & when we switch to a new thread. */
2956 previous_inferior_ptid
= inferior_ptid
;
2958 regcache
= get_current_regcache ();
2959 gdbarch
= regcache
->arch ();
2960 const address_space
*aspace
= regcache
->aspace ();
2962 pc
= regcache_read_pc_protected (regcache
);
2964 thread_info
*cur_thr
= inferior_thread ();
2966 /* Fill in with reasonable starting values. */
2967 init_thread_stepping_state (cur_thr
);
2969 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2972 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2973 process_stratum_target
*resume_target
2974 = user_visible_resume_target (resume_ptid
);
2976 check_multi_target_resumption (resume_target
);
2978 if (addr
== (CORE_ADDR
) -1)
2980 if (pc
== cur_thr
->suspend
.stop_pc
2981 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2982 && execution_direction
!= EXEC_REVERSE
)
2983 /* There is a breakpoint at the address we will resume at,
2984 step one instruction before inserting breakpoints so that
2985 we do not stop right away (and report a second hit at this
2988 Note, we don't do this in reverse, because we won't
2989 actually be executing the breakpoint insn anyway.
2990 We'll be (un-)executing the previous instruction. */
2991 cur_thr
->stepping_over_breakpoint
= 1;
2992 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2993 && gdbarch_single_step_through_delay (gdbarch
,
2994 get_current_frame ()))
2995 /* We stepped onto an instruction that needs to be stepped
2996 again before re-inserting the breakpoint, do so. */
2997 cur_thr
->stepping_over_breakpoint
= 1;
3001 regcache_write_pc (regcache
, addr
);
3004 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3005 cur_thr
->suspend
.stop_signal
= siggnal
;
3007 /* If an exception is thrown from this point on, make sure to
3008 propagate GDB's knowledge of the executing state to the
3009 frontend/user running state. */
3010 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3012 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3013 threads (e.g., we might need to set threads stepping over
3014 breakpoints first), from the user/frontend's point of view, all
3015 threads in RESUME_PTID are now running. Unless we're calling an
3016 inferior function, as in that case we pretend the inferior
3017 doesn't run at all. */
3018 if (!cur_thr
->control
.in_infcall
)
3019 set_running (resume_target
, resume_ptid
, true);
3021 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3022 gdb_signal_to_symbol_string (siggnal
));
3024 annotate_starting ();
3026 /* Make sure that output from GDB appears before output from the
3028 gdb_flush (gdb_stdout
);
3030 /* Since we've marked the inferior running, give it the terminal. A
3031 QUIT/Ctrl-C from here on is forwarded to the target (which can
3032 still detect attempts to unblock a stuck connection with repeated
3033 Ctrl-C from within target_pass_ctrlc). */
3034 target_terminal::inferior ();
3036 /* In a multi-threaded task we may select another thread and
3037 then continue or step.
3039 But if a thread that we're resuming had stopped at a breakpoint,
3040 it will immediately cause another breakpoint stop without any
3041 execution (i.e. it will report a breakpoint hit incorrectly). So
3042 we must step over it first.
3044 Look for threads other than the current (TP) that reported a
3045 breakpoint hit and haven't been resumed yet since. */
3047 /* If scheduler locking applies, we can avoid iterating over all
3049 if (!non_stop
&& !schedlock_applies (cur_thr
))
3051 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3054 switch_to_thread_no_regs (tp
);
3056 /* Ignore the current thread here. It's handled
3061 if (!thread_still_needs_step_over (tp
))
3064 gdb_assert (!thread_is_in_step_over_chain (tp
));
3066 infrun_log_debug ("need to step-over [%s] first",
3067 target_pid_to_str (tp
->ptid
).c_str ());
3069 global_thread_step_over_chain_enqueue (tp
);
3072 switch_to_thread (cur_thr
);
3075 /* Enqueue the current thread last, so that we move all other
3076 threads over their breakpoints first. */
3077 if (cur_thr
->stepping_over_breakpoint
)
3078 global_thread_step_over_chain_enqueue (cur_thr
);
3080 /* If the thread isn't started, we'll still need to set its prev_pc,
3081 so that switch_back_to_stepped_thread knows the thread hasn't
3082 advanced. Must do this before resuming any thread, as in
3083 all-stop/remote, once we resume we can't send any other packet
3084 until the target stops again. */
3085 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3088 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3090 started
= start_step_over ();
3092 if (step_over_info_valid_p ())
3094 /* Either this thread started a new in-line step over, or some
3095 other thread was already doing one. In either case, don't
3096 resume anything else until the step-over is finished. */
3098 else if (started
&& !target_is_non_stop_p ())
3100 /* A new displaced stepping sequence was started. In all-stop,
3101 we can't talk to the target anymore until it next stops. */
3103 else if (!non_stop
&& target_is_non_stop_p ())
3105 /* In all-stop, but the target is always in non-stop mode.
3106 Start all other threads that are implicitly resumed too. */
3107 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3110 switch_to_thread_no_regs (tp
);
3112 if (!tp
->inf
->has_execution ())
3114 infrun_log_debug ("[%s] target has no execution",
3115 target_pid_to_str (tp
->ptid
).c_str ());
3121 infrun_log_debug ("[%s] resumed",
3122 target_pid_to_str (tp
->ptid
).c_str ());
3123 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3127 if (thread_is_in_step_over_chain (tp
))
3129 infrun_log_debug ("[%s] needs step-over",
3130 target_pid_to_str (tp
->ptid
).c_str ());
3134 infrun_log_debug ("resuming %s",
3135 target_pid_to_str (tp
->ptid
).c_str ());
3137 reset_ecs (ecs
, tp
);
3138 switch_to_thread (tp
);
3139 keep_going_pass_signal (ecs
);
3140 if (!ecs
->wait_some_more
)
3141 error (_("Command aborted."));
3144 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3146 /* The thread wasn't started, and isn't queued, run it now. */
3147 reset_ecs (ecs
, cur_thr
);
3148 switch_to_thread (cur_thr
);
3149 keep_going_pass_signal (ecs
);
3150 if (!ecs
->wait_some_more
)
3151 error (_("Command aborted."));
3155 commit_resume_all_targets ();
3157 finish_state
.release ();
3159 /* If we've switched threads above, switch back to the previously
3160 current thread. We don't want the user to see a different
3162 switch_to_thread (cur_thr
);
3164 /* Tell the event loop to wait for it to stop. If the target
3165 supports asynchronous execution, it'll do this from within
3167 if (!target_can_async_p ())
3168 mark_async_event_handler (infrun_async_inferior_event_token
);
3172 /* Start remote-debugging of a machine over a serial link. */
3175 start_remote (int from_tty
)
3177 inferior
*inf
= current_inferior ();
3178 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3180 /* Always go on waiting for the target, regardless of the mode. */
3181 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3182 indicate to wait_for_inferior that a target should timeout if
3183 nothing is returned (instead of just blocking). Because of this,
3184 targets expecting an immediate response need to, internally, set
3185 things up so that the target_wait() is forced to eventually
3187 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3188 differentiate to its caller what the state of the target is after
3189 the initial open has been performed. Here we're assuming that
3190 the target has stopped. It should be possible to eventually have
3191 target_open() return to the caller an indication that the target
3192 is currently running and GDB state should be set to the same as
3193 for an async run. */
3194 wait_for_inferior (inf
);
3196 /* Now that the inferior has stopped, do any bookkeeping like
3197 loading shared libraries. We want to do this before normal_stop,
3198 so that the displayed frame is up to date. */
3199 post_create_inferior (current_top_target (), from_tty
);
3204 /* Initialize static vars when a new inferior begins. */
3207 init_wait_for_inferior (void)
3209 /* These are meaningless until the first time through wait_for_inferior. */
3211 breakpoint_init_inferior (inf_starting
);
3213 clear_proceed_status (0);
3215 nullify_last_target_wait_ptid ();
3217 previous_inferior_ptid
= inferior_ptid
;
3222 static void handle_inferior_event (struct execution_control_state
*ecs
);
3224 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3225 struct execution_control_state
*ecs
);
3226 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3227 struct execution_control_state
*ecs
);
3228 static void handle_signal_stop (struct execution_control_state
*ecs
);
3229 static void check_exception_resume (struct execution_control_state
*,
3230 struct frame_info
*);
3232 static void end_stepping_range (struct execution_control_state
*ecs
);
3233 static void stop_waiting (struct execution_control_state
*ecs
);
3234 static void keep_going (struct execution_control_state
*ecs
);
3235 static void process_event_stop_test (struct execution_control_state
*ecs
);
3236 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3238 /* This function is attached as a "thread_stop_requested" observer.
3239 Cleanup local state that assumed the PTID was to be resumed, and
3240 report the stop to the frontend. */
3243 infrun_thread_stop_requested (ptid_t ptid
)
3245 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3247 /* PTID was requested to stop. If the thread was already stopped,
3248 but the user/frontend doesn't know about that yet (e.g., the
3249 thread had been temporarily paused for some step-over), set up
3250 for reporting the stop now. */
3251 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3253 if (tp
->state
!= THREAD_RUNNING
)
3258 /* Remove matching threads from the step-over queue, so
3259 start_step_over doesn't try to resume them
3261 if (thread_is_in_step_over_chain (tp
))
3262 global_thread_step_over_chain_remove (tp
);
3264 /* If the thread is stopped, but the user/frontend doesn't
3265 know about that yet, queue a pending event, as if the
3266 thread had just stopped now. Unless the thread already had
3268 if (!tp
->suspend
.waitstatus_pending_p
)
3270 tp
->suspend
.waitstatus_pending_p
= 1;
3271 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3272 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3275 /* Clear the inline-frame state, since we're re-processing the
3277 clear_inline_frame_state (tp
);
3279 /* If this thread was paused because some other thread was
3280 doing an inline-step over, let that finish first. Once
3281 that happens, we'll restart all threads and consume pending
3282 stop events then. */
3283 if (step_over_info_valid_p ())
3286 /* Otherwise we can process the (new) pending event now. Set
3287 it so this pending event is considered by
3294 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3296 if (target_last_proc_target
== tp
->inf
->process_target ()
3297 && target_last_wait_ptid
== tp
->ptid
)
3298 nullify_last_target_wait_ptid ();
3301 /* Delete the step resume, single-step and longjmp/exception resume
3302 breakpoints of TP. */
3305 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3307 delete_step_resume_breakpoint (tp
);
3308 delete_exception_resume_breakpoint (tp
);
3309 delete_single_step_breakpoints (tp
);
3312 /* If the target still has execution, call FUNC for each thread that
3313 just stopped. In all-stop, that's all the non-exited threads; in
3314 non-stop, that's the current thread, only. */
3316 typedef void (*for_each_just_stopped_thread_callback_func
)
3317 (struct thread_info
*tp
);
3320 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3322 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3325 if (target_is_non_stop_p ())
3327 /* If in non-stop mode, only the current thread stopped. */
3328 func (inferior_thread ());
3332 /* In all-stop mode, all threads have stopped. */
3333 for (thread_info
*tp
: all_non_exited_threads ())
3338 /* Delete the step resume and longjmp/exception resume breakpoints of
3339 the threads that just stopped. */
3342 delete_just_stopped_threads_infrun_breakpoints (void)
3344 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3347 /* Delete the single-step breakpoints of the threads that just
3351 delete_just_stopped_threads_single_step_breakpoints (void)
3353 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3359 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3360 const struct target_waitstatus
*ws
)
3362 std::string status_string
= target_waitstatus_to_string (ws
);
3365 /* The text is split over several lines because it was getting too long.
3366 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3367 output as a unit; we want only one timestamp printed if debug_timestamp
3370 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3373 waiton_ptid
.tid ());
3374 if (waiton_ptid
.pid () != -1)
3375 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3376 stb
.printf (", status) =\n");
3377 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3381 target_pid_to_str (result_ptid
).c_str ());
3382 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3384 /* This uses %s in part to handle %'s in the text, but also to avoid
3385 a gcc error: the format attribute requires a string literal. */
3386 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3389 /* Select a thread at random, out of those which are resumed and have
3392 static struct thread_info
*
3393 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3397 auto has_event
= [&] (thread_info
*tp
)
3399 return (tp
->ptid
.matches (waiton_ptid
)
3401 && tp
->suspend
.waitstatus_pending_p
);
3404 /* First see how many events we have. Count only resumed threads
3405 that have an event pending. */
3406 for (thread_info
*tp
: inf
->non_exited_threads ())
3410 if (num_events
== 0)
3413 /* Now randomly pick a thread out of those that have had events. */
3414 int random_selector
= (int) ((num_events
* (double) rand ())
3415 / (RAND_MAX
+ 1.0));
3418 infrun_log_debug ("Found %d events, selecting #%d",
3419 num_events
, random_selector
);
3421 /* Select the Nth thread that has had an event. */
3422 for (thread_info
*tp
: inf
->non_exited_threads ())
3424 if (random_selector
-- == 0)
3427 gdb_assert_not_reached ("event thread not found");
3430 /* Wrapper for target_wait that first checks whether threads have
3431 pending statuses to report before actually asking the target for
3432 more events. INF is the inferior we're using to call target_wait
3436 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3437 target_waitstatus
*status
, int options
)
3440 struct thread_info
*tp
;
3442 /* We know that we are looking for an event in the target of inferior
3443 INF, but we don't know which thread the event might come from. As
3444 such we want to make sure that INFERIOR_PTID is reset so that none of
3445 the wait code relies on it - doing so is always a mistake. */
3446 switch_to_inferior_no_thread (inf
);
3448 /* First check if there is a resumed thread with a wait status
3450 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3452 tp
= random_pending_event_thread (inf
, ptid
);
3456 infrun_log_debug ("Waiting for specific thread %s.",
3457 target_pid_to_str (ptid
).c_str ());
3459 /* We have a specific thread to check. */
3460 tp
= find_thread_ptid (inf
, ptid
);
3461 gdb_assert (tp
!= NULL
);
3462 if (!tp
->suspend
.waitstatus_pending_p
)
3467 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3468 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3470 struct regcache
*regcache
= get_thread_regcache (tp
);
3471 struct gdbarch
*gdbarch
= regcache
->arch ();
3475 pc
= regcache_read_pc (regcache
);
3477 if (pc
!= tp
->suspend
.stop_pc
)
3479 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3480 target_pid_to_str (tp
->ptid
).c_str (),
3481 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3482 paddress (gdbarch
, pc
));
3485 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3487 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3488 target_pid_to_str (tp
->ptid
).c_str (),
3489 paddress (gdbarch
, pc
));
3496 infrun_log_debug ("pending event of %s cancelled.",
3497 target_pid_to_str (tp
->ptid
).c_str ());
3499 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3500 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3506 infrun_log_debug ("Using pending wait status %s for %s.",
3507 target_waitstatus_to_string
3508 (&tp
->suspend
.waitstatus
).c_str (),
3509 target_pid_to_str (tp
->ptid
).c_str ());
3511 /* Now that we've selected our final event LWP, un-adjust its PC
3512 if it was a software breakpoint (and the target doesn't
3513 always adjust the PC itself). */
3514 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3515 && !target_supports_stopped_by_sw_breakpoint ())
3517 struct regcache
*regcache
;
3518 struct gdbarch
*gdbarch
;
3521 regcache
= get_thread_regcache (tp
);
3522 gdbarch
= regcache
->arch ();
3524 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3529 pc
= regcache_read_pc (regcache
);
3530 regcache_write_pc (regcache
, pc
+ decr_pc
);
3534 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3535 *status
= tp
->suspend
.waitstatus
;
3536 tp
->suspend
.waitstatus_pending_p
= 0;
3538 /* Wake up the event loop again, until all pending events are
3540 if (target_is_async_p ())
3541 mark_async_event_handler (infrun_async_inferior_event_token
);
3545 /* But if we don't find one, we'll have to wait. */
3547 if (deprecated_target_wait_hook
)
3548 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3550 event_ptid
= target_wait (ptid
, status
, options
);
3555 /* Returns true if INF has any resumed thread with a status
3559 threads_are_resumed_pending_p (inferior
*inf
)
3561 for (thread_info
*tp
: inf
->non_exited_threads ())
3563 && tp
->suspend
.waitstatus_pending_p
)
3569 /* Wrapper for target_wait that first checks whether threads have
3570 pending statuses to report before actually asking the target for
3571 more events. Polls for events from all inferiors/targets. */
3574 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3576 int num_inferiors
= 0;
3577 int random_selector
;
3579 /* For fairness, we pick the first inferior/target to poll at
3580 random, and then continue polling the rest of the inferior list
3581 starting from that one in a circular fashion until the whole list
3584 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3586 return (inf
->process_target () != NULL
3587 && (threads_are_executing (inf
->process_target ())
3588 || threads_are_resumed_pending_p (inf
))
3589 && ptid_t (inf
->pid
).matches (wait_ptid
));
3592 /* First see how many resumed inferiors we have. */
3593 for (inferior
*inf
: all_inferiors ())
3594 if (inferior_matches (inf
))
3597 if (num_inferiors
== 0)
3599 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3603 /* Now randomly pick an inferior out of those that were resumed. */
3604 random_selector
= (int)
3605 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3607 if (num_inferiors
> 1)
3608 infrun_log_debug ("Found %d inferiors, starting at #%d",
3609 num_inferiors
, random_selector
);
3611 /* Select the Nth inferior that was resumed. */
3613 inferior
*selected
= nullptr;
3615 for (inferior
*inf
: all_inferiors ())
3616 if (inferior_matches (inf
))
3617 if (random_selector
-- == 0)
3623 /* Now poll for events out of each of the resumed inferior's
3624 targets, starting from the selected one. */
3626 auto do_wait
= [&] (inferior
*inf
)
3628 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3629 ecs
->target
= inf
->process_target ();
3630 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3633 /* Needed in all-stop+target-non-stop mode, because we end up here
3634 spuriously after the target is all stopped and we've already
3635 reported the stop to the user, polling for events. */
3636 scoped_restore_current_thread restore_thread
;
3638 int inf_num
= selected
->num
;
3639 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3640 if (inferior_matches (inf
))
3644 for (inferior
*inf
= inferior_list
;
3645 inf
!= NULL
&& inf
->num
< inf_num
;
3647 if (inferior_matches (inf
))
3651 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3655 /* Prepare and stabilize the inferior for detaching it. E.g.,
3656 detaching while a thread is displaced stepping is a recipe for
3657 crashing it, as nothing would readjust the PC out of the scratch
3661 prepare_for_detach (void)
3663 struct inferior
*inf
= current_inferior ();
3664 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3666 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3668 /* Is any thread of this process displaced stepping? If not,
3669 there's nothing else to do. */
3670 if (displaced_step_in_progress (inf
))
3673 infrun_log_debug ("displaced-stepping in-process while detaching");
3675 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3680 struct execution_control_state ecss
;
3681 struct execution_control_state
*ecs
;
3684 memset (ecs
, 0, sizeof (*ecs
));
3686 overlay_cache_invalid
= 1;
3687 /* Flush target cache before starting to handle each event.
3688 Target was running and cache could be stale. This is just a
3689 heuristic. Running threads may modify target memory, but we
3690 don't get any event. */
3691 target_dcache_invalidate ();
3693 do_target_wait (pid_ptid
, ecs
, 0);
3696 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3698 /* If an error happens while handling the event, propagate GDB's
3699 knowledge of the executing state to the frontend/user running
3701 scoped_finish_thread_state
finish_state (inf
->process_target (),
3704 /* Now figure out what to do with the result of the result. */
3705 handle_inferior_event (ecs
);
3707 /* No error, don't finish the state yet. */
3708 finish_state
.release ();
3710 /* Breakpoints and watchpoints are not installed on the target
3711 at this point, and signals are passed directly to the
3712 inferior, so this must mean the process is gone. */
3713 if (!ecs
->wait_some_more
)
3715 restore_detaching
.release ();
3716 error (_("Program exited while detaching"));
3720 restore_detaching
.release ();
3723 /* Wait for control to return from inferior to debugger.
3725 If inferior gets a signal, we may decide to start it up again
3726 instead of returning. That is why there is a loop in this function.
3727 When this function actually returns it means the inferior
3728 should be left stopped and GDB should read more commands. */
3731 wait_for_inferior (inferior
*inf
)
3733 infrun_log_debug ("wait_for_inferior ()");
3735 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3737 /* If an error happens while handling the event, propagate GDB's
3738 knowledge of the executing state to the frontend/user running
3740 scoped_finish_thread_state finish_state
3741 (inf
->process_target (), minus_one_ptid
);
3745 struct execution_control_state ecss
;
3746 struct execution_control_state
*ecs
= &ecss
;
3748 memset (ecs
, 0, sizeof (*ecs
));
3750 overlay_cache_invalid
= 1;
3752 /* Flush target cache before starting to handle each event.
3753 Target was running and cache could be stale. This is just a
3754 heuristic. Running threads may modify target memory, but we
3755 don't get any event. */
3756 target_dcache_invalidate ();
3758 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3759 ecs
->target
= inf
->process_target ();
3762 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3764 /* Now figure out what to do with the result of the result. */
3765 handle_inferior_event (ecs
);
3767 if (!ecs
->wait_some_more
)
3771 /* No error, don't finish the state yet. */
3772 finish_state
.release ();
3775 /* Cleanup that reinstalls the readline callback handler, if the
3776 target is running in the background. If while handling the target
3777 event something triggered a secondary prompt, like e.g., a
3778 pagination prompt, we'll have removed the callback handler (see
3779 gdb_readline_wrapper_line). Need to do this as we go back to the
3780 event loop, ready to process further input. Note this has no
3781 effect if the handler hasn't actually been removed, because calling
3782 rl_callback_handler_install resets the line buffer, thus losing
3786 reinstall_readline_callback_handler_cleanup ()
3788 struct ui
*ui
= current_ui
;
3792 /* We're not going back to the top level event loop yet. Don't
3793 install the readline callback, as it'd prep the terminal,
3794 readline-style (raw, noecho) (e.g., --batch). We'll install
3795 it the next time the prompt is displayed, when we're ready
3800 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3801 gdb_rl_callback_handler_reinstall ();
3804 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3805 that's just the event thread. In all-stop, that's all threads. */
3808 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3810 if (ecs
->event_thread
!= NULL
3811 && ecs
->event_thread
->thread_fsm
!= NULL
)
3812 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3816 for (thread_info
*thr
: all_non_exited_threads ())
3818 if (thr
->thread_fsm
== NULL
)
3820 if (thr
== ecs
->event_thread
)
3823 switch_to_thread (thr
);
3824 thr
->thread_fsm
->clean_up (thr
);
3827 if (ecs
->event_thread
!= NULL
)
3828 switch_to_thread (ecs
->event_thread
);
3832 /* Helper for all_uis_check_sync_execution_done that works on the
3836 check_curr_ui_sync_execution_done (void)
3838 struct ui
*ui
= current_ui
;
3840 if (ui
->prompt_state
== PROMPT_NEEDED
3842 && !gdb_in_secondary_prompt_p (ui
))
3844 target_terminal::ours ();
3845 gdb::observers::sync_execution_done
.notify ();
3846 ui_register_input_event_handler (ui
);
3853 all_uis_check_sync_execution_done (void)
3855 SWITCH_THRU_ALL_UIS ()
3857 check_curr_ui_sync_execution_done ();
3864 all_uis_on_sync_execution_starting (void)
3866 SWITCH_THRU_ALL_UIS ()
3868 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3869 async_disable_stdin ();
3873 /* Asynchronous version of wait_for_inferior. It is called by the
3874 event loop whenever a change of state is detected on the file
3875 descriptor corresponding to the target. It can be called more than
3876 once to complete a single execution command. In such cases we need
3877 to keep the state in a global variable ECSS. If it is the last time
3878 that this function is called for a single execution command, then
3879 report to the user that the inferior has stopped, and do the
3880 necessary cleanups. */
3883 fetch_inferior_event (void *client_data
)
3885 struct execution_control_state ecss
;
3886 struct execution_control_state
*ecs
= &ecss
;
3889 memset (ecs
, 0, sizeof (*ecs
));
3891 /* Events are always processed with the main UI as current UI. This
3892 way, warnings, debug output, etc. are always consistently sent to
3893 the main console. */
3894 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3896 /* End up with readline processing input, if necessary. */
3898 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3900 /* We're handling a live event, so make sure we're doing live
3901 debugging. If we're looking at traceframes while the target is
3902 running, we're going to need to get back to that mode after
3903 handling the event. */
3904 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3907 maybe_restore_traceframe
.emplace ();
3908 set_current_traceframe (-1);
3911 /* The user/frontend should not notice a thread switch due to
3912 internal events. Make sure we revert to the user selected
3913 thread and frame after handling the event and running any
3914 breakpoint commands. */
3915 scoped_restore_current_thread restore_thread
;
3917 overlay_cache_invalid
= 1;
3918 /* Flush target cache before starting to handle each event. Target
3919 was running and cache could be stale. This is just a heuristic.
3920 Running threads may modify target memory, but we don't get any
3922 target_dcache_invalidate ();
3924 scoped_restore save_exec_dir
3925 = make_scoped_restore (&execution_direction
,
3926 target_execution_direction ());
3928 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3931 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3933 /* Switch to the target that generated the event, so we can do
3934 target calls. Any inferior bound to the target will do, so we
3935 just switch to the first we find. */
3936 for (inferior
*inf
: all_inferiors (ecs
->target
))
3938 switch_to_inferior_no_thread (inf
);
3943 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3945 /* If an error happens while handling the event, propagate GDB's
3946 knowledge of the executing state to the frontend/user running
3948 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3949 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3951 /* Get executed before scoped_restore_current_thread above to apply
3952 still for the thread which has thrown the exception. */
3953 auto defer_bpstat_clear
3954 = make_scope_exit (bpstat_clear_actions
);
3955 auto defer_delete_threads
3956 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3958 /* Now figure out what to do with the result of the result. */
3959 handle_inferior_event (ecs
);
3961 if (!ecs
->wait_some_more
)
3963 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3964 int should_stop
= 1;
3965 struct thread_info
*thr
= ecs
->event_thread
;
3967 delete_just_stopped_threads_infrun_breakpoints ();
3971 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3973 if (thread_fsm
!= NULL
)
3974 should_stop
= thread_fsm
->should_stop (thr
);
3983 bool should_notify_stop
= true;
3986 clean_up_just_stopped_threads_fsms (ecs
);
3988 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3989 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3991 if (should_notify_stop
)
3993 /* We may not find an inferior if this was a process exit. */
3994 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3995 proceeded
= normal_stop ();
4000 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4004 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4005 previously selected thread is gone. We have two
4006 choices - switch to no thread selected, or restore the
4007 previously selected thread (now exited). We chose the
4008 later, just because that's what GDB used to do. After
4009 this, "info threads" says "The current thread <Thread
4010 ID 2> has terminated." instead of "No thread
4014 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4015 restore_thread
.dont_restore ();
4019 defer_delete_threads
.release ();
4020 defer_bpstat_clear
.release ();
4022 /* No error, don't finish the thread states yet. */
4023 finish_state
.release ();
4025 /* This scope is used to ensure that readline callbacks are
4026 reinstalled here. */
4029 /* If a UI was in sync execution mode, and now isn't, restore its
4030 prompt (a synchronous execution command has finished, and we're
4031 ready for input). */
4032 all_uis_check_sync_execution_done ();
4035 && exec_done_display_p
4036 && (inferior_ptid
== null_ptid
4037 || inferior_thread ()->state
!= THREAD_RUNNING
))
4038 printf_unfiltered (_("completed.\n"));
4044 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4045 struct symtab_and_line sal
)
4047 /* This can be removed once this function no longer implicitly relies on the
4048 inferior_ptid value. */
4049 gdb_assert (inferior_ptid
== tp
->ptid
);
4051 tp
->control
.step_frame_id
= get_frame_id (frame
);
4052 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4054 tp
->current_symtab
= sal
.symtab
;
4055 tp
->current_line
= sal
.line
;
4058 /* Clear context switchable stepping state. */
4061 init_thread_stepping_state (struct thread_info
*tss
)
4063 tss
->stepped_breakpoint
= 0;
4064 tss
->stepping_over_breakpoint
= 0;
4065 tss
->stepping_over_watchpoint
= 0;
4066 tss
->step_after_step_resume_breakpoint
= 0;
4072 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4073 target_waitstatus status
)
4075 target_last_proc_target
= target
;
4076 target_last_wait_ptid
= ptid
;
4077 target_last_waitstatus
= status
;
4083 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4084 target_waitstatus
*status
)
4086 if (target
!= nullptr)
4087 *target
= target_last_proc_target
;
4088 if (ptid
!= nullptr)
4089 *ptid
= target_last_wait_ptid
;
4090 if (status
!= nullptr)
4091 *status
= target_last_waitstatus
;
4097 nullify_last_target_wait_ptid (void)
4099 target_last_proc_target
= nullptr;
4100 target_last_wait_ptid
= minus_one_ptid
;
4101 target_last_waitstatus
= {};
4104 /* Switch thread contexts. */
4107 context_switch (execution_control_state
*ecs
)
4109 if (ecs
->ptid
!= inferior_ptid
4110 && (inferior_ptid
== null_ptid
4111 || ecs
->event_thread
!= inferior_thread ()))
4113 infrun_log_debug ("Switching context from %s to %s",
4114 target_pid_to_str (inferior_ptid
).c_str (),
4115 target_pid_to_str (ecs
->ptid
).c_str ());
4118 switch_to_thread (ecs
->event_thread
);
4121 /* If the target can't tell whether we've hit breakpoints
4122 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4123 check whether that could have been caused by a breakpoint. If so,
4124 adjust the PC, per gdbarch_decr_pc_after_break. */
4127 adjust_pc_after_break (struct thread_info
*thread
,
4128 struct target_waitstatus
*ws
)
4130 struct regcache
*regcache
;
4131 struct gdbarch
*gdbarch
;
4132 CORE_ADDR breakpoint_pc
, decr_pc
;
4134 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4135 we aren't, just return.
4137 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4138 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4139 implemented by software breakpoints should be handled through the normal
4142 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4143 different signals (SIGILL or SIGEMT for instance), but it is less
4144 clear where the PC is pointing afterwards. It may not match
4145 gdbarch_decr_pc_after_break. I don't know any specific target that
4146 generates these signals at breakpoints (the code has been in GDB since at
4147 least 1992) so I can not guess how to handle them here.
4149 In earlier versions of GDB, a target with
4150 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4151 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4152 target with both of these set in GDB history, and it seems unlikely to be
4153 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4155 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4158 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4161 /* In reverse execution, when a breakpoint is hit, the instruction
4162 under it has already been de-executed. The reported PC always
4163 points at the breakpoint address, so adjusting it further would
4164 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4167 B1 0x08000000 : INSN1
4168 B2 0x08000001 : INSN2
4170 PC -> 0x08000003 : INSN4
4172 Say you're stopped at 0x08000003 as above. Reverse continuing
4173 from that point should hit B2 as below. Reading the PC when the
4174 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4175 been de-executed already.
4177 B1 0x08000000 : INSN1
4178 B2 PC -> 0x08000001 : INSN2
4182 We can't apply the same logic as for forward execution, because
4183 we would wrongly adjust the PC to 0x08000000, since there's a
4184 breakpoint at PC - 1. We'd then report a hit on B1, although
4185 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4187 if (execution_direction
== EXEC_REVERSE
)
4190 /* If the target can tell whether the thread hit a SW breakpoint,
4191 trust it. Targets that can tell also adjust the PC
4193 if (target_supports_stopped_by_sw_breakpoint ())
4196 /* Note that relying on whether a breakpoint is planted in memory to
4197 determine this can fail. E.g,. the breakpoint could have been
4198 removed since. Or the thread could have been told to step an
4199 instruction the size of a breakpoint instruction, and only
4200 _after_ was a breakpoint inserted at its address. */
4202 /* If this target does not decrement the PC after breakpoints, then
4203 we have nothing to do. */
4204 regcache
= get_thread_regcache (thread
);
4205 gdbarch
= regcache
->arch ();
4207 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4211 const address_space
*aspace
= regcache
->aspace ();
4213 /* Find the location where (if we've hit a breakpoint) the
4214 breakpoint would be. */
4215 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4217 /* If the target can't tell whether a software breakpoint triggered,
4218 fallback to figuring it out based on breakpoints we think were
4219 inserted in the target, and on whether the thread was stepped or
4222 /* Check whether there actually is a software breakpoint inserted at
4225 If in non-stop mode, a race condition is possible where we've
4226 removed a breakpoint, but stop events for that breakpoint were
4227 already queued and arrive later. To suppress those spurious
4228 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4229 and retire them after a number of stop events are reported. Note
4230 this is an heuristic and can thus get confused. The real fix is
4231 to get the "stopped by SW BP and needs adjustment" info out of
4232 the target/kernel (and thus never reach here; see above). */
4233 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4234 || (target_is_non_stop_p ()
4235 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4237 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4239 if (record_full_is_used ())
4240 restore_operation_disable
.emplace
4241 (record_full_gdb_operation_disable_set ());
4243 /* When using hardware single-step, a SIGTRAP is reported for both
4244 a completed single-step and a software breakpoint. Need to
4245 differentiate between the two, as the latter needs adjusting
4246 but the former does not.
4248 The SIGTRAP can be due to a completed hardware single-step only if
4249 - we didn't insert software single-step breakpoints
4250 - this thread is currently being stepped
4252 If any of these events did not occur, we must have stopped due
4253 to hitting a software breakpoint, and have to back up to the
4256 As a special case, we could have hardware single-stepped a
4257 software breakpoint. In this case (prev_pc == breakpoint_pc),
4258 we also need to back up to the breakpoint address. */
4260 if (thread_has_single_step_breakpoints_set (thread
)
4261 || !currently_stepping (thread
)
4262 || (thread
->stepped_breakpoint
4263 && thread
->prev_pc
== breakpoint_pc
))
4264 regcache_write_pc (regcache
, breakpoint_pc
);
4269 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4271 for (frame
= get_prev_frame (frame
);
4273 frame
= get_prev_frame (frame
))
4275 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4277 if (get_frame_type (frame
) != INLINE_FRAME
)
4284 /* Look for an inline frame that is marked for skip.
4285 If PREV_FRAME is TRUE start at the previous frame,
4286 otherwise start at the current frame. Stop at the
4287 first non-inline frame, or at the frame where the
4291 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4293 struct frame_info
*frame
= get_current_frame ();
4296 frame
= get_prev_frame (frame
);
4298 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4300 const char *fn
= NULL
;
4301 symtab_and_line sal
;
4304 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4306 if (get_frame_type (frame
) != INLINE_FRAME
)
4309 sal
= find_frame_sal (frame
);
4310 sym
= get_frame_function (frame
);
4313 fn
= sym
->print_name ();
4316 && function_name_is_marked_for_skip (fn
, sal
))
4323 /* If the event thread has the stop requested flag set, pretend it
4324 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4328 handle_stop_requested (struct execution_control_state
*ecs
)
4330 if (ecs
->event_thread
->stop_requested
)
4332 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4333 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4334 handle_signal_stop (ecs
);
4340 /* Auxiliary function that handles syscall entry/return events.
4341 It returns 1 if the inferior should keep going (and GDB
4342 should ignore the event), or 0 if the event deserves to be
4346 handle_syscall_event (struct execution_control_state
*ecs
)
4348 struct regcache
*regcache
;
4351 context_switch (ecs
);
4353 regcache
= get_thread_regcache (ecs
->event_thread
);
4354 syscall_number
= ecs
->ws
.value
.syscall_number
;
4355 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4357 if (catch_syscall_enabled () > 0
4358 && catching_syscall_number (syscall_number
) > 0)
4360 infrun_log_debug ("syscall number=%d", syscall_number
);
4362 ecs
->event_thread
->control
.stop_bpstat
4363 = bpstat_stop_status (regcache
->aspace (),
4364 ecs
->event_thread
->suspend
.stop_pc
,
4365 ecs
->event_thread
, &ecs
->ws
);
4367 if (handle_stop_requested (ecs
))
4370 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4372 /* Catchpoint hit. */
4377 if (handle_stop_requested (ecs
))
4380 /* If no catchpoint triggered for this, then keep going. */
4385 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4388 fill_in_stop_func (struct gdbarch
*gdbarch
,
4389 struct execution_control_state
*ecs
)
4391 if (!ecs
->stop_func_filled_in
)
4395 /* Don't care about return value; stop_func_start and stop_func_name
4396 will both be 0 if it doesn't work. */
4397 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4398 &ecs
->stop_func_name
,
4399 &ecs
->stop_func_start
,
4400 &ecs
->stop_func_end
,
4403 /* The call to find_pc_partial_function, above, will set
4404 stop_func_start and stop_func_end to the start and end
4405 of the range containing the stop pc. If this range
4406 contains the entry pc for the block (which is always the
4407 case for contiguous blocks), advance stop_func_start past
4408 the function's start offset and entrypoint. Note that
4409 stop_func_start is NOT advanced when in a range of a
4410 non-contiguous block that does not contain the entry pc. */
4411 if (block
!= nullptr
4412 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4413 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4415 ecs
->stop_func_start
4416 += gdbarch_deprecated_function_start_offset (gdbarch
);
4418 if (gdbarch_skip_entrypoint_p (gdbarch
))
4419 ecs
->stop_func_start
4420 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4423 ecs
->stop_func_filled_in
= 1;
4428 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4430 static enum stop_kind
4431 get_inferior_stop_soon (execution_control_state
*ecs
)
4433 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4435 gdb_assert (inf
!= NULL
);
4436 return inf
->control
.stop_soon
;
4439 /* Poll for one event out of the current target. Store the resulting
4440 waitstatus in WS, and return the event ptid. Does not block. */
4443 poll_one_curr_target (struct target_waitstatus
*ws
)
4447 overlay_cache_invalid
= 1;
4449 /* Flush target cache before starting to handle each event.
4450 Target was running and cache could be stale. This is just a
4451 heuristic. Running threads may modify target memory, but we
4452 don't get any event. */
4453 target_dcache_invalidate ();
4455 if (deprecated_target_wait_hook
)
4456 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4458 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4461 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4466 /* An event reported by wait_one. */
4468 struct wait_one_event
4470 /* The target the event came out of. */
4471 process_stratum_target
*target
;
4473 /* The PTID the event was for. */
4476 /* The waitstatus. */
4477 target_waitstatus ws
;
4480 /* Wait for one event out of any target. */
4482 static wait_one_event
4487 for (inferior
*inf
: all_inferiors ())
4489 process_stratum_target
*target
= inf
->process_target ();
4491 || !target
->is_async_p ()
4492 || !target
->threads_executing
)
4495 switch_to_inferior_no_thread (inf
);
4497 wait_one_event event
;
4498 event
.target
= target
;
4499 event
.ptid
= poll_one_curr_target (&event
.ws
);
4501 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4503 /* If nothing is resumed, remove the target from the
4507 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4511 /* Block waiting for some event. */
4518 for (inferior
*inf
: all_inferiors ())
4520 process_stratum_target
*target
= inf
->process_target ();
4522 || !target
->is_async_p ()
4523 || !target
->threads_executing
)
4526 int fd
= target
->async_wait_fd ();
4527 FD_SET (fd
, &readfds
);
4534 /* No waitable targets left. All must be stopped. */
4535 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4540 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4546 perror_with_name ("interruptible_select");
4551 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4552 instead of the current thread. */
4553 #define THREAD_STOPPED_BY(REASON) \
4555 thread_stopped_by_ ## REASON (ptid_t ptid) \
4557 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4558 inferior_ptid = ptid; \
4560 return target_stopped_by_ ## REASON (); \
4563 /* Generate thread_stopped_by_watchpoint. */
4564 THREAD_STOPPED_BY (watchpoint
)
4565 /* Generate thread_stopped_by_sw_breakpoint. */
4566 THREAD_STOPPED_BY (sw_breakpoint
)
4567 /* Generate thread_stopped_by_hw_breakpoint. */
4568 THREAD_STOPPED_BY (hw_breakpoint
)
4570 /* Save the thread's event and stop reason to process it later. */
4573 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4575 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4576 target_waitstatus_to_string (ws
).c_str (),
4581 /* Record for later. */
4582 tp
->suspend
.waitstatus
= *ws
;
4583 tp
->suspend
.waitstatus_pending_p
= 1;
4585 struct regcache
*regcache
= get_thread_regcache (tp
);
4586 const address_space
*aspace
= regcache
->aspace ();
4588 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4589 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4591 CORE_ADDR pc
= regcache_read_pc (regcache
);
4593 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4595 if (thread_stopped_by_watchpoint (tp
->ptid
))
4597 tp
->suspend
.stop_reason
4598 = TARGET_STOPPED_BY_WATCHPOINT
;
4600 else if (target_supports_stopped_by_sw_breakpoint ()
4601 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4603 tp
->suspend
.stop_reason
4604 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4606 else if (target_supports_stopped_by_hw_breakpoint ()
4607 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4609 tp
->suspend
.stop_reason
4610 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4612 else if (!target_supports_stopped_by_hw_breakpoint ()
4613 && hardware_breakpoint_inserted_here_p (aspace
,
4616 tp
->suspend
.stop_reason
4617 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4619 else if (!target_supports_stopped_by_sw_breakpoint ()
4620 && software_breakpoint_inserted_here_p (aspace
,
4623 tp
->suspend
.stop_reason
4624 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4626 else if (!thread_has_single_step_breakpoints_set (tp
)
4627 && currently_stepping (tp
))
4629 tp
->suspend
.stop_reason
4630 = TARGET_STOPPED_BY_SINGLE_STEP
;
4635 /* Mark the non-executing threads accordingly. In all-stop, all
4636 threads of all processes are stopped when we get any event
4637 reported. In non-stop mode, only the event thread stops. */
4640 mark_non_executing_threads (process_stratum_target
*target
,
4642 struct target_waitstatus ws
)
4646 if (!target_is_non_stop_p ())
4647 mark_ptid
= minus_one_ptid
;
4648 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4649 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4651 /* If we're handling a process exit in non-stop mode, even
4652 though threads haven't been deleted yet, one would think
4653 that there is nothing to do, as threads of the dead process
4654 will be soon deleted, and threads of any other process were
4655 left running. However, on some targets, threads survive a
4656 process exit event. E.g., for the "checkpoint" command,
4657 when the current checkpoint/fork exits, linux-fork.c
4658 automatically switches to another fork from within
4659 target_mourn_inferior, by associating the same
4660 inferior/thread to another fork. We haven't mourned yet at
4661 this point, but we must mark any threads left in the
4662 process as not-executing so that finish_thread_state marks
4663 them stopped (in the user's perspective) if/when we present
4664 the stop to the user. */
4665 mark_ptid
= ptid_t (event_ptid
.pid ());
4668 mark_ptid
= event_ptid
;
4670 set_executing (target
, mark_ptid
, false);
4672 /* Likewise the resumed flag. */
4673 set_resumed (target
, mark_ptid
, false);
4679 stop_all_threads (void)
4681 /* We may need multiple passes to discover all threads. */
4685 gdb_assert (exists_non_stop_target ());
4687 infrun_log_debug ("stop_all_threads");
4689 scoped_restore_current_thread restore_thread
;
4691 /* Enable thread events of all targets. */
4692 for (auto *target
: all_non_exited_process_targets ())
4694 switch_to_target_no_thread (target
);
4695 target_thread_events (true);
4700 /* Disable thread events of all targets. */
4701 for (auto *target
: all_non_exited_process_targets ())
4703 switch_to_target_no_thread (target
);
4704 target_thread_events (false);
4708 infrun_log_debug ("stop_all_threads done");
4711 /* Request threads to stop, and then wait for the stops. Because
4712 threads we already know about can spawn more threads while we're
4713 trying to stop them, and we only learn about new threads when we
4714 update the thread list, do this in a loop, and keep iterating
4715 until two passes find no threads that need to be stopped. */
4716 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4718 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4722 int waits_needed
= 0;
4724 for (auto *target
: all_non_exited_process_targets ())
4726 switch_to_target_no_thread (target
);
4727 update_thread_list ();
4730 /* Go through all threads looking for threads that we need
4731 to tell the target to stop. */
4732 for (thread_info
*t
: all_non_exited_threads ())
4734 /* For a single-target setting with an all-stop target,
4735 we would not even arrive here. For a multi-target
4736 setting, until GDB is able to handle a mixture of
4737 all-stop and non-stop targets, simply skip all-stop
4738 targets' threads. This should be fine due to the
4739 protection of 'check_multi_target_resumption'. */
4741 switch_to_thread_no_regs (t
);
4742 if (!target_is_non_stop_p ())
4747 /* If already stopping, don't request a stop again.
4748 We just haven't seen the notification yet. */
4749 if (!t
->stop_requested
)
4751 infrun_log_debug (" %s executing, need stop",
4752 target_pid_to_str (t
->ptid
).c_str ());
4753 target_stop (t
->ptid
);
4754 t
->stop_requested
= 1;
4758 infrun_log_debug (" %s executing, already stopping",
4759 target_pid_to_str (t
->ptid
).c_str ());
4762 if (t
->stop_requested
)
4767 infrun_log_debug (" %s not executing",
4768 target_pid_to_str (t
->ptid
).c_str ());
4770 /* The thread may be not executing, but still be
4771 resumed with a pending status to process. */
4776 if (waits_needed
== 0)
4779 /* If we find new threads on the second iteration, restart
4780 over. We want to see two iterations in a row with all
4785 for (int i
= 0; i
< waits_needed
; i
++)
4787 wait_one_event event
= wait_one ();
4789 infrun_log_debug ("%s %s\n",
4790 target_waitstatus_to_string (&event
.ws
).c_str (),
4791 target_pid_to_str (event
.ptid
).c_str ());
4793 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4795 /* All resumed threads exited. */
4798 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4799 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4800 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4802 /* One thread/process exited/signalled. */
4804 thread_info
*t
= nullptr;
4806 /* The target may have reported just a pid. If so, try
4807 the first non-exited thread. */
4808 if (event
.ptid
.is_pid ())
4810 int pid
= event
.ptid
.pid ();
4811 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4812 for (thread_info
*tp
: inf
->non_exited_threads ())
4818 /* If there is no available thread, the event would
4819 have to be appended to a per-inferior event list,
4820 which does not exist (and if it did, we'd have
4821 to adjust run control command to be able to
4822 resume such an inferior). We assert here instead
4823 of going into an infinite loop. */
4824 gdb_assert (t
!= nullptr);
4826 infrun_log_debug ("using %s\n",
4827 target_pid_to_str (t
->ptid
).c_str ());
4831 t
= find_thread_ptid (event
.target
, event
.ptid
);
4832 /* Check if this is the first time we see this thread.
4833 Don't bother adding if it individually exited. */
4835 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4836 t
= add_thread (event
.target
, event
.ptid
);
4841 /* Set the threads as non-executing to avoid
4842 another stop attempt on them. */
4843 switch_to_thread_no_regs (t
);
4844 mark_non_executing_threads (event
.target
, event
.ptid
,
4846 save_waitstatus (t
, &event
.ws
);
4847 t
->stop_requested
= false;
4852 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4854 t
= add_thread (event
.target
, event
.ptid
);
4856 t
->stop_requested
= 0;
4859 t
->control
.may_range_step
= 0;
4861 /* This may be the first time we see the inferior report
4863 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4864 if (inf
->needs_setup
)
4866 switch_to_thread_no_regs (t
);
4870 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4871 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4873 /* We caught the event that we intended to catch, so
4874 there's no event pending. */
4875 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4876 t
->suspend
.waitstatus_pending_p
= 0;
4878 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4880 /* Add it back to the step-over queue. */
4881 infrun_log_debug ("displaced-step of %s "
4882 "canceled: adding back to the "
4883 "step-over queue\n",
4884 target_pid_to_str (t
->ptid
).c_str ());
4886 t
->control
.trap_expected
= 0;
4887 global_thread_step_over_chain_enqueue (t
);
4892 enum gdb_signal sig
;
4893 struct regcache
*regcache
;
4897 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4899 infrun_log_debug ("target_wait %s, saving "
4900 "status for %d.%ld.%ld\n",
4907 /* Record for later. */
4908 save_waitstatus (t
, &event
.ws
);
4910 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4911 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4913 if (displaced_step_finish (t
, sig
) < 0)
4915 /* Add it back to the step-over queue. */
4916 t
->control
.trap_expected
= 0;
4917 global_thread_step_over_chain_enqueue (t
);
4920 regcache
= get_thread_regcache (t
);
4921 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4923 infrun_log_debug ("saved stop_pc=%s for %s "
4924 "(currently_stepping=%d)\n",
4925 paddress (target_gdbarch (),
4926 t
->suspend
.stop_pc
),
4927 target_pid_to_str (t
->ptid
).c_str (),
4928 currently_stepping (t
));
4936 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4939 handle_no_resumed (struct execution_control_state
*ecs
)
4941 if (target_can_async_p ())
4945 for (ui
*ui
: all_uis ())
4947 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4955 /* There were no unwaited-for children left in the target, but,
4956 we're not synchronously waiting for events either. Just
4959 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4960 prepare_to_wait (ecs
);
4965 /* Otherwise, if we were running a synchronous execution command, we
4966 may need to cancel it and give the user back the terminal.
4968 In non-stop mode, the target can't tell whether we've already
4969 consumed previous stop events, so it can end up sending us a
4970 no-resumed event like so:
4972 #0 - thread 1 is left stopped
4974 #1 - thread 2 is resumed and hits breakpoint
4975 -> TARGET_WAITKIND_STOPPED
4977 #2 - thread 3 is resumed and exits
4978 this is the last resumed thread, so
4979 -> TARGET_WAITKIND_NO_RESUMED
4981 #3 - gdb processes stop for thread 2 and decides to re-resume
4984 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4985 thread 2 is now resumed, so the event should be ignored.
4987 IOW, if the stop for thread 2 doesn't end a foreground command,
4988 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4989 event. But it could be that the event meant that thread 2 itself
4990 (or whatever other thread was the last resumed thread) exited.
4992 To address this we refresh the thread list and check whether we
4993 have resumed threads _now_. In the example above, this removes
4994 thread 3 from the thread list. If thread 2 was re-resumed, we
4995 ignore this event. If we find no thread resumed, then we cancel
4996 the synchronous command show "no unwaited-for " to the user. */
4997 update_thread_list ();
4999 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
5001 if (thread
->executing
5002 || thread
->suspend
.waitstatus_pending_p
)
5004 /* There were no unwaited-for children left in the target at
5005 some point, but there are now. Just ignore. */
5006 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
5007 "(ignoring: found resumed)");
5008 prepare_to_wait (ecs
);
5013 /* Go ahead and report the event. */
5017 /* Given an execution control state that has been freshly filled in by
5018 an event from the inferior, figure out what it means and take
5021 The alternatives are:
5023 1) stop_waiting and return; to really stop and return to the
5026 2) keep_going and return; to wait for the next event (set
5027 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5031 handle_inferior_event (struct execution_control_state
*ecs
)
5033 /* Make sure that all temporary struct value objects that were
5034 created during the handling of the event get deleted at the
5036 scoped_value_mark free_values
;
5038 enum stop_kind stop_soon
;
5040 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5042 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5044 /* We had an event in the inferior, but we are not interested in
5045 handling it at this level. The lower layers have already
5046 done what needs to be done, if anything.
5048 One of the possible circumstances for this is when the
5049 inferior produces output for the console. The inferior has
5050 not stopped, and we are ignoring the event. Another possible
5051 circumstance is any event which the lower level knows will be
5052 reported multiple times without an intervening resume. */
5053 prepare_to_wait (ecs
);
5057 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5059 prepare_to_wait (ecs
);
5063 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5064 && handle_no_resumed (ecs
))
5067 /* Cache the last target/ptid/waitstatus. */
5068 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5070 /* Always clear state belonging to the previous time we stopped. */
5071 stop_stack_dummy
= STOP_NONE
;
5073 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5075 /* No unwaited-for children left. IOW, all resumed children
5077 stop_print_frame
= 0;
5082 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5083 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5085 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5086 /* If it's a new thread, add it to the thread database. */
5087 if (ecs
->event_thread
== NULL
)
5088 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5090 /* Disable range stepping. If the next step request could use a
5091 range, this will be end up re-enabled then. */
5092 ecs
->event_thread
->control
.may_range_step
= 0;
5095 /* Dependent on valid ECS->EVENT_THREAD. */
5096 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5098 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5099 reinit_frame_cache ();
5101 breakpoint_retire_moribund ();
5103 /* First, distinguish signals caused by the debugger from signals
5104 that have to do with the program's own actions. Note that
5105 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5106 on the operating system version. Here we detect when a SIGILL or
5107 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5108 something similar for SIGSEGV, since a SIGSEGV will be generated
5109 when we're trying to execute a breakpoint instruction on a
5110 non-executable stack. This happens for call dummy breakpoints
5111 for architectures like SPARC that place call dummies on the
5113 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5114 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5115 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5116 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5118 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5120 if (breakpoint_inserted_here_p (regcache
->aspace (),
5121 regcache_read_pc (regcache
)))
5123 infrun_log_debug ("Treating signal as SIGTRAP");
5124 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5128 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5130 switch (ecs
->ws
.kind
)
5132 case TARGET_WAITKIND_LOADED
:
5133 context_switch (ecs
);
5134 /* Ignore gracefully during startup of the inferior, as it might
5135 be the shell which has just loaded some objects, otherwise
5136 add the symbols for the newly loaded objects. Also ignore at
5137 the beginning of an attach or remote session; we will query
5138 the full list of libraries once the connection is
5141 stop_soon
= get_inferior_stop_soon (ecs
);
5142 if (stop_soon
== NO_STOP_QUIETLY
)
5144 struct regcache
*regcache
;
5146 regcache
= get_thread_regcache (ecs
->event_thread
);
5148 handle_solib_event ();
5150 ecs
->event_thread
->control
.stop_bpstat
5151 = bpstat_stop_status (regcache
->aspace (),
5152 ecs
->event_thread
->suspend
.stop_pc
,
5153 ecs
->event_thread
, &ecs
->ws
);
5155 if (handle_stop_requested (ecs
))
5158 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5160 /* A catchpoint triggered. */
5161 process_event_stop_test (ecs
);
5165 /* If requested, stop when the dynamic linker notifies
5166 gdb of events. This allows the user to get control
5167 and place breakpoints in initializer routines for
5168 dynamically loaded objects (among other things). */
5169 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5170 if (stop_on_solib_events
)
5172 /* Make sure we print "Stopped due to solib-event" in
5174 stop_print_frame
= 1;
5181 /* If we are skipping through a shell, or through shared library
5182 loading that we aren't interested in, resume the program. If
5183 we're running the program normally, also resume. */
5184 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5186 /* Loading of shared libraries might have changed breakpoint
5187 addresses. Make sure new breakpoints are inserted. */
5188 if (stop_soon
== NO_STOP_QUIETLY
)
5189 insert_breakpoints ();
5190 resume (GDB_SIGNAL_0
);
5191 prepare_to_wait (ecs
);
5195 /* But stop if we're attaching or setting up a remote
5197 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5198 || stop_soon
== STOP_QUIETLY_REMOTE
)
5200 infrun_log_debug ("quietly stopped");
5205 internal_error (__FILE__
, __LINE__
,
5206 _("unhandled stop_soon: %d"), (int) stop_soon
);
5208 case TARGET_WAITKIND_SPURIOUS
:
5209 if (handle_stop_requested (ecs
))
5211 context_switch (ecs
);
5212 resume (GDB_SIGNAL_0
);
5213 prepare_to_wait (ecs
);
5216 case TARGET_WAITKIND_THREAD_CREATED
:
5217 if (handle_stop_requested (ecs
))
5219 context_switch (ecs
);
5220 if (!switch_back_to_stepped_thread (ecs
))
5224 case TARGET_WAITKIND_EXITED
:
5225 case TARGET_WAITKIND_SIGNALLED
:
5226 inferior_ptid
= ecs
->ptid
;
5227 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5228 set_current_program_space (current_inferior ()->pspace
);
5229 handle_vfork_child_exec_or_exit (0);
5230 target_terminal::ours (); /* Must do this before mourn anyway. */
5232 /* Clearing any previous state of convenience variables. */
5233 clear_exit_convenience_vars ();
5235 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5237 /* Record the exit code in the convenience variable $_exitcode, so
5238 that the user can inspect this again later. */
5239 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5240 (LONGEST
) ecs
->ws
.value
.integer
);
5242 /* Also record this in the inferior itself. */
5243 current_inferior ()->has_exit_code
= 1;
5244 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5246 /* Support the --return-child-result option. */
5247 return_child_result_value
= ecs
->ws
.value
.integer
;
5249 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5253 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5255 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5257 /* Set the value of the internal variable $_exitsignal,
5258 which holds the signal uncaught by the inferior. */
5259 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5260 gdbarch_gdb_signal_to_target (gdbarch
,
5261 ecs
->ws
.value
.sig
));
5265 /* We don't have access to the target's method used for
5266 converting between signal numbers (GDB's internal
5267 representation <-> target's representation).
5268 Therefore, we cannot do a good job at displaying this
5269 information to the user. It's better to just warn
5270 her about it (if infrun debugging is enabled), and
5272 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5276 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5279 gdb_flush (gdb_stdout
);
5280 target_mourn_inferior (inferior_ptid
);
5281 stop_print_frame
= 0;
5285 case TARGET_WAITKIND_FORKED
:
5286 case TARGET_WAITKIND_VFORKED
:
5287 /* Check whether the inferior is displaced stepping. */
5289 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5290 struct gdbarch
*gdbarch
= regcache
->arch ();
5292 /* If checking displaced stepping is supported, and thread
5293 ecs->ptid is displaced stepping. */
5294 if (displaced_step_in_progress (ecs
->event_thread
))
5296 struct inferior
*parent_inf
5297 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5298 struct regcache
*child_regcache
;
5299 CORE_ADDR parent_pc
;
5301 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5303 // struct displaced_step_inferior_state *displaced
5304 // = get_displaced_stepping_state (parent_inf);
5306 /* Restore scratch pad for child process. */
5307 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5308 // FIXME: we should restore all the buffers that were currently in use
5311 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5312 indicating that the displaced stepping of syscall instruction
5313 has been done. Perform cleanup for parent process here. Note
5314 that this operation also cleans up the child process for vfork,
5315 because their pages are shared. */
5316 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5317 /* Start a new step-over in another thread if there's one
5321 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5322 the child's PC is also within the scratchpad. Set the child's PC
5323 to the parent's PC value, which has already been fixed up.
5324 FIXME: we use the parent's aspace here, although we're touching
5325 the child, because the child hasn't been added to the inferior
5326 list yet at this point. */
5329 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5330 ecs
->ws
.value
.related_pid
,
5332 parent_inf
->aspace
);
5333 /* Read PC value of parent process. */
5334 parent_pc
= regcache_read_pc (regcache
);
5336 if (debug_displaced
)
5337 fprintf_unfiltered (gdb_stdlog
,
5338 "displaced: write child pc from %s to %s\n",
5340 regcache_read_pc (child_regcache
)),
5341 paddress (gdbarch
, parent_pc
));
5343 regcache_write_pc (child_regcache
, parent_pc
);
5347 context_switch (ecs
);
5349 /* Immediately detach breakpoints from the child before there's
5350 any chance of letting the user delete breakpoints from the
5351 breakpoint lists. If we don't do this early, it's easy to
5352 leave left over traps in the child, vis: "break foo; catch
5353 fork; c; <fork>; del; c; <child calls foo>". We only follow
5354 the fork on the last `continue', and by that time the
5355 breakpoint at "foo" is long gone from the breakpoint table.
5356 If we vforked, then we don't need to unpatch here, since both
5357 parent and child are sharing the same memory pages; we'll
5358 need to unpatch at follow/detach time instead to be certain
5359 that new breakpoints added between catchpoint hit time and
5360 vfork follow are detached. */
5361 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5363 /* This won't actually modify the breakpoint list, but will
5364 physically remove the breakpoints from the child. */
5365 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5368 delete_just_stopped_threads_single_step_breakpoints ();
5370 /* In case the event is caught by a catchpoint, remember that
5371 the event is to be followed at the next resume of the thread,
5372 and not immediately. */
5373 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5375 ecs
->event_thread
->suspend
.stop_pc
5376 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5378 ecs
->event_thread
->control
.stop_bpstat
5379 = bpstat_stop_status (get_current_regcache ()->aspace (),
5380 ecs
->event_thread
->suspend
.stop_pc
,
5381 ecs
->event_thread
, &ecs
->ws
);
5383 if (handle_stop_requested (ecs
))
5386 /* If no catchpoint triggered for this, then keep going. Note
5387 that we're interested in knowing the bpstat actually causes a
5388 stop, not just if it may explain the signal. Software
5389 watchpoints, for example, always appear in the bpstat. */
5390 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5393 = (follow_fork_mode_string
== follow_fork_mode_child
);
5395 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5397 process_stratum_target
*targ
5398 = ecs
->event_thread
->inf
->process_target ();
5400 bool should_resume
= follow_fork ();
5402 /* Note that one of these may be an invalid pointer,
5403 depending on detach_fork. */
5404 thread_info
*parent
= ecs
->event_thread
;
5406 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5408 /* At this point, the parent is marked running, and the
5409 child is marked stopped. */
5411 /* If not resuming the parent, mark it stopped. */
5412 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5413 parent
->set_running (false);
5415 /* If resuming the child, mark it running. */
5416 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5417 child
->set_running (true);
5419 /* In non-stop mode, also resume the other branch. */
5420 if (!detach_fork
&& (non_stop
5421 || (sched_multi
&& target_is_non_stop_p ())))
5424 switch_to_thread (parent
);
5426 switch_to_thread (child
);
5428 ecs
->event_thread
= inferior_thread ();
5429 ecs
->ptid
= inferior_ptid
;
5434 switch_to_thread (child
);
5436 switch_to_thread (parent
);
5438 ecs
->event_thread
= inferior_thread ();
5439 ecs
->ptid
= inferior_ptid
;
5447 process_event_stop_test (ecs
);
5450 case TARGET_WAITKIND_VFORK_DONE
:
5451 /* Done with the shared memory region. Re-insert breakpoints in
5452 the parent, and keep going. */
5454 context_switch (ecs
);
5456 current_inferior ()->waiting_for_vfork_done
= 0;
5457 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5459 if (handle_stop_requested (ecs
))
5462 /* This also takes care of reinserting breakpoints in the
5463 previously locked inferior. */
5467 case TARGET_WAITKIND_EXECD
:
5469 /* Note we can't read registers yet (the stop_pc), because we
5470 don't yet know the inferior's post-exec architecture.
5471 'stop_pc' is explicitly read below instead. */
5472 switch_to_thread_no_regs (ecs
->event_thread
);
5474 /* Do whatever is necessary to the parent branch of the vfork. */
5475 handle_vfork_child_exec_or_exit (1);
5477 /* This causes the eventpoints and symbol table to be reset.
5478 Must do this now, before trying to determine whether to
5480 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5482 /* In follow_exec we may have deleted the original thread and
5483 created a new one. Make sure that the event thread is the
5484 execd thread for that case (this is a nop otherwise). */
5485 ecs
->event_thread
= inferior_thread ();
5487 ecs
->event_thread
->suspend
.stop_pc
5488 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5490 ecs
->event_thread
->control
.stop_bpstat
5491 = bpstat_stop_status (get_current_regcache ()->aspace (),
5492 ecs
->event_thread
->suspend
.stop_pc
,
5493 ecs
->event_thread
, &ecs
->ws
);
5495 /* Note that this may be referenced from inside
5496 bpstat_stop_status above, through inferior_has_execd. */
5497 xfree (ecs
->ws
.value
.execd_pathname
);
5498 ecs
->ws
.value
.execd_pathname
= NULL
;
5500 if (handle_stop_requested (ecs
))
5503 /* If no catchpoint triggered for this, then keep going. */
5504 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5506 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5510 process_event_stop_test (ecs
);
5513 /* Be careful not to try to gather much state about a thread
5514 that's in a syscall. It's frequently a losing proposition. */
5515 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5516 /* Getting the current syscall number. */
5517 if (handle_syscall_event (ecs
) == 0)
5518 process_event_stop_test (ecs
);
5521 /* Before examining the threads further, step this thread to
5522 get it entirely out of the syscall. (We get notice of the
5523 event when the thread is just on the verge of exiting a
5524 syscall. Stepping one instruction seems to get it back
5526 case TARGET_WAITKIND_SYSCALL_RETURN
:
5527 if (handle_syscall_event (ecs
) == 0)
5528 process_event_stop_test (ecs
);
5531 case TARGET_WAITKIND_STOPPED
:
5532 handle_signal_stop (ecs
);
5535 case TARGET_WAITKIND_NO_HISTORY
:
5536 /* Reverse execution: target ran out of history info. */
5538 /* Switch to the stopped thread. */
5539 context_switch (ecs
);
5540 infrun_log_debug ("stopped");
5542 delete_just_stopped_threads_single_step_breakpoints ();
5543 ecs
->event_thread
->suspend
.stop_pc
5544 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5546 if (handle_stop_requested (ecs
))
5549 gdb::observers::no_history
.notify ();
5555 /* Restart threads back to what they were trying to do back when we
5556 paused them for an in-line step-over. The EVENT_THREAD thread is
5560 restart_threads (struct thread_info
*event_thread
)
5562 /* In case the instruction just stepped spawned a new thread. */
5563 update_thread_list ();
5565 for (thread_info
*tp
: all_non_exited_threads ())
5567 switch_to_thread_no_regs (tp
);
5569 if (tp
== event_thread
)
5571 infrun_log_debug ("restart threads: [%s] is event thread",
5572 target_pid_to_str (tp
->ptid
).c_str ());
5576 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5578 infrun_log_debug ("restart threads: [%s] not meant to be running",
5579 target_pid_to_str (tp
->ptid
).c_str ());
5585 infrun_log_debug ("restart threads: [%s] resumed",
5586 target_pid_to_str (tp
->ptid
).c_str ());
5587 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5591 if (thread_is_in_step_over_chain (tp
))
5593 infrun_log_debug ("restart threads: [%s] needs step-over",
5594 target_pid_to_str (tp
->ptid
).c_str ());
5595 gdb_assert (!tp
->resumed
);
5600 if (tp
->suspend
.waitstatus_pending_p
)
5602 infrun_log_debug ("restart threads: [%s] has pending status",
5603 target_pid_to_str (tp
->ptid
).c_str ());
5608 gdb_assert (!tp
->stop_requested
);
5610 /* If some thread needs to start a step-over at this point, it
5611 should still be in the step-over queue, and thus skipped
5613 if (thread_still_needs_step_over (tp
))
5615 internal_error (__FILE__
, __LINE__
,
5616 "thread [%s] needs a step-over, but not in "
5617 "step-over queue\n",
5618 target_pid_to_str (tp
->ptid
).c_str ());
5621 if (currently_stepping (tp
))
5623 infrun_log_debug ("restart threads: [%s] was stepping",
5624 target_pid_to_str (tp
->ptid
).c_str ());
5625 keep_going_stepped_thread (tp
);
5629 struct execution_control_state ecss
;
5630 struct execution_control_state
*ecs
= &ecss
;
5632 infrun_log_debug ("restart threads: [%s] continuing",
5633 target_pid_to_str (tp
->ptid
).c_str ());
5634 reset_ecs (ecs
, tp
);
5635 switch_to_thread (tp
);
5636 keep_going_pass_signal (ecs
);
5641 /* Callback for iterate_over_threads. Find a resumed thread that has
5642 a pending waitstatus. */
5645 resumed_thread_with_pending_status (struct thread_info
*tp
,
5649 && tp
->suspend
.waitstatus_pending_p
);
5652 /* Called when we get an event that may finish an in-line or
5653 out-of-line (displaced stepping) step-over started previously.
5654 Return true if the event is processed and we should go back to the
5655 event loop; false if the caller should continue processing the
5659 finish_step_over (struct execution_control_state
*ecs
)
5661 int had_step_over_info
;
5663 displaced_step_finish (ecs
->event_thread
,
5664 ecs
->event_thread
->suspend
.stop_signal
);
5666 had_step_over_info
= step_over_info_valid_p ();
5668 if (had_step_over_info
)
5670 /* If we're stepping over a breakpoint with all threads locked,
5671 then only the thread that was stepped should be reporting
5673 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5675 clear_step_over_info ();
5678 if (!target_is_non_stop_p ())
5681 /* Start a new step-over in another thread if there's one that
5685 /* If we were stepping over a breakpoint before, and haven't started
5686 a new in-line step-over sequence, then restart all other threads
5687 (except the event thread). We can't do this in all-stop, as then
5688 e.g., we wouldn't be able to issue any other remote packet until
5689 these other threads stop. */
5690 if (had_step_over_info
&& !step_over_info_valid_p ())
5692 struct thread_info
*pending
;
5694 /* If we only have threads with pending statuses, the restart
5695 below won't restart any thread and so nothing re-inserts the
5696 breakpoint we just stepped over. But we need it inserted
5697 when we later process the pending events, otherwise if
5698 another thread has a pending event for this breakpoint too,
5699 we'd discard its event (because the breakpoint that
5700 originally caused the event was no longer inserted). */
5701 context_switch (ecs
);
5702 insert_breakpoints ();
5704 restart_threads (ecs
->event_thread
);
5706 /* If we have events pending, go through handle_inferior_event
5707 again, picking up a pending event at random. This avoids
5708 thread starvation. */
5710 /* But not if we just stepped over a watchpoint in order to let
5711 the instruction execute so we can evaluate its expression.
5712 The set of watchpoints that triggered is recorded in the
5713 breakpoint objects themselves (see bp->watchpoint_triggered).
5714 If we processed another event first, that other event could
5715 clobber this info. */
5716 if (ecs
->event_thread
->stepping_over_watchpoint
)
5719 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5721 if (pending
!= NULL
)
5723 struct thread_info
*tp
= ecs
->event_thread
;
5724 struct regcache
*regcache
;
5726 infrun_log_debug ("found resumed threads with "
5727 "pending events, saving status");
5729 gdb_assert (pending
!= tp
);
5731 /* Record the event thread's event for later. */
5732 save_waitstatus (tp
, &ecs
->ws
);
5733 /* This was cleared early, by handle_inferior_event. Set it
5734 so this pending event is considered by
5738 gdb_assert (!tp
->executing
);
5740 regcache
= get_thread_regcache (tp
);
5741 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5743 infrun_log_debug ("saved stop_pc=%s for %s "
5744 "(currently_stepping=%d)\n",
5745 paddress (target_gdbarch (),
5746 tp
->suspend
.stop_pc
),
5747 target_pid_to_str (tp
->ptid
).c_str (),
5748 currently_stepping (tp
));
5750 /* This in-line step-over finished; clear this so we won't
5751 start a new one. This is what handle_signal_stop would
5752 do, if we returned false. */
5753 tp
->stepping_over_breakpoint
= 0;
5755 /* Wake up the event loop again. */
5756 mark_async_event_handler (infrun_async_inferior_event_token
);
5758 prepare_to_wait (ecs
);
5766 /* Come here when the program has stopped with a signal. */
5769 handle_signal_stop (struct execution_control_state
*ecs
)
5771 struct frame_info
*frame
;
5772 struct gdbarch
*gdbarch
;
5773 int stopped_by_watchpoint
;
5774 enum stop_kind stop_soon
;
5777 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5779 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5781 /* Do we need to clean up the state of a thread that has
5782 completed a displaced single-step? (Doing so usually affects
5783 the PC, so do it here, before we set stop_pc.) */
5784 if (finish_step_over (ecs
))
5787 /* If we either finished a single-step or hit a breakpoint, but
5788 the user wanted this thread to be stopped, pretend we got a
5789 SIG0 (generic unsignaled stop). */
5790 if (ecs
->event_thread
->stop_requested
5791 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5792 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5794 ecs
->event_thread
->suspend
.stop_pc
5795 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5799 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5800 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5802 switch_to_thread (ecs
->event_thread
);
5804 infrun_log_debug ("stop_pc=%s",
5805 paddress (reg_gdbarch
,
5806 ecs
->event_thread
->suspend
.stop_pc
));
5807 if (target_stopped_by_watchpoint ())
5811 infrun_log_debug ("stopped by watchpoint");
5813 if (target_stopped_data_address (current_top_target (), &addr
))
5814 infrun_log_debug ("stopped data address=%s",
5815 paddress (reg_gdbarch
, addr
));
5817 infrun_log_debug ("(no data address available)");
5821 /* This is originated from start_remote(), start_inferior() and
5822 shared libraries hook functions. */
5823 stop_soon
= get_inferior_stop_soon (ecs
);
5824 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5826 context_switch (ecs
);
5827 infrun_log_debug ("quietly stopped");
5828 stop_print_frame
= 1;
5833 /* This originates from attach_command(). We need to overwrite
5834 the stop_signal here, because some kernels don't ignore a
5835 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5836 See more comments in inferior.h. On the other hand, if we
5837 get a non-SIGSTOP, report it to the user - assume the backend
5838 will handle the SIGSTOP if it should show up later.
5840 Also consider that the attach is complete when we see a
5841 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5842 target extended-remote report it instead of a SIGSTOP
5843 (e.g. gdbserver). We already rely on SIGTRAP being our
5844 signal, so this is no exception.
5846 Also consider that the attach is complete when we see a
5847 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5848 the target to stop all threads of the inferior, in case the
5849 low level attach operation doesn't stop them implicitly. If
5850 they weren't stopped implicitly, then the stub will report a
5851 GDB_SIGNAL_0, meaning: stopped for no particular reason
5852 other than GDB's request. */
5853 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5854 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5855 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5856 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5858 stop_print_frame
= 1;
5860 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5864 /* See if something interesting happened to the non-current thread. If
5865 so, then switch to that thread. */
5866 if (ecs
->ptid
!= inferior_ptid
)
5868 infrun_log_debug ("context switch");
5870 context_switch (ecs
);
5872 if (deprecated_context_hook
)
5873 deprecated_context_hook (ecs
->event_thread
->global_num
);
5876 /* At this point, get hold of the now-current thread's frame. */
5877 frame
= get_current_frame ();
5878 gdbarch
= get_frame_arch (frame
);
5880 /* Pull the single step breakpoints out of the target. */
5881 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5883 struct regcache
*regcache
;
5886 regcache
= get_thread_regcache (ecs
->event_thread
);
5887 const address_space
*aspace
= regcache
->aspace ();
5889 pc
= regcache_read_pc (regcache
);
5891 /* However, before doing so, if this single-step breakpoint was
5892 actually for another thread, set this thread up for moving
5894 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5897 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5899 infrun_log_debug ("[%s] hit another thread's single-step "
5901 target_pid_to_str (ecs
->ptid
).c_str ());
5902 ecs
->hit_singlestep_breakpoint
= 1;
5907 infrun_log_debug ("[%s] hit its single-step breakpoint",
5908 target_pid_to_str (ecs
->ptid
).c_str ());
5911 delete_just_stopped_threads_single_step_breakpoints ();
5913 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5914 && ecs
->event_thread
->control
.trap_expected
5915 && ecs
->event_thread
->stepping_over_watchpoint
)
5916 stopped_by_watchpoint
= 0;
5918 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5920 /* If necessary, step over this watchpoint. We'll be back to display
5922 if (stopped_by_watchpoint
5923 && (target_have_steppable_watchpoint
5924 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5926 /* At this point, we are stopped at an instruction which has
5927 attempted to write to a piece of memory under control of
5928 a watchpoint. The instruction hasn't actually executed
5929 yet. If we were to evaluate the watchpoint expression
5930 now, we would get the old value, and therefore no change
5931 would seem to have occurred.
5933 In order to make watchpoints work `right', we really need
5934 to complete the memory write, and then evaluate the
5935 watchpoint expression. We do this by single-stepping the
5938 It may not be necessary to disable the watchpoint to step over
5939 it. For example, the PA can (with some kernel cooperation)
5940 single step over a watchpoint without disabling the watchpoint.
5942 It is far more common to need to disable a watchpoint to step
5943 the inferior over it. If we have non-steppable watchpoints,
5944 we must disable the current watchpoint; it's simplest to
5945 disable all watchpoints.
5947 Any breakpoint at PC must also be stepped over -- if there's
5948 one, it will have already triggered before the watchpoint
5949 triggered, and we either already reported it to the user, or
5950 it didn't cause a stop and we called keep_going. In either
5951 case, if there was a breakpoint at PC, we must be trying to
5953 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5958 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5959 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5960 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5961 ecs
->event_thread
->control
.stop_step
= 0;
5962 stop_print_frame
= 1;
5963 stopped_by_random_signal
= 0;
5964 bpstat stop_chain
= NULL
;
5966 /* Hide inlined functions starting here, unless we just performed stepi or
5967 nexti. After stepi and nexti, always show the innermost frame (not any
5968 inline function call sites). */
5969 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5971 const address_space
*aspace
5972 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5974 /* skip_inline_frames is expensive, so we avoid it if we can
5975 determine that the address is one where functions cannot have
5976 been inlined. This improves performance with inferiors that
5977 load a lot of shared libraries, because the solib event
5978 breakpoint is defined as the address of a function (i.e. not
5979 inline). Note that we have to check the previous PC as well
5980 as the current one to catch cases when we have just
5981 single-stepped off a breakpoint prior to reinstating it.
5982 Note that we're assuming that the code we single-step to is
5983 not inline, but that's not definitive: there's nothing
5984 preventing the event breakpoint function from containing
5985 inlined code, and the single-step ending up there. If the
5986 user had set a breakpoint on that inlined code, the missing
5987 skip_inline_frames call would break things. Fortunately
5988 that's an extremely unlikely scenario. */
5989 if (!pc_at_non_inline_function (aspace
,
5990 ecs
->event_thread
->suspend
.stop_pc
,
5992 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5993 && ecs
->event_thread
->control
.trap_expected
5994 && pc_at_non_inline_function (aspace
,
5995 ecs
->event_thread
->prev_pc
,
5998 stop_chain
= build_bpstat_chain (aspace
,
5999 ecs
->event_thread
->suspend
.stop_pc
,
6001 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6003 /* Re-fetch current thread's frame in case that invalidated
6005 frame
= get_current_frame ();
6006 gdbarch
= get_frame_arch (frame
);
6010 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6011 && ecs
->event_thread
->control
.trap_expected
6012 && gdbarch_single_step_through_delay_p (gdbarch
)
6013 && currently_stepping (ecs
->event_thread
))
6015 /* We're trying to step off a breakpoint. Turns out that we're
6016 also on an instruction that needs to be stepped multiple
6017 times before it's been fully executing. E.g., architectures
6018 with a delay slot. It needs to be stepped twice, once for
6019 the instruction and once for the delay slot. */
6020 int step_through_delay
6021 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6023 if (step_through_delay
)
6024 infrun_log_debug ("step through delay");
6026 if (ecs
->event_thread
->control
.step_range_end
== 0
6027 && step_through_delay
)
6029 /* The user issued a continue when stopped at a breakpoint.
6030 Set up for another trap and get out of here. */
6031 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6035 else if (step_through_delay
)
6037 /* The user issued a step when stopped at a breakpoint.
6038 Maybe we should stop, maybe we should not - the delay
6039 slot *might* correspond to a line of source. In any
6040 case, don't decide that here, just set
6041 ecs->stepping_over_breakpoint, making sure we
6042 single-step again before breakpoints are re-inserted. */
6043 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6047 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6048 handles this event. */
6049 ecs
->event_thread
->control
.stop_bpstat
6050 = bpstat_stop_status (get_current_regcache ()->aspace (),
6051 ecs
->event_thread
->suspend
.stop_pc
,
6052 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6054 /* Following in case break condition called a
6056 stop_print_frame
= 1;
6058 /* This is where we handle "moribund" watchpoints. Unlike
6059 software breakpoints traps, hardware watchpoint traps are
6060 always distinguishable from random traps. If no high-level
6061 watchpoint is associated with the reported stop data address
6062 anymore, then the bpstat does not explain the signal ---
6063 simply make sure to ignore it if `stopped_by_watchpoint' is
6066 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6067 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6069 && stopped_by_watchpoint
)
6071 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6075 /* NOTE: cagney/2003-03-29: These checks for a random signal
6076 at one stage in the past included checks for an inferior
6077 function call's call dummy's return breakpoint. The original
6078 comment, that went with the test, read:
6080 ``End of a stack dummy. Some systems (e.g. Sony news) give
6081 another signal besides SIGTRAP, so check here as well as
6084 If someone ever tries to get call dummys on a
6085 non-executable stack to work (where the target would stop
6086 with something like a SIGSEGV), then those tests might need
6087 to be re-instated. Given, however, that the tests were only
6088 enabled when momentary breakpoints were not being used, I
6089 suspect that it won't be the case.
6091 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6092 be necessary for call dummies on a non-executable stack on
6095 /* See if the breakpoints module can explain the signal. */
6097 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6098 ecs
->event_thread
->suspend
.stop_signal
);
6100 /* Maybe this was a trap for a software breakpoint that has since
6102 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6104 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6105 ecs
->event_thread
->suspend
.stop_pc
))
6107 struct regcache
*regcache
;
6110 /* Re-adjust PC to what the program would see if GDB was not
6112 regcache
= get_thread_regcache (ecs
->event_thread
);
6113 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6116 gdb::optional
<scoped_restore_tmpl
<int>>
6117 restore_operation_disable
;
6119 if (record_full_is_used ())
6120 restore_operation_disable
.emplace
6121 (record_full_gdb_operation_disable_set ());
6123 regcache_write_pc (regcache
,
6124 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6129 /* A delayed software breakpoint event. Ignore the trap. */
6130 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6135 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6136 has since been removed. */
6137 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6139 /* A delayed hardware breakpoint event. Ignore the trap. */
6140 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6145 /* If not, perhaps stepping/nexting can. */
6147 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6148 && currently_stepping (ecs
->event_thread
));
6150 /* Perhaps the thread hit a single-step breakpoint of _another_
6151 thread. Single-step breakpoints are transparent to the
6152 breakpoints module. */
6154 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6156 /* No? Perhaps we got a moribund watchpoint. */
6158 random_signal
= !stopped_by_watchpoint
;
6160 /* Always stop if the user explicitly requested this thread to
6162 if (ecs
->event_thread
->stop_requested
)
6165 infrun_log_debug ("user-requested stop");
6168 /* For the program's own signals, act according to
6169 the signal handling tables. */
6173 /* Signal not for debugging purposes. */
6174 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6175 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6177 infrun_log_debug ("random signal (%s)",
6178 gdb_signal_to_symbol_string (stop_signal
));
6180 stopped_by_random_signal
= 1;
6182 /* Always stop on signals if we're either just gaining control
6183 of the program, or the user explicitly requested this thread
6184 to remain stopped. */
6185 if (stop_soon
!= NO_STOP_QUIETLY
6186 || ecs
->event_thread
->stop_requested
6188 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6194 /* Notify observers the signal has "handle print" set. Note we
6195 returned early above if stopping; normal_stop handles the
6196 printing in that case. */
6197 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6199 /* The signal table tells us to print about this signal. */
6200 target_terminal::ours_for_output ();
6201 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6202 target_terminal::inferior ();
6205 /* Clear the signal if it should not be passed. */
6206 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6207 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6209 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6210 && ecs
->event_thread
->control
.trap_expected
6211 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6213 /* We were just starting a new sequence, attempting to
6214 single-step off of a breakpoint and expecting a SIGTRAP.
6215 Instead this signal arrives. This signal will take us out
6216 of the stepping range so GDB needs to remember to, when
6217 the signal handler returns, resume stepping off that
6219 /* To simplify things, "continue" is forced to use the same
6220 code paths as single-step - set a breakpoint at the
6221 signal return address and then, once hit, step off that
6223 infrun_log_debug ("signal arrived while stepping over breakpoint");
6225 insert_hp_step_resume_breakpoint_at_frame (frame
);
6226 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6227 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6228 ecs
->event_thread
->control
.trap_expected
= 0;
6230 /* If we were nexting/stepping some other thread, switch to
6231 it, so that we don't continue it, losing control. */
6232 if (!switch_back_to_stepped_thread (ecs
))
6237 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6238 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6240 || ecs
->event_thread
->control
.step_range_end
== 1)
6241 && frame_id_eq (get_stack_frame_id (frame
),
6242 ecs
->event_thread
->control
.step_stack_frame_id
)
6243 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6245 /* The inferior is about to take a signal that will take it
6246 out of the single step range. Set a breakpoint at the
6247 current PC (which is presumably where the signal handler
6248 will eventually return) and then allow the inferior to
6251 Note that this is only needed for a signal delivered
6252 while in the single-step range. Nested signals aren't a
6253 problem as they eventually all return. */
6254 infrun_log_debug ("signal may take us out of single-step range");
6256 clear_step_over_info ();
6257 insert_hp_step_resume_breakpoint_at_frame (frame
);
6258 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6259 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6260 ecs
->event_thread
->control
.trap_expected
= 0;
6265 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6266 when either there's a nested signal, or when there's a
6267 pending signal enabled just as the signal handler returns
6268 (leaving the inferior at the step-resume-breakpoint without
6269 actually executing it). Either way continue until the
6270 breakpoint is really hit. */
6272 if (!switch_back_to_stepped_thread (ecs
))
6274 infrun_log_debug ("random signal, keep going");
6281 process_event_stop_test (ecs
);
6284 /* Come here when we've got some debug event / signal we can explain
6285 (IOW, not a random signal), and test whether it should cause a
6286 stop, or whether we should resume the inferior (transparently).
6287 E.g., could be a breakpoint whose condition evaluates false; we
6288 could be still stepping within the line; etc. */
6291 process_event_stop_test (struct execution_control_state
*ecs
)
6293 struct symtab_and_line stop_pc_sal
;
6294 struct frame_info
*frame
;
6295 struct gdbarch
*gdbarch
;
6296 CORE_ADDR jmp_buf_pc
;
6297 struct bpstat_what what
;
6299 /* Handle cases caused by hitting a breakpoint. */
6301 frame
= get_current_frame ();
6302 gdbarch
= get_frame_arch (frame
);
6304 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6306 if (what
.call_dummy
)
6308 stop_stack_dummy
= what
.call_dummy
;
6311 /* A few breakpoint types have callbacks associated (e.g.,
6312 bp_jit_event). Run them now. */
6313 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6315 /* If we hit an internal event that triggers symbol changes, the
6316 current frame will be invalidated within bpstat_what (e.g., if we
6317 hit an internal solib event). Re-fetch it. */
6318 frame
= get_current_frame ();
6319 gdbarch
= get_frame_arch (frame
);
6321 switch (what
.main_action
)
6323 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6324 /* If we hit the breakpoint at longjmp while stepping, we
6325 install a momentary breakpoint at the target of the
6328 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6330 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6332 if (what
.is_longjmp
)
6334 struct value
*arg_value
;
6336 /* If we set the longjmp breakpoint via a SystemTap probe,
6337 then use it to extract the arguments. The destination PC
6338 is the third argument to the probe. */
6339 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6342 jmp_buf_pc
= value_as_address (arg_value
);
6343 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6345 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6346 || !gdbarch_get_longjmp_target (gdbarch
,
6347 frame
, &jmp_buf_pc
))
6349 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6350 "(!gdbarch_get_longjmp_target)");
6355 /* Insert a breakpoint at resume address. */
6356 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6359 check_exception_resume (ecs
, frame
);
6363 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6365 struct frame_info
*init_frame
;
6367 /* There are several cases to consider.
6369 1. The initiating frame no longer exists. In this case we
6370 must stop, because the exception or longjmp has gone too
6373 2. The initiating frame exists, and is the same as the
6374 current frame. We stop, because the exception or longjmp
6377 3. The initiating frame exists and is different from the
6378 current frame. This means the exception or longjmp has
6379 been caught beneath the initiating frame, so keep going.
6381 4. longjmp breakpoint has been placed just to protect
6382 against stale dummy frames and user is not interested in
6383 stopping around longjmps. */
6385 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6387 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6389 delete_exception_resume_breakpoint (ecs
->event_thread
);
6391 if (what
.is_longjmp
)
6393 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6395 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6403 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6407 struct frame_id current_id
6408 = get_frame_id (get_current_frame ());
6409 if (frame_id_eq (current_id
,
6410 ecs
->event_thread
->initiating_frame
))
6412 /* Case 2. Fall through. */
6422 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6424 delete_step_resume_breakpoint (ecs
->event_thread
);
6426 end_stepping_range (ecs
);
6430 case BPSTAT_WHAT_SINGLE
:
6431 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6432 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6433 /* Still need to check other stuff, at least the case where we
6434 are stepping and step out of the right range. */
6437 case BPSTAT_WHAT_STEP_RESUME
:
6438 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6440 delete_step_resume_breakpoint (ecs
->event_thread
);
6441 if (ecs
->event_thread
->control
.proceed_to_finish
6442 && execution_direction
== EXEC_REVERSE
)
6444 struct thread_info
*tp
= ecs
->event_thread
;
6446 /* We are finishing a function in reverse, and just hit the
6447 step-resume breakpoint at the start address of the
6448 function, and we're almost there -- just need to back up
6449 by one more single-step, which should take us back to the
6451 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6455 fill_in_stop_func (gdbarch
, ecs
);
6456 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6457 && execution_direction
== EXEC_REVERSE
)
6459 /* We are stepping over a function call in reverse, and just
6460 hit the step-resume breakpoint at the start address of
6461 the function. Go back to single-stepping, which should
6462 take us back to the function call. */
6463 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6469 case BPSTAT_WHAT_STOP_NOISY
:
6470 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6471 stop_print_frame
= 1;
6473 /* Assume the thread stopped for a breapoint. We'll still check
6474 whether a/the breakpoint is there when the thread is next
6476 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6481 case BPSTAT_WHAT_STOP_SILENT
:
6482 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6483 stop_print_frame
= 0;
6485 /* Assume the thread stopped for a breapoint. We'll still check
6486 whether a/the breakpoint is there when the thread is next
6488 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6492 case BPSTAT_WHAT_HP_STEP_RESUME
:
6493 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6495 delete_step_resume_breakpoint (ecs
->event_thread
);
6496 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6498 /* Back when the step-resume breakpoint was inserted, we
6499 were trying to single-step off a breakpoint. Go back to
6501 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6502 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6508 case BPSTAT_WHAT_KEEP_CHECKING
:
6512 /* If we stepped a permanent breakpoint and we had a high priority
6513 step-resume breakpoint for the address we stepped, but we didn't
6514 hit it, then we must have stepped into the signal handler. The
6515 step-resume was only necessary to catch the case of _not_
6516 stepping into the handler, so delete it, and fall through to
6517 checking whether the step finished. */
6518 if (ecs
->event_thread
->stepped_breakpoint
)
6520 struct breakpoint
*sr_bp
6521 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6524 && sr_bp
->loc
->permanent
6525 && sr_bp
->type
== bp_hp_step_resume
6526 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6528 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6529 delete_step_resume_breakpoint (ecs
->event_thread
);
6530 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6534 /* We come here if we hit a breakpoint but should not stop for it.
6535 Possibly we also were stepping and should stop for that. So fall
6536 through and test for stepping. But, if not stepping, do not
6539 /* In all-stop mode, if we're currently stepping but have stopped in
6540 some other thread, we need to switch back to the stepped thread. */
6541 if (switch_back_to_stepped_thread (ecs
))
6544 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6546 infrun_log_debug ("step-resume breakpoint is inserted");
6548 /* Having a step-resume breakpoint overrides anything
6549 else having to do with stepping commands until
6550 that breakpoint is reached. */
6555 if (ecs
->event_thread
->control
.step_range_end
== 0)
6557 infrun_log_debug ("no stepping, continue");
6558 /* Likewise if we aren't even stepping. */
6563 /* Re-fetch current thread's frame in case the code above caused
6564 the frame cache to be re-initialized, making our FRAME variable
6565 a dangling pointer. */
6566 frame
= get_current_frame ();
6567 gdbarch
= get_frame_arch (frame
);
6568 fill_in_stop_func (gdbarch
, ecs
);
6570 /* If stepping through a line, keep going if still within it.
6572 Note that step_range_end is the address of the first instruction
6573 beyond the step range, and NOT the address of the last instruction
6576 Note also that during reverse execution, we may be stepping
6577 through a function epilogue and therefore must detect when
6578 the current-frame changes in the middle of a line. */
6580 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6582 && (execution_direction
!= EXEC_REVERSE
6583 || frame_id_eq (get_frame_id (frame
),
6584 ecs
->event_thread
->control
.step_frame_id
)))
6587 ("stepping inside range [%s-%s]",
6588 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6589 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6591 /* Tentatively re-enable range stepping; `resume' disables it if
6592 necessary (e.g., if we're stepping over a breakpoint or we
6593 have software watchpoints). */
6594 ecs
->event_thread
->control
.may_range_step
= 1;
6596 /* When stepping backward, stop at beginning of line range
6597 (unless it's the function entry point, in which case
6598 keep going back to the call point). */
6599 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6600 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6601 && stop_pc
!= ecs
->stop_func_start
6602 && execution_direction
== EXEC_REVERSE
)
6603 end_stepping_range (ecs
);
6610 /* We stepped out of the stepping range. */
6612 /* If we are stepping at the source level and entered the runtime
6613 loader dynamic symbol resolution code...
6615 EXEC_FORWARD: we keep on single stepping until we exit the run
6616 time loader code and reach the callee's address.
6618 EXEC_REVERSE: we've already executed the callee (backward), and
6619 the runtime loader code is handled just like any other
6620 undebuggable function call. Now we need only keep stepping
6621 backward through the trampoline code, and that's handled further
6622 down, so there is nothing for us to do here. */
6624 if (execution_direction
!= EXEC_REVERSE
6625 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6626 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6628 CORE_ADDR pc_after_resolver
=
6629 gdbarch_skip_solib_resolver (gdbarch
,
6630 ecs
->event_thread
->suspend
.stop_pc
);
6632 infrun_log_debug ("stepped into dynsym resolve code");
6634 if (pc_after_resolver
)
6636 /* Set up a step-resume breakpoint at the address
6637 indicated by SKIP_SOLIB_RESOLVER. */
6638 symtab_and_line sr_sal
;
6639 sr_sal
.pc
= pc_after_resolver
;
6640 sr_sal
.pspace
= get_frame_program_space (frame
);
6642 insert_step_resume_breakpoint_at_sal (gdbarch
,
6643 sr_sal
, null_frame_id
);
6650 /* Step through an indirect branch thunk. */
6651 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6652 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6653 ecs
->event_thread
->suspend
.stop_pc
))
6655 infrun_log_debug ("stepped into indirect branch thunk");
6660 if (ecs
->event_thread
->control
.step_range_end
!= 1
6661 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6662 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6663 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6665 infrun_log_debug ("stepped into signal trampoline");
6666 /* The inferior, while doing a "step" or "next", has ended up in
6667 a signal trampoline (either by a signal being delivered or by
6668 the signal handler returning). Just single-step until the
6669 inferior leaves the trampoline (either by calling the handler
6675 /* If we're in the return path from a shared library trampoline,
6676 we want to proceed through the trampoline when stepping. */
6677 /* macro/2012-04-25: This needs to come before the subroutine
6678 call check below as on some targets return trampolines look
6679 like subroutine calls (MIPS16 return thunks). */
6680 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6681 ecs
->event_thread
->suspend
.stop_pc
,
6682 ecs
->stop_func_name
)
6683 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6685 /* Determine where this trampoline returns. */
6686 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6687 CORE_ADDR real_stop_pc
6688 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6690 infrun_log_debug ("stepped into solib return tramp");
6692 /* Only proceed through if we know where it's going. */
6695 /* And put the step-breakpoint there and go until there. */
6696 symtab_and_line sr_sal
;
6697 sr_sal
.pc
= real_stop_pc
;
6698 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6699 sr_sal
.pspace
= get_frame_program_space (frame
);
6701 /* Do not specify what the fp should be when we stop since
6702 on some machines the prologue is where the new fp value
6704 insert_step_resume_breakpoint_at_sal (gdbarch
,
6705 sr_sal
, null_frame_id
);
6707 /* Restart without fiddling with the step ranges or
6714 /* Check for subroutine calls. The check for the current frame
6715 equalling the step ID is not necessary - the check of the
6716 previous frame's ID is sufficient - but it is a common case and
6717 cheaper than checking the previous frame's ID.
6719 NOTE: frame_id_eq will never report two invalid frame IDs as
6720 being equal, so to get into this block, both the current and
6721 previous frame must have valid frame IDs. */
6722 /* The outer_frame_id check is a heuristic to detect stepping
6723 through startup code. If we step over an instruction which
6724 sets the stack pointer from an invalid value to a valid value,
6725 we may detect that as a subroutine call from the mythical
6726 "outermost" function. This could be fixed by marking
6727 outermost frames as !stack_p,code_p,special_p. Then the
6728 initial outermost frame, before sp was valid, would
6729 have code_addr == &_start. See the comment in frame_id_eq
6731 if (!frame_id_eq (get_stack_frame_id (frame
),
6732 ecs
->event_thread
->control
.step_stack_frame_id
)
6733 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6734 ecs
->event_thread
->control
.step_stack_frame_id
)
6735 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6737 || (ecs
->event_thread
->control
.step_start_function
6738 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6740 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6741 CORE_ADDR real_stop_pc
;
6743 infrun_log_debug ("stepped into subroutine");
6745 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6747 /* I presume that step_over_calls is only 0 when we're
6748 supposed to be stepping at the assembly language level
6749 ("stepi"). Just stop. */
6750 /* And this works the same backward as frontward. MVS */
6751 end_stepping_range (ecs
);
6755 /* Reverse stepping through solib trampolines. */
6757 if (execution_direction
== EXEC_REVERSE
6758 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6759 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6760 || (ecs
->stop_func_start
== 0
6761 && in_solib_dynsym_resolve_code (stop_pc
))))
6763 /* Any solib trampoline code can be handled in reverse
6764 by simply continuing to single-step. We have already
6765 executed the solib function (backwards), and a few
6766 steps will take us back through the trampoline to the
6772 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6774 /* We're doing a "next".
6776 Normal (forward) execution: set a breakpoint at the
6777 callee's return address (the address at which the caller
6780 Reverse (backward) execution. set the step-resume
6781 breakpoint at the start of the function that we just
6782 stepped into (backwards), and continue to there. When we
6783 get there, we'll need to single-step back to the caller. */
6785 if (execution_direction
== EXEC_REVERSE
)
6787 /* If we're already at the start of the function, we've either
6788 just stepped backward into a single instruction function,
6789 or stepped back out of a signal handler to the first instruction
6790 of the function. Just keep going, which will single-step back
6792 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6794 /* Normal function call return (static or dynamic). */
6795 symtab_and_line sr_sal
;
6796 sr_sal
.pc
= ecs
->stop_func_start
;
6797 sr_sal
.pspace
= get_frame_program_space (frame
);
6798 insert_step_resume_breakpoint_at_sal (gdbarch
,
6799 sr_sal
, null_frame_id
);
6803 insert_step_resume_breakpoint_at_caller (frame
);
6809 /* If we are in a function call trampoline (a stub between the
6810 calling routine and the real function), locate the real
6811 function. That's what tells us (a) whether we want to step
6812 into it at all, and (b) what prologue we want to run to the
6813 end of, if we do step into it. */
6814 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6815 if (real_stop_pc
== 0)
6816 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6817 if (real_stop_pc
!= 0)
6818 ecs
->stop_func_start
= real_stop_pc
;
6820 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6822 symtab_and_line sr_sal
;
6823 sr_sal
.pc
= ecs
->stop_func_start
;
6824 sr_sal
.pspace
= get_frame_program_space (frame
);
6826 insert_step_resume_breakpoint_at_sal (gdbarch
,
6827 sr_sal
, null_frame_id
);
6832 /* If we have line number information for the function we are
6833 thinking of stepping into and the function isn't on the skip
6836 If there are several symtabs at that PC (e.g. with include
6837 files), just want to know whether *any* of them have line
6838 numbers. find_pc_line handles this. */
6840 struct symtab_and_line tmp_sal
;
6842 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6843 if (tmp_sal
.line
!= 0
6844 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6846 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6848 if (execution_direction
== EXEC_REVERSE
)
6849 handle_step_into_function_backward (gdbarch
, ecs
);
6851 handle_step_into_function (gdbarch
, ecs
);
6856 /* If we have no line number and the step-stop-if-no-debug is
6857 set, we stop the step so that the user has a chance to switch
6858 in assembly mode. */
6859 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6860 && step_stop_if_no_debug
)
6862 end_stepping_range (ecs
);
6866 if (execution_direction
== EXEC_REVERSE
)
6868 /* If we're already at the start of the function, we've either just
6869 stepped backward into a single instruction function without line
6870 number info, or stepped back out of a signal handler to the first
6871 instruction of the function without line number info. Just keep
6872 going, which will single-step back to the caller. */
6873 if (ecs
->stop_func_start
!= stop_pc
)
6875 /* Set a breakpoint at callee's start address.
6876 From there we can step once and be back in the caller. */
6877 symtab_and_line sr_sal
;
6878 sr_sal
.pc
= ecs
->stop_func_start
;
6879 sr_sal
.pspace
= get_frame_program_space (frame
);
6880 insert_step_resume_breakpoint_at_sal (gdbarch
,
6881 sr_sal
, null_frame_id
);
6885 /* Set a breakpoint at callee's return address (the address
6886 at which the caller will resume). */
6887 insert_step_resume_breakpoint_at_caller (frame
);
6893 /* Reverse stepping through solib trampolines. */
6895 if (execution_direction
== EXEC_REVERSE
6896 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6898 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6900 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6901 || (ecs
->stop_func_start
== 0
6902 && in_solib_dynsym_resolve_code (stop_pc
)))
6904 /* Any solib trampoline code can be handled in reverse
6905 by simply continuing to single-step. We have already
6906 executed the solib function (backwards), and a few
6907 steps will take us back through the trampoline to the
6912 else if (in_solib_dynsym_resolve_code (stop_pc
))
6914 /* Stepped backward into the solib dynsym resolver.
6915 Set a breakpoint at its start and continue, then
6916 one more step will take us out. */
6917 symtab_and_line sr_sal
;
6918 sr_sal
.pc
= ecs
->stop_func_start
;
6919 sr_sal
.pspace
= get_frame_program_space (frame
);
6920 insert_step_resume_breakpoint_at_sal (gdbarch
,
6921 sr_sal
, null_frame_id
);
6927 /* This always returns the sal for the inner-most frame when we are in a
6928 stack of inlined frames, even if GDB actually believes that it is in a
6929 more outer frame. This is checked for below by calls to
6930 inline_skipped_frames. */
6931 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6933 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6934 the trampoline processing logic, however, there are some trampolines
6935 that have no names, so we should do trampoline handling first. */
6936 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6937 && ecs
->stop_func_name
== NULL
6938 && stop_pc_sal
.line
== 0)
6940 infrun_log_debug ("stepped into undebuggable function");
6942 /* The inferior just stepped into, or returned to, an
6943 undebuggable function (where there is no debugging information
6944 and no line number corresponding to the address where the
6945 inferior stopped). Since we want to skip this kind of code,
6946 we keep going until the inferior returns from this
6947 function - unless the user has asked us not to (via
6948 set step-mode) or we no longer know how to get back
6949 to the call site. */
6950 if (step_stop_if_no_debug
6951 || !frame_id_p (frame_unwind_caller_id (frame
)))
6953 /* If we have no line number and the step-stop-if-no-debug
6954 is set, we stop the step so that the user has a chance to
6955 switch in assembly mode. */
6956 end_stepping_range (ecs
);
6961 /* Set a breakpoint at callee's return address (the address
6962 at which the caller will resume). */
6963 insert_step_resume_breakpoint_at_caller (frame
);
6969 if (ecs
->event_thread
->control
.step_range_end
== 1)
6971 /* It is stepi or nexti. We always want to stop stepping after
6973 infrun_log_debug ("stepi/nexti");
6974 end_stepping_range (ecs
);
6978 if (stop_pc_sal
.line
== 0)
6980 /* We have no line number information. That means to stop
6981 stepping (does this always happen right after one instruction,
6982 when we do "s" in a function with no line numbers,
6983 or can this happen as a result of a return or longjmp?). */
6984 infrun_log_debug ("line number info");
6985 end_stepping_range (ecs
);
6989 /* Look for "calls" to inlined functions, part one. If the inline
6990 frame machinery detected some skipped call sites, we have entered
6991 a new inline function. */
6993 if (frame_id_eq (get_frame_id (get_current_frame ()),
6994 ecs
->event_thread
->control
.step_frame_id
)
6995 && inline_skipped_frames (ecs
->event_thread
))
6997 infrun_log_debug ("stepped into inlined function");
6999 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7001 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7003 /* For "step", we're going to stop. But if the call site
7004 for this inlined function is on the same source line as
7005 we were previously stepping, go down into the function
7006 first. Otherwise stop at the call site. */
7008 if (call_sal
.line
== ecs
->event_thread
->current_line
7009 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7011 step_into_inline_frame (ecs
->event_thread
);
7012 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7019 end_stepping_range (ecs
);
7024 /* For "next", we should stop at the call site if it is on a
7025 different source line. Otherwise continue through the
7026 inlined function. */
7027 if (call_sal
.line
== ecs
->event_thread
->current_line
7028 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7031 end_stepping_range (ecs
);
7036 /* Look for "calls" to inlined functions, part two. If we are still
7037 in the same real function we were stepping through, but we have
7038 to go further up to find the exact frame ID, we are stepping
7039 through a more inlined call beyond its call site. */
7041 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7042 && !frame_id_eq (get_frame_id (get_current_frame ()),
7043 ecs
->event_thread
->control
.step_frame_id
)
7044 && stepped_in_from (get_current_frame (),
7045 ecs
->event_thread
->control
.step_frame_id
))
7047 infrun_log_debug ("stepping through inlined function");
7049 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7050 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7053 end_stepping_range (ecs
);
7057 bool refresh_step_info
= true;
7058 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7059 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7060 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7062 if (stop_pc_sal
.is_stmt
)
7064 /* We are at the start of a different line. So stop. Note that
7065 we don't stop if we step into the middle of a different line.
7066 That is said to make things like for (;;) statements work
7068 infrun_log_debug ("infrun: stepped to a different line\n");
7069 end_stepping_range (ecs
);
7072 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7073 ecs
->event_thread
->control
.step_frame_id
))
7075 /* We are at the start of a different line, however, this line is
7076 not marked as a statement, and we have not changed frame. We
7077 ignore this line table entry, and continue stepping forward,
7078 looking for a better place to stop. */
7079 refresh_step_info
= false;
7080 infrun_log_debug ("infrun: stepped to a different line, but "
7081 "it's not the start of a statement\n");
7085 /* We aren't done stepping.
7087 Optimize by setting the stepping range to the line.
7088 (We might not be in the original line, but if we entered a
7089 new line in mid-statement, we continue stepping. This makes
7090 things like for(;;) statements work better.)
7092 If we entered a SAL that indicates a non-statement line table entry,
7093 then we update the stepping range, but we don't update the step info,
7094 which includes things like the line number we are stepping away from.
7095 This means we will stop when we find a line table entry that is marked
7096 as is-statement, even if it matches the non-statement one we just
7099 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7100 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7101 ecs
->event_thread
->control
.may_range_step
= 1;
7102 if (refresh_step_info
)
7103 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7105 infrun_log_debug ("keep going");
7109 /* In all-stop mode, if we're currently stepping but have stopped in
7110 some other thread, we may need to switch back to the stepped
7111 thread. Returns true we set the inferior running, false if we left
7112 it stopped (and the event needs further processing). */
7115 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7117 if (!target_is_non_stop_p ())
7119 struct thread_info
*stepping_thread
;
7121 /* If any thread is blocked on some internal breakpoint, and we
7122 simply need to step over that breakpoint to get it going
7123 again, do that first. */
7125 /* However, if we see an event for the stepping thread, then we
7126 know all other threads have been moved past their breakpoints
7127 already. Let the caller check whether the step is finished,
7128 etc., before deciding to move it past a breakpoint. */
7129 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7132 /* Check if the current thread is blocked on an incomplete
7133 step-over, interrupted by a random signal. */
7134 if (ecs
->event_thread
->control
.trap_expected
7135 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7137 infrun_log_debug ("need to finish step-over of [%s]",
7138 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7143 /* Check if the current thread is blocked by a single-step
7144 breakpoint of another thread. */
7145 if (ecs
->hit_singlestep_breakpoint
)
7147 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7148 target_pid_to_str (ecs
->ptid
).c_str ());
7153 /* If this thread needs yet another step-over (e.g., stepping
7154 through a delay slot), do it first before moving on to
7156 if (thread_still_needs_step_over (ecs
->event_thread
))
7159 ("thread [%s] still needs step-over",
7160 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7165 /* If scheduler locking applies even if not stepping, there's no
7166 need to walk over threads. Above we've checked whether the
7167 current thread is stepping. If some other thread not the
7168 event thread is stepping, then it must be that scheduler
7169 locking is not in effect. */
7170 if (schedlock_applies (ecs
->event_thread
))
7173 /* Otherwise, we no longer expect a trap in the current thread.
7174 Clear the trap_expected flag before switching back -- this is
7175 what keep_going does as well, if we call it. */
7176 ecs
->event_thread
->control
.trap_expected
= 0;
7178 /* Likewise, clear the signal if it should not be passed. */
7179 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7180 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7182 /* Do all pending step-overs before actually proceeding with
7184 if (start_step_over ())
7186 prepare_to_wait (ecs
);
7190 /* Look for the stepping/nexting thread. */
7191 stepping_thread
= NULL
;
7193 for (thread_info
*tp
: all_non_exited_threads ())
7195 switch_to_thread_no_regs (tp
);
7197 /* Ignore threads of processes the caller is not
7200 && (tp
->inf
->process_target () != ecs
->target
7201 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7204 /* When stepping over a breakpoint, we lock all threads
7205 except the one that needs to move past the breakpoint.
7206 If a non-event thread has this set, the "incomplete
7207 step-over" check above should have caught it earlier. */
7208 if (tp
->control
.trap_expected
)
7210 internal_error (__FILE__
, __LINE__
,
7211 "[%s] has inconsistent state: "
7212 "trap_expected=%d\n",
7213 target_pid_to_str (tp
->ptid
).c_str (),
7214 tp
->control
.trap_expected
);
7217 /* Did we find the stepping thread? */
7218 if (tp
->control
.step_range_end
)
7220 /* Yep. There should only one though. */
7221 gdb_assert (stepping_thread
== NULL
);
7223 /* The event thread is handled at the top, before we
7225 gdb_assert (tp
!= ecs
->event_thread
);
7227 /* If some thread other than the event thread is
7228 stepping, then scheduler locking can't be in effect,
7229 otherwise we wouldn't have resumed the current event
7230 thread in the first place. */
7231 gdb_assert (!schedlock_applies (tp
));
7233 stepping_thread
= tp
;
7237 if (stepping_thread
!= NULL
)
7239 infrun_log_debug ("switching back to stepped thread");
7241 if (keep_going_stepped_thread (stepping_thread
))
7243 prepare_to_wait (ecs
);
7248 switch_to_thread (ecs
->event_thread
);
7254 /* Set a previously stepped thread back to stepping. Returns true on
7255 success, false if the resume is not possible (e.g., the thread
7259 keep_going_stepped_thread (struct thread_info
*tp
)
7261 struct frame_info
*frame
;
7262 struct execution_control_state ecss
;
7263 struct execution_control_state
*ecs
= &ecss
;
7265 /* If the stepping thread exited, then don't try to switch back and
7266 resume it, which could fail in several different ways depending
7267 on the target. Instead, just keep going.
7269 We can find a stepping dead thread in the thread list in two
7272 - The target supports thread exit events, and when the target
7273 tries to delete the thread from the thread list, inferior_ptid
7274 pointed at the exiting thread. In such case, calling
7275 delete_thread does not really remove the thread from the list;
7276 instead, the thread is left listed, with 'exited' state.
7278 - The target's debug interface does not support thread exit
7279 events, and so we have no idea whatsoever if the previously
7280 stepping thread is still alive. For that reason, we need to
7281 synchronously query the target now. */
7283 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7285 infrun_log_debug ("not resuming previously stepped thread, it has "
7292 infrun_log_debug ("resuming previously stepped thread");
7294 reset_ecs (ecs
, tp
);
7295 switch_to_thread (tp
);
7297 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7298 frame
= get_current_frame ();
7300 /* If the PC of the thread we were trying to single-step has
7301 changed, then that thread has trapped or been signaled, but the
7302 event has not been reported to GDB yet. Re-poll the target
7303 looking for this particular thread's event (i.e. temporarily
7304 enable schedlock) by:
7306 - setting a break at the current PC
7307 - resuming that particular thread, only (by setting trap
7310 This prevents us continuously moving the single-step breakpoint
7311 forward, one instruction at a time, overstepping. */
7313 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7317 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7318 paddress (target_gdbarch (), tp
->prev_pc
),
7319 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7321 /* Clear the info of the previous step-over, as it's no longer
7322 valid (if the thread was trying to step over a breakpoint, it
7323 has already succeeded). It's what keep_going would do too,
7324 if we called it. Do this before trying to insert the sss
7325 breakpoint, otherwise if we were previously trying to step
7326 over this exact address in another thread, the breakpoint is
7328 clear_step_over_info ();
7329 tp
->control
.trap_expected
= 0;
7331 insert_single_step_breakpoint (get_frame_arch (frame
),
7332 get_frame_address_space (frame
),
7333 tp
->suspend
.stop_pc
);
7336 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7337 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7341 infrun_log_debug ("expected thread still hasn't advanced");
7343 keep_going_pass_signal (ecs
);
7348 /* Is thread TP in the middle of (software or hardware)
7349 single-stepping? (Note the result of this function must never be
7350 passed directly as target_resume's STEP parameter.) */
7353 currently_stepping (struct thread_info
*tp
)
7355 return ((tp
->control
.step_range_end
7356 && tp
->control
.step_resume_breakpoint
== NULL
)
7357 || tp
->control
.trap_expected
7358 || tp
->stepped_breakpoint
7359 || bpstat_should_step ());
7362 /* Inferior has stepped into a subroutine call with source code that
7363 we should not step over. Do step to the first line of code in
7367 handle_step_into_function (struct gdbarch
*gdbarch
,
7368 struct execution_control_state
*ecs
)
7370 fill_in_stop_func (gdbarch
, ecs
);
7372 compunit_symtab
*cust
7373 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7374 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7375 ecs
->stop_func_start
7376 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7378 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7379 /* Use the step_resume_break to step until the end of the prologue,
7380 even if that involves jumps (as it seems to on the vax under
7382 /* If the prologue ends in the middle of a source line, continue to
7383 the end of that source line (if it is still within the function).
7384 Otherwise, just go to end of prologue. */
7385 if (stop_func_sal
.end
7386 && stop_func_sal
.pc
!= ecs
->stop_func_start
7387 && stop_func_sal
.end
< ecs
->stop_func_end
)
7388 ecs
->stop_func_start
= stop_func_sal
.end
;
7390 /* Architectures which require breakpoint adjustment might not be able
7391 to place a breakpoint at the computed address. If so, the test
7392 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7393 ecs->stop_func_start to an address at which a breakpoint may be
7394 legitimately placed.
7396 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7397 made, GDB will enter an infinite loop when stepping through
7398 optimized code consisting of VLIW instructions which contain
7399 subinstructions corresponding to different source lines. On
7400 FR-V, it's not permitted to place a breakpoint on any but the
7401 first subinstruction of a VLIW instruction. When a breakpoint is
7402 set, GDB will adjust the breakpoint address to the beginning of
7403 the VLIW instruction. Thus, we need to make the corresponding
7404 adjustment here when computing the stop address. */
7406 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7408 ecs
->stop_func_start
7409 = gdbarch_adjust_breakpoint_address (gdbarch
,
7410 ecs
->stop_func_start
);
7413 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7415 /* We are already there: stop now. */
7416 end_stepping_range (ecs
);
7421 /* Put the step-breakpoint there and go until there. */
7422 symtab_and_line sr_sal
;
7423 sr_sal
.pc
= ecs
->stop_func_start
;
7424 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7425 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7427 /* Do not specify what the fp should be when we stop since on
7428 some machines the prologue is where the new fp value is
7430 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7432 /* And make sure stepping stops right away then. */
7433 ecs
->event_thread
->control
.step_range_end
7434 = ecs
->event_thread
->control
.step_range_start
;
7439 /* Inferior has stepped backward into a subroutine call with source
7440 code that we should not step over. Do step to the beginning of the
7441 last line of code in it. */
7444 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7445 struct execution_control_state
*ecs
)
7447 struct compunit_symtab
*cust
;
7448 struct symtab_and_line stop_func_sal
;
7450 fill_in_stop_func (gdbarch
, ecs
);
7452 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7453 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7454 ecs
->stop_func_start
7455 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7457 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7459 /* OK, we're just going to keep stepping here. */
7460 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7462 /* We're there already. Just stop stepping now. */
7463 end_stepping_range (ecs
);
7467 /* Else just reset the step range and keep going.
7468 No step-resume breakpoint, they don't work for
7469 epilogues, which can have multiple entry paths. */
7470 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7471 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7477 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7478 This is used to both functions and to skip over code. */
7481 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7482 struct symtab_and_line sr_sal
,
7483 struct frame_id sr_id
,
7484 enum bptype sr_type
)
7486 /* There should never be more than one step-resume or longjmp-resume
7487 breakpoint per thread, so we should never be setting a new
7488 step_resume_breakpoint when one is already active. */
7489 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7490 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7492 infrun_log_debug ("inserting step-resume breakpoint at %s",
7493 paddress (gdbarch
, sr_sal
.pc
));
7495 inferior_thread ()->control
.step_resume_breakpoint
7496 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7500 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7501 struct symtab_and_line sr_sal
,
7502 struct frame_id sr_id
)
7504 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7509 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7510 This is used to skip a potential signal handler.
7512 This is called with the interrupted function's frame. The signal
7513 handler, when it returns, will resume the interrupted function at
7517 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7519 gdb_assert (return_frame
!= NULL
);
7521 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7523 symtab_and_line sr_sal
;
7524 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7525 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7526 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7528 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7529 get_stack_frame_id (return_frame
),
7533 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7534 is used to skip a function after stepping into it (for "next" or if
7535 the called function has no debugging information).
7537 The current function has almost always been reached by single
7538 stepping a call or return instruction. NEXT_FRAME belongs to the
7539 current function, and the breakpoint will be set at the caller's
7542 This is a separate function rather than reusing
7543 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7544 get_prev_frame, which may stop prematurely (see the implementation
7545 of frame_unwind_caller_id for an example). */
7548 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7550 /* We shouldn't have gotten here if we don't know where the call site
7552 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7554 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7556 symtab_and_line sr_sal
;
7557 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7558 frame_unwind_caller_pc (next_frame
));
7559 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7560 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7562 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7563 frame_unwind_caller_id (next_frame
));
7566 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7567 new breakpoint at the target of a jmp_buf. The handling of
7568 longjmp-resume uses the same mechanisms used for handling
7569 "step-resume" breakpoints. */
7572 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7574 /* There should never be more than one longjmp-resume breakpoint per
7575 thread, so we should never be setting a new
7576 longjmp_resume_breakpoint when one is already active. */
7577 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7579 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7580 paddress (gdbarch
, pc
));
7582 inferior_thread ()->control
.exception_resume_breakpoint
=
7583 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7586 /* Insert an exception resume breakpoint. TP is the thread throwing
7587 the exception. The block B is the block of the unwinder debug hook
7588 function. FRAME is the frame corresponding to the call to this
7589 function. SYM is the symbol of the function argument holding the
7590 target PC of the exception. */
7593 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7594 const struct block
*b
,
7595 struct frame_info
*frame
,
7600 struct block_symbol vsym
;
7601 struct value
*value
;
7603 struct breakpoint
*bp
;
7605 vsym
= lookup_symbol_search_name (sym
->search_name (),
7607 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7608 /* If the value was optimized out, revert to the old behavior. */
7609 if (! value_optimized_out (value
))
7611 handler
= value_as_address (value
);
7613 infrun_log_debug ("exception resume at %lx",
7614 (unsigned long) handler
);
7616 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7618 bp_exception_resume
).release ();
7620 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7623 bp
->thread
= tp
->global_num
;
7624 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7627 catch (const gdb_exception_error
&e
)
7629 /* We want to ignore errors here. */
7633 /* A helper for check_exception_resume that sets an
7634 exception-breakpoint based on a SystemTap probe. */
7637 insert_exception_resume_from_probe (struct thread_info
*tp
,
7638 const struct bound_probe
*probe
,
7639 struct frame_info
*frame
)
7641 struct value
*arg_value
;
7643 struct breakpoint
*bp
;
7645 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7649 handler
= value_as_address (arg_value
);
7651 infrun_log_debug ("exception resume at %s",
7652 paddress (probe
->objfile
->arch (), handler
));
7654 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7655 handler
, bp_exception_resume
).release ();
7656 bp
->thread
= tp
->global_num
;
7657 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7660 /* This is called when an exception has been intercepted. Check to
7661 see whether the exception's destination is of interest, and if so,
7662 set an exception resume breakpoint there. */
7665 check_exception_resume (struct execution_control_state
*ecs
,
7666 struct frame_info
*frame
)
7668 struct bound_probe probe
;
7669 struct symbol
*func
;
7671 /* First see if this exception unwinding breakpoint was set via a
7672 SystemTap probe point. If so, the probe has two arguments: the
7673 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7674 set a breakpoint there. */
7675 probe
= find_probe_by_pc (get_frame_pc (frame
));
7678 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7682 func
= get_frame_function (frame
);
7688 const struct block
*b
;
7689 struct block_iterator iter
;
7693 /* The exception breakpoint is a thread-specific breakpoint on
7694 the unwinder's debug hook, declared as:
7696 void _Unwind_DebugHook (void *cfa, void *handler);
7698 The CFA argument indicates the frame to which control is
7699 about to be transferred. HANDLER is the destination PC.
7701 We ignore the CFA and set a temporary breakpoint at HANDLER.
7702 This is not extremely efficient but it avoids issues in gdb
7703 with computing the DWARF CFA, and it also works even in weird
7704 cases such as throwing an exception from inside a signal
7707 b
= SYMBOL_BLOCK_VALUE (func
);
7708 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7710 if (!SYMBOL_IS_ARGUMENT (sym
))
7717 insert_exception_resume_breakpoint (ecs
->event_thread
,
7723 catch (const gdb_exception_error
&e
)
7729 stop_waiting (struct execution_control_state
*ecs
)
7731 infrun_log_debug ("stop_waiting");
7733 /* Let callers know we don't want to wait for the inferior anymore. */
7734 ecs
->wait_some_more
= 0;
7736 /* If all-stop, but there exists a non-stop target, stop all
7737 threads now that we're presenting the stop to the user. */
7738 if (!non_stop
&& exists_non_stop_target ())
7739 stop_all_threads ();
7742 /* Like keep_going, but passes the signal to the inferior, even if the
7743 signal is set to nopass. */
7746 keep_going_pass_signal (struct execution_control_state
*ecs
)
7748 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7749 gdb_assert (!ecs
->event_thread
->resumed
);
7751 /* Save the pc before execution, to compare with pc after stop. */
7752 ecs
->event_thread
->prev_pc
7753 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7755 if (ecs
->event_thread
->control
.trap_expected
)
7757 struct thread_info
*tp
= ecs
->event_thread
;
7759 infrun_log_debug ("%s has trap_expected set, "
7760 "resuming to collect trap",
7761 target_pid_to_str (tp
->ptid
).c_str ());
7763 /* We haven't yet gotten our trap, and either: intercepted a
7764 non-signal event (e.g., a fork); or took a signal which we
7765 are supposed to pass through to the inferior. Simply
7767 resume (ecs
->event_thread
->suspend
.stop_signal
);
7769 else if (step_over_info_valid_p ())
7771 /* Another thread is stepping over a breakpoint in-line. If
7772 this thread needs a step-over too, queue the request. In
7773 either case, this resume must be deferred for later. */
7774 struct thread_info
*tp
= ecs
->event_thread
;
7776 if (ecs
->hit_singlestep_breakpoint
7777 || thread_still_needs_step_over (tp
))
7779 infrun_log_debug ("step-over already in progress: "
7780 "step-over for %s deferred",
7781 target_pid_to_str (tp
->ptid
).c_str ());
7782 global_thread_step_over_chain_enqueue (tp
);
7786 infrun_log_debug ("step-over in progress: resume of %s deferred",
7787 target_pid_to_str (tp
->ptid
).c_str ());
7792 struct regcache
*regcache
= get_current_regcache ();
7795 step_over_what step_what
;
7797 /* Either the trap was not expected, but we are continuing
7798 anyway (if we got a signal, the user asked it be passed to
7801 We got our expected trap, but decided we should resume from
7804 We're going to run this baby now!
7806 Note that insert_breakpoints won't try to re-insert
7807 already inserted breakpoints. Therefore, we don't
7808 care if breakpoints were already inserted, or not. */
7810 /* If we need to step over a breakpoint, and we're not using
7811 displaced stepping to do so, insert all breakpoints
7812 (watchpoints, etc.) but the one we're stepping over, step one
7813 instruction, and then re-insert the breakpoint when that step
7816 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7818 remove_bp
= (ecs
->hit_singlestep_breakpoint
7819 || (step_what
& STEP_OVER_BREAKPOINT
));
7820 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7822 /* We can't use displaced stepping if we need to step past a
7823 watchpoint. The instruction copied to the scratch pad would
7824 still trigger the watchpoint. */
7826 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7828 set_step_over_info (regcache
->aspace (),
7829 regcache_read_pc (regcache
), remove_wps
,
7830 ecs
->event_thread
->global_num
);
7832 else if (remove_wps
)
7833 set_step_over_info (NULL
, 0, remove_wps
, -1);
7835 /* If we now need to do an in-line step-over, we need to stop
7836 all other threads. Note this must be done before
7837 insert_breakpoints below, because that removes the breakpoint
7838 we're about to step over, otherwise other threads could miss
7840 if (step_over_info_valid_p () && target_is_non_stop_p ())
7841 stop_all_threads ();
7843 /* Stop stepping if inserting breakpoints fails. */
7846 insert_breakpoints ();
7848 catch (const gdb_exception_error
&e
)
7850 exception_print (gdb_stderr
, e
);
7852 clear_step_over_info ();
7856 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7858 resume (ecs
->event_thread
->suspend
.stop_signal
);
7861 prepare_to_wait (ecs
);
7864 /* Called when we should continue running the inferior, because the
7865 current event doesn't cause a user visible stop. This does the
7866 resuming part; waiting for the next event is done elsewhere. */
7869 keep_going (struct execution_control_state
*ecs
)
7871 if (ecs
->event_thread
->control
.trap_expected
7872 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7873 ecs
->event_thread
->control
.trap_expected
= 0;
7875 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7876 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7877 keep_going_pass_signal (ecs
);
7880 /* This function normally comes after a resume, before
7881 handle_inferior_event exits. It takes care of any last bits of
7882 housekeeping, and sets the all-important wait_some_more flag. */
7885 prepare_to_wait (struct execution_control_state
*ecs
)
7887 infrun_log_debug ("prepare_to_wait");
7889 ecs
->wait_some_more
= 1;
7891 if (!target_is_async_p ())
7892 mark_infrun_async_event_handler ();
7895 /* We are done with the step range of a step/next/si/ni command.
7896 Called once for each n of a "step n" operation. */
7899 end_stepping_range (struct execution_control_state
*ecs
)
7901 ecs
->event_thread
->control
.stop_step
= 1;
7905 /* Several print_*_reason functions to print why the inferior has stopped.
7906 We always print something when the inferior exits, or receives a signal.
7907 The rest of the cases are dealt with later on in normal_stop and
7908 print_it_typical. Ideally there should be a call to one of these
7909 print_*_reason functions functions from handle_inferior_event each time
7910 stop_waiting is called.
7912 Note that we don't call these directly, instead we delegate that to
7913 the interpreters, through observers. Interpreters then call these
7914 with whatever uiout is right. */
7917 print_end_stepping_range_reason (struct ui_out
*uiout
)
7919 /* For CLI-like interpreters, print nothing. */
7921 if (uiout
->is_mi_like_p ())
7923 uiout
->field_string ("reason",
7924 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7929 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7931 annotate_signalled ();
7932 if (uiout
->is_mi_like_p ())
7934 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7935 uiout
->text ("\nProgram terminated with signal ");
7936 annotate_signal_name ();
7937 uiout
->field_string ("signal-name",
7938 gdb_signal_to_name (siggnal
));
7939 annotate_signal_name_end ();
7941 annotate_signal_string ();
7942 uiout
->field_string ("signal-meaning",
7943 gdb_signal_to_string (siggnal
));
7944 annotate_signal_string_end ();
7945 uiout
->text (".\n");
7946 uiout
->text ("The program no longer exists.\n");
7950 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7952 struct inferior
*inf
= current_inferior ();
7953 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7955 annotate_exited (exitstatus
);
7958 if (uiout
->is_mi_like_p ())
7959 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7960 std::string exit_code_str
7961 = string_printf ("0%o", (unsigned int) exitstatus
);
7962 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7963 plongest (inf
->num
), pidstr
.c_str (),
7964 string_field ("exit-code", exit_code_str
.c_str ()));
7968 if (uiout
->is_mi_like_p ())
7970 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7971 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7972 plongest (inf
->num
), pidstr
.c_str ());
7976 /* Some targets/architectures can do extra processing/display of
7977 segmentation faults. E.g., Intel MPX boundary faults.
7978 Call the architecture dependent function to handle the fault. */
7981 handle_segmentation_fault (struct ui_out
*uiout
)
7983 struct regcache
*regcache
= get_current_regcache ();
7984 struct gdbarch
*gdbarch
= regcache
->arch ();
7986 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7987 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7991 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7993 struct thread_info
*thr
= inferior_thread ();
7997 if (uiout
->is_mi_like_p ())
7999 else if (show_thread_that_caused_stop ())
8003 uiout
->text ("\nThread ");
8004 uiout
->field_string ("thread-id", print_thread_id (thr
));
8006 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8009 uiout
->text (" \"");
8010 uiout
->field_string ("name", name
);
8015 uiout
->text ("\nProgram");
8017 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8018 uiout
->text (" stopped");
8021 uiout
->text (" received signal ");
8022 annotate_signal_name ();
8023 if (uiout
->is_mi_like_p ())
8025 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8026 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8027 annotate_signal_name_end ();
8029 annotate_signal_string ();
8030 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8032 if (siggnal
== GDB_SIGNAL_SEGV
)
8033 handle_segmentation_fault (uiout
);
8035 annotate_signal_string_end ();
8037 uiout
->text (".\n");
8041 print_no_history_reason (struct ui_out
*uiout
)
8043 uiout
->text ("\nNo more reverse-execution history.\n");
8046 /* Print current location without a level number, if we have changed
8047 functions or hit a breakpoint. Print source line if we have one.
8048 bpstat_print contains the logic deciding in detail what to print,
8049 based on the event(s) that just occurred. */
8052 print_stop_location (struct target_waitstatus
*ws
)
8055 enum print_what source_flag
;
8056 int do_frame_printing
= 1;
8057 struct thread_info
*tp
= inferior_thread ();
8059 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8063 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8064 should) carry around the function and does (or should) use
8065 that when doing a frame comparison. */
8066 if (tp
->control
.stop_step
8067 && frame_id_eq (tp
->control
.step_frame_id
,
8068 get_frame_id (get_current_frame ()))
8069 && (tp
->control
.step_start_function
8070 == find_pc_function (tp
->suspend
.stop_pc
)))
8072 /* Finished step, just print source line. */
8073 source_flag
= SRC_LINE
;
8077 /* Print location and source line. */
8078 source_flag
= SRC_AND_LOC
;
8081 case PRINT_SRC_AND_LOC
:
8082 /* Print location and source line. */
8083 source_flag
= SRC_AND_LOC
;
8085 case PRINT_SRC_ONLY
:
8086 source_flag
= SRC_LINE
;
8089 /* Something bogus. */
8090 source_flag
= SRC_LINE
;
8091 do_frame_printing
= 0;
8094 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8097 /* The behavior of this routine with respect to the source
8099 SRC_LINE: Print only source line
8100 LOCATION: Print only location
8101 SRC_AND_LOC: Print location and source line. */
8102 if (do_frame_printing
)
8103 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8109 print_stop_event (struct ui_out
*uiout
, bool displays
)
8111 struct target_waitstatus last
;
8112 struct thread_info
*tp
;
8114 get_last_target_status (nullptr, nullptr, &last
);
8117 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8119 print_stop_location (&last
);
8121 /* Display the auto-display expressions. */
8126 tp
= inferior_thread ();
8127 if (tp
->thread_fsm
!= NULL
8128 && tp
->thread_fsm
->finished_p ())
8130 struct return_value_info
*rv
;
8132 rv
= tp
->thread_fsm
->return_value ();
8134 print_return_value (uiout
, rv
);
8141 maybe_remove_breakpoints (void)
8143 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8145 if (remove_breakpoints ())
8147 target_terminal::ours_for_output ();
8148 printf_filtered (_("Cannot remove breakpoints because "
8149 "program is no longer writable.\nFurther "
8150 "execution is probably impossible.\n"));
8155 /* The execution context that just caused a normal stop. */
8162 DISABLE_COPY_AND_ASSIGN (stop_context
);
8164 bool changed () const;
8169 /* The event PTID. */
8173 /* If stopp for a thread event, this is the thread that caused the
8175 struct thread_info
*thread
;
8177 /* The inferior that caused the stop. */
8181 /* Initializes a new stop context. If stopped for a thread event, this
8182 takes a strong reference to the thread. */
8184 stop_context::stop_context ()
8186 stop_id
= get_stop_id ();
8187 ptid
= inferior_ptid
;
8188 inf_num
= current_inferior ()->num
;
8190 if (inferior_ptid
!= null_ptid
)
8192 /* Take a strong reference so that the thread can't be deleted
8194 thread
= inferior_thread ();
8201 /* Release a stop context previously created with save_stop_context.
8202 Releases the strong reference to the thread as well. */
8204 stop_context::~stop_context ()
8210 /* Return true if the current context no longer matches the saved stop
8214 stop_context::changed () const
8216 if (ptid
!= inferior_ptid
)
8218 if (inf_num
!= current_inferior ()->num
)
8220 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8222 if (get_stop_id () != stop_id
)
8232 struct target_waitstatus last
;
8234 get_last_target_status (nullptr, nullptr, &last
);
8238 /* If an exception is thrown from this point on, make sure to
8239 propagate GDB's knowledge of the executing state to the
8240 frontend/user running state. A QUIT is an easy exception to see
8241 here, so do this before any filtered output. */
8243 ptid_t finish_ptid
= null_ptid
;
8246 finish_ptid
= minus_one_ptid
;
8247 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8248 || last
.kind
== TARGET_WAITKIND_EXITED
)
8250 /* On some targets, we may still have live threads in the
8251 inferior when we get a process exit event. E.g., for
8252 "checkpoint", when the current checkpoint/fork exits,
8253 linux-fork.c automatically switches to another fork from
8254 within target_mourn_inferior. */
8255 if (inferior_ptid
!= null_ptid
)
8256 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8258 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8259 finish_ptid
= inferior_ptid
;
8261 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8262 if (finish_ptid
!= null_ptid
)
8264 maybe_finish_thread_state
.emplace
8265 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8268 /* As we're presenting a stop, and potentially removing breakpoints,
8269 update the thread list so we can tell whether there are threads
8270 running on the target. With target remote, for example, we can
8271 only learn about new threads when we explicitly update the thread
8272 list. Do this before notifying the interpreters about signal
8273 stops, end of stepping ranges, etc., so that the "new thread"
8274 output is emitted before e.g., "Program received signal FOO",
8275 instead of after. */
8276 update_thread_list ();
8278 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8279 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8281 /* As with the notification of thread events, we want to delay
8282 notifying the user that we've switched thread context until
8283 the inferior actually stops.
8285 There's no point in saying anything if the inferior has exited.
8286 Note that SIGNALLED here means "exited with a signal", not
8287 "received a signal".
8289 Also skip saying anything in non-stop mode. In that mode, as we
8290 don't want GDB to switch threads behind the user's back, to avoid
8291 races where the user is typing a command to apply to thread x,
8292 but GDB switches to thread y before the user finishes entering
8293 the command, fetch_inferior_event installs a cleanup to restore
8294 the current thread back to the thread the user had selected right
8295 after this event is handled, so we're not really switching, only
8296 informing of a stop. */
8298 && previous_inferior_ptid
!= inferior_ptid
8299 && target_has_execution
8300 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8301 && last
.kind
!= TARGET_WAITKIND_EXITED
8302 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8304 SWITCH_THRU_ALL_UIS ()
8306 target_terminal::ours_for_output ();
8307 printf_filtered (_("[Switching to %s]\n"),
8308 target_pid_to_str (inferior_ptid
).c_str ());
8309 annotate_thread_changed ();
8311 previous_inferior_ptid
= inferior_ptid
;
8314 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8316 SWITCH_THRU_ALL_UIS ()
8317 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8319 target_terminal::ours_for_output ();
8320 printf_filtered (_("No unwaited-for children left.\n"));
8324 /* Note: this depends on the update_thread_list call above. */
8325 maybe_remove_breakpoints ();
8327 /* If an auto-display called a function and that got a signal,
8328 delete that auto-display to avoid an infinite recursion. */
8330 if (stopped_by_random_signal
)
8331 disable_current_display ();
8333 SWITCH_THRU_ALL_UIS ()
8335 async_enable_stdin ();
8338 /* Let the user/frontend see the threads as stopped. */
8339 maybe_finish_thread_state
.reset ();
8341 /* Select innermost stack frame - i.e., current frame is frame 0,
8342 and current location is based on that. Handle the case where the
8343 dummy call is returning after being stopped. E.g. the dummy call
8344 previously hit a breakpoint. (If the dummy call returns
8345 normally, we won't reach here.) Do this before the stop hook is
8346 run, so that it doesn't get to see the temporary dummy frame,
8347 which is not where we'll present the stop. */
8348 if (has_stack_frames ())
8350 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8352 /* Pop the empty frame that contains the stack dummy. This
8353 also restores inferior state prior to the call (struct
8354 infcall_suspend_state). */
8355 struct frame_info
*frame
= get_current_frame ();
8357 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8359 /* frame_pop calls reinit_frame_cache as the last thing it
8360 does which means there's now no selected frame. */
8363 select_frame (get_current_frame ());
8365 /* Set the current source location. */
8366 set_current_sal_from_frame (get_current_frame ());
8369 /* Look up the hook_stop and run it (CLI internally handles problem
8370 of stop_command's pre-hook not existing). */
8371 if (stop_command
!= NULL
)
8373 stop_context saved_context
;
8377 execute_cmd_pre_hook (stop_command
);
8379 catch (const gdb_exception
&ex
)
8381 exception_fprintf (gdb_stderr
, ex
,
8382 "Error while running hook_stop:\n");
8385 /* If the stop hook resumes the target, then there's no point in
8386 trying to notify about the previous stop; its context is
8387 gone. Likewise if the command switches thread or inferior --
8388 the observers would print a stop for the wrong
8390 if (saved_context
.changed ())
8394 /* Notify observers about the stop. This is where the interpreters
8395 print the stop event. */
8396 if (inferior_ptid
!= null_ptid
)
8397 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8400 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8402 annotate_stopped ();
8404 if (target_has_execution
)
8406 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8407 && last
.kind
!= TARGET_WAITKIND_EXITED
8408 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8409 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8410 Delete any breakpoint that is to be deleted at the next stop. */
8411 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8414 /* Try to get rid of automatically added inferiors that are no
8415 longer needed. Keeping those around slows down things linearly.
8416 Note that this never removes the current inferior. */
8423 signal_stop_state (int signo
)
8425 return signal_stop
[signo
];
8429 signal_print_state (int signo
)
8431 return signal_print
[signo
];
8435 signal_pass_state (int signo
)
8437 return signal_program
[signo
];
8441 signal_cache_update (int signo
)
8445 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8446 signal_cache_update (signo
);
8451 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8452 && signal_print
[signo
] == 0
8453 && signal_program
[signo
] == 1
8454 && signal_catch
[signo
] == 0);
8458 signal_stop_update (int signo
, int state
)
8460 int ret
= signal_stop
[signo
];
8462 signal_stop
[signo
] = state
;
8463 signal_cache_update (signo
);
8468 signal_print_update (int signo
, int state
)
8470 int ret
= signal_print
[signo
];
8472 signal_print
[signo
] = state
;
8473 signal_cache_update (signo
);
8478 signal_pass_update (int signo
, int state
)
8480 int ret
= signal_program
[signo
];
8482 signal_program
[signo
] = state
;
8483 signal_cache_update (signo
);
8487 /* Update the global 'signal_catch' from INFO and notify the
8491 signal_catch_update (const unsigned int *info
)
8495 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8496 signal_catch
[i
] = info
[i
] > 0;
8497 signal_cache_update (-1);
8498 target_pass_signals (signal_pass
);
8502 sig_print_header (void)
8504 printf_filtered (_("Signal Stop\tPrint\tPass "
8505 "to program\tDescription\n"));
8509 sig_print_info (enum gdb_signal oursig
)
8511 const char *name
= gdb_signal_to_name (oursig
);
8512 int name_padding
= 13 - strlen (name
);
8514 if (name_padding
<= 0)
8517 printf_filtered ("%s", name
);
8518 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8519 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8520 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8521 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8522 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8525 /* Specify how various signals in the inferior should be handled. */
8528 handle_command (const char *args
, int from_tty
)
8530 int digits
, wordlen
;
8531 int sigfirst
, siglast
;
8532 enum gdb_signal oursig
;
8537 error_no_arg (_("signal to handle"));
8540 /* Allocate and zero an array of flags for which signals to handle. */
8542 const size_t nsigs
= GDB_SIGNAL_LAST
;
8543 unsigned char sigs
[nsigs
] {};
8545 /* Break the command line up into args. */
8547 gdb_argv
built_argv (args
);
8549 /* Walk through the args, looking for signal oursigs, signal names, and
8550 actions. Signal numbers and signal names may be interspersed with
8551 actions, with the actions being performed for all signals cumulatively
8552 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8554 for (char *arg
: built_argv
)
8556 wordlen
= strlen (arg
);
8557 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8561 sigfirst
= siglast
= -1;
8563 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8565 /* Apply action to all signals except those used by the
8566 debugger. Silently skip those. */
8569 siglast
= nsigs
- 1;
8571 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8573 SET_SIGS (nsigs
, sigs
, signal_stop
);
8574 SET_SIGS (nsigs
, sigs
, signal_print
);
8576 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8578 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8580 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8582 SET_SIGS (nsigs
, sigs
, signal_print
);
8584 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8586 SET_SIGS (nsigs
, sigs
, signal_program
);
8588 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8590 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8592 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8594 SET_SIGS (nsigs
, sigs
, signal_program
);
8596 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8598 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8599 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8601 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8603 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8605 else if (digits
> 0)
8607 /* It is numeric. The numeric signal refers to our own
8608 internal signal numbering from target.h, not to host/target
8609 signal number. This is a feature; users really should be
8610 using symbolic names anyway, and the common ones like
8611 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8613 sigfirst
= siglast
= (int)
8614 gdb_signal_from_command (atoi (arg
));
8615 if (arg
[digits
] == '-')
8618 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8620 if (sigfirst
> siglast
)
8622 /* Bet he didn't figure we'd think of this case... */
8623 std::swap (sigfirst
, siglast
);
8628 oursig
= gdb_signal_from_name (arg
);
8629 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8631 sigfirst
= siglast
= (int) oursig
;
8635 /* Not a number and not a recognized flag word => complain. */
8636 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8640 /* If any signal numbers or symbol names were found, set flags for
8641 which signals to apply actions to. */
8643 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8645 switch ((enum gdb_signal
) signum
)
8647 case GDB_SIGNAL_TRAP
:
8648 case GDB_SIGNAL_INT
:
8649 if (!allsigs
&& !sigs
[signum
])
8651 if (query (_("%s is used by the debugger.\n\
8652 Are you sure you want to change it? "),
8653 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8658 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8662 case GDB_SIGNAL_DEFAULT
:
8663 case GDB_SIGNAL_UNKNOWN
:
8664 /* Make sure that "all" doesn't print these. */
8673 for (int signum
= 0; signum
< nsigs
; signum
++)
8676 signal_cache_update (-1);
8677 target_pass_signals (signal_pass
);
8678 target_program_signals (signal_program
);
8682 /* Show the results. */
8683 sig_print_header ();
8684 for (; signum
< nsigs
; signum
++)
8686 sig_print_info ((enum gdb_signal
) signum
);
8693 /* Complete the "handle" command. */
8696 handle_completer (struct cmd_list_element
*ignore
,
8697 completion_tracker
&tracker
,
8698 const char *text
, const char *word
)
8700 static const char * const keywords
[] =
8714 signal_completer (ignore
, tracker
, text
, word
);
8715 complete_on_enum (tracker
, keywords
, word
, word
);
8719 gdb_signal_from_command (int num
)
8721 if (num
>= 1 && num
<= 15)
8722 return (enum gdb_signal
) num
;
8723 error (_("Only signals 1-15 are valid as numeric signals.\n\
8724 Use \"info signals\" for a list of symbolic signals."));
8727 /* Print current contents of the tables set by the handle command.
8728 It is possible we should just be printing signals actually used
8729 by the current target (but for things to work right when switching
8730 targets, all signals should be in the signal tables). */
8733 info_signals_command (const char *signum_exp
, int from_tty
)
8735 enum gdb_signal oursig
;
8737 sig_print_header ();
8741 /* First see if this is a symbol name. */
8742 oursig
= gdb_signal_from_name (signum_exp
);
8743 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8745 /* No, try numeric. */
8747 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8749 sig_print_info (oursig
);
8753 printf_filtered ("\n");
8754 /* These ugly casts brought to you by the native VAX compiler. */
8755 for (oursig
= GDB_SIGNAL_FIRST
;
8756 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8757 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8761 if (oursig
!= GDB_SIGNAL_UNKNOWN
8762 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8763 sig_print_info (oursig
);
8766 printf_filtered (_("\nUse the \"handle\" command "
8767 "to change these tables.\n"));
8770 /* The $_siginfo convenience variable is a bit special. We don't know
8771 for sure the type of the value until we actually have a chance to
8772 fetch the data. The type can change depending on gdbarch, so it is
8773 also dependent on which thread you have selected.
8775 1. making $_siginfo be an internalvar that creates a new value on
8778 2. making the value of $_siginfo be an lval_computed value. */
8780 /* This function implements the lval_computed support for reading a
8784 siginfo_value_read (struct value
*v
)
8786 LONGEST transferred
;
8788 /* If we can access registers, so can we access $_siginfo. Likewise
8790 validate_registers_access ();
8793 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8795 value_contents_all_raw (v
),
8797 TYPE_LENGTH (value_type (v
)));
8799 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8800 error (_("Unable to read siginfo"));
8803 /* This function implements the lval_computed support for writing a
8807 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8809 LONGEST transferred
;
8811 /* If we can access registers, so can we access $_siginfo. Likewise
8813 validate_registers_access ();
8815 transferred
= target_write (current_top_target (),
8816 TARGET_OBJECT_SIGNAL_INFO
,
8818 value_contents_all_raw (fromval
),
8820 TYPE_LENGTH (value_type (fromval
)));
8822 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8823 error (_("Unable to write siginfo"));
8826 static const struct lval_funcs siginfo_value_funcs
=
8832 /* Return a new value with the correct type for the siginfo object of
8833 the current thread using architecture GDBARCH. Return a void value
8834 if there's no object available. */
8836 static struct value
*
8837 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8840 if (target_has_stack
8841 && inferior_ptid
!= null_ptid
8842 && gdbarch_get_siginfo_type_p (gdbarch
))
8844 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8846 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8849 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8853 /* infcall_suspend_state contains state about the program itself like its
8854 registers and any signal it received when it last stopped.
8855 This state must be restored regardless of how the inferior function call
8856 ends (either successfully, or after it hits a breakpoint or signal)
8857 if the program is to properly continue where it left off. */
8859 class infcall_suspend_state
8862 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8863 once the inferior function call has finished. */
8864 infcall_suspend_state (struct gdbarch
*gdbarch
,
8865 const struct thread_info
*tp
,
8866 struct regcache
*regcache
)
8867 : m_thread_suspend (tp
->suspend
),
8868 m_registers (new readonly_detached_regcache (*regcache
))
8870 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8872 if (gdbarch_get_siginfo_type_p (gdbarch
))
8874 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8875 size_t len
= TYPE_LENGTH (type
);
8877 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8879 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8880 siginfo_data
.get (), 0, len
) != len
)
8882 /* Errors ignored. */
8883 siginfo_data
.reset (nullptr);
8889 m_siginfo_gdbarch
= gdbarch
;
8890 m_siginfo_data
= std::move (siginfo_data
);
8894 /* Return a pointer to the stored register state. */
8896 readonly_detached_regcache
*registers () const
8898 return m_registers
.get ();
8901 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8903 void restore (struct gdbarch
*gdbarch
,
8904 struct thread_info
*tp
,
8905 struct regcache
*regcache
) const
8907 tp
->suspend
= m_thread_suspend
;
8909 if (m_siginfo_gdbarch
== gdbarch
)
8911 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8913 /* Errors ignored. */
8914 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8915 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8918 /* The inferior can be gone if the user types "print exit(0)"
8919 (and perhaps other times). */
8920 if (target_has_execution
)
8921 /* NB: The register write goes through to the target. */
8922 regcache
->restore (registers ());
8926 /* How the current thread stopped before the inferior function call was
8928 struct thread_suspend_state m_thread_suspend
;
8930 /* The registers before the inferior function call was executed. */
8931 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8933 /* Format of SIGINFO_DATA or NULL if it is not present. */
8934 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8936 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8937 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8938 content would be invalid. */
8939 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8942 infcall_suspend_state_up
8943 save_infcall_suspend_state ()
8945 struct thread_info
*tp
= inferior_thread ();
8946 struct regcache
*regcache
= get_current_regcache ();
8947 struct gdbarch
*gdbarch
= regcache
->arch ();
8949 infcall_suspend_state_up inf_state
8950 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8952 /* Having saved the current state, adjust the thread state, discarding
8953 any stop signal information. The stop signal is not useful when
8954 starting an inferior function call, and run_inferior_call will not use
8955 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8956 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8961 /* Restore inferior session state to INF_STATE. */
8964 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8966 struct thread_info
*tp
= inferior_thread ();
8967 struct regcache
*regcache
= get_current_regcache ();
8968 struct gdbarch
*gdbarch
= regcache
->arch ();
8970 inf_state
->restore (gdbarch
, tp
, regcache
);
8971 discard_infcall_suspend_state (inf_state
);
8975 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8980 readonly_detached_regcache
*
8981 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8983 return inf_state
->registers ();
8986 /* infcall_control_state contains state regarding gdb's control of the
8987 inferior itself like stepping control. It also contains session state like
8988 the user's currently selected frame. */
8990 struct infcall_control_state
8992 struct thread_control_state thread_control
;
8993 struct inferior_control_state inferior_control
;
8996 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8997 int stopped_by_random_signal
= 0;
8999 /* ID if the selected frame when the inferior function call was made. */
9000 struct frame_id selected_frame_id
{};
9003 /* Save all of the information associated with the inferior<==>gdb
9006 infcall_control_state_up
9007 save_infcall_control_state ()
9009 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9010 struct thread_info
*tp
= inferior_thread ();
9011 struct inferior
*inf
= current_inferior ();
9013 inf_status
->thread_control
= tp
->control
;
9014 inf_status
->inferior_control
= inf
->control
;
9016 tp
->control
.step_resume_breakpoint
= NULL
;
9017 tp
->control
.exception_resume_breakpoint
= NULL
;
9019 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9020 chain. If caller's caller is walking the chain, they'll be happier if we
9021 hand them back the original chain when restore_infcall_control_state is
9023 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9026 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9027 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9029 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9035 restore_selected_frame (const frame_id
&fid
)
9037 frame_info
*frame
= frame_find_by_id (fid
);
9039 /* If inf_status->selected_frame_id is NULL, there was no previously
9043 warning (_("Unable to restore previously selected frame."));
9047 select_frame (frame
);
9050 /* Restore inferior session state to INF_STATUS. */
9053 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9055 struct thread_info
*tp
= inferior_thread ();
9056 struct inferior
*inf
= current_inferior ();
9058 if (tp
->control
.step_resume_breakpoint
)
9059 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9061 if (tp
->control
.exception_resume_breakpoint
)
9062 tp
->control
.exception_resume_breakpoint
->disposition
9063 = disp_del_at_next_stop
;
9065 /* Handle the bpstat_copy of the chain. */
9066 bpstat_clear (&tp
->control
.stop_bpstat
);
9068 tp
->control
= inf_status
->thread_control
;
9069 inf
->control
= inf_status
->inferior_control
;
9072 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9073 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9075 if (target_has_stack
)
9077 /* The point of the try/catch is that if the stack is clobbered,
9078 walking the stack might encounter a garbage pointer and
9079 error() trying to dereference it. */
9082 restore_selected_frame (inf_status
->selected_frame_id
);
9084 catch (const gdb_exception_error
&ex
)
9086 exception_fprintf (gdb_stderr
, ex
,
9087 "Unable to restore previously selected frame:\n");
9088 /* Error in restoring the selected frame. Select the
9090 select_frame (get_current_frame ());
9098 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9100 if (inf_status
->thread_control
.step_resume_breakpoint
)
9101 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9102 = disp_del_at_next_stop
;
9104 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9105 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9106 = disp_del_at_next_stop
;
9108 /* See save_infcall_control_state for info on stop_bpstat. */
9109 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9117 clear_exit_convenience_vars (void)
9119 clear_internalvar (lookup_internalvar ("_exitsignal"));
9120 clear_internalvar (lookup_internalvar ("_exitcode"));
9124 /* User interface for reverse debugging:
9125 Set exec-direction / show exec-direction commands
9126 (returns error unless target implements to_set_exec_direction method). */
9128 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9129 static const char exec_forward
[] = "forward";
9130 static const char exec_reverse
[] = "reverse";
9131 static const char *exec_direction
= exec_forward
;
9132 static const char *const exec_direction_names
[] = {
9139 set_exec_direction_func (const char *args
, int from_tty
,
9140 struct cmd_list_element
*cmd
)
9142 if (target_can_execute_reverse
)
9144 if (!strcmp (exec_direction
, exec_forward
))
9145 execution_direction
= EXEC_FORWARD
;
9146 else if (!strcmp (exec_direction
, exec_reverse
))
9147 execution_direction
= EXEC_REVERSE
;
9151 exec_direction
= exec_forward
;
9152 error (_("Target does not support this operation."));
9157 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9158 struct cmd_list_element
*cmd
, const char *value
)
9160 switch (execution_direction
) {
9162 fprintf_filtered (out
, _("Forward.\n"));
9165 fprintf_filtered (out
, _("Reverse.\n"));
9168 internal_error (__FILE__
, __LINE__
,
9169 _("bogus execution_direction value: %d"),
9170 (int) execution_direction
);
9175 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9176 struct cmd_list_element
*c
, const char *value
)
9178 fprintf_filtered (file
, _("Resuming the execution of threads "
9179 "of all processes is %s.\n"), value
);
9182 /* Implementation of `siginfo' variable. */
9184 static const struct internalvar_funcs siginfo_funcs
=
9191 /* Callback for infrun's target events source. This is marked when a
9192 thread has a pending status to process. */
9195 infrun_async_inferior_event_handler (gdb_client_data data
)
9197 inferior_event_handler (INF_REG_EVENT
, NULL
);
9200 void _initialize_infrun ();
9202 _initialize_infrun ()
9204 struct cmd_list_element
*c
;
9206 /* Register extra event sources in the event loop. */
9207 infrun_async_inferior_event_token
9208 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9210 add_info ("signals", info_signals_command
, _("\
9211 What debugger does when program gets various signals.\n\
9212 Specify a signal as argument to print info on that signal only."));
9213 add_info_alias ("handle", "signals", 0);
9215 c
= add_com ("handle", class_run
, handle_command
, _("\
9216 Specify how to handle signals.\n\
9217 Usage: handle SIGNAL [ACTIONS]\n\
9218 Args are signals and actions to apply to those signals.\n\
9219 If no actions are specified, the current settings for the specified signals\n\
9220 will be displayed instead.\n\
9222 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9223 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9224 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9225 The special arg \"all\" is recognized to mean all signals except those\n\
9226 used by the debugger, typically SIGTRAP and SIGINT.\n\
9228 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9229 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9230 Stop means reenter debugger if this signal happens (implies print).\n\
9231 Print means print a message if this signal happens.\n\
9232 Pass means let program see this signal; otherwise program doesn't know.\n\
9233 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9234 Pass and Stop may be combined.\n\
9236 Multiple signals may be specified. Signal numbers and signal names\n\
9237 may be interspersed with actions, with the actions being performed for\n\
9238 all signals cumulatively specified."));
9239 set_cmd_completer (c
, handle_completer
);
9242 stop_command
= add_cmd ("stop", class_obscure
,
9243 not_just_help_class_command
, _("\
9244 There is no `stop' command, but you can set a hook on `stop'.\n\
9245 This allows you to set a list of commands to be run each time execution\n\
9246 of the program stops."), &cmdlist
);
9248 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9249 Set inferior debugging."), _("\
9250 Show inferior debugging."), _("\
9251 When non-zero, inferior specific debugging is enabled."),
9254 &setdebuglist
, &showdebuglist
);
9256 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9257 &debug_displaced
, _("\
9258 Set displaced stepping debugging."), _("\
9259 Show displaced stepping debugging."), _("\
9260 When non-zero, displaced stepping specific debugging is enabled."),
9262 show_debug_displaced
,
9263 &setdebuglist
, &showdebuglist
);
9265 add_setshow_boolean_cmd ("non-stop", no_class
,
9267 Set whether gdb controls the inferior in non-stop mode."), _("\
9268 Show whether gdb controls the inferior in non-stop mode."), _("\
9269 When debugging a multi-threaded program and this setting is\n\
9270 off (the default, also called all-stop mode), when one thread stops\n\
9271 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9272 all other threads in the program while you interact with the thread of\n\
9273 interest. When you continue or step a thread, you can allow the other\n\
9274 threads to run, or have them remain stopped, but while you inspect any\n\
9275 thread's state, all threads stop.\n\
9277 In non-stop mode, when one thread stops, other threads can continue\n\
9278 to run freely. You'll be able to step each thread independently,\n\
9279 leave it stopped or free to run as needed."),
9285 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9288 signal_print
[i
] = 1;
9289 signal_program
[i
] = 1;
9290 signal_catch
[i
] = 0;
9293 /* Signals caused by debugger's own actions should not be given to
9294 the program afterwards.
9296 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9297 explicitly specifies that it should be delivered to the target
9298 program. Typically, that would occur when a user is debugging a
9299 target monitor on a simulator: the target monitor sets a
9300 breakpoint; the simulator encounters this breakpoint and halts
9301 the simulation handing control to GDB; GDB, noting that the stop
9302 address doesn't map to any known breakpoint, returns control back
9303 to the simulator; the simulator then delivers the hardware
9304 equivalent of a GDB_SIGNAL_TRAP to the program being
9306 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9307 signal_program
[GDB_SIGNAL_INT
] = 0;
9309 /* Signals that are not errors should not normally enter the debugger. */
9310 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9311 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9312 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9313 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9314 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9315 signal_print
[GDB_SIGNAL_PROF
] = 0;
9316 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9317 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9318 signal_stop
[GDB_SIGNAL_IO
] = 0;
9319 signal_print
[GDB_SIGNAL_IO
] = 0;
9320 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9321 signal_print
[GDB_SIGNAL_POLL
] = 0;
9322 signal_stop
[GDB_SIGNAL_URG
] = 0;
9323 signal_print
[GDB_SIGNAL_URG
] = 0;
9324 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9325 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9326 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9327 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9329 /* These signals are used internally by user-level thread
9330 implementations. (See signal(5) on Solaris.) Like the above
9331 signals, a healthy program receives and handles them as part of
9332 its normal operation. */
9333 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9334 signal_print
[GDB_SIGNAL_LWP
] = 0;
9335 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9336 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9337 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9338 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9339 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9340 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9342 /* Update cached state. */
9343 signal_cache_update (-1);
9345 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9346 &stop_on_solib_events
, _("\
9347 Set stopping for shared library events."), _("\
9348 Show stopping for shared library events."), _("\
9349 If nonzero, gdb will give control to the user when the dynamic linker\n\
9350 notifies gdb of shared library events. The most common event of interest\n\
9351 to the user would be loading/unloading of a new library."),
9352 set_stop_on_solib_events
,
9353 show_stop_on_solib_events
,
9354 &setlist
, &showlist
);
9356 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9357 follow_fork_mode_kind_names
,
9358 &follow_fork_mode_string
, _("\
9359 Set debugger response to a program call of fork or vfork."), _("\
9360 Show debugger response to a program call of fork or vfork."), _("\
9361 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9362 parent - the original process is debugged after a fork\n\
9363 child - the new process is debugged after a fork\n\
9364 The unfollowed process will continue to run.\n\
9365 By default, the debugger will follow the parent process."),
9367 show_follow_fork_mode_string
,
9368 &setlist
, &showlist
);
9370 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9371 follow_exec_mode_names
,
9372 &follow_exec_mode_string
, _("\
9373 Set debugger response to a program call of exec."), _("\
9374 Show debugger response to a program call of exec."), _("\
9375 An exec call replaces the program image of a process.\n\
9377 follow-exec-mode can be:\n\
9379 new - the debugger creates a new inferior and rebinds the process\n\
9380 to this new inferior. The program the process was running before\n\
9381 the exec call can be restarted afterwards by restarting the original\n\
9384 same - the debugger keeps the process bound to the same inferior.\n\
9385 The new executable image replaces the previous executable loaded in\n\
9386 the inferior. Restarting the inferior after the exec call restarts\n\
9387 the executable the process was running after the exec call.\n\
9389 By default, the debugger will use the same inferior."),
9391 show_follow_exec_mode_string
,
9392 &setlist
, &showlist
);
9394 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9395 scheduler_enums
, &scheduler_mode
, _("\
9396 Set mode for locking scheduler during execution."), _("\
9397 Show mode for locking scheduler during execution."), _("\
9398 off == no locking (threads may preempt at any time)\n\
9399 on == full locking (no thread except the current thread may run)\n\
9400 This applies to both normal execution and replay mode.\n\
9401 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9402 In this mode, other threads may run during other commands.\n\
9403 This applies to both normal execution and replay mode.\n\
9404 replay == scheduler locked in replay mode and unlocked during normal execution."),
9405 set_schedlock_func
, /* traps on target vector */
9406 show_scheduler_mode
,
9407 &setlist
, &showlist
);
9409 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9410 Set mode for resuming threads of all processes."), _("\
9411 Show mode for resuming threads of all processes."), _("\
9412 When on, execution commands (such as 'continue' or 'next') resume all\n\
9413 threads of all processes. When off (which is the default), execution\n\
9414 commands only resume the threads of the current process. The set of\n\
9415 threads that are resumed is further refined by the scheduler-locking\n\
9416 mode (see help set scheduler-locking)."),
9418 show_schedule_multiple
,
9419 &setlist
, &showlist
);
9421 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9422 Set mode of the step operation."), _("\
9423 Show mode of the step operation."), _("\
9424 When set, doing a step over a function without debug line information\n\
9425 will stop at the first instruction of that function. Otherwise, the\n\
9426 function is skipped and the step command stops at a different source line."),
9428 show_step_stop_if_no_debug
,
9429 &setlist
, &showlist
);
9431 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9432 &can_use_displaced_stepping
, _("\
9433 Set debugger's willingness to use displaced stepping."), _("\
9434 Show debugger's willingness to use displaced stepping."), _("\
9435 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9436 supported by the target architecture. If off, gdb will not use displaced\n\
9437 stepping to step over breakpoints, even if such is supported by the target\n\
9438 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9439 if the target architecture supports it and non-stop mode is active, but will not\n\
9440 use it in all-stop mode (see help set non-stop)."),
9442 show_can_use_displaced_stepping
,
9443 &setlist
, &showlist
);
9445 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9446 &exec_direction
, _("Set direction of execution.\n\
9447 Options are 'forward' or 'reverse'."),
9448 _("Show direction of execution (forward/reverse)."),
9449 _("Tells gdb whether to execute forward or backward."),
9450 set_exec_direction_func
, show_exec_direction_func
,
9451 &setlist
, &showlist
);
9453 /* Set/show detach-on-fork: user-settable mode. */
9455 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9456 Set whether gdb will detach the child of a fork."), _("\
9457 Show whether gdb will detach the child of a fork."), _("\
9458 Tells gdb whether to detach the child of a fork."),
9459 NULL
, NULL
, &setlist
, &showlist
);
9461 /* Set/show disable address space randomization mode. */
9463 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9464 &disable_randomization
, _("\
9465 Set disabling of debuggee's virtual address space randomization."), _("\
9466 Show disabling of debuggee's virtual address space randomization."), _("\
9467 When this mode is on (which is the default), randomization of the virtual\n\
9468 address space is disabled. Standalone programs run with the randomization\n\
9469 enabled by default on some platforms."),
9470 &set_disable_randomization
,
9471 &show_disable_randomization
,
9472 &setlist
, &showlist
);
9474 /* ptid initializations */
9475 inferior_ptid
= null_ptid
;
9476 target_last_wait_ptid
= minus_one_ptid
;
9478 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9479 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9480 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9481 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9483 /* Explicitly create without lookup, since that tries to create a
9484 value with a void typed value, and when we get here, gdbarch
9485 isn't initialized yet. At this point, we're quite sure there
9486 isn't another convenience variable of the same name. */
9487 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9489 add_setshow_boolean_cmd ("observer", no_class
,
9490 &observer_mode_1
, _("\
9491 Set whether gdb controls the inferior in observer mode."), _("\
9492 Show whether gdb controls the inferior in observer mode."), _("\
9493 In observer mode, GDB can get data from the inferior, but not\n\
9494 affect its execution. Registers and memory may not be changed,\n\
9495 breakpoints may not be set, and the program cannot be interrupted\n\