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 thread_info
*child_thr
508 = add_thread_silent (child_inf
->process_target (), 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;
527 /* Now that the inferiors and program spaces are all
528 wired up, we can switch to the child thread (which
529 switches inferior and program space too). */
530 switch_to_thread (child_thr
);
534 child_inf
->aspace
= new_address_space ();
535 child_inf
->pspace
= new program_space (child_inf
->aspace
);
536 child_inf
->removable
= 1;
537 set_current_program_space (child_inf
->pspace
);
538 clone_program_space (child_inf
->pspace
, parent_inf
->pspace
);
540 /* solib_create_inferior_hook relies on the current
542 switch_to_thread (child_thr
);
544 /* Let the shared library layer (e.g., solib-svr4) learn
545 about this new process, relocate the cloned exec, pull
546 in shared libraries, and install the solib event
547 breakpoint. If a "cloned-VM" event was propagated
548 better throughout the core, this wouldn't be
550 solib_create_inferior_hook (0);
556 struct inferior
*parent_inf
;
558 parent_inf
= current_inferior ();
560 /* If we detached from the child, then we have to be careful
561 to not insert breakpoints in the parent until the child
562 is done with the shared memory region. However, if we're
563 staying attached to the child, then we can and should
564 insert breakpoints, so that we can debug it. A
565 subsequent child exec or exit is enough to know when does
566 the child stops using the parent's address space. */
567 parent_inf
->waiting_for_vfork_done
= detach_fork
;
568 parent_inf
->pspace
->breakpoints_not_allowed
= detach_fork
;
573 /* Follow the child. */
574 struct inferior
*parent_inf
, *child_inf
;
575 struct program_space
*parent_pspace
;
577 if (print_inferior_events
)
579 std::string parent_pid
= target_pid_to_str (parent_ptid
);
580 std::string child_pid
= target_pid_to_str (child_ptid
);
582 target_terminal::ours_for_output ();
583 fprintf_filtered (gdb_stdlog
,
584 _("[Attaching after %s %s to child %s]\n"),
586 has_vforked
? "vfork" : "fork",
590 /* Add the new inferior first, so that the target_detach below
591 doesn't unpush the target. */
593 child_inf
= add_inferior (child_ptid
.pid ());
595 parent_inf
= current_inferior ();
596 child_inf
->attach_flag
= parent_inf
->attach_flag
;
597 copy_terminal_info (child_inf
, parent_inf
);
598 child_inf
->gdbarch
= parent_inf
->gdbarch
;
599 copy_inferior_target_desc_info (child_inf
, parent_inf
);
601 parent_pspace
= parent_inf
->pspace
;
603 process_stratum_target
*target
= parent_inf
->process_target ();
606 /* Hold a strong reference to the target while (maybe)
607 detaching the parent. Otherwise detaching could close the
609 auto target_ref
= target_ops_ref::new_reference (target
);
611 /* If we're vforking, we want to hold on to the parent until
612 the child exits or execs. At child exec or exit time we
613 can remove the old breakpoints from the parent and detach
614 or resume debugging it. Otherwise, detach the parent now;
615 we'll want to reuse it's program/address spaces, but we
616 can't set them to the child before removing breakpoints
617 from the parent, otherwise, the breakpoints module could
618 decide to remove breakpoints from the wrong process (since
619 they'd be assigned to the same address space). */
623 gdb_assert (child_inf
->vfork_parent
== NULL
);
624 gdb_assert (parent_inf
->vfork_child
== NULL
);
625 child_inf
->vfork_parent
= parent_inf
;
626 child_inf
->pending_detach
= 0;
627 parent_inf
->vfork_child
= child_inf
;
628 parent_inf
->pending_detach
= detach_fork
;
629 parent_inf
->waiting_for_vfork_done
= 0;
631 else if (detach_fork
)
633 if (print_inferior_events
)
635 /* Ensure that we have a process ptid. */
636 ptid_t process_ptid
= ptid_t (parent_ptid
.pid ());
638 target_terminal::ours_for_output ();
639 fprintf_filtered (gdb_stdlog
,
640 _("[Detaching after fork from "
642 target_pid_to_str (process_ptid
).c_str ());
645 target_detach (parent_inf
, 0);
649 /* Note that the detach above makes PARENT_INF dangling. */
651 /* Add the child thread to the appropriate lists, and switch
652 to this new thread, before cloning the program space, and
653 informing the solib layer about this new process. */
655 set_current_inferior (child_inf
);
656 push_target (target
);
659 thread_info
*child_thr
= add_thread_silent (target
, child_ptid
);
661 /* If this is a vfork child, then the address-space is shared
662 with the parent. If we detached from the parent, then we can
663 reuse the parent's program/address spaces. */
664 if (has_vforked
|| detach_fork
)
666 child_inf
->pspace
= parent_pspace
;
667 child_inf
->aspace
= child_inf
->pspace
->aspace
;
673 child_inf
->aspace
= new_address_space ();
674 child_inf
->pspace
= new program_space (child_inf
->aspace
);
675 child_inf
->removable
= 1;
676 child_inf
->symfile_flags
= SYMFILE_NO_READ
;
677 set_current_program_space (child_inf
->pspace
);
678 clone_program_space (child_inf
->pspace
, parent_pspace
);
680 /* Let the shared library layer (e.g., solib-svr4) learn
681 about this new process, relocate the cloned exec, pull in
682 shared libraries, and install the solib event breakpoint.
683 If a "cloned-VM" event was propagated better throughout
684 the core, this wouldn't be required. */
685 solib_create_inferior_hook (0);
688 switch_to_thread (child_thr
);
691 return target_follow_fork (follow_child
, detach_fork
);
694 /* Tell the target to follow the fork we're stopped at. Returns true
695 if the inferior should be resumed; false, if the target for some
696 reason decided it's best not to resume. */
701 bool follow_child
= (follow_fork_mode_string
== follow_fork_mode_child
);
702 bool should_resume
= true;
703 struct thread_info
*tp
;
705 /* Copy user stepping state to the new inferior thread. FIXME: the
706 followed fork child thread should have a copy of most of the
707 parent thread structure's run control related fields, not just these.
708 Initialized to avoid "may be used uninitialized" warnings from gcc. */
709 struct breakpoint
*step_resume_breakpoint
= NULL
;
710 struct breakpoint
*exception_resume_breakpoint
= NULL
;
711 CORE_ADDR step_range_start
= 0;
712 CORE_ADDR step_range_end
= 0;
713 int current_line
= 0;
714 symtab
*current_symtab
= NULL
;
715 struct frame_id step_frame_id
= { 0 };
716 struct thread_fsm
*thread_fsm
= NULL
;
720 process_stratum_target
*wait_target
;
722 struct target_waitstatus wait_status
;
724 /* Get the last target status returned by target_wait(). */
725 get_last_target_status (&wait_target
, &wait_ptid
, &wait_status
);
727 /* If not stopped at a fork event, then there's nothing else to
729 if (wait_status
.kind
!= TARGET_WAITKIND_FORKED
730 && wait_status
.kind
!= TARGET_WAITKIND_VFORKED
)
733 /* Check if we switched over from WAIT_PTID, since the event was
735 if (wait_ptid
!= minus_one_ptid
736 && (current_inferior ()->process_target () != wait_target
737 || inferior_ptid
!= wait_ptid
))
739 /* We did. Switch back to WAIT_PTID thread, to tell the
740 target to follow it (in either direction). We'll
741 afterwards refuse to resume, and inform the user what
743 thread_info
*wait_thread
= find_thread_ptid (wait_target
, wait_ptid
);
744 switch_to_thread (wait_thread
);
745 should_resume
= false;
749 tp
= inferior_thread ();
751 /* If there were any forks/vforks that were caught and are now to be
752 followed, then do so now. */
753 switch (tp
->pending_follow
.kind
)
755 case TARGET_WAITKIND_FORKED
:
756 case TARGET_WAITKIND_VFORKED
:
758 ptid_t parent
, child
;
760 /* If the user did a next/step, etc, over a fork call,
761 preserve the stepping state in the fork child. */
762 if (follow_child
&& should_resume
)
764 step_resume_breakpoint
= clone_momentary_breakpoint
765 (tp
->control
.step_resume_breakpoint
);
766 step_range_start
= tp
->control
.step_range_start
;
767 step_range_end
= tp
->control
.step_range_end
;
768 current_line
= tp
->current_line
;
769 current_symtab
= tp
->current_symtab
;
770 step_frame_id
= tp
->control
.step_frame_id
;
771 exception_resume_breakpoint
772 = clone_momentary_breakpoint (tp
->control
.exception_resume_breakpoint
);
773 thread_fsm
= tp
->thread_fsm
;
775 /* For now, delete the parent's sr breakpoint, otherwise,
776 parent/child sr breakpoints are considered duplicates,
777 and the child version will not be installed. Remove
778 this when the breakpoints module becomes aware of
779 inferiors and address spaces. */
780 delete_step_resume_breakpoint (tp
);
781 tp
->control
.step_range_start
= 0;
782 tp
->control
.step_range_end
= 0;
783 tp
->control
.step_frame_id
= null_frame_id
;
784 delete_exception_resume_breakpoint (tp
);
785 tp
->thread_fsm
= NULL
;
788 parent
= inferior_ptid
;
789 child
= tp
->pending_follow
.value
.related_pid
;
791 process_stratum_target
*parent_targ
= tp
->inf
->process_target ();
792 /* Set up inferior(s) as specified by the caller, and tell the
793 target to do whatever is necessary to follow either parent
795 if (follow_fork_inferior (follow_child
, detach_fork
))
797 /* Target refused to follow, or there's some other reason
798 we shouldn't resume. */
803 /* This pending follow fork event is now handled, one way
804 or another. The previous selected thread may be gone
805 from the lists by now, but if it is still around, need
806 to clear the pending follow request. */
807 tp
= find_thread_ptid (parent_targ
, parent
);
809 tp
->pending_follow
.kind
= TARGET_WAITKIND_SPURIOUS
;
811 /* This makes sure we don't try to apply the "Switched
812 over from WAIT_PID" logic above. */
813 nullify_last_target_wait_ptid ();
815 /* If we followed the child, switch to it... */
818 thread_info
*child_thr
= find_thread_ptid (parent_targ
, child
);
819 switch_to_thread (child_thr
);
821 /* ... and preserve the stepping state, in case the
822 user was stepping over the fork call. */
825 tp
= inferior_thread ();
826 tp
->control
.step_resume_breakpoint
827 = step_resume_breakpoint
;
828 tp
->control
.step_range_start
= step_range_start
;
829 tp
->control
.step_range_end
= step_range_end
;
830 tp
->current_line
= current_line
;
831 tp
->current_symtab
= current_symtab
;
832 tp
->control
.step_frame_id
= step_frame_id
;
833 tp
->control
.exception_resume_breakpoint
834 = exception_resume_breakpoint
;
835 tp
->thread_fsm
= thread_fsm
;
839 /* If we get here, it was because we're trying to
840 resume from a fork catchpoint, but, the user
841 has switched threads away from the thread that
842 forked. In that case, the resume command
843 issued is most likely not applicable to the
844 child, so just warn, and refuse to resume. */
845 warning (_("Not resuming: switched threads "
846 "before following fork child."));
849 /* Reset breakpoints in the child as appropriate. */
850 follow_inferior_reset_breakpoints ();
855 case TARGET_WAITKIND_SPURIOUS
:
856 /* Nothing to follow. */
859 internal_error (__FILE__
, __LINE__
,
860 "Unexpected pending_follow.kind %d\n",
861 tp
->pending_follow
.kind
);
865 return should_resume
;
869 follow_inferior_reset_breakpoints (void)
871 struct thread_info
*tp
= inferior_thread ();
873 /* Was there a step_resume breakpoint? (There was if the user
874 did a "next" at the fork() call.) If so, explicitly reset its
875 thread number. Cloned step_resume breakpoints are disabled on
876 creation, so enable it here now that it is associated with the
879 step_resumes are a form of bp that are made to be per-thread.
880 Since we created the step_resume bp when the parent process
881 was being debugged, and now are switching to the child process,
882 from the breakpoint package's viewpoint, that's a switch of
883 "threads". We must update the bp's notion of which thread
884 it is for, or it'll be ignored when it triggers. */
886 if (tp
->control
.step_resume_breakpoint
)
888 breakpoint_re_set_thread (tp
->control
.step_resume_breakpoint
);
889 tp
->control
.step_resume_breakpoint
->loc
->enabled
= 1;
892 /* Treat exception_resume breakpoints like step_resume breakpoints. */
893 if (tp
->control
.exception_resume_breakpoint
)
895 breakpoint_re_set_thread (tp
->control
.exception_resume_breakpoint
);
896 tp
->control
.exception_resume_breakpoint
->loc
->enabled
= 1;
899 /* Reinsert all breakpoints in the child. The user may have set
900 breakpoints after catching the fork, in which case those
901 were never set in the child, but only in the parent. This makes
902 sure the inserted breakpoints match the breakpoint list. */
904 breakpoint_re_set ();
905 insert_breakpoints ();
908 /* The child has exited or execed: resume threads of the parent the
909 user wanted to be executing. */
912 proceed_after_vfork_done (struct thread_info
*thread
,
915 int pid
= * (int *) arg
;
917 if (thread
->ptid
.pid () == pid
918 && thread
->state
== THREAD_RUNNING
919 && !thread
->executing
920 && !thread
->stop_requested
921 && thread
->suspend
.stop_signal
== GDB_SIGNAL_0
)
923 infrun_log_debug ("resuming vfork parent thread %s",
924 target_pid_to_str (thread
->ptid
).c_str ());
926 switch_to_thread (thread
);
927 clear_proceed_status (0);
928 proceed ((CORE_ADDR
) -1, GDB_SIGNAL_DEFAULT
);
934 /* Called whenever we notice an exec or exit event, to handle
935 detaching or resuming a vfork parent. */
938 handle_vfork_child_exec_or_exit (int exec
)
940 struct inferior
*inf
= current_inferior ();
942 if (inf
->vfork_parent
)
944 int resume_parent
= -1;
946 /* This exec or exit marks the end of the shared memory region
947 between the parent and the child. Break the bonds. */
948 inferior
*vfork_parent
= inf
->vfork_parent
;
949 inf
->vfork_parent
->vfork_child
= NULL
;
950 inf
->vfork_parent
= NULL
;
952 /* If the user wanted to detach from the parent, now is the
954 if (vfork_parent
->pending_detach
)
956 struct program_space
*pspace
;
957 struct address_space
*aspace
;
959 /* follow-fork child, detach-on-fork on. */
961 vfork_parent
->pending_detach
= 0;
963 scoped_restore_current_pspace_and_thread restore_thread
;
965 /* We're letting loose of the parent. */
966 thread_info
*tp
= any_live_thread_of_inferior (vfork_parent
);
967 switch_to_thread (tp
);
969 /* We're about to detach from the parent, which implicitly
970 removes breakpoints from its address space. There's a
971 catch here: we want to reuse the spaces for the child,
972 but, parent/child are still sharing the pspace at this
973 point, although the exec in reality makes the kernel give
974 the child a fresh set of new pages. The problem here is
975 that the breakpoints module being unaware of this, would
976 likely chose the child process to write to the parent
977 address space. Swapping the child temporarily away from
978 the spaces has the desired effect. Yes, this is "sort
981 pspace
= inf
->pspace
;
982 aspace
= inf
->aspace
;
986 if (print_inferior_events
)
989 = target_pid_to_str (ptid_t (vfork_parent
->pid
));
991 target_terminal::ours_for_output ();
995 fprintf_filtered (gdb_stdlog
,
996 _("[Detaching vfork parent %s "
997 "after child exec]\n"), pidstr
.c_str ());
1001 fprintf_filtered (gdb_stdlog
,
1002 _("[Detaching vfork parent %s "
1003 "after child exit]\n"), pidstr
.c_str ());
1007 target_detach (vfork_parent
, 0);
1010 inf
->pspace
= pspace
;
1011 inf
->aspace
= aspace
;
1015 /* We're staying attached to the parent, so, really give the
1016 child a new address space. */
1017 inf
->pspace
= new program_space (maybe_new_address_space ());
1018 inf
->aspace
= inf
->pspace
->aspace
;
1020 set_current_program_space (inf
->pspace
);
1022 resume_parent
= vfork_parent
->pid
;
1026 /* If this is a vfork child exiting, then the pspace and
1027 aspaces were shared with the parent. Since we're
1028 reporting the process exit, we'll be mourning all that is
1029 found in the address space, and switching to null_ptid,
1030 preparing to start a new inferior. But, since we don't
1031 want to clobber the parent's address/program spaces, we
1032 go ahead and create a new one for this exiting
1035 /* Switch to no-thread while running clone_program_space, so
1036 that clone_program_space doesn't want to read the
1037 selected frame of a dead process. */
1038 scoped_restore_current_thread restore_thread
;
1039 switch_to_no_thread ();
1041 inf
->pspace
= new program_space (maybe_new_address_space ());
1042 inf
->aspace
= inf
->pspace
->aspace
;
1043 set_current_program_space (inf
->pspace
);
1045 inf
->symfile_flags
= SYMFILE_NO_READ
;
1046 clone_program_space (inf
->pspace
, vfork_parent
->pspace
);
1048 resume_parent
= vfork_parent
->pid
;
1051 gdb_assert (current_program_space
== inf
->pspace
);
1053 if (non_stop
&& resume_parent
!= -1)
1055 /* If the user wanted the parent to be running, let it go
1057 scoped_restore_current_thread restore_thread
;
1059 infrun_log_debug ("resuming vfork parent process %d",
1062 iterate_over_threads (proceed_after_vfork_done
, &resume_parent
);
1067 /* Enum strings for "set|show follow-exec-mode". */
1069 static const char follow_exec_mode_new
[] = "new";
1070 static const char follow_exec_mode_same
[] = "same";
1071 static const char *const follow_exec_mode_names
[] =
1073 follow_exec_mode_new
,
1074 follow_exec_mode_same
,
1078 static const char *follow_exec_mode_string
= follow_exec_mode_same
;
1080 show_follow_exec_mode_string (struct ui_file
*file
, int from_tty
,
1081 struct cmd_list_element
*c
, const char *value
)
1083 fprintf_filtered (file
, _("Follow exec mode is \"%s\".\n"), value
);
1086 /* EXEC_FILE_TARGET is assumed to be non-NULL. */
1089 follow_exec (ptid_t ptid
, const char *exec_file_target
)
1091 struct inferior
*inf
= current_inferior ();
1092 int pid
= ptid
.pid ();
1093 ptid_t process_ptid
;
1095 /* Switch terminal for any messages produced e.g. by
1096 breakpoint_re_set. */
1097 target_terminal::ours_for_output ();
1099 /* This is an exec event that we actually wish to pay attention to.
1100 Refresh our symbol table to the newly exec'd program, remove any
1101 momentary bp's, etc.
1103 If there are breakpoints, they aren't really inserted now,
1104 since the exec() transformed our inferior into a fresh set
1107 We want to preserve symbolic breakpoints on the list, since
1108 we have hopes that they can be reset after the new a.out's
1109 symbol table is read.
1111 However, any "raw" breakpoints must be removed from the list
1112 (e.g., the solib bp's), since their address is probably invalid
1115 And, we DON'T want to call delete_breakpoints() here, since
1116 that may write the bp's "shadow contents" (the instruction
1117 value that was overwritten with a TRAP instruction). Since
1118 we now have a new a.out, those shadow contents aren't valid. */
1120 mark_breakpoints_out ();
1122 /* The target reports the exec event to the main thread, even if
1123 some other thread does the exec, and even if the main thread was
1124 stopped or already gone. We may still have non-leader threads of
1125 the process on our list. E.g., on targets that don't have thread
1126 exit events (like remote); or on native Linux in non-stop mode if
1127 there were only two threads in the inferior and the non-leader
1128 one is the one that execs (and nothing forces an update of the
1129 thread list up to here). When debugging remotely, it's best to
1130 avoid extra traffic, when possible, so avoid syncing the thread
1131 list with the target, and instead go ahead and delete all threads
1132 of the process but one that reported the event. Note this must
1133 be done before calling update_breakpoints_after_exec, as
1134 otherwise clearing the threads' resources would reference stale
1135 thread breakpoints -- it may have been one of these threads that
1136 stepped across the exec. We could just clear their stepping
1137 states, but as long as we're iterating, might as well delete
1138 them. Deleting them now rather than at the next user-visible
1139 stop provides a nicer sequence of events for user and MI
1141 for (thread_info
*th
: all_threads_safe ())
1142 if (th
->ptid
.pid () == pid
&& th
->ptid
!= ptid
)
1145 /* We also need to clear any left over stale state for the
1146 leader/event thread. E.g., if there was any step-resume
1147 breakpoint or similar, it's gone now. We cannot truly
1148 step-to-next statement through an exec(). */
1149 thread_info
*th
= inferior_thread ();
1150 th
->control
.step_resume_breakpoint
= NULL
;
1151 th
->control
.exception_resume_breakpoint
= NULL
;
1152 th
->control
.single_step_breakpoints
= NULL
;
1153 th
->control
.step_range_start
= 0;
1154 th
->control
.step_range_end
= 0;
1156 /* The user may have had the main thread held stopped in the
1157 previous image (e.g., schedlock on, or non-stop). Release
1159 th
->stop_requested
= 0;
1161 update_breakpoints_after_exec ();
1163 /* What is this a.out's name? */
1164 process_ptid
= ptid_t (pid
);
1165 printf_unfiltered (_("%s is executing new program: %s\n"),
1166 target_pid_to_str (process_ptid
).c_str (),
1169 /* We've followed the inferior through an exec. Therefore, the
1170 inferior has essentially been killed & reborn. */
1172 breakpoint_init_inferior (inf_execd
);
1174 gdb::unique_xmalloc_ptr
<char> exec_file_host
1175 = exec_file_find (exec_file_target
, NULL
);
1177 /* If we were unable to map the executable target pathname onto a host
1178 pathname, tell the user that. Otherwise GDB's subsequent behavior
1179 is confusing. Maybe it would even be better to stop at this point
1180 so that the user can specify a file manually before continuing. */
1181 if (exec_file_host
== NULL
)
1182 warning (_("Could not load symbols for executable %s.\n"
1183 "Do you need \"set sysroot\"?"),
1186 /* Reset the shared library package. This ensures that we get a
1187 shlib event when the child reaches "_start", at which point the
1188 dld will have had a chance to initialize the child. */
1189 /* Also, loading a symbol file below may trigger symbol lookups, and
1190 we don't want those to be satisfied by the libraries of the
1191 previous incarnation of this process. */
1192 no_shared_libraries (NULL
, 0);
1194 if (follow_exec_mode_string
== follow_exec_mode_new
)
1196 /* The user wants to keep the old inferior and program spaces
1197 around. Create a new fresh one, and switch to it. */
1199 /* Do exit processing for the original inferior before setting the new
1200 inferior's pid. Having two inferiors with the same pid would confuse
1201 find_inferior_p(t)id. Transfer the terminal state and info from the
1202 old to the new inferior. */
1203 inf
= add_inferior_with_spaces ();
1204 swap_terminal_info (inf
, current_inferior ());
1205 exit_inferior_silent (current_inferior ());
1208 target_follow_exec (inf
, exec_file_target
);
1210 inferior
*org_inferior
= current_inferior ();
1211 switch_to_inferior_no_thread (inf
);
1212 push_target (org_inferior
->process_target ());
1213 thread_info
*thr
= add_thread (inf
->process_target (), ptid
);
1214 switch_to_thread (thr
);
1218 /* The old description may no longer be fit for the new image.
1219 E.g, a 64-bit process exec'ed a 32-bit process. Clear the
1220 old description; we'll read a new one below. No need to do
1221 this on "follow-exec-mode new", as the old inferior stays
1222 around (its description is later cleared/refetched on
1224 target_clear_description ();
1227 gdb_assert (current_program_space
== inf
->pspace
);
1229 /* Attempt to open the exec file. SYMFILE_DEFER_BP_RESET is used
1230 because the proper displacement for a PIE (Position Independent
1231 Executable) main symbol file will only be computed by
1232 solib_create_inferior_hook below. breakpoint_re_set would fail
1233 to insert the breakpoints with the zero displacement. */
1234 try_open_exec_file (exec_file_host
.get (), inf
, SYMFILE_DEFER_BP_RESET
);
1236 /* If the target can specify a description, read it. Must do this
1237 after flipping to the new executable (because the target supplied
1238 description must be compatible with the executable's
1239 architecture, and the old executable may e.g., be 32-bit, while
1240 the new one 64-bit), and before anything involving memory or
1242 target_find_description ();
1244 solib_create_inferior_hook (0);
1246 jit_inferior_created_hook ();
1248 breakpoint_re_set ();
1250 /* Reinsert all breakpoints. (Those which were symbolic have
1251 been reset to the proper address in the new a.out, thanks
1252 to symbol_file_command...). */
1253 insert_breakpoints ();
1255 /* The next resume of this inferior should bring it to the shlib
1256 startup breakpoints. (If the user had also set bp's on
1257 "main" from the old (parent) process, then they'll auto-
1258 matically get reset there in the new process.). */
1261 /* The queue of threads that need to do a step-over operation to get
1262 past e.g., a breakpoint. What technique is used to step over the
1263 breakpoint/watchpoint does not matter -- all threads end up in the
1264 same queue, to maintain rough temporal order of execution, in order
1265 to avoid starvation, otherwise, we could e.g., find ourselves
1266 constantly stepping the same couple threads past their breakpoints
1267 over and over, if the single-step finish fast enough. */
1268 struct thread_info
*global_thread_step_over_chain_head
;
1270 /* Bit flags indicating what the thread needs to step over. */
1272 enum step_over_what_flag
1274 /* Step over a breakpoint. */
1275 STEP_OVER_BREAKPOINT
= 1,
1277 /* Step past a non-continuable watchpoint, in order to let the
1278 instruction execute so we can evaluate the watchpoint
1280 STEP_OVER_WATCHPOINT
= 2
1282 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1284 /* Info about an instruction that is being stepped over. */
1286 struct step_over_info
1288 /* If we're stepping past a breakpoint, this is the address space
1289 and address of the instruction the breakpoint is set at. We'll
1290 skip inserting all breakpoints here. Valid iff ASPACE is
1292 const address_space
*aspace
;
1295 /* The instruction being stepped over triggers a nonsteppable
1296 watchpoint. If true, we'll skip inserting watchpoints. */
1297 int nonsteppable_watchpoint_p
;
1299 /* The thread's global number. */
1303 /* The step-over info of the location that is being stepped over.
1305 Note that with async/breakpoint always-inserted mode, a user might
1306 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1307 being stepped over. As setting a new breakpoint inserts all
1308 breakpoints, we need to make sure the breakpoint being stepped over
1309 isn't inserted then. We do that by only clearing the step-over
1310 info when the step-over is actually finished (or aborted).
1312 Presently GDB can only step over one breakpoint at any given time.
1313 Given threads that can't run code in the same address space as the
1314 breakpoint's can't really miss the breakpoint, GDB could be taught
1315 to step-over at most one breakpoint per address space (so this info
1316 could move to the address space object if/when GDB is extended).
1317 The set of breakpoints being stepped over will normally be much
1318 smaller than the set of all breakpoints, so a flag in the
1319 breakpoint location structure would be wasteful. A separate list
1320 also saves complexity and run-time, as otherwise we'd have to go
1321 through all breakpoint locations clearing their flag whenever we
1322 start a new sequence. Similar considerations weigh against storing
1323 this info in the thread object. Plus, not all step overs actually
1324 have breakpoint locations -- e.g., stepping past a single-step
1325 breakpoint, or stepping to complete a non-continuable
1327 static struct step_over_info step_over_info
;
1329 /* Record the address of the breakpoint/instruction we're currently
1331 N.B. We record the aspace and address now, instead of say just the thread,
1332 because when we need the info later the thread may be running. */
1335 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1336 int nonsteppable_watchpoint_p
,
1339 step_over_info
.aspace
= aspace
;
1340 step_over_info
.address
= address
;
1341 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1342 step_over_info
.thread
= thread
;
1345 /* Called when we're not longer stepping over a breakpoint / an
1346 instruction, so all breakpoints are free to be (re)inserted. */
1349 clear_step_over_info (void)
1351 infrun_log_debug ("clearing step over info");
1352 step_over_info
.aspace
= NULL
;
1353 step_over_info
.address
= 0;
1354 step_over_info
.nonsteppable_watchpoint_p
= 0;
1355 step_over_info
.thread
= -1;
1361 stepping_past_instruction_at (struct address_space
*aspace
,
1364 return (step_over_info
.aspace
!= NULL
1365 && breakpoint_address_match (aspace
, address
,
1366 step_over_info
.aspace
,
1367 step_over_info
.address
));
1373 thread_is_stepping_over_breakpoint (int thread
)
1375 return (step_over_info
.thread
!= -1
1376 && thread
== step_over_info
.thread
);
1382 stepping_past_nonsteppable_watchpoint (void)
1384 return step_over_info
.nonsteppable_watchpoint_p
;
1387 /* Returns true if step-over info is valid. */
1390 step_over_info_valid_p (void)
1392 return (step_over_info
.aspace
!= NULL
1393 || stepping_past_nonsteppable_watchpoint ());
1397 /* Displaced stepping. */
1399 /* In non-stop debugging mode, we must take special care to manage
1400 breakpoints properly; in particular, the traditional strategy for
1401 stepping a thread past a breakpoint it has hit is unsuitable.
1402 'Displaced stepping' is a tactic for stepping one thread past a
1403 breakpoint it has hit while ensuring that other threads running
1404 concurrently will hit the breakpoint as they should.
1406 The traditional way to step a thread T off a breakpoint in a
1407 multi-threaded program in all-stop mode is as follows:
1409 a0) Initially, all threads are stopped, and breakpoints are not
1411 a1) We single-step T, leaving breakpoints uninserted.
1412 a2) We insert breakpoints, and resume all threads.
1414 In non-stop debugging, however, this strategy is unsuitable: we
1415 don't want to have to stop all threads in the system in order to
1416 continue or step T past a breakpoint. Instead, we use displaced
1419 n0) Initially, T is stopped, other threads are running, and
1420 breakpoints are inserted.
1421 n1) We copy the instruction "under" the breakpoint to a separate
1422 location, outside the main code stream, making any adjustments
1423 to the instruction, register, and memory state as directed by
1425 n2) We single-step T over the instruction at its new location.
1426 n3) We adjust the resulting register and memory state as directed
1427 by T's architecture. This includes resetting T's PC to point
1428 back into the main instruction stream.
1431 This approach depends on the following gdbarch methods:
1433 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1434 indicate where to copy the instruction, and how much space must
1435 be reserved there. We use these in step n1.
1437 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1438 address, and makes any necessary adjustments to the instruction,
1439 register contents, and memory. We use this in step n1.
1441 - gdbarch_displaced_step_fixup adjusts registers and memory after
1442 we have successfully single-stepped the instruction, to yield the
1443 same effect the instruction would have had if we had executed it
1444 at its original address. We use this in step n3.
1446 The gdbarch_displaced_step_copy_insn and
1447 gdbarch_displaced_step_fixup functions must be written so that
1448 copying an instruction with gdbarch_displaced_step_copy_insn,
1449 single-stepping across the copied instruction, and then applying
1450 gdbarch_displaced_insn_fixup should have the same effects on the
1451 thread's memory and registers as stepping the instruction in place
1452 would have. Exactly which responsibilities fall to the copy and
1453 which fall to the fixup is up to the author of those functions.
1455 See the comments in gdbarch.sh for details.
1457 Note that displaced stepping and software single-step cannot
1458 currently be used in combination, although with some care I think
1459 they could be made to. Software single-step works by placing
1460 breakpoints on all possible subsequent instructions; if the
1461 displaced instruction is a PC-relative jump, those breakpoints
1462 could fall in very strange places --- on pages that aren't
1463 executable, or at addresses that are not proper instruction
1464 boundaries. (We do generally let other threads run while we wait
1465 to hit the software single-step breakpoint, and they might
1466 encounter such a corrupted instruction.) One way to work around
1467 this would be to have gdbarch_displaced_step_copy_insn fully
1468 simulate the effect of PC-relative instructions (and return NULL)
1469 on architectures that use software single-stepping.
1471 In non-stop mode, we can have independent and simultaneous step
1472 requests, so more than one thread may need to simultaneously step
1473 over a breakpoint. The current implementation assumes there is
1474 only one scratch space per process. In this case, we have to
1475 serialize access to the scratch space. If thread A wants to step
1476 over a breakpoint, but we are currently waiting for some other
1477 thread to complete a displaced step, we leave thread A stopped and
1478 place it in the displaced_step_request_queue. Whenever a displaced
1479 step finishes, we pick the next thread in the queue and start a new
1480 displaced step operation on it. See displaced_step_prepare and
1481 displaced_step_fixup for details. */
1483 /* Get the displaced stepping state of inferior INF. */
1485 static displaced_step_inferior_state
*
1486 get_displaced_stepping_state (inferior
*inf
)
1488 return &inf
->displaced_step_state
;
1491 /* Get the displaced stepping state of thread THREAD. */
1493 static displaced_step_thread_state
*
1494 get_displaced_stepping_state (thread_info
*thread
)
1496 return &thread
->displaced_step_state
;
1499 /* Return true if the given thread is doing a displaced step. */
1502 displaced_step_in_progress (thread_info
*thread
)
1504 gdb_assert (thread
!= NULL
);
1506 return get_displaced_stepping_state (thread
)->in_progress ();
1509 /* Return true if any thread of this inferior is doing a displaced step. */
1512 displaced_step_in_progress (inferior
*inf
)
1514 for (thread_info
*thread
: inf
->non_exited_threads ())
1516 if (displaced_step_in_progress (thread
))
1523 /* Return true if any thread is doing a displaced step. */
1526 displaced_step_in_progress_any_thread ()
1528 for (thread_info
*thread
: all_non_exited_threads ())
1530 if (displaced_step_in_progress (thread
))
1537 /* If inferior is in displaced stepping, and ADDR equals to starting address
1538 of copy area, return corresponding displaced_step_copy_insn_closure. Otherwise,
1541 struct displaced_step_copy_insn_closure
*
1542 get_displaced_step_copy_insn_closure_by_addr (CORE_ADDR addr
)
1544 // FIXME: implement me (only needed on ARM).
1545 // displaced_step_inferior_state *displaced
1546 // = get_displaced_stepping_state (current_inferior ());
1548 // /* If checking the mode of displaced instruction in copy area. */
1549 // if (displaced->step_thread != nullptr
1550 // && displaced->step_copy == addr)
1551 // return displaced->step_closure.get ();
1557 infrun_inferior_exit (struct inferior
*inf
)
1559 inf
->displaced_step_state
.reset ();
1562 /* If ON, and the architecture supports it, GDB will use displaced
1563 stepping to step over breakpoints. If OFF, or if the architecture
1564 doesn't support it, GDB will instead use the traditional
1565 hold-and-step approach. If AUTO (which is the default), GDB will
1566 decide which technique to use to step over breakpoints depending on
1567 whether the target works in a non-stop way (see use_displaced_stepping). */
1569 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1572 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1573 struct cmd_list_element
*c
,
1576 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1577 fprintf_filtered (file
,
1578 _("Debugger's willingness to use displaced stepping "
1579 "to step over breakpoints is %s (currently %s).\n"),
1580 value
, target_is_non_stop_p () ? "on" : "off");
1582 fprintf_filtered (file
,
1583 _("Debugger's willingness to use displaced stepping "
1584 "to step over breakpoints is %s.\n"), value
);
1587 /* Return true if the gdbarch implements the required methods to use
1588 displaced stepping. */
1591 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1593 /* Only check for the presence of copy_insn. Other required methods
1594 are checked by the gdbarch validation to be provided if copy_insn is
1596 return gdbarch_displaced_step_copy_insn_p (arch
);
1599 /* Return non-zero if displaced stepping can/should be used to step
1600 over breakpoints of thread TP. */
1603 use_displaced_stepping (thread_info
*tp
)
1605 /* If the user disabled it explicitly, don't use displaced stepping. */
1606 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1609 /* If "auto", only use displaced stepping if the target operates in a non-stop
1611 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1612 && !target_is_non_stop_p ())
1615 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1617 /* If the architecture doesn't implement displaced stepping, don't use
1619 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1622 /* If recording, don't use displaced stepping. */
1623 if (find_record_target () != nullptr)
1626 displaced_step_inferior_state
*displaced_state
1627 = get_displaced_stepping_state (tp
->inf
);
1629 /* If displaced stepping failed before for this inferior, don't bother trying
1631 if (displaced_state
->failed_before
)
1637 /* Simple function wrapper around displaced_step_thread_state::reset. */
1640 displaced_step_reset (displaced_step_thread_state
*displaced
)
1642 displaced
->reset ();
1645 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1646 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1648 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1650 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1652 displaced_step_dump_bytes (struct ui_file
*file
,
1653 const gdb_byte
*buf
,
1658 for (i
= 0; i
< len
; i
++)
1659 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1660 fputs_unfiltered ("\n", file
);
1663 /* Prepare to single-step, using displaced stepping.
1665 Note that we cannot use displaced stepping when we have a signal to
1666 deliver. If we have a signal to deliver and an instruction to step
1667 over, then after the step, there will be no indication from the
1668 target whether the thread entered a signal handler or ignored the
1669 signal and stepped over the instruction successfully --- both cases
1670 result in a simple SIGTRAP. In the first case we mustn't do a
1671 fixup, and in the second case we must --- but we can't tell which.
1672 Comments in the code for 'random signals' in handle_inferior_event
1673 explain how we handle this case instead.
1675 Returns 1 if preparing was successful -- this thread is going to be
1676 stepped now; 0 if displaced stepping this thread got queued; or -1
1677 if this instruction can't be displaced stepped. */
1679 static displaced_step_prepare_status
1680 displaced_step_prepare_throw (thread_info
*tp
)
1682 regcache
*regcache
= get_thread_regcache (tp
);
1683 struct gdbarch
*gdbarch
= regcache
->arch ();
1684 displaced_step_thread_state
*thread_disp_step_state
1685 = get_displaced_stepping_state (tp
);
1687 /* We should never reach this function if the architecture does not
1688 support displaced stepping. */
1689 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1691 /* Nor if the thread isn't meant to step over a breakpoint. */
1692 gdb_assert (tp
->control
.trap_expected
);
1694 /* Disable range stepping while executing in the scratch pad. We
1695 want a single-step even if executing the displaced instruction in
1696 the scratch buffer lands within the stepping range (e.g., a
1698 tp
->control
.may_range_step
= 0;
1700 /* We are about to start a displaced step for this thread, if one is already
1701 in progress, we goofed up somewhere. */
1702 gdb_assert (!thread_disp_step_state
->in_progress ());
1704 scoped_restore_current_thread restore_thread
;
1706 switch_to_thread (tp
);
1708 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1710 displaced_step_prepare_status status
=
1711 gdbarch_displaced_step_prepare (gdbarch
, tp
);
1713 if (status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
1715 if (debug_displaced
)
1716 fprintf_unfiltered (gdb_stdlog
,
1717 "displaced: failed to prepare (%s)",
1718 target_pid_to_str (tp
->ptid
).c_str ());
1720 return DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1722 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1724 /* Not enough displaced stepping resources available, defer this
1725 request by placing it the queue. */
1727 if (debug_displaced
)
1728 fprintf_unfiltered (gdb_stdlog
,
1729 "displaced: not enough resources available, "
1730 "deferring step of %s\n",
1731 target_pid_to_str (tp
->ptid
).c_str ());
1733 global_thread_step_over_chain_enqueue (tp
);
1735 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1738 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1740 // FIXME: Should probably replicated in the arch implementation now.
1742 // if (breakpoint_in_range_p (aspace, copy, len))
1744 // /* There's a breakpoint set in the scratch pad location range
1745 // (which is usually around the entry point). We'd either
1746 // install it before resuming, which would overwrite/corrupt the
1747 // scratch pad, or if it was already inserted, this displaced
1748 // step would overwrite it. The latter is OK in the sense that
1749 // we already assume that no thread is going to execute the code
1750 // in the scratch pad range (after initial startup) anyway, but
1751 // the former is unacceptable. Simply punt and fallback to
1752 // stepping over this breakpoint in-line. */
1753 // if (debug_displaced)
1755 // fprintf_unfiltered (gdb_stdlog,
1756 // "displaced: breakpoint set in scratch pad. "
1757 // "Stepping over breakpoint in-line instead.\n");
1760 // gdb_assert (false);
1761 // gdbarch_displaced_step_release_location (gdbarch, copy);
1766 /* Save the information we need to fix things up if the step
1768 thread_disp_step_state
->set (gdbarch
);
1770 // FIXME: get it from _prepare?
1771 CORE_ADDR displaced_pc
= 0;
1773 if (debug_displaced
)
1774 fprintf_unfiltered (gdb_stdlog
,
1775 "displaced: prepared successfully thread=%s, "
1776 "original_pc=%s, displaced_pc=%s\n",
1777 target_pid_to_str (tp
->ptid
).c_str (),
1778 paddress (gdbarch
, original_pc
),
1779 paddress (gdbarch
, displaced_pc
));
1781 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1784 /* Wrapper for displaced_step_prepare_throw that disabled further
1785 attempts at displaced stepping if we get a memory error. */
1787 static displaced_step_prepare_status
1788 displaced_step_prepare (thread_info
*thread
)
1790 displaced_step_prepare_status status
1791 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1795 status
= displaced_step_prepare_throw (thread
);
1797 catch (const gdb_exception_error
&ex
)
1799 struct displaced_step_inferior_state
*displaced_state
;
1801 if (ex
.error
!= MEMORY_ERROR
1802 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1805 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1808 /* Be verbose if "set displaced-stepping" is "on", silent if
1810 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1812 warning (_("disabling displaced stepping: %s"),
1816 /* Disable further displaced stepping attempts. */
1818 = get_displaced_stepping_state (thread
->inf
);
1819 displaced_state
->failed_before
= 1;
1825 /* If we displaced stepped an instruction successfully, adjust
1826 registers and memory to yield the same effect the instruction would
1827 have had if we had executed it at its original address, and return
1828 1. If the instruction didn't complete, relocate the PC and return
1829 -1. If the thread wasn't displaced stepping, return 0. */
1832 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1834 displaced_step_thread_state
*displaced
1835 = get_displaced_stepping_state (event_thread
);
1837 /* Was this thread performing a displaced step? */
1838 if (!displaced
->in_progress ())
1841 displaced_step_reset_cleanup
cleanup (displaced
);
1843 /* Fixup may need to read memory/registers. Switch to the thread
1844 that we're fixing up. Also, target_stopped_by_watchpoint checks
1845 the current thread, and displaced_step_restore performs ptid-dependent
1846 memory accesses using current_inferior() and current_top_target(). */
1847 switch_to_thread (event_thread
);
1849 /* Do the fixup, and release the resources acquired to do the displaced
1851 displaced_step_finish_status finish_status
=
1852 gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1853 event_thread
, signal
);
1855 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1861 /* Data to be passed around while handling an event. This data is
1862 discarded between events. */
1863 struct execution_control_state
1865 process_stratum_target
*target
;
1867 /* The thread that got the event, if this was a thread event; NULL
1869 struct thread_info
*event_thread
;
1871 struct target_waitstatus ws
;
1872 int stop_func_filled_in
;
1873 CORE_ADDR stop_func_start
;
1874 CORE_ADDR stop_func_end
;
1875 const char *stop_func_name
;
1878 /* True if the event thread hit the single-step breakpoint of
1879 another thread. Thus the event doesn't cause a stop, the thread
1880 needs to be single-stepped past the single-step breakpoint before
1881 we can switch back to the original stepping thread. */
1882 int hit_singlestep_breakpoint
;
1885 /* Clear ECS and set it to point at TP. */
1888 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1890 memset (ecs
, 0, sizeof (*ecs
));
1891 ecs
->event_thread
= tp
;
1892 ecs
->ptid
= tp
->ptid
;
1895 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1896 static void prepare_to_wait (struct execution_control_state
*ecs
);
1897 static int keep_going_stepped_thread (struct thread_info
*tp
);
1898 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1900 /* Are there any pending step-over requests? If so, run all we can
1901 now and return true. Otherwise, return false. */
1904 start_step_over (void)
1906 struct thread_info
*tp
, *next
;
1909 /* Don't start a new step-over if we already have an in-line
1910 step-over operation ongoing. */
1911 if (step_over_info_valid_p ())
1914 /* Steal the global thread step over chain. */
1915 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1916 global_thread_step_over_chain_head
= NULL
;
1919 fprintf_unfiltered (gdb_stdlog
,
1920 "infrun: stealing list of %d threads to step from global queue\n",
1921 thread_step_over_chain_length (threads_to_step
));
1923 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1925 struct execution_control_state ecss
;
1926 struct execution_control_state
*ecs
= &ecss
;
1927 step_over_what step_what
;
1928 int must_be_in_line
;
1930 gdb_assert (!tp
->stop_requested
);
1932 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1934 step_what
= thread_still_needs_step_over (tp
);
1935 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1936 || ((step_what
& STEP_OVER_BREAKPOINT
)
1937 && !use_displaced_stepping (tp
)));
1939 /* We currently stop all threads of all processes to step-over
1940 in-line. If we need to start a new in-line step-over, let
1941 any pending displaced steps finish first. */
1942 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1945 thread_step_over_chain_remove (&threads_to_step
, tp
);
1947 if (tp
->control
.trap_expected
1951 internal_error (__FILE__
, __LINE__
,
1952 "[%s] has inconsistent state: "
1953 "trap_expected=%d, resumed=%d, executing=%d\n",
1954 target_pid_to_str (tp
->ptid
).c_str (),
1955 tp
->control
.trap_expected
,
1960 infrun_log_debug ("resuming [%s] for step-over",
1961 target_pid_to_str (tp
->ptid
).c_str ());
1963 /* keep_going_pass_signal skips the step-over if the breakpoint
1964 is no longer inserted. In all-stop, we want to keep looking
1965 for a thread that needs a step-over instead of resuming TP,
1966 because we wouldn't be able to resume anything else until the
1967 target stops again. In non-stop, the resume always resumes
1968 only TP, so it's OK to let the thread resume freely. */
1969 if (!target_is_non_stop_p () && !step_what
)
1972 switch_to_thread (tp
);
1973 reset_ecs (ecs
, tp
);
1974 keep_going_pass_signal (ecs
);
1976 if (!ecs
->wait_some_more
)
1977 error (_("Command aborted."));
1979 /* If the thread's step over could not be initiated, it was re-added
1980 to the global step over chain. */
1983 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
1984 target_pid_to_str (tp
->ptid
).c_str ());
1985 gdb_assert (!thread_is_in_step_over_chain (tp
));
1989 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
1990 target_pid_to_str (tp
->ptid
).c_str ());
1991 gdb_assert (thread_is_in_step_over_chain (tp
));
1995 /* If we started a new in-line step-over, we're done. */
1996 if (step_over_info_valid_p ())
1998 gdb_assert (tp
->control
.trap_expected
);
2003 if (!target_is_non_stop_p ())
2005 /* On all-stop, shouldn't have resumed unless we needed a
2007 gdb_assert (tp
->control
.trap_expected
2008 || tp
->step_after_step_resume_breakpoint
);
2010 /* With remote targets (at least), in all-stop, we can't
2011 issue any further remote commands until the program stops
2017 /* Either the thread no longer needed a step-over, or a new
2018 displaced stepping sequence started. Even in the latter
2019 case, continue looking. Maybe we can also start another
2020 displaced step on a thread of other process. */
2023 /* If there are threads left in the THREADS_TO_STEP list, but we have
2024 detected that we can't start anything more, put back these threads
2025 in the global list. */
2026 if (threads_to_step
== NULL
)
2029 fprintf_unfiltered (gdb_stdlog
,
2030 "infrun: step-over queue now empty\n");
2035 fprintf_unfiltered (gdb_stdlog
,
2036 "infrun: putting back %d threads to step in global queue\n",
2037 thread_step_over_chain_length (threads_to_step
));
2038 while (threads_to_step
!= nullptr)
2040 thread_info
*thread
= threads_to_step
;
2042 /* Remove from that list. */
2043 thread_step_over_chain_remove (&threads_to_step
, thread
);
2045 /* Add to global list. */
2046 global_thread_step_over_chain_enqueue (thread
);
2054 /* Update global variables holding ptids to hold NEW_PTID if they were
2055 holding OLD_PTID. */
2057 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2059 if (inferior_ptid
== old_ptid
)
2060 inferior_ptid
= new_ptid
;
2065 static const char schedlock_off
[] = "off";
2066 static const char schedlock_on
[] = "on";
2067 static const char schedlock_step
[] = "step";
2068 static const char schedlock_replay
[] = "replay";
2069 static const char *const scheduler_enums
[] = {
2076 static const char *scheduler_mode
= schedlock_replay
;
2078 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2079 struct cmd_list_element
*c
, const char *value
)
2081 fprintf_filtered (file
,
2082 _("Mode for locking scheduler "
2083 "during execution is \"%s\".\n"),
2088 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2090 if (!target_can_lock_scheduler
)
2092 scheduler_mode
= schedlock_off
;
2093 error (_("Target '%s' cannot support this command."), target_shortname
);
2097 /* True if execution commands resume all threads of all processes by
2098 default; otherwise, resume only threads of the current inferior
2100 bool sched_multi
= false;
2102 /* Try to setup for software single stepping over the specified location.
2103 Return 1 if target_resume() should use hardware single step.
2105 GDBARCH the current gdbarch.
2106 PC the location to step over. */
2109 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2113 if (execution_direction
== EXEC_FORWARD
2114 && gdbarch_software_single_step_p (gdbarch
))
2115 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2123 user_visible_resume_ptid (int step
)
2129 /* With non-stop mode on, threads are always handled
2131 resume_ptid
= inferior_ptid
;
2133 else if ((scheduler_mode
== schedlock_on
)
2134 || (scheduler_mode
== schedlock_step
&& step
))
2136 /* User-settable 'scheduler' mode requires solo thread
2138 resume_ptid
= inferior_ptid
;
2140 else if ((scheduler_mode
== schedlock_replay
)
2141 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2143 /* User-settable 'scheduler' mode requires solo thread resume in replay
2145 resume_ptid
= inferior_ptid
;
2147 else if (!sched_multi
&& target_supports_multi_process ())
2149 /* Resume all threads of the current process (and none of other
2151 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2155 /* Resume all threads of all processes. */
2156 resume_ptid
= RESUME_ALL
;
2164 process_stratum_target
*
2165 user_visible_resume_target (ptid_t resume_ptid
)
2167 return (resume_ptid
== minus_one_ptid
&& sched_multi
2169 : current_inferior ()->process_target ());
2172 /* Return a ptid representing the set of threads that we will resume,
2173 in the perspective of the target, assuming run control handling
2174 does not require leaving some threads stopped (e.g., stepping past
2175 breakpoint). USER_STEP indicates whether we're about to start the
2176 target for a stepping command. */
2179 internal_resume_ptid (int user_step
)
2181 /* In non-stop, we always control threads individually. Note that
2182 the target may always work in non-stop mode even with "set
2183 non-stop off", in which case user_visible_resume_ptid could
2184 return a wildcard ptid. */
2185 if (target_is_non_stop_p ())
2186 return inferior_ptid
;
2188 return user_visible_resume_ptid (user_step
);
2191 /* Wrapper for target_resume, that handles infrun-specific
2195 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2197 struct thread_info
*tp
= inferior_thread ();
2199 gdb_assert (!tp
->stop_requested
);
2201 /* Install inferior's terminal modes. */
2202 target_terminal::inferior ();
2204 /* Avoid confusing the next resume, if the next stop/resume
2205 happens to apply to another thread. */
2206 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2208 /* Advise target which signals may be handled silently.
2210 If we have removed breakpoints because we are stepping over one
2211 in-line (in any thread), we need to receive all signals to avoid
2212 accidentally skipping a breakpoint during execution of a signal
2215 Likewise if we're displaced stepping, otherwise a trap for a
2216 breakpoint in a signal handler might be confused with the
2217 displaced step finishing. We don't make the displaced_step_fixup
2218 step distinguish the cases instead, because:
2220 - a backtrace while stopped in the signal handler would show the
2221 scratch pad as frame older than the signal handler, instead of
2222 the real mainline code.
2224 - when the thread is later resumed, the signal handler would
2225 return to the scratch pad area, which would no longer be
2227 if (step_over_info_valid_p ()
2228 || displaced_step_in_progress (tp
->inf
))
2229 target_pass_signals ({});
2231 target_pass_signals (signal_pass
);
2233 target_resume (resume_ptid
, step
, sig
);
2235 target_commit_resume ();
2237 if (target_can_async_p ())
2241 /* Resume the inferior. SIG is the signal to give the inferior
2242 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2243 call 'resume', which handles exceptions. */
2246 resume_1 (enum gdb_signal sig
)
2248 struct regcache
*regcache
= get_current_regcache ();
2249 struct gdbarch
*gdbarch
= regcache
->arch ();
2250 struct thread_info
*tp
= inferior_thread ();
2251 const address_space
*aspace
= regcache
->aspace ();
2253 /* This represents the user's step vs continue request. When
2254 deciding whether "set scheduler-locking step" applies, it's the
2255 user's intention that counts. */
2256 const int user_step
= tp
->control
.stepping_command
;
2257 /* This represents what we'll actually request the target to do.
2258 This can decay from a step to a continue, if e.g., we need to
2259 implement single-stepping with breakpoints (software
2263 gdb_assert (!tp
->stop_requested
);
2264 gdb_assert (!thread_is_in_step_over_chain (tp
));
2266 if (tp
->suspend
.waitstatus_pending_p
)
2269 ("thread %s has pending wait "
2270 "status %s (currently_stepping=%d).",
2271 target_pid_to_str (tp
->ptid
).c_str (),
2272 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2273 currently_stepping (tp
));
2275 tp
->inf
->process_target ()->threads_executing
= true;
2278 /* FIXME: What should we do if we are supposed to resume this
2279 thread with a signal? Maybe we should maintain a queue of
2280 pending signals to deliver. */
2281 if (sig
!= GDB_SIGNAL_0
)
2283 warning (_("Couldn't deliver signal %s to %s."),
2284 gdb_signal_to_name (sig
),
2285 target_pid_to_str (tp
->ptid
).c_str ());
2288 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2290 if (target_can_async_p ())
2293 /* Tell the event loop we have an event to process. */
2294 mark_async_event_handler (infrun_async_inferior_event_token
);
2299 tp
->stepped_breakpoint
= 0;
2301 /* Depends on stepped_breakpoint. */
2302 step
= currently_stepping (tp
);
2304 if (current_inferior ()->waiting_for_vfork_done
)
2306 /* Don't try to single-step a vfork parent that is waiting for
2307 the child to get out of the shared memory region (by exec'ing
2308 or exiting). This is particularly important on software
2309 single-step archs, as the child process would trip on the
2310 software single step breakpoint inserted for the parent
2311 process. Since the parent will not actually execute any
2312 instruction until the child is out of the shared region (such
2313 are vfork's semantics), it is safe to simply continue it.
2314 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2315 the parent, and tell it to `keep_going', which automatically
2316 re-sets it stepping. */
2317 infrun_log_debug ("resume : clear step");
2321 CORE_ADDR pc
= regcache_read_pc (regcache
);
2323 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2324 "current thread [%s] at %s",
2325 step
, gdb_signal_to_symbol_string (sig
),
2326 tp
->control
.trap_expected
,
2327 target_pid_to_str (inferior_ptid
).c_str (),
2328 paddress (gdbarch
, pc
));
2330 /* Normally, by the time we reach `resume', the breakpoints are either
2331 removed or inserted, as appropriate. The exception is if we're sitting
2332 at a permanent breakpoint; we need to step over it, but permanent
2333 breakpoints can't be removed. So we have to test for it here. */
2334 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2336 if (sig
!= GDB_SIGNAL_0
)
2338 /* We have a signal to pass to the inferior. The resume
2339 may, or may not take us to the signal handler. If this
2340 is a step, we'll need to stop in the signal handler, if
2341 there's one, (if the target supports stepping into
2342 handlers), or in the next mainline instruction, if
2343 there's no handler. If this is a continue, we need to be
2344 sure to run the handler with all breakpoints inserted.
2345 In all cases, set a breakpoint at the current address
2346 (where the handler returns to), and once that breakpoint
2347 is hit, resume skipping the permanent breakpoint. If
2348 that breakpoint isn't hit, then we've stepped into the
2349 signal handler (or hit some other event). We'll delete
2350 the step-resume breakpoint then. */
2352 infrun_log_debug ("resume: skipping permanent breakpoint, "
2353 "deliver signal first");
2355 clear_step_over_info ();
2356 tp
->control
.trap_expected
= 0;
2358 if (tp
->control
.step_resume_breakpoint
== NULL
)
2360 /* Set a "high-priority" step-resume, as we don't want
2361 user breakpoints at PC to trigger (again) when this
2363 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2364 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2366 tp
->step_after_step_resume_breakpoint
= step
;
2369 insert_breakpoints ();
2373 /* There's no signal to pass, we can go ahead and skip the
2374 permanent breakpoint manually. */
2375 infrun_log_debug ("skipping permanent breakpoint");
2376 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2377 /* Update pc to reflect the new address from which we will
2378 execute instructions. */
2379 pc
= regcache_read_pc (regcache
);
2383 /* We've already advanced the PC, so the stepping part
2384 is done. Now we need to arrange for a trap to be
2385 reported to handle_inferior_event. Set a breakpoint
2386 at the current PC, and run to it. Don't update
2387 prev_pc, because if we end in
2388 switch_back_to_stepped_thread, we want the "expected
2389 thread advanced also" branch to be taken. IOW, we
2390 don't want this thread to step further from PC
2392 gdb_assert (!step_over_info_valid_p ());
2393 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2394 insert_breakpoints ();
2396 resume_ptid
= internal_resume_ptid (user_step
);
2397 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2404 /* If we have a breakpoint to step over, make sure to do a single
2405 step only. Same if we have software watchpoints. */
2406 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2407 tp
->control
.may_range_step
= 0;
2409 /* If displaced stepping is enabled, step over breakpoints by executing a
2410 copy of the instruction at a different address.
2412 We can't use displaced stepping when we have a signal to deliver;
2413 the comments for displaced_step_prepare explain why. The
2414 comments in the handle_inferior event for dealing with 'random
2415 signals' explain what we do instead.
2417 We can't use displaced stepping when we are waiting for vfork_done
2418 event, displaced stepping breaks the vfork child similarly as single
2419 step software breakpoint. */
2420 if (tp
->control
.trap_expected
2421 && use_displaced_stepping (tp
)
2422 && !step_over_info_valid_p ()
2423 && sig
== GDB_SIGNAL_0
2424 && !current_inferior ()->waiting_for_vfork_done
)
2426 displaced_step_prepare_status prepare_status
2427 = displaced_step_prepare (tp
);
2429 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2431 infrun_log_debug ("Got placed in step-over queue");
2433 tp
->control
.trap_expected
= 0;
2436 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2438 /* Fallback to stepping over the breakpoint in-line. */
2440 if (target_is_non_stop_p ())
2441 stop_all_threads ();
2443 set_step_over_info (regcache
->aspace (),
2444 regcache_read_pc (regcache
), 0, tp
->global_num
);
2446 step
= maybe_software_singlestep (gdbarch
, pc
);
2448 insert_breakpoints ();
2450 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2452 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2455 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2458 /* Do we need to do it the hard way, w/temp breakpoints? */
2460 step
= maybe_software_singlestep (gdbarch
, pc
);
2462 /* Currently, our software single-step implementation leads to different
2463 results than hardware single-stepping in one situation: when stepping
2464 into delivering a signal which has an associated signal handler,
2465 hardware single-step will stop at the first instruction of the handler,
2466 while software single-step will simply skip execution of the handler.
2468 For now, this difference in behavior is accepted since there is no
2469 easy way to actually implement single-stepping into a signal handler
2470 without kernel support.
2472 However, there is one scenario where this difference leads to follow-on
2473 problems: if we're stepping off a breakpoint by removing all breakpoints
2474 and then single-stepping. In this case, the software single-step
2475 behavior means that even if there is a *breakpoint* in the signal
2476 handler, GDB still would not stop.
2478 Fortunately, we can at least fix this particular issue. We detect
2479 here the case where we are about to deliver a signal while software
2480 single-stepping with breakpoints removed. In this situation, we
2481 revert the decisions to remove all breakpoints and insert single-
2482 step breakpoints, and instead we install a step-resume breakpoint
2483 at the current address, deliver the signal without stepping, and
2484 once we arrive back at the step-resume breakpoint, actually step
2485 over the breakpoint we originally wanted to step over. */
2486 if (thread_has_single_step_breakpoints_set (tp
)
2487 && sig
!= GDB_SIGNAL_0
2488 && step_over_info_valid_p ())
2490 /* If we have nested signals or a pending signal is delivered
2491 immediately after a handler returns, might already have
2492 a step-resume breakpoint set on the earlier handler. We cannot
2493 set another step-resume breakpoint; just continue on until the
2494 original breakpoint is hit. */
2495 if (tp
->control
.step_resume_breakpoint
== NULL
)
2497 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2498 tp
->step_after_step_resume_breakpoint
= 1;
2501 delete_single_step_breakpoints (tp
);
2503 clear_step_over_info ();
2504 tp
->control
.trap_expected
= 0;
2506 insert_breakpoints ();
2509 /* If STEP is set, it's a request to use hardware stepping
2510 facilities. But in that case, we should never
2511 use singlestep breakpoint. */
2512 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2514 /* Decide the set of threads to ask the target to resume. */
2515 if (tp
->control
.trap_expected
)
2517 /* We're allowing a thread to run past a breakpoint it has
2518 hit, either by single-stepping the thread with the breakpoint
2519 removed, or by displaced stepping, with the breakpoint inserted.
2520 In the former case, we need to single-step only this thread,
2521 and keep others stopped, as they can miss this breakpoint if
2522 allowed to run. That's not really a problem for displaced
2523 stepping, but, we still keep other threads stopped, in case
2524 another thread is also stopped for a breakpoint waiting for
2525 its turn in the displaced stepping queue. */
2526 resume_ptid
= inferior_ptid
;
2529 resume_ptid
= internal_resume_ptid (user_step
);
2531 if (execution_direction
!= EXEC_REVERSE
2532 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2534 /* There are two cases where we currently need to step a
2535 breakpoint instruction when we have a signal to deliver:
2537 - See handle_signal_stop where we handle random signals that
2538 could take out us out of the stepping range. Normally, in
2539 that case we end up continuing (instead of stepping) over the
2540 signal handler with a breakpoint at PC, but there are cases
2541 where we should _always_ single-step, even if we have a
2542 step-resume breakpoint, like when a software watchpoint is
2543 set. Assuming single-stepping and delivering a signal at the
2544 same time would takes us to the signal handler, then we could
2545 have removed the breakpoint at PC to step over it. However,
2546 some hardware step targets (like e.g., Mac OS) can't step
2547 into signal handlers, and for those, we need to leave the
2548 breakpoint at PC inserted, as otherwise if the handler
2549 recurses and executes PC again, it'll miss the breakpoint.
2550 So we leave the breakpoint inserted anyway, but we need to
2551 record that we tried to step a breakpoint instruction, so
2552 that adjust_pc_after_break doesn't end up confused.
2554 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2555 in one thread after another thread that was stepping had been
2556 momentarily paused for a step-over. When we re-resume the
2557 stepping thread, it may be resumed from that address with a
2558 breakpoint that hasn't trapped yet. Seen with
2559 gdb.threads/non-stop-fair-events.exp, on targets that don't
2560 do displaced stepping. */
2562 infrun_log_debug ("resume: [%s] stepped breakpoint",
2563 target_pid_to_str (tp
->ptid
).c_str ());
2565 tp
->stepped_breakpoint
= 1;
2567 /* Most targets can step a breakpoint instruction, thus
2568 executing it normally. But if this one cannot, just
2569 continue and we will hit it anyway. */
2570 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2575 && tp
->control
.trap_expected
2576 && use_displaced_stepping (tp
)
2577 && !step_over_info_valid_p ())
2579 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2580 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2581 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2584 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2585 paddress (resume_gdbarch
, actual_pc
));
2586 read_memory (actual_pc
, buf
, sizeof (buf
));
2587 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2590 if (tp
->control
.may_range_step
)
2592 /* If we're resuming a thread with the PC out of the step
2593 range, then we're doing some nested/finer run control
2594 operation, like stepping the thread out of the dynamic
2595 linker or the displaced stepping scratch pad. We
2596 shouldn't have allowed a range step then. */
2597 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2600 do_target_resume (resume_ptid
, step
, sig
);
2604 /* Resume the inferior. SIG is the signal to give the inferior
2605 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2606 rolls back state on error. */
2609 resume (gdb_signal sig
)
2615 catch (const gdb_exception
&ex
)
2617 /* If resuming is being aborted for any reason, delete any
2618 single-step breakpoint resume_1 may have created, to avoid
2619 confusing the following resumption, and to avoid leaving
2620 single-step breakpoints perturbing other threads, in case
2621 we're running in non-stop mode. */
2622 if (inferior_ptid
!= null_ptid
)
2623 delete_single_step_breakpoints (inferior_thread ());
2633 /* Counter that tracks number of user visible stops. This can be used
2634 to tell whether a command has proceeded the inferior past the
2635 current location. This allows e.g., inferior function calls in
2636 breakpoint commands to not interrupt the command list. When the
2637 call finishes successfully, the inferior is standing at the same
2638 breakpoint as if nothing happened (and so we don't call
2640 static ULONGEST current_stop_id
;
2647 return current_stop_id
;
2650 /* Called when we report a user visible stop. */
2658 /* Clear out all variables saying what to do when inferior is continued.
2659 First do this, then set the ones you want, then call `proceed'. */
2662 clear_proceed_status_thread (struct thread_info
*tp
)
2664 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2666 /* If we're starting a new sequence, then the previous finished
2667 single-step is no longer relevant. */
2668 if (tp
->suspend
.waitstatus_pending_p
)
2670 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2672 infrun_log_debug ("pending event of %s was a finished step. "
2674 target_pid_to_str (tp
->ptid
).c_str ());
2676 tp
->suspend
.waitstatus_pending_p
= 0;
2677 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2682 ("thread %s has pending wait status %s (currently_stepping=%d).",
2683 target_pid_to_str (tp
->ptid
).c_str (),
2684 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2685 currently_stepping (tp
));
2689 /* If this signal should not be seen by program, give it zero.
2690 Used for debugging signals. */
2691 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2692 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2694 delete tp
->thread_fsm
;
2695 tp
->thread_fsm
= NULL
;
2697 tp
->control
.trap_expected
= 0;
2698 tp
->control
.step_range_start
= 0;
2699 tp
->control
.step_range_end
= 0;
2700 tp
->control
.may_range_step
= 0;
2701 tp
->control
.step_frame_id
= null_frame_id
;
2702 tp
->control
.step_stack_frame_id
= null_frame_id
;
2703 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2704 tp
->control
.step_start_function
= NULL
;
2705 tp
->stop_requested
= 0;
2707 tp
->control
.stop_step
= 0;
2709 tp
->control
.proceed_to_finish
= 0;
2711 tp
->control
.stepping_command
= 0;
2713 /* Discard any remaining commands or status from previous stop. */
2714 bpstat_clear (&tp
->control
.stop_bpstat
);
2718 clear_proceed_status (int step
)
2720 /* With scheduler-locking replay, stop replaying other threads if we're
2721 not replaying the user-visible resume ptid.
2723 This is a convenience feature to not require the user to explicitly
2724 stop replaying the other threads. We're assuming that the user's
2725 intent is to resume tracing the recorded process. */
2726 if (!non_stop
&& scheduler_mode
== schedlock_replay
2727 && target_record_is_replaying (minus_one_ptid
)
2728 && !target_record_will_replay (user_visible_resume_ptid (step
),
2729 execution_direction
))
2730 target_record_stop_replaying ();
2732 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2734 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2735 process_stratum_target
*resume_target
2736 = user_visible_resume_target (resume_ptid
);
2738 /* In all-stop mode, delete the per-thread status of all threads
2739 we're about to resume, implicitly and explicitly. */
2740 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2741 clear_proceed_status_thread (tp
);
2744 if (inferior_ptid
!= null_ptid
)
2746 struct inferior
*inferior
;
2750 /* If in non-stop mode, only delete the per-thread status of
2751 the current thread. */
2752 clear_proceed_status_thread (inferior_thread ());
2755 inferior
= current_inferior ();
2756 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2759 gdb::observers::about_to_proceed
.notify ();
2762 /* Returns true if TP is still stopped at a breakpoint that needs
2763 stepping-over in order to make progress. If the breakpoint is gone
2764 meanwhile, we can skip the whole step-over dance. */
2767 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2769 if (tp
->stepping_over_breakpoint
)
2771 struct regcache
*regcache
= get_thread_regcache (tp
);
2773 if (breakpoint_here_p (regcache
->aspace (),
2774 regcache_read_pc (regcache
))
2775 == ordinary_breakpoint_here
)
2778 tp
->stepping_over_breakpoint
= 0;
2784 /* Check whether thread TP still needs to start a step-over in order
2785 to make progress when resumed. Returns an bitwise or of enum
2786 step_over_what bits, indicating what needs to be stepped over. */
2788 static step_over_what
2789 thread_still_needs_step_over (struct thread_info
*tp
)
2791 step_over_what what
= 0;
2793 if (thread_still_needs_step_over_bp (tp
))
2794 what
|= STEP_OVER_BREAKPOINT
;
2796 if (tp
->stepping_over_watchpoint
2797 && !target_have_steppable_watchpoint
)
2798 what
|= STEP_OVER_WATCHPOINT
;
2803 /* Returns true if scheduler locking applies. STEP indicates whether
2804 we're about to do a step/next-like command to a thread. */
2807 schedlock_applies (struct thread_info
*tp
)
2809 return (scheduler_mode
== schedlock_on
2810 || (scheduler_mode
== schedlock_step
2811 && tp
->control
.stepping_command
)
2812 || (scheduler_mode
== schedlock_replay
2813 && target_record_will_replay (minus_one_ptid
,
2814 execution_direction
)));
2817 /* Calls target_commit_resume on all targets. */
2820 commit_resume_all_targets ()
2822 scoped_restore_current_thread restore_thread
;
2824 /* Map between process_target and a representative inferior. This
2825 is to avoid committing a resume in the same target more than
2826 once. Resumptions must be idempotent, so this is an
2828 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2830 for (inferior
*inf
: all_non_exited_inferiors ())
2831 if (inf
->has_execution ())
2832 conn_inf
[inf
->process_target ()] = inf
;
2834 for (const auto &ci
: conn_inf
)
2836 inferior
*inf
= ci
.second
;
2837 switch_to_inferior_no_thread (inf
);
2838 target_commit_resume ();
2842 /* Check that all the targets we're about to resume are in non-stop
2843 mode. Ideally, we'd only care whether all targets support
2844 target-async, but we're not there yet. E.g., stop_all_threads
2845 doesn't know how to handle all-stop targets. Also, the remote
2846 protocol in all-stop mode is synchronous, irrespective of
2847 target-async, which means that things like a breakpoint re-set
2848 triggered by one target would try to read memory from all targets
2852 check_multi_target_resumption (process_stratum_target
*resume_target
)
2854 if (!non_stop
&& resume_target
== nullptr)
2856 scoped_restore_current_thread restore_thread
;
2858 /* This is used to track whether we're resuming more than one
2860 process_stratum_target
*first_connection
= nullptr;
2862 /* The first inferior we see with a target that does not work in
2863 always-non-stop mode. */
2864 inferior
*first_not_non_stop
= nullptr;
2866 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2868 switch_to_inferior_no_thread (inf
);
2870 if (!target_has_execution
)
2873 process_stratum_target
*proc_target
2874 = current_inferior ()->process_target();
2876 if (!target_is_non_stop_p ())
2877 first_not_non_stop
= inf
;
2879 if (first_connection
== nullptr)
2880 first_connection
= proc_target
;
2881 else if (first_connection
!= proc_target
2882 && first_not_non_stop
!= nullptr)
2884 switch_to_inferior_no_thread (first_not_non_stop
);
2886 proc_target
= current_inferior ()->process_target();
2888 error (_("Connection %d (%s) does not support "
2889 "multi-target resumption."),
2890 proc_target
->connection_number
,
2891 make_target_connection_string (proc_target
).c_str ());
2897 /* Basic routine for continuing the program in various fashions.
2899 ADDR is the address to resume at, or -1 for resume where stopped.
2900 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2901 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2903 You should call clear_proceed_status before calling proceed. */
2906 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2908 struct regcache
*regcache
;
2909 struct gdbarch
*gdbarch
;
2911 struct execution_control_state ecss
;
2912 struct execution_control_state
*ecs
= &ecss
;
2915 /* If we're stopped at a fork/vfork, follow the branch set by the
2916 "set follow-fork-mode" command; otherwise, we'll just proceed
2917 resuming the current thread. */
2918 if (!follow_fork ())
2920 /* The target for some reason decided not to resume. */
2922 if (target_can_async_p ())
2923 inferior_event_handler (INF_EXEC_COMPLETE
);
2927 /* We'll update this if & when we switch to a new thread. */
2928 previous_inferior_ptid
= inferior_ptid
;
2930 regcache
= get_current_regcache ();
2931 gdbarch
= regcache
->arch ();
2932 const address_space
*aspace
= regcache
->aspace ();
2934 pc
= regcache_read_pc_protected (regcache
);
2936 thread_info
*cur_thr
= inferior_thread ();
2938 /* Fill in with reasonable starting values. */
2939 init_thread_stepping_state (cur_thr
);
2941 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2944 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2945 process_stratum_target
*resume_target
2946 = user_visible_resume_target (resume_ptid
);
2948 check_multi_target_resumption (resume_target
);
2950 if (addr
== (CORE_ADDR
) -1)
2952 if (pc
== cur_thr
->suspend
.stop_pc
2953 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2954 && execution_direction
!= EXEC_REVERSE
)
2955 /* There is a breakpoint at the address we will resume at,
2956 step one instruction before inserting breakpoints so that
2957 we do not stop right away (and report a second hit at this
2960 Note, we don't do this in reverse, because we won't
2961 actually be executing the breakpoint insn anyway.
2962 We'll be (un-)executing the previous instruction. */
2963 cur_thr
->stepping_over_breakpoint
= 1;
2964 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2965 && gdbarch_single_step_through_delay (gdbarch
,
2966 get_current_frame ()))
2967 /* We stepped onto an instruction that needs to be stepped
2968 again before re-inserting the breakpoint, do so. */
2969 cur_thr
->stepping_over_breakpoint
= 1;
2973 regcache_write_pc (regcache
, addr
);
2976 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2977 cur_thr
->suspend
.stop_signal
= siggnal
;
2979 /* If an exception is thrown from this point on, make sure to
2980 propagate GDB's knowledge of the executing state to the
2981 frontend/user running state. */
2982 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2984 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2985 threads (e.g., we might need to set threads stepping over
2986 breakpoints first), from the user/frontend's point of view, all
2987 threads in RESUME_PTID are now running. Unless we're calling an
2988 inferior function, as in that case we pretend the inferior
2989 doesn't run at all. */
2990 if (!cur_thr
->control
.in_infcall
)
2991 set_running (resume_target
, resume_ptid
, true);
2993 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
2994 gdb_signal_to_symbol_string (siggnal
));
2996 annotate_starting ();
2998 /* Make sure that output from GDB appears before output from the
3000 gdb_flush (gdb_stdout
);
3002 /* Since we've marked the inferior running, give it the terminal. A
3003 QUIT/Ctrl-C from here on is forwarded to the target (which can
3004 still detect attempts to unblock a stuck connection with repeated
3005 Ctrl-C from within target_pass_ctrlc). */
3006 target_terminal::inferior ();
3008 /* In a multi-threaded task we may select another thread and
3009 then continue or step.
3011 But if a thread that we're resuming had stopped at a breakpoint,
3012 it will immediately cause another breakpoint stop without any
3013 execution (i.e. it will report a breakpoint hit incorrectly). So
3014 we must step over it first.
3016 Look for threads other than the current (TP) that reported a
3017 breakpoint hit and haven't been resumed yet since. */
3019 /* If scheduler locking applies, we can avoid iterating over all
3021 if (!non_stop
&& !schedlock_applies (cur_thr
))
3023 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3026 switch_to_thread_no_regs (tp
);
3028 /* Ignore the current thread here. It's handled
3033 if (!thread_still_needs_step_over (tp
))
3036 gdb_assert (!thread_is_in_step_over_chain (tp
));
3038 infrun_log_debug ("need to step-over [%s] first",
3039 target_pid_to_str (tp
->ptid
).c_str ());
3041 global_thread_step_over_chain_enqueue (tp
);
3044 switch_to_thread (cur_thr
);
3047 /* Enqueue the current thread last, so that we move all other
3048 threads over their breakpoints first. */
3049 if (cur_thr
->stepping_over_breakpoint
)
3050 global_thread_step_over_chain_enqueue (cur_thr
);
3052 /* If the thread isn't started, we'll still need to set its prev_pc,
3053 so that switch_back_to_stepped_thread knows the thread hasn't
3054 advanced. Must do this before resuming any thread, as in
3055 all-stop/remote, once we resume we can't send any other packet
3056 until the target stops again. */
3057 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3060 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3062 started
= start_step_over ();
3064 if (step_over_info_valid_p ())
3066 /* Either this thread started a new in-line step over, or some
3067 other thread was already doing one. In either case, don't
3068 resume anything else until the step-over is finished. */
3070 else if (started
&& !target_is_non_stop_p ())
3072 /* A new displaced stepping sequence was started. In all-stop,
3073 we can't talk to the target anymore until it next stops. */
3075 else if (!non_stop
&& target_is_non_stop_p ())
3077 /* In all-stop, but the target is always in non-stop mode.
3078 Start all other threads that are implicitly resumed too. */
3079 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3082 switch_to_thread_no_regs (tp
);
3084 if (!tp
->inf
->has_execution ())
3086 infrun_log_debug ("[%s] target has no execution",
3087 target_pid_to_str (tp
->ptid
).c_str ());
3093 infrun_log_debug ("[%s] resumed",
3094 target_pid_to_str (tp
->ptid
).c_str ());
3095 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3099 if (thread_is_in_step_over_chain (tp
))
3101 infrun_log_debug ("[%s] needs step-over",
3102 target_pid_to_str (tp
->ptid
).c_str ());
3106 infrun_log_debug ("resuming %s",
3107 target_pid_to_str (tp
->ptid
).c_str ());
3109 reset_ecs (ecs
, tp
);
3110 switch_to_thread (tp
);
3111 keep_going_pass_signal (ecs
);
3112 if (!ecs
->wait_some_more
)
3113 error (_("Command aborted."));
3116 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3118 /* The thread wasn't started, and isn't queued, run it now. */
3119 reset_ecs (ecs
, cur_thr
);
3120 switch_to_thread (cur_thr
);
3121 keep_going_pass_signal (ecs
);
3122 if (!ecs
->wait_some_more
)
3123 error (_("Command aborted."));
3127 commit_resume_all_targets ();
3129 finish_state
.release ();
3131 /* If we've switched threads above, switch back to the previously
3132 current thread. We don't want the user to see a different
3134 switch_to_thread (cur_thr
);
3136 /* Tell the event loop to wait for it to stop. If the target
3137 supports asynchronous execution, it'll do this from within
3139 if (!target_can_async_p ())
3140 mark_async_event_handler (infrun_async_inferior_event_token
);
3144 /* Start remote-debugging of a machine over a serial link. */
3147 start_remote (int from_tty
)
3149 inferior
*inf
= current_inferior ();
3150 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3152 /* Always go on waiting for the target, regardless of the mode. */
3153 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3154 indicate to wait_for_inferior that a target should timeout if
3155 nothing is returned (instead of just blocking). Because of this,
3156 targets expecting an immediate response need to, internally, set
3157 things up so that the target_wait() is forced to eventually
3159 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3160 differentiate to its caller what the state of the target is after
3161 the initial open has been performed. Here we're assuming that
3162 the target has stopped. It should be possible to eventually have
3163 target_open() return to the caller an indication that the target
3164 is currently running and GDB state should be set to the same as
3165 for an async run. */
3166 wait_for_inferior (inf
);
3168 /* Now that the inferior has stopped, do any bookkeeping like
3169 loading shared libraries. We want to do this before normal_stop,
3170 so that the displayed frame is up to date. */
3171 post_create_inferior (current_top_target (), from_tty
);
3176 /* Initialize static vars when a new inferior begins. */
3179 init_wait_for_inferior (void)
3181 /* These are meaningless until the first time through wait_for_inferior. */
3183 breakpoint_init_inferior (inf_starting
);
3185 clear_proceed_status (0);
3187 nullify_last_target_wait_ptid ();
3189 previous_inferior_ptid
= inferior_ptid
;
3194 static void handle_inferior_event (struct execution_control_state
*ecs
);
3196 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3197 struct execution_control_state
*ecs
);
3198 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3199 struct execution_control_state
*ecs
);
3200 static void handle_signal_stop (struct execution_control_state
*ecs
);
3201 static void check_exception_resume (struct execution_control_state
*,
3202 struct frame_info
*);
3204 static void end_stepping_range (struct execution_control_state
*ecs
);
3205 static void stop_waiting (struct execution_control_state
*ecs
);
3206 static void keep_going (struct execution_control_state
*ecs
);
3207 static void process_event_stop_test (struct execution_control_state
*ecs
);
3208 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3210 /* This function is attached as a "thread_stop_requested" observer.
3211 Cleanup local state that assumed the PTID was to be resumed, and
3212 report the stop to the frontend. */
3215 infrun_thread_stop_requested (ptid_t ptid
)
3217 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3219 /* PTID was requested to stop. If the thread was already stopped,
3220 but the user/frontend doesn't know about that yet (e.g., the
3221 thread had been temporarily paused for some step-over), set up
3222 for reporting the stop now. */
3223 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3225 if (tp
->state
!= THREAD_RUNNING
)
3230 /* Remove matching threads from the step-over queue, so
3231 start_step_over doesn't try to resume them
3233 if (thread_is_in_step_over_chain (tp
))
3234 global_thread_step_over_chain_remove (tp
);
3236 /* If the thread is stopped, but the user/frontend doesn't
3237 know about that yet, queue a pending event, as if the
3238 thread had just stopped now. Unless the thread already had
3240 if (!tp
->suspend
.waitstatus_pending_p
)
3242 tp
->suspend
.waitstatus_pending_p
= 1;
3243 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3244 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3247 /* Clear the inline-frame state, since we're re-processing the
3249 clear_inline_frame_state (tp
);
3251 /* If this thread was paused because some other thread was
3252 doing an inline-step over, let that finish first. Once
3253 that happens, we'll restart all threads and consume pending
3254 stop events then. */
3255 if (step_over_info_valid_p ())
3258 /* Otherwise we can process the (new) pending event now. Set
3259 it so this pending event is considered by
3266 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3268 if (target_last_proc_target
== tp
->inf
->process_target ()
3269 && target_last_wait_ptid
== tp
->ptid
)
3270 nullify_last_target_wait_ptid ();
3273 /* Delete the step resume, single-step and longjmp/exception resume
3274 breakpoints of TP. */
3277 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3279 delete_step_resume_breakpoint (tp
);
3280 delete_exception_resume_breakpoint (tp
);
3281 delete_single_step_breakpoints (tp
);
3284 /* If the target still has execution, call FUNC for each thread that
3285 just stopped. In all-stop, that's all the non-exited threads; in
3286 non-stop, that's the current thread, only. */
3288 typedef void (*for_each_just_stopped_thread_callback_func
)
3289 (struct thread_info
*tp
);
3292 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3294 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3297 if (target_is_non_stop_p ())
3299 /* If in non-stop mode, only the current thread stopped. */
3300 func (inferior_thread ());
3304 /* In all-stop mode, all threads have stopped. */
3305 for (thread_info
*tp
: all_non_exited_threads ())
3310 /* Delete the step resume and longjmp/exception resume breakpoints of
3311 the threads that just stopped. */
3314 delete_just_stopped_threads_infrun_breakpoints (void)
3316 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3319 /* Delete the single-step breakpoints of the threads that just
3323 delete_just_stopped_threads_single_step_breakpoints (void)
3325 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3331 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3332 const struct target_waitstatus
*ws
)
3334 std::string status_string
= target_waitstatus_to_string (ws
);
3337 /* The text is split over several lines because it was getting too long.
3338 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3339 output as a unit; we want only one timestamp printed if debug_timestamp
3342 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3345 waiton_ptid
.tid ());
3346 if (waiton_ptid
.pid () != -1)
3347 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3348 stb
.printf (", status) =\n");
3349 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3353 target_pid_to_str (result_ptid
).c_str ());
3354 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3356 /* This uses %s in part to handle %'s in the text, but also to avoid
3357 a gcc error: the format attribute requires a string literal. */
3358 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3361 /* Select a thread at random, out of those which are resumed and have
3364 static struct thread_info
*
3365 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3369 auto has_event
= [&] (thread_info
*tp
)
3371 return (tp
->ptid
.matches (waiton_ptid
)
3373 && tp
->suspend
.waitstatus_pending_p
);
3376 /* First see how many events we have. Count only resumed threads
3377 that have an event pending. */
3378 for (thread_info
*tp
: inf
->non_exited_threads ())
3382 if (num_events
== 0)
3385 /* Now randomly pick a thread out of those that have had events. */
3386 int random_selector
= (int) ((num_events
* (double) rand ())
3387 / (RAND_MAX
+ 1.0));
3390 infrun_log_debug ("Found %d events, selecting #%d",
3391 num_events
, random_selector
);
3393 /* Select the Nth thread that has had an event. */
3394 for (thread_info
*tp
: inf
->non_exited_threads ())
3396 if (random_selector
-- == 0)
3399 gdb_assert_not_reached ("event thread not found");
3402 /* Wrapper for target_wait that first checks whether threads have
3403 pending statuses to report before actually asking the target for
3404 more events. INF is the inferior we're using to call target_wait
3408 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3409 target_waitstatus
*status
, int options
)
3412 struct thread_info
*tp
;
3414 /* We know that we are looking for an event in the target of inferior
3415 INF, but we don't know which thread the event might come from. As
3416 such we want to make sure that INFERIOR_PTID is reset so that none of
3417 the wait code relies on it - doing so is always a mistake. */
3418 switch_to_inferior_no_thread (inf
);
3420 /* First check if there is a resumed thread with a wait status
3422 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3424 tp
= random_pending_event_thread (inf
, ptid
);
3428 infrun_log_debug ("Waiting for specific thread %s.",
3429 target_pid_to_str (ptid
).c_str ());
3431 /* We have a specific thread to check. */
3432 tp
= find_thread_ptid (inf
, ptid
);
3433 gdb_assert (tp
!= NULL
);
3434 if (!tp
->suspend
.waitstatus_pending_p
)
3439 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3440 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3442 struct regcache
*regcache
= get_thread_regcache (tp
);
3443 struct gdbarch
*gdbarch
= regcache
->arch ();
3447 pc
= regcache_read_pc (regcache
);
3449 if (pc
!= tp
->suspend
.stop_pc
)
3451 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3452 target_pid_to_str (tp
->ptid
).c_str (),
3453 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3454 paddress (gdbarch
, pc
));
3457 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3459 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3460 target_pid_to_str (tp
->ptid
).c_str (),
3461 paddress (gdbarch
, pc
));
3468 infrun_log_debug ("pending event of %s cancelled.",
3469 target_pid_to_str (tp
->ptid
).c_str ());
3471 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3472 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3478 infrun_log_debug ("Using pending wait status %s for %s.",
3479 target_waitstatus_to_string
3480 (&tp
->suspend
.waitstatus
).c_str (),
3481 target_pid_to_str (tp
->ptid
).c_str ());
3483 /* Now that we've selected our final event LWP, un-adjust its PC
3484 if it was a software breakpoint (and the target doesn't
3485 always adjust the PC itself). */
3486 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3487 && !target_supports_stopped_by_sw_breakpoint ())
3489 struct regcache
*regcache
;
3490 struct gdbarch
*gdbarch
;
3493 regcache
= get_thread_regcache (tp
);
3494 gdbarch
= regcache
->arch ();
3496 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3501 pc
= regcache_read_pc (regcache
);
3502 regcache_write_pc (regcache
, pc
+ decr_pc
);
3506 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3507 *status
= tp
->suspend
.waitstatus
;
3508 tp
->suspend
.waitstatus_pending_p
= 0;
3510 /* Wake up the event loop again, until all pending events are
3512 if (target_is_async_p ())
3513 mark_async_event_handler (infrun_async_inferior_event_token
);
3517 /* But if we don't find one, we'll have to wait. */
3519 if (deprecated_target_wait_hook
)
3520 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3522 event_ptid
= target_wait (ptid
, status
, options
);
3527 /* Wrapper for target_wait that first checks whether threads have
3528 pending statuses to report before actually asking the target for
3529 more events. Polls for events from all inferiors/targets. */
3532 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3534 int num_inferiors
= 0;
3535 int random_selector
;
3537 /* For fairness, we pick the first inferior/target to poll at random
3538 out of all inferiors that may report events, and then continue
3539 polling the rest of the inferior list starting from that one in a
3540 circular fashion until the whole list is polled once. */
3542 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3544 return (inf
->process_target () != NULL
3545 && ptid_t (inf
->pid
).matches (wait_ptid
));
3548 /* First see how many matching inferiors we have. */
3549 for (inferior
*inf
: all_inferiors ())
3550 if (inferior_matches (inf
))
3553 if (num_inferiors
== 0)
3555 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3559 /* Now randomly pick an inferior out of those that matched. */
3560 random_selector
= (int)
3561 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3563 if (num_inferiors
> 1)
3564 infrun_log_debug ("Found %d inferiors, starting at #%d",
3565 num_inferiors
, random_selector
);
3567 /* Select the Nth inferior that matched. */
3569 inferior
*selected
= nullptr;
3571 for (inferior
*inf
: all_inferiors ())
3572 if (inferior_matches (inf
))
3573 if (random_selector
-- == 0)
3579 /* Now poll for events out of each of the matching inferior's
3580 targets, starting from the selected one. */
3582 auto do_wait
= [&] (inferior
*inf
)
3584 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3585 ecs
->target
= inf
->process_target ();
3586 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3589 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3590 here spuriously after the target is all stopped and we've already
3591 reported the stop to the user, polling for events. */
3592 scoped_restore_current_thread restore_thread
;
3594 int inf_num
= selected
->num
;
3595 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3596 if (inferior_matches (inf
))
3600 for (inferior
*inf
= inferior_list
;
3601 inf
!= NULL
&& inf
->num
< inf_num
;
3603 if (inferior_matches (inf
))
3607 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3611 /* Prepare and stabilize the inferior for detaching it. E.g.,
3612 detaching while a thread is displaced stepping is a recipe for
3613 crashing it, as nothing would readjust the PC out of the scratch
3617 prepare_for_detach (void)
3619 struct inferior
*inf
= current_inferior ();
3620 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3622 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3624 /* Is any thread of this process displaced stepping? If not,
3625 there's nothing else to do. */
3626 if (displaced_step_in_progress (inf
))
3629 infrun_log_debug ("displaced-stepping in-process while detaching");
3631 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3636 struct execution_control_state ecss
;
3637 struct execution_control_state
*ecs
;
3640 memset (ecs
, 0, sizeof (*ecs
));
3642 overlay_cache_invalid
= 1;
3643 /* Flush target cache before starting to handle each event.
3644 Target was running and cache could be stale. This is just a
3645 heuristic. Running threads may modify target memory, but we
3646 don't get any event. */
3647 target_dcache_invalidate ();
3649 do_target_wait (pid_ptid
, ecs
, 0);
3652 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3654 /* If an error happens while handling the event, propagate GDB's
3655 knowledge of the executing state to the frontend/user running
3657 scoped_finish_thread_state
finish_state (inf
->process_target (),
3660 /* Now figure out what to do with the result of the result. */
3661 handle_inferior_event (ecs
);
3663 /* No error, don't finish the state yet. */
3664 finish_state
.release ();
3666 /* Breakpoints and watchpoints are not installed on the target
3667 at this point, and signals are passed directly to the
3668 inferior, so this must mean the process is gone. */
3669 if (!ecs
->wait_some_more
)
3671 restore_detaching
.release ();
3672 error (_("Program exited while detaching"));
3676 restore_detaching
.release ();
3679 /* Wait for control to return from inferior to debugger.
3681 If inferior gets a signal, we may decide to start it up again
3682 instead of returning. That is why there is a loop in this function.
3683 When this function actually returns it means the inferior
3684 should be left stopped and GDB should read more commands. */
3687 wait_for_inferior (inferior
*inf
)
3689 infrun_log_debug ("wait_for_inferior ()");
3691 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3693 /* If an error happens while handling the event, propagate GDB's
3694 knowledge of the executing state to the frontend/user running
3696 scoped_finish_thread_state finish_state
3697 (inf
->process_target (), minus_one_ptid
);
3701 struct execution_control_state ecss
;
3702 struct execution_control_state
*ecs
= &ecss
;
3704 memset (ecs
, 0, sizeof (*ecs
));
3706 overlay_cache_invalid
= 1;
3708 /* Flush target cache before starting to handle each event.
3709 Target was running and cache could be stale. This is just a
3710 heuristic. Running threads may modify target memory, but we
3711 don't get any event. */
3712 target_dcache_invalidate ();
3714 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3715 ecs
->target
= inf
->process_target ();
3718 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3720 /* Now figure out what to do with the result of the result. */
3721 handle_inferior_event (ecs
);
3723 if (!ecs
->wait_some_more
)
3727 /* No error, don't finish the state yet. */
3728 finish_state
.release ();
3731 /* Cleanup that reinstalls the readline callback handler, if the
3732 target is running in the background. If while handling the target
3733 event something triggered a secondary prompt, like e.g., a
3734 pagination prompt, we'll have removed the callback handler (see
3735 gdb_readline_wrapper_line). Need to do this as we go back to the
3736 event loop, ready to process further input. Note this has no
3737 effect if the handler hasn't actually been removed, because calling
3738 rl_callback_handler_install resets the line buffer, thus losing
3742 reinstall_readline_callback_handler_cleanup ()
3744 struct ui
*ui
= current_ui
;
3748 /* We're not going back to the top level event loop yet. Don't
3749 install the readline callback, as it'd prep the terminal,
3750 readline-style (raw, noecho) (e.g., --batch). We'll install
3751 it the next time the prompt is displayed, when we're ready
3756 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3757 gdb_rl_callback_handler_reinstall ();
3760 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3761 that's just the event thread. In all-stop, that's all threads. */
3764 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3766 if (ecs
->event_thread
!= NULL
3767 && ecs
->event_thread
->thread_fsm
!= NULL
)
3768 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3772 for (thread_info
*thr
: all_non_exited_threads ())
3774 if (thr
->thread_fsm
== NULL
)
3776 if (thr
== ecs
->event_thread
)
3779 switch_to_thread (thr
);
3780 thr
->thread_fsm
->clean_up (thr
);
3783 if (ecs
->event_thread
!= NULL
)
3784 switch_to_thread (ecs
->event_thread
);
3788 /* Helper for all_uis_check_sync_execution_done that works on the
3792 check_curr_ui_sync_execution_done (void)
3794 struct ui
*ui
= current_ui
;
3796 if (ui
->prompt_state
== PROMPT_NEEDED
3798 && !gdb_in_secondary_prompt_p (ui
))
3800 target_terminal::ours ();
3801 gdb::observers::sync_execution_done
.notify ();
3802 ui_register_input_event_handler (ui
);
3809 all_uis_check_sync_execution_done (void)
3811 SWITCH_THRU_ALL_UIS ()
3813 check_curr_ui_sync_execution_done ();
3820 all_uis_on_sync_execution_starting (void)
3822 SWITCH_THRU_ALL_UIS ()
3824 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3825 async_disable_stdin ();
3829 /* Asynchronous version of wait_for_inferior. It is called by the
3830 event loop whenever a change of state is detected on the file
3831 descriptor corresponding to the target. It can be called more than
3832 once to complete a single execution command. In such cases we need
3833 to keep the state in a global variable ECSS. If it is the last time
3834 that this function is called for a single execution command, then
3835 report to the user that the inferior has stopped, and do the
3836 necessary cleanups. */
3839 fetch_inferior_event ()
3841 struct execution_control_state ecss
;
3842 struct execution_control_state
*ecs
= &ecss
;
3845 memset (ecs
, 0, sizeof (*ecs
));
3847 /* Events are always processed with the main UI as current UI. This
3848 way, warnings, debug output, etc. are always consistently sent to
3849 the main console. */
3850 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3852 /* End up with readline processing input, if necessary. */
3854 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3856 /* We're handling a live event, so make sure we're doing live
3857 debugging. If we're looking at traceframes while the target is
3858 running, we're going to need to get back to that mode after
3859 handling the event. */
3860 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3863 maybe_restore_traceframe
.emplace ();
3864 set_current_traceframe (-1);
3867 /* The user/frontend should not notice a thread switch due to
3868 internal events. Make sure we revert to the user selected
3869 thread and frame after handling the event and running any
3870 breakpoint commands. */
3871 scoped_restore_current_thread restore_thread
;
3873 overlay_cache_invalid
= 1;
3874 /* Flush target cache before starting to handle each event. Target
3875 was running and cache could be stale. This is just a heuristic.
3876 Running threads may modify target memory, but we don't get any
3878 target_dcache_invalidate ();
3880 scoped_restore save_exec_dir
3881 = make_scoped_restore (&execution_direction
,
3882 target_execution_direction ());
3884 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3887 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3889 /* Switch to the target that generated the event, so we can do
3890 target calls. Any inferior bound to the target will do, so we
3891 just switch to the first we find. */
3892 for (inferior
*inf
: all_inferiors (ecs
->target
))
3894 switch_to_inferior_no_thread (inf
);
3899 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3901 /* If an error happens while handling the event, propagate GDB's
3902 knowledge of the executing state to the frontend/user running
3904 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3905 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3907 /* Get executed before scoped_restore_current_thread above to apply
3908 still for the thread which has thrown the exception. */
3909 auto defer_bpstat_clear
3910 = make_scope_exit (bpstat_clear_actions
);
3911 auto defer_delete_threads
3912 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3914 /* Now figure out what to do with the result of the result. */
3915 handle_inferior_event (ecs
);
3917 if (!ecs
->wait_some_more
)
3919 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3920 int should_stop
= 1;
3921 struct thread_info
*thr
= ecs
->event_thread
;
3923 delete_just_stopped_threads_infrun_breakpoints ();
3927 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3929 if (thread_fsm
!= NULL
)
3930 should_stop
= thread_fsm
->should_stop (thr
);
3939 bool should_notify_stop
= true;
3942 clean_up_just_stopped_threads_fsms (ecs
);
3944 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3945 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3947 if (should_notify_stop
)
3949 /* We may not find an inferior if this was a process exit. */
3950 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3951 proceeded
= normal_stop ();
3956 inferior_event_handler (INF_EXEC_COMPLETE
);
3960 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3961 previously selected thread is gone. We have two
3962 choices - switch to no thread selected, or restore the
3963 previously selected thread (now exited). We chose the
3964 later, just because that's what GDB used to do. After
3965 this, "info threads" says "The current thread <Thread
3966 ID 2> has terminated." instead of "No thread
3970 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3971 restore_thread
.dont_restore ();
3975 defer_delete_threads
.release ();
3976 defer_bpstat_clear
.release ();
3978 /* No error, don't finish the thread states yet. */
3979 finish_state
.release ();
3981 /* This scope is used to ensure that readline callbacks are
3982 reinstalled here. */
3985 /* If a UI was in sync execution mode, and now isn't, restore its
3986 prompt (a synchronous execution command has finished, and we're
3987 ready for input). */
3988 all_uis_check_sync_execution_done ();
3991 && exec_done_display_p
3992 && (inferior_ptid
== null_ptid
3993 || inferior_thread ()->state
!= THREAD_RUNNING
))
3994 printf_unfiltered (_("completed.\n"));
4000 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4001 struct symtab_and_line sal
)
4003 /* This can be removed once this function no longer implicitly relies on the
4004 inferior_ptid value. */
4005 gdb_assert (inferior_ptid
== tp
->ptid
);
4007 tp
->control
.step_frame_id
= get_frame_id (frame
);
4008 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4010 tp
->current_symtab
= sal
.symtab
;
4011 tp
->current_line
= sal
.line
;
4014 /* Clear context switchable stepping state. */
4017 init_thread_stepping_state (struct thread_info
*tss
)
4019 tss
->stepped_breakpoint
= 0;
4020 tss
->stepping_over_breakpoint
= 0;
4021 tss
->stepping_over_watchpoint
= 0;
4022 tss
->step_after_step_resume_breakpoint
= 0;
4028 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4029 target_waitstatus status
)
4031 target_last_proc_target
= target
;
4032 target_last_wait_ptid
= ptid
;
4033 target_last_waitstatus
= status
;
4039 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4040 target_waitstatus
*status
)
4042 if (target
!= nullptr)
4043 *target
= target_last_proc_target
;
4044 if (ptid
!= nullptr)
4045 *ptid
= target_last_wait_ptid
;
4046 if (status
!= nullptr)
4047 *status
= target_last_waitstatus
;
4053 nullify_last_target_wait_ptid (void)
4055 target_last_proc_target
= nullptr;
4056 target_last_wait_ptid
= minus_one_ptid
;
4057 target_last_waitstatus
= {};
4060 /* Switch thread contexts. */
4063 context_switch (execution_control_state
*ecs
)
4065 if (ecs
->ptid
!= inferior_ptid
4066 && (inferior_ptid
== null_ptid
4067 || ecs
->event_thread
!= inferior_thread ()))
4069 infrun_log_debug ("Switching context from %s to %s",
4070 target_pid_to_str (inferior_ptid
).c_str (),
4071 target_pid_to_str (ecs
->ptid
).c_str ());
4074 switch_to_thread (ecs
->event_thread
);
4077 /* If the target can't tell whether we've hit breakpoints
4078 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4079 check whether that could have been caused by a breakpoint. If so,
4080 adjust the PC, per gdbarch_decr_pc_after_break. */
4083 adjust_pc_after_break (struct thread_info
*thread
,
4084 struct target_waitstatus
*ws
)
4086 struct regcache
*regcache
;
4087 struct gdbarch
*gdbarch
;
4088 CORE_ADDR breakpoint_pc
, decr_pc
;
4090 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4091 we aren't, just return.
4093 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4094 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4095 implemented by software breakpoints should be handled through the normal
4098 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4099 different signals (SIGILL or SIGEMT for instance), but it is less
4100 clear where the PC is pointing afterwards. It may not match
4101 gdbarch_decr_pc_after_break. I don't know any specific target that
4102 generates these signals at breakpoints (the code has been in GDB since at
4103 least 1992) so I can not guess how to handle them here.
4105 In earlier versions of GDB, a target with
4106 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4107 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4108 target with both of these set in GDB history, and it seems unlikely to be
4109 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4111 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4114 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4117 /* In reverse execution, when a breakpoint is hit, the instruction
4118 under it has already been de-executed. The reported PC always
4119 points at the breakpoint address, so adjusting it further would
4120 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4123 B1 0x08000000 : INSN1
4124 B2 0x08000001 : INSN2
4126 PC -> 0x08000003 : INSN4
4128 Say you're stopped at 0x08000003 as above. Reverse continuing
4129 from that point should hit B2 as below. Reading the PC when the
4130 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4131 been de-executed already.
4133 B1 0x08000000 : INSN1
4134 B2 PC -> 0x08000001 : INSN2
4138 We can't apply the same logic as for forward execution, because
4139 we would wrongly adjust the PC to 0x08000000, since there's a
4140 breakpoint at PC - 1. We'd then report a hit on B1, although
4141 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4143 if (execution_direction
== EXEC_REVERSE
)
4146 /* If the target can tell whether the thread hit a SW breakpoint,
4147 trust it. Targets that can tell also adjust the PC
4149 if (target_supports_stopped_by_sw_breakpoint ())
4152 /* Note that relying on whether a breakpoint is planted in memory to
4153 determine this can fail. E.g,. the breakpoint could have been
4154 removed since. Or the thread could have been told to step an
4155 instruction the size of a breakpoint instruction, and only
4156 _after_ was a breakpoint inserted at its address. */
4158 /* If this target does not decrement the PC after breakpoints, then
4159 we have nothing to do. */
4160 regcache
= get_thread_regcache (thread
);
4161 gdbarch
= regcache
->arch ();
4163 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4167 const address_space
*aspace
= regcache
->aspace ();
4169 /* Find the location where (if we've hit a breakpoint) the
4170 breakpoint would be. */
4171 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4173 /* If the target can't tell whether a software breakpoint triggered,
4174 fallback to figuring it out based on breakpoints we think were
4175 inserted in the target, and on whether the thread was stepped or
4178 /* Check whether there actually is a software breakpoint inserted at
4181 If in non-stop mode, a race condition is possible where we've
4182 removed a breakpoint, but stop events for that breakpoint were
4183 already queued and arrive later. To suppress those spurious
4184 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4185 and retire them after a number of stop events are reported. Note
4186 this is an heuristic and can thus get confused. The real fix is
4187 to get the "stopped by SW BP and needs adjustment" info out of
4188 the target/kernel (and thus never reach here; see above). */
4189 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4190 || (target_is_non_stop_p ()
4191 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4193 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4195 if (record_full_is_used ())
4196 restore_operation_disable
.emplace
4197 (record_full_gdb_operation_disable_set ());
4199 /* When using hardware single-step, a SIGTRAP is reported for both
4200 a completed single-step and a software breakpoint. Need to
4201 differentiate between the two, as the latter needs adjusting
4202 but the former does not.
4204 The SIGTRAP can be due to a completed hardware single-step only if
4205 - we didn't insert software single-step breakpoints
4206 - this thread is currently being stepped
4208 If any of these events did not occur, we must have stopped due
4209 to hitting a software breakpoint, and have to back up to the
4212 As a special case, we could have hardware single-stepped a
4213 software breakpoint. In this case (prev_pc == breakpoint_pc),
4214 we also need to back up to the breakpoint address. */
4216 if (thread_has_single_step_breakpoints_set (thread
)
4217 || !currently_stepping (thread
)
4218 || (thread
->stepped_breakpoint
4219 && thread
->prev_pc
== breakpoint_pc
))
4220 regcache_write_pc (regcache
, breakpoint_pc
);
4225 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4227 for (frame
= get_prev_frame (frame
);
4229 frame
= get_prev_frame (frame
))
4231 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4233 if (get_frame_type (frame
) != INLINE_FRAME
)
4240 /* Look for an inline frame that is marked for skip.
4241 If PREV_FRAME is TRUE start at the previous frame,
4242 otherwise start at the current frame. Stop at the
4243 first non-inline frame, or at the frame where the
4247 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4249 struct frame_info
*frame
= get_current_frame ();
4252 frame
= get_prev_frame (frame
);
4254 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4256 const char *fn
= NULL
;
4257 symtab_and_line sal
;
4260 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4262 if (get_frame_type (frame
) != INLINE_FRAME
)
4265 sal
= find_frame_sal (frame
);
4266 sym
= get_frame_function (frame
);
4269 fn
= sym
->print_name ();
4272 && function_name_is_marked_for_skip (fn
, sal
))
4279 /* If the event thread has the stop requested flag set, pretend it
4280 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4284 handle_stop_requested (struct execution_control_state
*ecs
)
4286 if (ecs
->event_thread
->stop_requested
)
4288 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4289 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4290 handle_signal_stop (ecs
);
4296 /* Auxiliary function that handles syscall entry/return events.
4297 It returns 1 if the inferior should keep going (and GDB
4298 should ignore the event), or 0 if the event deserves to be
4302 handle_syscall_event (struct execution_control_state
*ecs
)
4304 struct regcache
*regcache
;
4307 context_switch (ecs
);
4309 regcache
= get_thread_regcache (ecs
->event_thread
);
4310 syscall_number
= ecs
->ws
.value
.syscall_number
;
4311 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4313 if (catch_syscall_enabled () > 0
4314 && catching_syscall_number (syscall_number
) > 0)
4316 infrun_log_debug ("syscall number=%d", syscall_number
);
4318 ecs
->event_thread
->control
.stop_bpstat
4319 = bpstat_stop_status (regcache
->aspace (),
4320 ecs
->event_thread
->suspend
.stop_pc
,
4321 ecs
->event_thread
, &ecs
->ws
);
4323 if (handle_stop_requested (ecs
))
4326 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4328 /* Catchpoint hit. */
4333 if (handle_stop_requested (ecs
))
4336 /* If no catchpoint triggered for this, then keep going. */
4341 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4344 fill_in_stop_func (struct gdbarch
*gdbarch
,
4345 struct execution_control_state
*ecs
)
4347 if (!ecs
->stop_func_filled_in
)
4351 /* Don't care about return value; stop_func_start and stop_func_name
4352 will both be 0 if it doesn't work. */
4353 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4354 &ecs
->stop_func_name
,
4355 &ecs
->stop_func_start
,
4356 &ecs
->stop_func_end
,
4359 /* The call to find_pc_partial_function, above, will set
4360 stop_func_start and stop_func_end to the start and end
4361 of the range containing the stop pc. If this range
4362 contains the entry pc for the block (which is always the
4363 case for contiguous blocks), advance stop_func_start past
4364 the function's start offset and entrypoint. Note that
4365 stop_func_start is NOT advanced when in a range of a
4366 non-contiguous block that does not contain the entry pc. */
4367 if (block
!= nullptr
4368 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4369 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4371 ecs
->stop_func_start
4372 += gdbarch_deprecated_function_start_offset (gdbarch
);
4374 if (gdbarch_skip_entrypoint_p (gdbarch
))
4375 ecs
->stop_func_start
4376 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4379 ecs
->stop_func_filled_in
= 1;
4384 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4386 static enum stop_kind
4387 get_inferior_stop_soon (execution_control_state
*ecs
)
4389 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4391 gdb_assert (inf
!= NULL
);
4392 return inf
->control
.stop_soon
;
4395 /* Poll for one event out of the current target. Store the resulting
4396 waitstatus in WS, and return the event ptid. Does not block. */
4399 poll_one_curr_target (struct target_waitstatus
*ws
)
4403 overlay_cache_invalid
= 1;
4405 /* Flush target cache before starting to handle each event.
4406 Target was running and cache could be stale. This is just a
4407 heuristic. Running threads may modify target memory, but we
4408 don't get any event. */
4409 target_dcache_invalidate ();
4411 if (deprecated_target_wait_hook
)
4412 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4414 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4417 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4422 /* An event reported by wait_one. */
4424 struct wait_one_event
4426 /* The target the event came out of. */
4427 process_stratum_target
*target
;
4429 /* The PTID the event was for. */
4432 /* The waitstatus. */
4433 target_waitstatus ws
;
4436 /* Wait for one event out of any target. */
4438 static wait_one_event
4443 for (inferior
*inf
: all_inferiors ())
4445 process_stratum_target
*target
= inf
->process_target ();
4447 || !target
->is_async_p ()
4448 || !target
->threads_executing
)
4451 switch_to_inferior_no_thread (inf
);
4453 wait_one_event event
;
4454 event
.target
= target
;
4455 event
.ptid
= poll_one_curr_target (&event
.ws
);
4457 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4459 /* If nothing is resumed, remove the target from the
4463 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4467 /* Block waiting for some event. */
4474 for (inferior
*inf
: all_inferiors ())
4476 process_stratum_target
*target
= inf
->process_target ();
4478 || !target
->is_async_p ()
4479 || !target
->threads_executing
)
4482 int fd
= target
->async_wait_fd ();
4483 FD_SET (fd
, &readfds
);
4490 /* No waitable targets left. All must be stopped. */
4491 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4496 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4502 perror_with_name ("interruptible_select");
4507 /* Save the thread's event and stop reason to process it later. */
4510 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4512 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4513 target_waitstatus_to_string (ws
).c_str (),
4518 /* Record for later. */
4519 tp
->suspend
.waitstatus
= *ws
;
4520 tp
->suspend
.waitstatus_pending_p
= 1;
4522 struct regcache
*regcache
= get_thread_regcache (tp
);
4523 const address_space
*aspace
= regcache
->aspace ();
4525 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4526 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4528 CORE_ADDR pc
= regcache_read_pc (regcache
);
4530 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4532 scoped_restore_current_thread restore_thread
;
4533 switch_to_thread (tp
);
4535 if (target_stopped_by_watchpoint ())
4537 tp
->suspend
.stop_reason
4538 = TARGET_STOPPED_BY_WATCHPOINT
;
4540 else if (target_supports_stopped_by_sw_breakpoint ()
4541 && target_stopped_by_sw_breakpoint ())
4543 tp
->suspend
.stop_reason
4544 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4546 else if (target_supports_stopped_by_hw_breakpoint ()
4547 && target_stopped_by_hw_breakpoint ())
4549 tp
->suspend
.stop_reason
4550 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4552 else if (!target_supports_stopped_by_hw_breakpoint ()
4553 && hardware_breakpoint_inserted_here_p (aspace
,
4556 tp
->suspend
.stop_reason
4557 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4559 else if (!target_supports_stopped_by_sw_breakpoint ()
4560 && software_breakpoint_inserted_here_p (aspace
,
4563 tp
->suspend
.stop_reason
4564 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4566 else if (!thread_has_single_step_breakpoints_set (tp
)
4567 && currently_stepping (tp
))
4569 tp
->suspend
.stop_reason
4570 = TARGET_STOPPED_BY_SINGLE_STEP
;
4575 /* Mark the non-executing threads accordingly. In all-stop, all
4576 threads of all processes are stopped when we get any event
4577 reported. In non-stop mode, only the event thread stops. */
4580 mark_non_executing_threads (process_stratum_target
*target
,
4582 struct target_waitstatus ws
)
4586 if (!target_is_non_stop_p ())
4587 mark_ptid
= minus_one_ptid
;
4588 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4589 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4591 /* If we're handling a process exit in non-stop mode, even
4592 though threads haven't been deleted yet, one would think
4593 that there is nothing to do, as threads of the dead process
4594 will be soon deleted, and threads of any other process were
4595 left running. However, on some targets, threads survive a
4596 process exit event. E.g., for the "checkpoint" command,
4597 when the current checkpoint/fork exits, linux-fork.c
4598 automatically switches to another fork from within
4599 target_mourn_inferior, by associating the same
4600 inferior/thread to another fork. We haven't mourned yet at
4601 this point, but we must mark any threads left in the
4602 process as not-executing so that finish_thread_state marks
4603 them stopped (in the user's perspective) if/when we present
4604 the stop to the user. */
4605 mark_ptid
= ptid_t (event_ptid
.pid ());
4608 mark_ptid
= event_ptid
;
4610 set_executing (target
, mark_ptid
, false);
4612 /* Likewise the resumed flag. */
4613 set_resumed (target
, mark_ptid
, false);
4619 stop_all_threads (void)
4621 /* We may need multiple passes to discover all threads. */
4625 gdb_assert (exists_non_stop_target ());
4627 infrun_log_debug ("stop_all_threads");
4629 scoped_restore_current_thread restore_thread
;
4631 /* Enable thread events of all targets. */
4632 for (auto *target
: all_non_exited_process_targets ())
4634 switch_to_target_no_thread (target
);
4635 target_thread_events (true);
4640 /* Disable thread events of all targets. */
4641 for (auto *target
: all_non_exited_process_targets ())
4643 switch_to_target_no_thread (target
);
4644 target_thread_events (false);
4648 infrun_log_debug ("stop_all_threads done");
4651 /* Request threads to stop, and then wait for the stops. Because
4652 threads we already know about can spawn more threads while we're
4653 trying to stop them, and we only learn about new threads when we
4654 update the thread list, do this in a loop, and keep iterating
4655 until two passes find no threads that need to be stopped. */
4656 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4658 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4662 int waits_needed
= 0;
4664 for (auto *target
: all_non_exited_process_targets ())
4666 switch_to_target_no_thread (target
);
4667 update_thread_list ();
4670 /* Go through all threads looking for threads that we need
4671 to tell the target to stop. */
4672 for (thread_info
*t
: all_non_exited_threads ())
4674 /* For a single-target setting with an all-stop target,
4675 we would not even arrive here. For a multi-target
4676 setting, until GDB is able to handle a mixture of
4677 all-stop and non-stop targets, simply skip all-stop
4678 targets' threads. This should be fine due to the
4679 protection of 'check_multi_target_resumption'. */
4681 switch_to_thread_no_regs (t
);
4682 if (!target_is_non_stop_p ())
4687 /* If already stopping, don't request a stop again.
4688 We just haven't seen the notification yet. */
4689 if (!t
->stop_requested
)
4691 infrun_log_debug (" %s executing, need stop",
4692 target_pid_to_str (t
->ptid
).c_str ());
4693 target_stop (t
->ptid
);
4694 t
->stop_requested
= 1;
4698 infrun_log_debug (" %s executing, already stopping",
4699 target_pid_to_str (t
->ptid
).c_str ());
4702 if (t
->stop_requested
)
4707 infrun_log_debug (" %s not executing",
4708 target_pid_to_str (t
->ptid
).c_str ());
4710 /* The thread may be not executing, but still be
4711 resumed with a pending status to process. */
4716 if (waits_needed
== 0)
4719 /* If we find new threads on the second iteration, restart
4720 over. We want to see two iterations in a row with all
4725 for (int i
= 0; i
< waits_needed
; i
++)
4727 wait_one_event event
= wait_one ();
4729 infrun_log_debug ("%s %s\n",
4730 target_waitstatus_to_string (&event
.ws
).c_str (),
4731 target_pid_to_str (event
.ptid
).c_str ());
4733 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4735 /* All resumed threads exited. */
4738 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4739 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4740 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4742 /* One thread/process exited/signalled. */
4744 thread_info
*t
= nullptr;
4746 /* The target may have reported just a pid. If so, try
4747 the first non-exited thread. */
4748 if (event
.ptid
.is_pid ())
4750 int pid
= event
.ptid
.pid ();
4751 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4752 for (thread_info
*tp
: inf
->non_exited_threads ())
4758 /* If there is no available thread, the event would
4759 have to be appended to a per-inferior event list,
4760 which does not exist (and if it did, we'd have
4761 to adjust run control command to be able to
4762 resume such an inferior). We assert here instead
4763 of going into an infinite loop. */
4764 gdb_assert (t
!= nullptr);
4766 infrun_log_debug ("using %s\n",
4767 target_pid_to_str (t
->ptid
).c_str ());
4771 t
= find_thread_ptid (event
.target
, event
.ptid
);
4772 /* Check if this is the first time we see this thread.
4773 Don't bother adding if it individually exited. */
4775 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4776 t
= add_thread (event
.target
, event
.ptid
);
4781 /* Set the threads as non-executing to avoid
4782 another stop attempt on them. */
4783 switch_to_thread_no_regs (t
);
4784 mark_non_executing_threads (event
.target
, event
.ptid
,
4786 save_waitstatus (t
, &event
.ws
);
4787 t
->stop_requested
= false;
4792 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4794 t
= add_thread (event
.target
, event
.ptid
);
4796 t
->stop_requested
= 0;
4799 t
->control
.may_range_step
= 0;
4801 /* This may be the first time we see the inferior report
4803 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4804 if (inf
->needs_setup
)
4806 switch_to_thread_no_regs (t
);
4810 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4811 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4813 /* We caught the event that we intended to catch, so
4814 there's no event pending. */
4815 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4816 t
->suspend
.waitstatus_pending_p
= 0;
4818 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4820 /* Add it back to the step-over queue. */
4821 infrun_log_debug ("displaced-step of %s "
4822 "canceled: adding back to the "
4823 "step-over queue\n",
4824 target_pid_to_str (t
->ptid
).c_str ());
4826 t
->control
.trap_expected
= 0;
4827 global_thread_step_over_chain_enqueue (t
);
4832 enum gdb_signal sig
;
4833 struct regcache
*regcache
;
4837 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4839 infrun_log_debug ("target_wait %s, saving "
4840 "status for %d.%ld.%ld\n",
4847 /* Record for later. */
4848 save_waitstatus (t
, &event
.ws
);
4850 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4851 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4853 if (displaced_step_finish (t
, sig
) < 0)
4855 /* Add it back to the step-over queue. */
4856 t
->control
.trap_expected
= 0;
4857 global_thread_step_over_chain_enqueue (t
);
4860 regcache
= get_thread_regcache (t
);
4861 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4863 infrun_log_debug ("saved stop_pc=%s for %s "
4864 "(currently_stepping=%d)\n",
4865 paddress (target_gdbarch (),
4866 t
->suspend
.stop_pc
),
4867 target_pid_to_str (t
->ptid
).c_str (),
4868 currently_stepping (t
));
4876 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4879 handle_no_resumed (struct execution_control_state
*ecs
)
4881 if (target_can_async_p ())
4885 for (ui
*ui
: all_uis ())
4887 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4895 /* There were no unwaited-for children left in the target, but,
4896 we're not synchronously waiting for events either. Just
4899 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4900 prepare_to_wait (ecs
);
4905 /* Otherwise, if we were running a synchronous execution command, we
4906 may need to cancel it and give the user back the terminal.
4908 In non-stop mode, the target can't tell whether we've already
4909 consumed previous stop events, so it can end up sending us a
4910 no-resumed event like so:
4912 #0 - thread 1 is left stopped
4914 #1 - thread 2 is resumed and hits breakpoint
4915 -> TARGET_WAITKIND_STOPPED
4917 #2 - thread 3 is resumed and exits
4918 this is the last resumed thread, so
4919 -> TARGET_WAITKIND_NO_RESUMED
4921 #3 - gdb processes stop for thread 2 and decides to re-resume
4924 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4925 thread 2 is now resumed, so the event should be ignored.
4927 IOW, if the stop for thread 2 doesn't end a foreground command,
4928 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4929 event. But it could be that the event meant that thread 2 itself
4930 (or whatever other thread was the last resumed thread) exited.
4932 To address this we refresh the thread list and check whether we
4933 have resumed threads _now_. In the example above, this removes
4934 thread 3 from the thread list. If thread 2 was re-resumed, we
4935 ignore this event. If we find no thread resumed, then we cancel
4936 the synchronous command and show "no unwaited-for " to the
4939 inferior
*curr_inf
= current_inferior ();
4941 scoped_restore_current_thread restore_thread
;
4943 for (auto *target
: all_non_exited_process_targets ())
4945 switch_to_target_no_thread (target
);
4946 update_thread_list ();
4951 - the current target has no thread executing, and
4952 - the current inferior is native, and
4953 - the current inferior is the one which has the terminal, and
4956 then a Ctrl-C from this point on would remain stuck in the
4957 kernel, until a thread resumes and dequeues it. That would
4958 result in the GDB CLI not reacting to Ctrl-C, not able to
4959 interrupt the program. To address this, if the current inferior
4960 no longer has any thread executing, we give the terminal to some
4961 other inferior that has at least one thread executing. */
4962 bool swap_terminal
= true;
4964 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4965 whether to report it to the user. */
4966 bool ignore_event
= false;
4968 for (thread_info
*thread
: all_non_exited_threads ())
4970 if (swap_terminal
&& thread
->executing
)
4972 if (thread
->inf
!= curr_inf
)
4974 target_terminal::ours ();
4976 switch_to_thread (thread
);
4977 target_terminal::inferior ();
4979 swap_terminal
= false;
4983 && (thread
->executing
4984 || thread
->suspend
.waitstatus_pending_p
))
4986 /* Either there were no unwaited-for children left in the
4987 target at some point, but there are now, or some target
4988 other than the eventing one has unwaited-for children
4989 left. Just ignore. */
4990 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
4991 "(ignoring: found resumed)\n");
4993 ignore_event
= true;
4996 if (ignore_event
&& !swap_terminal
)
5002 switch_to_inferior_no_thread (curr_inf
);
5003 prepare_to_wait (ecs
);
5007 /* Go ahead and report the event. */
5011 /* Given an execution control state that has been freshly filled in by
5012 an event from the inferior, figure out what it means and take
5015 The alternatives are:
5017 1) stop_waiting and return; to really stop and return to the
5020 2) keep_going and return; to wait for the next event (set
5021 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5025 handle_inferior_event (struct execution_control_state
*ecs
)
5027 /* Make sure that all temporary struct value objects that were
5028 created during the handling of the event get deleted at the
5030 scoped_value_mark free_values
;
5032 enum stop_kind stop_soon
;
5034 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5036 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5038 /* We had an event in the inferior, but we are not interested in
5039 handling it at this level. The lower layers have already
5040 done what needs to be done, if anything.
5042 One of the possible circumstances for this is when the
5043 inferior produces output for the console. The inferior has
5044 not stopped, and we are ignoring the event. Another possible
5045 circumstance is any event which the lower level knows will be
5046 reported multiple times without an intervening resume. */
5047 prepare_to_wait (ecs
);
5051 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5053 prepare_to_wait (ecs
);
5057 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5058 && handle_no_resumed (ecs
))
5061 /* Cache the last target/ptid/waitstatus. */
5062 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5064 /* Always clear state belonging to the previous time we stopped. */
5065 stop_stack_dummy
= STOP_NONE
;
5067 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5069 /* No unwaited-for children left. IOW, all resumed children
5071 stop_print_frame
= 0;
5076 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5077 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5079 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5080 /* If it's a new thread, add it to the thread database. */
5081 if (ecs
->event_thread
== NULL
)
5082 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5084 /* Disable range stepping. If the next step request could use a
5085 range, this will be end up re-enabled then. */
5086 ecs
->event_thread
->control
.may_range_step
= 0;
5089 /* Dependent on valid ECS->EVENT_THREAD. */
5090 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5092 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5093 reinit_frame_cache ();
5095 breakpoint_retire_moribund ();
5097 /* First, distinguish signals caused by the debugger from signals
5098 that have to do with the program's own actions. Note that
5099 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5100 on the operating system version. Here we detect when a SIGILL or
5101 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5102 something similar for SIGSEGV, since a SIGSEGV will be generated
5103 when we're trying to execute a breakpoint instruction on a
5104 non-executable stack. This happens for call dummy breakpoints
5105 for architectures like SPARC that place call dummies on the
5107 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5108 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5109 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5110 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5112 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5114 if (breakpoint_inserted_here_p (regcache
->aspace (),
5115 regcache_read_pc (regcache
)))
5117 infrun_log_debug ("Treating signal as SIGTRAP");
5118 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5122 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5124 switch (ecs
->ws
.kind
)
5126 case TARGET_WAITKIND_LOADED
:
5127 context_switch (ecs
);
5128 /* Ignore gracefully during startup of the inferior, as it might
5129 be the shell which has just loaded some objects, otherwise
5130 add the symbols for the newly loaded objects. Also ignore at
5131 the beginning of an attach or remote session; we will query
5132 the full list of libraries once the connection is
5135 stop_soon
= get_inferior_stop_soon (ecs
);
5136 if (stop_soon
== NO_STOP_QUIETLY
)
5138 struct regcache
*regcache
;
5140 regcache
= get_thread_regcache (ecs
->event_thread
);
5142 handle_solib_event ();
5144 ecs
->event_thread
->control
.stop_bpstat
5145 = bpstat_stop_status (regcache
->aspace (),
5146 ecs
->event_thread
->suspend
.stop_pc
,
5147 ecs
->event_thread
, &ecs
->ws
);
5149 if (handle_stop_requested (ecs
))
5152 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5154 /* A catchpoint triggered. */
5155 process_event_stop_test (ecs
);
5159 /* If requested, stop when the dynamic linker notifies
5160 gdb of events. This allows the user to get control
5161 and place breakpoints in initializer routines for
5162 dynamically loaded objects (among other things). */
5163 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5164 if (stop_on_solib_events
)
5166 /* Make sure we print "Stopped due to solib-event" in
5168 stop_print_frame
= 1;
5175 /* If we are skipping through a shell, or through shared library
5176 loading that we aren't interested in, resume the program. If
5177 we're running the program normally, also resume. */
5178 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5180 /* Loading of shared libraries might have changed breakpoint
5181 addresses. Make sure new breakpoints are inserted. */
5182 if (stop_soon
== NO_STOP_QUIETLY
)
5183 insert_breakpoints ();
5184 resume (GDB_SIGNAL_0
);
5185 prepare_to_wait (ecs
);
5189 /* But stop if we're attaching or setting up a remote
5191 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5192 || stop_soon
== STOP_QUIETLY_REMOTE
)
5194 infrun_log_debug ("quietly stopped");
5199 internal_error (__FILE__
, __LINE__
,
5200 _("unhandled stop_soon: %d"), (int) stop_soon
);
5202 case TARGET_WAITKIND_SPURIOUS
:
5203 if (handle_stop_requested (ecs
))
5205 context_switch (ecs
);
5206 resume (GDB_SIGNAL_0
);
5207 prepare_to_wait (ecs
);
5210 case TARGET_WAITKIND_THREAD_CREATED
:
5211 if (handle_stop_requested (ecs
))
5213 context_switch (ecs
);
5214 if (!switch_back_to_stepped_thread (ecs
))
5218 case TARGET_WAITKIND_EXITED
:
5219 case TARGET_WAITKIND_SIGNALLED
:
5221 /* Depending on the system, ecs->ptid may point to a thread or
5222 to a process. On some targets, target_mourn_inferior may
5223 need to have access to the just-exited thread. That is the
5224 case of GNU/Linux's "checkpoint" support, for example.
5225 Call the switch_to_xxx routine as appropriate. */
5226 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5228 switch_to_thread (thr
);
5231 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5232 switch_to_inferior_no_thread (inf
);
5235 handle_vfork_child_exec_or_exit (0);
5236 target_terminal::ours (); /* Must do this before mourn anyway. */
5238 /* Clearing any previous state of convenience variables. */
5239 clear_exit_convenience_vars ();
5241 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5243 /* Record the exit code in the convenience variable $_exitcode, so
5244 that the user can inspect this again later. */
5245 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5246 (LONGEST
) ecs
->ws
.value
.integer
);
5248 /* Also record this in the inferior itself. */
5249 current_inferior ()->has_exit_code
= 1;
5250 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5252 /* Support the --return-child-result option. */
5253 return_child_result_value
= ecs
->ws
.value
.integer
;
5255 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5259 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5261 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5263 /* Set the value of the internal variable $_exitsignal,
5264 which holds the signal uncaught by the inferior. */
5265 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5266 gdbarch_gdb_signal_to_target (gdbarch
,
5267 ecs
->ws
.value
.sig
));
5271 /* We don't have access to the target's method used for
5272 converting between signal numbers (GDB's internal
5273 representation <-> target's representation).
5274 Therefore, we cannot do a good job at displaying this
5275 information to the user. It's better to just warn
5276 her about it (if infrun debugging is enabled), and
5278 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5282 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5285 gdb_flush (gdb_stdout
);
5286 target_mourn_inferior (inferior_ptid
);
5287 stop_print_frame
= 0;
5291 case TARGET_WAITKIND_FORKED
:
5292 case TARGET_WAITKIND_VFORKED
:
5293 /* Check whether the inferior is displaced stepping. */
5295 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5296 struct gdbarch
*gdbarch
= regcache
->arch ();
5298 /* If checking displaced stepping is supported, and thread
5299 ecs->ptid is displaced stepping. */
5300 if (displaced_step_in_progress (ecs
->event_thread
))
5302 struct inferior
*parent_inf
5303 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5304 struct regcache
*child_regcache
;
5305 CORE_ADDR parent_pc
;
5307 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5309 // struct displaced_step_inferior_state *displaced
5310 // = get_displaced_stepping_state (parent_inf);
5312 /* Restore scratch pad for child process. */
5313 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5314 // FIXME: we should restore all the buffers that were currently in use
5317 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5318 indicating that the displaced stepping of syscall instruction
5319 has been done. Perform cleanup for parent process here. Note
5320 that this operation also cleans up the child process for vfork,
5321 because their pages are shared. */
5322 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5323 /* Start a new step-over in another thread if there's one
5327 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5328 the child's PC is also within the scratchpad. Set the child's PC
5329 to the parent's PC value, which has already been fixed up.
5330 FIXME: we use the parent's aspace here, although we're touching
5331 the child, because the child hasn't been added to the inferior
5332 list yet at this point. */
5335 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5336 ecs
->ws
.value
.related_pid
,
5338 parent_inf
->aspace
);
5339 /* Read PC value of parent process. */
5340 parent_pc
= regcache_read_pc (regcache
);
5342 if (debug_displaced
)
5343 fprintf_unfiltered (gdb_stdlog
,
5344 "displaced: write child pc from %s to %s\n",
5346 regcache_read_pc (child_regcache
)),
5347 paddress (gdbarch
, parent_pc
));
5349 regcache_write_pc (child_regcache
, parent_pc
);
5353 context_switch (ecs
);
5355 /* Immediately detach breakpoints from the child before there's
5356 any chance of letting the user delete breakpoints from the
5357 breakpoint lists. If we don't do this early, it's easy to
5358 leave left over traps in the child, vis: "break foo; catch
5359 fork; c; <fork>; del; c; <child calls foo>". We only follow
5360 the fork on the last `continue', and by that time the
5361 breakpoint at "foo" is long gone from the breakpoint table.
5362 If we vforked, then we don't need to unpatch here, since both
5363 parent and child are sharing the same memory pages; we'll
5364 need to unpatch at follow/detach time instead to be certain
5365 that new breakpoints added between catchpoint hit time and
5366 vfork follow are detached. */
5367 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5369 /* This won't actually modify the breakpoint list, but will
5370 physically remove the breakpoints from the child. */
5371 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5374 delete_just_stopped_threads_single_step_breakpoints ();
5376 /* In case the event is caught by a catchpoint, remember that
5377 the event is to be followed at the next resume of the thread,
5378 and not immediately. */
5379 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5381 ecs
->event_thread
->suspend
.stop_pc
5382 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5384 ecs
->event_thread
->control
.stop_bpstat
5385 = bpstat_stop_status (get_current_regcache ()->aspace (),
5386 ecs
->event_thread
->suspend
.stop_pc
,
5387 ecs
->event_thread
, &ecs
->ws
);
5389 if (handle_stop_requested (ecs
))
5392 /* If no catchpoint triggered for this, then keep going. Note
5393 that we're interested in knowing the bpstat actually causes a
5394 stop, not just if it may explain the signal. Software
5395 watchpoints, for example, always appear in the bpstat. */
5396 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5399 = (follow_fork_mode_string
== follow_fork_mode_child
);
5401 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5403 process_stratum_target
*targ
5404 = ecs
->event_thread
->inf
->process_target ();
5406 bool should_resume
= follow_fork ();
5408 /* Note that one of these may be an invalid pointer,
5409 depending on detach_fork. */
5410 thread_info
*parent
= ecs
->event_thread
;
5412 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5414 /* At this point, the parent is marked running, and the
5415 child is marked stopped. */
5417 /* If not resuming the parent, mark it stopped. */
5418 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5419 parent
->set_running (false);
5421 /* If resuming the child, mark it running. */
5422 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5423 child
->set_running (true);
5425 /* In non-stop mode, also resume the other branch. */
5426 if (!detach_fork
&& (non_stop
5427 || (sched_multi
&& target_is_non_stop_p ())))
5430 switch_to_thread (parent
);
5432 switch_to_thread (child
);
5434 ecs
->event_thread
= inferior_thread ();
5435 ecs
->ptid
= inferior_ptid
;
5440 switch_to_thread (child
);
5442 switch_to_thread (parent
);
5444 ecs
->event_thread
= inferior_thread ();
5445 ecs
->ptid
= inferior_ptid
;
5453 process_event_stop_test (ecs
);
5456 case TARGET_WAITKIND_VFORK_DONE
:
5457 /* Done with the shared memory region. Re-insert breakpoints in
5458 the parent, and keep going. */
5460 context_switch (ecs
);
5462 current_inferior ()->waiting_for_vfork_done
= 0;
5463 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5465 if (handle_stop_requested (ecs
))
5468 /* This also takes care of reinserting breakpoints in the
5469 previously locked inferior. */
5473 case TARGET_WAITKIND_EXECD
:
5475 /* Note we can't read registers yet (the stop_pc), because we
5476 don't yet know the inferior's post-exec architecture.
5477 'stop_pc' is explicitly read below instead. */
5478 switch_to_thread_no_regs (ecs
->event_thread
);
5480 /* Do whatever is necessary to the parent branch of the vfork. */
5481 handle_vfork_child_exec_or_exit (1);
5483 /* This causes the eventpoints and symbol table to be reset.
5484 Must do this now, before trying to determine whether to
5486 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5488 /* In follow_exec we may have deleted the original thread and
5489 created a new one. Make sure that the event thread is the
5490 execd thread for that case (this is a nop otherwise). */
5491 ecs
->event_thread
= inferior_thread ();
5493 ecs
->event_thread
->suspend
.stop_pc
5494 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5496 ecs
->event_thread
->control
.stop_bpstat
5497 = bpstat_stop_status (get_current_regcache ()->aspace (),
5498 ecs
->event_thread
->suspend
.stop_pc
,
5499 ecs
->event_thread
, &ecs
->ws
);
5501 /* Note that this may be referenced from inside
5502 bpstat_stop_status above, through inferior_has_execd. */
5503 xfree (ecs
->ws
.value
.execd_pathname
);
5504 ecs
->ws
.value
.execd_pathname
= NULL
;
5506 if (handle_stop_requested (ecs
))
5509 /* If no catchpoint triggered for this, then keep going. */
5510 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5512 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5516 process_event_stop_test (ecs
);
5519 /* Be careful not to try to gather much state about a thread
5520 that's in a syscall. It's frequently a losing proposition. */
5521 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5522 /* Getting the current syscall number. */
5523 if (handle_syscall_event (ecs
) == 0)
5524 process_event_stop_test (ecs
);
5527 /* Before examining the threads further, step this thread to
5528 get it entirely out of the syscall. (We get notice of the
5529 event when the thread is just on the verge of exiting a
5530 syscall. Stepping one instruction seems to get it back
5532 case TARGET_WAITKIND_SYSCALL_RETURN
:
5533 if (handle_syscall_event (ecs
) == 0)
5534 process_event_stop_test (ecs
);
5537 case TARGET_WAITKIND_STOPPED
:
5538 handle_signal_stop (ecs
);
5541 case TARGET_WAITKIND_NO_HISTORY
:
5542 /* Reverse execution: target ran out of history info. */
5544 /* Switch to the stopped thread. */
5545 context_switch (ecs
);
5546 infrun_log_debug ("stopped");
5548 delete_just_stopped_threads_single_step_breakpoints ();
5549 ecs
->event_thread
->suspend
.stop_pc
5550 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5552 if (handle_stop_requested (ecs
))
5555 gdb::observers::no_history
.notify ();
5561 /* Restart threads back to what they were trying to do back when we
5562 paused them for an in-line step-over. The EVENT_THREAD thread is
5566 restart_threads (struct thread_info
*event_thread
)
5568 /* In case the instruction just stepped spawned a new thread. */
5569 update_thread_list ();
5571 for (thread_info
*tp
: all_non_exited_threads ())
5573 switch_to_thread_no_regs (tp
);
5575 if (tp
== event_thread
)
5577 infrun_log_debug ("restart threads: [%s] is event thread",
5578 target_pid_to_str (tp
->ptid
).c_str ());
5582 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5584 infrun_log_debug ("restart threads: [%s] not meant to be running",
5585 target_pid_to_str (tp
->ptid
).c_str ());
5591 infrun_log_debug ("restart threads: [%s] resumed",
5592 target_pid_to_str (tp
->ptid
).c_str ());
5593 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5597 if (thread_is_in_step_over_chain (tp
))
5599 infrun_log_debug ("restart threads: [%s] needs step-over",
5600 target_pid_to_str (tp
->ptid
).c_str ());
5601 gdb_assert (!tp
->resumed
);
5606 if (tp
->suspend
.waitstatus_pending_p
)
5608 infrun_log_debug ("restart threads: [%s] has pending status",
5609 target_pid_to_str (tp
->ptid
).c_str ());
5614 gdb_assert (!tp
->stop_requested
);
5616 /* If some thread needs to start a step-over at this point, it
5617 should still be in the step-over queue, and thus skipped
5619 if (thread_still_needs_step_over (tp
))
5621 internal_error (__FILE__
, __LINE__
,
5622 "thread [%s] needs a step-over, but not in "
5623 "step-over queue\n",
5624 target_pid_to_str (tp
->ptid
).c_str ());
5627 if (currently_stepping (tp
))
5629 infrun_log_debug ("restart threads: [%s] was stepping",
5630 target_pid_to_str (tp
->ptid
).c_str ());
5631 keep_going_stepped_thread (tp
);
5635 struct execution_control_state ecss
;
5636 struct execution_control_state
*ecs
= &ecss
;
5638 infrun_log_debug ("restart threads: [%s] continuing",
5639 target_pid_to_str (tp
->ptid
).c_str ());
5640 reset_ecs (ecs
, tp
);
5641 switch_to_thread (tp
);
5642 keep_going_pass_signal (ecs
);
5647 /* Callback for iterate_over_threads. Find a resumed thread that has
5648 a pending waitstatus. */
5651 resumed_thread_with_pending_status (struct thread_info
*tp
,
5655 && tp
->suspend
.waitstatus_pending_p
);
5658 /* Called when we get an event that may finish an in-line or
5659 out-of-line (displaced stepping) step-over started previously.
5660 Return true if the event is processed and we should go back to the
5661 event loop; false if the caller should continue processing the
5665 finish_step_over (struct execution_control_state
*ecs
)
5667 int had_step_over_info
;
5669 displaced_step_finish (ecs
->event_thread
,
5670 ecs
->event_thread
->suspend
.stop_signal
);
5672 had_step_over_info
= step_over_info_valid_p ();
5674 if (had_step_over_info
)
5676 /* If we're stepping over a breakpoint with all threads locked,
5677 then only the thread that was stepped should be reporting
5679 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5681 clear_step_over_info ();
5684 if (!target_is_non_stop_p ())
5687 /* Start a new step-over in another thread if there's one that
5691 /* If we were stepping over a breakpoint before, and haven't started
5692 a new in-line step-over sequence, then restart all other threads
5693 (except the event thread). We can't do this in all-stop, as then
5694 e.g., we wouldn't be able to issue any other remote packet until
5695 these other threads stop. */
5696 if (had_step_over_info
&& !step_over_info_valid_p ())
5698 struct thread_info
*pending
;
5700 /* If we only have threads with pending statuses, the restart
5701 below won't restart any thread and so nothing re-inserts the
5702 breakpoint we just stepped over. But we need it inserted
5703 when we later process the pending events, otherwise if
5704 another thread has a pending event for this breakpoint too,
5705 we'd discard its event (because the breakpoint that
5706 originally caused the event was no longer inserted). */
5707 context_switch (ecs
);
5708 insert_breakpoints ();
5710 restart_threads (ecs
->event_thread
);
5712 /* If we have events pending, go through handle_inferior_event
5713 again, picking up a pending event at random. This avoids
5714 thread starvation. */
5716 /* But not if we just stepped over a watchpoint in order to let
5717 the instruction execute so we can evaluate its expression.
5718 The set of watchpoints that triggered is recorded in the
5719 breakpoint objects themselves (see bp->watchpoint_triggered).
5720 If we processed another event first, that other event could
5721 clobber this info. */
5722 if (ecs
->event_thread
->stepping_over_watchpoint
)
5725 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5727 if (pending
!= NULL
)
5729 struct thread_info
*tp
= ecs
->event_thread
;
5730 struct regcache
*regcache
;
5732 infrun_log_debug ("found resumed threads with "
5733 "pending events, saving status");
5735 gdb_assert (pending
!= tp
);
5737 /* Record the event thread's event for later. */
5738 save_waitstatus (tp
, &ecs
->ws
);
5739 /* This was cleared early, by handle_inferior_event. Set it
5740 so this pending event is considered by
5744 gdb_assert (!tp
->executing
);
5746 regcache
= get_thread_regcache (tp
);
5747 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5749 infrun_log_debug ("saved stop_pc=%s for %s "
5750 "(currently_stepping=%d)\n",
5751 paddress (target_gdbarch (),
5752 tp
->suspend
.stop_pc
),
5753 target_pid_to_str (tp
->ptid
).c_str (),
5754 currently_stepping (tp
));
5756 /* This in-line step-over finished; clear this so we won't
5757 start a new one. This is what handle_signal_stop would
5758 do, if we returned false. */
5759 tp
->stepping_over_breakpoint
= 0;
5761 /* Wake up the event loop again. */
5762 mark_async_event_handler (infrun_async_inferior_event_token
);
5764 prepare_to_wait (ecs
);
5772 /* Come here when the program has stopped with a signal. */
5775 handle_signal_stop (struct execution_control_state
*ecs
)
5777 struct frame_info
*frame
;
5778 struct gdbarch
*gdbarch
;
5779 int stopped_by_watchpoint
;
5780 enum stop_kind stop_soon
;
5783 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5785 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5787 /* Do we need to clean up the state of a thread that has
5788 completed a displaced single-step? (Doing so usually affects
5789 the PC, so do it here, before we set stop_pc.) */
5790 if (finish_step_over (ecs
))
5793 /* If we either finished a single-step or hit a breakpoint, but
5794 the user wanted this thread to be stopped, pretend we got a
5795 SIG0 (generic unsignaled stop). */
5796 if (ecs
->event_thread
->stop_requested
5797 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5798 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5800 ecs
->event_thread
->suspend
.stop_pc
5801 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5805 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5806 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5808 switch_to_thread (ecs
->event_thread
);
5810 infrun_log_debug ("stop_pc=%s",
5811 paddress (reg_gdbarch
,
5812 ecs
->event_thread
->suspend
.stop_pc
));
5813 if (target_stopped_by_watchpoint ())
5817 infrun_log_debug ("stopped by watchpoint");
5819 if (target_stopped_data_address (current_top_target (), &addr
))
5820 infrun_log_debug ("stopped data address=%s",
5821 paddress (reg_gdbarch
, addr
));
5823 infrun_log_debug ("(no data address available)");
5827 /* This is originated from start_remote(), start_inferior() and
5828 shared libraries hook functions. */
5829 stop_soon
= get_inferior_stop_soon (ecs
);
5830 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5832 context_switch (ecs
);
5833 infrun_log_debug ("quietly stopped");
5834 stop_print_frame
= 1;
5839 /* This originates from attach_command(). We need to overwrite
5840 the stop_signal here, because some kernels don't ignore a
5841 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5842 See more comments in inferior.h. On the other hand, if we
5843 get a non-SIGSTOP, report it to the user - assume the backend
5844 will handle the SIGSTOP if it should show up later.
5846 Also consider that the attach is complete when we see a
5847 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5848 target extended-remote report it instead of a SIGSTOP
5849 (e.g. gdbserver). We already rely on SIGTRAP being our
5850 signal, so this is no exception.
5852 Also consider that the attach is complete when we see a
5853 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5854 the target to stop all threads of the inferior, in case the
5855 low level attach operation doesn't stop them implicitly. If
5856 they weren't stopped implicitly, then the stub will report a
5857 GDB_SIGNAL_0, meaning: stopped for no particular reason
5858 other than GDB's request. */
5859 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5860 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5861 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5862 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5864 stop_print_frame
= 1;
5866 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5870 /* See if something interesting happened to the non-current thread. If
5871 so, then switch to that thread. */
5872 if (ecs
->ptid
!= inferior_ptid
)
5874 infrun_log_debug ("context switch");
5876 context_switch (ecs
);
5878 if (deprecated_context_hook
)
5879 deprecated_context_hook (ecs
->event_thread
->global_num
);
5882 /* At this point, get hold of the now-current thread's frame. */
5883 frame
= get_current_frame ();
5884 gdbarch
= get_frame_arch (frame
);
5886 /* Pull the single step breakpoints out of the target. */
5887 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5889 struct regcache
*regcache
;
5892 regcache
= get_thread_regcache (ecs
->event_thread
);
5893 const address_space
*aspace
= regcache
->aspace ();
5895 pc
= regcache_read_pc (regcache
);
5897 /* However, before doing so, if this single-step breakpoint was
5898 actually for another thread, set this thread up for moving
5900 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5903 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5905 infrun_log_debug ("[%s] hit another thread's single-step "
5907 target_pid_to_str (ecs
->ptid
).c_str ());
5908 ecs
->hit_singlestep_breakpoint
= 1;
5913 infrun_log_debug ("[%s] hit its single-step breakpoint",
5914 target_pid_to_str (ecs
->ptid
).c_str ());
5917 delete_just_stopped_threads_single_step_breakpoints ();
5919 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5920 && ecs
->event_thread
->control
.trap_expected
5921 && ecs
->event_thread
->stepping_over_watchpoint
)
5922 stopped_by_watchpoint
= 0;
5924 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5926 /* If necessary, step over this watchpoint. We'll be back to display
5928 if (stopped_by_watchpoint
5929 && (target_have_steppable_watchpoint
5930 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5932 /* At this point, we are stopped at an instruction which has
5933 attempted to write to a piece of memory under control of
5934 a watchpoint. The instruction hasn't actually executed
5935 yet. If we were to evaluate the watchpoint expression
5936 now, we would get the old value, and therefore no change
5937 would seem to have occurred.
5939 In order to make watchpoints work `right', we really need
5940 to complete the memory write, and then evaluate the
5941 watchpoint expression. We do this by single-stepping the
5944 It may not be necessary to disable the watchpoint to step over
5945 it. For example, the PA can (with some kernel cooperation)
5946 single step over a watchpoint without disabling the watchpoint.
5948 It is far more common to need to disable a watchpoint to step
5949 the inferior over it. If we have non-steppable watchpoints,
5950 we must disable the current watchpoint; it's simplest to
5951 disable all watchpoints.
5953 Any breakpoint at PC must also be stepped over -- if there's
5954 one, it will have already triggered before the watchpoint
5955 triggered, and we either already reported it to the user, or
5956 it didn't cause a stop and we called keep_going. In either
5957 case, if there was a breakpoint at PC, we must be trying to
5959 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5964 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5965 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5966 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5967 ecs
->event_thread
->control
.stop_step
= 0;
5968 stop_print_frame
= 1;
5969 stopped_by_random_signal
= 0;
5970 bpstat stop_chain
= NULL
;
5972 /* Hide inlined functions starting here, unless we just performed stepi or
5973 nexti. After stepi and nexti, always show the innermost frame (not any
5974 inline function call sites). */
5975 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5977 const address_space
*aspace
5978 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5980 /* skip_inline_frames is expensive, so we avoid it if we can
5981 determine that the address is one where functions cannot have
5982 been inlined. This improves performance with inferiors that
5983 load a lot of shared libraries, because the solib event
5984 breakpoint is defined as the address of a function (i.e. not
5985 inline). Note that we have to check the previous PC as well
5986 as the current one to catch cases when we have just
5987 single-stepped off a breakpoint prior to reinstating it.
5988 Note that we're assuming that the code we single-step to is
5989 not inline, but that's not definitive: there's nothing
5990 preventing the event breakpoint function from containing
5991 inlined code, and the single-step ending up there. If the
5992 user had set a breakpoint on that inlined code, the missing
5993 skip_inline_frames call would break things. Fortunately
5994 that's an extremely unlikely scenario. */
5995 if (!pc_at_non_inline_function (aspace
,
5996 ecs
->event_thread
->suspend
.stop_pc
,
5998 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5999 && ecs
->event_thread
->control
.trap_expected
6000 && pc_at_non_inline_function (aspace
,
6001 ecs
->event_thread
->prev_pc
,
6004 stop_chain
= build_bpstat_chain (aspace
,
6005 ecs
->event_thread
->suspend
.stop_pc
,
6007 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6009 /* Re-fetch current thread's frame in case that invalidated
6011 frame
= get_current_frame ();
6012 gdbarch
= get_frame_arch (frame
);
6016 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6017 && ecs
->event_thread
->control
.trap_expected
6018 && gdbarch_single_step_through_delay_p (gdbarch
)
6019 && currently_stepping (ecs
->event_thread
))
6021 /* We're trying to step off a breakpoint. Turns out that we're
6022 also on an instruction that needs to be stepped multiple
6023 times before it's been fully executing. E.g., architectures
6024 with a delay slot. It needs to be stepped twice, once for
6025 the instruction and once for the delay slot. */
6026 int step_through_delay
6027 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6029 if (step_through_delay
)
6030 infrun_log_debug ("step through delay");
6032 if (ecs
->event_thread
->control
.step_range_end
== 0
6033 && step_through_delay
)
6035 /* The user issued a continue when stopped at a breakpoint.
6036 Set up for another trap and get out of here. */
6037 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6041 else if (step_through_delay
)
6043 /* The user issued a step when stopped at a breakpoint.
6044 Maybe we should stop, maybe we should not - the delay
6045 slot *might* correspond to a line of source. In any
6046 case, don't decide that here, just set
6047 ecs->stepping_over_breakpoint, making sure we
6048 single-step again before breakpoints are re-inserted. */
6049 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6053 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6054 handles this event. */
6055 ecs
->event_thread
->control
.stop_bpstat
6056 = bpstat_stop_status (get_current_regcache ()->aspace (),
6057 ecs
->event_thread
->suspend
.stop_pc
,
6058 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6060 /* Following in case break condition called a
6062 stop_print_frame
= 1;
6064 /* This is where we handle "moribund" watchpoints. Unlike
6065 software breakpoints traps, hardware watchpoint traps are
6066 always distinguishable from random traps. If no high-level
6067 watchpoint is associated with the reported stop data address
6068 anymore, then the bpstat does not explain the signal ---
6069 simply make sure to ignore it if `stopped_by_watchpoint' is
6072 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6073 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6075 && stopped_by_watchpoint
)
6077 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6081 /* NOTE: cagney/2003-03-29: These checks for a random signal
6082 at one stage in the past included checks for an inferior
6083 function call's call dummy's return breakpoint. The original
6084 comment, that went with the test, read:
6086 ``End of a stack dummy. Some systems (e.g. Sony news) give
6087 another signal besides SIGTRAP, so check here as well as
6090 If someone ever tries to get call dummys on a
6091 non-executable stack to work (where the target would stop
6092 with something like a SIGSEGV), then those tests might need
6093 to be re-instated. Given, however, that the tests were only
6094 enabled when momentary breakpoints were not being used, I
6095 suspect that it won't be the case.
6097 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6098 be necessary for call dummies on a non-executable stack on
6101 /* See if the breakpoints module can explain the signal. */
6103 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6104 ecs
->event_thread
->suspend
.stop_signal
);
6106 /* Maybe this was a trap for a software breakpoint that has since
6108 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6110 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6111 ecs
->event_thread
->suspend
.stop_pc
))
6113 struct regcache
*regcache
;
6116 /* Re-adjust PC to what the program would see if GDB was not
6118 regcache
= get_thread_regcache (ecs
->event_thread
);
6119 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6122 gdb::optional
<scoped_restore_tmpl
<int>>
6123 restore_operation_disable
;
6125 if (record_full_is_used ())
6126 restore_operation_disable
.emplace
6127 (record_full_gdb_operation_disable_set ());
6129 regcache_write_pc (regcache
,
6130 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6135 /* A delayed software breakpoint event. Ignore the trap. */
6136 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6141 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6142 has since been removed. */
6143 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6145 /* A delayed hardware breakpoint event. Ignore the trap. */
6146 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6151 /* If not, perhaps stepping/nexting can. */
6153 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6154 && currently_stepping (ecs
->event_thread
));
6156 /* Perhaps the thread hit a single-step breakpoint of _another_
6157 thread. Single-step breakpoints are transparent to the
6158 breakpoints module. */
6160 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6162 /* No? Perhaps we got a moribund watchpoint. */
6164 random_signal
= !stopped_by_watchpoint
;
6166 /* Always stop if the user explicitly requested this thread to
6168 if (ecs
->event_thread
->stop_requested
)
6171 infrun_log_debug ("user-requested stop");
6174 /* For the program's own signals, act according to
6175 the signal handling tables. */
6179 /* Signal not for debugging purposes. */
6180 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6181 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6183 infrun_log_debug ("random signal (%s)",
6184 gdb_signal_to_symbol_string (stop_signal
));
6186 stopped_by_random_signal
= 1;
6188 /* Always stop on signals if we're either just gaining control
6189 of the program, or the user explicitly requested this thread
6190 to remain stopped. */
6191 if (stop_soon
!= NO_STOP_QUIETLY
6192 || ecs
->event_thread
->stop_requested
6194 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6200 /* Notify observers the signal has "handle print" set. Note we
6201 returned early above if stopping; normal_stop handles the
6202 printing in that case. */
6203 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6205 /* The signal table tells us to print about this signal. */
6206 target_terminal::ours_for_output ();
6207 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6208 target_terminal::inferior ();
6211 /* Clear the signal if it should not be passed. */
6212 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6213 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6215 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6216 && ecs
->event_thread
->control
.trap_expected
6217 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6219 /* We were just starting a new sequence, attempting to
6220 single-step off of a breakpoint and expecting a SIGTRAP.
6221 Instead this signal arrives. This signal will take us out
6222 of the stepping range so GDB needs to remember to, when
6223 the signal handler returns, resume stepping off that
6225 /* To simplify things, "continue" is forced to use the same
6226 code paths as single-step - set a breakpoint at the
6227 signal return address and then, once hit, step off that
6229 infrun_log_debug ("signal arrived while stepping over breakpoint");
6231 insert_hp_step_resume_breakpoint_at_frame (frame
);
6232 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6233 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6234 ecs
->event_thread
->control
.trap_expected
= 0;
6236 /* If we were nexting/stepping some other thread, switch to
6237 it, so that we don't continue it, losing control. */
6238 if (!switch_back_to_stepped_thread (ecs
))
6243 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6244 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6246 || ecs
->event_thread
->control
.step_range_end
== 1)
6247 && frame_id_eq (get_stack_frame_id (frame
),
6248 ecs
->event_thread
->control
.step_stack_frame_id
)
6249 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6251 /* The inferior is about to take a signal that will take it
6252 out of the single step range. Set a breakpoint at the
6253 current PC (which is presumably where the signal handler
6254 will eventually return) and then allow the inferior to
6257 Note that this is only needed for a signal delivered
6258 while in the single-step range. Nested signals aren't a
6259 problem as they eventually all return. */
6260 infrun_log_debug ("signal may take us out of single-step range");
6262 clear_step_over_info ();
6263 insert_hp_step_resume_breakpoint_at_frame (frame
);
6264 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6265 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6266 ecs
->event_thread
->control
.trap_expected
= 0;
6271 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6272 when either there's a nested signal, or when there's a
6273 pending signal enabled just as the signal handler returns
6274 (leaving the inferior at the step-resume-breakpoint without
6275 actually executing it). Either way continue until the
6276 breakpoint is really hit. */
6278 if (!switch_back_to_stepped_thread (ecs
))
6280 infrun_log_debug ("random signal, keep going");
6287 process_event_stop_test (ecs
);
6290 /* Come here when we've got some debug event / signal we can explain
6291 (IOW, not a random signal), and test whether it should cause a
6292 stop, or whether we should resume the inferior (transparently).
6293 E.g., could be a breakpoint whose condition evaluates false; we
6294 could be still stepping within the line; etc. */
6297 process_event_stop_test (struct execution_control_state
*ecs
)
6299 struct symtab_and_line stop_pc_sal
;
6300 struct frame_info
*frame
;
6301 struct gdbarch
*gdbarch
;
6302 CORE_ADDR jmp_buf_pc
;
6303 struct bpstat_what what
;
6305 /* Handle cases caused by hitting a breakpoint. */
6307 frame
= get_current_frame ();
6308 gdbarch
= get_frame_arch (frame
);
6310 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6312 if (what
.call_dummy
)
6314 stop_stack_dummy
= what
.call_dummy
;
6317 /* A few breakpoint types have callbacks associated (e.g.,
6318 bp_jit_event). Run them now. */
6319 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6321 /* If we hit an internal event that triggers symbol changes, the
6322 current frame will be invalidated within bpstat_what (e.g., if we
6323 hit an internal solib event). Re-fetch it. */
6324 frame
= get_current_frame ();
6325 gdbarch
= get_frame_arch (frame
);
6327 switch (what
.main_action
)
6329 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6330 /* If we hit the breakpoint at longjmp while stepping, we
6331 install a momentary breakpoint at the target of the
6334 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6336 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6338 if (what
.is_longjmp
)
6340 struct value
*arg_value
;
6342 /* If we set the longjmp breakpoint via a SystemTap probe,
6343 then use it to extract the arguments. The destination PC
6344 is the third argument to the probe. */
6345 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6348 jmp_buf_pc
= value_as_address (arg_value
);
6349 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6351 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6352 || !gdbarch_get_longjmp_target (gdbarch
,
6353 frame
, &jmp_buf_pc
))
6355 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6356 "(!gdbarch_get_longjmp_target)");
6361 /* Insert a breakpoint at resume address. */
6362 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6365 check_exception_resume (ecs
, frame
);
6369 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6371 struct frame_info
*init_frame
;
6373 /* There are several cases to consider.
6375 1. The initiating frame no longer exists. In this case we
6376 must stop, because the exception or longjmp has gone too
6379 2. The initiating frame exists, and is the same as the
6380 current frame. We stop, because the exception or longjmp
6383 3. The initiating frame exists and is different from the
6384 current frame. This means the exception or longjmp has
6385 been caught beneath the initiating frame, so keep going.
6387 4. longjmp breakpoint has been placed just to protect
6388 against stale dummy frames and user is not interested in
6389 stopping around longjmps. */
6391 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6393 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6395 delete_exception_resume_breakpoint (ecs
->event_thread
);
6397 if (what
.is_longjmp
)
6399 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6401 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6409 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6413 struct frame_id current_id
6414 = get_frame_id (get_current_frame ());
6415 if (frame_id_eq (current_id
,
6416 ecs
->event_thread
->initiating_frame
))
6418 /* Case 2. Fall through. */
6428 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6430 delete_step_resume_breakpoint (ecs
->event_thread
);
6432 end_stepping_range (ecs
);
6436 case BPSTAT_WHAT_SINGLE
:
6437 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6438 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6439 /* Still need to check other stuff, at least the case where we
6440 are stepping and step out of the right range. */
6443 case BPSTAT_WHAT_STEP_RESUME
:
6444 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6446 delete_step_resume_breakpoint (ecs
->event_thread
);
6447 if (ecs
->event_thread
->control
.proceed_to_finish
6448 && execution_direction
== EXEC_REVERSE
)
6450 struct thread_info
*tp
= ecs
->event_thread
;
6452 /* We are finishing a function in reverse, and just hit the
6453 step-resume breakpoint at the start address of the
6454 function, and we're almost there -- just need to back up
6455 by one more single-step, which should take us back to the
6457 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6461 fill_in_stop_func (gdbarch
, ecs
);
6462 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6463 && execution_direction
== EXEC_REVERSE
)
6465 /* We are stepping over a function call in reverse, and just
6466 hit the step-resume breakpoint at the start address of
6467 the function. Go back to single-stepping, which should
6468 take us back to the function call. */
6469 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6475 case BPSTAT_WHAT_STOP_NOISY
:
6476 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6477 stop_print_frame
= 1;
6479 /* Assume the thread stopped for a breapoint. We'll still check
6480 whether a/the breakpoint is there when the thread is next
6482 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6487 case BPSTAT_WHAT_STOP_SILENT
:
6488 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6489 stop_print_frame
= 0;
6491 /* Assume the thread stopped for a breapoint. We'll still check
6492 whether a/the breakpoint is there when the thread is next
6494 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6498 case BPSTAT_WHAT_HP_STEP_RESUME
:
6499 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6501 delete_step_resume_breakpoint (ecs
->event_thread
);
6502 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6504 /* Back when the step-resume breakpoint was inserted, we
6505 were trying to single-step off a breakpoint. Go back to
6507 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6508 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6514 case BPSTAT_WHAT_KEEP_CHECKING
:
6518 /* If we stepped a permanent breakpoint and we had a high priority
6519 step-resume breakpoint for the address we stepped, but we didn't
6520 hit it, then we must have stepped into the signal handler. The
6521 step-resume was only necessary to catch the case of _not_
6522 stepping into the handler, so delete it, and fall through to
6523 checking whether the step finished. */
6524 if (ecs
->event_thread
->stepped_breakpoint
)
6526 struct breakpoint
*sr_bp
6527 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6530 && sr_bp
->loc
->permanent
6531 && sr_bp
->type
== bp_hp_step_resume
6532 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6534 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6535 delete_step_resume_breakpoint (ecs
->event_thread
);
6536 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6540 /* We come here if we hit a breakpoint but should not stop for it.
6541 Possibly we also were stepping and should stop for that. So fall
6542 through and test for stepping. But, if not stepping, do not
6545 /* In all-stop mode, if we're currently stepping but have stopped in
6546 some other thread, we need to switch back to the stepped thread. */
6547 if (switch_back_to_stepped_thread (ecs
))
6550 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6552 infrun_log_debug ("step-resume breakpoint is inserted");
6554 /* Having a step-resume breakpoint overrides anything
6555 else having to do with stepping commands until
6556 that breakpoint is reached. */
6561 if (ecs
->event_thread
->control
.step_range_end
== 0)
6563 infrun_log_debug ("no stepping, continue");
6564 /* Likewise if we aren't even stepping. */
6569 /* Re-fetch current thread's frame in case the code above caused
6570 the frame cache to be re-initialized, making our FRAME variable
6571 a dangling pointer. */
6572 frame
= get_current_frame ();
6573 gdbarch
= get_frame_arch (frame
);
6574 fill_in_stop_func (gdbarch
, ecs
);
6576 /* If stepping through a line, keep going if still within it.
6578 Note that step_range_end is the address of the first instruction
6579 beyond the step range, and NOT the address of the last instruction
6582 Note also that during reverse execution, we may be stepping
6583 through a function epilogue and therefore must detect when
6584 the current-frame changes in the middle of a line. */
6586 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6588 && (execution_direction
!= EXEC_REVERSE
6589 || frame_id_eq (get_frame_id (frame
),
6590 ecs
->event_thread
->control
.step_frame_id
)))
6593 ("stepping inside range [%s-%s]",
6594 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6595 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6597 /* Tentatively re-enable range stepping; `resume' disables it if
6598 necessary (e.g., if we're stepping over a breakpoint or we
6599 have software watchpoints). */
6600 ecs
->event_thread
->control
.may_range_step
= 1;
6602 /* When stepping backward, stop at beginning of line range
6603 (unless it's the function entry point, in which case
6604 keep going back to the call point). */
6605 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6606 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6607 && stop_pc
!= ecs
->stop_func_start
6608 && execution_direction
== EXEC_REVERSE
)
6609 end_stepping_range (ecs
);
6616 /* We stepped out of the stepping range. */
6618 /* If we are stepping at the source level and entered the runtime
6619 loader dynamic symbol resolution code...
6621 EXEC_FORWARD: we keep on single stepping until we exit the run
6622 time loader code and reach the callee's address.
6624 EXEC_REVERSE: we've already executed the callee (backward), and
6625 the runtime loader code is handled just like any other
6626 undebuggable function call. Now we need only keep stepping
6627 backward through the trampoline code, and that's handled further
6628 down, so there is nothing for us to do here. */
6630 if (execution_direction
!= EXEC_REVERSE
6631 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6632 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6634 CORE_ADDR pc_after_resolver
=
6635 gdbarch_skip_solib_resolver (gdbarch
,
6636 ecs
->event_thread
->suspend
.stop_pc
);
6638 infrun_log_debug ("stepped into dynsym resolve code");
6640 if (pc_after_resolver
)
6642 /* Set up a step-resume breakpoint at the address
6643 indicated by SKIP_SOLIB_RESOLVER. */
6644 symtab_and_line sr_sal
;
6645 sr_sal
.pc
= pc_after_resolver
;
6646 sr_sal
.pspace
= get_frame_program_space (frame
);
6648 insert_step_resume_breakpoint_at_sal (gdbarch
,
6649 sr_sal
, null_frame_id
);
6656 /* Step through an indirect branch thunk. */
6657 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6658 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6659 ecs
->event_thread
->suspend
.stop_pc
))
6661 infrun_log_debug ("stepped into indirect branch thunk");
6666 if (ecs
->event_thread
->control
.step_range_end
!= 1
6667 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6668 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6669 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6671 infrun_log_debug ("stepped into signal trampoline");
6672 /* The inferior, while doing a "step" or "next", has ended up in
6673 a signal trampoline (either by a signal being delivered or by
6674 the signal handler returning). Just single-step until the
6675 inferior leaves the trampoline (either by calling the handler
6681 /* If we're in the return path from a shared library trampoline,
6682 we want to proceed through the trampoline when stepping. */
6683 /* macro/2012-04-25: This needs to come before the subroutine
6684 call check below as on some targets return trampolines look
6685 like subroutine calls (MIPS16 return thunks). */
6686 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6687 ecs
->event_thread
->suspend
.stop_pc
,
6688 ecs
->stop_func_name
)
6689 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6691 /* Determine where this trampoline returns. */
6692 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6693 CORE_ADDR real_stop_pc
6694 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6696 infrun_log_debug ("stepped into solib return tramp");
6698 /* Only proceed through if we know where it's going. */
6701 /* And put the step-breakpoint there and go until there. */
6702 symtab_and_line sr_sal
;
6703 sr_sal
.pc
= real_stop_pc
;
6704 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6705 sr_sal
.pspace
= get_frame_program_space (frame
);
6707 /* Do not specify what the fp should be when we stop since
6708 on some machines the prologue is where the new fp value
6710 insert_step_resume_breakpoint_at_sal (gdbarch
,
6711 sr_sal
, null_frame_id
);
6713 /* Restart without fiddling with the step ranges or
6720 /* Check for subroutine calls. The check for the current frame
6721 equalling the step ID is not necessary - the check of the
6722 previous frame's ID is sufficient - but it is a common case and
6723 cheaper than checking the previous frame's ID.
6725 NOTE: frame_id_eq will never report two invalid frame IDs as
6726 being equal, so to get into this block, both the current and
6727 previous frame must have valid frame IDs. */
6728 /* The outer_frame_id check is a heuristic to detect stepping
6729 through startup code. If we step over an instruction which
6730 sets the stack pointer from an invalid value to a valid value,
6731 we may detect that as a subroutine call from the mythical
6732 "outermost" function. This could be fixed by marking
6733 outermost frames as !stack_p,code_p,special_p. Then the
6734 initial outermost frame, before sp was valid, would
6735 have code_addr == &_start. See the comment in frame_id_eq
6737 if (!frame_id_eq (get_stack_frame_id (frame
),
6738 ecs
->event_thread
->control
.step_stack_frame_id
)
6739 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6740 ecs
->event_thread
->control
.step_stack_frame_id
)
6741 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6743 || (ecs
->event_thread
->control
.step_start_function
6744 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6746 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6747 CORE_ADDR real_stop_pc
;
6749 infrun_log_debug ("stepped into subroutine");
6751 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6753 /* I presume that step_over_calls is only 0 when we're
6754 supposed to be stepping at the assembly language level
6755 ("stepi"). Just stop. */
6756 /* And this works the same backward as frontward. MVS */
6757 end_stepping_range (ecs
);
6761 /* Reverse stepping through solib trampolines. */
6763 if (execution_direction
== EXEC_REVERSE
6764 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6765 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6766 || (ecs
->stop_func_start
== 0
6767 && in_solib_dynsym_resolve_code (stop_pc
))))
6769 /* Any solib trampoline code can be handled in reverse
6770 by simply continuing to single-step. We have already
6771 executed the solib function (backwards), and a few
6772 steps will take us back through the trampoline to the
6778 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6780 /* We're doing a "next".
6782 Normal (forward) execution: set a breakpoint at the
6783 callee's return address (the address at which the caller
6786 Reverse (backward) execution. set the step-resume
6787 breakpoint at the start of the function that we just
6788 stepped into (backwards), and continue to there. When we
6789 get there, we'll need to single-step back to the caller. */
6791 if (execution_direction
== EXEC_REVERSE
)
6793 /* If we're already at the start of the function, we've either
6794 just stepped backward into a single instruction function,
6795 or stepped back out of a signal handler to the first instruction
6796 of the function. Just keep going, which will single-step back
6798 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6800 /* Normal function call return (static or dynamic). */
6801 symtab_and_line sr_sal
;
6802 sr_sal
.pc
= ecs
->stop_func_start
;
6803 sr_sal
.pspace
= get_frame_program_space (frame
);
6804 insert_step_resume_breakpoint_at_sal (gdbarch
,
6805 sr_sal
, null_frame_id
);
6809 insert_step_resume_breakpoint_at_caller (frame
);
6815 /* If we are in a function call trampoline (a stub between the
6816 calling routine and the real function), locate the real
6817 function. That's what tells us (a) whether we want to step
6818 into it at all, and (b) what prologue we want to run to the
6819 end of, if we do step into it. */
6820 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6821 if (real_stop_pc
== 0)
6822 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6823 if (real_stop_pc
!= 0)
6824 ecs
->stop_func_start
= real_stop_pc
;
6826 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6828 symtab_and_line sr_sal
;
6829 sr_sal
.pc
= ecs
->stop_func_start
;
6830 sr_sal
.pspace
= get_frame_program_space (frame
);
6832 insert_step_resume_breakpoint_at_sal (gdbarch
,
6833 sr_sal
, null_frame_id
);
6838 /* If we have line number information for the function we are
6839 thinking of stepping into and the function isn't on the skip
6842 If there are several symtabs at that PC (e.g. with include
6843 files), just want to know whether *any* of them have line
6844 numbers. find_pc_line handles this. */
6846 struct symtab_and_line tmp_sal
;
6848 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6849 if (tmp_sal
.line
!= 0
6850 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6852 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6854 if (execution_direction
== EXEC_REVERSE
)
6855 handle_step_into_function_backward (gdbarch
, ecs
);
6857 handle_step_into_function (gdbarch
, ecs
);
6862 /* If we have no line number and the step-stop-if-no-debug is
6863 set, we stop the step so that the user has a chance to switch
6864 in assembly mode. */
6865 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6866 && step_stop_if_no_debug
)
6868 end_stepping_range (ecs
);
6872 if (execution_direction
== EXEC_REVERSE
)
6874 /* If we're already at the start of the function, we've either just
6875 stepped backward into a single instruction function without line
6876 number info, or stepped back out of a signal handler to the first
6877 instruction of the function without line number info. Just keep
6878 going, which will single-step back to the caller. */
6879 if (ecs
->stop_func_start
!= stop_pc
)
6881 /* Set a breakpoint at callee's start address.
6882 From there we can step once and be back in the caller. */
6883 symtab_and_line sr_sal
;
6884 sr_sal
.pc
= ecs
->stop_func_start
;
6885 sr_sal
.pspace
= get_frame_program_space (frame
);
6886 insert_step_resume_breakpoint_at_sal (gdbarch
,
6887 sr_sal
, null_frame_id
);
6891 /* Set a breakpoint at callee's return address (the address
6892 at which the caller will resume). */
6893 insert_step_resume_breakpoint_at_caller (frame
);
6899 /* Reverse stepping through solib trampolines. */
6901 if (execution_direction
== EXEC_REVERSE
6902 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6904 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6906 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6907 || (ecs
->stop_func_start
== 0
6908 && in_solib_dynsym_resolve_code (stop_pc
)))
6910 /* Any solib trampoline code can be handled in reverse
6911 by simply continuing to single-step. We have already
6912 executed the solib function (backwards), and a few
6913 steps will take us back through the trampoline to the
6918 else if (in_solib_dynsym_resolve_code (stop_pc
))
6920 /* Stepped backward into the solib dynsym resolver.
6921 Set a breakpoint at its start and continue, then
6922 one more step will take us out. */
6923 symtab_and_line sr_sal
;
6924 sr_sal
.pc
= ecs
->stop_func_start
;
6925 sr_sal
.pspace
= get_frame_program_space (frame
);
6926 insert_step_resume_breakpoint_at_sal (gdbarch
,
6927 sr_sal
, null_frame_id
);
6933 /* This always returns the sal for the inner-most frame when we are in a
6934 stack of inlined frames, even if GDB actually believes that it is in a
6935 more outer frame. This is checked for below by calls to
6936 inline_skipped_frames. */
6937 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6939 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6940 the trampoline processing logic, however, there are some trampolines
6941 that have no names, so we should do trampoline handling first. */
6942 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6943 && ecs
->stop_func_name
== NULL
6944 && stop_pc_sal
.line
== 0)
6946 infrun_log_debug ("stepped into undebuggable function");
6948 /* The inferior just stepped into, or returned to, an
6949 undebuggable function (where there is no debugging information
6950 and no line number corresponding to the address where the
6951 inferior stopped). Since we want to skip this kind of code,
6952 we keep going until the inferior returns from this
6953 function - unless the user has asked us not to (via
6954 set step-mode) or we no longer know how to get back
6955 to the call site. */
6956 if (step_stop_if_no_debug
6957 || !frame_id_p (frame_unwind_caller_id (frame
)))
6959 /* If we have no line number and the step-stop-if-no-debug
6960 is set, we stop the step so that the user has a chance to
6961 switch in assembly mode. */
6962 end_stepping_range (ecs
);
6967 /* Set a breakpoint at callee's return address (the address
6968 at which the caller will resume). */
6969 insert_step_resume_breakpoint_at_caller (frame
);
6975 if (ecs
->event_thread
->control
.step_range_end
== 1)
6977 /* It is stepi or nexti. We always want to stop stepping after
6979 infrun_log_debug ("stepi/nexti");
6980 end_stepping_range (ecs
);
6984 if (stop_pc_sal
.line
== 0)
6986 /* We have no line number information. That means to stop
6987 stepping (does this always happen right after one instruction,
6988 when we do "s" in a function with no line numbers,
6989 or can this happen as a result of a return or longjmp?). */
6990 infrun_log_debug ("line number info");
6991 end_stepping_range (ecs
);
6995 /* Look for "calls" to inlined functions, part one. If the inline
6996 frame machinery detected some skipped call sites, we have entered
6997 a new inline function. */
6999 if (frame_id_eq (get_frame_id (get_current_frame ()),
7000 ecs
->event_thread
->control
.step_frame_id
)
7001 && inline_skipped_frames (ecs
->event_thread
))
7003 infrun_log_debug ("stepped into inlined function");
7005 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7007 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7009 /* For "step", we're going to stop. But if the call site
7010 for this inlined function is on the same source line as
7011 we were previously stepping, go down into the function
7012 first. Otherwise stop at the call site. */
7014 if (call_sal
.line
== ecs
->event_thread
->current_line
7015 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7017 step_into_inline_frame (ecs
->event_thread
);
7018 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7025 end_stepping_range (ecs
);
7030 /* For "next", we should stop at the call site if it is on a
7031 different source line. Otherwise continue through the
7032 inlined function. */
7033 if (call_sal
.line
== ecs
->event_thread
->current_line
7034 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7037 end_stepping_range (ecs
);
7042 /* Look for "calls" to inlined functions, part two. If we are still
7043 in the same real function we were stepping through, but we have
7044 to go further up to find the exact frame ID, we are stepping
7045 through a more inlined call beyond its call site. */
7047 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7048 && !frame_id_eq (get_frame_id (get_current_frame ()),
7049 ecs
->event_thread
->control
.step_frame_id
)
7050 && stepped_in_from (get_current_frame (),
7051 ecs
->event_thread
->control
.step_frame_id
))
7053 infrun_log_debug ("stepping through inlined function");
7055 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7056 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7059 end_stepping_range (ecs
);
7063 bool refresh_step_info
= true;
7064 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7065 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7066 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7068 if (stop_pc_sal
.is_stmt
)
7070 /* We are at the start of a different line. So stop. Note that
7071 we don't stop if we step into the middle of a different line.
7072 That is said to make things like for (;;) statements work
7074 infrun_log_debug ("infrun: stepped to a different line\n");
7075 end_stepping_range (ecs
);
7078 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7079 ecs
->event_thread
->control
.step_frame_id
))
7081 /* We are at the start of a different line, however, this line is
7082 not marked as a statement, and we have not changed frame. We
7083 ignore this line table entry, and continue stepping forward,
7084 looking for a better place to stop. */
7085 refresh_step_info
= false;
7086 infrun_log_debug ("infrun: stepped to a different line, but "
7087 "it's not the start of a statement\n");
7091 /* We aren't done stepping.
7093 Optimize by setting the stepping range to the line.
7094 (We might not be in the original line, but if we entered a
7095 new line in mid-statement, we continue stepping. This makes
7096 things like for(;;) statements work better.)
7098 If we entered a SAL that indicates a non-statement line table entry,
7099 then we update the stepping range, but we don't update the step info,
7100 which includes things like the line number we are stepping away from.
7101 This means we will stop when we find a line table entry that is marked
7102 as is-statement, even if it matches the non-statement one we just
7105 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7106 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7107 ecs
->event_thread
->control
.may_range_step
= 1;
7108 if (refresh_step_info
)
7109 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7111 infrun_log_debug ("keep going");
7115 /* In all-stop mode, if we're currently stepping but have stopped in
7116 some other thread, we may need to switch back to the stepped
7117 thread. Returns true we set the inferior running, false if we left
7118 it stopped (and the event needs further processing). */
7121 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7123 if (!target_is_non_stop_p ())
7125 struct thread_info
*stepping_thread
;
7127 /* If any thread is blocked on some internal breakpoint, and we
7128 simply need to step over that breakpoint to get it going
7129 again, do that first. */
7131 /* However, if we see an event for the stepping thread, then we
7132 know all other threads have been moved past their breakpoints
7133 already. Let the caller check whether the step is finished,
7134 etc., before deciding to move it past a breakpoint. */
7135 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7138 /* Check if the current thread is blocked on an incomplete
7139 step-over, interrupted by a random signal. */
7140 if (ecs
->event_thread
->control
.trap_expected
7141 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7143 infrun_log_debug ("need to finish step-over of [%s]",
7144 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7149 /* Check if the current thread is blocked by a single-step
7150 breakpoint of another thread. */
7151 if (ecs
->hit_singlestep_breakpoint
)
7153 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7154 target_pid_to_str (ecs
->ptid
).c_str ());
7159 /* If this thread needs yet another step-over (e.g., stepping
7160 through a delay slot), do it first before moving on to
7162 if (thread_still_needs_step_over (ecs
->event_thread
))
7165 ("thread [%s] still needs step-over",
7166 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7171 /* If scheduler locking applies even if not stepping, there's no
7172 need to walk over threads. Above we've checked whether the
7173 current thread is stepping. If some other thread not the
7174 event thread is stepping, then it must be that scheduler
7175 locking is not in effect. */
7176 if (schedlock_applies (ecs
->event_thread
))
7179 /* Otherwise, we no longer expect a trap in the current thread.
7180 Clear the trap_expected flag before switching back -- this is
7181 what keep_going does as well, if we call it. */
7182 ecs
->event_thread
->control
.trap_expected
= 0;
7184 /* Likewise, clear the signal if it should not be passed. */
7185 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7186 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7188 /* Do all pending step-overs before actually proceeding with
7190 if (start_step_over ())
7192 prepare_to_wait (ecs
);
7196 /* Look for the stepping/nexting thread. */
7197 stepping_thread
= NULL
;
7199 for (thread_info
*tp
: all_non_exited_threads ())
7201 switch_to_thread_no_regs (tp
);
7203 /* Ignore threads of processes the caller is not
7206 && (tp
->inf
->process_target () != ecs
->target
7207 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7210 /* When stepping over a breakpoint, we lock all threads
7211 except the one that needs to move past the breakpoint.
7212 If a non-event thread has this set, the "incomplete
7213 step-over" check above should have caught it earlier. */
7214 if (tp
->control
.trap_expected
)
7216 internal_error (__FILE__
, __LINE__
,
7217 "[%s] has inconsistent state: "
7218 "trap_expected=%d\n",
7219 target_pid_to_str (tp
->ptid
).c_str (),
7220 tp
->control
.trap_expected
);
7223 /* Did we find the stepping thread? */
7224 if (tp
->control
.step_range_end
)
7226 /* Yep. There should only one though. */
7227 gdb_assert (stepping_thread
== NULL
);
7229 /* The event thread is handled at the top, before we
7231 gdb_assert (tp
!= ecs
->event_thread
);
7233 /* If some thread other than the event thread is
7234 stepping, then scheduler locking can't be in effect,
7235 otherwise we wouldn't have resumed the current event
7236 thread in the first place. */
7237 gdb_assert (!schedlock_applies (tp
));
7239 stepping_thread
= tp
;
7243 if (stepping_thread
!= NULL
)
7245 infrun_log_debug ("switching back to stepped thread");
7247 if (keep_going_stepped_thread (stepping_thread
))
7249 prepare_to_wait (ecs
);
7254 switch_to_thread (ecs
->event_thread
);
7260 /* Set a previously stepped thread back to stepping. Returns true on
7261 success, false if the resume is not possible (e.g., the thread
7265 keep_going_stepped_thread (struct thread_info
*tp
)
7267 struct frame_info
*frame
;
7268 struct execution_control_state ecss
;
7269 struct execution_control_state
*ecs
= &ecss
;
7271 /* If the stepping thread exited, then don't try to switch back and
7272 resume it, which could fail in several different ways depending
7273 on the target. Instead, just keep going.
7275 We can find a stepping dead thread in the thread list in two
7278 - The target supports thread exit events, and when the target
7279 tries to delete the thread from the thread list, inferior_ptid
7280 pointed at the exiting thread. In such case, calling
7281 delete_thread does not really remove the thread from the list;
7282 instead, the thread is left listed, with 'exited' state.
7284 - The target's debug interface does not support thread exit
7285 events, and so we have no idea whatsoever if the previously
7286 stepping thread is still alive. For that reason, we need to
7287 synchronously query the target now. */
7289 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7291 infrun_log_debug ("not resuming previously stepped thread, it has "
7298 infrun_log_debug ("resuming previously stepped thread");
7300 reset_ecs (ecs
, tp
);
7301 switch_to_thread (tp
);
7303 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7304 frame
= get_current_frame ();
7306 /* If the PC of the thread we were trying to single-step has
7307 changed, then that thread has trapped or been signaled, but the
7308 event has not been reported to GDB yet. Re-poll the target
7309 looking for this particular thread's event (i.e. temporarily
7310 enable schedlock) by:
7312 - setting a break at the current PC
7313 - resuming that particular thread, only (by setting trap
7316 This prevents us continuously moving the single-step breakpoint
7317 forward, one instruction at a time, overstepping. */
7319 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7323 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7324 paddress (target_gdbarch (), tp
->prev_pc
),
7325 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7327 /* Clear the info of the previous step-over, as it's no longer
7328 valid (if the thread was trying to step over a breakpoint, it
7329 has already succeeded). It's what keep_going would do too,
7330 if we called it. Do this before trying to insert the sss
7331 breakpoint, otherwise if we were previously trying to step
7332 over this exact address in another thread, the breakpoint is
7334 clear_step_over_info ();
7335 tp
->control
.trap_expected
= 0;
7337 insert_single_step_breakpoint (get_frame_arch (frame
),
7338 get_frame_address_space (frame
),
7339 tp
->suspend
.stop_pc
);
7342 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7343 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7347 infrun_log_debug ("expected thread still hasn't advanced");
7349 keep_going_pass_signal (ecs
);
7354 /* Is thread TP in the middle of (software or hardware)
7355 single-stepping? (Note the result of this function must never be
7356 passed directly as target_resume's STEP parameter.) */
7359 currently_stepping (struct thread_info
*tp
)
7361 return ((tp
->control
.step_range_end
7362 && tp
->control
.step_resume_breakpoint
== NULL
)
7363 || tp
->control
.trap_expected
7364 || tp
->stepped_breakpoint
7365 || bpstat_should_step ());
7368 /* Inferior has stepped into a subroutine call with source code that
7369 we should not step over. Do step to the first line of code in
7373 handle_step_into_function (struct gdbarch
*gdbarch
,
7374 struct execution_control_state
*ecs
)
7376 fill_in_stop_func (gdbarch
, ecs
);
7378 compunit_symtab
*cust
7379 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7380 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7381 ecs
->stop_func_start
7382 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7384 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7385 /* Use the step_resume_break to step until the end of the prologue,
7386 even if that involves jumps (as it seems to on the vax under
7388 /* If the prologue ends in the middle of a source line, continue to
7389 the end of that source line (if it is still within the function).
7390 Otherwise, just go to end of prologue. */
7391 if (stop_func_sal
.end
7392 && stop_func_sal
.pc
!= ecs
->stop_func_start
7393 && stop_func_sal
.end
< ecs
->stop_func_end
)
7394 ecs
->stop_func_start
= stop_func_sal
.end
;
7396 /* Architectures which require breakpoint adjustment might not be able
7397 to place a breakpoint at the computed address. If so, the test
7398 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7399 ecs->stop_func_start to an address at which a breakpoint may be
7400 legitimately placed.
7402 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7403 made, GDB will enter an infinite loop when stepping through
7404 optimized code consisting of VLIW instructions which contain
7405 subinstructions corresponding to different source lines. On
7406 FR-V, it's not permitted to place a breakpoint on any but the
7407 first subinstruction of a VLIW instruction. When a breakpoint is
7408 set, GDB will adjust the breakpoint address to the beginning of
7409 the VLIW instruction. Thus, we need to make the corresponding
7410 adjustment here when computing the stop address. */
7412 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7414 ecs
->stop_func_start
7415 = gdbarch_adjust_breakpoint_address (gdbarch
,
7416 ecs
->stop_func_start
);
7419 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7421 /* We are already there: stop now. */
7422 end_stepping_range (ecs
);
7427 /* Put the step-breakpoint there and go until there. */
7428 symtab_and_line sr_sal
;
7429 sr_sal
.pc
= ecs
->stop_func_start
;
7430 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7431 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7433 /* Do not specify what the fp should be when we stop since on
7434 some machines the prologue is where the new fp value is
7436 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7438 /* And make sure stepping stops right away then. */
7439 ecs
->event_thread
->control
.step_range_end
7440 = ecs
->event_thread
->control
.step_range_start
;
7445 /* Inferior has stepped backward into a subroutine call with source
7446 code that we should not step over. Do step to the beginning of the
7447 last line of code in it. */
7450 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7451 struct execution_control_state
*ecs
)
7453 struct compunit_symtab
*cust
;
7454 struct symtab_and_line stop_func_sal
;
7456 fill_in_stop_func (gdbarch
, ecs
);
7458 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7459 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7460 ecs
->stop_func_start
7461 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7463 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7465 /* OK, we're just going to keep stepping here. */
7466 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7468 /* We're there already. Just stop stepping now. */
7469 end_stepping_range (ecs
);
7473 /* Else just reset the step range and keep going.
7474 No step-resume breakpoint, they don't work for
7475 epilogues, which can have multiple entry paths. */
7476 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7477 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7483 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7484 This is used to both functions and to skip over code. */
7487 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7488 struct symtab_and_line sr_sal
,
7489 struct frame_id sr_id
,
7490 enum bptype sr_type
)
7492 /* There should never be more than one step-resume or longjmp-resume
7493 breakpoint per thread, so we should never be setting a new
7494 step_resume_breakpoint when one is already active. */
7495 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7496 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7498 infrun_log_debug ("inserting step-resume breakpoint at %s",
7499 paddress (gdbarch
, sr_sal
.pc
));
7501 inferior_thread ()->control
.step_resume_breakpoint
7502 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7506 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7507 struct symtab_and_line sr_sal
,
7508 struct frame_id sr_id
)
7510 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7515 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7516 This is used to skip a potential signal handler.
7518 This is called with the interrupted function's frame. The signal
7519 handler, when it returns, will resume the interrupted function at
7523 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7525 gdb_assert (return_frame
!= NULL
);
7527 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7529 symtab_and_line sr_sal
;
7530 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7531 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7532 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7534 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7535 get_stack_frame_id (return_frame
),
7539 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7540 is used to skip a function after stepping into it (for "next" or if
7541 the called function has no debugging information).
7543 The current function has almost always been reached by single
7544 stepping a call or return instruction. NEXT_FRAME belongs to the
7545 current function, and the breakpoint will be set at the caller's
7548 This is a separate function rather than reusing
7549 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7550 get_prev_frame, which may stop prematurely (see the implementation
7551 of frame_unwind_caller_id for an example). */
7554 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7556 /* We shouldn't have gotten here if we don't know where the call site
7558 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7560 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7562 symtab_and_line sr_sal
;
7563 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7564 frame_unwind_caller_pc (next_frame
));
7565 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7566 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7568 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7569 frame_unwind_caller_id (next_frame
));
7572 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7573 new breakpoint at the target of a jmp_buf. The handling of
7574 longjmp-resume uses the same mechanisms used for handling
7575 "step-resume" breakpoints. */
7578 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7580 /* There should never be more than one longjmp-resume breakpoint per
7581 thread, so we should never be setting a new
7582 longjmp_resume_breakpoint when one is already active. */
7583 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7585 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7586 paddress (gdbarch
, pc
));
7588 inferior_thread ()->control
.exception_resume_breakpoint
=
7589 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7592 /* Insert an exception resume breakpoint. TP is the thread throwing
7593 the exception. The block B is the block of the unwinder debug hook
7594 function. FRAME is the frame corresponding to the call to this
7595 function. SYM is the symbol of the function argument holding the
7596 target PC of the exception. */
7599 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7600 const struct block
*b
,
7601 struct frame_info
*frame
,
7606 struct block_symbol vsym
;
7607 struct value
*value
;
7609 struct breakpoint
*bp
;
7611 vsym
= lookup_symbol_search_name (sym
->search_name (),
7613 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7614 /* If the value was optimized out, revert to the old behavior. */
7615 if (! value_optimized_out (value
))
7617 handler
= value_as_address (value
);
7619 infrun_log_debug ("exception resume at %lx",
7620 (unsigned long) handler
);
7622 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7624 bp_exception_resume
).release ();
7626 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7629 bp
->thread
= tp
->global_num
;
7630 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7633 catch (const gdb_exception_error
&e
)
7635 /* We want to ignore errors here. */
7639 /* A helper for check_exception_resume that sets an
7640 exception-breakpoint based on a SystemTap probe. */
7643 insert_exception_resume_from_probe (struct thread_info
*tp
,
7644 const struct bound_probe
*probe
,
7645 struct frame_info
*frame
)
7647 struct value
*arg_value
;
7649 struct breakpoint
*bp
;
7651 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7655 handler
= value_as_address (arg_value
);
7657 infrun_log_debug ("exception resume at %s",
7658 paddress (probe
->objfile
->arch (), handler
));
7660 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7661 handler
, bp_exception_resume
).release ();
7662 bp
->thread
= tp
->global_num
;
7663 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7666 /* This is called when an exception has been intercepted. Check to
7667 see whether the exception's destination is of interest, and if so,
7668 set an exception resume breakpoint there. */
7671 check_exception_resume (struct execution_control_state
*ecs
,
7672 struct frame_info
*frame
)
7674 struct bound_probe probe
;
7675 struct symbol
*func
;
7677 /* First see if this exception unwinding breakpoint was set via a
7678 SystemTap probe point. If so, the probe has two arguments: the
7679 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7680 set a breakpoint there. */
7681 probe
= find_probe_by_pc (get_frame_pc (frame
));
7684 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7688 func
= get_frame_function (frame
);
7694 const struct block
*b
;
7695 struct block_iterator iter
;
7699 /* The exception breakpoint is a thread-specific breakpoint on
7700 the unwinder's debug hook, declared as:
7702 void _Unwind_DebugHook (void *cfa, void *handler);
7704 The CFA argument indicates the frame to which control is
7705 about to be transferred. HANDLER is the destination PC.
7707 We ignore the CFA and set a temporary breakpoint at HANDLER.
7708 This is not extremely efficient but it avoids issues in gdb
7709 with computing the DWARF CFA, and it also works even in weird
7710 cases such as throwing an exception from inside a signal
7713 b
= SYMBOL_BLOCK_VALUE (func
);
7714 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7716 if (!SYMBOL_IS_ARGUMENT (sym
))
7723 insert_exception_resume_breakpoint (ecs
->event_thread
,
7729 catch (const gdb_exception_error
&e
)
7735 stop_waiting (struct execution_control_state
*ecs
)
7737 infrun_log_debug ("stop_waiting");
7739 /* Let callers know we don't want to wait for the inferior anymore. */
7740 ecs
->wait_some_more
= 0;
7742 /* If all-stop, but there exists a non-stop target, stop all
7743 threads now that we're presenting the stop to the user. */
7744 if (!non_stop
&& exists_non_stop_target ())
7745 stop_all_threads ();
7748 /* Like keep_going, but passes the signal to the inferior, even if the
7749 signal is set to nopass. */
7752 keep_going_pass_signal (struct execution_control_state
*ecs
)
7754 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7755 gdb_assert (!ecs
->event_thread
->resumed
);
7757 /* Save the pc before execution, to compare with pc after stop. */
7758 ecs
->event_thread
->prev_pc
7759 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7761 if (ecs
->event_thread
->control
.trap_expected
)
7763 struct thread_info
*tp
= ecs
->event_thread
;
7765 infrun_log_debug ("%s has trap_expected set, "
7766 "resuming to collect trap",
7767 target_pid_to_str (tp
->ptid
).c_str ());
7769 /* We haven't yet gotten our trap, and either: intercepted a
7770 non-signal event (e.g., a fork); or took a signal which we
7771 are supposed to pass through to the inferior. Simply
7773 resume (ecs
->event_thread
->suspend
.stop_signal
);
7775 else if (step_over_info_valid_p ())
7777 /* Another thread is stepping over a breakpoint in-line. If
7778 this thread needs a step-over too, queue the request. In
7779 either case, this resume must be deferred for later. */
7780 struct thread_info
*tp
= ecs
->event_thread
;
7782 if (ecs
->hit_singlestep_breakpoint
7783 || thread_still_needs_step_over (tp
))
7785 infrun_log_debug ("step-over already in progress: "
7786 "step-over for %s deferred",
7787 target_pid_to_str (tp
->ptid
).c_str ());
7788 global_thread_step_over_chain_enqueue (tp
);
7792 infrun_log_debug ("step-over in progress: resume of %s deferred",
7793 target_pid_to_str (tp
->ptid
).c_str ());
7798 struct regcache
*regcache
= get_current_regcache ();
7801 step_over_what step_what
;
7803 /* Either the trap was not expected, but we are continuing
7804 anyway (if we got a signal, the user asked it be passed to
7807 We got our expected trap, but decided we should resume from
7810 We're going to run this baby now!
7812 Note that insert_breakpoints won't try to re-insert
7813 already inserted breakpoints. Therefore, we don't
7814 care if breakpoints were already inserted, or not. */
7816 /* If we need to step over a breakpoint, and we're not using
7817 displaced stepping to do so, insert all breakpoints
7818 (watchpoints, etc.) but the one we're stepping over, step one
7819 instruction, and then re-insert the breakpoint when that step
7822 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7824 remove_bp
= (ecs
->hit_singlestep_breakpoint
7825 || (step_what
& STEP_OVER_BREAKPOINT
));
7826 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7828 /* We can't use displaced stepping if we need to step past a
7829 watchpoint. The instruction copied to the scratch pad would
7830 still trigger the watchpoint. */
7832 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7834 set_step_over_info (regcache
->aspace (),
7835 regcache_read_pc (regcache
), remove_wps
,
7836 ecs
->event_thread
->global_num
);
7838 else if (remove_wps
)
7839 set_step_over_info (NULL
, 0, remove_wps
, -1);
7841 /* If we now need to do an in-line step-over, we need to stop
7842 all other threads. Note this must be done before
7843 insert_breakpoints below, because that removes the breakpoint
7844 we're about to step over, otherwise other threads could miss
7846 if (step_over_info_valid_p () && target_is_non_stop_p ())
7847 stop_all_threads ();
7849 /* Stop stepping if inserting breakpoints fails. */
7852 insert_breakpoints ();
7854 catch (const gdb_exception_error
&e
)
7856 exception_print (gdb_stderr
, e
);
7858 clear_step_over_info ();
7862 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7864 resume (ecs
->event_thread
->suspend
.stop_signal
);
7867 prepare_to_wait (ecs
);
7870 /* Called when we should continue running the inferior, because the
7871 current event doesn't cause a user visible stop. This does the
7872 resuming part; waiting for the next event is done elsewhere. */
7875 keep_going (struct execution_control_state
*ecs
)
7877 if (ecs
->event_thread
->control
.trap_expected
7878 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7879 ecs
->event_thread
->control
.trap_expected
= 0;
7881 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7882 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7883 keep_going_pass_signal (ecs
);
7886 /* This function normally comes after a resume, before
7887 handle_inferior_event exits. It takes care of any last bits of
7888 housekeeping, and sets the all-important wait_some_more flag. */
7891 prepare_to_wait (struct execution_control_state
*ecs
)
7893 infrun_log_debug ("prepare_to_wait");
7895 ecs
->wait_some_more
= 1;
7897 /* If the target can't async, emulate it by marking the infrun event
7898 handler such that as soon as we get back to the event-loop, we
7899 immediately end up in fetch_inferior_event again calling
7901 if (!target_can_async_p ())
7902 mark_infrun_async_event_handler ();
7905 /* We are done with the step range of a step/next/si/ni command.
7906 Called once for each n of a "step n" operation. */
7909 end_stepping_range (struct execution_control_state
*ecs
)
7911 ecs
->event_thread
->control
.stop_step
= 1;
7915 /* Several print_*_reason functions to print why the inferior has stopped.
7916 We always print something when the inferior exits, or receives a signal.
7917 The rest of the cases are dealt with later on in normal_stop and
7918 print_it_typical. Ideally there should be a call to one of these
7919 print_*_reason functions functions from handle_inferior_event each time
7920 stop_waiting is called.
7922 Note that we don't call these directly, instead we delegate that to
7923 the interpreters, through observers. Interpreters then call these
7924 with whatever uiout is right. */
7927 print_end_stepping_range_reason (struct ui_out
*uiout
)
7929 /* For CLI-like interpreters, print nothing. */
7931 if (uiout
->is_mi_like_p ())
7933 uiout
->field_string ("reason",
7934 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7939 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7941 annotate_signalled ();
7942 if (uiout
->is_mi_like_p ())
7944 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7945 uiout
->text ("\nProgram terminated with signal ");
7946 annotate_signal_name ();
7947 uiout
->field_string ("signal-name",
7948 gdb_signal_to_name (siggnal
));
7949 annotate_signal_name_end ();
7951 annotate_signal_string ();
7952 uiout
->field_string ("signal-meaning",
7953 gdb_signal_to_string (siggnal
));
7954 annotate_signal_string_end ();
7955 uiout
->text (".\n");
7956 uiout
->text ("The program no longer exists.\n");
7960 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7962 struct inferior
*inf
= current_inferior ();
7963 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7965 annotate_exited (exitstatus
);
7968 if (uiout
->is_mi_like_p ())
7969 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7970 std::string exit_code_str
7971 = string_printf ("0%o", (unsigned int) exitstatus
);
7972 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7973 plongest (inf
->num
), pidstr
.c_str (),
7974 string_field ("exit-code", exit_code_str
.c_str ()));
7978 if (uiout
->is_mi_like_p ())
7980 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7981 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7982 plongest (inf
->num
), pidstr
.c_str ());
7986 /* Some targets/architectures can do extra processing/display of
7987 segmentation faults. E.g., Intel MPX boundary faults.
7988 Call the architecture dependent function to handle the fault. */
7991 handle_segmentation_fault (struct ui_out
*uiout
)
7993 struct regcache
*regcache
= get_current_regcache ();
7994 struct gdbarch
*gdbarch
= regcache
->arch ();
7996 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
7997 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8001 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8003 struct thread_info
*thr
= inferior_thread ();
8007 if (uiout
->is_mi_like_p ())
8009 else if (show_thread_that_caused_stop ())
8013 uiout
->text ("\nThread ");
8014 uiout
->field_string ("thread-id", print_thread_id (thr
));
8016 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8019 uiout
->text (" \"");
8020 uiout
->field_string ("name", name
);
8025 uiout
->text ("\nProgram");
8027 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8028 uiout
->text (" stopped");
8031 uiout
->text (" received signal ");
8032 annotate_signal_name ();
8033 if (uiout
->is_mi_like_p ())
8035 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8036 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8037 annotate_signal_name_end ();
8039 annotate_signal_string ();
8040 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8042 if (siggnal
== GDB_SIGNAL_SEGV
)
8043 handle_segmentation_fault (uiout
);
8045 annotate_signal_string_end ();
8047 uiout
->text (".\n");
8051 print_no_history_reason (struct ui_out
*uiout
)
8053 uiout
->text ("\nNo more reverse-execution history.\n");
8056 /* Print current location without a level number, if we have changed
8057 functions or hit a breakpoint. Print source line if we have one.
8058 bpstat_print contains the logic deciding in detail what to print,
8059 based on the event(s) that just occurred. */
8062 print_stop_location (struct target_waitstatus
*ws
)
8065 enum print_what source_flag
;
8066 int do_frame_printing
= 1;
8067 struct thread_info
*tp
= inferior_thread ();
8069 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8073 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8074 should) carry around the function and does (or should) use
8075 that when doing a frame comparison. */
8076 if (tp
->control
.stop_step
8077 && frame_id_eq (tp
->control
.step_frame_id
,
8078 get_frame_id (get_current_frame ()))
8079 && (tp
->control
.step_start_function
8080 == find_pc_function (tp
->suspend
.stop_pc
)))
8082 /* Finished step, just print source line. */
8083 source_flag
= SRC_LINE
;
8087 /* Print location and source line. */
8088 source_flag
= SRC_AND_LOC
;
8091 case PRINT_SRC_AND_LOC
:
8092 /* Print location and source line. */
8093 source_flag
= SRC_AND_LOC
;
8095 case PRINT_SRC_ONLY
:
8096 source_flag
= SRC_LINE
;
8099 /* Something bogus. */
8100 source_flag
= SRC_LINE
;
8101 do_frame_printing
= 0;
8104 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8107 /* The behavior of this routine with respect to the source
8109 SRC_LINE: Print only source line
8110 LOCATION: Print only location
8111 SRC_AND_LOC: Print location and source line. */
8112 if (do_frame_printing
)
8113 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8119 print_stop_event (struct ui_out
*uiout
, bool displays
)
8121 struct target_waitstatus last
;
8122 struct thread_info
*tp
;
8124 get_last_target_status (nullptr, nullptr, &last
);
8127 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8129 print_stop_location (&last
);
8131 /* Display the auto-display expressions. */
8136 tp
= inferior_thread ();
8137 if (tp
->thread_fsm
!= NULL
8138 && tp
->thread_fsm
->finished_p ())
8140 struct return_value_info
*rv
;
8142 rv
= tp
->thread_fsm
->return_value ();
8144 print_return_value (uiout
, rv
);
8151 maybe_remove_breakpoints (void)
8153 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8155 if (remove_breakpoints ())
8157 target_terminal::ours_for_output ();
8158 printf_filtered (_("Cannot remove breakpoints because "
8159 "program is no longer writable.\nFurther "
8160 "execution is probably impossible.\n"));
8165 /* The execution context that just caused a normal stop. */
8172 DISABLE_COPY_AND_ASSIGN (stop_context
);
8174 bool changed () const;
8179 /* The event PTID. */
8183 /* If stopp for a thread event, this is the thread that caused the
8185 struct thread_info
*thread
;
8187 /* The inferior that caused the stop. */
8191 /* Initializes a new stop context. If stopped for a thread event, this
8192 takes a strong reference to the thread. */
8194 stop_context::stop_context ()
8196 stop_id
= get_stop_id ();
8197 ptid
= inferior_ptid
;
8198 inf_num
= current_inferior ()->num
;
8200 if (inferior_ptid
!= null_ptid
)
8202 /* Take a strong reference so that the thread can't be deleted
8204 thread
= inferior_thread ();
8211 /* Release a stop context previously created with save_stop_context.
8212 Releases the strong reference to the thread as well. */
8214 stop_context::~stop_context ()
8220 /* Return true if the current context no longer matches the saved stop
8224 stop_context::changed () const
8226 if (ptid
!= inferior_ptid
)
8228 if (inf_num
!= current_inferior ()->num
)
8230 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8232 if (get_stop_id () != stop_id
)
8242 struct target_waitstatus last
;
8244 get_last_target_status (nullptr, nullptr, &last
);
8248 /* If an exception is thrown from this point on, make sure to
8249 propagate GDB's knowledge of the executing state to the
8250 frontend/user running state. A QUIT is an easy exception to see
8251 here, so do this before any filtered output. */
8253 ptid_t finish_ptid
= null_ptid
;
8256 finish_ptid
= minus_one_ptid
;
8257 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8258 || last
.kind
== TARGET_WAITKIND_EXITED
)
8260 /* On some targets, we may still have live threads in the
8261 inferior when we get a process exit event. E.g., for
8262 "checkpoint", when the current checkpoint/fork exits,
8263 linux-fork.c automatically switches to another fork from
8264 within target_mourn_inferior. */
8265 if (inferior_ptid
!= null_ptid
)
8266 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8268 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8269 finish_ptid
= inferior_ptid
;
8271 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8272 if (finish_ptid
!= null_ptid
)
8274 maybe_finish_thread_state
.emplace
8275 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8278 /* As we're presenting a stop, and potentially removing breakpoints,
8279 update the thread list so we can tell whether there are threads
8280 running on the target. With target remote, for example, we can
8281 only learn about new threads when we explicitly update the thread
8282 list. Do this before notifying the interpreters about signal
8283 stops, end of stepping ranges, etc., so that the "new thread"
8284 output is emitted before e.g., "Program received signal FOO",
8285 instead of after. */
8286 update_thread_list ();
8288 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8289 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8291 /* As with the notification of thread events, we want to delay
8292 notifying the user that we've switched thread context until
8293 the inferior actually stops.
8295 There's no point in saying anything if the inferior has exited.
8296 Note that SIGNALLED here means "exited with a signal", not
8297 "received a signal".
8299 Also skip saying anything in non-stop mode. In that mode, as we
8300 don't want GDB to switch threads behind the user's back, to avoid
8301 races where the user is typing a command to apply to thread x,
8302 but GDB switches to thread y before the user finishes entering
8303 the command, fetch_inferior_event installs a cleanup to restore
8304 the current thread back to the thread the user had selected right
8305 after this event is handled, so we're not really switching, only
8306 informing of a stop. */
8308 && previous_inferior_ptid
!= inferior_ptid
8309 && target_has_execution
8310 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8311 && last
.kind
!= TARGET_WAITKIND_EXITED
8312 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8314 SWITCH_THRU_ALL_UIS ()
8316 target_terminal::ours_for_output ();
8317 printf_filtered (_("[Switching to %s]\n"),
8318 target_pid_to_str (inferior_ptid
).c_str ());
8319 annotate_thread_changed ();
8321 previous_inferior_ptid
= inferior_ptid
;
8324 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8326 SWITCH_THRU_ALL_UIS ()
8327 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8329 target_terminal::ours_for_output ();
8330 printf_filtered (_("No unwaited-for children left.\n"));
8334 /* Note: this depends on the update_thread_list call above. */
8335 maybe_remove_breakpoints ();
8337 /* If an auto-display called a function and that got a signal,
8338 delete that auto-display to avoid an infinite recursion. */
8340 if (stopped_by_random_signal
)
8341 disable_current_display ();
8343 SWITCH_THRU_ALL_UIS ()
8345 async_enable_stdin ();
8348 /* Let the user/frontend see the threads as stopped. */
8349 maybe_finish_thread_state
.reset ();
8351 /* Select innermost stack frame - i.e., current frame is frame 0,
8352 and current location is based on that. Handle the case where the
8353 dummy call is returning after being stopped. E.g. the dummy call
8354 previously hit a breakpoint. (If the dummy call returns
8355 normally, we won't reach here.) Do this before the stop hook is
8356 run, so that it doesn't get to see the temporary dummy frame,
8357 which is not where we'll present the stop. */
8358 if (has_stack_frames ())
8360 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8362 /* Pop the empty frame that contains the stack dummy. This
8363 also restores inferior state prior to the call (struct
8364 infcall_suspend_state). */
8365 struct frame_info
*frame
= get_current_frame ();
8367 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8369 /* frame_pop calls reinit_frame_cache as the last thing it
8370 does which means there's now no selected frame. */
8373 select_frame (get_current_frame ());
8375 /* Set the current source location. */
8376 set_current_sal_from_frame (get_current_frame ());
8379 /* Look up the hook_stop and run it (CLI internally handles problem
8380 of stop_command's pre-hook not existing). */
8381 if (stop_command
!= NULL
)
8383 stop_context saved_context
;
8387 execute_cmd_pre_hook (stop_command
);
8389 catch (const gdb_exception
&ex
)
8391 exception_fprintf (gdb_stderr
, ex
,
8392 "Error while running hook_stop:\n");
8395 /* If the stop hook resumes the target, then there's no point in
8396 trying to notify about the previous stop; its context is
8397 gone. Likewise if the command switches thread or inferior --
8398 the observers would print a stop for the wrong
8400 if (saved_context
.changed ())
8404 /* Notify observers about the stop. This is where the interpreters
8405 print the stop event. */
8406 if (inferior_ptid
!= null_ptid
)
8407 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8410 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8412 annotate_stopped ();
8414 if (target_has_execution
)
8416 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8417 && last
.kind
!= TARGET_WAITKIND_EXITED
8418 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8419 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8420 Delete any breakpoint that is to be deleted at the next stop. */
8421 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8424 /* Try to get rid of automatically added inferiors that are no
8425 longer needed. Keeping those around slows down things linearly.
8426 Note that this never removes the current inferior. */
8433 signal_stop_state (int signo
)
8435 return signal_stop
[signo
];
8439 signal_print_state (int signo
)
8441 return signal_print
[signo
];
8445 signal_pass_state (int signo
)
8447 return signal_program
[signo
];
8451 signal_cache_update (int signo
)
8455 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8456 signal_cache_update (signo
);
8461 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8462 && signal_print
[signo
] == 0
8463 && signal_program
[signo
] == 1
8464 && signal_catch
[signo
] == 0);
8468 signal_stop_update (int signo
, int state
)
8470 int ret
= signal_stop
[signo
];
8472 signal_stop
[signo
] = state
;
8473 signal_cache_update (signo
);
8478 signal_print_update (int signo
, int state
)
8480 int ret
= signal_print
[signo
];
8482 signal_print
[signo
] = state
;
8483 signal_cache_update (signo
);
8488 signal_pass_update (int signo
, int state
)
8490 int ret
= signal_program
[signo
];
8492 signal_program
[signo
] = state
;
8493 signal_cache_update (signo
);
8497 /* Update the global 'signal_catch' from INFO and notify the
8501 signal_catch_update (const unsigned int *info
)
8505 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8506 signal_catch
[i
] = info
[i
] > 0;
8507 signal_cache_update (-1);
8508 target_pass_signals (signal_pass
);
8512 sig_print_header (void)
8514 printf_filtered (_("Signal Stop\tPrint\tPass "
8515 "to program\tDescription\n"));
8519 sig_print_info (enum gdb_signal oursig
)
8521 const char *name
= gdb_signal_to_name (oursig
);
8522 int name_padding
= 13 - strlen (name
);
8524 if (name_padding
<= 0)
8527 printf_filtered ("%s", name
);
8528 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8529 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8530 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8531 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8532 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8535 /* Specify how various signals in the inferior should be handled. */
8538 handle_command (const char *args
, int from_tty
)
8540 int digits
, wordlen
;
8541 int sigfirst
, siglast
;
8542 enum gdb_signal oursig
;
8547 error_no_arg (_("signal to handle"));
8550 /* Allocate and zero an array of flags for which signals to handle. */
8552 const size_t nsigs
= GDB_SIGNAL_LAST
;
8553 unsigned char sigs
[nsigs
] {};
8555 /* Break the command line up into args. */
8557 gdb_argv
built_argv (args
);
8559 /* Walk through the args, looking for signal oursigs, signal names, and
8560 actions. Signal numbers and signal names may be interspersed with
8561 actions, with the actions being performed for all signals cumulatively
8562 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8564 for (char *arg
: built_argv
)
8566 wordlen
= strlen (arg
);
8567 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8571 sigfirst
= siglast
= -1;
8573 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8575 /* Apply action to all signals except those used by the
8576 debugger. Silently skip those. */
8579 siglast
= nsigs
- 1;
8581 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8583 SET_SIGS (nsigs
, sigs
, signal_stop
);
8584 SET_SIGS (nsigs
, sigs
, signal_print
);
8586 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8588 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8590 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8592 SET_SIGS (nsigs
, sigs
, signal_print
);
8594 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8596 SET_SIGS (nsigs
, sigs
, signal_program
);
8598 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8600 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8602 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8604 SET_SIGS (nsigs
, sigs
, signal_program
);
8606 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8608 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8609 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8611 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8613 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8615 else if (digits
> 0)
8617 /* It is numeric. The numeric signal refers to our own
8618 internal signal numbering from target.h, not to host/target
8619 signal number. This is a feature; users really should be
8620 using symbolic names anyway, and the common ones like
8621 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8623 sigfirst
= siglast
= (int)
8624 gdb_signal_from_command (atoi (arg
));
8625 if (arg
[digits
] == '-')
8628 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8630 if (sigfirst
> siglast
)
8632 /* Bet he didn't figure we'd think of this case... */
8633 std::swap (sigfirst
, siglast
);
8638 oursig
= gdb_signal_from_name (arg
);
8639 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8641 sigfirst
= siglast
= (int) oursig
;
8645 /* Not a number and not a recognized flag word => complain. */
8646 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8650 /* If any signal numbers or symbol names were found, set flags for
8651 which signals to apply actions to. */
8653 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8655 switch ((enum gdb_signal
) signum
)
8657 case GDB_SIGNAL_TRAP
:
8658 case GDB_SIGNAL_INT
:
8659 if (!allsigs
&& !sigs
[signum
])
8661 if (query (_("%s is used by the debugger.\n\
8662 Are you sure you want to change it? "),
8663 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8668 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8672 case GDB_SIGNAL_DEFAULT
:
8673 case GDB_SIGNAL_UNKNOWN
:
8674 /* Make sure that "all" doesn't print these. */
8683 for (int signum
= 0; signum
< nsigs
; signum
++)
8686 signal_cache_update (-1);
8687 target_pass_signals (signal_pass
);
8688 target_program_signals (signal_program
);
8692 /* Show the results. */
8693 sig_print_header ();
8694 for (; signum
< nsigs
; signum
++)
8696 sig_print_info ((enum gdb_signal
) signum
);
8703 /* Complete the "handle" command. */
8706 handle_completer (struct cmd_list_element
*ignore
,
8707 completion_tracker
&tracker
,
8708 const char *text
, const char *word
)
8710 static const char * const keywords
[] =
8724 signal_completer (ignore
, tracker
, text
, word
);
8725 complete_on_enum (tracker
, keywords
, word
, word
);
8729 gdb_signal_from_command (int num
)
8731 if (num
>= 1 && num
<= 15)
8732 return (enum gdb_signal
) num
;
8733 error (_("Only signals 1-15 are valid as numeric signals.\n\
8734 Use \"info signals\" for a list of symbolic signals."));
8737 /* Print current contents of the tables set by the handle command.
8738 It is possible we should just be printing signals actually used
8739 by the current target (but for things to work right when switching
8740 targets, all signals should be in the signal tables). */
8743 info_signals_command (const char *signum_exp
, int from_tty
)
8745 enum gdb_signal oursig
;
8747 sig_print_header ();
8751 /* First see if this is a symbol name. */
8752 oursig
= gdb_signal_from_name (signum_exp
);
8753 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8755 /* No, try numeric. */
8757 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8759 sig_print_info (oursig
);
8763 printf_filtered ("\n");
8764 /* These ugly casts brought to you by the native VAX compiler. */
8765 for (oursig
= GDB_SIGNAL_FIRST
;
8766 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8767 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8771 if (oursig
!= GDB_SIGNAL_UNKNOWN
8772 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8773 sig_print_info (oursig
);
8776 printf_filtered (_("\nUse the \"handle\" command "
8777 "to change these tables.\n"));
8780 /* The $_siginfo convenience variable is a bit special. We don't know
8781 for sure the type of the value until we actually have a chance to
8782 fetch the data. The type can change depending on gdbarch, so it is
8783 also dependent on which thread you have selected.
8785 1. making $_siginfo be an internalvar that creates a new value on
8788 2. making the value of $_siginfo be an lval_computed value. */
8790 /* This function implements the lval_computed support for reading a
8794 siginfo_value_read (struct value
*v
)
8796 LONGEST transferred
;
8798 /* If we can access registers, so can we access $_siginfo. Likewise
8800 validate_registers_access ();
8803 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8805 value_contents_all_raw (v
),
8807 TYPE_LENGTH (value_type (v
)));
8809 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8810 error (_("Unable to read siginfo"));
8813 /* This function implements the lval_computed support for writing a
8817 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8819 LONGEST transferred
;
8821 /* If we can access registers, so can we access $_siginfo. Likewise
8823 validate_registers_access ();
8825 transferred
= target_write (current_top_target (),
8826 TARGET_OBJECT_SIGNAL_INFO
,
8828 value_contents_all_raw (fromval
),
8830 TYPE_LENGTH (value_type (fromval
)));
8832 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8833 error (_("Unable to write siginfo"));
8836 static const struct lval_funcs siginfo_value_funcs
=
8842 /* Return a new value with the correct type for the siginfo object of
8843 the current thread using architecture GDBARCH. Return a void value
8844 if there's no object available. */
8846 static struct value
*
8847 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8850 if (target_has_stack
8851 && inferior_ptid
!= null_ptid
8852 && gdbarch_get_siginfo_type_p (gdbarch
))
8854 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8856 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8859 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8863 /* infcall_suspend_state contains state about the program itself like its
8864 registers and any signal it received when it last stopped.
8865 This state must be restored regardless of how the inferior function call
8866 ends (either successfully, or after it hits a breakpoint or signal)
8867 if the program is to properly continue where it left off. */
8869 class infcall_suspend_state
8872 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8873 once the inferior function call has finished. */
8874 infcall_suspend_state (struct gdbarch
*gdbarch
,
8875 const struct thread_info
*tp
,
8876 struct regcache
*regcache
)
8877 : m_thread_suspend (tp
->suspend
),
8878 m_registers (new readonly_detached_regcache (*regcache
))
8880 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8882 if (gdbarch_get_siginfo_type_p (gdbarch
))
8884 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8885 size_t len
= TYPE_LENGTH (type
);
8887 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8889 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8890 siginfo_data
.get (), 0, len
) != len
)
8892 /* Errors ignored. */
8893 siginfo_data
.reset (nullptr);
8899 m_siginfo_gdbarch
= gdbarch
;
8900 m_siginfo_data
= std::move (siginfo_data
);
8904 /* Return a pointer to the stored register state. */
8906 readonly_detached_regcache
*registers () const
8908 return m_registers
.get ();
8911 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8913 void restore (struct gdbarch
*gdbarch
,
8914 struct thread_info
*tp
,
8915 struct regcache
*regcache
) const
8917 tp
->suspend
= m_thread_suspend
;
8919 if (m_siginfo_gdbarch
== gdbarch
)
8921 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8923 /* Errors ignored. */
8924 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8925 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8928 /* The inferior can be gone if the user types "print exit(0)"
8929 (and perhaps other times). */
8930 if (target_has_execution
)
8931 /* NB: The register write goes through to the target. */
8932 regcache
->restore (registers ());
8936 /* How the current thread stopped before the inferior function call was
8938 struct thread_suspend_state m_thread_suspend
;
8940 /* The registers before the inferior function call was executed. */
8941 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8943 /* Format of SIGINFO_DATA or NULL if it is not present. */
8944 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8946 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8947 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8948 content would be invalid. */
8949 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8952 infcall_suspend_state_up
8953 save_infcall_suspend_state ()
8955 struct thread_info
*tp
= inferior_thread ();
8956 struct regcache
*regcache
= get_current_regcache ();
8957 struct gdbarch
*gdbarch
= regcache
->arch ();
8959 infcall_suspend_state_up inf_state
8960 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8962 /* Having saved the current state, adjust the thread state, discarding
8963 any stop signal information. The stop signal is not useful when
8964 starting an inferior function call, and run_inferior_call will not use
8965 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8966 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8971 /* Restore inferior session state to INF_STATE. */
8974 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8976 struct thread_info
*tp
= inferior_thread ();
8977 struct regcache
*regcache
= get_current_regcache ();
8978 struct gdbarch
*gdbarch
= regcache
->arch ();
8980 inf_state
->restore (gdbarch
, tp
, regcache
);
8981 discard_infcall_suspend_state (inf_state
);
8985 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8990 readonly_detached_regcache
*
8991 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
8993 return inf_state
->registers ();
8996 /* infcall_control_state contains state regarding gdb's control of the
8997 inferior itself like stepping control. It also contains session state like
8998 the user's currently selected frame. */
9000 struct infcall_control_state
9002 struct thread_control_state thread_control
;
9003 struct inferior_control_state inferior_control
;
9006 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9007 int stopped_by_random_signal
= 0;
9009 /* ID if the selected frame when the inferior function call was made. */
9010 struct frame_id selected_frame_id
{};
9013 /* Save all of the information associated with the inferior<==>gdb
9016 infcall_control_state_up
9017 save_infcall_control_state ()
9019 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9020 struct thread_info
*tp
= inferior_thread ();
9021 struct inferior
*inf
= current_inferior ();
9023 inf_status
->thread_control
= tp
->control
;
9024 inf_status
->inferior_control
= inf
->control
;
9026 tp
->control
.step_resume_breakpoint
= NULL
;
9027 tp
->control
.exception_resume_breakpoint
= NULL
;
9029 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9030 chain. If caller's caller is walking the chain, they'll be happier if we
9031 hand them back the original chain when restore_infcall_control_state is
9033 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9036 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9037 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9039 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9045 restore_selected_frame (const frame_id
&fid
)
9047 frame_info
*frame
= frame_find_by_id (fid
);
9049 /* If inf_status->selected_frame_id is NULL, there was no previously
9053 warning (_("Unable to restore previously selected frame."));
9057 select_frame (frame
);
9060 /* Restore inferior session state to INF_STATUS. */
9063 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9065 struct thread_info
*tp
= inferior_thread ();
9066 struct inferior
*inf
= current_inferior ();
9068 if (tp
->control
.step_resume_breakpoint
)
9069 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9071 if (tp
->control
.exception_resume_breakpoint
)
9072 tp
->control
.exception_resume_breakpoint
->disposition
9073 = disp_del_at_next_stop
;
9075 /* Handle the bpstat_copy of the chain. */
9076 bpstat_clear (&tp
->control
.stop_bpstat
);
9078 tp
->control
= inf_status
->thread_control
;
9079 inf
->control
= inf_status
->inferior_control
;
9082 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9083 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9085 if (target_has_stack
)
9087 /* The point of the try/catch is that if the stack is clobbered,
9088 walking the stack might encounter a garbage pointer and
9089 error() trying to dereference it. */
9092 restore_selected_frame (inf_status
->selected_frame_id
);
9094 catch (const gdb_exception_error
&ex
)
9096 exception_fprintf (gdb_stderr
, ex
,
9097 "Unable to restore previously selected frame:\n");
9098 /* Error in restoring the selected frame. Select the
9100 select_frame (get_current_frame ());
9108 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9110 if (inf_status
->thread_control
.step_resume_breakpoint
)
9111 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9112 = disp_del_at_next_stop
;
9114 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9115 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9116 = disp_del_at_next_stop
;
9118 /* See save_infcall_control_state for info on stop_bpstat. */
9119 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9127 clear_exit_convenience_vars (void)
9129 clear_internalvar (lookup_internalvar ("_exitsignal"));
9130 clear_internalvar (lookup_internalvar ("_exitcode"));
9134 /* User interface for reverse debugging:
9135 Set exec-direction / show exec-direction commands
9136 (returns error unless target implements to_set_exec_direction method). */
9138 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9139 static const char exec_forward
[] = "forward";
9140 static const char exec_reverse
[] = "reverse";
9141 static const char *exec_direction
= exec_forward
;
9142 static const char *const exec_direction_names
[] = {
9149 set_exec_direction_func (const char *args
, int from_tty
,
9150 struct cmd_list_element
*cmd
)
9152 if (target_can_execute_reverse
)
9154 if (!strcmp (exec_direction
, exec_forward
))
9155 execution_direction
= EXEC_FORWARD
;
9156 else if (!strcmp (exec_direction
, exec_reverse
))
9157 execution_direction
= EXEC_REVERSE
;
9161 exec_direction
= exec_forward
;
9162 error (_("Target does not support this operation."));
9167 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9168 struct cmd_list_element
*cmd
, const char *value
)
9170 switch (execution_direction
) {
9172 fprintf_filtered (out
, _("Forward.\n"));
9175 fprintf_filtered (out
, _("Reverse.\n"));
9178 internal_error (__FILE__
, __LINE__
,
9179 _("bogus execution_direction value: %d"),
9180 (int) execution_direction
);
9185 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9186 struct cmd_list_element
*c
, const char *value
)
9188 fprintf_filtered (file
, _("Resuming the execution of threads "
9189 "of all processes is %s.\n"), value
);
9192 /* Implementation of `siginfo' variable. */
9194 static const struct internalvar_funcs siginfo_funcs
=
9201 /* Callback for infrun's target events source. This is marked when a
9202 thread has a pending status to process. */
9205 infrun_async_inferior_event_handler (gdb_client_data data
)
9207 inferior_event_handler (INF_REG_EVENT
);
9210 void _initialize_infrun ();
9212 _initialize_infrun ()
9214 struct cmd_list_element
*c
;
9216 /* Register extra event sources in the event loop. */
9217 infrun_async_inferior_event_token
9218 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9220 add_info ("signals", info_signals_command
, _("\
9221 What debugger does when program gets various signals.\n\
9222 Specify a signal as argument to print info on that signal only."));
9223 add_info_alias ("handle", "signals", 0);
9225 c
= add_com ("handle", class_run
, handle_command
, _("\
9226 Specify how to handle signals.\n\
9227 Usage: handle SIGNAL [ACTIONS]\n\
9228 Args are signals and actions to apply to those signals.\n\
9229 If no actions are specified, the current settings for the specified signals\n\
9230 will be displayed instead.\n\
9232 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9233 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9234 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9235 The special arg \"all\" is recognized to mean all signals except those\n\
9236 used by the debugger, typically SIGTRAP and SIGINT.\n\
9238 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9239 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9240 Stop means reenter debugger if this signal happens (implies print).\n\
9241 Print means print a message if this signal happens.\n\
9242 Pass means let program see this signal; otherwise program doesn't know.\n\
9243 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9244 Pass and Stop may be combined.\n\
9246 Multiple signals may be specified. Signal numbers and signal names\n\
9247 may be interspersed with actions, with the actions being performed for\n\
9248 all signals cumulatively specified."));
9249 set_cmd_completer (c
, handle_completer
);
9252 stop_command
= add_cmd ("stop", class_obscure
,
9253 not_just_help_class_command
, _("\
9254 There is no `stop' command, but you can set a hook on `stop'.\n\
9255 This allows you to set a list of commands to be run each time execution\n\
9256 of the program stops."), &cmdlist
);
9258 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9259 Set inferior debugging."), _("\
9260 Show inferior debugging."), _("\
9261 When non-zero, inferior specific debugging is enabled."),
9264 &setdebuglist
, &showdebuglist
);
9266 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9267 &debug_displaced
, _("\
9268 Set displaced stepping debugging."), _("\
9269 Show displaced stepping debugging."), _("\
9270 When non-zero, displaced stepping specific debugging is enabled."),
9272 show_debug_displaced
,
9273 &setdebuglist
, &showdebuglist
);
9275 add_setshow_boolean_cmd ("non-stop", no_class
,
9277 Set whether gdb controls the inferior in non-stop mode."), _("\
9278 Show whether gdb controls the inferior in non-stop mode."), _("\
9279 When debugging a multi-threaded program and this setting is\n\
9280 off (the default, also called all-stop mode), when one thread stops\n\
9281 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9282 all other threads in the program while you interact with the thread of\n\
9283 interest. When you continue or step a thread, you can allow the other\n\
9284 threads to run, or have them remain stopped, but while you inspect any\n\
9285 thread's state, all threads stop.\n\
9287 In non-stop mode, when one thread stops, other threads can continue\n\
9288 to run freely. You'll be able to step each thread independently,\n\
9289 leave it stopped or free to run as needed."),
9295 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9298 signal_print
[i
] = 1;
9299 signal_program
[i
] = 1;
9300 signal_catch
[i
] = 0;
9303 /* Signals caused by debugger's own actions should not be given to
9304 the program afterwards.
9306 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9307 explicitly specifies that it should be delivered to the target
9308 program. Typically, that would occur when a user is debugging a
9309 target monitor on a simulator: the target monitor sets a
9310 breakpoint; the simulator encounters this breakpoint and halts
9311 the simulation handing control to GDB; GDB, noting that the stop
9312 address doesn't map to any known breakpoint, returns control back
9313 to the simulator; the simulator then delivers the hardware
9314 equivalent of a GDB_SIGNAL_TRAP to the program being
9316 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9317 signal_program
[GDB_SIGNAL_INT
] = 0;
9319 /* Signals that are not errors should not normally enter the debugger. */
9320 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9321 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9322 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9323 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9324 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9325 signal_print
[GDB_SIGNAL_PROF
] = 0;
9326 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9327 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9328 signal_stop
[GDB_SIGNAL_IO
] = 0;
9329 signal_print
[GDB_SIGNAL_IO
] = 0;
9330 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9331 signal_print
[GDB_SIGNAL_POLL
] = 0;
9332 signal_stop
[GDB_SIGNAL_URG
] = 0;
9333 signal_print
[GDB_SIGNAL_URG
] = 0;
9334 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9335 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9336 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9337 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9339 /* These signals are used internally by user-level thread
9340 implementations. (See signal(5) on Solaris.) Like the above
9341 signals, a healthy program receives and handles them as part of
9342 its normal operation. */
9343 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9344 signal_print
[GDB_SIGNAL_LWP
] = 0;
9345 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9346 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9347 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9348 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9349 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9350 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9352 /* Update cached state. */
9353 signal_cache_update (-1);
9355 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9356 &stop_on_solib_events
, _("\
9357 Set stopping for shared library events."), _("\
9358 Show stopping for shared library events."), _("\
9359 If nonzero, gdb will give control to the user when the dynamic linker\n\
9360 notifies gdb of shared library events. The most common event of interest\n\
9361 to the user would be loading/unloading of a new library."),
9362 set_stop_on_solib_events
,
9363 show_stop_on_solib_events
,
9364 &setlist
, &showlist
);
9366 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9367 follow_fork_mode_kind_names
,
9368 &follow_fork_mode_string
, _("\
9369 Set debugger response to a program call of fork or vfork."), _("\
9370 Show debugger response to a program call of fork or vfork."), _("\
9371 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9372 parent - the original process is debugged after a fork\n\
9373 child - the new process is debugged after a fork\n\
9374 The unfollowed process will continue to run.\n\
9375 By default, the debugger will follow the parent process."),
9377 show_follow_fork_mode_string
,
9378 &setlist
, &showlist
);
9380 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9381 follow_exec_mode_names
,
9382 &follow_exec_mode_string
, _("\
9383 Set debugger response to a program call of exec."), _("\
9384 Show debugger response to a program call of exec."), _("\
9385 An exec call replaces the program image of a process.\n\
9387 follow-exec-mode can be:\n\
9389 new - the debugger creates a new inferior and rebinds the process\n\
9390 to this new inferior. The program the process was running before\n\
9391 the exec call can be restarted afterwards by restarting the original\n\
9394 same - the debugger keeps the process bound to the same inferior.\n\
9395 The new executable image replaces the previous executable loaded in\n\
9396 the inferior. Restarting the inferior after the exec call restarts\n\
9397 the executable the process was running after the exec call.\n\
9399 By default, the debugger will use the same inferior."),
9401 show_follow_exec_mode_string
,
9402 &setlist
, &showlist
);
9404 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9405 scheduler_enums
, &scheduler_mode
, _("\
9406 Set mode for locking scheduler during execution."), _("\
9407 Show mode for locking scheduler during execution."), _("\
9408 off == no locking (threads may preempt at any time)\n\
9409 on == full locking (no thread except the current thread may run)\n\
9410 This applies to both normal execution and replay mode.\n\
9411 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9412 In this mode, other threads may run during other commands.\n\
9413 This applies to both normal execution and replay mode.\n\
9414 replay == scheduler locked in replay mode and unlocked during normal execution."),
9415 set_schedlock_func
, /* traps on target vector */
9416 show_scheduler_mode
,
9417 &setlist
, &showlist
);
9419 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9420 Set mode for resuming threads of all processes."), _("\
9421 Show mode for resuming threads of all processes."), _("\
9422 When on, execution commands (such as 'continue' or 'next') resume all\n\
9423 threads of all processes. When off (which is the default), execution\n\
9424 commands only resume the threads of the current process. The set of\n\
9425 threads that are resumed is further refined by the scheduler-locking\n\
9426 mode (see help set scheduler-locking)."),
9428 show_schedule_multiple
,
9429 &setlist
, &showlist
);
9431 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9432 Set mode of the step operation."), _("\
9433 Show mode of the step operation."), _("\
9434 When set, doing a step over a function without debug line information\n\
9435 will stop at the first instruction of that function. Otherwise, the\n\
9436 function is skipped and the step command stops at a different source line."),
9438 show_step_stop_if_no_debug
,
9439 &setlist
, &showlist
);
9441 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9442 &can_use_displaced_stepping
, _("\
9443 Set debugger's willingness to use displaced stepping."), _("\
9444 Show debugger's willingness to use displaced stepping."), _("\
9445 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9446 supported by the target architecture. If off, gdb will not use displaced\n\
9447 stepping to step over breakpoints, even if such is supported by the target\n\
9448 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9449 if the target architecture supports it and non-stop mode is active, but will not\n\
9450 use it in all-stop mode (see help set non-stop)."),
9452 show_can_use_displaced_stepping
,
9453 &setlist
, &showlist
);
9455 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9456 &exec_direction
, _("Set direction of execution.\n\
9457 Options are 'forward' or 'reverse'."),
9458 _("Show direction of execution (forward/reverse)."),
9459 _("Tells gdb whether to execute forward or backward."),
9460 set_exec_direction_func
, show_exec_direction_func
,
9461 &setlist
, &showlist
);
9463 /* Set/show detach-on-fork: user-settable mode. */
9465 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9466 Set whether gdb will detach the child of a fork."), _("\
9467 Show whether gdb will detach the child of a fork."), _("\
9468 Tells gdb whether to detach the child of a fork."),
9469 NULL
, NULL
, &setlist
, &showlist
);
9471 /* Set/show disable address space randomization mode. */
9473 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9474 &disable_randomization
, _("\
9475 Set disabling of debuggee's virtual address space randomization."), _("\
9476 Show disabling of debuggee's virtual address space randomization."), _("\
9477 When this mode is on (which is the default), randomization of the virtual\n\
9478 address space is disabled. Standalone programs run with the randomization\n\
9479 enabled by default on some platforms."),
9480 &set_disable_randomization
,
9481 &show_disable_randomization
,
9482 &setlist
, &showlist
);
9484 /* ptid initializations */
9485 inferior_ptid
= null_ptid
;
9486 target_last_wait_ptid
= minus_one_ptid
;
9488 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9489 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9490 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9491 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9493 /* Explicitly create without lookup, since that tries to create a
9494 value with a void typed value, and when we get here, gdbarch
9495 isn't initialized yet. At this point, we're quite sure there
9496 isn't another convenience variable of the same name. */
9497 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9499 add_setshow_boolean_cmd ("observer", no_class
,
9500 &observer_mode_1
, _("\
9501 Set whether gdb controls the inferior in observer mode."), _("\
9502 Show whether gdb controls the inferior in observer mode."), _("\
9503 In observer mode, GDB can get data from the inferior, but not\n\
9504 affect its execution. Registers and memory may not be changed,\n\
9505 breakpoints may not be set, and the program cannot be interrupted\n\