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
);
1751 tp
->inf
->displaced_step_state
.unavailable
= true;
1753 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1756 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1758 // FIXME: Should probably replicated in the arch implementation now.
1760 // if (breakpoint_in_range_p (aspace, copy, len))
1762 // /* There's a breakpoint set in the scratch pad location range
1763 // (which is usually around the entry point). We'd either
1764 // install it before resuming, which would overwrite/corrupt the
1765 // scratch pad, or if it was already inserted, this displaced
1766 // step would overwrite it. The latter is OK in the sense that
1767 // we already assume that no thread is going to execute the code
1768 // in the scratch pad range (after initial startup) anyway, but
1769 // the former is unacceptable. Simply punt and fallback to
1770 // stepping over this breakpoint in-line. */
1771 // if (debug_displaced)
1773 // fprintf_unfiltered (gdb_stdlog,
1774 // "displaced: breakpoint set in scratch pad. "
1775 // "Stepping over breakpoint in-line instead.\n");
1778 // gdb_assert (false);
1779 // gdbarch_displaced_step_release_location (gdbarch, copy);
1784 /* Save the information we need to fix things up if the step
1786 thread_disp_step_state
->set (gdbarch
);
1788 // FIXME: get it from _prepare?
1789 CORE_ADDR displaced_pc
= 0;
1791 if (debug_displaced
)
1792 fprintf_unfiltered (gdb_stdlog
,
1793 "displaced: prepared successfully thread=%s, "
1794 "original_pc=%s, displaced_pc=%s\n",
1795 target_pid_to_str (tp
->ptid
).c_str (),
1796 paddress (gdbarch
, original_pc
),
1797 paddress (gdbarch
, displaced_pc
));
1799 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1802 /* Wrapper for displaced_step_prepare_throw that disabled further
1803 attempts at displaced stepping if we get a memory error. */
1805 static displaced_step_prepare_status
1806 displaced_step_prepare (thread_info
*thread
)
1808 displaced_step_prepare_status status
1809 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1813 status
= displaced_step_prepare_throw (thread
);
1815 catch (const gdb_exception_error
&ex
)
1817 struct displaced_step_inferior_state
*displaced_state
;
1819 if (ex
.error
!= MEMORY_ERROR
1820 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1823 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1826 /* Be verbose if "set displaced-stepping" is "on", silent if
1828 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1830 warning (_("disabling displaced stepping: %s"),
1834 /* Disable further displaced stepping attempts. */
1836 = get_displaced_stepping_state (thread
->inf
);
1837 displaced_state
->failed_before
= 1;
1843 /* If we displaced stepped an instruction successfully, adjust
1844 registers and memory to yield the same effect the instruction would
1845 have had if we had executed it at its original address, and return
1846 1. If the instruction didn't complete, relocate the PC and return
1847 -1. If the thread wasn't displaced stepping, return 0. */
1850 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1852 displaced_step_thread_state
*displaced
1853 = get_displaced_stepping_state (event_thread
);
1855 /* Was this thread performing a displaced step? */
1856 if (!displaced
->in_progress ())
1859 displaced_step_reset_cleanup
cleanup (displaced
);
1861 /* Fixup may need to read memory/registers. Switch to the thread
1862 that we're fixing up. Also, target_stopped_by_watchpoint checks
1863 the current thread, and displaced_step_restore performs ptid-dependent
1864 memory accesses using current_inferior() and current_top_target(). */
1865 switch_to_thread (event_thread
);
1867 /* Do the fixup, and release the resources acquired to do the displaced
1869 displaced_step_finish_status finish_status
=
1870 gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1871 event_thread
, signal
);
1873 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1879 /* Data to be passed around while handling an event. This data is
1880 discarded between events. */
1881 struct execution_control_state
1883 process_stratum_target
*target
;
1885 /* The thread that got the event, if this was a thread event; NULL
1887 struct thread_info
*event_thread
;
1889 struct target_waitstatus ws
;
1890 int stop_func_filled_in
;
1891 CORE_ADDR stop_func_start
;
1892 CORE_ADDR stop_func_end
;
1893 const char *stop_func_name
;
1896 /* True if the event thread hit the single-step breakpoint of
1897 another thread. Thus the event doesn't cause a stop, the thread
1898 needs to be single-stepped past the single-step breakpoint before
1899 we can switch back to the original stepping thread. */
1900 int hit_singlestep_breakpoint
;
1903 /* Clear ECS and set it to point at TP. */
1906 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1908 memset (ecs
, 0, sizeof (*ecs
));
1909 ecs
->event_thread
= tp
;
1910 ecs
->ptid
= tp
->ptid
;
1913 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1914 static void prepare_to_wait (struct execution_control_state
*ecs
);
1915 static int keep_going_stepped_thread (struct thread_info
*tp
);
1916 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1918 /* Are there any pending step-over requests? If so, run all we can
1919 now and return true. Otherwise, return false. */
1922 start_step_over (void)
1924 struct thread_info
*tp
, *next
;
1927 /* Don't start a new step-over if we already have an in-line
1928 step-over operation ongoing. */
1929 if (step_over_info_valid_p ())
1932 /* Steal the global thread step over chain. */
1933 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1934 global_thread_step_over_chain_head
= NULL
;
1937 fprintf_unfiltered (gdb_stdlog
,
1938 "infrun: stealing list of %d threads to step from global queue\n",
1939 thread_step_over_chain_length (threads_to_step
));
1941 for (inferior
*inf
: all_inferiors ())
1942 inf
->displaced_step_state
.unavailable
= false;
1944 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1946 struct execution_control_state ecss
;
1947 struct execution_control_state
*ecs
= &ecss
;
1948 step_over_what step_what
;
1949 int must_be_in_line
;
1951 gdb_assert (!tp
->stop_requested
);
1953 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1955 step_what
= thread_still_needs_step_over (tp
);
1956 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1957 || ((step_what
& STEP_OVER_BREAKPOINT
)
1958 && !use_displaced_stepping (tp
)));
1960 /* We currently stop all threads of all processes to step-over
1961 in-line. If we need to start a new in-line step-over, let
1962 any pending displaced steps finish first. */
1963 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1966 thread_step_over_chain_remove (&threads_to_step
, tp
);
1968 if (tp
->control
.trap_expected
1972 internal_error (__FILE__
, __LINE__
,
1973 "[%s] has inconsistent state: "
1974 "trap_expected=%d, resumed=%d, executing=%d\n",
1975 target_pid_to_str (tp
->ptid
).c_str (),
1976 tp
->control
.trap_expected
,
1981 infrun_log_debug ("resuming [%s] for step-over",
1982 target_pid_to_str (tp
->ptid
).c_str ());
1984 /* keep_going_pass_signal skips the step-over if the breakpoint
1985 is no longer inserted. In all-stop, we want to keep looking
1986 for a thread that needs a step-over instead of resuming TP,
1987 because we wouldn't be able to resume anything else until the
1988 target stops again. In non-stop, the resume always resumes
1989 only TP, so it's OK to let the thread resume freely. */
1990 if (!target_is_non_stop_p () && !step_what
)
1993 if (tp
->inf
->displaced_step_state
.unavailable
)
1995 global_thread_step_over_chain_enqueue (tp
);
1999 switch_to_thread (tp
);
2000 reset_ecs (ecs
, tp
);
2001 keep_going_pass_signal (ecs
);
2003 if (!ecs
->wait_some_more
)
2004 error (_("Command aborted."));
2006 /* If the thread's step over could not be initiated, it was re-added
2007 to the global step over chain. */
2010 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
2011 target_pid_to_str (tp
->ptid
).c_str ());
2012 gdb_assert (!thread_is_in_step_over_chain (tp
));
2016 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
2017 target_pid_to_str (tp
->ptid
).c_str ());
2018 gdb_assert (thread_is_in_step_over_chain (tp
));
2022 /* If we started a new in-line step-over, we're done. */
2023 if (step_over_info_valid_p ())
2025 gdb_assert (tp
->control
.trap_expected
);
2030 if (!target_is_non_stop_p ())
2032 /* On all-stop, shouldn't have resumed unless we needed a
2034 gdb_assert (tp
->control
.trap_expected
2035 || tp
->step_after_step_resume_breakpoint
);
2037 /* With remote targets (at least), in all-stop, we can't
2038 issue any further remote commands until the program stops
2044 /* Either the thread no longer needed a step-over, or a new
2045 displaced stepping sequence started. Even in the latter
2046 case, continue looking. Maybe we can also start another
2047 displaced step on a thread of other process. */
2050 /* If there are threads left in the THREADS_TO_STEP list, but we have
2051 detected that we can't start anything more, put back these threads
2052 in the global list. */
2053 if (threads_to_step
== NULL
)
2056 fprintf_unfiltered (gdb_stdlog
,
2057 "infrun: step-over queue now empty\n");
2062 fprintf_unfiltered (gdb_stdlog
,
2063 "infrun: putting back %d threads to step in global queue\n",
2064 thread_step_over_chain_length (threads_to_step
));
2065 while (threads_to_step
!= nullptr)
2067 thread_info
*thread
= threads_to_step
;
2069 /* Remove from that list. */
2070 thread_step_over_chain_remove (&threads_to_step
, thread
);
2072 /* Add to global list. */
2073 global_thread_step_over_chain_enqueue (thread
);
2081 /* Update global variables holding ptids to hold NEW_PTID if they were
2082 holding OLD_PTID. */
2084 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2086 if (inferior_ptid
== old_ptid
)
2087 inferior_ptid
= new_ptid
;
2092 static const char schedlock_off
[] = "off";
2093 static const char schedlock_on
[] = "on";
2094 static const char schedlock_step
[] = "step";
2095 static const char schedlock_replay
[] = "replay";
2096 static const char *const scheduler_enums
[] = {
2103 static const char *scheduler_mode
= schedlock_replay
;
2105 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2106 struct cmd_list_element
*c
, const char *value
)
2108 fprintf_filtered (file
,
2109 _("Mode for locking scheduler "
2110 "during execution is \"%s\".\n"),
2115 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2117 if (!target_can_lock_scheduler
)
2119 scheduler_mode
= schedlock_off
;
2120 error (_("Target '%s' cannot support this command."), target_shortname
);
2124 /* True if execution commands resume all threads of all processes by
2125 default; otherwise, resume only threads of the current inferior
2127 bool sched_multi
= false;
2129 /* Try to setup for software single stepping over the specified location.
2130 Return 1 if target_resume() should use hardware single step.
2132 GDBARCH the current gdbarch.
2133 PC the location to step over. */
2136 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2140 if (execution_direction
== EXEC_FORWARD
2141 && gdbarch_software_single_step_p (gdbarch
))
2142 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2150 user_visible_resume_ptid (int step
)
2156 /* With non-stop mode on, threads are always handled
2158 resume_ptid
= inferior_ptid
;
2160 else if ((scheduler_mode
== schedlock_on
)
2161 || (scheduler_mode
== schedlock_step
&& step
))
2163 /* User-settable 'scheduler' mode requires solo thread
2165 resume_ptid
= inferior_ptid
;
2167 else if ((scheduler_mode
== schedlock_replay
)
2168 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2170 /* User-settable 'scheduler' mode requires solo thread resume in replay
2172 resume_ptid
= inferior_ptid
;
2174 else if (!sched_multi
&& target_supports_multi_process ())
2176 /* Resume all threads of the current process (and none of other
2178 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2182 /* Resume all threads of all processes. */
2183 resume_ptid
= RESUME_ALL
;
2191 process_stratum_target
*
2192 user_visible_resume_target (ptid_t resume_ptid
)
2194 return (resume_ptid
== minus_one_ptid
&& sched_multi
2196 : current_inferior ()->process_target ());
2199 /* Return a ptid representing the set of threads that we will resume,
2200 in the perspective of the target, assuming run control handling
2201 does not require leaving some threads stopped (e.g., stepping past
2202 breakpoint). USER_STEP indicates whether we're about to start the
2203 target for a stepping command. */
2206 internal_resume_ptid (int user_step
)
2208 /* In non-stop, we always control threads individually. Note that
2209 the target may always work in non-stop mode even with "set
2210 non-stop off", in which case user_visible_resume_ptid could
2211 return a wildcard ptid. */
2212 if (target_is_non_stop_p ())
2213 return inferior_ptid
;
2215 return user_visible_resume_ptid (user_step
);
2218 /* Wrapper for target_resume, that handles infrun-specific
2222 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2224 struct thread_info
*tp
= inferior_thread ();
2226 gdb_assert (!tp
->stop_requested
);
2228 /* Install inferior's terminal modes. */
2229 target_terminal::inferior ();
2231 /* Avoid confusing the next resume, if the next stop/resume
2232 happens to apply to another thread. */
2233 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2235 /* Advise target which signals may be handled silently.
2237 If we have removed breakpoints because we are stepping over one
2238 in-line (in any thread), we need to receive all signals to avoid
2239 accidentally skipping a breakpoint during execution of a signal
2242 Likewise if we're displaced stepping, otherwise a trap for a
2243 breakpoint in a signal handler might be confused with the
2244 displaced step finishing. We don't make the displaced_step_fixup
2245 step distinguish the cases instead, because:
2247 - a backtrace while stopped in the signal handler would show the
2248 scratch pad as frame older than the signal handler, instead of
2249 the real mainline code.
2251 - when the thread is later resumed, the signal handler would
2252 return to the scratch pad area, which would no longer be
2254 if (step_over_info_valid_p ()
2255 || displaced_step_in_progress (tp
->inf
))
2256 target_pass_signals ({});
2258 target_pass_signals (signal_pass
);
2260 target_resume (resume_ptid
, step
, sig
);
2262 target_commit_resume ();
2264 if (target_can_async_p ())
2268 /* Resume the inferior. SIG is the signal to give the inferior
2269 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2270 call 'resume', which handles exceptions. */
2273 resume_1 (enum gdb_signal sig
)
2275 struct regcache
*regcache
= get_current_regcache ();
2276 struct gdbarch
*gdbarch
= regcache
->arch ();
2277 struct thread_info
*tp
= inferior_thread ();
2278 const address_space
*aspace
= regcache
->aspace ();
2280 /* This represents the user's step vs continue request. When
2281 deciding whether "set scheduler-locking step" applies, it's the
2282 user's intention that counts. */
2283 const int user_step
= tp
->control
.stepping_command
;
2284 /* This represents what we'll actually request the target to do.
2285 This can decay from a step to a continue, if e.g., we need to
2286 implement single-stepping with breakpoints (software
2290 gdb_assert (!tp
->stop_requested
);
2291 gdb_assert (!thread_is_in_step_over_chain (tp
));
2293 if (tp
->suspend
.waitstatus_pending_p
)
2296 ("thread %s has pending wait "
2297 "status %s (currently_stepping=%d).",
2298 target_pid_to_str (tp
->ptid
).c_str (),
2299 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2300 currently_stepping (tp
));
2302 tp
->inf
->process_target ()->threads_executing
= true;
2305 /* FIXME: What should we do if we are supposed to resume this
2306 thread with a signal? Maybe we should maintain a queue of
2307 pending signals to deliver. */
2308 if (sig
!= GDB_SIGNAL_0
)
2310 warning (_("Couldn't deliver signal %s to %s."),
2311 gdb_signal_to_name (sig
),
2312 target_pid_to_str (tp
->ptid
).c_str ());
2315 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2317 if (target_can_async_p ())
2320 /* Tell the event loop we have an event to process. */
2321 mark_async_event_handler (infrun_async_inferior_event_token
);
2326 tp
->stepped_breakpoint
= 0;
2328 /* Depends on stepped_breakpoint. */
2329 step
= currently_stepping (tp
);
2331 if (current_inferior ()->waiting_for_vfork_done
)
2333 /* Don't try to single-step a vfork parent that is waiting for
2334 the child to get out of the shared memory region (by exec'ing
2335 or exiting). This is particularly important on software
2336 single-step archs, as the child process would trip on the
2337 software single step breakpoint inserted for the parent
2338 process. Since the parent will not actually execute any
2339 instruction until the child is out of the shared region (such
2340 are vfork's semantics), it is safe to simply continue it.
2341 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2342 the parent, and tell it to `keep_going', which automatically
2343 re-sets it stepping. */
2344 infrun_log_debug ("resume : clear step");
2348 CORE_ADDR pc
= regcache_read_pc (regcache
);
2350 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2351 "current thread [%s] at %s",
2352 step
, gdb_signal_to_symbol_string (sig
),
2353 tp
->control
.trap_expected
,
2354 target_pid_to_str (inferior_ptid
).c_str (),
2355 paddress (gdbarch
, pc
));
2357 /* Normally, by the time we reach `resume', the breakpoints are either
2358 removed or inserted, as appropriate. The exception is if we're sitting
2359 at a permanent breakpoint; we need to step over it, but permanent
2360 breakpoints can't be removed. So we have to test for it here. */
2361 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2363 if (sig
!= GDB_SIGNAL_0
)
2365 /* We have a signal to pass to the inferior. The resume
2366 may, or may not take us to the signal handler. If this
2367 is a step, we'll need to stop in the signal handler, if
2368 there's one, (if the target supports stepping into
2369 handlers), or in the next mainline instruction, if
2370 there's no handler. If this is a continue, we need to be
2371 sure to run the handler with all breakpoints inserted.
2372 In all cases, set a breakpoint at the current address
2373 (where the handler returns to), and once that breakpoint
2374 is hit, resume skipping the permanent breakpoint. If
2375 that breakpoint isn't hit, then we've stepped into the
2376 signal handler (or hit some other event). We'll delete
2377 the step-resume breakpoint then. */
2379 infrun_log_debug ("resume: skipping permanent breakpoint, "
2380 "deliver signal first");
2382 clear_step_over_info ();
2383 tp
->control
.trap_expected
= 0;
2385 if (tp
->control
.step_resume_breakpoint
== NULL
)
2387 /* Set a "high-priority" step-resume, as we don't want
2388 user breakpoints at PC to trigger (again) when this
2390 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2391 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2393 tp
->step_after_step_resume_breakpoint
= step
;
2396 insert_breakpoints ();
2400 /* There's no signal to pass, we can go ahead and skip the
2401 permanent breakpoint manually. */
2402 infrun_log_debug ("skipping permanent breakpoint");
2403 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2404 /* Update pc to reflect the new address from which we will
2405 execute instructions. */
2406 pc
= regcache_read_pc (regcache
);
2410 /* We've already advanced the PC, so the stepping part
2411 is done. Now we need to arrange for a trap to be
2412 reported to handle_inferior_event. Set a breakpoint
2413 at the current PC, and run to it. Don't update
2414 prev_pc, because if we end in
2415 switch_back_to_stepped_thread, we want the "expected
2416 thread advanced also" branch to be taken. IOW, we
2417 don't want this thread to step further from PC
2419 gdb_assert (!step_over_info_valid_p ());
2420 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2421 insert_breakpoints ();
2423 resume_ptid
= internal_resume_ptid (user_step
);
2424 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2431 /* If we have a breakpoint to step over, make sure to do a single
2432 step only. Same if we have software watchpoints. */
2433 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2434 tp
->control
.may_range_step
= 0;
2436 /* If displaced stepping is enabled, step over breakpoints by executing a
2437 copy of the instruction at a different address.
2439 We can't use displaced stepping when we have a signal to deliver;
2440 the comments for displaced_step_prepare explain why. The
2441 comments in the handle_inferior event for dealing with 'random
2442 signals' explain what we do instead.
2444 We can't use displaced stepping when we are waiting for vfork_done
2445 event, displaced stepping breaks the vfork child similarly as single
2446 step software breakpoint. */
2447 if (tp
->control
.trap_expected
2448 && use_displaced_stepping (tp
)
2449 && !step_over_info_valid_p ()
2450 && sig
== GDB_SIGNAL_0
2451 && !current_inferior ()->waiting_for_vfork_done
)
2453 displaced_step_prepare_status prepare_status
2454 = displaced_step_prepare (tp
);
2456 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2458 infrun_log_debug ("Got placed in step-over queue");
2460 tp
->control
.trap_expected
= 0;
2463 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2465 /* Fallback to stepping over the breakpoint in-line. */
2467 if (target_is_non_stop_p ())
2468 stop_all_threads ();
2470 set_step_over_info (regcache
->aspace (),
2471 regcache_read_pc (regcache
), 0, tp
->global_num
);
2473 step
= maybe_software_singlestep (gdbarch
, pc
);
2475 insert_breakpoints ();
2477 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2479 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2482 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2485 /* Do we need to do it the hard way, w/temp breakpoints? */
2487 step
= maybe_software_singlestep (gdbarch
, pc
);
2489 /* Currently, our software single-step implementation leads to different
2490 results than hardware single-stepping in one situation: when stepping
2491 into delivering a signal which has an associated signal handler,
2492 hardware single-step will stop at the first instruction of the handler,
2493 while software single-step will simply skip execution of the handler.
2495 For now, this difference in behavior is accepted since there is no
2496 easy way to actually implement single-stepping into a signal handler
2497 without kernel support.
2499 However, there is one scenario where this difference leads to follow-on
2500 problems: if we're stepping off a breakpoint by removing all breakpoints
2501 and then single-stepping. In this case, the software single-step
2502 behavior means that even if there is a *breakpoint* in the signal
2503 handler, GDB still would not stop.
2505 Fortunately, we can at least fix this particular issue. We detect
2506 here the case where we are about to deliver a signal while software
2507 single-stepping with breakpoints removed. In this situation, we
2508 revert the decisions to remove all breakpoints and insert single-
2509 step breakpoints, and instead we install a step-resume breakpoint
2510 at the current address, deliver the signal without stepping, and
2511 once we arrive back at the step-resume breakpoint, actually step
2512 over the breakpoint we originally wanted to step over. */
2513 if (thread_has_single_step_breakpoints_set (tp
)
2514 && sig
!= GDB_SIGNAL_0
2515 && step_over_info_valid_p ())
2517 /* If we have nested signals or a pending signal is delivered
2518 immediately after a handler returns, might already have
2519 a step-resume breakpoint set on the earlier handler. We cannot
2520 set another step-resume breakpoint; just continue on until the
2521 original breakpoint is hit. */
2522 if (tp
->control
.step_resume_breakpoint
== NULL
)
2524 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2525 tp
->step_after_step_resume_breakpoint
= 1;
2528 delete_single_step_breakpoints (tp
);
2530 clear_step_over_info ();
2531 tp
->control
.trap_expected
= 0;
2533 insert_breakpoints ();
2536 /* If STEP is set, it's a request to use hardware stepping
2537 facilities. But in that case, we should never
2538 use singlestep breakpoint. */
2539 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2541 /* Decide the set of threads to ask the target to resume. */
2542 if (tp
->control
.trap_expected
)
2544 /* We're allowing a thread to run past a breakpoint it has
2545 hit, either by single-stepping the thread with the breakpoint
2546 removed, or by displaced stepping, with the breakpoint inserted.
2547 In the former case, we need to single-step only this thread,
2548 and keep others stopped, as they can miss this breakpoint if
2549 allowed to run. That's not really a problem for displaced
2550 stepping, but, we still keep other threads stopped, in case
2551 another thread is also stopped for a breakpoint waiting for
2552 its turn in the displaced stepping queue. */
2553 resume_ptid
= inferior_ptid
;
2556 resume_ptid
= internal_resume_ptid (user_step
);
2558 if (execution_direction
!= EXEC_REVERSE
2559 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2561 /* There are two cases where we currently need to step a
2562 breakpoint instruction when we have a signal to deliver:
2564 - See handle_signal_stop where we handle random signals that
2565 could take out us out of the stepping range. Normally, in
2566 that case we end up continuing (instead of stepping) over the
2567 signal handler with a breakpoint at PC, but there are cases
2568 where we should _always_ single-step, even if we have a
2569 step-resume breakpoint, like when a software watchpoint is
2570 set. Assuming single-stepping and delivering a signal at the
2571 same time would takes us to the signal handler, then we could
2572 have removed the breakpoint at PC to step over it. However,
2573 some hardware step targets (like e.g., Mac OS) can't step
2574 into signal handlers, and for those, we need to leave the
2575 breakpoint at PC inserted, as otherwise if the handler
2576 recurses and executes PC again, it'll miss the breakpoint.
2577 So we leave the breakpoint inserted anyway, but we need to
2578 record that we tried to step a breakpoint instruction, so
2579 that adjust_pc_after_break doesn't end up confused.
2581 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2582 in one thread after another thread that was stepping had been
2583 momentarily paused for a step-over. When we re-resume the
2584 stepping thread, it may be resumed from that address with a
2585 breakpoint that hasn't trapped yet. Seen with
2586 gdb.threads/non-stop-fair-events.exp, on targets that don't
2587 do displaced stepping. */
2589 infrun_log_debug ("resume: [%s] stepped breakpoint",
2590 target_pid_to_str (tp
->ptid
).c_str ());
2592 tp
->stepped_breakpoint
= 1;
2594 /* Most targets can step a breakpoint instruction, thus
2595 executing it normally. But if this one cannot, just
2596 continue and we will hit it anyway. */
2597 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2602 && tp
->control
.trap_expected
2603 && use_displaced_stepping (tp
)
2604 && !step_over_info_valid_p ())
2606 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2607 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2608 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2611 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2612 paddress (resume_gdbarch
, actual_pc
));
2613 read_memory (actual_pc
, buf
, sizeof (buf
));
2614 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2617 if (tp
->control
.may_range_step
)
2619 /* If we're resuming a thread with the PC out of the step
2620 range, then we're doing some nested/finer run control
2621 operation, like stepping the thread out of the dynamic
2622 linker or the displaced stepping scratch pad. We
2623 shouldn't have allowed a range step then. */
2624 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2627 do_target_resume (resume_ptid
, step
, sig
);
2631 /* Resume the inferior. SIG is the signal to give the inferior
2632 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2633 rolls back state on error. */
2636 resume (gdb_signal sig
)
2642 catch (const gdb_exception
&ex
)
2644 /* If resuming is being aborted for any reason, delete any
2645 single-step breakpoint resume_1 may have created, to avoid
2646 confusing the following resumption, and to avoid leaving
2647 single-step breakpoints perturbing other threads, in case
2648 we're running in non-stop mode. */
2649 if (inferior_ptid
!= null_ptid
)
2650 delete_single_step_breakpoints (inferior_thread ());
2660 /* Counter that tracks number of user visible stops. This can be used
2661 to tell whether a command has proceeded the inferior past the
2662 current location. This allows e.g., inferior function calls in
2663 breakpoint commands to not interrupt the command list. When the
2664 call finishes successfully, the inferior is standing at the same
2665 breakpoint as if nothing happened (and so we don't call
2667 static ULONGEST current_stop_id
;
2674 return current_stop_id
;
2677 /* Called when we report a user visible stop. */
2685 /* Clear out all variables saying what to do when inferior is continued.
2686 First do this, then set the ones you want, then call `proceed'. */
2689 clear_proceed_status_thread (struct thread_info
*tp
)
2691 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2693 /* If we're starting a new sequence, then the previous finished
2694 single-step is no longer relevant. */
2695 if (tp
->suspend
.waitstatus_pending_p
)
2697 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2699 infrun_log_debug ("pending event of %s was a finished step. "
2701 target_pid_to_str (tp
->ptid
).c_str ());
2703 tp
->suspend
.waitstatus_pending_p
= 0;
2704 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2709 ("thread %s has pending wait status %s (currently_stepping=%d).",
2710 target_pid_to_str (tp
->ptid
).c_str (),
2711 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2712 currently_stepping (tp
));
2716 /* If this signal should not be seen by program, give it zero.
2717 Used for debugging signals. */
2718 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2719 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2721 delete tp
->thread_fsm
;
2722 tp
->thread_fsm
= NULL
;
2724 tp
->control
.trap_expected
= 0;
2725 tp
->control
.step_range_start
= 0;
2726 tp
->control
.step_range_end
= 0;
2727 tp
->control
.may_range_step
= 0;
2728 tp
->control
.step_frame_id
= null_frame_id
;
2729 tp
->control
.step_stack_frame_id
= null_frame_id
;
2730 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2731 tp
->control
.step_start_function
= NULL
;
2732 tp
->stop_requested
= 0;
2734 tp
->control
.stop_step
= 0;
2736 tp
->control
.proceed_to_finish
= 0;
2738 tp
->control
.stepping_command
= 0;
2740 /* Discard any remaining commands or status from previous stop. */
2741 bpstat_clear (&tp
->control
.stop_bpstat
);
2745 clear_proceed_status (int step
)
2747 /* With scheduler-locking replay, stop replaying other threads if we're
2748 not replaying the user-visible resume ptid.
2750 This is a convenience feature to not require the user to explicitly
2751 stop replaying the other threads. We're assuming that the user's
2752 intent is to resume tracing the recorded process. */
2753 if (!non_stop
&& scheduler_mode
== schedlock_replay
2754 && target_record_is_replaying (minus_one_ptid
)
2755 && !target_record_will_replay (user_visible_resume_ptid (step
),
2756 execution_direction
))
2757 target_record_stop_replaying ();
2759 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2761 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2762 process_stratum_target
*resume_target
2763 = user_visible_resume_target (resume_ptid
);
2765 /* In all-stop mode, delete the per-thread status of all threads
2766 we're about to resume, implicitly and explicitly. */
2767 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2768 clear_proceed_status_thread (tp
);
2771 if (inferior_ptid
!= null_ptid
)
2773 struct inferior
*inferior
;
2777 /* If in non-stop mode, only delete the per-thread status of
2778 the current thread. */
2779 clear_proceed_status_thread (inferior_thread ());
2782 inferior
= current_inferior ();
2783 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2786 gdb::observers::about_to_proceed
.notify ();
2789 /* Returns true if TP is still stopped at a breakpoint that needs
2790 stepping-over in order to make progress. If the breakpoint is gone
2791 meanwhile, we can skip the whole step-over dance. */
2794 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2796 if (tp
->stepping_over_breakpoint
)
2798 struct regcache
*regcache
= get_thread_regcache (tp
);
2800 if (breakpoint_here_p (regcache
->aspace (),
2801 regcache_read_pc (regcache
))
2802 == ordinary_breakpoint_here
)
2805 tp
->stepping_over_breakpoint
= 0;
2811 /* Check whether thread TP still needs to start a step-over in order
2812 to make progress when resumed. Returns an bitwise or of enum
2813 step_over_what bits, indicating what needs to be stepped over. */
2815 static step_over_what
2816 thread_still_needs_step_over (struct thread_info
*tp
)
2818 step_over_what what
= 0;
2820 if (thread_still_needs_step_over_bp (tp
))
2821 what
|= STEP_OVER_BREAKPOINT
;
2823 if (tp
->stepping_over_watchpoint
2824 && !target_have_steppable_watchpoint
)
2825 what
|= STEP_OVER_WATCHPOINT
;
2830 /* Returns true if scheduler locking applies. STEP indicates whether
2831 we're about to do a step/next-like command to a thread. */
2834 schedlock_applies (struct thread_info
*tp
)
2836 return (scheduler_mode
== schedlock_on
2837 || (scheduler_mode
== schedlock_step
2838 && tp
->control
.stepping_command
)
2839 || (scheduler_mode
== schedlock_replay
2840 && target_record_will_replay (minus_one_ptid
,
2841 execution_direction
)));
2844 /* Calls target_commit_resume on all targets. */
2847 commit_resume_all_targets ()
2849 scoped_restore_current_thread restore_thread
;
2851 /* Map between process_target and a representative inferior. This
2852 is to avoid committing a resume in the same target more than
2853 once. Resumptions must be idempotent, so this is an
2855 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2857 for (inferior
*inf
: all_non_exited_inferiors ())
2858 if (inf
->has_execution ())
2859 conn_inf
[inf
->process_target ()] = inf
;
2861 for (const auto &ci
: conn_inf
)
2863 inferior
*inf
= ci
.second
;
2864 switch_to_inferior_no_thread (inf
);
2865 target_commit_resume ();
2869 /* Check that all the targets we're about to resume are in non-stop
2870 mode. Ideally, we'd only care whether all targets support
2871 target-async, but we're not there yet. E.g., stop_all_threads
2872 doesn't know how to handle all-stop targets. Also, the remote
2873 protocol in all-stop mode is synchronous, irrespective of
2874 target-async, which means that things like a breakpoint re-set
2875 triggered by one target would try to read memory from all targets
2879 check_multi_target_resumption (process_stratum_target
*resume_target
)
2881 if (!non_stop
&& resume_target
== nullptr)
2883 scoped_restore_current_thread restore_thread
;
2885 /* This is used to track whether we're resuming more than one
2887 process_stratum_target
*first_connection
= nullptr;
2889 /* The first inferior we see with a target that does not work in
2890 always-non-stop mode. */
2891 inferior
*first_not_non_stop
= nullptr;
2893 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2895 switch_to_inferior_no_thread (inf
);
2897 if (!target_has_execution
)
2900 process_stratum_target
*proc_target
2901 = current_inferior ()->process_target();
2903 if (!target_is_non_stop_p ())
2904 first_not_non_stop
= inf
;
2906 if (first_connection
== nullptr)
2907 first_connection
= proc_target
;
2908 else if (first_connection
!= proc_target
2909 && first_not_non_stop
!= nullptr)
2911 switch_to_inferior_no_thread (first_not_non_stop
);
2913 proc_target
= current_inferior ()->process_target();
2915 error (_("Connection %d (%s) does not support "
2916 "multi-target resumption."),
2917 proc_target
->connection_number
,
2918 make_target_connection_string (proc_target
).c_str ());
2924 /* Basic routine for continuing the program in various fashions.
2926 ADDR is the address to resume at, or -1 for resume where stopped.
2927 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2928 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2930 You should call clear_proceed_status before calling proceed. */
2933 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2935 struct regcache
*regcache
;
2936 struct gdbarch
*gdbarch
;
2938 struct execution_control_state ecss
;
2939 struct execution_control_state
*ecs
= &ecss
;
2942 /* If we're stopped at a fork/vfork, follow the branch set by the
2943 "set follow-fork-mode" command; otherwise, we'll just proceed
2944 resuming the current thread. */
2945 if (!follow_fork ())
2947 /* The target for some reason decided not to resume. */
2949 if (target_can_async_p ())
2950 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
2954 /* We'll update this if & when we switch to a new thread. */
2955 previous_inferior_ptid
= inferior_ptid
;
2957 regcache
= get_current_regcache ();
2958 gdbarch
= regcache
->arch ();
2959 const address_space
*aspace
= regcache
->aspace ();
2961 pc
= regcache_read_pc_protected (regcache
);
2963 thread_info
*cur_thr
= inferior_thread ();
2965 /* Fill in with reasonable starting values. */
2966 init_thread_stepping_state (cur_thr
);
2968 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2971 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2972 process_stratum_target
*resume_target
2973 = user_visible_resume_target (resume_ptid
);
2975 check_multi_target_resumption (resume_target
);
2977 if (addr
== (CORE_ADDR
) -1)
2979 if (pc
== cur_thr
->suspend
.stop_pc
2980 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2981 && execution_direction
!= EXEC_REVERSE
)
2982 /* There is a breakpoint at the address we will resume at,
2983 step one instruction before inserting breakpoints so that
2984 we do not stop right away (and report a second hit at this
2987 Note, we don't do this in reverse, because we won't
2988 actually be executing the breakpoint insn anyway.
2989 We'll be (un-)executing the previous instruction. */
2990 cur_thr
->stepping_over_breakpoint
= 1;
2991 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2992 && gdbarch_single_step_through_delay (gdbarch
,
2993 get_current_frame ()))
2994 /* We stepped onto an instruction that needs to be stepped
2995 again before re-inserting the breakpoint, do so. */
2996 cur_thr
->stepping_over_breakpoint
= 1;
3000 regcache_write_pc (regcache
, addr
);
3003 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
3004 cur_thr
->suspend
.stop_signal
= siggnal
;
3006 /* If an exception is thrown from this point on, make sure to
3007 propagate GDB's knowledge of the executing state to the
3008 frontend/user running state. */
3009 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
3011 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
3012 threads (e.g., we might need to set threads stepping over
3013 breakpoints first), from the user/frontend's point of view, all
3014 threads in RESUME_PTID are now running. Unless we're calling an
3015 inferior function, as in that case we pretend the inferior
3016 doesn't run at all. */
3017 if (!cur_thr
->control
.in_infcall
)
3018 set_running (resume_target
, resume_ptid
, true);
3020 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3021 gdb_signal_to_symbol_string (siggnal
));
3023 annotate_starting ();
3025 /* Make sure that output from GDB appears before output from the
3027 gdb_flush (gdb_stdout
);
3029 /* Since we've marked the inferior running, give it the terminal. A
3030 QUIT/Ctrl-C from here on is forwarded to the target (which can
3031 still detect attempts to unblock a stuck connection with repeated
3032 Ctrl-C from within target_pass_ctrlc). */
3033 target_terminal::inferior ();
3035 /* In a multi-threaded task we may select another thread and
3036 then continue or step.
3038 But if a thread that we're resuming had stopped at a breakpoint,
3039 it will immediately cause another breakpoint stop without any
3040 execution (i.e. it will report a breakpoint hit incorrectly). So
3041 we must step over it first.
3043 Look for threads other than the current (TP) that reported a
3044 breakpoint hit and haven't been resumed yet since. */
3046 /* If scheduler locking applies, we can avoid iterating over all
3048 if (!non_stop
&& !schedlock_applies (cur_thr
))
3050 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3053 switch_to_thread_no_regs (tp
);
3055 /* Ignore the current thread here. It's handled
3060 if (!thread_still_needs_step_over (tp
))
3063 gdb_assert (!thread_is_in_step_over_chain (tp
));
3065 infrun_log_debug ("need to step-over [%s] first",
3066 target_pid_to_str (tp
->ptid
).c_str ());
3068 global_thread_step_over_chain_enqueue (tp
);
3071 switch_to_thread (cur_thr
);
3074 /* Enqueue the current thread last, so that we move all other
3075 threads over their breakpoints first. */
3076 if (cur_thr
->stepping_over_breakpoint
)
3077 global_thread_step_over_chain_enqueue (cur_thr
);
3079 /* If the thread isn't started, we'll still need to set its prev_pc,
3080 so that switch_back_to_stepped_thread knows the thread hasn't
3081 advanced. Must do this before resuming any thread, as in
3082 all-stop/remote, once we resume we can't send any other packet
3083 until the target stops again. */
3084 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3087 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3089 started
= start_step_over ();
3091 if (step_over_info_valid_p ())
3093 /* Either this thread started a new in-line step over, or some
3094 other thread was already doing one. In either case, don't
3095 resume anything else until the step-over is finished. */
3097 else if (started
&& !target_is_non_stop_p ())
3099 /* A new displaced stepping sequence was started. In all-stop,
3100 we can't talk to the target anymore until it next stops. */
3102 else if (!non_stop
&& target_is_non_stop_p ())
3104 /* In all-stop, but the target is always in non-stop mode.
3105 Start all other threads that are implicitly resumed too. */
3106 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3109 switch_to_thread_no_regs (tp
);
3111 if (!tp
->inf
->has_execution ())
3113 infrun_log_debug ("[%s] target has no execution",
3114 target_pid_to_str (tp
->ptid
).c_str ());
3120 infrun_log_debug ("[%s] resumed",
3121 target_pid_to_str (tp
->ptid
).c_str ());
3122 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3126 if (thread_is_in_step_over_chain (tp
))
3128 infrun_log_debug ("[%s] needs step-over",
3129 target_pid_to_str (tp
->ptid
).c_str ());
3133 infrun_log_debug ("resuming %s",
3134 target_pid_to_str (tp
->ptid
).c_str ());
3136 reset_ecs (ecs
, tp
);
3137 switch_to_thread (tp
);
3138 keep_going_pass_signal (ecs
);
3139 if (!ecs
->wait_some_more
)
3140 error (_("Command aborted."));
3143 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3145 /* The thread wasn't started, and isn't queued, run it now. */
3146 reset_ecs (ecs
, cur_thr
);
3147 switch_to_thread (cur_thr
);
3148 keep_going_pass_signal (ecs
);
3149 if (!ecs
->wait_some_more
)
3150 error (_("Command aborted."));
3154 commit_resume_all_targets ();
3156 finish_state
.release ();
3158 /* If we've switched threads above, switch back to the previously
3159 current thread. We don't want the user to see a different
3161 switch_to_thread (cur_thr
);
3163 /* Tell the event loop to wait for it to stop. If the target
3164 supports asynchronous execution, it'll do this from within
3166 if (!target_can_async_p ())
3167 mark_async_event_handler (infrun_async_inferior_event_token
);
3171 /* Start remote-debugging of a machine over a serial link. */
3174 start_remote (int from_tty
)
3176 inferior
*inf
= current_inferior ();
3177 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3179 /* Always go on waiting for the target, regardless of the mode. */
3180 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3181 indicate to wait_for_inferior that a target should timeout if
3182 nothing is returned (instead of just blocking). Because of this,
3183 targets expecting an immediate response need to, internally, set
3184 things up so that the target_wait() is forced to eventually
3186 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3187 differentiate to its caller what the state of the target is after
3188 the initial open has been performed. Here we're assuming that
3189 the target has stopped. It should be possible to eventually have
3190 target_open() return to the caller an indication that the target
3191 is currently running and GDB state should be set to the same as
3192 for an async run. */
3193 wait_for_inferior (inf
);
3195 /* Now that the inferior has stopped, do any bookkeeping like
3196 loading shared libraries. We want to do this before normal_stop,
3197 so that the displayed frame is up to date. */
3198 post_create_inferior (current_top_target (), from_tty
);
3203 /* Initialize static vars when a new inferior begins. */
3206 init_wait_for_inferior (void)
3208 /* These are meaningless until the first time through wait_for_inferior. */
3210 breakpoint_init_inferior (inf_starting
);
3212 clear_proceed_status (0);
3214 nullify_last_target_wait_ptid ();
3216 previous_inferior_ptid
= inferior_ptid
;
3221 static void handle_inferior_event (struct execution_control_state
*ecs
);
3223 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3224 struct execution_control_state
*ecs
);
3225 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3226 struct execution_control_state
*ecs
);
3227 static void handle_signal_stop (struct execution_control_state
*ecs
);
3228 static void check_exception_resume (struct execution_control_state
*,
3229 struct frame_info
*);
3231 static void end_stepping_range (struct execution_control_state
*ecs
);
3232 static void stop_waiting (struct execution_control_state
*ecs
);
3233 static void keep_going (struct execution_control_state
*ecs
);
3234 static void process_event_stop_test (struct execution_control_state
*ecs
);
3235 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3237 /* This function is attached as a "thread_stop_requested" observer.
3238 Cleanup local state that assumed the PTID was to be resumed, and
3239 report the stop to the frontend. */
3242 infrun_thread_stop_requested (ptid_t ptid
)
3244 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3246 /* PTID was requested to stop. If the thread was already stopped,
3247 but the user/frontend doesn't know about that yet (e.g., the
3248 thread had been temporarily paused for some step-over), set up
3249 for reporting the stop now. */
3250 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3252 if (tp
->state
!= THREAD_RUNNING
)
3257 /* Remove matching threads from the step-over queue, so
3258 start_step_over doesn't try to resume them
3260 if (thread_is_in_step_over_chain (tp
))
3261 global_thread_step_over_chain_remove (tp
);
3263 /* If the thread is stopped, but the user/frontend doesn't
3264 know about that yet, queue a pending event, as if the
3265 thread had just stopped now. Unless the thread already had
3267 if (!tp
->suspend
.waitstatus_pending_p
)
3269 tp
->suspend
.waitstatus_pending_p
= 1;
3270 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3271 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3274 /* Clear the inline-frame state, since we're re-processing the
3276 clear_inline_frame_state (tp
);
3278 /* If this thread was paused because some other thread was
3279 doing an inline-step over, let that finish first. Once
3280 that happens, we'll restart all threads and consume pending
3281 stop events then. */
3282 if (step_over_info_valid_p ())
3285 /* Otherwise we can process the (new) pending event now. Set
3286 it so this pending event is considered by
3293 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3295 if (target_last_proc_target
== tp
->inf
->process_target ()
3296 && target_last_wait_ptid
== tp
->ptid
)
3297 nullify_last_target_wait_ptid ();
3300 /* Delete the step resume, single-step and longjmp/exception resume
3301 breakpoints of TP. */
3304 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3306 delete_step_resume_breakpoint (tp
);
3307 delete_exception_resume_breakpoint (tp
);
3308 delete_single_step_breakpoints (tp
);
3311 /* If the target still has execution, call FUNC for each thread that
3312 just stopped. In all-stop, that's all the non-exited threads; in
3313 non-stop, that's the current thread, only. */
3315 typedef void (*for_each_just_stopped_thread_callback_func
)
3316 (struct thread_info
*tp
);
3319 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3321 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3324 if (target_is_non_stop_p ())
3326 /* If in non-stop mode, only the current thread stopped. */
3327 func (inferior_thread ());
3331 /* In all-stop mode, all threads have stopped. */
3332 for (thread_info
*tp
: all_non_exited_threads ())
3337 /* Delete the step resume and longjmp/exception resume breakpoints of
3338 the threads that just stopped. */
3341 delete_just_stopped_threads_infrun_breakpoints (void)
3343 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3346 /* Delete the single-step breakpoints of the threads that just
3350 delete_just_stopped_threads_single_step_breakpoints (void)
3352 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3358 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3359 const struct target_waitstatus
*ws
)
3361 std::string status_string
= target_waitstatus_to_string (ws
);
3364 /* The text is split over several lines because it was getting too long.
3365 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3366 output as a unit; we want only one timestamp printed if debug_timestamp
3369 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3372 waiton_ptid
.tid ());
3373 if (waiton_ptid
.pid () != -1)
3374 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3375 stb
.printf (", status) =\n");
3376 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3380 target_pid_to_str (result_ptid
).c_str ());
3381 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3383 /* This uses %s in part to handle %'s in the text, but also to avoid
3384 a gcc error: the format attribute requires a string literal. */
3385 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3388 /* Select a thread at random, out of those which are resumed and have
3391 static struct thread_info
*
3392 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3396 auto has_event
= [&] (thread_info
*tp
)
3398 return (tp
->ptid
.matches (waiton_ptid
)
3400 && tp
->suspend
.waitstatus_pending_p
);
3403 /* First see how many events we have. Count only resumed threads
3404 that have an event pending. */
3405 for (thread_info
*tp
: inf
->non_exited_threads ())
3409 if (num_events
== 0)
3412 /* Now randomly pick a thread out of those that have had events. */
3413 int random_selector
= (int) ((num_events
* (double) rand ())
3414 / (RAND_MAX
+ 1.0));
3417 infrun_log_debug ("Found %d events, selecting #%d",
3418 num_events
, random_selector
);
3420 /* Select the Nth thread that has had an event. */
3421 for (thread_info
*tp
: inf
->non_exited_threads ())
3423 if (random_selector
-- == 0)
3426 gdb_assert_not_reached ("event thread not found");
3429 /* Wrapper for target_wait that first checks whether threads have
3430 pending statuses to report before actually asking the target for
3431 more events. INF is the inferior we're using to call target_wait
3435 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3436 target_waitstatus
*status
, int options
)
3439 struct thread_info
*tp
;
3441 /* We know that we are looking for an event in the target of inferior
3442 INF, but we don't know which thread the event might come from. As
3443 such we want to make sure that INFERIOR_PTID is reset so that none of
3444 the wait code relies on it - doing so is always a mistake. */
3445 switch_to_inferior_no_thread (inf
);
3447 /* First check if there is a resumed thread with a wait status
3449 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3451 tp
= random_pending_event_thread (inf
, ptid
);
3455 infrun_log_debug ("Waiting for specific thread %s.",
3456 target_pid_to_str (ptid
).c_str ());
3458 /* We have a specific thread to check. */
3459 tp
= find_thread_ptid (inf
, ptid
);
3460 gdb_assert (tp
!= NULL
);
3461 if (!tp
->suspend
.waitstatus_pending_p
)
3466 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3467 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3469 struct regcache
*regcache
= get_thread_regcache (tp
);
3470 struct gdbarch
*gdbarch
= regcache
->arch ();
3474 pc
= regcache_read_pc (regcache
);
3476 if (pc
!= tp
->suspend
.stop_pc
)
3478 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3479 target_pid_to_str (tp
->ptid
).c_str (),
3480 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3481 paddress (gdbarch
, pc
));
3484 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3486 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3487 target_pid_to_str (tp
->ptid
).c_str (),
3488 paddress (gdbarch
, pc
));
3495 infrun_log_debug ("pending event of %s cancelled.",
3496 target_pid_to_str (tp
->ptid
).c_str ());
3498 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3499 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3505 infrun_log_debug ("Using pending wait status %s for %s.",
3506 target_waitstatus_to_string
3507 (&tp
->suspend
.waitstatus
).c_str (),
3508 target_pid_to_str (tp
->ptid
).c_str ());
3510 /* Now that we've selected our final event LWP, un-adjust its PC
3511 if it was a software breakpoint (and the target doesn't
3512 always adjust the PC itself). */
3513 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3514 && !target_supports_stopped_by_sw_breakpoint ())
3516 struct regcache
*regcache
;
3517 struct gdbarch
*gdbarch
;
3520 regcache
= get_thread_regcache (tp
);
3521 gdbarch
= regcache
->arch ();
3523 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3528 pc
= regcache_read_pc (regcache
);
3529 regcache_write_pc (regcache
, pc
+ decr_pc
);
3533 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3534 *status
= tp
->suspend
.waitstatus
;
3535 tp
->suspend
.waitstatus_pending_p
= 0;
3537 /* Wake up the event loop again, until all pending events are
3539 if (target_is_async_p ())
3540 mark_async_event_handler (infrun_async_inferior_event_token
);
3544 /* But if we don't find one, we'll have to wait. */
3546 if (deprecated_target_wait_hook
)
3547 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3549 event_ptid
= target_wait (ptid
, status
, options
);
3554 /* Returns true if INF has any resumed thread with a status
3558 threads_are_resumed_pending_p (inferior
*inf
)
3560 for (thread_info
*tp
: inf
->non_exited_threads ())
3562 && tp
->suspend
.waitstatus_pending_p
)
3568 /* Wrapper for target_wait that first checks whether threads have
3569 pending statuses to report before actually asking the target for
3570 more events. Polls for events from all inferiors/targets. */
3573 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3575 int num_inferiors
= 0;
3576 int random_selector
;
3578 /* For fairness, we pick the first inferior/target to poll at
3579 random, and then continue polling the rest of the inferior list
3580 starting from that one in a circular fashion until the whole list
3583 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3585 return (inf
->process_target () != NULL
3586 && (threads_are_executing (inf
->process_target ())
3587 || threads_are_resumed_pending_p (inf
))
3588 && ptid_t (inf
->pid
).matches (wait_ptid
));
3591 /* First see how many resumed inferiors we have. */
3592 for (inferior
*inf
: all_inferiors ())
3593 if (inferior_matches (inf
))
3596 if (num_inferiors
== 0)
3598 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3602 /* Now randomly pick an inferior out of those that were resumed. */
3603 random_selector
= (int)
3604 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3606 if (num_inferiors
> 1)
3607 infrun_log_debug ("Found %d inferiors, starting at #%d",
3608 num_inferiors
, random_selector
);
3610 /* Select the Nth inferior that was resumed. */
3612 inferior
*selected
= nullptr;
3614 for (inferior
*inf
: all_inferiors ())
3615 if (inferior_matches (inf
))
3616 if (random_selector
-- == 0)
3622 /* Now poll for events out of each of the resumed inferior's
3623 targets, starting from the selected one. */
3625 auto do_wait
= [&] (inferior
*inf
)
3627 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3628 ecs
->target
= inf
->process_target ();
3629 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3632 /* Needed in all-stop+target-non-stop mode, because we end up here
3633 spuriously after the target is all stopped and we've already
3634 reported the stop to the user, polling for events. */
3635 scoped_restore_current_thread restore_thread
;
3637 int inf_num
= selected
->num
;
3638 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3639 if (inferior_matches (inf
))
3643 for (inferior
*inf
= inferior_list
;
3644 inf
!= NULL
&& inf
->num
< inf_num
;
3646 if (inferior_matches (inf
))
3650 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3654 /* Prepare and stabilize the inferior for detaching it. E.g.,
3655 detaching while a thread is displaced stepping is a recipe for
3656 crashing it, as nothing would readjust the PC out of the scratch
3660 prepare_for_detach (void)
3662 struct inferior
*inf
= current_inferior ();
3663 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3665 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3667 /* Is any thread of this process displaced stepping? If not,
3668 there's nothing else to do. */
3669 if (displaced_step_in_progress (inf
))
3672 infrun_log_debug ("displaced-stepping in-process while detaching");
3674 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3679 struct execution_control_state ecss
;
3680 struct execution_control_state
*ecs
;
3683 memset (ecs
, 0, sizeof (*ecs
));
3685 overlay_cache_invalid
= 1;
3686 /* Flush target cache before starting to handle each event.
3687 Target was running and cache could be stale. This is just a
3688 heuristic. Running threads may modify target memory, but we
3689 don't get any event. */
3690 target_dcache_invalidate ();
3692 do_target_wait (pid_ptid
, ecs
, 0);
3695 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3697 /* If an error happens while handling the event, propagate GDB's
3698 knowledge of the executing state to the frontend/user running
3700 scoped_finish_thread_state
finish_state (inf
->process_target (),
3703 /* Now figure out what to do with the result of the result. */
3704 handle_inferior_event (ecs
);
3706 /* No error, don't finish the state yet. */
3707 finish_state
.release ();
3709 /* Breakpoints and watchpoints are not installed on the target
3710 at this point, and signals are passed directly to the
3711 inferior, so this must mean the process is gone. */
3712 if (!ecs
->wait_some_more
)
3714 restore_detaching
.release ();
3715 error (_("Program exited while detaching"));
3719 restore_detaching
.release ();
3722 /* Wait for control to return from inferior to debugger.
3724 If inferior gets a signal, we may decide to start it up again
3725 instead of returning. That is why there is a loop in this function.
3726 When this function actually returns it means the inferior
3727 should be left stopped and GDB should read more commands. */
3730 wait_for_inferior (inferior
*inf
)
3732 infrun_log_debug ("wait_for_inferior ()");
3734 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3736 /* If an error happens while handling the event, propagate GDB's
3737 knowledge of the executing state to the frontend/user running
3739 scoped_finish_thread_state finish_state
3740 (inf
->process_target (), minus_one_ptid
);
3744 struct execution_control_state ecss
;
3745 struct execution_control_state
*ecs
= &ecss
;
3747 memset (ecs
, 0, sizeof (*ecs
));
3749 overlay_cache_invalid
= 1;
3751 /* Flush target cache before starting to handle each event.
3752 Target was running and cache could be stale. This is just a
3753 heuristic. Running threads may modify target memory, but we
3754 don't get any event. */
3755 target_dcache_invalidate ();
3757 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3758 ecs
->target
= inf
->process_target ();
3761 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3763 /* Now figure out what to do with the result of the result. */
3764 handle_inferior_event (ecs
);
3766 if (!ecs
->wait_some_more
)
3770 /* No error, don't finish the state yet. */
3771 finish_state
.release ();
3774 /* Cleanup that reinstalls the readline callback handler, if the
3775 target is running in the background. If while handling the target
3776 event something triggered a secondary prompt, like e.g., a
3777 pagination prompt, we'll have removed the callback handler (see
3778 gdb_readline_wrapper_line). Need to do this as we go back to the
3779 event loop, ready to process further input. Note this has no
3780 effect if the handler hasn't actually been removed, because calling
3781 rl_callback_handler_install resets the line buffer, thus losing
3785 reinstall_readline_callback_handler_cleanup ()
3787 struct ui
*ui
= current_ui
;
3791 /* We're not going back to the top level event loop yet. Don't
3792 install the readline callback, as it'd prep the terminal,
3793 readline-style (raw, noecho) (e.g., --batch). We'll install
3794 it the next time the prompt is displayed, when we're ready
3799 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3800 gdb_rl_callback_handler_reinstall ();
3803 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3804 that's just the event thread. In all-stop, that's all threads. */
3807 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3809 if (ecs
->event_thread
!= NULL
3810 && ecs
->event_thread
->thread_fsm
!= NULL
)
3811 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3815 for (thread_info
*thr
: all_non_exited_threads ())
3817 if (thr
->thread_fsm
== NULL
)
3819 if (thr
== ecs
->event_thread
)
3822 switch_to_thread (thr
);
3823 thr
->thread_fsm
->clean_up (thr
);
3826 if (ecs
->event_thread
!= NULL
)
3827 switch_to_thread (ecs
->event_thread
);
3831 /* Helper for all_uis_check_sync_execution_done that works on the
3835 check_curr_ui_sync_execution_done (void)
3837 struct ui
*ui
= current_ui
;
3839 if (ui
->prompt_state
== PROMPT_NEEDED
3841 && !gdb_in_secondary_prompt_p (ui
))
3843 target_terminal::ours ();
3844 gdb::observers::sync_execution_done
.notify ();
3845 ui_register_input_event_handler (ui
);
3852 all_uis_check_sync_execution_done (void)
3854 SWITCH_THRU_ALL_UIS ()
3856 check_curr_ui_sync_execution_done ();
3863 all_uis_on_sync_execution_starting (void)
3865 SWITCH_THRU_ALL_UIS ()
3867 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3868 async_disable_stdin ();
3872 /* Asynchronous version of wait_for_inferior. It is called by the
3873 event loop whenever a change of state is detected on the file
3874 descriptor corresponding to the target. It can be called more than
3875 once to complete a single execution command. In such cases we need
3876 to keep the state in a global variable ECSS. If it is the last time
3877 that this function is called for a single execution command, then
3878 report to the user that the inferior has stopped, and do the
3879 necessary cleanups. */
3882 fetch_inferior_event (void *client_data
)
3884 struct execution_control_state ecss
;
3885 struct execution_control_state
*ecs
= &ecss
;
3888 memset (ecs
, 0, sizeof (*ecs
));
3890 /* Events are always processed with the main UI as current UI. This
3891 way, warnings, debug output, etc. are always consistently sent to
3892 the main console. */
3893 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3895 /* End up with readline processing input, if necessary. */
3897 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3899 /* We're handling a live event, so make sure we're doing live
3900 debugging. If we're looking at traceframes while the target is
3901 running, we're going to need to get back to that mode after
3902 handling the event. */
3903 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3906 maybe_restore_traceframe
.emplace ();
3907 set_current_traceframe (-1);
3910 /* The user/frontend should not notice a thread switch due to
3911 internal events. Make sure we revert to the user selected
3912 thread and frame after handling the event and running any
3913 breakpoint commands. */
3914 scoped_restore_current_thread restore_thread
;
3916 overlay_cache_invalid
= 1;
3917 /* Flush target cache before starting to handle each event. Target
3918 was running and cache could be stale. This is just a heuristic.
3919 Running threads may modify target memory, but we don't get any
3921 target_dcache_invalidate ();
3923 scoped_restore save_exec_dir
3924 = make_scoped_restore (&execution_direction
,
3925 target_execution_direction ());
3927 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3930 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3932 /* Switch to the target that generated the event, so we can do
3933 target calls. Any inferior bound to the target will do, so we
3934 just switch to the first we find. */
3935 for (inferior
*inf
: all_inferiors (ecs
->target
))
3937 switch_to_inferior_no_thread (inf
);
3942 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3944 /* If an error happens while handling the event, propagate GDB's
3945 knowledge of the executing state to the frontend/user running
3947 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3948 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3950 /* Get executed before scoped_restore_current_thread above to apply
3951 still for the thread which has thrown the exception. */
3952 auto defer_bpstat_clear
3953 = make_scope_exit (bpstat_clear_actions
);
3954 auto defer_delete_threads
3955 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3957 /* Now figure out what to do with the result of the result. */
3958 handle_inferior_event (ecs
);
3960 if (!ecs
->wait_some_more
)
3962 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3963 int should_stop
= 1;
3964 struct thread_info
*thr
= ecs
->event_thread
;
3966 delete_just_stopped_threads_infrun_breakpoints ();
3970 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3972 if (thread_fsm
!= NULL
)
3973 should_stop
= thread_fsm
->should_stop (thr
);
3982 bool should_notify_stop
= true;
3985 clean_up_just_stopped_threads_fsms (ecs
);
3987 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3988 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3990 if (should_notify_stop
)
3992 /* We may not find an inferior if this was a process exit. */
3993 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3994 proceeded
= normal_stop ();
3999 inferior_event_handler (INF_EXEC_COMPLETE
, NULL
);
4003 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
4004 previously selected thread is gone. We have two
4005 choices - switch to no thread selected, or restore the
4006 previously selected thread (now exited). We chose the
4007 later, just because that's what GDB used to do. After
4008 this, "info threads" says "The current thread <Thread
4009 ID 2> has terminated." instead of "No thread
4013 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
4014 restore_thread
.dont_restore ();
4018 defer_delete_threads
.release ();
4019 defer_bpstat_clear
.release ();
4021 /* No error, don't finish the thread states yet. */
4022 finish_state
.release ();
4024 /* This scope is used to ensure that readline callbacks are
4025 reinstalled here. */
4028 /* If a UI was in sync execution mode, and now isn't, restore its
4029 prompt (a synchronous execution command has finished, and we're
4030 ready for input). */
4031 all_uis_check_sync_execution_done ();
4034 && exec_done_display_p
4035 && (inferior_ptid
== null_ptid
4036 || inferior_thread ()->state
!= THREAD_RUNNING
))
4037 printf_unfiltered (_("completed.\n"));
4043 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4044 struct symtab_and_line sal
)
4046 /* This can be removed once this function no longer implicitly relies on the
4047 inferior_ptid value. */
4048 gdb_assert (inferior_ptid
== tp
->ptid
);
4050 tp
->control
.step_frame_id
= get_frame_id (frame
);
4051 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4053 tp
->current_symtab
= sal
.symtab
;
4054 tp
->current_line
= sal
.line
;
4057 /* Clear context switchable stepping state. */
4060 init_thread_stepping_state (struct thread_info
*tss
)
4062 tss
->stepped_breakpoint
= 0;
4063 tss
->stepping_over_breakpoint
= 0;
4064 tss
->stepping_over_watchpoint
= 0;
4065 tss
->step_after_step_resume_breakpoint
= 0;
4071 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4072 target_waitstatus status
)
4074 target_last_proc_target
= target
;
4075 target_last_wait_ptid
= ptid
;
4076 target_last_waitstatus
= status
;
4082 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4083 target_waitstatus
*status
)
4085 if (target
!= nullptr)
4086 *target
= target_last_proc_target
;
4087 if (ptid
!= nullptr)
4088 *ptid
= target_last_wait_ptid
;
4089 if (status
!= nullptr)
4090 *status
= target_last_waitstatus
;
4096 nullify_last_target_wait_ptid (void)
4098 target_last_proc_target
= nullptr;
4099 target_last_wait_ptid
= minus_one_ptid
;
4100 target_last_waitstatus
= {};
4103 /* Switch thread contexts. */
4106 context_switch (execution_control_state
*ecs
)
4108 if (ecs
->ptid
!= inferior_ptid
4109 && (inferior_ptid
== null_ptid
4110 || ecs
->event_thread
!= inferior_thread ()))
4112 infrun_log_debug ("Switching context from %s to %s",
4113 target_pid_to_str (inferior_ptid
).c_str (),
4114 target_pid_to_str (ecs
->ptid
).c_str ());
4117 switch_to_thread (ecs
->event_thread
);
4120 /* If the target can't tell whether we've hit breakpoints
4121 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4122 check whether that could have been caused by a breakpoint. If so,
4123 adjust the PC, per gdbarch_decr_pc_after_break. */
4126 adjust_pc_after_break (struct thread_info
*thread
,
4127 struct target_waitstatus
*ws
)
4129 struct regcache
*regcache
;
4130 struct gdbarch
*gdbarch
;
4131 CORE_ADDR breakpoint_pc
, decr_pc
;
4133 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4134 we aren't, just return.
4136 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4137 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4138 implemented by software breakpoints should be handled through the normal
4141 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4142 different signals (SIGILL or SIGEMT for instance), but it is less
4143 clear where the PC is pointing afterwards. It may not match
4144 gdbarch_decr_pc_after_break. I don't know any specific target that
4145 generates these signals at breakpoints (the code has been in GDB since at
4146 least 1992) so I can not guess how to handle them here.
4148 In earlier versions of GDB, a target with
4149 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4150 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4151 target with both of these set in GDB history, and it seems unlikely to be
4152 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4154 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4157 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4160 /* In reverse execution, when a breakpoint is hit, the instruction
4161 under it has already been de-executed. The reported PC always
4162 points at the breakpoint address, so adjusting it further would
4163 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4166 B1 0x08000000 : INSN1
4167 B2 0x08000001 : INSN2
4169 PC -> 0x08000003 : INSN4
4171 Say you're stopped at 0x08000003 as above. Reverse continuing
4172 from that point should hit B2 as below. Reading the PC when the
4173 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4174 been de-executed already.
4176 B1 0x08000000 : INSN1
4177 B2 PC -> 0x08000001 : INSN2
4181 We can't apply the same logic as for forward execution, because
4182 we would wrongly adjust the PC to 0x08000000, since there's a
4183 breakpoint at PC - 1. We'd then report a hit on B1, although
4184 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4186 if (execution_direction
== EXEC_REVERSE
)
4189 /* If the target can tell whether the thread hit a SW breakpoint,
4190 trust it. Targets that can tell also adjust the PC
4192 if (target_supports_stopped_by_sw_breakpoint ())
4195 /* Note that relying on whether a breakpoint is planted in memory to
4196 determine this can fail. E.g,. the breakpoint could have been
4197 removed since. Or the thread could have been told to step an
4198 instruction the size of a breakpoint instruction, and only
4199 _after_ was a breakpoint inserted at its address. */
4201 /* If this target does not decrement the PC after breakpoints, then
4202 we have nothing to do. */
4203 regcache
= get_thread_regcache (thread
);
4204 gdbarch
= regcache
->arch ();
4206 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4210 const address_space
*aspace
= regcache
->aspace ();
4212 /* Find the location where (if we've hit a breakpoint) the
4213 breakpoint would be. */
4214 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4216 /* If the target can't tell whether a software breakpoint triggered,
4217 fallback to figuring it out based on breakpoints we think were
4218 inserted in the target, and on whether the thread was stepped or
4221 /* Check whether there actually is a software breakpoint inserted at
4224 If in non-stop mode, a race condition is possible where we've
4225 removed a breakpoint, but stop events for that breakpoint were
4226 already queued and arrive later. To suppress those spurious
4227 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4228 and retire them after a number of stop events are reported. Note
4229 this is an heuristic and can thus get confused. The real fix is
4230 to get the "stopped by SW BP and needs adjustment" info out of
4231 the target/kernel (and thus never reach here; see above). */
4232 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4233 || (target_is_non_stop_p ()
4234 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4236 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4238 if (record_full_is_used ())
4239 restore_operation_disable
.emplace
4240 (record_full_gdb_operation_disable_set ());
4242 /* When using hardware single-step, a SIGTRAP is reported for both
4243 a completed single-step and a software breakpoint. Need to
4244 differentiate between the two, as the latter needs adjusting
4245 but the former does not.
4247 The SIGTRAP can be due to a completed hardware single-step only if
4248 - we didn't insert software single-step breakpoints
4249 - this thread is currently being stepped
4251 If any of these events did not occur, we must have stopped due
4252 to hitting a software breakpoint, and have to back up to the
4255 As a special case, we could have hardware single-stepped a
4256 software breakpoint. In this case (prev_pc == breakpoint_pc),
4257 we also need to back up to the breakpoint address. */
4259 if (thread_has_single_step_breakpoints_set (thread
)
4260 || !currently_stepping (thread
)
4261 || (thread
->stepped_breakpoint
4262 && thread
->prev_pc
== breakpoint_pc
))
4263 regcache_write_pc (regcache
, breakpoint_pc
);
4268 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4270 for (frame
= get_prev_frame (frame
);
4272 frame
= get_prev_frame (frame
))
4274 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4276 if (get_frame_type (frame
) != INLINE_FRAME
)
4283 /* Look for an inline frame that is marked for skip.
4284 If PREV_FRAME is TRUE start at the previous frame,
4285 otherwise start at the current frame. Stop at the
4286 first non-inline frame, or at the frame where the
4290 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4292 struct frame_info
*frame
= get_current_frame ();
4295 frame
= get_prev_frame (frame
);
4297 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4299 const char *fn
= NULL
;
4300 symtab_and_line sal
;
4303 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4305 if (get_frame_type (frame
) != INLINE_FRAME
)
4308 sal
= find_frame_sal (frame
);
4309 sym
= get_frame_function (frame
);
4312 fn
= sym
->print_name ();
4315 && function_name_is_marked_for_skip (fn
, sal
))
4322 /* If the event thread has the stop requested flag set, pretend it
4323 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4327 handle_stop_requested (struct execution_control_state
*ecs
)
4329 if (ecs
->event_thread
->stop_requested
)
4331 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4332 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4333 handle_signal_stop (ecs
);
4339 /* Auxiliary function that handles syscall entry/return events.
4340 It returns 1 if the inferior should keep going (and GDB
4341 should ignore the event), or 0 if the event deserves to be
4345 handle_syscall_event (struct execution_control_state
*ecs
)
4347 struct regcache
*regcache
;
4350 context_switch (ecs
);
4352 regcache
= get_thread_regcache (ecs
->event_thread
);
4353 syscall_number
= ecs
->ws
.value
.syscall_number
;
4354 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4356 if (catch_syscall_enabled () > 0
4357 && catching_syscall_number (syscall_number
) > 0)
4359 infrun_log_debug ("syscall number=%d", syscall_number
);
4361 ecs
->event_thread
->control
.stop_bpstat
4362 = bpstat_stop_status (regcache
->aspace (),
4363 ecs
->event_thread
->suspend
.stop_pc
,
4364 ecs
->event_thread
, &ecs
->ws
);
4366 if (handle_stop_requested (ecs
))
4369 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4371 /* Catchpoint hit. */
4376 if (handle_stop_requested (ecs
))
4379 /* If no catchpoint triggered for this, then keep going. */
4384 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4387 fill_in_stop_func (struct gdbarch
*gdbarch
,
4388 struct execution_control_state
*ecs
)
4390 if (!ecs
->stop_func_filled_in
)
4394 /* Don't care about return value; stop_func_start and stop_func_name
4395 will both be 0 if it doesn't work. */
4396 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4397 &ecs
->stop_func_name
,
4398 &ecs
->stop_func_start
,
4399 &ecs
->stop_func_end
,
4402 /* The call to find_pc_partial_function, above, will set
4403 stop_func_start and stop_func_end to the start and end
4404 of the range containing the stop pc. If this range
4405 contains the entry pc for the block (which is always the
4406 case for contiguous blocks), advance stop_func_start past
4407 the function's start offset and entrypoint. Note that
4408 stop_func_start is NOT advanced when in a range of a
4409 non-contiguous block that does not contain the entry pc. */
4410 if (block
!= nullptr
4411 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4412 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4414 ecs
->stop_func_start
4415 += gdbarch_deprecated_function_start_offset (gdbarch
);
4417 if (gdbarch_skip_entrypoint_p (gdbarch
))
4418 ecs
->stop_func_start
4419 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4422 ecs
->stop_func_filled_in
= 1;
4427 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4429 static enum stop_kind
4430 get_inferior_stop_soon (execution_control_state
*ecs
)
4432 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4434 gdb_assert (inf
!= NULL
);
4435 return inf
->control
.stop_soon
;
4438 /* Poll for one event out of the current target. Store the resulting
4439 waitstatus in WS, and return the event ptid. Does not block. */
4442 poll_one_curr_target (struct target_waitstatus
*ws
)
4446 overlay_cache_invalid
= 1;
4448 /* Flush target cache before starting to handle each event.
4449 Target was running and cache could be stale. This is just a
4450 heuristic. Running threads may modify target memory, but we
4451 don't get any event. */
4452 target_dcache_invalidate ();
4454 if (deprecated_target_wait_hook
)
4455 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4457 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4460 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4465 /* An event reported by wait_one. */
4467 struct wait_one_event
4469 /* The target the event came out of. */
4470 process_stratum_target
*target
;
4472 /* The PTID the event was for. */
4475 /* The waitstatus. */
4476 target_waitstatus ws
;
4479 /* Wait for one event out of any target. */
4481 static wait_one_event
4486 for (inferior
*inf
: all_inferiors ())
4488 process_stratum_target
*target
= inf
->process_target ();
4490 || !target
->is_async_p ()
4491 || !target
->threads_executing
)
4494 switch_to_inferior_no_thread (inf
);
4496 wait_one_event event
;
4497 event
.target
= target
;
4498 event
.ptid
= poll_one_curr_target (&event
.ws
);
4500 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4502 /* If nothing is resumed, remove the target from the
4506 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4510 /* Block waiting for some event. */
4517 for (inferior
*inf
: all_inferiors ())
4519 process_stratum_target
*target
= inf
->process_target ();
4521 || !target
->is_async_p ()
4522 || !target
->threads_executing
)
4525 int fd
= target
->async_wait_fd ();
4526 FD_SET (fd
, &readfds
);
4533 /* No waitable targets left. All must be stopped. */
4534 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4539 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4545 perror_with_name ("interruptible_select");
4550 /* Generate a wrapper for target_stopped_by_REASON that works on PTID
4551 instead of the current thread. */
4552 #define THREAD_STOPPED_BY(REASON) \
4554 thread_stopped_by_ ## REASON (ptid_t ptid) \
4556 scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid); \
4557 inferior_ptid = ptid; \
4559 return target_stopped_by_ ## REASON (); \
4562 /* Generate thread_stopped_by_watchpoint. */
4563 THREAD_STOPPED_BY (watchpoint
)
4564 /* Generate thread_stopped_by_sw_breakpoint. */
4565 THREAD_STOPPED_BY (sw_breakpoint
)
4566 /* Generate thread_stopped_by_hw_breakpoint. */
4567 THREAD_STOPPED_BY (hw_breakpoint
)
4569 /* Save the thread's event and stop reason to process it later. */
4572 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4574 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4575 target_waitstatus_to_string (ws
).c_str (),
4580 /* Record for later. */
4581 tp
->suspend
.waitstatus
= *ws
;
4582 tp
->suspend
.waitstatus_pending_p
= 1;
4584 struct regcache
*regcache
= get_thread_regcache (tp
);
4585 const address_space
*aspace
= regcache
->aspace ();
4587 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4588 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4590 CORE_ADDR pc
= regcache_read_pc (regcache
);
4592 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4594 if (thread_stopped_by_watchpoint (tp
->ptid
))
4596 tp
->suspend
.stop_reason
4597 = TARGET_STOPPED_BY_WATCHPOINT
;
4599 else if (target_supports_stopped_by_sw_breakpoint ()
4600 && thread_stopped_by_sw_breakpoint (tp
->ptid
))
4602 tp
->suspend
.stop_reason
4603 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4605 else if (target_supports_stopped_by_hw_breakpoint ()
4606 && thread_stopped_by_hw_breakpoint (tp
->ptid
))
4608 tp
->suspend
.stop_reason
4609 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4611 else if (!target_supports_stopped_by_hw_breakpoint ()
4612 && hardware_breakpoint_inserted_here_p (aspace
,
4615 tp
->suspend
.stop_reason
4616 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4618 else if (!target_supports_stopped_by_sw_breakpoint ()
4619 && software_breakpoint_inserted_here_p (aspace
,
4622 tp
->suspend
.stop_reason
4623 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4625 else if (!thread_has_single_step_breakpoints_set (tp
)
4626 && currently_stepping (tp
))
4628 tp
->suspend
.stop_reason
4629 = TARGET_STOPPED_BY_SINGLE_STEP
;
4634 /* Mark the non-executing threads accordingly. In all-stop, all
4635 threads of all processes are stopped when we get any event
4636 reported. In non-stop mode, only the event thread stops. */
4639 mark_non_executing_threads (process_stratum_target
*target
,
4641 struct target_waitstatus ws
)
4645 if (!target_is_non_stop_p ())
4646 mark_ptid
= minus_one_ptid
;
4647 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4648 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4650 /* If we're handling a process exit in non-stop mode, even
4651 though threads haven't been deleted yet, one would think
4652 that there is nothing to do, as threads of the dead process
4653 will be soon deleted, and threads of any other process were
4654 left running. However, on some targets, threads survive a
4655 process exit event. E.g., for the "checkpoint" command,
4656 when the current checkpoint/fork exits, linux-fork.c
4657 automatically switches to another fork from within
4658 target_mourn_inferior, by associating the same
4659 inferior/thread to another fork. We haven't mourned yet at
4660 this point, but we must mark any threads left in the
4661 process as not-executing so that finish_thread_state marks
4662 them stopped (in the user's perspective) if/when we present
4663 the stop to the user. */
4664 mark_ptid
= ptid_t (event_ptid
.pid ());
4667 mark_ptid
= event_ptid
;
4669 set_executing (target
, mark_ptid
, false);
4671 /* Likewise the resumed flag. */
4672 set_resumed (target
, mark_ptid
, false);
4678 stop_all_threads (void)
4680 /* We may need multiple passes to discover all threads. */
4684 gdb_assert (exists_non_stop_target ());
4686 infrun_log_debug ("stop_all_threads");
4688 scoped_restore_current_thread restore_thread
;
4690 /* Enable thread events of all targets. */
4691 for (auto *target
: all_non_exited_process_targets ())
4693 switch_to_target_no_thread (target
);
4694 target_thread_events (true);
4699 /* Disable thread events of all targets. */
4700 for (auto *target
: all_non_exited_process_targets ())
4702 switch_to_target_no_thread (target
);
4703 target_thread_events (false);
4707 infrun_log_debug ("stop_all_threads done");
4710 /* Request threads to stop, and then wait for the stops. Because
4711 threads we already know about can spawn more threads while we're
4712 trying to stop them, and we only learn about new threads when we
4713 update the thread list, do this in a loop, and keep iterating
4714 until two passes find no threads that need to be stopped. */
4715 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4717 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4721 int waits_needed
= 0;
4723 for (auto *target
: all_non_exited_process_targets ())
4725 switch_to_target_no_thread (target
);
4726 update_thread_list ();
4729 /* Go through all threads looking for threads that we need
4730 to tell the target to stop. */
4731 for (thread_info
*t
: all_non_exited_threads ())
4733 /* For a single-target setting with an all-stop target,
4734 we would not even arrive here. For a multi-target
4735 setting, until GDB is able to handle a mixture of
4736 all-stop and non-stop targets, simply skip all-stop
4737 targets' threads. This should be fine due to the
4738 protection of 'check_multi_target_resumption'. */
4740 switch_to_thread_no_regs (t
);
4741 if (!target_is_non_stop_p ())
4746 /* If already stopping, don't request a stop again.
4747 We just haven't seen the notification yet. */
4748 if (!t
->stop_requested
)
4750 infrun_log_debug (" %s executing, need stop",
4751 target_pid_to_str (t
->ptid
).c_str ());
4752 target_stop (t
->ptid
);
4753 t
->stop_requested
= 1;
4757 infrun_log_debug (" %s executing, already stopping",
4758 target_pid_to_str (t
->ptid
).c_str ());
4761 if (t
->stop_requested
)
4766 infrun_log_debug (" %s not executing",
4767 target_pid_to_str (t
->ptid
).c_str ());
4769 /* The thread may be not executing, but still be
4770 resumed with a pending status to process. */
4775 if (waits_needed
== 0)
4778 /* If we find new threads on the second iteration, restart
4779 over. We want to see two iterations in a row with all
4784 for (int i
= 0; i
< waits_needed
; i
++)
4786 wait_one_event event
= wait_one ();
4788 infrun_log_debug ("%s %s\n",
4789 target_waitstatus_to_string (&event
.ws
).c_str (),
4790 target_pid_to_str (event
.ptid
).c_str ());
4792 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4794 /* All resumed threads exited. */
4797 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4798 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4799 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4801 /* One thread/process exited/signalled. */
4803 thread_info
*t
= nullptr;
4805 /* The target may have reported just a pid. If so, try
4806 the first non-exited thread. */
4807 if (event
.ptid
.is_pid ())
4809 int pid
= event
.ptid
.pid ();
4810 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4811 for (thread_info
*tp
: inf
->non_exited_threads ())
4817 /* If there is no available thread, the event would
4818 have to be appended to a per-inferior event list,
4819 which does not exist (and if it did, we'd have
4820 to adjust run control command to be able to
4821 resume such an inferior). We assert here instead
4822 of going into an infinite loop. */
4823 gdb_assert (t
!= nullptr);
4825 infrun_log_debug ("using %s\n",
4826 target_pid_to_str (t
->ptid
).c_str ());
4830 t
= find_thread_ptid (event
.target
, event
.ptid
);
4831 /* Check if this is the first time we see this thread.
4832 Don't bother adding if it individually exited. */
4834 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4835 t
= add_thread (event
.target
, event
.ptid
);
4840 /* Set the threads as non-executing to avoid
4841 another stop attempt on them. */
4842 switch_to_thread_no_regs (t
);
4843 mark_non_executing_threads (event
.target
, event
.ptid
,
4845 save_waitstatus (t
, &event
.ws
);
4846 t
->stop_requested
= false;
4851 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4853 t
= add_thread (event
.target
, event
.ptid
);
4855 t
->stop_requested
= 0;
4858 t
->control
.may_range_step
= 0;
4860 /* This may be the first time we see the inferior report
4862 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4863 if (inf
->needs_setup
)
4865 switch_to_thread_no_regs (t
);
4869 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4870 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4872 /* We caught the event that we intended to catch, so
4873 there's no event pending. */
4874 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4875 t
->suspend
.waitstatus_pending_p
= 0;
4877 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4879 /* Add it back to the step-over queue. */
4880 infrun_log_debug ("displaced-step of %s "
4881 "canceled: adding back to the "
4882 "step-over queue\n",
4883 target_pid_to_str (t
->ptid
).c_str ());
4885 t
->control
.trap_expected
= 0;
4886 global_thread_step_over_chain_enqueue (t
);
4891 enum gdb_signal sig
;
4892 struct regcache
*regcache
;
4896 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4898 infrun_log_debug ("target_wait %s, saving "
4899 "status for %d.%ld.%ld\n",
4906 /* Record for later. */
4907 save_waitstatus (t
, &event
.ws
);
4909 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4910 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4912 if (displaced_step_finish (t
, sig
) < 0)
4914 /* Add it back to the step-over queue. */
4915 t
->control
.trap_expected
= 0;
4916 global_thread_step_over_chain_enqueue (t
);
4919 regcache
= get_thread_regcache (t
);
4920 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4922 infrun_log_debug ("saved stop_pc=%s for %s "
4923 "(currently_stepping=%d)\n",
4924 paddress (target_gdbarch (),
4925 t
->suspend
.stop_pc
),
4926 target_pid_to_str (t
->ptid
).c_str (),
4927 currently_stepping (t
));
4935 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4938 handle_no_resumed (struct execution_control_state
*ecs
)
4940 if (target_can_async_p ())
4944 for (ui
*ui
: all_uis ())
4946 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4954 /* There were no unwaited-for children left in the target, but,
4955 we're not synchronously waiting for events either. Just
4958 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4959 prepare_to_wait (ecs
);
4964 /* Otherwise, if we were running a synchronous execution command, we
4965 may need to cancel it and give the user back the terminal.
4967 In non-stop mode, the target can't tell whether we've already
4968 consumed previous stop events, so it can end up sending us a
4969 no-resumed event like so:
4971 #0 - thread 1 is left stopped
4973 #1 - thread 2 is resumed and hits breakpoint
4974 -> TARGET_WAITKIND_STOPPED
4976 #2 - thread 3 is resumed and exits
4977 this is the last resumed thread, so
4978 -> TARGET_WAITKIND_NO_RESUMED
4980 #3 - gdb processes stop for thread 2 and decides to re-resume
4983 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4984 thread 2 is now resumed, so the event should be ignored.
4986 IOW, if the stop for thread 2 doesn't end a foreground command,
4987 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4988 event. But it could be that the event meant that thread 2 itself
4989 (or whatever other thread was the last resumed thread) exited.
4991 To address this we refresh the thread list and check whether we
4992 have resumed threads _now_. In the example above, this removes
4993 thread 3 from the thread list. If thread 2 was re-resumed, we
4994 ignore this event. If we find no thread resumed, then we cancel
4995 the synchronous command show "no unwaited-for " to the user. */
4996 update_thread_list ();
4998 for (thread_info
*thread
: all_non_exited_threads (ecs
->target
))
5000 if (thread
->executing
5001 || thread
->suspend
.waitstatus_pending_p
)
5003 /* There were no unwaited-for children left in the target at
5004 some point, but there are now. Just ignore. */
5005 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
5006 "(ignoring: found resumed)");
5007 prepare_to_wait (ecs
);
5012 /* Go ahead and report the event. */
5016 /* Given an execution control state that has been freshly filled in by
5017 an event from the inferior, figure out what it means and take
5020 The alternatives are:
5022 1) stop_waiting and return; to really stop and return to the
5025 2) keep_going and return; to wait for the next event (set
5026 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5030 handle_inferior_event (struct execution_control_state
*ecs
)
5032 /* Make sure that all temporary struct value objects that were
5033 created during the handling of the event get deleted at the
5035 scoped_value_mark free_values
;
5037 enum stop_kind stop_soon
;
5039 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5041 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5043 /* We had an event in the inferior, but we are not interested in
5044 handling it at this level. The lower layers have already
5045 done what needs to be done, if anything.
5047 One of the possible circumstances for this is when the
5048 inferior produces output for the console. The inferior has
5049 not stopped, and we are ignoring the event. Another possible
5050 circumstance is any event which the lower level knows will be
5051 reported multiple times without an intervening resume. */
5052 prepare_to_wait (ecs
);
5056 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5058 prepare_to_wait (ecs
);
5062 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5063 && handle_no_resumed (ecs
))
5066 /* Cache the last target/ptid/waitstatus. */
5067 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5069 /* Always clear state belonging to the previous time we stopped. */
5070 stop_stack_dummy
= STOP_NONE
;
5072 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5074 /* No unwaited-for children left. IOW, all resumed children
5076 stop_print_frame
= 0;
5081 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5082 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5084 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5085 /* If it's a new thread, add it to the thread database. */
5086 if (ecs
->event_thread
== NULL
)
5087 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5089 /* Disable range stepping. If the next step request could use a
5090 range, this will be end up re-enabled then. */
5091 ecs
->event_thread
->control
.may_range_step
= 0;
5094 /* Dependent on valid ECS->EVENT_THREAD. */
5095 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5097 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5098 reinit_frame_cache ();
5100 breakpoint_retire_moribund ();
5102 /* First, distinguish signals caused by the debugger from signals
5103 that have to do with the program's own actions. Note that
5104 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5105 on the operating system version. Here we detect when a SIGILL or
5106 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5107 something similar for SIGSEGV, since a SIGSEGV will be generated
5108 when we're trying to execute a breakpoint instruction on a
5109 non-executable stack. This happens for call dummy breakpoints
5110 for architectures like SPARC that place call dummies on the
5112 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5113 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5114 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5115 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5117 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5119 if (breakpoint_inserted_here_p (regcache
->aspace (),
5120 regcache_read_pc (regcache
)))
5122 infrun_log_debug ("Treating signal as SIGTRAP");
5123 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5127 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5129 switch (ecs
->ws
.kind
)
5131 case TARGET_WAITKIND_LOADED
:
5132 context_switch (ecs
);
5133 /* Ignore gracefully during startup of the inferior, as it might
5134 be the shell which has just loaded some objects, otherwise
5135 add the symbols for the newly loaded objects. Also ignore at
5136 the beginning of an attach or remote session; we will query
5137 the full list of libraries once the connection is
5140 stop_soon
= get_inferior_stop_soon (ecs
);
5141 if (stop_soon
== NO_STOP_QUIETLY
)
5143 struct regcache
*regcache
;
5145 regcache
= get_thread_regcache (ecs
->event_thread
);
5147 handle_solib_event ();
5149 ecs
->event_thread
->control
.stop_bpstat
5150 = bpstat_stop_status (regcache
->aspace (),
5151 ecs
->event_thread
->suspend
.stop_pc
,
5152 ecs
->event_thread
, &ecs
->ws
);
5154 if (handle_stop_requested (ecs
))
5157 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5159 /* A catchpoint triggered. */
5160 process_event_stop_test (ecs
);
5164 /* If requested, stop when the dynamic linker notifies
5165 gdb of events. This allows the user to get control
5166 and place breakpoints in initializer routines for
5167 dynamically loaded objects (among other things). */
5168 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5169 if (stop_on_solib_events
)
5171 /* Make sure we print "Stopped due to solib-event" in
5173 stop_print_frame
= 1;
5180 /* If we are skipping through a shell, or through shared library
5181 loading that we aren't interested in, resume the program. If
5182 we're running the program normally, also resume. */
5183 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5185 /* Loading of shared libraries might have changed breakpoint
5186 addresses. Make sure new breakpoints are inserted. */
5187 if (stop_soon
== NO_STOP_QUIETLY
)
5188 insert_breakpoints ();
5189 resume (GDB_SIGNAL_0
);
5190 prepare_to_wait (ecs
);
5194 /* But stop if we're attaching or setting up a remote
5196 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5197 || stop_soon
== STOP_QUIETLY_REMOTE
)
5199 infrun_log_debug ("quietly stopped");
5204 internal_error (__FILE__
, __LINE__
,
5205 _("unhandled stop_soon: %d"), (int) stop_soon
);
5207 case TARGET_WAITKIND_SPURIOUS
:
5208 if (handle_stop_requested (ecs
))
5210 context_switch (ecs
);
5211 resume (GDB_SIGNAL_0
);
5212 prepare_to_wait (ecs
);
5215 case TARGET_WAITKIND_THREAD_CREATED
:
5216 if (handle_stop_requested (ecs
))
5218 context_switch (ecs
);
5219 if (!switch_back_to_stepped_thread (ecs
))
5223 case TARGET_WAITKIND_EXITED
:
5224 case TARGET_WAITKIND_SIGNALLED
:
5225 inferior_ptid
= ecs
->ptid
;
5226 set_current_inferior (find_inferior_ptid (ecs
->target
, ecs
->ptid
));
5227 set_current_program_space (current_inferior ()->pspace
);
5228 handle_vfork_child_exec_or_exit (0);
5229 target_terminal::ours (); /* Must do this before mourn anyway. */
5231 /* Clearing any previous state of convenience variables. */
5232 clear_exit_convenience_vars ();
5234 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5236 /* Record the exit code in the convenience variable $_exitcode, so
5237 that the user can inspect this again later. */
5238 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5239 (LONGEST
) ecs
->ws
.value
.integer
);
5241 /* Also record this in the inferior itself. */
5242 current_inferior ()->has_exit_code
= 1;
5243 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5245 /* Support the --return-child-result option. */
5246 return_child_result_value
= ecs
->ws
.value
.integer
;
5248 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5252 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5254 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5256 /* Set the value of the internal variable $_exitsignal,
5257 which holds the signal uncaught by the inferior. */
5258 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5259 gdbarch_gdb_signal_to_target (gdbarch
,
5260 ecs
->ws
.value
.sig
));
5264 /* We don't have access to the target's method used for
5265 converting between signal numbers (GDB's internal
5266 representation <-> target's representation).
5267 Therefore, we cannot do a good job at displaying this
5268 information to the user. It's better to just warn
5269 her about it (if infrun debugging is enabled), and
5271 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5275 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5278 gdb_flush (gdb_stdout
);
5279 target_mourn_inferior (inferior_ptid
);
5280 stop_print_frame
= 0;
5284 case TARGET_WAITKIND_FORKED
:
5285 case TARGET_WAITKIND_VFORKED
:
5286 /* Check whether the inferior is displaced stepping. */
5288 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5289 struct gdbarch
*gdbarch
= regcache
->arch ();
5291 /* If checking displaced stepping is supported, and thread
5292 ecs->ptid is displaced stepping. */
5293 if (displaced_step_in_progress (ecs
->event_thread
))
5295 struct inferior
*parent_inf
5296 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5297 struct regcache
*child_regcache
;
5298 CORE_ADDR parent_pc
;
5300 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5302 // struct displaced_step_inferior_state *displaced
5303 // = get_displaced_stepping_state (parent_inf);
5305 /* Restore scratch pad for child process. */
5306 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5307 // FIXME: we should restore all the buffers that were currently in use
5310 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5311 indicating that the displaced stepping of syscall instruction
5312 has been done. Perform cleanup for parent process here. Note
5313 that this operation also cleans up the child process for vfork,
5314 because their pages are shared. */
5315 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5316 /* Start a new step-over in another thread if there's one
5320 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5321 the child's PC is also within the scratchpad. Set the child's PC
5322 to the parent's PC value, which has already been fixed up.
5323 FIXME: we use the parent's aspace here, although we're touching
5324 the child, because the child hasn't been added to the inferior
5325 list yet at this point. */
5328 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5329 ecs
->ws
.value
.related_pid
,
5331 parent_inf
->aspace
);
5332 /* Read PC value of parent process. */
5333 parent_pc
= regcache_read_pc (regcache
);
5335 if (debug_displaced
)
5336 fprintf_unfiltered (gdb_stdlog
,
5337 "displaced: write child pc from %s to %s\n",
5339 regcache_read_pc (child_regcache
)),
5340 paddress (gdbarch
, parent_pc
));
5342 regcache_write_pc (child_regcache
, parent_pc
);
5346 context_switch (ecs
);
5348 /* Immediately detach breakpoints from the child before there's
5349 any chance of letting the user delete breakpoints from the
5350 breakpoint lists. If we don't do this early, it's easy to
5351 leave left over traps in the child, vis: "break foo; catch
5352 fork; c; <fork>; del; c; <child calls foo>". We only follow
5353 the fork on the last `continue', and by that time the
5354 breakpoint at "foo" is long gone from the breakpoint table.
5355 If we vforked, then we don't need to unpatch here, since both
5356 parent and child are sharing the same memory pages; we'll
5357 need to unpatch at follow/detach time instead to be certain
5358 that new breakpoints added between catchpoint hit time and
5359 vfork follow are detached. */
5360 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5362 /* This won't actually modify the breakpoint list, but will
5363 physically remove the breakpoints from the child. */
5364 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5367 delete_just_stopped_threads_single_step_breakpoints ();
5369 /* In case the event is caught by a catchpoint, remember that
5370 the event is to be followed at the next resume of the thread,
5371 and not immediately. */
5372 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5374 ecs
->event_thread
->suspend
.stop_pc
5375 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5377 ecs
->event_thread
->control
.stop_bpstat
5378 = bpstat_stop_status (get_current_regcache ()->aspace (),
5379 ecs
->event_thread
->suspend
.stop_pc
,
5380 ecs
->event_thread
, &ecs
->ws
);
5382 if (handle_stop_requested (ecs
))
5385 /* If no catchpoint triggered for this, then keep going. Note
5386 that we're interested in knowing the bpstat actually causes a
5387 stop, not just if it may explain the signal. Software
5388 watchpoints, for example, always appear in the bpstat. */
5389 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5392 = (follow_fork_mode_string
== follow_fork_mode_child
);
5394 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5396 process_stratum_target
*targ
5397 = ecs
->event_thread
->inf
->process_target ();
5399 bool should_resume
= follow_fork ();
5401 /* Note that one of these may be an invalid pointer,
5402 depending on detach_fork. */
5403 thread_info
*parent
= ecs
->event_thread
;
5405 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5407 /* At this point, the parent is marked running, and the
5408 child is marked stopped. */
5410 /* If not resuming the parent, mark it stopped. */
5411 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5412 parent
->set_running (false);
5414 /* If resuming the child, mark it running. */
5415 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5416 child
->set_running (true);
5418 /* In non-stop mode, also resume the other branch. */
5419 if (!detach_fork
&& (non_stop
5420 || (sched_multi
&& target_is_non_stop_p ())))
5423 switch_to_thread (parent
);
5425 switch_to_thread (child
);
5427 ecs
->event_thread
= inferior_thread ();
5428 ecs
->ptid
= inferior_ptid
;
5433 switch_to_thread (child
);
5435 switch_to_thread (parent
);
5437 ecs
->event_thread
= inferior_thread ();
5438 ecs
->ptid
= inferior_ptid
;
5446 process_event_stop_test (ecs
);
5449 case TARGET_WAITKIND_VFORK_DONE
:
5450 /* Done with the shared memory region. Re-insert breakpoints in
5451 the parent, and keep going. */
5453 context_switch (ecs
);
5455 current_inferior ()->waiting_for_vfork_done
= 0;
5456 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5458 if (handle_stop_requested (ecs
))
5461 /* This also takes care of reinserting breakpoints in the
5462 previously locked inferior. */
5466 case TARGET_WAITKIND_EXECD
:
5468 /* Note we can't read registers yet (the stop_pc), because we
5469 don't yet know the inferior's post-exec architecture.
5470 'stop_pc' is explicitly read below instead. */
5471 switch_to_thread_no_regs (ecs
->event_thread
);
5473 /* Do whatever is necessary to the parent branch of the vfork. */
5474 handle_vfork_child_exec_or_exit (1);
5476 /* This causes the eventpoints and symbol table to be reset.
5477 Must do this now, before trying to determine whether to
5479 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5481 /* In follow_exec we may have deleted the original thread and
5482 created a new one. Make sure that the event thread is the
5483 execd thread for that case (this is a nop otherwise). */
5484 ecs
->event_thread
= inferior_thread ();
5486 ecs
->event_thread
->suspend
.stop_pc
5487 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5489 ecs
->event_thread
->control
.stop_bpstat
5490 = bpstat_stop_status (get_current_regcache ()->aspace (),
5491 ecs
->event_thread
->suspend
.stop_pc
,
5492 ecs
->event_thread
, &ecs
->ws
);
5494 /* Note that this may be referenced from inside
5495 bpstat_stop_status above, through inferior_has_execd. */
5496 xfree (ecs
->ws
.value
.execd_pathname
);
5497 ecs
->ws
.value
.execd_pathname
= NULL
;
5499 if (handle_stop_requested (ecs
))
5502 /* If no catchpoint triggered for this, then keep going. */
5503 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5505 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5509 process_event_stop_test (ecs
);
5512 /* Be careful not to try to gather much state about a thread
5513 that's in a syscall. It's frequently a losing proposition. */
5514 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5515 /* Getting the current syscall number. */
5516 if (handle_syscall_event (ecs
) == 0)
5517 process_event_stop_test (ecs
);
5520 /* Before examining the threads further, step this thread to
5521 get it entirely out of the syscall. (We get notice of the
5522 event when the thread is just on the verge of exiting a
5523 syscall. Stepping one instruction seems to get it back
5525 case TARGET_WAITKIND_SYSCALL_RETURN
:
5526 if (handle_syscall_event (ecs
) == 0)
5527 process_event_stop_test (ecs
);
5530 case TARGET_WAITKIND_STOPPED
:
5531 handle_signal_stop (ecs
);
5534 case TARGET_WAITKIND_NO_HISTORY
:
5535 /* Reverse execution: target ran out of history info. */
5537 /* Switch to the stopped thread. */
5538 context_switch (ecs
);
5539 infrun_log_debug ("stopped");
5541 delete_just_stopped_threads_single_step_breakpoints ();
5542 ecs
->event_thread
->suspend
.stop_pc
5543 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5545 if (handle_stop_requested (ecs
))
5548 gdb::observers::no_history
.notify ();
5554 /* Restart threads back to what they were trying to do back when we
5555 paused them for an in-line step-over. The EVENT_THREAD thread is
5559 restart_threads (struct thread_info
*event_thread
)
5561 /* In case the instruction just stepped spawned a new thread. */
5562 update_thread_list ();
5564 for (thread_info
*tp
: all_non_exited_threads ())
5566 switch_to_thread_no_regs (tp
);
5568 if (tp
== event_thread
)
5570 infrun_log_debug ("restart threads: [%s] is event thread",
5571 target_pid_to_str (tp
->ptid
).c_str ());
5575 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5577 infrun_log_debug ("restart threads: [%s] not meant to be running",
5578 target_pid_to_str (tp
->ptid
).c_str ());
5584 infrun_log_debug ("restart threads: [%s] resumed",
5585 target_pid_to_str (tp
->ptid
).c_str ());
5586 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5590 if (thread_is_in_step_over_chain (tp
))
5592 infrun_log_debug ("restart threads: [%s] needs step-over",
5593 target_pid_to_str (tp
->ptid
).c_str ());
5594 gdb_assert (!tp
->resumed
);
5599 if (tp
->suspend
.waitstatus_pending_p
)
5601 infrun_log_debug ("restart threads: [%s] has pending status",
5602 target_pid_to_str (tp
->ptid
).c_str ());
5607 gdb_assert (!tp
->stop_requested
);
5609 /* If some thread needs to start a step-over at this point, it
5610 should still be in the step-over queue, and thus skipped
5612 if (thread_still_needs_step_over (tp
))
5614 internal_error (__FILE__
, __LINE__
,
5615 "thread [%s] needs a step-over, but not in "
5616 "step-over queue\n",
5617 target_pid_to_str (tp
->ptid
).c_str ());
5620 if (currently_stepping (tp
))
5622 infrun_log_debug ("restart threads: [%s] was stepping",
5623 target_pid_to_str (tp
->ptid
).c_str ());
5624 keep_going_stepped_thread (tp
);
5628 struct execution_control_state ecss
;
5629 struct execution_control_state
*ecs
= &ecss
;
5631 infrun_log_debug ("restart threads: [%s] continuing",
5632 target_pid_to_str (tp
->ptid
).c_str ());
5633 reset_ecs (ecs
, tp
);
5634 switch_to_thread (tp
);
5635 keep_going_pass_signal (ecs
);
5640 /* Callback for iterate_over_threads. Find a resumed thread that has
5641 a pending waitstatus. */
5644 resumed_thread_with_pending_status (struct thread_info
*tp
,
5648 && tp
->suspend
.waitstatus_pending_p
);
5651 /* Called when we get an event that may finish an in-line or
5652 out-of-line (displaced stepping) step-over started previously.
5653 Return true if the event is processed and we should go back to the
5654 event loop; false if the caller should continue processing the
5658 finish_step_over (struct execution_control_state
*ecs
)
5660 int had_step_over_info
;
5662 displaced_step_finish (ecs
->event_thread
,
5663 ecs
->event_thread
->suspend
.stop_signal
);
5665 had_step_over_info
= step_over_info_valid_p ();
5667 if (had_step_over_info
)
5669 /* If we're stepping over a breakpoint with all threads locked,
5670 then only the thread that was stepped should be reporting
5672 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5674 clear_step_over_info ();
5677 if (!target_is_non_stop_p ())
5680 /* Start a new step-over in another thread if there's one that
5684 /* If we were stepping over a breakpoint before, and haven't started
5685 a new in-line step-over sequence, then restart all other threads
5686 (except the event thread). We can't do this in all-stop, as then
5687 e.g., we wouldn't be able to issue any other remote packet until
5688 these other threads stop. */
5689 if (had_step_over_info
&& !step_over_info_valid_p ())
5691 struct thread_info
*pending
;
5693 /* If we only have threads with pending statuses, the restart
5694 below won't restart any thread and so nothing re-inserts the
5695 breakpoint we just stepped over. But we need it inserted
5696 when we later process the pending events, otherwise if
5697 another thread has a pending event for this breakpoint too,
5698 we'd discard its event (because the breakpoint that
5699 originally caused the event was no longer inserted). */
5700 context_switch (ecs
);
5701 insert_breakpoints ();
5703 restart_threads (ecs
->event_thread
);
5705 /* If we have events pending, go through handle_inferior_event
5706 again, picking up a pending event at random. This avoids
5707 thread starvation. */
5709 /* But not if we just stepped over a watchpoint in order to let
5710 the instruction execute so we can evaluate its expression.
5711 The set of watchpoints that triggered is recorded in the
5712 breakpoint objects themselves (see bp->watchpoint_triggered).
5713 If we processed another event first, that other event could
5714 clobber this info. */
5715 if (ecs
->event_thread
->stepping_over_watchpoint
)
5718 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5720 if (pending
!= NULL
)
5722 struct thread_info
*tp
= ecs
->event_thread
;
5723 struct regcache
*regcache
;
5725 infrun_log_debug ("found resumed threads with "
5726 "pending events, saving status");
5728 gdb_assert (pending
!= tp
);
5730 /* Record the event thread's event for later. */
5731 save_waitstatus (tp
, &ecs
->ws
);
5732 /* This was cleared early, by handle_inferior_event. Set it
5733 so this pending event is considered by
5737 gdb_assert (!tp
->executing
);
5739 regcache
= get_thread_regcache (tp
);
5740 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5742 infrun_log_debug ("saved stop_pc=%s for %s "
5743 "(currently_stepping=%d)\n",
5744 paddress (target_gdbarch (),
5745 tp
->suspend
.stop_pc
),
5746 target_pid_to_str (tp
->ptid
).c_str (),
5747 currently_stepping (tp
));
5749 /* This in-line step-over finished; clear this so we won't
5750 start a new one. This is what handle_signal_stop would
5751 do, if we returned false. */
5752 tp
->stepping_over_breakpoint
= 0;
5754 /* Wake up the event loop again. */
5755 mark_async_event_handler (infrun_async_inferior_event_token
);
5757 prepare_to_wait (ecs
);
5765 /* Come here when the program has stopped with a signal. */
5768 handle_signal_stop (struct execution_control_state
*ecs
)
5770 struct frame_info
*frame
;
5771 struct gdbarch
*gdbarch
;
5772 int stopped_by_watchpoint
;
5773 enum stop_kind stop_soon
;
5776 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5778 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5780 /* Do we need to clean up the state of a thread that has
5781 completed a displaced single-step? (Doing so usually affects
5782 the PC, so do it here, before we set stop_pc.) */
5783 if (finish_step_over (ecs
))
5786 /* If we either finished a single-step or hit a breakpoint, but
5787 the user wanted this thread to be stopped, pretend we got a
5788 SIG0 (generic unsignaled stop). */
5789 if (ecs
->event_thread
->stop_requested
5790 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5791 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5793 ecs
->event_thread
->suspend
.stop_pc
5794 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5798 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5799 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5801 switch_to_thread (ecs
->event_thread
);
5803 infrun_log_debug ("stop_pc=%s",
5804 paddress (reg_gdbarch
,
5805 ecs
->event_thread
->suspend
.stop_pc
));
5806 if (target_stopped_by_watchpoint ())
5810 infrun_log_debug ("stopped by watchpoint");
5812 if (target_stopped_data_address (current_top_target (), &addr
))
5813 infrun_log_debug ("stopped data address=%s",
5814 paddress (reg_gdbarch
, addr
));
5816 infrun_log_debug ("(no data address available)");
5820 /* This is originated from start_remote(), start_inferior() and
5821 shared libraries hook functions. */
5822 stop_soon
= get_inferior_stop_soon (ecs
);
5823 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5825 context_switch (ecs
);
5826 infrun_log_debug ("quietly stopped");
5827 stop_print_frame
= 1;
5832 /* This originates from attach_command(). We need to overwrite
5833 the stop_signal here, because some kernels don't ignore a
5834 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5835 See more comments in inferior.h. On the other hand, if we
5836 get a non-SIGSTOP, report it to the user - assume the backend
5837 will handle the SIGSTOP if it should show up later.
5839 Also consider that the attach is complete when we see a
5840 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5841 target extended-remote report it instead of a SIGSTOP
5842 (e.g. gdbserver). We already rely on SIGTRAP being our
5843 signal, so this is no exception.
5845 Also consider that the attach is complete when we see a
5846 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5847 the target to stop all threads of the inferior, in case the
5848 low level attach operation doesn't stop them implicitly. If
5849 they weren't stopped implicitly, then the stub will report a
5850 GDB_SIGNAL_0, meaning: stopped for no particular reason
5851 other than GDB's request. */
5852 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5853 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5854 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5855 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5857 stop_print_frame
= 1;
5859 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5863 /* See if something interesting happened to the non-current thread. If
5864 so, then switch to that thread. */
5865 if (ecs
->ptid
!= inferior_ptid
)
5867 infrun_log_debug ("context switch");
5869 context_switch (ecs
);
5871 if (deprecated_context_hook
)
5872 deprecated_context_hook (ecs
->event_thread
->global_num
);
5875 /* At this point, get hold of the now-current thread's frame. */
5876 frame
= get_current_frame ();
5877 gdbarch
= get_frame_arch (frame
);
5879 /* Pull the single step breakpoints out of the target. */
5880 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5882 struct regcache
*regcache
;
5885 regcache
= get_thread_regcache (ecs
->event_thread
);
5886 const address_space
*aspace
= regcache
->aspace ();
5888 pc
= regcache_read_pc (regcache
);
5890 /* However, before doing so, if this single-step breakpoint was
5891 actually for another thread, set this thread up for moving
5893 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5896 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5898 infrun_log_debug ("[%s] hit another thread's single-step "
5900 target_pid_to_str (ecs
->ptid
).c_str ());
5901 ecs
->hit_singlestep_breakpoint
= 1;
5906 infrun_log_debug ("[%s] hit its single-step breakpoint",
5907 target_pid_to_str (ecs
->ptid
).c_str ());
5910 delete_just_stopped_threads_single_step_breakpoints ();
5912 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5913 && ecs
->event_thread
->control
.trap_expected
5914 && ecs
->event_thread
->stepping_over_watchpoint
)
5915 stopped_by_watchpoint
= 0;
5917 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5919 /* If necessary, step over this watchpoint. We'll be back to display
5921 if (stopped_by_watchpoint
5922 && (target_have_steppable_watchpoint
5923 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5925 /* At this point, we are stopped at an instruction which has
5926 attempted to write to a piece of memory under control of
5927 a watchpoint. The instruction hasn't actually executed
5928 yet. If we were to evaluate the watchpoint expression
5929 now, we would get the old value, and therefore no change
5930 would seem to have occurred.
5932 In order to make watchpoints work `right', we really need
5933 to complete the memory write, and then evaluate the
5934 watchpoint expression. We do this by single-stepping the
5937 It may not be necessary to disable the watchpoint to step over
5938 it. For example, the PA can (with some kernel cooperation)
5939 single step over a watchpoint without disabling the watchpoint.
5941 It is far more common to need to disable a watchpoint to step
5942 the inferior over it. If we have non-steppable watchpoints,
5943 we must disable the current watchpoint; it's simplest to
5944 disable all watchpoints.
5946 Any breakpoint at PC must also be stepped over -- if there's
5947 one, it will have already triggered before the watchpoint
5948 triggered, and we either already reported it to the user, or
5949 it didn't cause a stop and we called keep_going. In either
5950 case, if there was a breakpoint at PC, we must be trying to
5952 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5957 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5958 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5959 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5960 ecs
->event_thread
->control
.stop_step
= 0;
5961 stop_print_frame
= 1;
5962 stopped_by_random_signal
= 0;
5963 bpstat stop_chain
= NULL
;
5965 /* Hide inlined functions starting here, unless we just performed stepi or
5966 nexti. After stepi and nexti, always show the innermost frame (not any
5967 inline function call sites). */
5968 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5970 const address_space
*aspace
5971 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5973 /* skip_inline_frames is expensive, so we avoid it if we can
5974 determine that the address is one where functions cannot have
5975 been inlined. This improves performance with inferiors that
5976 load a lot of shared libraries, because the solib event
5977 breakpoint is defined as the address of a function (i.e. not
5978 inline). Note that we have to check the previous PC as well
5979 as the current one to catch cases when we have just
5980 single-stepped off a breakpoint prior to reinstating it.
5981 Note that we're assuming that the code we single-step to is
5982 not inline, but that's not definitive: there's nothing
5983 preventing the event breakpoint function from containing
5984 inlined code, and the single-step ending up there. If the
5985 user had set a breakpoint on that inlined code, the missing
5986 skip_inline_frames call would break things. Fortunately
5987 that's an extremely unlikely scenario. */
5988 if (!pc_at_non_inline_function (aspace
,
5989 ecs
->event_thread
->suspend
.stop_pc
,
5991 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5992 && ecs
->event_thread
->control
.trap_expected
5993 && pc_at_non_inline_function (aspace
,
5994 ecs
->event_thread
->prev_pc
,
5997 stop_chain
= build_bpstat_chain (aspace
,
5998 ecs
->event_thread
->suspend
.stop_pc
,
6000 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6002 /* Re-fetch current thread's frame in case that invalidated
6004 frame
= get_current_frame ();
6005 gdbarch
= get_frame_arch (frame
);
6009 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6010 && ecs
->event_thread
->control
.trap_expected
6011 && gdbarch_single_step_through_delay_p (gdbarch
)
6012 && currently_stepping (ecs
->event_thread
))
6014 /* We're trying to step off a breakpoint. Turns out that we're
6015 also on an instruction that needs to be stepped multiple
6016 times before it's been fully executing. E.g., architectures
6017 with a delay slot. It needs to be stepped twice, once for
6018 the instruction and once for the delay slot. */
6019 int step_through_delay
6020 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6022 if (step_through_delay
)
6023 infrun_log_debug ("step through delay");
6025 if (ecs
->event_thread
->control
.step_range_end
== 0
6026 && step_through_delay
)
6028 /* The user issued a continue when stopped at a breakpoint.
6029 Set up for another trap and get out of here. */
6030 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6034 else if (step_through_delay
)
6036 /* The user issued a step when stopped at a breakpoint.
6037 Maybe we should stop, maybe we should not - the delay
6038 slot *might* correspond to a line of source. In any
6039 case, don't decide that here, just set
6040 ecs->stepping_over_breakpoint, making sure we
6041 single-step again before breakpoints are re-inserted. */
6042 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6046 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6047 handles this event. */
6048 ecs
->event_thread
->control
.stop_bpstat
6049 = bpstat_stop_status (get_current_regcache ()->aspace (),
6050 ecs
->event_thread
->suspend
.stop_pc
,
6051 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6053 /* Following in case break condition called a
6055 stop_print_frame
= 1;
6057 /* This is where we handle "moribund" watchpoints. Unlike
6058 software breakpoints traps, hardware watchpoint traps are
6059 always distinguishable from random traps. If no high-level
6060 watchpoint is associated with the reported stop data address
6061 anymore, then the bpstat does not explain the signal ---
6062 simply make sure to ignore it if `stopped_by_watchpoint' is
6065 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6066 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6068 && stopped_by_watchpoint
)
6070 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6074 /* NOTE: cagney/2003-03-29: These checks for a random signal
6075 at one stage in the past included checks for an inferior
6076 function call's call dummy's return breakpoint. The original
6077 comment, that went with the test, read:
6079 ``End of a stack dummy. Some systems (e.g. Sony news) give
6080 another signal besides SIGTRAP, so check here as well as
6083 If someone ever tries to get call dummys on a
6084 non-executable stack to work (where the target would stop
6085 with something like a SIGSEGV), then those tests might need
6086 to be re-instated. Given, however, that the tests were only
6087 enabled when momentary breakpoints were not being used, I
6088 suspect that it won't be the case.
6090 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6091 be necessary for call dummies on a non-executable stack on
6094 /* See if the breakpoints module can explain the signal. */
6096 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6097 ecs
->event_thread
->suspend
.stop_signal
);
6099 /* Maybe this was a trap for a software breakpoint that has since
6101 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6103 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6104 ecs
->event_thread
->suspend
.stop_pc
))
6106 struct regcache
*regcache
;
6109 /* Re-adjust PC to what the program would see if GDB was not
6111 regcache
= get_thread_regcache (ecs
->event_thread
);
6112 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6115 gdb::optional
<scoped_restore_tmpl
<int>>
6116 restore_operation_disable
;
6118 if (record_full_is_used ())
6119 restore_operation_disable
.emplace
6120 (record_full_gdb_operation_disable_set ());
6122 regcache_write_pc (regcache
,
6123 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6128 /* A delayed software breakpoint event. Ignore the trap. */
6129 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6134 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6135 has since been removed. */
6136 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6138 /* A delayed hardware breakpoint event. Ignore the trap. */
6139 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6144 /* If not, perhaps stepping/nexting can. */
6146 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6147 && currently_stepping (ecs
->event_thread
));
6149 /* Perhaps the thread hit a single-step breakpoint of _another_
6150 thread. Single-step breakpoints are transparent to the
6151 breakpoints module. */
6153 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6155 /* No? Perhaps we got a moribund watchpoint. */
6157 random_signal
= !stopped_by_watchpoint
;
6159 /* Always stop if the user explicitly requested this thread to
6161 if (ecs
->event_thread
->stop_requested
)
6164 infrun_log_debug ("user-requested stop");
6167 /* For the program's own signals, act according to
6168 the signal handling tables. */
6172 /* Signal not for debugging purposes. */
6173 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6174 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6176 infrun_log_debug ("random signal (%s)",
6177 gdb_signal_to_symbol_string (stop_signal
));
6179 stopped_by_random_signal
= 1;
6181 /* Always stop on signals if we're either just gaining control
6182 of the program, or the user explicitly requested this thread
6183 to remain stopped. */
6184 if (stop_soon
!= NO_STOP_QUIETLY
6185 || ecs
->event_thread
->stop_requested
6187 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6193 /* Notify observers the signal has "handle print" set. Note we
6194 returned early above if stopping; normal_stop handles the
6195 printing in that case. */
6196 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6198 /* The signal table tells us to print about this signal. */
6199 target_terminal::ours_for_output ();
6200 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6201 target_terminal::inferior ();
6204 /* Clear the signal if it should not be passed. */
6205 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6206 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6208 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6209 && ecs
->event_thread
->control
.trap_expected
6210 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6212 /* We were just starting a new sequence, attempting to
6213 single-step off of a breakpoint and expecting a SIGTRAP.
6214 Instead this signal arrives. This signal will take us out
6215 of the stepping range so GDB needs to remember to, when
6216 the signal handler returns, resume stepping off that
6218 /* To simplify things, "continue" is forced to use the same
6219 code paths as single-step - set a breakpoint at the
6220 signal return address and then, once hit, step off that
6222 infrun_log_debug ("signal arrived while stepping over breakpoint");
6224 insert_hp_step_resume_breakpoint_at_frame (frame
);
6225 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6226 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6227 ecs
->event_thread
->control
.trap_expected
= 0;
6229 /* If we were nexting/stepping some other thread, switch to
6230 it, so that we don't continue it, losing control. */
6231 if (!switch_back_to_stepped_thread (ecs
))
6236 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6237 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6239 || ecs
->event_thread
->control
.step_range_end
== 1)
6240 && frame_id_eq (get_stack_frame_id (frame
),
6241 ecs
->event_thread
->control
.step_stack_frame_id
)
6242 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6244 /* The inferior is about to take a signal that will take it
6245 out of the single step range. Set a breakpoint at the
6246 current PC (which is presumably where the signal handler
6247 will eventually return) and then allow the inferior to
6250 Note that this is only needed for a signal delivered
6251 while in the single-step range. Nested signals aren't a
6252 problem as they eventually all return. */
6253 infrun_log_debug ("signal may take us out of single-step range");
6255 clear_step_over_info ();
6256 insert_hp_step_resume_breakpoint_at_frame (frame
);
6257 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6258 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6259 ecs
->event_thread
->control
.trap_expected
= 0;
6264 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6265 when either there's a nested signal, or when there's a
6266 pending signal enabled just as the signal handler returns
6267 (leaving the inferior at the step-resume-breakpoint without
6268 actually executing it). Either way continue until the
6269 breakpoint is really hit. */
6271 if (!switch_back_to_stepped_thread (ecs
))
6273 infrun_log_debug ("random signal, keep going");
6280 process_event_stop_test (ecs
);
6283 /* Come here when we've got some debug event / signal we can explain
6284 (IOW, not a random signal), and test whether it should cause a
6285 stop, or whether we should resume the inferior (transparently).
6286 E.g., could be a breakpoint whose condition evaluates false; we
6287 could be still stepping within the line; etc. */
6290 process_event_stop_test (struct execution_control_state
*ecs
)
6292 struct symtab_and_line stop_pc_sal
;
6293 struct frame_info
*frame
;
6294 struct gdbarch
*gdbarch
;
6295 CORE_ADDR jmp_buf_pc
;
6296 struct bpstat_what what
;
6298 /* Handle cases caused by hitting a breakpoint. */
6300 frame
= get_current_frame ();
6301 gdbarch
= get_frame_arch (frame
);
6303 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6305 if (what
.call_dummy
)
6307 stop_stack_dummy
= what
.call_dummy
;
6310 /* A few breakpoint types have callbacks associated (e.g.,
6311 bp_jit_event). Run them now. */
6312 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6314 /* If we hit an internal event that triggers symbol changes, the
6315 current frame will be invalidated within bpstat_what (e.g., if we
6316 hit an internal solib event). Re-fetch it. */
6317 frame
= get_current_frame ();
6318 gdbarch
= get_frame_arch (frame
);
6320 switch (what
.main_action
)
6322 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6323 /* If we hit the breakpoint at longjmp while stepping, we
6324 install a momentary breakpoint at the target of the
6327 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6329 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6331 if (what
.is_longjmp
)
6333 struct value
*arg_value
;
6335 /* If we set the longjmp breakpoint via a SystemTap probe,
6336 then use it to extract the arguments. The destination PC
6337 is the third argument to the probe. */
6338 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6341 jmp_buf_pc
= value_as_address (arg_value
);
6342 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6344 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6345 || !gdbarch_get_longjmp_target (gdbarch
,
6346 frame
, &jmp_buf_pc
))
6348 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6349 "(!gdbarch_get_longjmp_target)");
6354 /* Insert a breakpoint at resume address. */
6355 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6358 check_exception_resume (ecs
, frame
);
6362 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6364 struct frame_info
*init_frame
;
6366 /* There are several cases to consider.
6368 1. The initiating frame no longer exists. In this case we
6369 must stop, because the exception or longjmp has gone too
6372 2. The initiating frame exists, and is the same as the
6373 current frame. We stop, because the exception or longjmp
6376 3. The initiating frame exists and is different from the
6377 current frame. This means the exception or longjmp has
6378 been caught beneath the initiating frame, so keep going.
6380 4. longjmp breakpoint has been placed just to protect
6381 against stale dummy frames and user is not interested in
6382 stopping around longjmps. */
6384 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6386 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6388 delete_exception_resume_breakpoint (ecs
->event_thread
);
6390 if (what
.is_longjmp
)
6392 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6394 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6402 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6406 struct frame_id current_id
6407 = get_frame_id (get_current_frame ());
6408 if (frame_id_eq (current_id
,
6409 ecs
->event_thread
->initiating_frame
))
6411 /* Case 2. Fall through. */
6421 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6423 delete_step_resume_breakpoint (ecs
->event_thread
);
6425 end_stepping_range (ecs
);
6429 case BPSTAT_WHAT_SINGLE
:
6430 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6431 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6432 /* Still need to check other stuff, at least the case where we
6433 are stepping and step out of the right range. */
6436 case BPSTAT_WHAT_STEP_RESUME
:
6437 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6439 delete_step_resume_breakpoint (ecs
->event_thread
);
6440 if (ecs
->event_thread
->control
.proceed_to_finish
6441 && execution_direction
== EXEC_REVERSE
)
6443 struct thread_info
*tp
= ecs
->event_thread
;
6445 /* We are finishing a function in reverse, and just hit the
6446 step-resume breakpoint at the start address of the
6447 function, and we're almost there -- just need to back up
6448 by one more single-step, which should take us back to the
6450 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6454 fill_in_stop_func (gdbarch
, ecs
);
6455 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6456 && execution_direction
== EXEC_REVERSE
)
6458 /* We are stepping over a function call in reverse, and just
6459 hit the step-resume breakpoint at the start address of
6460 the function. Go back to single-stepping, which should
6461 take us back to the function call. */
6462 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6468 case BPSTAT_WHAT_STOP_NOISY
:
6469 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6470 stop_print_frame
= 1;
6472 /* Assume the thread stopped for a breapoint. We'll still check
6473 whether a/the breakpoint is there when the thread is next
6475 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6480 case BPSTAT_WHAT_STOP_SILENT
:
6481 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6482 stop_print_frame
= 0;
6484 /* Assume the thread stopped for a breapoint. We'll still check
6485 whether a/the breakpoint is there when the thread is next
6487 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6491 case BPSTAT_WHAT_HP_STEP_RESUME
:
6492 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6494 delete_step_resume_breakpoint (ecs
->event_thread
);
6495 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6497 /* Back when the step-resume breakpoint was inserted, we
6498 were trying to single-step off a breakpoint. Go back to
6500 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6501 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6507 case BPSTAT_WHAT_KEEP_CHECKING
:
6511 /* If we stepped a permanent breakpoint and we had a high priority
6512 step-resume breakpoint for the address we stepped, but we didn't
6513 hit it, then we must have stepped into the signal handler. The
6514 step-resume was only necessary to catch the case of _not_
6515 stepping into the handler, so delete it, and fall through to
6516 checking whether the step finished. */
6517 if (ecs
->event_thread
->stepped_breakpoint
)
6519 struct breakpoint
*sr_bp
6520 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6523 && sr_bp
->loc
->permanent
6524 && sr_bp
->type
== bp_hp_step_resume
6525 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6527 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6528 delete_step_resume_breakpoint (ecs
->event_thread
);
6529 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6533 /* We come here if we hit a breakpoint but should not stop for it.
6534 Possibly we also were stepping and should stop for that. So fall
6535 through and test for stepping. But, if not stepping, do not
6538 /* In all-stop mode, if we're currently stepping but have stopped in
6539 some other thread, we need to switch back to the stepped thread. */
6540 if (switch_back_to_stepped_thread (ecs
))
6543 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6545 infrun_log_debug ("step-resume breakpoint is inserted");
6547 /* Having a step-resume breakpoint overrides anything
6548 else having to do with stepping commands until
6549 that breakpoint is reached. */
6554 if (ecs
->event_thread
->control
.step_range_end
== 0)
6556 infrun_log_debug ("no stepping, continue");
6557 /* Likewise if we aren't even stepping. */
6562 /* Re-fetch current thread's frame in case the code above caused
6563 the frame cache to be re-initialized, making our FRAME variable
6564 a dangling pointer. */
6565 frame
= get_current_frame ();
6566 gdbarch
= get_frame_arch (frame
);
6567 fill_in_stop_func (gdbarch
, ecs
);
6569 /* If stepping through a line, keep going if still within it.
6571 Note that step_range_end is the address of the first instruction
6572 beyond the step range, and NOT the address of the last instruction
6575 Note also that during reverse execution, we may be stepping
6576 through a function epilogue and therefore must detect when
6577 the current-frame changes in the middle of a line. */
6579 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6581 && (execution_direction
!= EXEC_REVERSE
6582 || frame_id_eq (get_frame_id (frame
),
6583 ecs
->event_thread
->control
.step_frame_id
)))
6586 ("stepping inside range [%s-%s]",
6587 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6588 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6590 /* Tentatively re-enable range stepping; `resume' disables it if
6591 necessary (e.g., if we're stepping over a breakpoint or we
6592 have software watchpoints). */
6593 ecs
->event_thread
->control
.may_range_step
= 1;
6595 /* When stepping backward, stop at beginning of line range
6596 (unless it's the function entry point, in which case
6597 keep going back to the call point). */
6598 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6599 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6600 && stop_pc
!= ecs
->stop_func_start
6601 && execution_direction
== EXEC_REVERSE
)
6602 end_stepping_range (ecs
);
6609 /* We stepped out of the stepping range. */
6611 /* If we are stepping at the source level and entered the runtime
6612 loader dynamic symbol resolution code...
6614 EXEC_FORWARD: we keep on single stepping until we exit the run
6615 time loader code and reach the callee's address.
6617 EXEC_REVERSE: we've already executed the callee (backward), and
6618 the runtime loader code is handled just like any other
6619 undebuggable function call. Now we need only keep stepping
6620 backward through the trampoline code, and that's handled further
6621 down, so there is nothing for us to do here. */
6623 if (execution_direction
!= EXEC_REVERSE
6624 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6625 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6627 CORE_ADDR pc_after_resolver
=
6628 gdbarch_skip_solib_resolver (gdbarch
,
6629 ecs
->event_thread
->suspend
.stop_pc
);
6631 infrun_log_debug ("stepped into dynsym resolve code");
6633 if (pc_after_resolver
)
6635 /* Set up a step-resume breakpoint at the address
6636 indicated by SKIP_SOLIB_RESOLVER. */
6637 symtab_and_line sr_sal
;
6638 sr_sal
.pc
= pc_after_resolver
;
6639 sr_sal
.pspace
= get_frame_program_space (frame
);
6641 insert_step_resume_breakpoint_at_sal (gdbarch
,
6642 sr_sal
, null_frame_id
);
6649 /* Step through an indirect branch thunk. */
6650 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6651 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6652 ecs
->event_thread
->suspend
.stop_pc
))
6654 infrun_log_debug ("stepped into indirect branch thunk");
6659 if (ecs
->event_thread
->control
.step_range_end
!= 1
6660 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6661 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6662 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6664 infrun_log_debug ("stepped into signal trampoline");
6665 /* The inferior, while doing a "step" or "next", has ended up in
6666 a signal trampoline (either by a signal being delivered or by
6667 the signal handler returning). Just single-step until the
6668 inferior leaves the trampoline (either by calling the handler
6674 /* If we're in the return path from a shared library trampoline,
6675 we want to proceed through the trampoline when stepping. */
6676 /* macro/2012-04-25: This needs to come before the subroutine
6677 call check below as on some targets return trampolines look
6678 like subroutine calls (MIPS16 return thunks). */
6679 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6680 ecs
->event_thread
->suspend
.stop_pc
,
6681 ecs
->stop_func_name
)
6682 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6684 /* Determine where this trampoline returns. */
6685 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6686 CORE_ADDR real_stop_pc
6687 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6689 infrun_log_debug ("stepped into solib return tramp");
6691 /* Only proceed through if we know where it's going. */
6694 /* And put the step-breakpoint there and go until there. */
6695 symtab_and_line sr_sal
;
6696 sr_sal
.pc
= real_stop_pc
;
6697 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6698 sr_sal
.pspace
= get_frame_program_space (frame
);
6700 /* Do not specify what the fp should be when we stop since
6701 on some machines the prologue is where the new fp value
6703 insert_step_resume_breakpoint_at_sal (gdbarch
,
6704 sr_sal
, null_frame_id
);
6706 /* Restart without fiddling with the step ranges or
6713 /* Check for subroutine calls. The check for the current frame
6714 equalling the step ID is not necessary - the check of the
6715 previous frame's ID is sufficient - but it is a common case and
6716 cheaper than checking the previous frame's ID.
6718 NOTE: frame_id_eq will never report two invalid frame IDs as
6719 being equal, so to get into this block, both the current and
6720 previous frame must have valid frame IDs. */
6721 /* The outer_frame_id check is a heuristic to detect stepping
6722 through startup code. If we step over an instruction which
6723 sets the stack pointer from an invalid value to a valid value,
6724 we may detect that as a subroutine call from the mythical
6725 "outermost" function. This could be fixed by marking
6726 outermost frames as !stack_p,code_p,special_p. Then the
6727 initial outermost frame, before sp was valid, would
6728 have code_addr == &_start. See the comment in frame_id_eq
6730 if (!frame_id_eq (get_stack_frame_id (frame
),
6731 ecs
->event_thread
->control
.step_stack_frame_id
)
6732 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6733 ecs
->event_thread
->control
.step_stack_frame_id
)
6734 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6736 || (ecs
->event_thread
->control
.step_start_function
6737 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6739 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6740 CORE_ADDR real_stop_pc
;
6742 infrun_log_debug ("stepped into subroutine");
6744 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6746 /* I presume that step_over_calls is only 0 when we're
6747 supposed to be stepping at the assembly language level
6748 ("stepi"). Just stop. */
6749 /* And this works the same backward as frontward. MVS */
6750 end_stepping_range (ecs
);
6754 /* Reverse stepping through solib trampolines. */
6756 if (execution_direction
== EXEC_REVERSE
6757 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6758 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6759 || (ecs
->stop_func_start
== 0
6760 && in_solib_dynsym_resolve_code (stop_pc
))))
6762 /* Any solib trampoline code can be handled in reverse
6763 by simply continuing to single-step. We have already
6764 executed the solib function (backwards), and a few
6765 steps will take us back through the trampoline to the
6771 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6773 /* We're doing a "next".
6775 Normal (forward) execution: set a breakpoint at the
6776 callee's return address (the address at which the caller
6779 Reverse (backward) execution. set the step-resume
6780 breakpoint at the start of the function that we just
6781 stepped into (backwards), and continue to there. When we
6782 get there, we'll need to single-step back to the caller. */
6784 if (execution_direction
== EXEC_REVERSE
)
6786 /* If we're already at the start of the function, we've either
6787 just stepped backward into a single instruction function,
6788 or stepped back out of a signal handler to the first instruction
6789 of the function. Just keep going, which will single-step back
6791 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6793 /* Normal function call return (static or dynamic). */
6794 symtab_and_line sr_sal
;
6795 sr_sal
.pc
= ecs
->stop_func_start
;
6796 sr_sal
.pspace
= get_frame_program_space (frame
);
6797 insert_step_resume_breakpoint_at_sal (gdbarch
,
6798 sr_sal
, null_frame_id
);
6802 insert_step_resume_breakpoint_at_caller (frame
);
6808 /* If we are in a function call trampoline (a stub between the
6809 calling routine and the real function), locate the real
6810 function. That's what tells us (a) whether we want to step
6811 into it at all, and (b) what prologue we want to run to the
6812 end of, if we do step into it. */
6813 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6814 if (real_stop_pc
== 0)
6815 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6816 if (real_stop_pc
!= 0)
6817 ecs
->stop_func_start
= real_stop_pc
;
6819 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6821 symtab_and_line sr_sal
;
6822 sr_sal
.pc
= ecs
->stop_func_start
;
6823 sr_sal
.pspace
= get_frame_program_space (frame
);
6825 insert_step_resume_breakpoint_at_sal (gdbarch
,
6826 sr_sal
, null_frame_id
);
6831 /* If we have line number information for the function we are
6832 thinking of stepping into and the function isn't on the skip
6835 If there are several symtabs at that PC (e.g. with include
6836 files), just want to know whether *any* of them have line
6837 numbers. find_pc_line handles this. */
6839 struct symtab_and_line tmp_sal
;
6841 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6842 if (tmp_sal
.line
!= 0
6843 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6845 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6847 if (execution_direction
== EXEC_REVERSE
)
6848 handle_step_into_function_backward (gdbarch
, ecs
);
6850 handle_step_into_function (gdbarch
, ecs
);
6855 /* If we have no line number and the step-stop-if-no-debug is
6856 set, we stop the step so that the user has a chance to switch
6857 in assembly mode. */
6858 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6859 && step_stop_if_no_debug
)
6861 end_stepping_range (ecs
);
6865 if (execution_direction
== EXEC_REVERSE
)
6867 /* If we're already at the start of the function, we've either just
6868 stepped backward into a single instruction function without line
6869 number info, or stepped back out of a signal handler to the first
6870 instruction of the function without line number info. Just keep
6871 going, which will single-step back to the caller. */
6872 if (ecs
->stop_func_start
!= stop_pc
)
6874 /* Set a breakpoint at callee's start address.
6875 From there we can step once and be back in the caller. */
6876 symtab_and_line sr_sal
;
6877 sr_sal
.pc
= ecs
->stop_func_start
;
6878 sr_sal
.pspace
= get_frame_program_space (frame
);
6879 insert_step_resume_breakpoint_at_sal (gdbarch
,
6880 sr_sal
, null_frame_id
);
6884 /* Set a breakpoint at callee's return address (the address
6885 at which the caller will resume). */
6886 insert_step_resume_breakpoint_at_caller (frame
);
6892 /* Reverse stepping through solib trampolines. */
6894 if (execution_direction
== EXEC_REVERSE
6895 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6897 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6899 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6900 || (ecs
->stop_func_start
== 0
6901 && in_solib_dynsym_resolve_code (stop_pc
)))
6903 /* Any solib trampoline code can be handled in reverse
6904 by simply continuing to single-step. We have already
6905 executed the solib function (backwards), and a few
6906 steps will take us back through the trampoline to the
6911 else if (in_solib_dynsym_resolve_code (stop_pc
))
6913 /* Stepped backward into the solib dynsym resolver.
6914 Set a breakpoint at its start and continue, then
6915 one more step will take us out. */
6916 symtab_and_line sr_sal
;
6917 sr_sal
.pc
= ecs
->stop_func_start
;
6918 sr_sal
.pspace
= get_frame_program_space (frame
);
6919 insert_step_resume_breakpoint_at_sal (gdbarch
,
6920 sr_sal
, null_frame_id
);
6926 /* This always returns the sal for the inner-most frame when we are in a
6927 stack of inlined frames, even if GDB actually believes that it is in a
6928 more outer frame. This is checked for below by calls to
6929 inline_skipped_frames. */
6930 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6932 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6933 the trampoline processing logic, however, there are some trampolines
6934 that have no names, so we should do trampoline handling first. */
6935 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6936 && ecs
->stop_func_name
== NULL
6937 && stop_pc_sal
.line
== 0)
6939 infrun_log_debug ("stepped into undebuggable function");
6941 /* The inferior just stepped into, or returned to, an
6942 undebuggable function (where there is no debugging information
6943 and no line number corresponding to the address where the
6944 inferior stopped). Since we want to skip this kind of code,
6945 we keep going until the inferior returns from this
6946 function - unless the user has asked us not to (via
6947 set step-mode) or we no longer know how to get back
6948 to the call site. */
6949 if (step_stop_if_no_debug
6950 || !frame_id_p (frame_unwind_caller_id (frame
)))
6952 /* If we have no line number and the step-stop-if-no-debug
6953 is set, we stop the step so that the user has a chance to
6954 switch in assembly mode. */
6955 end_stepping_range (ecs
);
6960 /* Set a breakpoint at callee's return address (the address
6961 at which the caller will resume). */
6962 insert_step_resume_breakpoint_at_caller (frame
);
6968 if (ecs
->event_thread
->control
.step_range_end
== 1)
6970 /* It is stepi or nexti. We always want to stop stepping after
6972 infrun_log_debug ("stepi/nexti");
6973 end_stepping_range (ecs
);
6977 if (stop_pc_sal
.line
== 0)
6979 /* We have no line number information. That means to stop
6980 stepping (does this always happen right after one instruction,
6981 when we do "s" in a function with no line numbers,
6982 or can this happen as a result of a return or longjmp?). */
6983 infrun_log_debug ("line number info");
6984 end_stepping_range (ecs
);
6988 /* Look for "calls" to inlined functions, part one. If the inline
6989 frame machinery detected some skipped call sites, we have entered
6990 a new inline function. */
6992 if (frame_id_eq (get_frame_id (get_current_frame ()),
6993 ecs
->event_thread
->control
.step_frame_id
)
6994 && inline_skipped_frames (ecs
->event_thread
))
6996 infrun_log_debug ("stepped into inlined function");
6998 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7000 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7002 /* For "step", we're going to stop. But if the call site
7003 for this inlined function is on the same source line as
7004 we were previously stepping, go down into the function
7005 first. Otherwise stop at the call site. */
7007 if (call_sal
.line
== ecs
->event_thread
->current_line
7008 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7010 step_into_inline_frame (ecs
->event_thread
);
7011 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7018 end_stepping_range (ecs
);
7023 /* For "next", we should stop at the call site if it is on a
7024 different source line. Otherwise continue through the
7025 inlined function. */
7026 if (call_sal
.line
== ecs
->event_thread
->current_line
7027 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7030 end_stepping_range (ecs
);
7035 /* Look for "calls" to inlined functions, part two. If we are still
7036 in the same real function we were stepping through, but we have
7037 to go further up to find the exact frame ID, we are stepping
7038 through a more inlined call beyond its call site. */
7040 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7041 && !frame_id_eq (get_frame_id (get_current_frame ()),
7042 ecs
->event_thread
->control
.step_frame_id
)
7043 && stepped_in_from (get_current_frame (),
7044 ecs
->event_thread
->control
.step_frame_id
))
7046 infrun_log_debug ("stepping through inlined function");
7048 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7049 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7052 end_stepping_range (ecs
);
7056 bool refresh_step_info
= true;
7057 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7058 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7059 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7061 if (stop_pc_sal
.is_stmt
)
7063 /* We are at the start of a different line. So stop. Note that
7064 we don't stop if we step into the middle of a different line.
7065 That is said to make things like for (;;) statements work
7067 infrun_log_debug ("infrun: stepped to a different line\n");
7068 end_stepping_range (ecs
);
7071 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7072 ecs
->event_thread
->control
.step_frame_id
))
7074 /* We are at the start of a different line, however, this line is
7075 not marked as a statement, and we have not changed frame. We
7076 ignore this line table entry, and continue stepping forward,
7077 looking for a better place to stop. */
7078 refresh_step_info
= false;
7079 infrun_log_debug ("infrun: stepped to a different line, but "
7080 "it's not the start of a statement\n");
7084 /* We aren't done stepping.
7086 Optimize by setting the stepping range to the line.
7087 (We might not be in the original line, but if we entered a
7088 new line in mid-statement, we continue stepping. This makes
7089 things like for(;;) statements work better.)
7091 If we entered a SAL that indicates a non-statement line table entry,
7092 then we update the stepping range, but we don't update the step info,
7093 which includes things like the line number we are stepping away from.
7094 This means we will stop when we find a line table entry that is marked
7095 as is-statement, even if it matches the non-statement one we just
7098 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7099 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7100 ecs
->event_thread
->control
.may_range_step
= 1;
7101 if (refresh_step_info
)
7102 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7104 infrun_log_debug ("keep going");
7108 /* In all-stop mode, if we're currently stepping but have stopped in
7109 some other thread, we may need to switch back to the stepped
7110 thread. Returns true we set the inferior running, false if we left
7111 it stopped (and the event needs further processing). */
7114 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7116 if (!target_is_non_stop_p ())
7118 struct thread_info
*stepping_thread
;
7120 /* If any thread is blocked on some internal breakpoint, and we
7121 simply need to step over that breakpoint to get it going
7122 again, do that first. */
7124 /* However, if we see an event for the stepping thread, then we
7125 know all other threads have been moved past their breakpoints
7126 already. Let the caller check whether the step is finished,
7127 etc., before deciding to move it past a breakpoint. */
7128 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7131 /* Check if the current thread is blocked on an incomplete
7132 step-over, interrupted by a random signal. */
7133 if (ecs
->event_thread
->control
.trap_expected
7134 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7136 infrun_log_debug ("need to finish step-over of [%s]",
7137 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7142 /* Check if the current thread is blocked by a single-step
7143 breakpoint of another thread. */
7144 if (ecs
->hit_singlestep_breakpoint
)
7146 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7147 target_pid_to_str (ecs
->ptid
).c_str ());
7152 /* If this thread needs yet another step-over (e.g., stepping
7153 through a delay slot), do it first before moving on to
7155 if (thread_still_needs_step_over (ecs
->event_thread
))
7158 ("thread [%s] still needs step-over",
7159 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7164 /* If scheduler locking applies even if not stepping, there's no
7165 need to walk over threads. Above we've checked whether the
7166 current thread is stepping. If some other thread not the
7167 event thread is stepping, then it must be that scheduler
7168 locking is not in effect. */
7169 if (schedlock_applies (ecs
->event_thread
))
7172 /* Otherwise, we no longer expect a trap in the current thread.
7173 Clear the trap_expected flag before switching back -- this is
7174 what keep_going does as well, if we call it. */
7175 ecs
->event_thread
->control
.trap_expected
= 0;
7177 /* Likewise, clear the signal if it should not be passed. */
7178 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7179 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7181 /* Do all pending step-overs before actually proceeding with
7183 if (start_step_over ())
7185 prepare_to_wait (ecs
);
7189 /* Look for the stepping/nexting thread. */
7190 stepping_thread
= NULL
;
7192 for (thread_info
*tp
: all_non_exited_threads ())
7194 switch_to_thread_no_regs (tp
);
7196 /* Ignore threads of processes the caller is not
7199 && (tp
->inf
->process_target () != ecs
->target
7200 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7203 /* When stepping over a breakpoint, we lock all threads
7204 except the one that needs to move past the breakpoint.
7205 If a non-event thread has this set, the "incomplete
7206 step-over" check above should have caught it earlier. */
7207 if (tp
->control
.trap_expected
)
7209 internal_error (__FILE__
, __LINE__
,
7210 "[%s] has inconsistent state: "
7211 "trap_expected=%d\n",
7212 target_pid_to_str (tp
->ptid
).c_str (),
7213 tp
->control
.trap_expected
);
7216 /* Did we find the stepping thread? */
7217 if (tp
->control
.step_range_end
)
7219 /* Yep. There should only one though. */
7220 gdb_assert (stepping_thread
== NULL
);
7222 /* The event thread is handled at the top, before we
7224 gdb_assert (tp
!= ecs
->event_thread
);
7226 /* If some thread other than the event thread is
7227 stepping, then scheduler locking can't be in effect,
7228 otherwise we wouldn't have resumed the current event
7229 thread in the first place. */
7230 gdb_assert (!schedlock_applies (tp
));
7232 stepping_thread
= tp
;
7236 if (stepping_thread
!= NULL
)
7238 infrun_log_debug ("switching back to stepped thread");
7240 if (keep_going_stepped_thread (stepping_thread
))
7242 prepare_to_wait (ecs
);
7247 switch_to_thread (ecs
->event_thread
);
7253 /* Set a previously stepped thread back to stepping. Returns true on
7254 success, false if the resume is not possible (e.g., the thread
7258 keep_going_stepped_thread (struct thread_info
*tp
)
7260 struct frame_info
*frame
;
7261 struct execution_control_state ecss
;
7262 struct execution_control_state
*ecs
= &ecss
;
7264 /* If the stepping thread exited, then don't try to switch back and
7265 resume it, which could fail in several different ways depending
7266 on the target. Instead, just keep going.
7268 We can find a stepping dead thread in the thread list in two
7271 - The target supports thread exit events, and when the target
7272 tries to delete the thread from the thread list, inferior_ptid
7273 pointed at the exiting thread. In such case, calling
7274 delete_thread does not really remove the thread from the list;
7275 instead, the thread is left listed, with 'exited' state.
7277 - The target's debug interface does not support thread exit
7278 events, and so we have no idea whatsoever if the previously
7279 stepping thread is still alive. For that reason, we need to
7280 synchronously query the target now. */
7282 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7284 infrun_log_debug ("not resuming previously stepped thread, it has "
7291 infrun_log_debug ("resuming previously stepped thread");
7293 reset_ecs (ecs
, tp
);
7294 switch_to_thread (tp
);
7296 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7297 frame
= get_current_frame ();
7299 /* If the PC of the thread we were trying to single-step has
7300 changed, then that thread has trapped or been signaled, but the
7301 event has not been reported to GDB yet. Re-poll the target
7302 looking for this particular thread's event (i.e. temporarily
7303 enable schedlock) by:
7305 - setting a break at the current PC
7306 - resuming that particular thread, only (by setting trap
7309 This prevents us continuously moving the single-step breakpoint
7310 forward, one instruction at a time, overstepping. */
7312 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7316 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7317 paddress (target_gdbarch (), tp
->prev_pc
),
7318 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7320 /* Clear the info of the previous step-over, as it's no longer
7321 valid (if the thread was trying to step over a breakpoint, it
7322 has already succeeded). It's what keep_going would do too,
7323 if we called it. Do this before trying to insert the sss
7324 breakpoint, otherwise if we were previously trying to step
7325 over this exact address in another thread, the breakpoint is
7327 clear_step_over_info ();
7328 tp
->control
.trap_expected
= 0;
7330 insert_single_step_breakpoint (get_frame_arch (frame
),
7331 get_frame_address_space (frame
),
7332 tp
->suspend
.stop_pc
);
7335 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7336 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7340 infrun_log_debug ("expected thread still hasn't advanced");
7342 keep_going_pass_signal (ecs
);
7347 /* Is thread TP in the middle of (software or hardware)
7348 single-stepping? (Note the result of this function must never be
7349 passed directly as target_resume's STEP parameter.) */
7352 currently_stepping (struct thread_info
*tp
)
7354 return ((tp
->control
.step_range_end
7355 && tp
->control
.step_resume_breakpoint
== NULL
)
7356 || tp
->control
.trap_expected
7357 || tp
->stepped_breakpoint
7358 || bpstat_should_step ());
7361 /* Inferior has stepped into a subroutine call with source code that
7362 we should not step over. Do step to the first line of code in
7366 handle_step_into_function (struct gdbarch
*gdbarch
,
7367 struct execution_control_state
*ecs
)
7369 fill_in_stop_func (gdbarch
, ecs
);
7371 compunit_symtab
*cust
7372 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7373 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7374 ecs
->stop_func_start
7375 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7377 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7378 /* Use the step_resume_break to step until the end of the prologue,
7379 even if that involves jumps (as it seems to on the vax under
7381 /* If the prologue ends in the middle of a source line, continue to
7382 the end of that source line (if it is still within the function).
7383 Otherwise, just go to end of prologue. */
7384 if (stop_func_sal
.end
7385 && stop_func_sal
.pc
!= ecs
->stop_func_start
7386 && stop_func_sal
.end
< ecs
->stop_func_end
)
7387 ecs
->stop_func_start
= stop_func_sal
.end
;
7389 /* Architectures which require breakpoint adjustment might not be able
7390 to place a breakpoint at the computed address. If so, the test
7391 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7392 ecs->stop_func_start to an address at which a breakpoint may be
7393 legitimately placed.
7395 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7396 made, GDB will enter an infinite loop when stepping through
7397 optimized code consisting of VLIW instructions which contain
7398 subinstructions corresponding to different source lines. On
7399 FR-V, it's not permitted to place a breakpoint on any but the
7400 first subinstruction of a VLIW instruction. When a breakpoint is
7401 set, GDB will adjust the breakpoint address to the beginning of
7402 the VLIW instruction. Thus, we need to make the corresponding
7403 adjustment here when computing the stop address. */
7405 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7407 ecs
->stop_func_start
7408 = gdbarch_adjust_breakpoint_address (gdbarch
,
7409 ecs
->stop_func_start
);
7412 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7414 /* We are already there: stop now. */
7415 end_stepping_range (ecs
);
7420 /* Put the step-breakpoint there and go until there. */
7421 symtab_and_line sr_sal
;
7422 sr_sal
.pc
= ecs
->stop_func_start
;
7423 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7424 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7426 /* Do not specify what the fp should be when we stop since on
7427 some machines the prologue is where the new fp value is
7429 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7431 /* And make sure stepping stops right away then. */
7432 ecs
->event_thread
->control
.step_range_end
7433 = ecs
->event_thread
->control
.step_range_start
;
7438 /* Inferior has stepped backward into a subroutine call with source
7439 code that we should not step over. Do step to the beginning of the
7440 last line of code in it. */
7443 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7444 struct execution_control_state
*ecs
)
7446 struct compunit_symtab
*cust
;
7447 struct symtab_and_line stop_func_sal
;
7449 fill_in_stop_func (gdbarch
, ecs
);
7451 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7452 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7453 ecs
->stop_func_start
7454 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7456 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7458 /* OK, we're just going to keep stepping here. */
7459 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7461 /* We're there already. Just stop stepping now. */
7462 end_stepping_range (ecs
);
7466 /* Else just reset the step range and keep going.
7467 No step-resume breakpoint, they don't work for
7468 epilogues, which can have multiple entry paths. */
7469 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7470 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7476 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7477 This is used to both functions and to skip over code. */
7480 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7481 struct symtab_and_line sr_sal
,
7482 struct frame_id sr_id
,
7483 enum bptype sr_type
)
7485 /* There should never be more than one step-resume or longjmp-resume
7486 breakpoint per thread, so we should never be setting a new
7487 step_resume_breakpoint when one is already active. */
7488 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7489 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7491 infrun_log_debug ("inserting step-resume breakpoint at %s",
7492 paddress (gdbarch
, sr_sal
.pc
));
7494 inferior_thread ()->control
.step_resume_breakpoint
7495 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7499 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7500 struct symtab_and_line sr_sal
,
7501 struct frame_id sr_id
)
7503 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7508 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7509 This is used to skip a potential signal handler.
7511 This is called with the interrupted function's frame. The signal
7512 handler, when it returns, will resume the interrupted function at
7516 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7518 gdb_assert (return_frame
!= NULL
);
7520 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7522 symtab_and_line sr_sal
;
7523 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7524 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7525 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7527 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7528 get_stack_frame_id (return_frame
),
7532 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7533 is used to skip a function after stepping into it (for "next" or if
7534 the called function has no debugging information).
7536 The current function has almost always been reached by single
7537 stepping a call or return instruction. NEXT_FRAME belongs to the
7538 current function, and the breakpoint will be set at the caller's
7541 This is a separate function rather than reusing
7542 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7543 get_prev_frame, which may stop prematurely (see the implementation
7544 of frame_unwind_caller_id for an example). */
7547 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7549 /* We shouldn't have gotten here if we don't know where the call site
7551 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7553 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7555 symtab_and_line sr_sal
;
7556 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7557 frame_unwind_caller_pc (next_frame
));
7558 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7559 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7561 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7562 frame_unwind_caller_id (next_frame
));
7565 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7566 new breakpoint at the target of a jmp_buf. The handling of
7567 longjmp-resume uses the same mechanisms used for handling
7568 "step-resume" breakpoints. */
7571 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7573 /* There should never be more than one longjmp-resume breakpoint per
7574 thread, so we should never be setting a new
7575 longjmp_resume_breakpoint when one is already active. */
7576 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7578 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7579 paddress (gdbarch
, pc
));
7581 inferior_thread ()->control
.exception_resume_breakpoint
=
7582 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7585 /* Insert an exception resume breakpoint. TP is the thread throwing
7586 the exception. The block B is the block of the unwinder debug hook
7587 function. FRAME is the frame corresponding to the call to this
7588 function. SYM is the symbol of the function argument holding the
7589 target PC of the exception. */
7592 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7593 const struct block
*b
,
7594 struct frame_info
*frame
,
7599 struct block_symbol vsym
;
7600 struct value
*value
;
7602 struct breakpoint
*bp
;
7604 vsym
= lookup_symbol_search_name (sym
->search_name (),
7606 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7607 /* If the value was optimized out, revert to the old behavior. */
7608 if (! value_optimized_out (value
))
7610 handler
= value_as_address (value
);
7612 infrun_log_debug ("exception resume at %lx",
7613 (unsigned long) handler
);
7615 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7617 bp_exception_resume
).release ();
7619 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7622 bp
->thread
= tp
->global_num
;
7623 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7626 catch (const gdb_exception_error
&e
)
7628 /* We want to ignore errors here. */
7632 /* A helper for check_exception_resume that sets an
7633 exception-breakpoint based on a SystemTap probe. */
7636 insert_exception_resume_from_probe (struct thread_info
*tp
,
7637 const struct bound_probe
*probe
,
7638 struct frame_info
*frame
)
7640 struct value
*arg_value
;
7642 struct breakpoint
*bp
;
7644 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7648 handler
= value_as_address (arg_value
);
7650 infrun_log_debug ("exception resume at %s",
7651 paddress (probe
->objfile
->arch (), handler
));
7653 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7654 handler
, bp_exception_resume
).release ();
7655 bp
->thread
= tp
->global_num
;
7656 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7659 /* This is called when an exception has been intercepted. Check to
7660 see whether the exception's destination is of interest, and if so,
7661 set an exception resume breakpoint there. */
7664 check_exception_resume (struct execution_control_state
*ecs
,
7665 struct frame_info
*frame
)
7667 struct bound_probe probe
;
7668 struct symbol
*func
;
7670 /* First see if this exception unwinding breakpoint was set via a
7671 SystemTap probe point. If so, the probe has two arguments: the
7672 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7673 set a breakpoint there. */
7674 probe
= find_probe_by_pc (get_frame_pc (frame
));
7677 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7681 func
= get_frame_function (frame
);
7687 const struct block
*b
;
7688 struct block_iterator iter
;
7692 /* The exception breakpoint is a thread-specific breakpoint on
7693 the unwinder's debug hook, declared as:
7695 void _Unwind_DebugHook (void *cfa, void *handler);
7697 The CFA argument indicates the frame to which control is
7698 about to be transferred. HANDLER is the destination PC.
7700 We ignore the CFA and set a temporary breakpoint at HANDLER.
7701 This is not extremely efficient but it avoids issues in gdb
7702 with computing the DWARF CFA, and it also works even in weird
7703 cases such as throwing an exception from inside a signal
7706 b
= SYMBOL_BLOCK_VALUE (func
);
7707 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7709 if (!SYMBOL_IS_ARGUMENT (sym
))
7716 insert_exception_resume_breakpoint (ecs
->event_thread
,
7722 catch (const gdb_exception_error
&e
)
7728 stop_waiting (struct execution_control_state
*ecs
)
7730 infrun_log_debug ("stop_waiting");
7732 /* Let callers know we don't want to wait for the inferior anymore. */
7733 ecs
->wait_some_more
= 0;
7735 /* If all-stop, but there exists a non-stop target, stop all
7736 threads now that we're presenting the stop to the user. */
7737 if (!non_stop
&& exists_non_stop_target ())
7738 stop_all_threads ();
7741 /* Like keep_going, but passes the signal to the inferior, even if the
7742 signal is set to nopass. */
7745 keep_going_pass_signal (struct execution_control_state
*ecs
)
7747 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7748 gdb_assert (!ecs
->event_thread
->resumed
);
7750 /* Save the pc before execution, to compare with pc after stop. */
7751 ecs
->event_thread
->prev_pc
7752 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7754 if (ecs
->event_thread
->control
.trap_expected
)
7756 struct thread_info
*tp
= ecs
->event_thread
;
7758 infrun_log_debug ("%s has trap_expected set, "
7759 "resuming to collect trap",
7760 target_pid_to_str (tp
->ptid
).c_str ());
7762 /* We haven't yet gotten our trap, and either: intercepted a
7763 non-signal event (e.g., a fork); or took a signal which we
7764 are supposed to pass through to the inferior. Simply
7766 resume (ecs
->event_thread
->suspend
.stop_signal
);
7768 else if (step_over_info_valid_p ())
7770 /* Another thread is stepping over a breakpoint in-line. If
7771 this thread needs a step-over too, queue the request. In
7772 either case, this resume must be deferred for later. */
7773 struct thread_info
*tp
= ecs
->event_thread
;
7775 if (ecs
->hit_singlestep_breakpoint
7776 || thread_still_needs_step_over (tp
))
7778 infrun_log_debug ("step-over already in progress: "
7779 "step-over for %s deferred",
7780 target_pid_to_str (tp
->ptid
).c_str ());
7781 global_thread_step_over_chain_enqueue (tp
);
7785 infrun_log_debug ("step-over in progress: resume of %s deferred",
7786 target_pid_to_str (tp
->ptid
).c_str ());
7791 struct regcache
*regcache
= get_current_regcache ();
7794 step_over_what step_what
;
7796 /* Either the trap was not expected, but we are continuing
7797 anyway (if we got a signal, the user asked it be passed to
7800 We got our expected trap, but decided we should resume from
7803 We're going to run this baby now!
7805 Note that insert_breakpoints won't try to re-insert
7806 already inserted breakpoints. Therefore, we don't
7807 care if breakpoints were already inserted, or not. */
7809 /* If we need to step over a breakpoint, and we're not using
7810 displaced stepping to do so, insert all breakpoints
7811 (watchpoints, etc.) but the one we're stepping over, step one
7812 instruction, and then re-insert the breakpoint when that step
7815 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7817 remove_bp
= (ecs
->hit_singlestep_breakpoint
7818 || (step_what
& STEP_OVER_BREAKPOINT
));
7819 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7821 /* We can't use displaced stepping if we need to step past a
7822 watchpoint. The instruction copied to the scratch pad would
7823 still trigger the watchpoint. */
7825 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7827 set_step_over_info (regcache
->aspace (),
7828 regcache_read_pc (regcache
), remove_wps
,
7829 ecs
->event_thread
->global_num
);
7831 else if (remove_wps
)
7832 set_step_over_info (NULL
, 0, remove_wps
, -1);
7834 /* If we now need to do an in-line step-over, we need to stop
7835 all other threads. Note this must be done before
7836 insert_breakpoints below, because that removes the breakpoint
7837 we're about to step over, otherwise other threads could miss
7839 if (step_over_info_valid_p () && target_is_non_stop_p ())
7840 stop_all_threads ();
7842 /* Stop stepping if inserting breakpoints fails. */
7845 insert_breakpoints ();
7847 catch (const gdb_exception_error
&e
)
7849 exception_print (gdb_stderr
, e
);
7851 clear_step_over_info ();
7855 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7857 resume (ecs
->event_thread
->suspend
.stop_signal
);
7860 prepare_to_wait (ecs
);
7863 /* Called when we should continue running the inferior, because the
7864 current event doesn't cause a user visible stop. This does the
7865 resuming part; waiting for the next event is done elsewhere. */
7868 keep_going (struct execution_control_state
*ecs
)
7870 if (ecs
->event_thread
->control
.trap_expected
7871 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7872 ecs
->event_thread
->control
.trap_expected
= 0;
7874 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7875 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7876 keep_going_pass_signal (ecs
);
7879 /* This function normally comes after a resume, before
7880 handle_inferior_event exits. It takes care of any last bits of
7881 housekeeping, and sets the all-important wait_some_more flag. */
7884 prepare_to_wait (struct execution_control_state
*ecs
)
7886 infrun_log_debug ("prepare_to_wait");
7888 ecs
->wait_some_more
= 1;
7890 if (!target_is_async_p ())
7891 mark_infrun_async_event_handler ();
7894 /* We are done with the step range of a step/next/si/ni command.
7895 Called once for each n of a "step n" operation. */
7898 end_stepping_range (struct execution_control_state
*ecs
)
7900 ecs
->event_thread
->control
.stop_step
= 1;
7904 /* Several print_*_reason functions to print why the inferior has stopped.
7905 We always print something when the inferior exits, or receives a signal.
7906 The rest of the cases are dealt with later on in normal_stop and
7907 print_it_typical. Ideally there should be a call to one of these
7908 print_*_reason functions functions from handle_inferior_event each time
7909 stop_waiting is called.
7911 Note that we don't call these directly, instead we delegate that to
7912 the interpreters, through observers. Interpreters then call these
7913 with whatever uiout is right. */
7916 print_end_stepping_range_reason (struct ui_out
*uiout
)
7918 /* For CLI-like interpreters, print nothing. */
7920 if (uiout
->is_mi_like_p ())
7922 uiout
->field_string ("reason",
7923 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7928 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7930 annotate_signalled ();
7931 if (uiout
->is_mi_like_p ())
7933 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7934 uiout
->text ("\nProgram terminated with signal ");
7935 annotate_signal_name ();
7936 uiout
->field_string ("signal-name",
7937 gdb_signal_to_name (siggnal
));
7938 annotate_signal_name_end ();
7940 annotate_signal_string ();
7941 uiout
->field_string ("signal-meaning",
7942 gdb_signal_to_string (siggnal
));
7943 annotate_signal_string_end ();
7944 uiout
->text (".\n");
7945 uiout
->text ("The program no longer exists.\n");
7949 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7951 struct inferior
*inf
= current_inferior ();
7952 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7954 annotate_exited (exitstatus
);
7957 if (uiout
->is_mi_like_p ())
7958 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7959 std::string exit_code_str
7960 = string_printf ("0%o", (unsigned int) exitstatus
);
7961 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7962 plongest (inf
->num
), pidstr
.c_str (),
7963 string_field ("exit-code", exit_code_str
.c_str ()));
7967 if (uiout
->is_mi_like_p ())
7969 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7970 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7971 plongest (inf
->num
), pidstr
.c_str ());
7975 /* Some targets/architectures can do extra processing/display of
7976 segmentation faults. E.g., Intel MPX boundary faults.
7977 Call the architecture dependent function to handle the fault. */
7980 handle_segmentation_fault (struct ui_out
*uiout
)
7982 struct regcache
*regcache
= get_current_regcache ();
7983 struct gdbarch
*gdbarch
= regcache
->arch ();
7985 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7986 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
7990 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7992 struct thread_info
*thr
= inferior_thread ();
7996 if (uiout
->is_mi_like_p ())
7998 else if (show_thread_that_caused_stop ())
8002 uiout
->text ("\nThread ");
8003 uiout
->field_string ("thread-id", print_thread_id (thr
));
8005 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8008 uiout
->text (" \"");
8009 uiout
->field_string ("name", name
);
8014 uiout
->text ("\nProgram");
8016 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8017 uiout
->text (" stopped");
8020 uiout
->text (" received signal ");
8021 annotate_signal_name ();
8022 if (uiout
->is_mi_like_p ())
8024 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8025 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8026 annotate_signal_name_end ();
8028 annotate_signal_string ();
8029 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8031 if (siggnal
== GDB_SIGNAL_SEGV
)
8032 handle_segmentation_fault (uiout
);
8034 annotate_signal_string_end ();
8036 uiout
->text (".\n");
8040 print_no_history_reason (struct ui_out
*uiout
)
8042 uiout
->text ("\nNo more reverse-execution history.\n");
8045 /* Print current location without a level number, if we have changed
8046 functions or hit a breakpoint. Print source line if we have one.
8047 bpstat_print contains the logic deciding in detail what to print,
8048 based on the event(s) that just occurred. */
8051 print_stop_location (struct target_waitstatus
*ws
)
8054 enum print_what source_flag
;
8055 int do_frame_printing
= 1;
8056 struct thread_info
*tp
= inferior_thread ();
8058 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8062 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8063 should) carry around the function and does (or should) use
8064 that when doing a frame comparison. */
8065 if (tp
->control
.stop_step
8066 && frame_id_eq (tp
->control
.step_frame_id
,
8067 get_frame_id (get_current_frame ()))
8068 && (tp
->control
.step_start_function
8069 == find_pc_function (tp
->suspend
.stop_pc
)))
8071 /* Finished step, just print source line. */
8072 source_flag
= SRC_LINE
;
8076 /* Print location and source line. */
8077 source_flag
= SRC_AND_LOC
;
8080 case PRINT_SRC_AND_LOC
:
8081 /* Print location and source line. */
8082 source_flag
= SRC_AND_LOC
;
8084 case PRINT_SRC_ONLY
:
8085 source_flag
= SRC_LINE
;
8088 /* Something bogus. */
8089 source_flag
= SRC_LINE
;
8090 do_frame_printing
= 0;
8093 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8096 /* The behavior of this routine with respect to the source
8098 SRC_LINE: Print only source line
8099 LOCATION: Print only location
8100 SRC_AND_LOC: Print location and source line. */
8101 if (do_frame_printing
)
8102 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8108 print_stop_event (struct ui_out
*uiout
, bool displays
)
8110 struct target_waitstatus last
;
8111 struct thread_info
*tp
;
8113 get_last_target_status (nullptr, nullptr, &last
);
8116 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8118 print_stop_location (&last
);
8120 /* Display the auto-display expressions. */
8125 tp
= inferior_thread ();
8126 if (tp
->thread_fsm
!= NULL
8127 && tp
->thread_fsm
->finished_p ())
8129 struct return_value_info
*rv
;
8131 rv
= tp
->thread_fsm
->return_value ();
8133 print_return_value (uiout
, rv
);
8140 maybe_remove_breakpoints (void)
8142 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8144 if (remove_breakpoints ())
8146 target_terminal::ours_for_output ();
8147 printf_filtered (_("Cannot remove breakpoints because "
8148 "program is no longer writable.\nFurther "
8149 "execution is probably impossible.\n"));
8154 /* The execution context that just caused a normal stop. */
8161 DISABLE_COPY_AND_ASSIGN (stop_context
);
8163 bool changed () const;
8168 /* The event PTID. */
8172 /* If stopp for a thread event, this is the thread that caused the
8174 struct thread_info
*thread
;
8176 /* The inferior that caused the stop. */
8180 /* Initializes a new stop context. If stopped for a thread event, this
8181 takes a strong reference to the thread. */
8183 stop_context::stop_context ()
8185 stop_id
= get_stop_id ();
8186 ptid
= inferior_ptid
;
8187 inf_num
= current_inferior ()->num
;
8189 if (inferior_ptid
!= null_ptid
)
8191 /* Take a strong reference so that the thread can't be deleted
8193 thread
= inferior_thread ();
8200 /* Release a stop context previously created with save_stop_context.
8201 Releases the strong reference to the thread as well. */
8203 stop_context::~stop_context ()
8209 /* Return true if the current context no longer matches the saved stop
8213 stop_context::changed () const
8215 if (ptid
!= inferior_ptid
)
8217 if (inf_num
!= current_inferior ()->num
)
8219 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8221 if (get_stop_id () != stop_id
)
8231 struct target_waitstatus last
;
8233 get_last_target_status (nullptr, nullptr, &last
);
8237 /* If an exception is thrown from this point on, make sure to
8238 propagate GDB's knowledge of the executing state to the
8239 frontend/user running state. A QUIT is an easy exception to see
8240 here, so do this before any filtered output. */
8242 ptid_t finish_ptid
= null_ptid
;
8245 finish_ptid
= minus_one_ptid
;
8246 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8247 || last
.kind
== TARGET_WAITKIND_EXITED
)
8249 /* On some targets, we may still have live threads in the
8250 inferior when we get a process exit event. E.g., for
8251 "checkpoint", when the current checkpoint/fork exits,
8252 linux-fork.c automatically switches to another fork from
8253 within target_mourn_inferior. */
8254 if (inferior_ptid
!= null_ptid
)
8255 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8257 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8258 finish_ptid
= inferior_ptid
;
8260 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8261 if (finish_ptid
!= null_ptid
)
8263 maybe_finish_thread_state
.emplace
8264 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8267 /* As we're presenting a stop, and potentially removing breakpoints,
8268 update the thread list so we can tell whether there are threads
8269 running on the target. With target remote, for example, we can
8270 only learn about new threads when we explicitly update the thread
8271 list. Do this before notifying the interpreters about signal
8272 stops, end of stepping ranges, etc., so that the "new thread"
8273 output is emitted before e.g., "Program received signal FOO",
8274 instead of after. */
8275 update_thread_list ();
8277 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8278 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8280 /* As with the notification of thread events, we want to delay
8281 notifying the user that we've switched thread context until
8282 the inferior actually stops.
8284 There's no point in saying anything if the inferior has exited.
8285 Note that SIGNALLED here means "exited with a signal", not
8286 "received a signal".
8288 Also skip saying anything in non-stop mode. In that mode, as we
8289 don't want GDB to switch threads behind the user's back, to avoid
8290 races where the user is typing a command to apply to thread x,
8291 but GDB switches to thread y before the user finishes entering
8292 the command, fetch_inferior_event installs a cleanup to restore
8293 the current thread back to the thread the user had selected right
8294 after this event is handled, so we're not really switching, only
8295 informing of a stop. */
8297 && previous_inferior_ptid
!= inferior_ptid
8298 && target_has_execution
8299 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8300 && last
.kind
!= TARGET_WAITKIND_EXITED
8301 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8303 SWITCH_THRU_ALL_UIS ()
8305 target_terminal::ours_for_output ();
8306 printf_filtered (_("[Switching to %s]\n"),
8307 target_pid_to_str (inferior_ptid
).c_str ());
8308 annotate_thread_changed ();
8310 previous_inferior_ptid
= inferior_ptid
;
8313 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8315 SWITCH_THRU_ALL_UIS ()
8316 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8318 target_terminal::ours_for_output ();
8319 printf_filtered (_("No unwaited-for children left.\n"));
8323 /* Note: this depends on the update_thread_list call above. */
8324 maybe_remove_breakpoints ();
8326 /* If an auto-display called a function and that got a signal,
8327 delete that auto-display to avoid an infinite recursion. */
8329 if (stopped_by_random_signal
)
8330 disable_current_display ();
8332 SWITCH_THRU_ALL_UIS ()
8334 async_enable_stdin ();
8337 /* Let the user/frontend see the threads as stopped. */
8338 maybe_finish_thread_state
.reset ();
8340 /* Select innermost stack frame - i.e., current frame is frame 0,
8341 and current location is based on that. Handle the case where the
8342 dummy call is returning after being stopped. E.g. the dummy call
8343 previously hit a breakpoint. (If the dummy call returns
8344 normally, we won't reach here.) Do this before the stop hook is
8345 run, so that it doesn't get to see the temporary dummy frame,
8346 which is not where we'll present the stop. */
8347 if (has_stack_frames ())
8349 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8351 /* Pop the empty frame that contains the stack dummy. This
8352 also restores inferior state prior to the call (struct
8353 infcall_suspend_state). */
8354 struct frame_info
*frame
= get_current_frame ();
8356 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8358 /* frame_pop calls reinit_frame_cache as the last thing it
8359 does which means there's now no selected frame. */
8362 select_frame (get_current_frame ());
8364 /* Set the current source location. */
8365 set_current_sal_from_frame (get_current_frame ());
8368 /* Look up the hook_stop and run it (CLI internally handles problem
8369 of stop_command's pre-hook not existing). */
8370 if (stop_command
!= NULL
)
8372 stop_context saved_context
;
8376 execute_cmd_pre_hook (stop_command
);
8378 catch (const gdb_exception
&ex
)
8380 exception_fprintf (gdb_stderr
, ex
,
8381 "Error while running hook_stop:\n");
8384 /* If the stop hook resumes the target, then there's no point in
8385 trying to notify about the previous stop; its context is
8386 gone. Likewise if the command switches thread or inferior --
8387 the observers would print a stop for the wrong
8389 if (saved_context
.changed ())
8393 /* Notify observers about the stop. This is where the interpreters
8394 print the stop event. */
8395 if (inferior_ptid
!= null_ptid
)
8396 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8399 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8401 annotate_stopped ();
8403 if (target_has_execution
)
8405 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8406 && last
.kind
!= TARGET_WAITKIND_EXITED
8407 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8408 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8409 Delete any breakpoint that is to be deleted at the next stop. */
8410 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8413 /* Try to get rid of automatically added inferiors that are no
8414 longer needed. Keeping those around slows down things linearly.
8415 Note that this never removes the current inferior. */
8422 signal_stop_state (int signo
)
8424 return signal_stop
[signo
];
8428 signal_print_state (int signo
)
8430 return signal_print
[signo
];
8434 signal_pass_state (int signo
)
8436 return signal_program
[signo
];
8440 signal_cache_update (int signo
)
8444 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8445 signal_cache_update (signo
);
8450 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8451 && signal_print
[signo
] == 0
8452 && signal_program
[signo
] == 1
8453 && signal_catch
[signo
] == 0);
8457 signal_stop_update (int signo
, int state
)
8459 int ret
= signal_stop
[signo
];
8461 signal_stop
[signo
] = state
;
8462 signal_cache_update (signo
);
8467 signal_print_update (int signo
, int state
)
8469 int ret
= signal_print
[signo
];
8471 signal_print
[signo
] = state
;
8472 signal_cache_update (signo
);
8477 signal_pass_update (int signo
, int state
)
8479 int ret
= signal_program
[signo
];
8481 signal_program
[signo
] = state
;
8482 signal_cache_update (signo
);
8486 /* Update the global 'signal_catch' from INFO and notify the
8490 signal_catch_update (const unsigned int *info
)
8494 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8495 signal_catch
[i
] = info
[i
] > 0;
8496 signal_cache_update (-1);
8497 target_pass_signals (signal_pass
);
8501 sig_print_header (void)
8503 printf_filtered (_("Signal Stop\tPrint\tPass "
8504 "to program\tDescription\n"));
8508 sig_print_info (enum gdb_signal oursig
)
8510 const char *name
= gdb_signal_to_name (oursig
);
8511 int name_padding
= 13 - strlen (name
);
8513 if (name_padding
<= 0)
8516 printf_filtered ("%s", name
);
8517 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8518 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8519 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8520 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8521 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8524 /* Specify how various signals in the inferior should be handled. */
8527 handle_command (const char *args
, int from_tty
)
8529 int digits
, wordlen
;
8530 int sigfirst
, siglast
;
8531 enum gdb_signal oursig
;
8536 error_no_arg (_("signal to handle"));
8539 /* Allocate and zero an array of flags for which signals to handle. */
8541 const size_t nsigs
= GDB_SIGNAL_LAST
;
8542 unsigned char sigs
[nsigs
] {};
8544 /* Break the command line up into args. */
8546 gdb_argv
built_argv (args
);
8548 /* Walk through the args, looking for signal oursigs, signal names, and
8549 actions. Signal numbers and signal names may be interspersed with
8550 actions, with the actions being performed for all signals cumulatively
8551 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8553 for (char *arg
: built_argv
)
8555 wordlen
= strlen (arg
);
8556 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8560 sigfirst
= siglast
= -1;
8562 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8564 /* Apply action to all signals except those used by the
8565 debugger. Silently skip those. */
8568 siglast
= nsigs
- 1;
8570 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8572 SET_SIGS (nsigs
, sigs
, signal_stop
);
8573 SET_SIGS (nsigs
, sigs
, signal_print
);
8575 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8577 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8579 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8581 SET_SIGS (nsigs
, sigs
, signal_print
);
8583 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8585 SET_SIGS (nsigs
, sigs
, signal_program
);
8587 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8589 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8591 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8593 SET_SIGS (nsigs
, sigs
, signal_program
);
8595 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8597 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8598 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8600 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8602 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8604 else if (digits
> 0)
8606 /* It is numeric. The numeric signal refers to our own
8607 internal signal numbering from target.h, not to host/target
8608 signal number. This is a feature; users really should be
8609 using symbolic names anyway, and the common ones like
8610 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8612 sigfirst
= siglast
= (int)
8613 gdb_signal_from_command (atoi (arg
));
8614 if (arg
[digits
] == '-')
8617 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8619 if (sigfirst
> siglast
)
8621 /* Bet he didn't figure we'd think of this case... */
8622 std::swap (sigfirst
, siglast
);
8627 oursig
= gdb_signal_from_name (arg
);
8628 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8630 sigfirst
= siglast
= (int) oursig
;
8634 /* Not a number and not a recognized flag word => complain. */
8635 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8639 /* If any signal numbers or symbol names were found, set flags for
8640 which signals to apply actions to. */
8642 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8644 switch ((enum gdb_signal
) signum
)
8646 case GDB_SIGNAL_TRAP
:
8647 case GDB_SIGNAL_INT
:
8648 if (!allsigs
&& !sigs
[signum
])
8650 if (query (_("%s is used by the debugger.\n\
8651 Are you sure you want to change it? "),
8652 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8657 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8661 case GDB_SIGNAL_DEFAULT
:
8662 case GDB_SIGNAL_UNKNOWN
:
8663 /* Make sure that "all" doesn't print these. */
8672 for (int signum
= 0; signum
< nsigs
; signum
++)
8675 signal_cache_update (-1);
8676 target_pass_signals (signal_pass
);
8677 target_program_signals (signal_program
);
8681 /* Show the results. */
8682 sig_print_header ();
8683 for (; signum
< nsigs
; signum
++)
8685 sig_print_info ((enum gdb_signal
) signum
);
8692 /* Complete the "handle" command. */
8695 handle_completer (struct cmd_list_element
*ignore
,
8696 completion_tracker
&tracker
,
8697 const char *text
, const char *word
)
8699 static const char * const keywords
[] =
8713 signal_completer (ignore
, tracker
, text
, word
);
8714 complete_on_enum (tracker
, keywords
, word
, word
);
8718 gdb_signal_from_command (int num
)
8720 if (num
>= 1 && num
<= 15)
8721 return (enum gdb_signal
) num
;
8722 error (_("Only signals 1-15 are valid as numeric signals.\n\
8723 Use \"info signals\" for a list of symbolic signals."));
8726 /* Print current contents of the tables set by the handle command.
8727 It is possible we should just be printing signals actually used
8728 by the current target (but for things to work right when switching
8729 targets, all signals should be in the signal tables). */
8732 info_signals_command (const char *signum_exp
, int from_tty
)
8734 enum gdb_signal oursig
;
8736 sig_print_header ();
8740 /* First see if this is a symbol name. */
8741 oursig
= gdb_signal_from_name (signum_exp
);
8742 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8744 /* No, try numeric. */
8746 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8748 sig_print_info (oursig
);
8752 printf_filtered ("\n");
8753 /* These ugly casts brought to you by the native VAX compiler. */
8754 for (oursig
= GDB_SIGNAL_FIRST
;
8755 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8756 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8760 if (oursig
!= GDB_SIGNAL_UNKNOWN
8761 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8762 sig_print_info (oursig
);
8765 printf_filtered (_("\nUse the \"handle\" command "
8766 "to change these tables.\n"));
8769 /* The $_siginfo convenience variable is a bit special. We don't know
8770 for sure the type of the value until we actually have a chance to
8771 fetch the data. The type can change depending on gdbarch, so it is
8772 also dependent on which thread you have selected.
8774 1. making $_siginfo be an internalvar that creates a new value on
8777 2. making the value of $_siginfo be an lval_computed value. */
8779 /* This function implements the lval_computed support for reading a
8783 siginfo_value_read (struct value
*v
)
8785 LONGEST transferred
;
8787 /* If we can access registers, so can we access $_siginfo. Likewise
8789 validate_registers_access ();
8792 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8794 value_contents_all_raw (v
),
8796 TYPE_LENGTH (value_type (v
)));
8798 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8799 error (_("Unable to read siginfo"));
8802 /* This function implements the lval_computed support for writing a
8806 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8808 LONGEST transferred
;
8810 /* If we can access registers, so can we access $_siginfo. Likewise
8812 validate_registers_access ();
8814 transferred
= target_write (current_top_target (),
8815 TARGET_OBJECT_SIGNAL_INFO
,
8817 value_contents_all_raw (fromval
),
8819 TYPE_LENGTH (value_type (fromval
)));
8821 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8822 error (_("Unable to write siginfo"));
8825 static const struct lval_funcs siginfo_value_funcs
=
8831 /* Return a new value with the correct type for the siginfo object of
8832 the current thread using architecture GDBARCH. Return a void value
8833 if there's no object available. */
8835 static struct value
*
8836 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8839 if (target_has_stack
8840 && inferior_ptid
!= null_ptid
8841 && gdbarch_get_siginfo_type_p (gdbarch
))
8843 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8845 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8848 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8852 /* infcall_suspend_state contains state about the program itself like its
8853 registers and any signal it received when it last stopped.
8854 This state must be restored regardless of how the inferior function call
8855 ends (either successfully, or after it hits a breakpoint or signal)
8856 if the program is to properly continue where it left off. */
8858 class infcall_suspend_state
8861 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8862 once the inferior function call has finished. */
8863 infcall_suspend_state (struct gdbarch
*gdbarch
,
8864 const struct thread_info
*tp
,
8865 struct regcache
*regcache
)
8866 : m_thread_suspend (tp
->suspend
),
8867 m_registers (new readonly_detached_regcache (*regcache
))
8869 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8871 if (gdbarch_get_siginfo_type_p (gdbarch
))
8873 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8874 size_t len
= TYPE_LENGTH (type
);
8876 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8878 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8879 siginfo_data
.get (), 0, len
) != len
)
8881 /* Errors ignored. */
8882 siginfo_data
.reset (nullptr);
8888 m_siginfo_gdbarch
= gdbarch
;
8889 m_siginfo_data
= std::move (siginfo_data
);
8893 /* Return a pointer to the stored register state. */
8895 readonly_detached_regcache
*registers () const
8897 return m_registers
.get ();
8900 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8902 void restore (struct gdbarch
*gdbarch
,
8903 struct thread_info
*tp
,
8904 struct regcache
*regcache
) const
8906 tp
->suspend
= m_thread_suspend
;
8908 if (m_siginfo_gdbarch
== gdbarch
)
8910 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8912 /* Errors ignored. */
8913 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8914 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8917 /* The inferior can be gone if the user types "print exit(0)"
8918 (and perhaps other times). */
8919 if (target_has_execution
)
8920 /* NB: The register write goes through to the target. */
8921 regcache
->restore (registers ());
8925 /* How the current thread stopped before the inferior function call was
8927 struct thread_suspend_state m_thread_suspend
;
8929 /* The registers before the inferior function call was executed. */
8930 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8932 /* Format of SIGINFO_DATA or NULL if it is not present. */
8933 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8935 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8936 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8937 content would be invalid. */
8938 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8941 infcall_suspend_state_up
8942 save_infcall_suspend_state ()
8944 struct thread_info
*tp
= inferior_thread ();
8945 struct regcache
*regcache
= get_current_regcache ();
8946 struct gdbarch
*gdbarch
= regcache
->arch ();
8948 infcall_suspend_state_up inf_state
8949 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8951 /* Having saved the current state, adjust the thread state, discarding
8952 any stop signal information. The stop signal is not useful when
8953 starting an inferior function call, and run_inferior_call will not use
8954 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8955 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8960 /* Restore inferior session state to INF_STATE. */
8963 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8965 struct thread_info
*tp
= inferior_thread ();
8966 struct regcache
*regcache
= get_current_regcache ();
8967 struct gdbarch
*gdbarch
= regcache
->arch ();
8969 inf_state
->restore (gdbarch
, tp
, regcache
);
8970 discard_infcall_suspend_state (inf_state
);
8974 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8979 readonly_detached_regcache
*
8980 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8982 return inf_state
->registers ();
8985 /* infcall_control_state contains state regarding gdb's control of the
8986 inferior itself like stepping control. It also contains session state like
8987 the user's currently selected frame. */
8989 struct infcall_control_state
8991 struct thread_control_state thread_control
;
8992 struct inferior_control_state inferior_control
;
8995 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
8996 int stopped_by_random_signal
= 0;
8998 /* ID if the selected frame when the inferior function call was made. */
8999 struct frame_id selected_frame_id
{};
9002 /* Save all of the information associated with the inferior<==>gdb
9005 infcall_control_state_up
9006 save_infcall_control_state ()
9008 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9009 struct thread_info
*tp
= inferior_thread ();
9010 struct inferior
*inf
= current_inferior ();
9012 inf_status
->thread_control
= tp
->control
;
9013 inf_status
->inferior_control
= inf
->control
;
9015 tp
->control
.step_resume_breakpoint
= NULL
;
9016 tp
->control
.exception_resume_breakpoint
= NULL
;
9018 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9019 chain. If caller's caller is walking the chain, they'll be happier if we
9020 hand them back the original chain when restore_infcall_control_state is
9022 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9025 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9026 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9028 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9034 restore_selected_frame (const frame_id
&fid
)
9036 frame_info
*frame
= frame_find_by_id (fid
);
9038 /* If inf_status->selected_frame_id is NULL, there was no previously
9042 warning (_("Unable to restore previously selected frame."));
9046 select_frame (frame
);
9049 /* Restore inferior session state to INF_STATUS. */
9052 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9054 struct thread_info
*tp
= inferior_thread ();
9055 struct inferior
*inf
= current_inferior ();
9057 if (tp
->control
.step_resume_breakpoint
)
9058 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9060 if (tp
->control
.exception_resume_breakpoint
)
9061 tp
->control
.exception_resume_breakpoint
->disposition
9062 = disp_del_at_next_stop
;
9064 /* Handle the bpstat_copy of the chain. */
9065 bpstat_clear (&tp
->control
.stop_bpstat
);
9067 tp
->control
= inf_status
->thread_control
;
9068 inf
->control
= inf_status
->inferior_control
;
9071 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9072 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9074 if (target_has_stack
)
9076 /* The point of the try/catch is that if the stack is clobbered,
9077 walking the stack might encounter a garbage pointer and
9078 error() trying to dereference it. */
9081 restore_selected_frame (inf_status
->selected_frame_id
);
9083 catch (const gdb_exception_error
&ex
)
9085 exception_fprintf (gdb_stderr
, ex
,
9086 "Unable to restore previously selected frame:\n");
9087 /* Error in restoring the selected frame. Select the
9089 select_frame (get_current_frame ());
9097 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9099 if (inf_status
->thread_control
.step_resume_breakpoint
)
9100 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9101 = disp_del_at_next_stop
;
9103 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9104 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9105 = disp_del_at_next_stop
;
9107 /* See save_infcall_control_state for info on stop_bpstat. */
9108 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9116 clear_exit_convenience_vars (void)
9118 clear_internalvar (lookup_internalvar ("_exitsignal"));
9119 clear_internalvar (lookup_internalvar ("_exitcode"));
9123 /* User interface for reverse debugging:
9124 Set exec-direction / show exec-direction commands
9125 (returns error unless target implements to_set_exec_direction method). */
9127 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9128 static const char exec_forward
[] = "forward";
9129 static const char exec_reverse
[] = "reverse";
9130 static const char *exec_direction
= exec_forward
;
9131 static const char *const exec_direction_names
[] = {
9138 set_exec_direction_func (const char *args
, int from_tty
,
9139 struct cmd_list_element
*cmd
)
9141 if (target_can_execute_reverse
)
9143 if (!strcmp (exec_direction
, exec_forward
))
9144 execution_direction
= EXEC_FORWARD
;
9145 else if (!strcmp (exec_direction
, exec_reverse
))
9146 execution_direction
= EXEC_REVERSE
;
9150 exec_direction
= exec_forward
;
9151 error (_("Target does not support this operation."));
9156 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9157 struct cmd_list_element
*cmd
, const char *value
)
9159 switch (execution_direction
) {
9161 fprintf_filtered (out
, _("Forward.\n"));
9164 fprintf_filtered (out
, _("Reverse.\n"));
9167 internal_error (__FILE__
, __LINE__
,
9168 _("bogus execution_direction value: %d"),
9169 (int) execution_direction
);
9174 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9175 struct cmd_list_element
*c
, const char *value
)
9177 fprintf_filtered (file
, _("Resuming the execution of threads "
9178 "of all processes is %s.\n"), value
);
9181 /* Implementation of `siginfo' variable. */
9183 static const struct internalvar_funcs siginfo_funcs
=
9190 /* Callback for infrun's target events source. This is marked when a
9191 thread has a pending status to process. */
9194 infrun_async_inferior_event_handler (gdb_client_data data
)
9196 inferior_event_handler (INF_REG_EVENT
, NULL
);
9199 void _initialize_infrun ();
9201 _initialize_infrun ()
9203 struct cmd_list_element
*c
;
9205 /* Register extra event sources in the event loop. */
9206 infrun_async_inferior_event_token
9207 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9209 add_info ("signals", info_signals_command
, _("\
9210 What debugger does when program gets various signals.\n\
9211 Specify a signal as argument to print info on that signal only."));
9212 add_info_alias ("handle", "signals", 0);
9214 c
= add_com ("handle", class_run
, handle_command
, _("\
9215 Specify how to handle signals.\n\
9216 Usage: handle SIGNAL [ACTIONS]\n\
9217 Args are signals and actions to apply to those signals.\n\
9218 If no actions are specified, the current settings for the specified signals\n\
9219 will be displayed instead.\n\
9221 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9222 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9223 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9224 The special arg \"all\" is recognized to mean all signals except those\n\
9225 used by the debugger, typically SIGTRAP and SIGINT.\n\
9227 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9228 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9229 Stop means reenter debugger if this signal happens (implies print).\n\
9230 Print means print a message if this signal happens.\n\
9231 Pass means let program see this signal; otherwise program doesn't know.\n\
9232 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9233 Pass and Stop may be combined.\n\
9235 Multiple signals may be specified. Signal numbers and signal names\n\
9236 may be interspersed with actions, with the actions being performed for\n\
9237 all signals cumulatively specified."));
9238 set_cmd_completer (c
, handle_completer
);
9241 stop_command
= add_cmd ("stop", class_obscure
,
9242 not_just_help_class_command
, _("\
9243 There is no `stop' command, but you can set a hook on `stop'.\n\
9244 This allows you to set a list of commands to be run each time execution\n\
9245 of the program stops."), &cmdlist
);
9247 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9248 Set inferior debugging."), _("\
9249 Show inferior debugging."), _("\
9250 When non-zero, inferior specific debugging is enabled."),
9253 &setdebuglist
, &showdebuglist
);
9255 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9256 &debug_displaced
, _("\
9257 Set displaced stepping debugging."), _("\
9258 Show displaced stepping debugging."), _("\
9259 When non-zero, displaced stepping specific debugging is enabled."),
9261 show_debug_displaced
,
9262 &setdebuglist
, &showdebuglist
);
9264 add_setshow_boolean_cmd ("non-stop", no_class
,
9266 Set whether gdb controls the inferior in non-stop mode."), _("\
9267 Show whether gdb controls the inferior in non-stop mode."), _("\
9268 When debugging a multi-threaded program and this setting is\n\
9269 off (the default, also called all-stop mode), when one thread stops\n\
9270 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9271 all other threads in the program while you interact with the thread of\n\
9272 interest. When you continue or step a thread, you can allow the other\n\
9273 threads to run, or have them remain stopped, but while you inspect any\n\
9274 thread's state, all threads stop.\n\
9276 In non-stop mode, when one thread stops, other threads can continue\n\
9277 to run freely. You'll be able to step each thread independently,\n\
9278 leave it stopped or free to run as needed."),
9284 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9287 signal_print
[i
] = 1;
9288 signal_program
[i
] = 1;
9289 signal_catch
[i
] = 0;
9292 /* Signals caused by debugger's own actions should not be given to
9293 the program afterwards.
9295 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9296 explicitly specifies that it should be delivered to the target
9297 program. Typically, that would occur when a user is debugging a
9298 target monitor on a simulator: the target monitor sets a
9299 breakpoint; the simulator encounters this breakpoint and halts
9300 the simulation handing control to GDB; GDB, noting that the stop
9301 address doesn't map to any known breakpoint, returns control back
9302 to the simulator; the simulator then delivers the hardware
9303 equivalent of a GDB_SIGNAL_TRAP to the program being
9305 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9306 signal_program
[GDB_SIGNAL_INT
] = 0;
9308 /* Signals that are not errors should not normally enter the debugger. */
9309 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9310 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9311 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9312 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9313 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9314 signal_print
[GDB_SIGNAL_PROF
] = 0;
9315 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9316 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9317 signal_stop
[GDB_SIGNAL_IO
] = 0;
9318 signal_print
[GDB_SIGNAL_IO
] = 0;
9319 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9320 signal_print
[GDB_SIGNAL_POLL
] = 0;
9321 signal_stop
[GDB_SIGNAL_URG
] = 0;
9322 signal_print
[GDB_SIGNAL_URG
] = 0;
9323 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9324 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9325 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9326 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9328 /* These signals are used internally by user-level thread
9329 implementations. (See signal(5) on Solaris.) Like the above
9330 signals, a healthy program receives and handles them as part of
9331 its normal operation. */
9332 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9333 signal_print
[GDB_SIGNAL_LWP
] = 0;
9334 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9335 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9336 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9337 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9338 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9339 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9341 /* Update cached state. */
9342 signal_cache_update (-1);
9344 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9345 &stop_on_solib_events
, _("\
9346 Set stopping for shared library events."), _("\
9347 Show stopping for shared library events."), _("\
9348 If nonzero, gdb will give control to the user when the dynamic linker\n\
9349 notifies gdb of shared library events. The most common event of interest\n\
9350 to the user would be loading/unloading of a new library."),
9351 set_stop_on_solib_events
,
9352 show_stop_on_solib_events
,
9353 &setlist
, &showlist
);
9355 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9356 follow_fork_mode_kind_names
,
9357 &follow_fork_mode_string
, _("\
9358 Set debugger response to a program call of fork or vfork."), _("\
9359 Show debugger response to a program call of fork or vfork."), _("\
9360 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9361 parent - the original process is debugged after a fork\n\
9362 child - the new process is debugged after a fork\n\
9363 The unfollowed process will continue to run.\n\
9364 By default, the debugger will follow the parent process."),
9366 show_follow_fork_mode_string
,
9367 &setlist
, &showlist
);
9369 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9370 follow_exec_mode_names
,
9371 &follow_exec_mode_string
, _("\
9372 Set debugger response to a program call of exec."), _("\
9373 Show debugger response to a program call of exec."), _("\
9374 An exec call replaces the program image of a process.\n\
9376 follow-exec-mode can be:\n\
9378 new - the debugger creates a new inferior and rebinds the process\n\
9379 to this new inferior. The program the process was running before\n\
9380 the exec call can be restarted afterwards by restarting the original\n\
9383 same - the debugger keeps the process bound to the same inferior.\n\
9384 The new executable image replaces the previous executable loaded in\n\
9385 the inferior. Restarting the inferior after the exec call restarts\n\
9386 the executable the process was running after the exec call.\n\
9388 By default, the debugger will use the same inferior."),
9390 show_follow_exec_mode_string
,
9391 &setlist
, &showlist
);
9393 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9394 scheduler_enums
, &scheduler_mode
, _("\
9395 Set mode for locking scheduler during execution."), _("\
9396 Show mode for locking scheduler during execution."), _("\
9397 off == no locking (threads may preempt at any time)\n\
9398 on == full locking (no thread except the current thread may run)\n\
9399 This applies to both normal execution and replay mode.\n\
9400 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9401 In this mode, other threads may run during other commands.\n\
9402 This applies to both normal execution and replay mode.\n\
9403 replay == scheduler locked in replay mode and unlocked during normal execution."),
9404 set_schedlock_func
, /* traps on target vector */
9405 show_scheduler_mode
,
9406 &setlist
, &showlist
);
9408 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9409 Set mode for resuming threads of all processes."), _("\
9410 Show mode for resuming threads of all processes."), _("\
9411 When on, execution commands (such as 'continue' or 'next') resume all\n\
9412 threads of all processes. When off (which is the default), execution\n\
9413 commands only resume the threads of the current process. The set of\n\
9414 threads that are resumed is further refined by the scheduler-locking\n\
9415 mode (see help set scheduler-locking)."),
9417 show_schedule_multiple
,
9418 &setlist
, &showlist
);
9420 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9421 Set mode of the step operation."), _("\
9422 Show mode of the step operation."), _("\
9423 When set, doing a step over a function without debug line information\n\
9424 will stop at the first instruction of that function. Otherwise, the\n\
9425 function is skipped and the step command stops at a different source line."),
9427 show_step_stop_if_no_debug
,
9428 &setlist
, &showlist
);
9430 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9431 &can_use_displaced_stepping
, _("\
9432 Set debugger's willingness to use displaced stepping."), _("\
9433 Show debugger's willingness to use displaced stepping."), _("\
9434 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9435 supported by the target architecture. If off, gdb will not use displaced\n\
9436 stepping to step over breakpoints, even if such is supported by the target\n\
9437 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9438 if the target architecture supports it and non-stop mode is active, but will not\n\
9439 use it in all-stop mode (see help set non-stop)."),
9441 show_can_use_displaced_stepping
,
9442 &setlist
, &showlist
);
9444 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9445 &exec_direction
, _("Set direction of execution.\n\
9446 Options are 'forward' or 'reverse'."),
9447 _("Show direction of execution (forward/reverse)."),
9448 _("Tells gdb whether to execute forward or backward."),
9449 set_exec_direction_func
, show_exec_direction_func
,
9450 &setlist
, &showlist
);
9452 /* Set/show detach-on-fork: user-settable mode. */
9454 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9455 Set whether gdb will detach the child of a fork."), _("\
9456 Show whether gdb will detach the child of a fork."), _("\
9457 Tells gdb whether to detach the child of a fork."),
9458 NULL
, NULL
, &setlist
, &showlist
);
9460 /* Set/show disable address space randomization mode. */
9462 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9463 &disable_randomization
, _("\
9464 Set disabling of debuggee's virtual address space randomization."), _("\
9465 Show disabling of debuggee's virtual address space randomization."), _("\
9466 When this mode is on (which is the default), randomization of the virtual\n\
9467 address space is disabled. Standalone programs run with the randomization\n\
9468 enabled by default on some platforms."),
9469 &set_disable_randomization
,
9470 &show_disable_randomization
,
9471 &setlist
, &showlist
);
9473 /* ptid initializations */
9474 inferior_ptid
= null_ptid
;
9475 target_last_wait_ptid
= minus_one_ptid
;
9477 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9478 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9479 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9480 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9482 /* Explicitly create without lookup, since that tries to create a
9483 value with a void typed value, and when we get here, gdbarch
9484 isn't initialized yet. At this point, we're quite sure there
9485 isn't another convenience variable of the same name. */
9486 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9488 add_setshow_boolean_cmd ("observer", no_class
,
9489 &observer_mode_1
, _("\
9490 Set whether gdb controls the inferior in observer mode."), _("\
9491 Show whether gdb controls the inferior in observer mode."), _("\
9492 In observer mode, GDB can get data from the inferior, but not\n\
9493 affect its execution. Registers and memory may not be changed,\n\
9494 breakpoints may not be set, and the program cannot be interrupted\n\