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 /* The next resume of this inferior should bring it to the shlib
1273 startup breakpoints. (If the user had also set bp's on
1274 "main" from the old (parent) process, then they'll auto-
1275 matically get reset there in the new process.). */
1278 /* The queue of threads that need to do a step-over operation to get
1279 past e.g., a breakpoint. What technique is used to step over the
1280 breakpoint/watchpoint does not matter -- all threads end up in the
1281 same queue, to maintain rough temporal order of execution, in order
1282 to avoid starvation, otherwise, we could e.g., find ourselves
1283 constantly stepping the same couple threads past their breakpoints
1284 over and over, if the single-step finish fast enough. */
1285 struct thread_info
*global_thread_step_over_chain_head
;
1287 /* Bit flags indicating what the thread needs to step over. */
1289 enum step_over_what_flag
1291 /* Step over a breakpoint. */
1292 STEP_OVER_BREAKPOINT
= 1,
1294 /* Step past a non-continuable watchpoint, in order to let the
1295 instruction execute so we can evaluate the watchpoint
1297 STEP_OVER_WATCHPOINT
= 2
1299 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1301 /* Info about an instruction that is being stepped over. */
1303 struct step_over_info
1305 /* If we're stepping past a breakpoint, this is the address space
1306 and address of the instruction the breakpoint is set at. We'll
1307 skip inserting all breakpoints here. Valid iff ASPACE is
1309 const address_space
*aspace
;
1312 /* The instruction being stepped over triggers a nonsteppable
1313 watchpoint. If true, we'll skip inserting watchpoints. */
1314 int nonsteppable_watchpoint_p
;
1316 /* The thread's global number. */
1320 /* The step-over info of the location that is being stepped over.
1322 Note that with async/breakpoint always-inserted mode, a user might
1323 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1324 being stepped over. As setting a new breakpoint inserts all
1325 breakpoints, we need to make sure the breakpoint being stepped over
1326 isn't inserted then. We do that by only clearing the step-over
1327 info when the step-over is actually finished (or aborted).
1329 Presently GDB can only step over one breakpoint at any given time.
1330 Given threads that can't run code in the same address space as the
1331 breakpoint's can't really miss the breakpoint, GDB could be taught
1332 to step-over at most one breakpoint per address space (so this info
1333 could move to the address space object if/when GDB is extended).
1334 The set of breakpoints being stepped over will normally be much
1335 smaller than the set of all breakpoints, so a flag in the
1336 breakpoint location structure would be wasteful. A separate list
1337 also saves complexity and run-time, as otherwise we'd have to go
1338 through all breakpoint locations clearing their flag whenever we
1339 start a new sequence. Similar considerations weigh against storing
1340 this info in the thread object. Plus, not all step overs actually
1341 have breakpoint locations -- e.g., stepping past a single-step
1342 breakpoint, or stepping to complete a non-continuable
1344 static struct step_over_info step_over_info
;
1346 /* Record the address of the breakpoint/instruction we're currently
1348 N.B. We record the aspace and address now, instead of say just the thread,
1349 because when we need the info later the thread may be running. */
1352 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1353 int nonsteppable_watchpoint_p
,
1356 step_over_info
.aspace
= aspace
;
1357 step_over_info
.address
= address
;
1358 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1359 step_over_info
.thread
= thread
;
1362 /* Called when we're not longer stepping over a breakpoint / an
1363 instruction, so all breakpoints are free to be (re)inserted. */
1366 clear_step_over_info (void)
1368 infrun_log_debug ("clearing step over info");
1369 step_over_info
.aspace
= NULL
;
1370 step_over_info
.address
= 0;
1371 step_over_info
.nonsteppable_watchpoint_p
= 0;
1372 step_over_info
.thread
= -1;
1378 stepping_past_instruction_at (struct address_space
*aspace
,
1381 return (step_over_info
.aspace
!= NULL
1382 && breakpoint_address_match (aspace
, address
,
1383 step_over_info
.aspace
,
1384 step_over_info
.address
));
1390 thread_is_stepping_over_breakpoint (int thread
)
1392 return (step_over_info
.thread
!= -1
1393 && thread
== step_over_info
.thread
);
1399 stepping_past_nonsteppable_watchpoint (void)
1401 return step_over_info
.nonsteppable_watchpoint_p
;
1404 /* Returns true if step-over info is valid. */
1407 step_over_info_valid_p (void)
1409 return (step_over_info
.aspace
!= NULL
1410 || stepping_past_nonsteppable_watchpoint ());
1414 /* Displaced stepping. */
1416 /* In non-stop debugging mode, we must take special care to manage
1417 breakpoints properly; in particular, the traditional strategy for
1418 stepping a thread past a breakpoint it has hit is unsuitable.
1419 'Displaced stepping' is a tactic for stepping one thread past a
1420 breakpoint it has hit while ensuring that other threads running
1421 concurrently will hit the breakpoint as they should.
1423 The traditional way to step a thread T off a breakpoint in a
1424 multi-threaded program in all-stop mode is as follows:
1426 a0) Initially, all threads are stopped, and breakpoints are not
1428 a1) We single-step T, leaving breakpoints uninserted.
1429 a2) We insert breakpoints, and resume all threads.
1431 In non-stop debugging, however, this strategy is unsuitable: we
1432 don't want to have to stop all threads in the system in order to
1433 continue or step T past a breakpoint. Instead, we use displaced
1436 n0) Initially, T is stopped, other threads are running, and
1437 breakpoints are inserted.
1438 n1) We copy the instruction "under" the breakpoint to a separate
1439 location, outside the main code stream, making any adjustments
1440 to the instruction, register, and memory state as directed by
1442 n2) We single-step T over the instruction at its new location.
1443 n3) We adjust the resulting register and memory state as directed
1444 by T's architecture. This includes resetting T's PC to point
1445 back into the main instruction stream.
1448 This approach depends on the following gdbarch methods:
1450 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1451 indicate where to copy the instruction, and how much space must
1452 be reserved there. We use these in step n1.
1454 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1455 address, and makes any necessary adjustments to the instruction,
1456 register contents, and memory. We use this in step n1.
1458 - gdbarch_displaced_step_fixup adjusts registers and memory after
1459 we have successfully single-stepped the instruction, to yield the
1460 same effect the instruction would have had if we had executed it
1461 at its original address. We use this in step n3.
1463 The gdbarch_displaced_step_copy_insn and
1464 gdbarch_displaced_step_fixup functions must be written so that
1465 copying an instruction with gdbarch_displaced_step_copy_insn,
1466 single-stepping across the copied instruction, and then applying
1467 gdbarch_displaced_insn_fixup should have the same effects on the
1468 thread's memory and registers as stepping the instruction in place
1469 would have. Exactly which responsibilities fall to the copy and
1470 which fall to the fixup is up to the author of those functions.
1472 See the comments in gdbarch.sh for details.
1474 Note that displaced stepping and software single-step cannot
1475 currently be used in combination, although with some care I think
1476 they could be made to. Software single-step works by placing
1477 breakpoints on all possible subsequent instructions; if the
1478 displaced instruction is a PC-relative jump, those breakpoints
1479 could fall in very strange places --- on pages that aren't
1480 executable, or at addresses that are not proper instruction
1481 boundaries. (We do generally let other threads run while we wait
1482 to hit the software single-step breakpoint, and they might
1483 encounter such a corrupted instruction.) One way to work around
1484 this would be to have gdbarch_displaced_step_copy_insn fully
1485 simulate the effect of PC-relative instructions (and return NULL)
1486 on architectures that use software single-stepping.
1488 In non-stop mode, we can have independent and simultaneous step
1489 requests, so more than one thread may need to simultaneously step
1490 over a breakpoint. The current implementation assumes there is
1491 only one scratch space per process. In this case, we have to
1492 serialize access to the scratch space. If thread A wants to step
1493 over a breakpoint, but we are currently waiting for some other
1494 thread to complete a displaced step, we leave thread A stopped and
1495 place it in the displaced_step_request_queue. Whenever a displaced
1496 step finishes, we pick the next thread in the queue and start a new
1497 displaced step operation on it. See displaced_step_prepare and
1498 displaced_step_fixup for details. */
1500 /* Get the displaced stepping state of inferior INF. */
1502 static displaced_step_inferior_state
*
1503 get_displaced_stepping_state (inferior
*inf
)
1505 return &inf
->displaced_step_state
;
1508 /* Get the displaced stepping state of thread THREAD. */
1510 static displaced_step_thread_state
*
1511 get_displaced_stepping_state (thread_info
*thread
)
1513 return &thread
->displaced_step_state
;
1516 /* Return true if the given thread is doing a displaced step. */
1519 displaced_step_in_progress (thread_info
*thread
)
1521 gdb_assert (thread
!= NULL
);
1523 return get_displaced_stepping_state (thread
)->in_progress ();
1526 /* Return true if any thread of this inferior is doing a displaced step. */
1529 displaced_step_in_progress (inferior
*inf
)
1531 for (thread_info
*thread
: inf
->non_exited_threads ())
1533 if (displaced_step_in_progress (thread
))
1540 /* Return true if any thread is doing a displaced step. */
1543 displaced_step_in_progress_any_thread ()
1545 for (thread_info
*thread
: all_non_exited_threads ())
1547 if (displaced_step_in_progress (thread
))
1554 /* If inferior is in displaced stepping, and ADDR equals to starting address
1555 of copy area, return corresponding displaced_step_copy_insn_closure. Otherwise,
1558 struct displaced_step_copy_insn_closure
*
1559 get_displaced_step_copy_insn_closure_by_addr (CORE_ADDR addr
)
1561 // FIXME: implement me (only needed on ARM).
1562 // displaced_step_inferior_state *displaced
1563 // = get_displaced_stepping_state (current_inferior ());
1565 // /* If checking the mode of displaced instruction in copy area. */
1566 // if (displaced->step_thread != nullptr
1567 // && displaced->step_copy == addr)
1568 // return displaced->step_closure.get ();
1574 infrun_inferior_exit (struct inferior
*inf
)
1576 inf
->displaced_step_state
.reset ();
1579 /* If ON, and the architecture supports it, GDB will use displaced
1580 stepping to step over breakpoints. If OFF, or if the architecture
1581 doesn't support it, GDB will instead use the traditional
1582 hold-and-step approach. If AUTO (which is the default), GDB will
1583 decide which technique to use to step over breakpoints depending on
1584 whether the target works in a non-stop way (see use_displaced_stepping). */
1586 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1589 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1590 struct cmd_list_element
*c
,
1593 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1594 fprintf_filtered (file
,
1595 _("Debugger's willingness to use displaced stepping "
1596 "to step over breakpoints is %s (currently %s).\n"),
1597 value
, target_is_non_stop_p () ? "on" : "off");
1599 fprintf_filtered (file
,
1600 _("Debugger's willingness to use displaced stepping "
1601 "to step over breakpoints is %s.\n"), value
);
1604 /* Return true if the gdbarch implements the required methods to use
1605 displaced stepping. */
1608 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1610 /* Only check for the presence of copy_insn. Other required methods
1611 are checked by the gdbarch validation to be provided if copy_insn is
1613 return gdbarch_displaced_step_copy_insn_p (arch
);
1616 /* Return non-zero if displaced stepping can/should be used to step
1617 over breakpoints of thread TP. */
1620 use_displaced_stepping (thread_info
*tp
)
1622 /* If the user disabled it explicitly, don't use displaced stepping. */
1623 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1626 /* If "auto", only use displaced stepping if the target operates in a non-stop
1628 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1629 && !target_is_non_stop_p ())
1632 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1634 /* If the architecture doesn't implement displaced stepping, don't use
1636 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1639 /* If recording, don't use displaced stepping. */
1640 if (find_record_target () != nullptr)
1643 displaced_step_inferior_state
*displaced_state
1644 = get_displaced_stepping_state (tp
->inf
);
1646 /* If displaced stepping failed before for this inferior, don't bother trying
1648 if (displaced_state
->failed_before
)
1654 /* Simple function wrapper around displaced_step_thread_state::reset. */
1657 displaced_step_reset (displaced_step_thread_state
*displaced
)
1659 displaced
->reset ();
1662 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1663 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1665 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1667 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1669 displaced_step_dump_bytes (struct ui_file
*file
,
1670 const gdb_byte
*buf
,
1675 for (i
= 0; i
< len
; i
++)
1676 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1677 fputs_unfiltered ("\n", file
);
1680 /* Prepare to single-step, using displaced stepping.
1682 Note that we cannot use displaced stepping when we have a signal to
1683 deliver. If we have a signal to deliver and an instruction to step
1684 over, then after the step, there will be no indication from the
1685 target whether the thread entered a signal handler or ignored the
1686 signal and stepped over the instruction successfully --- both cases
1687 result in a simple SIGTRAP. In the first case we mustn't do a
1688 fixup, and in the second case we must --- but we can't tell which.
1689 Comments in the code for 'random signals' in handle_inferior_event
1690 explain how we handle this case instead.
1692 Returns 1 if preparing was successful -- this thread is going to be
1693 stepped now; 0 if displaced stepping this thread got queued; or -1
1694 if this instruction can't be displaced stepped. */
1696 static displaced_step_prepare_status
1697 displaced_step_prepare_throw (thread_info
*tp
)
1699 regcache
*regcache
= get_thread_regcache (tp
);
1700 struct gdbarch
*gdbarch
= regcache
->arch ();
1701 displaced_step_thread_state
*thread_disp_step_state
1702 = get_displaced_stepping_state (tp
);
1704 /* We should never reach this function if the architecture does not
1705 support displaced stepping. */
1706 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1708 /* Nor if the thread isn't meant to step over a breakpoint. */
1709 gdb_assert (tp
->control
.trap_expected
);
1711 /* Disable range stepping while executing in the scratch pad. We
1712 want a single-step even if executing the displaced instruction in
1713 the scratch buffer lands within the stepping range (e.g., a
1715 tp
->control
.may_range_step
= 0;
1717 /* We are about to start a displaced step for this thread, if one is already
1718 in progress, we goofed up somewhere. */
1719 gdb_assert (!thread_disp_step_state
->in_progress ());
1721 scoped_restore_current_thread restore_thread
;
1723 switch_to_thread (tp
);
1725 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1727 displaced_step_prepare_status status
=
1728 gdbarch_displaced_step_prepare (gdbarch
, tp
);
1730 if (status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
1732 if (debug_displaced
)
1733 fprintf_unfiltered (gdb_stdlog
,
1734 "displaced: failed to prepare (%s)",
1735 target_pid_to_str (tp
->ptid
).c_str ());
1737 return DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1739 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1741 /* Not enough displaced stepping resources available, defer this
1742 request by placing it the queue. */
1744 if (debug_displaced
)
1745 fprintf_unfiltered (gdb_stdlog
,
1746 "displaced: not enough resources available, "
1747 "deferring step of %s\n",
1748 target_pid_to_str (tp
->ptid
).c_str ());
1750 global_thread_step_over_chain_enqueue (tp
);
1752 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1755 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1757 // FIXME: Should probably replicated in the arch implementation now.
1759 // if (breakpoint_in_range_p (aspace, copy, len))
1761 // /* There's a breakpoint set in the scratch pad location range
1762 // (which is usually around the entry point). We'd either
1763 // install it before resuming, which would overwrite/corrupt the
1764 // scratch pad, or if it was already inserted, this displaced
1765 // step would overwrite it. The latter is OK in the sense that
1766 // we already assume that no thread is going to execute the code
1767 // in the scratch pad range (after initial startup) anyway, but
1768 // the former is unacceptable. Simply punt and fallback to
1769 // stepping over this breakpoint in-line. */
1770 // if (debug_displaced)
1772 // fprintf_unfiltered (gdb_stdlog,
1773 // "displaced: breakpoint set in scratch pad. "
1774 // "Stepping over breakpoint in-line instead.\n");
1777 // gdb_assert (false);
1778 // gdbarch_displaced_step_release_location (gdbarch, copy);
1783 /* Save the information we need to fix things up if the step
1785 thread_disp_step_state
->set (gdbarch
);
1787 // FIXME: get it from _prepare?
1788 CORE_ADDR displaced_pc
= 0;
1790 if (debug_displaced
)
1791 fprintf_unfiltered (gdb_stdlog
,
1792 "displaced: prepared successfully thread=%s, "
1793 "original_pc=%s, displaced_pc=%s\n",
1794 target_pid_to_str (tp
->ptid
).c_str (),
1795 paddress (gdbarch
, original_pc
),
1796 paddress (gdbarch
, displaced_pc
));
1798 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1801 /* Wrapper for displaced_step_prepare_throw that disabled further
1802 attempts at displaced stepping if we get a memory error. */
1804 static displaced_step_prepare_status
1805 displaced_step_prepare (thread_info
*thread
)
1807 displaced_step_prepare_status status
1808 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1812 status
= displaced_step_prepare_throw (thread
);
1814 catch (const gdb_exception_error
&ex
)
1816 struct displaced_step_inferior_state
*displaced_state
;
1818 if (ex
.error
!= MEMORY_ERROR
1819 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1822 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1825 /* Be verbose if "set displaced-stepping" is "on", silent if
1827 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1829 warning (_("disabling displaced stepping: %s"),
1833 /* Disable further displaced stepping attempts. */
1835 = get_displaced_stepping_state (thread
->inf
);
1836 displaced_state
->failed_before
= 1;
1842 /* If we displaced stepped an instruction successfully, adjust
1843 registers and memory to yield the same effect the instruction would
1844 have had if we had executed it at its original address, and return
1845 1. If the instruction didn't complete, relocate the PC and return
1846 -1. If the thread wasn't displaced stepping, return 0. */
1849 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1851 displaced_step_thread_state
*displaced
1852 = get_displaced_stepping_state (event_thread
);
1854 /* Was this thread performing a displaced step? */
1855 if (!displaced
->in_progress ())
1858 displaced_step_reset_cleanup
cleanup (displaced
);
1860 /* Fixup may need to read memory/registers. Switch to the thread
1861 that we're fixing up. Also, target_stopped_by_watchpoint checks
1862 the current thread, and displaced_step_restore performs ptid-dependent
1863 memory accesses using current_inferior() and current_top_target(). */
1864 switch_to_thread (event_thread
);
1866 /* Do the fixup, and release the resources acquired to do the displaced
1868 displaced_step_finish_status finish_status
=
1869 gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1870 event_thread
, signal
);
1872 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1878 /* Data to be passed around while handling an event. This data is
1879 discarded between events. */
1880 struct execution_control_state
1882 process_stratum_target
*target
;
1884 /* The thread that got the event, if this was a thread event; NULL
1886 struct thread_info
*event_thread
;
1888 struct target_waitstatus ws
;
1889 int stop_func_filled_in
;
1890 CORE_ADDR stop_func_start
;
1891 CORE_ADDR stop_func_end
;
1892 const char *stop_func_name
;
1895 /* True if the event thread hit the single-step breakpoint of
1896 another thread. Thus the event doesn't cause a stop, the thread
1897 needs to be single-stepped past the single-step breakpoint before
1898 we can switch back to the original stepping thread. */
1899 int hit_singlestep_breakpoint
;
1902 /* Clear ECS and set it to point at TP. */
1905 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1907 memset (ecs
, 0, sizeof (*ecs
));
1908 ecs
->event_thread
= tp
;
1909 ecs
->ptid
= tp
->ptid
;
1912 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1913 static void prepare_to_wait (struct execution_control_state
*ecs
);
1914 static int keep_going_stepped_thread (struct thread_info
*tp
);
1915 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1917 /* Are there any pending step-over requests? If so, run all we can
1918 now and return true. Otherwise, return false. */
1921 start_step_over (void)
1923 struct thread_info
*tp
, *next
;
1926 /* Don't start a new step-over if we already have an in-line
1927 step-over operation ongoing. */
1928 if (step_over_info_valid_p ())
1931 /* Steal the global thread step over chain. */
1932 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1933 global_thread_step_over_chain_head
= NULL
;
1936 fprintf_unfiltered (gdb_stdlog
,
1937 "infrun: stealing list of %d threads to step from global queue\n",
1938 thread_step_over_chain_length (threads_to_step
));
1940 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1942 struct execution_control_state ecss
;
1943 struct execution_control_state
*ecs
= &ecss
;
1944 step_over_what step_what
;
1945 int must_be_in_line
;
1947 gdb_assert (!tp
->stop_requested
);
1949 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1951 step_what
= thread_still_needs_step_over (tp
);
1952 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1953 || ((step_what
& STEP_OVER_BREAKPOINT
)
1954 && !use_displaced_stepping (tp
)));
1956 /* We currently stop all threads of all processes to step-over
1957 in-line. If we need to start a new in-line step-over, let
1958 any pending displaced steps finish first. */
1959 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1962 thread_step_over_chain_remove (&threads_to_step
, tp
);
1964 if (tp
->control
.trap_expected
1968 internal_error (__FILE__
, __LINE__
,
1969 "[%s] has inconsistent state: "
1970 "trap_expected=%d, resumed=%d, executing=%d\n",
1971 target_pid_to_str (tp
->ptid
).c_str (),
1972 tp
->control
.trap_expected
,
1977 infrun_log_debug ("resuming [%s] for step-over",
1978 target_pid_to_str (tp
->ptid
).c_str ());
1980 /* keep_going_pass_signal skips the step-over if the breakpoint
1981 is no longer inserted. In all-stop, we want to keep looking
1982 for a thread that needs a step-over instead of resuming TP,
1983 because we wouldn't be able to resume anything else until the
1984 target stops again. In non-stop, the resume always resumes
1985 only TP, so it's OK to let the thread resume freely. */
1986 if (!target_is_non_stop_p () && !step_what
)
1989 switch_to_thread (tp
);
1990 reset_ecs (ecs
, tp
);
1991 keep_going_pass_signal (ecs
);
1993 if (!ecs
->wait_some_more
)
1994 error (_("Command aborted."));
1996 /* If the thread's step over could not be initiated, it was re-added
1997 to the global step over chain. */
2000 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
2001 target_pid_to_str (tp
->ptid
).c_str ());
2002 gdb_assert (!thread_is_in_step_over_chain (tp
));
2006 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
2007 target_pid_to_str (tp
->ptid
).c_str ());
2008 gdb_assert (thread_is_in_step_over_chain (tp
));
2012 /* If we started a new in-line step-over, we're done. */
2013 if (step_over_info_valid_p ())
2015 gdb_assert (tp
->control
.trap_expected
);
2020 if (!target_is_non_stop_p ())
2022 /* On all-stop, shouldn't have resumed unless we needed a
2024 gdb_assert (tp
->control
.trap_expected
2025 || tp
->step_after_step_resume_breakpoint
);
2027 /* With remote targets (at least), in all-stop, we can't
2028 issue any further remote commands until the program stops
2034 /* Either the thread no longer needed a step-over, or a new
2035 displaced stepping sequence started. Even in the latter
2036 case, continue looking. Maybe we can also start another
2037 displaced step on a thread of other process. */
2040 /* If there are threads left in the THREADS_TO_STEP list, but we have
2041 detected that we can't start anything more, put back these threads
2042 in the global list. */
2043 if (threads_to_step
== NULL
)
2046 fprintf_unfiltered (gdb_stdlog
,
2047 "infrun: step-over queue now empty\n");
2052 fprintf_unfiltered (gdb_stdlog
,
2053 "infrun: putting back %d threads to step in global queue\n",
2054 thread_step_over_chain_length (threads_to_step
));
2055 while (threads_to_step
!= nullptr)
2057 thread_info
*thread
= threads_to_step
;
2059 /* Remove from that list. */
2060 thread_step_over_chain_remove (&threads_to_step
, thread
);
2062 /* Add to global list. */
2063 global_thread_step_over_chain_enqueue (thread
);
2071 /* Update global variables holding ptids to hold NEW_PTID if they were
2072 holding OLD_PTID. */
2074 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2076 if (inferior_ptid
== old_ptid
)
2077 inferior_ptid
= new_ptid
;
2082 static const char schedlock_off
[] = "off";
2083 static const char schedlock_on
[] = "on";
2084 static const char schedlock_step
[] = "step";
2085 static const char schedlock_replay
[] = "replay";
2086 static const char *const scheduler_enums
[] = {
2093 static const char *scheduler_mode
= schedlock_replay
;
2095 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2096 struct cmd_list_element
*c
, const char *value
)
2098 fprintf_filtered (file
,
2099 _("Mode for locking scheduler "
2100 "during execution is \"%s\".\n"),
2105 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2107 if (!target_can_lock_scheduler
)
2109 scheduler_mode
= schedlock_off
;
2110 error (_("Target '%s' cannot support this command."), target_shortname
);
2114 /* True if execution commands resume all threads of all processes by
2115 default; otherwise, resume only threads of the current inferior
2117 bool sched_multi
= false;
2119 /* Try to setup for software single stepping over the specified location.
2120 Return 1 if target_resume() should use hardware single step.
2122 GDBARCH the current gdbarch.
2123 PC the location to step over. */
2126 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2130 if (execution_direction
== EXEC_FORWARD
2131 && gdbarch_software_single_step_p (gdbarch
))
2132 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2140 user_visible_resume_ptid (int step
)
2146 /* With non-stop mode on, threads are always handled
2148 resume_ptid
= inferior_ptid
;
2150 else if ((scheduler_mode
== schedlock_on
)
2151 || (scheduler_mode
== schedlock_step
&& step
))
2153 /* User-settable 'scheduler' mode requires solo thread
2155 resume_ptid
= inferior_ptid
;
2157 else if ((scheduler_mode
== schedlock_replay
)
2158 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2160 /* User-settable 'scheduler' mode requires solo thread resume in replay
2162 resume_ptid
= inferior_ptid
;
2164 else if (!sched_multi
&& target_supports_multi_process ())
2166 /* Resume all threads of the current process (and none of other
2168 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2172 /* Resume all threads of all processes. */
2173 resume_ptid
= RESUME_ALL
;
2181 process_stratum_target
*
2182 user_visible_resume_target (ptid_t resume_ptid
)
2184 return (resume_ptid
== minus_one_ptid
&& sched_multi
2186 : current_inferior ()->process_target ());
2189 /* Return a ptid representing the set of threads that we will resume,
2190 in the perspective of the target, assuming run control handling
2191 does not require leaving some threads stopped (e.g., stepping past
2192 breakpoint). USER_STEP indicates whether we're about to start the
2193 target for a stepping command. */
2196 internal_resume_ptid (int user_step
)
2198 /* In non-stop, we always control threads individually. Note that
2199 the target may always work in non-stop mode even with "set
2200 non-stop off", in which case user_visible_resume_ptid could
2201 return a wildcard ptid. */
2202 if (target_is_non_stop_p ())
2203 return inferior_ptid
;
2205 return user_visible_resume_ptid (user_step
);
2208 /* Wrapper for target_resume, that handles infrun-specific
2212 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2214 struct thread_info
*tp
= inferior_thread ();
2216 gdb_assert (!tp
->stop_requested
);
2218 /* Install inferior's terminal modes. */
2219 target_terminal::inferior ();
2221 /* Avoid confusing the next resume, if the next stop/resume
2222 happens to apply to another thread. */
2223 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2225 /* Advise target which signals may be handled silently.
2227 If we have removed breakpoints because we are stepping over one
2228 in-line (in any thread), we need to receive all signals to avoid
2229 accidentally skipping a breakpoint during execution of a signal
2232 Likewise if we're displaced stepping, otherwise a trap for a
2233 breakpoint in a signal handler might be confused with the
2234 displaced step finishing. We don't make the displaced_step_fixup
2235 step distinguish the cases instead, because:
2237 - a backtrace while stopped in the signal handler would show the
2238 scratch pad as frame older than the signal handler, instead of
2239 the real mainline code.
2241 - when the thread is later resumed, the signal handler would
2242 return to the scratch pad area, which would no longer be
2244 if (step_over_info_valid_p ()
2245 || displaced_step_in_progress (tp
->inf
))
2246 target_pass_signals ({});
2248 target_pass_signals (signal_pass
);
2250 target_resume (resume_ptid
, step
, sig
);
2252 target_commit_resume ();
2254 if (target_can_async_p ())
2258 /* Resume the inferior. SIG is the signal to give the inferior
2259 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2260 call 'resume', which handles exceptions. */
2263 resume_1 (enum gdb_signal sig
)
2265 struct regcache
*regcache
= get_current_regcache ();
2266 struct gdbarch
*gdbarch
= regcache
->arch ();
2267 struct thread_info
*tp
= inferior_thread ();
2268 const address_space
*aspace
= regcache
->aspace ();
2270 /* This represents the user's step vs continue request. When
2271 deciding whether "set scheduler-locking step" applies, it's the
2272 user's intention that counts. */
2273 const int user_step
= tp
->control
.stepping_command
;
2274 /* This represents what we'll actually request the target to do.
2275 This can decay from a step to a continue, if e.g., we need to
2276 implement single-stepping with breakpoints (software
2280 gdb_assert (!tp
->stop_requested
);
2281 gdb_assert (!thread_is_in_step_over_chain (tp
));
2283 if (tp
->suspend
.waitstatus_pending_p
)
2286 ("thread %s has pending wait "
2287 "status %s (currently_stepping=%d).",
2288 target_pid_to_str (tp
->ptid
).c_str (),
2289 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2290 currently_stepping (tp
));
2292 tp
->inf
->process_target ()->threads_executing
= true;
2295 /* FIXME: What should we do if we are supposed to resume this
2296 thread with a signal? Maybe we should maintain a queue of
2297 pending signals to deliver. */
2298 if (sig
!= GDB_SIGNAL_0
)
2300 warning (_("Couldn't deliver signal %s to %s."),
2301 gdb_signal_to_name (sig
),
2302 target_pid_to_str (tp
->ptid
).c_str ());
2305 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2307 if (target_can_async_p ())
2310 /* Tell the event loop we have an event to process. */
2311 mark_async_event_handler (infrun_async_inferior_event_token
);
2316 tp
->stepped_breakpoint
= 0;
2318 /* Depends on stepped_breakpoint. */
2319 step
= currently_stepping (tp
);
2321 if (current_inferior ()->waiting_for_vfork_done
)
2323 /* Don't try to single-step a vfork parent that is waiting for
2324 the child to get out of the shared memory region (by exec'ing
2325 or exiting). This is particularly important on software
2326 single-step archs, as the child process would trip on the
2327 software single step breakpoint inserted for the parent
2328 process. Since the parent will not actually execute any
2329 instruction until the child is out of the shared region (such
2330 are vfork's semantics), it is safe to simply continue it.
2331 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2332 the parent, and tell it to `keep_going', which automatically
2333 re-sets it stepping. */
2334 infrun_log_debug ("resume : clear step");
2338 CORE_ADDR pc
= regcache_read_pc (regcache
);
2340 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2341 "current thread [%s] at %s",
2342 step
, gdb_signal_to_symbol_string (sig
),
2343 tp
->control
.trap_expected
,
2344 target_pid_to_str (inferior_ptid
).c_str (),
2345 paddress (gdbarch
, pc
));
2347 /* Normally, by the time we reach `resume', the breakpoints are either
2348 removed or inserted, as appropriate. The exception is if we're sitting
2349 at a permanent breakpoint; we need to step over it, but permanent
2350 breakpoints can't be removed. So we have to test for it here. */
2351 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2353 if (sig
!= GDB_SIGNAL_0
)
2355 /* We have a signal to pass to the inferior. The resume
2356 may, or may not take us to the signal handler. If this
2357 is a step, we'll need to stop in the signal handler, if
2358 there's one, (if the target supports stepping into
2359 handlers), or in the next mainline instruction, if
2360 there's no handler. If this is a continue, we need to be
2361 sure to run the handler with all breakpoints inserted.
2362 In all cases, set a breakpoint at the current address
2363 (where the handler returns to), and once that breakpoint
2364 is hit, resume skipping the permanent breakpoint. If
2365 that breakpoint isn't hit, then we've stepped into the
2366 signal handler (or hit some other event). We'll delete
2367 the step-resume breakpoint then. */
2369 infrun_log_debug ("resume: skipping permanent breakpoint, "
2370 "deliver signal first");
2372 clear_step_over_info ();
2373 tp
->control
.trap_expected
= 0;
2375 if (tp
->control
.step_resume_breakpoint
== NULL
)
2377 /* Set a "high-priority" step-resume, as we don't want
2378 user breakpoints at PC to trigger (again) when this
2380 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2381 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2383 tp
->step_after_step_resume_breakpoint
= step
;
2386 insert_breakpoints ();
2390 /* There's no signal to pass, we can go ahead and skip the
2391 permanent breakpoint manually. */
2392 infrun_log_debug ("skipping permanent breakpoint");
2393 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2394 /* Update pc to reflect the new address from which we will
2395 execute instructions. */
2396 pc
= regcache_read_pc (regcache
);
2400 /* We've already advanced the PC, so the stepping part
2401 is done. Now we need to arrange for a trap to be
2402 reported to handle_inferior_event. Set a breakpoint
2403 at the current PC, and run to it. Don't update
2404 prev_pc, because if we end in
2405 switch_back_to_stepped_thread, we want the "expected
2406 thread advanced also" branch to be taken. IOW, we
2407 don't want this thread to step further from PC
2409 gdb_assert (!step_over_info_valid_p ());
2410 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2411 insert_breakpoints ();
2413 resume_ptid
= internal_resume_ptid (user_step
);
2414 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2421 /* If we have a breakpoint to step over, make sure to do a single
2422 step only. Same if we have software watchpoints. */
2423 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2424 tp
->control
.may_range_step
= 0;
2426 /* If displaced stepping is enabled, step over breakpoints by executing a
2427 copy of the instruction at a different address.
2429 We can't use displaced stepping when we have a signal to deliver;
2430 the comments for displaced_step_prepare explain why. The
2431 comments in the handle_inferior event for dealing with 'random
2432 signals' explain what we do instead.
2434 We can't use displaced stepping when we are waiting for vfork_done
2435 event, displaced stepping breaks the vfork child similarly as single
2436 step software breakpoint. */
2437 if (tp
->control
.trap_expected
2438 && use_displaced_stepping (tp
)
2439 && !step_over_info_valid_p ()
2440 && sig
== GDB_SIGNAL_0
2441 && !current_inferior ()->waiting_for_vfork_done
)
2443 displaced_step_prepare_status prepare_status
2444 = displaced_step_prepare (tp
);
2446 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2448 infrun_log_debug ("Got placed in step-over queue");
2450 tp
->control
.trap_expected
= 0;
2453 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2455 /* Fallback to stepping over the breakpoint in-line. */
2457 if (target_is_non_stop_p ())
2458 stop_all_threads ();
2460 set_step_over_info (regcache
->aspace (),
2461 regcache_read_pc (regcache
), 0, tp
->global_num
);
2463 step
= maybe_software_singlestep (gdbarch
, pc
);
2465 insert_breakpoints ();
2467 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2469 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2472 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2475 /* Do we need to do it the hard way, w/temp breakpoints? */
2477 step
= maybe_software_singlestep (gdbarch
, pc
);
2479 /* Currently, our software single-step implementation leads to different
2480 results than hardware single-stepping in one situation: when stepping
2481 into delivering a signal which has an associated signal handler,
2482 hardware single-step will stop at the first instruction of the handler,
2483 while software single-step will simply skip execution of the handler.
2485 For now, this difference in behavior is accepted since there is no
2486 easy way to actually implement single-stepping into a signal handler
2487 without kernel support.
2489 However, there is one scenario where this difference leads to follow-on
2490 problems: if we're stepping off a breakpoint by removing all breakpoints
2491 and then single-stepping. In this case, the software single-step
2492 behavior means that even if there is a *breakpoint* in the signal
2493 handler, GDB still would not stop.
2495 Fortunately, we can at least fix this particular issue. We detect
2496 here the case where we are about to deliver a signal while software
2497 single-stepping with breakpoints removed. In this situation, we
2498 revert the decisions to remove all breakpoints and insert single-
2499 step breakpoints, and instead we install a step-resume breakpoint
2500 at the current address, deliver the signal without stepping, and
2501 once we arrive back at the step-resume breakpoint, actually step
2502 over the breakpoint we originally wanted to step over. */
2503 if (thread_has_single_step_breakpoints_set (tp
)
2504 && sig
!= GDB_SIGNAL_0
2505 && step_over_info_valid_p ())
2507 /* If we have nested signals or a pending signal is delivered
2508 immediately after a handler returns, might already have
2509 a step-resume breakpoint set on the earlier handler. We cannot
2510 set another step-resume breakpoint; just continue on until the
2511 original breakpoint is hit. */
2512 if (tp
->control
.step_resume_breakpoint
== NULL
)
2514 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2515 tp
->step_after_step_resume_breakpoint
= 1;
2518 delete_single_step_breakpoints (tp
);
2520 clear_step_over_info ();
2521 tp
->control
.trap_expected
= 0;
2523 insert_breakpoints ();
2526 /* If STEP is set, it's a request to use hardware stepping
2527 facilities. But in that case, we should never
2528 use singlestep breakpoint. */
2529 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2531 /* Decide the set of threads to ask the target to resume. */
2532 if (tp
->control
.trap_expected
)
2534 /* We're allowing a thread to run past a breakpoint it has
2535 hit, either by single-stepping the thread with the breakpoint
2536 removed, or by displaced stepping, with the breakpoint inserted.
2537 In the former case, we need to single-step only this thread,
2538 and keep others stopped, as they can miss this breakpoint if
2539 allowed to run. That's not really a problem for displaced
2540 stepping, but, we still keep other threads stopped, in case
2541 another thread is also stopped for a breakpoint waiting for
2542 its turn in the displaced stepping queue. */
2543 resume_ptid
= inferior_ptid
;
2546 resume_ptid
= internal_resume_ptid (user_step
);
2548 if (execution_direction
!= EXEC_REVERSE
2549 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2551 /* There are two cases where we currently need to step a
2552 breakpoint instruction when we have a signal to deliver:
2554 - See handle_signal_stop where we handle random signals that
2555 could take out us out of the stepping range. Normally, in
2556 that case we end up continuing (instead of stepping) over the
2557 signal handler with a breakpoint at PC, but there are cases
2558 where we should _always_ single-step, even if we have a
2559 step-resume breakpoint, like when a software watchpoint is
2560 set. Assuming single-stepping and delivering a signal at the
2561 same time would takes us to the signal handler, then we could
2562 have removed the breakpoint at PC to step over it. However,
2563 some hardware step targets (like e.g., Mac OS) can't step
2564 into signal handlers, and for those, we need to leave the
2565 breakpoint at PC inserted, as otherwise if the handler
2566 recurses and executes PC again, it'll miss the breakpoint.
2567 So we leave the breakpoint inserted anyway, but we need to
2568 record that we tried to step a breakpoint instruction, so
2569 that adjust_pc_after_break doesn't end up confused.
2571 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2572 in one thread after another thread that was stepping had been
2573 momentarily paused for a step-over. When we re-resume the
2574 stepping thread, it may be resumed from that address with a
2575 breakpoint that hasn't trapped yet. Seen with
2576 gdb.threads/non-stop-fair-events.exp, on targets that don't
2577 do displaced stepping. */
2579 infrun_log_debug ("resume: [%s] stepped breakpoint",
2580 target_pid_to_str (tp
->ptid
).c_str ());
2582 tp
->stepped_breakpoint
= 1;
2584 /* Most targets can step a breakpoint instruction, thus
2585 executing it normally. But if this one cannot, just
2586 continue and we will hit it anyway. */
2587 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2592 && tp
->control
.trap_expected
2593 && use_displaced_stepping (tp
)
2594 && !step_over_info_valid_p ())
2596 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2597 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2598 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2601 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2602 paddress (resume_gdbarch
, actual_pc
));
2603 read_memory (actual_pc
, buf
, sizeof (buf
));
2604 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2607 if (tp
->control
.may_range_step
)
2609 /* If we're resuming a thread with the PC out of the step
2610 range, then we're doing some nested/finer run control
2611 operation, like stepping the thread out of the dynamic
2612 linker or the displaced stepping scratch pad. We
2613 shouldn't have allowed a range step then. */
2614 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2617 do_target_resume (resume_ptid
, step
, sig
);
2621 /* Resume the inferior. SIG is the signal to give the inferior
2622 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2623 rolls back state on error. */
2626 resume (gdb_signal sig
)
2632 catch (const gdb_exception
&ex
)
2634 /* If resuming is being aborted for any reason, delete any
2635 single-step breakpoint resume_1 may have created, to avoid
2636 confusing the following resumption, and to avoid leaving
2637 single-step breakpoints perturbing other threads, in case
2638 we're running in non-stop mode. */
2639 if (inferior_ptid
!= null_ptid
)
2640 delete_single_step_breakpoints (inferior_thread ());
2650 /* Counter that tracks number of user visible stops. This can be used
2651 to tell whether a command has proceeded the inferior past the
2652 current location. This allows e.g., inferior function calls in
2653 breakpoint commands to not interrupt the command list. When the
2654 call finishes successfully, the inferior is standing at the same
2655 breakpoint as if nothing happened (and so we don't call
2657 static ULONGEST current_stop_id
;
2664 return current_stop_id
;
2667 /* Called when we report a user visible stop. */
2675 /* Clear out all variables saying what to do when inferior is continued.
2676 First do this, then set the ones you want, then call `proceed'. */
2679 clear_proceed_status_thread (struct thread_info
*tp
)
2681 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2683 /* If we're starting a new sequence, then the previous finished
2684 single-step is no longer relevant. */
2685 if (tp
->suspend
.waitstatus_pending_p
)
2687 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2689 infrun_log_debug ("pending event of %s was a finished step. "
2691 target_pid_to_str (tp
->ptid
).c_str ());
2693 tp
->suspend
.waitstatus_pending_p
= 0;
2694 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2699 ("thread %s has pending wait status %s (currently_stepping=%d).",
2700 target_pid_to_str (tp
->ptid
).c_str (),
2701 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2702 currently_stepping (tp
));
2706 /* If this signal should not be seen by program, give it zero.
2707 Used for debugging signals. */
2708 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2709 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2711 delete tp
->thread_fsm
;
2712 tp
->thread_fsm
= NULL
;
2714 tp
->control
.trap_expected
= 0;
2715 tp
->control
.step_range_start
= 0;
2716 tp
->control
.step_range_end
= 0;
2717 tp
->control
.may_range_step
= 0;
2718 tp
->control
.step_frame_id
= null_frame_id
;
2719 tp
->control
.step_stack_frame_id
= null_frame_id
;
2720 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2721 tp
->control
.step_start_function
= NULL
;
2722 tp
->stop_requested
= 0;
2724 tp
->control
.stop_step
= 0;
2726 tp
->control
.proceed_to_finish
= 0;
2728 tp
->control
.stepping_command
= 0;
2730 /* Discard any remaining commands or status from previous stop. */
2731 bpstat_clear (&tp
->control
.stop_bpstat
);
2735 clear_proceed_status (int step
)
2737 /* With scheduler-locking replay, stop replaying other threads if we're
2738 not replaying the user-visible resume ptid.
2740 This is a convenience feature to not require the user to explicitly
2741 stop replaying the other threads. We're assuming that the user's
2742 intent is to resume tracing the recorded process. */
2743 if (!non_stop
&& scheduler_mode
== schedlock_replay
2744 && target_record_is_replaying (minus_one_ptid
)
2745 && !target_record_will_replay (user_visible_resume_ptid (step
),
2746 execution_direction
))
2747 target_record_stop_replaying ();
2749 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2751 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2752 process_stratum_target
*resume_target
2753 = user_visible_resume_target (resume_ptid
);
2755 /* In all-stop mode, delete the per-thread status of all threads
2756 we're about to resume, implicitly and explicitly. */
2757 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2758 clear_proceed_status_thread (tp
);
2761 if (inferior_ptid
!= null_ptid
)
2763 struct inferior
*inferior
;
2767 /* If in non-stop mode, only delete the per-thread status of
2768 the current thread. */
2769 clear_proceed_status_thread (inferior_thread ());
2772 inferior
= current_inferior ();
2773 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2776 gdb::observers::about_to_proceed
.notify ();
2779 /* Returns true if TP is still stopped at a breakpoint that needs
2780 stepping-over in order to make progress. If the breakpoint is gone
2781 meanwhile, we can skip the whole step-over dance. */
2784 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2786 if (tp
->stepping_over_breakpoint
)
2788 struct regcache
*regcache
= get_thread_regcache (tp
);
2790 if (breakpoint_here_p (regcache
->aspace (),
2791 regcache_read_pc (regcache
))
2792 == ordinary_breakpoint_here
)
2795 tp
->stepping_over_breakpoint
= 0;
2801 /* Check whether thread TP still needs to start a step-over in order
2802 to make progress when resumed. Returns an bitwise or of enum
2803 step_over_what bits, indicating what needs to be stepped over. */
2805 static step_over_what
2806 thread_still_needs_step_over (struct thread_info
*tp
)
2808 step_over_what what
= 0;
2810 if (thread_still_needs_step_over_bp (tp
))
2811 what
|= STEP_OVER_BREAKPOINT
;
2813 if (tp
->stepping_over_watchpoint
2814 && !target_have_steppable_watchpoint
)
2815 what
|= STEP_OVER_WATCHPOINT
;
2820 /* Returns true if scheduler locking applies. STEP indicates whether
2821 we're about to do a step/next-like command to a thread. */
2824 schedlock_applies (struct thread_info
*tp
)
2826 return (scheduler_mode
== schedlock_on
2827 || (scheduler_mode
== schedlock_step
2828 && tp
->control
.stepping_command
)
2829 || (scheduler_mode
== schedlock_replay
2830 && target_record_will_replay (minus_one_ptid
,
2831 execution_direction
)));
2834 /* Calls target_commit_resume on all targets. */
2837 commit_resume_all_targets ()
2839 scoped_restore_current_thread restore_thread
;
2841 /* Map between process_target and a representative inferior. This
2842 is to avoid committing a resume in the same target more than
2843 once. Resumptions must be idempotent, so this is an
2845 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2847 for (inferior
*inf
: all_non_exited_inferiors ())
2848 if (inf
->has_execution ())
2849 conn_inf
[inf
->process_target ()] = inf
;
2851 for (const auto &ci
: conn_inf
)
2853 inferior
*inf
= ci
.second
;
2854 switch_to_inferior_no_thread (inf
);
2855 target_commit_resume ();
2859 /* Check that all the targets we're about to resume are in non-stop
2860 mode. Ideally, we'd only care whether all targets support
2861 target-async, but we're not there yet. E.g., stop_all_threads
2862 doesn't know how to handle all-stop targets. Also, the remote
2863 protocol in all-stop mode is synchronous, irrespective of
2864 target-async, which means that things like a breakpoint re-set
2865 triggered by one target would try to read memory from all targets
2869 check_multi_target_resumption (process_stratum_target
*resume_target
)
2871 if (!non_stop
&& resume_target
== nullptr)
2873 scoped_restore_current_thread restore_thread
;
2875 /* This is used to track whether we're resuming more than one
2877 process_stratum_target
*first_connection
= nullptr;
2879 /* The first inferior we see with a target that does not work in
2880 always-non-stop mode. */
2881 inferior
*first_not_non_stop
= nullptr;
2883 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2885 switch_to_inferior_no_thread (inf
);
2887 if (!target_has_execution
)
2890 process_stratum_target
*proc_target
2891 = current_inferior ()->process_target();
2893 if (!target_is_non_stop_p ())
2894 first_not_non_stop
= inf
;
2896 if (first_connection
== nullptr)
2897 first_connection
= proc_target
;
2898 else if (first_connection
!= proc_target
2899 && first_not_non_stop
!= nullptr)
2901 switch_to_inferior_no_thread (first_not_non_stop
);
2903 proc_target
= current_inferior ()->process_target();
2905 error (_("Connection %d (%s) does not support "
2906 "multi-target resumption."),
2907 proc_target
->connection_number
,
2908 make_target_connection_string (proc_target
).c_str ());
2914 /* Basic routine for continuing the program in various fashions.
2916 ADDR is the address to resume at, or -1 for resume where stopped.
2917 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2918 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2920 You should call clear_proceed_status before calling proceed. */
2923 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2925 struct regcache
*regcache
;
2926 struct gdbarch
*gdbarch
;
2928 struct execution_control_state ecss
;
2929 struct execution_control_state
*ecs
= &ecss
;
2932 /* If we're stopped at a fork/vfork, follow the branch set by the
2933 "set follow-fork-mode" command; otherwise, we'll just proceed
2934 resuming the current thread. */
2935 if (!follow_fork ())
2937 /* The target for some reason decided not to resume. */
2939 if (target_can_async_p ())
2940 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2944 /* We'll update this if & when we switch to a new thread. */
2945 previous_inferior_ptid
= inferior_ptid
;
2947 regcache
= get_current_regcache ();
2948 gdbarch
= regcache
->arch ();
2949 const address_space
*aspace
= regcache
->aspace ();
2951 pc
= regcache_read_pc_protected (regcache
);
2953 thread_info
*cur_thr
= inferior_thread ();
2955 /* Fill in with reasonable starting values. */
2956 init_thread_stepping_state (cur_thr
);
2958 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2961 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2962 process_stratum_target
*resume_target
2963 = user_visible_resume_target (resume_ptid
);
2965 check_multi_target_resumption (resume_target
);
2967 if (addr
== (CORE_ADDR
) -1)
2969 if (pc
== cur_thr
->suspend
.stop_pc
2970 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2971 && execution_direction
!= EXEC_REVERSE
)
2972 /* There is a breakpoint at the address we will resume at,
2973 step one instruction before inserting breakpoints so that
2974 we do not stop right away (and report a second hit at this
2977 Note, we don't do this in reverse, because we won't
2978 actually be executing the breakpoint insn anyway.
2979 We'll be (un-)executing the previous instruction. */
2980 cur_thr
->stepping_over_breakpoint
= 1;
2981 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2982 && gdbarch_single_step_through_delay (gdbarch
,
2983 get_current_frame ()))
2984 /* We stepped onto an instruction that needs to be stepped
2985 again before re-inserting the breakpoint, do so. */
2986 cur_thr
->stepping_over_breakpoint
= 1;
2990 regcache_write_pc (regcache
, addr
);
2993 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2994 cur_thr
->suspend
.stop_signal
= siggnal
;
2996 /* If an exception is thrown from this point on, make sure to
2997 propagate GDB's knowledge of the executing state to the
2998 frontend/user running state. */
2999 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3001 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3002 threads (e.g., we might need to set threads stepping over
3003 breakpoints first), from the user/frontend's point of view, all
3004 threads in RESUME_PTID are now running. Unless we're calling an
3005 inferior function, as in that case we pretend the inferior
3006 doesn't run at all. */
3007 if (!cur_thr
->control
.in_infcall
)
3008 set_running (resume_target
, resume_ptid
, true);
3010 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3011 gdb_signal_to_symbol_string (siggnal
));
3013 annotate_starting ();
3015 /* Make sure that output from GDB appears before output from the
3017 gdb_flush (gdb_stdout
);
3019 /* Since we've marked the inferior running, give it the terminal. A
3020 QUIT/Ctrl-C from here on is forwarded to the target (which can
3021 still detect attempts to unblock a stuck connection with repeated
3022 Ctrl-C from within target_pass_ctrlc). */
3023 target_terminal::inferior ();
3025 /* In a multi-threaded task we may select another thread and
3026 then continue or step.
3028 But if a thread that we're resuming had stopped at a breakpoint,
3029 it will immediately cause another breakpoint stop without any
3030 execution (i.e. it will report a breakpoint hit incorrectly). So
3031 we must step over it first.
3033 Look for threads other than the current (TP) that reported a
3034 breakpoint hit and haven't been resumed yet since. */
3036 /* If scheduler locking applies, we can avoid iterating over all
3038 if (!non_stop
&& !schedlock_applies (cur_thr
))
3040 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3043 switch_to_thread_no_regs (tp
);
3045 /* Ignore the current thread here. It's handled
3050 if (!thread_still_needs_step_over (tp
))
3053 gdb_assert (!thread_is_in_step_over_chain (tp
));
3055 infrun_log_debug ("need to step-over [%s] first",
3056 target_pid_to_str (tp
->ptid
).c_str ());
3058 global_thread_step_over_chain_enqueue (tp
);
3061 switch_to_thread (cur_thr
);
3064 /* Enqueue the current thread last, so that we move all other
3065 threads over their breakpoints first. */
3066 if (cur_thr
->stepping_over_breakpoint
)
3067 global_thread_step_over_chain_enqueue (cur_thr
);
3069 /* If the thread isn't started, we'll still need to set its prev_pc,
3070 so that switch_back_to_stepped_thread knows the thread hasn't
3071 advanced. Must do this before resuming any thread, as in
3072 all-stop/remote, once we resume we can't send any other packet
3073 until the target stops again. */
3074 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3077 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3079 started
= start_step_over ();
3081 if (step_over_info_valid_p ())
3083 /* Either this thread started a new in-line step over, or some
3084 other thread was already doing one. In either case, don't
3085 resume anything else until the step-over is finished. */
3087 else if (started
&& !target_is_non_stop_p ())
3089 /* A new displaced stepping sequence was started. In all-stop,
3090 we can't talk to the target anymore until it next stops. */
3092 else if (!non_stop
&& target_is_non_stop_p ())
3094 /* In all-stop, but the target is always in non-stop mode.
3095 Start all other threads that are implicitly resumed too. */
3096 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3099 switch_to_thread_no_regs (tp
);
3101 if (!tp
->inf
->has_execution ())
3103 infrun_log_debug ("[%s] target has no execution",
3104 target_pid_to_str (tp
->ptid
).c_str ());
3110 infrun_log_debug ("[%s] resumed",
3111 target_pid_to_str (tp
->ptid
).c_str ());
3112 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3116 if (thread_is_in_step_over_chain (tp
))
3118 infrun_log_debug ("[%s] needs step-over",
3119 target_pid_to_str (tp
->ptid
).c_str ());
3123 infrun_log_debug ("resuming %s",
3124 target_pid_to_str (tp
->ptid
).c_str ());
3126 reset_ecs (ecs
, tp
);
3127 switch_to_thread (tp
);
3128 keep_going_pass_signal (ecs
);
3129 if (!ecs
->wait_some_more
)
3130 error (_("Command aborted."));
3133 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3135 /* The thread wasn't started, and isn't queued, run it now. */
3136 reset_ecs (ecs
, cur_thr
);
3137 switch_to_thread (cur_thr
);
3138 keep_going_pass_signal (ecs
);
3139 if (!ecs
->wait_some_more
)
3140 error (_("Command aborted."));
3144 commit_resume_all_targets ();
3146 finish_state
.release ();
3148 /* If we've switched threads above, switch back to the previously
3149 current thread. We don't want the user to see a different
3151 switch_to_thread (cur_thr
);
3153 /* Tell the event loop to wait for it to stop. If the target
3154 supports asynchronous execution, it'll do this from within
3156 if (!target_can_async_p ())
3157 mark_async_event_handler (infrun_async_inferior_event_token
);
3161 /* Start remote-debugging of a machine over a serial link. */
3164 start_remote (int from_tty
)
3166 inferior
*inf
= current_inferior ();
3167 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3169 /* Always go on waiting for the target, regardless of the mode. */
3170 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3171 indicate to wait_for_inferior that a target should timeout if
3172 nothing is returned (instead of just blocking). Because of this,
3173 targets expecting an immediate response need to, internally, set
3174 things up so that the target_wait() is forced to eventually
3176 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3177 differentiate to its caller what the state of the target is after
3178 the initial open has been performed. Here we're assuming that
3179 the target has stopped. It should be possible to eventually have
3180 target_open() return to the caller an indication that the target
3181 is currently running and GDB state should be set to the same as
3182 for an async run. */
3183 wait_for_inferior (inf
);
3185 /* Now that the inferior has stopped, do any bookkeeping like
3186 loading shared libraries. We want to do this before normal_stop,
3187 so that the displayed frame is up to date. */
3188 post_create_inferior (current_top_target (), from_tty
);
3193 /* Initialize static vars when a new inferior begins. */
3196 init_wait_for_inferior (void)
3198 /* These are meaningless until the first time through wait_for_inferior. */
3200 breakpoint_init_inferior (inf_starting
);
3202 clear_proceed_status (0);
3204 nullify_last_target_wait_ptid ();
3206 previous_inferior_ptid
= inferior_ptid
;
3211 static void handle_inferior_event (struct execution_control_state
*ecs
);
3213 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3214 struct execution_control_state
*ecs
);
3215 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3216 struct execution_control_state
*ecs
);
3217 static void handle_signal_stop (struct execution_control_state
*ecs
);
3218 static void check_exception_resume (struct execution_control_state
*,
3219 struct frame_info
*);
3221 static void end_stepping_range (struct execution_control_state
*ecs
);
3222 static void stop_waiting (struct execution_control_state
*ecs
);
3223 static void keep_going (struct execution_control_state
*ecs
);
3224 static void process_event_stop_test (struct execution_control_state
*ecs
);
3225 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3227 /* This function is attached as a "thread_stop_requested" observer.
3228 Cleanup local state that assumed the PTID was to be resumed, and
3229 report the stop to the frontend. */
3232 infrun_thread_stop_requested (ptid_t ptid
)
3234 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3236 /* PTID was requested to stop. If the thread was already stopped,
3237 but the user/frontend doesn't know about that yet (e.g., the
3238 thread had been temporarily paused for some step-over), set up
3239 for reporting the stop now. */
3240 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3242 if (tp
->state
!= THREAD_RUNNING
)
3247 /* Remove matching threads from the step-over queue, so
3248 start_step_over doesn't try to resume them
3250 if (thread_is_in_step_over_chain (tp
))
3251 global_thread_step_over_chain_remove (tp
);
3253 /* If the thread is stopped, but the user/frontend doesn't
3254 know about that yet, queue a pending event, as if the
3255 thread had just stopped now. Unless the thread already had
3257 if (!tp
->suspend
.waitstatus_pending_p
)
3259 tp
->suspend
.waitstatus_pending_p
= 1;
3260 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3261 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3264 /* Clear the inline-frame state, since we're re-processing the
3266 clear_inline_frame_state (tp
);
3268 /* If this thread was paused because some other thread was
3269 doing an inline-step over, let that finish first. Once
3270 that happens, we'll restart all threads and consume pending
3271 stop events then. */
3272 if (step_over_info_valid_p ())
3275 /* Otherwise we can process the (new) pending event now. Set
3276 it so this pending event is considered by
3283 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3285 if (target_last_proc_target
== tp
->inf
->process_target ()
3286 && target_last_wait_ptid
== tp
->ptid
)
3287 nullify_last_target_wait_ptid ();
3290 /* Delete the step resume, single-step and longjmp/exception resume
3291 breakpoints of TP. */
3294 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3296 delete_step_resume_breakpoint (tp
);
3297 delete_exception_resume_breakpoint (tp
);
3298 delete_single_step_breakpoints (tp
);
3301 /* If the target still has execution, call FUNC for each thread that
3302 just stopped. In all-stop, that's all the non-exited threads; in
3303 non-stop, that's the current thread, only. */
3305 typedef void (*for_each_just_stopped_thread_callback_func
)
3306 (struct thread_info
*tp
);
3309 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3311 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3314 if (target_is_non_stop_p ())
3316 /* If in non-stop mode, only the current thread stopped. */
3317 func (inferior_thread ());
3321 /* In all-stop mode, all threads have stopped. */
3322 for (thread_info
*tp
: all_non_exited_threads ())
3327 /* Delete the step resume and longjmp/exception resume breakpoints of
3328 the threads that just stopped. */
3331 delete_just_stopped_threads_infrun_breakpoints (void)
3333 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3336 /* Delete the single-step breakpoints of the threads that just
3340 delete_just_stopped_threads_single_step_breakpoints (void)
3342 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3348 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3349 const struct target_waitstatus
*ws
)
3351 std::string status_string
= target_waitstatus_to_string (ws
);
3354 /* The text is split over several lines because it was getting too long.
3355 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3356 output as a unit; we want only one timestamp printed if debug_timestamp
3359 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3362 waiton_ptid
.tid ());
3363 if (waiton_ptid
.pid () != -1)
3364 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3365 stb
.printf (", status) =\n");
3366 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3370 target_pid_to_str (result_ptid
).c_str ());
3371 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3373 /* This uses %s in part to handle %'s in the text, but also to avoid
3374 a gcc error: the format attribute requires a string literal. */
3375 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3378 /* Select a thread at random, out of those which are resumed and have
3381 static struct thread_info
*
3382 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3386 auto has_event
= [&] (thread_info
*tp
)
3388 return (tp
->ptid
.matches (waiton_ptid
)
3390 && tp
->suspend
.waitstatus_pending_p
);
3393 /* First see how many events we have. Count only resumed threads
3394 that have an event pending. */
3395 for (thread_info
*tp
: inf
->non_exited_threads ())
3399 if (num_events
== 0)
3402 /* Now randomly pick a thread out of those that have had events. */
3403 int random_selector
= (int) ((num_events
* (double) rand ())
3404 / (RAND_MAX
+ 1.0));
3407 infrun_log_debug ("Found %d events, selecting #%d",
3408 num_events
, random_selector
);
3410 /* Select the Nth thread that has had an event. */
3411 for (thread_info
*tp
: inf
->non_exited_threads ())
3413 if (random_selector
-- == 0)
3416 gdb_assert_not_reached ("event thread not found");
3419 /* Wrapper for target_wait that first checks whether threads have
3420 pending statuses to report before actually asking the target for
3421 more events. INF is the inferior we're using to call target_wait
3425 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3426 target_waitstatus
*status
, int options
)
3429 struct thread_info
*tp
;
3431 /* We know that we are looking for an event in the target of inferior
3432 INF, but we don't know which thread the event might come from. As
3433 such we want to make sure that INFERIOR_PTID is reset so that none of
3434 the wait code relies on it - doing so is always a mistake. */
3435 switch_to_inferior_no_thread (inf
);
3437 /* First check if there is a resumed thread with a wait status
3439 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3441 tp
= random_pending_event_thread (inf
, ptid
);
3445 infrun_log_debug ("Waiting for specific thread %s.",
3446 target_pid_to_str (ptid
).c_str ());
3448 /* We have a specific thread to check. */
3449 tp
= find_thread_ptid (inf
, ptid
);
3450 gdb_assert (tp
!= NULL
);
3451 if (!tp
->suspend
.waitstatus_pending_p
)
3456 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3457 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3459 struct regcache
*regcache
= get_thread_regcache (tp
);
3460 struct gdbarch
*gdbarch
= regcache
->arch ();
3464 pc
= regcache_read_pc (regcache
);
3466 if (pc
!= tp
->suspend
.stop_pc
)
3468 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3469 target_pid_to_str (tp
->ptid
).c_str (),
3470 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3471 paddress (gdbarch
, pc
));
3474 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3476 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3477 target_pid_to_str (tp
->ptid
).c_str (),
3478 paddress (gdbarch
, pc
));
3485 infrun_log_debug ("pending event of %s cancelled.",
3486 target_pid_to_str (tp
->ptid
).c_str ());
3488 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3489 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3495 infrun_log_debug ("Using pending wait status %s for %s.",
3496 target_waitstatus_to_string
3497 (&tp
->suspend
.waitstatus
).c_str (),
3498 target_pid_to_str (tp
->ptid
).c_str ());
3500 /* Now that we've selected our final event LWP, un-adjust its PC
3501 if it was a software breakpoint (and the target doesn't
3502 always adjust the PC itself). */
3503 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3504 && !target_supports_stopped_by_sw_breakpoint ())
3506 struct regcache
*regcache
;
3507 struct gdbarch
*gdbarch
;
3510 regcache
= get_thread_regcache (tp
);
3511 gdbarch
= regcache
->arch ();
3513 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3518 pc
= regcache_read_pc (regcache
);
3519 regcache_write_pc (regcache
, pc
+ decr_pc
);
3523 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3524 *status
= tp
->suspend
.waitstatus
;
3525 tp
->suspend
.waitstatus_pending_p
= 0;
3527 /* Wake up the event loop again, until all pending events are
3529 if (target_is_async_p ())
3530 mark_async_event_handler (infrun_async_inferior_event_token
);
3534 /* But if we don't find one, we'll have to wait. */
3536 if (deprecated_target_wait_hook
)
3537 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3539 event_ptid
= target_wait (ptid
, status
, options
);
3544 /* Returns true if INF has any resumed thread with a status
3548 threads_are_resumed_pending_p (inferior
*inf
)
3550 for (thread_info
*tp
: inf
->non_exited_threads ())
3552 && tp
->suspend
.waitstatus_pending_p
)
3558 /* Wrapper for target_wait that first checks whether threads have
3559 pending statuses to report before actually asking the target for
3560 more events. Polls for events from all inferiors/targets. */
3563 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3565 int num_inferiors
= 0;
3566 int random_selector
;
3568 /* For fairness, we pick the first inferior/target to poll at
3569 random, and then continue polling the rest of the inferior list
3570 starting from that one in a circular fashion until the whole list
3573 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3575 return (inf
->process_target () != NULL
3576 && (threads_are_executing (inf
->process_target ())
3577 || threads_are_resumed_pending_p (inf
))
3578 && ptid_t (inf
->pid
).matches (wait_ptid
));
3581 /* First see how many resumed inferiors we have. */
3582 for (inferior
*inf
: all_inferiors ())
3583 if (inferior_matches (inf
))
3586 if (num_inferiors
== 0)
3588 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3592 /* Now randomly pick an inferior out of those that were resumed. */
3593 random_selector
= (int)
3594 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3596 if (num_inferiors
> 1)
3597 infrun_log_debug ("Found %d inferiors, starting at #%d",
3598 num_inferiors
, random_selector
);
3600 /* Select the Nth inferior that was resumed. */
3602 inferior
*selected
= nullptr;
3604 for (inferior
*inf
: all_inferiors ())
3605 if (inferior_matches (inf
))
3606 if (random_selector
-- == 0)
3612 /* Now poll for events out of each of the resumed inferior's
3613 targets, starting from the selected one. */
3615 auto do_wait
= [&] (inferior
*inf
)
3617 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3618 ecs
->target
= inf
->process_target ();
3619 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3622 /* Needed in all-stop+target-non-stop mode, because we end up here
3623 spuriously after the target is all stopped and we've already
3624 reported the stop to the user, polling for events. */
3625 scoped_restore_current_thread restore_thread
;
3627 int inf_num
= selected
->num
;
3628 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3629 if (inferior_matches (inf
))
3633 for (inferior
*inf
= inferior_list
;
3634 inf
!= NULL
&& inf
->num
< inf_num
;
3636 if (inferior_matches (inf
))
3640 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3644 /* Prepare and stabilize the inferior for detaching it. E.g.,
3645 detaching while a thread is displaced stepping is a recipe for
3646 crashing it, as nothing would readjust the PC out of the scratch
3650 prepare_for_detach (void)
3652 struct inferior
*inf
= current_inferior ();
3653 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3655 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3657 /* Is any thread of this process displaced stepping? If not,
3658 there's nothing else to do. */
3659 if (displaced_step_in_progress (inf
))
3662 infrun_log_debug ("displaced-stepping in-process while detaching");
3664 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3669 struct execution_control_state ecss
;
3670 struct execution_control_state
*ecs
;
3673 memset (ecs
, 0, sizeof (*ecs
));
3675 overlay_cache_invalid
= 1;
3676 /* Flush target cache before starting to handle each event.
3677 Target was running and cache could be stale. This is just a
3678 heuristic. Running threads may modify target memory, but we
3679 don't get any event. */
3680 target_dcache_invalidate ();
3682 do_target_wait (pid_ptid
, ecs
, 0);
3685 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3687 /* If an error happens while handling the event, propagate GDB's
3688 knowledge of the executing state to the frontend/user running
3690 scoped_finish_thread_state
finish_state (inf
->process_target (),
3693 /* Now figure out what to do with the result of the result. */
3694 handle_inferior_event (ecs
);
3696 /* No error, don't finish the state yet. */
3697 finish_state
.release ();
3699 /* Breakpoints and watchpoints are not installed on the target
3700 at this point, and signals are passed directly to the
3701 inferior, so this must mean the process is gone. */
3702 if (!ecs
->wait_some_more
)
3704 restore_detaching
.release ();
3705 error (_("Program exited while detaching"));
3709 restore_detaching
.release ();
3712 /* Wait for control to return from inferior to debugger.
3714 If inferior gets a signal, we may decide to start it up again
3715 instead of returning. That is why there is a loop in this function.
3716 When this function actually returns it means the inferior
3717 should be left stopped and GDB should read more commands. */
3720 wait_for_inferior (inferior
*inf
)
3722 infrun_log_debug ("wait_for_inferior ()");
3724 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3726 /* If an error happens while handling the event, propagate GDB's
3727 knowledge of the executing state to the frontend/user running
3729 scoped_finish_thread_state finish_state
3730 (inf
->process_target (), minus_one_ptid
);
3734 struct execution_control_state ecss
;
3735 struct execution_control_state
*ecs
= &ecss
;
3737 memset (ecs
, 0, sizeof (*ecs
));
3739 overlay_cache_invalid
= 1;
3741 /* Flush target cache before starting to handle each event.
3742 Target was running and cache could be stale. This is just a
3743 heuristic. Running threads may modify target memory, but we
3744 don't get any event. */
3745 target_dcache_invalidate ();
3747 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3748 ecs
->target
= inf
->process_target ();
3751 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3753 /* Now figure out what to do with the result of the result. */
3754 handle_inferior_event (ecs
);
3756 if (!ecs
->wait_some_more
)
3760 /* No error, don't finish the state yet. */
3761 finish_state
.release ();
3764 /* Cleanup that reinstalls the readline callback handler, if the
3765 target is running in the background. If while handling the target
3766 event something triggered a secondary prompt, like e.g., a
3767 pagination prompt, we'll have removed the callback handler (see
3768 gdb_readline_wrapper_line). Need to do this as we go back to the
3769 event loop, ready to process further input. Note this has no
3770 effect if the handler hasn't actually been removed, because calling
3771 rl_callback_handler_install resets the line buffer, thus losing
3775 reinstall_readline_callback_handler_cleanup ()
3777 struct ui
*ui
= current_ui
;
3781 /* We're not going back to the top level event loop yet. Don't
3782 install the readline callback, as it'd prep the terminal,
3783 readline-style (raw, noecho) (e.g., --batch). We'll install
3784 it the next time the prompt is displayed, when we're ready
3789 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3790 gdb_rl_callback_handler_reinstall ();
3793 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3794 that's just the event thread. In all-stop, that's all threads. */
3797 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3799 if (ecs
->event_thread
!= NULL
3800 && ecs
->event_thread
->thread_fsm
!= NULL
)
3801 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3805 for (thread_info
*thr
: all_non_exited_threads ())
3807 if (thr
->thread_fsm
== NULL
)
3809 if (thr
== ecs
->event_thread
)
3812 switch_to_thread (thr
);
3813 thr
->thread_fsm
->clean_up (thr
);
3816 if (ecs
->event_thread
!= NULL
)
3817 switch_to_thread (ecs
->event_thread
);
3821 /* Helper for all_uis_check_sync_execution_done that works on the
3825 check_curr_ui_sync_execution_done (void)
3827 struct ui
*ui
= current_ui
;
3829 if (ui
->prompt_state
== PROMPT_NEEDED
3831 && !gdb_in_secondary_prompt_p (ui
))
3833 target_terminal::ours ();
3834 gdb::observers::sync_execution_done
.notify ();
3835 ui_register_input_event_handler (ui
);
3842 all_uis_check_sync_execution_done (void)
3844 SWITCH_THRU_ALL_UIS ()
3846 check_curr_ui_sync_execution_done ();
3853 all_uis_on_sync_execution_starting (void)
3855 SWITCH_THRU_ALL_UIS ()
3857 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3858 async_disable_stdin ();
3862 /* Asynchronous version of wait_for_inferior. It is called by the
3863 event loop whenever a change of state is detected on the file
3864 descriptor corresponding to the target. It can be called more than
3865 once to complete a single execution command. In such cases we need
3866 to keep the state in a global variable ECSS. If it is the last time
3867 that this function is called for a single execution command, then
3868 report to the user that the inferior has stopped, and do the
3869 necessary cleanups. */
3872 fetch_inferior_event (void *client_data
)
3874 struct execution_control_state ecss
;
3875 struct execution_control_state
*ecs
= &ecss
;
3878 memset (ecs
, 0, sizeof (*ecs
));
3880 /* Events are always processed with the main UI as current UI. This
3881 way, warnings, debug output, etc. are always consistently sent to
3882 the main console. */
3883 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3885 /* End up with readline processing input, if necessary. */
3887 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3889 /* We're handling a live event, so make sure we're doing live
3890 debugging. If we're looking at traceframes while the target is
3891 running, we're going to need to get back to that mode after
3892 handling the event. */
3893 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3896 maybe_restore_traceframe
.emplace ();
3897 set_current_traceframe (-1);
3900 /* The user/frontend should not notice a thread switch due to
3901 internal events. Make sure we revert to the user selected
3902 thread and frame after handling the event and running any
3903 breakpoint commands. */
3904 scoped_restore_current_thread restore_thread
;
3906 overlay_cache_invalid
= 1;
3907 /* Flush target cache before starting to handle each event. Target
3908 was running and cache could be stale. This is just a heuristic.
3909 Running threads may modify target memory, but we don't get any
3911 target_dcache_invalidate ();
3913 scoped_restore save_exec_dir
3914 = make_scoped_restore (&execution_direction
,
3915 target_execution_direction ());
3917 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3920 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3922 /* Switch to the target that generated the event, so we can do
3923 target calls. Any inferior bound to the target will do, so we
3924 just switch to the first we find. */
3925 for (inferior
*inf
: all_inferiors (ecs
->target
))
3927 switch_to_inferior_no_thread (inf
);
3932 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3934 /* If an error happens while handling the event, propagate GDB's
3935 knowledge of the executing state to the frontend/user running
3937 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3938 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3940 /* Get executed before scoped_restore_current_thread above to apply
3941 still for the thread which has thrown the exception. */
3942 auto defer_bpstat_clear
3943 = make_scope_exit (bpstat_clear_actions
);
3944 auto defer_delete_threads
3945 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3947 /* Now figure out what to do with the result of the result. */
3948 handle_inferior_event (ecs
);
3950 if (!ecs
->wait_some_more
)
3952 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3953 int should_stop
= 1;
3954 struct thread_info
*thr
= ecs
->event_thread
;
3956 delete_just_stopped_threads_infrun_breakpoints ();
3960 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3962 if (thread_fsm
!= NULL
)
3963 should_stop
= thread_fsm
->should_stop (thr
);
3972 bool should_notify_stop
= true;
3975 clean_up_just_stopped_threads_fsms (ecs
);
3977 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3978 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3980 if (should_notify_stop
)
3982 /* We may not find an inferior if this was a process exit. */
3983 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3984 proceeded
= normal_stop ();
3989 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
3993 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3994 previously selected thread is gone. We have two
3995 choices - switch to no thread selected, or restore the
3996 previously selected thread (now exited). We chose the
3997 later, just because that's what GDB used to do. After
3998 this, "info threads" says "The current thread <Thread
3999 ID 2> has terminated." instead of "No thread
4003 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4004 restore_thread
.dont_restore ();
4008 defer_delete_threads
.release ();
4009 defer_bpstat_clear
.release ();
4011 /* No error, don't finish the thread states yet. */
4012 finish_state
.release ();
4014 /* This scope is used to ensure that readline callbacks are
4015 reinstalled here. */
4018 /* If a UI was in sync execution mode, and now isn't, restore its
4019 prompt (a synchronous execution command has finished, and we're
4020 ready for input). */
4021 all_uis_check_sync_execution_done ();
4024 && exec_done_display_p
4025 && (inferior_ptid
== null_ptid
4026 || inferior_thread ()->state
!= THREAD_RUNNING
))
4027 printf_unfiltered (_("completed.\n"));
4033 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4034 struct symtab_and_line sal
)
4036 /* This can be removed once this function no longer implicitly relies on the
4037 inferior_ptid value. */
4038 gdb_assert (inferior_ptid
== tp
->ptid
);
4040 tp
->control
.step_frame_id
= get_frame_id (frame
);
4041 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4043 tp
->current_symtab
= sal
.symtab
;
4044 tp
->current_line
= sal
.line
;
4047 /* Clear context switchable stepping state. */
4050 init_thread_stepping_state (struct thread_info
*tss
)
4052 tss
->stepped_breakpoint
= 0;
4053 tss
->stepping_over_breakpoint
= 0;
4054 tss
->stepping_over_watchpoint
= 0;
4055 tss
->step_after_step_resume_breakpoint
= 0;
4061 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4062 target_waitstatus status
)
4064 target_last_proc_target
= target
;
4065 target_last_wait_ptid
= ptid
;
4066 target_last_waitstatus
= status
;
4072 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4073 target_waitstatus
*status
)
4075 if (target
!= nullptr)
4076 *target
= target_last_proc_target
;
4077 if (ptid
!= nullptr)
4078 *ptid
= target_last_wait_ptid
;
4079 if (status
!= nullptr)
4080 *status
= target_last_waitstatus
;
4086 nullify_last_target_wait_ptid (void)
4088 target_last_proc_target
= nullptr;
4089 target_last_wait_ptid
= minus_one_ptid
;
4090 target_last_waitstatus
= {};
4093 /* Switch thread contexts. */
4096 context_switch (execution_control_state
*ecs
)
4098 if (ecs
->ptid
!= inferior_ptid
4099 && (inferior_ptid
== null_ptid
4100 || ecs
->event_thread
!= inferior_thread ()))
4102 infrun_log_debug ("Switching context from %s to %s",
4103 target_pid_to_str (inferior_ptid
).c_str (),
4104 target_pid_to_str (ecs
->ptid
).c_str ());
4107 switch_to_thread (ecs
->event_thread
);
4110 /* If the target can't tell whether we've hit breakpoints
4111 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4112 check whether that could have been caused by a breakpoint. If so,
4113 adjust the PC, per gdbarch_decr_pc_after_break. */
4116 adjust_pc_after_break (struct thread_info
*thread
,
4117 struct target_waitstatus
*ws
)
4119 struct regcache
*regcache
;
4120 struct gdbarch
*gdbarch
;
4121 CORE_ADDR breakpoint_pc
, decr_pc
;
4123 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4124 we aren't, just return.
4126 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4127 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4128 implemented by software breakpoints should be handled through the normal
4131 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4132 different signals (SIGILL or SIGEMT for instance), but it is less
4133 clear where the PC is pointing afterwards. It may not match
4134 gdbarch_decr_pc_after_break. I don't know any specific target that
4135 generates these signals at breakpoints (the code has been in GDB since at
4136 least 1992) so I can not guess how to handle them here.
4138 In earlier versions of GDB, a target with
4139 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4140 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4141 target with both of these set in GDB history, and it seems unlikely to be
4142 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4144 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4147 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4150 /* In reverse execution, when a breakpoint is hit, the instruction
4151 under it has already been de-executed. The reported PC always
4152 points at the breakpoint address, so adjusting it further would
4153 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4156 B1 0x08000000 : INSN1
4157 B2 0x08000001 : INSN2
4159 PC -> 0x08000003 : INSN4
4161 Say you're stopped at 0x08000003 as above. Reverse continuing
4162 from that point should hit B2 as below. Reading the PC when the
4163 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4164 been de-executed already.
4166 B1 0x08000000 : INSN1
4167 B2 PC -> 0x08000001 : INSN2
4171 We can't apply the same logic as for forward execution, because
4172 we would wrongly adjust the PC to 0x08000000, since there's a
4173 breakpoint at PC - 1. We'd then report a hit on B1, although
4174 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4176 if (execution_direction
== EXEC_REVERSE
)
4179 /* If the target can tell whether the thread hit a SW breakpoint,
4180 trust it. Targets that can tell also adjust the PC
4182 if (target_supports_stopped_by_sw_breakpoint ())
4185 /* Note that relying on whether a breakpoint is planted in memory to
4186 determine this can fail. E.g,. the breakpoint could have been
4187 removed since. Or the thread could have been told to step an
4188 instruction the size of a breakpoint instruction, and only
4189 _after_ was a breakpoint inserted at its address. */
4191 /* If this target does not decrement the PC after breakpoints, then
4192 we have nothing to do. */
4193 regcache
= get_thread_regcache (thread
);
4194 gdbarch
= regcache
->arch ();
4196 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4200 const address_space
*aspace
= regcache
->aspace ();
4202 /* Find the location where (if we've hit a breakpoint) the
4203 breakpoint would be. */
4204 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4206 /* If the target can't tell whether a software breakpoint triggered,
4207 fallback to figuring it out based on breakpoints we think were
4208 inserted in the target, and on whether the thread was stepped or
4211 /* Check whether there actually is a software breakpoint inserted at
4214 If in non-stop mode, a race condition is possible where we've
4215 removed a breakpoint, but stop events for that breakpoint were
4216 already queued and arrive later. To suppress those spurious
4217 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4218 and retire them after a number of stop events are reported. Note
4219 this is an heuristic and can thus get confused. The real fix is
4220 to get the "stopped by SW BP and needs adjustment" info out of
4221 the target/kernel (and thus never reach here; see above). */
4222 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4223 || (target_is_non_stop_p ()
4224 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4226 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4228 if (record_full_is_used ())
4229 restore_operation_disable
.emplace
4230 (record_full_gdb_operation_disable_set ());
4232 /* When using hardware single-step, a SIGTRAP is reported for both
4233 a completed single-step and a software breakpoint. Need to
4234 differentiate between the two, as the latter needs adjusting
4235 but the former does not.
4237 The SIGTRAP can be due to a completed hardware single-step only if
4238 - we didn't insert software single-step breakpoints
4239 - this thread is currently being stepped
4241 If any of these events did not occur, we must have stopped due
4242 to hitting a software breakpoint, and have to back up to the
4245 As a special case, we could have hardware single-stepped a
4246 software breakpoint. In this case (prev_pc == breakpoint_pc),
4247 we also need to back up to the breakpoint address. */
4249 if (thread_has_single_step_breakpoints_set (thread
)
4250 || !currently_stepping (thread
)
4251 || (thread
->stepped_breakpoint
4252 && thread
->prev_pc
== breakpoint_pc
))
4253 regcache_write_pc (regcache
, breakpoint_pc
);
4258 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4260 for (frame
= get_prev_frame (frame
);
4262 frame
= get_prev_frame (frame
))
4264 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4266 if (get_frame_type (frame
) != INLINE_FRAME
)
4273 /* Look for an inline frame that is marked for skip.
4274 If PREV_FRAME is TRUE start at the previous frame,
4275 otherwise start at the current frame. Stop at the
4276 first non-inline frame, or at the frame where the
4280 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4282 struct frame_info
*frame
= get_current_frame ();
4285 frame
= get_prev_frame (frame
);
4287 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4289 const char *fn
= NULL
;
4290 symtab_and_line sal
;
4293 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4295 if (get_frame_type (frame
) != INLINE_FRAME
)
4298 sal
= find_frame_sal (frame
);
4299 sym
= get_frame_function (frame
);
4302 fn
= sym
->print_name ();
4305 && function_name_is_marked_for_skip (fn
, sal
))
4312 /* If the event thread has the stop requested flag set, pretend it
4313 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4317 handle_stop_requested (struct execution_control_state
*ecs
)
4319 if (ecs
->event_thread
->stop_requested
)
4321 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4322 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4323 handle_signal_stop (ecs
);
4329 /* Auxiliary function that handles syscall entry/return events.
4330 It returns 1 if the inferior should keep going (and GDB
4331 should ignore the event), or 0 if the event deserves to be
4335 handle_syscall_event (struct execution_control_state
*ecs
)
4337 struct regcache
*regcache
;
4340 context_switch (ecs
);
4342 regcache
= get_thread_regcache (ecs
->event_thread
);
4343 syscall_number
= ecs
->ws
.value
.syscall_number
;
4344 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4346 if (catch_syscall_enabled () > 0
4347 && catching_syscall_number (syscall_number
) > 0)
4349 infrun_log_debug ("syscall number=%d", syscall_number
);
4351 ecs
->event_thread
->control
.stop_bpstat
4352 = bpstat_stop_status (regcache
->aspace (),
4353 ecs
->event_thread
->suspend
.stop_pc
,
4354 ecs
->event_thread
, &ecs
->ws
);
4356 if (handle_stop_requested (ecs
))
4359 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4361 /* Catchpoint hit. */
4366 if (handle_stop_requested (ecs
))
4369 /* If no catchpoint triggered for this, then keep going. */
4374 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4377 fill_in_stop_func (struct gdbarch
*gdbarch
,
4378 struct execution_control_state
*ecs
)
4380 if (!ecs
->stop_func_filled_in
)
4384 /* Don't care about return value; stop_func_start and stop_func_name
4385 will both be 0 if it doesn't work. */
4386 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4387 &ecs
->stop_func_name
,
4388 &ecs
->stop_func_start
,
4389 &ecs
->stop_func_end
,
4392 /* The call to find_pc_partial_function, above, will set
4393 stop_func_start and stop_func_end to the start and end
4394 of the range containing the stop pc. If this range
4395 contains the entry pc for the block (which is always the
4396 case for contiguous blocks), advance stop_func_start past
4397 the function's start offset and entrypoint. Note that
4398 stop_func_start is NOT advanced when in a range of a
4399 non-contiguous block that does not contain the entry pc. */
4400 if (block
!= nullptr
4401 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4402 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4404 ecs
->stop_func_start
4405 += gdbarch_deprecated_function_start_offset (gdbarch
);
4407 if (gdbarch_skip_entrypoint_p (gdbarch
))
4408 ecs
->stop_func_start
4409 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4412 ecs
->stop_func_filled_in
= 1;
4417 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4419 static enum stop_kind
4420 get_inferior_stop_soon (execution_control_state
*ecs
)
4422 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4424 gdb_assert (inf
!= NULL
);
4425 return inf
->control
.stop_soon
;
4428 /* Poll for one event out of the current target. Store the resulting
4429 waitstatus in WS, and return the event ptid. Does not block. */
4432 poll_one_curr_target (struct target_waitstatus
*ws
)
4436 overlay_cache_invalid
= 1;
4438 /* Flush target cache before starting to handle each event.
4439 Target was running and cache could be stale. This is just a
4440 heuristic. Running threads may modify target memory, but we
4441 don't get any event. */
4442 target_dcache_invalidate ();
4444 if (deprecated_target_wait_hook
)
4445 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4447 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4450 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4455 /* An event reported by wait_one. */
4457 struct wait_one_event
4459 /* The target the event came out of. */
4460 process_stratum_target
*target
;
4462 /* The PTID the event was for. */
4465 /* The waitstatus. */
4466 target_waitstatus ws
;
4469 /* Wait for one event out of any target. */
4471 static wait_one_event
4476 for (inferior
*inf
: all_inferiors ())
4478 process_stratum_target
*target
= inf
->process_target ();
4480 || !target
->is_async_p ()
4481 || !target
->threads_executing
)
4484 switch_to_inferior_no_thread (inf
);
4486 wait_one_event event
;
4487 event
.target
= target
;
4488 event
.ptid
= poll_one_curr_target (&event
.ws
);
4490 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4492 /* If nothing is resumed, remove the target from the
4496 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4500 /* Block waiting for some event. */
4507 for (inferior
*inf
: all_inferiors ())
4509 process_stratum_target
*target
= inf
->process_target ();
4511 || !target
->is_async_p ()
4512 || !target
->threads_executing
)
4515 int fd
= target
->async_wait_fd ();
4516 FD_SET (fd
, &readfds
);
4523 /* No waitable targets left. All must be stopped. */
4524 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4529 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4535 perror_with_name ("interruptible_select");
4540 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4541 instead of the current thread. */
4542 #define THREAD_STOPPED_BY(REASON) \
4544 thread_stopped_by_ ## REASON (ptid_t ptid) \
4546 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4547 inferior_ptid = ptid; \
4549 return target_stopped_by_ ## REASON (); \
4552 /* Generate thread_stopped_by_watchpoint. */
4553 THREAD_STOPPED_BY (watchpoint
)
4554 /* Generate thread_stopped_by_sw_breakpoint. */
4555 THREAD_STOPPED_BY (sw_breakpoint
)
4556 /* Generate thread_stopped_by_hw_breakpoint. */
4557 THREAD_STOPPED_BY (hw_breakpoint
)
4559 /* Save the thread's event and stop reason to process it later. */
4562 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4564 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4565 target_waitstatus_to_string (ws
).c_str (),
4570 /* Record for later. */
4571 tp
->suspend
.waitstatus
= *ws
;
4572 tp
->suspend
.waitstatus_pending_p
= 1;
4574 struct regcache
*regcache
= get_thread_regcache (tp
);
4575 const address_space
*aspace
= regcache
->aspace ();
4577 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4578 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4580 CORE_ADDR pc
= regcache_read_pc (regcache
);
4582 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4584 if (thread_stopped_by_watchpoint (tp
->ptid
))
4586 tp
->suspend
.stop_reason
4587 = TARGET_STOPPED_BY_WATCHPOINT
;
4589 else if (target_supports_stopped_by_sw_breakpoint ()
4590 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4592 tp
->suspend
.stop_reason
4593 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4595 else if (target_supports_stopped_by_hw_breakpoint ()
4596 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4598 tp
->suspend
.stop_reason
4599 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4601 else if (!target_supports_stopped_by_hw_breakpoint ()
4602 && hardware_breakpoint_inserted_here_p (aspace
,
4605 tp
->suspend
.stop_reason
4606 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4608 else if (!target_supports_stopped_by_sw_breakpoint ()
4609 && software_breakpoint_inserted_here_p (aspace
,
4612 tp
->suspend
.stop_reason
4613 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4615 else if (!thread_has_single_step_breakpoints_set (tp
)
4616 && currently_stepping (tp
))
4618 tp
->suspend
.stop_reason
4619 = TARGET_STOPPED_BY_SINGLE_STEP
;
4624 /* Mark the non-executing threads accordingly. In all-stop, all
4625 threads of all processes are stopped when we get any event
4626 reported. In non-stop mode, only the event thread stops. */
4629 mark_non_executing_threads (process_stratum_target
*target
,
4631 struct target_waitstatus ws
)
4635 if (!target_is_non_stop_p ())
4636 mark_ptid
= minus_one_ptid
;
4637 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4638 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4640 /* If we're handling a process exit in non-stop mode, even
4641 though threads haven't been deleted yet, one would think
4642 that there is nothing to do, as threads of the dead process
4643 will be soon deleted, and threads of any other process were
4644 left running. However, on some targets, threads survive a
4645 process exit event. E.g., for the "checkpoint" command,
4646 when the current checkpoint/fork exits, linux-fork.c
4647 automatically switches to another fork from within
4648 target_mourn_inferior, by associating the same
4649 inferior/thread to another fork. We haven't mourned yet at
4650 this point, but we must mark any threads left in the
4651 process as not-executing so that finish_thread_state marks
4652 them stopped (in the user's perspective) if/when we present
4653 the stop to the user. */
4654 mark_ptid
= ptid_t (event_ptid
.pid ());
4657 mark_ptid
= event_ptid
;
4659 set_executing (target
, mark_ptid
, false);
4661 /* Likewise the resumed flag. */
4662 set_resumed (target
, mark_ptid
, false);
4668 stop_all_threads (void)
4670 /* We may need multiple passes to discover all threads. */
4674 gdb_assert (exists_non_stop_target ());
4676 infrun_log_debug ("stop_all_threads");
4678 scoped_restore_current_thread restore_thread
;
4680 /* Enable thread events of all targets. */
4681 for (auto *target
: all_non_exited_process_targets ())
4683 switch_to_target_no_thread (target
);
4684 target_thread_events (true);
4689 /* Disable thread events of all targets. */
4690 for (auto *target
: all_non_exited_process_targets ())
4692 switch_to_target_no_thread (target
);
4693 target_thread_events (false);
4697 infrun_log_debug ("stop_all_threads done");
4700 /* Request threads to stop, and then wait for the stops. Because
4701 threads we already know about can spawn more threads while we're
4702 trying to stop them, and we only learn about new threads when we
4703 update the thread list, do this in a loop, and keep iterating
4704 until two passes find no threads that need to be stopped. */
4705 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4707 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4711 int waits_needed
= 0;
4713 for (auto *target
: all_non_exited_process_targets ())
4715 switch_to_target_no_thread (target
);
4716 update_thread_list ();
4719 /* Go through all threads looking for threads that we need
4720 to tell the target to stop. */
4721 for (thread_info
*t
: all_non_exited_threads ())
4723 /* For a single-target setting with an all-stop target,
4724 we would not even arrive here. For a multi-target
4725 setting, until GDB is able to handle a mixture of
4726 all-stop and non-stop targets, simply skip all-stop
4727 targets' threads. This should be fine due to the
4728 protection of 'check_multi_target_resumption'. */
4730 switch_to_thread_no_regs (t
);
4731 if (!target_is_non_stop_p ())
4736 /* If already stopping, don't request a stop again.
4737 We just haven't seen the notification yet. */
4738 if (!t
->stop_requested
)
4740 infrun_log_debug (" %s executing, need stop",
4741 target_pid_to_str (t
->ptid
).c_str ());
4742 target_stop (t
->ptid
);
4743 t
->stop_requested
= 1;
4747 infrun_log_debug (" %s executing, already stopping",
4748 target_pid_to_str (t
->ptid
).c_str ());
4751 if (t
->stop_requested
)
4756 infrun_log_debug (" %s not executing",
4757 target_pid_to_str (t
->ptid
).c_str ());
4759 /* The thread may be not executing, but still be
4760 resumed with a pending status to process. */
4765 if (waits_needed
== 0)
4768 /* If we find new threads on the second iteration, restart
4769 over. We want to see two iterations in a row with all
4774 for (int i
= 0; i
< waits_needed
; i
++)
4776 wait_one_event event
= wait_one ();
4778 infrun_log_debug ("%s %s\n",
4779 target_waitstatus_to_string (&event
.ws
).c_str (),
4780 target_pid_to_str (event
.ptid
).c_str ());
4782 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4784 /* All resumed threads exited. */
4787 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4788 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4789 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4791 /* One thread/process exited/signalled. */
4793 thread_info
*t
= nullptr;
4795 /* The target may have reported just a pid. If so, try
4796 the first non-exited thread. */
4797 if (event
.ptid
.is_pid ())
4799 int pid
= event
.ptid
.pid ();
4800 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4801 for (thread_info
*tp
: inf
->non_exited_threads ())
4807 /* If there is no available thread, the event would
4808 have to be appended to a per-inferior event list,
4809 which does not exist (and if it did, we'd have
4810 to adjust run control command to be able to
4811 resume such an inferior). We assert here instead
4812 of going into an infinite loop. */
4813 gdb_assert (t
!= nullptr);
4815 infrun_log_debug ("using %s\n",
4816 target_pid_to_str (t
->ptid
).c_str ());
4820 t
= find_thread_ptid (event
.target
, event
.ptid
);
4821 /* Check if this is the first time we see this thread.
4822 Don't bother adding if it individually exited. */
4824 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4825 t
= add_thread (event
.target
, event
.ptid
);
4830 /* Set the threads as non-executing to avoid
4831 another stop attempt on them. */
4832 switch_to_thread_no_regs (t
);
4833 mark_non_executing_threads (event
.target
, event
.ptid
,
4835 save_waitstatus (t
, &event
.ws
);
4836 t
->stop_requested
= false;
4841 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4843 t
= add_thread (event
.target
, event
.ptid
);
4845 t
->stop_requested
= 0;
4848 t
->control
.may_range_step
= 0;
4850 /* This may be the first time we see the inferior report
4852 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4853 if (inf
->needs_setup
)
4855 switch_to_thread_no_regs (t
);
4859 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4860 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4862 /* We caught the event that we intended to catch, so
4863 there's no event pending. */
4864 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4865 t
->suspend
.waitstatus_pending_p
= 0;
4867 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4869 /* Add it back to the step-over queue. */
4870 infrun_log_debug ("displaced-step of %s "
4871 "canceled: adding back to the "
4872 "step-over queue\n",
4873 target_pid_to_str (t
->ptid
).c_str ());
4875 t
->control
.trap_expected
= 0;
4876 global_thread_step_over_chain_enqueue (t
);
4881 enum gdb_signal sig
;
4882 struct regcache
*regcache
;
4886 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4888 infrun_log_debug ("target_wait %s, saving "
4889 "status for %d.%ld.%ld\n",
4896 /* Record for later. */
4897 save_waitstatus (t
, &event
.ws
);
4899 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4900 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4902 if (displaced_step_finish (t
, sig
) < 0)
4904 /* Add it back to the step-over queue. */
4905 t
->control
.trap_expected
= 0;
4906 global_thread_step_over_chain_enqueue (t
);
4909 regcache
= get_thread_regcache (t
);
4910 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4912 infrun_log_debug ("saved stop_pc=%s for %s "
4913 "(currently_stepping=%d)\n",
4914 paddress (target_gdbarch (),
4915 t
->suspend
.stop_pc
),
4916 target_pid_to_str (t
->ptid
).c_str (),
4917 currently_stepping (t
));
4925 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4928 handle_no_resumed (struct execution_control_state
*ecs
)
4930 if (target_can_async_p ())
4934 for (ui
*ui
: all_uis ())
4936 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4944 /* There were no unwaited-for children left in the target, but,
4945 we're not synchronously waiting for events either. Just
4948 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4949 prepare_to_wait (ecs
);
4954 /* Otherwise, if we were running a synchronous execution command, we
4955 may need to cancel it and give the user back the terminal.
4957 In non-stop mode, the target can't tell whether we've already
4958 consumed previous stop events, so it can end up sending us a
4959 no-resumed event like so:
4961 #0 - thread 1 is left stopped
4963 #1 - thread 2 is resumed and hits breakpoint
4964 -> TARGET_WAITKIND_STOPPED
4966 #2 - thread 3 is resumed and exits
4967 this is the last resumed thread, so
4968 -> TARGET_WAITKIND_NO_RESUMED
4970 #3 - gdb processes stop for thread 2 and decides to re-resume
4973 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4974 thread 2 is now resumed, so the event should be ignored.
4976 IOW, if the stop for thread 2 doesn't end a foreground command,
4977 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4978 event. But it could be that the event meant that thread 2 itself
4979 (or whatever other thread was the last resumed thread) exited.
4981 To address this we refresh the thread list and check whether we
4982 have resumed threads _now_. In the example above, this removes
4983 thread 3 from the thread list. If thread 2 was re-resumed, we
4984 ignore this event. If we find no thread resumed, then we cancel
4985 the synchronous command show "no unwaited-for " to the user. */
4986 update_thread_list ();
4988 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
4990 if (thread
->executing
4991 || thread
->suspend
.waitstatus_pending_p
)
4993 /* There were no unwaited-for children left in the target at
4994 some point, but there are now. Just ignore. */
4995 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
4996 "(ignoring: found resumed)");
4997 prepare_to_wait (ecs
);
5002 /* Go ahead and report the event. */
5006 /* Given an execution control state that has been freshly filled in by
5007 an event from the inferior, figure out what it means and take
5010 The alternatives are:
5012 1) stop_waiting and return; to really stop and return to the
5015 2) keep_going and return; to wait for the next event (set
5016 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5020 handle_inferior_event (struct execution_control_state
*ecs
)
5022 /* Make sure that all temporary struct value objects that were
5023 created during the handling of the event get deleted at the
5025 scoped_value_mark free_values
;
5027 enum stop_kind stop_soon
;
5029 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5031 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5033 /* We had an event in the inferior, but we are not interested in
5034 handling it at this level. The lower layers have already
5035 done what needs to be done, if anything.
5037 One of the possible circumstances for this is when the
5038 inferior produces output for the console. The inferior has
5039 not stopped, and we are ignoring the event. Another possible
5040 circumstance is any event which the lower level knows will be
5041 reported multiple times without an intervening resume. */
5042 prepare_to_wait (ecs
);
5046 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5048 prepare_to_wait (ecs
);
5052 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5053 && handle_no_resumed (ecs
))
5056 /* Cache the last target/ptid/waitstatus. */
5057 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5059 /* Always clear state belonging to the previous time we stopped. */
5060 stop_stack_dummy
= STOP_NONE
;
5062 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5064 /* No unwaited-for children left. IOW, all resumed children
5066 stop_print_frame
= 0;
5071 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5072 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5074 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5075 /* If it's a new thread, add it to the thread database. */
5076 if (ecs
->event_thread
== NULL
)
5077 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5079 /* Disable range stepping. If the next step request could use a
5080 range, this will be end up re-enabled then. */
5081 ecs
->event_thread
->control
.may_range_step
= 0;
5084 /* Dependent on valid ECS->EVENT_THREAD. */
5085 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5087 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5088 reinit_frame_cache ();
5090 breakpoint_retire_moribund ();
5092 /* First, distinguish signals caused by the debugger from signals
5093 that have to do with the program's own actions. Note that
5094 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5095 on the operating system version. Here we detect when a SIGILL or
5096 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5097 something similar for SIGSEGV, since a SIGSEGV will be generated
5098 when we're trying to execute a breakpoint instruction on a
5099 non-executable stack. This happens for call dummy breakpoints
5100 for architectures like SPARC that place call dummies on the
5102 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5103 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5104 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5105 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5107 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5109 if (breakpoint_inserted_here_p (regcache
->aspace (),
5110 regcache_read_pc (regcache
)))
5112 infrun_log_debug ("Treating signal as SIGTRAP");
5113 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5117 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5119 switch (ecs
->ws
.kind
)
5121 case TARGET_WAITKIND_LOADED
:
5122 context_switch (ecs
);
5123 /* Ignore gracefully during startup of the inferior, as it might
5124 be the shell which has just loaded some objects, otherwise
5125 add the symbols for the newly loaded objects. Also ignore at
5126 the beginning of an attach or remote session; we will query
5127 the full list of libraries once the connection is
5130 stop_soon
= get_inferior_stop_soon (ecs
);
5131 if (stop_soon
== NO_STOP_QUIETLY
)
5133 struct regcache
*regcache
;
5135 regcache
= get_thread_regcache (ecs
->event_thread
);
5137 handle_solib_event ();
5139 ecs
->event_thread
->control
.stop_bpstat
5140 = bpstat_stop_status (regcache
->aspace (),
5141 ecs
->event_thread
->suspend
.stop_pc
,
5142 ecs
->event_thread
, &ecs
->ws
);
5144 if (handle_stop_requested (ecs
))
5147 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5149 /* A catchpoint triggered. */
5150 process_event_stop_test (ecs
);
5154 /* If requested, stop when the dynamic linker notifies
5155 gdb of events. This allows the user to get control
5156 and place breakpoints in initializer routines for
5157 dynamically loaded objects (among other things). */
5158 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5159 if (stop_on_solib_events
)
5161 /* Make sure we print "Stopped due to solib-event" in
5163 stop_print_frame
= 1;
5170 /* If we are skipping through a shell, or through shared library
5171 loading that we aren't interested in, resume the program. If
5172 we're running the program normally, also resume. */
5173 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5175 /* Loading of shared libraries might have changed breakpoint
5176 addresses. Make sure new breakpoints are inserted. */
5177 if (stop_soon
== NO_STOP_QUIETLY
)
5178 insert_breakpoints ();
5179 resume (GDB_SIGNAL_0
);
5180 prepare_to_wait (ecs
);
5184 /* But stop if we're attaching or setting up a remote
5186 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5187 || stop_soon
== STOP_QUIETLY_REMOTE
)
5189 infrun_log_debug ("quietly stopped");
5194 internal_error (__FILE__
, __LINE__
,
5195 _("unhandled stop_soon: %d"), (int) stop_soon
);
5197 case TARGET_WAITKIND_SPURIOUS
:
5198 if (handle_stop_requested (ecs
))
5200 context_switch (ecs
);
5201 resume (GDB_SIGNAL_0
);
5202 prepare_to_wait (ecs
);
5205 case TARGET_WAITKIND_THREAD_CREATED
:
5206 if (handle_stop_requested (ecs
))
5208 context_switch (ecs
);
5209 if (!switch_back_to_stepped_thread (ecs
))
5213 case TARGET_WAITKIND_EXITED
:
5214 case TARGET_WAITKIND_SIGNALLED
:
5215 inferior_ptid
= ecs
->ptid
;
5216 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5217 set_current_program_space (current_inferior ()->pspace
);
5218 handle_vfork_child_exec_or_exit (0);
5219 target_terminal::ours (); /* Must do this before mourn anyway. */
5221 /* Clearing any previous state of convenience variables. */
5222 clear_exit_convenience_vars ();
5224 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5226 /* Record the exit code in the convenience variable $_exitcode, so
5227 that the user can inspect this again later. */
5228 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5229 (LONGEST
) ecs
->ws
.value
.integer
);
5231 /* Also record this in the inferior itself. */
5232 current_inferior ()->has_exit_code
= 1;
5233 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5235 /* Support the --return-child-result option. */
5236 return_child_result_value
= ecs
->ws
.value
.integer
;
5238 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5242 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5244 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5246 /* Set the value of the internal variable $_exitsignal,
5247 which holds the signal uncaught by the inferior. */
5248 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5249 gdbarch_gdb_signal_to_target (gdbarch
,
5250 ecs
->ws
.value
.sig
));
5254 /* We don't have access to the target's method used for
5255 converting between signal numbers (GDB's internal
5256 representation <-> target's representation).
5257 Therefore, we cannot do a good job at displaying this
5258 information to the user. It's better to just warn
5259 her about it (if infrun debugging is enabled), and
5261 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5265 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5268 gdb_flush (gdb_stdout
);
5269 target_mourn_inferior (inferior_ptid
);
5270 stop_print_frame
= 0;
5274 case TARGET_WAITKIND_FORKED
:
5275 case TARGET_WAITKIND_VFORKED
:
5276 /* Check whether the inferior is displaced stepping. */
5278 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5279 struct gdbarch
*gdbarch
= regcache
->arch ();
5281 /* If checking displaced stepping is supported, and thread
5282 ecs->ptid is displaced stepping. */
5283 if (displaced_step_in_progress (ecs
->event_thread
))
5285 struct inferior
*parent_inf
5286 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5287 struct regcache
*child_regcache
;
5288 CORE_ADDR parent_pc
;
5290 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5292 // struct displaced_step_inferior_state *displaced
5293 // = get_displaced_stepping_state (parent_inf);
5295 /* Restore scratch pad for child process. */
5296 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5297 // FIXME: we should restore all the buffers that were currently in use
5300 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5301 indicating that the displaced stepping of syscall instruction
5302 has been done. Perform cleanup for parent process here. Note
5303 that this operation also cleans up the child process for vfork,
5304 because their pages are shared. */
5305 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5306 /* Start a new step-over in another thread if there's one
5310 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5311 the child's PC is also within the scratchpad. Set the child's PC
5312 to the parent's PC value, which has already been fixed up.
5313 FIXME: we use the parent's aspace here, although we're touching
5314 the child, because the child hasn't been added to the inferior
5315 list yet at this point. */
5318 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5319 ecs
->ws
.value
.related_pid
,
5321 parent_inf
->aspace
);
5322 /* Read PC value of parent process. */
5323 parent_pc
= regcache_read_pc (regcache
);
5325 if (debug_displaced
)
5326 fprintf_unfiltered (gdb_stdlog
,
5327 "displaced: write child pc from %s to %s\n",
5329 regcache_read_pc (child_regcache
)),
5330 paddress (gdbarch
, parent_pc
));
5332 regcache_write_pc (child_regcache
, parent_pc
);
5336 context_switch (ecs
);
5338 /* Immediately detach breakpoints from the child before there's
5339 any chance of letting the user delete breakpoints from the
5340 breakpoint lists. If we don't do this early, it's easy to
5341 leave left over traps in the child, vis: "break foo; catch
5342 fork; c; <fork>; del; c; <child calls foo>". We only follow
5343 the fork on the last `continue', and by that time the
5344 breakpoint at "foo" is long gone from the breakpoint table.
5345 If we vforked, then we don't need to unpatch here, since both
5346 parent and child are sharing the same memory pages; we'll
5347 need to unpatch at follow/detach time instead to be certain
5348 that new breakpoints added between catchpoint hit time and
5349 vfork follow are detached. */
5350 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5352 /* This won't actually modify the breakpoint list, but will
5353 physically remove the breakpoints from the child. */
5354 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5357 delete_just_stopped_threads_single_step_breakpoints ();
5359 /* In case the event is caught by a catchpoint, remember that
5360 the event is to be followed at the next resume of the thread,
5361 and not immediately. */
5362 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5364 ecs
->event_thread
->suspend
.stop_pc
5365 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5367 ecs
->event_thread
->control
.stop_bpstat
5368 = bpstat_stop_status (get_current_regcache ()->aspace (),
5369 ecs
->event_thread
->suspend
.stop_pc
,
5370 ecs
->event_thread
, &ecs
->ws
);
5372 if (handle_stop_requested (ecs
))
5375 /* If no catchpoint triggered for this, then keep going. Note
5376 that we're interested in knowing the bpstat actually causes a
5377 stop, not just if it may explain the signal. Software
5378 watchpoints, for example, always appear in the bpstat. */
5379 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5382 = (follow_fork_mode_string
== follow_fork_mode_child
);
5384 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5386 process_stratum_target
*targ
5387 = ecs
->event_thread
->inf
->process_target ();
5389 bool should_resume
= follow_fork ();
5391 /* Note that one of these may be an invalid pointer,
5392 depending on detach_fork. */
5393 thread_info
*parent
= ecs
->event_thread
;
5395 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5397 /* At this point, the parent is marked running, and the
5398 child is marked stopped. */
5400 /* If not resuming the parent, mark it stopped. */
5401 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5402 parent
->set_running (false);
5404 /* If resuming the child, mark it running. */
5405 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5406 child
->set_running (true);
5408 /* In non-stop mode, also resume the other branch. */
5409 if (!detach_fork
&& (non_stop
5410 || (sched_multi
&& target_is_non_stop_p ())))
5413 switch_to_thread (parent
);
5415 switch_to_thread (child
);
5417 ecs
->event_thread
= inferior_thread ();
5418 ecs
->ptid
= inferior_ptid
;
5423 switch_to_thread (child
);
5425 switch_to_thread (parent
);
5427 ecs
->event_thread
= inferior_thread ();
5428 ecs
->ptid
= inferior_ptid
;
5436 process_event_stop_test (ecs
);
5439 case TARGET_WAITKIND_VFORK_DONE
:
5440 /* Done with the shared memory region. Re-insert breakpoints in
5441 the parent, and keep going. */
5443 context_switch (ecs
);
5445 current_inferior ()->waiting_for_vfork_done
= 0;
5446 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5448 if (handle_stop_requested (ecs
))
5451 /* This also takes care of reinserting breakpoints in the
5452 previously locked inferior. */
5456 case TARGET_WAITKIND_EXECD
:
5458 /* Note we can't read registers yet (the stop_pc), because we
5459 don't yet know the inferior's post-exec architecture.
5460 'stop_pc' is explicitly read below instead. */
5461 switch_to_thread_no_regs (ecs
->event_thread
);
5463 /* Do whatever is necessary to the parent branch of the vfork. */
5464 handle_vfork_child_exec_or_exit (1);
5466 /* This causes the eventpoints and symbol table to be reset.
5467 Must do this now, before trying to determine whether to
5469 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5471 /* In follow_exec we may have deleted the original thread and
5472 created a new one. Make sure that the event thread is the
5473 execd thread for that case (this is a nop otherwise). */
5474 ecs
->event_thread
= inferior_thread ();
5476 ecs
->event_thread
->suspend
.stop_pc
5477 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5479 ecs
->event_thread
->control
.stop_bpstat
5480 = bpstat_stop_status (get_current_regcache ()->aspace (),
5481 ecs
->event_thread
->suspend
.stop_pc
,
5482 ecs
->event_thread
, &ecs
->ws
);
5484 /* Note that this may be referenced from inside
5485 bpstat_stop_status above, through inferior_has_execd. */
5486 xfree (ecs
->ws
.value
.execd_pathname
);
5487 ecs
->ws
.value
.execd_pathname
= NULL
;
5489 if (handle_stop_requested (ecs
))
5492 /* If no catchpoint triggered for this, then keep going. */
5493 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5495 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5499 process_event_stop_test (ecs
);
5502 /* Be careful not to try to gather much state about a thread
5503 that's in a syscall. It's frequently a losing proposition. */
5504 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5505 /* Getting the current syscall number. */
5506 if (handle_syscall_event (ecs
) == 0)
5507 process_event_stop_test (ecs
);
5510 /* Before examining the threads further, step this thread to
5511 get it entirely out of the syscall. (We get notice of the
5512 event when the thread is just on the verge of exiting a
5513 syscall. Stepping one instruction seems to get it back
5515 case TARGET_WAITKIND_SYSCALL_RETURN
:
5516 if (handle_syscall_event (ecs
) == 0)
5517 process_event_stop_test (ecs
);
5520 case TARGET_WAITKIND_STOPPED
:
5521 handle_signal_stop (ecs
);
5524 case TARGET_WAITKIND_NO_HISTORY
:
5525 /* Reverse execution: target ran out of history info. */
5527 /* Switch to the stopped thread. */
5528 context_switch (ecs
);
5529 infrun_log_debug ("stopped");
5531 delete_just_stopped_threads_single_step_breakpoints ();
5532 ecs
->event_thread
->suspend
.stop_pc
5533 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5535 if (handle_stop_requested (ecs
))
5538 gdb::observers::no_history
.notify ();
5544 /* Restart threads back to what they were trying to do back when we
5545 paused them for an in-line step-over. The EVENT_THREAD thread is
5549 restart_threads (struct thread_info
*event_thread
)
5551 /* In case the instruction just stepped spawned a new thread. */
5552 update_thread_list ();
5554 for (thread_info
*tp
: all_non_exited_threads ())
5556 switch_to_thread_no_regs (tp
);
5558 if (tp
== event_thread
)
5560 infrun_log_debug ("restart threads: [%s] is event thread",
5561 target_pid_to_str (tp
->ptid
).c_str ());
5565 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5567 infrun_log_debug ("restart threads: [%s] not meant to be running",
5568 target_pid_to_str (tp
->ptid
).c_str ());
5574 infrun_log_debug ("restart threads: [%s] resumed",
5575 target_pid_to_str (tp
->ptid
).c_str ());
5576 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5580 if (thread_is_in_step_over_chain (tp
))
5582 infrun_log_debug ("restart threads: [%s] needs step-over",
5583 target_pid_to_str (tp
->ptid
).c_str ());
5584 gdb_assert (!tp
->resumed
);
5589 if (tp
->suspend
.waitstatus_pending_p
)
5591 infrun_log_debug ("restart threads: [%s] has pending status",
5592 target_pid_to_str (tp
->ptid
).c_str ());
5597 gdb_assert (!tp
->stop_requested
);
5599 /* If some thread needs to start a step-over at this point, it
5600 should still be in the step-over queue, and thus skipped
5602 if (thread_still_needs_step_over (tp
))
5604 internal_error (__FILE__
, __LINE__
,
5605 "thread [%s] needs a step-over, but not in "
5606 "step-over queue\n",
5607 target_pid_to_str (tp
->ptid
).c_str ());
5610 if (currently_stepping (tp
))
5612 infrun_log_debug ("restart threads: [%s] was stepping",
5613 target_pid_to_str (tp
->ptid
).c_str ());
5614 keep_going_stepped_thread (tp
);
5618 struct execution_control_state ecss
;
5619 struct execution_control_state
*ecs
= &ecss
;
5621 infrun_log_debug ("restart threads: [%s] continuing",
5622 target_pid_to_str (tp
->ptid
).c_str ());
5623 reset_ecs (ecs
, tp
);
5624 switch_to_thread (tp
);
5625 keep_going_pass_signal (ecs
);
5630 /* Callback for iterate_over_threads. Find a resumed thread that has
5631 a pending waitstatus. */
5634 resumed_thread_with_pending_status (struct thread_info
*tp
,
5638 && tp
->suspend
.waitstatus_pending_p
);
5641 /* Called when we get an event that may finish an in-line or
5642 out-of-line (displaced stepping) step-over started previously.
5643 Return true if the event is processed and we should go back to the
5644 event loop; false if the caller should continue processing the
5648 finish_step_over (struct execution_control_state
*ecs
)
5650 int had_step_over_info
;
5652 displaced_step_finish (ecs
->event_thread
,
5653 ecs
->event_thread
->suspend
.stop_signal
);
5655 had_step_over_info
= step_over_info_valid_p ();
5657 if (had_step_over_info
)
5659 /* If we're stepping over a breakpoint with all threads locked,
5660 then only the thread that was stepped should be reporting
5662 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5664 clear_step_over_info ();
5667 if (!target_is_non_stop_p ())
5670 /* Start a new step-over in another thread if there's one that
5674 /* If we were stepping over a breakpoint before, and haven't started
5675 a new in-line step-over sequence, then restart all other threads
5676 (except the event thread). We can't do this in all-stop, as then
5677 e.g., we wouldn't be able to issue any other remote packet until
5678 these other threads stop. */
5679 if (had_step_over_info
&& !step_over_info_valid_p ())
5681 struct thread_info
*pending
;
5683 /* If we only have threads with pending statuses, the restart
5684 below won't restart any thread and so nothing re-inserts the
5685 breakpoint we just stepped over. But we need it inserted
5686 when we later process the pending events, otherwise if
5687 another thread has a pending event for this breakpoint too,
5688 we'd discard its event (because the breakpoint that
5689 originally caused the event was no longer inserted). */
5690 context_switch (ecs
);
5691 insert_breakpoints ();
5693 restart_threads (ecs
->event_thread
);
5695 /* If we have events pending, go through handle_inferior_event
5696 again, picking up a pending event at random. This avoids
5697 thread starvation. */
5699 /* But not if we just stepped over a watchpoint in order to let
5700 the instruction execute so we can evaluate its expression.
5701 The set of watchpoints that triggered is recorded in the
5702 breakpoint objects themselves (see bp->watchpoint_triggered).
5703 If we processed another event first, that other event could
5704 clobber this info. */
5705 if (ecs
->event_thread
->stepping_over_watchpoint
)
5708 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5710 if (pending
!= NULL
)
5712 struct thread_info
*tp
= ecs
->event_thread
;
5713 struct regcache
*regcache
;
5715 infrun_log_debug ("found resumed threads with "
5716 "pending events, saving status");
5718 gdb_assert (pending
!= tp
);
5720 /* Record the event thread's event for later. */
5721 save_waitstatus (tp
, &ecs
->ws
);
5722 /* This was cleared early, by handle_inferior_event. Set it
5723 so this pending event is considered by
5727 gdb_assert (!tp
->executing
);
5729 regcache
= get_thread_regcache (tp
);
5730 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5732 infrun_log_debug ("saved stop_pc=%s for %s "
5733 "(currently_stepping=%d)\n",
5734 paddress (target_gdbarch (),
5735 tp
->suspend
.stop_pc
),
5736 target_pid_to_str (tp
->ptid
).c_str (),
5737 currently_stepping (tp
));
5739 /* This in-line step-over finished; clear this so we won't
5740 start a new one. This is what handle_signal_stop would
5741 do, if we returned false. */
5742 tp
->stepping_over_breakpoint
= 0;
5744 /* Wake up the event loop again. */
5745 mark_async_event_handler (infrun_async_inferior_event_token
);
5747 prepare_to_wait (ecs
);
5755 /* Come here when the program has stopped with a signal. */
5758 handle_signal_stop (struct execution_control_state
*ecs
)
5760 struct frame_info
*frame
;
5761 struct gdbarch
*gdbarch
;
5762 int stopped_by_watchpoint
;
5763 enum stop_kind stop_soon
;
5766 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5768 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5770 /* Do we need to clean up the state of a thread that has
5771 completed a displaced single-step? (Doing so usually affects
5772 the PC, so do it here, before we set stop_pc.) */
5773 if (finish_step_over (ecs
))
5776 /* If we either finished a single-step or hit a breakpoint, but
5777 the user wanted this thread to be stopped, pretend we got a
5778 SIG0 (generic unsignaled stop). */
5779 if (ecs
->event_thread
->stop_requested
5780 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5781 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5783 ecs
->event_thread
->suspend
.stop_pc
5784 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5788 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5789 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5791 switch_to_thread (ecs
->event_thread
);
5793 infrun_log_debug ("stop_pc=%s",
5794 paddress (reg_gdbarch
,
5795 ecs
->event_thread
->suspend
.stop_pc
));
5796 if (target_stopped_by_watchpoint ())
5800 infrun_log_debug ("stopped by watchpoint");
5802 if (target_stopped_data_address (current_top_target (), &addr
))
5803 infrun_log_debug ("stopped data address=%s",
5804 paddress (reg_gdbarch
, addr
));
5806 infrun_log_debug ("(no data address available)");
5810 /* This is originated from start_remote(), start_inferior() and
5811 shared libraries hook functions. */
5812 stop_soon
= get_inferior_stop_soon (ecs
);
5813 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5815 context_switch (ecs
);
5816 infrun_log_debug ("quietly stopped");
5817 stop_print_frame
= 1;
5822 /* This originates from attach_command(). We need to overwrite
5823 the stop_signal here, because some kernels don't ignore a
5824 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5825 See more comments in inferior.h. On the other hand, if we
5826 get a non-SIGSTOP, report it to the user - assume the backend
5827 will handle the SIGSTOP if it should show up later.
5829 Also consider that the attach is complete when we see a
5830 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5831 target extended-remote report it instead of a SIGSTOP
5832 (e.g. gdbserver). We already rely on SIGTRAP being our
5833 signal, so this is no exception.
5835 Also consider that the attach is complete when we see a
5836 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5837 the target to stop all threads of the inferior, in case the
5838 low level attach operation doesn't stop them implicitly. If
5839 they weren't stopped implicitly, then the stub will report a
5840 GDB_SIGNAL_0, meaning: stopped for no particular reason
5841 other than GDB's request. */
5842 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5843 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5844 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5845 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5847 stop_print_frame
= 1;
5849 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5853 /* See if something interesting happened to the non-current thread. If
5854 so, then switch to that thread. */
5855 if (ecs
->ptid
!= inferior_ptid
)
5857 infrun_log_debug ("context switch");
5859 context_switch (ecs
);
5861 if (deprecated_context_hook
)
5862 deprecated_context_hook (ecs
->event_thread
->global_num
);
5865 /* At this point, get hold of the now-current thread's frame. */
5866 frame
= get_current_frame ();
5867 gdbarch
= get_frame_arch (frame
);
5869 /* Pull the single step breakpoints out of the target. */
5870 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5872 struct regcache
*regcache
;
5875 regcache
= get_thread_regcache (ecs
->event_thread
);
5876 const address_space
*aspace
= regcache
->aspace ();
5878 pc
= regcache_read_pc (regcache
);
5880 /* However, before doing so, if this single-step breakpoint was
5881 actually for another thread, set this thread up for moving
5883 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5886 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5888 infrun_log_debug ("[%s] hit another thread's single-step "
5890 target_pid_to_str (ecs
->ptid
).c_str ());
5891 ecs
->hit_singlestep_breakpoint
= 1;
5896 infrun_log_debug ("[%s] hit its single-step breakpoint",
5897 target_pid_to_str (ecs
->ptid
).c_str ());
5900 delete_just_stopped_threads_single_step_breakpoints ();
5902 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5903 && ecs
->event_thread
->control
.trap_expected
5904 && ecs
->event_thread
->stepping_over_watchpoint
)
5905 stopped_by_watchpoint
= 0;
5907 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5909 /* If necessary, step over this watchpoint. We'll be back to display
5911 if (stopped_by_watchpoint
5912 && (target_have_steppable_watchpoint
5913 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5915 /* At this point, we are stopped at an instruction which has
5916 attempted to write to a piece of memory under control of
5917 a watchpoint. The instruction hasn't actually executed
5918 yet. If we were to evaluate the watchpoint expression
5919 now, we would get the old value, and therefore no change
5920 would seem to have occurred.
5922 In order to make watchpoints work `right', we really need
5923 to complete the memory write, and then evaluate the
5924 watchpoint expression. We do this by single-stepping the
5927 It may not be necessary to disable the watchpoint to step over
5928 it. For example, the PA can (with some kernel cooperation)
5929 single step over a watchpoint without disabling the watchpoint.
5931 It is far more common to need to disable a watchpoint to step
5932 the inferior over it. If we have non-steppable watchpoints,
5933 we must disable the current watchpoint; it's simplest to
5934 disable all watchpoints.
5936 Any breakpoint at PC must also be stepped over -- if there's
5937 one, it will have already triggered before the watchpoint
5938 triggered, and we either already reported it to the user, or
5939 it didn't cause a stop and we called keep_going. In either
5940 case, if there was a breakpoint at PC, we must be trying to
5942 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5947 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5948 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5949 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5950 ecs
->event_thread
->control
.stop_step
= 0;
5951 stop_print_frame
= 1;
5952 stopped_by_random_signal
= 0;
5953 bpstat stop_chain
= NULL
;
5955 /* Hide inlined functions starting here, unless we just performed stepi or
5956 nexti. After stepi and nexti, always show the innermost frame (not any
5957 inline function call sites). */
5958 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5960 const address_space
*aspace
5961 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5963 /* skip_inline_frames is expensive, so we avoid it if we can
5964 determine that the address is one where functions cannot have
5965 been inlined. This improves performance with inferiors that
5966 load a lot of shared libraries, because the solib event
5967 breakpoint is defined as the address of a function (i.e. not
5968 inline). Note that we have to check the previous PC as well
5969 as the current one to catch cases when we have just
5970 single-stepped off a breakpoint prior to reinstating it.
5971 Note that we're assuming that the code we single-step to is
5972 not inline, but that's not definitive: there's nothing
5973 preventing the event breakpoint function from containing
5974 inlined code, and the single-step ending up there. If the
5975 user had set a breakpoint on that inlined code, the missing
5976 skip_inline_frames call would break things. Fortunately
5977 that's an extremely unlikely scenario. */
5978 if (!pc_at_non_inline_function (aspace
,
5979 ecs
->event_thread
->suspend
.stop_pc
,
5981 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5982 && ecs
->event_thread
->control
.trap_expected
5983 && pc_at_non_inline_function (aspace
,
5984 ecs
->event_thread
->prev_pc
,
5987 stop_chain
= build_bpstat_chain (aspace
,
5988 ecs
->event_thread
->suspend
.stop_pc
,
5990 skip_inline_frames (ecs
->event_thread
, stop_chain
);
5992 /* Re-fetch current thread's frame in case that invalidated
5994 frame
= get_current_frame ();
5995 gdbarch
= get_frame_arch (frame
);
5999 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6000 && ecs
->event_thread
->control
.trap_expected
6001 && gdbarch_single_step_through_delay_p (gdbarch
)
6002 && currently_stepping (ecs
->event_thread
))
6004 /* We're trying to step off a breakpoint. Turns out that we're
6005 also on an instruction that needs to be stepped multiple
6006 times before it's been fully executing. E.g., architectures
6007 with a delay slot. It needs to be stepped twice, once for
6008 the instruction and once for the delay slot. */
6009 int step_through_delay
6010 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6012 if (step_through_delay
)
6013 infrun_log_debug ("step through delay");
6015 if (ecs
->event_thread
->control
.step_range_end
== 0
6016 && step_through_delay
)
6018 /* The user issued a continue when stopped at a breakpoint.
6019 Set up for another trap and get out of here. */
6020 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6024 else if (step_through_delay
)
6026 /* The user issued a step when stopped at a breakpoint.
6027 Maybe we should stop, maybe we should not - the delay
6028 slot *might* correspond to a line of source. In any
6029 case, don't decide that here, just set
6030 ecs->stepping_over_breakpoint, making sure we
6031 single-step again before breakpoints are re-inserted. */
6032 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6036 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6037 handles this event. */
6038 ecs
->event_thread
->control
.stop_bpstat
6039 = bpstat_stop_status (get_current_regcache ()->aspace (),
6040 ecs
->event_thread
->suspend
.stop_pc
,
6041 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6043 /* Following in case break condition called a
6045 stop_print_frame
= 1;
6047 /* This is where we handle "moribund" watchpoints. Unlike
6048 software breakpoints traps, hardware watchpoint traps are
6049 always distinguishable from random traps. If no high-level
6050 watchpoint is associated with the reported stop data address
6051 anymore, then the bpstat does not explain the signal ---
6052 simply make sure to ignore it if `stopped_by_watchpoint' is
6055 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6056 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6058 && stopped_by_watchpoint
)
6060 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6064 /* NOTE: cagney/2003-03-29: These checks for a random signal
6065 at one stage in the past included checks for an inferior
6066 function call's call dummy's return breakpoint. The original
6067 comment, that went with the test, read:
6069 ``End of a stack dummy. Some systems (e.g. Sony news) give
6070 another signal besides SIGTRAP, so check here as well as
6073 If someone ever tries to get call dummys on a
6074 non-executable stack to work (where the target would stop
6075 with something like a SIGSEGV), then those tests might need
6076 to be re-instated. Given, however, that the tests were only
6077 enabled when momentary breakpoints were not being used, I
6078 suspect that it won't be the case.
6080 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6081 be necessary for call dummies on a non-executable stack on
6084 /* See if the breakpoints module can explain the signal. */
6086 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6087 ecs
->event_thread
->suspend
.stop_signal
);
6089 /* Maybe this was a trap for a software breakpoint that has since
6091 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6093 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6094 ecs
->event_thread
->suspend
.stop_pc
))
6096 struct regcache
*regcache
;
6099 /* Re-adjust PC to what the program would see if GDB was not
6101 regcache
= get_thread_regcache (ecs
->event_thread
);
6102 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6105 gdb::optional
<scoped_restore_tmpl
<int>>
6106 restore_operation_disable
;
6108 if (record_full_is_used ())
6109 restore_operation_disable
.emplace
6110 (record_full_gdb_operation_disable_set ());
6112 regcache_write_pc (regcache
,
6113 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6118 /* A delayed software breakpoint event. Ignore the trap. */
6119 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6124 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6125 has since been removed. */
6126 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6128 /* A delayed hardware breakpoint event. Ignore the trap. */
6129 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6134 /* If not, perhaps stepping/nexting can. */
6136 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6137 && currently_stepping (ecs
->event_thread
));
6139 /* Perhaps the thread hit a single-step breakpoint of _another_
6140 thread. Single-step breakpoints are transparent to the
6141 breakpoints module. */
6143 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6145 /* No? Perhaps we got a moribund watchpoint. */
6147 random_signal
= !stopped_by_watchpoint
;
6149 /* Always stop if the user explicitly requested this thread to
6151 if (ecs
->event_thread
->stop_requested
)
6154 infrun_log_debug ("user-requested stop");
6157 /* For the program's own signals, act according to
6158 the signal handling tables. */
6162 /* Signal not for debugging purposes. */
6163 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6164 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6166 infrun_log_debug ("random signal (%s)",
6167 gdb_signal_to_symbol_string (stop_signal
));
6169 stopped_by_random_signal
= 1;
6171 /* Always stop on signals if we're either just gaining control
6172 of the program, or the user explicitly requested this thread
6173 to remain stopped. */
6174 if (stop_soon
!= NO_STOP_QUIETLY
6175 || ecs
->event_thread
->stop_requested
6177 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6183 /* Notify observers the signal has "handle print" set. Note we
6184 returned early above if stopping; normal_stop handles the
6185 printing in that case. */
6186 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6188 /* The signal table tells us to print about this signal. */
6189 target_terminal::ours_for_output ();
6190 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6191 target_terminal::inferior ();
6194 /* Clear the signal if it should not be passed. */
6195 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6196 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6198 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6199 && ecs
->event_thread
->control
.trap_expected
6200 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6202 /* We were just starting a new sequence, attempting to
6203 single-step off of a breakpoint and expecting a SIGTRAP.
6204 Instead this signal arrives. This signal will take us out
6205 of the stepping range so GDB needs to remember to, when
6206 the signal handler returns, resume stepping off that
6208 /* To simplify things, "continue" is forced to use the same
6209 code paths as single-step - set a breakpoint at the
6210 signal return address and then, once hit, step off that
6212 infrun_log_debug ("signal arrived while stepping over breakpoint");
6214 insert_hp_step_resume_breakpoint_at_frame (frame
);
6215 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6216 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6217 ecs
->event_thread
->control
.trap_expected
= 0;
6219 /* If we were nexting/stepping some other thread, switch to
6220 it, so that we don't continue it, losing control. */
6221 if (!switch_back_to_stepped_thread (ecs
))
6226 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6227 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6229 || ecs
->event_thread
->control
.step_range_end
== 1)
6230 && frame_id_eq (get_stack_frame_id (frame
),
6231 ecs
->event_thread
->control
.step_stack_frame_id
)
6232 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6234 /* The inferior is about to take a signal that will take it
6235 out of the single step range. Set a breakpoint at the
6236 current PC (which is presumably where the signal handler
6237 will eventually return) and then allow the inferior to
6240 Note that this is only needed for a signal delivered
6241 while in the single-step range. Nested signals aren't a
6242 problem as they eventually all return. */
6243 infrun_log_debug ("signal may take us out of single-step range");
6245 clear_step_over_info ();
6246 insert_hp_step_resume_breakpoint_at_frame (frame
);
6247 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6248 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6249 ecs
->event_thread
->control
.trap_expected
= 0;
6254 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6255 when either there's a nested signal, or when there's a
6256 pending signal enabled just as the signal handler returns
6257 (leaving the inferior at the step-resume-breakpoint without
6258 actually executing it). Either way continue until the
6259 breakpoint is really hit. */
6261 if (!switch_back_to_stepped_thread (ecs
))
6263 infrun_log_debug ("random signal, keep going");
6270 process_event_stop_test (ecs
);
6273 /* Come here when we've got some debug event / signal we can explain
6274 (IOW, not a random signal), and test whether it should cause a
6275 stop, or whether we should resume the inferior (transparently).
6276 E.g., could be a breakpoint whose condition evaluates false; we
6277 could be still stepping within the line; etc. */
6280 process_event_stop_test (struct execution_control_state
*ecs
)
6282 struct symtab_and_line stop_pc_sal
;
6283 struct frame_info
*frame
;
6284 struct gdbarch
*gdbarch
;
6285 CORE_ADDR jmp_buf_pc
;
6286 struct bpstat_what what
;
6288 /* Handle cases caused by hitting a breakpoint. */
6290 frame
= get_current_frame ();
6291 gdbarch
= get_frame_arch (frame
);
6293 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6295 if (what
.call_dummy
)
6297 stop_stack_dummy
= what
.call_dummy
;
6300 /* A few breakpoint types have callbacks associated (e.g.,
6301 bp_jit_event). Run them now. */
6302 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6304 /* If we hit an internal event that triggers symbol changes, the
6305 current frame will be invalidated within bpstat_what (e.g., if we
6306 hit an internal solib event). Re-fetch it. */
6307 frame
= get_current_frame ();
6308 gdbarch
= get_frame_arch (frame
);
6310 switch (what
.main_action
)
6312 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6313 /* If we hit the breakpoint at longjmp while stepping, we
6314 install a momentary breakpoint at the target of the
6317 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6319 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6321 if (what
.is_longjmp
)
6323 struct value
*arg_value
;
6325 /* If we set the longjmp breakpoint via a SystemTap probe,
6326 then use it to extract the arguments. The destination PC
6327 is the third argument to the probe. */
6328 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6331 jmp_buf_pc
= value_as_address (arg_value
);
6332 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6334 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6335 || !gdbarch_get_longjmp_target (gdbarch
,
6336 frame
, &jmp_buf_pc
))
6338 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6339 "(!gdbarch_get_longjmp_target)");
6344 /* Insert a breakpoint at resume address. */
6345 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6348 check_exception_resume (ecs
, frame
);
6352 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6354 struct frame_info
*init_frame
;
6356 /* There are several cases to consider.
6358 1. The initiating frame no longer exists. In this case we
6359 must stop, because the exception or longjmp has gone too
6362 2. The initiating frame exists, and is the same as the
6363 current frame. We stop, because the exception or longjmp
6366 3. The initiating frame exists and is different from the
6367 current frame. This means the exception or longjmp has
6368 been caught beneath the initiating frame, so keep going.
6370 4. longjmp breakpoint has been placed just to protect
6371 against stale dummy frames and user is not interested in
6372 stopping around longjmps. */
6374 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6376 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6378 delete_exception_resume_breakpoint (ecs
->event_thread
);
6380 if (what
.is_longjmp
)
6382 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6384 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6392 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6396 struct frame_id current_id
6397 = get_frame_id (get_current_frame ());
6398 if (frame_id_eq (current_id
,
6399 ecs
->event_thread
->initiating_frame
))
6401 /* Case 2. Fall through. */
6411 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6413 delete_step_resume_breakpoint (ecs
->event_thread
);
6415 end_stepping_range (ecs
);
6419 case BPSTAT_WHAT_SINGLE
:
6420 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6421 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6422 /* Still need to check other stuff, at least the case where we
6423 are stepping and step out of the right range. */
6426 case BPSTAT_WHAT_STEP_RESUME
:
6427 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6429 delete_step_resume_breakpoint (ecs
->event_thread
);
6430 if (ecs
->event_thread
->control
.proceed_to_finish
6431 && execution_direction
== EXEC_REVERSE
)
6433 struct thread_info
*tp
= ecs
->event_thread
;
6435 /* We are finishing a function in reverse, and just hit the
6436 step-resume breakpoint at the start address of the
6437 function, and we're almost there -- just need to back up
6438 by one more single-step, which should take us back to the
6440 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6444 fill_in_stop_func (gdbarch
, ecs
);
6445 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6446 && execution_direction
== EXEC_REVERSE
)
6448 /* We are stepping over a function call in reverse, and just
6449 hit the step-resume breakpoint at the start address of
6450 the function. Go back to single-stepping, which should
6451 take us back to the function call. */
6452 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6458 case BPSTAT_WHAT_STOP_NOISY
:
6459 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6460 stop_print_frame
= 1;
6462 /* Assume the thread stopped for a breapoint. We'll still check
6463 whether a/the breakpoint is there when the thread is next
6465 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6470 case BPSTAT_WHAT_STOP_SILENT
:
6471 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6472 stop_print_frame
= 0;
6474 /* Assume the thread stopped for a breapoint. We'll still check
6475 whether a/the breakpoint is there when the thread is next
6477 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6481 case BPSTAT_WHAT_HP_STEP_RESUME
:
6482 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6484 delete_step_resume_breakpoint (ecs
->event_thread
);
6485 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6487 /* Back when the step-resume breakpoint was inserted, we
6488 were trying to single-step off a breakpoint. Go back to
6490 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6491 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6497 case BPSTAT_WHAT_KEEP_CHECKING
:
6501 /* If we stepped a permanent breakpoint and we had a high priority
6502 step-resume breakpoint for the address we stepped, but we didn't
6503 hit it, then we must have stepped into the signal handler. The
6504 step-resume was only necessary to catch the case of _not_
6505 stepping into the handler, so delete it, and fall through to
6506 checking whether the step finished. */
6507 if (ecs
->event_thread
->stepped_breakpoint
)
6509 struct breakpoint
*sr_bp
6510 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6513 && sr_bp
->loc
->permanent
6514 && sr_bp
->type
== bp_hp_step_resume
6515 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6517 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6518 delete_step_resume_breakpoint (ecs
->event_thread
);
6519 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6523 /* We come here if we hit a breakpoint but should not stop for it.
6524 Possibly we also were stepping and should stop for that. So fall
6525 through and test for stepping. But, if not stepping, do not
6528 /* In all-stop mode, if we're currently stepping but have stopped in
6529 some other thread, we need to switch back to the stepped thread. */
6530 if (switch_back_to_stepped_thread (ecs
))
6533 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6535 infrun_log_debug ("step-resume breakpoint is inserted");
6537 /* Having a step-resume breakpoint overrides anything
6538 else having to do with stepping commands until
6539 that breakpoint is reached. */
6544 if (ecs
->event_thread
->control
.step_range_end
== 0)
6546 infrun_log_debug ("no stepping, continue");
6547 /* Likewise if we aren't even stepping. */
6552 /* Re-fetch current thread's frame in case the code above caused
6553 the frame cache to be re-initialized, making our FRAME variable
6554 a dangling pointer. */
6555 frame
= get_current_frame ();
6556 gdbarch
= get_frame_arch (frame
);
6557 fill_in_stop_func (gdbarch
, ecs
);
6559 /* If stepping through a line, keep going if still within it.
6561 Note that step_range_end is the address of the first instruction
6562 beyond the step range, and NOT the address of the last instruction
6565 Note also that during reverse execution, we may be stepping
6566 through a function epilogue and therefore must detect when
6567 the current-frame changes in the middle of a line. */
6569 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6571 && (execution_direction
!= EXEC_REVERSE
6572 || frame_id_eq (get_frame_id (frame
),
6573 ecs
->event_thread
->control
.step_frame_id
)))
6576 ("stepping inside range [%s-%s]",
6577 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6578 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6580 /* Tentatively re-enable range stepping; `resume' disables it if
6581 necessary (e.g., if we're stepping over a breakpoint or we
6582 have software watchpoints). */
6583 ecs
->event_thread
->control
.may_range_step
= 1;
6585 /* When stepping backward, stop at beginning of line range
6586 (unless it's the function entry point, in which case
6587 keep going back to the call point). */
6588 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6589 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6590 && stop_pc
!= ecs
->stop_func_start
6591 && execution_direction
== EXEC_REVERSE
)
6592 end_stepping_range (ecs
);
6599 /* We stepped out of the stepping range. */
6601 /* If we are stepping at the source level and entered the runtime
6602 loader dynamic symbol resolution code...
6604 EXEC_FORWARD: we keep on single stepping until we exit the run
6605 time loader code and reach the callee's address.
6607 EXEC_REVERSE: we've already executed the callee (backward), and
6608 the runtime loader code is handled just like any other
6609 undebuggable function call. Now we need only keep stepping
6610 backward through the trampoline code, and that's handled further
6611 down, so there is nothing for us to do here. */
6613 if (execution_direction
!= EXEC_REVERSE
6614 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6615 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6617 CORE_ADDR pc_after_resolver
=
6618 gdbarch_skip_solib_resolver (gdbarch
,
6619 ecs
->event_thread
->suspend
.stop_pc
);
6621 infrun_log_debug ("stepped into dynsym resolve code");
6623 if (pc_after_resolver
)
6625 /* Set up a step-resume breakpoint at the address
6626 indicated by SKIP_SOLIB_RESOLVER. */
6627 symtab_and_line sr_sal
;
6628 sr_sal
.pc
= pc_after_resolver
;
6629 sr_sal
.pspace
= get_frame_program_space (frame
);
6631 insert_step_resume_breakpoint_at_sal (gdbarch
,
6632 sr_sal
, null_frame_id
);
6639 /* Step through an indirect branch thunk. */
6640 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6641 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6642 ecs
->event_thread
->suspend
.stop_pc
))
6644 infrun_log_debug ("stepped into indirect branch thunk");
6649 if (ecs
->event_thread
->control
.step_range_end
!= 1
6650 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6651 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6652 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6654 infrun_log_debug ("stepped into signal trampoline");
6655 /* The inferior, while doing a "step" or "next", has ended up in
6656 a signal trampoline (either by a signal being delivered or by
6657 the signal handler returning). Just single-step until the
6658 inferior leaves the trampoline (either by calling the handler
6664 /* If we're in the return path from a shared library trampoline,
6665 we want to proceed through the trampoline when stepping. */
6666 /* macro/2012-04-25: This needs to come before the subroutine
6667 call check below as on some targets return trampolines look
6668 like subroutine calls (MIPS16 return thunks). */
6669 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6670 ecs
->event_thread
->suspend
.stop_pc
,
6671 ecs
->stop_func_name
)
6672 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6674 /* Determine where this trampoline returns. */
6675 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6676 CORE_ADDR real_stop_pc
6677 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6679 infrun_log_debug ("stepped into solib return tramp");
6681 /* Only proceed through if we know where it's going. */
6684 /* And put the step-breakpoint there and go until there. */
6685 symtab_and_line sr_sal
;
6686 sr_sal
.pc
= real_stop_pc
;
6687 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6688 sr_sal
.pspace
= get_frame_program_space (frame
);
6690 /* Do not specify what the fp should be when we stop since
6691 on some machines the prologue is where the new fp value
6693 insert_step_resume_breakpoint_at_sal (gdbarch
,
6694 sr_sal
, null_frame_id
);
6696 /* Restart without fiddling with the step ranges or
6703 /* Check for subroutine calls. The check for the current frame
6704 equalling the step ID is not necessary - the check of the
6705 previous frame's ID is sufficient - but it is a common case and
6706 cheaper than checking the previous frame's ID.
6708 NOTE: frame_id_eq will never report two invalid frame IDs as
6709 being equal, so to get into this block, both the current and
6710 previous frame must have valid frame IDs. */
6711 /* The outer_frame_id check is a heuristic to detect stepping
6712 through startup code. If we step over an instruction which
6713 sets the stack pointer from an invalid value to a valid value,
6714 we may detect that as a subroutine call from the mythical
6715 "outermost" function. This could be fixed by marking
6716 outermost frames as !stack_p,code_p,special_p. Then the
6717 initial outermost frame, before sp was valid, would
6718 have code_addr == &_start. See the comment in frame_id_eq
6720 if (!frame_id_eq (get_stack_frame_id (frame
),
6721 ecs
->event_thread
->control
.step_stack_frame_id
)
6722 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6723 ecs
->event_thread
->control
.step_stack_frame_id
)
6724 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6726 || (ecs
->event_thread
->control
.step_start_function
6727 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6729 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6730 CORE_ADDR real_stop_pc
;
6732 infrun_log_debug ("stepped into subroutine");
6734 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6736 /* I presume that step_over_calls is only 0 when we're
6737 supposed to be stepping at the assembly language level
6738 ("stepi"). Just stop. */
6739 /* And this works the same backward as frontward. MVS */
6740 end_stepping_range (ecs
);
6744 /* Reverse stepping through solib trampolines. */
6746 if (execution_direction
== EXEC_REVERSE
6747 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6748 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6749 || (ecs
->stop_func_start
== 0
6750 && in_solib_dynsym_resolve_code (stop_pc
))))
6752 /* Any solib trampoline code can be handled in reverse
6753 by simply continuing to single-step. We have already
6754 executed the solib function (backwards), and a few
6755 steps will take us back through the trampoline to the
6761 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6763 /* We're doing a "next".
6765 Normal (forward) execution: set a breakpoint at the
6766 callee's return address (the address at which the caller
6769 Reverse (backward) execution. set the step-resume
6770 breakpoint at the start of the function that we just
6771 stepped into (backwards), and continue to there. When we
6772 get there, we'll need to single-step back to the caller. */
6774 if (execution_direction
== EXEC_REVERSE
)
6776 /* If we're already at the start of the function, we've either
6777 just stepped backward into a single instruction function,
6778 or stepped back out of a signal handler to the first instruction
6779 of the function. Just keep going, which will single-step back
6781 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6783 /* Normal function call return (static or dynamic). */
6784 symtab_and_line sr_sal
;
6785 sr_sal
.pc
= ecs
->stop_func_start
;
6786 sr_sal
.pspace
= get_frame_program_space (frame
);
6787 insert_step_resume_breakpoint_at_sal (gdbarch
,
6788 sr_sal
, null_frame_id
);
6792 insert_step_resume_breakpoint_at_caller (frame
);
6798 /* If we are in a function call trampoline (a stub between the
6799 calling routine and the real function), locate the real
6800 function. That's what tells us (a) whether we want to step
6801 into it at all, and (b) what prologue we want to run to the
6802 end of, if we do step into it. */
6803 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6804 if (real_stop_pc
== 0)
6805 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6806 if (real_stop_pc
!= 0)
6807 ecs
->stop_func_start
= real_stop_pc
;
6809 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6811 symtab_and_line sr_sal
;
6812 sr_sal
.pc
= ecs
->stop_func_start
;
6813 sr_sal
.pspace
= get_frame_program_space (frame
);
6815 insert_step_resume_breakpoint_at_sal (gdbarch
,
6816 sr_sal
, null_frame_id
);
6821 /* If we have line number information for the function we are
6822 thinking of stepping into and the function isn't on the skip
6825 If there are several symtabs at that PC (e.g. with include
6826 files), just want to know whether *any* of them have line
6827 numbers. find_pc_line handles this. */
6829 struct symtab_and_line tmp_sal
;
6831 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6832 if (tmp_sal
.line
!= 0
6833 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6835 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6837 if (execution_direction
== EXEC_REVERSE
)
6838 handle_step_into_function_backward (gdbarch
, ecs
);
6840 handle_step_into_function (gdbarch
, ecs
);
6845 /* If we have no line number and the step-stop-if-no-debug is
6846 set, we stop the step so that the user has a chance to switch
6847 in assembly mode. */
6848 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6849 && step_stop_if_no_debug
)
6851 end_stepping_range (ecs
);
6855 if (execution_direction
== EXEC_REVERSE
)
6857 /* If we're already at the start of the function, we've either just
6858 stepped backward into a single instruction function without line
6859 number info, or stepped back out of a signal handler to the first
6860 instruction of the function without line number info. Just keep
6861 going, which will single-step back to the caller. */
6862 if (ecs
->stop_func_start
!= stop_pc
)
6864 /* Set a breakpoint at callee's start address.
6865 From there we can step once and be back in the caller. */
6866 symtab_and_line sr_sal
;
6867 sr_sal
.pc
= ecs
->stop_func_start
;
6868 sr_sal
.pspace
= get_frame_program_space (frame
);
6869 insert_step_resume_breakpoint_at_sal (gdbarch
,
6870 sr_sal
, null_frame_id
);
6874 /* Set a breakpoint at callee's return address (the address
6875 at which the caller will resume). */
6876 insert_step_resume_breakpoint_at_caller (frame
);
6882 /* Reverse stepping through solib trampolines. */
6884 if (execution_direction
== EXEC_REVERSE
6885 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6887 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6889 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6890 || (ecs
->stop_func_start
== 0
6891 && in_solib_dynsym_resolve_code (stop_pc
)))
6893 /* Any solib trampoline code can be handled in reverse
6894 by simply continuing to single-step. We have already
6895 executed the solib function (backwards), and a few
6896 steps will take us back through the trampoline to the
6901 else if (in_solib_dynsym_resolve_code (stop_pc
))
6903 /* Stepped backward into the solib dynsym resolver.
6904 Set a breakpoint at its start and continue, then
6905 one more step will take us out. */
6906 symtab_and_line sr_sal
;
6907 sr_sal
.pc
= ecs
->stop_func_start
;
6908 sr_sal
.pspace
= get_frame_program_space (frame
);
6909 insert_step_resume_breakpoint_at_sal (gdbarch
,
6910 sr_sal
, null_frame_id
);
6916 /* This always returns the sal for the inner-most frame when we are in a
6917 stack of inlined frames, even if GDB actually believes that it is in a
6918 more outer frame. This is checked for below by calls to
6919 inline_skipped_frames. */
6920 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6922 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6923 the trampoline processing logic, however, there are some trampolines
6924 that have no names, so we should do trampoline handling first. */
6925 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6926 && ecs
->stop_func_name
== NULL
6927 && stop_pc_sal
.line
== 0)
6929 infrun_log_debug ("stepped into undebuggable function");
6931 /* The inferior just stepped into, or returned to, an
6932 undebuggable function (where there is no debugging information
6933 and no line number corresponding to the address where the
6934 inferior stopped). Since we want to skip this kind of code,
6935 we keep going until the inferior returns from this
6936 function - unless the user has asked us not to (via
6937 set step-mode) or we no longer know how to get back
6938 to the call site. */
6939 if (step_stop_if_no_debug
6940 || !frame_id_p (frame_unwind_caller_id (frame
)))
6942 /* If we have no line number and the step-stop-if-no-debug
6943 is set, we stop the step so that the user has a chance to
6944 switch in assembly mode. */
6945 end_stepping_range (ecs
);
6950 /* Set a breakpoint at callee's return address (the address
6951 at which the caller will resume). */
6952 insert_step_resume_breakpoint_at_caller (frame
);
6958 if (ecs
->event_thread
->control
.step_range_end
== 1)
6960 /* It is stepi or nexti. We always want to stop stepping after
6962 infrun_log_debug ("stepi/nexti");
6963 end_stepping_range (ecs
);
6967 if (stop_pc_sal
.line
== 0)
6969 /* We have no line number information. That means to stop
6970 stepping (does this always happen right after one instruction,
6971 when we do "s" in a function with no line numbers,
6972 or can this happen as a result of a return or longjmp?). */
6973 infrun_log_debug ("line number info");
6974 end_stepping_range (ecs
);
6978 /* Look for "calls" to inlined functions, part one. If the inline
6979 frame machinery detected some skipped call sites, we have entered
6980 a new inline function. */
6982 if (frame_id_eq (get_frame_id (get_current_frame ()),
6983 ecs
->event_thread
->control
.step_frame_id
)
6984 && inline_skipped_frames (ecs
->event_thread
))
6986 infrun_log_debug ("stepped into inlined function");
6988 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
6990 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
6992 /* For "step", we're going to stop. But if the call site
6993 for this inlined function is on the same source line as
6994 we were previously stepping, go down into the function
6995 first. Otherwise stop at the call site. */
6997 if (call_sal
.line
== ecs
->event_thread
->current_line
6998 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7000 step_into_inline_frame (ecs
->event_thread
);
7001 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7008 end_stepping_range (ecs
);
7013 /* For "next", we should stop at the call site if it is on a
7014 different source line. Otherwise continue through the
7015 inlined function. */
7016 if (call_sal
.line
== ecs
->event_thread
->current_line
7017 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7020 end_stepping_range (ecs
);
7025 /* Look for "calls" to inlined functions, part two. If we are still
7026 in the same real function we were stepping through, but we have
7027 to go further up to find the exact frame ID, we are stepping
7028 through a more inlined call beyond its call site. */
7030 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7031 && !frame_id_eq (get_frame_id (get_current_frame ()),
7032 ecs
->event_thread
->control
.step_frame_id
)
7033 && stepped_in_from (get_current_frame (),
7034 ecs
->event_thread
->control
.step_frame_id
))
7036 infrun_log_debug ("stepping through inlined function");
7038 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7039 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7042 end_stepping_range (ecs
);
7046 bool refresh_step_info
= true;
7047 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7048 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7049 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7051 if (stop_pc_sal
.is_stmt
)
7053 /* We are at the start of a different line. So stop. Note that
7054 we don't stop if we step into the middle of a different line.
7055 That is said to make things like for (;;) statements work
7057 infrun_log_debug ("infrun: stepped to a different line\n");
7058 end_stepping_range (ecs
);
7061 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7062 ecs
->event_thread
->control
.step_frame_id
))
7064 /* We are at the start of a different line, however, this line is
7065 not marked as a statement, and we have not changed frame. We
7066 ignore this line table entry, and continue stepping forward,
7067 looking for a better place to stop. */
7068 refresh_step_info
= false;
7069 infrun_log_debug ("infrun: stepped to a different line, but "
7070 "it's not the start of a statement\n");
7074 /* We aren't done stepping.
7076 Optimize by setting the stepping range to the line.
7077 (We might not be in the original line, but if we entered a
7078 new line in mid-statement, we continue stepping. This makes
7079 things like for(;;) statements work better.)
7081 If we entered a SAL that indicates a non-statement line table entry,
7082 then we update the stepping range, but we don't update the step info,
7083 which includes things like the line number we are stepping away from.
7084 This means we will stop when we find a line table entry that is marked
7085 as is-statement, even if it matches the non-statement one we just
7088 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7089 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7090 ecs
->event_thread
->control
.may_range_step
= 1;
7091 if (refresh_step_info
)
7092 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7094 infrun_log_debug ("keep going");
7098 /* In all-stop mode, if we're currently stepping but have stopped in
7099 some other thread, we may need to switch back to the stepped
7100 thread. Returns true we set the inferior running, false if we left
7101 it stopped (and the event needs further processing). */
7104 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7106 if (!target_is_non_stop_p ())
7108 struct thread_info
*stepping_thread
;
7110 /* If any thread is blocked on some internal breakpoint, and we
7111 simply need to step over that breakpoint to get it going
7112 again, do that first. */
7114 /* However, if we see an event for the stepping thread, then we
7115 know all other threads have been moved past their breakpoints
7116 already. Let the caller check whether the step is finished,
7117 etc., before deciding to move it past a breakpoint. */
7118 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7121 /* Check if the current thread is blocked on an incomplete
7122 step-over, interrupted by a random signal. */
7123 if (ecs
->event_thread
->control
.trap_expected
7124 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7126 infrun_log_debug ("need to finish step-over of [%s]",
7127 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7132 /* Check if the current thread is blocked by a single-step
7133 breakpoint of another thread. */
7134 if (ecs
->hit_singlestep_breakpoint
)
7136 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7137 target_pid_to_str (ecs
->ptid
).c_str ());
7142 /* If this thread needs yet another step-over (e.g., stepping
7143 through a delay slot), do it first before moving on to
7145 if (thread_still_needs_step_over (ecs
->event_thread
))
7148 ("thread [%s] still needs step-over",
7149 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7154 /* If scheduler locking applies even if not stepping, there's no
7155 need to walk over threads. Above we've checked whether the
7156 current thread is stepping. If some other thread not the
7157 event thread is stepping, then it must be that scheduler
7158 locking is not in effect. */
7159 if (schedlock_applies (ecs
->event_thread
))
7162 /* Otherwise, we no longer expect a trap in the current thread.
7163 Clear the trap_expected flag before switching back -- this is
7164 what keep_going does as well, if we call it. */
7165 ecs
->event_thread
->control
.trap_expected
= 0;
7167 /* Likewise, clear the signal if it should not be passed. */
7168 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7169 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7171 /* Do all pending step-overs before actually proceeding with
7173 if (start_step_over ())
7175 prepare_to_wait (ecs
);
7179 /* Look for the stepping/nexting thread. */
7180 stepping_thread
= NULL
;
7182 for (thread_info
*tp
: all_non_exited_threads ())
7184 switch_to_thread_no_regs (tp
);
7186 /* Ignore threads of processes the caller is not
7189 && (tp
->inf
->process_target () != ecs
->target
7190 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7193 /* When stepping over a breakpoint, we lock all threads
7194 except the one that needs to move past the breakpoint.
7195 If a non-event thread has this set, the "incomplete
7196 step-over" check above should have caught it earlier. */
7197 if (tp
->control
.trap_expected
)
7199 internal_error (__FILE__
, __LINE__
,
7200 "[%s] has inconsistent state: "
7201 "trap_expected=%d\n",
7202 target_pid_to_str (tp
->ptid
).c_str (),
7203 tp
->control
.trap_expected
);
7206 /* Did we find the stepping thread? */
7207 if (tp
->control
.step_range_end
)
7209 /* Yep. There should only one though. */
7210 gdb_assert (stepping_thread
== NULL
);
7212 /* The event thread is handled at the top, before we
7214 gdb_assert (tp
!= ecs
->event_thread
);
7216 /* If some thread other than the event thread is
7217 stepping, then scheduler locking can't be in effect,
7218 otherwise we wouldn't have resumed the current event
7219 thread in the first place. */
7220 gdb_assert (!schedlock_applies (tp
));
7222 stepping_thread
= tp
;
7226 if (stepping_thread
!= NULL
)
7228 infrun_log_debug ("switching back to stepped thread");
7230 if (keep_going_stepped_thread (stepping_thread
))
7232 prepare_to_wait (ecs
);
7237 switch_to_thread (ecs
->event_thread
);
7243 /* Set a previously stepped thread back to stepping. Returns true on
7244 success, false if the resume is not possible (e.g., the thread
7248 keep_going_stepped_thread (struct thread_info
*tp
)
7250 struct frame_info
*frame
;
7251 struct execution_control_state ecss
;
7252 struct execution_control_state
*ecs
= &ecss
;
7254 /* If the stepping thread exited, then don't try to switch back and
7255 resume it, which could fail in several different ways depending
7256 on the target. Instead, just keep going.
7258 We can find a stepping dead thread in the thread list in two
7261 - The target supports thread exit events, and when the target
7262 tries to delete the thread from the thread list, inferior_ptid
7263 pointed at the exiting thread. In such case, calling
7264 delete_thread does not really remove the thread from the list;
7265 instead, the thread is left listed, with 'exited' state.
7267 - The target's debug interface does not support thread exit
7268 events, and so we have no idea whatsoever if the previously
7269 stepping thread is still alive. For that reason, we need to
7270 synchronously query the target now. */
7272 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7274 infrun_log_debug ("not resuming previously stepped thread, it has "
7281 infrun_log_debug ("resuming previously stepped thread");
7283 reset_ecs (ecs
, tp
);
7284 switch_to_thread (tp
);
7286 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7287 frame
= get_current_frame ();
7289 /* If the PC of the thread we were trying to single-step has
7290 changed, then that thread has trapped or been signaled, but the
7291 event has not been reported to GDB yet. Re-poll the target
7292 looking for this particular thread's event (i.e. temporarily
7293 enable schedlock) by:
7295 - setting a break at the current PC
7296 - resuming that particular thread, only (by setting trap
7299 This prevents us continuously moving the single-step breakpoint
7300 forward, one instruction at a time, overstepping. */
7302 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7306 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7307 paddress (target_gdbarch (), tp
->prev_pc
),
7308 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7310 /* Clear the info of the previous step-over, as it's no longer
7311 valid (if the thread was trying to step over a breakpoint, it
7312 has already succeeded). It's what keep_going would do too,
7313 if we called it. Do this before trying to insert the sss
7314 breakpoint, otherwise if we were previously trying to step
7315 over this exact address in another thread, the breakpoint is
7317 clear_step_over_info ();
7318 tp
->control
.trap_expected
= 0;
7320 insert_single_step_breakpoint (get_frame_arch (frame
),
7321 get_frame_address_space (frame
),
7322 tp
->suspend
.stop_pc
);
7325 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7326 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7330 infrun_log_debug ("expected thread still hasn't advanced");
7332 keep_going_pass_signal (ecs
);
7337 /* Is thread TP in the middle of (software or hardware)
7338 single-stepping? (Note the result of this function must never be
7339 passed directly as target_resume's STEP parameter.) */
7342 currently_stepping (struct thread_info
*tp
)
7344 return ((tp
->control
.step_range_end
7345 && tp
->control
.step_resume_breakpoint
== NULL
)
7346 || tp
->control
.trap_expected
7347 || tp
->stepped_breakpoint
7348 || bpstat_should_step ());
7351 /* Inferior has stepped into a subroutine call with source code that
7352 we should not step over. Do step to the first line of code in
7356 handle_step_into_function (struct gdbarch
*gdbarch
,
7357 struct execution_control_state
*ecs
)
7359 fill_in_stop_func (gdbarch
, ecs
);
7361 compunit_symtab
*cust
7362 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7363 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7364 ecs
->stop_func_start
7365 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7367 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7368 /* Use the step_resume_break to step until the end of the prologue,
7369 even if that involves jumps (as it seems to on the vax under
7371 /* If the prologue ends in the middle of a source line, continue to
7372 the end of that source line (if it is still within the function).
7373 Otherwise, just go to end of prologue. */
7374 if (stop_func_sal
.end
7375 && stop_func_sal
.pc
!= ecs
->stop_func_start
7376 && stop_func_sal
.end
< ecs
->stop_func_end
)
7377 ecs
->stop_func_start
= stop_func_sal
.end
;
7379 /* Architectures which require breakpoint adjustment might not be able
7380 to place a breakpoint at the computed address. If so, the test
7381 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7382 ecs->stop_func_start to an address at which a breakpoint may be
7383 legitimately placed.
7385 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7386 made, GDB will enter an infinite loop when stepping through
7387 optimized code consisting of VLIW instructions which contain
7388 subinstructions corresponding to different source lines. On
7389 FR-V, it's not permitted to place a breakpoint on any but the
7390 first subinstruction of a VLIW instruction. When a breakpoint is
7391 set, GDB will adjust the breakpoint address to the beginning of
7392 the VLIW instruction. Thus, we need to make the corresponding
7393 adjustment here when computing the stop address. */
7395 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7397 ecs
->stop_func_start
7398 = gdbarch_adjust_breakpoint_address (gdbarch
,
7399 ecs
->stop_func_start
);
7402 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7404 /* We are already there: stop now. */
7405 end_stepping_range (ecs
);
7410 /* Put the step-breakpoint there and go until there. */
7411 symtab_and_line sr_sal
;
7412 sr_sal
.pc
= ecs
->stop_func_start
;
7413 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7414 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7416 /* Do not specify what the fp should be when we stop since on
7417 some machines the prologue is where the new fp value is
7419 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7421 /* And make sure stepping stops right away then. */
7422 ecs
->event_thread
->control
.step_range_end
7423 = ecs
->event_thread
->control
.step_range_start
;
7428 /* Inferior has stepped backward into a subroutine call with source
7429 code that we should not step over. Do step to the beginning of the
7430 last line of code in it. */
7433 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7434 struct execution_control_state
*ecs
)
7436 struct compunit_symtab
*cust
;
7437 struct symtab_and_line stop_func_sal
;
7439 fill_in_stop_func (gdbarch
, ecs
);
7441 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7442 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7443 ecs
->stop_func_start
7444 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7446 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7448 /* OK, we're just going to keep stepping here. */
7449 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7451 /* We're there already. Just stop stepping now. */
7452 end_stepping_range (ecs
);
7456 /* Else just reset the step range and keep going.
7457 No step-resume breakpoint, they don't work for
7458 epilogues, which can have multiple entry paths. */
7459 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7460 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7466 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7467 This is used to both functions and to skip over code. */
7470 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7471 struct symtab_and_line sr_sal
,
7472 struct frame_id sr_id
,
7473 enum bptype sr_type
)
7475 /* There should never be more than one step-resume or longjmp-resume
7476 breakpoint per thread, so we should never be setting a new
7477 step_resume_breakpoint when one is already active. */
7478 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7479 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7481 infrun_log_debug ("inserting step-resume breakpoint at %s",
7482 paddress (gdbarch
, sr_sal
.pc
));
7484 inferior_thread ()->control
.step_resume_breakpoint
7485 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7489 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7490 struct symtab_and_line sr_sal
,
7491 struct frame_id sr_id
)
7493 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7498 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7499 This is used to skip a potential signal handler.
7501 This is called with the interrupted function's frame. The signal
7502 handler, when it returns, will resume the interrupted function at
7506 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7508 gdb_assert (return_frame
!= NULL
);
7510 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7512 symtab_and_line sr_sal
;
7513 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7514 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7515 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7517 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7518 get_stack_frame_id (return_frame
),
7522 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7523 is used to skip a function after stepping into it (for "next" or if
7524 the called function has no debugging information).
7526 The current function has almost always been reached by single
7527 stepping a call or return instruction. NEXT_FRAME belongs to the
7528 current function, and the breakpoint will be set at the caller's
7531 This is a separate function rather than reusing
7532 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7533 get_prev_frame, which may stop prematurely (see the implementation
7534 of frame_unwind_caller_id for an example). */
7537 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7539 /* We shouldn't have gotten here if we don't know where the call site
7541 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7543 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7545 symtab_and_line sr_sal
;
7546 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7547 frame_unwind_caller_pc (next_frame
));
7548 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7549 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7551 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7552 frame_unwind_caller_id (next_frame
));
7555 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7556 new breakpoint at the target of a jmp_buf. The handling of
7557 longjmp-resume uses the same mechanisms used for handling
7558 "step-resume" breakpoints. */
7561 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7563 /* There should never be more than one longjmp-resume breakpoint per
7564 thread, so we should never be setting a new
7565 longjmp_resume_breakpoint when one is already active. */
7566 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7568 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7569 paddress (gdbarch
, pc
));
7571 inferior_thread ()->control
.exception_resume_breakpoint
=
7572 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7575 /* Insert an exception resume breakpoint. TP is the thread throwing
7576 the exception. The block B is the block of the unwinder debug hook
7577 function. FRAME is the frame corresponding to the call to this
7578 function. SYM is the symbol of the function argument holding the
7579 target PC of the exception. */
7582 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7583 const struct block
*b
,
7584 struct frame_info
*frame
,
7589 struct block_symbol vsym
;
7590 struct value
*value
;
7592 struct breakpoint
*bp
;
7594 vsym
= lookup_symbol_search_name (sym
->search_name (),
7596 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7597 /* If the value was optimized out, revert to the old behavior. */
7598 if (! value_optimized_out (value
))
7600 handler
= value_as_address (value
);
7602 infrun_log_debug ("exception resume at %lx",
7603 (unsigned long) handler
);
7605 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7607 bp_exception_resume
).release ();
7609 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7612 bp
->thread
= tp
->global_num
;
7613 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7616 catch (const gdb_exception_error
&e
)
7618 /* We want to ignore errors here. */
7622 /* A helper for check_exception_resume that sets an
7623 exception-breakpoint based on a SystemTap probe. */
7626 insert_exception_resume_from_probe (struct thread_info
*tp
,
7627 const struct bound_probe
*probe
,
7628 struct frame_info
*frame
)
7630 struct value
*arg_value
;
7632 struct breakpoint
*bp
;
7634 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7638 handler
= value_as_address (arg_value
);
7640 infrun_log_debug ("exception resume at %s",
7641 paddress (probe
->objfile
->arch (), handler
));
7643 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7644 handler
, bp_exception_resume
).release ();
7645 bp
->thread
= tp
->global_num
;
7646 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7649 /* This is called when an exception has been intercepted. Check to
7650 see whether the exception's destination is of interest, and if so,
7651 set an exception resume breakpoint there. */
7654 check_exception_resume (struct execution_control_state
*ecs
,
7655 struct frame_info
*frame
)
7657 struct bound_probe probe
;
7658 struct symbol
*func
;
7660 /* First see if this exception unwinding breakpoint was set via a
7661 SystemTap probe point. If so, the probe has two arguments: the
7662 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7663 set a breakpoint there. */
7664 probe
= find_probe_by_pc (get_frame_pc (frame
));
7667 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7671 func
= get_frame_function (frame
);
7677 const struct block
*b
;
7678 struct block_iterator iter
;
7682 /* The exception breakpoint is a thread-specific breakpoint on
7683 the unwinder's debug hook, declared as:
7685 void _Unwind_DebugHook (void *cfa, void *handler);
7687 The CFA argument indicates the frame to which control is
7688 about to be transferred. HANDLER is the destination PC.
7690 We ignore the CFA and set a temporary breakpoint at HANDLER.
7691 This is not extremely efficient but it avoids issues in gdb
7692 with computing the DWARF CFA, and it also works even in weird
7693 cases such as throwing an exception from inside a signal
7696 b
= SYMBOL_BLOCK_VALUE (func
);
7697 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7699 if (!SYMBOL_IS_ARGUMENT (sym
))
7706 insert_exception_resume_breakpoint (ecs
->event_thread
,
7712 catch (const gdb_exception_error
&e
)
7718 stop_waiting (struct execution_control_state
*ecs
)
7720 infrun_log_debug ("stop_waiting");
7722 /* Let callers know we don't want to wait for the inferior anymore. */
7723 ecs
->wait_some_more
= 0;
7725 /* If all-stop, but there exists a non-stop target, stop all
7726 threads now that we're presenting the stop to the user. */
7727 if (!non_stop
&& exists_non_stop_target ())
7728 stop_all_threads ();
7731 /* Like keep_going, but passes the signal to the inferior, even if the
7732 signal is set to nopass. */
7735 keep_going_pass_signal (struct execution_control_state
*ecs
)
7737 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7738 gdb_assert (!ecs
->event_thread
->resumed
);
7740 /* Save the pc before execution, to compare with pc after stop. */
7741 ecs
->event_thread
->prev_pc
7742 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7744 if (ecs
->event_thread
->control
.trap_expected
)
7746 struct thread_info
*tp
= ecs
->event_thread
;
7748 infrun_log_debug ("%s has trap_expected set, "
7749 "resuming to collect trap",
7750 target_pid_to_str (tp
->ptid
).c_str ());
7752 /* We haven't yet gotten our trap, and either: intercepted a
7753 non-signal event (e.g., a fork); or took a signal which we
7754 are supposed to pass through to the inferior. Simply
7756 resume (ecs
->event_thread
->suspend
.stop_signal
);
7758 else if (step_over_info_valid_p ())
7760 /* Another thread is stepping over a breakpoint in-line. If
7761 this thread needs a step-over too, queue the request. In
7762 either case, this resume must be deferred for later. */
7763 struct thread_info
*tp
= ecs
->event_thread
;
7765 if (ecs
->hit_singlestep_breakpoint
7766 || thread_still_needs_step_over (tp
))
7768 infrun_log_debug ("step-over already in progress: "
7769 "step-over for %s deferred",
7770 target_pid_to_str (tp
->ptid
).c_str ());
7771 global_thread_step_over_chain_enqueue (tp
);
7775 infrun_log_debug ("step-over in progress: resume of %s deferred",
7776 target_pid_to_str (tp
->ptid
).c_str ());
7781 struct regcache
*regcache
= get_current_regcache ();
7784 step_over_what step_what
;
7786 /* Either the trap was not expected, but we are continuing
7787 anyway (if we got a signal, the user asked it be passed to
7790 We got our expected trap, but decided we should resume from
7793 We're going to run this baby now!
7795 Note that insert_breakpoints won't try to re-insert
7796 already inserted breakpoints. Therefore, we don't
7797 care if breakpoints were already inserted, or not. */
7799 /* If we need to step over a breakpoint, and we're not using
7800 displaced stepping to do so, insert all breakpoints
7801 (watchpoints, etc.) but the one we're stepping over, step one
7802 instruction, and then re-insert the breakpoint when that step
7805 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7807 remove_bp
= (ecs
->hit_singlestep_breakpoint
7808 || (step_what
& STEP_OVER_BREAKPOINT
));
7809 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7811 /* We can't use displaced stepping if we need to step past a
7812 watchpoint. The instruction copied to the scratch pad would
7813 still trigger the watchpoint. */
7815 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7817 set_step_over_info (regcache
->aspace (),
7818 regcache_read_pc (regcache
), remove_wps
,
7819 ecs
->event_thread
->global_num
);
7821 else if (remove_wps
)
7822 set_step_over_info (NULL
, 0, remove_wps
, -1);
7824 /* If we now need to do an in-line step-over, we need to stop
7825 all other threads. Note this must be done before
7826 insert_breakpoints below, because that removes the breakpoint
7827 we're about to step over, otherwise other threads could miss
7829 if (step_over_info_valid_p () && target_is_non_stop_p ())
7830 stop_all_threads ();
7832 /* Stop stepping if inserting breakpoints fails. */
7835 insert_breakpoints ();
7837 catch (const gdb_exception_error
&e
)
7839 exception_print (gdb_stderr
, e
);
7841 clear_step_over_info ();
7845 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7847 resume (ecs
->event_thread
->suspend
.stop_signal
);
7850 prepare_to_wait (ecs
);
7853 /* Called when we should continue running the inferior, because the
7854 current event doesn't cause a user visible stop. This does the
7855 resuming part; waiting for the next event is done elsewhere. */
7858 keep_going (struct execution_control_state
*ecs
)
7860 if (ecs
->event_thread
->control
.trap_expected
7861 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7862 ecs
->event_thread
->control
.trap_expected
= 0;
7864 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7865 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7866 keep_going_pass_signal (ecs
);
7869 /* This function normally comes after a resume, before
7870 handle_inferior_event exits. It takes care of any last bits of
7871 housekeeping, and sets the all-important wait_some_more flag. */
7874 prepare_to_wait (struct execution_control_state
*ecs
)
7876 infrun_log_debug ("prepare_to_wait");
7878 ecs
->wait_some_more
= 1;
7880 if (!target_is_async_p ())
7881 mark_infrun_async_event_handler ();
7884 /* We are done with the step range of a step/next/si/ni command.
7885 Called once for each n of a "step n" operation. */
7888 end_stepping_range (struct execution_control_state
*ecs
)
7890 ecs
->event_thread
->control
.stop_step
= 1;
7894 /* Several print_*_reason functions to print why the inferior has stopped.
7895 We always print something when the inferior exits, or receives a signal.
7896 The rest of the cases are dealt with later on in normal_stop and
7897 print_it_typical. Ideally there should be a call to one of these
7898 print_*_reason functions functions from handle_inferior_event each time
7899 stop_waiting is called.
7901 Note that we don't call these directly, instead we delegate that to
7902 the interpreters, through observers. Interpreters then call these
7903 with whatever uiout is right. */
7906 print_end_stepping_range_reason (struct ui_out
*uiout
)
7908 /* For CLI-like interpreters, print nothing. */
7910 if (uiout
->is_mi_like_p ())
7912 uiout
->field_string ("reason",
7913 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7918 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7920 annotate_signalled ();
7921 if (uiout
->is_mi_like_p ())
7923 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7924 uiout
->text ("\nProgram terminated with signal ");
7925 annotate_signal_name ();
7926 uiout
->field_string ("signal-name",
7927 gdb_signal_to_name (siggnal
));
7928 annotate_signal_name_end ();
7930 annotate_signal_string ();
7931 uiout
->field_string ("signal-meaning",
7932 gdb_signal_to_string (siggnal
));
7933 annotate_signal_string_end ();
7934 uiout
->text (".\n");
7935 uiout
->text ("The program no longer exists.\n");
7939 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7941 struct inferior
*inf
= current_inferior ();
7942 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7944 annotate_exited (exitstatus
);
7947 if (uiout
->is_mi_like_p ())
7948 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7949 std::string exit_code_str
7950 = string_printf ("0%o", (unsigned int) exitstatus
);
7951 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7952 plongest (inf
->num
), pidstr
.c_str (),
7953 string_field ("exit-code", exit_code_str
.c_str ()));
7957 if (uiout
->is_mi_like_p ())
7959 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7960 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7961 plongest (inf
->num
), pidstr
.c_str ());
7965 /* Some targets/architectures can do extra processing/display of
7966 segmentation faults. E.g., Intel MPX boundary faults.
7967 Call the architecture dependent function to handle the fault. */
7970 handle_segmentation_fault (struct ui_out
*uiout
)
7972 struct regcache
*regcache
= get_current_regcache ();
7973 struct gdbarch
*gdbarch
= regcache
->arch ();
7975 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7976 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7980 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7982 struct thread_info
*thr
= inferior_thread ();
7986 if (uiout
->is_mi_like_p ())
7988 else if (show_thread_that_caused_stop ())
7992 uiout
->text ("\nThread ");
7993 uiout
->field_string ("thread-id", print_thread_id (thr
));
7995 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
7998 uiout
->text (" \"");
7999 uiout
->field_string ("name", name
);
8004 uiout
->text ("\nProgram");
8006 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8007 uiout
->text (" stopped");
8010 uiout
->text (" received signal ");
8011 annotate_signal_name ();
8012 if (uiout
->is_mi_like_p ())
8014 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8015 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8016 annotate_signal_name_end ();
8018 annotate_signal_string ();
8019 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8021 if (siggnal
== GDB_SIGNAL_SEGV
)
8022 handle_segmentation_fault (uiout
);
8024 annotate_signal_string_end ();
8026 uiout
->text (".\n");
8030 print_no_history_reason (struct ui_out
*uiout
)
8032 uiout
->text ("\nNo more reverse-execution history.\n");
8035 /* Print current location without a level number, if we have changed
8036 functions or hit a breakpoint. Print source line if we have one.
8037 bpstat_print contains the logic deciding in detail what to print,
8038 based on the event(s) that just occurred. */
8041 print_stop_location (struct target_waitstatus
*ws
)
8044 enum print_what source_flag
;
8045 int do_frame_printing
= 1;
8046 struct thread_info
*tp
= inferior_thread ();
8048 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8052 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8053 should) carry around the function and does (or should) use
8054 that when doing a frame comparison. */
8055 if (tp
->control
.stop_step
8056 && frame_id_eq (tp
->control
.step_frame_id
,
8057 get_frame_id (get_current_frame ()))
8058 && (tp
->control
.step_start_function
8059 == find_pc_function (tp
->suspend
.stop_pc
)))
8061 /* Finished step, just print source line. */
8062 source_flag
= SRC_LINE
;
8066 /* Print location and source line. */
8067 source_flag
= SRC_AND_LOC
;
8070 case PRINT_SRC_AND_LOC
:
8071 /* Print location and source line. */
8072 source_flag
= SRC_AND_LOC
;
8074 case PRINT_SRC_ONLY
:
8075 source_flag
= SRC_LINE
;
8078 /* Something bogus. */
8079 source_flag
= SRC_LINE
;
8080 do_frame_printing
= 0;
8083 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8086 /* The behavior of this routine with respect to the source
8088 SRC_LINE: Print only source line
8089 LOCATION: Print only location
8090 SRC_AND_LOC: Print location and source line. */
8091 if (do_frame_printing
)
8092 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8098 print_stop_event (struct ui_out
*uiout
, bool displays
)
8100 struct target_waitstatus last
;
8101 struct thread_info
*tp
;
8103 get_last_target_status (nullptr, nullptr, &last
);
8106 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8108 print_stop_location (&last
);
8110 /* Display the auto-display expressions. */
8115 tp
= inferior_thread ();
8116 if (tp
->thread_fsm
!= NULL
8117 && tp
->thread_fsm
->finished_p ())
8119 struct return_value_info
*rv
;
8121 rv
= tp
->thread_fsm
->return_value ();
8123 print_return_value (uiout
, rv
);
8130 maybe_remove_breakpoints (void)
8132 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8134 if (remove_breakpoints ())
8136 target_terminal::ours_for_output ();
8137 printf_filtered (_("Cannot remove breakpoints because "
8138 "program is no longer writable.\nFurther "
8139 "execution is probably impossible.\n"));
8144 /* The execution context that just caused a normal stop. */
8151 DISABLE_COPY_AND_ASSIGN (stop_context
);
8153 bool changed () const;
8158 /* The event PTID. */
8162 /* If stopp for a thread event, this is the thread that caused the
8164 struct thread_info
*thread
;
8166 /* The inferior that caused the stop. */
8170 /* Initializes a new stop context. If stopped for a thread event, this
8171 takes a strong reference to the thread. */
8173 stop_context::stop_context ()
8175 stop_id
= get_stop_id ();
8176 ptid
= inferior_ptid
;
8177 inf_num
= current_inferior ()->num
;
8179 if (inferior_ptid
!= null_ptid
)
8181 /* Take a strong reference so that the thread can't be deleted
8183 thread
= inferior_thread ();
8190 /* Release a stop context previously created with save_stop_context.
8191 Releases the strong reference to the thread as well. */
8193 stop_context::~stop_context ()
8199 /* Return true if the current context no longer matches the saved stop
8203 stop_context::changed () const
8205 if (ptid
!= inferior_ptid
)
8207 if (inf_num
!= current_inferior ()->num
)
8209 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8211 if (get_stop_id () != stop_id
)
8221 struct target_waitstatus last
;
8223 get_last_target_status (nullptr, nullptr, &last
);
8227 /* If an exception is thrown from this point on, make sure to
8228 propagate GDB's knowledge of the executing state to the
8229 frontend/user running state. A QUIT is an easy exception to see
8230 here, so do this before any filtered output. */
8232 ptid_t finish_ptid
= null_ptid
;
8235 finish_ptid
= minus_one_ptid
;
8236 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8237 || last
.kind
== TARGET_WAITKIND_EXITED
)
8239 /* On some targets, we may still have live threads in the
8240 inferior when we get a process exit event. E.g., for
8241 "checkpoint", when the current checkpoint/fork exits,
8242 linux-fork.c automatically switches to another fork from
8243 within target_mourn_inferior. */
8244 if (inferior_ptid
!= null_ptid
)
8245 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8247 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8248 finish_ptid
= inferior_ptid
;
8250 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8251 if (finish_ptid
!= null_ptid
)
8253 maybe_finish_thread_state
.emplace
8254 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8257 /* As we're presenting a stop, and potentially removing breakpoints,
8258 update the thread list so we can tell whether there are threads
8259 running on the target. With target remote, for example, we can
8260 only learn about new threads when we explicitly update the thread
8261 list. Do this before notifying the interpreters about signal
8262 stops, end of stepping ranges, etc., so that the "new thread"
8263 output is emitted before e.g., "Program received signal FOO",
8264 instead of after. */
8265 update_thread_list ();
8267 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8268 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8270 /* As with the notification of thread events, we want to delay
8271 notifying the user that we've switched thread context until
8272 the inferior actually stops.
8274 There's no point in saying anything if the inferior has exited.
8275 Note that SIGNALLED here means "exited with a signal", not
8276 "received a signal".
8278 Also skip saying anything in non-stop mode. In that mode, as we
8279 don't want GDB to switch threads behind the user's back, to avoid
8280 races where the user is typing a command to apply to thread x,
8281 but GDB switches to thread y before the user finishes entering
8282 the command, fetch_inferior_event installs a cleanup to restore
8283 the current thread back to the thread the user had selected right
8284 after this event is handled, so we're not really switching, only
8285 informing of a stop. */
8287 && previous_inferior_ptid
!= inferior_ptid
8288 && target_has_execution
8289 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8290 && last
.kind
!= TARGET_WAITKIND_EXITED
8291 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8293 SWITCH_THRU_ALL_UIS ()
8295 target_terminal::ours_for_output ();
8296 printf_filtered (_("[Switching to %s]\n"),
8297 target_pid_to_str (inferior_ptid
).c_str ());
8298 annotate_thread_changed ();
8300 previous_inferior_ptid
= inferior_ptid
;
8303 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8305 SWITCH_THRU_ALL_UIS ()
8306 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8308 target_terminal::ours_for_output ();
8309 printf_filtered (_("No unwaited-for children left.\n"));
8313 /* Note: this depends on the update_thread_list call above. */
8314 maybe_remove_breakpoints ();
8316 /* If an auto-display called a function and that got a signal,
8317 delete that auto-display to avoid an infinite recursion. */
8319 if (stopped_by_random_signal
)
8320 disable_current_display ();
8322 SWITCH_THRU_ALL_UIS ()
8324 async_enable_stdin ();
8327 /* Let the user/frontend see the threads as stopped. */
8328 maybe_finish_thread_state
.reset ();
8330 /* Select innermost stack frame - i.e., current frame is frame 0,
8331 and current location is based on that. Handle the case where the
8332 dummy call is returning after being stopped. E.g. the dummy call
8333 previously hit a breakpoint. (If the dummy call returns
8334 normally, we won't reach here.) Do this before the stop hook is
8335 run, so that it doesn't get to see the temporary dummy frame,
8336 which is not where we'll present the stop. */
8337 if (has_stack_frames ())
8339 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8341 /* Pop the empty frame that contains the stack dummy. This
8342 also restores inferior state prior to the call (struct
8343 infcall_suspend_state). */
8344 struct frame_info
*frame
= get_current_frame ();
8346 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8348 /* frame_pop calls reinit_frame_cache as the last thing it
8349 does which means there's now no selected frame. */
8352 select_frame (get_current_frame ());
8354 /* Set the current source location. */
8355 set_current_sal_from_frame (get_current_frame ());
8358 /* Look up the hook_stop and run it (CLI internally handles problem
8359 of stop_command's pre-hook not existing). */
8360 if (stop_command
!= NULL
)
8362 stop_context saved_context
;
8366 execute_cmd_pre_hook (stop_command
);
8368 catch (const gdb_exception
&ex
)
8370 exception_fprintf (gdb_stderr
, ex
,
8371 "Error while running hook_stop:\n");
8374 /* If the stop hook resumes the target, then there's no point in
8375 trying to notify about the previous stop; its context is
8376 gone. Likewise if the command switches thread or inferior --
8377 the observers would print a stop for the wrong
8379 if (saved_context
.changed ())
8383 /* Notify observers about the stop. This is where the interpreters
8384 print the stop event. */
8385 if (inferior_ptid
!= null_ptid
)
8386 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8389 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8391 annotate_stopped ();
8393 if (target_has_execution
)
8395 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8396 && last
.kind
!= TARGET_WAITKIND_EXITED
8397 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8398 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8399 Delete any breakpoint that is to be deleted at the next stop. */
8400 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8403 /* Try to get rid of automatically added inferiors that are no
8404 longer needed. Keeping those around slows down things linearly.
8405 Note that this never removes the current inferior. */
8412 signal_stop_state (int signo
)
8414 return signal_stop
[signo
];
8418 signal_print_state (int signo
)
8420 return signal_print
[signo
];
8424 signal_pass_state (int signo
)
8426 return signal_program
[signo
];
8430 signal_cache_update (int signo
)
8434 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8435 signal_cache_update (signo
);
8440 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8441 && signal_print
[signo
] == 0
8442 && signal_program
[signo
] == 1
8443 && signal_catch
[signo
] == 0);
8447 signal_stop_update (int signo
, int state
)
8449 int ret
= signal_stop
[signo
];
8451 signal_stop
[signo
] = state
;
8452 signal_cache_update (signo
);
8457 signal_print_update (int signo
, int state
)
8459 int ret
= signal_print
[signo
];
8461 signal_print
[signo
] = state
;
8462 signal_cache_update (signo
);
8467 signal_pass_update (int signo
, int state
)
8469 int ret
= signal_program
[signo
];
8471 signal_program
[signo
] = state
;
8472 signal_cache_update (signo
);
8476 /* Update the global 'signal_catch' from INFO and notify the
8480 signal_catch_update (const unsigned int *info
)
8484 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8485 signal_catch
[i
] = info
[i
] > 0;
8486 signal_cache_update (-1);
8487 target_pass_signals (signal_pass
);
8491 sig_print_header (void)
8493 printf_filtered (_("Signal Stop\tPrint\tPass "
8494 "to program\tDescription\n"));
8498 sig_print_info (enum gdb_signal oursig
)
8500 const char *name
= gdb_signal_to_name (oursig
);
8501 int name_padding
= 13 - strlen (name
);
8503 if (name_padding
<= 0)
8506 printf_filtered ("%s", name
);
8507 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8508 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8509 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8510 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8511 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8514 /* Specify how various signals in the inferior should be handled. */
8517 handle_command (const char *args
, int from_tty
)
8519 int digits
, wordlen
;
8520 int sigfirst
, siglast
;
8521 enum gdb_signal oursig
;
8526 error_no_arg (_("signal to handle"));
8529 /* Allocate and zero an array of flags for which signals to handle. */
8531 const size_t nsigs
= GDB_SIGNAL_LAST
;
8532 unsigned char sigs
[nsigs
] {};
8534 /* Break the command line up into args. */
8536 gdb_argv
built_argv (args
);
8538 /* Walk through the args, looking for signal oursigs, signal names, and
8539 actions. Signal numbers and signal names may be interspersed with
8540 actions, with the actions being performed for all signals cumulatively
8541 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8543 for (char *arg
: built_argv
)
8545 wordlen
= strlen (arg
);
8546 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8550 sigfirst
= siglast
= -1;
8552 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8554 /* Apply action to all signals except those used by the
8555 debugger. Silently skip those. */
8558 siglast
= nsigs
- 1;
8560 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8562 SET_SIGS (nsigs
, sigs
, signal_stop
);
8563 SET_SIGS (nsigs
, sigs
, signal_print
);
8565 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8567 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8569 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8571 SET_SIGS (nsigs
, sigs
, signal_print
);
8573 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8575 SET_SIGS (nsigs
, sigs
, signal_program
);
8577 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8579 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8581 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8583 SET_SIGS (nsigs
, sigs
, signal_program
);
8585 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8587 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8588 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8590 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8592 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8594 else if (digits
> 0)
8596 /* It is numeric. The numeric signal refers to our own
8597 internal signal numbering from target.h, not to host/target
8598 signal number. This is a feature; users really should be
8599 using symbolic names anyway, and the common ones like
8600 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8602 sigfirst
= siglast
= (int)
8603 gdb_signal_from_command (atoi (arg
));
8604 if (arg
[digits
] == '-')
8607 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8609 if (sigfirst
> siglast
)
8611 /* Bet he didn't figure we'd think of this case... */
8612 std::swap (sigfirst
, siglast
);
8617 oursig
= gdb_signal_from_name (arg
);
8618 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8620 sigfirst
= siglast
= (int) oursig
;
8624 /* Not a number and not a recognized flag word => complain. */
8625 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8629 /* If any signal numbers or symbol names were found, set flags for
8630 which signals to apply actions to. */
8632 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8634 switch ((enum gdb_signal
) signum
)
8636 case GDB_SIGNAL_TRAP
:
8637 case GDB_SIGNAL_INT
:
8638 if (!allsigs
&& !sigs
[signum
])
8640 if (query (_("%s is used by the debugger.\n\
8641 Are you sure you want to change it? "),
8642 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8647 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8651 case GDB_SIGNAL_DEFAULT
:
8652 case GDB_SIGNAL_UNKNOWN
:
8653 /* Make sure that "all" doesn't print these. */
8662 for (int signum
= 0; signum
< nsigs
; signum
++)
8665 signal_cache_update (-1);
8666 target_pass_signals (signal_pass
);
8667 target_program_signals (signal_program
);
8671 /* Show the results. */
8672 sig_print_header ();
8673 for (; signum
< nsigs
; signum
++)
8675 sig_print_info ((enum gdb_signal
) signum
);
8682 /* Complete the "handle" command. */
8685 handle_completer (struct cmd_list_element
*ignore
,
8686 completion_tracker
&tracker
,
8687 const char *text
, const char *word
)
8689 static const char * const keywords
[] =
8703 signal_completer (ignore
, tracker
, text
, word
);
8704 complete_on_enum (tracker
, keywords
, word
, word
);
8708 gdb_signal_from_command (int num
)
8710 if (num
>= 1 && num
<= 15)
8711 return (enum gdb_signal
) num
;
8712 error (_("Only signals 1-15 are valid as numeric signals.\n\
8713 Use \"info signals\" for a list of symbolic signals."));
8716 /* Print current contents of the tables set by the handle command.
8717 It is possible we should just be printing signals actually used
8718 by the current target (but for things to work right when switching
8719 targets, all signals should be in the signal tables). */
8722 info_signals_command (const char *signum_exp
, int from_tty
)
8724 enum gdb_signal oursig
;
8726 sig_print_header ();
8730 /* First see if this is a symbol name. */
8731 oursig
= gdb_signal_from_name (signum_exp
);
8732 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8734 /* No, try numeric. */
8736 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8738 sig_print_info (oursig
);
8742 printf_filtered ("\n");
8743 /* These ugly casts brought to you by the native VAX compiler. */
8744 for (oursig
= GDB_SIGNAL_FIRST
;
8745 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8746 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8750 if (oursig
!= GDB_SIGNAL_UNKNOWN
8751 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8752 sig_print_info (oursig
);
8755 printf_filtered (_("\nUse the \"handle\" command "
8756 "to change these tables.\n"));
8759 /* The $_siginfo convenience variable is a bit special. We don't know
8760 for sure the type of the value until we actually have a chance to
8761 fetch the data. The type can change depending on gdbarch, so it is
8762 also dependent on which thread you have selected.
8764 1. making $_siginfo be an internalvar that creates a new value on
8767 2. making the value of $_siginfo be an lval_computed value. */
8769 /* This function implements the lval_computed support for reading a
8773 siginfo_value_read (struct value
*v
)
8775 LONGEST transferred
;
8777 /* If we can access registers, so can we access $_siginfo. Likewise
8779 validate_registers_access ();
8782 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8784 value_contents_all_raw (v
),
8786 TYPE_LENGTH (value_type (v
)));
8788 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8789 error (_("Unable to read siginfo"));
8792 /* This function implements the lval_computed support for writing a
8796 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8798 LONGEST transferred
;
8800 /* If we can access registers, so can we access $_siginfo. Likewise
8802 validate_registers_access ();
8804 transferred
= target_write (current_top_target (),
8805 TARGET_OBJECT_SIGNAL_INFO
,
8807 value_contents_all_raw (fromval
),
8809 TYPE_LENGTH (value_type (fromval
)));
8811 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8812 error (_("Unable to write siginfo"));
8815 static const struct lval_funcs siginfo_value_funcs
=
8821 /* Return a new value with the correct type for the siginfo object of
8822 the current thread using architecture GDBARCH. Return a void value
8823 if there's no object available. */
8825 static struct value
*
8826 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8829 if (target_has_stack
8830 && inferior_ptid
!= null_ptid
8831 && gdbarch_get_siginfo_type_p (gdbarch
))
8833 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8835 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8838 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8842 /* infcall_suspend_state contains state about the program itself like its
8843 registers and any signal it received when it last stopped.
8844 This state must be restored regardless of how the inferior function call
8845 ends (either successfully, or after it hits a breakpoint or signal)
8846 if the program is to properly continue where it left off. */
8848 class infcall_suspend_state
8851 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8852 once the inferior function call has finished. */
8853 infcall_suspend_state (struct gdbarch
*gdbarch
,
8854 const struct thread_info
*tp
,
8855 struct regcache
*regcache
)
8856 : m_thread_suspend (tp
->suspend
),
8857 m_registers (new readonly_detached_regcache (*regcache
))
8859 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8861 if (gdbarch_get_siginfo_type_p (gdbarch
))
8863 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8864 size_t len
= TYPE_LENGTH (type
);
8866 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8868 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8869 siginfo_data
.get (), 0, len
) != len
)
8871 /* Errors ignored. */
8872 siginfo_data
.reset (nullptr);
8878 m_siginfo_gdbarch
= gdbarch
;
8879 m_siginfo_data
= std::move (siginfo_data
);
8883 /* Return a pointer to the stored register state. */
8885 readonly_detached_regcache
*registers () const
8887 return m_registers
.get ();
8890 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8892 void restore (struct gdbarch
*gdbarch
,
8893 struct thread_info
*tp
,
8894 struct regcache
*regcache
) const
8896 tp
->suspend
= m_thread_suspend
;
8898 if (m_siginfo_gdbarch
== gdbarch
)
8900 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8902 /* Errors ignored. */
8903 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8904 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8907 /* The inferior can be gone if the user types "print exit(0)"
8908 (and perhaps other times). */
8909 if (target_has_execution
)
8910 /* NB: The register write goes through to the target. */
8911 regcache
->restore (registers ());
8915 /* How the current thread stopped before the inferior function call was
8917 struct thread_suspend_state m_thread_suspend
;
8919 /* The registers before the inferior function call was executed. */
8920 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8922 /* Format of SIGINFO_DATA or NULL if it is not present. */
8923 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8925 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8926 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8927 content would be invalid. */
8928 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8931 infcall_suspend_state_up
8932 save_infcall_suspend_state ()
8934 struct thread_info
*tp
= inferior_thread ();
8935 struct regcache
*regcache
= get_current_regcache ();
8936 struct gdbarch
*gdbarch
= regcache
->arch ();
8938 infcall_suspend_state_up inf_state
8939 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8941 /* Having saved the current state, adjust the thread state, discarding
8942 any stop signal information. The stop signal is not useful when
8943 starting an inferior function call, and run_inferior_call will not use
8944 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8945 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8950 /* Restore inferior session state to INF_STATE. */
8953 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8955 struct thread_info
*tp
= inferior_thread ();
8956 struct regcache
*regcache
= get_current_regcache ();
8957 struct gdbarch
*gdbarch
= regcache
->arch ();
8959 inf_state
->restore (gdbarch
, tp
, regcache
);
8960 discard_infcall_suspend_state (inf_state
);
8964 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8969 readonly_detached_regcache
*
8970 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8972 return inf_state
->registers ();
8975 /* infcall_control_state contains state regarding gdb's control of the
8976 inferior itself like stepping control. It also contains session state like
8977 the user's currently selected frame. */
8979 struct infcall_control_state
8981 struct thread_control_state thread_control
;
8982 struct inferior_control_state inferior_control
;
8985 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8986 int stopped_by_random_signal
= 0;
8988 /* ID if the selected frame when the inferior function call was made. */
8989 struct frame_id selected_frame_id
{};
8992 /* Save all of the information associated with the inferior<==>gdb
8995 infcall_control_state_up
8996 save_infcall_control_state ()
8998 infcall_control_state_up
inf_status (new struct infcall_control_state
);
8999 struct thread_info
*tp
= inferior_thread ();
9000 struct inferior
*inf
= current_inferior ();
9002 inf_status
->thread_control
= tp
->control
;
9003 inf_status
->inferior_control
= inf
->control
;
9005 tp
->control
.step_resume_breakpoint
= NULL
;
9006 tp
->control
.exception_resume_breakpoint
= NULL
;
9008 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9009 chain. If caller's caller is walking the chain, they'll be happier if we
9010 hand them back the original chain when restore_infcall_control_state is
9012 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9015 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9016 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9018 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9024 restore_selected_frame (const frame_id
&fid
)
9026 frame_info
*frame
= frame_find_by_id (fid
);
9028 /* If inf_status->selected_frame_id is NULL, there was no previously
9032 warning (_("Unable to restore previously selected frame."));
9036 select_frame (frame
);
9039 /* Restore inferior session state to INF_STATUS. */
9042 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9044 struct thread_info
*tp
= inferior_thread ();
9045 struct inferior
*inf
= current_inferior ();
9047 if (tp
->control
.step_resume_breakpoint
)
9048 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9050 if (tp
->control
.exception_resume_breakpoint
)
9051 tp
->control
.exception_resume_breakpoint
->disposition
9052 = disp_del_at_next_stop
;
9054 /* Handle the bpstat_copy of the chain. */
9055 bpstat_clear (&tp
->control
.stop_bpstat
);
9057 tp
->control
= inf_status
->thread_control
;
9058 inf
->control
= inf_status
->inferior_control
;
9061 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9062 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9064 if (target_has_stack
)
9066 /* The point of the try/catch is that if the stack is clobbered,
9067 walking the stack might encounter a garbage pointer and
9068 error() trying to dereference it. */
9071 restore_selected_frame (inf_status
->selected_frame_id
);
9073 catch (const gdb_exception_error
&ex
)
9075 exception_fprintf (gdb_stderr
, ex
,
9076 "Unable to restore previously selected frame:\n");
9077 /* Error in restoring the selected frame. Select the
9079 select_frame (get_current_frame ());
9087 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9089 if (inf_status
->thread_control
.step_resume_breakpoint
)
9090 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9091 = disp_del_at_next_stop
;
9093 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9094 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9095 = disp_del_at_next_stop
;
9097 /* See save_infcall_control_state for info on stop_bpstat. */
9098 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9106 clear_exit_convenience_vars (void)
9108 clear_internalvar (lookup_internalvar ("_exitsignal"));
9109 clear_internalvar (lookup_internalvar ("_exitcode"));
9113 /* User interface for reverse debugging:
9114 Set exec-direction / show exec-direction commands
9115 (returns error unless target implements to_set_exec_direction method). */
9117 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9118 static const char exec_forward
[] = "forward";
9119 static const char exec_reverse
[] = "reverse";
9120 static const char *exec_direction
= exec_forward
;
9121 static const char *const exec_direction_names
[] = {
9128 set_exec_direction_func (const char *args
, int from_tty
,
9129 struct cmd_list_element
*cmd
)
9131 if (target_can_execute_reverse
)
9133 if (!strcmp (exec_direction
, exec_forward
))
9134 execution_direction
= EXEC_FORWARD
;
9135 else if (!strcmp (exec_direction
, exec_reverse
))
9136 execution_direction
= EXEC_REVERSE
;
9140 exec_direction
= exec_forward
;
9141 error (_("Target does not support this operation."));
9146 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9147 struct cmd_list_element
*cmd
, const char *value
)
9149 switch (execution_direction
) {
9151 fprintf_filtered (out
, _("Forward.\n"));
9154 fprintf_filtered (out
, _("Reverse.\n"));
9157 internal_error (__FILE__
, __LINE__
,
9158 _("bogus execution_direction value: %d"),
9159 (int) execution_direction
);
9164 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9165 struct cmd_list_element
*c
, const char *value
)
9167 fprintf_filtered (file
, _("Resuming the execution of threads "
9168 "of all processes is %s.\n"), value
);
9171 /* Implementation of `siginfo' variable. */
9173 static const struct internalvar_funcs siginfo_funcs
=
9180 /* Callback for infrun's target events source. This is marked when a
9181 thread has a pending status to process. */
9184 infrun_async_inferior_event_handler (gdb_client_data data
)
9186 inferior_event_handler (INF_REG_EVENT
, NULL
);
9189 void _initialize_infrun ();
9191 _initialize_infrun ()
9193 struct cmd_list_element
*c
;
9195 /* Register extra event sources in the event loop. */
9196 infrun_async_inferior_event_token
9197 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9199 add_info ("signals", info_signals_command
, _("\
9200 What debugger does when program gets various signals.\n\
9201 Specify a signal as argument to print info on that signal only."));
9202 add_info_alias ("handle", "signals", 0);
9204 c
= add_com ("handle", class_run
, handle_command
, _("\
9205 Specify how to handle signals.\n\
9206 Usage: handle SIGNAL [ACTIONS]\n\
9207 Args are signals and actions to apply to those signals.\n\
9208 If no actions are specified, the current settings for the specified signals\n\
9209 will be displayed instead.\n\
9211 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9212 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9213 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9214 The special arg \"all\" is recognized to mean all signals except those\n\
9215 used by the debugger, typically SIGTRAP and SIGINT.\n\
9217 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9218 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9219 Stop means reenter debugger if this signal happens (implies print).\n\
9220 Print means print a message if this signal happens.\n\
9221 Pass means let program see this signal; otherwise program doesn't know.\n\
9222 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9223 Pass and Stop may be combined.\n\
9225 Multiple signals may be specified. Signal numbers and signal names\n\
9226 may be interspersed with actions, with the actions being performed for\n\
9227 all signals cumulatively specified."));
9228 set_cmd_completer (c
, handle_completer
);
9231 stop_command
= add_cmd ("stop", class_obscure
,
9232 not_just_help_class_command
, _("\
9233 There is no `stop' command, but you can set a hook on `stop'.\n\
9234 This allows you to set a list of commands to be run each time execution\n\
9235 of the program stops."), &cmdlist
);
9237 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9238 Set inferior debugging."), _("\
9239 Show inferior debugging."), _("\
9240 When non-zero, inferior specific debugging is enabled."),
9243 &setdebuglist
, &showdebuglist
);
9245 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9246 &debug_displaced
, _("\
9247 Set displaced stepping debugging."), _("\
9248 Show displaced stepping debugging."), _("\
9249 When non-zero, displaced stepping specific debugging is enabled."),
9251 show_debug_displaced
,
9252 &setdebuglist
, &showdebuglist
);
9254 add_setshow_boolean_cmd ("non-stop", no_class
,
9256 Set whether gdb controls the inferior in non-stop mode."), _("\
9257 Show whether gdb controls the inferior in non-stop mode."), _("\
9258 When debugging a multi-threaded program and this setting is\n\
9259 off (the default, also called all-stop mode), when one thread stops\n\
9260 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9261 all other threads in the program while you interact with the thread of\n\
9262 interest. When you continue or step a thread, you can allow the other\n\
9263 threads to run, or have them remain stopped, but while you inspect any\n\
9264 thread's state, all threads stop.\n\
9266 In non-stop mode, when one thread stops, other threads can continue\n\
9267 to run freely. You'll be able to step each thread independently,\n\
9268 leave it stopped or free to run as needed."),
9274 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9277 signal_print
[i
] = 1;
9278 signal_program
[i
] = 1;
9279 signal_catch
[i
] = 0;
9282 /* Signals caused by debugger's own actions should not be given to
9283 the program afterwards.
9285 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9286 explicitly specifies that it should be delivered to the target
9287 program. Typically, that would occur when a user is debugging a
9288 target monitor on a simulator: the target monitor sets a
9289 breakpoint; the simulator encounters this breakpoint and halts
9290 the simulation handing control to GDB; GDB, noting that the stop
9291 address doesn't map to any known breakpoint, returns control back
9292 to the simulator; the simulator then delivers the hardware
9293 equivalent of a GDB_SIGNAL_TRAP to the program being
9295 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9296 signal_program
[GDB_SIGNAL_INT
] = 0;
9298 /* Signals that are not errors should not normally enter the debugger. */
9299 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9300 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9301 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9302 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9303 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9304 signal_print
[GDB_SIGNAL_PROF
] = 0;
9305 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9306 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9307 signal_stop
[GDB_SIGNAL_IO
] = 0;
9308 signal_print
[GDB_SIGNAL_IO
] = 0;
9309 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9310 signal_print
[GDB_SIGNAL_POLL
] = 0;
9311 signal_stop
[GDB_SIGNAL_URG
] = 0;
9312 signal_print
[GDB_SIGNAL_URG
] = 0;
9313 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9314 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9315 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9316 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9318 /* These signals are used internally by user-level thread
9319 implementations. (See signal(5) on Solaris.) Like the above
9320 signals, a healthy program receives and handles them as part of
9321 its normal operation. */
9322 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9323 signal_print
[GDB_SIGNAL_LWP
] = 0;
9324 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9325 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9326 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9327 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9328 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9329 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9331 /* Update cached state. */
9332 signal_cache_update (-1);
9334 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9335 &stop_on_solib_events
, _("\
9336 Set stopping for shared library events."), _("\
9337 Show stopping for shared library events."), _("\
9338 If nonzero, gdb will give control to the user when the dynamic linker\n\
9339 notifies gdb of shared library events. The most common event of interest\n\
9340 to the user would be loading/unloading of a new library."),
9341 set_stop_on_solib_events
,
9342 show_stop_on_solib_events
,
9343 &setlist
, &showlist
);
9345 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9346 follow_fork_mode_kind_names
,
9347 &follow_fork_mode_string
, _("\
9348 Set debugger response to a program call of fork or vfork."), _("\
9349 Show debugger response to a program call of fork or vfork."), _("\
9350 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9351 parent - the original process is debugged after a fork\n\
9352 child - the new process is debugged after a fork\n\
9353 The unfollowed process will continue to run.\n\
9354 By default, the debugger will follow the parent process."),
9356 show_follow_fork_mode_string
,
9357 &setlist
, &showlist
);
9359 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9360 follow_exec_mode_names
,
9361 &follow_exec_mode_string
, _("\
9362 Set debugger response to a program call of exec."), _("\
9363 Show debugger response to a program call of exec."), _("\
9364 An exec call replaces the program image of a process.\n\
9366 follow-exec-mode can be:\n\
9368 new - the debugger creates a new inferior and rebinds the process\n\
9369 to this new inferior. The program the process was running before\n\
9370 the exec call can be restarted afterwards by restarting the original\n\
9373 same - the debugger keeps the process bound to the same inferior.\n\
9374 The new executable image replaces the previous executable loaded in\n\
9375 the inferior. Restarting the inferior after the exec call restarts\n\
9376 the executable the process was running after the exec call.\n\
9378 By default, the debugger will use the same inferior."),
9380 show_follow_exec_mode_string
,
9381 &setlist
, &showlist
);
9383 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9384 scheduler_enums
, &scheduler_mode
, _("\
9385 Set mode for locking scheduler during execution."), _("\
9386 Show mode for locking scheduler during execution."), _("\
9387 off == no locking (threads may preempt at any time)\n\
9388 on == full locking (no thread except the current thread may run)\n\
9389 This applies to both normal execution and replay mode.\n\
9390 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9391 In this mode, other threads may run during other commands.\n\
9392 This applies to both normal execution and replay mode.\n\
9393 replay == scheduler locked in replay mode and unlocked during normal execution."),
9394 set_schedlock_func
, /* traps on target vector */
9395 show_scheduler_mode
,
9396 &setlist
, &showlist
);
9398 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9399 Set mode for resuming threads of all processes."), _("\
9400 Show mode for resuming threads of all processes."), _("\
9401 When on, execution commands (such as 'continue' or 'next') resume all\n\
9402 threads of all processes. When off (which is the default), execution\n\
9403 commands only resume the threads of the current process. The set of\n\
9404 threads that are resumed is further refined by the scheduler-locking\n\
9405 mode (see help set scheduler-locking)."),
9407 show_schedule_multiple
,
9408 &setlist
, &showlist
);
9410 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9411 Set mode of the step operation."), _("\
9412 Show mode of the step operation."), _("\
9413 When set, doing a step over a function without debug line information\n\
9414 will stop at the first instruction of that function. Otherwise, the\n\
9415 function is skipped and the step command stops at a different source line."),
9417 show_step_stop_if_no_debug
,
9418 &setlist
, &showlist
);
9420 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9421 &can_use_displaced_stepping
, _("\
9422 Set debugger's willingness to use displaced stepping."), _("\
9423 Show debugger's willingness to use displaced stepping."), _("\
9424 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9425 supported by the target architecture. If off, gdb will not use displaced\n\
9426 stepping to step over breakpoints, even if such is supported by the target\n\
9427 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9428 if the target architecture supports it and non-stop mode is active, but will not\n\
9429 use it in all-stop mode (see help set non-stop)."),
9431 show_can_use_displaced_stepping
,
9432 &setlist
, &showlist
);
9434 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9435 &exec_direction
, _("Set direction of execution.\n\
9436 Options are 'forward' or 'reverse'."),
9437 _("Show direction of execution (forward/reverse)."),
9438 _("Tells gdb whether to execute forward or backward."),
9439 set_exec_direction_func
, show_exec_direction_func
,
9440 &setlist
, &showlist
);
9442 /* Set/show detach-on-fork: user-settable mode. */
9444 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9445 Set whether gdb will detach the child of a fork."), _("\
9446 Show whether gdb will detach the child of a fork."), _("\
9447 Tells gdb whether to detach the child of a fork."),
9448 NULL
, NULL
, &setlist
, &showlist
);
9450 /* Set/show disable address space randomization mode. */
9452 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9453 &disable_randomization
, _("\
9454 Set disabling of debuggee's virtual address space randomization."), _("\
9455 Show disabling of debuggee's virtual address space randomization."), _("\
9456 When this mode is on (which is the default), randomization of the virtual\n\
9457 address space is disabled. Standalone programs run with the randomization\n\
9458 enabled by default on some platforms."),
9459 &set_disable_randomization
,
9460 &show_disable_randomization
,
9461 &setlist
, &showlist
);
9463 /* ptid initializations */
9464 inferior_ptid
= null_ptid
;
9465 target_last_wait_ptid
= minus_one_ptid
;
9467 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9468 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9469 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9470 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9472 /* Explicitly create without lookup, since that tries to create a
9473 value with a void typed value, and when we get here, gdbarch
9474 isn't initialized yet. At this point, we're quite sure there
9475 isn't another convenience variable of the same name. */
9476 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9478 add_setshow_boolean_cmd ("observer", no_class
,
9479 &observer_mode_1
, _("\
9480 Set whether gdb controls the inferior in observer mode."), _("\
9481 Show whether gdb controls the inferior in observer mode."), _("\
9482 In observer mode, GDB can get data from the inferior, but not\n\
9483 affect its execution. Registers and memory may not be changed,\n\
9484 breakpoints may not be set, and the program cannot be interrupted\n\