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
);
1734 tp
->inf
->displaced_step_state
.unavailable
= true;
1736 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1739 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1741 // FIXME: Should probably replicated in the arch implementation now.
1743 // if (breakpoint_in_range_p (aspace, copy, len))
1745 // /* There's a breakpoint set in the scratch pad location range
1746 // (which is usually around the entry point). We'd either
1747 // install it before resuming, which would overwrite/corrupt the
1748 // scratch pad, or if it was already inserted, this displaced
1749 // step would overwrite it. The latter is OK in the sense that
1750 // we already assume that no thread is going to execute the code
1751 // in the scratch pad range (after initial startup) anyway, but
1752 // the former is unacceptable. Simply punt and fallback to
1753 // stepping over this breakpoint in-line. */
1754 // if (debug_displaced)
1756 // fprintf_unfiltered (gdb_stdlog,
1757 // "displaced: breakpoint set in scratch pad. "
1758 // "Stepping over breakpoint in-line instead.\n");
1761 // gdb_assert (false);
1762 // gdbarch_displaced_step_release_location (gdbarch, copy);
1767 /* Save the information we need to fix things up if the step
1769 thread_disp_step_state
->set (gdbarch
);
1771 // FIXME: get it from _prepare?
1772 CORE_ADDR displaced_pc
= 0;
1774 if (debug_displaced
)
1775 fprintf_unfiltered (gdb_stdlog
,
1776 "displaced: prepared successfully thread=%s, "
1777 "original_pc=%s, displaced_pc=%s\n",
1778 target_pid_to_str (tp
->ptid
).c_str (),
1779 paddress (gdbarch
, original_pc
),
1780 paddress (gdbarch
, displaced_pc
));
1782 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1785 /* Wrapper for displaced_step_prepare_throw that disabled further
1786 attempts at displaced stepping if we get a memory error. */
1788 static displaced_step_prepare_status
1789 displaced_step_prepare (thread_info
*thread
)
1791 displaced_step_prepare_status status
1792 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1796 status
= displaced_step_prepare_throw (thread
);
1798 catch (const gdb_exception_error
&ex
)
1800 struct displaced_step_inferior_state
*displaced_state
;
1802 if (ex
.error
!= MEMORY_ERROR
1803 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1806 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1809 /* Be verbose if "set displaced-stepping" is "on", silent if
1811 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1813 warning (_("disabling displaced stepping: %s"),
1817 /* Disable further displaced stepping attempts. */
1819 = get_displaced_stepping_state (thread
->inf
);
1820 displaced_state
->failed_before
= 1;
1826 /* If we displaced stepped an instruction successfully, adjust
1827 registers and memory to yield the same effect the instruction would
1828 have had if we had executed it at its original address, and return
1829 1. If the instruction didn't complete, relocate the PC and return
1830 -1. If the thread wasn't displaced stepping, return 0. */
1833 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1835 displaced_step_thread_state
*displaced
1836 = get_displaced_stepping_state (event_thread
);
1838 /* Was this thread performing a displaced step? */
1839 if (!displaced
->in_progress ())
1842 displaced_step_reset_cleanup
cleanup (displaced
);
1844 /* Fixup may need to read memory/registers. Switch to the thread
1845 that we're fixing up. Also, target_stopped_by_watchpoint checks
1846 the current thread, and displaced_step_restore performs ptid-dependent
1847 memory accesses using current_inferior() and current_top_target(). */
1848 switch_to_thread (event_thread
);
1850 /* Do the fixup, and release the resources acquired to do the displaced
1852 displaced_step_finish_status finish_status
=
1853 gdbarch_displaced_step_finish (displaced
->get_original_gdbarch (),
1854 event_thread
, signal
);
1856 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1862 /* Data to be passed around while handling an event. This data is
1863 discarded between events. */
1864 struct execution_control_state
1866 process_stratum_target
*target
;
1868 /* The thread that got the event, if this was a thread event; NULL
1870 struct thread_info
*event_thread
;
1872 struct target_waitstatus ws
;
1873 int stop_func_filled_in
;
1874 CORE_ADDR stop_func_start
;
1875 CORE_ADDR stop_func_end
;
1876 const char *stop_func_name
;
1879 /* True if the event thread hit the single-step breakpoint of
1880 another thread. Thus the event doesn't cause a stop, the thread
1881 needs to be single-stepped past the single-step breakpoint before
1882 we can switch back to the original stepping thread. */
1883 int hit_singlestep_breakpoint
;
1886 /* Clear ECS and set it to point at TP. */
1889 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1891 memset (ecs
, 0, sizeof (*ecs
));
1892 ecs
->event_thread
= tp
;
1893 ecs
->ptid
= tp
->ptid
;
1896 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1897 static void prepare_to_wait (struct execution_control_state
*ecs
);
1898 static int keep_going_stepped_thread (struct thread_info
*tp
);
1899 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1901 /* Are there any pending step-over requests? If so, run all we can
1902 now and return true. Otherwise, return false. */
1905 start_step_over (void)
1907 struct thread_info
*tp
, *next
;
1910 /* Don't start a new step-over if we already have an in-line
1911 step-over operation ongoing. */
1912 if (step_over_info_valid_p ())
1915 /* Steal the global thread step over chain. */
1916 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1917 global_thread_step_over_chain_head
= NULL
;
1920 fprintf_unfiltered (gdb_stdlog
,
1921 "infrun: stealing list of %d threads to step from global queue\n",
1922 thread_step_over_chain_length (threads_to_step
));
1924 for (inferior
*inf
: all_inferiors ())
1925 inf
->displaced_step_state
.unavailable
= false;
1927 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1929 struct execution_control_state ecss
;
1930 struct execution_control_state
*ecs
= &ecss
;
1931 step_over_what step_what
;
1932 int must_be_in_line
;
1934 gdb_assert (!tp
->stop_requested
);
1936 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1938 step_what
= thread_still_needs_step_over (tp
);
1939 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1940 || ((step_what
& STEP_OVER_BREAKPOINT
)
1941 && !use_displaced_stepping (tp
)));
1943 /* We currently stop all threads of all processes to step-over
1944 in-line. If we need to start a new in-line step-over, let
1945 any pending displaced steps finish first. */
1946 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1949 thread_step_over_chain_remove (&threads_to_step
, tp
);
1951 if (tp
->control
.trap_expected
1955 internal_error (__FILE__
, __LINE__
,
1956 "[%s] has inconsistent state: "
1957 "trap_expected=%d, resumed=%d, executing=%d\n",
1958 target_pid_to_str (tp
->ptid
).c_str (),
1959 tp
->control
.trap_expected
,
1964 infrun_log_debug ("resuming [%s] for step-over",
1965 target_pid_to_str (tp
->ptid
).c_str ());
1967 /* keep_going_pass_signal skips the step-over if the breakpoint
1968 is no longer inserted. In all-stop, we want to keep looking
1969 for a thread that needs a step-over instead of resuming TP,
1970 because we wouldn't be able to resume anything else until the
1971 target stops again. In non-stop, the resume always resumes
1972 only TP, so it's OK to let the thread resume freely. */
1973 if (!target_is_non_stop_p () && !step_what
)
1976 if (tp
->inf
->displaced_step_state
.unavailable
)
1978 global_thread_step_over_chain_enqueue (tp
);
1982 switch_to_thread (tp
);
1983 reset_ecs (ecs
, tp
);
1984 keep_going_pass_signal (ecs
);
1986 if (!ecs
->wait_some_more
)
1987 error (_("Command aborted."));
1989 /* If the thread's step over could not be initiated, it was re-added
1990 to the global step over chain. */
1993 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
1994 target_pid_to_str (tp
->ptid
).c_str ());
1995 gdb_assert (!thread_is_in_step_over_chain (tp
));
1999 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
2000 target_pid_to_str (tp
->ptid
).c_str ());
2001 gdb_assert (thread_is_in_step_over_chain (tp
));
2005 /* If we started a new in-line step-over, we're done. */
2006 if (step_over_info_valid_p ())
2008 gdb_assert (tp
->control
.trap_expected
);
2013 if (!target_is_non_stop_p ())
2015 /* On all-stop, shouldn't have resumed unless we needed a
2017 gdb_assert (tp
->control
.trap_expected
2018 || tp
->step_after_step_resume_breakpoint
);
2020 /* With remote targets (at least), in all-stop, we can't
2021 issue any further remote commands until the program stops
2027 /* Either the thread no longer needed a step-over, or a new
2028 displaced stepping sequence started. Even in the latter
2029 case, continue looking. Maybe we can also start another
2030 displaced step on a thread of other process. */
2033 /* If there are threads left in the THREADS_TO_STEP list, but we have
2034 detected that we can't start anything more, put back these threads
2035 in the global list. */
2036 if (threads_to_step
== NULL
)
2039 fprintf_unfiltered (gdb_stdlog
,
2040 "infrun: step-over queue now empty\n");
2045 fprintf_unfiltered (gdb_stdlog
,
2046 "infrun: putting back %d threads to step in global queue\n",
2047 thread_step_over_chain_length (threads_to_step
));
2048 while (threads_to_step
!= nullptr)
2050 thread_info
*thread
= threads_to_step
;
2052 /* Remove from that list. */
2053 thread_step_over_chain_remove (&threads_to_step
, thread
);
2055 /* Add to global list. */
2056 global_thread_step_over_chain_enqueue (thread
);
2064 /* Update global variables holding ptids to hold NEW_PTID if they were
2065 holding OLD_PTID. */
2067 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2069 if (inferior_ptid
== old_ptid
)
2070 inferior_ptid
= new_ptid
;
2075 static const char schedlock_off
[] = "off";
2076 static const char schedlock_on
[] = "on";
2077 static const char schedlock_step
[] = "step";
2078 static const char schedlock_replay
[] = "replay";
2079 static const char *const scheduler_enums
[] = {
2086 static const char *scheduler_mode
= schedlock_replay
;
2088 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2089 struct cmd_list_element
*c
, const char *value
)
2091 fprintf_filtered (file
,
2092 _("Mode for locking scheduler "
2093 "during execution is \"%s\".\n"),
2098 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2100 if (!target_can_lock_scheduler
)
2102 scheduler_mode
= schedlock_off
;
2103 error (_("Target '%s' cannot support this command."), target_shortname
);
2107 /* True if execution commands resume all threads of all processes by
2108 default; otherwise, resume only threads of the current inferior
2110 bool sched_multi
= false;
2112 /* Try to setup for software single stepping over the specified location.
2113 Return 1 if target_resume() should use hardware single step.
2115 GDBARCH the current gdbarch.
2116 PC the location to step over. */
2119 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2123 if (execution_direction
== EXEC_FORWARD
2124 && gdbarch_software_single_step_p (gdbarch
))
2125 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2133 user_visible_resume_ptid (int step
)
2139 /* With non-stop mode on, threads are always handled
2141 resume_ptid
= inferior_ptid
;
2143 else if ((scheduler_mode
== schedlock_on
)
2144 || (scheduler_mode
== schedlock_step
&& step
))
2146 /* User-settable 'scheduler' mode requires solo thread
2148 resume_ptid
= inferior_ptid
;
2150 else if ((scheduler_mode
== schedlock_replay
)
2151 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2153 /* User-settable 'scheduler' mode requires solo thread resume in replay
2155 resume_ptid
= inferior_ptid
;
2157 else if (!sched_multi
&& target_supports_multi_process ())
2159 /* Resume all threads of the current process (and none of other
2161 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2165 /* Resume all threads of all processes. */
2166 resume_ptid
= RESUME_ALL
;
2174 process_stratum_target
*
2175 user_visible_resume_target (ptid_t resume_ptid
)
2177 return (resume_ptid
== minus_one_ptid
&& sched_multi
2179 : current_inferior ()->process_target ());
2182 /* Return a ptid representing the set of threads that we will resume,
2183 in the perspective of the target, assuming run control handling
2184 does not require leaving some threads stopped (e.g., stepping past
2185 breakpoint). USER_STEP indicates whether we're about to start the
2186 target for a stepping command. */
2189 internal_resume_ptid (int user_step
)
2191 /* In non-stop, we always control threads individually. Note that
2192 the target may always work in non-stop mode even with "set
2193 non-stop off", in which case user_visible_resume_ptid could
2194 return a wildcard ptid. */
2195 if (target_is_non_stop_p ())
2196 return inferior_ptid
;
2198 return user_visible_resume_ptid (user_step
);
2201 /* Wrapper for target_resume, that handles infrun-specific
2205 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2207 struct thread_info
*tp
= inferior_thread ();
2209 gdb_assert (!tp
->stop_requested
);
2211 /* Install inferior's terminal modes. */
2212 target_terminal::inferior ();
2214 /* Avoid confusing the next resume, if the next stop/resume
2215 happens to apply to another thread. */
2216 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2218 /* Advise target which signals may be handled silently.
2220 If we have removed breakpoints because we are stepping over one
2221 in-line (in any thread), we need to receive all signals to avoid
2222 accidentally skipping a breakpoint during execution of a signal
2225 Likewise if we're displaced stepping, otherwise a trap for a
2226 breakpoint in a signal handler might be confused with the
2227 displaced step finishing. We don't make the displaced_step_fixup
2228 step distinguish the cases instead, because:
2230 - a backtrace while stopped in the signal handler would show the
2231 scratch pad as frame older than the signal handler, instead of
2232 the real mainline code.
2234 - when the thread is later resumed, the signal handler would
2235 return to the scratch pad area, which would no longer be
2237 if (step_over_info_valid_p ()
2238 || displaced_step_in_progress (tp
->inf
))
2239 target_pass_signals ({});
2241 target_pass_signals (signal_pass
);
2243 target_resume (resume_ptid
, step
, sig
);
2245 target_commit_resume ();
2247 if (target_can_async_p ())
2251 /* Resume the inferior. SIG is the signal to give the inferior
2252 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2253 call 'resume', which handles exceptions. */
2256 resume_1 (enum gdb_signal sig
)
2258 struct regcache
*regcache
= get_current_regcache ();
2259 struct gdbarch
*gdbarch
= regcache
->arch ();
2260 struct thread_info
*tp
= inferior_thread ();
2261 const address_space
*aspace
= regcache
->aspace ();
2263 /* This represents the user's step vs continue request. When
2264 deciding whether "set scheduler-locking step" applies, it's the
2265 user's intention that counts. */
2266 const int user_step
= tp
->control
.stepping_command
;
2267 /* This represents what we'll actually request the target to do.
2268 This can decay from a step to a continue, if e.g., we need to
2269 implement single-stepping with breakpoints (software
2273 gdb_assert (!tp
->stop_requested
);
2274 gdb_assert (!thread_is_in_step_over_chain (tp
));
2276 if (tp
->suspend
.waitstatus_pending_p
)
2279 ("thread %s has pending wait "
2280 "status %s (currently_stepping=%d).",
2281 target_pid_to_str (tp
->ptid
).c_str (),
2282 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2283 currently_stepping (tp
));
2285 tp
->inf
->process_target ()->threads_executing
= true;
2288 /* FIXME: What should we do if we are supposed to resume this
2289 thread with a signal? Maybe we should maintain a queue of
2290 pending signals to deliver. */
2291 if (sig
!= GDB_SIGNAL_0
)
2293 warning (_("Couldn't deliver signal %s to %s."),
2294 gdb_signal_to_name (sig
),
2295 target_pid_to_str (tp
->ptid
).c_str ());
2298 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2300 if (target_can_async_p ())
2303 /* Tell the event loop we have an event to process. */
2304 mark_async_event_handler (infrun_async_inferior_event_token
);
2309 tp
->stepped_breakpoint
= 0;
2311 /* Depends on stepped_breakpoint. */
2312 step
= currently_stepping (tp
);
2314 if (current_inferior ()->waiting_for_vfork_done
)
2316 /* Don't try to single-step a vfork parent that is waiting for
2317 the child to get out of the shared memory region (by exec'ing
2318 or exiting). This is particularly important on software
2319 single-step archs, as the child process would trip on the
2320 software single step breakpoint inserted for the parent
2321 process. Since the parent will not actually execute any
2322 instruction until the child is out of the shared region (such
2323 are vfork's semantics), it is safe to simply continue it.
2324 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2325 the parent, and tell it to `keep_going', which automatically
2326 re-sets it stepping. */
2327 infrun_log_debug ("resume : clear step");
2331 CORE_ADDR pc
= regcache_read_pc (regcache
);
2333 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2334 "current thread [%s] at %s",
2335 step
, gdb_signal_to_symbol_string (sig
),
2336 tp
->control
.trap_expected
,
2337 target_pid_to_str (inferior_ptid
).c_str (),
2338 paddress (gdbarch
, pc
));
2340 /* Normally, by the time we reach `resume', the breakpoints are either
2341 removed or inserted, as appropriate. The exception is if we're sitting
2342 at a permanent breakpoint; we need to step over it, but permanent
2343 breakpoints can't be removed. So we have to test for it here. */
2344 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2346 if (sig
!= GDB_SIGNAL_0
)
2348 /* We have a signal to pass to the inferior. The resume
2349 may, or may not take us to the signal handler. If this
2350 is a step, we'll need to stop in the signal handler, if
2351 there's one, (if the target supports stepping into
2352 handlers), or in the next mainline instruction, if
2353 there's no handler. If this is a continue, we need to be
2354 sure to run the handler with all breakpoints inserted.
2355 In all cases, set a breakpoint at the current address
2356 (where the handler returns to), and once that breakpoint
2357 is hit, resume skipping the permanent breakpoint. If
2358 that breakpoint isn't hit, then we've stepped into the
2359 signal handler (or hit some other event). We'll delete
2360 the step-resume breakpoint then. */
2362 infrun_log_debug ("resume: skipping permanent breakpoint, "
2363 "deliver signal first");
2365 clear_step_over_info ();
2366 tp
->control
.trap_expected
= 0;
2368 if (tp
->control
.step_resume_breakpoint
== NULL
)
2370 /* Set a "high-priority" step-resume, as we don't want
2371 user breakpoints at PC to trigger (again) when this
2373 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2374 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2376 tp
->step_after_step_resume_breakpoint
= step
;
2379 insert_breakpoints ();
2383 /* There's no signal to pass, we can go ahead and skip the
2384 permanent breakpoint manually. */
2385 infrun_log_debug ("skipping permanent breakpoint");
2386 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2387 /* Update pc to reflect the new address from which we will
2388 execute instructions. */
2389 pc
= regcache_read_pc (regcache
);
2393 /* We've already advanced the PC, so the stepping part
2394 is done. Now we need to arrange for a trap to be
2395 reported to handle_inferior_event. Set a breakpoint
2396 at the current PC, and run to it. Don't update
2397 prev_pc, because if we end in
2398 switch_back_to_stepped_thread, we want the "expected
2399 thread advanced also" branch to be taken. IOW, we
2400 don't want this thread to step further from PC
2402 gdb_assert (!step_over_info_valid_p ());
2403 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2404 insert_breakpoints ();
2406 resume_ptid
= internal_resume_ptid (user_step
);
2407 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2414 /* If we have a breakpoint to step over, make sure to do a single
2415 step only. Same if we have software watchpoints. */
2416 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2417 tp
->control
.may_range_step
= 0;
2419 /* If displaced stepping is enabled, step over breakpoints by executing a
2420 copy of the instruction at a different address.
2422 We can't use displaced stepping when we have a signal to deliver;
2423 the comments for displaced_step_prepare explain why. The
2424 comments in the handle_inferior event for dealing with 'random
2425 signals' explain what we do instead.
2427 We can't use displaced stepping when we are waiting for vfork_done
2428 event, displaced stepping breaks the vfork child similarly as single
2429 step software breakpoint. */
2430 if (tp
->control
.trap_expected
2431 && use_displaced_stepping (tp
)
2432 && !step_over_info_valid_p ()
2433 && sig
== GDB_SIGNAL_0
2434 && !current_inferior ()->waiting_for_vfork_done
)
2436 displaced_step_prepare_status prepare_status
2437 = displaced_step_prepare (tp
);
2439 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2441 infrun_log_debug ("Got placed in step-over queue");
2443 tp
->control
.trap_expected
= 0;
2446 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2448 /* Fallback to stepping over the breakpoint in-line. */
2450 if (target_is_non_stop_p ())
2451 stop_all_threads ();
2453 set_step_over_info (regcache
->aspace (),
2454 regcache_read_pc (regcache
), 0, tp
->global_num
);
2456 step
= maybe_software_singlestep (gdbarch
, pc
);
2458 insert_breakpoints ();
2460 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2462 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2465 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2468 /* Do we need to do it the hard way, w/temp breakpoints? */
2470 step
= maybe_software_singlestep (gdbarch
, pc
);
2472 /* Currently, our software single-step implementation leads to different
2473 results than hardware single-stepping in one situation: when stepping
2474 into delivering a signal which has an associated signal handler,
2475 hardware single-step will stop at the first instruction of the handler,
2476 while software single-step will simply skip execution of the handler.
2478 For now, this difference in behavior is accepted since there is no
2479 easy way to actually implement single-stepping into a signal handler
2480 without kernel support.
2482 However, there is one scenario where this difference leads to follow-on
2483 problems: if we're stepping off a breakpoint by removing all breakpoints
2484 and then single-stepping. In this case, the software single-step
2485 behavior means that even if there is a *breakpoint* in the signal
2486 handler, GDB still would not stop.
2488 Fortunately, we can at least fix this particular issue. We detect
2489 here the case where we are about to deliver a signal while software
2490 single-stepping with breakpoints removed. In this situation, we
2491 revert the decisions to remove all breakpoints and insert single-
2492 step breakpoints, and instead we install a step-resume breakpoint
2493 at the current address, deliver the signal without stepping, and
2494 once we arrive back at the step-resume breakpoint, actually step
2495 over the breakpoint we originally wanted to step over. */
2496 if (thread_has_single_step_breakpoints_set (tp
)
2497 && sig
!= GDB_SIGNAL_0
2498 && step_over_info_valid_p ())
2500 /* If we have nested signals or a pending signal is delivered
2501 immediately after a handler returns, might already have
2502 a step-resume breakpoint set on the earlier handler. We cannot
2503 set another step-resume breakpoint; just continue on until the
2504 original breakpoint is hit. */
2505 if (tp
->control
.step_resume_breakpoint
== NULL
)
2507 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2508 tp
->step_after_step_resume_breakpoint
= 1;
2511 delete_single_step_breakpoints (tp
);
2513 clear_step_over_info ();
2514 tp
->control
.trap_expected
= 0;
2516 insert_breakpoints ();
2519 /* If STEP is set, it's a request to use hardware stepping
2520 facilities. But in that case, we should never
2521 use singlestep breakpoint. */
2522 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2524 /* Decide the set of threads to ask the target to resume. */
2525 if (tp
->control
.trap_expected
)
2527 /* We're allowing a thread to run past a breakpoint it has
2528 hit, either by single-stepping the thread with the breakpoint
2529 removed, or by displaced stepping, with the breakpoint inserted.
2530 In the former case, we need to single-step only this thread,
2531 and keep others stopped, as they can miss this breakpoint if
2532 allowed to run. That's not really a problem for displaced
2533 stepping, but, we still keep other threads stopped, in case
2534 another thread is also stopped for a breakpoint waiting for
2535 its turn in the displaced stepping queue. */
2536 resume_ptid
= inferior_ptid
;
2539 resume_ptid
= internal_resume_ptid (user_step
);
2541 if (execution_direction
!= EXEC_REVERSE
2542 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2544 /* There are two cases where we currently need to step a
2545 breakpoint instruction when we have a signal to deliver:
2547 - See handle_signal_stop where we handle random signals that
2548 could take out us out of the stepping range. Normally, in
2549 that case we end up continuing (instead of stepping) over the
2550 signal handler with a breakpoint at PC, but there are cases
2551 where we should _always_ single-step, even if we have a
2552 step-resume breakpoint, like when a software watchpoint is
2553 set. Assuming single-stepping and delivering a signal at the
2554 same time would takes us to the signal handler, then we could
2555 have removed the breakpoint at PC to step over it. However,
2556 some hardware step targets (like e.g., Mac OS) can't step
2557 into signal handlers, and for those, we need to leave the
2558 breakpoint at PC inserted, as otherwise if the handler
2559 recurses and executes PC again, it'll miss the breakpoint.
2560 So we leave the breakpoint inserted anyway, but we need to
2561 record that we tried to step a breakpoint instruction, so
2562 that adjust_pc_after_break doesn't end up confused.
2564 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2565 in one thread after another thread that was stepping had been
2566 momentarily paused for a step-over. When we re-resume the
2567 stepping thread, it may be resumed from that address with a
2568 breakpoint that hasn't trapped yet. Seen with
2569 gdb.threads/non-stop-fair-events.exp, on targets that don't
2570 do displaced stepping. */
2572 infrun_log_debug ("resume: [%s] stepped breakpoint",
2573 target_pid_to_str (tp
->ptid
).c_str ());
2575 tp
->stepped_breakpoint
= 1;
2577 /* Most targets can step a breakpoint instruction, thus
2578 executing it normally. But if this one cannot, just
2579 continue and we will hit it anyway. */
2580 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2585 && tp
->control
.trap_expected
2586 && use_displaced_stepping (tp
)
2587 && !step_over_info_valid_p ())
2589 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2590 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2591 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2594 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2595 paddress (resume_gdbarch
, actual_pc
));
2596 read_memory (actual_pc
, buf
, sizeof (buf
));
2597 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2600 if (tp
->control
.may_range_step
)
2602 /* If we're resuming a thread with the PC out of the step
2603 range, then we're doing some nested/finer run control
2604 operation, like stepping the thread out of the dynamic
2605 linker or the displaced stepping scratch pad. We
2606 shouldn't have allowed a range step then. */
2607 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2610 do_target_resume (resume_ptid
, step
, sig
);
2614 /* Resume the inferior. SIG is the signal to give the inferior
2615 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2616 rolls back state on error. */
2619 resume (gdb_signal sig
)
2625 catch (const gdb_exception
&ex
)
2627 /* If resuming is being aborted for any reason, delete any
2628 single-step breakpoint resume_1 may have created, to avoid
2629 confusing the following resumption, and to avoid leaving
2630 single-step breakpoints perturbing other threads, in case
2631 we're running in non-stop mode. */
2632 if (inferior_ptid
!= null_ptid
)
2633 delete_single_step_breakpoints (inferior_thread ());
2643 /* Counter that tracks number of user visible stops. This can be used
2644 to tell whether a command has proceeded the inferior past the
2645 current location. This allows e.g., inferior function calls in
2646 breakpoint commands to not interrupt the command list. When the
2647 call finishes successfully, the inferior is standing at the same
2648 breakpoint as if nothing happened (and so we don't call
2650 static ULONGEST current_stop_id
;
2657 return current_stop_id
;
2660 /* Called when we report a user visible stop. */
2668 /* Clear out all variables saying what to do when inferior is continued.
2669 First do this, then set the ones you want, then call `proceed'. */
2672 clear_proceed_status_thread (struct thread_info
*tp
)
2674 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2676 /* If we're starting a new sequence, then the previous finished
2677 single-step is no longer relevant. */
2678 if (tp
->suspend
.waitstatus_pending_p
)
2680 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2682 infrun_log_debug ("pending event of %s was a finished step. "
2684 target_pid_to_str (tp
->ptid
).c_str ());
2686 tp
->suspend
.waitstatus_pending_p
= 0;
2687 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2692 ("thread %s has pending wait status %s (currently_stepping=%d).",
2693 target_pid_to_str (tp
->ptid
).c_str (),
2694 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2695 currently_stepping (tp
));
2699 /* If this signal should not be seen by program, give it zero.
2700 Used for debugging signals. */
2701 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2702 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2704 delete tp
->thread_fsm
;
2705 tp
->thread_fsm
= NULL
;
2707 tp
->control
.trap_expected
= 0;
2708 tp
->control
.step_range_start
= 0;
2709 tp
->control
.step_range_end
= 0;
2710 tp
->control
.may_range_step
= 0;
2711 tp
->control
.step_frame_id
= null_frame_id
;
2712 tp
->control
.step_stack_frame_id
= null_frame_id
;
2713 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2714 tp
->control
.step_start_function
= NULL
;
2715 tp
->stop_requested
= 0;
2717 tp
->control
.stop_step
= 0;
2719 tp
->control
.proceed_to_finish
= 0;
2721 tp
->control
.stepping_command
= 0;
2723 /* Discard any remaining commands or status from previous stop. */
2724 bpstat_clear (&tp
->control
.stop_bpstat
);
2728 clear_proceed_status (int step
)
2730 /* With scheduler-locking replay, stop replaying other threads if we're
2731 not replaying the user-visible resume ptid.
2733 This is a convenience feature to not require the user to explicitly
2734 stop replaying the other threads. We're assuming that the user's
2735 intent is to resume tracing the recorded process. */
2736 if (!non_stop
&& scheduler_mode
== schedlock_replay
2737 && target_record_is_replaying (minus_one_ptid
)
2738 && !target_record_will_replay (user_visible_resume_ptid (step
),
2739 execution_direction
))
2740 target_record_stop_replaying ();
2742 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2744 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2745 process_stratum_target
*resume_target
2746 = user_visible_resume_target (resume_ptid
);
2748 /* In all-stop mode, delete the per-thread status of all threads
2749 we're about to resume, implicitly and explicitly. */
2750 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2751 clear_proceed_status_thread (tp
);
2754 if (inferior_ptid
!= null_ptid
)
2756 struct inferior
*inferior
;
2760 /* If in non-stop mode, only delete the per-thread status of
2761 the current thread. */
2762 clear_proceed_status_thread (inferior_thread ());
2765 inferior
= current_inferior ();
2766 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2769 gdb::observers::about_to_proceed
.notify ();
2772 /* Returns true if TP is still stopped at a breakpoint that needs
2773 stepping-over in order to make progress. If the breakpoint is gone
2774 meanwhile, we can skip the whole step-over dance. */
2777 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2779 if (tp
->stepping_over_breakpoint
)
2781 struct regcache
*regcache
= get_thread_regcache (tp
);
2783 if (breakpoint_here_p (regcache
->aspace (),
2784 regcache_read_pc (regcache
))
2785 == ordinary_breakpoint_here
)
2788 tp
->stepping_over_breakpoint
= 0;
2794 /* Check whether thread TP still needs to start a step-over in order
2795 to make progress when resumed. Returns an bitwise or of enum
2796 step_over_what bits, indicating what needs to be stepped over. */
2798 static step_over_what
2799 thread_still_needs_step_over (struct thread_info
*tp
)
2801 step_over_what what
= 0;
2803 if (thread_still_needs_step_over_bp (tp
))
2804 what
|= STEP_OVER_BREAKPOINT
;
2806 if (tp
->stepping_over_watchpoint
2807 && !target_have_steppable_watchpoint
)
2808 what
|= STEP_OVER_WATCHPOINT
;
2813 /* Returns true if scheduler locking applies. STEP indicates whether
2814 we're about to do a step/next-like command to a thread. */
2817 schedlock_applies (struct thread_info
*tp
)
2819 return (scheduler_mode
== schedlock_on
2820 || (scheduler_mode
== schedlock_step
2821 && tp
->control
.stepping_command
)
2822 || (scheduler_mode
== schedlock_replay
2823 && target_record_will_replay (minus_one_ptid
,
2824 execution_direction
)));
2827 /* Calls target_commit_resume on all targets. */
2830 commit_resume_all_targets ()
2832 scoped_restore_current_thread restore_thread
;
2834 /* Map between process_target and a representative inferior. This
2835 is to avoid committing a resume in the same target more than
2836 once. Resumptions must be idempotent, so this is an
2838 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2840 for (inferior
*inf
: all_non_exited_inferiors ())
2841 if (inf
->has_execution ())
2842 conn_inf
[inf
->process_target ()] = inf
;
2844 for (const auto &ci
: conn_inf
)
2846 inferior
*inf
= ci
.second
;
2847 switch_to_inferior_no_thread (inf
);
2848 target_commit_resume ();
2852 /* Check that all the targets we're about to resume are in non-stop
2853 mode. Ideally, we'd only care whether all targets support
2854 target-async, but we're not there yet. E.g., stop_all_threads
2855 doesn't know how to handle all-stop targets. Also, the remote
2856 protocol in all-stop mode is synchronous, irrespective of
2857 target-async, which means that things like a breakpoint re-set
2858 triggered by one target would try to read memory from all targets
2862 check_multi_target_resumption (process_stratum_target
*resume_target
)
2864 if (!non_stop
&& resume_target
== nullptr)
2866 scoped_restore_current_thread restore_thread
;
2868 /* This is used to track whether we're resuming more than one
2870 process_stratum_target
*first_connection
= nullptr;
2872 /* The first inferior we see with a target that does not work in
2873 always-non-stop mode. */
2874 inferior
*first_not_non_stop
= nullptr;
2876 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2878 switch_to_inferior_no_thread (inf
);
2880 if (!target_has_execution
)
2883 process_stratum_target
*proc_target
2884 = current_inferior ()->process_target();
2886 if (!target_is_non_stop_p ())
2887 first_not_non_stop
= inf
;
2889 if (first_connection
== nullptr)
2890 first_connection
= proc_target
;
2891 else if (first_connection
!= proc_target
2892 && first_not_non_stop
!= nullptr)
2894 switch_to_inferior_no_thread (first_not_non_stop
);
2896 proc_target
= current_inferior ()->process_target();
2898 error (_("Connection %d (%s) does not support "
2899 "multi-target resumption."),
2900 proc_target
->connection_number
,
2901 make_target_connection_string (proc_target
).c_str ());
2907 /* Basic routine for continuing the program in various fashions.
2909 ADDR is the address to resume at, or -1 for resume where stopped.
2910 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2911 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2913 You should call clear_proceed_status before calling proceed. */
2916 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2918 struct regcache
*regcache
;
2919 struct gdbarch
*gdbarch
;
2921 struct execution_control_state ecss
;
2922 struct execution_control_state
*ecs
= &ecss
;
2925 /* If we're stopped at a fork/vfork, follow the branch set by the
2926 "set follow-fork-mode" command; otherwise, we'll just proceed
2927 resuming the current thread. */
2928 if (!follow_fork ())
2930 /* The target for some reason decided not to resume. */
2932 if (target_can_async_p ())
2933 inferior_event_handler (INF_EXEC_COMPLETE
);
2937 /* We'll update this if & when we switch to a new thread. */
2938 previous_inferior_ptid
= inferior_ptid
;
2940 regcache
= get_current_regcache ();
2941 gdbarch
= regcache
->arch ();
2942 const address_space
*aspace
= regcache
->aspace ();
2944 pc
= regcache_read_pc_protected (regcache
);
2946 thread_info
*cur_thr
= inferior_thread ();
2948 /* Fill in with reasonable starting values. */
2949 init_thread_stepping_state (cur_thr
);
2951 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2954 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2955 process_stratum_target
*resume_target
2956 = user_visible_resume_target (resume_ptid
);
2958 check_multi_target_resumption (resume_target
);
2960 if (addr
== (CORE_ADDR
) -1)
2962 if (pc
== cur_thr
->suspend
.stop_pc
2963 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2964 && execution_direction
!= EXEC_REVERSE
)
2965 /* There is a breakpoint at the address we will resume at,
2966 step one instruction before inserting breakpoints so that
2967 we do not stop right away (and report a second hit at this
2970 Note, we don't do this in reverse, because we won't
2971 actually be executing the breakpoint insn anyway.
2972 We'll be (un-)executing the previous instruction. */
2973 cur_thr
->stepping_over_breakpoint
= 1;
2974 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2975 && gdbarch_single_step_through_delay (gdbarch
,
2976 get_current_frame ()))
2977 /* We stepped onto an instruction that needs to be stepped
2978 again before re-inserting the breakpoint, do so. */
2979 cur_thr
->stepping_over_breakpoint
= 1;
2983 regcache_write_pc (regcache
, addr
);
2986 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2987 cur_thr
->suspend
.stop_signal
= siggnal
;
2989 /* If an exception is thrown from this point on, make sure to
2990 propagate GDB's knowledge of the executing state to the
2991 frontend/user running state. */
2992 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2994 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2995 threads (e.g., we might need to set threads stepping over
2996 breakpoints first), from the user/frontend's point of view, all
2997 threads in RESUME_PTID are now running. Unless we're calling an
2998 inferior function, as in that case we pretend the inferior
2999 doesn't run at all. */
3000 if (!cur_thr
->control
.in_infcall
)
3001 set_running (resume_target
, resume_ptid
, true);
3003 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3004 gdb_signal_to_symbol_string (siggnal
));
3006 annotate_starting ();
3008 /* Make sure that output from GDB appears before output from the
3010 gdb_flush (gdb_stdout
);
3012 /* Since we've marked the inferior running, give it the terminal. A
3013 QUIT/Ctrl-C from here on is forwarded to the target (which can
3014 still detect attempts to unblock a stuck connection with repeated
3015 Ctrl-C from within target_pass_ctrlc). */
3016 target_terminal::inferior ();
3018 /* In a multi-threaded task we may select another thread and
3019 then continue or step.
3021 But if a thread that we're resuming had stopped at a breakpoint,
3022 it will immediately cause another breakpoint stop without any
3023 execution (i.e. it will report a breakpoint hit incorrectly). So
3024 we must step over it first.
3026 Look for threads other than the current (TP) that reported a
3027 breakpoint hit and haven't been resumed yet since. */
3029 /* If scheduler locking applies, we can avoid iterating over all
3031 if (!non_stop
&& !schedlock_applies (cur_thr
))
3033 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3036 switch_to_thread_no_regs (tp
);
3038 /* Ignore the current thread here. It's handled
3043 if (!thread_still_needs_step_over (tp
))
3046 gdb_assert (!thread_is_in_step_over_chain (tp
));
3048 infrun_log_debug ("need to step-over [%s] first",
3049 target_pid_to_str (tp
->ptid
).c_str ());
3051 global_thread_step_over_chain_enqueue (tp
);
3054 switch_to_thread (cur_thr
);
3057 /* Enqueue the current thread last, so that we move all other
3058 threads over their breakpoints first. */
3059 if (cur_thr
->stepping_over_breakpoint
)
3060 global_thread_step_over_chain_enqueue (cur_thr
);
3062 /* If the thread isn't started, we'll still need to set its prev_pc,
3063 so that switch_back_to_stepped_thread knows the thread hasn't
3064 advanced. Must do this before resuming any thread, as in
3065 all-stop/remote, once we resume we can't send any other packet
3066 until the target stops again. */
3067 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3070 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3072 started
= start_step_over ();
3074 if (step_over_info_valid_p ())
3076 /* Either this thread started a new in-line step over, or some
3077 other thread was already doing one. In either case, don't
3078 resume anything else until the step-over is finished. */
3080 else if (started
&& !target_is_non_stop_p ())
3082 /* A new displaced stepping sequence was started. In all-stop,
3083 we can't talk to the target anymore until it next stops. */
3085 else if (!non_stop
&& target_is_non_stop_p ())
3087 /* In all-stop, but the target is always in non-stop mode.
3088 Start all other threads that are implicitly resumed too. */
3089 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3092 switch_to_thread_no_regs (tp
);
3094 if (!tp
->inf
->has_execution ())
3096 infrun_log_debug ("[%s] target has no execution",
3097 target_pid_to_str (tp
->ptid
).c_str ());
3103 infrun_log_debug ("[%s] resumed",
3104 target_pid_to_str (tp
->ptid
).c_str ());
3105 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3109 if (thread_is_in_step_over_chain (tp
))
3111 infrun_log_debug ("[%s] needs step-over",
3112 target_pid_to_str (tp
->ptid
).c_str ());
3116 infrun_log_debug ("resuming %s",
3117 target_pid_to_str (tp
->ptid
).c_str ());
3119 reset_ecs (ecs
, tp
);
3120 switch_to_thread (tp
);
3121 keep_going_pass_signal (ecs
);
3122 if (!ecs
->wait_some_more
)
3123 error (_("Command aborted."));
3126 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3128 /* The thread wasn't started, and isn't queued, run it now. */
3129 reset_ecs (ecs
, cur_thr
);
3130 switch_to_thread (cur_thr
);
3131 keep_going_pass_signal (ecs
);
3132 if (!ecs
->wait_some_more
)
3133 error (_("Command aborted."));
3137 commit_resume_all_targets ();
3139 finish_state
.release ();
3141 /* If we've switched threads above, switch back to the previously
3142 current thread. We don't want the user to see a different
3144 switch_to_thread (cur_thr
);
3146 /* Tell the event loop to wait for it to stop. If the target
3147 supports asynchronous execution, it'll do this from within
3149 if (!target_can_async_p ())
3150 mark_async_event_handler (infrun_async_inferior_event_token
);
3154 /* Start remote-debugging of a machine over a serial link. */
3157 start_remote (int from_tty
)
3159 inferior
*inf
= current_inferior ();
3160 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3162 /* Always go on waiting for the target, regardless of the mode. */
3163 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3164 indicate to wait_for_inferior that a target should timeout if
3165 nothing is returned (instead of just blocking). Because of this,
3166 targets expecting an immediate response need to, internally, set
3167 things up so that the target_wait() is forced to eventually
3169 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3170 differentiate to its caller what the state of the target is after
3171 the initial open has been performed. Here we're assuming that
3172 the target has stopped. It should be possible to eventually have
3173 target_open() return to the caller an indication that the target
3174 is currently running and GDB state should be set to the same as
3175 for an async run. */
3176 wait_for_inferior (inf
);
3178 /* Now that the inferior has stopped, do any bookkeeping like
3179 loading shared libraries. We want to do this before normal_stop,
3180 so that the displayed frame is up to date. */
3181 post_create_inferior (current_top_target (), from_tty
);
3186 /* Initialize static vars when a new inferior begins. */
3189 init_wait_for_inferior (void)
3191 /* These are meaningless until the first time through wait_for_inferior. */
3193 breakpoint_init_inferior (inf_starting
);
3195 clear_proceed_status (0);
3197 nullify_last_target_wait_ptid ();
3199 previous_inferior_ptid
= inferior_ptid
;
3204 static void handle_inferior_event (struct execution_control_state
*ecs
);
3206 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3207 struct execution_control_state
*ecs
);
3208 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3209 struct execution_control_state
*ecs
);
3210 static void handle_signal_stop (struct execution_control_state
*ecs
);
3211 static void check_exception_resume (struct execution_control_state
*,
3212 struct frame_info
*);
3214 static void end_stepping_range (struct execution_control_state
*ecs
);
3215 static void stop_waiting (struct execution_control_state
*ecs
);
3216 static void keep_going (struct execution_control_state
*ecs
);
3217 static void process_event_stop_test (struct execution_control_state
*ecs
);
3218 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3220 /* This function is attached as a "thread_stop_requested" observer.
3221 Cleanup local state that assumed the PTID was to be resumed, and
3222 report the stop to the frontend. */
3225 infrun_thread_stop_requested (ptid_t ptid
)
3227 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3229 /* PTID was requested to stop. If the thread was already stopped,
3230 but the user/frontend doesn't know about that yet (e.g., the
3231 thread had been temporarily paused for some step-over), set up
3232 for reporting the stop now. */
3233 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3235 if (tp
->state
!= THREAD_RUNNING
)
3240 /* Remove matching threads from the step-over queue, so
3241 start_step_over doesn't try to resume them
3243 if (thread_is_in_step_over_chain (tp
))
3244 global_thread_step_over_chain_remove (tp
);
3246 /* If the thread is stopped, but the user/frontend doesn't
3247 know about that yet, queue a pending event, as if the
3248 thread had just stopped now. Unless the thread already had
3250 if (!tp
->suspend
.waitstatus_pending_p
)
3252 tp
->suspend
.waitstatus_pending_p
= 1;
3253 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3254 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3257 /* Clear the inline-frame state, since we're re-processing the
3259 clear_inline_frame_state (tp
);
3261 /* If this thread was paused because some other thread was
3262 doing an inline-step over, let that finish first. Once
3263 that happens, we'll restart all threads and consume pending
3264 stop events then. */
3265 if (step_over_info_valid_p ())
3268 /* Otherwise we can process the (new) pending event now. Set
3269 it so this pending event is considered by
3276 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3278 if (target_last_proc_target
== tp
->inf
->process_target ()
3279 && target_last_wait_ptid
== tp
->ptid
)
3280 nullify_last_target_wait_ptid ();
3283 /* Delete the step resume, single-step and longjmp/exception resume
3284 breakpoints of TP. */
3287 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3289 delete_step_resume_breakpoint (tp
);
3290 delete_exception_resume_breakpoint (tp
);
3291 delete_single_step_breakpoints (tp
);
3294 /* If the target still has execution, call FUNC for each thread that
3295 just stopped. In all-stop, that's all the non-exited threads; in
3296 non-stop, that's the current thread, only. */
3298 typedef void (*for_each_just_stopped_thread_callback_func
)
3299 (struct thread_info
*tp
);
3302 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3304 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3307 if (target_is_non_stop_p ())
3309 /* If in non-stop mode, only the current thread stopped. */
3310 func (inferior_thread ());
3314 /* In all-stop mode, all threads have stopped. */
3315 for (thread_info
*tp
: all_non_exited_threads ())
3320 /* Delete the step resume and longjmp/exception resume breakpoints of
3321 the threads that just stopped. */
3324 delete_just_stopped_threads_infrun_breakpoints (void)
3326 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3329 /* Delete the single-step breakpoints of the threads that just
3333 delete_just_stopped_threads_single_step_breakpoints (void)
3335 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3341 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3342 const struct target_waitstatus
*ws
)
3344 std::string status_string
= target_waitstatus_to_string (ws
);
3347 /* The text is split over several lines because it was getting too long.
3348 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3349 output as a unit; we want only one timestamp printed if debug_timestamp
3352 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3355 waiton_ptid
.tid ());
3356 if (waiton_ptid
.pid () != -1)
3357 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3358 stb
.printf (", status) =\n");
3359 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3363 target_pid_to_str (result_ptid
).c_str ());
3364 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3366 /* This uses %s in part to handle %'s in the text, but also to avoid
3367 a gcc error: the format attribute requires a string literal. */
3368 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3371 /* Select a thread at random, out of those which are resumed and have
3374 static struct thread_info
*
3375 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3379 auto has_event
= [&] (thread_info
*tp
)
3381 return (tp
->ptid
.matches (waiton_ptid
)
3383 && tp
->suspend
.waitstatus_pending_p
);
3386 /* First see how many events we have. Count only resumed threads
3387 that have an event pending. */
3388 for (thread_info
*tp
: inf
->non_exited_threads ())
3392 if (num_events
== 0)
3395 /* Now randomly pick a thread out of those that have had events. */
3396 int random_selector
= (int) ((num_events
* (double) rand ())
3397 / (RAND_MAX
+ 1.0));
3400 infrun_log_debug ("Found %d events, selecting #%d",
3401 num_events
, random_selector
);
3403 /* Select the Nth thread that has had an event. */
3404 for (thread_info
*tp
: inf
->non_exited_threads ())
3406 if (random_selector
-- == 0)
3409 gdb_assert_not_reached ("event thread not found");
3412 /* Wrapper for target_wait that first checks whether threads have
3413 pending statuses to report before actually asking the target for
3414 more events. INF is the inferior we're using to call target_wait
3418 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3419 target_waitstatus
*status
, int options
)
3422 struct thread_info
*tp
;
3424 /* We know that we are looking for an event in the target of inferior
3425 INF, but we don't know which thread the event might come from. As
3426 such we want to make sure that INFERIOR_PTID is reset so that none of
3427 the wait code relies on it - doing so is always a mistake. */
3428 switch_to_inferior_no_thread (inf
);
3430 /* First check if there is a resumed thread with a wait status
3432 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3434 tp
= random_pending_event_thread (inf
, ptid
);
3438 infrun_log_debug ("Waiting for specific thread %s.",
3439 target_pid_to_str (ptid
).c_str ());
3441 /* We have a specific thread to check. */
3442 tp
= find_thread_ptid (inf
, ptid
);
3443 gdb_assert (tp
!= NULL
);
3444 if (!tp
->suspend
.waitstatus_pending_p
)
3449 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3450 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3452 struct regcache
*regcache
= get_thread_regcache (tp
);
3453 struct gdbarch
*gdbarch
= regcache
->arch ();
3457 pc
= regcache_read_pc (regcache
);
3459 if (pc
!= tp
->suspend
.stop_pc
)
3461 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3462 target_pid_to_str (tp
->ptid
).c_str (),
3463 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3464 paddress (gdbarch
, pc
));
3467 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3469 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3470 target_pid_to_str (tp
->ptid
).c_str (),
3471 paddress (gdbarch
, pc
));
3478 infrun_log_debug ("pending event of %s cancelled.",
3479 target_pid_to_str (tp
->ptid
).c_str ());
3481 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3482 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3488 infrun_log_debug ("Using pending wait status %s for %s.",
3489 target_waitstatus_to_string
3490 (&tp
->suspend
.waitstatus
).c_str (),
3491 target_pid_to_str (tp
->ptid
).c_str ());
3493 /* Now that we've selected our final event LWP, un-adjust its PC
3494 if it was a software breakpoint (and the target doesn't
3495 always adjust the PC itself). */
3496 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3497 && !target_supports_stopped_by_sw_breakpoint ())
3499 struct regcache
*regcache
;
3500 struct gdbarch
*gdbarch
;
3503 regcache
= get_thread_regcache (tp
);
3504 gdbarch
= regcache
->arch ();
3506 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3511 pc
= regcache_read_pc (regcache
);
3512 regcache_write_pc (regcache
, pc
+ decr_pc
);
3516 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3517 *status
= tp
->suspend
.waitstatus
;
3518 tp
->suspend
.waitstatus_pending_p
= 0;
3520 /* Wake up the event loop again, until all pending events are
3522 if (target_is_async_p ())
3523 mark_async_event_handler (infrun_async_inferior_event_token
);
3527 /* But if we don't find one, we'll have to wait. */
3529 if (deprecated_target_wait_hook
)
3530 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3532 event_ptid
= target_wait (ptid
, status
, options
);
3537 /* Wrapper for target_wait that first checks whether threads have
3538 pending statuses to report before actually asking the target for
3539 more events. Polls for events from all inferiors/targets. */
3542 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3544 int num_inferiors
= 0;
3545 int random_selector
;
3547 /* For fairness, we pick the first inferior/target to poll at random
3548 out of all inferiors that may report events, and then continue
3549 polling the rest of the inferior list starting from that one in a
3550 circular fashion until the whole list is polled once. */
3552 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3554 return (inf
->process_target () != NULL
3555 && ptid_t (inf
->pid
).matches (wait_ptid
));
3558 /* First see how many matching inferiors we have. */
3559 for (inferior
*inf
: all_inferiors ())
3560 if (inferior_matches (inf
))
3563 if (num_inferiors
== 0)
3565 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3569 /* Now randomly pick an inferior out of those that matched. */
3570 random_selector
= (int)
3571 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3573 if (num_inferiors
> 1)
3574 infrun_log_debug ("Found %d inferiors, starting at #%d",
3575 num_inferiors
, random_selector
);
3577 /* Select the Nth inferior that matched. */
3579 inferior
*selected
= nullptr;
3581 for (inferior
*inf
: all_inferiors ())
3582 if (inferior_matches (inf
))
3583 if (random_selector
-- == 0)
3589 /* Now poll for events out of each of the matching inferior's
3590 targets, starting from the selected one. */
3592 auto do_wait
= [&] (inferior
*inf
)
3594 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3595 ecs
->target
= inf
->process_target ();
3596 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3599 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3600 here spuriously after the target is all stopped and we've already
3601 reported the stop to the user, polling for events. */
3602 scoped_restore_current_thread restore_thread
;
3604 int inf_num
= selected
->num
;
3605 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3606 if (inferior_matches (inf
))
3610 for (inferior
*inf
= inferior_list
;
3611 inf
!= NULL
&& inf
->num
< inf_num
;
3613 if (inferior_matches (inf
))
3617 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3621 /* Prepare and stabilize the inferior for detaching it. E.g.,
3622 detaching while a thread is displaced stepping is a recipe for
3623 crashing it, as nothing would readjust the PC out of the scratch
3627 prepare_for_detach (void)
3629 struct inferior
*inf
= current_inferior ();
3630 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3632 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3634 /* Is any thread of this process displaced stepping? If not,
3635 there's nothing else to do. */
3636 if (displaced_step_in_progress (inf
))
3639 infrun_log_debug ("displaced-stepping in-process while detaching");
3641 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3646 struct execution_control_state ecss
;
3647 struct execution_control_state
*ecs
;
3650 memset (ecs
, 0, sizeof (*ecs
));
3652 overlay_cache_invalid
= 1;
3653 /* Flush target cache before starting to handle each event.
3654 Target was running and cache could be stale. This is just a
3655 heuristic. Running threads may modify target memory, but we
3656 don't get any event. */
3657 target_dcache_invalidate ();
3659 do_target_wait (pid_ptid
, ecs
, 0);
3662 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3664 /* If an error happens while handling the event, propagate GDB's
3665 knowledge of the executing state to the frontend/user running
3667 scoped_finish_thread_state
finish_state (inf
->process_target (),
3670 /* Now figure out what to do with the result of the result. */
3671 handle_inferior_event (ecs
);
3673 /* No error, don't finish the state yet. */
3674 finish_state
.release ();
3676 /* Breakpoints and watchpoints are not installed on the target
3677 at this point, and signals are passed directly to the
3678 inferior, so this must mean the process is gone. */
3679 if (!ecs
->wait_some_more
)
3681 restore_detaching
.release ();
3682 error (_("Program exited while detaching"));
3686 restore_detaching
.release ();
3689 /* Wait for control to return from inferior to debugger.
3691 If inferior gets a signal, we may decide to start it up again
3692 instead of returning. That is why there is a loop in this function.
3693 When this function actually returns it means the inferior
3694 should be left stopped and GDB should read more commands. */
3697 wait_for_inferior (inferior
*inf
)
3699 infrun_log_debug ("wait_for_inferior ()");
3701 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3703 /* If an error happens while handling the event, propagate GDB's
3704 knowledge of the executing state to the frontend/user running
3706 scoped_finish_thread_state finish_state
3707 (inf
->process_target (), minus_one_ptid
);
3711 struct execution_control_state ecss
;
3712 struct execution_control_state
*ecs
= &ecss
;
3714 memset (ecs
, 0, sizeof (*ecs
));
3716 overlay_cache_invalid
= 1;
3718 /* Flush target cache before starting to handle each event.
3719 Target was running and cache could be stale. This is just a
3720 heuristic. Running threads may modify target memory, but we
3721 don't get any event. */
3722 target_dcache_invalidate ();
3724 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3725 ecs
->target
= inf
->process_target ();
3728 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3730 /* Now figure out what to do with the result of the result. */
3731 handle_inferior_event (ecs
);
3733 if (!ecs
->wait_some_more
)
3737 /* No error, don't finish the state yet. */
3738 finish_state
.release ();
3741 /* Cleanup that reinstalls the readline callback handler, if the
3742 target is running in the background. If while handling the target
3743 event something triggered a secondary prompt, like e.g., a
3744 pagination prompt, we'll have removed the callback handler (see
3745 gdb_readline_wrapper_line). Need to do this as we go back to the
3746 event loop, ready to process further input. Note this has no
3747 effect if the handler hasn't actually been removed, because calling
3748 rl_callback_handler_install resets the line buffer, thus losing
3752 reinstall_readline_callback_handler_cleanup ()
3754 struct ui
*ui
= current_ui
;
3758 /* We're not going back to the top level event loop yet. Don't
3759 install the readline callback, as it'd prep the terminal,
3760 readline-style (raw, noecho) (e.g., --batch). We'll install
3761 it the next time the prompt is displayed, when we're ready
3766 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3767 gdb_rl_callback_handler_reinstall ();
3770 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3771 that's just the event thread. In all-stop, that's all threads. */
3774 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3776 if (ecs
->event_thread
!= NULL
3777 && ecs
->event_thread
->thread_fsm
!= NULL
)
3778 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3782 for (thread_info
*thr
: all_non_exited_threads ())
3784 if (thr
->thread_fsm
== NULL
)
3786 if (thr
== ecs
->event_thread
)
3789 switch_to_thread (thr
);
3790 thr
->thread_fsm
->clean_up (thr
);
3793 if (ecs
->event_thread
!= NULL
)
3794 switch_to_thread (ecs
->event_thread
);
3798 /* Helper for all_uis_check_sync_execution_done that works on the
3802 check_curr_ui_sync_execution_done (void)
3804 struct ui
*ui
= current_ui
;
3806 if (ui
->prompt_state
== PROMPT_NEEDED
3808 && !gdb_in_secondary_prompt_p (ui
))
3810 target_terminal::ours ();
3811 gdb::observers::sync_execution_done
.notify ();
3812 ui_register_input_event_handler (ui
);
3819 all_uis_check_sync_execution_done (void)
3821 SWITCH_THRU_ALL_UIS ()
3823 check_curr_ui_sync_execution_done ();
3830 all_uis_on_sync_execution_starting (void)
3832 SWITCH_THRU_ALL_UIS ()
3834 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3835 async_disable_stdin ();
3839 /* Asynchronous version of wait_for_inferior. It is called by the
3840 event loop whenever a change of state is detected on the file
3841 descriptor corresponding to the target. It can be called more than
3842 once to complete a single execution command. In such cases we need
3843 to keep the state in a global variable ECSS. If it is the last time
3844 that this function is called for a single execution command, then
3845 report to the user that the inferior has stopped, and do the
3846 necessary cleanups. */
3849 fetch_inferior_event ()
3851 struct execution_control_state ecss
;
3852 struct execution_control_state
*ecs
= &ecss
;
3855 memset (ecs
, 0, sizeof (*ecs
));
3857 /* Events are always processed with the main UI as current UI. This
3858 way, warnings, debug output, etc. are always consistently sent to
3859 the main console. */
3860 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3862 /* End up with readline processing input, if necessary. */
3864 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3866 /* We're handling a live event, so make sure we're doing live
3867 debugging. If we're looking at traceframes while the target is
3868 running, we're going to need to get back to that mode after
3869 handling the event. */
3870 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3873 maybe_restore_traceframe
.emplace ();
3874 set_current_traceframe (-1);
3877 /* The user/frontend should not notice a thread switch due to
3878 internal events. Make sure we revert to the user selected
3879 thread and frame after handling the event and running any
3880 breakpoint commands. */
3881 scoped_restore_current_thread restore_thread
;
3883 overlay_cache_invalid
= 1;
3884 /* Flush target cache before starting to handle each event. Target
3885 was running and cache could be stale. This is just a heuristic.
3886 Running threads may modify target memory, but we don't get any
3888 target_dcache_invalidate ();
3890 scoped_restore save_exec_dir
3891 = make_scoped_restore (&execution_direction
,
3892 target_execution_direction ());
3894 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3897 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3899 /* Switch to the target that generated the event, so we can do
3900 target calls. Any inferior bound to the target will do, so we
3901 just switch to the first we find. */
3902 for (inferior
*inf
: all_inferiors (ecs
->target
))
3904 switch_to_inferior_no_thread (inf
);
3909 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3911 /* If an error happens while handling the event, propagate GDB's
3912 knowledge of the executing state to the frontend/user running
3914 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3915 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3917 /* Get executed before scoped_restore_current_thread above to apply
3918 still for the thread which has thrown the exception. */
3919 auto defer_bpstat_clear
3920 = make_scope_exit (bpstat_clear_actions
);
3921 auto defer_delete_threads
3922 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3924 /* Now figure out what to do with the result of the result. */
3925 handle_inferior_event (ecs
);
3927 if (!ecs
->wait_some_more
)
3929 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3930 int should_stop
= 1;
3931 struct thread_info
*thr
= ecs
->event_thread
;
3933 delete_just_stopped_threads_infrun_breakpoints ();
3937 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3939 if (thread_fsm
!= NULL
)
3940 should_stop
= thread_fsm
->should_stop (thr
);
3949 bool should_notify_stop
= true;
3952 clean_up_just_stopped_threads_fsms (ecs
);
3954 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3955 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3957 if (should_notify_stop
)
3959 /* We may not find an inferior if this was a process exit. */
3960 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3961 proceeded
= normal_stop ();
3966 inferior_event_handler (INF_EXEC_COMPLETE
);
3970 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3971 previously selected thread is gone. We have two
3972 choices - switch to no thread selected, or restore the
3973 previously selected thread (now exited). We chose the
3974 later, just because that's what GDB used to do. After
3975 this, "info threads" says "The current thread <Thread
3976 ID 2> has terminated." instead of "No thread
3980 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3981 restore_thread
.dont_restore ();
3985 defer_delete_threads
.release ();
3986 defer_bpstat_clear
.release ();
3988 /* No error, don't finish the thread states yet. */
3989 finish_state
.release ();
3991 /* This scope is used to ensure that readline callbacks are
3992 reinstalled here. */
3995 /* If a UI was in sync execution mode, and now isn't, restore its
3996 prompt (a synchronous execution command has finished, and we're
3997 ready for input). */
3998 all_uis_check_sync_execution_done ();
4001 && exec_done_display_p
4002 && (inferior_ptid
== null_ptid
4003 || inferior_thread ()->state
!= THREAD_RUNNING
))
4004 printf_unfiltered (_("completed.\n"));
4010 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4011 struct symtab_and_line sal
)
4013 /* This can be removed once this function no longer implicitly relies on the
4014 inferior_ptid value. */
4015 gdb_assert (inferior_ptid
== tp
->ptid
);
4017 tp
->control
.step_frame_id
= get_frame_id (frame
);
4018 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4020 tp
->current_symtab
= sal
.symtab
;
4021 tp
->current_line
= sal
.line
;
4024 /* Clear context switchable stepping state. */
4027 init_thread_stepping_state (struct thread_info
*tss
)
4029 tss
->stepped_breakpoint
= 0;
4030 tss
->stepping_over_breakpoint
= 0;
4031 tss
->stepping_over_watchpoint
= 0;
4032 tss
->step_after_step_resume_breakpoint
= 0;
4038 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4039 target_waitstatus status
)
4041 target_last_proc_target
= target
;
4042 target_last_wait_ptid
= ptid
;
4043 target_last_waitstatus
= status
;
4049 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4050 target_waitstatus
*status
)
4052 if (target
!= nullptr)
4053 *target
= target_last_proc_target
;
4054 if (ptid
!= nullptr)
4055 *ptid
= target_last_wait_ptid
;
4056 if (status
!= nullptr)
4057 *status
= target_last_waitstatus
;
4063 nullify_last_target_wait_ptid (void)
4065 target_last_proc_target
= nullptr;
4066 target_last_wait_ptid
= minus_one_ptid
;
4067 target_last_waitstatus
= {};
4070 /* Switch thread contexts. */
4073 context_switch (execution_control_state
*ecs
)
4075 if (ecs
->ptid
!= inferior_ptid
4076 && (inferior_ptid
== null_ptid
4077 || ecs
->event_thread
!= inferior_thread ()))
4079 infrun_log_debug ("Switching context from %s to %s",
4080 target_pid_to_str (inferior_ptid
).c_str (),
4081 target_pid_to_str (ecs
->ptid
).c_str ());
4084 switch_to_thread (ecs
->event_thread
);
4087 /* If the target can't tell whether we've hit breakpoints
4088 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4089 check whether that could have been caused by a breakpoint. If so,
4090 adjust the PC, per gdbarch_decr_pc_after_break. */
4093 adjust_pc_after_break (struct thread_info
*thread
,
4094 struct target_waitstatus
*ws
)
4096 struct regcache
*regcache
;
4097 struct gdbarch
*gdbarch
;
4098 CORE_ADDR breakpoint_pc
, decr_pc
;
4100 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4101 we aren't, just return.
4103 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4104 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4105 implemented by software breakpoints should be handled through the normal
4108 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4109 different signals (SIGILL or SIGEMT for instance), but it is less
4110 clear where the PC is pointing afterwards. It may not match
4111 gdbarch_decr_pc_after_break. I don't know any specific target that
4112 generates these signals at breakpoints (the code has been in GDB since at
4113 least 1992) so I can not guess how to handle them here.
4115 In earlier versions of GDB, a target with
4116 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4117 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4118 target with both of these set in GDB history, and it seems unlikely to be
4119 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4121 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4124 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4127 /* In reverse execution, when a breakpoint is hit, the instruction
4128 under it has already been de-executed. The reported PC always
4129 points at the breakpoint address, so adjusting it further would
4130 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4133 B1 0x08000000 : INSN1
4134 B2 0x08000001 : INSN2
4136 PC -> 0x08000003 : INSN4
4138 Say you're stopped at 0x08000003 as above. Reverse continuing
4139 from that point should hit B2 as below. Reading the PC when the
4140 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4141 been de-executed already.
4143 B1 0x08000000 : INSN1
4144 B2 PC -> 0x08000001 : INSN2
4148 We can't apply the same logic as for forward execution, because
4149 we would wrongly adjust the PC to 0x08000000, since there's a
4150 breakpoint at PC - 1. We'd then report a hit on B1, although
4151 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4153 if (execution_direction
== EXEC_REVERSE
)
4156 /* If the target can tell whether the thread hit a SW breakpoint,
4157 trust it. Targets that can tell also adjust the PC
4159 if (target_supports_stopped_by_sw_breakpoint ())
4162 /* Note that relying on whether a breakpoint is planted in memory to
4163 determine this can fail. E.g,. the breakpoint could have been
4164 removed since. Or the thread could have been told to step an
4165 instruction the size of a breakpoint instruction, and only
4166 _after_ was a breakpoint inserted at its address. */
4168 /* If this target does not decrement the PC after breakpoints, then
4169 we have nothing to do. */
4170 regcache
= get_thread_regcache (thread
);
4171 gdbarch
= regcache
->arch ();
4173 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4177 const address_space
*aspace
= regcache
->aspace ();
4179 /* Find the location where (if we've hit a breakpoint) the
4180 breakpoint would be. */
4181 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4183 /* If the target can't tell whether a software breakpoint triggered,
4184 fallback to figuring it out based on breakpoints we think were
4185 inserted in the target, and on whether the thread was stepped or
4188 /* Check whether there actually is a software breakpoint inserted at
4191 If in non-stop mode, a race condition is possible where we've
4192 removed a breakpoint, but stop events for that breakpoint were
4193 already queued and arrive later. To suppress those spurious
4194 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4195 and retire them after a number of stop events are reported. Note
4196 this is an heuristic and can thus get confused. The real fix is
4197 to get the "stopped by SW BP and needs adjustment" info out of
4198 the target/kernel (and thus never reach here; see above). */
4199 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4200 || (target_is_non_stop_p ()
4201 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4203 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4205 if (record_full_is_used ())
4206 restore_operation_disable
.emplace
4207 (record_full_gdb_operation_disable_set ());
4209 /* When using hardware single-step, a SIGTRAP is reported for both
4210 a completed single-step and a software breakpoint. Need to
4211 differentiate between the two, as the latter needs adjusting
4212 but the former does not.
4214 The SIGTRAP can be due to a completed hardware single-step only if
4215 - we didn't insert software single-step breakpoints
4216 - this thread is currently being stepped
4218 If any of these events did not occur, we must have stopped due
4219 to hitting a software breakpoint, and have to back up to the
4222 As a special case, we could have hardware single-stepped a
4223 software breakpoint. In this case (prev_pc == breakpoint_pc),
4224 we also need to back up to the breakpoint address. */
4226 if (thread_has_single_step_breakpoints_set (thread
)
4227 || !currently_stepping (thread
)
4228 || (thread
->stepped_breakpoint
4229 && thread
->prev_pc
== breakpoint_pc
))
4230 regcache_write_pc (regcache
, breakpoint_pc
);
4235 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4237 for (frame
= get_prev_frame (frame
);
4239 frame
= get_prev_frame (frame
))
4241 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4243 if (get_frame_type (frame
) != INLINE_FRAME
)
4250 /* Look for an inline frame that is marked for skip.
4251 If PREV_FRAME is TRUE start at the previous frame,
4252 otherwise start at the current frame. Stop at the
4253 first non-inline frame, or at the frame where the
4257 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4259 struct frame_info
*frame
= get_current_frame ();
4262 frame
= get_prev_frame (frame
);
4264 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4266 const char *fn
= NULL
;
4267 symtab_and_line sal
;
4270 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4272 if (get_frame_type (frame
) != INLINE_FRAME
)
4275 sal
= find_frame_sal (frame
);
4276 sym
= get_frame_function (frame
);
4279 fn
= sym
->print_name ();
4282 && function_name_is_marked_for_skip (fn
, sal
))
4289 /* If the event thread has the stop requested flag set, pretend it
4290 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4294 handle_stop_requested (struct execution_control_state
*ecs
)
4296 if (ecs
->event_thread
->stop_requested
)
4298 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4299 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4300 handle_signal_stop (ecs
);
4306 /* Auxiliary function that handles syscall entry/return events.
4307 It returns 1 if the inferior should keep going (and GDB
4308 should ignore the event), or 0 if the event deserves to be
4312 handle_syscall_event (struct execution_control_state
*ecs
)
4314 struct regcache
*regcache
;
4317 context_switch (ecs
);
4319 regcache
= get_thread_regcache (ecs
->event_thread
);
4320 syscall_number
= ecs
->ws
.value
.syscall_number
;
4321 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4323 if (catch_syscall_enabled () > 0
4324 && catching_syscall_number (syscall_number
) > 0)
4326 infrun_log_debug ("syscall number=%d", syscall_number
);
4328 ecs
->event_thread
->control
.stop_bpstat
4329 = bpstat_stop_status (regcache
->aspace (),
4330 ecs
->event_thread
->suspend
.stop_pc
,
4331 ecs
->event_thread
, &ecs
->ws
);
4333 if (handle_stop_requested (ecs
))
4336 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4338 /* Catchpoint hit. */
4343 if (handle_stop_requested (ecs
))
4346 /* If no catchpoint triggered for this, then keep going. */
4351 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4354 fill_in_stop_func (struct gdbarch
*gdbarch
,
4355 struct execution_control_state
*ecs
)
4357 if (!ecs
->stop_func_filled_in
)
4361 /* Don't care about return value; stop_func_start and stop_func_name
4362 will both be 0 if it doesn't work. */
4363 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4364 &ecs
->stop_func_name
,
4365 &ecs
->stop_func_start
,
4366 &ecs
->stop_func_end
,
4369 /* The call to find_pc_partial_function, above, will set
4370 stop_func_start and stop_func_end to the start and end
4371 of the range containing the stop pc. If this range
4372 contains the entry pc for the block (which is always the
4373 case for contiguous blocks), advance stop_func_start past
4374 the function's start offset and entrypoint. Note that
4375 stop_func_start is NOT advanced when in a range of a
4376 non-contiguous block that does not contain the entry pc. */
4377 if (block
!= nullptr
4378 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4379 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4381 ecs
->stop_func_start
4382 += gdbarch_deprecated_function_start_offset (gdbarch
);
4384 if (gdbarch_skip_entrypoint_p (gdbarch
))
4385 ecs
->stop_func_start
4386 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4389 ecs
->stop_func_filled_in
= 1;
4394 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4396 static enum stop_kind
4397 get_inferior_stop_soon (execution_control_state
*ecs
)
4399 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4401 gdb_assert (inf
!= NULL
);
4402 return inf
->control
.stop_soon
;
4405 /* Poll for one event out of the current target. Store the resulting
4406 waitstatus in WS, and return the event ptid. Does not block. */
4409 poll_one_curr_target (struct target_waitstatus
*ws
)
4413 overlay_cache_invalid
= 1;
4415 /* Flush target cache before starting to handle each event.
4416 Target was running and cache could be stale. This is just a
4417 heuristic. Running threads may modify target memory, but we
4418 don't get any event. */
4419 target_dcache_invalidate ();
4421 if (deprecated_target_wait_hook
)
4422 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4424 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4427 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4432 /* An event reported by wait_one. */
4434 struct wait_one_event
4436 /* The target the event came out of. */
4437 process_stratum_target
*target
;
4439 /* The PTID the event was for. */
4442 /* The waitstatus. */
4443 target_waitstatus ws
;
4446 /* Wait for one event out of any target. */
4448 static wait_one_event
4453 for (inferior
*inf
: all_inferiors ())
4455 process_stratum_target
*target
= inf
->process_target ();
4457 || !target
->is_async_p ()
4458 || !target
->threads_executing
)
4461 switch_to_inferior_no_thread (inf
);
4463 wait_one_event event
;
4464 event
.target
= target
;
4465 event
.ptid
= poll_one_curr_target (&event
.ws
);
4467 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4469 /* If nothing is resumed, remove the target from the
4473 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4477 /* Block waiting for some event. */
4484 for (inferior
*inf
: all_inferiors ())
4486 process_stratum_target
*target
= inf
->process_target ();
4488 || !target
->is_async_p ()
4489 || !target
->threads_executing
)
4492 int fd
= target
->async_wait_fd ();
4493 FD_SET (fd
, &readfds
);
4500 /* No waitable targets left. All must be stopped. */
4501 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4506 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4512 perror_with_name ("interruptible_select");
4517 /* Save the thread's event and stop reason to process it later. */
4520 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4522 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4523 target_waitstatus_to_string (ws
).c_str (),
4528 /* Record for later. */
4529 tp
->suspend
.waitstatus
= *ws
;
4530 tp
->suspend
.waitstatus_pending_p
= 1;
4532 struct regcache
*regcache
= get_thread_regcache (tp
);
4533 const address_space
*aspace
= regcache
->aspace ();
4535 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4536 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4538 CORE_ADDR pc
= regcache_read_pc (regcache
);
4540 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4542 scoped_restore_current_thread restore_thread
;
4543 switch_to_thread (tp
);
4545 if (target_stopped_by_watchpoint ())
4547 tp
->suspend
.stop_reason
4548 = TARGET_STOPPED_BY_WATCHPOINT
;
4550 else if (target_supports_stopped_by_sw_breakpoint ()
4551 && target_stopped_by_sw_breakpoint ())
4553 tp
->suspend
.stop_reason
4554 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4556 else if (target_supports_stopped_by_hw_breakpoint ()
4557 && target_stopped_by_hw_breakpoint ())
4559 tp
->suspend
.stop_reason
4560 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4562 else if (!target_supports_stopped_by_hw_breakpoint ()
4563 && hardware_breakpoint_inserted_here_p (aspace
,
4566 tp
->suspend
.stop_reason
4567 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4569 else if (!target_supports_stopped_by_sw_breakpoint ()
4570 && software_breakpoint_inserted_here_p (aspace
,
4573 tp
->suspend
.stop_reason
4574 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4576 else if (!thread_has_single_step_breakpoints_set (tp
)
4577 && currently_stepping (tp
))
4579 tp
->suspend
.stop_reason
4580 = TARGET_STOPPED_BY_SINGLE_STEP
;
4585 /* Mark the non-executing threads accordingly. In all-stop, all
4586 threads of all processes are stopped when we get any event
4587 reported. In non-stop mode, only the event thread stops. */
4590 mark_non_executing_threads (process_stratum_target
*target
,
4592 struct target_waitstatus ws
)
4596 if (!target_is_non_stop_p ())
4597 mark_ptid
= minus_one_ptid
;
4598 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4599 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4601 /* If we're handling a process exit in non-stop mode, even
4602 though threads haven't been deleted yet, one would think
4603 that there is nothing to do, as threads of the dead process
4604 will be soon deleted, and threads of any other process were
4605 left running. However, on some targets, threads survive a
4606 process exit event. E.g., for the "checkpoint" command,
4607 when the current checkpoint/fork exits, linux-fork.c
4608 automatically switches to another fork from within
4609 target_mourn_inferior, by associating the same
4610 inferior/thread to another fork. We haven't mourned yet at
4611 this point, but we must mark any threads left in the
4612 process as not-executing so that finish_thread_state marks
4613 them stopped (in the user's perspective) if/when we present
4614 the stop to the user. */
4615 mark_ptid
= ptid_t (event_ptid
.pid ());
4618 mark_ptid
= event_ptid
;
4620 set_executing (target
, mark_ptid
, false);
4622 /* Likewise the resumed flag. */
4623 set_resumed (target
, mark_ptid
, false);
4629 stop_all_threads (void)
4631 /* We may need multiple passes to discover all threads. */
4635 gdb_assert (exists_non_stop_target ());
4637 infrun_log_debug ("stop_all_threads");
4639 scoped_restore_current_thread restore_thread
;
4641 /* Enable thread events of all targets. */
4642 for (auto *target
: all_non_exited_process_targets ())
4644 switch_to_target_no_thread (target
);
4645 target_thread_events (true);
4650 /* Disable thread events of all targets. */
4651 for (auto *target
: all_non_exited_process_targets ())
4653 switch_to_target_no_thread (target
);
4654 target_thread_events (false);
4658 infrun_log_debug ("stop_all_threads done");
4661 /* Request threads to stop, and then wait for the stops. Because
4662 threads we already know about can spawn more threads while we're
4663 trying to stop them, and we only learn about new threads when we
4664 update the thread list, do this in a loop, and keep iterating
4665 until two passes find no threads that need to be stopped. */
4666 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4668 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4672 int waits_needed
= 0;
4674 for (auto *target
: all_non_exited_process_targets ())
4676 switch_to_target_no_thread (target
);
4677 update_thread_list ();
4680 /* Go through all threads looking for threads that we need
4681 to tell the target to stop. */
4682 for (thread_info
*t
: all_non_exited_threads ())
4684 /* For a single-target setting with an all-stop target,
4685 we would not even arrive here. For a multi-target
4686 setting, until GDB is able to handle a mixture of
4687 all-stop and non-stop targets, simply skip all-stop
4688 targets' threads. This should be fine due to the
4689 protection of 'check_multi_target_resumption'. */
4691 switch_to_thread_no_regs (t
);
4692 if (!target_is_non_stop_p ())
4697 /* If already stopping, don't request a stop again.
4698 We just haven't seen the notification yet. */
4699 if (!t
->stop_requested
)
4701 infrun_log_debug (" %s executing, need stop",
4702 target_pid_to_str (t
->ptid
).c_str ());
4703 target_stop (t
->ptid
);
4704 t
->stop_requested
= 1;
4708 infrun_log_debug (" %s executing, already stopping",
4709 target_pid_to_str (t
->ptid
).c_str ());
4712 if (t
->stop_requested
)
4717 infrun_log_debug (" %s not executing",
4718 target_pid_to_str (t
->ptid
).c_str ());
4720 /* The thread may be not executing, but still be
4721 resumed with a pending status to process. */
4726 if (waits_needed
== 0)
4729 /* If we find new threads on the second iteration, restart
4730 over. We want to see two iterations in a row with all
4735 for (int i
= 0; i
< waits_needed
; i
++)
4737 wait_one_event event
= wait_one ();
4739 infrun_log_debug ("%s %s\n",
4740 target_waitstatus_to_string (&event
.ws
).c_str (),
4741 target_pid_to_str (event
.ptid
).c_str ());
4743 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4745 /* All resumed threads exited. */
4748 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4749 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4750 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4752 /* One thread/process exited/signalled. */
4754 thread_info
*t
= nullptr;
4756 /* The target may have reported just a pid. If so, try
4757 the first non-exited thread. */
4758 if (event
.ptid
.is_pid ())
4760 int pid
= event
.ptid
.pid ();
4761 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4762 for (thread_info
*tp
: inf
->non_exited_threads ())
4768 /* If there is no available thread, the event would
4769 have to be appended to a per-inferior event list,
4770 which does not exist (and if it did, we'd have
4771 to adjust run control command to be able to
4772 resume such an inferior). We assert here instead
4773 of going into an infinite loop. */
4774 gdb_assert (t
!= nullptr);
4776 infrun_log_debug ("using %s\n",
4777 target_pid_to_str (t
->ptid
).c_str ());
4781 t
= find_thread_ptid (event
.target
, event
.ptid
);
4782 /* Check if this is the first time we see this thread.
4783 Don't bother adding if it individually exited. */
4785 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4786 t
= add_thread (event
.target
, event
.ptid
);
4791 /* Set the threads as non-executing to avoid
4792 another stop attempt on them. */
4793 switch_to_thread_no_regs (t
);
4794 mark_non_executing_threads (event
.target
, event
.ptid
,
4796 save_waitstatus (t
, &event
.ws
);
4797 t
->stop_requested
= false;
4802 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4804 t
= add_thread (event
.target
, event
.ptid
);
4806 t
->stop_requested
= 0;
4809 t
->control
.may_range_step
= 0;
4811 /* This may be the first time we see the inferior report
4813 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4814 if (inf
->needs_setup
)
4816 switch_to_thread_no_regs (t
);
4820 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4821 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4823 /* We caught the event that we intended to catch, so
4824 there's no event pending. */
4825 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4826 t
->suspend
.waitstatus_pending_p
= 0;
4828 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4830 /* Add it back to the step-over queue. */
4831 infrun_log_debug ("displaced-step of %s "
4832 "canceled: adding back to the "
4833 "step-over queue\n",
4834 target_pid_to_str (t
->ptid
).c_str ());
4836 t
->control
.trap_expected
= 0;
4837 global_thread_step_over_chain_enqueue (t
);
4842 enum gdb_signal sig
;
4843 struct regcache
*regcache
;
4847 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4849 infrun_log_debug ("target_wait %s, saving "
4850 "status for %d.%ld.%ld\n",
4857 /* Record for later. */
4858 save_waitstatus (t
, &event
.ws
);
4860 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4861 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4863 if (displaced_step_finish (t
, sig
) < 0)
4865 /* Add it back to the step-over queue. */
4866 t
->control
.trap_expected
= 0;
4867 global_thread_step_over_chain_enqueue (t
);
4870 regcache
= get_thread_regcache (t
);
4871 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4873 infrun_log_debug ("saved stop_pc=%s for %s "
4874 "(currently_stepping=%d)\n",
4875 paddress (target_gdbarch (),
4876 t
->suspend
.stop_pc
),
4877 target_pid_to_str (t
->ptid
).c_str (),
4878 currently_stepping (t
));
4886 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4889 handle_no_resumed (struct execution_control_state
*ecs
)
4891 if (target_can_async_p ())
4895 for (ui
*ui
: all_uis ())
4897 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4905 /* There were no unwaited-for children left in the target, but,
4906 we're not synchronously waiting for events either. Just
4909 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4910 prepare_to_wait (ecs
);
4915 /* Otherwise, if we were running a synchronous execution command, we
4916 may need to cancel it and give the user back the terminal.
4918 In non-stop mode, the target can't tell whether we've already
4919 consumed previous stop events, so it can end up sending us a
4920 no-resumed event like so:
4922 #0 - thread 1 is left stopped
4924 #1 - thread 2 is resumed and hits breakpoint
4925 -> TARGET_WAITKIND_STOPPED
4927 #2 - thread 3 is resumed and exits
4928 this is the last resumed thread, so
4929 -> TARGET_WAITKIND_NO_RESUMED
4931 #3 - gdb processes stop for thread 2 and decides to re-resume
4934 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4935 thread 2 is now resumed, so the event should be ignored.
4937 IOW, if the stop for thread 2 doesn't end a foreground command,
4938 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4939 event. But it could be that the event meant that thread 2 itself
4940 (or whatever other thread was the last resumed thread) exited.
4942 To address this we refresh the thread list and check whether we
4943 have resumed threads _now_. In the example above, this removes
4944 thread 3 from the thread list. If thread 2 was re-resumed, we
4945 ignore this event. If we find no thread resumed, then we cancel
4946 the synchronous command and show "no unwaited-for " to the
4949 inferior
*curr_inf
= current_inferior ();
4951 scoped_restore_current_thread restore_thread
;
4953 for (auto *target
: all_non_exited_process_targets ())
4955 switch_to_target_no_thread (target
);
4956 update_thread_list ();
4961 - the current target has no thread executing, and
4962 - the current inferior is native, and
4963 - the current inferior is the one which has the terminal, and
4966 then a Ctrl-C from this point on would remain stuck in the
4967 kernel, until a thread resumes and dequeues it. That would
4968 result in the GDB CLI not reacting to Ctrl-C, not able to
4969 interrupt the program. To address this, if the current inferior
4970 no longer has any thread executing, we give the terminal to some
4971 other inferior that has at least one thread executing. */
4972 bool swap_terminal
= true;
4974 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4975 whether to report it to the user. */
4976 bool ignore_event
= false;
4978 for (thread_info
*thread
: all_non_exited_threads ())
4980 if (swap_terminal
&& thread
->executing
)
4982 if (thread
->inf
!= curr_inf
)
4984 target_terminal::ours ();
4986 switch_to_thread (thread
);
4987 target_terminal::inferior ();
4989 swap_terminal
= false;
4993 && (thread
->executing
4994 || thread
->suspend
.waitstatus_pending_p
))
4996 /* Either there were no unwaited-for children left in the
4997 target at some point, but there are now, or some target
4998 other than the eventing one has unwaited-for children
4999 left. Just ignore. */
5000 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
5001 "(ignoring: found resumed)\n");
5003 ignore_event
= true;
5006 if (ignore_event
&& !swap_terminal
)
5012 switch_to_inferior_no_thread (curr_inf
);
5013 prepare_to_wait (ecs
);
5017 /* Go ahead and report the event. */
5021 /* Given an execution control state that has been freshly filled in by
5022 an event from the inferior, figure out what it means and take
5025 The alternatives are:
5027 1) stop_waiting and return; to really stop and return to the
5030 2) keep_going and return; to wait for the next event (set
5031 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5035 handle_inferior_event (struct execution_control_state
*ecs
)
5037 /* Make sure that all temporary struct value objects that were
5038 created during the handling of the event get deleted at the
5040 scoped_value_mark free_values
;
5042 enum stop_kind stop_soon
;
5044 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5046 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5048 /* We had an event in the inferior, but we are not interested in
5049 handling it at this level. The lower layers have already
5050 done what needs to be done, if anything.
5052 One of the possible circumstances for this is when the
5053 inferior produces output for the console. The inferior has
5054 not stopped, and we are ignoring the event. Another possible
5055 circumstance is any event which the lower level knows will be
5056 reported multiple times without an intervening resume. */
5057 prepare_to_wait (ecs
);
5061 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5063 prepare_to_wait (ecs
);
5067 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5068 && handle_no_resumed (ecs
))
5071 /* Cache the last target/ptid/waitstatus. */
5072 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5074 /* Always clear state belonging to the previous time we stopped. */
5075 stop_stack_dummy
= STOP_NONE
;
5077 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5079 /* No unwaited-for children left. IOW, all resumed children
5081 stop_print_frame
= 0;
5086 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5087 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5089 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5090 /* If it's a new thread, add it to the thread database. */
5091 if (ecs
->event_thread
== NULL
)
5092 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5094 /* Disable range stepping. If the next step request could use a
5095 range, this will be end up re-enabled then. */
5096 ecs
->event_thread
->control
.may_range_step
= 0;
5099 /* Dependent on valid ECS->EVENT_THREAD. */
5100 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5102 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5103 reinit_frame_cache ();
5105 breakpoint_retire_moribund ();
5107 /* First, distinguish signals caused by the debugger from signals
5108 that have to do with the program's own actions. Note that
5109 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5110 on the operating system version. Here we detect when a SIGILL or
5111 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5112 something similar for SIGSEGV, since a SIGSEGV will be generated
5113 when we're trying to execute a breakpoint instruction on a
5114 non-executable stack. This happens for call dummy breakpoints
5115 for architectures like SPARC that place call dummies on the
5117 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5118 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5119 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5120 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5122 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5124 if (breakpoint_inserted_here_p (regcache
->aspace (),
5125 regcache_read_pc (regcache
)))
5127 infrun_log_debug ("Treating signal as SIGTRAP");
5128 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5132 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5134 switch (ecs
->ws
.kind
)
5136 case TARGET_WAITKIND_LOADED
:
5137 context_switch (ecs
);
5138 /* Ignore gracefully during startup of the inferior, as it might
5139 be the shell which has just loaded some objects, otherwise
5140 add the symbols for the newly loaded objects. Also ignore at
5141 the beginning of an attach or remote session; we will query
5142 the full list of libraries once the connection is
5145 stop_soon
= get_inferior_stop_soon (ecs
);
5146 if (stop_soon
== NO_STOP_QUIETLY
)
5148 struct regcache
*regcache
;
5150 regcache
= get_thread_regcache (ecs
->event_thread
);
5152 handle_solib_event ();
5154 ecs
->event_thread
->control
.stop_bpstat
5155 = bpstat_stop_status (regcache
->aspace (),
5156 ecs
->event_thread
->suspend
.stop_pc
,
5157 ecs
->event_thread
, &ecs
->ws
);
5159 if (handle_stop_requested (ecs
))
5162 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5164 /* A catchpoint triggered. */
5165 process_event_stop_test (ecs
);
5169 /* If requested, stop when the dynamic linker notifies
5170 gdb of events. This allows the user to get control
5171 and place breakpoints in initializer routines for
5172 dynamically loaded objects (among other things). */
5173 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5174 if (stop_on_solib_events
)
5176 /* Make sure we print "Stopped due to solib-event" in
5178 stop_print_frame
= 1;
5185 /* If we are skipping through a shell, or through shared library
5186 loading that we aren't interested in, resume the program. If
5187 we're running the program normally, also resume. */
5188 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5190 /* Loading of shared libraries might have changed breakpoint
5191 addresses. Make sure new breakpoints are inserted. */
5192 if (stop_soon
== NO_STOP_QUIETLY
)
5193 insert_breakpoints ();
5194 resume (GDB_SIGNAL_0
);
5195 prepare_to_wait (ecs
);
5199 /* But stop if we're attaching or setting up a remote
5201 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5202 || stop_soon
== STOP_QUIETLY_REMOTE
)
5204 infrun_log_debug ("quietly stopped");
5209 internal_error (__FILE__
, __LINE__
,
5210 _("unhandled stop_soon: %d"), (int) stop_soon
);
5212 case TARGET_WAITKIND_SPURIOUS
:
5213 if (handle_stop_requested (ecs
))
5215 context_switch (ecs
);
5216 resume (GDB_SIGNAL_0
);
5217 prepare_to_wait (ecs
);
5220 case TARGET_WAITKIND_THREAD_CREATED
:
5221 if (handle_stop_requested (ecs
))
5223 context_switch (ecs
);
5224 if (!switch_back_to_stepped_thread (ecs
))
5228 case TARGET_WAITKIND_EXITED
:
5229 case TARGET_WAITKIND_SIGNALLED
:
5231 /* Depending on the system, ecs->ptid may point to a thread or
5232 to a process. On some targets, target_mourn_inferior may
5233 need to have access to the just-exited thread. That is the
5234 case of GNU/Linux's "checkpoint" support, for example.
5235 Call the switch_to_xxx routine as appropriate. */
5236 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5238 switch_to_thread (thr
);
5241 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5242 switch_to_inferior_no_thread (inf
);
5245 handle_vfork_child_exec_or_exit (0);
5246 target_terminal::ours (); /* Must do this before mourn anyway. */
5248 /* Clearing any previous state of convenience variables. */
5249 clear_exit_convenience_vars ();
5251 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5253 /* Record the exit code in the convenience variable $_exitcode, so
5254 that the user can inspect this again later. */
5255 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5256 (LONGEST
) ecs
->ws
.value
.integer
);
5258 /* Also record this in the inferior itself. */
5259 current_inferior ()->has_exit_code
= 1;
5260 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5262 /* Support the --return-child-result option. */
5263 return_child_result_value
= ecs
->ws
.value
.integer
;
5265 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5269 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5271 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5273 /* Set the value of the internal variable $_exitsignal,
5274 which holds the signal uncaught by the inferior. */
5275 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5276 gdbarch_gdb_signal_to_target (gdbarch
,
5277 ecs
->ws
.value
.sig
));
5281 /* We don't have access to the target's method used for
5282 converting between signal numbers (GDB's internal
5283 representation <-> target's representation).
5284 Therefore, we cannot do a good job at displaying this
5285 information to the user. It's better to just warn
5286 her about it (if infrun debugging is enabled), and
5288 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5292 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5295 gdb_flush (gdb_stdout
);
5296 target_mourn_inferior (inferior_ptid
);
5297 stop_print_frame
= 0;
5301 case TARGET_WAITKIND_FORKED
:
5302 case TARGET_WAITKIND_VFORKED
:
5303 /* Check whether the inferior is displaced stepping. */
5305 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5306 struct gdbarch
*gdbarch
= regcache
->arch ();
5308 /* If checking displaced stepping is supported, and thread
5309 ecs->ptid is displaced stepping. */
5310 if (displaced_step_in_progress (ecs
->event_thread
))
5312 struct inferior
*parent_inf
5313 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5314 struct regcache
*child_regcache
;
5315 CORE_ADDR parent_pc
;
5317 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5319 // struct displaced_step_inferior_state *displaced
5320 // = get_displaced_stepping_state (parent_inf);
5322 /* Restore scratch pad for child process. */
5323 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5324 // FIXME: we should restore all the buffers that were currently in use
5327 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5328 indicating that the displaced stepping of syscall instruction
5329 has been done. Perform cleanup for parent process here. Note
5330 that this operation also cleans up the child process for vfork,
5331 because their pages are shared. */
5332 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5333 /* Start a new step-over in another thread if there's one
5337 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5338 the child's PC is also within the scratchpad. Set the child's PC
5339 to the parent's PC value, which has already been fixed up.
5340 FIXME: we use the parent's aspace here, although we're touching
5341 the child, because the child hasn't been added to the inferior
5342 list yet at this point. */
5345 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5346 ecs
->ws
.value
.related_pid
,
5348 parent_inf
->aspace
);
5349 /* Read PC value of parent process. */
5350 parent_pc
= regcache_read_pc (regcache
);
5352 if (debug_displaced
)
5353 fprintf_unfiltered (gdb_stdlog
,
5354 "displaced: write child pc from %s to %s\n",
5356 regcache_read_pc (child_regcache
)),
5357 paddress (gdbarch
, parent_pc
));
5359 regcache_write_pc (child_regcache
, parent_pc
);
5363 context_switch (ecs
);
5365 /* Immediately detach breakpoints from the child before there's
5366 any chance of letting the user delete breakpoints from the
5367 breakpoint lists. If we don't do this early, it's easy to
5368 leave left over traps in the child, vis: "break foo; catch
5369 fork; c; <fork>; del; c; <child calls foo>". We only follow
5370 the fork on the last `continue', and by that time the
5371 breakpoint at "foo" is long gone from the breakpoint table.
5372 If we vforked, then we don't need to unpatch here, since both
5373 parent and child are sharing the same memory pages; we'll
5374 need to unpatch at follow/detach time instead to be certain
5375 that new breakpoints added between catchpoint hit time and
5376 vfork follow are detached. */
5377 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5379 /* This won't actually modify the breakpoint list, but will
5380 physically remove the breakpoints from the child. */
5381 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5384 delete_just_stopped_threads_single_step_breakpoints ();
5386 /* In case the event is caught by a catchpoint, remember that
5387 the event is to be followed at the next resume of the thread,
5388 and not immediately. */
5389 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5391 ecs
->event_thread
->suspend
.stop_pc
5392 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5394 ecs
->event_thread
->control
.stop_bpstat
5395 = bpstat_stop_status (get_current_regcache ()->aspace (),
5396 ecs
->event_thread
->suspend
.stop_pc
,
5397 ecs
->event_thread
, &ecs
->ws
);
5399 if (handle_stop_requested (ecs
))
5402 /* If no catchpoint triggered for this, then keep going. Note
5403 that we're interested in knowing the bpstat actually causes a
5404 stop, not just if it may explain the signal. Software
5405 watchpoints, for example, always appear in the bpstat. */
5406 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5409 = (follow_fork_mode_string
== follow_fork_mode_child
);
5411 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5413 process_stratum_target
*targ
5414 = ecs
->event_thread
->inf
->process_target ();
5416 bool should_resume
= follow_fork ();
5418 /* Note that one of these may be an invalid pointer,
5419 depending on detach_fork. */
5420 thread_info
*parent
= ecs
->event_thread
;
5422 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5424 /* At this point, the parent is marked running, and the
5425 child is marked stopped. */
5427 /* If not resuming the parent, mark it stopped. */
5428 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5429 parent
->set_running (false);
5431 /* If resuming the child, mark it running. */
5432 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5433 child
->set_running (true);
5435 /* In non-stop mode, also resume the other branch. */
5436 if (!detach_fork
&& (non_stop
5437 || (sched_multi
&& target_is_non_stop_p ())))
5440 switch_to_thread (parent
);
5442 switch_to_thread (child
);
5444 ecs
->event_thread
= inferior_thread ();
5445 ecs
->ptid
= inferior_ptid
;
5450 switch_to_thread (child
);
5452 switch_to_thread (parent
);
5454 ecs
->event_thread
= inferior_thread ();
5455 ecs
->ptid
= inferior_ptid
;
5463 process_event_stop_test (ecs
);
5466 case TARGET_WAITKIND_VFORK_DONE
:
5467 /* Done with the shared memory region. Re-insert breakpoints in
5468 the parent, and keep going. */
5470 context_switch (ecs
);
5472 current_inferior ()->waiting_for_vfork_done
= 0;
5473 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5475 if (handle_stop_requested (ecs
))
5478 /* This also takes care of reinserting breakpoints in the
5479 previously locked inferior. */
5483 case TARGET_WAITKIND_EXECD
:
5485 /* Note we can't read registers yet (the stop_pc), because we
5486 don't yet know the inferior's post-exec architecture.
5487 'stop_pc' is explicitly read below instead. */
5488 switch_to_thread_no_regs (ecs
->event_thread
);
5490 /* Do whatever is necessary to the parent branch of the vfork. */
5491 handle_vfork_child_exec_or_exit (1);
5493 /* This causes the eventpoints and symbol table to be reset.
5494 Must do this now, before trying to determine whether to
5496 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5498 /* In follow_exec we may have deleted the original thread and
5499 created a new one. Make sure that the event thread is the
5500 execd thread for that case (this is a nop otherwise). */
5501 ecs
->event_thread
= inferior_thread ();
5503 ecs
->event_thread
->suspend
.stop_pc
5504 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5506 ecs
->event_thread
->control
.stop_bpstat
5507 = bpstat_stop_status (get_current_regcache ()->aspace (),
5508 ecs
->event_thread
->suspend
.stop_pc
,
5509 ecs
->event_thread
, &ecs
->ws
);
5511 /* Note that this may be referenced from inside
5512 bpstat_stop_status above, through inferior_has_execd. */
5513 xfree (ecs
->ws
.value
.execd_pathname
);
5514 ecs
->ws
.value
.execd_pathname
= NULL
;
5516 if (handle_stop_requested (ecs
))
5519 /* If no catchpoint triggered for this, then keep going. */
5520 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5522 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5526 process_event_stop_test (ecs
);
5529 /* Be careful not to try to gather much state about a thread
5530 that's in a syscall. It's frequently a losing proposition. */
5531 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5532 /* Getting the current syscall number. */
5533 if (handle_syscall_event (ecs
) == 0)
5534 process_event_stop_test (ecs
);
5537 /* Before examining the threads further, step this thread to
5538 get it entirely out of the syscall. (We get notice of the
5539 event when the thread is just on the verge of exiting a
5540 syscall. Stepping one instruction seems to get it back
5542 case TARGET_WAITKIND_SYSCALL_RETURN
:
5543 if (handle_syscall_event (ecs
) == 0)
5544 process_event_stop_test (ecs
);
5547 case TARGET_WAITKIND_STOPPED
:
5548 handle_signal_stop (ecs
);
5551 case TARGET_WAITKIND_NO_HISTORY
:
5552 /* Reverse execution: target ran out of history info. */
5554 /* Switch to the stopped thread. */
5555 context_switch (ecs
);
5556 infrun_log_debug ("stopped");
5558 delete_just_stopped_threads_single_step_breakpoints ();
5559 ecs
->event_thread
->suspend
.stop_pc
5560 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5562 if (handle_stop_requested (ecs
))
5565 gdb::observers::no_history
.notify ();
5571 /* Restart threads back to what they were trying to do back when we
5572 paused them for an in-line step-over. The EVENT_THREAD thread is
5576 restart_threads (struct thread_info
*event_thread
)
5578 /* In case the instruction just stepped spawned a new thread. */
5579 update_thread_list ();
5581 for (thread_info
*tp
: all_non_exited_threads ())
5583 switch_to_thread_no_regs (tp
);
5585 if (tp
== event_thread
)
5587 infrun_log_debug ("restart threads: [%s] is event thread",
5588 target_pid_to_str (tp
->ptid
).c_str ());
5592 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5594 infrun_log_debug ("restart threads: [%s] not meant to be running",
5595 target_pid_to_str (tp
->ptid
).c_str ());
5601 infrun_log_debug ("restart threads: [%s] resumed",
5602 target_pid_to_str (tp
->ptid
).c_str ());
5603 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5607 if (thread_is_in_step_over_chain (tp
))
5609 infrun_log_debug ("restart threads: [%s] needs step-over",
5610 target_pid_to_str (tp
->ptid
).c_str ());
5611 gdb_assert (!tp
->resumed
);
5616 if (tp
->suspend
.waitstatus_pending_p
)
5618 infrun_log_debug ("restart threads: [%s] has pending status",
5619 target_pid_to_str (tp
->ptid
).c_str ());
5624 gdb_assert (!tp
->stop_requested
);
5626 /* If some thread needs to start a step-over at this point, it
5627 should still be in the step-over queue, and thus skipped
5629 if (thread_still_needs_step_over (tp
))
5631 internal_error (__FILE__
, __LINE__
,
5632 "thread [%s] needs a step-over, but not in "
5633 "step-over queue\n",
5634 target_pid_to_str (tp
->ptid
).c_str ());
5637 if (currently_stepping (tp
))
5639 infrun_log_debug ("restart threads: [%s] was stepping",
5640 target_pid_to_str (tp
->ptid
).c_str ());
5641 keep_going_stepped_thread (tp
);
5645 struct execution_control_state ecss
;
5646 struct execution_control_state
*ecs
= &ecss
;
5648 infrun_log_debug ("restart threads: [%s] continuing",
5649 target_pid_to_str (tp
->ptid
).c_str ());
5650 reset_ecs (ecs
, tp
);
5651 switch_to_thread (tp
);
5652 keep_going_pass_signal (ecs
);
5657 /* Callback for iterate_over_threads. Find a resumed thread that has
5658 a pending waitstatus. */
5661 resumed_thread_with_pending_status (struct thread_info
*tp
,
5665 && tp
->suspend
.waitstatus_pending_p
);
5668 /* Called when we get an event that may finish an in-line or
5669 out-of-line (displaced stepping) step-over started previously.
5670 Return true if the event is processed and we should go back to the
5671 event loop; false if the caller should continue processing the
5675 finish_step_over (struct execution_control_state
*ecs
)
5677 int had_step_over_info
;
5679 displaced_step_finish (ecs
->event_thread
,
5680 ecs
->event_thread
->suspend
.stop_signal
);
5682 had_step_over_info
= step_over_info_valid_p ();
5684 if (had_step_over_info
)
5686 /* If we're stepping over a breakpoint with all threads locked,
5687 then only the thread that was stepped should be reporting
5689 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5691 clear_step_over_info ();
5694 if (!target_is_non_stop_p ())
5697 /* Start a new step-over in another thread if there's one that
5701 /* If we were stepping over a breakpoint before, and haven't started
5702 a new in-line step-over sequence, then restart all other threads
5703 (except the event thread). We can't do this in all-stop, as then
5704 e.g., we wouldn't be able to issue any other remote packet until
5705 these other threads stop. */
5706 if (had_step_over_info
&& !step_over_info_valid_p ())
5708 struct thread_info
*pending
;
5710 /* If we only have threads with pending statuses, the restart
5711 below won't restart any thread and so nothing re-inserts the
5712 breakpoint we just stepped over. But we need it inserted
5713 when we later process the pending events, otherwise if
5714 another thread has a pending event for this breakpoint too,
5715 we'd discard its event (because the breakpoint that
5716 originally caused the event was no longer inserted). */
5717 context_switch (ecs
);
5718 insert_breakpoints ();
5720 restart_threads (ecs
->event_thread
);
5722 /* If we have events pending, go through handle_inferior_event
5723 again, picking up a pending event at random. This avoids
5724 thread starvation. */
5726 /* But not if we just stepped over a watchpoint in order to let
5727 the instruction execute so we can evaluate its expression.
5728 The set of watchpoints that triggered is recorded in the
5729 breakpoint objects themselves (see bp->watchpoint_triggered).
5730 If we processed another event first, that other event could
5731 clobber this info. */
5732 if (ecs
->event_thread
->stepping_over_watchpoint
)
5735 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5737 if (pending
!= NULL
)
5739 struct thread_info
*tp
= ecs
->event_thread
;
5740 struct regcache
*regcache
;
5742 infrun_log_debug ("found resumed threads with "
5743 "pending events, saving status");
5745 gdb_assert (pending
!= tp
);
5747 /* Record the event thread's event for later. */
5748 save_waitstatus (tp
, &ecs
->ws
);
5749 /* This was cleared early, by handle_inferior_event. Set it
5750 so this pending event is considered by
5754 gdb_assert (!tp
->executing
);
5756 regcache
= get_thread_regcache (tp
);
5757 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5759 infrun_log_debug ("saved stop_pc=%s for %s "
5760 "(currently_stepping=%d)\n",
5761 paddress (target_gdbarch (),
5762 tp
->suspend
.stop_pc
),
5763 target_pid_to_str (tp
->ptid
).c_str (),
5764 currently_stepping (tp
));
5766 /* This in-line step-over finished; clear this so we won't
5767 start a new one. This is what handle_signal_stop would
5768 do, if we returned false. */
5769 tp
->stepping_over_breakpoint
= 0;
5771 /* Wake up the event loop again. */
5772 mark_async_event_handler (infrun_async_inferior_event_token
);
5774 prepare_to_wait (ecs
);
5782 /* Come here when the program has stopped with a signal. */
5785 handle_signal_stop (struct execution_control_state
*ecs
)
5787 struct frame_info
*frame
;
5788 struct gdbarch
*gdbarch
;
5789 int stopped_by_watchpoint
;
5790 enum stop_kind stop_soon
;
5793 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5795 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5797 /* Do we need to clean up the state of a thread that has
5798 completed a displaced single-step? (Doing so usually affects
5799 the PC, so do it here, before we set stop_pc.) */
5800 if (finish_step_over (ecs
))
5803 /* If we either finished a single-step or hit a breakpoint, but
5804 the user wanted this thread to be stopped, pretend we got a
5805 SIG0 (generic unsignaled stop). */
5806 if (ecs
->event_thread
->stop_requested
5807 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5808 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5810 ecs
->event_thread
->suspend
.stop_pc
5811 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5815 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5816 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5818 switch_to_thread (ecs
->event_thread
);
5820 infrun_log_debug ("stop_pc=%s",
5821 paddress (reg_gdbarch
,
5822 ecs
->event_thread
->suspend
.stop_pc
));
5823 if (target_stopped_by_watchpoint ())
5827 infrun_log_debug ("stopped by watchpoint");
5829 if (target_stopped_data_address (current_top_target (), &addr
))
5830 infrun_log_debug ("stopped data address=%s",
5831 paddress (reg_gdbarch
, addr
));
5833 infrun_log_debug ("(no data address available)");
5837 /* This is originated from start_remote(), start_inferior() and
5838 shared libraries hook functions. */
5839 stop_soon
= get_inferior_stop_soon (ecs
);
5840 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5842 context_switch (ecs
);
5843 infrun_log_debug ("quietly stopped");
5844 stop_print_frame
= 1;
5849 /* This originates from attach_command(). We need to overwrite
5850 the stop_signal here, because some kernels don't ignore a
5851 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5852 See more comments in inferior.h. On the other hand, if we
5853 get a non-SIGSTOP, report it to the user - assume the backend
5854 will handle the SIGSTOP if it should show up later.
5856 Also consider that the attach is complete when we see a
5857 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5858 target extended-remote report it instead of a SIGSTOP
5859 (e.g. gdbserver). We already rely on SIGTRAP being our
5860 signal, so this is no exception.
5862 Also consider that the attach is complete when we see a
5863 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5864 the target to stop all threads of the inferior, in case the
5865 low level attach operation doesn't stop them implicitly. If
5866 they weren't stopped implicitly, then the stub will report a
5867 GDB_SIGNAL_0, meaning: stopped for no particular reason
5868 other than GDB's request. */
5869 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5870 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5871 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5872 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5874 stop_print_frame
= 1;
5876 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5880 /* See if something interesting happened to the non-current thread. If
5881 so, then switch to that thread. */
5882 if (ecs
->ptid
!= inferior_ptid
)
5884 infrun_log_debug ("context switch");
5886 context_switch (ecs
);
5888 if (deprecated_context_hook
)
5889 deprecated_context_hook (ecs
->event_thread
->global_num
);
5892 /* At this point, get hold of the now-current thread's frame. */
5893 frame
= get_current_frame ();
5894 gdbarch
= get_frame_arch (frame
);
5896 /* Pull the single step breakpoints out of the target. */
5897 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5899 struct regcache
*regcache
;
5902 regcache
= get_thread_regcache (ecs
->event_thread
);
5903 const address_space
*aspace
= regcache
->aspace ();
5905 pc
= regcache_read_pc (regcache
);
5907 /* However, before doing so, if this single-step breakpoint was
5908 actually for another thread, set this thread up for moving
5910 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5913 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5915 infrun_log_debug ("[%s] hit another thread's single-step "
5917 target_pid_to_str (ecs
->ptid
).c_str ());
5918 ecs
->hit_singlestep_breakpoint
= 1;
5923 infrun_log_debug ("[%s] hit its single-step breakpoint",
5924 target_pid_to_str (ecs
->ptid
).c_str ());
5927 delete_just_stopped_threads_single_step_breakpoints ();
5929 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5930 && ecs
->event_thread
->control
.trap_expected
5931 && ecs
->event_thread
->stepping_over_watchpoint
)
5932 stopped_by_watchpoint
= 0;
5934 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5936 /* If necessary, step over this watchpoint. We'll be back to display
5938 if (stopped_by_watchpoint
5939 && (target_have_steppable_watchpoint
5940 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5942 /* At this point, we are stopped at an instruction which has
5943 attempted to write to a piece of memory under control of
5944 a watchpoint. The instruction hasn't actually executed
5945 yet. If we were to evaluate the watchpoint expression
5946 now, we would get the old value, and therefore no change
5947 would seem to have occurred.
5949 In order to make watchpoints work `right', we really need
5950 to complete the memory write, and then evaluate the
5951 watchpoint expression. We do this by single-stepping the
5954 It may not be necessary to disable the watchpoint to step over
5955 it. For example, the PA can (with some kernel cooperation)
5956 single step over a watchpoint without disabling the watchpoint.
5958 It is far more common to need to disable a watchpoint to step
5959 the inferior over it. If we have non-steppable watchpoints,
5960 we must disable the current watchpoint; it's simplest to
5961 disable all watchpoints.
5963 Any breakpoint at PC must also be stepped over -- if there's
5964 one, it will have already triggered before the watchpoint
5965 triggered, and we either already reported it to the user, or
5966 it didn't cause a stop and we called keep_going. In either
5967 case, if there was a breakpoint at PC, we must be trying to
5969 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5974 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5975 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5976 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5977 ecs
->event_thread
->control
.stop_step
= 0;
5978 stop_print_frame
= 1;
5979 stopped_by_random_signal
= 0;
5980 bpstat stop_chain
= NULL
;
5982 /* Hide inlined functions starting here, unless we just performed stepi or
5983 nexti. After stepi and nexti, always show the innermost frame (not any
5984 inline function call sites). */
5985 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5987 const address_space
*aspace
5988 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5990 /* skip_inline_frames is expensive, so we avoid it if we can
5991 determine that the address is one where functions cannot have
5992 been inlined. This improves performance with inferiors that
5993 load a lot of shared libraries, because the solib event
5994 breakpoint is defined as the address of a function (i.e. not
5995 inline). Note that we have to check the previous PC as well
5996 as the current one to catch cases when we have just
5997 single-stepped off a breakpoint prior to reinstating it.
5998 Note that we're assuming that the code we single-step to is
5999 not inline, but that's not definitive: there's nothing
6000 preventing the event breakpoint function from containing
6001 inlined code, and the single-step ending up there. If the
6002 user had set a breakpoint on that inlined code, the missing
6003 skip_inline_frames call would break things. Fortunately
6004 that's an extremely unlikely scenario. */
6005 if (!pc_at_non_inline_function (aspace
,
6006 ecs
->event_thread
->suspend
.stop_pc
,
6008 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6009 && ecs
->event_thread
->control
.trap_expected
6010 && pc_at_non_inline_function (aspace
,
6011 ecs
->event_thread
->prev_pc
,
6014 stop_chain
= build_bpstat_chain (aspace
,
6015 ecs
->event_thread
->suspend
.stop_pc
,
6017 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6019 /* Re-fetch current thread's frame in case that invalidated
6021 frame
= get_current_frame ();
6022 gdbarch
= get_frame_arch (frame
);
6026 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6027 && ecs
->event_thread
->control
.trap_expected
6028 && gdbarch_single_step_through_delay_p (gdbarch
)
6029 && currently_stepping (ecs
->event_thread
))
6031 /* We're trying to step off a breakpoint. Turns out that we're
6032 also on an instruction that needs to be stepped multiple
6033 times before it's been fully executing. E.g., architectures
6034 with a delay slot. It needs to be stepped twice, once for
6035 the instruction and once for the delay slot. */
6036 int step_through_delay
6037 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6039 if (step_through_delay
)
6040 infrun_log_debug ("step through delay");
6042 if (ecs
->event_thread
->control
.step_range_end
== 0
6043 && step_through_delay
)
6045 /* The user issued a continue when stopped at a breakpoint.
6046 Set up for another trap and get out of here. */
6047 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6051 else if (step_through_delay
)
6053 /* The user issued a step when stopped at a breakpoint.
6054 Maybe we should stop, maybe we should not - the delay
6055 slot *might* correspond to a line of source. In any
6056 case, don't decide that here, just set
6057 ecs->stepping_over_breakpoint, making sure we
6058 single-step again before breakpoints are re-inserted. */
6059 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6063 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6064 handles this event. */
6065 ecs
->event_thread
->control
.stop_bpstat
6066 = bpstat_stop_status (get_current_regcache ()->aspace (),
6067 ecs
->event_thread
->suspend
.stop_pc
,
6068 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6070 /* Following in case break condition called a
6072 stop_print_frame
= 1;
6074 /* This is where we handle "moribund" watchpoints. Unlike
6075 software breakpoints traps, hardware watchpoint traps are
6076 always distinguishable from random traps. If no high-level
6077 watchpoint is associated with the reported stop data address
6078 anymore, then the bpstat does not explain the signal ---
6079 simply make sure to ignore it if `stopped_by_watchpoint' is
6082 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6083 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6085 && stopped_by_watchpoint
)
6087 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6091 /* NOTE: cagney/2003-03-29: These checks for a random signal
6092 at one stage in the past included checks for an inferior
6093 function call's call dummy's return breakpoint. The original
6094 comment, that went with the test, read:
6096 ``End of a stack dummy. Some systems (e.g. Sony news) give
6097 another signal besides SIGTRAP, so check here as well as
6100 If someone ever tries to get call dummys on a
6101 non-executable stack to work (where the target would stop
6102 with something like a SIGSEGV), then those tests might need
6103 to be re-instated. Given, however, that the tests were only
6104 enabled when momentary breakpoints were not being used, I
6105 suspect that it won't be the case.
6107 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6108 be necessary for call dummies on a non-executable stack on
6111 /* See if the breakpoints module can explain the signal. */
6113 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6114 ecs
->event_thread
->suspend
.stop_signal
);
6116 /* Maybe this was a trap for a software breakpoint that has since
6118 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6120 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6121 ecs
->event_thread
->suspend
.stop_pc
))
6123 struct regcache
*regcache
;
6126 /* Re-adjust PC to what the program would see if GDB was not
6128 regcache
= get_thread_regcache (ecs
->event_thread
);
6129 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6132 gdb::optional
<scoped_restore_tmpl
<int>>
6133 restore_operation_disable
;
6135 if (record_full_is_used ())
6136 restore_operation_disable
.emplace
6137 (record_full_gdb_operation_disable_set ());
6139 regcache_write_pc (regcache
,
6140 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6145 /* A delayed software breakpoint event. Ignore the trap. */
6146 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6151 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6152 has since been removed. */
6153 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6155 /* A delayed hardware breakpoint event. Ignore the trap. */
6156 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6161 /* If not, perhaps stepping/nexting can. */
6163 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6164 && currently_stepping (ecs
->event_thread
));
6166 /* Perhaps the thread hit a single-step breakpoint of _another_
6167 thread. Single-step breakpoints are transparent to the
6168 breakpoints module. */
6170 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6172 /* No? Perhaps we got a moribund watchpoint. */
6174 random_signal
= !stopped_by_watchpoint
;
6176 /* Always stop if the user explicitly requested this thread to
6178 if (ecs
->event_thread
->stop_requested
)
6181 infrun_log_debug ("user-requested stop");
6184 /* For the program's own signals, act according to
6185 the signal handling tables. */
6189 /* Signal not for debugging purposes. */
6190 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6191 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6193 infrun_log_debug ("random signal (%s)",
6194 gdb_signal_to_symbol_string (stop_signal
));
6196 stopped_by_random_signal
= 1;
6198 /* Always stop on signals if we're either just gaining control
6199 of the program, or the user explicitly requested this thread
6200 to remain stopped. */
6201 if (stop_soon
!= NO_STOP_QUIETLY
6202 || ecs
->event_thread
->stop_requested
6204 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6210 /* Notify observers the signal has "handle print" set. Note we
6211 returned early above if stopping; normal_stop handles the
6212 printing in that case. */
6213 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6215 /* The signal table tells us to print about this signal. */
6216 target_terminal::ours_for_output ();
6217 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6218 target_terminal::inferior ();
6221 /* Clear the signal if it should not be passed. */
6222 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6223 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6225 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6226 && ecs
->event_thread
->control
.trap_expected
6227 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6229 /* We were just starting a new sequence, attempting to
6230 single-step off of a breakpoint and expecting a SIGTRAP.
6231 Instead this signal arrives. This signal will take us out
6232 of the stepping range so GDB needs to remember to, when
6233 the signal handler returns, resume stepping off that
6235 /* To simplify things, "continue" is forced to use the same
6236 code paths as single-step - set a breakpoint at the
6237 signal return address and then, once hit, step off that
6239 infrun_log_debug ("signal arrived while stepping over breakpoint");
6241 insert_hp_step_resume_breakpoint_at_frame (frame
);
6242 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6243 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6244 ecs
->event_thread
->control
.trap_expected
= 0;
6246 /* If we were nexting/stepping some other thread, switch to
6247 it, so that we don't continue it, losing control. */
6248 if (!switch_back_to_stepped_thread (ecs
))
6253 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6254 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6256 || ecs
->event_thread
->control
.step_range_end
== 1)
6257 && frame_id_eq (get_stack_frame_id (frame
),
6258 ecs
->event_thread
->control
.step_stack_frame_id
)
6259 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6261 /* The inferior is about to take a signal that will take it
6262 out of the single step range. Set a breakpoint at the
6263 current PC (which is presumably where the signal handler
6264 will eventually return) and then allow the inferior to
6267 Note that this is only needed for a signal delivered
6268 while in the single-step range. Nested signals aren't a
6269 problem as they eventually all return. */
6270 infrun_log_debug ("signal may take us out of single-step range");
6272 clear_step_over_info ();
6273 insert_hp_step_resume_breakpoint_at_frame (frame
);
6274 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6275 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6276 ecs
->event_thread
->control
.trap_expected
= 0;
6281 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6282 when either there's a nested signal, or when there's a
6283 pending signal enabled just as the signal handler returns
6284 (leaving the inferior at the step-resume-breakpoint without
6285 actually executing it). Either way continue until the
6286 breakpoint is really hit. */
6288 if (!switch_back_to_stepped_thread (ecs
))
6290 infrun_log_debug ("random signal, keep going");
6297 process_event_stop_test (ecs
);
6300 /* Come here when we've got some debug event / signal we can explain
6301 (IOW, not a random signal), and test whether it should cause a
6302 stop, or whether we should resume the inferior (transparently).
6303 E.g., could be a breakpoint whose condition evaluates false; we
6304 could be still stepping within the line; etc. */
6307 process_event_stop_test (struct execution_control_state
*ecs
)
6309 struct symtab_and_line stop_pc_sal
;
6310 struct frame_info
*frame
;
6311 struct gdbarch
*gdbarch
;
6312 CORE_ADDR jmp_buf_pc
;
6313 struct bpstat_what what
;
6315 /* Handle cases caused by hitting a breakpoint. */
6317 frame
= get_current_frame ();
6318 gdbarch
= get_frame_arch (frame
);
6320 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6322 if (what
.call_dummy
)
6324 stop_stack_dummy
= what
.call_dummy
;
6327 /* A few breakpoint types have callbacks associated (e.g.,
6328 bp_jit_event). Run them now. */
6329 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6331 /* If we hit an internal event that triggers symbol changes, the
6332 current frame will be invalidated within bpstat_what (e.g., if we
6333 hit an internal solib event). Re-fetch it. */
6334 frame
= get_current_frame ();
6335 gdbarch
= get_frame_arch (frame
);
6337 switch (what
.main_action
)
6339 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6340 /* If we hit the breakpoint at longjmp while stepping, we
6341 install a momentary breakpoint at the target of the
6344 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6346 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6348 if (what
.is_longjmp
)
6350 struct value
*arg_value
;
6352 /* If we set the longjmp breakpoint via a SystemTap probe,
6353 then use it to extract the arguments. The destination PC
6354 is the third argument to the probe. */
6355 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6358 jmp_buf_pc
= value_as_address (arg_value
);
6359 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6361 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6362 || !gdbarch_get_longjmp_target (gdbarch
,
6363 frame
, &jmp_buf_pc
))
6365 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6366 "(!gdbarch_get_longjmp_target)");
6371 /* Insert a breakpoint at resume address. */
6372 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6375 check_exception_resume (ecs
, frame
);
6379 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6381 struct frame_info
*init_frame
;
6383 /* There are several cases to consider.
6385 1. The initiating frame no longer exists. In this case we
6386 must stop, because the exception or longjmp has gone too
6389 2. The initiating frame exists, and is the same as the
6390 current frame. We stop, because the exception or longjmp
6393 3. The initiating frame exists and is different from the
6394 current frame. This means the exception or longjmp has
6395 been caught beneath the initiating frame, so keep going.
6397 4. longjmp breakpoint has been placed just to protect
6398 against stale dummy frames and user is not interested in
6399 stopping around longjmps. */
6401 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6403 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6405 delete_exception_resume_breakpoint (ecs
->event_thread
);
6407 if (what
.is_longjmp
)
6409 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6411 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6419 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6423 struct frame_id current_id
6424 = get_frame_id (get_current_frame ());
6425 if (frame_id_eq (current_id
,
6426 ecs
->event_thread
->initiating_frame
))
6428 /* Case 2. Fall through. */
6438 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6440 delete_step_resume_breakpoint (ecs
->event_thread
);
6442 end_stepping_range (ecs
);
6446 case BPSTAT_WHAT_SINGLE
:
6447 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6448 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6449 /* Still need to check other stuff, at least the case where we
6450 are stepping and step out of the right range. */
6453 case BPSTAT_WHAT_STEP_RESUME
:
6454 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6456 delete_step_resume_breakpoint (ecs
->event_thread
);
6457 if (ecs
->event_thread
->control
.proceed_to_finish
6458 && execution_direction
== EXEC_REVERSE
)
6460 struct thread_info
*tp
= ecs
->event_thread
;
6462 /* We are finishing a function in reverse, and just hit the
6463 step-resume breakpoint at the start address of the
6464 function, and we're almost there -- just need to back up
6465 by one more single-step, which should take us back to the
6467 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6471 fill_in_stop_func (gdbarch
, ecs
);
6472 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6473 && execution_direction
== EXEC_REVERSE
)
6475 /* We are stepping over a function call in reverse, and just
6476 hit the step-resume breakpoint at the start address of
6477 the function. Go back to single-stepping, which should
6478 take us back to the function call. */
6479 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6485 case BPSTAT_WHAT_STOP_NOISY
:
6486 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6487 stop_print_frame
= 1;
6489 /* Assume the thread stopped for a breapoint. We'll still check
6490 whether a/the breakpoint is there when the thread is next
6492 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6497 case BPSTAT_WHAT_STOP_SILENT
:
6498 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6499 stop_print_frame
= 0;
6501 /* Assume the thread stopped for a breapoint. We'll still check
6502 whether a/the breakpoint is there when the thread is next
6504 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6508 case BPSTAT_WHAT_HP_STEP_RESUME
:
6509 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6511 delete_step_resume_breakpoint (ecs
->event_thread
);
6512 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6514 /* Back when the step-resume breakpoint was inserted, we
6515 were trying to single-step off a breakpoint. Go back to
6517 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6518 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6524 case BPSTAT_WHAT_KEEP_CHECKING
:
6528 /* If we stepped a permanent breakpoint and we had a high priority
6529 step-resume breakpoint for the address we stepped, but we didn't
6530 hit it, then we must have stepped into the signal handler. The
6531 step-resume was only necessary to catch the case of _not_
6532 stepping into the handler, so delete it, and fall through to
6533 checking whether the step finished. */
6534 if (ecs
->event_thread
->stepped_breakpoint
)
6536 struct breakpoint
*sr_bp
6537 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6540 && sr_bp
->loc
->permanent
6541 && sr_bp
->type
== bp_hp_step_resume
6542 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6544 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6545 delete_step_resume_breakpoint (ecs
->event_thread
);
6546 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6550 /* We come here if we hit a breakpoint but should not stop for it.
6551 Possibly we also were stepping and should stop for that. So fall
6552 through and test for stepping. But, if not stepping, do not
6555 /* In all-stop mode, if we're currently stepping but have stopped in
6556 some other thread, we need to switch back to the stepped thread. */
6557 if (switch_back_to_stepped_thread (ecs
))
6560 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6562 infrun_log_debug ("step-resume breakpoint is inserted");
6564 /* Having a step-resume breakpoint overrides anything
6565 else having to do with stepping commands until
6566 that breakpoint is reached. */
6571 if (ecs
->event_thread
->control
.step_range_end
== 0)
6573 infrun_log_debug ("no stepping, continue");
6574 /* Likewise if we aren't even stepping. */
6579 /* Re-fetch current thread's frame in case the code above caused
6580 the frame cache to be re-initialized, making our FRAME variable
6581 a dangling pointer. */
6582 frame
= get_current_frame ();
6583 gdbarch
= get_frame_arch (frame
);
6584 fill_in_stop_func (gdbarch
, ecs
);
6586 /* If stepping through a line, keep going if still within it.
6588 Note that step_range_end is the address of the first instruction
6589 beyond the step range, and NOT the address of the last instruction
6592 Note also that during reverse execution, we may be stepping
6593 through a function epilogue and therefore must detect when
6594 the current-frame changes in the middle of a line. */
6596 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6598 && (execution_direction
!= EXEC_REVERSE
6599 || frame_id_eq (get_frame_id (frame
),
6600 ecs
->event_thread
->control
.step_frame_id
)))
6603 ("stepping inside range [%s-%s]",
6604 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6605 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6607 /* Tentatively re-enable range stepping; `resume' disables it if
6608 necessary (e.g., if we're stepping over a breakpoint or we
6609 have software watchpoints). */
6610 ecs
->event_thread
->control
.may_range_step
= 1;
6612 /* When stepping backward, stop at beginning of line range
6613 (unless it's the function entry point, in which case
6614 keep going back to the call point). */
6615 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6616 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6617 && stop_pc
!= ecs
->stop_func_start
6618 && execution_direction
== EXEC_REVERSE
)
6619 end_stepping_range (ecs
);
6626 /* We stepped out of the stepping range. */
6628 /* If we are stepping at the source level and entered the runtime
6629 loader dynamic symbol resolution code...
6631 EXEC_FORWARD: we keep on single stepping until we exit the run
6632 time loader code and reach the callee's address.
6634 EXEC_REVERSE: we've already executed the callee (backward), and
6635 the runtime loader code is handled just like any other
6636 undebuggable function call. Now we need only keep stepping
6637 backward through the trampoline code, and that's handled further
6638 down, so there is nothing for us to do here. */
6640 if (execution_direction
!= EXEC_REVERSE
6641 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6642 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6644 CORE_ADDR pc_after_resolver
=
6645 gdbarch_skip_solib_resolver (gdbarch
,
6646 ecs
->event_thread
->suspend
.stop_pc
);
6648 infrun_log_debug ("stepped into dynsym resolve code");
6650 if (pc_after_resolver
)
6652 /* Set up a step-resume breakpoint at the address
6653 indicated by SKIP_SOLIB_RESOLVER. */
6654 symtab_and_line sr_sal
;
6655 sr_sal
.pc
= pc_after_resolver
;
6656 sr_sal
.pspace
= get_frame_program_space (frame
);
6658 insert_step_resume_breakpoint_at_sal (gdbarch
,
6659 sr_sal
, null_frame_id
);
6666 /* Step through an indirect branch thunk. */
6667 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6668 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6669 ecs
->event_thread
->suspend
.stop_pc
))
6671 infrun_log_debug ("stepped into indirect branch thunk");
6676 if (ecs
->event_thread
->control
.step_range_end
!= 1
6677 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6678 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6679 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6681 infrun_log_debug ("stepped into signal trampoline");
6682 /* The inferior, while doing a "step" or "next", has ended up in
6683 a signal trampoline (either by a signal being delivered or by
6684 the signal handler returning). Just single-step until the
6685 inferior leaves the trampoline (either by calling the handler
6691 /* If we're in the return path from a shared library trampoline,
6692 we want to proceed through the trampoline when stepping. */
6693 /* macro/2012-04-25: This needs to come before the subroutine
6694 call check below as on some targets return trampolines look
6695 like subroutine calls (MIPS16 return thunks). */
6696 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6697 ecs
->event_thread
->suspend
.stop_pc
,
6698 ecs
->stop_func_name
)
6699 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6701 /* Determine where this trampoline returns. */
6702 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6703 CORE_ADDR real_stop_pc
6704 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6706 infrun_log_debug ("stepped into solib return tramp");
6708 /* Only proceed through if we know where it's going. */
6711 /* And put the step-breakpoint there and go until there. */
6712 symtab_and_line sr_sal
;
6713 sr_sal
.pc
= real_stop_pc
;
6714 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6715 sr_sal
.pspace
= get_frame_program_space (frame
);
6717 /* Do not specify what the fp should be when we stop since
6718 on some machines the prologue is where the new fp value
6720 insert_step_resume_breakpoint_at_sal (gdbarch
,
6721 sr_sal
, null_frame_id
);
6723 /* Restart without fiddling with the step ranges or
6730 /* Check for subroutine calls. The check for the current frame
6731 equalling the step ID is not necessary - the check of the
6732 previous frame's ID is sufficient - but it is a common case and
6733 cheaper than checking the previous frame's ID.
6735 NOTE: frame_id_eq will never report two invalid frame IDs as
6736 being equal, so to get into this block, both the current and
6737 previous frame must have valid frame IDs. */
6738 /* The outer_frame_id check is a heuristic to detect stepping
6739 through startup code. If we step over an instruction which
6740 sets the stack pointer from an invalid value to a valid value,
6741 we may detect that as a subroutine call from the mythical
6742 "outermost" function. This could be fixed by marking
6743 outermost frames as !stack_p,code_p,special_p. Then the
6744 initial outermost frame, before sp was valid, would
6745 have code_addr == &_start. See the comment in frame_id_eq
6747 if (!frame_id_eq (get_stack_frame_id (frame
),
6748 ecs
->event_thread
->control
.step_stack_frame_id
)
6749 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6750 ecs
->event_thread
->control
.step_stack_frame_id
)
6751 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6753 || (ecs
->event_thread
->control
.step_start_function
6754 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6756 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6757 CORE_ADDR real_stop_pc
;
6759 infrun_log_debug ("stepped into subroutine");
6761 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6763 /* I presume that step_over_calls is only 0 when we're
6764 supposed to be stepping at the assembly language level
6765 ("stepi"). Just stop. */
6766 /* And this works the same backward as frontward. MVS */
6767 end_stepping_range (ecs
);
6771 /* Reverse stepping through solib trampolines. */
6773 if (execution_direction
== EXEC_REVERSE
6774 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6775 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6776 || (ecs
->stop_func_start
== 0
6777 && in_solib_dynsym_resolve_code (stop_pc
))))
6779 /* Any solib trampoline code can be handled in reverse
6780 by simply continuing to single-step. We have already
6781 executed the solib function (backwards), and a few
6782 steps will take us back through the trampoline to the
6788 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6790 /* We're doing a "next".
6792 Normal (forward) execution: set a breakpoint at the
6793 callee's return address (the address at which the caller
6796 Reverse (backward) execution. set the step-resume
6797 breakpoint at the start of the function that we just
6798 stepped into (backwards), and continue to there. When we
6799 get there, we'll need to single-step back to the caller. */
6801 if (execution_direction
== EXEC_REVERSE
)
6803 /* If we're already at the start of the function, we've either
6804 just stepped backward into a single instruction function,
6805 or stepped back out of a signal handler to the first instruction
6806 of the function. Just keep going, which will single-step back
6808 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6810 /* Normal function call return (static or dynamic). */
6811 symtab_and_line sr_sal
;
6812 sr_sal
.pc
= ecs
->stop_func_start
;
6813 sr_sal
.pspace
= get_frame_program_space (frame
);
6814 insert_step_resume_breakpoint_at_sal (gdbarch
,
6815 sr_sal
, null_frame_id
);
6819 insert_step_resume_breakpoint_at_caller (frame
);
6825 /* If we are in a function call trampoline (a stub between the
6826 calling routine and the real function), locate the real
6827 function. That's what tells us (a) whether we want to step
6828 into it at all, and (b) what prologue we want to run to the
6829 end of, if we do step into it. */
6830 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6831 if (real_stop_pc
== 0)
6832 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6833 if (real_stop_pc
!= 0)
6834 ecs
->stop_func_start
= real_stop_pc
;
6836 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6838 symtab_and_line sr_sal
;
6839 sr_sal
.pc
= ecs
->stop_func_start
;
6840 sr_sal
.pspace
= get_frame_program_space (frame
);
6842 insert_step_resume_breakpoint_at_sal (gdbarch
,
6843 sr_sal
, null_frame_id
);
6848 /* If we have line number information for the function we are
6849 thinking of stepping into and the function isn't on the skip
6852 If there are several symtabs at that PC (e.g. with include
6853 files), just want to know whether *any* of them have line
6854 numbers. find_pc_line handles this. */
6856 struct symtab_and_line tmp_sal
;
6858 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6859 if (tmp_sal
.line
!= 0
6860 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6862 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6864 if (execution_direction
== EXEC_REVERSE
)
6865 handle_step_into_function_backward (gdbarch
, ecs
);
6867 handle_step_into_function (gdbarch
, ecs
);
6872 /* If we have no line number and the step-stop-if-no-debug is
6873 set, we stop the step so that the user has a chance to switch
6874 in assembly mode. */
6875 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6876 && step_stop_if_no_debug
)
6878 end_stepping_range (ecs
);
6882 if (execution_direction
== EXEC_REVERSE
)
6884 /* If we're already at the start of the function, we've either just
6885 stepped backward into a single instruction function without line
6886 number info, or stepped back out of a signal handler to the first
6887 instruction of the function without line number info. Just keep
6888 going, which will single-step back to the caller. */
6889 if (ecs
->stop_func_start
!= stop_pc
)
6891 /* Set a breakpoint at callee's start address.
6892 From there we can step once and be back in the caller. */
6893 symtab_and_line sr_sal
;
6894 sr_sal
.pc
= ecs
->stop_func_start
;
6895 sr_sal
.pspace
= get_frame_program_space (frame
);
6896 insert_step_resume_breakpoint_at_sal (gdbarch
,
6897 sr_sal
, null_frame_id
);
6901 /* Set a breakpoint at callee's return address (the address
6902 at which the caller will resume). */
6903 insert_step_resume_breakpoint_at_caller (frame
);
6909 /* Reverse stepping through solib trampolines. */
6911 if (execution_direction
== EXEC_REVERSE
6912 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6914 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6916 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6917 || (ecs
->stop_func_start
== 0
6918 && in_solib_dynsym_resolve_code (stop_pc
)))
6920 /* Any solib trampoline code can be handled in reverse
6921 by simply continuing to single-step. We have already
6922 executed the solib function (backwards), and a few
6923 steps will take us back through the trampoline to the
6928 else if (in_solib_dynsym_resolve_code (stop_pc
))
6930 /* Stepped backward into the solib dynsym resolver.
6931 Set a breakpoint at its start and continue, then
6932 one more step will take us out. */
6933 symtab_and_line sr_sal
;
6934 sr_sal
.pc
= ecs
->stop_func_start
;
6935 sr_sal
.pspace
= get_frame_program_space (frame
);
6936 insert_step_resume_breakpoint_at_sal (gdbarch
,
6937 sr_sal
, null_frame_id
);
6943 /* This always returns the sal for the inner-most frame when we are in a
6944 stack of inlined frames, even if GDB actually believes that it is in a
6945 more outer frame. This is checked for below by calls to
6946 inline_skipped_frames. */
6947 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6949 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6950 the trampoline processing logic, however, there are some trampolines
6951 that have no names, so we should do trampoline handling first. */
6952 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6953 && ecs
->stop_func_name
== NULL
6954 && stop_pc_sal
.line
== 0)
6956 infrun_log_debug ("stepped into undebuggable function");
6958 /* The inferior just stepped into, or returned to, an
6959 undebuggable function (where there is no debugging information
6960 and no line number corresponding to the address where the
6961 inferior stopped). Since we want to skip this kind of code,
6962 we keep going until the inferior returns from this
6963 function - unless the user has asked us not to (via
6964 set step-mode) or we no longer know how to get back
6965 to the call site. */
6966 if (step_stop_if_no_debug
6967 || !frame_id_p (frame_unwind_caller_id (frame
)))
6969 /* If we have no line number and the step-stop-if-no-debug
6970 is set, we stop the step so that the user has a chance to
6971 switch in assembly mode. */
6972 end_stepping_range (ecs
);
6977 /* Set a breakpoint at callee's return address (the address
6978 at which the caller will resume). */
6979 insert_step_resume_breakpoint_at_caller (frame
);
6985 if (ecs
->event_thread
->control
.step_range_end
== 1)
6987 /* It is stepi or nexti. We always want to stop stepping after
6989 infrun_log_debug ("stepi/nexti");
6990 end_stepping_range (ecs
);
6994 if (stop_pc_sal
.line
== 0)
6996 /* We have no line number information. That means to stop
6997 stepping (does this always happen right after one instruction,
6998 when we do "s" in a function with no line numbers,
6999 or can this happen as a result of a return or longjmp?). */
7000 infrun_log_debug ("line number info");
7001 end_stepping_range (ecs
);
7005 /* Look for "calls" to inlined functions, part one. If the inline
7006 frame machinery detected some skipped call sites, we have entered
7007 a new inline function. */
7009 if (frame_id_eq (get_frame_id (get_current_frame ()),
7010 ecs
->event_thread
->control
.step_frame_id
)
7011 && inline_skipped_frames (ecs
->event_thread
))
7013 infrun_log_debug ("stepped into inlined function");
7015 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7017 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7019 /* For "step", we're going to stop. But if the call site
7020 for this inlined function is on the same source line as
7021 we were previously stepping, go down into the function
7022 first. Otherwise stop at the call site. */
7024 if (call_sal
.line
== ecs
->event_thread
->current_line
7025 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7027 step_into_inline_frame (ecs
->event_thread
);
7028 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7035 end_stepping_range (ecs
);
7040 /* For "next", we should stop at the call site if it is on a
7041 different source line. Otherwise continue through the
7042 inlined function. */
7043 if (call_sal
.line
== ecs
->event_thread
->current_line
7044 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7047 end_stepping_range (ecs
);
7052 /* Look for "calls" to inlined functions, part two. If we are still
7053 in the same real function we were stepping through, but we have
7054 to go further up to find the exact frame ID, we are stepping
7055 through a more inlined call beyond its call site. */
7057 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7058 && !frame_id_eq (get_frame_id (get_current_frame ()),
7059 ecs
->event_thread
->control
.step_frame_id
)
7060 && stepped_in_from (get_current_frame (),
7061 ecs
->event_thread
->control
.step_frame_id
))
7063 infrun_log_debug ("stepping through inlined function");
7065 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7066 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7069 end_stepping_range (ecs
);
7073 bool refresh_step_info
= true;
7074 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7075 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7076 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7078 if (stop_pc_sal
.is_stmt
)
7080 /* We are at the start of a different line. So stop. Note that
7081 we don't stop if we step into the middle of a different line.
7082 That is said to make things like for (;;) statements work
7084 infrun_log_debug ("infrun: stepped to a different line\n");
7085 end_stepping_range (ecs
);
7088 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7089 ecs
->event_thread
->control
.step_frame_id
))
7091 /* We are at the start of a different line, however, this line is
7092 not marked as a statement, and we have not changed frame. We
7093 ignore this line table entry, and continue stepping forward,
7094 looking for a better place to stop. */
7095 refresh_step_info
= false;
7096 infrun_log_debug ("infrun: stepped to a different line, but "
7097 "it's not the start of a statement\n");
7101 /* We aren't done stepping.
7103 Optimize by setting the stepping range to the line.
7104 (We might not be in the original line, but if we entered a
7105 new line in mid-statement, we continue stepping. This makes
7106 things like for(;;) statements work better.)
7108 If we entered a SAL that indicates a non-statement line table entry,
7109 then we update the stepping range, but we don't update the step info,
7110 which includes things like the line number we are stepping away from.
7111 This means we will stop when we find a line table entry that is marked
7112 as is-statement, even if it matches the non-statement one we just
7115 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7116 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7117 ecs
->event_thread
->control
.may_range_step
= 1;
7118 if (refresh_step_info
)
7119 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7121 infrun_log_debug ("keep going");
7125 /* In all-stop mode, if we're currently stepping but have stopped in
7126 some other thread, we may need to switch back to the stepped
7127 thread. Returns true we set the inferior running, false if we left
7128 it stopped (and the event needs further processing). */
7131 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7133 if (!target_is_non_stop_p ())
7135 struct thread_info
*stepping_thread
;
7137 /* If any thread is blocked on some internal breakpoint, and we
7138 simply need to step over that breakpoint to get it going
7139 again, do that first. */
7141 /* However, if we see an event for the stepping thread, then we
7142 know all other threads have been moved past their breakpoints
7143 already. Let the caller check whether the step is finished,
7144 etc., before deciding to move it past a breakpoint. */
7145 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7148 /* Check if the current thread is blocked on an incomplete
7149 step-over, interrupted by a random signal. */
7150 if (ecs
->event_thread
->control
.trap_expected
7151 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7153 infrun_log_debug ("need to finish step-over of [%s]",
7154 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7159 /* Check if the current thread is blocked by a single-step
7160 breakpoint of another thread. */
7161 if (ecs
->hit_singlestep_breakpoint
)
7163 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7164 target_pid_to_str (ecs
->ptid
).c_str ());
7169 /* If this thread needs yet another step-over (e.g., stepping
7170 through a delay slot), do it first before moving on to
7172 if (thread_still_needs_step_over (ecs
->event_thread
))
7175 ("thread [%s] still needs step-over",
7176 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7181 /* If scheduler locking applies even if not stepping, there's no
7182 need to walk over threads. Above we've checked whether the
7183 current thread is stepping. If some other thread not the
7184 event thread is stepping, then it must be that scheduler
7185 locking is not in effect. */
7186 if (schedlock_applies (ecs
->event_thread
))
7189 /* Otherwise, we no longer expect a trap in the current thread.
7190 Clear the trap_expected flag before switching back -- this is
7191 what keep_going does as well, if we call it. */
7192 ecs
->event_thread
->control
.trap_expected
= 0;
7194 /* Likewise, clear the signal if it should not be passed. */
7195 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7196 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7198 /* Do all pending step-overs before actually proceeding with
7200 if (start_step_over ())
7202 prepare_to_wait (ecs
);
7206 /* Look for the stepping/nexting thread. */
7207 stepping_thread
= NULL
;
7209 for (thread_info
*tp
: all_non_exited_threads ())
7211 switch_to_thread_no_regs (tp
);
7213 /* Ignore threads of processes the caller is not
7216 && (tp
->inf
->process_target () != ecs
->target
7217 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7220 /* When stepping over a breakpoint, we lock all threads
7221 except the one that needs to move past the breakpoint.
7222 If a non-event thread has this set, the "incomplete
7223 step-over" check above should have caught it earlier. */
7224 if (tp
->control
.trap_expected
)
7226 internal_error (__FILE__
, __LINE__
,
7227 "[%s] has inconsistent state: "
7228 "trap_expected=%d\n",
7229 target_pid_to_str (tp
->ptid
).c_str (),
7230 tp
->control
.trap_expected
);
7233 /* Did we find the stepping thread? */
7234 if (tp
->control
.step_range_end
)
7236 /* Yep. There should only one though. */
7237 gdb_assert (stepping_thread
== NULL
);
7239 /* The event thread is handled at the top, before we
7241 gdb_assert (tp
!= ecs
->event_thread
);
7243 /* If some thread other than the event thread is
7244 stepping, then scheduler locking can't be in effect,
7245 otherwise we wouldn't have resumed the current event
7246 thread in the first place. */
7247 gdb_assert (!schedlock_applies (tp
));
7249 stepping_thread
= tp
;
7253 if (stepping_thread
!= NULL
)
7255 infrun_log_debug ("switching back to stepped thread");
7257 if (keep_going_stepped_thread (stepping_thread
))
7259 prepare_to_wait (ecs
);
7264 switch_to_thread (ecs
->event_thread
);
7270 /* Set a previously stepped thread back to stepping. Returns true on
7271 success, false if the resume is not possible (e.g., the thread
7275 keep_going_stepped_thread (struct thread_info
*tp
)
7277 struct frame_info
*frame
;
7278 struct execution_control_state ecss
;
7279 struct execution_control_state
*ecs
= &ecss
;
7281 /* If the stepping thread exited, then don't try to switch back and
7282 resume it, which could fail in several different ways depending
7283 on the target. Instead, just keep going.
7285 We can find a stepping dead thread in the thread list in two
7288 - The target supports thread exit events, and when the target
7289 tries to delete the thread from the thread list, inferior_ptid
7290 pointed at the exiting thread. In such case, calling
7291 delete_thread does not really remove the thread from the list;
7292 instead, the thread is left listed, with 'exited' state.
7294 - The target's debug interface does not support thread exit
7295 events, and so we have no idea whatsoever if the previously
7296 stepping thread is still alive. For that reason, we need to
7297 synchronously query the target now. */
7299 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7301 infrun_log_debug ("not resuming previously stepped thread, it has "
7308 infrun_log_debug ("resuming previously stepped thread");
7310 reset_ecs (ecs
, tp
);
7311 switch_to_thread (tp
);
7313 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7314 frame
= get_current_frame ();
7316 /* If the PC of the thread we were trying to single-step has
7317 changed, then that thread has trapped or been signaled, but the
7318 event has not been reported to GDB yet. Re-poll the target
7319 looking for this particular thread's event (i.e. temporarily
7320 enable schedlock) by:
7322 - setting a break at the current PC
7323 - resuming that particular thread, only (by setting trap
7326 This prevents us continuously moving the single-step breakpoint
7327 forward, one instruction at a time, overstepping. */
7329 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7333 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7334 paddress (target_gdbarch (), tp
->prev_pc
),
7335 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7337 /* Clear the info of the previous step-over, as it's no longer
7338 valid (if the thread was trying to step over a breakpoint, it
7339 has already succeeded). It's what keep_going would do too,
7340 if we called it. Do this before trying to insert the sss
7341 breakpoint, otherwise if we were previously trying to step
7342 over this exact address in another thread, the breakpoint is
7344 clear_step_over_info ();
7345 tp
->control
.trap_expected
= 0;
7347 insert_single_step_breakpoint (get_frame_arch (frame
),
7348 get_frame_address_space (frame
),
7349 tp
->suspend
.stop_pc
);
7352 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7353 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7357 infrun_log_debug ("expected thread still hasn't advanced");
7359 keep_going_pass_signal (ecs
);
7364 /* Is thread TP in the middle of (software or hardware)
7365 single-stepping? (Note the result of this function must never be
7366 passed directly as target_resume's STEP parameter.) */
7369 currently_stepping (struct thread_info
*tp
)
7371 return ((tp
->control
.step_range_end
7372 && tp
->control
.step_resume_breakpoint
== NULL
)
7373 || tp
->control
.trap_expected
7374 || tp
->stepped_breakpoint
7375 || bpstat_should_step ());
7378 /* Inferior has stepped into a subroutine call with source code that
7379 we should not step over. Do step to the first line of code in
7383 handle_step_into_function (struct gdbarch
*gdbarch
,
7384 struct execution_control_state
*ecs
)
7386 fill_in_stop_func (gdbarch
, ecs
);
7388 compunit_symtab
*cust
7389 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7390 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7391 ecs
->stop_func_start
7392 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7394 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7395 /* Use the step_resume_break to step until the end of the prologue,
7396 even if that involves jumps (as it seems to on the vax under
7398 /* If the prologue ends in the middle of a source line, continue to
7399 the end of that source line (if it is still within the function).
7400 Otherwise, just go to end of prologue. */
7401 if (stop_func_sal
.end
7402 && stop_func_sal
.pc
!= ecs
->stop_func_start
7403 && stop_func_sal
.end
< ecs
->stop_func_end
)
7404 ecs
->stop_func_start
= stop_func_sal
.end
;
7406 /* Architectures which require breakpoint adjustment might not be able
7407 to place a breakpoint at the computed address. If so, the test
7408 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7409 ecs->stop_func_start to an address at which a breakpoint may be
7410 legitimately placed.
7412 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7413 made, GDB will enter an infinite loop when stepping through
7414 optimized code consisting of VLIW instructions which contain
7415 subinstructions corresponding to different source lines. On
7416 FR-V, it's not permitted to place a breakpoint on any but the
7417 first subinstruction of a VLIW instruction. When a breakpoint is
7418 set, GDB will adjust the breakpoint address to the beginning of
7419 the VLIW instruction. Thus, we need to make the corresponding
7420 adjustment here when computing the stop address. */
7422 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7424 ecs
->stop_func_start
7425 = gdbarch_adjust_breakpoint_address (gdbarch
,
7426 ecs
->stop_func_start
);
7429 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7431 /* We are already there: stop now. */
7432 end_stepping_range (ecs
);
7437 /* Put the step-breakpoint there and go until there. */
7438 symtab_and_line sr_sal
;
7439 sr_sal
.pc
= ecs
->stop_func_start
;
7440 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7441 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7443 /* Do not specify what the fp should be when we stop since on
7444 some machines the prologue is where the new fp value is
7446 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7448 /* And make sure stepping stops right away then. */
7449 ecs
->event_thread
->control
.step_range_end
7450 = ecs
->event_thread
->control
.step_range_start
;
7455 /* Inferior has stepped backward into a subroutine call with source
7456 code that we should not step over. Do step to the beginning of the
7457 last line of code in it. */
7460 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7461 struct execution_control_state
*ecs
)
7463 struct compunit_symtab
*cust
;
7464 struct symtab_and_line stop_func_sal
;
7466 fill_in_stop_func (gdbarch
, ecs
);
7468 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7469 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7470 ecs
->stop_func_start
7471 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7473 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7475 /* OK, we're just going to keep stepping here. */
7476 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7478 /* We're there already. Just stop stepping now. */
7479 end_stepping_range (ecs
);
7483 /* Else just reset the step range and keep going.
7484 No step-resume breakpoint, they don't work for
7485 epilogues, which can have multiple entry paths. */
7486 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7487 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7493 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7494 This is used to both functions and to skip over code. */
7497 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7498 struct symtab_and_line sr_sal
,
7499 struct frame_id sr_id
,
7500 enum bptype sr_type
)
7502 /* There should never be more than one step-resume or longjmp-resume
7503 breakpoint per thread, so we should never be setting a new
7504 step_resume_breakpoint when one is already active. */
7505 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7506 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7508 infrun_log_debug ("inserting step-resume breakpoint at %s",
7509 paddress (gdbarch
, sr_sal
.pc
));
7511 inferior_thread ()->control
.step_resume_breakpoint
7512 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7516 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7517 struct symtab_and_line sr_sal
,
7518 struct frame_id sr_id
)
7520 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7525 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7526 This is used to skip a potential signal handler.
7528 This is called with the interrupted function's frame. The signal
7529 handler, when it returns, will resume the interrupted function at
7533 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7535 gdb_assert (return_frame
!= NULL
);
7537 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7539 symtab_and_line sr_sal
;
7540 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7541 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7542 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7544 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7545 get_stack_frame_id (return_frame
),
7549 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7550 is used to skip a function after stepping into it (for "next" or if
7551 the called function has no debugging information).
7553 The current function has almost always been reached by single
7554 stepping a call or return instruction. NEXT_FRAME belongs to the
7555 current function, and the breakpoint will be set at the caller's
7558 This is a separate function rather than reusing
7559 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7560 get_prev_frame, which may stop prematurely (see the implementation
7561 of frame_unwind_caller_id for an example). */
7564 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7566 /* We shouldn't have gotten here if we don't know where the call site
7568 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7570 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7572 symtab_and_line sr_sal
;
7573 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7574 frame_unwind_caller_pc (next_frame
));
7575 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7576 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7578 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7579 frame_unwind_caller_id (next_frame
));
7582 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7583 new breakpoint at the target of a jmp_buf. The handling of
7584 longjmp-resume uses the same mechanisms used for handling
7585 "step-resume" breakpoints. */
7588 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7590 /* There should never be more than one longjmp-resume breakpoint per
7591 thread, so we should never be setting a new
7592 longjmp_resume_breakpoint when one is already active. */
7593 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7595 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7596 paddress (gdbarch
, pc
));
7598 inferior_thread ()->control
.exception_resume_breakpoint
=
7599 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7602 /* Insert an exception resume breakpoint. TP is the thread throwing
7603 the exception. The block B is the block of the unwinder debug hook
7604 function. FRAME is the frame corresponding to the call to this
7605 function. SYM is the symbol of the function argument holding the
7606 target PC of the exception. */
7609 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7610 const struct block
*b
,
7611 struct frame_info
*frame
,
7616 struct block_symbol vsym
;
7617 struct value
*value
;
7619 struct breakpoint
*bp
;
7621 vsym
= lookup_symbol_search_name (sym
->search_name (),
7623 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7624 /* If the value was optimized out, revert to the old behavior. */
7625 if (! value_optimized_out (value
))
7627 handler
= value_as_address (value
);
7629 infrun_log_debug ("exception resume at %lx",
7630 (unsigned long) handler
);
7632 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7634 bp_exception_resume
).release ();
7636 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7639 bp
->thread
= tp
->global_num
;
7640 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7643 catch (const gdb_exception_error
&e
)
7645 /* We want to ignore errors here. */
7649 /* A helper for check_exception_resume that sets an
7650 exception-breakpoint based on a SystemTap probe. */
7653 insert_exception_resume_from_probe (struct thread_info
*tp
,
7654 const struct bound_probe
*probe
,
7655 struct frame_info
*frame
)
7657 struct value
*arg_value
;
7659 struct breakpoint
*bp
;
7661 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7665 handler
= value_as_address (arg_value
);
7667 infrun_log_debug ("exception resume at %s",
7668 paddress (probe
->objfile
->arch (), handler
));
7670 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7671 handler
, bp_exception_resume
).release ();
7672 bp
->thread
= tp
->global_num
;
7673 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7676 /* This is called when an exception has been intercepted. Check to
7677 see whether the exception's destination is of interest, and if so,
7678 set an exception resume breakpoint there. */
7681 check_exception_resume (struct execution_control_state
*ecs
,
7682 struct frame_info
*frame
)
7684 struct bound_probe probe
;
7685 struct symbol
*func
;
7687 /* First see if this exception unwinding breakpoint was set via a
7688 SystemTap probe point. If so, the probe has two arguments: the
7689 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7690 set a breakpoint there. */
7691 probe
= find_probe_by_pc (get_frame_pc (frame
));
7694 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7698 func
= get_frame_function (frame
);
7704 const struct block
*b
;
7705 struct block_iterator iter
;
7709 /* The exception breakpoint is a thread-specific breakpoint on
7710 the unwinder's debug hook, declared as:
7712 void _Unwind_DebugHook (void *cfa, void *handler);
7714 The CFA argument indicates the frame to which control is
7715 about to be transferred. HANDLER is the destination PC.
7717 We ignore the CFA and set a temporary breakpoint at HANDLER.
7718 This is not extremely efficient but it avoids issues in gdb
7719 with computing the DWARF CFA, and it also works even in weird
7720 cases such as throwing an exception from inside a signal
7723 b
= SYMBOL_BLOCK_VALUE (func
);
7724 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7726 if (!SYMBOL_IS_ARGUMENT (sym
))
7733 insert_exception_resume_breakpoint (ecs
->event_thread
,
7739 catch (const gdb_exception_error
&e
)
7745 stop_waiting (struct execution_control_state
*ecs
)
7747 infrun_log_debug ("stop_waiting");
7749 /* Let callers know we don't want to wait for the inferior anymore. */
7750 ecs
->wait_some_more
= 0;
7752 /* If all-stop, but there exists a non-stop target, stop all
7753 threads now that we're presenting the stop to the user. */
7754 if (!non_stop
&& exists_non_stop_target ())
7755 stop_all_threads ();
7758 /* Like keep_going, but passes the signal to the inferior, even if the
7759 signal is set to nopass. */
7762 keep_going_pass_signal (struct execution_control_state
*ecs
)
7764 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7765 gdb_assert (!ecs
->event_thread
->resumed
);
7767 /* Save the pc before execution, to compare with pc after stop. */
7768 ecs
->event_thread
->prev_pc
7769 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7771 if (ecs
->event_thread
->control
.trap_expected
)
7773 struct thread_info
*tp
= ecs
->event_thread
;
7775 infrun_log_debug ("%s has trap_expected set, "
7776 "resuming to collect trap",
7777 target_pid_to_str (tp
->ptid
).c_str ());
7779 /* We haven't yet gotten our trap, and either: intercepted a
7780 non-signal event (e.g., a fork); or took a signal which we
7781 are supposed to pass through to the inferior. Simply
7783 resume (ecs
->event_thread
->suspend
.stop_signal
);
7785 else if (step_over_info_valid_p ())
7787 /* Another thread is stepping over a breakpoint in-line. If
7788 this thread needs a step-over too, queue the request. In
7789 either case, this resume must be deferred for later. */
7790 struct thread_info
*tp
= ecs
->event_thread
;
7792 if (ecs
->hit_singlestep_breakpoint
7793 || thread_still_needs_step_over (tp
))
7795 infrun_log_debug ("step-over already in progress: "
7796 "step-over for %s deferred",
7797 target_pid_to_str (tp
->ptid
).c_str ());
7798 global_thread_step_over_chain_enqueue (tp
);
7802 infrun_log_debug ("step-over in progress: resume of %s deferred",
7803 target_pid_to_str (tp
->ptid
).c_str ());
7808 struct regcache
*regcache
= get_current_regcache ();
7811 step_over_what step_what
;
7813 /* Either the trap was not expected, but we are continuing
7814 anyway (if we got a signal, the user asked it be passed to
7817 We got our expected trap, but decided we should resume from
7820 We're going to run this baby now!
7822 Note that insert_breakpoints won't try to re-insert
7823 already inserted breakpoints. Therefore, we don't
7824 care if breakpoints were already inserted, or not. */
7826 /* If we need to step over a breakpoint, and we're not using
7827 displaced stepping to do so, insert all breakpoints
7828 (watchpoints, etc.) but the one we're stepping over, step one
7829 instruction, and then re-insert the breakpoint when that step
7832 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7834 remove_bp
= (ecs
->hit_singlestep_breakpoint
7835 || (step_what
& STEP_OVER_BREAKPOINT
));
7836 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7838 /* We can't use displaced stepping if we need to step past a
7839 watchpoint. The instruction copied to the scratch pad would
7840 still trigger the watchpoint. */
7842 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7844 set_step_over_info (regcache
->aspace (),
7845 regcache_read_pc (regcache
), remove_wps
,
7846 ecs
->event_thread
->global_num
);
7848 else if (remove_wps
)
7849 set_step_over_info (NULL
, 0, remove_wps
, -1);
7851 /* If we now need to do an in-line step-over, we need to stop
7852 all other threads. Note this must be done before
7853 insert_breakpoints below, because that removes the breakpoint
7854 we're about to step over, otherwise other threads could miss
7856 if (step_over_info_valid_p () && target_is_non_stop_p ())
7857 stop_all_threads ();
7859 /* Stop stepping if inserting breakpoints fails. */
7862 insert_breakpoints ();
7864 catch (const gdb_exception_error
&e
)
7866 exception_print (gdb_stderr
, e
);
7868 clear_step_over_info ();
7872 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7874 resume (ecs
->event_thread
->suspend
.stop_signal
);
7877 prepare_to_wait (ecs
);
7880 /* Called when we should continue running the inferior, because the
7881 current event doesn't cause a user visible stop. This does the
7882 resuming part; waiting for the next event is done elsewhere. */
7885 keep_going (struct execution_control_state
*ecs
)
7887 if (ecs
->event_thread
->control
.trap_expected
7888 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7889 ecs
->event_thread
->control
.trap_expected
= 0;
7891 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7892 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7893 keep_going_pass_signal (ecs
);
7896 /* This function normally comes after a resume, before
7897 handle_inferior_event exits. It takes care of any last bits of
7898 housekeeping, and sets the all-important wait_some_more flag. */
7901 prepare_to_wait (struct execution_control_state
*ecs
)
7903 infrun_log_debug ("prepare_to_wait");
7905 ecs
->wait_some_more
= 1;
7907 /* If the target can't async, emulate it by marking the infrun event
7908 handler such that as soon as we get back to the event-loop, we
7909 immediately end up in fetch_inferior_event again calling
7911 if (!target_can_async_p ())
7912 mark_infrun_async_event_handler ();
7915 /* We are done with the step range of a step/next/si/ni command.
7916 Called once for each n of a "step n" operation. */
7919 end_stepping_range (struct execution_control_state
*ecs
)
7921 ecs
->event_thread
->control
.stop_step
= 1;
7925 /* Several print_*_reason functions to print why the inferior has stopped.
7926 We always print something when the inferior exits, or receives a signal.
7927 The rest of the cases are dealt with later on in normal_stop and
7928 print_it_typical. Ideally there should be a call to one of these
7929 print_*_reason functions functions from handle_inferior_event each time
7930 stop_waiting is called.
7932 Note that we don't call these directly, instead we delegate that to
7933 the interpreters, through observers. Interpreters then call these
7934 with whatever uiout is right. */
7937 print_end_stepping_range_reason (struct ui_out
*uiout
)
7939 /* For CLI-like interpreters, print nothing. */
7941 if (uiout
->is_mi_like_p ())
7943 uiout
->field_string ("reason",
7944 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7949 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7951 annotate_signalled ();
7952 if (uiout
->is_mi_like_p ())
7954 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7955 uiout
->text ("\nProgram terminated with signal ");
7956 annotate_signal_name ();
7957 uiout
->field_string ("signal-name",
7958 gdb_signal_to_name (siggnal
));
7959 annotate_signal_name_end ();
7961 annotate_signal_string ();
7962 uiout
->field_string ("signal-meaning",
7963 gdb_signal_to_string (siggnal
));
7964 annotate_signal_string_end ();
7965 uiout
->text (".\n");
7966 uiout
->text ("The program no longer exists.\n");
7970 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7972 struct inferior
*inf
= current_inferior ();
7973 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7975 annotate_exited (exitstatus
);
7978 if (uiout
->is_mi_like_p ())
7979 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7980 std::string exit_code_str
7981 = string_printf ("0%o", (unsigned int) exitstatus
);
7982 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7983 plongest (inf
->num
), pidstr
.c_str (),
7984 string_field ("exit-code", exit_code_str
.c_str ()));
7988 if (uiout
->is_mi_like_p ())
7990 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7991 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7992 plongest (inf
->num
), pidstr
.c_str ());
7996 /* Some targets/architectures can do extra processing/display of
7997 segmentation faults. E.g., Intel MPX boundary faults.
7998 Call the architecture dependent function to handle the fault. */
8001 handle_segmentation_fault (struct ui_out
*uiout
)
8003 struct regcache
*regcache
= get_current_regcache ();
8004 struct gdbarch
*gdbarch
= regcache
->arch ();
8006 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8007 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8011 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8013 struct thread_info
*thr
= inferior_thread ();
8017 if (uiout
->is_mi_like_p ())
8019 else if (show_thread_that_caused_stop ())
8023 uiout
->text ("\nThread ");
8024 uiout
->field_string ("thread-id", print_thread_id (thr
));
8026 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8029 uiout
->text (" \"");
8030 uiout
->field_string ("name", name
);
8035 uiout
->text ("\nProgram");
8037 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8038 uiout
->text (" stopped");
8041 uiout
->text (" received signal ");
8042 annotate_signal_name ();
8043 if (uiout
->is_mi_like_p ())
8045 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8046 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8047 annotate_signal_name_end ();
8049 annotate_signal_string ();
8050 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8052 if (siggnal
== GDB_SIGNAL_SEGV
)
8053 handle_segmentation_fault (uiout
);
8055 annotate_signal_string_end ();
8057 uiout
->text (".\n");
8061 print_no_history_reason (struct ui_out
*uiout
)
8063 uiout
->text ("\nNo more reverse-execution history.\n");
8066 /* Print current location without a level number, if we have changed
8067 functions or hit a breakpoint. Print source line if we have one.
8068 bpstat_print contains the logic deciding in detail what to print,
8069 based on the event(s) that just occurred. */
8072 print_stop_location (struct target_waitstatus
*ws
)
8075 enum print_what source_flag
;
8076 int do_frame_printing
= 1;
8077 struct thread_info
*tp
= inferior_thread ();
8079 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8083 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8084 should) carry around the function and does (or should) use
8085 that when doing a frame comparison. */
8086 if (tp
->control
.stop_step
8087 && frame_id_eq (tp
->control
.step_frame_id
,
8088 get_frame_id (get_current_frame ()))
8089 && (tp
->control
.step_start_function
8090 == find_pc_function (tp
->suspend
.stop_pc
)))
8092 /* Finished step, just print source line. */
8093 source_flag
= SRC_LINE
;
8097 /* Print location and source line. */
8098 source_flag
= SRC_AND_LOC
;
8101 case PRINT_SRC_AND_LOC
:
8102 /* Print location and source line. */
8103 source_flag
= SRC_AND_LOC
;
8105 case PRINT_SRC_ONLY
:
8106 source_flag
= SRC_LINE
;
8109 /* Something bogus. */
8110 source_flag
= SRC_LINE
;
8111 do_frame_printing
= 0;
8114 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8117 /* The behavior of this routine with respect to the source
8119 SRC_LINE: Print only source line
8120 LOCATION: Print only location
8121 SRC_AND_LOC: Print location and source line. */
8122 if (do_frame_printing
)
8123 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8129 print_stop_event (struct ui_out
*uiout
, bool displays
)
8131 struct target_waitstatus last
;
8132 struct thread_info
*tp
;
8134 get_last_target_status (nullptr, nullptr, &last
);
8137 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8139 print_stop_location (&last
);
8141 /* Display the auto-display expressions. */
8146 tp
= inferior_thread ();
8147 if (tp
->thread_fsm
!= NULL
8148 && tp
->thread_fsm
->finished_p ())
8150 struct return_value_info
*rv
;
8152 rv
= tp
->thread_fsm
->return_value ();
8154 print_return_value (uiout
, rv
);
8161 maybe_remove_breakpoints (void)
8163 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8165 if (remove_breakpoints ())
8167 target_terminal::ours_for_output ();
8168 printf_filtered (_("Cannot remove breakpoints because "
8169 "program is no longer writable.\nFurther "
8170 "execution is probably impossible.\n"));
8175 /* The execution context that just caused a normal stop. */
8182 DISABLE_COPY_AND_ASSIGN (stop_context
);
8184 bool changed () const;
8189 /* The event PTID. */
8193 /* If stopp for a thread event, this is the thread that caused the
8195 struct thread_info
*thread
;
8197 /* The inferior that caused the stop. */
8201 /* Initializes a new stop context. If stopped for a thread event, this
8202 takes a strong reference to the thread. */
8204 stop_context::stop_context ()
8206 stop_id
= get_stop_id ();
8207 ptid
= inferior_ptid
;
8208 inf_num
= current_inferior ()->num
;
8210 if (inferior_ptid
!= null_ptid
)
8212 /* Take a strong reference so that the thread can't be deleted
8214 thread
= inferior_thread ();
8221 /* Release a stop context previously created with save_stop_context.
8222 Releases the strong reference to the thread as well. */
8224 stop_context::~stop_context ()
8230 /* Return true if the current context no longer matches the saved stop
8234 stop_context::changed () const
8236 if (ptid
!= inferior_ptid
)
8238 if (inf_num
!= current_inferior ()->num
)
8240 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8242 if (get_stop_id () != stop_id
)
8252 struct target_waitstatus last
;
8254 get_last_target_status (nullptr, nullptr, &last
);
8258 /* If an exception is thrown from this point on, make sure to
8259 propagate GDB's knowledge of the executing state to the
8260 frontend/user running state. A QUIT is an easy exception to see
8261 here, so do this before any filtered output. */
8263 ptid_t finish_ptid
= null_ptid
;
8266 finish_ptid
= minus_one_ptid
;
8267 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8268 || last
.kind
== TARGET_WAITKIND_EXITED
)
8270 /* On some targets, we may still have live threads in the
8271 inferior when we get a process exit event. E.g., for
8272 "checkpoint", when the current checkpoint/fork exits,
8273 linux-fork.c automatically switches to another fork from
8274 within target_mourn_inferior. */
8275 if (inferior_ptid
!= null_ptid
)
8276 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8278 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8279 finish_ptid
= inferior_ptid
;
8281 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8282 if (finish_ptid
!= null_ptid
)
8284 maybe_finish_thread_state
.emplace
8285 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8288 /* As we're presenting a stop, and potentially removing breakpoints,
8289 update the thread list so we can tell whether there are threads
8290 running on the target. With target remote, for example, we can
8291 only learn about new threads when we explicitly update the thread
8292 list. Do this before notifying the interpreters about signal
8293 stops, end of stepping ranges, etc., so that the "new thread"
8294 output is emitted before e.g., "Program received signal FOO",
8295 instead of after. */
8296 update_thread_list ();
8298 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8299 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8301 /* As with the notification of thread events, we want to delay
8302 notifying the user that we've switched thread context until
8303 the inferior actually stops.
8305 There's no point in saying anything if the inferior has exited.
8306 Note that SIGNALLED here means "exited with a signal", not
8307 "received a signal".
8309 Also skip saying anything in non-stop mode. In that mode, as we
8310 don't want GDB to switch threads behind the user's back, to avoid
8311 races where the user is typing a command to apply to thread x,
8312 but GDB switches to thread y before the user finishes entering
8313 the command, fetch_inferior_event installs a cleanup to restore
8314 the current thread back to the thread the user had selected right
8315 after this event is handled, so we're not really switching, only
8316 informing of a stop. */
8318 && previous_inferior_ptid
!= inferior_ptid
8319 && target_has_execution
8320 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8321 && last
.kind
!= TARGET_WAITKIND_EXITED
8322 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8324 SWITCH_THRU_ALL_UIS ()
8326 target_terminal::ours_for_output ();
8327 printf_filtered (_("[Switching to %s]\n"),
8328 target_pid_to_str (inferior_ptid
).c_str ());
8329 annotate_thread_changed ();
8331 previous_inferior_ptid
= inferior_ptid
;
8334 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8336 SWITCH_THRU_ALL_UIS ()
8337 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8339 target_terminal::ours_for_output ();
8340 printf_filtered (_("No unwaited-for children left.\n"));
8344 /* Note: this depends on the update_thread_list call above. */
8345 maybe_remove_breakpoints ();
8347 /* If an auto-display called a function and that got a signal,
8348 delete that auto-display to avoid an infinite recursion. */
8350 if (stopped_by_random_signal
)
8351 disable_current_display ();
8353 SWITCH_THRU_ALL_UIS ()
8355 async_enable_stdin ();
8358 /* Let the user/frontend see the threads as stopped. */
8359 maybe_finish_thread_state
.reset ();
8361 /* Select innermost stack frame - i.e., current frame is frame 0,
8362 and current location is based on that. Handle the case where the
8363 dummy call is returning after being stopped. E.g. the dummy call
8364 previously hit a breakpoint. (If the dummy call returns
8365 normally, we won't reach here.) Do this before the stop hook is
8366 run, so that it doesn't get to see the temporary dummy frame,
8367 which is not where we'll present the stop. */
8368 if (has_stack_frames ())
8370 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8372 /* Pop the empty frame that contains the stack dummy. This
8373 also restores inferior state prior to the call (struct
8374 infcall_suspend_state). */
8375 struct frame_info
*frame
= get_current_frame ();
8377 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8379 /* frame_pop calls reinit_frame_cache as the last thing it
8380 does which means there's now no selected frame. */
8383 select_frame (get_current_frame ());
8385 /* Set the current source location. */
8386 set_current_sal_from_frame (get_current_frame ());
8389 /* Look up the hook_stop and run it (CLI internally handles problem
8390 of stop_command's pre-hook not existing). */
8391 if (stop_command
!= NULL
)
8393 stop_context saved_context
;
8397 execute_cmd_pre_hook (stop_command
);
8399 catch (const gdb_exception
&ex
)
8401 exception_fprintf (gdb_stderr
, ex
,
8402 "Error while running hook_stop:\n");
8405 /* If the stop hook resumes the target, then there's no point in
8406 trying to notify about the previous stop; its context is
8407 gone. Likewise if the command switches thread or inferior --
8408 the observers would print a stop for the wrong
8410 if (saved_context
.changed ())
8414 /* Notify observers about the stop. This is where the interpreters
8415 print the stop event. */
8416 if (inferior_ptid
!= null_ptid
)
8417 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8420 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8422 annotate_stopped ();
8424 if (target_has_execution
)
8426 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8427 && last
.kind
!= TARGET_WAITKIND_EXITED
8428 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8429 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8430 Delete any breakpoint that is to be deleted at the next stop. */
8431 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8434 /* Try to get rid of automatically added inferiors that are no
8435 longer needed. Keeping those around slows down things linearly.
8436 Note that this never removes the current inferior. */
8443 signal_stop_state (int signo
)
8445 return signal_stop
[signo
];
8449 signal_print_state (int signo
)
8451 return signal_print
[signo
];
8455 signal_pass_state (int signo
)
8457 return signal_program
[signo
];
8461 signal_cache_update (int signo
)
8465 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8466 signal_cache_update (signo
);
8471 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8472 && signal_print
[signo
] == 0
8473 && signal_program
[signo
] == 1
8474 && signal_catch
[signo
] == 0);
8478 signal_stop_update (int signo
, int state
)
8480 int ret
= signal_stop
[signo
];
8482 signal_stop
[signo
] = state
;
8483 signal_cache_update (signo
);
8488 signal_print_update (int signo
, int state
)
8490 int ret
= signal_print
[signo
];
8492 signal_print
[signo
] = state
;
8493 signal_cache_update (signo
);
8498 signal_pass_update (int signo
, int state
)
8500 int ret
= signal_program
[signo
];
8502 signal_program
[signo
] = state
;
8503 signal_cache_update (signo
);
8507 /* Update the global 'signal_catch' from INFO and notify the
8511 signal_catch_update (const unsigned int *info
)
8515 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8516 signal_catch
[i
] = info
[i
] > 0;
8517 signal_cache_update (-1);
8518 target_pass_signals (signal_pass
);
8522 sig_print_header (void)
8524 printf_filtered (_("Signal Stop\tPrint\tPass "
8525 "to program\tDescription\n"));
8529 sig_print_info (enum gdb_signal oursig
)
8531 const char *name
= gdb_signal_to_name (oursig
);
8532 int name_padding
= 13 - strlen (name
);
8534 if (name_padding
<= 0)
8537 printf_filtered ("%s", name
);
8538 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8539 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8540 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8541 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8542 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8545 /* Specify how various signals in the inferior should be handled. */
8548 handle_command (const char *args
, int from_tty
)
8550 int digits
, wordlen
;
8551 int sigfirst
, siglast
;
8552 enum gdb_signal oursig
;
8557 error_no_arg (_("signal to handle"));
8560 /* Allocate and zero an array of flags for which signals to handle. */
8562 const size_t nsigs
= GDB_SIGNAL_LAST
;
8563 unsigned char sigs
[nsigs
] {};
8565 /* Break the command line up into args. */
8567 gdb_argv
built_argv (args
);
8569 /* Walk through the args, looking for signal oursigs, signal names, and
8570 actions. Signal numbers and signal names may be interspersed with
8571 actions, with the actions being performed for all signals cumulatively
8572 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8574 for (char *arg
: built_argv
)
8576 wordlen
= strlen (arg
);
8577 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8581 sigfirst
= siglast
= -1;
8583 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8585 /* Apply action to all signals except those used by the
8586 debugger. Silently skip those. */
8589 siglast
= nsigs
- 1;
8591 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8593 SET_SIGS (nsigs
, sigs
, signal_stop
);
8594 SET_SIGS (nsigs
, sigs
, signal_print
);
8596 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8598 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8600 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8602 SET_SIGS (nsigs
, sigs
, signal_print
);
8604 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8606 SET_SIGS (nsigs
, sigs
, signal_program
);
8608 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8610 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8612 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8614 SET_SIGS (nsigs
, sigs
, signal_program
);
8616 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8618 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8619 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8621 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8623 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8625 else if (digits
> 0)
8627 /* It is numeric. The numeric signal refers to our own
8628 internal signal numbering from target.h, not to host/target
8629 signal number. This is a feature; users really should be
8630 using symbolic names anyway, and the common ones like
8631 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8633 sigfirst
= siglast
= (int)
8634 gdb_signal_from_command (atoi (arg
));
8635 if (arg
[digits
] == '-')
8638 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8640 if (sigfirst
> siglast
)
8642 /* Bet he didn't figure we'd think of this case... */
8643 std::swap (sigfirst
, siglast
);
8648 oursig
= gdb_signal_from_name (arg
);
8649 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8651 sigfirst
= siglast
= (int) oursig
;
8655 /* Not a number and not a recognized flag word => complain. */
8656 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8660 /* If any signal numbers or symbol names were found, set flags for
8661 which signals to apply actions to. */
8663 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8665 switch ((enum gdb_signal
) signum
)
8667 case GDB_SIGNAL_TRAP
:
8668 case GDB_SIGNAL_INT
:
8669 if (!allsigs
&& !sigs
[signum
])
8671 if (query (_("%s is used by the debugger.\n\
8672 Are you sure you want to change it? "),
8673 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8678 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8682 case GDB_SIGNAL_DEFAULT
:
8683 case GDB_SIGNAL_UNKNOWN
:
8684 /* Make sure that "all" doesn't print these. */
8693 for (int signum
= 0; signum
< nsigs
; signum
++)
8696 signal_cache_update (-1);
8697 target_pass_signals (signal_pass
);
8698 target_program_signals (signal_program
);
8702 /* Show the results. */
8703 sig_print_header ();
8704 for (; signum
< nsigs
; signum
++)
8706 sig_print_info ((enum gdb_signal
) signum
);
8713 /* Complete the "handle" command. */
8716 handle_completer (struct cmd_list_element
*ignore
,
8717 completion_tracker
&tracker
,
8718 const char *text
, const char *word
)
8720 static const char * const keywords
[] =
8734 signal_completer (ignore
, tracker
, text
, word
);
8735 complete_on_enum (tracker
, keywords
, word
, word
);
8739 gdb_signal_from_command (int num
)
8741 if (num
>= 1 && num
<= 15)
8742 return (enum gdb_signal
) num
;
8743 error (_("Only signals 1-15 are valid as numeric signals.\n\
8744 Use \"info signals\" for a list of symbolic signals."));
8747 /* Print current contents of the tables set by the handle command.
8748 It is possible we should just be printing signals actually used
8749 by the current target (but for things to work right when switching
8750 targets, all signals should be in the signal tables). */
8753 info_signals_command (const char *signum_exp
, int from_tty
)
8755 enum gdb_signal oursig
;
8757 sig_print_header ();
8761 /* First see if this is a symbol name. */
8762 oursig
= gdb_signal_from_name (signum_exp
);
8763 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8765 /* No, try numeric. */
8767 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8769 sig_print_info (oursig
);
8773 printf_filtered ("\n");
8774 /* These ugly casts brought to you by the native VAX compiler. */
8775 for (oursig
= GDB_SIGNAL_FIRST
;
8776 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8777 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8781 if (oursig
!= GDB_SIGNAL_UNKNOWN
8782 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8783 sig_print_info (oursig
);
8786 printf_filtered (_("\nUse the \"handle\" command "
8787 "to change these tables.\n"));
8790 /* The $_siginfo convenience variable is a bit special. We don't know
8791 for sure the type of the value until we actually have a chance to
8792 fetch the data. The type can change depending on gdbarch, so it is
8793 also dependent on which thread you have selected.
8795 1. making $_siginfo be an internalvar that creates a new value on
8798 2. making the value of $_siginfo be an lval_computed value. */
8800 /* This function implements the lval_computed support for reading a
8804 siginfo_value_read (struct value
*v
)
8806 LONGEST transferred
;
8808 /* If we can access registers, so can we access $_siginfo. Likewise
8810 validate_registers_access ();
8813 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8815 value_contents_all_raw (v
),
8817 TYPE_LENGTH (value_type (v
)));
8819 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8820 error (_("Unable to read siginfo"));
8823 /* This function implements the lval_computed support for writing a
8827 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8829 LONGEST transferred
;
8831 /* If we can access registers, so can we access $_siginfo. Likewise
8833 validate_registers_access ();
8835 transferred
= target_write (current_top_target (),
8836 TARGET_OBJECT_SIGNAL_INFO
,
8838 value_contents_all_raw (fromval
),
8840 TYPE_LENGTH (value_type (fromval
)));
8842 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8843 error (_("Unable to write siginfo"));
8846 static const struct lval_funcs siginfo_value_funcs
=
8852 /* Return a new value with the correct type for the siginfo object of
8853 the current thread using architecture GDBARCH. Return a void value
8854 if there's no object available. */
8856 static struct value
*
8857 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8860 if (target_has_stack
8861 && inferior_ptid
!= null_ptid
8862 && gdbarch_get_siginfo_type_p (gdbarch
))
8864 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8866 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8869 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8873 /* infcall_suspend_state contains state about the program itself like its
8874 registers and any signal it received when it last stopped.
8875 This state must be restored regardless of how the inferior function call
8876 ends (either successfully, or after it hits a breakpoint or signal)
8877 if the program is to properly continue where it left off. */
8879 class infcall_suspend_state
8882 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8883 once the inferior function call has finished. */
8884 infcall_suspend_state (struct gdbarch
*gdbarch
,
8885 const struct thread_info
*tp
,
8886 struct regcache
*regcache
)
8887 : m_thread_suspend (tp
->suspend
),
8888 m_registers (new readonly_detached_regcache (*regcache
))
8890 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8892 if (gdbarch_get_siginfo_type_p (gdbarch
))
8894 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8895 size_t len
= TYPE_LENGTH (type
);
8897 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8899 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8900 siginfo_data
.get (), 0, len
) != len
)
8902 /* Errors ignored. */
8903 siginfo_data
.reset (nullptr);
8909 m_siginfo_gdbarch
= gdbarch
;
8910 m_siginfo_data
= std::move (siginfo_data
);
8914 /* Return a pointer to the stored register state. */
8916 readonly_detached_regcache
*registers () const
8918 return m_registers
.get ();
8921 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8923 void restore (struct gdbarch
*gdbarch
,
8924 struct thread_info
*tp
,
8925 struct regcache
*regcache
) const
8927 tp
->suspend
= m_thread_suspend
;
8929 if (m_siginfo_gdbarch
== gdbarch
)
8931 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8933 /* Errors ignored. */
8934 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8935 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8938 /* The inferior can be gone if the user types "print exit(0)"
8939 (and perhaps other times). */
8940 if (target_has_execution
)
8941 /* NB: The register write goes through to the target. */
8942 regcache
->restore (registers ());
8946 /* How the current thread stopped before the inferior function call was
8948 struct thread_suspend_state m_thread_suspend
;
8950 /* The registers before the inferior function call was executed. */
8951 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8953 /* Format of SIGINFO_DATA or NULL if it is not present. */
8954 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8956 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8957 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8958 content would be invalid. */
8959 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8962 infcall_suspend_state_up
8963 save_infcall_suspend_state ()
8965 struct thread_info
*tp
= inferior_thread ();
8966 struct regcache
*regcache
= get_current_regcache ();
8967 struct gdbarch
*gdbarch
= regcache
->arch ();
8969 infcall_suspend_state_up inf_state
8970 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8972 /* Having saved the current state, adjust the thread state, discarding
8973 any stop signal information. The stop signal is not useful when
8974 starting an inferior function call, and run_inferior_call will not use
8975 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8976 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8981 /* Restore inferior session state to INF_STATE. */
8984 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8986 struct thread_info
*tp
= inferior_thread ();
8987 struct regcache
*regcache
= get_current_regcache ();
8988 struct gdbarch
*gdbarch
= regcache
->arch ();
8990 inf_state
->restore (gdbarch
, tp
, regcache
);
8991 discard_infcall_suspend_state (inf_state
);
8995 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9000 readonly_detached_regcache
*
9001 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9003 return inf_state
->registers ();
9006 /* infcall_control_state contains state regarding gdb's control of the
9007 inferior itself like stepping control. It also contains session state like
9008 the user's currently selected frame. */
9010 struct infcall_control_state
9012 struct thread_control_state thread_control
;
9013 struct inferior_control_state inferior_control
;
9016 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9017 int stopped_by_random_signal
= 0;
9019 /* ID if the selected frame when the inferior function call was made. */
9020 struct frame_id selected_frame_id
{};
9023 /* Save all of the information associated with the inferior<==>gdb
9026 infcall_control_state_up
9027 save_infcall_control_state ()
9029 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9030 struct thread_info
*tp
= inferior_thread ();
9031 struct inferior
*inf
= current_inferior ();
9033 inf_status
->thread_control
= tp
->control
;
9034 inf_status
->inferior_control
= inf
->control
;
9036 tp
->control
.step_resume_breakpoint
= NULL
;
9037 tp
->control
.exception_resume_breakpoint
= NULL
;
9039 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9040 chain. If caller's caller is walking the chain, they'll be happier if we
9041 hand them back the original chain when restore_infcall_control_state is
9043 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9046 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9047 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9049 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9055 restore_selected_frame (const frame_id
&fid
)
9057 frame_info
*frame
= frame_find_by_id (fid
);
9059 /* If inf_status->selected_frame_id is NULL, there was no previously
9063 warning (_("Unable to restore previously selected frame."));
9067 select_frame (frame
);
9070 /* Restore inferior session state to INF_STATUS. */
9073 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9075 struct thread_info
*tp
= inferior_thread ();
9076 struct inferior
*inf
= current_inferior ();
9078 if (tp
->control
.step_resume_breakpoint
)
9079 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9081 if (tp
->control
.exception_resume_breakpoint
)
9082 tp
->control
.exception_resume_breakpoint
->disposition
9083 = disp_del_at_next_stop
;
9085 /* Handle the bpstat_copy of the chain. */
9086 bpstat_clear (&tp
->control
.stop_bpstat
);
9088 tp
->control
= inf_status
->thread_control
;
9089 inf
->control
= inf_status
->inferior_control
;
9092 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9093 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9095 if (target_has_stack
)
9097 /* The point of the try/catch is that if the stack is clobbered,
9098 walking the stack might encounter a garbage pointer and
9099 error() trying to dereference it. */
9102 restore_selected_frame (inf_status
->selected_frame_id
);
9104 catch (const gdb_exception_error
&ex
)
9106 exception_fprintf (gdb_stderr
, ex
,
9107 "Unable to restore previously selected frame:\n");
9108 /* Error in restoring the selected frame. Select the
9110 select_frame (get_current_frame ());
9118 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9120 if (inf_status
->thread_control
.step_resume_breakpoint
)
9121 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9122 = disp_del_at_next_stop
;
9124 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9125 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9126 = disp_del_at_next_stop
;
9128 /* See save_infcall_control_state for info on stop_bpstat. */
9129 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9137 clear_exit_convenience_vars (void)
9139 clear_internalvar (lookup_internalvar ("_exitsignal"));
9140 clear_internalvar (lookup_internalvar ("_exitcode"));
9144 /* User interface for reverse debugging:
9145 Set exec-direction / show exec-direction commands
9146 (returns error unless target implements to_set_exec_direction method). */
9148 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9149 static const char exec_forward
[] = "forward";
9150 static const char exec_reverse
[] = "reverse";
9151 static const char *exec_direction
= exec_forward
;
9152 static const char *const exec_direction_names
[] = {
9159 set_exec_direction_func (const char *args
, int from_tty
,
9160 struct cmd_list_element
*cmd
)
9162 if (target_can_execute_reverse
)
9164 if (!strcmp (exec_direction
, exec_forward
))
9165 execution_direction
= EXEC_FORWARD
;
9166 else if (!strcmp (exec_direction
, exec_reverse
))
9167 execution_direction
= EXEC_REVERSE
;
9171 exec_direction
= exec_forward
;
9172 error (_("Target does not support this operation."));
9177 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9178 struct cmd_list_element
*cmd
, const char *value
)
9180 switch (execution_direction
) {
9182 fprintf_filtered (out
, _("Forward.\n"));
9185 fprintf_filtered (out
, _("Reverse.\n"));
9188 internal_error (__FILE__
, __LINE__
,
9189 _("bogus execution_direction value: %d"),
9190 (int) execution_direction
);
9195 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9196 struct cmd_list_element
*c
, const char *value
)
9198 fprintf_filtered (file
, _("Resuming the execution of threads "
9199 "of all processes is %s.\n"), value
);
9202 /* Implementation of `siginfo' variable. */
9204 static const struct internalvar_funcs siginfo_funcs
=
9211 /* Callback for infrun's target events source. This is marked when a
9212 thread has a pending status to process. */
9215 infrun_async_inferior_event_handler (gdb_client_data data
)
9217 inferior_event_handler (INF_REG_EVENT
);
9220 void _initialize_infrun ();
9222 _initialize_infrun ()
9224 struct cmd_list_element
*c
;
9226 /* Register extra event sources in the event loop. */
9227 infrun_async_inferior_event_token
9228 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9230 add_info ("signals", info_signals_command
, _("\
9231 What debugger does when program gets various signals.\n\
9232 Specify a signal as argument to print info on that signal only."));
9233 add_info_alias ("handle", "signals", 0);
9235 c
= add_com ("handle", class_run
, handle_command
, _("\
9236 Specify how to handle signals.\n\
9237 Usage: handle SIGNAL [ACTIONS]\n\
9238 Args are signals and actions to apply to those signals.\n\
9239 If no actions are specified, the current settings for the specified signals\n\
9240 will be displayed instead.\n\
9242 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9243 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9244 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9245 The special arg \"all\" is recognized to mean all signals except those\n\
9246 used by the debugger, typically SIGTRAP and SIGINT.\n\
9248 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9249 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9250 Stop means reenter debugger if this signal happens (implies print).\n\
9251 Print means print a message if this signal happens.\n\
9252 Pass means let program see this signal; otherwise program doesn't know.\n\
9253 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9254 Pass and Stop may be combined.\n\
9256 Multiple signals may be specified. Signal numbers and signal names\n\
9257 may be interspersed with actions, with the actions being performed for\n\
9258 all signals cumulatively specified."));
9259 set_cmd_completer (c
, handle_completer
);
9262 stop_command
= add_cmd ("stop", class_obscure
,
9263 not_just_help_class_command
, _("\
9264 There is no `stop' command, but you can set a hook on `stop'.\n\
9265 This allows you to set a list of commands to be run each time execution\n\
9266 of the program stops."), &cmdlist
);
9268 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9269 Set inferior debugging."), _("\
9270 Show inferior debugging."), _("\
9271 When non-zero, inferior specific debugging is enabled."),
9274 &setdebuglist
, &showdebuglist
);
9276 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9277 &debug_displaced
, _("\
9278 Set displaced stepping debugging."), _("\
9279 Show displaced stepping debugging."), _("\
9280 When non-zero, displaced stepping specific debugging is enabled."),
9282 show_debug_displaced
,
9283 &setdebuglist
, &showdebuglist
);
9285 add_setshow_boolean_cmd ("non-stop", no_class
,
9287 Set whether gdb controls the inferior in non-stop mode."), _("\
9288 Show whether gdb controls the inferior in non-stop mode."), _("\
9289 When debugging a multi-threaded program and this setting is\n\
9290 off (the default, also called all-stop mode), when one thread stops\n\
9291 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9292 all other threads in the program while you interact with the thread of\n\
9293 interest. When you continue or step a thread, you can allow the other\n\
9294 threads to run, or have them remain stopped, but while you inspect any\n\
9295 thread's state, all threads stop.\n\
9297 In non-stop mode, when one thread stops, other threads can continue\n\
9298 to run freely. You'll be able to step each thread independently,\n\
9299 leave it stopped or free to run as needed."),
9305 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9308 signal_print
[i
] = 1;
9309 signal_program
[i
] = 1;
9310 signal_catch
[i
] = 0;
9313 /* Signals caused by debugger's own actions should not be given to
9314 the program afterwards.
9316 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9317 explicitly specifies that it should be delivered to the target
9318 program. Typically, that would occur when a user is debugging a
9319 target monitor on a simulator: the target monitor sets a
9320 breakpoint; the simulator encounters this breakpoint and halts
9321 the simulation handing control to GDB; GDB, noting that the stop
9322 address doesn't map to any known breakpoint, returns control back
9323 to the simulator; the simulator then delivers the hardware
9324 equivalent of a GDB_SIGNAL_TRAP to the program being
9326 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9327 signal_program
[GDB_SIGNAL_INT
] = 0;
9329 /* Signals that are not errors should not normally enter the debugger. */
9330 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9331 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9332 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9333 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9334 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9335 signal_print
[GDB_SIGNAL_PROF
] = 0;
9336 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9337 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9338 signal_stop
[GDB_SIGNAL_IO
] = 0;
9339 signal_print
[GDB_SIGNAL_IO
] = 0;
9340 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9341 signal_print
[GDB_SIGNAL_POLL
] = 0;
9342 signal_stop
[GDB_SIGNAL_URG
] = 0;
9343 signal_print
[GDB_SIGNAL_URG
] = 0;
9344 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9345 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9346 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9347 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9349 /* These signals are used internally by user-level thread
9350 implementations. (See signal(5) on Solaris.) Like the above
9351 signals, a healthy program receives and handles them as part of
9352 its normal operation. */
9353 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9354 signal_print
[GDB_SIGNAL_LWP
] = 0;
9355 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9356 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9357 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9358 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9359 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9360 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9362 /* Update cached state. */
9363 signal_cache_update (-1);
9365 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9366 &stop_on_solib_events
, _("\
9367 Set stopping for shared library events."), _("\
9368 Show stopping for shared library events."), _("\
9369 If nonzero, gdb will give control to the user when the dynamic linker\n\
9370 notifies gdb of shared library events. The most common event of interest\n\
9371 to the user would be loading/unloading of a new library."),
9372 set_stop_on_solib_events
,
9373 show_stop_on_solib_events
,
9374 &setlist
, &showlist
);
9376 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9377 follow_fork_mode_kind_names
,
9378 &follow_fork_mode_string
, _("\
9379 Set debugger response to a program call of fork or vfork."), _("\
9380 Show debugger response to a program call of fork or vfork."), _("\
9381 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9382 parent - the original process is debugged after a fork\n\
9383 child - the new process is debugged after a fork\n\
9384 The unfollowed process will continue to run.\n\
9385 By default, the debugger will follow the parent process."),
9387 show_follow_fork_mode_string
,
9388 &setlist
, &showlist
);
9390 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9391 follow_exec_mode_names
,
9392 &follow_exec_mode_string
, _("\
9393 Set debugger response to a program call of exec."), _("\
9394 Show debugger response to a program call of exec."), _("\
9395 An exec call replaces the program image of a process.\n\
9397 follow-exec-mode can be:\n\
9399 new - the debugger creates a new inferior and rebinds the process\n\
9400 to this new inferior. The program the process was running before\n\
9401 the exec call can be restarted afterwards by restarting the original\n\
9404 same - the debugger keeps the process bound to the same inferior.\n\
9405 The new executable image replaces the previous executable loaded in\n\
9406 the inferior. Restarting the inferior after the exec call restarts\n\
9407 the executable the process was running after the exec call.\n\
9409 By default, the debugger will use the same inferior."),
9411 show_follow_exec_mode_string
,
9412 &setlist
, &showlist
);
9414 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9415 scheduler_enums
, &scheduler_mode
, _("\
9416 Set mode for locking scheduler during execution."), _("\
9417 Show mode for locking scheduler during execution."), _("\
9418 off == no locking (threads may preempt at any time)\n\
9419 on == full locking (no thread except the current thread may run)\n\
9420 This applies to both normal execution and replay mode.\n\
9421 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9422 In this mode, other threads may run during other commands.\n\
9423 This applies to both normal execution and replay mode.\n\
9424 replay == scheduler locked in replay mode and unlocked during normal execution."),
9425 set_schedlock_func
, /* traps on target vector */
9426 show_scheduler_mode
,
9427 &setlist
, &showlist
);
9429 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9430 Set mode for resuming threads of all processes."), _("\
9431 Show mode for resuming threads of all processes."), _("\
9432 When on, execution commands (such as 'continue' or 'next') resume all\n\
9433 threads of all processes. When off (which is the default), execution\n\
9434 commands only resume the threads of the current process. The set of\n\
9435 threads that are resumed is further refined by the scheduler-locking\n\
9436 mode (see help set scheduler-locking)."),
9438 show_schedule_multiple
,
9439 &setlist
, &showlist
);
9441 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9442 Set mode of the step operation."), _("\
9443 Show mode of the step operation."), _("\
9444 When set, doing a step over a function without debug line information\n\
9445 will stop at the first instruction of that function. Otherwise, the\n\
9446 function is skipped and the step command stops at a different source line."),
9448 show_step_stop_if_no_debug
,
9449 &setlist
, &showlist
);
9451 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9452 &can_use_displaced_stepping
, _("\
9453 Set debugger's willingness to use displaced stepping."), _("\
9454 Show debugger's willingness to use displaced stepping."), _("\
9455 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9456 supported by the target architecture. If off, gdb will not use displaced\n\
9457 stepping to step over breakpoints, even if such is supported by the target\n\
9458 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9459 if the target architecture supports it and non-stop mode is active, but will not\n\
9460 use it in all-stop mode (see help set non-stop)."),
9462 show_can_use_displaced_stepping
,
9463 &setlist
, &showlist
);
9465 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9466 &exec_direction
, _("Set direction of execution.\n\
9467 Options are 'forward' or 'reverse'."),
9468 _("Show direction of execution (forward/reverse)."),
9469 _("Tells gdb whether to execute forward or backward."),
9470 set_exec_direction_func
, show_exec_direction_func
,
9471 &setlist
, &showlist
);
9473 /* Set/show detach-on-fork: user-settable mode. */
9475 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9476 Set whether gdb will detach the child of a fork."), _("\
9477 Show whether gdb will detach the child of a fork."), _("\
9478 Tells gdb whether to detach the child of a fork."),
9479 NULL
, NULL
, &setlist
, &showlist
);
9481 /* Set/show disable address space randomization mode. */
9483 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9484 &disable_randomization
, _("\
9485 Set disabling of debuggee's virtual address space randomization."), _("\
9486 Show disabling of debuggee's virtual address space randomization."), _("\
9487 When this mode is on (which is the default), randomization of the virtual\n\
9488 address space is disabled. Standalone programs run with the randomization\n\
9489 enabled by default on some platforms."),
9490 &set_disable_randomization
,
9491 &show_disable_randomization
,
9492 &setlist
, &showlist
);
9494 /* ptid initializations */
9495 inferior_ptid
= null_ptid
;
9496 target_last_wait_ptid
= minus_one_ptid
;
9498 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9499 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9500 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9501 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9503 /* Explicitly create without lookup, since that tries to create a
9504 value with a void typed value, and when we get here, gdbarch
9505 isn't initialized yet. At this point, we're quite sure there
9506 isn't another convenience variable of the same name. */
9507 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9509 add_setshow_boolean_cmd ("observer", no_class
,
9510 &observer_mode_1
, _("\
9511 Set whether gdb controls the inferior in observer mode."), _("\
9512 Show whether gdb controls the inferior in observer mode."), _("\
9513 In observer mode, GDB can get data from the inferior, but not\n\
9514 affect its execution. Registers and memory may not be changed,\n\
9515 breakpoints may not be set, and the program cannot be interrupted\n\