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 gdb::observers::inferior_execd
.notify (inf
);
1257 /* The next resume of this inferior should bring it to the shlib
1258 startup breakpoints. (If the user had also set bp's on
1259 "main" from the old (parent) process, then they'll auto-
1260 matically get reset there in the new process.). */
1263 /* The queue of threads that need to do a step-over operation to get
1264 past e.g., a breakpoint. What technique is used to step over the
1265 breakpoint/watchpoint does not matter -- all threads end up in the
1266 same queue, to maintain rough temporal order of execution, in order
1267 to avoid starvation, otherwise, we could e.g., find ourselves
1268 constantly stepping the same couple threads past their breakpoints
1269 over and over, if the single-step finish fast enough. */
1270 struct thread_info
*global_thread_step_over_chain_head
;
1272 /* Bit flags indicating what the thread needs to step over. */
1274 enum step_over_what_flag
1276 /* Step over a breakpoint. */
1277 STEP_OVER_BREAKPOINT
= 1,
1279 /* Step past a non-continuable watchpoint, in order to let the
1280 instruction execute so we can evaluate the watchpoint
1282 STEP_OVER_WATCHPOINT
= 2
1284 DEF_ENUM_FLAGS_TYPE (enum step_over_what_flag
, step_over_what
);
1286 /* Info about an instruction that is being stepped over. */
1288 struct step_over_info
1290 /* If we're stepping past a breakpoint, this is the address space
1291 and address of the instruction the breakpoint is set at. We'll
1292 skip inserting all breakpoints here. Valid iff ASPACE is
1294 const address_space
*aspace
;
1297 /* The instruction being stepped over triggers a nonsteppable
1298 watchpoint. If true, we'll skip inserting watchpoints. */
1299 int nonsteppable_watchpoint_p
;
1301 /* The thread's global number. */
1305 /* The step-over info of the location that is being stepped over.
1307 Note that with async/breakpoint always-inserted mode, a user might
1308 set a new breakpoint/watchpoint/etc. exactly while a breakpoint is
1309 being stepped over. As setting a new breakpoint inserts all
1310 breakpoints, we need to make sure the breakpoint being stepped over
1311 isn't inserted then. We do that by only clearing the step-over
1312 info when the step-over is actually finished (or aborted).
1314 Presently GDB can only step over one breakpoint at any given time.
1315 Given threads that can't run code in the same address space as the
1316 breakpoint's can't really miss the breakpoint, GDB could be taught
1317 to step-over at most one breakpoint per address space (so this info
1318 could move to the address space object if/when GDB is extended).
1319 The set of breakpoints being stepped over will normally be much
1320 smaller than the set of all breakpoints, so a flag in the
1321 breakpoint location structure would be wasteful. A separate list
1322 also saves complexity and run-time, as otherwise we'd have to go
1323 through all breakpoint locations clearing their flag whenever we
1324 start a new sequence. Similar considerations weigh against storing
1325 this info in the thread object. Plus, not all step overs actually
1326 have breakpoint locations -- e.g., stepping past a single-step
1327 breakpoint, or stepping to complete a non-continuable
1329 static struct step_over_info step_over_info
;
1331 /* Record the address of the breakpoint/instruction we're currently
1333 N.B. We record the aspace and address now, instead of say just the thread,
1334 because when we need the info later the thread may be running. */
1337 set_step_over_info (const address_space
*aspace
, CORE_ADDR address
,
1338 int nonsteppable_watchpoint_p
,
1341 step_over_info
.aspace
= aspace
;
1342 step_over_info
.address
= address
;
1343 step_over_info
.nonsteppable_watchpoint_p
= nonsteppable_watchpoint_p
;
1344 step_over_info
.thread
= thread
;
1347 /* Called when we're not longer stepping over a breakpoint / an
1348 instruction, so all breakpoints are free to be (re)inserted. */
1351 clear_step_over_info (void)
1353 infrun_log_debug ("clearing step over info");
1354 step_over_info
.aspace
= NULL
;
1355 step_over_info
.address
= 0;
1356 step_over_info
.nonsteppable_watchpoint_p
= 0;
1357 step_over_info
.thread
= -1;
1363 stepping_past_instruction_at (struct address_space
*aspace
,
1366 return (step_over_info
.aspace
!= NULL
1367 && breakpoint_address_match (aspace
, address
,
1368 step_over_info
.aspace
,
1369 step_over_info
.address
));
1375 thread_is_stepping_over_breakpoint (int thread
)
1377 return (step_over_info
.thread
!= -1
1378 && thread
== step_over_info
.thread
);
1384 stepping_past_nonsteppable_watchpoint (void)
1386 return step_over_info
.nonsteppable_watchpoint_p
;
1389 /* Returns true if step-over info is valid. */
1392 step_over_info_valid_p (void)
1394 return (step_over_info
.aspace
!= NULL
1395 || stepping_past_nonsteppable_watchpoint ());
1399 /* Displaced stepping. */
1401 /* In non-stop debugging mode, we must take special care to manage
1402 breakpoints properly; in particular, the traditional strategy for
1403 stepping a thread past a breakpoint it has hit is unsuitable.
1404 'Displaced stepping' is a tactic for stepping one thread past a
1405 breakpoint it has hit while ensuring that other threads running
1406 concurrently will hit the breakpoint as they should.
1408 The traditional way to step a thread T off a breakpoint in a
1409 multi-threaded program in all-stop mode is as follows:
1411 a0) Initially, all threads are stopped, and breakpoints are not
1413 a1) We single-step T, leaving breakpoints uninserted.
1414 a2) We insert breakpoints, and resume all threads.
1416 In non-stop debugging, however, this strategy is unsuitable: we
1417 don't want to have to stop all threads in the system in order to
1418 continue or step T past a breakpoint. Instead, we use displaced
1421 n0) Initially, T is stopped, other threads are running, and
1422 breakpoints are inserted.
1423 n1) We copy the instruction "under" the breakpoint to a separate
1424 location, outside the main code stream, making any adjustments
1425 to the instruction, register, and memory state as directed by
1427 n2) We single-step T over the instruction at its new location.
1428 n3) We adjust the resulting register and memory state as directed
1429 by T's architecture. This includes resetting T's PC to point
1430 back into the main instruction stream.
1433 This approach depends on the following gdbarch methods:
1435 - gdbarch_max_insn_length and gdbarch_displaced_step_location
1436 indicate where to copy the instruction, and how much space must
1437 be reserved there. We use these in step n1.
1439 - gdbarch_displaced_step_copy_insn copies a instruction to a new
1440 address, and makes any necessary adjustments to the instruction,
1441 register contents, and memory. We use this in step n1.
1443 - gdbarch_displaced_step_fixup adjusts registers and memory after
1444 we have successfully single-stepped the instruction, to yield the
1445 same effect the instruction would have had if we had executed it
1446 at its original address. We use this in step n3.
1448 The gdbarch_displaced_step_copy_insn and
1449 gdbarch_displaced_step_fixup functions must be written so that
1450 copying an instruction with gdbarch_displaced_step_copy_insn,
1451 single-stepping across the copied instruction, and then applying
1452 gdbarch_displaced_insn_fixup should have the same effects on the
1453 thread's memory and registers as stepping the instruction in place
1454 would have. Exactly which responsibilities fall to the copy and
1455 which fall to the fixup is up to the author of those functions.
1457 See the comments in gdbarch.sh for details.
1459 Note that displaced stepping and software single-step cannot
1460 currently be used in combination, although with some care I think
1461 they could be made to. Software single-step works by placing
1462 breakpoints on all possible subsequent instructions; if the
1463 displaced instruction is a PC-relative jump, those breakpoints
1464 could fall in very strange places --- on pages that aren't
1465 executable, or at addresses that are not proper instruction
1466 boundaries. (We do generally let other threads run while we wait
1467 to hit the software single-step breakpoint, and they might
1468 encounter such a corrupted instruction.) One way to work around
1469 this would be to have gdbarch_displaced_step_copy_insn fully
1470 simulate the effect of PC-relative instructions (and return NULL)
1471 on architectures that use software single-stepping.
1473 In non-stop mode, we can have independent and simultaneous step
1474 requests, so more than one thread may need to simultaneously step
1475 over a breakpoint. The current implementation assumes there is
1476 only one scratch space per process. In this case, we have to
1477 serialize access to the scratch space. If thread A wants to step
1478 over a breakpoint, but we are currently waiting for some other
1479 thread to complete a displaced step, we leave thread A stopped and
1480 place it in the displaced_step_request_queue. Whenever a displaced
1481 step finishes, we pick the next thread in the queue and start a new
1482 displaced step operation on it. See displaced_step_prepare and
1483 displaced_step_fixup for details. */
1485 /* Get the displaced stepping state of inferior INF. */
1487 static displaced_step_inferior_state
*
1488 get_displaced_stepping_state (inferior
*inf
)
1490 return &inf
->displaced_step_state
;
1493 /* Get the displaced stepping state of thread THREAD. */
1495 static displaced_step_thread_state
*
1496 get_displaced_stepping_state (thread_info
*thread
)
1498 return &thread
->displaced_step_state
;
1501 /* Return true if the given thread is doing a displaced step. */
1504 displaced_step_in_progress (thread_info
*thread
)
1506 gdb_assert (thread
!= NULL
);
1508 return get_displaced_stepping_state (thread
)->in_progress ();
1511 /* Return true if any thread of this inferior is doing a displaced step. */
1514 displaced_step_in_progress (inferior
*inf
)
1516 for (thread_info
*thread
: inf
->non_exited_threads ())
1518 if (displaced_step_in_progress (thread
))
1525 /* Return true if any thread is doing a displaced step. */
1528 displaced_step_in_progress_any_thread ()
1530 for (thread_info
*thread
: all_non_exited_threads ())
1532 if (displaced_step_in_progress (thread
))
1539 /* If inferior is in displaced stepping, and ADDR equals to starting address
1540 of copy area, return corresponding displaced_step_copy_insn_closure. Otherwise,
1543 struct displaced_step_copy_insn_closure
*
1544 get_displaced_step_copy_insn_closure_by_addr (CORE_ADDR addr
)
1546 // FIXME: implement me (only needed on ARM).
1547 // displaced_step_inferior_state *displaced
1548 // = get_displaced_stepping_state (current_inferior ());
1550 // /* If checking the mode of displaced instruction in copy area. */
1551 // if (displaced->step_thread != nullptr
1552 // && displaced->step_copy == addr)
1553 // return displaced->step_closure.get ();
1559 infrun_inferior_exit (struct inferior
*inf
)
1561 inf
->displaced_step_state
.reset ();
1564 /* If ON, and the architecture supports it, GDB will use displaced
1565 stepping to step over breakpoints. If OFF, or if the architecture
1566 doesn't support it, GDB will instead use the traditional
1567 hold-and-step approach. If AUTO (which is the default), GDB will
1568 decide which technique to use to step over breakpoints depending on
1569 whether the target works in a non-stop way (see use_displaced_stepping). */
1571 static enum auto_boolean can_use_displaced_stepping
= AUTO_BOOLEAN_AUTO
;
1574 show_can_use_displaced_stepping (struct ui_file
*file
, int from_tty
,
1575 struct cmd_list_element
*c
,
1578 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
)
1579 fprintf_filtered (file
,
1580 _("Debugger's willingness to use displaced stepping "
1581 "to step over breakpoints is %s (currently %s).\n"),
1582 value
, target_is_non_stop_p () ? "on" : "off");
1584 fprintf_filtered (file
,
1585 _("Debugger's willingness to use displaced stepping "
1586 "to step over breakpoints is %s.\n"), value
);
1589 /* Return true if the target behing THREAD supports displaced stepping. */
1592 target_supports_displaced_stepping (thread_info
*thread
)
1594 inferior
*inf
= thread
->inf
;
1595 target_ops
*target
= inf
->top_target ();
1597 return target
->supports_displaced_step (thread
);
1600 /* Return non-zero if displaced stepping can/should be used to step
1601 over breakpoints of thread TP. */
1604 use_displaced_stepping (thread_info
*tp
)
1606 /* If the user disabled it explicitly, don't use displaced stepping. */
1607 if (can_use_displaced_stepping
== AUTO_BOOLEAN_FALSE
)
1610 /* If "auto", only use displaced stepping if the target operates in a non-stop
1612 if (can_use_displaced_stepping
== AUTO_BOOLEAN_AUTO
1613 && !target_is_non_stop_p ())
1616 /* If the target doesn't support displaced stepping, don't use it. */
1617 if (!target_supports_displaced_stepping (tp
))
1620 /* If recording, don't use displaced stepping. */
1621 if (find_record_target () != nullptr)
1624 displaced_step_inferior_state
*displaced_state
1625 = get_displaced_stepping_state (tp
->inf
);
1627 /* If displaced stepping failed before for this inferior, don't bother trying
1629 if (displaced_state
->failed_before
)
1635 /* Simple function wrapper around displaced_step_thread_state::reset. */
1638 displaced_step_reset (displaced_step_thread_state
*displaced
)
1640 displaced
->reset ();
1643 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1644 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1646 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1648 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1650 displaced_step_dump_bytes (struct ui_file
*file
,
1651 const gdb_byte
*buf
,
1656 for (i
= 0; i
< len
; i
++)
1657 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1658 fputs_unfiltered ("\n", file
);
1661 /* Prepare to single-step, using displaced stepping.
1663 Note that we cannot use displaced stepping when we have a signal to
1664 deliver. If we have a signal to deliver and an instruction to step
1665 over, then after the step, there will be no indication from the
1666 target whether the thread entered a signal handler or ignored the
1667 signal and stepped over the instruction successfully --- both cases
1668 result in a simple SIGTRAP. In the first case we mustn't do a
1669 fixup, and in the second case we must --- but we can't tell which.
1670 Comments in the code for 'random signals' in handle_inferior_event
1671 explain how we handle this case instead.
1673 Returns 1 if preparing was successful -- this thread is going to be
1674 stepped now; 0 if displaced stepping this thread got queued; or -1
1675 if this instruction can't be displaced stepped. */
1677 static displaced_step_prepare_status
1678 displaced_step_prepare_throw (thread_info
*tp
)
1680 regcache
*regcache
= get_thread_regcache (tp
);
1681 struct gdbarch
*gdbarch
= regcache
->arch ();
1682 displaced_step_thread_state
*thread_disp_step_state
1683 = get_displaced_stepping_state (tp
);
1685 /* We should never reach this function if the target does not
1686 support displaced stepping. */
1687 gdb_assert (target_supports_displaced_stepping (tp
));
1689 /* Nor if the thread isn't meant to step over a breakpoint. */
1690 gdb_assert (tp
->control
.trap_expected
);
1692 /* Disable range stepping while executing in the scratch pad. We
1693 want a single-step even if executing the displaced instruction in
1694 the scratch buffer lands within the stepping range (e.g., a
1696 tp
->control
.may_range_step
= 0;
1698 /* We are about to start a displaced step for this thread, if one is already
1699 in progress, we goofed up somewhere. */
1700 gdb_assert (!thread_disp_step_state
->in_progress ());
1702 scoped_restore_current_thread restore_thread
;
1704 switch_to_thread (tp
);
1706 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1708 displaced_step_prepare_status status
=
1709 tp
->inf
->top_target ()->displaced_step_prepare (tp
);
1711 if (status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
1713 if (debug_displaced
)
1714 fprintf_unfiltered (gdb_stdlog
,
1715 "displaced: failed to prepare (%s)",
1716 target_pid_to_str (tp
->ptid
).c_str ());
1718 return DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1720 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1722 /* Not enough displaced stepping resources available, defer this
1723 request by placing it the queue. */
1725 if (debug_displaced
)
1726 fprintf_unfiltered (gdb_stdlog
,
1727 "displaced: not enough resources available, "
1728 "deferring step of %s\n",
1729 target_pid_to_str (tp
->ptid
).c_str ());
1731 global_thread_step_over_chain_enqueue (tp
);
1732 tp
->inf
->displaced_step_state
.unavailable
= true;
1734 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1737 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1739 // FIXME: Should probably replicated in the arch implementation now.
1741 // if (breakpoint_in_range_p (aspace, copy, len))
1743 // /* There's a breakpoint set in the scratch pad location range
1744 // (which is usually around the entry point). We'd either
1745 // install it before resuming, which would overwrite/corrupt the
1746 // scratch pad, or if it was already inserted, this displaced
1747 // step would overwrite it. The latter is OK in the sense that
1748 // we already assume that no thread is going to execute the code
1749 // in the scratch pad range (after initial startup) anyway, but
1750 // the former is unacceptable. Simply punt and fallback to
1751 // stepping over this breakpoint in-line. */
1752 // if (debug_displaced)
1754 // fprintf_unfiltered (gdb_stdlog,
1755 // "displaced: breakpoint set in scratch pad. "
1756 // "Stepping over breakpoint in-line instead.\n");
1759 // gdb_assert (false);
1760 // gdbarch_displaced_step_release_location (gdbarch, copy);
1765 /* Save the information we need to fix things up if the step
1767 thread_disp_step_state
->set (gdbarch
);
1769 // FIXME: get it from _prepare?
1770 CORE_ADDR displaced_pc
= 0;
1772 if (debug_displaced
)
1773 fprintf_unfiltered (gdb_stdlog
,
1774 "displaced: prepared successfully thread=%s, "
1775 "original_pc=%s, displaced_pc=%s\n",
1776 target_pid_to_str (tp
->ptid
).c_str (),
1777 paddress (gdbarch
, original_pc
),
1778 paddress (gdbarch
, displaced_pc
));
1780 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1783 /* Wrapper for displaced_step_prepare_throw that disabled further
1784 attempts at displaced stepping if we get a memory error. */
1786 static displaced_step_prepare_status
1787 displaced_step_prepare (thread_info
*thread
)
1789 displaced_step_prepare_status status
1790 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1794 status
= displaced_step_prepare_throw (thread
);
1796 catch (const gdb_exception_error
&ex
)
1798 struct displaced_step_inferior_state
*displaced_state
;
1800 if (ex
.error
!= MEMORY_ERROR
1801 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1804 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1807 /* Be verbose if "set displaced-stepping" is "on", silent if
1809 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1811 warning (_("disabling displaced stepping: %s"),
1815 /* Disable further displaced stepping attempts. */
1817 = get_displaced_stepping_state (thread
->inf
);
1818 displaced_state
->failed_before
= 1;
1824 /* If we displaced stepped an instruction successfully, adjust
1825 registers and memory to yield the same effect the instruction would
1826 have had if we had executed it at its original address, and return
1827 1. If the instruction didn't complete, relocate the PC and return
1828 -1. If the thread wasn't displaced stepping, return 0. */
1831 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1833 displaced_step_thread_state
*displaced
1834 = get_displaced_stepping_state (event_thread
);
1836 /* Was this thread performing a displaced step? */
1837 if (!displaced
->in_progress ())
1840 displaced_step_reset_cleanup
cleanup (displaced
);
1842 /* Fixup may need to read memory/registers. Switch to the thread
1843 that we're fixing up. Also, target_stopped_by_watchpoint checks
1844 the current thread, and displaced_step_restore performs ptid-dependent
1845 memory accesses using current_inferior() and current_top_target(). */
1846 switch_to_thread (event_thread
);
1848 /* Do the fixup, and release the resources acquired to do the displaced
1850 displaced_step_finish_status finish_status
=
1851 event_thread
->inf
->top_target ()->displaced_step_finish (event_thread
,
1854 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1860 /* Data to be passed around while handling an event. This data is
1861 discarded between events. */
1862 struct execution_control_state
1864 process_stratum_target
*target
;
1866 /* The thread that got the event, if this was a thread event; NULL
1868 struct thread_info
*event_thread
;
1870 struct target_waitstatus ws
;
1871 int stop_func_filled_in
;
1872 CORE_ADDR stop_func_start
;
1873 CORE_ADDR stop_func_end
;
1874 const char *stop_func_name
;
1877 /* True if the event thread hit the single-step breakpoint of
1878 another thread. Thus the event doesn't cause a stop, the thread
1879 needs to be single-stepped past the single-step breakpoint before
1880 we can switch back to the original stepping thread. */
1881 int hit_singlestep_breakpoint
;
1884 /* Clear ECS and set it to point at TP. */
1887 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1889 memset (ecs
, 0, sizeof (*ecs
));
1890 ecs
->event_thread
= tp
;
1891 ecs
->ptid
= tp
->ptid
;
1894 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1895 static void prepare_to_wait (struct execution_control_state
*ecs
);
1896 static int keep_going_stepped_thread (struct thread_info
*tp
);
1897 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1899 /* Are there any pending step-over requests? If so, run all we can
1900 now and return true. Otherwise, return false. */
1903 start_step_over (void)
1905 struct thread_info
*tp
, *next
;
1908 /* Don't start a new step-over if we already have an in-line
1909 step-over operation ongoing. */
1910 if (step_over_info_valid_p ())
1913 /* Steal the global thread step over chain. */
1914 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1915 global_thread_step_over_chain_head
= NULL
;
1918 fprintf_unfiltered (gdb_stdlog
,
1919 "infrun: stealing list of %d threads to step from global queue\n",
1920 thread_step_over_chain_length (threads_to_step
));
1922 for (inferior
*inf
: all_inferiors ())
1923 inf
->displaced_step_state
.unavailable
= false;
1925 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1927 struct execution_control_state ecss
;
1928 struct execution_control_state
*ecs
= &ecss
;
1929 step_over_what step_what
;
1930 int must_be_in_line
;
1932 gdb_assert (!tp
->stop_requested
);
1934 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1936 step_what
= thread_still_needs_step_over (tp
);
1937 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1938 || ((step_what
& STEP_OVER_BREAKPOINT
)
1939 && !use_displaced_stepping (tp
)));
1941 /* We currently stop all threads of all processes to step-over
1942 in-line. If we need to start a new in-line step-over, let
1943 any pending displaced steps finish first. */
1944 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1947 thread_step_over_chain_remove (&threads_to_step
, tp
);
1949 if (tp
->control
.trap_expected
1953 internal_error (__FILE__
, __LINE__
,
1954 "[%s] has inconsistent state: "
1955 "trap_expected=%d, resumed=%d, executing=%d\n",
1956 target_pid_to_str (tp
->ptid
).c_str (),
1957 tp
->control
.trap_expected
,
1962 infrun_log_debug ("resuming [%s] for step-over",
1963 target_pid_to_str (tp
->ptid
).c_str ());
1965 /* keep_going_pass_signal skips the step-over if the breakpoint
1966 is no longer inserted. In all-stop, we want to keep looking
1967 for a thread that needs a step-over instead of resuming TP,
1968 because we wouldn't be able to resume anything else until the
1969 target stops again. In non-stop, the resume always resumes
1970 only TP, so it's OK to let the thread resume freely. */
1971 if (!target_is_non_stop_p () && !step_what
)
1974 if (tp
->inf
->displaced_step_state
.unavailable
)
1976 global_thread_step_over_chain_enqueue (tp
);
1980 switch_to_thread (tp
);
1981 reset_ecs (ecs
, tp
);
1982 keep_going_pass_signal (ecs
);
1984 if (!ecs
->wait_some_more
)
1985 error (_("Command aborted."));
1987 /* If the thread's step over could not be initiated, it was re-added
1988 to the global step over chain. */
1991 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
1992 target_pid_to_str (tp
->ptid
).c_str ());
1993 gdb_assert (!thread_is_in_step_over_chain (tp
));
1997 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
1998 target_pid_to_str (tp
->ptid
).c_str ());
1999 gdb_assert (thread_is_in_step_over_chain (tp
));
2003 /* If we started a new in-line step-over, we're done. */
2004 if (step_over_info_valid_p ())
2006 gdb_assert (tp
->control
.trap_expected
);
2011 if (!target_is_non_stop_p ())
2013 /* On all-stop, shouldn't have resumed unless we needed a
2015 gdb_assert (tp
->control
.trap_expected
2016 || tp
->step_after_step_resume_breakpoint
);
2018 /* With remote targets (at least), in all-stop, we can't
2019 issue any further remote commands until the program stops
2025 /* Either the thread no longer needed a step-over, or a new
2026 displaced stepping sequence started. Even in the latter
2027 case, continue looking. Maybe we can also start another
2028 displaced step on a thread of other process. */
2031 /* If there are threads left in the THREADS_TO_STEP list, but we have
2032 detected that we can't start anything more, put back these threads
2033 in the global list. */
2034 if (threads_to_step
== NULL
)
2037 fprintf_unfiltered (gdb_stdlog
,
2038 "infrun: step-over queue now empty\n");
2043 fprintf_unfiltered (gdb_stdlog
,
2044 "infrun: putting back %d threads to step in global queue\n",
2045 thread_step_over_chain_length (threads_to_step
));
2046 while (threads_to_step
!= nullptr)
2048 thread_info
*thread
= threads_to_step
;
2050 /* Remove from that list. */
2051 thread_step_over_chain_remove (&threads_to_step
, thread
);
2053 /* Add to global list. */
2054 global_thread_step_over_chain_enqueue (thread
);
2062 /* Update global variables holding ptids to hold NEW_PTID if they were
2063 holding OLD_PTID. */
2065 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2067 if (inferior_ptid
== old_ptid
)
2068 inferior_ptid
= new_ptid
;
2073 static const char schedlock_off
[] = "off";
2074 static const char schedlock_on
[] = "on";
2075 static const char schedlock_step
[] = "step";
2076 static const char schedlock_replay
[] = "replay";
2077 static const char *const scheduler_enums
[] = {
2084 static const char *scheduler_mode
= schedlock_replay
;
2086 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2087 struct cmd_list_element
*c
, const char *value
)
2089 fprintf_filtered (file
,
2090 _("Mode for locking scheduler "
2091 "during execution is \"%s\".\n"),
2096 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2098 if (!target_can_lock_scheduler
)
2100 scheduler_mode
= schedlock_off
;
2101 error (_("Target '%s' cannot support this command."), target_shortname
);
2105 /* True if execution commands resume all threads of all processes by
2106 default; otherwise, resume only threads of the current inferior
2108 bool sched_multi
= false;
2110 /* Try to setup for software single stepping over the specified location.
2111 Return 1 if target_resume() should use hardware single step.
2113 GDBARCH the current gdbarch.
2114 PC the location to step over. */
2117 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2121 if (execution_direction
== EXEC_FORWARD
2122 && gdbarch_software_single_step_p (gdbarch
))
2123 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2131 user_visible_resume_ptid (int step
)
2137 /* With non-stop mode on, threads are always handled
2139 resume_ptid
= inferior_ptid
;
2141 else if ((scheduler_mode
== schedlock_on
)
2142 || (scheduler_mode
== schedlock_step
&& step
))
2144 /* User-settable 'scheduler' mode requires solo thread
2146 resume_ptid
= inferior_ptid
;
2148 else if ((scheduler_mode
== schedlock_replay
)
2149 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2151 /* User-settable 'scheduler' mode requires solo thread resume in replay
2153 resume_ptid
= inferior_ptid
;
2155 else if (!sched_multi
&& target_supports_multi_process ())
2157 /* Resume all threads of the current process (and none of other
2159 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2163 /* Resume all threads of all processes. */
2164 resume_ptid
= RESUME_ALL
;
2172 process_stratum_target
*
2173 user_visible_resume_target (ptid_t resume_ptid
)
2175 return (resume_ptid
== minus_one_ptid
&& sched_multi
2177 : current_inferior ()->process_target ());
2180 /* Return a ptid representing the set of threads that we will resume,
2181 in the perspective of the target, assuming run control handling
2182 does not require leaving some threads stopped (e.g., stepping past
2183 breakpoint). USER_STEP indicates whether we're about to start the
2184 target for a stepping command. */
2187 internal_resume_ptid (int user_step
)
2189 /* In non-stop, we always control threads individually. Note that
2190 the target may always work in non-stop mode even with "set
2191 non-stop off", in which case user_visible_resume_ptid could
2192 return a wildcard ptid. */
2193 if (target_is_non_stop_p ())
2194 return inferior_ptid
;
2196 return user_visible_resume_ptid (user_step
);
2199 /* Wrapper for target_resume, that handles infrun-specific
2203 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2205 struct thread_info
*tp
= inferior_thread ();
2207 gdb_assert (!tp
->stop_requested
);
2209 /* Install inferior's terminal modes. */
2210 target_terminal::inferior ();
2212 /* Avoid confusing the next resume, if the next stop/resume
2213 happens to apply to another thread. */
2214 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2216 /* Advise target which signals may be handled silently.
2218 If we have removed breakpoints because we are stepping over one
2219 in-line (in any thread), we need to receive all signals to avoid
2220 accidentally skipping a breakpoint during execution of a signal
2223 Likewise if we're displaced stepping, otherwise a trap for a
2224 breakpoint in a signal handler might be confused with the
2225 displaced step finishing. We don't make the displaced_step_fixup
2226 step distinguish the cases instead, because:
2228 - a backtrace while stopped in the signal handler would show the
2229 scratch pad as frame older than the signal handler, instead of
2230 the real mainline code.
2232 - when the thread is later resumed, the signal handler would
2233 return to the scratch pad area, which would no longer be
2235 if (step_over_info_valid_p ()
2236 || displaced_step_in_progress (tp
->inf
))
2237 target_pass_signals ({});
2239 target_pass_signals (signal_pass
);
2241 target_resume (resume_ptid
, step
, sig
);
2243 target_commit_resume ();
2245 if (target_can_async_p ())
2249 /* Resume the inferior. SIG is the signal to give the inferior
2250 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2251 call 'resume', which handles exceptions. */
2254 resume_1 (enum gdb_signal sig
)
2256 struct regcache
*regcache
= get_current_regcache ();
2257 struct gdbarch
*gdbarch
= regcache
->arch ();
2258 struct thread_info
*tp
= inferior_thread ();
2259 const address_space
*aspace
= regcache
->aspace ();
2261 /* This represents the user's step vs continue request. When
2262 deciding whether "set scheduler-locking step" applies, it's the
2263 user's intention that counts. */
2264 const int user_step
= tp
->control
.stepping_command
;
2265 /* This represents what we'll actually request the target to do.
2266 This can decay from a step to a continue, if e.g., we need to
2267 implement single-stepping with breakpoints (software
2271 gdb_assert (!tp
->stop_requested
);
2272 gdb_assert (!thread_is_in_step_over_chain (tp
));
2274 if (tp
->suspend
.waitstatus_pending_p
)
2277 ("thread %s has pending wait "
2278 "status %s (currently_stepping=%d).",
2279 target_pid_to_str (tp
->ptid
).c_str (),
2280 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2281 currently_stepping (tp
));
2283 tp
->inf
->process_target ()->threads_executing
= true;
2286 /* FIXME: What should we do if we are supposed to resume this
2287 thread with a signal? Maybe we should maintain a queue of
2288 pending signals to deliver. */
2289 if (sig
!= GDB_SIGNAL_0
)
2291 warning (_("Couldn't deliver signal %s to %s."),
2292 gdb_signal_to_name (sig
),
2293 target_pid_to_str (tp
->ptid
).c_str ());
2296 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2298 if (target_can_async_p ())
2301 /* Tell the event loop we have an event to process. */
2302 mark_async_event_handler (infrun_async_inferior_event_token
);
2307 tp
->stepped_breakpoint
= 0;
2309 /* Depends on stepped_breakpoint. */
2310 step
= currently_stepping (tp
);
2312 if (current_inferior ()->waiting_for_vfork_done
)
2314 /* Don't try to single-step a vfork parent that is waiting for
2315 the child to get out of the shared memory region (by exec'ing
2316 or exiting). This is particularly important on software
2317 single-step archs, as the child process would trip on the
2318 software single step breakpoint inserted for the parent
2319 process. Since the parent will not actually execute any
2320 instruction until the child is out of the shared region (such
2321 are vfork's semantics), it is safe to simply continue it.
2322 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2323 the parent, and tell it to `keep_going', which automatically
2324 re-sets it stepping. */
2325 infrun_log_debug ("resume : clear step");
2329 CORE_ADDR pc
= regcache_read_pc (regcache
);
2331 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2332 "current thread [%s] at %s",
2333 step
, gdb_signal_to_symbol_string (sig
),
2334 tp
->control
.trap_expected
,
2335 target_pid_to_str (inferior_ptid
).c_str (),
2336 paddress (gdbarch
, pc
));
2338 /* Normally, by the time we reach `resume', the breakpoints are either
2339 removed or inserted, as appropriate. The exception is if we're sitting
2340 at a permanent breakpoint; we need to step over it, but permanent
2341 breakpoints can't be removed. So we have to test for it here. */
2342 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2344 if (sig
!= GDB_SIGNAL_0
)
2346 /* We have a signal to pass to the inferior. The resume
2347 may, or may not take us to the signal handler. If this
2348 is a step, we'll need to stop in the signal handler, if
2349 there's one, (if the target supports stepping into
2350 handlers), or in the next mainline instruction, if
2351 there's no handler. If this is a continue, we need to be
2352 sure to run the handler with all breakpoints inserted.
2353 In all cases, set a breakpoint at the current address
2354 (where the handler returns to), and once that breakpoint
2355 is hit, resume skipping the permanent breakpoint. If
2356 that breakpoint isn't hit, then we've stepped into the
2357 signal handler (or hit some other event). We'll delete
2358 the step-resume breakpoint then. */
2360 infrun_log_debug ("resume: skipping permanent breakpoint, "
2361 "deliver signal first");
2363 clear_step_over_info ();
2364 tp
->control
.trap_expected
= 0;
2366 if (tp
->control
.step_resume_breakpoint
== NULL
)
2368 /* Set a "high-priority" step-resume, as we don't want
2369 user breakpoints at PC to trigger (again) when this
2371 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2372 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2374 tp
->step_after_step_resume_breakpoint
= step
;
2377 insert_breakpoints ();
2381 /* There's no signal to pass, we can go ahead and skip the
2382 permanent breakpoint manually. */
2383 infrun_log_debug ("skipping permanent breakpoint");
2384 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2385 /* Update pc to reflect the new address from which we will
2386 execute instructions. */
2387 pc
= regcache_read_pc (regcache
);
2391 /* We've already advanced the PC, so the stepping part
2392 is done. Now we need to arrange for a trap to be
2393 reported to handle_inferior_event. Set a breakpoint
2394 at the current PC, and run to it. Don't update
2395 prev_pc, because if we end in
2396 switch_back_to_stepped_thread, we want the "expected
2397 thread advanced also" branch to be taken. IOW, we
2398 don't want this thread to step further from PC
2400 gdb_assert (!step_over_info_valid_p ());
2401 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2402 insert_breakpoints ();
2404 resume_ptid
= internal_resume_ptid (user_step
);
2405 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2412 /* If we have a breakpoint to step over, make sure to do a single
2413 step only. Same if we have software watchpoints. */
2414 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2415 tp
->control
.may_range_step
= 0;
2417 /* If displaced stepping is enabled, step over breakpoints by executing a
2418 copy of the instruction at a different address.
2420 We can't use displaced stepping when we have a signal to deliver;
2421 the comments for displaced_step_prepare explain why. The
2422 comments in the handle_inferior event for dealing with 'random
2423 signals' explain what we do instead.
2425 We can't use displaced stepping when we are waiting for vfork_done
2426 event, displaced stepping breaks the vfork child similarly as single
2427 step software breakpoint. */
2428 if (tp
->control
.trap_expected
2429 && use_displaced_stepping (tp
)
2430 && !step_over_info_valid_p ()
2431 && sig
== GDB_SIGNAL_0
2432 && !current_inferior ()->waiting_for_vfork_done
)
2434 displaced_step_prepare_status prepare_status
2435 = displaced_step_prepare (tp
);
2437 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2439 infrun_log_debug ("Got placed in step-over queue");
2441 tp
->control
.trap_expected
= 0;
2444 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2446 /* Fallback to stepping over the breakpoint in-line. */
2448 if (target_is_non_stop_p ())
2449 stop_all_threads ();
2451 set_step_over_info (regcache
->aspace (),
2452 regcache_read_pc (regcache
), 0, tp
->global_num
);
2454 step
= maybe_software_singlestep (gdbarch
, pc
);
2456 insert_breakpoints ();
2458 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2460 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2463 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2466 /* Do we need to do it the hard way, w/temp breakpoints? */
2468 step
= maybe_software_singlestep (gdbarch
, pc
);
2470 /* Currently, our software single-step implementation leads to different
2471 results than hardware single-stepping in one situation: when stepping
2472 into delivering a signal which has an associated signal handler,
2473 hardware single-step will stop at the first instruction of the handler,
2474 while software single-step will simply skip execution of the handler.
2476 For now, this difference in behavior is accepted since there is no
2477 easy way to actually implement single-stepping into a signal handler
2478 without kernel support.
2480 However, there is one scenario where this difference leads to follow-on
2481 problems: if we're stepping off a breakpoint by removing all breakpoints
2482 and then single-stepping. In this case, the software single-step
2483 behavior means that even if there is a *breakpoint* in the signal
2484 handler, GDB still would not stop.
2486 Fortunately, we can at least fix this particular issue. We detect
2487 here the case where we are about to deliver a signal while software
2488 single-stepping with breakpoints removed. In this situation, we
2489 revert the decisions to remove all breakpoints and insert single-
2490 step breakpoints, and instead we install a step-resume breakpoint
2491 at the current address, deliver the signal without stepping, and
2492 once we arrive back at the step-resume breakpoint, actually step
2493 over the breakpoint we originally wanted to step over. */
2494 if (thread_has_single_step_breakpoints_set (tp
)
2495 && sig
!= GDB_SIGNAL_0
2496 && step_over_info_valid_p ())
2498 /* If we have nested signals or a pending signal is delivered
2499 immediately after a handler returns, might already have
2500 a step-resume breakpoint set on the earlier handler. We cannot
2501 set another step-resume breakpoint; just continue on until the
2502 original breakpoint is hit. */
2503 if (tp
->control
.step_resume_breakpoint
== NULL
)
2505 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2506 tp
->step_after_step_resume_breakpoint
= 1;
2509 delete_single_step_breakpoints (tp
);
2511 clear_step_over_info ();
2512 tp
->control
.trap_expected
= 0;
2514 insert_breakpoints ();
2517 /* If STEP is set, it's a request to use hardware stepping
2518 facilities. But in that case, we should never
2519 use singlestep breakpoint. */
2520 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2522 /* Decide the set of threads to ask the target to resume. */
2523 if (tp
->control
.trap_expected
)
2525 /* We're allowing a thread to run past a breakpoint it has
2526 hit, either by single-stepping the thread with the breakpoint
2527 removed, or by displaced stepping, with the breakpoint inserted.
2528 In the former case, we need to single-step only this thread,
2529 and keep others stopped, as they can miss this breakpoint if
2530 allowed to run. That's not really a problem for displaced
2531 stepping, but, we still keep other threads stopped, in case
2532 another thread is also stopped for a breakpoint waiting for
2533 its turn in the displaced stepping queue. */
2534 resume_ptid
= inferior_ptid
;
2537 resume_ptid
= internal_resume_ptid (user_step
);
2539 if (execution_direction
!= EXEC_REVERSE
2540 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2542 /* There are two cases where we currently need to step a
2543 breakpoint instruction when we have a signal to deliver:
2545 - See handle_signal_stop where we handle random signals that
2546 could take out us out of the stepping range. Normally, in
2547 that case we end up continuing (instead of stepping) over the
2548 signal handler with a breakpoint at PC, but there are cases
2549 where we should _always_ single-step, even if we have a
2550 step-resume breakpoint, like when a software watchpoint is
2551 set. Assuming single-stepping and delivering a signal at the
2552 same time would takes us to the signal handler, then we could
2553 have removed the breakpoint at PC to step over it. However,
2554 some hardware step targets (like e.g., Mac OS) can't step
2555 into signal handlers, and for those, we need to leave the
2556 breakpoint at PC inserted, as otherwise if the handler
2557 recurses and executes PC again, it'll miss the breakpoint.
2558 So we leave the breakpoint inserted anyway, but we need to
2559 record that we tried to step a breakpoint instruction, so
2560 that adjust_pc_after_break doesn't end up confused.
2562 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2563 in one thread after another thread that was stepping had been
2564 momentarily paused for a step-over. When we re-resume the
2565 stepping thread, it may be resumed from that address with a
2566 breakpoint that hasn't trapped yet. Seen with
2567 gdb.threads/non-stop-fair-events.exp, on targets that don't
2568 do displaced stepping. */
2570 infrun_log_debug ("resume: [%s] stepped breakpoint",
2571 target_pid_to_str (tp
->ptid
).c_str ());
2573 tp
->stepped_breakpoint
= 1;
2575 /* Most targets can step a breakpoint instruction, thus
2576 executing it normally. But if this one cannot, just
2577 continue and we will hit it anyway. */
2578 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2583 && tp
->control
.trap_expected
2584 && use_displaced_stepping (tp
)
2585 && !step_over_info_valid_p ())
2587 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2588 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2589 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2592 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2593 paddress (resume_gdbarch
, actual_pc
));
2594 read_memory (actual_pc
, buf
, sizeof (buf
));
2595 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2598 if (tp
->control
.may_range_step
)
2600 /* If we're resuming a thread with the PC out of the step
2601 range, then we're doing some nested/finer run control
2602 operation, like stepping the thread out of the dynamic
2603 linker or the displaced stepping scratch pad. We
2604 shouldn't have allowed a range step then. */
2605 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2608 do_target_resume (resume_ptid
, step
, sig
);
2612 /* Resume the inferior. SIG is the signal to give the inferior
2613 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2614 rolls back state on error. */
2617 resume (gdb_signal sig
)
2623 catch (const gdb_exception
&ex
)
2625 /* If resuming is being aborted for any reason, delete any
2626 single-step breakpoint resume_1 may have created, to avoid
2627 confusing the following resumption, and to avoid leaving
2628 single-step breakpoints perturbing other threads, in case
2629 we're running in non-stop mode. */
2630 if (inferior_ptid
!= null_ptid
)
2631 delete_single_step_breakpoints (inferior_thread ());
2641 /* Counter that tracks number of user visible stops. This can be used
2642 to tell whether a command has proceeded the inferior past the
2643 current location. This allows e.g., inferior function calls in
2644 breakpoint commands to not interrupt the command list. When the
2645 call finishes successfully, the inferior is standing at the same
2646 breakpoint as if nothing happened (and so we don't call
2648 static ULONGEST current_stop_id
;
2655 return current_stop_id
;
2658 /* Called when we report a user visible stop. */
2666 /* Clear out all variables saying what to do when inferior is continued.
2667 First do this, then set the ones you want, then call `proceed'. */
2670 clear_proceed_status_thread (struct thread_info
*tp
)
2672 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2674 /* If we're starting a new sequence, then the previous finished
2675 single-step is no longer relevant. */
2676 if (tp
->suspend
.waitstatus_pending_p
)
2678 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2680 infrun_log_debug ("pending event of %s was a finished step. "
2682 target_pid_to_str (tp
->ptid
).c_str ());
2684 tp
->suspend
.waitstatus_pending_p
= 0;
2685 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2690 ("thread %s has pending wait status %s (currently_stepping=%d).",
2691 target_pid_to_str (tp
->ptid
).c_str (),
2692 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2693 currently_stepping (tp
));
2697 /* If this signal should not be seen by program, give it zero.
2698 Used for debugging signals. */
2699 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2700 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2702 delete tp
->thread_fsm
;
2703 tp
->thread_fsm
= NULL
;
2705 tp
->control
.trap_expected
= 0;
2706 tp
->control
.step_range_start
= 0;
2707 tp
->control
.step_range_end
= 0;
2708 tp
->control
.may_range_step
= 0;
2709 tp
->control
.step_frame_id
= null_frame_id
;
2710 tp
->control
.step_stack_frame_id
= null_frame_id
;
2711 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2712 tp
->control
.step_start_function
= NULL
;
2713 tp
->stop_requested
= 0;
2715 tp
->control
.stop_step
= 0;
2717 tp
->control
.proceed_to_finish
= 0;
2719 tp
->control
.stepping_command
= 0;
2721 /* Discard any remaining commands or status from previous stop. */
2722 bpstat_clear (&tp
->control
.stop_bpstat
);
2726 clear_proceed_status (int step
)
2728 /* With scheduler-locking replay, stop replaying other threads if we're
2729 not replaying the user-visible resume ptid.
2731 This is a convenience feature to not require the user to explicitly
2732 stop replaying the other threads. We're assuming that the user's
2733 intent is to resume tracing the recorded process. */
2734 if (!non_stop
&& scheduler_mode
== schedlock_replay
2735 && target_record_is_replaying (minus_one_ptid
)
2736 && !target_record_will_replay (user_visible_resume_ptid (step
),
2737 execution_direction
))
2738 target_record_stop_replaying ();
2740 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2742 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2743 process_stratum_target
*resume_target
2744 = user_visible_resume_target (resume_ptid
);
2746 /* In all-stop mode, delete the per-thread status of all threads
2747 we're about to resume, implicitly and explicitly. */
2748 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2749 clear_proceed_status_thread (tp
);
2752 if (inferior_ptid
!= null_ptid
)
2754 struct inferior
*inferior
;
2758 /* If in non-stop mode, only delete the per-thread status of
2759 the current thread. */
2760 clear_proceed_status_thread (inferior_thread ());
2763 inferior
= current_inferior ();
2764 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2767 gdb::observers::about_to_proceed
.notify ();
2770 /* Returns true if TP is still stopped at a breakpoint that needs
2771 stepping-over in order to make progress. If the breakpoint is gone
2772 meanwhile, we can skip the whole step-over dance. */
2775 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2777 if (tp
->stepping_over_breakpoint
)
2779 struct regcache
*regcache
= get_thread_regcache (tp
);
2781 if (breakpoint_here_p (regcache
->aspace (),
2782 regcache_read_pc (regcache
))
2783 == ordinary_breakpoint_here
)
2786 tp
->stepping_over_breakpoint
= 0;
2792 /* Check whether thread TP still needs to start a step-over in order
2793 to make progress when resumed. Returns an bitwise or of enum
2794 step_over_what bits, indicating what needs to be stepped over. */
2796 static step_over_what
2797 thread_still_needs_step_over (struct thread_info
*tp
)
2799 step_over_what what
= 0;
2801 if (thread_still_needs_step_over_bp (tp
))
2802 what
|= STEP_OVER_BREAKPOINT
;
2804 if (tp
->stepping_over_watchpoint
2805 && !target_have_steppable_watchpoint
)
2806 what
|= STEP_OVER_WATCHPOINT
;
2811 /* Returns true if scheduler locking applies. STEP indicates whether
2812 we're about to do a step/next-like command to a thread. */
2815 schedlock_applies (struct thread_info
*tp
)
2817 return (scheduler_mode
== schedlock_on
2818 || (scheduler_mode
== schedlock_step
2819 && tp
->control
.stepping_command
)
2820 || (scheduler_mode
== schedlock_replay
2821 && target_record_will_replay (minus_one_ptid
,
2822 execution_direction
)));
2825 /* Calls target_commit_resume on all targets. */
2828 commit_resume_all_targets ()
2830 scoped_restore_current_thread restore_thread
;
2832 /* Map between process_target and a representative inferior. This
2833 is to avoid committing a resume in the same target more than
2834 once. Resumptions must be idempotent, so this is an
2836 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2838 for (inferior
*inf
: all_non_exited_inferiors ())
2839 if (inf
->has_execution ())
2840 conn_inf
[inf
->process_target ()] = inf
;
2842 for (const auto &ci
: conn_inf
)
2844 inferior
*inf
= ci
.second
;
2845 switch_to_inferior_no_thread (inf
);
2846 target_commit_resume ();
2850 /* Check that all the targets we're about to resume are in non-stop
2851 mode. Ideally, we'd only care whether all targets support
2852 target-async, but we're not there yet. E.g., stop_all_threads
2853 doesn't know how to handle all-stop targets. Also, the remote
2854 protocol in all-stop mode is synchronous, irrespective of
2855 target-async, which means that things like a breakpoint re-set
2856 triggered by one target would try to read memory from all targets
2860 check_multi_target_resumption (process_stratum_target
*resume_target
)
2862 if (!non_stop
&& resume_target
== nullptr)
2864 scoped_restore_current_thread restore_thread
;
2866 /* This is used to track whether we're resuming more than one
2868 process_stratum_target
*first_connection
= nullptr;
2870 /* The first inferior we see with a target that does not work in
2871 always-non-stop mode. */
2872 inferior
*first_not_non_stop
= nullptr;
2874 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2876 switch_to_inferior_no_thread (inf
);
2878 if (!target_has_execution
)
2881 process_stratum_target
*proc_target
2882 = current_inferior ()->process_target();
2884 if (!target_is_non_stop_p ())
2885 first_not_non_stop
= inf
;
2887 if (first_connection
== nullptr)
2888 first_connection
= proc_target
;
2889 else if (first_connection
!= proc_target
2890 && first_not_non_stop
!= nullptr)
2892 switch_to_inferior_no_thread (first_not_non_stop
);
2894 proc_target
= current_inferior ()->process_target();
2896 error (_("Connection %d (%s) does not support "
2897 "multi-target resumption."),
2898 proc_target
->connection_number
,
2899 make_target_connection_string (proc_target
).c_str ());
2905 /* Basic routine for continuing the program in various fashions.
2907 ADDR is the address to resume at, or -1 for resume where stopped.
2908 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2909 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2911 You should call clear_proceed_status before calling proceed. */
2914 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2916 struct regcache
*regcache
;
2917 struct gdbarch
*gdbarch
;
2919 struct execution_control_state ecss
;
2920 struct execution_control_state
*ecs
= &ecss
;
2923 /* If we're stopped at a fork/vfork, follow the branch set by the
2924 "set follow-fork-mode" command; otherwise, we'll just proceed
2925 resuming the current thread. */
2926 if (!follow_fork ())
2928 /* The target for some reason decided not to resume. */
2930 if (target_can_async_p ())
2931 inferior_event_handler (INF_EXEC_COMPLETE
);
2935 /* We'll update this if & when we switch to a new thread. */
2936 previous_inferior_ptid
= inferior_ptid
;
2938 regcache
= get_current_regcache ();
2939 gdbarch
= regcache
->arch ();
2940 const address_space
*aspace
= regcache
->aspace ();
2942 pc
= regcache_read_pc_protected (regcache
);
2944 thread_info
*cur_thr
= inferior_thread ();
2946 /* Fill in with reasonable starting values. */
2947 init_thread_stepping_state (cur_thr
);
2949 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2952 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2953 process_stratum_target
*resume_target
2954 = user_visible_resume_target (resume_ptid
);
2956 check_multi_target_resumption (resume_target
);
2958 if (addr
== (CORE_ADDR
) -1)
2960 if (pc
== cur_thr
->suspend
.stop_pc
2961 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2962 && execution_direction
!= EXEC_REVERSE
)
2963 /* There is a breakpoint at the address we will resume at,
2964 step one instruction before inserting breakpoints so that
2965 we do not stop right away (and report a second hit at this
2968 Note, we don't do this in reverse, because we won't
2969 actually be executing the breakpoint insn anyway.
2970 We'll be (un-)executing the previous instruction. */
2971 cur_thr
->stepping_over_breakpoint
= 1;
2972 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2973 && gdbarch_single_step_through_delay (gdbarch
,
2974 get_current_frame ()))
2975 /* We stepped onto an instruction that needs to be stepped
2976 again before re-inserting the breakpoint, do so. */
2977 cur_thr
->stepping_over_breakpoint
= 1;
2981 regcache_write_pc (regcache
, addr
);
2984 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2985 cur_thr
->suspend
.stop_signal
= siggnal
;
2987 /* If an exception is thrown from this point on, make sure to
2988 propagate GDB's knowledge of the executing state to the
2989 frontend/user running state. */
2990 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2992 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2993 threads (e.g., we might need to set threads stepping over
2994 breakpoints first), from the user/frontend's point of view, all
2995 threads in RESUME_PTID are now running. Unless we're calling an
2996 inferior function, as in that case we pretend the inferior
2997 doesn't run at all. */
2998 if (!cur_thr
->control
.in_infcall
)
2999 set_running (resume_target
, resume_ptid
, true);
3001 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3002 gdb_signal_to_symbol_string (siggnal
));
3004 annotate_starting ();
3006 /* Make sure that output from GDB appears before output from the
3008 gdb_flush (gdb_stdout
);
3010 /* Since we've marked the inferior running, give it the terminal. A
3011 QUIT/Ctrl-C from here on is forwarded to the target (which can
3012 still detect attempts to unblock a stuck connection with repeated
3013 Ctrl-C from within target_pass_ctrlc). */
3014 target_terminal::inferior ();
3016 /* In a multi-threaded task we may select another thread and
3017 then continue or step.
3019 But if a thread that we're resuming had stopped at a breakpoint,
3020 it will immediately cause another breakpoint stop without any
3021 execution (i.e. it will report a breakpoint hit incorrectly). So
3022 we must step over it first.
3024 Look for threads other than the current (TP) that reported a
3025 breakpoint hit and haven't been resumed yet since. */
3027 /* If scheduler locking applies, we can avoid iterating over all
3029 if (!non_stop
&& !schedlock_applies (cur_thr
))
3031 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3034 switch_to_thread_no_regs (tp
);
3036 /* Ignore the current thread here. It's handled
3041 if (!thread_still_needs_step_over (tp
))
3044 gdb_assert (!thread_is_in_step_over_chain (tp
));
3046 infrun_log_debug ("need to step-over [%s] first",
3047 target_pid_to_str (tp
->ptid
).c_str ());
3049 global_thread_step_over_chain_enqueue (tp
);
3052 switch_to_thread (cur_thr
);
3055 /* Enqueue the current thread last, so that we move all other
3056 threads over their breakpoints first. */
3057 if (cur_thr
->stepping_over_breakpoint
)
3058 global_thread_step_over_chain_enqueue (cur_thr
);
3060 /* If the thread isn't started, we'll still need to set its prev_pc,
3061 so that switch_back_to_stepped_thread knows the thread hasn't
3062 advanced. Must do this before resuming any thread, as in
3063 all-stop/remote, once we resume we can't send any other packet
3064 until the target stops again. */
3065 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3068 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3070 started
= start_step_over ();
3072 if (step_over_info_valid_p ())
3074 /* Either this thread started a new in-line step over, or some
3075 other thread was already doing one. In either case, don't
3076 resume anything else until the step-over is finished. */
3078 else if (started
&& !target_is_non_stop_p ())
3080 /* A new displaced stepping sequence was started. In all-stop,
3081 we can't talk to the target anymore until it next stops. */
3083 else if (!non_stop
&& target_is_non_stop_p ())
3085 /* In all-stop, but the target is always in non-stop mode.
3086 Start all other threads that are implicitly resumed too. */
3087 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3090 switch_to_thread_no_regs (tp
);
3092 if (!tp
->inf
->has_execution ())
3094 infrun_log_debug ("[%s] target has no execution",
3095 target_pid_to_str (tp
->ptid
).c_str ());
3101 infrun_log_debug ("[%s] resumed",
3102 target_pid_to_str (tp
->ptid
).c_str ());
3103 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3107 if (thread_is_in_step_over_chain (tp
))
3109 infrun_log_debug ("[%s] needs step-over",
3110 target_pid_to_str (tp
->ptid
).c_str ());
3114 infrun_log_debug ("resuming %s",
3115 target_pid_to_str (tp
->ptid
).c_str ());
3117 reset_ecs (ecs
, tp
);
3118 switch_to_thread (tp
);
3119 keep_going_pass_signal (ecs
);
3120 if (!ecs
->wait_some_more
)
3121 error (_("Command aborted."));
3124 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3126 /* The thread wasn't started, and isn't queued, run it now. */
3127 reset_ecs (ecs
, cur_thr
);
3128 switch_to_thread (cur_thr
);
3129 keep_going_pass_signal (ecs
);
3130 if (!ecs
->wait_some_more
)
3131 error (_("Command aborted."));
3135 commit_resume_all_targets ();
3137 finish_state
.release ();
3139 /* If we've switched threads above, switch back to the previously
3140 current thread. We don't want the user to see a different
3142 switch_to_thread (cur_thr
);
3144 /* Tell the event loop to wait for it to stop. If the target
3145 supports asynchronous execution, it'll do this from within
3147 if (!target_can_async_p ())
3148 mark_async_event_handler (infrun_async_inferior_event_token
);
3152 /* Start remote-debugging of a machine over a serial link. */
3155 start_remote (int from_tty
)
3157 inferior
*inf
= current_inferior ();
3158 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3160 /* Always go on waiting for the target, regardless of the mode. */
3161 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3162 indicate to wait_for_inferior that a target should timeout if
3163 nothing is returned (instead of just blocking). Because of this,
3164 targets expecting an immediate response need to, internally, set
3165 things up so that the target_wait() is forced to eventually
3167 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3168 differentiate to its caller what the state of the target is after
3169 the initial open has been performed. Here we're assuming that
3170 the target has stopped. It should be possible to eventually have
3171 target_open() return to the caller an indication that the target
3172 is currently running and GDB state should be set to the same as
3173 for an async run. */
3174 wait_for_inferior (inf
);
3176 /* Now that the inferior has stopped, do any bookkeeping like
3177 loading shared libraries. We want to do this before normal_stop,
3178 so that the displayed frame is up to date. */
3179 post_create_inferior (current_top_target (), from_tty
);
3184 /* Initialize static vars when a new inferior begins. */
3187 init_wait_for_inferior (void)
3189 /* These are meaningless until the first time through wait_for_inferior. */
3191 breakpoint_init_inferior (inf_starting
);
3193 clear_proceed_status (0);
3195 nullify_last_target_wait_ptid ();
3197 previous_inferior_ptid
= inferior_ptid
;
3202 static void handle_inferior_event (struct execution_control_state
*ecs
);
3204 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3205 struct execution_control_state
*ecs
);
3206 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3207 struct execution_control_state
*ecs
);
3208 static void handle_signal_stop (struct execution_control_state
*ecs
);
3209 static void check_exception_resume (struct execution_control_state
*,
3210 struct frame_info
*);
3212 static void end_stepping_range (struct execution_control_state
*ecs
);
3213 static void stop_waiting (struct execution_control_state
*ecs
);
3214 static void keep_going (struct execution_control_state
*ecs
);
3215 static void process_event_stop_test (struct execution_control_state
*ecs
);
3216 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3218 /* This function is attached as a "thread_stop_requested" observer.
3219 Cleanup local state that assumed the PTID was to be resumed, and
3220 report the stop to the frontend. */
3223 infrun_thread_stop_requested (ptid_t ptid
)
3225 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3227 /* PTID was requested to stop. If the thread was already stopped,
3228 but the user/frontend doesn't know about that yet (e.g., the
3229 thread had been temporarily paused for some step-over), set up
3230 for reporting the stop now. */
3231 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3233 if (tp
->state
!= THREAD_RUNNING
)
3238 /* Remove matching threads from the step-over queue, so
3239 start_step_over doesn't try to resume them
3241 if (thread_is_in_step_over_chain (tp
))
3242 global_thread_step_over_chain_remove (tp
);
3244 /* If the thread is stopped, but the user/frontend doesn't
3245 know about that yet, queue a pending event, as if the
3246 thread had just stopped now. Unless the thread already had
3248 if (!tp
->suspend
.waitstatus_pending_p
)
3250 tp
->suspend
.waitstatus_pending_p
= 1;
3251 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3252 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3255 /* Clear the inline-frame state, since we're re-processing the
3257 clear_inline_frame_state (tp
);
3259 /* If this thread was paused because some other thread was
3260 doing an inline-step over, let that finish first. Once
3261 that happens, we'll restart all threads and consume pending
3262 stop events then. */
3263 if (step_over_info_valid_p ())
3266 /* Otherwise we can process the (new) pending event now. Set
3267 it so this pending event is considered by
3274 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3276 if (target_last_proc_target
== tp
->inf
->process_target ()
3277 && target_last_wait_ptid
== tp
->ptid
)
3278 nullify_last_target_wait_ptid ();
3281 /* Delete the step resume, single-step and longjmp/exception resume
3282 breakpoints of TP. */
3285 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3287 delete_step_resume_breakpoint (tp
);
3288 delete_exception_resume_breakpoint (tp
);
3289 delete_single_step_breakpoints (tp
);
3292 /* If the target still has execution, call FUNC for each thread that
3293 just stopped. In all-stop, that's all the non-exited threads; in
3294 non-stop, that's the current thread, only. */
3296 typedef void (*for_each_just_stopped_thread_callback_func
)
3297 (struct thread_info
*tp
);
3300 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3302 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3305 if (target_is_non_stop_p ())
3307 /* If in non-stop mode, only the current thread stopped. */
3308 func (inferior_thread ());
3312 /* In all-stop mode, all threads have stopped. */
3313 for (thread_info
*tp
: all_non_exited_threads ())
3318 /* Delete the step resume and longjmp/exception resume breakpoints of
3319 the threads that just stopped. */
3322 delete_just_stopped_threads_infrun_breakpoints (void)
3324 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3327 /* Delete the single-step breakpoints of the threads that just
3331 delete_just_stopped_threads_single_step_breakpoints (void)
3333 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3339 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3340 const struct target_waitstatus
*ws
)
3342 std::string status_string
= target_waitstatus_to_string (ws
);
3345 /* The text is split over several lines because it was getting too long.
3346 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3347 output as a unit; we want only one timestamp printed if debug_timestamp
3350 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3353 waiton_ptid
.tid ());
3354 if (waiton_ptid
.pid () != -1)
3355 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3356 stb
.printf (", status) =\n");
3357 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3361 target_pid_to_str (result_ptid
).c_str ());
3362 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3364 /* This uses %s in part to handle %'s in the text, but also to avoid
3365 a gcc error: the format attribute requires a string literal. */
3366 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3369 /* Select a thread at random, out of those which are resumed and have
3372 static struct thread_info
*
3373 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3377 auto has_event
= [&] (thread_info
*tp
)
3379 return (tp
->ptid
.matches (waiton_ptid
)
3381 && tp
->suspend
.waitstatus_pending_p
);
3384 /* First see how many events we have. Count only resumed threads
3385 that have an event pending. */
3386 for (thread_info
*tp
: inf
->non_exited_threads ())
3390 if (num_events
== 0)
3393 /* Now randomly pick a thread out of those that have had events. */
3394 int random_selector
= (int) ((num_events
* (double) rand ())
3395 / (RAND_MAX
+ 1.0));
3398 infrun_log_debug ("Found %d events, selecting #%d",
3399 num_events
, random_selector
);
3401 /* Select the Nth thread that has had an event. */
3402 for (thread_info
*tp
: inf
->non_exited_threads ())
3404 if (random_selector
-- == 0)
3407 gdb_assert_not_reached ("event thread not found");
3410 /* Wrapper for target_wait that first checks whether threads have
3411 pending statuses to report before actually asking the target for
3412 more events. INF is the inferior we're using to call target_wait
3416 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3417 target_waitstatus
*status
, int options
)
3420 struct thread_info
*tp
;
3422 /* We know that we are looking for an event in the target of inferior
3423 INF, but we don't know which thread the event might come from. As
3424 such we want to make sure that INFERIOR_PTID is reset so that none of
3425 the wait code relies on it - doing so is always a mistake. */
3426 switch_to_inferior_no_thread (inf
);
3428 /* First check if there is a resumed thread with a wait status
3430 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3432 tp
= random_pending_event_thread (inf
, ptid
);
3436 infrun_log_debug ("Waiting for specific thread %s.",
3437 target_pid_to_str (ptid
).c_str ());
3439 /* We have a specific thread to check. */
3440 tp
= find_thread_ptid (inf
, ptid
);
3441 gdb_assert (tp
!= NULL
);
3442 if (!tp
->suspend
.waitstatus_pending_p
)
3447 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3448 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3450 struct regcache
*regcache
= get_thread_regcache (tp
);
3451 struct gdbarch
*gdbarch
= regcache
->arch ();
3455 pc
= regcache_read_pc (regcache
);
3457 if (pc
!= tp
->suspend
.stop_pc
)
3459 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3460 target_pid_to_str (tp
->ptid
).c_str (),
3461 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3462 paddress (gdbarch
, pc
));
3465 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3467 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3468 target_pid_to_str (tp
->ptid
).c_str (),
3469 paddress (gdbarch
, pc
));
3476 infrun_log_debug ("pending event of %s cancelled.",
3477 target_pid_to_str (tp
->ptid
).c_str ());
3479 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3480 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3486 infrun_log_debug ("Using pending wait status %s for %s.",
3487 target_waitstatus_to_string
3488 (&tp
->suspend
.waitstatus
).c_str (),
3489 target_pid_to_str (tp
->ptid
).c_str ());
3491 /* Now that we've selected our final event LWP, un-adjust its PC
3492 if it was a software breakpoint (and the target doesn't
3493 always adjust the PC itself). */
3494 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3495 && !target_supports_stopped_by_sw_breakpoint ())
3497 struct regcache
*regcache
;
3498 struct gdbarch
*gdbarch
;
3501 regcache
= get_thread_regcache (tp
);
3502 gdbarch
= regcache
->arch ();
3504 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3509 pc
= regcache_read_pc (regcache
);
3510 regcache_write_pc (regcache
, pc
+ decr_pc
);
3514 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3515 *status
= tp
->suspend
.waitstatus
;
3516 tp
->suspend
.waitstatus_pending_p
= 0;
3518 /* Wake up the event loop again, until all pending events are
3520 if (target_is_async_p ())
3521 mark_async_event_handler (infrun_async_inferior_event_token
);
3525 /* But if we don't find one, we'll have to wait. */
3527 if (deprecated_target_wait_hook
)
3528 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3530 event_ptid
= target_wait (ptid
, status
, options
);
3535 /* Wrapper for target_wait that first checks whether threads have
3536 pending statuses to report before actually asking the target for
3537 more events. Polls for events from all inferiors/targets. */
3540 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3542 int num_inferiors
= 0;
3543 int random_selector
;
3545 /* For fairness, we pick the first inferior/target to poll at random
3546 out of all inferiors that may report events, and then continue
3547 polling the rest of the inferior list starting from that one in a
3548 circular fashion until the whole list is polled once. */
3550 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3552 return (inf
->process_target () != NULL
3553 && ptid_t (inf
->pid
).matches (wait_ptid
));
3556 /* First see how many matching inferiors we have. */
3557 for (inferior
*inf
: all_inferiors ())
3558 if (inferior_matches (inf
))
3561 if (num_inferiors
== 0)
3563 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3567 /* Now randomly pick an inferior out of those that matched. */
3568 random_selector
= (int)
3569 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3571 if (num_inferiors
> 1)
3572 infrun_log_debug ("Found %d inferiors, starting at #%d",
3573 num_inferiors
, random_selector
);
3575 /* Select the Nth inferior that matched. */
3577 inferior
*selected
= nullptr;
3579 for (inferior
*inf
: all_inferiors ())
3580 if (inferior_matches (inf
))
3581 if (random_selector
-- == 0)
3587 /* Now poll for events out of each of the matching inferior's
3588 targets, starting from the selected one. */
3590 auto do_wait
= [&] (inferior
*inf
)
3592 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3593 ecs
->target
= inf
->process_target ();
3594 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3597 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3598 here spuriously after the target is all stopped and we've already
3599 reported the stop to the user, polling for events. */
3600 scoped_restore_current_thread restore_thread
;
3602 int inf_num
= selected
->num
;
3603 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3604 if (inferior_matches (inf
))
3608 for (inferior
*inf
= inferior_list
;
3609 inf
!= NULL
&& inf
->num
< inf_num
;
3611 if (inferior_matches (inf
))
3615 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3619 /* Prepare and stabilize the inferior for detaching it. E.g.,
3620 detaching while a thread is displaced stepping is a recipe for
3621 crashing it, as nothing would readjust the PC out of the scratch
3625 prepare_for_detach (void)
3627 struct inferior
*inf
= current_inferior ();
3628 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3630 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3632 /* Is any thread of this process displaced stepping? If not,
3633 there's nothing else to do. */
3634 if (displaced_step_in_progress (inf
))
3637 infrun_log_debug ("displaced-stepping in-process while detaching");
3639 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3644 struct execution_control_state ecss
;
3645 struct execution_control_state
*ecs
;
3648 memset (ecs
, 0, sizeof (*ecs
));
3650 overlay_cache_invalid
= 1;
3651 /* Flush target cache before starting to handle each event.
3652 Target was running and cache could be stale. This is just a
3653 heuristic. Running threads may modify target memory, but we
3654 don't get any event. */
3655 target_dcache_invalidate ();
3657 do_target_wait (pid_ptid
, ecs
, 0);
3660 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3662 /* If an error happens while handling the event, propagate GDB's
3663 knowledge of the executing state to the frontend/user running
3665 scoped_finish_thread_state
finish_state (inf
->process_target (),
3668 /* Now figure out what to do with the result of the result. */
3669 handle_inferior_event (ecs
);
3671 /* No error, don't finish the state yet. */
3672 finish_state
.release ();
3674 /* Breakpoints and watchpoints are not installed on the target
3675 at this point, and signals are passed directly to the
3676 inferior, so this must mean the process is gone. */
3677 if (!ecs
->wait_some_more
)
3679 restore_detaching
.release ();
3680 error (_("Program exited while detaching"));
3684 restore_detaching
.release ();
3687 /* Wait for control to return from inferior to debugger.
3689 If inferior gets a signal, we may decide to start it up again
3690 instead of returning. That is why there is a loop in this function.
3691 When this function actually returns it means the inferior
3692 should be left stopped and GDB should read more commands. */
3695 wait_for_inferior (inferior
*inf
)
3697 infrun_log_debug ("wait_for_inferior ()");
3699 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3701 /* If an error happens while handling the event, propagate GDB's
3702 knowledge of the executing state to the frontend/user running
3704 scoped_finish_thread_state finish_state
3705 (inf
->process_target (), minus_one_ptid
);
3709 struct execution_control_state ecss
;
3710 struct execution_control_state
*ecs
= &ecss
;
3712 memset (ecs
, 0, sizeof (*ecs
));
3714 overlay_cache_invalid
= 1;
3716 /* Flush target cache before starting to handle each event.
3717 Target was running and cache could be stale. This is just a
3718 heuristic. Running threads may modify target memory, but we
3719 don't get any event. */
3720 target_dcache_invalidate ();
3722 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3723 ecs
->target
= inf
->process_target ();
3726 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3728 /* Now figure out what to do with the result of the result. */
3729 handle_inferior_event (ecs
);
3731 if (!ecs
->wait_some_more
)
3735 /* No error, don't finish the state yet. */
3736 finish_state
.release ();
3739 /* Cleanup that reinstalls the readline callback handler, if the
3740 target is running in the background. If while handling the target
3741 event something triggered a secondary prompt, like e.g., a
3742 pagination prompt, we'll have removed the callback handler (see
3743 gdb_readline_wrapper_line). Need to do this as we go back to the
3744 event loop, ready to process further input. Note this has no
3745 effect if the handler hasn't actually been removed, because calling
3746 rl_callback_handler_install resets the line buffer, thus losing
3750 reinstall_readline_callback_handler_cleanup ()
3752 struct ui
*ui
= current_ui
;
3756 /* We're not going back to the top level event loop yet. Don't
3757 install the readline callback, as it'd prep the terminal,
3758 readline-style (raw, noecho) (e.g., --batch). We'll install
3759 it the next time the prompt is displayed, when we're ready
3764 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3765 gdb_rl_callback_handler_reinstall ();
3768 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3769 that's just the event thread. In all-stop, that's all threads. */
3772 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3774 if (ecs
->event_thread
!= NULL
3775 && ecs
->event_thread
->thread_fsm
!= NULL
)
3776 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3780 for (thread_info
*thr
: all_non_exited_threads ())
3782 if (thr
->thread_fsm
== NULL
)
3784 if (thr
== ecs
->event_thread
)
3787 switch_to_thread (thr
);
3788 thr
->thread_fsm
->clean_up (thr
);
3791 if (ecs
->event_thread
!= NULL
)
3792 switch_to_thread (ecs
->event_thread
);
3796 /* Helper for all_uis_check_sync_execution_done that works on the
3800 check_curr_ui_sync_execution_done (void)
3802 struct ui
*ui
= current_ui
;
3804 if (ui
->prompt_state
== PROMPT_NEEDED
3806 && !gdb_in_secondary_prompt_p (ui
))
3808 target_terminal::ours ();
3809 gdb::observers::sync_execution_done
.notify ();
3810 ui_register_input_event_handler (ui
);
3817 all_uis_check_sync_execution_done (void)
3819 SWITCH_THRU_ALL_UIS ()
3821 check_curr_ui_sync_execution_done ();
3828 all_uis_on_sync_execution_starting (void)
3830 SWITCH_THRU_ALL_UIS ()
3832 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3833 async_disable_stdin ();
3837 /* Asynchronous version of wait_for_inferior. It is called by the
3838 event loop whenever a change of state is detected on the file
3839 descriptor corresponding to the target. It can be called more than
3840 once to complete a single execution command. In such cases we need
3841 to keep the state in a global variable ECSS. If it is the last time
3842 that this function is called for a single execution command, then
3843 report to the user that the inferior has stopped, and do the
3844 necessary cleanups. */
3847 fetch_inferior_event ()
3849 struct execution_control_state ecss
;
3850 struct execution_control_state
*ecs
= &ecss
;
3853 memset (ecs
, 0, sizeof (*ecs
));
3855 /* Events are always processed with the main UI as current UI. This
3856 way, warnings, debug output, etc. are always consistently sent to
3857 the main console. */
3858 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3860 /* End up with readline processing input, if necessary. */
3862 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3864 /* We're handling a live event, so make sure we're doing live
3865 debugging. If we're looking at traceframes while the target is
3866 running, we're going to need to get back to that mode after
3867 handling the event. */
3868 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3871 maybe_restore_traceframe
.emplace ();
3872 set_current_traceframe (-1);
3875 /* The user/frontend should not notice a thread switch due to
3876 internal events. Make sure we revert to the user selected
3877 thread and frame after handling the event and running any
3878 breakpoint commands. */
3879 scoped_restore_current_thread restore_thread
;
3881 overlay_cache_invalid
= 1;
3882 /* Flush target cache before starting to handle each event. Target
3883 was running and cache could be stale. This is just a heuristic.
3884 Running threads may modify target memory, but we don't get any
3886 target_dcache_invalidate ();
3888 scoped_restore save_exec_dir
3889 = make_scoped_restore (&execution_direction
,
3890 target_execution_direction ());
3892 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3895 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3897 /* Switch to the target that generated the event, so we can do
3898 target calls. Any inferior bound to the target will do, so we
3899 just switch to the first we find. */
3900 for (inferior
*inf
: all_inferiors (ecs
->target
))
3902 switch_to_inferior_no_thread (inf
);
3907 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3909 /* If an error happens while handling the event, propagate GDB's
3910 knowledge of the executing state to the frontend/user running
3912 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3913 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3915 /* Get executed before scoped_restore_current_thread above to apply
3916 still for the thread which has thrown the exception. */
3917 auto defer_bpstat_clear
3918 = make_scope_exit (bpstat_clear_actions
);
3919 auto defer_delete_threads
3920 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3922 /* Now figure out what to do with the result of the result. */
3923 handle_inferior_event (ecs
);
3925 if (!ecs
->wait_some_more
)
3927 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3928 int should_stop
= 1;
3929 struct thread_info
*thr
= ecs
->event_thread
;
3931 delete_just_stopped_threads_infrun_breakpoints ();
3935 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3937 if (thread_fsm
!= NULL
)
3938 should_stop
= thread_fsm
->should_stop (thr
);
3947 bool should_notify_stop
= true;
3950 clean_up_just_stopped_threads_fsms (ecs
);
3952 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3953 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3955 if (should_notify_stop
)
3957 /* We may not find an inferior if this was a process exit. */
3958 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3959 proceeded
= normal_stop ();
3964 inferior_event_handler (INF_EXEC_COMPLETE
);
3968 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3969 previously selected thread is gone. We have two
3970 choices - switch to no thread selected, or restore the
3971 previously selected thread (now exited). We chose the
3972 later, just because that's what GDB used to do. After
3973 this, "info threads" says "The current thread <Thread
3974 ID 2> has terminated." instead of "No thread
3978 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3979 restore_thread
.dont_restore ();
3983 defer_delete_threads
.release ();
3984 defer_bpstat_clear
.release ();
3986 /* No error, don't finish the thread states yet. */
3987 finish_state
.release ();
3989 /* This scope is used to ensure that readline callbacks are
3990 reinstalled here. */
3993 /* If a UI was in sync execution mode, and now isn't, restore its
3994 prompt (a synchronous execution command has finished, and we're
3995 ready for input). */
3996 all_uis_check_sync_execution_done ();
3999 && exec_done_display_p
4000 && (inferior_ptid
== null_ptid
4001 || inferior_thread ()->state
!= THREAD_RUNNING
))
4002 printf_unfiltered (_("completed.\n"));
4008 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4009 struct symtab_and_line sal
)
4011 /* This can be removed once this function no longer implicitly relies on the
4012 inferior_ptid value. */
4013 gdb_assert (inferior_ptid
== tp
->ptid
);
4015 tp
->control
.step_frame_id
= get_frame_id (frame
);
4016 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4018 tp
->current_symtab
= sal
.symtab
;
4019 tp
->current_line
= sal
.line
;
4022 /* Clear context switchable stepping state. */
4025 init_thread_stepping_state (struct thread_info
*tss
)
4027 tss
->stepped_breakpoint
= 0;
4028 tss
->stepping_over_breakpoint
= 0;
4029 tss
->stepping_over_watchpoint
= 0;
4030 tss
->step_after_step_resume_breakpoint
= 0;
4036 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4037 target_waitstatus status
)
4039 target_last_proc_target
= target
;
4040 target_last_wait_ptid
= ptid
;
4041 target_last_waitstatus
= status
;
4047 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4048 target_waitstatus
*status
)
4050 if (target
!= nullptr)
4051 *target
= target_last_proc_target
;
4052 if (ptid
!= nullptr)
4053 *ptid
= target_last_wait_ptid
;
4054 if (status
!= nullptr)
4055 *status
= target_last_waitstatus
;
4061 nullify_last_target_wait_ptid (void)
4063 target_last_proc_target
= nullptr;
4064 target_last_wait_ptid
= minus_one_ptid
;
4065 target_last_waitstatus
= {};
4068 /* Switch thread contexts. */
4071 context_switch (execution_control_state
*ecs
)
4073 if (ecs
->ptid
!= inferior_ptid
4074 && (inferior_ptid
== null_ptid
4075 || ecs
->event_thread
!= inferior_thread ()))
4077 infrun_log_debug ("Switching context from %s to %s",
4078 target_pid_to_str (inferior_ptid
).c_str (),
4079 target_pid_to_str (ecs
->ptid
).c_str ());
4082 switch_to_thread (ecs
->event_thread
);
4085 /* If the target can't tell whether we've hit breakpoints
4086 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4087 check whether that could have been caused by a breakpoint. If so,
4088 adjust the PC, per gdbarch_decr_pc_after_break. */
4091 adjust_pc_after_break (struct thread_info
*thread
,
4092 struct target_waitstatus
*ws
)
4094 struct regcache
*regcache
;
4095 struct gdbarch
*gdbarch
;
4096 CORE_ADDR breakpoint_pc
, decr_pc
;
4098 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4099 we aren't, just return.
4101 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4102 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4103 implemented by software breakpoints should be handled through the normal
4106 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4107 different signals (SIGILL or SIGEMT for instance), but it is less
4108 clear where the PC is pointing afterwards. It may not match
4109 gdbarch_decr_pc_after_break. I don't know any specific target that
4110 generates these signals at breakpoints (the code has been in GDB since at
4111 least 1992) so I can not guess how to handle them here.
4113 In earlier versions of GDB, a target with
4114 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4115 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4116 target with both of these set in GDB history, and it seems unlikely to be
4117 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4119 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4122 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4125 /* In reverse execution, when a breakpoint is hit, the instruction
4126 under it has already been de-executed. The reported PC always
4127 points at the breakpoint address, so adjusting it further would
4128 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4131 B1 0x08000000 : INSN1
4132 B2 0x08000001 : INSN2
4134 PC -> 0x08000003 : INSN4
4136 Say you're stopped at 0x08000003 as above. Reverse continuing
4137 from that point should hit B2 as below. Reading the PC when the
4138 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4139 been de-executed already.
4141 B1 0x08000000 : INSN1
4142 B2 PC -> 0x08000001 : INSN2
4146 We can't apply the same logic as for forward execution, because
4147 we would wrongly adjust the PC to 0x08000000, since there's a
4148 breakpoint at PC - 1. We'd then report a hit on B1, although
4149 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4151 if (execution_direction
== EXEC_REVERSE
)
4154 /* If the target can tell whether the thread hit a SW breakpoint,
4155 trust it. Targets that can tell also adjust the PC
4157 if (target_supports_stopped_by_sw_breakpoint ())
4160 /* Note that relying on whether a breakpoint is planted in memory to
4161 determine this can fail. E.g,. the breakpoint could have been
4162 removed since. Or the thread could have been told to step an
4163 instruction the size of a breakpoint instruction, and only
4164 _after_ was a breakpoint inserted at its address. */
4166 /* If this target does not decrement the PC after breakpoints, then
4167 we have nothing to do. */
4168 regcache
= get_thread_regcache (thread
);
4169 gdbarch
= regcache
->arch ();
4171 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4175 const address_space
*aspace
= regcache
->aspace ();
4177 /* Find the location where (if we've hit a breakpoint) the
4178 breakpoint would be. */
4179 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4181 /* If the target can't tell whether a software breakpoint triggered,
4182 fallback to figuring it out based on breakpoints we think were
4183 inserted in the target, and on whether the thread was stepped or
4186 /* Check whether there actually is a software breakpoint inserted at
4189 If in non-stop mode, a race condition is possible where we've
4190 removed a breakpoint, but stop events for that breakpoint were
4191 already queued and arrive later. To suppress those spurious
4192 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4193 and retire them after a number of stop events are reported. Note
4194 this is an heuristic and can thus get confused. The real fix is
4195 to get the "stopped by SW BP and needs adjustment" info out of
4196 the target/kernel (and thus never reach here; see above). */
4197 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4198 || (target_is_non_stop_p ()
4199 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4201 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4203 if (record_full_is_used ())
4204 restore_operation_disable
.emplace
4205 (record_full_gdb_operation_disable_set ());
4207 /* When using hardware single-step, a SIGTRAP is reported for both
4208 a completed single-step and a software breakpoint. Need to
4209 differentiate between the two, as the latter needs adjusting
4210 but the former does not.
4212 The SIGTRAP can be due to a completed hardware single-step only if
4213 - we didn't insert software single-step breakpoints
4214 - this thread is currently being stepped
4216 If any of these events did not occur, we must have stopped due
4217 to hitting a software breakpoint, and have to back up to the
4220 As a special case, we could have hardware single-stepped a
4221 software breakpoint. In this case (prev_pc == breakpoint_pc),
4222 we also need to back up to the breakpoint address. */
4224 if (thread_has_single_step_breakpoints_set (thread
)
4225 || !currently_stepping (thread
)
4226 || (thread
->stepped_breakpoint
4227 && thread
->prev_pc
== breakpoint_pc
))
4228 regcache_write_pc (regcache
, breakpoint_pc
);
4233 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4235 for (frame
= get_prev_frame (frame
);
4237 frame
= get_prev_frame (frame
))
4239 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4241 if (get_frame_type (frame
) != INLINE_FRAME
)
4248 /* Look for an inline frame that is marked for skip.
4249 If PREV_FRAME is TRUE start at the previous frame,
4250 otherwise start at the current frame. Stop at the
4251 first non-inline frame, or at the frame where the
4255 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4257 struct frame_info
*frame
= get_current_frame ();
4260 frame
= get_prev_frame (frame
);
4262 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4264 const char *fn
= NULL
;
4265 symtab_and_line sal
;
4268 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4270 if (get_frame_type (frame
) != INLINE_FRAME
)
4273 sal
= find_frame_sal (frame
);
4274 sym
= get_frame_function (frame
);
4277 fn
= sym
->print_name ();
4280 && function_name_is_marked_for_skip (fn
, sal
))
4287 /* If the event thread has the stop requested flag set, pretend it
4288 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4292 handle_stop_requested (struct execution_control_state
*ecs
)
4294 if (ecs
->event_thread
->stop_requested
)
4296 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4297 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4298 handle_signal_stop (ecs
);
4304 /* Auxiliary function that handles syscall entry/return events.
4305 It returns 1 if the inferior should keep going (and GDB
4306 should ignore the event), or 0 if the event deserves to be
4310 handle_syscall_event (struct execution_control_state
*ecs
)
4312 struct regcache
*regcache
;
4315 context_switch (ecs
);
4317 regcache
= get_thread_regcache (ecs
->event_thread
);
4318 syscall_number
= ecs
->ws
.value
.syscall_number
;
4319 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4321 if (catch_syscall_enabled () > 0
4322 && catching_syscall_number (syscall_number
) > 0)
4324 infrun_log_debug ("syscall number=%d", syscall_number
);
4326 ecs
->event_thread
->control
.stop_bpstat
4327 = bpstat_stop_status (regcache
->aspace (),
4328 ecs
->event_thread
->suspend
.stop_pc
,
4329 ecs
->event_thread
, &ecs
->ws
);
4331 if (handle_stop_requested (ecs
))
4334 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4336 /* Catchpoint hit. */
4341 if (handle_stop_requested (ecs
))
4344 /* If no catchpoint triggered for this, then keep going. */
4349 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4352 fill_in_stop_func (struct gdbarch
*gdbarch
,
4353 struct execution_control_state
*ecs
)
4355 if (!ecs
->stop_func_filled_in
)
4359 /* Don't care about return value; stop_func_start and stop_func_name
4360 will both be 0 if it doesn't work. */
4361 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4362 &ecs
->stop_func_name
,
4363 &ecs
->stop_func_start
,
4364 &ecs
->stop_func_end
,
4367 /* The call to find_pc_partial_function, above, will set
4368 stop_func_start and stop_func_end to the start and end
4369 of the range containing the stop pc. If this range
4370 contains the entry pc for the block (which is always the
4371 case for contiguous blocks), advance stop_func_start past
4372 the function's start offset and entrypoint. Note that
4373 stop_func_start is NOT advanced when in a range of a
4374 non-contiguous block that does not contain the entry pc. */
4375 if (block
!= nullptr
4376 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4377 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4379 ecs
->stop_func_start
4380 += gdbarch_deprecated_function_start_offset (gdbarch
);
4382 if (gdbarch_skip_entrypoint_p (gdbarch
))
4383 ecs
->stop_func_start
4384 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4387 ecs
->stop_func_filled_in
= 1;
4392 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4394 static enum stop_kind
4395 get_inferior_stop_soon (execution_control_state
*ecs
)
4397 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4399 gdb_assert (inf
!= NULL
);
4400 return inf
->control
.stop_soon
;
4403 /* Poll for one event out of the current target. Store the resulting
4404 waitstatus in WS, and return the event ptid. Does not block. */
4407 poll_one_curr_target (struct target_waitstatus
*ws
)
4411 overlay_cache_invalid
= 1;
4413 /* Flush target cache before starting to handle each event.
4414 Target was running and cache could be stale. This is just a
4415 heuristic. Running threads may modify target memory, but we
4416 don't get any event. */
4417 target_dcache_invalidate ();
4419 if (deprecated_target_wait_hook
)
4420 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4422 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4425 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4430 /* An event reported by wait_one. */
4432 struct wait_one_event
4434 /* The target the event came out of. */
4435 process_stratum_target
*target
;
4437 /* The PTID the event was for. */
4440 /* The waitstatus. */
4441 target_waitstatus ws
;
4444 /* Wait for one event out of any target. */
4446 static wait_one_event
4451 for (inferior
*inf
: all_inferiors ())
4453 process_stratum_target
*target
= inf
->process_target ();
4455 || !target
->is_async_p ()
4456 || !target
->threads_executing
)
4459 switch_to_inferior_no_thread (inf
);
4461 wait_one_event event
;
4462 event
.target
= target
;
4463 event
.ptid
= poll_one_curr_target (&event
.ws
);
4465 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4467 /* If nothing is resumed, remove the target from the
4471 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4475 /* Block waiting for some event. */
4482 for (inferior
*inf
: all_inferiors ())
4484 process_stratum_target
*target
= inf
->process_target ();
4486 || !target
->is_async_p ()
4487 || !target
->threads_executing
)
4490 int fd
= target
->async_wait_fd ();
4491 FD_SET (fd
, &readfds
);
4498 /* No waitable targets left. All must be stopped. */
4499 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4504 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4510 perror_with_name ("interruptible_select");
4515 /* Save the thread's event and stop reason to process it later. */
4518 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4520 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4521 target_waitstatus_to_string (ws
).c_str (),
4526 /* Record for later. */
4527 tp
->suspend
.waitstatus
= *ws
;
4528 tp
->suspend
.waitstatus_pending_p
= 1;
4530 struct regcache
*regcache
= get_thread_regcache (tp
);
4531 const address_space
*aspace
= regcache
->aspace ();
4533 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4534 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4536 CORE_ADDR pc
= regcache_read_pc (regcache
);
4538 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4540 scoped_restore_current_thread restore_thread
;
4541 switch_to_thread (tp
);
4543 if (target_stopped_by_watchpoint ())
4545 tp
->suspend
.stop_reason
4546 = TARGET_STOPPED_BY_WATCHPOINT
;
4548 else if (target_supports_stopped_by_sw_breakpoint ()
4549 && target_stopped_by_sw_breakpoint ())
4551 tp
->suspend
.stop_reason
4552 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4554 else if (target_supports_stopped_by_hw_breakpoint ()
4555 && target_stopped_by_hw_breakpoint ())
4557 tp
->suspend
.stop_reason
4558 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4560 else if (!target_supports_stopped_by_hw_breakpoint ()
4561 && hardware_breakpoint_inserted_here_p (aspace
,
4564 tp
->suspend
.stop_reason
4565 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4567 else if (!target_supports_stopped_by_sw_breakpoint ()
4568 && software_breakpoint_inserted_here_p (aspace
,
4571 tp
->suspend
.stop_reason
4572 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4574 else if (!thread_has_single_step_breakpoints_set (tp
)
4575 && currently_stepping (tp
))
4577 tp
->suspend
.stop_reason
4578 = TARGET_STOPPED_BY_SINGLE_STEP
;
4583 /* Mark the non-executing threads accordingly. In all-stop, all
4584 threads of all processes are stopped when we get any event
4585 reported. In non-stop mode, only the event thread stops. */
4588 mark_non_executing_threads (process_stratum_target
*target
,
4590 struct target_waitstatus ws
)
4594 if (!target_is_non_stop_p ())
4595 mark_ptid
= minus_one_ptid
;
4596 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4597 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4599 /* If we're handling a process exit in non-stop mode, even
4600 though threads haven't been deleted yet, one would think
4601 that there is nothing to do, as threads of the dead process
4602 will be soon deleted, and threads of any other process were
4603 left running. However, on some targets, threads survive a
4604 process exit event. E.g., for the "checkpoint" command,
4605 when the current checkpoint/fork exits, linux-fork.c
4606 automatically switches to another fork from within
4607 target_mourn_inferior, by associating the same
4608 inferior/thread to another fork. We haven't mourned yet at
4609 this point, but we must mark any threads left in the
4610 process as not-executing so that finish_thread_state marks
4611 them stopped (in the user's perspective) if/when we present
4612 the stop to the user. */
4613 mark_ptid
= ptid_t (event_ptid
.pid ());
4616 mark_ptid
= event_ptid
;
4618 set_executing (target
, mark_ptid
, false);
4620 /* Likewise the resumed flag. */
4621 set_resumed (target
, mark_ptid
, false);
4627 stop_all_threads (void)
4629 /* We may need multiple passes to discover all threads. */
4633 gdb_assert (exists_non_stop_target ());
4635 infrun_log_debug ("stop_all_threads");
4637 scoped_restore_current_thread restore_thread
;
4639 /* Enable thread events of all targets. */
4640 for (auto *target
: all_non_exited_process_targets ())
4642 switch_to_target_no_thread (target
);
4643 target_thread_events (true);
4648 /* Disable thread events of all targets. */
4649 for (auto *target
: all_non_exited_process_targets ())
4651 switch_to_target_no_thread (target
);
4652 target_thread_events (false);
4656 infrun_log_debug ("stop_all_threads done");
4659 /* Request threads to stop, and then wait for the stops. Because
4660 threads we already know about can spawn more threads while we're
4661 trying to stop them, and we only learn about new threads when we
4662 update the thread list, do this in a loop, and keep iterating
4663 until two passes find no threads that need to be stopped. */
4664 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4666 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4670 int waits_needed
= 0;
4672 for (auto *target
: all_non_exited_process_targets ())
4674 switch_to_target_no_thread (target
);
4675 update_thread_list ();
4678 /* Go through all threads looking for threads that we need
4679 to tell the target to stop. */
4680 for (thread_info
*t
: all_non_exited_threads ())
4682 /* For a single-target setting with an all-stop target,
4683 we would not even arrive here. For a multi-target
4684 setting, until GDB is able to handle a mixture of
4685 all-stop and non-stop targets, simply skip all-stop
4686 targets' threads. This should be fine due to the
4687 protection of 'check_multi_target_resumption'. */
4689 switch_to_thread_no_regs (t
);
4690 if (!target_is_non_stop_p ())
4695 /* If already stopping, don't request a stop again.
4696 We just haven't seen the notification yet. */
4697 if (!t
->stop_requested
)
4699 infrun_log_debug (" %s executing, need stop",
4700 target_pid_to_str (t
->ptid
).c_str ());
4701 target_stop (t
->ptid
);
4702 t
->stop_requested
= 1;
4706 infrun_log_debug (" %s executing, already stopping",
4707 target_pid_to_str (t
->ptid
).c_str ());
4710 if (t
->stop_requested
)
4715 infrun_log_debug (" %s not executing",
4716 target_pid_to_str (t
->ptid
).c_str ());
4718 /* The thread may be not executing, but still be
4719 resumed with a pending status to process. */
4724 if (waits_needed
== 0)
4727 /* If we find new threads on the second iteration, restart
4728 over. We want to see two iterations in a row with all
4733 for (int i
= 0; i
< waits_needed
; i
++)
4735 wait_one_event event
= wait_one ();
4737 infrun_log_debug ("%s %s\n",
4738 target_waitstatus_to_string (&event
.ws
).c_str (),
4739 target_pid_to_str (event
.ptid
).c_str ());
4741 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4743 /* All resumed threads exited. */
4746 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4747 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4748 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4750 /* One thread/process exited/signalled. */
4752 thread_info
*t
= nullptr;
4754 /* The target may have reported just a pid. If so, try
4755 the first non-exited thread. */
4756 if (event
.ptid
.is_pid ())
4758 int pid
= event
.ptid
.pid ();
4759 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4760 for (thread_info
*tp
: inf
->non_exited_threads ())
4766 /* If there is no available thread, the event would
4767 have to be appended to a per-inferior event list,
4768 which does not exist (and if it did, we'd have
4769 to adjust run control command to be able to
4770 resume such an inferior). We assert here instead
4771 of going into an infinite loop. */
4772 gdb_assert (t
!= nullptr);
4774 infrun_log_debug ("using %s\n",
4775 target_pid_to_str (t
->ptid
).c_str ());
4779 t
= find_thread_ptid (event
.target
, event
.ptid
);
4780 /* Check if this is the first time we see this thread.
4781 Don't bother adding if it individually exited. */
4783 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4784 t
= add_thread (event
.target
, event
.ptid
);
4789 /* Set the threads as non-executing to avoid
4790 another stop attempt on them. */
4791 switch_to_thread_no_regs (t
);
4792 mark_non_executing_threads (event
.target
, event
.ptid
,
4794 save_waitstatus (t
, &event
.ws
);
4795 t
->stop_requested
= false;
4800 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4802 t
= add_thread (event
.target
, event
.ptid
);
4804 t
->stop_requested
= 0;
4807 t
->control
.may_range_step
= 0;
4809 /* This may be the first time we see the inferior report
4811 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4812 if (inf
->needs_setup
)
4814 switch_to_thread_no_regs (t
);
4818 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4819 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4821 /* We caught the event that we intended to catch, so
4822 there's no event pending. */
4823 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4824 t
->suspend
.waitstatus_pending_p
= 0;
4826 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4828 /* Add it back to the step-over queue. */
4829 infrun_log_debug ("displaced-step of %s "
4830 "canceled: adding back to the "
4831 "step-over queue\n",
4832 target_pid_to_str (t
->ptid
).c_str ());
4834 t
->control
.trap_expected
= 0;
4835 global_thread_step_over_chain_enqueue (t
);
4840 enum gdb_signal sig
;
4841 struct regcache
*regcache
;
4845 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4847 infrun_log_debug ("target_wait %s, saving "
4848 "status for %d.%ld.%ld\n",
4855 /* Record for later. */
4856 save_waitstatus (t
, &event
.ws
);
4858 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4859 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4861 if (displaced_step_finish (t
, sig
) < 0)
4863 /* Add it back to the step-over queue. */
4864 t
->control
.trap_expected
= 0;
4865 global_thread_step_over_chain_enqueue (t
);
4868 regcache
= get_thread_regcache (t
);
4869 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4871 infrun_log_debug ("saved stop_pc=%s for %s "
4872 "(currently_stepping=%d)\n",
4873 paddress (target_gdbarch (),
4874 t
->suspend
.stop_pc
),
4875 target_pid_to_str (t
->ptid
).c_str (),
4876 currently_stepping (t
));
4884 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4887 handle_no_resumed (struct execution_control_state
*ecs
)
4889 if (target_can_async_p ())
4893 for (ui
*ui
: all_uis ())
4895 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4903 /* There were no unwaited-for children left in the target, but,
4904 we're not synchronously waiting for events either. Just
4907 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4908 prepare_to_wait (ecs
);
4913 /* Otherwise, if we were running a synchronous execution command, we
4914 may need to cancel it and give the user back the terminal.
4916 In non-stop mode, the target can't tell whether we've already
4917 consumed previous stop events, so it can end up sending us a
4918 no-resumed event like so:
4920 #0 - thread 1 is left stopped
4922 #1 - thread 2 is resumed and hits breakpoint
4923 -> TARGET_WAITKIND_STOPPED
4925 #2 - thread 3 is resumed and exits
4926 this is the last resumed thread, so
4927 -> TARGET_WAITKIND_NO_RESUMED
4929 #3 - gdb processes stop for thread 2 and decides to re-resume
4932 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4933 thread 2 is now resumed, so the event should be ignored.
4935 IOW, if the stop for thread 2 doesn't end a foreground command,
4936 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4937 event. But it could be that the event meant that thread 2 itself
4938 (or whatever other thread was the last resumed thread) exited.
4940 To address this we refresh the thread list and check whether we
4941 have resumed threads _now_. In the example above, this removes
4942 thread 3 from the thread list. If thread 2 was re-resumed, we
4943 ignore this event. If we find no thread resumed, then we cancel
4944 the synchronous command and show "no unwaited-for " to the
4947 inferior
*curr_inf
= current_inferior ();
4949 scoped_restore_current_thread restore_thread
;
4951 for (auto *target
: all_non_exited_process_targets ())
4953 switch_to_target_no_thread (target
);
4954 update_thread_list ();
4959 - the current target has no thread executing, and
4960 - the current inferior is native, and
4961 - the current inferior is the one which has the terminal, and
4964 then a Ctrl-C from this point on would remain stuck in the
4965 kernel, until a thread resumes and dequeues it. That would
4966 result in the GDB CLI not reacting to Ctrl-C, not able to
4967 interrupt the program. To address this, if the current inferior
4968 no longer has any thread executing, we give the terminal to some
4969 other inferior that has at least one thread executing. */
4970 bool swap_terminal
= true;
4972 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4973 whether to report it to the user. */
4974 bool ignore_event
= false;
4976 for (thread_info
*thread
: all_non_exited_threads ())
4978 if (swap_terminal
&& thread
->executing
)
4980 if (thread
->inf
!= curr_inf
)
4982 target_terminal::ours ();
4984 switch_to_thread (thread
);
4985 target_terminal::inferior ();
4987 swap_terminal
= false;
4991 && (thread
->executing
4992 || thread
->suspend
.waitstatus_pending_p
))
4994 /* Either there were no unwaited-for children left in the
4995 target at some point, but there are now, or some target
4996 other than the eventing one has unwaited-for children
4997 left. Just ignore. */
4998 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
4999 "(ignoring: found resumed)\n");
5001 ignore_event
= true;
5004 if (ignore_event
&& !swap_terminal
)
5010 switch_to_inferior_no_thread (curr_inf
);
5011 prepare_to_wait (ecs
);
5015 /* Go ahead and report the event. */
5019 /* Given an execution control state that has been freshly filled in by
5020 an event from the inferior, figure out what it means and take
5023 The alternatives are:
5025 1) stop_waiting and return; to really stop and return to the
5028 2) keep_going and return; to wait for the next event (set
5029 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5033 handle_inferior_event (struct execution_control_state
*ecs
)
5035 /* Make sure that all temporary struct value objects that were
5036 created during the handling of the event get deleted at the
5038 scoped_value_mark free_values
;
5040 enum stop_kind stop_soon
;
5042 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5044 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5046 /* We had an event in the inferior, but we are not interested in
5047 handling it at this level. The lower layers have already
5048 done what needs to be done, if anything.
5050 One of the possible circumstances for this is when the
5051 inferior produces output for the console. The inferior has
5052 not stopped, and we are ignoring the event. Another possible
5053 circumstance is any event which the lower level knows will be
5054 reported multiple times without an intervening resume. */
5055 prepare_to_wait (ecs
);
5059 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5061 prepare_to_wait (ecs
);
5065 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5066 && handle_no_resumed (ecs
))
5069 /* Cache the last target/ptid/waitstatus. */
5070 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5072 /* Always clear state belonging to the previous time we stopped. */
5073 stop_stack_dummy
= STOP_NONE
;
5075 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5077 /* No unwaited-for children left. IOW, all resumed children
5079 stop_print_frame
= 0;
5084 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5085 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5087 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5088 /* If it's a new thread, add it to the thread database. */
5089 if (ecs
->event_thread
== NULL
)
5090 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5092 /* Disable range stepping. If the next step request could use a
5093 range, this will be end up re-enabled then. */
5094 ecs
->event_thread
->control
.may_range_step
= 0;
5097 /* Dependent on valid ECS->EVENT_THREAD. */
5098 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5100 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5101 reinit_frame_cache ();
5103 breakpoint_retire_moribund ();
5105 /* First, distinguish signals caused by the debugger from signals
5106 that have to do with the program's own actions. Note that
5107 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5108 on the operating system version. Here we detect when a SIGILL or
5109 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5110 something similar for SIGSEGV, since a SIGSEGV will be generated
5111 when we're trying to execute a breakpoint instruction on a
5112 non-executable stack. This happens for call dummy breakpoints
5113 for architectures like SPARC that place call dummies on the
5115 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5116 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5117 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5118 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5120 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5122 if (breakpoint_inserted_here_p (regcache
->aspace (),
5123 regcache_read_pc (regcache
)))
5125 infrun_log_debug ("Treating signal as SIGTRAP");
5126 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5130 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5132 switch (ecs
->ws
.kind
)
5134 case TARGET_WAITKIND_LOADED
:
5135 context_switch (ecs
);
5136 /* Ignore gracefully during startup of the inferior, as it might
5137 be the shell which has just loaded some objects, otherwise
5138 add the symbols for the newly loaded objects. Also ignore at
5139 the beginning of an attach or remote session; we will query
5140 the full list of libraries once the connection is
5143 stop_soon
= get_inferior_stop_soon (ecs
);
5144 if (stop_soon
== NO_STOP_QUIETLY
)
5146 struct regcache
*regcache
;
5148 regcache
= get_thread_regcache (ecs
->event_thread
);
5150 handle_solib_event ();
5152 ecs
->event_thread
->control
.stop_bpstat
5153 = bpstat_stop_status (regcache
->aspace (),
5154 ecs
->event_thread
->suspend
.stop_pc
,
5155 ecs
->event_thread
, &ecs
->ws
);
5157 if (handle_stop_requested (ecs
))
5160 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5162 /* A catchpoint triggered. */
5163 process_event_stop_test (ecs
);
5167 /* If requested, stop when the dynamic linker notifies
5168 gdb of events. This allows the user to get control
5169 and place breakpoints in initializer routines for
5170 dynamically loaded objects (among other things). */
5171 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5172 if (stop_on_solib_events
)
5174 /* Make sure we print "Stopped due to solib-event" in
5176 stop_print_frame
= 1;
5183 /* If we are skipping through a shell, or through shared library
5184 loading that we aren't interested in, resume the program. If
5185 we're running the program normally, also resume. */
5186 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5188 /* Loading of shared libraries might have changed breakpoint
5189 addresses. Make sure new breakpoints are inserted. */
5190 if (stop_soon
== NO_STOP_QUIETLY
)
5191 insert_breakpoints ();
5192 resume (GDB_SIGNAL_0
);
5193 prepare_to_wait (ecs
);
5197 /* But stop if we're attaching or setting up a remote
5199 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5200 || stop_soon
== STOP_QUIETLY_REMOTE
)
5202 infrun_log_debug ("quietly stopped");
5207 internal_error (__FILE__
, __LINE__
,
5208 _("unhandled stop_soon: %d"), (int) stop_soon
);
5210 case TARGET_WAITKIND_SPURIOUS
:
5211 if (handle_stop_requested (ecs
))
5213 context_switch (ecs
);
5214 resume (GDB_SIGNAL_0
);
5215 prepare_to_wait (ecs
);
5218 case TARGET_WAITKIND_THREAD_CREATED
:
5219 if (handle_stop_requested (ecs
))
5221 context_switch (ecs
);
5222 if (!switch_back_to_stepped_thread (ecs
))
5226 case TARGET_WAITKIND_EXITED
:
5227 case TARGET_WAITKIND_SIGNALLED
:
5229 /* Depending on the system, ecs->ptid may point to a thread or
5230 to a process. On some targets, target_mourn_inferior may
5231 need to have access to the just-exited thread. That is the
5232 case of GNU/Linux's "checkpoint" support, for example.
5233 Call the switch_to_xxx routine as appropriate. */
5234 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5236 switch_to_thread (thr
);
5239 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5240 switch_to_inferior_no_thread (inf
);
5243 handle_vfork_child_exec_or_exit (0);
5244 target_terminal::ours (); /* Must do this before mourn anyway. */
5246 /* Clearing any previous state of convenience variables. */
5247 clear_exit_convenience_vars ();
5249 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5251 /* Record the exit code in the convenience variable $_exitcode, so
5252 that the user can inspect this again later. */
5253 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5254 (LONGEST
) ecs
->ws
.value
.integer
);
5256 /* Also record this in the inferior itself. */
5257 current_inferior ()->has_exit_code
= 1;
5258 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5260 /* Support the --return-child-result option. */
5261 return_child_result_value
= ecs
->ws
.value
.integer
;
5263 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5267 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5269 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5271 /* Set the value of the internal variable $_exitsignal,
5272 which holds the signal uncaught by the inferior. */
5273 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5274 gdbarch_gdb_signal_to_target (gdbarch
,
5275 ecs
->ws
.value
.sig
));
5279 /* We don't have access to the target's method used for
5280 converting between signal numbers (GDB's internal
5281 representation <-> target's representation).
5282 Therefore, we cannot do a good job at displaying this
5283 information to the user. It's better to just warn
5284 her about it (if infrun debugging is enabled), and
5286 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5290 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5293 gdb_flush (gdb_stdout
);
5294 target_mourn_inferior (inferior_ptid
);
5295 stop_print_frame
= 0;
5299 case TARGET_WAITKIND_FORKED
:
5300 case TARGET_WAITKIND_VFORKED
:
5301 /* Check whether the inferior is displaced stepping. */
5303 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5304 struct gdbarch
*gdbarch
= regcache
->arch ();
5306 /* If checking displaced stepping is supported, and thread
5307 ecs->ptid is displaced stepping. */
5308 if (displaced_step_in_progress (ecs
->event_thread
))
5310 struct inferior
*parent_inf
5311 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5312 struct regcache
*child_regcache
;
5313 CORE_ADDR parent_pc
;
5315 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5317 // struct displaced_step_inferior_state *displaced
5318 // = get_displaced_stepping_state (parent_inf);
5320 /* Restore scratch pad for child process. */
5321 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5322 // FIXME: we should restore all the buffers that were currently in use
5325 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5326 indicating that the displaced stepping of syscall instruction
5327 has been done. Perform cleanup for parent process here. Note
5328 that this operation also cleans up the child process for vfork,
5329 because their pages are shared. */
5330 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5331 /* Start a new step-over in another thread if there's one
5335 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5336 the child's PC is also within the scratchpad. Set the child's PC
5337 to the parent's PC value, which has already been fixed up.
5338 FIXME: we use the parent's aspace here, although we're touching
5339 the child, because the child hasn't been added to the inferior
5340 list yet at this point. */
5343 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5344 ecs
->ws
.value
.related_pid
,
5346 parent_inf
->aspace
);
5347 /* Read PC value of parent process. */
5348 parent_pc
= regcache_read_pc (regcache
);
5350 if (debug_displaced
)
5351 fprintf_unfiltered (gdb_stdlog
,
5352 "displaced: write child pc from %s to %s\n",
5354 regcache_read_pc (child_regcache
)),
5355 paddress (gdbarch
, parent_pc
));
5357 regcache_write_pc (child_regcache
, parent_pc
);
5361 context_switch (ecs
);
5363 /* Immediately detach breakpoints from the child before there's
5364 any chance of letting the user delete breakpoints from the
5365 breakpoint lists. If we don't do this early, it's easy to
5366 leave left over traps in the child, vis: "break foo; catch
5367 fork; c; <fork>; del; c; <child calls foo>". We only follow
5368 the fork on the last `continue', and by that time the
5369 breakpoint at "foo" is long gone from the breakpoint table.
5370 If we vforked, then we don't need to unpatch here, since both
5371 parent and child are sharing the same memory pages; we'll
5372 need to unpatch at follow/detach time instead to be certain
5373 that new breakpoints added between catchpoint hit time and
5374 vfork follow are detached. */
5375 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5377 /* This won't actually modify the breakpoint list, but will
5378 physically remove the breakpoints from the child. */
5379 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5382 delete_just_stopped_threads_single_step_breakpoints ();
5384 /* In case the event is caught by a catchpoint, remember that
5385 the event is to be followed at the next resume of the thread,
5386 and not immediately. */
5387 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5389 ecs
->event_thread
->suspend
.stop_pc
5390 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5392 ecs
->event_thread
->control
.stop_bpstat
5393 = bpstat_stop_status (get_current_regcache ()->aspace (),
5394 ecs
->event_thread
->suspend
.stop_pc
,
5395 ecs
->event_thread
, &ecs
->ws
);
5397 if (handle_stop_requested (ecs
))
5400 /* If no catchpoint triggered for this, then keep going. Note
5401 that we're interested in knowing the bpstat actually causes a
5402 stop, not just if it may explain the signal. Software
5403 watchpoints, for example, always appear in the bpstat. */
5404 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5407 = (follow_fork_mode_string
== follow_fork_mode_child
);
5409 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5411 process_stratum_target
*targ
5412 = ecs
->event_thread
->inf
->process_target ();
5414 bool should_resume
= follow_fork ();
5416 /* Note that one of these may be an invalid pointer,
5417 depending on detach_fork. */
5418 thread_info
*parent
= ecs
->event_thread
;
5420 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5422 /* At this point, the parent is marked running, and the
5423 child is marked stopped. */
5425 /* If not resuming the parent, mark it stopped. */
5426 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5427 parent
->set_running (false);
5429 /* If resuming the child, mark it running. */
5430 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5431 child
->set_running (true);
5433 /* In non-stop mode, also resume the other branch. */
5434 if (!detach_fork
&& (non_stop
5435 || (sched_multi
&& target_is_non_stop_p ())))
5438 switch_to_thread (parent
);
5440 switch_to_thread (child
);
5442 ecs
->event_thread
= inferior_thread ();
5443 ecs
->ptid
= inferior_ptid
;
5448 switch_to_thread (child
);
5450 switch_to_thread (parent
);
5452 ecs
->event_thread
= inferior_thread ();
5453 ecs
->ptid
= inferior_ptid
;
5461 process_event_stop_test (ecs
);
5464 case TARGET_WAITKIND_VFORK_DONE
:
5465 /* Done with the shared memory region. Re-insert breakpoints in
5466 the parent, and keep going. */
5468 context_switch (ecs
);
5470 current_inferior ()->waiting_for_vfork_done
= 0;
5471 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5473 if (handle_stop_requested (ecs
))
5476 /* This also takes care of reinserting breakpoints in the
5477 previously locked inferior. */
5481 case TARGET_WAITKIND_EXECD
:
5483 /* Note we can't read registers yet (the stop_pc), because we
5484 don't yet know the inferior's post-exec architecture.
5485 'stop_pc' is explicitly read below instead. */
5486 switch_to_thread_no_regs (ecs
->event_thread
);
5488 /* Do whatever is necessary to the parent branch of the vfork. */
5489 handle_vfork_child_exec_or_exit (1);
5491 /* This causes the eventpoints and symbol table to be reset.
5492 Must do this now, before trying to determine whether to
5494 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5496 /* In follow_exec we may have deleted the original thread and
5497 created a new one. Make sure that the event thread is the
5498 execd thread for that case (this is a nop otherwise). */
5499 ecs
->event_thread
= inferior_thread ();
5501 ecs
->event_thread
->suspend
.stop_pc
5502 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5504 ecs
->event_thread
->control
.stop_bpstat
5505 = bpstat_stop_status (get_current_regcache ()->aspace (),
5506 ecs
->event_thread
->suspend
.stop_pc
,
5507 ecs
->event_thread
, &ecs
->ws
);
5509 /* Note that this may be referenced from inside
5510 bpstat_stop_status above, through inferior_has_execd. */
5511 xfree (ecs
->ws
.value
.execd_pathname
);
5512 ecs
->ws
.value
.execd_pathname
= NULL
;
5514 if (handle_stop_requested (ecs
))
5517 /* If no catchpoint triggered for this, then keep going. */
5518 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5520 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5524 process_event_stop_test (ecs
);
5527 /* Be careful not to try to gather much state about a thread
5528 that's in a syscall. It's frequently a losing proposition. */
5529 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5530 /* Getting the current syscall number. */
5531 if (handle_syscall_event (ecs
) == 0)
5532 process_event_stop_test (ecs
);
5535 /* Before examining the threads further, step this thread to
5536 get it entirely out of the syscall. (We get notice of the
5537 event when the thread is just on the verge of exiting a
5538 syscall. Stepping one instruction seems to get it back
5540 case TARGET_WAITKIND_SYSCALL_RETURN
:
5541 if (handle_syscall_event (ecs
) == 0)
5542 process_event_stop_test (ecs
);
5545 case TARGET_WAITKIND_STOPPED
:
5546 handle_signal_stop (ecs
);
5549 case TARGET_WAITKIND_NO_HISTORY
:
5550 /* Reverse execution: target ran out of history info. */
5552 /* Switch to the stopped thread. */
5553 context_switch (ecs
);
5554 infrun_log_debug ("stopped");
5556 delete_just_stopped_threads_single_step_breakpoints ();
5557 ecs
->event_thread
->suspend
.stop_pc
5558 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5560 if (handle_stop_requested (ecs
))
5563 gdb::observers::no_history
.notify ();
5569 /* Restart threads back to what they were trying to do back when we
5570 paused them for an in-line step-over. The EVENT_THREAD thread is
5574 restart_threads (struct thread_info
*event_thread
)
5576 /* In case the instruction just stepped spawned a new thread. */
5577 update_thread_list ();
5579 for (thread_info
*tp
: all_non_exited_threads ())
5581 switch_to_thread_no_regs (tp
);
5583 if (tp
== event_thread
)
5585 infrun_log_debug ("restart threads: [%s] is event thread",
5586 target_pid_to_str (tp
->ptid
).c_str ());
5590 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5592 infrun_log_debug ("restart threads: [%s] not meant to be running",
5593 target_pid_to_str (tp
->ptid
).c_str ());
5599 infrun_log_debug ("restart threads: [%s] resumed",
5600 target_pid_to_str (tp
->ptid
).c_str ());
5601 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5605 if (thread_is_in_step_over_chain (tp
))
5607 infrun_log_debug ("restart threads: [%s] needs step-over",
5608 target_pid_to_str (tp
->ptid
).c_str ());
5609 gdb_assert (!tp
->resumed
);
5614 if (tp
->suspend
.waitstatus_pending_p
)
5616 infrun_log_debug ("restart threads: [%s] has pending status",
5617 target_pid_to_str (tp
->ptid
).c_str ());
5622 gdb_assert (!tp
->stop_requested
);
5624 /* If some thread needs to start a step-over at this point, it
5625 should still be in the step-over queue, and thus skipped
5627 if (thread_still_needs_step_over (tp
))
5629 internal_error (__FILE__
, __LINE__
,
5630 "thread [%s] needs a step-over, but not in "
5631 "step-over queue\n",
5632 target_pid_to_str (tp
->ptid
).c_str ());
5635 if (currently_stepping (tp
))
5637 infrun_log_debug ("restart threads: [%s] was stepping",
5638 target_pid_to_str (tp
->ptid
).c_str ());
5639 keep_going_stepped_thread (tp
);
5643 struct execution_control_state ecss
;
5644 struct execution_control_state
*ecs
= &ecss
;
5646 infrun_log_debug ("restart threads: [%s] continuing",
5647 target_pid_to_str (tp
->ptid
).c_str ());
5648 reset_ecs (ecs
, tp
);
5649 switch_to_thread (tp
);
5650 keep_going_pass_signal (ecs
);
5655 /* Callback for iterate_over_threads. Find a resumed thread that has
5656 a pending waitstatus. */
5659 resumed_thread_with_pending_status (struct thread_info
*tp
,
5663 && tp
->suspend
.waitstatus_pending_p
);
5666 /* Called when we get an event that may finish an in-line or
5667 out-of-line (displaced stepping) step-over started previously.
5668 Return true if the event is processed and we should go back to the
5669 event loop; false if the caller should continue processing the
5673 finish_step_over (struct execution_control_state
*ecs
)
5675 int had_step_over_info
;
5677 displaced_step_finish (ecs
->event_thread
,
5678 ecs
->event_thread
->suspend
.stop_signal
);
5680 had_step_over_info
= step_over_info_valid_p ();
5682 if (had_step_over_info
)
5684 /* If we're stepping over a breakpoint with all threads locked,
5685 then only the thread that was stepped should be reporting
5687 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5689 clear_step_over_info ();
5692 if (!target_is_non_stop_p ())
5695 /* Start a new step-over in another thread if there's one that
5699 /* If we were stepping over a breakpoint before, and haven't started
5700 a new in-line step-over sequence, then restart all other threads
5701 (except the event thread). We can't do this in all-stop, as then
5702 e.g., we wouldn't be able to issue any other remote packet until
5703 these other threads stop. */
5704 if (had_step_over_info
&& !step_over_info_valid_p ())
5706 struct thread_info
*pending
;
5708 /* If we only have threads with pending statuses, the restart
5709 below won't restart any thread and so nothing re-inserts the
5710 breakpoint we just stepped over. But we need it inserted
5711 when we later process the pending events, otherwise if
5712 another thread has a pending event for this breakpoint too,
5713 we'd discard its event (because the breakpoint that
5714 originally caused the event was no longer inserted). */
5715 context_switch (ecs
);
5716 insert_breakpoints ();
5718 restart_threads (ecs
->event_thread
);
5720 /* If we have events pending, go through handle_inferior_event
5721 again, picking up a pending event at random. This avoids
5722 thread starvation. */
5724 /* But not if we just stepped over a watchpoint in order to let
5725 the instruction execute so we can evaluate its expression.
5726 The set of watchpoints that triggered is recorded in the
5727 breakpoint objects themselves (see bp->watchpoint_triggered).
5728 If we processed another event first, that other event could
5729 clobber this info. */
5730 if (ecs
->event_thread
->stepping_over_watchpoint
)
5733 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5735 if (pending
!= NULL
)
5737 struct thread_info
*tp
= ecs
->event_thread
;
5738 struct regcache
*regcache
;
5740 infrun_log_debug ("found resumed threads with "
5741 "pending events, saving status");
5743 gdb_assert (pending
!= tp
);
5745 /* Record the event thread's event for later. */
5746 save_waitstatus (tp
, &ecs
->ws
);
5747 /* This was cleared early, by handle_inferior_event. Set it
5748 so this pending event is considered by
5752 gdb_assert (!tp
->executing
);
5754 regcache
= get_thread_regcache (tp
);
5755 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5757 infrun_log_debug ("saved stop_pc=%s for %s "
5758 "(currently_stepping=%d)\n",
5759 paddress (target_gdbarch (),
5760 tp
->suspend
.stop_pc
),
5761 target_pid_to_str (tp
->ptid
).c_str (),
5762 currently_stepping (tp
));
5764 /* This in-line step-over finished; clear this so we won't
5765 start a new one. This is what handle_signal_stop would
5766 do, if we returned false. */
5767 tp
->stepping_over_breakpoint
= 0;
5769 /* Wake up the event loop again. */
5770 mark_async_event_handler (infrun_async_inferior_event_token
);
5772 prepare_to_wait (ecs
);
5780 /* Come here when the program has stopped with a signal. */
5783 handle_signal_stop (struct execution_control_state
*ecs
)
5785 struct frame_info
*frame
;
5786 struct gdbarch
*gdbarch
;
5787 int stopped_by_watchpoint
;
5788 enum stop_kind stop_soon
;
5791 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5793 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5795 /* Do we need to clean up the state of a thread that has
5796 completed a displaced single-step? (Doing so usually affects
5797 the PC, so do it here, before we set stop_pc.) */
5798 if (finish_step_over (ecs
))
5801 /* If we either finished a single-step or hit a breakpoint, but
5802 the user wanted this thread to be stopped, pretend we got a
5803 SIG0 (generic unsignaled stop). */
5804 if (ecs
->event_thread
->stop_requested
5805 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5806 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5808 ecs
->event_thread
->suspend
.stop_pc
5809 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5813 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5814 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5816 switch_to_thread (ecs
->event_thread
);
5818 infrun_log_debug ("stop_pc=%s",
5819 paddress (reg_gdbarch
,
5820 ecs
->event_thread
->suspend
.stop_pc
));
5821 if (target_stopped_by_watchpoint ())
5825 infrun_log_debug ("stopped by watchpoint");
5827 if (target_stopped_data_address (current_top_target (), &addr
))
5828 infrun_log_debug ("stopped data address=%s",
5829 paddress (reg_gdbarch
, addr
));
5831 infrun_log_debug ("(no data address available)");
5835 /* This is originated from start_remote(), start_inferior() and
5836 shared libraries hook functions. */
5837 stop_soon
= get_inferior_stop_soon (ecs
);
5838 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5840 context_switch (ecs
);
5841 infrun_log_debug ("quietly stopped");
5842 stop_print_frame
= 1;
5847 /* This originates from attach_command(). We need to overwrite
5848 the stop_signal here, because some kernels don't ignore a
5849 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5850 See more comments in inferior.h. On the other hand, if we
5851 get a non-SIGSTOP, report it to the user - assume the backend
5852 will handle the SIGSTOP if it should show up later.
5854 Also consider that the attach is complete when we see a
5855 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5856 target extended-remote report it instead of a SIGSTOP
5857 (e.g. gdbserver). We already rely on SIGTRAP being our
5858 signal, so this is no exception.
5860 Also consider that the attach is complete when we see a
5861 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5862 the target to stop all threads of the inferior, in case the
5863 low level attach operation doesn't stop them implicitly. If
5864 they weren't stopped implicitly, then the stub will report a
5865 GDB_SIGNAL_0, meaning: stopped for no particular reason
5866 other than GDB's request. */
5867 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5868 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5869 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5870 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5872 stop_print_frame
= 1;
5874 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5878 /* See if something interesting happened to the non-current thread. If
5879 so, then switch to that thread. */
5880 if (ecs
->ptid
!= inferior_ptid
)
5882 infrun_log_debug ("context switch");
5884 context_switch (ecs
);
5886 if (deprecated_context_hook
)
5887 deprecated_context_hook (ecs
->event_thread
->global_num
);
5890 /* At this point, get hold of the now-current thread's frame. */
5891 frame
= get_current_frame ();
5892 gdbarch
= get_frame_arch (frame
);
5894 /* Pull the single step breakpoints out of the target. */
5895 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5897 struct regcache
*regcache
;
5900 regcache
= get_thread_regcache (ecs
->event_thread
);
5901 const address_space
*aspace
= regcache
->aspace ();
5903 pc
= regcache_read_pc (regcache
);
5905 /* However, before doing so, if this single-step breakpoint was
5906 actually for another thread, set this thread up for moving
5908 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5911 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5913 infrun_log_debug ("[%s] hit another thread's single-step "
5915 target_pid_to_str (ecs
->ptid
).c_str ());
5916 ecs
->hit_singlestep_breakpoint
= 1;
5921 infrun_log_debug ("[%s] hit its single-step breakpoint",
5922 target_pid_to_str (ecs
->ptid
).c_str ());
5925 delete_just_stopped_threads_single_step_breakpoints ();
5927 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5928 && ecs
->event_thread
->control
.trap_expected
5929 && ecs
->event_thread
->stepping_over_watchpoint
)
5930 stopped_by_watchpoint
= 0;
5932 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5934 /* If necessary, step over this watchpoint. We'll be back to display
5936 if (stopped_by_watchpoint
5937 && (target_have_steppable_watchpoint
5938 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5940 /* At this point, we are stopped at an instruction which has
5941 attempted to write to a piece of memory under control of
5942 a watchpoint. The instruction hasn't actually executed
5943 yet. If we were to evaluate the watchpoint expression
5944 now, we would get the old value, and therefore no change
5945 would seem to have occurred.
5947 In order to make watchpoints work `right', we really need
5948 to complete the memory write, and then evaluate the
5949 watchpoint expression. We do this by single-stepping the
5952 It may not be necessary to disable the watchpoint to step over
5953 it. For example, the PA can (with some kernel cooperation)
5954 single step over a watchpoint without disabling the watchpoint.
5956 It is far more common to need to disable a watchpoint to step
5957 the inferior over it. If we have non-steppable watchpoints,
5958 we must disable the current watchpoint; it's simplest to
5959 disable all watchpoints.
5961 Any breakpoint at PC must also be stepped over -- if there's
5962 one, it will have already triggered before the watchpoint
5963 triggered, and we either already reported it to the user, or
5964 it didn't cause a stop and we called keep_going. In either
5965 case, if there was a breakpoint at PC, we must be trying to
5967 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5972 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5973 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5974 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5975 ecs
->event_thread
->control
.stop_step
= 0;
5976 stop_print_frame
= 1;
5977 stopped_by_random_signal
= 0;
5978 bpstat stop_chain
= NULL
;
5980 /* Hide inlined functions starting here, unless we just performed stepi or
5981 nexti. After stepi and nexti, always show the innermost frame (not any
5982 inline function call sites). */
5983 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5985 const address_space
*aspace
5986 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5988 /* skip_inline_frames is expensive, so we avoid it if we can
5989 determine that the address is one where functions cannot have
5990 been inlined. This improves performance with inferiors that
5991 load a lot of shared libraries, because the solib event
5992 breakpoint is defined as the address of a function (i.e. not
5993 inline). Note that we have to check the previous PC as well
5994 as the current one to catch cases when we have just
5995 single-stepped off a breakpoint prior to reinstating it.
5996 Note that we're assuming that the code we single-step to is
5997 not inline, but that's not definitive: there's nothing
5998 preventing the event breakpoint function from containing
5999 inlined code, and the single-step ending up there. If the
6000 user had set a breakpoint on that inlined code, the missing
6001 skip_inline_frames call would break things. Fortunately
6002 that's an extremely unlikely scenario. */
6003 if (!pc_at_non_inline_function (aspace
,
6004 ecs
->event_thread
->suspend
.stop_pc
,
6006 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6007 && ecs
->event_thread
->control
.trap_expected
6008 && pc_at_non_inline_function (aspace
,
6009 ecs
->event_thread
->prev_pc
,
6012 stop_chain
= build_bpstat_chain (aspace
,
6013 ecs
->event_thread
->suspend
.stop_pc
,
6015 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6017 /* Re-fetch current thread's frame in case that invalidated
6019 frame
= get_current_frame ();
6020 gdbarch
= get_frame_arch (frame
);
6024 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6025 && ecs
->event_thread
->control
.trap_expected
6026 && gdbarch_single_step_through_delay_p (gdbarch
)
6027 && currently_stepping (ecs
->event_thread
))
6029 /* We're trying to step off a breakpoint. Turns out that we're
6030 also on an instruction that needs to be stepped multiple
6031 times before it's been fully executing. E.g., architectures
6032 with a delay slot. It needs to be stepped twice, once for
6033 the instruction and once for the delay slot. */
6034 int step_through_delay
6035 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6037 if (step_through_delay
)
6038 infrun_log_debug ("step through delay");
6040 if (ecs
->event_thread
->control
.step_range_end
== 0
6041 && step_through_delay
)
6043 /* The user issued a continue when stopped at a breakpoint.
6044 Set up for another trap and get out of here. */
6045 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6049 else if (step_through_delay
)
6051 /* The user issued a step when stopped at a breakpoint.
6052 Maybe we should stop, maybe we should not - the delay
6053 slot *might* correspond to a line of source. In any
6054 case, don't decide that here, just set
6055 ecs->stepping_over_breakpoint, making sure we
6056 single-step again before breakpoints are re-inserted. */
6057 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6061 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6062 handles this event. */
6063 ecs
->event_thread
->control
.stop_bpstat
6064 = bpstat_stop_status (get_current_regcache ()->aspace (),
6065 ecs
->event_thread
->suspend
.stop_pc
,
6066 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6068 /* Following in case break condition called a
6070 stop_print_frame
= 1;
6072 /* This is where we handle "moribund" watchpoints. Unlike
6073 software breakpoints traps, hardware watchpoint traps are
6074 always distinguishable from random traps. If no high-level
6075 watchpoint is associated with the reported stop data address
6076 anymore, then the bpstat does not explain the signal ---
6077 simply make sure to ignore it if `stopped_by_watchpoint' is
6080 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6081 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6083 && stopped_by_watchpoint
)
6085 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6089 /* NOTE: cagney/2003-03-29: These checks for a random signal
6090 at one stage in the past included checks for an inferior
6091 function call's call dummy's return breakpoint. The original
6092 comment, that went with the test, read:
6094 ``End of a stack dummy. Some systems (e.g. Sony news) give
6095 another signal besides SIGTRAP, so check here as well as
6098 If someone ever tries to get call dummys on a
6099 non-executable stack to work (where the target would stop
6100 with something like a SIGSEGV), then those tests might need
6101 to be re-instated. Given, however, that the tests were only
6102 enabled when momentary breakpoints were not being used, I
6103 suspect that it won't be the case.
6105 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6106 be necessary for call dummies on a non-executable stack on
6109 /* See if the breakpoints module can explain the signal. */
6111 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6112 ecs
->event_thread
->suspend
.stop_signal
);
6114 /* Maybe this was a trap for a software breakpoint that has since
6116 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6118 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6119 ecs
->event_thread
->suspend
.stop_pc
))
6121 struct regcache
*regcache
;
6124 /* Re-adjust PC to what the program would see if GDB was not
6126 regcache
= get_thread_regcache (ecs
->event_thread
);
6127 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6130 gdb::optional
<scoped_restore_tmpl
<int>>
6131 restore_operation_disable
;
6133 if (record_full_is_used ())
6134 restore_operation_disable
.emplace
6135 (record_full_gdb_operation_disable_set ());
6137 regcache_write_pc (regcache
,
6138 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6143 /* A delayed software breakpoint event. Ignore the trap. */
6144 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6149 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6150 has since been removed. */
6151 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6153 /* A delayed hardware breakpoint event. Ignore the trap. */
6154 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6159 /* If not, perhaps stepping/nexting can. */
6161 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6162 && currently_stepping (ecs
->event_thread
));
6164 /* Perhaps the thread hit a single-step breakpoint of _another_
6165 thread. Single-step breakpoints are transparent to the
6166 breakpoints module. */
6168 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6170 /* No? Perhaps we got a moribund watchpoint. */
6172 random_signal
= !stopped_by_watchpoint
;
6174 /* Always stop if the user explicitly requested this thread to
6176 if (ecs
->event_thread
->stop_requested
)
6179 infrun_log_debug ("user-requested stop");
6182 /* For the program's own signals, act according to
6183 the signal handling tables. */
6187 /* Signal not for debugging purposes. */
6188 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6189 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6191 infrun_log_debug ("random signal (%s)",
6192 gdb_signal_to_symbol_string (stop_signal
));
6194 stopped_by_random_signal
= 1;
6196 /* Always stop on signals if we're either just gaining control
6197 of the program, or the user explicitly requested this thread
6198 to remain stopped. */
6199 if (stop_soon
!= NO_STOP_QUIETLY
6200 || ecs
->event_thread
->stop_requested
6202 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6208 /* Notify observers the signal has "handle print" set. Note we
6209 returned early above if stopping; normal_stop handles the
6210 printing in that case. */
6211 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6213 /* The signal table tells us to print about this signal. */
6214 target_terminal::ours_for_output ();
6215 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6216 target_terminal::inferior ();
6219 /* Clear the signal if it should not be passed. */
6220 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6221 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6223 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6224 && ecs
->event_thread
->control
.trap_expected
6225 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6227 /* We were just starting a new sequence, attempting to
6228 single-step off of a breakpoint and expecting a SIGTRAP.
6229 Instead this signal arrives. This signal will take us out
6230 of the stepping range so GDB needs to remember to, when
6231 the signal handler returns, resume stepping off that
6233 /* To simplify things, "continue" is forced to use the same
6234 code paths as single-step - set a breakpoint at the
6235 signal return address and then, once hit, step off that
6237 infrun_log_debug ("signal arrived while stepping over breakpoint");
6239 insert_hp_step_resume_breakpoint_at_frame (frame
);
6240 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6241 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6242 ecs
->event_thread
->control
.trap_expected
= 0;
6244 /* If we were nexting/stepping some other thread, switch to
6245 it, so that we don't continue it, losing control. */
6246 if (!switch_back_to_stepped_thread (ecs
))
6251 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6252 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6254 || ecs
->event_thread
->control
.step_range_end
== 1)
6255 && frame_id_eq (get_stack_frame_id (frame
),
6256 ecs
->event_thread
->control
.step_stack_frame_id
)
6257 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6259 /* The inferior is about to take a signal that will take it
6260 out of the single step range. Set a breakpoint at the
6261 current PC (which is presumably where the signal handler
6262 will eventually return) and then allow the inferior to
6265 Note that this is only needed for a signal delivered
6266 while in the single-step range. Nested signals aren't a
6267 problem as they eventually all return. */
6268 infrun_log_debug ("signal may take us out of single-step range");
6270 clear_step_over_info ();
6271 insert_hp_step_resume_breakpoint_at_frame (frame
);
6272 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6273 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6274 ecs
->event_thread
->control
.trap_expected
= 0;
6279 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6280 when either there's a nested signal, or when there's a
6281 pending signal enabled just as the signal handler returns
6282 (leaving the inferior at the step-resume-breakpoint without
6283 actually executing it). Either way continue until the
6284 breakpoint is really hit. */
6286 if (!switch_back_to_stepped_thread (ecs
))
6288 infrun_log_debug ("random signal, keep going");
6295 process_event_stop_test (ecs
);
6298 /* Come here when we've got some debug event / signal we can explain
6299 (IOW, not a random signal), and test whether it should cause a
6300 stop, or whether we should resume the inferior (transparently).
6301 E.g., could be a breakpoint whose condition evaluates false; we
6302 could be still stepping within the line; etc. */
6305 process_event_stop_test (struct execution_control_state
*ecs
)
6307 struct symtab_and_line stop_pc_sal
;
6308 struct frame_info
*frame
;
6309 struct gdbarch
*gdbarch
;
6310 CORE_ADDR jmp_buf_pc
;
6311 struct bpstat_what what
;
6313 /* Handle cases caused by hitting a breakpoint. */
6315 frame
= get_current_frame ();
6316 gdbarch
= get_frame_arch (frame
);
6318 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6320 if (what
.call_dummy
)
6322 stop_stack_dummy
= what
.call_dummy
;
6325 /* A few breakpoint types have callbacks associated (e.g.,
6326 bp_jit_event). Run them now. */
6327 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6329 /* If we hit an internal event that triggers symbol changes, the
6330 current frame will be invalidated within bpstat_what (e.g., if we
6331 hit an internal solib event). Re-fetch it. */
6332 frame
= get_current_frame ();
6333 gdbarch
= get_frame_arch (frame
);
6335 switch (what
.main_action
)
6337 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6338 /* If we hit the breakpoint at longjmp while stepping, we
6339 install a momentary breakpoint at the target of the
6342 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6344 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6346 if (what
.is_longjmp
)
6348 struct value
*arg_value
;
6350 /* If we set the longjmp breakpoint via a SystemTap probe,
6351 then use it to extract the arguments. The destination PC
6352 is the third argument to the probe. */
6353 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6356 jmp_buf_pc
= value_as_address (arg_value
);
6357 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6359 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6360 || !gdbarch_get_longjmp_target (gdbarch
,
6361 frame
, &jmp_buf_pc
))
6363 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6364 "(!gdbarch_get_longjmp_target)");
6369 /* Insert a breakpoint at resume address. */
6370 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6373 check_exception_resume (ecs
, frame
);
6377 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6379 struct frame_info
*init_frame
;
6381 /* There are several cases to consider.
6383 1. The initiating frame no longer exists. In this case we
6384 must stop, because the exception or longjmp has gone too
6387 2. The initiating frame exists, and is the same as the
6388 current frame. We stop, because the exception or longjmp
6391 3. The initiating frame exists and is different from the
6392 current frame. This means the exception or longjmp has
6393 been caught beneath the initiating frame, so keep going.
6395 4. longjmp breakpoint has been placed just to protect
6396 against stale dummy frames and user is not interested in
6397 stopping around longjmps. */
6399 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6401 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6403 delete_exception_resume_breakpoint (ecs
->event_thread
);
6405 if (what
.is_longjmp
)
6407 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6409 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6417 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6421 struct frame_id current_id
6422 = get_frame_id (get_current_frame ());
6423 if (frame_id_eq (current_id
,
6424 ecs
->event_thread
->initiating_frame
))
6426 /* Case 2. Fall through. */
6436 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6438 delete_step_resume_breakpoint (ecs
->event_thread
);
6440 end_stepping_range (ecs
);
6444 case BPSTAT_WHAT_SINGLE
:
6445 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6446 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6447 /* Still need to check other stuff, at least the case where we
6448 are stepping and step out of the right range. */
6451 case BPSTAT_WHAT_STEP_RESUME
:
6452 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6454 delete_step_resume_breakpoint (ecs
->event_thread
);
6455 if (ecs
->event_thread
->control
.proceed_to_finish
6456 && execution_direction
== EXEC_REVERSE
)
6458 struct thread_info
*tp
= ecs
->event_thread
;
6460 /* We are finishing a function in reverse, and just hit the
6461 step-resume breakpoint at the start address of the
6462 function, and we're almost there -- just need to back up
6463 by one more single-step, which should take us back to the
6465 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6469 fill_in_stop_func (gdbarch
, ecs
);
6470 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6471 && execution_direction
== EXEC_REVERSE
)
6473 /* We are stepping over a function call in reverse, and just
6474 hit the step-resume breakpoint at the start address of
6475 the function. Go back to single-stepping, which should
6476 take us back to the function call. */
6477 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6483 case BPSTAT_WHAT_STOP_NOISY
:
6484 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6485 stop_print_frame
= 1;
6487 /* Assume the thread stopped for a breapoint. We'll still check
6488 whether a/the breakpoint is there when the thread is next
6490 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6495 case BPSTAT_WHAT_STOP_SILENT
:
6496 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6497 stop_print_frame
= 0;
6499 /* Assume the thread stopped for a breapoint. We'll still check
6500 whether a/the breakpoint is there when the thread is next
6502 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6506 case BPSTAT_WHAT_HP_STEP_RESUME
:
6507 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6509 delete_step_resume_breakpoint (ecs
->event_thread
);
6510 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6512 /* Back when the step-resume breakpoint was inserted, we
6513 were trying to single-step off a breakpoint. Go back to
6515 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6516 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6522 case BPSTAT_WHAT_KEEP_CHECKING
:
6526 /* If we stepped a permanent breakpoint and we had a high priority
6527 step-resume breakpoint for the address we stepped, but we didn't
6528 hit it, then we must have stepped into the signal handler. The
6529 step-resume was only necessary to catch the case of _not_
6530 stepping into the handler, so delete it, and fall through to
6531 checking whether the step finished. */
6532 if (ecs
->event_thread
->stepped_breakpoint
)
6534 struct breakpoint
*sr_bp
6535 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6538 && sr_bp
->loc
->permanent
6539 && sr_bp
->type
== bp_hp_step_resume
6540 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6542 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6543 delete_step_resume_breakpoint (ecs
->event_thread
);
6544 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6548 /* We come here if we hit a breakpoint but should not stop for it.
6549 Possibly we also were stepping and should stop for that. So fall
6550 through and test for stepping. But, if not stepping, do not
6553 /* In all-stop mode, if we're currently stepping but have stopped in
6554 some other thread, we need to switch back to the stepped thread. */
6555 if (switch_back_to_stepped_thread (ecs
))
6558 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6560 infrun_log_debug ("step-resume breakpoint is inserted");
6562 /* Having a step-resume breakpoint overrides anything
6563 else having to do with stepping commands until
6564 that breakpoint is reached. */
6569 if (ecs
->event_thread
->control
.step_range_end
== 0)
6571 infrun_log_debug ("no stepping, continue");
6572 /* Likewise if we aren't even stepping. */
6577 /* Re-fetch current thread's frame in case the code above caused
6578 the frame cache to be re-initialized, making our FRAME variable
6579 a dangling pointer. */
6580 frame
= get_current_frame ();
6581 gdbarch
= get_frame_arch (frame
);
6582 fill_in_stop_func (gdbarch
, ecs
);
6584 /* If stepping through a line, keep going if still within it.
6586 Note that step_range_end is the address of the first instruction
6587 beyond the step range, and NOT the address of the last instruction
6590 Note also that during reverse execution, we may be stepping
6591 through a function epilogue and therefore must detect when
6592 the current-frame changes in the middle of a line. */
6594 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6596 && (execution_direction
!= EXEC_REVERSE
6597 || frame_id_eq (get_frame_id (frame
),
6598 ecs
->event_thread
->control
.step_frame_id
)))
6601 ("stepping inside range [%s-%s]",
6602 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6603 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6605 /* Tentatively re-enable range stepping; `resume' disables it if
6606 necessary (e.g., if we're stepping over a breakpoint or we
6607 have software watchpoints). */
6608 ecs
->event_thread
->control
.may_range_step
= 1;
6610 /* When stepping backward, stop at beginning of line range
6611 (unless it's the function entry point, in which case
6612 keep going back to the call point). */
6613 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6614 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6615 && stop_pc
!= ecs
->stop_func_start
6616 && execution_direction
== EXEC_REVERSE
)
6617 end_stepping_range (ecs
);
6624 /* We stepped out of the stepping range. */
6626 /* If we are stepping at the source level and entered the runtime
6627 loader dynamic symbol resolution code...
6629 EXEC_FORWARD: we keep on single stepping until we exit the run
6630 time loader code and reach the callee's address.
6632 EXEC_REVERSE: we've already executed the callee (backward), and
6633 the runtime loader code is handled just like any other
6634 undebuggable function call. Now we need only keep stepping
6635 backward through the trampoline code, and that's handled further
6636 down, so there is nothing for us to do here. */
6638 if (execution_direction
!= EXEC_REVERSE
6639 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6640 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6642 CORE_ADDR pc_after_resolver
=
6643 gdbarch_skip_solib_resolver (gdbarch
,
6644 ecs
->event_thread
->suspend
.stop_pc
);
6646 infrun_log_debug ("stepped into dynsym resolve code");
6648 if (pc_after_resolver
)
6650 /* Set up a step-resume breakpoint at the address
6651 indicated by SKIP_SOLIB_RESOLVER. */
6652 symtab_and_line sr_sal
;
6653 sr_sal
.pc
= pc_after_resolver
;
6654 sr_sal
.pspace
= get_frame_program_space (frame
);
6656 insert_step_resume_breakpoint_at_sal (gdbarch
,
6657 sr_sal
, null_frame_id
);
6664 /* Step through an indirect branch thunk. */
6665 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6666 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6667 ecs
->event_thread
->suspend
.stop_pc
))
6669 infrun_log_debug ("stepped into indirect branch thunk");
6674 if (ecs
->event_thread
->control
.step_range_end
!= 1
6675 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6676 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6677 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6679 infrun_log_debug ("stepped into signal trampoline");
6680 /* The inferior, while doing a "step" or "next", has ended up in
6681 a signal trampoline (either by a signal being delivered or by
6682 the signal handler returning). Just single-step until the
6683 inferior leaves the trampoline (either by calling the handler
6689 /* If we're in the return path from a shared library trampoline,
6690 we want to proceed through the trampoline when stepping. */
6691 /* macro/2012-04-25: This needs to come before the subroutine
6692 call check below as on some targets return trampolines look
6693 like subroutine calls (MIPS16 return thunks). */
6694 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6695 ecs
->event_thread
->suspend
.stop_pc
,
6696 ecs
->stop_func_name
)
6697 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6699 /* Determine where this trampoline returns. */
6700 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6701 CORE_ADDR real_stop_pc
6702 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6704 infrun_log_debug ("stepped into solib return tramp");
6706 /* Only proceed through if we know where it's going. */
6709 /* And put the step-breakpoint there and go until there. */
6710 symtab_and_line sr_sal
;
6711 sr_sal
.pc
= real_stop_pc
;
6712 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6713 sr_sal
.pspace
= get_frame_program_space (frame
);
6715 /* Do not specify what the fp should be when we stop since
6716 on some machines the prologue is where the new fp value
6718 insert_step_resume_breakpoint_at_sal (gdbarch
,
6719 sr_sal
, null_frame_id
);
6721 /* Restart without fiddling with the step ranges or
6728 /* Check for subroutine calls. The check for the current frame
6729 equalling the step ID is not necessary - the check of the
6730 previous frame's ID is sufficient - but it is a common case and
6731 cheaper than checking the previous frame's ID.
6733 NOTE: frame_id_eq will never report two invalid frame IDs as
6734 being equal, so to get into this block, both the current and
6735 previous frame must have valid frame IDs. */
6736 /* The outer_frame_id check is a heuristic to detect stepping
6737 through startup code. If we step over an instruction which
6738 sets the stack pointer from an invalid value to a valid value,
6739 we may detect that as a subroutine call from the mythical
6740 "outermost" function. This could be fixed by marking
6741 outermost frames as !stack_p,code_p,special_p. Then the
6742 initial outermost frame, before sp was valid, would
6743 have code_addr == &_start. See the comment in frame_id_eq
6745 if (!frame_id_eq (get_stack_frame_id (frame
),
6746 ecs
->event_thread
->control
.step_stack_frame_id
)
6747 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6748 ecs
->event_thread
->control
.step_stack_frame_id
)
6749 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6751 || (ecs
->event_thread
->control
.step_start_function
6752 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6754 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6755 CORE_ADDR real_stop_pc
;
6757 infrun_log_debug ("stepped into subroutine");
6759 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6761 /* I presume that step_over_calls is only 0 when we're
6762 supposed to be stepping at the assembly language level
6763 ("stepi"). Just stop. */
6764 /* And this works the same backward as frontward. MVS */
6765 end_stepping_range (ecs
);
6769 /* Reverse stepping through solib trampolines. */
6771 if (execution_direction
== EXEC_REVERSE
6772 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6773 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6774 || (ecs
->stop_func_start
== 0
6775 && in_solib_dynsym_resolve_code (stop_pc
))))
6777 /* Any solib trampoline code can be handled in reverse
6778 by simply continuing to single-step. We have already
6779 executed the solib function (backwards), and a few
6780 steps will take us back through the trampoline to the
6786 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6788 /* We're doing a "next".
6790 Normal (forward) execution: set a breakpoint at the
6791 callee's return address (the address at which the caller
6794 Reverse (backward) execution. set the step-resume
6795 breakpoint at the start of the function that we just
6796 stepped into (backwards), and continue to there. When we
6797 get there, we'll need to single-step back to the caller. */
6799 if (execution_direction
== EXEC_REVERSE
)
6801 /* If we're already at the start of the function, we've either
6802 just stepped backward into a single instruction function,
6803 or stepped back out of a signal handler to the first instruction
6804 of the function. Just keep going, which will single-step back
6806 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6808 /* Normal function call return (static or dynamic). */
6809 symtab_and_line sr_sal
;
6810 sr_sal
.pc
= ecs
->stop_func_start
;
6811 sr_sal
.pspace
= get_frame_program_space (frame
);
6812 insert_step_resume_breakpoint_at_sal (gdbarch
,
6813 sr_sal
, null_frame_id
);
6817 insert_step_resume_breakpoint_at_caller (frame
);
6823 /* If we are in a function call trampoline (a stub between the
6824 calling routine and the real function), locate the real
6825 function. That's what tells us (a) whether we want to step
6826 into it at all, and (b) what prologue we want to run to the
6827 end of, if we do step into it. */
6828 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6829 if (real_stop_pc
== 0)
6830 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6831 if (real_stop_pc
!= 0)
6832 ecs
->stop_func_start
= real_stop_pc
;
6834 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6836 symtab_and_line sr_sal
;
6837 sr_sal
.pc
= ecs
->stop_func_start
;
6838 sr_sal
.pspace
= get_frame_program_space (frame
);
6840 insert_step_resume_breakpoint_at_sal (gdbarch
,
6841 sr_sal
, null_frame_id
);
6846 /* If we have line number information for the function we are
6847 thinking of stepping into and the function isn't on the skip
6850 If there are several symtabs at that PC (e.g. with include
6851 files), just want to know whether *any* of them have line
6852 numbers. find_pc_line handles this. */
6854 struct symtab_and_line tmp_sal
;
6856 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6857 if (tmp_sal
.line
!= 0
6858 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6860 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6862 if (execution_direction
== EXEC_REVERSE
)
6863 handle_step_into_function_backward (gdbarch
, ecs
);
6865 handle_step_into_function (gdbarch
, ecs
);
6870 /* If we have no line number and the step-stop-if-no-debug is
6871 set, we stop the step so that the user has a chance to switch
6872 in assembly mode. */
6873 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6874 && step_stop_if_no_debug
)
6876 end_stepping_range (ecs
);
6880 if (execution_direction
== EXEC_REVERSE
)
6882 /* If we're already at the start of the function, we've either just
6883 stepped backward into a single instruction function without line
6884 number info, or stepped back out of a signal handler to the first
6885 instruction of the function without line number info. Just keep
6886 going, which will single-step back to the caller. */
6887 if (ecs
->stop_func_start
!= stop_pc
)
6889 /* Set a breakpoint at callee's start address.
6890 From there we can step once and be back in the caller. */
6891 symtab_and_line sr_sal
;
6892 sr_sal
.pc
= ecs
->stop_func_start
;
6893 sr_sal
.pspace
= get_frame_program_space (frame
);
6894 insert_step_resume_breakpoint_at_sal (gdbarch
,
6895 sr_sal
, null_frame_id
);
6899 /* Set a breakpoint at callee's return address (the address
6900 at which the caller will resume). */
6901 insert_step_resume_breakpoint_at_caller (frame
);
6907 /* Reverse stepping through solib trampolines. */
6909 if (execution_direction
== EXEC_REVERSE
6910 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6912 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6914 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6915 || (ecs
->stop_func_start
== 0
6916 && in_solib_dynsym_resolve_code (stop_pc
)))
6918 /* Any solib trampoline code can be handled in reverse
6919 by simply continuing to single-step. We have already
6920 executed the solib function (backwards), and a few
6921 steps will take us back through the trampoline to the
6926 else if (in_solib_dynsym_resolve_code (stop_pc
))
6928 /* Stepped backward into the solib dynsym resolver.
6929 Set a breakpoint at its start and continue, then
6930 one more step will take us out. */
6931 symtab_and_line sr_sal
;
6932 sr_sal
.pc
= ecs
->stop_func_start
;
6933 sr_sal
.pspace
= get_frame_program_space (frame
);
6934 insert_step_resume_breakpoint_at_sal (gdbarch
,
6935 sr_sal
, null_frame_id
);
6941 /* This always returns the sal for the inner-most frame when we are in a
6942 stack of inlined frames, even if GDB actually believes that it is in a
6943 more outer frame. This is checked for below by calls to
6944 inline_skipped_frames. */
6945 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6947 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6948 the trampoline processing logic, however, there are some trampolines
6949 that have no names, so we should do trampoline handling first. */
6950 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6951 && ecs
->stop_func_name
== NULL
6952 && stop_pc_sal
.line
== 0)
6954 infrun_log_debug ("stepped into undebuggable function");
6956 /* The inferior just stepped into, or returned to, an
6957 undebuggable function (where there is no debugging information
6958 and no line number corresponding to the address where the
6959 inferior stopped). Since we want to skip this kind of code,
6960 we keep going until the inferior returns from this
6961 function - unless the user has asked us not to (via
6962 set step-mode) or we no longer know how to get back
6963 to the call site. */
6964 if (step_stop_if_no_debug
6965 || !frame_id_p (frame_unwind_caller_id (frame
)))
6967 /* If we have no line number and the step-stop-if-no-debug
6968 is set, we stop the step so that the user has a chance to
6969 switch in assembly mode. */
6970 end_stepping_range (ecs
);
6975 /* Set a breakpoint at callee's return address (the address
6976 at which the caller will resume). */
6977 insert_step_resume_breakpoint_at_caller (frame
);
6983 if (ecs
->event_thread
->control
.step_range_end
== 1)
6985 /* It is stepi or nexti. We always want to stop stepping after
6987 infrun_log_debug ("stepi/nexti");
6988 end_stepping_range (ecs
);
6992 if (stop_pc_sal
.line
== 0)
6994 /* We have no line number information. That means to stop
6995 stepping (does this always happen right after one instruction,
6996 when we do "s" in a function with no line numbers,
6997 or can this happen as a result of a return or longjmp?). */
6998 infrun_log_debug ("line number info");
6999 end_stepping_range (ecs
);
7003 /* Look for "calls" to inlined functions, part one. If the inline
7004 frame machinery detected some skipped call sites, we have entered
7005 a new inline function. */
7007 if (frame_id_eq (get_frame_id (get_current_frame ()),
7008 ecs
->event_thread
->control
.step_frame_id
)
7009 && inline_skipped_frames (ecs
->event_thread
))
7011 infrun_log_debug ("stepped into inlined function");
7013 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7015 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7017 /* For "step", we're going to stop. But if the call site
7018 for this inlined function is on the same source line as
7019 we were previously stepping, go down into the function
7020 first. Otherwise stop at the call site. */
7022 if (call_sal
.line
== ecs
->event_thread
->current_line
7023 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7025 step_into_inline_frame (ecs
->event_thread
);
7026 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7033 end_stepping_range (ecs
);
7038 /* For "next", we should stop at the call site if it is on a
7039 different source line. Otherwise continue through the
7040 inlined function. */
7041 if (call_sal
.line
== ecs
->event_thread
->current_line
7042 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7045 end_stepping_range (ecs
);
7050 /* Look for "calls" to inlined functions, part two. If we are still
7051 in the same real function we were stepping through, but we have
7052 to go further up to find the exact frame ID, we are stepping
7053 through a more inlined call beyond its call site. */
7055 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7056 && !frame_id_eq (get_frame_id (get_current_frame ()),
7057 ecs
->event_thread
->control
.step_frame_id
)
7058 && stepped_in_from (get_current_frame (),
7059 ecs
->event_thread
->control
.step_frame_id
))
7061 infrun_log_debug ("stepping through inlined function");
7063 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7064 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7067 end_stepping_range (ecs
);
7071 bool refresh_step_info
= true;
7072 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7073 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7074 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7076 if (stop_pc_sal
.is_stmt
)
7078 /* We are at the start of a different line. So stop. Note that
7079 we don't stop if we step into the middle of a different line.
7080 That is said to make things like for (;;) statements work
7082 infrun_log_debug ("infrun: stepped to a different line\n");
7083 end_stepping_range (ecs
);
7086 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7087 ecs
->event_thread
->control
.step_frame_id
))
7089 /* We are at the start of a different line, however, this line is
7090 not marked as a statement, and we have not changed frame. We
7091 ignore this line table entry, and continue stepping forward,
7092 looking for a better place to stop. */
7093 refresh_step_info
= false;
7094 infrun_log_debug ("infrun: stepped to a different line, but "
7095 "it's not the start of a statement\n");
7099 /* We aren't done stepping.
7101 Optimize by setting the stepping range to the line.
7102 (We might not be in the original line, but if we entered a
7103 new line in mid-statement, we continue stepping. This makes
7104 things like for(;;) statements work better.)
7106 If we entered a SAL that indicates a non-statement line table entry,
7107 then we update the stepping range, but we don't update the step info,
7108 which includes things like the line number we are stepping away from.
7109 This means we will stop when we find a line table entry that is marked
7110 as is-statement, even if it matches the non-statement one we just
7113 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7114 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7115 ecs
->event_thread
->control
.may_range_step
= 1;
7116 if (refresh_step_info
)
7117 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7119 infrun_log_debug ("keep going");
7123 /* In all-stop mode, if we're currently stepping but have stopped in
7124 some other thread, we may need to switch back to the stepped
7125 thread. Returns true we set the inferior running, false if we left
7126 it stopped (and the event needs further processing). */
7129 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7131 if (!target_is_non_stop_p ())
7133 struct thread_info
*stepping_thread
;
7135 /* If any thread is blocked on some internal breakpoint, and we
7136 simply need to step over that breakpoint to get it going
7137 again, do that first. */
7139 /* However, if we see an event for the stepping thread, then we
7140 know all other threads have been moved past their breakpoints
7141 already. Let the caller check whether the step is finished,
7142 etc., before deciding to move it past a breakpoint. */
7143 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7146 /* Check if the current thread is blocked on an incomplete
7147 step-over, interrupted by a random signal. */
7148 if (ecs
->event_thread
->control
.trap_expected
7149 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7151 infrun_log_debug ("need to finish step-over of [%s]",
7152 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7157 /* Check if the current thread is blocked by a single-step
7158 breakpoint of another thread. */
7159 if (ecs
->hit_singlestep_breakpoint
)
7161 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7162 target_pid_to_str (ecs
->ptid
).c_str ());
7167 /* If this thread needs yet another step-over (e.g., stepping
7168 through a delay slot), do it first before moving on to
7170 if (thread_still_needs_step_over (ecs
->event_thread
))
7173 ("thread [%s] still needs step-over",
7174 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7179 /* If scheduler locking applies even if not stepping, there's no
7180 need to walk over threads. Above we've checked whether the
7181 current thread is stepping. If some other thread not the
7182 event thread is stepping, then it must be that scheduler
7183 locking is not in effect. */
7184 if (schedlock_applies (ecs
->event_thread
))
7187 /* Otherwise, we no longer expect a trap in the current thread.
7188 Clear the trap_expected flag before switching back -- this is
7189 what keep_going does as well, if we call it. */
7190 ecs
->event_thread
->control
.trap_expected
= 0;
7192 /* Likewise, clear the signal if it should not be passed. */
7193 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7194 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7196 /* Do all pending step-overs before actually proceeding with
7198 if (start_step_over ())
7200 prepare_to_wait (ecs
);
7204 /* Look for the stepping/nexting thread. */
7205 stepping_thread
= NULL
;
7207 for (thread_info
*tp
: all_non_exited_threads ())
7209 switch_to_thread_no_regs (tp
);
7211 /* Ignore threads of processes the caller is not
7214 && (tp
->inf
->process_target () != ecs
->target
7215 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7218 /* When stepping over a breakpoint, we lock all threads
7219 except the one that needs to move past the breakpoint.
7220 If a non-event thread has this set, the "incomplete
7221 step-over" check above should have caught it earlier. */
7222 if (tp
->control
.trap_expected
)
7224 internal_error (__FILE__
, __LINE__
,
7225 "[%s] has inconsistent state: "
7226 "trap_expected=%d\n",
7227 target_pid_to_str (tp
->ptid
).c_str (),
7228 tp
->control
.trap_expected
);
7231 /* Did we find the stepping thread? */
7232 if (tp
->control
.step_range_end
)
7234 /* Yep. There should only one though. */
7235 gdb_assert (stepping_thread
== NULL
);
7237 /* The event thread is handled at the top, before we
7239 gdb_assert (tp
!= ecs
->event_thread
);
7241 /* If some thread other than the event thread is
7242 stepping, then scheduler locking can't be in effect,
7243 otherwise we wouldn't have resumed the current event
7244 thread in the first place. */
7245 gdb_assert (!schedlock_applies (tp
));
7247 stepping_thread
= tp
;
7251 if (stepping_thread
!= NULL
)
7253 infrun_log_debug ("switching back to stepped thread");
7255 if (keep_going_stepped_thread (stepping_thread
))
7257 prepare_to_wait (ecs
);
7262 switch_to_thread (ecs
->event_thread
);
7268 /* Set a previously stepped thread back to stepping. Returns true on
7269 success, false if the resume is not possible (e.g., the thread
7273 keep_going_stepped_thread (struct thread_info
*tp
)
7275 struct frame_info
*frame
;
7276 struct execution_control_state ecss
;
7277 struct execution_control_state
*ecs
= &ecss
;
7279 /* If the stepping thread exited, then don't try to switch back and
7280 resume it, which could fail in several different ways depending
7281 on the target. Instead, just keep going.
7283 We can find a stepping dead thread in the thread list in two
7286 - The target supports thread exit events, and when the target
7287 tries to delete the thread from the thread list, inferior_ptid
7288 pointed at the exiting thread. In such case, calling
7289 delete_thread does not really remove the thread from the list;
7290 instead, the thread is left listed, with 'exited' state.
7292 - The target's debug interface does not support thread exit
7293 events, and so we have no idea whatsoever if the previously
7294 stepping thread is still alive. For that reason, we need to
7295 synchronously query the target now. */
7297 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7299 infrun_log_debug ("not resuming previously stepped thread, it has "
7306 infrun_log_debug ("resuming previously stepped thread");
7308 reset_ecs (ecs
, tp
);
7309 switch_to_thread (tp
);
7311 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7312 frame
= get_current_frame ();
7314 /* If the PC of the thread we were trying to single-step has
7315 changed, then that thread has trapped or been signaled, but the
7316 event has not been reported to GDB yet. Re-poll the target
7317 looking for this particular thread's event (i.e. temporarily
7318 enable schedlock) by:
7320 - setting a break at the current PC
7321 - resuming that particular thread, only (by setting trap
7324 This prevents us continuously moving the single-step breakpoint
7325 forward, one instruction at a time, overstepping. */
7327 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7331 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7332 paddress (target_gdbarch (), tp
->prev_pc
),
7333 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7335 /* Clear the info of the previous step-over, as it's no longer
7336 valid (if the thread was trying to step over a breakpoint, it
7337 has already succeeded). It's what keep_going would do too,
7338 if we called it. Do this before trying to insert the sss
7339 breakpoint, otherwise if we were previously trying to step
7340 over this exact address in another thread, the breakpoint is
7342 clear_step_over_info ();
7343 tp
->control
.trap_expected
= 0;
7345 insert_single_step_breakpoint (get_frame_arch (frame
),
7346 get_frame_address_space (frame
),
7347 tp
->suspend
.stop_pc
);
7350 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7351 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7355 infrun_log_debug ("expected thread still hasn't advanced");
7357 keep_going_pass_signal (ecs
);
7362 /* Is thread TP in the middle of (software or hardware)
7363 single-stepping? (Note the result of this function must never be
7364 passed directly as target_resume's STEP parameter.) */
7367 currently_stepping (struct thread_info
*tp
)
7369 return ((tp
->control
.step_range_end
7370 && tp
->control
.step_resume_breakpoint
== NULL
)
7371 || tp
->control
.trap_expected
7372 || tp
->stepped_breakpoint
7373 || bpstat_should_step ());
7376 /* Inferior has stepped into a subroutine call with source code that
7377 we should not step over. Do step to the first line of code in
7381 handle_step_into_function (struct gdbarch
*gdbarch
,
7382 struct execution_control_state
*ecs
)
7384 fill_in_stop_func (gdbarch
, ecs
);
7386 compunit_symtab
*cust
7387 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7388 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7389 ecs
->stop_func_start
7390 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7392 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7393 /* Use the step_resume_break to step until the end of the prologue,
7394 even if that involves jumps (as it seems to on the vax under
7396 /* If the prologue ends in the middle of a source line, continue to
7397 the end of that source line (if it is still within the function).
7398 Otherwise, just go to end of prologue. */
7399 if (stop_func_sal
.end
7400 && stop_func_sal
.pc
!= ecs
->stop_func_start
7401 && stop_func_sal
.end
< ecs
->stop_func_end
)
7402 ecs
->stop_func_start
= stop_func_sal
.end
;
7404 /* Architectures which require breakpoint adjustment might not be able
7405 to place a breakpoint at the computed address. If so, the test
7406 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7407 ecs->stop_func_start to an address at which a breakpoint may be
7408 legitimately placed.
7410 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7411 made, GDB will enter an infinite loop when stepping through
7412 optimized code consisting of VLIW instructions which contain
7413 subinstructions corresponding to different source lines. On
7414 FR-V, it's not permitted to place a breakpoint on any but the
7415 first subinstruction of a VLIW instruction. When a breakpoint is
7416 set, GDB will adjust the breakpoint address to the beginning of
7417 the VLIW instruction. Thus, we need to make the corresponding
7418 adjustment here when computing the stop address. */
7420 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7422 ecs
->stop_func_start
7423 = gdbarch_adjust_breakpoint_address (gdbarch
,
7424 ecs
->stop_func_start
);
7427 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7429 /* We are already there: stop now. */
7430 end_stepping_range (ecs
);
7435 /* Put the step-breakpoint there and go until there. */
7436 symtab_and_line sr_sal
;
7437 sr_sal
.pc
= ecs
->stop_func_start
;
7438 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7439 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7441 /* Do not specify what the fp should be when we stop since on
7442 some machines the prologue is where the new fp value is
7444 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7446 /* And make sure stepping stops right away then. */
7447 ecs
->event_thread
->control
.step_range_end
7448 = ecs
->event_thread
->control
.step_range_start
;
7453 /* Inferior has stepped backward into a subroutine call with source
7454 code that we should not step over. Do step to the beginning of the
7455 last line of code in it. */
7458 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7459 struct execution_control_state
*ecs
)
7461 struct compunit_symtab
*cust
;
7462 struct symtab_and_line stop_func_sal
;
7464 fill_in_stop_func (gdbarch
, ecs
);
7466 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7467 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7468 ecs
->stop_func_start
7469 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7471 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7473 /* OK, we're just going to keep stepping here. */
7474 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7476 /* We're there already. Just stop stepping now. */
7477 end_stepping_range (ecs
);
7481 /* Else just reset the step range and keep going.
7482 No step-resume breakpoint, they don't work for
7483 epilogues, which can have multiple entry paths. */
7484 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7485 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7491 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7492 This is used to both functions and to skip over code. */
7495 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7496 struct symtab_and_line sr_sal
,
7497 struct frame_id sr_id
,
7498 enum bptype sr_type
)
7500 /* There should never be more than one step-resume or longjmp-resume
7501 breakpoint per thread, so we should never be setting a new
7502 step_resume_breakpoint when one is already active. */
7503 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7504 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7506 infrun_log_debug ("inserting step-resume breakpoint at %s",
7507 paddress (gdbarch
, sr_sal
.pc
));
7509 inferior_thread ()->control
.step_resume_breakpoint
7510 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7514 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7515 struct symtab_and_line sr_sal
,
7516 struct frame_id sr_id
)
7518 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7523 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7524 This is used to skip a potential signal handler.
7526 This is called with the interrupted function's frame. The signal
7527 handler, when it returns, will resume the interrupted function at
7531 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7533 gdb_assert (return_frame
!= NULL
);
7535 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7537 symtab_and_line sr_sal
;
7538 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7539 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7540 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7542 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7543 get_stack_frame_id (return_frame
),
7547 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7548 is used to skip a function after stepping into it (for "next" or if
7549 the called function has no debugging information).
7551 The current function has almost always been reached by single
7552 stepping a call or return instruction. NEXT_FRAME belongs to the
7553 current function, and the breakpoint will be set at the caller's
7556 This is a separate function rather than reusing
7557 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7558 get_prev_frame, which may stop prematurely (see the implementation
7559 of frame_unwind_caller_id for an example). */
7562 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7564 /* We shouldn't have gotten here if we don't know where the call site
7566 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7568 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7570 symtab_and_line sr_sal
;
7571 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7572 frame_unwind_caller_pc (next_frame
));
7573 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7574 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7576 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7577 frame_unwind_caller_id (next_frame
));
7580 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7581 new breakpoint at the target of a jmp_buf. The handling of
7582 longjmp-resume uses the same mechanisms used for handling
7583 "step-resume" breakpoints. */
7586 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7588 /* There should never be more than one longjmp-resume breakpoint per
7589 thread, so we should never be setting a new
7590 longjmp_resume_breakpoint when one is already active. */
7591 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7593 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7594 paddress (gdbarch
, pc
));
7596 inferior_thread ()->control
.exception_resume_breakpoint
=
7597 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7600 /* Insert an exception resume breakpoint. TP is the thread throwing
7601 the exception. The block B is the block of the unwinder debug hook
7602 function. FRAME is the frame corresponding to the call to this
7603 function. SYM is the symbol of the function argument holding the
7604 target PC of the exception. */
7607 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7608 const struct block
*b
,
7609 struct frame_info
*frame
,
7614 struct block_symbol vsym
;
7615 struct value
*value
;
7617 struct breakpoint
*bp
;
7619 vsym
= lookup_symbol_search_name (sym
->search_name (),
7621 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7622 /* If the value was optimized out, revert to the old behavior. */
7623 if (! value_optimized_out (value
))
7625 handler
= value_as_address (value
);
7627 infrun_log_debug ("exception resume at %lx",
7628 (unsigned long) handler
);
7630 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7632 bp_exception_resume
).release ();
7634 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7637 bp
->thread
= tp
->global_num
;
7638 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7641 catch (const gdb_exception_error
&e
)
7643 /* We want to ignore errors here. */
7647 /* A helper for check_exception_resume that sets an
7648 exception-breakpoint based on a SystemTap probe. */
7651 insert_exception_resume_from_probe (struct thread_info
*tp
,
7652 const struct bound_probe
*probe
,
7653 struct frame_info
*frame
)
7655 struct value
*arg_value
;
7657 struct breakpoint
*bp
;
7659 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7663 handler
= value_as_address (arg_value
);
7665 infrun_log_debug ("exception resume at %s",
7666 paddress (probe
->objfile
->arch (), handler
));
7668 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7669 handler
, bp_exception_resume
).release ();
7670 bp
->thread
= tp
->global_num
;
7671 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7674 /* This is called when an exception has been intercepted. Check to
7675 see whether the exception's destination is of interest, and if so,
7676 set an exception resume breakpoint there. */
7679 check_exception_resume (struct execution_control_state
*ecs
,
7680 struct frame_info
*frame
)
7682 struct bound_probe probe
;
7683 struct symbol
*func
;
7685 /* First see if this exception unwinding breakpoint was set via a
7686 SystemTap probe point. If so, the probe has two arguments: the
7687 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7688 set a breakpoint there. */
7689 probe
= find_probe_by_pc (get_frame_pc (frame
));
7692 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7696 func
= get_frame_function (frame
);
7702 const struct block
*b
;
7703 struct block_iterator iter
;
7707 /* The exception breakpoint is a thread-specific breakpoint on
7708 the unwinder's debug hook, declared as:
7710 void _Unwind_DebugHook (void *cfa, void *handler);
7712 The CFA argument indicates the frame to which control is
7713 about to be transferred. HANDLER is the destination PC.
7715 We ignore the CFA and set a temporary breakpoint at HANDLER.
7716 This is not extremely efficient but it avoids issues in gdb
7717 with computing the DWARF CFA, and it also works even in weird
7718 cases such as throwing an exception from inside a signal
7721 b
= SYMBOL_BLOCK_VALUE (func
);
7722 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7724 if (!SYMBOL_IS_ARGUMENT (sym
))
7731 insert_exception_resume_breakpoint (ecs
->event_thread
,
7737 catch (const gdb_exception_error
&e
)
7743 stop_waiting (struct execution_control_state
*ecs
)
7745 infrun_log_debug ("stop_waiting");
7747 /* Let callers know we don't want to wait for the inferior anymore. */
7748 ecs
->wait_some_more
= 0;
7750 /* If all-stop, but there exists a non-stop target, stop all
7751 threads now that we're presenting the stop to the user. */
7752 if (!non_stop
&& exists_non_stop_target ())
7753 stop_all_threads ();
7756 /* Like keep_going, but passes the signal to the inferior, even if the
7757 signal is set to nopass. */
7760 keep_going_pass_signal (struct execution_control_state
*ecs
)
7762 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7763 gdb_assert (!ecs
->event_thread
->resumed
);
7765 /* Save the pc before execution, to compare with pc after stop. */
7766 ecs
->event_thread
->prev_pc
7767 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7769 if (ecs
->event_thread
->control
.trap_expected
)
7771 struct thread_info
*tp
= ecs
->event_thread
;
7773 infrun_log_debug ("%s has trap_expected set, "
7774 "resuming to collect trap",
7775 target_pid_to_str (tp
->ptid
).c_str ());
7777 /* We haven't yet gotten our trap, and either: intercepted a
7778 non-signal event (e.g., a fork); or took a signal which we
7779 are supposed to pass through to the inferior. Simply
7781 resume (ecs
->event_thread
->suspend
.stop_signal
);
7783 else if (step_over_info_valid_p ())
7785 /* Another thread is stepping over a breakpoint in-line. If
7786 this thread needs a step-over too, queue the request. In
7787 either case, this resume must be deferred for later. */
7788 struct thread_info
*tp
= ecs
->event_thread
;
7790 if (ecs
->hit_singlestep_breakpoint
7791 || thread_still_needs_step_over (tp
))
7793 infrun_log_debug ("step-over already in progress: "
7794 "step-over for %s deferred",
7795 target_pid_to_str (tp
->ptid
).c_str ());
7796 global_thread_step_over_chain_enqueue (tp
);
7800 infrun_log_debug ("step-over in progress: resume of %s deferred",
7801 target_pid_to_str (tp
->ptid
).c_str ());
7806 struct regcache
*regcache
= get_current_regcache ();
7809 step_over_what step_what
;
7811 /* Either the trap was not expected, but we are continuing
7812 anyway (if we got a signal, the user asked it be passed to
7815 We got our expected trap, but decided we should resume from
7818 We're going to run this baby now!
7820 Note that insert_breakpoints won't try to re-insert
7821 already inserted breakpoints. Therefore, we don't
7822 care if breakpoints were already inserted, or not. */
7824 /* If we need to step over a breakpoint, and we're not using
7825 displaced stepping to do so, insert all breakpoints
7826 (watchpoints, etc.) but the one we're stepping over, step one
7827 instruction, and then re-insert the breakpoint when that step
7830 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7832 remove_bp
= (ecs
->hit_singlestep_breakpoint
7833 || (step_what
& STEP_OVER_BREAKPOINT
));
7834 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7836 /* We can't use displaced stepping if we need to step past a
7837 watchpoint. The instruction copied to the scratch pad would
7838 still trigger the watchpoint. */
7840 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7842 set_step_over_info (regcache
->aspace (),
7843 regcache_read_pc (regcache
), remove_wps
,
7844 ecs
->event_thread
->global_num
);
7846 else if (remove_wps
)
7847 set_step_over_info (NULL
, 0, remove_wps
, -1);
7849 /* If we now need to do an in-line step-over, we need to stop
7850 all other threads. Note this must be done before
7851 insert_breakpoints below, because that removes the breakpoint
7852 we're about to step over, otherwise other threads could miss
7854 if (step_over_info_valid_p () && target_is_non_stop_p ())
7855 stop_all_threads ();
7857 /* Stop stepping if inserting breakpoints fails. */
7860 insert_breakpoints ();
7862 catch (const gdb_exception_error
&e
)
7864 exception_print (gdb_stderr
, e
);
7866 clear_step_over_info ();
7870 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7872 resume (ecs
->event_thread
->suspend
.stop_signal
);
7875 prepare_to_wait (ecs
);
7878 /* Called when we should continue running the inferior, because the
7879 current event doesn't cause a user visible stop. This does the
7880 resuming part; waiting for the next event is done elsewhere. */
7883 keep_going (struct execution_control_state
*ecs
)
7885 if (ecs
->event_thread
->control
.trap_expected
7886 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7887 ecs
->event_thread
->control
.trap_expected
= 0;
7889 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7890 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7891 keep_going_pass_signal (ecs
);
7894 /* This function normally comes after a resume, before
7895 handle_inferior_event exits. It takes care of any last bits of
7896 housekeeping, and sets the all-important wait_some_more flag. */
7899 prepare_to_wait (struct execution_control_state
*ecs
)
7901 infrun_log_debug ("prepare_to_wait");
7903 ecs
->wait_some_more
= 1;
7905 /* If the target can't async, emulate it by marking the infrun event
7906 handler such that as soon as we get back to the event-loop, we
7907 immediately end up in fetch_inferior_event again calling
7909 if (!target_can_async_p ())
7910 mark_infrun_async_event_handler ();
7913 /* We are done with the step range of a step/next/si/ni command.
7914 Called once for each n of a "step n" operation. */
7917 end_stepping_range (struct execution_control_state
*ecs
)
7919 ecs
->event_thread
->control
.stop_step
= 1;
7923 /* Several print_*_reason functions to print why the inferior has stopped.
7924 We always print something when the inferior exits, or receives a signal.
7925 The rest of the cases are dealt with later on in normal_stop and
7926 print_it_typical. Ideally there should be a call to one of these
7927 print_*_reason functions functions from handle_inferior_event each time
7928 stop_waiting is called.
7930 Note that we don't call these directly, instead we delegate that to
7931 the interpreters, through observers. Interpreters then call these
7932 with whatever uiout is right. */
7935 print_end_stepping_range_reason (struct ui_out
*uiout
)
7937 /* For CLI-like interpreters, print nothing. */
7939 if (uiout
->is_mi_like_p ())
7941 uiout
->field_string ("reason",
7942 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7947 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7949 annotate_signalled ();
7950 if (uiout
->is_mi_like_p ())
7952 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7953 uiout
->text ("\nProgram terminated with signal ");
7954 annotate_signal_name ();
7955 uiout
->field_string ("signal-name",
7956 gdb_signal_to_name (siggnal
));
7957 annotate_signal_name_end ();
7959 annotate_signal_string ();
7960 uiout
->field_string ("signal-meaning",
7961 gdb_signal_to_string (siggnal
));
7962 annotate_signal_string_end ();
7963 uiout
->text (".\n");
7964 uiout
->text ("The program no longer exists.\n");
7968 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7970 struct inferior
*inf
= current_inferior ();
7971 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7973 annotate_exited (exitstatus
);
7976 if (uiout
->is_mi_like_p ())
7977 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7978 std::string exit_code_str
7979 = string_printf ("0%o", (unsigned int) exitstatus
);
7980 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7981 plongest (inf
->num
), pidstr
.c_str (),
7982 string_field ("exit-code", exit_code_str
.c_str ()));
7986 if (uiout
->is_mi_like_p ())
7988 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7989 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7990 plongest (inf
->num
), pidstr
.c_str ());
7994 /* Some targets/architectures can do extra processing/display of
7995 segmentation faults. E.g., Intel MPX boundary faults.
7996 Call the architecture dependent function to handle the fault. */
7999 handle_segmentation_fault (struct ui_out
*uiout
)
8001 struct regcache
*regcache
= get_current_regcache ();
8002 struct gdbarch
*gdbarch
= regcache
->arch ();
8004 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8005 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8009 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8011 struct thread_info
*thr
= inferior_thread ();
8015 if (uiout
->is_mi_like_p ())
8017 else if (show_thread_that_caused_stop ())
8021 uiout
->text ("\nThread ");
8022 uiout
->field_string ("thread-id", print_thread_id (thr
));
8024 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8027 uiout
->text (" \"");
8028 uiout
->field_string ("name", name
);
8033 uiout
->text ("\nProgram");
8035 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8036 uiout
->text (" stopped");
8039 uiout
->text (" received signal ");
8040 annotate_signal_name ();
8041 if (uiout
->is_mi_like_p ())
8043 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8044 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8045 annotate_signal_name_end ();
8047 annotate_signal_string ();
8048 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8050 if (siggnal
== GDB_SIGNAL_SEGV
)
8051 handle_segmentation_fault (uiout
);
8053 annotate_signal_string_end ();
8055 uiout
->text (".\n");
8059 print_no_history_reason (struct ui_out
*uiout
)
8061 uiout
->text ("\nNo more reverse-execution history.\n");
8064 /* Print current location without a level number, if we have changed
8065 functions or hit a breakpoint. Print source line if we have one.
8066 bpstat_print contains the logic deciding in detail what to print,
8067 based on the event(s) that just occurred. */
8070 print_stop_location (struct target_waitstatus
*ws
)
8073 enum print_what source_flag
;
8074 int do_frame_printing
= 1;
8075 struct thread_info
*tp
= inferior_thread ();
8077 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8081 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8082 should) carry around the function and does (or should) use
8083 that when doing a frame comparison. */
8084 if (tp
->control
.stop_step
8085 && frame_id_eq (tp
->control
.step_frame_id
,
8086 get_frame_id (get_current_frame ()))
8087 && (tp
->control
.step_start_function
8088 == find_pc_function (tp
->suspend
.stop_pc
)))
8090 /* Finished step, just print source line. */
8091 source_flag
= SRC_LINE
;
8095 /* Print location and source line. */
8096 source_flag
= SRC_AND_LOC
;
8099 case PRINT_SRC_AND_LOC
:
8100 /* Print location and source line. */
8101 source_flag
= SRC_AND_LOC
;
8103 case PRINT_SRC_ONLY
:
8104 source_flag
= SRC_LINE
;
8107 /* Something bogus. */
8108 source_flag
= SRC_LINE
;
8109 do_frame_printing
= 0;
8112 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8115 /* The behavior of this routine with respect to the source
8117 SRC_LINE: Print only source line
8118 LOCATION: Print only location
8119 SRC_AND_LOC: Print location and source line. */
8120 if (do_frame_printing
)
8121 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8127 print_stop_event (struct ui_out
*uiout
, bool displays
)
8129 struct target_waitstatus last
;
8130 struct thread_info
*tp
;
8132 get_last_target_status (nullptr, nullptr, &last
);
8135 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8137 print_stop_location (&last
);
8139 /* Display the auto-display expressions. */
8144 tp
= inferior_thread ();
8145 if (tp
->thread_fsm
!= NULL
8146 && tp
->thread_fsm
->finished_p ())
8148 struct return_value_info
*rv
;
8150 rv
= tp
->thread_fsm
->return_value ();
8152 print_return_value (uiout
, rv
);
8159 maybe_remove_breakpoints (void)
8161 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8163 if (remove_breakpoints ())
8165 target_terminal::ours_for_output ();
8166 printf_filtered (_("Cannot remove breakpoints because "
8167 "program is no longer writable.\nFurther "
8168 "execution is probably impossible.\n"));
8173 /* The execution context that just caused a normal stop. */
8180 DISABLE_COPY_AND_ASSIGN (stop_context
);
8182 bool changed () const;
8187 /* The event PTID. */
8191 /* If stopp for a thread event, this is the thread that caused the
8193 struct thread_info
*thread
;
8195 /* The inferior that caused the stop. */
8199 /* Initializes a new stop context. If stopped for a thread event, this
8200 takes a strong reference to the thread. */
8202 stop_context::stop_context ()
8204 stop_id
= get_stop_id ();
8205 ptid
= inferior_ptid
;
8206 inf_num
= current_inferior ()->num
;
8208 if (inferior_ptid
!= null_ptid
)
8210 /* Take a strong reference so that the thread can't be deleted
8212 thread
= inferior_thread ();
8219 /* Release a stop context previously created with save_stop_context.
8220 Releases the strong reference to the thread as well. */
8222 stop_context::~stop_context ()
8228 /* Return true if the current context no longer matches the saved stop
8232 stop_context::changed () const
8234 if (ptid
!= inferior_ptid
)
8236 if (inf_num
!= current_inferior ()->num
)
8238 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8240 if (get_stop_id () != stop_id
)
8250 struct target_waitstatus last
;
8252 get_last_target_status (nullptr, nullptr, &last
);
8256 /* If an exception is thrown from this point on, make sure to
8257 propagate GDB's knowledge of the executing state to the
8258 frontend/user running state. A QUIT is an easy exception to see
8259 here, so do this before any filtered output. */
8261 ptid_t finish_ptid
= null_ptid
;
8264 finish_ptid
= minus_one_ptid
;
8265 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8266 || last
.kind
== TARGET_WAITKIND_EXITED
)
8268 /* On some targets, we may still have live threads in the
8269 inferior when we get a process exit event. E.g., for
8270 "checkpoint", when the current checkpoint/fork exits,
8271 linux-fork.c automatically switches to another fork from
8272 within target_mourn_inferior. */
8273 if (inferior_ptid
!= null_ptid
)
8274 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8276 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8277 finish_ptid
= inferior_ptid
;
8279 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8280 if (finish_ptid
!= null_ptid
)
8282 maybe_finish_thread_state
.emplace
8283 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8286 /* As we're presenting a stop, and potentially removing breakpoints,
8287 update the thread list so we can tell whether there are threads
8288 running on the target. With target remote, for example, we can
8289 only learn about new threads when we explicitly update the thread
8290 list. Do this before notifying the interpreters about signal
8291 stops, end of stepping ranges, etc., so that the "new thread"
8292 output is emitted before e.g., "Program received signal FOO",
8293 instead of after. */
8294 update_thread_list ();
8296 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8297 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8299 /* As with the notification of thread events, we want to delay
8300 notifying the user that we've switched thread context until
8301 the inferior actually stops.
8303 There's no point in saying anything if the inferior has exited.
8304 Note that SIGNALLED here means "exited with a signal", not
8305 "received a signal".
8307 Also skip saying anything in non-stop mode. In that mode, as we
8308 don't want GDB to switch threads behind the user's back, to avoid
8309 races where the user is typing a command to apply to thread x,
8310 but GDB switches to thread y before the user finishes entering
8311 the command, fetch_inferior_event installs a cleanup to restore
8312 the current thread back to the thread the user had selected right
8313 after this event is handled, so we're not really switching, only
8314 informing of a stop. */
8316 && previous_inferior_ptid
!= inferior_ptid
8317 && target_has_execution
8318 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8319 && last
.kind
!= TARGET_WAITKIND_EXITED
8320 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8322 SWITCH_THRU_ALL_UIS ()
8324 target_terminal::ours_for_output ();
8325 printf_filtered (_("[Switching to %s]\n"),
8326 target_pid_to_str (inferior_ptid
).c_str ());
8327 annotate_thread_changed ();
8329 previous_inferior_ptid
= inferior_ptid
;
8332 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8334 SWITCH_THRU_ALL_UIS ()
8335 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8337 target_terminal::ours_for_output ();
8338 printf_filtered (_("No unwaited-for children left.\n"));
8342 /* Note: this depends on the update_thread_list call above. */
8343 maybe_remove_breakpoints ();
8345 /* If an auto-display called a function and that got a signal,
8346 delete that auto-display to avoid an infinite recursion. */
8348 if (stopped_by_random_signal
)
8349 disable_current_display ();
8351 SWITCH_THRU_ALL_UIS ()
8353 async_enable_stdin ();
8356 /* Let the user/frontend see the threads as stopped. */
8357 maybe_finish_thread_state
.reset ();
8359 /* Select innermost stack frame - i.e., current frame is frame 0,
8360 and current location is based on that. Handle the case where the
8361 dummy call is returning after being stopped. E.g. the dummy call
8362 previously hit a breakpoint. (If the dummy call returns
8363 normally, we won't reach here.) Do this before the stop hook is
8364 run, so that it doesn't get to see the temporary dummy frame,
8365 which is not where we'll present the stop. */
8366 if (has_stack_frames ())
8368 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8370 /* Pop the empty frame that contains the stack dummy. This
8371 also restores inferior state prior to the call (struct
8372 infcall_suspend_state). */
8373 struct frame_info
*frame
= get_current_frame ();
8375 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8377 /* frame_pop calls reinit_frame_cache as the last thing it
8378 does which means there's now no selected frame. */
8381 select_frame (get_current_frame ());
8383 /* Set the current source location. */
8384 set_current_sal_from_frame (get_current_frame ());
8387 /* Look up the hook_stop and run it (CLI internally handles problem
8388 of stop_command's pre-hook not existing). */
8389 if (stop_command
!= NULL
)
8391 stop_context saved_context
;
8395 execute_cmd_pre_hook (stop_command
);
8397 catch (const gdb_exception
&ex
)
8399 exception_fprintf (gdb_stderr
, ex
,
8400 "Error while running hook_stop:\n");
8403 /* If the stop hook resumes the target, then there's no point in
8404 trying to notify about the previous stop; its context is
8405 gone. Likewise if the command switches thread or inferior --
8406 the observers would print a stop for the wrong
8408 if (saved_context
.changed ())
8412 /* Notify observers about the stop. This is where the interpreters
8413 print the stop event. */
8414 if (inferior_ptid
!= null_ptid
)
8415 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8418 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8420 annotate_stopped ();
8422 if (target_has_execution
)
8424 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8425 && last
.kind
!= TARGET_WAITKIND_EXITED
8426 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8427 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8428 Delete any breakpoint that is to be deleted at the next stop. */
8429 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8432 /* Try to get rid of automatically added inferiors that are no
8433 longer needed. Keeping those around slows down things linearly.
8434 Note that this never removes the current inferior. */
8441 signal_stop_state (int signo
)
8443 return signal_stop
[signo
];
8447 signal_print_state (int signo
)
8449 return signal_print
[signo
];
8453 signal_pass_state (int signo
)
8455 return signal_program
[signo
];
8459 signal_cache_update (int signo
)
8463 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8464 signal_cache_update (signo
);
8469 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8470 && signal_print
[signo
] == 0
8471 && signal_program
[signo
] == 1
8472 && signal_catch
[signo
] == 0);
8476 signal_stop_update (int signo
, int state
)
8478 int ret
= signal_stop
[signo
];
8480 signal_stop
[signo
] = state
;
8481 signal_cache_update (signo
);
8486 signal_print_update (int signo
, int state
)
8488 int ret
= signal_print
[signo
];
8490 signal_print
[signo
] = state
;
8491 signal_cache_update (signo
);
8496 signal_pass_update (int signo
, int state
)
8498 int ret
= signal_program
[signo
];
8500 signal_program
[signo
] = state
;
8501 signal_cache_update (signo
);
8505 /* Update the global 'signal_catch' from INFO and notify the
8509 signal_catch_update (const unsigned int *info
)
8513 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8514 signal_catch
[i
] = info
[i
] > 0;
8515 signal_cache_update (-1);
8516 target_pass_signals (signal_pass
);
8520 sig_print_header (void)
8522 printf_filtered (_("Signal Stop\tPrint\tPass "
8523 "to program\tDescription\n"));
8527 sig_print_info (enum gdb_signal oursig
)
8529 const char *name
= gdb_signal_to_name (oursig
);
8530 int name_padding
= 13 - strlen (name
);
8532 if (name_padding
<= 0)
8535 printf_filtered ("%s", name
);
8536 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8537 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8538 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8539 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8540 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8543 /* Specify how various signals in the inferior should be handled. */
8546 handle_command (const char *args
, int from_tty
)
8548 int digits
, wordlen
;
8549 int sigfirst
, siglast
;
8550 enum gdb_signal oursig
;
8555 error_no_arg (_("signal to handle"));
8558 /* Allocate and zero an array of flags for which signals to handle. */
8560 const size_t nsigs
= GDB_SIGNAL_LAST
;
8561 unsigned char sigs
[nsigs
] {};
8563 /* Break the command line up into args. */
8565 gdb_argv
built_argv (args
);
8567 /* Walk through the args, looking for signal oursigs, signal names, and
8568 actions. Signal numbers and signal names may be interspersed with
8569 actions, with the actions being performed for all signals cumulatively
8570 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8572 for (char *arg
: built_argv
)
8574 wordlen
= strlen (arg
);
8575 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8579 sigfirst
= siglast
= -1;
8581 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8583 /* Apply action to all signals except those used by the
8584 debugger. Silently skip those. */
8587 siglast
= nsigs
- 1;
8589 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8591 SET_SIGS (nsigs
, sigs
, signal_stop
);
8592 SET_SIGS (nsigs
, sigs
, signal_print
);
8594 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8596 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8598 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8600 SET_SIGS (nsigs
, sigs
, signal_print
);
8602 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8604 SET_SIGS (nsigs
, sigs
, signal_program
);
8606 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8608 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8610 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8612 SET_SIGS (nsigs
, sigs
, signal_program
);
8614 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8616 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8617 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8619 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8621 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8623 else if (digits
> 0)
8625 /* It is numeric. The numeric signal refers to our own
8626 internal signal numbering from target.h, not to host/target
8627 signal number. This is a feature; users really should be
8628 using symbolic names anyway, and the common ones like
8629 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8631 sigfirst
= siglast
= (int)
8632 gdb_signal_from_command (atoi (arg
));
8633 if (arg
[digits
] == '-')
8636 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8638 if (sigfirst
> siglast
)
8640 /* Bet he didn't figure we'd think of this case... */
8641 std::swap (sigfirst
, siglast
);
8646 oursig
= gdb_signal_from_name (arg
);
8647 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8649 sigfirst
= siglast
= (int) oursig
;
8653 /* Not a number and not a recognized flag word => complain. */
8654 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8658 /* If any signal numbers or symbol names were found, set flags for
8659 which signals to apply actions to. */
8661 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8663 switch ((enum gdb_signal
) signum
)
8665 case GDB_SIGNAL_TRAP
:
8666 case GDB_SIGNAL_INT
:
8667 if (!allsigs
&& !sigs
[signum
])
8669 if (query (_("%s is used by the debugger.\n\
8670 Are you sure you want to change it? "),
8671 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8676 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8680 case GDB_SIGNAL_DEFAULT
:
8681 case GDB_SIGNAL_UNKNOWN
:
8682 /* Make sure that "all" doesn't print these. */
8691 for (int signum
= 0; signum
< nsigs
; signum
++)
8694 signal_cache_update (-1);
8695 target_pass_signals (signal_pass
);
8696 target_program_signals (signal_program
);
8700 /* Show the results. */
8701 sig_print_header ();
8702 for (; signum
< nsigs
; signum
++)
8704 sig_print_info ((enum gdb_signal
) signum
);
8711 /* Complete the "handle" command. */
8714 handle_completer (struct cmd_list_element
*ignore
,
8715 completion_tracker
&tracker
,
8716 const char *text
, const char *word
)
8718 static const char * const keywords
[] =
8732 signal_completer (ignore
, tracker
, text
, word
);
8733 complete_on_enum (tracker
, keywords
, word
, word
);
8737 gdb_signal_from_command (int num
)
8739 if (num
>= 1 && num
<= 15)
8740 return (enum gdb_signal
) num
;
8741 error (_("Only signals 1-15 are valid as numeric signals.\n\
8742 Use \"info signals\" for a list of symbolic signals."));
8745 /* Print current contents of the tables set by the handle command.
8746 It is possible we should just be printing signals actually used
8747 by the current target (but for things to work right when switching
8748 targets, all signals should be in the signal tables). */
8751 info_signals_command (const char *signum_exp
, int from_tty
)
8753 enum gdb_signal oursig
;
8755 sig_print_header ();
8759 /* First see if this is a symbol name. */
8760 oursig
= gdb_signal_from_name (signum_exp
);
8761 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8763 /* No, try numeric. */
8765 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8767 sig_print_info (oursig
);
8771 printf_filtered ("\n");
8772 /* These ugly casts brought to you by the native VAX compiler. */
8773 for (oursig
= GDB_SIGNAL_FIRST
;
8774 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8775 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8779 if (oursig
!= GDB_SIGNAL_UNKNOWN
8780 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8781 sig_print_info (oursig
);
8784 printf_filtered (_("\nUse the \"handle\" command "
8785 "to change these tables.\n"));
8788 /* The $_siginfo convenience variable is a bit special. We don't know
8789 for sure the type of the value until we actually have a chance to
8790 fetch the data. The type can change depending on gdbarch, so it is
8791 also dependent on which thread you have selected.
8793 1. making $_siginfo be an internalvar that creates a new value on
8796 2. making the value of $_siginfo be an lval_computed value. */
8798 /* This function implements the lval_computed support for reading a
8802 siginfo_value_read (struct value
*v
)
8804 LONGEST transferred
;
8806 /* If we can access registers, so can we access $_siginfo. Likewise
8808 validate_registers_access ();
8811 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8813 value_contents_all_raw (v
),
8815 TYPE_LENGTH (value_type (v
)));
8817 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8818 error (_("Unable to read siginfo"));
8821 /* This function implements the lval_computed support for writing a
8825 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8827 LONGEST transferred
;
8829 /* If we can access registers, so can we access $_siginfo. Likewise
8831 validate_registers_access ();
8833 transferred
= target_write (current_top_target (),
8834 TARGET_OBJECT_SIGNAL_INFO
,
8836 value_contents_all_raw (fromval
),
8838 TYPE_LENGTH (value_type (fromval
)));
8840 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8841 error (_("Unable to write siginfo"));
8844 static const struct lval_funcs siginfo_value_funcs
=
8850 /* Return a new value with the correct type for the siginfo object of
8851 the current thread using architecture GDBARCH. Return a void value
8852 if there's no object available. */
8854 static struct value
*
8855 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8858 if (target_has_stack
8859 && inferior_ptid
!= null_ptid
8860 && gdbarch_get_siginfo_type_p (gdbarch
))
8862 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8864 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8867 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8871 /* infcall_suspend_state contains state about the program itself like its
8872 registers and any signal it received when it last stopped.
8873 This state must be restored regardless of how the inferior function call
8874 ends (either successfully, or after it hits a breakpoint or signal)
8875 if the program is to properly continue where it left off. */
8877 class infcall_suspend_state
8880 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8881 once the inferior function call has finished. */
8882 infcall_suspend_state (struct gdbarch
*gdbarch
,
8883 const struct thread_info
*tp
,
8884 struct regcache
*regcache
)
8885 : m_thread_suspend (tp
->suspend
),
8886 m_registers (new readonly_detached_regcache (*regcache
))
8888 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8890 if (gdbarch_get_siginfo_type_p (gdbarch
))
8892 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8893 size_t len
= TYPE_LENGTH (type
);
8895 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8897 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8898 siginfo_data
.get (), 0, len
) != len
)
8900 /* Errors ignored. */
8901 siginfo_data
.reset (nullptr);
8907 m_siginfo_gdbarch
= gdbarch
;
8908 m_siginfo_data
= std::move (siginfo_data
);
8912 /* Return a pointer to the stored register state. */
8914 readonly_detached_regcache
*registers () const
8916 return m_registers
.get ();
8919 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8921 void restore (struct gdbarch
*gdbarch
,
8922 struct thread_info
*tp
,
8923 struct regcache
*regcache
) const
8925 tp
->suspend
= m_thread_suspend
;
8927 if (m_siginfo_gdbarch
== gdbarch
)
8929 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8931 /* Errors ignored. */
8932 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8933 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8936 /* The inferior can be gone if the user types "print exit(0)"
8937 (and perhaps other times). */
8938 if (target_has_execution
)
8939 /* NB: The register write goes through to the target. */
8940 regcache
->restore (registers ());
8944 /* How the current thread stopped before the inferior function call was
8946 struct thread_suspend_state m_thread_suspend
;
8948 /* The registers before the inferior function call was executed. */
8949 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8951 /* Format of SIGINFO_DATA or NULL if it is not present. */
8952 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8954 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8955 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8956 content would be invalid. */
8957 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8960 infcall_suspend_state_up
8961 save_infcall_suspend_state ()
8963 struct thread_info
*tp
= inferior_thread ();
8964 struct regcache
*regcache
= get_current_regcache ();
8965 struct gdbarch
*gdbarch
= regcache
->arch ();
8967 infcall_suspend_state_up inf_state
8968 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8970 /* Having saved the current state, adjust the thread state, discarding
8971 any stop signal information. The stop signal is not useful when
8972 starting an inferior function call, and run_inferior_call will not use
8973 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8974 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8979 /* Restore inferior session state to INF_STATE. */
8982 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8984 struct thread_info
*tp
= inferior_thread ();
8985 struct regcache
*regcache
= get_current_regcache ();
8986 struct gdbarch
*gdbarch
= regcache
->arch ();
8988 inf_state
->restore (gdbarch
, tp
, regcache
);
8989 discard_infcall_suspend_state (inf_state
);
8993 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8998 readonly_detached_regcache
*
8999 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9001 return inf_state
->registers ();
9004 /* infcall_control_state contains state regarding gdb's control of the
9005 inferior itself like stepping control. It also contains session state like
9006 the user's currently selected frame. */
9008 struct infcall_control_state
9010 struct thread_control_state thread_control
;
9011 struct inferior_control_state inferior_control
;
9014 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9015 int stopped_by_random_signal
= 0;
9017 /* ID if the selected frame when the inferior function call was made. */
9018 struct frame_id selected_frame_id
{};
9021 /* Save all of the information associated with the inferior<==>gdb
9024 infcall_control_state_up
9025 save_infcall_control_state ()
9027 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9028 struct thread_info
*tp
= inferior_thread ();
9029 struct inferior
*inf
= current_inferior ();
9031 inf_status
->thread_control
= tp
->control
;
9032 inf_status
->inferior_control
= inf
->control
;
9034 tp
->control
.step_resume_breakpoint
= NULL
;
9035 tp
->control
.exception_resume_breakpoint
= NULL
;
9037 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9038 chain. If caller's caller is walking the chain, they'll be happier if we
9039 hand them back the original chain when restore_infcall_control_state is
9041 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9044 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9045 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9047 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9053 restore_selected_frame (const frame_id
&fid
)
9055 frame_info
*frame
= frame_find_by_id (fid
);
9057 /* If inf_status->selected_frame_id is NULL, there was no previously
9061 warning (_("Unable to restore previously selected frame."));
9065 select_frame (frame
);
9068 /* Restore inferior session state to INF_STATUS. */
9071 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9073 struct thread_info
*tp
= inferior_thread ();
9074 struct inferior
*inf
= current_inferior ();
9076 if (tp
->control
.step_resume_breakpoint
)
9077 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9079 if (tp
->control
.exception_resume_breakpoint
)
9080 tp
->control
.exception_resume_breakpoint
->disposition
9081 = disp_del_at_next_stop
;
9083 /* Handle the bpstat_copy of the chain. */
9084 bpstat_clear (&tp
->control
.stop_bpstat
);
9086 tp
->control
= inf_status
->thread_control
;
9087 inf
->control
= inf_status
->inferior_control
;
9090 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9091 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9093 if (target_has_stack
)
9095 /* The point of the try/catch is that if the stack is clobbered,
9096 walking the stack might encounter a garbage pointer and
9097 error() trying to dereference it. */
9100 restore_selected_frame (inf_status
->selected_frame_id
);
9102 catch (const gdb_exception_error
&ex
)
9104 exception_fprintf (gdb_stderr
, ex
,
9105 "Unable to restore previously selected frame:\n");
9106 /* Error in restoring the selected frame. Select the
9108 select_frame (get_current_frame ());
9116 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9118 if (inf_status
->thread_control
.step_resume_breakpoint
)
9119 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9120 = disp_del_at_next_stop
;
9122 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9123 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9124 = disp_del_at_next_stop
;
9126 /* See save_infcall_control_state for info on stop_bpstat. */
9127 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9135 clear_exit_convenience_vars (void)
9137 clear_internalvar (lookup_internalvar ("_exitsignal"));
9138 clear_internalvar (lookup_internalvar ("_exitcode"));
9142 /* User interface for reverse debugging:
9143 Set exec-direction / show exec-direction commands
9144 (returns error unless target implements to_set_exec_direction method). */
9146 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9147 static const char exec_forward
[] = "forward";
9148 static const char exec_reverse
[] = "reverse";
9149 static const char *exec_direction
= exec_forward
;
9150 static const char *const exec_direction_names
[] = {
9157 set_exec_direction_func (const char *args
, int from_tty
,
9158 struct cmd_list_element
*cmd
)
9160 if (target_can_execute_reverse
)
9162 if (!strcmp (exec_direction
, exec_forward
))
9163 execution_direction
= EXEC_FORWARD
;
9164 else if (!strcmp (exec_direction
, exec_reverse
))
9165 execution_direction
= EXEC_REVERSE
;
9169 exec_direction
= exec_forward
;
9170 error (_("Target does not support this operation."));
9175 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9176 struct cmd_list_element
*cmd
, const char *value
)
9178 switch (execution_direction
) {
9180 fprintf_filtered (out
, _("Forward.\n"));
9183 fprintf_filtered (out
, _("Reverse.\n"));
9186 internal_error (__FILE__
, __LINE__
,
9187 _("bogus execution_direction value: %d"),
9188 (int) execution_direction
);
9193 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9194 struct cmd_list_element
*c
, const char *value
)
9196 fprintf_filtered (file
, _("Resuming the execution of threads "
9197 "of all processes is %s.\n"), value
);
9200 /* Implementation of `siginfo' variable. */
9202 static const struct internalvar_funcs siginfo_funcs
=
9209 /* Callback for infrun's target events source. This is marked when a
9210 thread has a pending status to process. */
9213 infrun_async_inferior_event_handler (gdb_client_data data
)
9215 inferior_event_handler (INF_REG_EVENT
);
9218 void _initialize_infrun ();
9220 _initialize_infrun ()
9222 struct cmd_list_element
*c
;
9224 /* Register extra event sources in the event loop. */
9225 infrun_async_inferior_event_token
9226 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9228 add_info ("signals", info_signals_command
, _("\
9229 What debugger does when program gets various signals.\n\
9230 Specify a signal as argument to print info on that signal only."));
9231 add_info_alias ("handle", "signals", 0);
9233 c
= add_com ("handle", class_run
, handle_command
, _("\
9234 Specify how to handle signals.\n\
9235 Usage: handle SIGNAL [ACTIONS]\n\
9236 Args are signals and actions to apply to those signals.\n\
9237 If no actions are specified, the current settings for the specified signals\n\
9238 will be displayed instead.\n\
9240 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9241 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9242 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9243 The special arg \"all\" is recognized to mean all signals except those\n\
9244 used by the debugger, typically SIGTRAP and SIGINT.\n\
9246 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9247 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9248 Stop means reenter debugger if this signal happens (implies print).\n\
9249 Print means print a message if this signal happens.\n\
9250 Pass means let program see this signal; otherwise program doesn't know.\n\
9251 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9252 Pass and Stop may be combined.\n\
9254 Multiple signals may be specified. Signal numbers and signal names\n\
9255 may be interspersed with actions, with the actions being performed for\n\
9256 all signals cumulatively specified."));
9257 set_cmd_completer (c
, handle_completer
);
9260 stop_command
= add_cmd ("stop", class_obscure
,
9261 not_just_help_class_command
, _("\
9262 There is no `stop' command, but you can set a hook on `stop'.\n\
9263 This allows you to set a list of commands to be run each time execution\n\
9264 of the program stops."), &cmdlist
);
9266 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9267 Set inferior debugging."), _("\
9268 Show inferior debugging."), _("\
9269 When non-zero, inferior specific debugging is enabled."),
9272 &setdebuglist
, &showdebuglist
);
9274 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9275 &debug_displaced
, _("\
9276 Set displaced stepping debugging."), _("\
9277 Show displaced stepping debugging."), _("\
9278 When non-zero, displaced stepping specific debugging is enabled."),
9280 show_debug_displaced
,
9281 &setdebuglist
, &showdebuglist
);
9283 add_setshow_boolean_cmd ("non-stop", no_class
,
9285 Set whether gdb controls the inferior in non-stop mode."), _("\
9286 Show whether gdb controls the inferior in non-stop mode."), _("\
9287 When debugging a multi-threaded program and this setting is\n\
9288 off (the default, also called all-stop mode), when one thread stops\n\
9289 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9290 all other threads in the program while you interact with the thread of\n\
9291 interest. When you continue or step a thread, you can allow the other\n\
9292 threads to run, or have them remain stopped, but while you inspect any\n\
9293 thread's state, all threads stop.\n\
9295 In non-stop mode, when one thread stops, other threads can continue\n\
9296 to run freely. You'll be able to step each thread independently,\n\
9297 leave it stopped or free to run as needed."),
9303 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9306 signal_print
[i
] = 1;
9307 signal_program
[i
] = 1;
9308 signal_catch
[i
] = 0;
9311 /* Signals caused by debugger's own actions should not be given to
9312 the program afterwards.
9314 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9315 explicitly specifies that it should be delivered to the target
9316 program. Typically, that would occur when a user is debugging a
9317 target monitor on a simulator: the target monitor sets a
9318 breakpoint; the simulator encounters this breakpoint and halts
9319 the simulation handing control to GDB; GDB, noting that the stop
9320 address doesn't map to any known breakpoint, returns control back
9321 to the simulator; the simulator then delivers the hardware
9322 equivalent of a GDB_SIGNAL_TRAP to the program being
9324 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9325 signal_program
[GDB_SIGNAL_INT
] = 0;
9327 /* Signals that are not errors should not normally enter the debugger. */
9328 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9329 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9330 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9331 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9332 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9333 signal_print
[GDB_SIGNAL_PROF
] = 0;
9334 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9335 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9336 signal_stop
[GDB_SIGNAL_IO
] = 0;
9337 signal_print
[GDB_SIGNAL_IO
] = 0;
9338 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9339 signal_print
[GDB_SIGNAL_POLL
] = 0;
9340 signal_stop
[GDB_SIGNAL_URG
] = 0;
9341 signal_print
[GDB_SIGNAL_URG
] = 0;
9342 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9343 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9344 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9345 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9347 /* These signals are used internally by user-level thread
9348 implementations. (See signal(5) on Solaris.) Like the above
9349 signals, a healthy program receives and handles them as part of
9350 its normal operation. */
9351 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9352 signal_print
[GDB_SIGNAL_LWP
] = 0;
9353 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9354 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9355 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9356 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9357 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9358 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9360 /* Update cached state. */
9361 signal_cache_update (-1);
9363 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9364 &stop_on_solib_events
, _("\
9365 Set stopping for shared library events."), _("\
9366 Show stopping for shared library events."), _("\
9367 If nonzero, gdb will give control to the user when the dynamic linker\n\
9368 notifies gdb of shared library events. The most common event of interest\n\
9369 to the user would be loading/unloading of a new library."),
9370 set_stop_on_solib_events
,
9371 show_stop_on_solib_events
,
9372 &setlist
, &showlist
);
9374 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9375 follow_fork_mode_kind_names
,
9376 &follow_fork_mode_string
, _("\
9377 Set debugger response to a program call of fork or vfork."), _("\
9378 Show debugger response to a program call of fork or vfork."), _("\
9379 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9380 parent - the original process is debugged after a fork\n\
9381 child - the new process is debugged after a fork\n\
9382 The unfollowed process will continue to run.\n\
9383 By default, the debugger will follow the parent process."),
9385 show_follow_fork_mode_string
,
9386 &setlist
, &showlist
);
9388 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9389 follow_exec_mode_names
,
9390 &follow_exec_mode_string
, _("\
9391 Set debugger response to a program call of exec."), _("\
9392 Show debugger response to a program call of exec."), _("\
9393 An exec call replaces the program image of a process.\n\
9395 follow-exec-mode can be:\n\
9397 new - the debugger creates a new inferior and rebinds the process\n\
9398 to this new inferior. The program the process was running before\n\
9399 the exec call can be restarted afterwards by restarting the original\n\
9402 same - the debugger keeps the process bound to the same inferior.\n\
9403 The new executable image replaces the previous executable loaded in\n\
9404 the inferior. Restarting the inferior after the exec call restarts\n\
9405 the executable the process was running after the exec call.\n\
9407 By default, the debugger will use the same inferior."),
9409 show_follow_exec_mode_string
,
9410 &setlist
, &showlist
);
9412 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9413 scheduler_enums
, &scheduler_mode
, _("\
9414 Set mode for locking scheduler during execution."), _("\
9415 Show mode for locking scheduler during execution."), _("\
9416 off == no locking (threads may preempt at any time)\n\
9417 on == full locking (no thread except the current thread may run)\n\
9418 This applies to both normal execution and replay mode.\n\
9419 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9420 In this mode, other threads may run during other commands.\n\
9421 This applies to both normal execution and replay mode.\n\
9422 replay == scheduler locked in replay mode and unlocked during normal execution."),
9423 set_schedlock_func
, /* traps on target vector */
9424 show_scheduler_mode
,
9425 &setlist
, &showlist
);
9427 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9428 Set mode for resuming threads of all processes."), _("\
9429 Show mode for resuming threads of all processes."), _("\
9430 When on, execution commands (such as 'continue' or 'next') resume all\n\
9431 threads of all processes. When off (which is the default), execution\n\
9432 commands only resume the threads of the current process. The set of\n\
9433 threads that are resumed is further refined by the scheduler-locking\n\
9434 mode (see help set scheduler-locking)."),
9436 show_schedule_multiple
,
9437 &setlist
, &showlist
);
9439 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9440 Set mode of the step operation."), _("\
9441 Show mode of the step operation."), _("\
9442 When set, doing a step over a function without debug line information\n\
9443 will stop at the first instruction of that function. Otherwise, the\n\
9444 function is skipped and the step command stops at a different source line."),
9446 show_step_stop_if_no_debug
,
9447 &setlist
, &showlist
);
9449 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9450 &can_use_displaced_stepping
, _("\
9451 Set debugger's willingness to use displaced stepping."), _("\
9452 Show debugger's willingness to use displaced stepping."), _("\
9453 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9454 supported by the target architecture. If off, gdb will not use displaced\n\
9455 stepping to step over breakpoints, even if such is supported by the target\n\
9456 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9457 if the target architecture supports it and non-stop mode is active, but will not\n\
9458 use it in all-stop mode (see help set non-stop)."),
9460 show_can_use_displaced_stepping
,
9461 &setlist
, &showlist
);
9463 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9464 &exec_direction
, _("Set direction of execution.\n\
9465 Options are 'forward' or 'reverse'."),
9466 _("Show direction of execution (forward/reverse)."),
9467 _("Tells gdb whether to execute forward or backward."),
9468 set_exec_direction_func
, show_exec_direction_func
,
9469 &setlist
, &showlist
);
9471 /* Set/show detach-on-fork: user-settable mode. */
9473 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9474 Set whether gdb will detach the child of a fork."), _("\
9475 Show whether gdb will detach the child of a fork."), _("\
9476 Tells gdb whether to detach the child of a fork."),
9477 NULL
, NULL
, &setlist
, &showlist
);
9479 /* Set/show disable address space randomization mode. */
9481 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9482 &disable_randomization
, _("\
9483 Set disabling of debuggee's virtual address space randomization."), _("\
9484 Show disabling of debuggee's virtual address space randomization."), _("\
9485 When this mode is on (which is the default), randomization of the virtual\n\
9486 address space is disabled. Standalone programs run with the randomization\n\
9487 enabled by default on some platforms."),
9488 &set_disable_randomization
,
9489 &show_disable_randomization
,
9490 &setlist
, &showlist
);
9492 /* ptid initializations */
9493 inferior_ptid
= null_ptid
;
9494 target_last_wait_ptid
= minus_one_ptid
;
9496 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9497 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9498 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9499 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9501 /* Explicitly create without lookup, since that tries to create a
9502 value with a void typed value, and when we get here, gdbarch
9503 isn't initialized yet. At this point, we're quite sure there
9504 isn't another convenience variable of the same name. */
9505 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9507 add_setshow_boolean_cmd ("observer", no_class
,
9508 &observer_mode_1
, _("\
9509 Set whether gdb controls the inferior in observer mode."), _("\
9510 Show whether gdb controls the inferior in observer mode."), _("\
9511 In observer mode, GDB can get data from the inferior, but not\n\
9512 affect its execution. Registers and memory may not be changed,\n\
9513 breakpoints may not be set, and the program cannot be interrupted\n\