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 gdbarch implements the required methods to use
1590 displaced stepping. */
1593 gdbarch_supports_displaced_stepping (gdbarch
*arch
)
1595 /* Only check for the presence of `prepare`. `finish` is required by the
1596 gdbarch verification to be provided if `prepare` is provided. */
1597 return gdbarch_displaced_step_prepare_p (arch
);
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 gdbarch
*gdbarch
= get_thread_regcache (tp
)->arch ();
1618 /* If the architecture doesn't implement displaced stepping, don't use
1620 if (!gdbarch_supports_displaced_stepping (gdbarch
))
1623 /* If recording, don't use displaced stepping. */
1624 if (find_record_target () != nullptr)
1627 displaced_step_inferior_state
*displaced_state
1628 = get_displaced_stepping_state (tp
->inf
);
1630 /* If displaced stepping failed before for this inferior, don't bother trying
1632 if (displaced_state
->failed_before
)
1638 /* Simple function wrapper around displaced_step_thread_state::reset. */
1641 displaced_step_reset (displaced_step_thread_state
*displaced
)
1643 displaced
->reset ();
1646 /* A cleanup that wraps displaced_step_reset. We use this instead of, say,
1647 SCOPE_EXIT, because it needs to be discardable with "cleanup.release ()". */
1649 using displaced_step_reset_cleanup
= FORWARD_SCOPE_EXIT (displaced_step_reset
);
1651 /* Dump LEN bytes at BUF in hex to FILE, followed by a newline. */
1653 displaced_step_dump_bytes (struct ui_file
*file
,
1654 const gdb_byte
*buf
,
1659 for (i
= 0; i
< len
; i
++)
1660 fprintf_unfiltered (file
, "%02x ", buf
[i
]);
1661 fputs_unfiltered ("\n", file
);
1664 /* Prepare to single-step, using displaced stepping.
1666 Note that we cannot use displaced stepping when we have a signal to
1667 deliver. If we have a signal to deliver and an instruction to step
1668 over, then after the step, there will be no indication from the
1669 target whether the thread entered a signal handler or ignored the
1670 signal and stepped over the instruction successfully --- both cases
1671 result in a simple SIGTRAP. In the first case we mustn't do a
1672 fixup, and in the second case we must --- but we can't tell which.
1673 Comments in the code for 'random signals' in handle_inferior_event
1674 explain how we handle this case instead.
1676 Returns 1 if preparing was successful -- this thread is going to be
1677 stepped now; 0 if displaced stepping this thread got queued; or -1
1678 if this instruction can't be displaced stepped. */
1680 static displaced_step_prepare_status
1681 displaced_step_prepare_throw (thread_info
*tp
)
1683 regcache
*regcache
= get_thread_regcache (tp
);
1684 struct gdbarch
*gdbarch
= regcache
->arch ();
1685 displaced_step_thread_state
*thread_disp_step_state
1686 = get_displaced_stepping_state (tp
);
1688 /* We should never reach this function if the architecture does not
1689 support displaced stepping. */
1690 gdb_assert (gdbarch_supports_displaced_stepping (gdbarch
));
1692 /* Nor if the thread isn't meant to step over a breakpoint. */
1693 gdb_assert (tp
->control
.trap_expected
);
1695 /* Disable range stepping while executing in the scratch pad. We
1696 want a single-step even if executing the displaced instruction in
1697 the scratch buffer lands within the stepping range (e.g., a
1699 tp
->control
.may_range_step
= 0;
1701 /* We are about to start a displaced step for this thread, if one is already
1702 in progress, we goofed up somewhere. */
1703 gdb_assert (!thread_disp_step_state
->in_progress ());
1705 scoped_restore_current_thread restore_thread
;
1707 switch_to_thread (tp
);
1709 CORE_ADDR original_pc
= regcache_read_pc (regcache
);
1711 displaced_step_prepare_status status
=
1712 tp
->inf
->top_target ()->displaced_step_prepare (tp
);
1714 if (status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
1716 if (debug_displaced
)
1717 fprintf_unfiltered (gdb_stdlog
,
1718 "displaced: failed to prepare (%s)",
1719 target_pid_to_str (tp
->ptid
).c_str ());
1721 return DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1723 else if (status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
1725 /* Not enough displaced stepping resources available, defer this
1726 request by placing it the queue. */
1728 if (debug_displaced
)
1729 fprintf_unfiltered (gdb_stdlog
,
1730 "displaced: not enough resources available, "
1731 "deferring step of %s\n",
1732 target_pid_to_str (tp
->ptid
).c_str ());
1734 global_thread_step_over_chain_enqueue (tp
);
1735 tp
->inf
->displaced_step_state
.unavailable
= true;
1737 return DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
;
1740 gdb_assert (status
== DISPLACED_STEP_PREPARE_STATUS_OK
);
1742 // FIXME: Should probably replicated in the arch implementation now.
1744 // if (breakpoint_in_range_p (aspace, copy, len))
1746 // /* There's a breakpoint set in the scratch pad location range
1747 // (which is usually around the entry point). We'd either
1748 // install it before resuming, which would overwrite/corrupt the
1749 // scratch pad, or if it was already inserted, this displaced
1750 // step would overwrite it. The latter is OK in the sense that
1751 // we already assume that no thread is going to execute the code
1752 // in the scratch pad range (after initial startup) anyway, but
1753 // the former is unacceptable. Simply punt and fallback to
1754 // stepping over this breakpoint in-line. */
1755 // if (debug_displaced)
1757 // fprintf_unfiltered (gdb_stdlog,
1758 // "displaced: breakpoint set in scratch pad. "
1759 // "Stepping over breakpoint in-line instead.\n");
1762 // gdb_assert (false);
1763 // gdbarch_displaced_step_release_location (gdbarch, copy);
1768 /* Save the information we need to fix things up if the step
1770 thread_disp_step_state
->set (gdbarch
);
1772 // FIXME: get it from _prepare?
1773 CORE_ADDR displaced_pc
= 0;
1775 if (debug_displaced
)
1776 fprintf_unfiltered (gdb_stdlog
,
1777 "displaced: prepared successfully thread=%s, "
1778 "original_pc=%s, displaced_pc=%s\n",
1779 target_pid_to_str (tp
->ptid
).c_str (),
1780 paddress (gdbarch
, original_pc
),
1781 paddress (gdbarch
, displaced_pc
));
1783 return DISPLACED_STEP_PREPARE_STATUS_OK
;
1786 /* Wrapper for displaced_step_prepare_throw that disabled further
1787 attempts at displaced stepping if we get a memory error. */
1789 static displaced_step_prepare_status
1790 displaced_step_prepare (thread_info
*thread
)
1792 displaced_step_prepare_status status
1793 = DISPLACED_STEP_PREPARE_STATUS_ERROR
;
1797 status
= displaced_step_prepare_throw (thread
);
1799 catch (const gdb_exception_error
&ex
)
1801 struct displaced_step_inferior_state
*displaced_state
;
1803 if (ex
.error
!= MEMORY_ERROR
1804 && ex
.error
!= NOT_SUPPORTED_ERROR
)
1807 infrun_log_debug ("caught exception, disabling displaced stepping: %s",
1810 /* Be verbose if "set displaced-stepping" is "on", silent if
1812 if (can_use_displaced_stepping
== AUTO_BOOLEAN_TRUE
)
1814 warning (_("disabling displaced stepping: %s"),
1818 /* Disable further displaced stepping attempts. */
1820 = get_displaced_stepping_state (thread
->inf
);
1821 displaced_state
->failed_before
= 1;
1827 /* If we displaced stepped an instruction successfully, adjust
1828 registers and memory to yield the same effect the instruction would
1829 have had if we had executed it at its original address, and return
1830 1. If the instruction didn't complete, relocate the PC and return
1831 -1. If the thread wasn't displaced stepping, return 0. */
1834 displaced_step_finish (thread_info
*event_thread
, enum gdb_signal signal
)
1836 displaced_step_thread_state
*displaced
1837 = get_displaced_stepping_state (event_thread
);
1839 /* Was this thread performing a displaced step? */
1840 if (!displaced
->in_progress ())
1843 displaced_step_reset_cleanup
cleanup (displaced
);
1845 /* Fixup may need to read memory/registers. Switch to the thread
1846 that we're fixing up. Also, target_stopped_by_watchpoint checks
1847 the current thread, and displaced_step_restore performs ptid-dependent
1848 memory accesses using current_inferior() and current_top_target(). */
1849 switch_to_thread (event_thread
);
1851 /* Do the fixup, and release the resources acquired to do the displaced
1853 displaced_step_finish_status finish_status
=
1854 event_thread
->inf
->top_target ()->displaced_step_finish (event_thread
,
1857 if (finish_status
== DISPLACED_STEP_FINISH_STATUS_OK
)
1863 /* Data to be passed around while handling an event. This data is
1864 discarded between events. */
1865 struct execution_control_state
1867 process_stratum_target
*target
;
1869 /* The thread that got the event, if this was a thread event; NULL
1871 struct thread_info
*event_thread
;
1873 struct target_waitstatus ws
;
1874 int stop_func_filled_in
;
1875 CORE_ADDR stop_func_start
;
1876 CORE_ADDR stop_func_end
;
1877 const char *stop_func_name
;
1880 /* True if the event thread hit the single-step breakpoint of
1881 another thread. Thus the event doesn't cause a stop, the thread
1882 needs to be single-stepped past the single-step breakpoint before
1883 we can switch back to the original stepping thread. */
1884 int hit_singlestep_breakpoint
;
1887 /* Clear ECS and set it to point at TP. */
1890 reset_ecs (struct execution_control_state
*ecs
, struct thread_info
*tp
)
1892 memset (ecs
, 0, sizeof (*ecs
));
1893 ecs
->event_thread
= tp
;
1894 ecs
->ptid
= tp
->ptid
;
1897 static void keep_going_pass_signal (struct execution_control_state
*ecs
);
1898 static void prepare_to_wait (struct execution_control_state
*ecs
);
1899 static int keep_going_stepped_thread (struct thread_info
*tp
);
1900 static step_over_what
thread_still_needs_step_over (struct thread_info
*tp
);
1902 /* Are there any pending step-over requests? If so, run all we can
1903 now and return true. Otherwise, return false. */
1906 start_step_over (void)
1908 struct thread_info
*tp
, *next
;
1911 /* Don't start a new step-over if we already have an in-line
1912 step-over operation ongoing. */
1913 if (step_over_info_valid_p ())
1916 /* Steal the global thread step over chain. */
1917 thread_info
*threads_to_step
= global_thread_step_over_chain_head
;
1918 global_thread_step_over_chain_head
= NULL
;
1921 fprintf_unfiltered (gdb_stdlog
,
1922 "infrun: stealing list of %d threads to step from global queue\n",
1923 thread_step_over_chain_length (threads_to_step
));
1925 for (inferior
*inf
: all_inferiors ())
1926 inf
->displaced_step_state
.unavailable
= false;
1928 for (tp
= threads_to_step
; tp
!= NULL
; tp
= next
)
1930 struct execution_control_state ecss
;
1931 struct execution_control_state
*ecs
= &ecss
;
1932 step_over_what step_what
;
1933 int must_be_in_line
;
1935 gdb_assert (!tp
->stop_requested
);
1937 next
= thread_step_over_chain_next (threads_to_step
, tp
);
1939 step_what
= thread_still_needs_step_over (tp
);
1940 must_be_in_line
= ((step_what
& STEP_OVER_WATCHPOINT
)
1941 || ((step_what
& STEP_OVER_BREAKPOINT
)
1942 && !use_displaced_stepping (tp
)));
1944 /* We currently stop all threads of all processes to step-over
1945 in-line. If we need to start a new in-line step-over, let
1946 any pending displaced steps finish first. */
1947 if (must_be_in_line
&& displaced_step_in_progress_any_thread ())
1950 thread_step_over_chain_remove (&threads_to_step
, tp
);
1952 if (tp
->control
.trap_expected
1956 internal_error (__FILE__
, __LINE__
,
1957 "[%s] has inconsistent state: "
1958 "trap_expected=%d, resumed=%d, executing=%d\n",
1959 target_pid_to_str (tp
->ptid
).c_str (),
1960 tp
->control
.trap_expected
,
1965 infrun_log_debug ("resuming [%s] for step-over",
1966 target_pid_to_str (tp
->ptid
).c_str ());
1968 /* keep_going_pass_signal skips the step-over if the breakpoint
1969 is no longer inserted. In all-stop, we want to keep looking
1970 for a thread that needs a step-over instead of resuming TP,
1971 because we wouldn't be able to resume anything else until the
1972 target stops again. In non-stop, the resume always resumes
1973 only TP, so it's OK to let the thread resume freely. */
1974 if (!target_is_non_stop_p () && !step_what
)
1977 if (tp
->inf
->displaced_step_state
.unavailable
)
1979 global_thread_step_over_chain_enqueue (tp
);
1983 switch_to_thread (tp
);
1984 reset_ecs (ecs
, tp
);
1985 keep_going_pass_signal (ecs
);
1987 if (!ecs
->wait_some_more
)
1988 error (_("Command aborted."));
1990 /* If the thread's step over could not be initiated, it was re-added
1991 to the global step over chain. */
1994 infrun_log_debug ("start_step_over: [%s] was resumed.\n",
1995 target_pid_to_str (tp
->ptid
).c_str ());
1996 gdb_assert (!thread_is_in_step_over_chain (tp
));
2000 infrun_log_debug ("infrun: start_step_over: [%s] was NOT resumed.\n",
2001 target_pid_to_str (tp
->ptid
).c_str ());
2002 gdb_assert (thread_is_in_step_over_chain (tp
));
2006 /* If we started a new in-line step-over, we're done. */
2007 if (step_over_info_valid_p ())
2009 gdb_assert (tp
->control
.trap_expected
);
2014 if (!target_is_non_stop_p ())
2016 /* On all-stop, shouldn't have resumed unless we needed a
2018 gdb_assert (tp
->control
.trap_expected
2019 || tp
->step_after_step_resume_breakpoint
);
2021 /* With remote targets (at least), in all-stop, we can't
2022 issue any further remote commands until the program stops
2028 /* Either the thread no longer needed a step-over, or a new
2029 displaced stepping sequence started. Even in the latter
2030 case, continue looking. Maybe we can also start another
2031 displaced step on a thread of other process. */
2034 /* If there are threads left in the THREADS_TO_STEP list, but we have
2035 detected that we can't start anything more, put back these threads
2036 in the global list. */
2037 if (threads_to_step
== NULL
)
2040 fprintf_unfiltered (gdb_stdlog
,
2041 "infrun: step-over queue now empty\n");
2046 fprintf_unfiltered (gdb_stdlog
,
2047 "infrun: putting back %d threads to step in global queue\n",
2048 thread_step_over_chain_length (threads_to_step
));
2049 while (threads_to_step
!= nullptr)
2051 thread_info
*thread
= threads_to_step
;
2053 /* Remove from that list. */
2054 thread_step_over_chain_remove (&threads_to_step
, thread
);
2056 /* Add to global list. */
2057 global_thread_step_over_chain_enqueue (thread
);
2065 /* Update global variables holding ptids to hold NEW_PTID if they were
2066 holding OLD_PTID. */
2068 infrun_thread_ptid_changed (ptid_t old_ptid
, ptid_t new_ptid
)
2070 if (inferior_ptid
== old_ptid
)
2071 inferior_ptid
= new_ptid
;
2076 static const char schedlock_off
[] = "off";
2077 static const char schedlock_on
[] = "on";
2078 static const char schedlock_step
[] = "step";
2079 static const char schedlock_replay
[] = "replay";
2080 static const char *const scheduler_enums
[] = {
2087 static const char *scheduler_mode
= schedlock_replay
;
2089 show_scheduler_mode (struct ui_file
*file
, int from_tty
,
2090 struct cmd_list_element
*c
, const char *value
)
2092 fprintf_filtered (file
,
2093 _("Mode for locking scheduler "
2094 "during execution is \"%s\".\n"),
2099 set_schedlock_func (const char *args
, int from_tty
, struct cmd_list_element
*c
)
2101 if (!target_can_lock_scheduler
)
2103 scheduler_mode
= schedlock_off
;
2104 error (_("Target '%s' cannot support this command."), target_shortname
);
2108 /* True if execution commands resume all threads of all processes by
2109 default; otherwise, resume only threads of the current inferior
2111 bool sched_multi
= false;
2113 /* Try to setup for software single stepping over the specified location.
2114 Return 1 if target_resume() should use hardware single step.
2116 GDBARCH the current gdbarch.
2117 PC the location to step over. */
2120 maybe_software_singlestep (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
2124 if (execution_direction
== EXEC_FORWARD
2125 && gdbarch_software_single_step_p (gdbarch
))
2126 hw_step
= !insert_single_step_breakpoints (gdbarch
);
2134 user_visible_resume_ptid (int step
)
2140 /* With non-stop mode on, threads are always handled
2142 resume_ptid
= inferior_ptid
;
2144 else if ((scheduler_mode
== schedlock_on
)
2145 || (scheduler_mode
== schedlock_step
&& step
))
2147 /* User-settable 'scheduler' mode requires solo thread
2149 resume_ptid
= inferior_ptid
;
2151 else if ((scheduler_mode
== schedlock_replay
)
2152 && target_record_will_replay (minus_one_ptid
, execution_direction
))
2154 /* User-settable 'scheduler' mode requires solo thread resume in replay
2156 resume_ptid
= inferior_ptid
;
2158 else if (!sched_multi
&& target_supports_multi_process ())
2160 /* Resume all threads of the current process (and none of other
2162 resume_ptid
= ptid_t (inferior_ptid
.pid ());
2166 /* Resume all threads of all processes. */
2167 resume_ptid
= RESUME_ALL
;
2175 process_stratum_target
*
2176 user_visible_resume_target (ptid_t resume_ptid
)
2178 return (resume_ptid
== minus_one_ptid
&& sched_multi
2180 : current_inferior ()->process_target ());
2183 /* Return a ptid representing the set of threads that we will resume,
2184 in the perspective of the target, assuming run control handling
2185 does not require leaving some threads stopped (e.g., stepping past
2186 breakpoint). USER_STEP indicates whether we're about to start the
2187 target for a stepping command. */
2190 internal_resume_ptid (int user_step
)
2192 /* In non-stop, we always control threads individually. Note that
2193 the target may always work in non-stop mode even with "set
2194 non-stop off", in which case user_visible_resume_ptid could
2195 return a wildcard ptid. */
2196 if (target_is_non_stop_p ())
2197 return inferior_ptid
;
2199 return user_visible_resume_ptid (user_step
);
2202 /* Wrapper for target_resume, that handles infrun-specific
2206 do_target_resume (ptid_t resume_ptid
, int step
, enum gdb_signal sig
)
2208 struct thread_info
*tp
= inferior_thread ();
2210 gdb_assert (!tp
->stop_requested
);
2212 /* Install inferior's terminal modes. */
2213 target_terminal::inferior ();
2215 /* Avoid confusing the next resume, if the next stop/resume
2216 happens to apply to another thread. */
2217 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2219 /* Advise target which signals may be handled silently.
2221 If we have removed breakpoints because we are stepping over one
2222 in-line (in any thread), we need to receive all signals to avoid
2223 accidentally skipping a breakpoint during execution of a signal
2226 Likewise if we're displaced stepping, otherwise a trap for a
2227 breakpoint in a signal handler might be confused with the
2228 displaced step finishing. We don't make the displaced_step_fixup
2229 step distinguish the cases instead, because:
2231 - a backtrace while stopped in the signal handler would show the
2232 scratch pad as frame older than the signal handler, instead of
2233 the real mainline code.
2235 - when the thread is later resumed, the signal handler would
2236 return to the scratch pad area, which would no longer be
2238 if (step_over_info_valid_p ()
2239 || displaced_step_in_progress (tp
->inf
))
2240 target_pass_signals ({});
2242 target_pass_signals (signal_pass
);
2244 target_resume (resume_ptid
, step
, sig
);
2246 target_commit_resume ();
2248 if (target_can_async_p ())
2252 /* Resume the inferior. SIG is the signal to give the inferior
2253 (GDB_SIGNAL_0 for none). Note: don't call this directly; instead
2254 call 'resume', which handles exceptions. */
2257 resume_1 (enum gdb_signal sig
)
2259 struct regcache
*regcache
= get_current_regcache ();
2260 struct gdbarch
*gdbarch
= regcache
->arch ();
2261 struct thread_info
*tp
= inferior_thread ();
2262 const address_space
*aspace
= regcache
->aspace ();
2264 /* This represents the user's step vs continue request. When
2265 deciding whether "set scheduler-locking step" applies, it's the
2266 user's intention that counts. */
2267 const int user_step
= tp
->control
.stepping_command
;
2268 /* This represents what we'll actually request the target to do.
2269 This can decay from a step to a continue, if e.g., we need to
2270 implement single-stepping with breakpoints (software
2274 gdb_assert (!tp
->stop_requested
);
2275 gdb_assert (!thread_is_in_step_over_chain (tp
));
2277 if (tp
->suspend
.waitstatus_pending_p
)
2280 ("thread %s has pending wait "
2281 "status %s (currently_stepping=%d).",
2282 target_pid_to_str (tp
->ptid
).c_str (),
2283 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2284 currently_stepping (tp
));
2286 tp
->inf
->process_target ()->threads_executing
= true;
2289 /* FIXME: What should we do if we are supposed to resume this
2290 thread with a signal? Maybe we should maintain a queue of
2291 pending signals to deliver. */
2292 if (sig
!= GDB_SIGNAL_0
)
2294 warning (_("Couldn't deliver signal %s to %s."),
2295 gdb_signal_to_name (sig
),
2296 target_pid_to_str (tp
->ptid
).c_str ());
2299 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2301 if (target_can_async_p ())
2304 /* Tell the event loop we have an event to process. */
2305 mark_async_event_handler (infrun_async_inferior_event_token
);
2310 tp
->stepped_breakpoint
= 0;
2312 /* Depends on stepped_breakpoint. */
2313 step
= currently_stepping (tp
);
2315 if (current_inferior ()->waiting_for_vfork_done
)
2317 /* Don't try to single-step a vfork parent that is waiting for
2318 the child to get out of the shared memory region (by exec'ing
2319 or exiting). This is particularly important on software
2320 single-step archs, as the child process would trip on the
2321 software single step breakpoint inserted for the parent
2322 process. Since the parent will not actually execute any
2323 instruction until the child is out of the shared region (such
2324 are vfork's semantics), it is safe to simply continue it.
2325 Eventually, we'll see a TARGET_WAITKIND_VFORK_DONE event for
2326 the parent, and tell it to `keep_going', which automatically
2327 re-sets it stepping. */
2328 infrun_log_debug ("resume : clear step");
2332 CORE_ADDR pc
= regcache_read_pc (regcache
);
2334 infrun_log_debug ("step=%d, signal=%s, trap_expected=%d, "
2335 "current thread [%s] at %s",
2336 step
, gdb_signal_to_symbol_string (sig
),
2337 tp
->control
.trap_expected
,
2338 target_pid_to_str (inferior_ptid
).c_str (),
2339 paddress (gdbarch
, pc
));
2341 /* Normally, by the time we reach `resume', the breakpoints are either
2342 removed or inserted, as appropriate. The exception is if we're sitting
2343 at a permanent breakpoint; we need to step over it, but permanent
2344 breakpoints can't be removed. So we have to test for it here. */
2345 if (breakpoint_here_p (aspace
, pc
) == permanent_breakpoint_here
)
2347 if (sig
!= GDB_SIGNAL_0
)
2349 /* We have a signal to pass to the inferior. The resume
2350 may, or may not take us to the signal handler. If this
2351 is a step, we'll need to stop in the signal handler, if
2352 there's one, (if the target supports stepping into
2353 handlers), or in the next mainline instruction, if
2354 there's no handler. If this is a continue, we need to be
2355 sure to run the handler with all breakpoints inserted.
2356 In all cases, set a breakpoint at the current address
2357 (where the handler returns to), and once that breakpoint
2358 is hit, resume skipping the permanent breakpoint. If
2359 that breakpoint isn't hit, then we've stepped into the
2360 signal handler (or hit some other event). We'll delete
2361 the step-resume breakpoint then. */
2363 infrun_log_debug ("resume: skipping permanent breakpoint, "
2364 "deliver signal first");
2366 clear_step_over_info ();
2367 tp
->control
.trap_expected
= 0;
2369 if (tp
->control
.step_resume_breakpoint
== NULL
)
2371 /* Set a "high-priority" step-resume, as we don't want
2372 user breakpoints at PC to trigger (again) when this
2374 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2375 gdb_assert (tp
->control
.step_resume_breakpoint
->loc
->permanent
);
2377 tp
->step_after_step_resume_breakpoint
= step
;
2380 insert_breakpoints ();
2384 /* There's no signal to pass, we can go ahead and skip the
2385 permanent breakpoint manually. */
2386 infrun_log_debug ("skipping permanent breakpoint");
2387 gdbarch_skip_permanent_breakpoint (gdbarch
, regcache
);
2388 /* Update pc to reflect the new address from which we will
2389 execute instructions. */
2390 pc
= regcache_read_pc (regcache
);
2394 /* We've already advanced the PC, so the stepping part
2395 is done. Now we need to arrange for a trap to be
2396 reported to handle_inferior_event. Set a breakpoint
2397 at the current PC, and run to it. Don't update
2398 prev_pc, because if we end in
2399 switch_back_to_stepped_thread, we want the "expected
2400 thread advanced also" branch to be taken. IOW, we
2401 don't want this thread to step further from PC
2403 gdb_assert (!step_over_info_valid_p ());
2404 insert_single_step_breakpoint (gdbarch
, aspace
, pc
);
2405 insert_breakpoints ();
2407 resume_ptid
= internal_resume_ptid (user_step
);
2408 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
2415 /* If we have a breakpoint to step over, make sure to do a single
2416 step only. Same if we have software watchpoints. */
2417 if (tp
->control
.trap_expected
|| bpstat_should_step ())
2418 tp
->control
.may_range_step
= 0;
2420 /* If displaced stepping is enabled, step over breakpoints by executing a
2421 copy of the instruction at a different address.
2423 We can't use displaced stepping when we have a signal to deliver;
2424 the comments for displaced_step_prepare explain why. The
2425 comments in the handle_inferior event for dealing with 'random
2426 signals' explain what we do instead.
2428 We can't use displaced stepping when we are waiting for vfork_done
2429 event, displaced stepping breaks the vfork child similarly as single
2430 step software breakpoint. */
2431 if (tp
->control
.trap_expected
2432 && use_displaced_stepping (tp
)
2433 && !step_over_info_valid_p ()
2434 && sig
== GDB_SIGNAL_0
2435 && !current_inferior ()->waiting_for_vfork_done
)
2437 displaced_step_prepare_status prepare_status
2438 = displaced_step_prepare (tp
);
2440 if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_UNAVAILABLE
)
2442 infrun_log_debug ("Got placed in step-over queue");
2444 tp
->control
.trap_expected
= 0;
2447 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_ERROR
)
2449 /* Fallback to stepping over the breakpoint in-line. */
2451 if (target_is_non_stop_p ())
2452 stop_all_threads ();
2454 set_step_over_info (regcache
->aspace (),
2455 regcache_read_pc (regcache
), 0, tp
->global_num
);
2457 step
= maybe_software_singlestep (gdbarch
, pc
);
2459 insert_breakpoints ();
2461 else if (prepare_status
== DISPLACED_STEP_PREPARE_STATUS_OK
)
2463 step
= gdbarch_displaced_step_hw_singlestep (gdbarch
, NULL
);
2466 gdb_assert_not_reached ("invalid displaced_step_prepare_status value");
2469 /* Do we need to do it the hard way, w/temp breakpoints? */
2471 step
= maybe_software_singlestep (gdbarch
, pc
);
2473 /* Currently, our software single-step implementation leads to different
2474 results than hardware single-stepping in one situation: when stepping
2475 into delivering a signal which has an associated signal handler,
2476 hardware single-step will stop at the first instruction of the handler,
2477 while software single-step will simply skip execution of the handler.
2479 For now, this difference in behavior is accepted since there is no
2480 easy way to actually implement single-stepping into a signal handler
2481 without kernel support.
2483 However, there is one scenario where this difference leads to follow-on
2484 problems: if we're stepping off a breakpoint by removing all breakpoints
2485 and then single-stepping. In this case, the software single-step
2486 behavior means that even if there is a *breakpoint* in the signal
2487 handler, GDB still would not stop.
2489 Fortunately, we can at least fix this particular issue. We detect
2490 here the case where we are about to deliver a signal while software
2491 single-stepping with breakpoints removed. In this situation, we
2492 revert the decisions to remove all breakpoints and insert single-
2493 step breakpoints, and instead we install a step-resume breakpoint
2494 at the current address, deliver the signal without stepping, and
2495 once we arrive back at the step-resume breakpoint, actually step
2496 over the breakpoint we originally wanted to step over. */
2497 if (thread_has_single_step_breakpoints_set (tp
)
2498 && sig
!= GDB_SIGNAL_0
2499 && step_over_info_valid_p ())
2501 /* If we have nested signals or a pending signal is delivered
2502 immediately after a handler returns, might already have
2503 a step-resume breakpoint set on the earlier handler. We cannot
2504 set another step-resume breakpoint; just continue on until the
2505 original breakpoint is hit. */
2506 if (tp
->control
.step_resume_breakpoint
== NULL
)
2508 insert_hp_step_resume_breakpoint_at_frame (get_current_frame ());
2509 tp
->step_after_step_resume_breakpoint
= 1;
2512 delete_single_step_breakpoints (tp
);
2514 clear_step_over_info ();
2515 tp
->control
.trap_expected
= 0;
2517 insert_breakpoints ();
2520 /* If STEP is set, it's a request to use hardware stepping
2521 facilities. But in that case, we should never
2522 use singlestep breakpoint. */
2523 gdb_assert (!(thread_has_single_step_breakpoints_set (tp
) && step
));
2525 /* Decide the set of threads to ask the target to resume. */
2526 if (tp
->control
.trap_expected
)
2528 /* We're allowing a thread to run past a breakpoint it has
2529 hit, either by single-stepping the thread with the breakpoint
2530 removed, or by displaced stepping, with the breakpoint inserted.
2531 In the former case, we need to single-step only this thread,
2532 and keep others stopped, as they can miss this breakpoint if
2533 allowed to run. That's not really a problem for displaced
2534 stepping, but, we still keep other threads stopped, in case
2535 another thread is also stopped for a breakpoint waiting for
2536 its turn in the displaced stepping queue. */
2537 resume_ptid
= inferior_ptid
;
2540 resume_ptid
= internal_resume_ptid (user_step
);
2542 if (execution_direction
!= EXEC_REVERSE
2543 && step
&& breakpoint_inserted_here_p (aspace
, pc
))
2545 /* There are two cases where we currently need to step a
2546 breakpoint instruction when we have a signal to deliver:
2548 - See handle_signal_stop where we handle random signals that
2549 could take out us out of the stepping range. Normally, in
2550 that case we end up continuing (instead of stepping) over the
2551 signal handler with a breakpoint at PC, but there are cases
2552 where we should _always_ single-step, even if we have a
2553 step-resume breakpoint, like when a software watchpoint is
2554 set. Assuming single-stepping and delivering a signal at the
2555 same time would takes us to the signal handler, then we could
2556 have removed the breakpoint at PC to step over it. However,
2557 some hardware step targets (like e.g., Mac OS) can't step
2558 into signal handlers, and for those, we need to leave the
2559 breakpoint at PC inserted, as otherwise if the handler
2560 recurses and executes PC again, it'll miss the breakpoint.
2561 So we leave the breakpoint inserted anyway, but we need to
2562 record that we tried to step a breakpoint instruction, so
2563 that adjust_pc_after_break doesn't end up confused.
2565 - In non-stop if we insert a breakpoint (e.g., a step-resume)
2566 in one thread after another thread that was stepping had been
2567 momentarily paused for a step-over. When we re-resume the
2568 stepping thread, it may be resumed from that address with a
2569 breakpoint that hasn't trapped yet. Seen with
2570 gdb.threads/non-stop-fair-events.exp, on targets that don't
2571 do displaced stepping. */
2573 infrun_log_debug ("resume: [%s] stepped breakpoint",
2574 target_pid_to_str (tp
->ptid
).c_str ());
2576 tp
->stepped_breakpoint
= 1;
2578 /* Most targets can step a breakpoint instruction, thus
2579 executing it normally. But if this one cannot, just
2580 continue and we will hit it anyway. */
2581 if (gdbarch_cannot_step_breakpoint (gdbarch
))
2586 && tp
->control
.trap_expected
2587 && use_displaced_stepping (tp
)
2588 && !step_over_info_valid_p ())
2590 struct regcache
*resume_regcache
= get_thread_regcache (tp
);
2591 struct gdbarch
*resume_gdbarch
= resume_regcache
->arch ();
2592 CORE_ADDR actual_pc
= regcache_read_pc (resume_regcache
);
2595 fprintf_unfiltered (gdb_stdlog
, "displaced: run %s: ",
2596 paddress (resume_gdbarch
, actual_pc
));
2597 read_memory (actual_pc
, buf
, sizeof (buf
));
2598 displaced_step_dump_bytes (gdb_stdlog
, buf
, sizeof (buf
));
2601 if (tp
->control
.may_range_step
)
2603 /* If we're resuming a thread with the PC out of the step
2604 range, then we're doing some nested/finer run control
2605 operation, like stepping the thread out of the dynamic
2606 linker or the displaced stepping scratch pad. We
2607 shouldn't have allowed a range step then. */
2608 gdb_assert (pc_in_thread_step_range (pc
, tp
));
2611 do_target_resume (resume_ptid
, step
, sig
);
2615 /* Resume the inferior. SIG is the signal to give the inferior
2616 (GDB_SIGNAL_0 for none). This is a wrapper around 'resume_1' that
2617 rolls back state on error. */
2620 resume (gdb_signal sig
)
2626 catch (const gdb_exception
&ex
)
2628 /* If resuming is being aborted for any reason, delete any
2629 single-step breakpoint resume_1 may have created, to avoid
2630 confusing the following resumption, and to avoid leaving
2631 single-step breakpoints perturbing other threads, in case
2632 we're running in non-stop mode. */
2633 if (inferior_ptid
!= null_ptid
)
2634 delete_single_step_breakpoints (inferior_thread ());
2644 /* Counter that tracks number of user visible stops. This can be used
2645 to tell whether a command has proceeded the inferior past the
2646 current location. This allows e.g., inferior function calls in
2647 breakpoint commands to not interrupt the command list. When the
2648 call finishes successfully, the inferior is standing at the same
2649 breakpoint as if nothing happened (and so we don't call
2651 static ULONGEST current_stop_id
;
2658 return current_stop_id
;
2661 /* Called when we report a user visible stop. */
2669 /* Clear out all variables saying what to do when inferior is continued.
2670 First do this, then set the ones you want, then call `proceed'. */
2673 clear_proceed_status_thread (struct thread_info
*tp
)
2675 infrun_log_debug ("%s", target_pid_to_str (tp
->ptid
).c_str ());
2677 /* If we're starting a new sequence, then the previous finished
2678 single-step is no longer relevant. */
2679 if (tp
->suspend
.waitstatus_pending_p
)
2681 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SINGLE_STEP
)
2683 infrun_log_debug ("pending event of %s was a finished step. "
2685 target_pid_to_str (tp
->ptid
).c_str ());
2687 tp
->suspend
.waitstatus_pending_p
= 0;
2688 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
2693 ("thread %s has pending wait status %s (currently_stepping=%d).",
2694 target_pid_to_str (tp
->ptid
).c_str (),
2695 target_waitstatus_to_string (&tp
->suspend
.waitstatus
).c_str (),
2696 currently_stepping (tp
));
2700 /* If this signal should not be seen by program, give it zero.
2701 Used for debugging signals. */
2702 if (!signal_pass_state (tp
->suspend
.stop_signal
))
2703 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
2705 delete tp
->thread_fsm
;
2706 tp
->thread_fsm
= NULL
;
2708 tp
->control
.trap_expected
= 0;
2709 tp
->control
.step_range_start
= 0;
2710 tp
->control
.step_range_end
= 0;
2711 tp
->control
.may_range_step
= 0;
2712 tp
->control
.step_frame_id
= null_frame_id
;
2713 tp
->control
.step_stack_frame_id
= null_frame_id
;
2714 tp
->control
.step_over_calls
= STEP_OVER_UNDEBUGGABLE
;
2715 tp
->control
.step_start_function
= NULL
;
2716 tp
->stop_requested
= 0;
2718 tp
->control
.stop_step
= 0;
2720 tp
->control
.proceed_to_finish
= 0;
2722 tp
->control
.stepping_command
= 0;
2724 /* Discard any remaining commands or status from previous stop. */
2725 bpstat_clear (&tp
->control
.stop_bpstat
);
2729 clear_proceed_status (int step
)
2731 /* With scheduler-locking replay, stop replaying other threads if we're
2732 not replaying the user-visible resume ptid.
2734 This is a convenience feature to not require the user to explicitly
2735 stop replaying the other threads. We're assuming that the user's
2736 intent is to resume tracing the recorded process. */
2737 if (!non_stop
&& scheduler_mode
== schedlock_replay
2738 && target_record_is_replaying (minus_one_ptid
)
2739 && !target_record_will_replay (user_visible_resume_ptid (step
),
2740 execution_direction
))
2741 target_record_stop_replaying ();
2743 if (!non_stop
&& inferior_ptid
!= null_ptid
)
2745 ptid_t resume_ptid
= user_visible_resume_ptid (step
);
2746 process_stratum_target
*resume_target
2747 = user_visible_resume_target (resume_ptid
);
2749 /* In all-stop mode, delete the per-thread status of all threads
2750 we're about to resume, implicitly and explicitly. */
2751 for (thread_info
*tp
: all_non_exited_threads (resume_target
, resume_ptid
))
2752 clear_proceed_status_thread (tp
);
2755 if (inferior_ptid
!= null_ptid
)
2757 struct inferior
*inferior
;
2761 /* If in non-stop mode, only delete the per-thread status of
2762 the current thread. */
2763 clear_proceed_status_thread (inferior_thread ());
2766 inferior
= current_inferior ();
2767 inferior
->control
.stop_soon
= NO_STOP_QUIETLY
;
2770 gdb::observers::about_to_proceed
.notify ();
2773 /* Returns true if TP is still stopped at a breakpoint that needs
2774 stepping-over in order to make progress. If the breakpoint is gone
2775 meanwhile, we can skip the whole step-over dance. */
2778 thread_still_needs_step_over_bp (struct thread_info
*tp
)
2780 if (tp
->stepping_over_breakpoint
)
2782 struct regcache
*regcache
= get_thread_regcache (tp
);
2784 if (breakpoint_here_p (regcache
->aspace (),
2785 regcache_read_pc (regcache
))
2786 == ordinary_breakpoint_here
)
2789 tp
->stepping_over_breakpoint
= 0;
2795 /* Check whether thread TP still needs to start a step-over in order
2796 to make progress when resumed. Returns an bitwise or of enum
2797 step_over_what bits, indicating what needs to be stepped over. */
2799 static step_over_what
2800 thread_still_needs_step_over (struct thread_info
*tp
)
2802 step_over_what what
= 0;
2804 if (thread_still_needs_step_over_bp (tp
))
2805 what
|= STEP_OVER_BREAKPOINT
;
2807 if (tp
->stepping_over_watchpoint
2808 && !target_have_steppable_watchpoint
)
2809 what
|= STEP_OVER_WATCHPOINT
;
2814 /* Returns true if scheduler locking applies. STEP indicates whether
2815 we're about to do a step/next-like command to a thread. */
2818 schedlock_applies (struct thread_info
*tp
)
2820 return (scheduler_mode
== schedlock_on
2821 || (scheduler_mode
== schedlock_step
2822 && tp
->control
.stepping_command
)
2823 || (scheduler_mode
== schedlock_replay
2824 && target_record_will_replay (minus_one_ptid
,
2825 execution_direction
)));
2828 /* Calls target_commit_resume on all targets. */
2831 commit_resume_all_targets ()
2833 scoped_restore_current_thread restore_thread
;
2835 /* Map between process_target and a representative inferior. This
2836 is to avoid committing a resume in the same target more than
2837 once. Resumptions must be idempotent, so this is an
2839 std::unordered_map
<process_stratum_target
*, inferior
*> conn_inf
;
2841 for (inferior
*inf
: all_non_exited_inferiors ())
2842 if (inf
->has_execution ())
2843 conn_inf
[inf
->process_target ()] = inf
;
2845 for (const auto &ci
: conn_inf
)
2847 inferior
*inf
= ci
.second
;
2848 switch_to_inferior_no_thread (inf
);
2849 target_commit_resume ();
2853 /* Check that all the targets we're about to resume are in non-stop
2854 mode. Ideally, we'd only care whether all targets support
2855 target-async, but we're not there yet. E.g., stop_all_threads
2856 doesn't know how to handle all-stop targets. Also, the remote
2857 protocol in all-stop mode is synchronous, irrespective of
2858 target-async, which means that things like a breakpoint re-set
2859 triggered by one target would try to read memory from all targets
2863 check_multi_target_resumption (process_stratum_target
*resume_target
)
2865 if (!non_stop
&& resume_target
== nullptr)
2867 scoped_restore_current_thread restore_thread
;
2869 /* This is used to track whether we're resuming more than one
2871 process_stratum_target
*first_connection
= nullptr;
2873 /* The first inferior we see with a target that does not work in
2874 always-non-stop mode. */
2875 inferior
*first_not_non_stop
= nullptr;
2877 for (inferior
*inf
: all_non_exited_inferiors (resume_target
))
2879 switch_to_inferior_no_thread (inf
);
2881 if (!target_has_execution
)
2884 process_stratum_target
*proc_target
2885 = current_inferior ()->process_target();
2887 if (!target_is_non_stop_p ())
2888 first_not_non_stop
= inf
;
2890 if (first_connection
== nullptr)
2891 first_connection
= proc_target
;
2892 else if (first_connection
!= proc_target
2893 && first_not_non_stop
!= nullptr)
2895 switch_to_inferior_no_thread (first_not_non_stop
);
2897 proc_target
= current_inferior ()->process_target();
2899 error (_("Connection %d (%s) does not support "
2900 "multi-target resumption."),
2901 proc_target
->connection_number
,
2902 make_target_connection_string (proc_target
).c_str ());
2908 /* Basic routine for continuing the program in various fashions.
2910 ADDR is the address to resume at, or -1 for resume where stopped.
2911 SIGGNAL is the signal to give it, or GDB_SIGNAL_0 for none,
2912 or GDB_SIGNAL_DEFAULT for act according to how it stopped.
2914 You should call clear_proceed_status before calling proceed. */
2917 proceed (CORE_ADDR addr
, enum gdb_signal siggnal
)
2919 struct regcache
*regcache
;
2920 struct gdbarch
*gdbarch
;
2922 struct execution_control_state ecss
;
2923 struct execution_control_state
*ecs
= &ecss
;
2926 /* If we're stopped at a fork/vfork, follow the branch set by the
2927 "set follow-fork-mode" command; otherwise, we'll just proceed
2928 resuming the current thread. */
2929 if (!follow_fork ())
2931 /* The target for some reason decided not to resume. */
2933 if (target_can_async_p ())
2934 inferior_event_handler (INF_EXEC_COMPLETE
);
2938 /* We'll update this if & when we switch to a new thread. */
2939 previous_inferior_ptid
= inferior_ptid
;
2941 regcache
= get_current_regcache ();
2942 gdbarch
= regcache
->arch ();
2943 const address_space
*aspace
= regcache
->aspace ();
2945 pc
= regcache_read_pc_protected (regcache
);
2947 thread_info
*cur_thr
= inferior_thread ();
2949 /* Fill in with reasonable starting values. */
2950 init_thread_stepping_state (cur_thr
);
2952 gdb_assert (!thread_is_in_step_over_chain (cur_thr
));
2955 = user_visible_resume_ptid (cur_thr
->control
.stepping_command
);
2956 process_stratum_target
*resume_target
2957 = user_visible_resume_target (resume_ptid
);
2959 check_multi_target_resumption (resume_target
);
2961 if (addr
== (CORE_ADDR
) -1)
2963 if (pc
== cur_thr
->suspend
.stop_pc
2964 && breakpoint_here_p (aspace
, pc
) == ordinary_breakpoint_here
2965 && execution_direction
!= EXEC_REVERSE
)
2966 /* There is a breakpoint at the address we will resume at,
2967 step one instruction before inserting breakpoints so that
2968 we do not stop right away (and report a second hit at this
2971 Note, we don't do this in reverse, because we won't
2972 actually be executing the breakpoint insn anyway.
2973 We'll be (un-)executing the previous instruction. */
2974 cur_thr
->stepping_over_breakpoint
= 1;
2975 else if (gdbarch_single_step_through_delay_p (gdbarch
)
2976 && gdbarch_single_step_through_delay (gdbarch
,
2977 get_current_frame ()))
2978 /* We stepped onto an instruction that needs to be stepped
2979 again before re-inserting the breakpoint, do so. */
2980 cur_thr
->stepping_over_breakpoint
= 1;
2984 regcache_write_pc (regcache
, addr
);
2987 if (siggnal
!= GDB_SIGNAL_DEFAULT
)
2988 cur_thr
->suspend
.stop_signal
= siggnal
;
2990 /* If an exception is thrown from this point on, make sure to
2991 propagate GDB's knowledge of the executing state to the
2992 frontend/user running state. */
2993 scoped_finish_thread_state
finish_state (resume_target
, resume_ptid
);
2995 /* Even if RESUME_PTID is a wildcard, and we end up resuming fewer
2996 threads (e.g., we might need to set threads stepping over
2997 breakpoints first), from the user/frontend's point of view, all
2998 threads in RESUME_PTID are now running. Unless we're calling an
2999 inferior function, as in that case we pretend the inferior
3000 doesn't run at all. */
3001 if (!cur_thr
->control
.in_infcall
)
3002 set_running (resume_target
, resume_ptid
, true);
3004 infrun_log_debug ("addr=%s, signal=%s", paddress (gdbarch
, addr
),
3005 gdb_signal_to_symbol_string (siggnal
));
3007 annotate_starting ();
3009 /* Make sure that output from GDB appears before output from the
3011 gdb_flush (gdb_stdout
);
3013 /* Since we've marked the inferior running, give it the terminal. A
3014 QUIT/Ctrl-C from here on is forwarded to the target (which can
3015 still detect attempts to unblock a stuck connection with repeated
3016 Ctrl-C from within target_pass_ctrlc). */
3017 target_terminal::inferior ();
3019 /* In a multi-threaded task we may select another thread and
3020 then continue or step.
3022 But if a thread that we're resuming had stopped at a breakpoint,
3023 it will immediately cause another breakpoint stop without any
3024 execution (i.e. it will report a breakpoint hit incorrectly). So
3025 we must step over it first.
3027 Look for threads other than the current (TP) that reported a
3028 breakpoint hit and haven't been resumed yet since. */
3030 /* If scheduler locking applies, we can avoid iterating over all
3032 if (!non_stop
&& !schedlock_applies (cur_thr
))
3034 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3037 switch_to_thread_no_regs (tp
);
3039 /* Ignore the current thread here. It's handled
3044 if (!thread_still_needs_step_over (tp
))
3047 gdb_assert (!thread_is_in_step_over_chain (tp
));
3049 infrun_log_debug ("need to step-over [%s] first",
3050 target_pid_to_str (tp
->ptid
).c_str ());
3052 global_thread_step_over_chain_enqueue (tp
);
3055 switch_to_thread (cur_thr
);
3058 /* Enqueue the current thread last, so that we move all other
3059 threads over their breakpoints first. */
3060 if (cur_thr
->stepping_over_breakpoint
)
3061 global_thread_step_over_chain_enqueue (cur_thr
);
3063 /* If the thread isn't started, we'll still need to set its prev_pc,
3064 so that switch_back_to_stepped_thread knows the thread hasn't
3065 advanced. Must do this before resuming any thread, as in
3066 all-stop/remote, once we resume we can't send any other packet
3067 until the target stops again. */
3068 cur_thr
->prev_pc
= regcache_read_pc_protected (regcache
);
3071 scoped_restore save_defer_tc
= make_scoped_defer_target_commit_resume ();
3073 started
= start_step_over ();
3075 if (step_over_info_valid_p ())
3077 /* Either this thread started a new in-line step over, or some
3078 other thread was already doing one. In either case, don't
3079 resume anything else until the step-over is finished. */
3081 else if (started
&& !target_is_non_stop_p ())
3083 /* A new displaced stepping sequence was started. In all-stop,
3084 we can't talk to the target anymore until it next stops. */
3086 else if (!non_stop
&& target_is_non_stop_p ())
3088 /* In all-stop, but the target is always in non-stop mode.
3089 Start all other threads that are implicitly resumed too. */
3090 for (thread_info
*tp
: all_non_exited_threads (resume_target
,
3093 switch_to_thread_no_regs (tp
);
3095 if (!tp
->inf
->has_execution ())
3097 infrun_log_debug ("[%s] target has no execution",
3098 target_pid_to_str (tp
->ptid
).c_str ());
3104 infrun_log_debug ("[%s] resumed",
3105 target_pid_to_str (tp
->ptid
).c_str ());
3106 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
3110 if (thread_is_in_step_over_chain (tp
))
3112 infrun_log_debug ("[%s] needs step-over",
3113 target_pid_to_str (tp
->ptid
).c_str ());
3117 infrun_log_debug ("resuming %s",
3118 target_pid_to_str (tp
->ptid
).c_str ());
3120 reset_ecs (ecs
, tp
);
3121 switch_to_thread (tp
);
3122 keep_going_pass_signal (ecs
);
3123 if (!ecs
->wait_some_more
)
3124 error (_("Command aborted."));
3127 else if (!cur_thr
->resumed
&& !thread_is_in_step_over_chain (cur_thr
))
3129 /* The thread wasn't started, and isn't queued, run it now. */
3130 reset_ecs (ecs
, cur_thr
);
3131 switch_to_thread (cur_thr
);
3132 keep_going_pass_signal (ecs
);
3133 if (!ecs
->wait_some_more
)
3134 error (_("Command aborted."));
3138 commit_resume_all_targets ();
3140 finish_state
.release ();
3142 /* If we've switched threads above, switch back to the previously
3143 current thread. We don't want the user to see a different
3145 switch_to_thread (cur_thr
);
3147 /* Tell the event loop to wait for it to stop. If the target
3148 supports asynchronous execution, it'll do this from within
3150 if (!target_can_async_p ())
3151 mark_async_event_handler (infrun_async_inferior_event_token
);
3155 /* Start remote-debugging of a machine over a serial link. */
3158 start_remote (int from_tty
)
3160 inferior
*inf
= current_inferior ();
3161 inf
->control
.stop_soon
= STOP_QUIETLY_REMOTE
;
3163 /* Always go on waiting for the target, regardless of the mode. */
3164 /* FIXME: cagney/1999-09-23: At present it isn't possible to
3165 indicate to wait_for_inferior that a target should timeout if
3166 nothing is returned (instead of just blocking). Because of this,
3167 targets expecting an immediate response need to, internally, set
3168 things up so that the target_wait() is forced to eventually
3170 /* FIXME: cagney/1999-09-24: It isn't possible for target_open() to
3171 differentiate to its caller what the state of the target is after
3172 the initial open has been performed. Here we're assuming that
3173 the target has stopped. It should be possible to eventually have
3174 target_open() return to the caller an indication that the target
3175 is currently running and GDB state should be set to the same as
3176 for an async run. */
3177 wait_for_inferior (inf
);
3179 /* Now that the inferior has stopped, do any bookkeeping like
3180 loading shared libraries. We want to do this before normal_stop,
3181 so that the displayed frame is up to date. */
3182 post_create_inferior (current_top_target (), from_tty
);
3187 /* Initialize static vars when a new inferior begins. */
3190 init_wait_for_inferior (void)
3192 /* These are meaningless until the first time through wait_for_inferior. */
3194 breakpoint_init_inferior (inf_starting
);
3196 clear_proceed_status (0);
3198 nullify_last_target_wait_ptid ();
3200 previous_inferior_ptid
= inferior_ptid
;
3205 static void handle_inferior_event (struct execution_control_state
*ecs
);
3207 static void handle_step_into_function (struct gdbarch
*gdbarch
,
3208 struct execution_control_state
*ecs
);
3209 static void handle_step_into_function_backward (struct gdbarch
*gdbarch
,
3210 struct execution_control_state
*ecs
);
3211 static void handle_signal_stop (struct execution_control_state
*ecs
);
3212 static void check_exception_resume (struct execution_control_state
*,
3213 struct frame_info
*);
3215 static void end_stepping_range (struct execution_control_state
*ecs
);
3216 static void stop_waiting (struct execution_control_state
*ecs
);
3217 static void keep_going (struct execution_control_state
*ecs
);
3218 static void process_event_stop_test (struct execution_control_state
*ecs
);
3219 static int switch_back_to_stepped_thread (struct execution_control_state
*ecs
);
3221 /* This function is attached as a "thread_stop_requested" observer.
3222 Cleanup local state that assumed the PTID was to be resumed, and
3223 report the stop to the frontend. */
3226 infrun_thread_stop_requested (ptid_t ptid
)
3228 process_stratum_target
*curr_target
= current_inferior ()->process_target ();
3230 /* PTID was requested to stop. If the thread was already stopped,
3231 but the user/frontend doesn't know about that yet (e.g., the
3232 thread had been temporarily paused for some step-over), set up
3233 for reporting the stop now. */
3234 for (thread_info
*tp
: all_threads (curr_target
, ptid
))
3236 if (tp
->state
!= THREAD_RUNNING
)
3241 /* Remove matching threads from the step-over queue, so
3242 start_step_over doesn't try to resume them
3244 if (thread_is_in_step_over_chain (tp
))
3245 global_thread_step_over_chain_remove (tp
);
3247 /* If the thread is stopped, but the user/frontend doesn't
3248 know about that yet, queue a pending event, as if the
3249 thread had just stopped now. Unless the thread already had
3251 if (!tp
->suspend
.waitstatus_pending_p
)
3253 tp
->suspend
.waitstatus_pending_p
= 1;
3254 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_STOPPED
;
3255 tp
->suspend
.waitstatus
.value
.sig
= GDB_SIGNAL_0
;
3258 /* Clear the inline-frame state, since we're re-processing the
3260 clear_inline_frame_state (tp
);
3262 /* If this thread was paused because some other thread was
3263 doing an inline-step over, let that finish first. Once
3264 that happens, we'll restart all threads and consume pending
3265 stop events then. */
3266 if (step_over_info_valid_p ())
3269 /* Otherwise we can process the (new) pending event now. Set
3270 it so this pending event is considered by
3277 infrun_thread_thread_exit (struct thread_info
*tp
, int silent
)
3279 if (target_last_proc_target
== tp
->inf
->process_target ()
3280 && target_last_wait_ptid
== tp
->ptid
)
3281 nullify_last_target_wait_ptid ();
3284 /* Delete the step resume, single-step and longjmp/exception resume
3285 breakpoints of TP. */
3288 delete_thread_infrun_breakpoints (struct thread_info
*tp
)
3290 delete_step_resume_breakpoint (tp
);
3291 delete_exception_resume_breakpoint (tp
);
3292 delete_single_step_breakpoints (tp
);
3295 /* If the target still has execution, call FUNC for each thread that
3296 just stopped. In all-stop, that's all the non-exited threads; in
3297 non-stop, that's the current thread, only. */
3299 typedef void (*for_each_just_stopped_thread_callback_func
)
3300 (struct thread_info
*tp
);
3303 for_each_just_stopped_thread (for_each_just_stopped_thread_callback_func func
)
3305 if (!target_has_execution
|| inferior_ptid
== null_ptid
)
3308 if (target_is_non_stop_p ())
3310 /* If in non-stop mode, only the current thread stopped. */
3311 func (inferior_thread ());
3315 /* In all-stop mode, all threads have stopped. */
3316 for (thread_info
*tp
: all_non_exited_threads ())
3321 /* Delete the step resume and longjmp/exception resume breakpoints of
3322 the threads that just stopped. */
3325 delete_just_stopped_threads_infrun_breakpoints (void)
3327 for_each_just_stopped_thread (delete_thread_infrun_breakpoints
);
3330 /* Delete the single-step breakpoints of the threads that just
3334 delete_just_stopped_threads_single_step_breakpoints (void)
3336 for_each_just_stopped_thread (delete_single_step_breakpoints
);
3342 print_target_wait_results (ptid_t waiton_ptid
, ptid_t result_ptid
,
3343 const struct target_waitstatus
*ws
)
3345 std::string status_string
= target_waitstatus_to_string (ws
);
3348 /* The text is split over several lines because it was getting too long.
3349 Call fprintf_unfiltered (gdb_stdlog) once so that the text is still
3350 output as a unit; we want only one timestamp printed if debug_timestamp
3353 stb
.printf ("infrun: target_wait (%d.%ld.%ld",
3356 waiton_ptid
.tid ());
3357 if (waiton_ptid
.pid () != -1)
3358 stb
.printf (" [%s]", target_pid_to_str (waiton_ptid
).c_str ());
3359 stb
.printf (", status) =\n");
3360 stb
.printf ("infrun: %d.%ld.%ld [%s],\n",
3364 target_pid_to_str (result_ptid
).c_str ());
3365 stb
.printf ("infrun: %s\n", status_string
.c_str ());
3367 /* This uses %s in part to handle %'s in the text, but also to avoid
3368 a gcc error: the format attribute requires a string literal. */
3369 fprintf_unfiltered (gdb_stdlog
, "%s", stb
.c_str ());
3372 /* Select a thread at random, out of those which are resumed and have
3375 static struct thread_info
*
3376 random_pending_event_thread (inferior
*inf
, ptid_t waiton_ptid
)
3380 auto has_event
= [&] (thread_info
*tp
)
3382 return (tp
->ptid
.matches (waiton_ptid
)
3384 && tp
->suspend
.waitstatus_pending_p
);
3387 /* First see how many events we have. Count only resumed threads
3388 that have an event pending. */
3389 for (thread_info
*tp
: inf
->non_exited_threads ())
3393 if (num_events
== 0)
3396 /* Now randomly pick a thread out of those that have had events. */
3397 int random_selector
= (int) ((num_events
* (double) rand ())
3398 / (RAND_MAX
+ 1.0));
3401 infrun_log_debug ("Found %d events, selecting #%d",
3402 num_events
, random_selector
);
3404 /* Select the Nth thread that has had an event. */
3405 for (thread_info
*tp
: inf
->non_exited_threads ())
3407 if (random_selector
-- == 0)
3410 gdb_assert_not_reached ("event thread not found");
3413 /* Wrapper for target_wait that first checks whether threads have
3414 pending statuses to report before actually asking the target for
3415 more events. INF is the inferior we're using to call target_wait
3419 do_target_wait_1 (inferior
*inf
, ptid_t ptid
,
3420 target_waitstatus
*status
, int options
)
3423 struct thread_info
*tp
;
3425 /* We know that we are looking for an event in the target of inferior
3426 INF, but we don't know which thread the event might come from. As
3427 such we want to make sure that INFERIOR_PTID is reset so that none of
3428 the wait code relies on it - doing so is always a mistake. */
3429 switch_to_inferior_no_thread (inf
);
3431 /* First check if there is a resumed thread with a wait status
3433 if (ptid
== minus_one_ptid
|| ptid
.is_pid ())
3435 tp
= random_pending_event_thread (inf
, ptid
);
3439 infrun_log_debug ("Waiting for specific thread %s.",
3440 target_pid_to_str (ptid
).c_str ());
3442 /* We have a specific thread to check. */
3443 tp
= find_thread_ptid (inf
, ptid
);
3444 gdb_assert (tp
!= NULL
);
3445 if (!tp
->suspend
.waitstatus_pending_p
)
3450 && (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3451 || tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_HW_BREAKPOINT
))
3453 struct regcache
*regcache
= get_thread_regcache (tp
);
3454 struct gdbarch
*gdbarch
= regcache
->arch ();
3458 pc
= regcache_read_pc (regcache
);
3460 if (pc
!= tp
->suspend
.stop_pc
)
3462 infrun_log_debug ("PC of %s changed. was=%s, now=%s",
3463 target_pid_to_str (tp
->ptid
).c_str (),
3464 paddress (gdbarch
, tp
->suspend
.stop_pc
),
3465 paddress (gdbarch
, pc
));
3468 else if (!breakpoint_inserted_here_p (regcache
->aspace (), pc
))
3470 infrun_log_debug ("previous breakpoint of %s, at %s gone",
3471 target_pid_to_str (tp
->ptid
).c_str (),
3472 paddress (gdbarch
, pc
));
3479 infrun_log_debug ("pending event of %s cancelled.",
3480 target_pid_to_str (tp
->ptid
).c_str ());
3482 tp
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_SPURIOUS
;
3483 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3489 infrun_log_debug ("Using pending wait status %s for %s.",
3490 target_waitstatus_to_string
3491 (&tp
->suspend
.waitstatus
).c_str (),
3492 target_pid_to_str (tp
->ptid
).c_str ());
3494 /* Now that we've selected our final event LWP, un-adjust its PC
3495 if it was a software breakpoint (and the target doesn't
3496 always adjust the PC itself). */
3497 if (tp
->suspend
.stop_reason
== TARGET_STOPPED_BY_SW_BREAKPOINT
3498 && !target_supports_stopped_by_sw_breakpoint ())
3500 struct regcache
*regcache
;
3501 struct gdbarch
*gdbarch
;
3504 regcache
= get_thread_regcache (tp
);
3505 gdbarch
= regcache
->arch ();
3507 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
3512 pc
= regcache_read_pc (regcache
);
3513 regcache_write_pc (regcache
, pc
+ decr_pc
);
3517 tp
->suspend
.stop_reason
= TARGET_STOPPED_BY_NO_REASON
;
3518 *status
= tp
->suspend
.waitstatus
;
3519 tp
->suspend
.waitstatus_pending_p
= 0;
3521 /* Wake up the event loop again, until all pending events are
3523 if (target_is_async_p ())
3524 mark_async_event_handler (infrun_async_inferior_event_token
);
3528 /* But if we don't find one, we'll have to wait. */
3530 if (deprecated_target_wait_hook
)
3531 event_ptid
= deprecated_target_wait_hook (ptid
, status
, options
);
3533 event_ptid
= target_wait (ptid
, status
, options
);
3538 /* Wrapper for target_wait that first checks whether threads have
3539 pending statuses to report before actually asking the target for
3540 more events. Polls for events from all inferiors/targets. */
3543 do_target_wait (ptid_t wait_ptid
, execution_control_state
*ecs
, int options
)
3545 int num_inferiors
= 0;
3546 int random_selector
;
3548 /* For fairness, we pick the first inferior/target to poll at random
3549 out of all inferiors that may report events, and then continue
3550 polling the rest of the inferior list starting from that one in a
3551 circular fashion until the whole list is polled once. */
3553 auto inferior_matches
= [&wait_ptid
] (inferior
*inf
)
3555 return (inf
->process_target () != NULL
3556 && ptid_t (inf
->pid
).matches (wait_ptid
));
3559 /* First see how many matching inferiors we have. */
3560 for (inferior
*inf
: all_inferiors ())
3561 if (inferior_matches (inf
))
3564 if (num_inferiors
== 0)
3566 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3570 /* Now randomly pick an inferior out of those that matched. */
3571 random_selector
= (int)
3572 ((num_inferiors
* (double) rand ()) / (RAND_MAX
+ 1.0));
3574 if (num_inferiors
> 1)
3575 infrun_log_debug ("Found %d inferiors, starting at #%d",
3576 num_inferiors
, random_selector
);
3578 /* Select the Nth inferior that matched. */
3580 inferior
*selected
= nullptr;
3582 for (inferior
*inf
: all_inferiors ())
3583 if (inferior_matches (inf
))
3584 if (random_selector
-- == 0)
3590 /* Now poll for events out of each of the matching inferior's
3591 targets, starting from the selected one. */
3593 auto do_wait
= [&] (inferior
*inf
)
3595 ecs
->ptid
= do_target_wait_1 (inf
, wait_ptid
, &ecs
->ws
, options
);
3596 ecs
->target
= inf
->process_target ();
3597 return (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3600 /* Needed in 'all-stop + target-non-stop' mode, because we end up
3601 here spuriously after the target is all stopped and we've already
3602 reported the stop to the user, polling for events. */
3603 scoped_restore_current_thread restore_thread
;
3605 int inf_num
= selected
->num
;
3606 for (inferior
*inf
= selected
; inf
!= NULL
; inf
= inf
->next
)
3607 if (inferior_matches (inf
))
3611 for (inferior
*inf
= inferior_list
;
3612 inf
!= NULL
&& inf
->num
< inf_num
;
3614 if (inferior_matches (inf
))
3618 ecs
->ws
.kind
= TARGET_WAITKIND_IGNORE
;
3622 /* Prepare and stabilize the inferior for detaching it. E.g.,
3623 detaching while a thread is displaced stepping is a recipe for
3624 crashing it, as nothing would readjust the PC out of the scratch
3628 prepare_for_detach (void)
3630 struct inferior
*inf
= current_inferior ();
3631 ptid_t pid_ptid
= ptid_t (inf
->pid
);
3633 // displaced_step_inferior_state *displaced = get_displaced_stepping_state (inf);
3635 /* Is any thread of this process displaced stepping? If not,
3636 there's nothing else to do. */
3637 if (displaced_step_in_progress (inf
))
3640 infrun_log_debug ("displaced-stepping in-process while detaching");
3642 scoped_restore restore_detaching
= make_scoped_restore (&inf
->detaching
, true);
3647 struct execution_control_state ecss
;
3648 struct execution_control_state
*ecs
;
3651 memset (ecs
, 0, sizeof (*ecs
));
3653 overlay_cache_invalid
= 1;
3654 /* Flush target cache before starting to handle each event.
3655 Target was running and cache could be stale. This is just a
3656 heuristic. Running threads may modify target memory, but we
3657 don't get any event. */
3658 target_dcache_invalidate ();
3660 do_target_wait (pid_ptid
, ecs
, 0);
3663 print_target_wait_results (pid_ptid
, ecs
->ptid
, &ecs
->ws
);
3665 /* If an error happens while handling the event, propagate GDB's
3666 knowledge of the executing state to the frontend/user running
3668 scoped_finish_thread_state
finish_state (inf
->process_target (),
3671 /* Now figure out what to do with the result of the result. */
3672 handle_inferior_event (ecs
);
3674 /* No error, don't finish the state yet. */
3675 finish_state
.release ();
3677 /* Breakpoints and watchpoints are not installed on the target
3678 at this point, and signals are passed directly to the
3679 inferior, so this must mean the process is gone. */
3680 if (!ecs
->wait_some_more
)
3682 restore_detaching
.release ();
3683 error (_("Program exited while detaching"));
3687 restore_detaching
.release ();
3690 /* Wait for control to return from inferior to debugger.
3692 If inferior gets a signal, we may decide to start it up again
3693 instead of returning. That is why there is a loop in this function.
3694 When this function actually returns it means the inferior
3695 should be left stopped and GDB should read more commands. */
3698 wait_for_inferior (inferior
*inf
)
3700 infrun_log_debug ("wait_for_inferior ()");
3702 SCOPE_EXIT
{ delete_just_stopped_threads_infrun_breakpoints (); };
3704 /* If an error happens while handling the event, propagate GDB's
3705 knowledge of the executing state to the frontend/user running
3707 scoped_finish_thread_state finish_state
3708 (inf
->process_target (), minus_one_ptid
);
3712 struct execution_control_state ecss
;
3713 struct execution_control_state
*ecs
= &ecss
;
3715 memset (ecs
, 0, sizeof (*ecs
));
3717 overlay_cache_invalid
= 1;
3719 /* Flush target cache before starting to handle each event.
3720 Target was running and cache could be stale. This is just a
3721 heuristic. Running threads may modify target memory, but we
3722 don't get any event. */
3723 target_dcache_invalidate ();
3725 ecs
->ptid
= do_target_wait_1 (inf
, minus_one_ptid
, &ecs
->ws
, 0);
3726 ecs
->target
= inf
->process_target ();
3729 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3731 /* Now figure out what to do with the result of the result. */
3732 handle_inferior_event (ecs
);
3734 if (!ecs
->wait_some_more
)
3738 /* No error, don't finish the state yet. */
3739 finish_state
.release ();
3742 /* Cleanup that reinstalls the readline callback handler, if the
3743 target is running in the background. If while handling the target
3744 event something triggered a secondary prompt, like e.g., a
3745 pagination prompt, we'll have removed the callback handler (see
3746 gdb_readline_wrapper_line). Need to do this as we go back to the
3747 event loop, ready to process further input. Note this has no
3748 effect if the handler hasn't actually been removed, because calling
3749 rl_callback_handler_install resets the line buffer, thus losing
3753 reinstall_readline_callback_handler_cleanup ()
3755 struct ui
*ui
= current_ui
;
3759 /* We're not going back to the top level event loop yet. Don't
3760 install the readline callback, as it'd prep the terminal,
3761 readline-style (raw, noecho) (e.g., --batch). We'll install
3762 it the next time the prompt is displayed, when we're ready
3767 if (ui
->command_editing
&& ui
->prompt_state
!= PROMPT_BLOCKED
)
3768 gdb_rl_callback_handler_reinstall ();
3771 /* Clean up the FSMs of threads that are now stopped. In non-stop,
3772 that's just the event thread. In all-stop, that's all threads. */
3775 clean_up_just_stopped_threads_fsms (struct execution_control_state
*ecs
)
3777 if (ecs
->event_thread
!= NULL
3778 && ecs
->event_thread
->thread_fsm
!= NULL
)
3779 ecs
->event_thread
->thread_fsm
->clean_up (ecs
->event_thread
);
3783 for (thread_info
*thr
: all_non_exited_threads ())
3785 if (thr
->thread_fsm
== NULL
)
3787 if (thr
== ecs
->event_thread
)
3790 switch_to_thread (thr
);
3791 thr
->thread_fsm
->clean_up (thr
);
3794 if (ecs
->event_thread
!= NULL
)
3795 switch_to_thread (ecs
->event_thread
);
3799 /* Helper for all_uis_check_sync_execution_done that works on the
3803 check_curr_ui_sync_execution_done (void)
3805 struct ui
*ui
= current_ui
;
3807 if (ui
->prompt_state
== PROMPT_NEEDED
3809 && !gdb_in_secondary_prompt_p (ui
))
3811 target_terminal::ours ();
3812 gdb::observers::sync_execution_done
.notify ();
3813 ui_register_input_event_handler (ui
);
3820 all_uis_check_sync_execution_done (void)
3822 SWITCH_THRU_ALL_UIS ()
3824 check_curr_ui_sync_execution_done ();
3831 all_uis_on_sync_execution_starting (void)
3833 SWITCH_THRU_ALL_UIS ()
3835 if (current_ui
->prompt_state
== PROMPT_NEEDED
)
3836 async_disable_stdin ();
3840 /* Asynchronous version of wait_for_inferior. It is called by the
3841 event loop whenever a change of state is detected on the file
3842 descriptor corresponding to the target. It can be called more than
3843 once to complete a single execution command. In such cases we need
3844 to keep the state in a global variable ECSS. If it is the last time
3845 that this function is called for a single execution command, then
3846 report to the user that the inferior has stopped, and do the
3847 necessary cleanups. */
3850 fetch_inferior_event ()
3852 struct execution_control_state ecss
;
3853 struct execution_control_state
*ecs
= &ecss
;
3856 memset (ecs
, 0, sizeof (*ecs
));
3858 /* Events are always processed with the main UI as current UI. This
3859 way, warnings, debug output, etc. are always consistently sent to
3860 the main console. */
3861 scoped_restore save_ui
= make_scoped_restore (¤t_ui
, main_ui
);
3863 /* End up with readline processing input, if necessary. */
3865 SCOPE_EXIT
{ reinstall_readline_callback_handler_cleanup (); };
3867 /* We're handling a live event, so make sure we're doing live
3868 debugging. If we're looking at traceframes while the target is
3869 running, we're going to need to get back to that mode after
3870 handling the event. */
3871 gdb::optional
<scoped_restore_current_traceframe
> maybe_restore_traceframe
;
3874 maybe_restore_traceframe
.emplace ();
3875 set_current_traceframe (-1);
3878 /* The user/frontend should not notice a thread switch due to
3879 internal events. Make sure we revert to the user selected
3880 thread and frame after handling the event and running any
3881 breakpoint commands. */
3882 scoped_restore_current_thread restore_thread
;
3884 overlay_cache_invalid
= 1;
3885 /* Flush target cache before starting to handle each event. Target
3886 was running and cache could be stale. This is just a heuristic.
3887 Running threads may modify target memory, but we don't get any
3889 target_dcache_invalidate ();
3891 scoped_restore save_exec_dir
3892 = make_scoped_restore (&execution_direction
,
3893 target_execution_direction ());
3895 if (!do_target_wait (minus_one_ptid
, ecs
, TARGET_WNOHANG
))
3898 gdb_assert (ecs
->ws
.kind
!= TARGET_WAITKIND_IGNORE
);
3900 /* Switch to the target that generated the event, so we can do
3901 target calls. Any inferior bound to the target will do, so we
3902 just switch to the first we find. */
3903 for (inferior
*inf
: all_inferiors (ecs
->target
))
3905 switch_to_inferior_no_thread (inf
);
3910 print_target_wait_results (minus_one_ptid
, ecs
->ptid
, &ecs
->ws
);
3912 /* If an error happens while handling the event, propagate GDB's
3913 knowledge of the executing state to the frontend/user running
3915 ptid_t finish_ptid
= !target_is_non_stop_p () ? minus_one_ptid
: ecs
->ptid
;
3916 scoped_finish_thread_state
finish_state (ecs
->target
, finish_ptid
);
3918 /* Get executed before scoped_restore_current_thread above to apply
3919 still for the thread which has thrown the exception. */
3920 auto defer_bpstat_clear
3921 = make_scope_exit (bpstat_clear_actions
);
3922 auto defer_delete_threads
3923 = make_scope_exit (delete_just_stopped_threads_infrun_breakpoints
);
3925 /* Now figure out what to do with the result of the result. */
3926 handle_inferior_event (ecs
);
3928 if (!ecs
->wait_some_more
)
3930 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
3931 int should_stop
= 1;
3932 struct thread_info
*thr
= ecs
->event_thread
;
3934 delete_just_stopped_threads_infrun_breakpoints ();
3938 struct thread_fsm
*thread_fsm
= thr
->thread_fsm
;
3940 if (thread_fsm
!= NULL
)
3941 should_stop
= thread_fsm
->should_stop (thr
);
3950 bool should_notify_stop
= true;
3953 clean_up_just_stopped_threads_fsms (ecs
);
3955 if (thr
!= NULL
&& thr
->thread_fsm
!= NULL
)
3956 should_notify_stop
= thr
->thread_fsm
->should_notify_stop ();
3958 if (should_notify_stop
)
3960 /* We may not find an inferior if this was a process exit. */
3961 if (inf
== NULL
|| inf
->control
.stop_soon
== NO_STOP_QUIETLY
)
3962 proceeded
= normal_stop ();
3967 inferior_event_handler (INF_EXEC_COMPLETE
);
3971 /* If we got a TARGET_WAITKIND_NO_RESUMED event, then the
3972 previously selected thread is gone. We have two
3973 choices - switch to no thread selected, or restore the
3974 previously selected thread (now exited). We chose the
3975 later, just because that's what GDB used to do. After
3976 this, "info threads" says "The current thread <Thread
3977 ID 2> has terminated." instead of "No thread
3981 && ecs
->ws
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
3982 restore_thread
.dont_restore ();
3986 defer_delete_threads
.release ();
3987 defer_bpstat_clear
.release ();
3989 /* No error, don't finish the thread states yet. */
3990 finish_state
.release ();
3992 /* This scope is used to ensure that readline callbacks are
3993 reinstalled here. */
3996 /* If a UI was in sync execution mode, and now isn't, restore its
3997 prompt (a synchronous execution command has finished, and we're
3998 ready for input). */
3999 all_uis_check_sync_execution_done ();
4002 && exec_done_display_p
4003 && (inferior_ptid
== null_ptid
4004 || inferior_thread ()->state
!= THREAD_RUNNING
))
4005 printf_unfiltered (_("completed.\n"));
4011 set_step_info (thread_info
*tp
, struct frame_info
*frame
,
4012 struct symtab_and_line sal
)
4014 /* This can be removed once this function no longer implicitly relies on the
4015 inferior_ptid value. */
4016 gdb_assert (inferior_ptid
== tp
->ptid
);
4018 tp
->control
.step_frame_id
= get_frame_id (frame
);
4019 tp
->control
.step_stack_frame_id
= get_stack_frame_id (frame
);
4021 tp
->current_symtab
= sal
.symtab
;
4022 tp
->current_line
= sal
.line
;
4025 /* Clear context switchable stepping state. */
4028 init_thread_stepping_state (struct thread_info
*tss
)
4030 tss
->stepped_breakpoint
= 0;
4031 tss
->stepping_over_breakpoint
= 0;
4032 tss
->stepping_over_watchpoint
= 0;
4033 tss
->step_after_step_resume_breakpoint
= 0;
4039 set_last_target_status (process_stratum_target
*target
, ptid_t ptid
,
4040 target_waitstatus status
)
4042 target_last_proc_target
= target
;
4043 target_last_wait_ptid
= ptid
;
4044 target_last_waitstatus
= status
;
4050 get_last_target_status (process_stratum_target
**target
, ptid_t
*ptid
,
4051 target_waitstatus
*status
)
4053 if (target
!= nullptr)
4054 *target
= target_last_proc_target
;
4055 if (ptid
!= nullptr)
4056 *ptid
= target_last_wait_ptid
;
4057 if (status
!= nullptr)
4058 *status
= target_last_waitstatus
;
4064 nullify_last_target_wait_ptid (void)
4066 target_last_proc_target
= nullptr;
4067 target_last_wait_ptid
= minus_one_ptid
;
4068 target_last_waitstatus
= {};
4071 /* Switch thread contexts. */
4074 context_switch (execution_control_state
*ecs
)
4076 if (ecs
->ptid
!= inferior_ptid
4077 && (inferior_ptid
== null_ptid
4078 || ecs
->event_thread
!= inferior_thread ()))
4080 infrun_log_debug ("Switching context from %s to %s",
4081 target_pid_to_str (inferior_ptid
).c_str (),
4082 target_pid_to_str (ecs
->ptid
).c_str ());
4085 switch_to_thread (ecs
->event_thread
);
4088 /* If the target can't tell whether we've hit breakpoints
4089 (target_supports_stopped_by_sw_breakpoint), and we got a SIGTRAP,
4090 check whether that could have been caused by a breakpoint. If so,
4091 adjust the PC, per gdbarch_decr_pc_after_break. */
4094 adjust_pc_after_break (struct thread_info
*thread
,
4095 struct target_waitstatus
*ws
)
4097 struct regcache
*regcache
;
4098 struct gdbarch
*gdbarch
;
4099 CORE_ADDR breakpoint_pc
, decr_pc
;
4101 /* If we've hit a breakpoint, we'll normally be stopped with SIGTRAP. If
4102 we aren't, just return.
4104 We assume that waitkinds other than TARGET_WAITKIND_STOPPED are not
4105 affected by gdbarch_decr_pc_after_break. Other waitkinds which are
4106 implemented by software breakpoints should be handled through the normal
4109 NOTE drow/2004-01-31: On some targets, breakpoints may generate
4110 different signals (SIGILL or SIGEMT for instance), but it is less
4111 clear where the PC is pointing afterwards. It may not match
4112 gdbarch_decr_pc_after_break. I don't know any specific target that
4113 generates these signals at breakpoints (the code has been in GDB since at
4114 least 1992) so I can not guess how to handle them here.
4116 In earlier versions of GDB, a target with
4117 gdbarch_have_nonsteppable_watchpoint would have the PC after hitting a
4118 watchpoint affected by gdbarch_decr_pc_after_break. I haven't found any
4119 target with both of these set in GDB history, and it seems unlikely to be
4120 correct, so gdbarch_have_nonsteppable_watchpoint is not checked here. */
4122 if (ws
->kind
!= TARGET_WAITKIND_STOPPED
)
4125 if (ws
->value
.sig
!= GDB_SIGNAL_TRAP
)
4128 /* In reverse execution, when a breakpoint is hit, the instruction
4129 under it has already been de-executed. The reported PC always
4130 points at the breakpoint address, so adjusting it further would
4131 be wrong. E.g., consider this case on a decr_pc_after_break == 1
4134 B1 0x08000000 : INSN1
4135 B2 0x08000001 : INSN2
4137 PC -> 0x08000003 : INSN4
4139 Say you're stopped at 0x08000003 as above. Reverse continuing
4140 from that point should hit B2 as below. Reading the PC when the
4141 SIGTRAP is reported should read 0x08000001 and INSN2 should have
4142 been de-executed already.
4144 B1 0x08000000 : INSN1
4145 B2 PC -> 0x08000001 : INSN2
4149 We can't apply the same logic as for forward execution, because
4150 we would wrongly adjust the PC to 0x08000000, since there's a
4151 breakpoint at PC - 1. We'd then report a hit on B1, although
4152 INSN1 hadn't been de-executed yet. Doing nothing is the correct
4154 if (execution_direction
== EXEC_REVERSE
)
4157 /* If the target can tell whether the thread hit a SW breakpoint,
4158 trust it. Targets that can tell also adjust the PC
4160 if (target_supports_stopped_by_sw_breakpoint ())
4163 /* Note that relying on whether a breakpoint is planted in memory to
4164 determine this can fail. E.g,. the breakpoint could have been
4165 removed since. Or the thread could have been told to step an
4166 instruction the size of a breakpoint instruction, and only
4167 _after_ was a breakpoint inserted at its address. */
4169 /* If this target does not decrement the PC after breakpoints, then
4170 we have nothing to do. */
4171 regcache
= get_thread_regcache (thread
);
4172 gdbarch
= regcache
->arch ();
4174 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
4178 const address_space
*aspace
= regcache
->aspace ();
4180 /* Find the location where (if we've hit a breakpoint) the
4181 breakpoint would be. */
4182 breakpoint_pc
= regcache_read_pc (regcache
) - decr_pc
;
4184 /* If the target can't tell whether a software breakpoint triggered,
4185 fallback to figuring it out based on breakpoints we think were
4186 inserted in the target, and on whether the thread was stepped or
4189 /* Check whether there actually is a software breakpoint inserted at
4192 If in non-stop mode, a race condition is possible where we've
4193 removed a breakpoint, but stop events for that breakpoint were
4194 already queued and arrive later. To suppress those spurious
4195 SIGTRAPs, we keep a list of such breakpoint locations for a bit,
4196 and retire them after a number of stop events are reported. Note
4197 this is an heuristic and can thus get confused. The real fix is
4198 to get the "stopped by SW BP and needs adjustment" info out of
4199 the target/kernel (and thus never reach here; see above). */
4200 if (software_breakpoint_inserted_here_p (aspace
, breakpoint_pc
)
4201 || (target_is_non_stop_p ()
4202 && moribund_breakpoint_here_p (aspace
, breakpoint_pc
)))
4204 gdb::optional
<scoped_restore_tmpl
<int>> restore_operation_disable
;
4206 if (record_full_is_used ())
4207 restore_operation_disable
.emplace
4208 (record_full_gdb_operation_disable_set ());
4210 /* When using hardware single-step, a SIGTRAP is reported for both
4211 a completed single-step and a software breakpoint. Need to
4212 differentiate between the two, as the latter needs adjusting
4213 but the former does not.
4215 The SIGTRAP can be due to a completed hardware single-step only if
4216 - we didn't insert software single-step breakpoints
4217 - this thread is currently being stepped
4219 If any of these events did not occur, we must have stopped due
4220 to hitting a software breakpoint, and have to back up to the
4223 As a special case, we could have hardware single-stepped a
4224 software breakpoint. In this case (prev_pc == breakpoint_pc),
4225 we also need to back up to the breakpoint address. */
4227 if (thread_has_single_step_breakpoints_set (thread
)
4228 || !currently_stepping (thread
)
4229 || (thread
->stepped_breakpoint
4230 && thread
->prev_pc
== breakpoint_pc
))
4231 regcache_write_pc (regcache
, breakpoint_pc
);
4236 stepped_in_from (struct frame_info
*frame
, struct frame_id step_frame_id
)
4238 for (frame
= get_prev_frame (frame
);
4240 frame
= get_prev_frame (frame
))
4242 if (frame_id_eq (get_frame_id (frame
), step_frame_id
))
4244 if (get_frame_type (frame
) != INLINE_FRAME
)
4251 /* Look for an inline frame that is marked for skip.
4252 If PREV_FRAME is TRUE start at the previous frame,
4253 otherwise start at the current frame. Stop at the
4254 first non-inline frame, or at the frame where the
4258 inline_frame_is_marked_for_skip (bool prev_frame
, struct thread_info
*tp
)
4260 struct frame_info
*frame
= get_current_frame ();
4263 frame
= get_prev_frame (frame
);
4265 for (; frame
!= NULL
; frame
= get_prev_frame (frame
))
4267 const char *fn
= NULL
;
4268 symtab_and_line sal
;
4271 if (frame_id_eq (get_frame_id (frame
), tp
->control
.step_frame_id
))
4273 if (get_frame_type (frame
) != INLINE_FRAME
)
4276 sal
= find_frame_sal (frame
);
4277 sym
= get_frame_function (frame
);
4280 fn
= sym
->print_name ();
4283 && function_name_is_marked_for_skip (fn
, sal
))
4290 /* If the event thread has the stop requested flag set, pretend it
4291 stopped for a GDB_SIGNAL_0 (i.e., as if it stopped due to
4295 handle_stop_requested (struct execution_control_state
*ecs
)
4297 if (ecs
->event_thread
->stop_requested
)
4299 ecs
->ws
.kind
= TARGET_WAITKIND_STOPPED
;
4300 ecs
->ws
.value
.sig
= GDB_SIGNAL_0
;
4301 handle_signal_stop (ecs
);
4307 /* Auxiliary function that handles syscall entry/return events.
4308 It returns 1 if the inferior should keep going (and GDB
4309 should ignore the event), or 0 if the event deserves to be
4313 handle_syscall_event (struct execution_control_state
*ecs
)
4315 struct regcache
*regcache
;
4318 context_switch (ecs
);
4320 regcache
= get_thread_regcache (ecs
->event_thread
);
4321 syscall_number
= ecs
->ws
.value
.syscall_number
;
4322 ecs
->event_thread
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4324 if (catch_syscall_enabled () > 0
4325 && catching_syscall_number (syscall_number
) > 0)
4327 infrun_log_debug ("syscall number=%d", syscall_number
);
4329 ecs
->event_thread
->control
.stop_bpstat
4330 = bpstat_stop_status (regcache
->aspace (),
4331 ecs
->event_thread
->suspend
.stop_pc
,
4332 ecs
->event_thread
, &ecs
->ws
);
4334 if (handle_stop_requested (ecs
))
4337 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
4339 /* Catchpoint hit. */
4344 if (handle_stop_requested (ecs
))
4347 /* If no catchpoint triggered for this, then keep going. */
4352 /* Lazily fill in the execution_control_state's stop_func_* fields. */
4355 fill_in_stop_func (struct gdbarch
*gdbarch
,
4356 struct execution_control_state
*ecs
)
4358 if (!ecs
->stop_func_filled_in
)
4362 /* Don't care about return value; stop_func_start and stop_func_name
4363 will both be 0 if it doesn't work. */
4364 find_pc_partial_function (ecs
->event_thread
->suspend
.stop_pc
,
4365 &ecs
->stop_func_name
,
4366 &ecs
->stop_func_start
,
4367 &ecs
->stop_func_end
,
4370 /* The call to find_pc_partial_function, above, will set
4371 stop_func_start and stop_func_end to the start and end
4372 of the range containing the stop pc. If this range
4373 contains the entry pc for the block (which is always the
4374 case for contiguous blocks), advance stop_func_start past
4375 the function's start offset and entrypoint. Note that
4376 stop_func_start is NOT advanced when in a range of a
4377 non-contiguous block that does not contain the entry pc. */
4378 if (block
!= nullptr
4379 && ecs
->stop_func_start
<= BLOCK_ENTRY_PC (block
)
4380 && BLOCK_ENTRY_PC (block
) < ecs
->stop_func_end
)
4382 ecs
->stop_func_start
4383 += gdbarch_deprecated_function_start_offset (gdbarch
);
4385 if (gdbarch_skip_entrypoint_p (gdbarch
))
4386 ecs
->stop_func_start
4387 = gdbarch_skip_entrypoint (gdbarch
, ecs
->stop_func_start
);
4390 ecs
->stop_func_filled_in
= 1;
4395 /* Return the STOP_SOON field of the inferior pointed at by ECS. */
4397 static enum stop_kind
4398 get_inferior_stop_soon (execution_control_state
*ecs
)
4400 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
4402 gdb_assert (inf
!= NULL
);
4403 return inf
->control
.stop_soon
;
4406 /* Poll for one event out of the current target. Store the resulting
4407 waitstatus in WS, and return the event ptid. Does not block. */
4410 poll_one_curr_target (struct target_waitstatus
*ws
)
4414 overlay_cache_invalid
= 1;
4416 /* Flush target cache before starting to handle each event.
4417 Target was running and cache could be stale. This is just a
4418 heuristic. Running threads may modify target memory, but we
4419 don't get any event. */
4420 target_dcache_invalidate ();
4422 if (deprecated_target_wait_hook
)
4423 event_ptid
= deprecated_target_wait_hook (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4425 event_ptid
= target_wait (minus_one_ptid
, ws
, TARGET_WNOHANG
);
4428 print_target_wait_results (minus_one_ptid
, event_ptid
, ws
);
4433 /* An event reported by wait_one. */
4435 struct wait_one_event
4437 /* The target the event came out of. */
4438 process_stratum_target
*target
;
4440 /* The PTID the event was for. */
4443 /* The waitstatus. */
4444 target_waitstatus ws
;
4447 /* Wait for one event out of any target. */
4449 static wait_one_event
4454 for (inferior
*inf
: all_inferiors ())
4456 process_stratum_target
*target
= inf
->process_target ();
4458 || !target
->is_async_p ()
4459 || !target
->threads_executing
)
4462 switch_to_inferior_no_thread (inf
);
4464 wait_one_event event
;
4465 event
.target
= target
;
4466 event
.ptid
= poll_one_curr_target (&event
.ws
);
4468 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4470 /* If nothing is resumed, remove the target from the
4474 else if (event
.ws
.kind
!= TARGET_WAITKIND_IGNORE
)
4478 /* Block waiting for some event. */
4485 for (inferior
*inf
: all_inferiors ())
4487 process_stratum_target
*target
= inf
->process_target ();
4489 || !target
->is_async_p ()
4490 || !target
->threads_executing
)
4493 int fd
= target
->async_wait_fd ();
4494 FD_SET (fd
, &readfds
);
4501 /* No waitable targets left. All must be stopped. */
4502 return {NULL
, minus_one_ptid
, {TARGET_WAITKIND_NO_RESUMED
}};
4507 int numfds
= interruptible_select (nfds
, &readfds
, 0, NULL
, 0);
4513 perror_with_name ("interruptible_select");
4518 /* Save the thread's event and stop reason to process it later. */
4521 save_waitstatus (struct thread_info
*tp
, const target_waitstatus
*ws
)
4523 infrun_log_debug ("saving status %s for %d.%ld.%ld",
4524 target_waitstatus_to_string (ws
).c_str (),
4529 /* Record for later. */
4530 tp
->suspend
.waitstatus
= *ws
;
4531 tp
->suspend
.waitstatus_pending_p
= 1;
4533 struct regcache
*regcache
= get_thread_regcache (tp
);
4534 const address_space
*aspace
= regcache
->aspace ();
4536 if (ws
->kind
== TARGET_WAITKIND_STOPPED
4537 && ws
->value
.sig
== GDB_SIGNAL_TRAP
)
4539 CORE_ADDR pc
= regcache_read_pc (regcache
);
4541 adjust_pc_after_break (tp
, &tp
->suspend
.waitstatus
);
4543 scoped_restore_current_thread restore_thread
;
4544 switch_to_thread (tp
);
4546 if (target_stopped_by_watchpoint ())
4548 tp
->suspend
.stop_reason
4549 = TARGET_STOPPED_BY_WATCHPOINT
;
4551 else if (target_supports_stopped_by_sw_breakpoint ()
4552 && target_stopped_by_sw_breakpoint ())
4554 tp
->suspend
.stop_reason
4555 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4557 else if (target_supports_stopped_by_hw_breakpoint ()
4558 && target_stopped_by_hw_breakpoint ())
4560 tp
->suspend
.stop_reason
4561 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4563 else if (!target_supports_stopped_by_hw_breakpoint ()
4564 && hardware_breakpoint_inserted_here_p (aspace
,
4567 tp
->suspend
.stop_reason
4568 = TARGET_STOPPED_BY_HW_BREAKPOINT
;
4570 else if (!target_supports_stopped_by_sw_breakpoint ()
4571 && software_breakpoint_inserted_here_p (aspace
,
4574 tp
->suspend
.stop_reason
4575 = TARGET_STOPPED_BY_SW_BREAKPOINT
;
4577 else if (!thread_has_single_step_breakpoints_set (tp
)
4578 && currently_stepping (tp
))
4580 tp
->suspend
.stop_reason
4581 = TARGET_STOPPED_BY_SINGLE_STEP
;
4586 /* Mark the non-executing threads accordingly. In all-stop, all
4587 threads of all processes are stopped when we get any event
4588 reported. In non-stop mode, only the event thread stops. */
4591 mark_non_executing_threads (process_stratum_target
*target
,
4593 struct target_waitstatus ws
)
4597 if (!target_is_non_stop_p ())
4598 mark_ptid
= minus_one_ptid
;
4599 else if (ws
.kind
== TARGET_WAITKIND_SIGNALLED
4600 || ws
.kind
== TARGET_WAITKIND_EXITED
)
4602 /* If we're handling a process exit in non-stop mode, even
4603 though threads haven't been deleted yet, one would think
4604 that there is nothing to do, as threads of the dead process
4605 will be soon deleted, and threads of any other process were
4606 left running. However, on some targets, threads survive a
4607 process exit event. E.g., for the "checkpoint" command,
4608 when the current checkpoint/fork exits, linux-fork.c
4609 automatically switches to another fork from within
4610 target_mourn_inferior, by associating the same
4611 inferior/thread to another fork. We haven't mourned yet at
4612 this point, but we must mark any threads left in the
4613 process as not-executing so that finish_thread_state marks
4614 them stopped (in the user's perspective) if/when we present
4615 the stop to the user. */
4616 mark_ptid
= ptid_t (event_ptid
.pid ());
4619 mark_ptid
= event_ptid
;
4621 set_executing (target
, mark_ptid
, false);
4623 /* Likewise the resumed flag. */
4624 set_resumed (target
, mark_ptid
, false);
4630 stop_all_threads (void)
4632 /* We may need multiple passes to discover all threads. */
4636 gdb_assert (exists_non_stop_target ());
4638 infrun_log_debug ("stop_all_threads");
4640 scoped_restore_current_thread restore_thread
;
4642 /* Enable thread events of all targets. */
4643 for (auto *target
: all_non_exited_process_targets ())
4645 switch_to_target_no_thread (target
);
4646 target_thread_events (true);
4651 /* Disable thread events of all targets. */
4652 for (auto *target
: all_non_exited_process_targets ())
4654 switch_to_target_no_thread (target
);
4655 target_thread_events (false);
4659 infrun_log_debug ("stop_all_threads done");
4662 /* Request threads to stop, and then wait for the stops. Because
4663 threads we already know about can spawn more threads while we're
4664 trying to stop them, and we only learn about new threads when we
4665 update the thread list, do this in a loop, and keep iterating
4666 until two passes find no threads that need to be stopped. */
4667 for (pass
= 0; pass
< 2; pass
++, iterations
++)
4669 infrun_log_debug ("stop_all_threads, pass=%d, iterations=%d",
4673 int waits_needed
= 0;
4675 for (auto *target
: all_non_exited_process_targets ())
4677 switch_to_target_no_thread (target
);
4678 update_thread_list ();
4681 /* Go through all threads looking for threads that we need
4682 to tell the target to stop. */
4683 for (thread_info
*t
: all_non_exited_threads ())
4685 /* For a single-target setting with an all-stop target,
4686 we would not even arrive here. For a multi-target
4687 setting, until GDB is able to handle a mixture of
4688 all-stop and non-stop targets, simply skip all-stop
4689 targets' threads. This should be fine due to the
4690 protection of 'check_multi_target_resumption'. */
4692 switch_to_thread_no_regs (t
);
4693 if (!target_is_non_stop_p ())
4698 /* If already stopping, don't request a stop again.
4699 We just haven't seen the notification yet. */
4700 if (!t
->stop_requested
)
4702 infrun_log_debug (" %s executing, need stop",
4703 target_pid_to_str (t
->ptid
).c_str ());
4704 target_stop (t
->ptid
);
4705 t
->stop_requested
= 1;
4709 infrun_log_debug (" %s executing, already stopping",
4710 target_pid_to_str (t
->ptid
).c_str ());
4713 if (t
->stop_requested
)
4718 infrun_log_debug (" %s not executing",
4719 target_pid_to_str (t
->ptid
).c_str ());
4721 /* The thread may be not executing, but still be
4722 resumed with a pending status to process. */
4727 if (waits_needed
== 0)
4730 /* If we find new threads on the second iteration, restart
4731 over. We want to see two iterations in a row with all
4736 for (int i
= 0; i
< waits_needed
; i
++)
4738 wait_one_event event
= wait_one ();
4740 infrun_log_debug ("%s %s\n",
4741 target_waitstatus_to_string (&event
.ws
).c_str (),
4742 target_pid_to_str (event
.ptid
).c_str ());
4744 if (event
.ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
4746 /* All resumed threads exited. */
4749 else if (event
.ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
4750 || event
.ws
.kind
== TARGET_WAITKIND_EXITED
4751 || event
.ws
.kind
== TARGET_WAITKIND_SIGNALLED
)
4753 /* One thread/process exited/signalled. */
4755 thread_info
*t
= nullptr;
4757 /* The target may have reported just a pid. If so, try
4758 the first non-exited thread. */
4759 if (event
.ptid
.is_pid ())
4761 int pid
= event
.ptid
.pid ();
4762 inferior
*inf
= find_inferior_pid (event
.target
, pid
);
4763 for (thread_info
*tp
: inf
->non_exited_threads ())
4769 /* If there is no available thread, the event would
4770 have to be appended to a per-inferior event list,
4771 which does not exist (and if it did, we'd have
4772 to adjust run control command to be able to
4773 resume such an inferior). We assert here instead
4774 of going into an infinite loop. */
4775 gdb_assert (t
!= nullptr);
4777 infrun_log_debug ("using %s\n",
4778 target_pid_to_str (t
->ptid
).c_str ());
4782 t
= find_thread_ptid (event
.target
, event
.ptid
);
4783 /* Check if this is the first time we see this thread.
4784 Don't bother adding if it individually exited. */
4786 && event
.ws
.kind
!= TARGET_WAITKIND_THREAD_EXITED
)
4787 t
= add_thread (event
.target
, event
.ptid
);
4792 /* Set the threads as non-executing to avoid
4793 another stop attempt on them. */
4794 switch_to_thread_no_regs (t
);
4795 mark_non_executing_threads (event
.target
, event
.ptid
,
4797 save_waitstatus (t
, &event
.ws
);
4798 t
->stop_requested
= false;
4803 thread_info
*t
= find_thread_ptid (event
.target
, event
.ptid
);
4805 t
= add_thread (event
.target
, event
.ptid
);
4807 t
->stop_requested
= 0;
4810 t
->control
.may_range_step
= 0;
4812 /* This may be the first time we see the inferior report
4814 inferior
*inf
= find_inferior_ptid (event
.target
, event
.ptid
);
4815 if (inf
->needs_setup
)
4817 switch_to_thread_no_regs (t
);
4821 if (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4822 && event
.ws
.value
.sig
== GDB_SIGNAL_0
)
4824 /* We caught the event that we intended to catch, so
4825 there's no event pending. */
4826 t
->suspend
.waitstatus
.kind
= TARGET_WAITKIND_IGNORE
;
4827 t
->suspend
.waitstatus_pending_p
= 0;
4829 if (displaced_step_finish (t
, GDB_SIGNAL_0
) < 0)
4831 /* Add it back to the step-over queue. */
4832 infrun_log_debug ("displaced-step of %s "
4833 "canceled: adding back to the "
4834 "step-over queue\n",
4835 target_pid_to_str (t
->ptid
).c_str ());
4837 t
->control
.trap_expected
= 0;
4838 global_thread_step_over_chain_enqueue (t
);
4843 enum gdb_signal sig
;
4844 struct regcache
*regcache
;
4848 std::string statstr
= target_waitstatus_to_string (&event
.ws
);
4850 infrun_log_debug ("target_wait %s, saving "
4851 "status for %d.%ld.%ld\n",
4858 /* Record for later. */
4859 save_waitstatus (t
, &event
.ws
);
4861 sig
= (event
.ws
.kind
== TARGET_WAITKIND_STOPPED
4862 ? event
.ws
.value
.sig
: GDB_SIGNAL_0
);
4864 if (displaced_step_finish (t
, sig
) < 0)
4866 /* Add it back to the step-over queue. */
4867 t
->control
.trap_expected
= 0;
4868 global_thread_step_over_chain_enqueue (t
);
4871 regcache
= get_thread_regcache (t
);
4872 t
->suspend
.stop_pc
= regcache_read_pc (regcache
);
4874 infrun_log_debug ("saved stop_pc=%s for %s "
4875 "(currently_stepping=%d)\n",
4876 paddress (target_gdbarch (),
4877 t
->suspend
.stop_pc
),
4878 target_pid_to_str (t
->ptid
).c_str (),
4879 currently_stepping (t
));
4887 /* Handle a TARGET_WAITKIND_NO_RESUMED event. */
4890 handle_no_resumed (struct execution_control_state
*ecs
)
4892 if (target_can_async_p ())
4896 for (ui
*ui
: all_uis ())
4898 if (ui
->prompt_state
== PROMPT_BLOCKED
)
4906 /* There were no unwaited-for children left in the target, but,
4907 we're not synchronously waiting for events either. Just
4910 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED (ignoring: bg)");
4911 prepare_to_wait (ecs
);
4916 /* Otherwise, if we were running a synchronous execution command, we
4917 may need to cancel it and give the user back the terminal.
4919 In non-stop mode, the target can't tell whether we've already
4920 consumed previous stop events, so it can end up sending us a
4921 no-resumed event like so:
4923 #0 - thread 1 is left stopped
4925 #1 - thread 2 is resumed and hits breakpoint
4926 -> TARGET_WAITKIND_STOPPED
4928 #2 - thread 3 is resumed and exits
4929 this is the last resumed thread, so
4930 -> TARGET_WAITKIND_NO_RESUMED
4932 #3 - gdb processes stop for thread 2 and decides to re-resume
4935 #4 - gdb processes the TARGET_WAITKIND_NO_RESUMED event.
4936 thread 2 is now resumed, so the event should be ignored.
4938 IOW, if the stop for thread 2 doesn't end a foreground command,
4939 then we need to ignore the following TARGET_WAITKIND_NO_RESUMED
4940 event. But it could be that the event meant that thread 2 itself
4941 (or whatever other thread was the last resumed thread) exited.
4943 To address this we refresh the thread list and check whether we
4944 have resumed threads _now_. In the example above, this removes
4945 thread 3 from the thread list. If thread 2 was re-resumed, we
4946 ignore this event. If we find no thread resumed, then we cancel
4947 the synchronous command and show "no unwaited-for " to the
4950 inferior
*curr_inf
= current_inferior ();
4952 scoped_restore_current_thread restore_thread
;
4954 for (auto *target
: all_non_exited_process_targets ())
4956 switch_to_target_no_thread (target
);
4957 update_thread_list ();
4962 - the current target has no thread executing, and
4963 - the current inferior is native, and
4964 - the current inferior is the one which has the terminal, and
4967 then a Ctrl-C from this point on would remain stuck in the
4968 kernel, until a thread resumes and dequeues it. That would
4969 result in the GDB CLI not reacting to Ctrl-C, not able to
4970 interrupt the program. To address this, if the current inferior
4971 no longer has any thread executing, we give the terminal to some
4972 other inferior that has at least one thread executing. */
4973 bool swap_terminal
= true;
4975 /* Whether to ignore this TARGET_WAITKIND_NO_RESUMED event, or
4976 whether to report it to the user. */
4977 bool ignore_event
= false;
4979 for (thread_info
*thread
: all_non_exited_threads ())
4981 if (swap_terminal
&& thread
->executing
)
4983 if (thread
->inf
!= curr_inf
)
4985 target_terminal::ours ();
4987 switch_to_thread (thread
);
4988 target_terminal::inferior ();
4990 swap_terminal
= false;
4994 && (thread
->executing
4995 || thread
->suspend
.waitstatus_pending_p
))
4997 /* Either there were no unwaited-for children left in the
4998 target at some point, but there are now, or some target
4999 other than the eventing one has unwaited-for children
5000 left. Just ignore. */
5001 infrun_log_debug ("TARGET_WAITKIND_NO_RESUMED "
5002 "(ignoring: found resumed)\n");
5004 ignore_event
= true;
5007 if (ignore_event
&& !swap_terminal
)
5013 switch_to_inferior_no_thread (curr_inf
);
5014 prepare_to_wait (ecs
);
5018 /* Go ahead and report the event. */
5022 /* Given an execution control state that has been freshly filled in by
5023 an event from the inferior, figure out what it means and take
5026 The alternatives are:
5028 1) stop_waiting and return; to really stop and return to the
5031 2) keep_going and return; to wait for the next event (set
5032 ecs->event_thread->stepping_over_breakpoint to 1 to single step
5036 handle_inferior_event (struct execution_control_state
*ecs
)
5038 /* Make sure that all temporary struct value objects that were
5039 created during the handling of the event get deleted at the
5041 scoped_value_mark free_values
;
5043 enum stop_kind stop_soon
;
5045 infrun_log_debug ("%s", target_waitstatus_to_string (&ecs
->ws
).c_str ());
5047 if (ecs
->ws
.kind
== TARGET_WAITKIND_IGNORE
)
5049 /* We had an event in the inferior, but we are not interested in
5050 handling it at this level. The lower layers have already
5051 done what needs to be done, if anything.
5053 One of the possible circumstances for this is when the
5054 inferior produces output for the console. The inferior has
5055 not stopped, and we are ignoring the event. Another possible
5056 circumstance is any event which the lower level knows will be
5057 reported multiple times without an intervening resume. */
5058 prepare_to_wait (ecs
);
5062 if (ecs
->ws
.kind
== TARGET_WAITKIND_THREAD_EXITED
)
5064 prepare_to_wait (ecs
);
5068 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
5069 && handle_no_resumed (ecs
))
5072 /* Cache the last target/ptid/waitstatus. */
5073 set_last_target_status (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5075 /* Always clear state belonging to the previous time we stopped. */
5076 stop_stack_dummy
= STOP_NONE
;
5078 if (ecs
->ws
.kind
== TARGET_WAITKIND_NO_RESUMED
)
5080 /* No unwaited-for children left. IOW, all resumed children
5082 stop_print_frame
= 0;
5087 if (ecs
->ws
.kind
!= TARGET_WAITKIND_EXITED
5088 && ecs
->ws
.kind
!= TARGET_WAITKIND_SIGNALLED
)
5090 ecs
->event_thread
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5091 /* If it's a new thread, add it to the thread database. */
5092 if (ecs
->event_thread
== NULL
)
5093 ecs
->event_thread
= add_thread (ecs
->target
, ecs
->ptid
);
5095 /* Disable range stepping. If the next step request could use a
5096 range, this will be end up re-enabled then. */
5097 ecs
->event_thread
->control
.may_range_step
= 0;
5100 /* Dependent on valid ECS->EVENT_THREAD. */
5101 adjust_pc_after_break (ecs
->event_thread
, &ecs
->ws
);
5103 /* Dependent on the current PC value modified by adjust_pc_after_break. */
5104 reinit_frame_cache ();
5106 breakpoint_retire_moribund ();
5108 /* First, distinguish signals caused by the debugger from signals
5109 that have to do with the program's own actions. Note that
5110 breakpoint insns may cause SIGTRAP or SIGILL or SIGEMT, depending
5111 on the operating system version. Here we detect when a SIGILL or
5112 SIGEMT is really a breakpoint and change it to SIGTRAP. We do
5113 something similar for SIGSEGV, since a SIGSEGV will be generated
5114 when we're trying to execute a breakpoint instruction on a
5115 non-executable stack. This happens for call dummy breakpoints
5116 for architectures like SPARC that place call dummies on the
5118 if (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
5119 && (ecs
->ws
.value
.sig
== GDB_SIGNAL_ILL
5120 || ecs
->ws
.value
.sig
== GDB_SIGNAL_SEGV
5121 || ecs
->ws
.value
.sig
== GDB_SIGNAL_EMT
))
5123 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5125 if (breakpoint_inserted_here_p (regcache
->aspace (),
5126 regcache_read_pc (regcache
)))
5128 infrun_log_debug ("Treating signal as SIGTRAP");
5129 ecs
->ws
.value
.sig
= GDB_SIGNAL_TRAP
;
5133 mark_non_executing_threads (ecs
->target
, ecs
->ptid
, ecs
->ws
);
5135 switch (ecs
->ws
.kind
)
5137 case TARGET_WAITKIND_LOADED
:
5138 context_switch (ecs
);
5139 /* Ignore gracefully during startup of the inferior, as it might
5140 be the shell which has just loaded some objects, otherwise
5141 add the symbols for the newly loaded objects. Also ignore at
5142 the beginning of an attach or remote session; we will query
5143 the full list of libraries once the connection is
5146 stop_soon
= get_inferior_stop_soon (ecs
);
5147 if (stop_soon
== NO_STOP_QUIETLY
)
5149 struct regcache
*regcache
;
5151 regcache
= get_thread_regcache (ecs
->event_thread
);
5153 handle_solib_event ();
5155 ecs
->event_thread
->control
.stop_bpstat
5156 = bpstat_stop_status (regcache
->aspace (),
5157 ecs
->event_thread
->suspend
.stop_pc
,
5158 ecs
->event_thread
, &ecs
->ws
);
5160 if (handle_stop_requested (ecs
))
5163 if (bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5165 /* A catchpoint triggered. */
5166 process_event_stop_test (ecs
);
5170 /* If requested, stop when the dynamic linker notifies
5171 gdb of events. This allows the user to get control
5172 and place breakpoints in initializer routines for
5173 dynamically loaded objects (among other things). */
5174 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5175 if (stop_on_solib_events
)
5177 /* Make sure we print "Stopped due to solib-event" in
5179 stop_print_frame
= 1;
5186 /* If we are skipping through a shell, or through shared library
5187 loading that we aren't interested in, resume the program. If
5188 we're running the program normally, also resume. */
5189 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== NO_STOP_QUIETLY
)
5191 /* Loading of shared libraries might have changed breakpoint
5192 addresses. Make sure new breakpoints are inserted. */
5193 if (stop_soon
== NO_STOP_QUIETLY
)
5194 insert_breakpoints ();
5195 resume (GDB_SIGNAL_0
);
5196 prepare_to_wait (ecs
);
5200 /* But stop if we're attaching or setting up a remote
5202 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5203 || stop_soon
== STOP_QUIETLY_REMOTE
)
5205 infrun_log_debug ("quietly stopped");
5210 internal_error (__FILE__
, __LINE__
,
5211 _("unhandled stop_soon: %d"), (int) stop_soon
);
5213 case TARGET_WAITKIND_SPURIOUS
:
5214 if (handle_stop_requested (ecs
))
5216 context_switch (ecs
);
5217 resume (GDB_SIGNAL_0
);
5218 prepare_to_wait (ecs
);
5221 case TARGET_WAITKIND_THREAD_CREATED
:
5222 if (handle_stop_requested (ecs
))
5224 context_switch (ecs
);
5225 if (!switch_back_to_stepped_thread (ecs
))
5229 case TARGET_WAITKIND_EXITED
:
5230 case TARGET_WAITKIND_SIGNALLED
:
5232 /* Depending on the system, ecs->ptid may point to a thread or
5233 to a process. On some targets, target_mourn_inferior may
5234 need to have access to the just-exited thread. That is the
5235 case of GNU/Linux's "checkpoint" support, for example.
5236 Call the switch_to_xxx routine as appropriate. */
5237 thread_info
*thr
= find_thread_ptid (ecs
->target
, ecs
->ptid
);
5239 switch_to_thread (thr
);
5242 inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5243 switch_to_inferior_no_thread (inf
);
5246 handle_vfork_child_exec_or_exit (0);
5247 target_terminal::ours (); /* Must do this before mourn anyway. */
5249 /* Clearing any previous state of convenience variables. */
5250 clear_exit_convenience_vars ();
5252 if (ecs
->ws
.kind
== TARGET_WAITKIND_EXITED
)
5254 /* Record the exit code in the convenience variable $_exitcode, so
5255 that the user can inspect this again later. */
5256 set_internalvar_integer (lookup_internalvar ("_exitcode"),
5257 (LONGEST
) ecs
->ws
.value
.integer
);
5259 /* Also record this in the inferior itself. */
5260 current_inferior ()->has_exit_code
= 1;
5261 current_inferior ()->exit_code
= (LONGEST
) ecs
->ws
.value
.integer
;
5263 /* Support the --return-child-result option. */
5264 return_child_result_value
= ecs
->ws
.value
.integer
;
5266 gdb::observers::exited
.notify (ecs
->ws
.value
.integer
);
5270 struct gdbarch
*gdbarch
= current_inferior ()->gdbarch
;
5272 if (gdbarch_gdb_signal_to_target_p (gdbarch
))
5274 /* Set the value of the internal variable $_exitsignal,
5275 which holds the signal uncaught by the inferior. */
5276 set_internalvar_integer (lookup_internalvar ("_exitsignal"),
5277 gdbarch_gdb_signal_to_target (gdbarch
,
5278 ecs
->ws
.value
.sig
));
5282 /* We don't have access to the target's method used for
5283 converting between signal numbers (GDB's internal
5284 representation <-> target's representation).
5285 Therefore, we cannot do a good job at displaying this
5286 information to the user. It's better to just warn
5287 her about it (if infrun debugging is enabled), and
5289 infrun_log_debug ("Cannot fill $_exitsignal with the correct "
5293 gdb::observers::signal_exited
.notify (ecs
->ws
.value
.sig
);
5296 gdb_flush (gdb_stdout
);
5297 target_mourn_inferior (inferior_ptid
);
5298 stop_print_frame
= 0;
5302 case TARGET_WAITKIND_FORKED
:
5303 case TARGET_WAITKIND_VFORKED
:
5304 /* Check whether the inferior is displaced stepping. */
5306 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5307 struct gdbarch
*gdbarch
= regcache
->arch ();
5309 /* If checking displaced stepping is supported, and thread
5310 ecs->ptid is displaced stepping. */
5311 if (displaced_step_in_progress (ecs
->event_thread
))
5313 struct inferior
*parent_inf
5314 = find_inferior_ptid (ecs
->target
, ecs
->ptid
);
5315 struct regcache
*child_regcache
;
5316 CORE_ADDR parent_pc
;
5318 if (ecs
->ws
.kind
== TARGET_WAITKIND_FORKED
)
5320 // struct displaced_step_inferior_state *displaced
5321 // = get_displaced_stepping_state (parent_inf);
5323 /* Restore scratch pad for child process. */
5324 //displaced_step_restore (displaced, ecs->ws.value.related_pid);
5325 // FIXME: we should restore all the buffers that were currently in use
5328 /* GDB has got TARGET_WAITKIND_FORKED or TARGET_WAITKIND_VFORKED,
5329 indicating that the displaced stepping of syscall instruction
5330 has been done. Perform cleanup for parent process here. Note
5331 that this operation also cleans up the child process for vfork,
5332 because their pages are shared. */
5333 displaced_step_finish (ecs
->event_thread
, GDB_SIGNAL_TRAP
);
5334 /* Start a new step-over in another thread if there's one
5338 /* Since the vfork/fork syscall instruction was executed in the scratchpad,
5339 the child's PC is also within the scratchpad. Set the child's PC
5340 to the parent's PC value, which has already been fixed up.
5341 FIXME: we use the parent's aspace here, although we're touching
5342 the child, because the child hasn't been added to the inferior
5343 list yet at this point. */
5346 = get_thread_arch_aspace_regcache (parent_inf
->process_target (),
5347 ecs
->ws
.value
.related_pid
,
5349 parent_inf
->aspace
);
5350 /* Read PC value of parent process. */
5351 parent_pc
= regcache_read_pc (regcache
);
5353 if (debug_displaced
)
5354 fprintf_unfiltered (gdb_stdlog
,
5355 "displaced: write child pc from %s to %s\n",
5357 regcache_read_pc (child_regcache
)),
5358 paddress (gdbarch
, parent_pc
));
5360 regcache_write_pc (child_regcache
, parent_pc
);
5364 context_switch (ecs
);
5366 /* Immediately detach breakpoints from the child before there's
5367 any chance of letting the user delete breakpoints from the
5368 breakpoint lists. If we don't do this early, it's easy to
5369 leave left over traps in the child, vis: "break foo; catch
5370 fork; c; <fork>; del; c; <child calls foo>". We only follow
5371 the fork on the last `continue', and by that time the
5372 breakpoint at "foo" is long gone from the breakpoint table.
5373 If we vforked, then we don't need to unpatch here, since both
5374 parent and child are sharing the same memory pages; we'll
5375 need to unpatch at follow/detach time instead to be certain
5376 that new breakpoints added between catchpoint hit time and
5377 vfork follow are detached. */
5378 if (ecs
->ws
.kind
!= TARGET_WAITKIND_VFORKED
)
5380 /* This won't actually modify the breakpoint list, but will
5381 physically remove the breakpoints from the child. */
5382 detach_breakpoints (ecs
->ws
.value
.related_pid
);
5385 delete_just_stopped_threads_single_step_breakpoints ();
5387 /* In case the event is caught by a catchpoint, remember that
5388 the event is to be followed at the next resume of the thread,
5389 and not immediately. */
5390 ecs
->event_thread
->pending_follow
= ecs
->ws
;
5392 ecs
->event_thread
->suspend
.stop_pc
5393 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5395 ecs
->event_thread
->control
.stop_bpstat
5396 = bpstat_stop_status (get_current_regcache ()->aspace (),
5397 ecs
->event_thread
->suspend
.stop_pc
,
5398 ecs
->event_thread
, &ecs
->ws
);
5400 if (handle_stop_requested (ecs
))
5403 /* If no catchpoint triggered for this, then keep going. Note
5404 that we're interested in knowing the bpstat actually causes a
5405 stop, not just if it may explain the signal. Software
5406 watchpoints, for example, always appear in the bpstat. */
5407 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5410 = (follow_fork_mode_string
== follow_fork_mode_child
);
5412 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5414 process_stratum_target
*targ
5415 = ecs
->event_thread
->inf
->process_target ();
5417 bool should_resume
= follow_fork ();
5419 /* Note that one of these may be an invalid pointer,
5420 depending on detach_fork. */
5421 thread_info
*parent
= ecs
->event_thread
;
5423 = find_thread_ptid (targ
, ecs
->ws
.value
.related_pid
);
5425 /* At this point, the parent is marked running, and the
5426 child is marked stopped. */
5428 /* If not resuming the parent, mark it stopped. */
5429 if (follow_child
&& !detach_fork
&& !non_stop
&& !sched_multi
)
5430 parent
->set_running (false);
5432 /* If resuming the child, mark it running. */
5433 if (follow_child
|| (!detach_fork
&& (non_stop
|| sched_multi
)))
5434 child
->set_running (true);
5436 /* In non-stop mode, also resume the other branch. */
5437 if (!detach_fork
&& (non_stop
5438 || (sched_multi
&& target_is_non_stop_p ())))
5441 switch_to_thread (parent
);
5443 switch_to_thread (child
);
5445 ecs
->event_thread
= inferior_thread ();
5446 ecs
->ptid
= inferior_ptid
;
5451 switch_to_thread (child
);
5453 switch_to_thread (parent
);
5455 ecs
->event_thread
= inferior_thread ();
5456 ecs
->ptid
= inferior_ptid
;
5464 process_event_stop_test (ecs
);
5467 case TARGET_WAITKIND_VFORK_DONE
:
5468 /* Done with the shared memory region. Re-insert breakpoints in
5469 the parent, and keep going. */
5471 context_switch (ecs
);
5473 current_inferior ()->waiting_for_vfork_done
= 0;
5474 current_inferior ()->pspace
->breakpoints_not_allowed
= 0;
5476 if (handle_stop_requested (ecs
))
5479 /* This also takes care of reinserting breakpoints in the
5480 previously locked inferior. */
5484 case TARGET_WAITKIND_EXECD
:
5486 /* Note we can't read registers yet (the stop_pc), because we
5487 don't yet know the inferior's post-exec architecture.
5488 'stop_pc' is explicitly read below instead. */
5489 switch_to_thread_no_regs (ecs
->event_thread
);
5491 /* Do whatever is necessary to the parent branch of the vfork. */
5492 handle_vfork_child_exec_or_exit (1);
5494 /* This causes the eventpoints and symbol table to be reset.
5495 Must do this now, before trying to determine whether to
5497 follow_exec (inferior_ptid
, ecs
->ws
.value
.execd_pathname
);
5499 /* In follow_exec we may have deleted the original thread and
5500 created a new one. Make sure that the event thread is the
5501 execd thread for that case (this is a nop otherwise). */
5502 ecs
->event_thread
= inferior_thread ();
5504 ecs
->event_thread
->suspend
.stop_pc
5505 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5507 ecs
->event_thread
->control
.stop_bpstat
5508 = bpstat_stop_status (get_current_regcache ()->aspace (),
5509 ecs
->event_thread
->suspend
.stop_pc
,
5510 ecs
->event_thread
, &ecs
->ws
);
5512 /* Note that this may be referenced from inside
5513 bpstat_stop_status above, through inferior_has_execd. */
5514 xfree (ecs
->ws
.value
.execd_pathname
);
5515 ecs
->ws
.value
.execd_pathname
= NULL
;
5517 if (handle_stop_requested (ecs
))
5520 /* If no catchpoint triggered for this, then keep going. */
5521 if (!bpstat_causes_stop (ecs
->event_thread
->control
.stop_bpstat
))
5523 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5527 process_event_stop_test (ecs
);
5530 /* Be careful not to try to gather much state about a thread
5531 that's in a syscall. It's frequently a losing proposition. */
5532 case TARGET_WAITKIND_SYSCALL_ENTRY
:
5533 /* Getting the current syscall number. */
5534 if (handle_syscall_event (ecs
) == 0)
5535 process_event_stop_test (ecs
);
5538 /* Before examining the threads further, step this thread to
5539 get it entirely out of the syscall. (We get notice of the
5540 event when the thread is just on the verge of exiting a
5541 syscall. Stepping one instruction seems to get it back
5543 case TARGET_WAITKIND_SYSCALL_RETURN
:
5544 if (handle_syscall_event (ecs
) == 0)
5545 process_event_stop_test (ecs
);
5548 case TARGET_WAITKIND_STOPPED
:
5549 handle_signal_stop (ecs
);
5552 case TARGET_WAITKIND_NO_HISTORY
:
5553 /* Reverse execution: target ran out of history info. */
5555 /* Switch to the stopped thread. */
5556 context_switch (ecs
);
5557 infrun_log_debug ("stopped");
5559 delete_just_stopped_threads_single_step_breakpoints ();
5560 ecs
->event_thread
->suspend
.stop_pc
5561 = regcache_read_pc (get_thread_regcache (inferior_thread ()));
5563 if (handle_stop_requested (ecs
))
5566 gdb::observers::no_history
.notify ();
5572 /* Restart threads back to what they were trying to do back when we
5573 paused them for an in-line step-over. The EVENT_THREAD thread is
5577 restart_threads (struct thread_info
*event_thread
)
5579 /* In case the instruction just stepped spawned a new thread. */
5580 update_thread_list ();
5582 for (thread_info
*tp
: all_non_exited_threads ())
5584 switch_to_thread_no_regs (tp
);
5586 if (tp
== event_thread
)
5588 infrun_log_debug ("restart threads: [%s] is event thread",
5589 target_pid_to_str (tp
->ptid
).c_str ());
5593 if (!(tp
->state
== THREAD_RUNNING
|| tp
->control
.in_infcall
))
5595 infrun_log_debug ("restart threads: [%s] not meant to be running",
5596 target_pid_to_str (tp
->ptid
).c_str ());
5602 infrun_log_debug ("restart threads: [%s] resumed",
5603 target_pid_to_str (tp
->ptid
).c_str ());
5604 gdb_assert (tp
->executing
|| tp
->suspend
.waitstatus_pending_p
);
5608 if (thread_is_in_step_over_chain (tp
))
5610 infrun_log_debug ("restart threads: [%s] needs step-over",
5611 target_pid_to_str (tp
->ptid
).c_str ());
5612 gdb_assert (!tp
->resumed
);
5617 if (tp
->suspend
.waitstatus_pending_p
)
5619 infrun_log_debug ("restart threads: [%s] has pending status",
5620 target_pid_to_str (tp
->ptid
).c_str ());
5625 gdb_assert (!tp
->stop_requested
);
5627 /* If some thread needs to start a step-over at this point, it
5628 should still be in the step-over queue, and thus skipped
5630 if (thread_still_needs_step_over (tp
))
5632 internal_error (__FILE__
, __LINE__
,
5633 "thread [%s] needs a step-over, but not in "
5634 "step-over queue\n",
5635 target_pid_to_str (tp
->ptid
).c_str ());
5638 if (currently_stepping (tp
))
5640 infrun_log_debug ("restart threads: [%s] was stepping",
5641 target_pid_to_str (tp
->ptid
).c_str ());
5642 keep_going_stepped_thread (tp
);
5646 struct execution_control_state ecss
;
5647 struct execution_control_state
*ecs
= &ecss
;
5649 infrun_log_debug ("restart threads: [%s] continuing",
5650 target_pid_to_str (tp
->ptid
).c_str ());
5651 reset_ecs (ecs
, tp
);
5652 switch_to_thread (tp
);
5653 keep_going_pass_signal (ecs
);
5658 /* Callback for iterate_over_threads. Find a resumed thread that has
5659 a pending waitstatus. */
5662 resumed_thread_with_pending_status (struct thread_info
*tp
,
5666 && tp
->suspend
.waitstatus_pending_p
);
5669 /* Called when we get an event that may finish an in-line or
5670 out-of-line (displaced stepping) step-over started previously.
5671 Return true if the event is processed and we should go back to the
5672 event loop; false if the caller should continue processing the
5676 finish_step_over (struct execution_control_state
*ecs
)
5678 int had_step_over_info
;
5680 displaced_step_finish (ecs
->event_thread
,
5681 ecs
->event_thread
->suspend
.stop_signal
);
5683 had_step_over_info
= step_over_info_valid_p ();
5685 if (had_step_over_info
)
5687 /* If we're stepping over a breakpoint with all threads locked,
5688 then only the thread that was stepped should be reporting
5690 gdb_assert (ecs
->event_thread
->control
.trap_expected
);
5692 clear_step_over_info ();
5695 if (!target_is_non_stop_p ())
5698 /* Start a new step-over in another thread if there's one that
5702 /* If we were stepping over a breakpoint before, and haven't started
5703 a new in-line step-over sequence, then restart all other threads
5704 (except the event thread). We can't do this in all-stop, as then
5705 e.g., we wouldn't be able to issue any other remote packet until
5706 these other threads stop. */
5707 if (had_step_over_info
&& !step_over_info_valid_p ())
5709 struct thread_info
*pending
;
5711 /* If we only have threads with pending statuses, the restart
5712 below won't restart any thread and so nothing re-inserts the
5713 breakpoint we just stepped over. But we need it inserted
5714 when we later process the pending events, otherwise if
5715 another thread has a pending event for this breakpoint too,
5716 we'd discard its event (because the breakpoint that
5717 originally caused the event was no longer inserted). */
5718 context_switch (ecs
);
5719 insert_breakpoints ();
5721 restart_threads (ecs
->event_thread
);
5723 /* If we have events pending, go through handle_inferior_event
5724 again, picking up a pending event at random. This avoids
5725 thread starvation. */
5727 /* But not if we just stepped over a watchpoint in order to let
5728 the instruction execute so we can evaluate its expression.
5729 The set of watchpoints that triggered is recorded in the
5730 breakpoint objects themselves (see bp->watchpoint_triggered).
5731 If we processed another event first, that other event could
5732 clobber this info. */
5733 if (ecs
->event_thread
->stepping_over_watchpoint
)
5736 pending
= iterate_over_threads (resumed_thread_with_pending_status
,
5738 if (pending
!= NULL
)
5740 struct thread_info
*tp
= ecs
->event_thread
;
5741 struct regcache
*regcache
;
5743 infrun_log_debug ("found resumed threads with "
5744 "pending events, saving status");
5746 gdb_assert (pending
!= tp
);
5748 /* Record the event thread's event for later. */
5749 save_waitstatus (tp
, &ecs
->ws
);
5750 /* This was cleared early, by handle_inferior_event. Set it
5751 so this pending event is considered by
5755 gdb_assert (!tp
->executing
);
5757 regcache
= get_thread_regcache (tp
);
5758 tp
->suspend
.stop_pc
= regcache_read_pc (regcache
);
5760 infrun_log_debug ("saved stop_pc=%s for %s "
5761 "(currently_stepping=%d)\n",
5762 paddress (target_gdbarch (),
5763 tp
->suspend
.stop_pc
),
5764 target_pid_to_str (tp
->ptid
).c_str (),
5765 currently_stepping (tp
));
5767 /* This in-line step-over finished; clear this so we won't
5768 start a new one. This is what handle_signal_stop would
5769 do, if we returned false. */
5770 tp
->stepping_over_breakpoint
= 0;
5772 /* Wake up the event loop again. */
5773 mark_async_event_handler (infrun_async_inferior_event_token
);
5775 prepare_to_wait (ecs
);
5783 /* Come here when the program has stopped with a signal. */
5786 handle_signal_stop (struct execution_control_state
*ecs
)
5788 struct frame_info
*frame
;
5789 struct gdbarch
*gdbarch
;
5790 int stopped_by_watchpoint
;
5791 enum stop_kind stop_soon
;
5794 gdb_assert (ecs
->ws
.kind
== TARGET_WAITKIND_STOPPED
);
5796 ecs
->event_thread
->suspend
.stop_signal
= ecs
->ws
.value
.sig
;
5798 /* Do we need to clean up the state of a thread that has
5799 completed a displaced single-step? (Doing so usually affects
5800 the PC, so do it here, before we set stop_pc.) */
5801 if (finish_step_over (ecs
))
5804 /* If we either finished a single-step or hit a breakpoint, but
5805 the user wanted this thread to be stopped, pretend we got a
5806 SIG0 (generic unsignaled stop). */
5807 if (ecs
->event_thread
->stop_requested
5808 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5809 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5811 ecs
->event_thread
->suspend
.stop_pc
5812 = regcache_read_pc (get_thread_regcache (ecs
->event_thread
));
5816 struct regcache
*regcache
= get_thread_regcache (ecs
->event_thread
);
5817 struct gdbarch
*reg_gdbarch
= regcache
->arch ();
5819 switch_to_thread (ecs
->event_thread
);
5821 infrun_log_debug ("stop_pc=%s",
5822 paddress (reg_gdbarch
,
5823 ecs
->event_thread
->suspend
.stop_pc
));
5824 if (target_stopped_by_watchpoint ())
5828 infrun_log_debug ("stopped by watchpoint");
5830 if (target_stopped_data_address (current_top_target (), &addr
))
5831 infrun_log_debug ("stopped data address=%s",
5832 paddress (reg_gdbarch
, addr
));
5834 infrun_log_debug ("(no data address available)");
5838 /* This is originated from start_remote(), start_inferior() and
5839 shared libraries hook functions. */
5840 stop_soon
= get_inferior_stop_soon (ecs
);
5841 if (stop_soon
== STOP_QUIETLY
|| stop_soon
== STOP_QUIETLY_REMOTE
)
5843 context_switch (ecs
);
5844 infrun_log_debug ("quietly stopped");
5845 stop_print_frame
= 1;
5850 /* This originates from attach_command(). We need to overwrite
5851 the stop_signal here, because some kernels don't ignore a
5852 SIGSTOP in a subsequent ptrace(PTRACE_CONT,SIGSTOP) call.
5853 See more comments in inferior.h. On the other hand, if we
5854 get a non-SIGSTOP, report it to the user - assume the backend
5855 will handle the SIGSTOP if it should show up later.
5857 Also consider that the attach is complete when we see a
5858 SIGTRAP. Some systems (e.g. Windows), and stubs supporting
5859 target extended-remote report it instead of a SIGSTOP
5860 (e.g. gdbserver). We already rely on SIGTRAP being our
5861 signal, so this is no exception.
5863 Also consider that the attach is complete when we see a
5864 GDB_SIGNAL_0. In non-stop mode, GDB will explicitly tell
5865 the target to stop all threads of the inferior, in case the
5866 low level attach operation doesn't stop them implicitly. If
5867 they weren't stopped implicitly, then the stub will report a
5868 GDB_SIGNAL_0, meaning: stopped for no particular reason
5869 other than GDB's request. */
5870 if (stop_soon
== STOP_QUIETLY_NO_SIGSTOP
5871 && (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_STOP
5872 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5873 || ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_0
))
5875 stop_print_frame
= 1;
5877 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
5881 /* See if something interesting happened to the non-current thread. If
5882 so, then switch to that thread. */
5883 if (ecs
->ptid
!= inferior_ptid
)
5885 infrun_log_debug ("context switch");
5887 context_switch (ecs
);
5889 if (deprecated_context_hook
)
5890 deprecated_context_hook (ecs
->event_thread
->global_num
);
5893 /* At this point, get hold of the now-current thread's frame. */
5894 frame
= get_current_frame ();
5895 gdbarch
= get_frame_arch (frame
);
5897 /* Pull the single step breakpoints out of the target. */
5898 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
5900 struct regcache
*regcache
;
5903 regcache
= get_thread_regcache (ecs
->event_thread
);
5904 const address_space
*aspace
= regcache
->aspace ();
5906 pc
= regcache_read_pc (regcache
);
5908 /* However, before doing so, if this single-step breakpoint was
5909 actually for another thread, set this thread up for moving
5911 if (!thread_has_single_step_breakpoint_here (ecs
->event_thread
,
5914 if (single_step_breakpoint_inserted_here_p (aspace
, pc
))
5916 infrun_log_debug ("[%s] hit another thread's single-step "
5918 target_pid_to_str (ecs
->ptid
).c_str ());
5919 ecs
->hit_singlestep_breakpoint
= 1;
5924 infrun_log_debug ("[%s] hit its single-step breakpoint",
5925 target_pid_to_str (ecs
->ptid
).c_str ());
5928 delete_just_stopped_threads_single_step_breakpoints ();
5930 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
5931 && ecs
->event_thread
->control
.trap_expected
5932 && ecs
->event_thread
->stepping_over_watchpoint
)
5933 stopped_by_watchpoint
= 0;
5935 stopped_by_watchpoint
= watchpoints_triggered (&ecs
->ws
);
5937 /* If necessary, step over this watchpoint. We'll be back to display
5939 if (stopped_by_watchpoint
5940 && (target_have_steppable_watchpoint
5941 || gdbarch_have_nonsteppable_watchpoint (gdbarch
)))
5943 /* At this point, we are stopped at an instruction which has
5944 attempted to write to a piece of memory under control of
5945 a watchpoint. The instruction hasn't actually executed
5946 yet. If we were to evaluate the watchpoint expression
5947 now, we would get the old value, and therefore no change
5948 would seem to have occurred.
5950 In order to make watchpoints work `right', we really need
5951 to complete the memory write, and then evaluate the
5952 watchpoint expression. We do this by single-stepping the
5955 It may not be necessary to disable the watchpoint to step over
5956 it. For example, the PA can (with some kernel cooperation)
5957 single step over a watchpoint without disabling the watchpoint.
5959 It is far more common to need to disable a watchpoint to step
5960 the inferior over it. If we have non-steppable watchpoints,
5961 we must disable the current watchpoint; it's simplest to
5962 disable all watchpoints.
5964 Any breakpoint at PC must also be stepped over -- if there's
5965 one, it will have already triggered before the watchpoint
5966 triggered, and we either already reported it to the user, or
5967 it didn't cause a stop and we called keep_going. In either
5968 case, if there was a breakpoint at PC, we must be trying to
5970 ecs
->event_thread
->stepping_over_watchpoint
= 1;
5975 ecs
->event_thread
->stepping_over_breakpoint
= 0;
5976 ecs
->event_thread
->stepping_over_watchpoint
= 0;
5977 bpstat_clear (&ecs
->event_thread
->control
.stop_bpstat
);
5978 ecs
->event_thread
->control
.stop_step
= 0;
5979 stop_print_frame
= 1;
5980 stopped_by_random_signal
= 0;
5981 bpstat stop_chain
= NULL
;
5983 /* Hide inlined functions starting here, unless we just performed stepi or
5984 nexti. After stepi and nexti, always show the innermost frame (not any
5985 inline function call sites). */
5986 if (ecs
->event_thread
->control
.step_range_end
!= 1)
5988 const address_space
*aspace
5989 = get_thread_regcache (ecs
->event_thread
)->aspace ();
5991 /* skip_inline_frames is expensive, so we avoid it if we can
5992 determine that the address is one where functions cannot have
5993 been inlined. This improves performance with inferiors that
5994 load a lot of shared libraries, because the solib event
5995 breakpoint is defined as the address of a function (i.e. not
5996 inline). Note that we have to check the previous PC as well
5997 as the current one to catch cases when we have just
5998 single-stepped off a breakpoint prior to reinstating it.
5999 Note that we're assuming that the code we single-step to is
6000 not inline, but that's not definitive: there's nothing
6001 preventing the event breakpoint function from containing
6002 inlined code, and the single-step ending up there. If the
6003 user had set a breakpoint on that inlined code, the missing
6004 skip_inline_frames call would break things. Fortunately
6005 that's an extremely unlikely scenario. */
6006 if (!pc_at_non_inline_function (aspace
,
6007 ecs
->event_thread
->suspend
.stop_pc
,
6009 && !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6010 && ecs
->event_thread
->control
.trap_expected
6011 && pc_at_non_inline_function (aspace
,
6012 ecs
->event_thread
->prev_pc
,
6015 stop_chain
= build_bpstat_chain (aspace
,
6016 ecs
->event_thread
->suspend
.stop_pc
,
6018 skip_inline_frames (ecs
->event_thread
, stop_chain
);
6020 /* Re-fetch current thread's frame in case that invalidated
6022 frame
= get_current_frame ();
6023 gdbarch
= get_frame_arch (frame
);
6027 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6028 && ecs
->event_thread
->control
.trap_expected
6029 && gdbarch_single_step_through_delay_p (gdbarch
)
6030 && currently_stepping (ecs
->event_thread
))
6032 /* We're trying to step off a breakpoint. Turns out that we're
6033 also on an instruction that needs to be stepped multiple
6034 times before it's been fully executing. E.g., architectures
6035 with a delay slot. It needs to be stepped twice, once for
6036 the instruction and once for the delay slot. */
6037 int step_through_delay
6038 = gdbarch_single_step_through_delay (gdbarch
, frame
);
6040 if (step_through_delay
)
6041 infrun_log_debug ("step through delay");
6043 if (ecs
->event_thread
->control
.step_range_end
== 0
6044 && step_through_delay
)
6046 /* The user issued a continue when stopped at a breakpoint.
6047 Set up for another trap and get out of here. */
6048 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6052 else if (step_through_delay
)
6054 /* The user issued a step when stopped at a breakpoint.
6055 Maybe we should stop, maybe we should not - the delay
6056 slot *might* correspond to a line of source. In any
6057 case, don't decide that here, just set
6058 ecs->stepping_over_breakpoint, making sure we
6059 single-step again before breakpoints are re-inserted. */
6060 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6064 /* See if there is a breakpoint/watchpoint/catchpoint/etc. that
6065 handles this event. */
6066 ecs
->event_thread
->control
.stop_bpstat
6067 = bpstat_stop_status (get_current_regcache ()->aspace (),
6068 ecs
->event_thread
->suspend
.stop_pc
,
6069 ecs
->event_thread
, &ecs
->ws
, stop_chain
);
6071 /* Following in case break condition called a
6073 stop_print_frame
= 1;
6075 /* This is where we handle "moribund" watchpoints. Unlike
6076 software breakpoints traps, hardware watchpoint traps are
6077 always distinguishable from random traps. If no high-level
6078 watchpoint is associated with the reported stop data address
6079 anymore, then the bpstat does not explain the signal ---
6080 simply make sure to ignore it if `stopped_by_watchpoint' is
6083 if (ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6084 && !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6086 && stopped_by_watchpoint
)
6088 infrun_log_debug ("no user watchpoint explains watchpoint SIGTRAP, "
6092 /* NOTE: cagney/2003-03-29: These checks for a random signal
6093 at one stage in the past included checks for an inferior
6094 function call's call dummy's return breakpoint. The original
6095 comment, that went with the test, read:
6097 ``End of a stack dummy. Some systems (e.g. Sony news) give
6098 another signal besides SIGTRAP, so check here as well as
6101 If someone ever tries to get call dummys on a
6102 non-executable stack to work (where the target would stop
6103 with something like a SIGSEGV), then those tests might need
6104 to be re-instated. Given, however, that the tests were only
6105 enabled when momentary breakpoints were not being used, I
6106 suspect that it won't be the case.
6108 NOTE: kettenis/2004-02-05: Indeed such checks don't seem to
6109 be necessary for call dummies on a non-executable stack on
6112 /* See if the breakpoints module can explain the signal. */
6114 = !bpstat_explains_signal (ecs
->event_thread
->control
.stop_bpstat
,
6115 ecs
->event_thread
->suspend
.stop_signal
);
6117 /* Maybe this was a trap for a software breakpoint that has since
6119 if (random_signal
&& target_stopped_by_sw_breakpoint ())
6121 if (gdbarch_program_breakpoint_here_p (gdbarch
,
6122 ecs
->event_thread
->suspend
.stop_pc
))
6124 struct regcache
*regcache
;
6127 /* Re-adjust PC to what the program would see if GDB was not
6129 regcache
= get_thread_regcache (ecs
->event_thread
);
6130 decr_pc
= gdbarch_decr_pc_after_break (gdbarch
);
6133 gdb::optional
<scoped_restore_tmpl
<int>>
6134 restore_operation_disable
;
6136 if (record_full_is_used ())
6137 restore_operation_disable
.emplace
6138 (record_full_gdb_operation_disable_set ());
6140 regcache_write_pc (regcache
,
6141 ecs
->event_thread
->suspend
.stop_pc
+ decr_pc
);
6146 /* A delayed software breakpoint event. Ignore the trap. */
6147 infrun_log_debug ("delayed software breakpoint trap, ignoring");
6152 /* Maybe this was a trap for a hardware breakpoint/watchpoint that
6153 has since been removed. */
6154 if (random_signal
&& target_stopped_by_hw_breakpoint ())
6156 /* A delayed hardware breakpoint event. Ignore the trap. */
6157 infrun_log_debug ("delayed hardware breakpoint/watchpoint "
6162 /* If not, perhaps stepping/nexting can. */
6164 random_signal
= !(ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
6165 && currently_stepping (ecs
->event_thread
));
6167 /* Perhaps the thread hit a single-step breakpoint of _another_
6168 thread. Single-step breakpoints are transparent to the
6169 breakpoints module. */
6171 random_signal
= !ecs
->hit_singlestep_breakpoint
;
6173 /* No? Perhaps we got a moribund watchpoint. */
6175 random_signal
= !stopped_by_watchpoint
;
6177 /* Always stop if the user explicitly requested this thread to
6179 if (ecs
->event_thread
->stop_requested
)
6182 infrun_log_debug ("user-requested stop");
6185 /* For the program's own signals, act according to
6186 the signal handling tables. */
6190 /* Signal not for debugging purposes. */
6191 struct inferior
*inf
= find_inferior_ptid (ecs
->target
, ecs
->ptid
);
6192 enum gdb_signal stop_signal
= ecs
->event_thread
->suspend
.stop_signal
;
6194 infrun_log_debug ("random signal (%s)",
6195 gdb_signal_to_symbol_string (stop_signal
));
6197 stopped_by_random_signal
= 1;
6199 /* Always stop on signals if we're either just gaining control
6200 of the program, or the user explicitly requested this thread
6201 to remain stopped. */
6202 if (stop_soon
!= NO_STOP_QUIETLY
6203 || ecs
->event_thread
->stop_requested
6205 && signal_stop_state (ecs
->event_thread
->suspend
.stop_signal
)))
6211 /* Notify observers the signal has "handle print" set. Note we
6212 returned early above if stopping; normal_stop handles the
6213 printing in that case. */
6214 if (signal_print
[ecs
->event_thread
->suspend
.stop_signal
])
6216 /* The signal table tells us to print about this signal. */
6217 target_terminal::ours_for_output ();
6218 gdb::observers::signal_received
.notify (ecs
->event_thread
->suspend
.stop_signal
);
6219 target_terminal::inferior ();
6222 /* Clear the signal if it should not be passed. */
6223 if (signal_program
[ecs
->event_thread
->suspend
.stop_signal
] == 0)
6224 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
6226 if (ecs
->event_thread
->prev_pc
== ecs
->event_thread
->suspend
.stop_pc
6227 && ecs
->event_thread
->control
.trap_expected
6228 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6230 /* We were just starting a new sequence, attempting to
6231 single-step off of a breakpoint and expecting a SIGTRAP.
6232 Instead this signal arrives. This signal will take us out
6233 of the stepping range so GDB needs to remember to, when
6234 the signal handler returns, resume stepping off that
6236 /* To simplify things, "continue" is forced to use the same
6237 code paths as single-step - set a breakpoint at the
6238 signal return address and then, once hit, step off that
6240 infrun_log_debug ("signal arrived while stepping over breakpoint");
6242 insert_hp_step_resume_breakpoint_at_frame (frame
);
6243 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6244 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6245 ecs
->event_thread
->control
.trap_expected
= 0;
6247 /* If we were nexting/stepping some other thread, switch to
6248 it, so that we don't continue it, losing control. */
6249 if (!switch_back_to_stepped_thread (ecs
))
6254 if (ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_0
6255 && (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6257 || ecs
->event_thread
->control
.step_range_end
== 1)
6258 && frame_id_eq (get_stack_frame_id (frame
),
6259 ecs
->event_thread
->control
.step_stack_frame_id
)
6260 && ecs
->event_thread
->control
.step_resume_breakpoint
== NULL
)
6262 /* The inferior is about to take a signal that will take it
6263 out of the single step range. Set a breakpoint at the
6264 current PC (which is presumably where the signal handler
6265 will eventually return) and then allow the inferior to
6268 Note that this is only needed for a signal delivered
6269 while in the single-step range. Nested signals aren't a
6270 problem as they eventually all return. */
6271 infrun_log_debug ("signal may take us out of single-step range");
6273 clear_step_over_info ();
6274 insert_hp_step_resume_breakpoint_at_frame (frame
);
6275 ecs
->event_thread
->step_after_step_resume_breakpoint
= 1;
6276 /* Reset trap_expected to ensure breakpoints are re-inserted. */
6277 ecs
->event_thread
->control
.trap_expected
= 0;
6282 /* Note: step_resume_breakpoint may be non-NULL. This occurs
6283 when either there's a nested signal, or when there's a
6284 pending signal enabled just as the signal handler returns
6285 (leaving the inferior at the step-resume-breakpoint without
6286 actually executing it). Either way continue until the
6287 breakpoint is really hit. */
6289 if (!switch_back_to_stepped_thread (ecs
))
6291 infrun_log_debug ("random signal, keep going");
6298 process_event_stop_test (ecs
);
6301 /* Come here when we've got some debug event / signal we can explain
6302 (IOW, not a random signal), and test whether it should cause a
6303 stop, or whether we should resume the inferior (transparently).
6304 E.g., could be a breakpoint whose condition evaluates false; we
6305 could be still stepping within the line; etc. */
6308 process_event_stop_test (struct execution_control_state
*ecs
)
6310 struct symtab_and_line stop_pc_sal
;
6311 struct frame_info
*frame
;
6312 struct gdbarch
*gdbarch
;
6313 CORE_ADDR jmp_buf_pc
;
6314 struct bpstat_what what
;
6316 /* Handle cases caused by hitting a breakpoint. */
6318 frame
= get_current_frame ();
6319 gdbarch
= get_frame_arch (frame
);
6321 what
= bpstat_what (ecs
->event_thread
->control
.stop_bpstat
);
6323 if (what
.call_dummy
)
6325 stop_stack_dummy
= what
.call_dummy
;
6328 /* A few breakpoint types have callbacks associated (e.g.,
6329 bp_jit_event). Run them now. */
6330 bpstat_run_callbacks (ecs
->event_thread
->control
.stop_bpstat
);
6332 /* If we hit an internal event that triggers symbol changes, the
6333 current frame will be invalidated within bpstat_what (e.g., if we
6334 hit an internal solib event). Re-fetch it. */
6335 frame
= get_current_frame ();
6336 gdbarch
= get_frame_arch (frame
);
6338 switch (what
.main_action
)
6340 case BPSTAT_WHAT_SET_LONGJMP_RESUME
:
6341 /* If we hit the breakpoint at longjmp while stepping, we
6342 install a momentary breakpoint at the target of the
6345 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME");
6347 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6349 if (what
.is_longjmp
)
6351 struct value
*arg_value
;
6353 /* If we set the longjmp breakpoint via a SystemTap probe,
6354 then use it to extract the arguments. The destination PC
6355 is the third argument to the probe. */
6356 arg_value
= probe_safe_evaluate_at_pc (frame
, 2);
6359 jmp_buf_pc
= value_as_address (arg_value
);
6360 jmp_buf_pc
= gdbarch_addr_bits_remove (gdbarch
, jmp_buf_pc
);
6362 else if (!gdbarch_get_longjmp_target_p (gdbarch
)
6363 || !gdbarch_get_longjmp_target (gdbarch
,
6364 frame
, &jmp_buf_pc
))
6366 infrun_log_debug ("BPSTAT_WHAT_SET_LONGJMP_RESUME "
6367 "(!gdbarch_get_longjmp_target)");
6372 /* Insert a breakpoint at resume address. */
6373 insert_longjmp_resume_breakpoint (gdbarch
, jmp_buf_pc
);
6376 check_exception_resume (ecs
, frame
);
6380 case BPSTAT_WHAT_CLEAR_LONGJMP_RESUME
:
6382 struct frame_info
*init_frame
;
6384 /* There are several cases to consider.
6386 1. The initiating frame no longer exists. In this case we
6387 must stop, because the exception or longjmp has gone too
6390 2. The initiating frame exists, and is the same as the
6391 current frame. We stop, because the exception or longjmp
6394 3. The initiating frame exists and is different from the
6395 current frame. This means the exception or longjmp has
6396 been caught beneath the initiating frame, so keep going.
6398 4. longjmp breakpoint has been placed just to protect
6399 against stale dummy frames and user is not interested in
6400 stopping around longjmps. */
6402 infrun_log_debug ("BPSTAT_WHAT_CLEAR_LONGJMP_RESUME");
6404 gdb_assert (ecs
->event_thread
->control
.exception_resume_breakpoint
6406 delete_exception_resume_breakpoint (ecs
->event_thread
);
6408 if (what
.is_longjmp
)
6410 check_longjmp_breakpoint_for_call_dummy (ecs
->event_thread
);
6412 if (!frame_id_p (ecs
->event_thread
->initiating_frame
))
6420 init_frame
= frame_find_by_id (ecs
->event_thread
->initiating_frame
);
6424 struct frame_id current_id
6425 = get_frame_id (get_current_frame ());
6426 if (frame_id_eq (current_id
,
6427 ecs
->event_thread
->initiating_frame
))
6429 /* Case 2. Fall through. */
6439 /* For Cases 1 and 2, remove the step-resume breakpoint, if it
6441 delete_step_resume_breakpoint (ecs
->event_thread
);
6443 end_stepping_range (ecs
);
6447 case BPSTAT_WHAT_SINGLE
:
6448 infrun_log_debug ("BPSTAT_WHAT_SINGLE");
6449 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6450 /* Still need to check other stuff, at least the case where we
6451 are stepping and step out of the right range. */
6454 case BPSTAT_WHAT_STEP_RESUME
:
6455 infrun_log_debug ("BPSTAT_WHAT_STEP_RESUME");
6457 delete_step_resume_breakpoint (ecs
->event_thread
);
6458 if (ecs
->event_thread
->control
.proceed_to_finish
6459 && execution_direction
== EXEC_REVERSE
)
6461 struct thread_info
*tp
= ecs
->event_thread
;
6463 /* We are finishing a function in reverse, and just hit the
6464 step-resume breakpoint at the start address of the
6465 function, and we're almost there -- just need to back up
6466 by one more single-step, which should take us back to the
6468 tp
->control
.step_range_start
= tp
->control
.step_range_end
= 1;
6472 fill_in_stop_func (gdbarch
, ecs
);
6473 if (ecs
->event_thread
->suspend
.stop_pc
== ecs
->stop_func_start
6474 && execution_direction
== EXEC_REVERSE
)
6476 /* We are stepping over a function call in reverse, and just
6477 hit the step-resume breakpoint at the start address of
6478 the function. Go back to single-stepping, which should
6479 take us back to the function call. */
6480 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6486 case BPSTAT_WHAT_STOP_NOISY
:
6487 infrun_log_debug ("BPSTAT_WHAT_STOP_NOISY");
6488 stop_print_frame
= 1;
6490 /* Assume the thread stopped for a breapoint. We'll still check
6491 whether a/the breakpoint is there when the thread is next
6493 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6498 case BPSTAT_WHAT_STOP_SILENT
:
6499 infrun_log_debug ("BPSTAT_WHAT_STOP_SILENT");
6500 stop_print_frame
= 0;
6502 /* Assume the thread stopped for a breapoint. We'll still check
6503 whether a/the breakpoint is there when the thread is next
6505 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6509 case BPSTAT_WHAT_HP_STEP_RESUME
:
6510 infrun_log_debug ("BPSTAT_WHAT_HP_STEP_RESUME");
6512 delete_step_resume_breakpoint (ecs
->event_thread
);
6513 if (ecs
->event_thread
->step_after_step_resume_breakpoint
)
6515 /* Back when the step-resume breakpoint was inserted, we
6516 were trying to single-step off a breakpoint. Go back to
6518 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6519 ecs
->event_thread
->stepping_over_breakpoint
= 1;
6525 case BPSTAT_WHAT_KEEP_CHECKING
:
6529 /* If we stepped a permanent breakpoint and we had a high priority
6530 step-resume breakpoint for the address we stepped, but we didn't
6531 hit it, then we must have stepped into the signal handler. The
6532 step-resume was only necessary to catch the case of _not_
6533 stepping into the handler, so delete it, and fall through to
6534 checking whether the step finished. */
6535 if (ecs
->event_thread
->stepped_breakpoint
)
6537 struct breakpoint
*sr_bp
6538 = ecs
->event_thread
->control
.step_resume_breakpoint
;
6541 && sr_bp
->loc
->permanent
6542 && sr_bp
->type
== bp_hp_step_resume
6543 && sr_bp
->loc
->address
== ecs
->event_thread
->prev_pc
)
6545 infrun_log_debug ("stepped permanent breakpoint, stopped in handler");
6546 delete_step_resume_breakpoint (ecs
->event_thread
);
6547 ecs
->event_thread
->step_after_step_resume_breakpoint
= 0;
6551 /* We come here if we hit a breakpoint but should not stop for it.
6552 Possibly we also were stepping and should stop for that. So fall
6553 through and test for stepping. But, if not stepping, do not
6556 /* In all-stop mode, if we're currently stepping but have stopped in
6557 some other thread, we need to switch back to the stepped thread. */
6558 if (switch_back_to_stepped_thread (ecs
))
6561 if (ecs
->event_thread
->control
.step_resume_breakpoint
)
6563 infrun_log_debug ("step-resume breakpoint is inserted");
6565 /* Having a step-resume breakpoint overrides anything
6566 else having to do with stepping commands until
6567 that breakpoint is reached. */
6572 if (ecs
->event_thread
->control
.step_range_end
== 0)
6574 infrun_log_debug ("no stepping, continue");
6575 /* Likewise if we aren't even stepping. */
6580 /* Re-fetch current thread's frame in case the code above caused
6581 the frame cache to be re-initialized, making our FRAME variable
6582 a dangling pointer. */
6583 frame
= get_current_frame ();
6584 gdbarch
= get_frame_arch (frame
);
6585 fill_in_stop_func (gdbarch
, ecs
);
6587 /* If stepping through a line, keep going if still within it.
6589 Note that step_range_end is the address of the first instruction
6590 beyond the step range, and NOT the address of the last instruction
6593 Note also that during reverse execution, we may be stepping
6594 through a function epilogue and therefore must detect when
6595 the current-frame changes in the middle of a line. */
6597 if (pc_in_thread_step_range (ecs
->event_thread
->suspend
.stop_pc
,
6599 && (execution_direction
!= EXEC_REVERSE
6600 || frame_id_eq (get_frame_id (frame
),
6601 ecs
->event_thread
->control
.step_frame_id
)))
6604 ("stepping inside range [%s-%s]",
6605 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_start
),
6606 paddress (gdbarch
, ecs
->event_thread
->control
.step_range_end
));
6608 /* Tentatively re-enable range stepping; `resume' disables it if
6609 necessary (e.g., if we're stepping over a breakpoint or we
6610 have software watchpoints). */
6611 ecs
->event_thread
->control
.may_range_step
= 1;
6613 /* When stepping backward, stop at beginning of line range
6614 (unless it's the function entry point, in which case
6615 keep going back to the call point). */
6616 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6617 if (stop_pc
== ecs
->event_thread
->control
.step_range_start
6618 && stop_pc
!= ecs
->stop_func_start
6619 && execution_direction
== EXEC_REVERSE
)
6620 end_stepping_range (ecs
);
6627 /* We stepped out of the stepping range. */
6629 /* If we are stepping at the source level and entered the runtime
6630 loader dynamic symbol resolution code...
6632 EXEC_FORWARD: we keep on single stepping until we exit the run
6633 time loader code and reach the callee's address.
6635 EXEC_REVERSE: we've already executed the callee (backward), and
6636 the runtime loader code is handled just like any other
6637 undebuggable function call. Now we need only keep stepping
6638 backward through the trampoline code, and that's handled further
6639 down, so there is nothing for us to do here. */
6641 if (execution_direction
!= EXEC_REVERSE
6642 && ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6643 && in_solib_dynsym_resolve_code (ecs
->event_thread
->suspend
.stop_pc
))
6645 CORE_ADDR pc_after_resolver
=
6646 gdbarch_skip_solib_resolver (gdbarch
,
6647 ecs
->event_thread
->suspend
.stop_pc
);
6649 infrun_log_debug ("stepped into dynsym resolve code");
6651 if (pc_after_resolver
)
6653 /* Set up a step-resume breakpoint at the address
6654 indicated by SKIP_SOLIB_RESOLVER. */
6655 symtab_and_line sr_sal
;
6656 sr_sal
.pc
= pc_after_resolver
;
6657 sr_sal
.pspace
= get_frame_program_space (frame
);
6659 insert_step_resume_breakpoint_at_sal (gdbarch
,
6660 sr_sal
, null_frame_id
);
6667 /* Step through an indirect branch thunk. */
6668 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6669 && gdbarch_in_indirect_branch_thunk (gdbarch
,
6670 ecs
->event_thread
->suspend
.stop_pc
))
6672 infrun_log_debug ("stepped into indirect branch thunk");
6677 if (ecs
->event_thread
->control
.step_range_end
!= 1
6678 && (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6679 || ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6680 && get_frame_type (frame
) == SIGTRAMP_FRAME
)
6682 infrun_log_debug ("stepped into signal trampoline");
6683 /* The inferior, while doing a "step" or "next", has ended up in
6684 a signal trampoline (either by a signal being delivered or by
6685 the signal handler returning). Just single-step until the
6686 inferior leaves the trampoline (either by calling the handler
6692 /* If we're in the return path from a shared library trampoline,
6693 we want to proceed through the trampoline when stepping. */
6694 /* macro/2012-04-25: This needs to come before the subroutine
6695 call check below as on some targets return trampolines look
6696 like subroutine calls (MIPS16 return thunks). */
6697 if (gdbarch_in_solib_return_trampoline (gdbarch
,
6698 ecs
->event_thread
->suspend
.stop_pc
,
6699 ecs
->stop_func_name
)
6700 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6702 /* Determine where this trampoline returns. */
6703 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6704 CORE_ADDR real_stop_pc
6705 = gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6707 infrun_log_debug ("stepped into solib return tramp");
6709 /* Only proceed through if we know where it's going. */
6712 /* And put the step-breakpoint there and go until there. */
6713 symtab_and_line sr_sal
;
6714 sr_sal
.pc
= real_stop_pc
;
6715 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
6716 sr_sal
.pspace
= get_frame_program_space (frame
);
6718 /* Do not specify what the fp should be when we stop since
6719 on some machines the prologue is where the new fp value
6721 insert_step_resume_breakpoint_at_sal (gdbarch
,
6722 sr_sal
, null_frame_id
);
6724 /* Restart without fiddling with the step ranges or
6731 /* Check for subroutine calls. The check for the current frame
6732 equalling the step ID is not necessary - the check of the
6733 previous frame's ID is sufficient - but it is a common case and
6734 cheaper than checking the previous frame's ID.
6736 NOTE: frame_id_eq will never report two invalid frame IDs as
6737 being equal, so to get into this block, both the current and
6738 previous frame must have valid frame IDs. */
6739 /* The outer_frame_id check is a heuristic to detect stepping
6740 through startup code. If we step over an instruction which
6741 sets the stack pointer from an invalid value to a valid value,
6742 we may detect that as a subroutine call from the mythical
6743 "outermost" function. This could be fixed by marking
6744 outermost frames as !stack_p,code_p,special_p. Then the
6745 initial outermost frame, before sp was valid, would
6746 have code_addr == &_start. See the comment in frame_id_eq
6748 if (!frame_id_eq (get_stack_frame_id (frame
),
6749 ecs
->event_thread
->control
.step_stack_frame_id
)
6750 && (frame_id_eq (frame_unwind_caller_id (get_current_frame ()),
6751 ecs
->event_thread
->control
.step_stack_frame_id
)
6752 && (!frame_id_eq (ecs
->event_thread
->control
.step_stack_frame_id
,
6754 || (ecs
->event_thread
->control
.step_start_function
6755 != find_pc_function (ecs
->event_thread
->suspend
.stop_pc
)))))
6757 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6758 CORE_ADDR real_stop_pc
;
6760 infrun_log_debug ("stepped into subroutine");
6762 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_NONE
)
6764 /* I presume that step_over_calls is only 0 when we're
6765 supposed to be stepping at the assembly language level
6766 ("stepi"). Just stop. */
6767 /* And this works the same backward as frontward. MVS */
6768 end_stepping_range (ecs
);
6772 /* Reverse stepping through solib trampolines. */
6774 if (execution_direction
== EXEC_REVERSE
6775 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
6776 && (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6777 || (ecs
->stop_func_start
== 0
6778 && in_solib_dynsym_resolve_code (stop_pc
))))
6780 /* Any solib trampoline code can be handled in reverse
6781 by simply continuing to single-step. We have already
6782 executed the solib function (backwards), and a few
6783 steps will take us back through the trampoline to the
6789 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
)
6791 /* We're doing a "next".
6793 Normal (forward) execution: set a breakpoint at the
6794 callee's return address (the address at which the caller
6797 Reverse (backward) execution. set the step-resume
6798 breakpoint at the start of the function that we just
6799 stepped into (backwards), and continue to there. When we
6800 get there, we'll need to single-step back to the caller. */
6802 if (execution_direction
== EXEC_REVERSE
)
6804 /* If we're already at the start of the function, we've either
6805 just stepped backward into a single instruction function,
6806 or stepped back out of a signal handler to the first instruction
6807 of the function. Just keep going, which will single-step back
6809 if (ecs
->stop_func_start
!= stop_pc
&& ecs
->stop_func_start
!= 0)
6811 /* Normal function call return (static or dynamic). */
6812 symtab_and_line sr_sal
;
6813 sr_sal
.pc
= ecs
->stop_func_start
;
6814 sr_sal
.pspace
= get_frame_program_space (frame
);
6815 insert_step_resume_breakpoint_at_sal (gdbarch
,
6816 sr_sal
, null_frame_id
);
6820 insert_step_resume_breakpoint_at_caller (frame
);
6826 /* If we are in a function call trampoline (a stub between the
6827 calling routine and the real function), locate the real
6828 function. That's what tells us (a) whether we want to step
6829 into it at all, and (b) what prologue we want to run to the
6830 end of, if we do step into it. */
6831 real_stop_pc
= skip_language_trampoline (frame
, stop_pc
);
6832 if (real_stop_pc
== 0)
6833 real_stop_pc
= gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
);
6834 if (real_stop_pc
!= 0)
6835 ecs
->stop_func_start
= real_stop_pc
;
6837 if (real_stop_pc
!= 0 && in_solib_dynsym_resolve_code (real_stop_pc
))
6839 symtab_and_line sr_sal
;
6840 sr_sal
.pc
= ecs
->stop_func_start
;
6841 sr_sal
.pspace
= get_frame_program_space (frame
);
6843 insert_step_resume_breakpoint_at_sal (gdbarch
,
6844 sr_sal
, null_frame_id
);
6849 /* If we have line number information for the function we are
6850 thinking of stepping into and the function isn't on the skip
6853 If there are several symtabs at that PC (e.g. with include
6854 files), just want to know whether *any* of them have line
6855 numbers. find_pc_line handles this. */
6857 struct symtab_and_line tmp_sal
;
6859 tmp_sal
= find_pc_line (ecs
->stop_func_start
, 0);
6860 if (tmp_sal
.line
!= 0
6861 && !function_name_is_marked_for_skip (ecs
->stop_func_name
,
6863 && !inline_frame_is_marked_for_skip (true, ecs
->event_thread
))
6865 if (execution_direction
== EXEC_REVERSE
)
6866 handle_step_into_function_backward (gdbarch
, ecs
);
6868 handle_step_into_function (gdbarch
, ecs
);
6873 /* If we have no line number and the step-stop-if-no-debug is
6874 set, we stop the step so that the user has a chance to switch
6875 in assembly mode. */
6876 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6877 && step_stop_if_no_debug
)
6879 end_stepping_range (ecs
);
6883 if (execution_direction
== EXEC_REVERSE
)
6885 /* If we're already at the start of the function, we've either just
6886 stepped backward into a single instruction function without line
6887 number info, or stepped back out of a signal handler to the first
6888 instruction of the function without line number info. Just keep
6889 going, which will single-step back to the caller. */
6890 if (ecs
->stop_func_start
!= stop_pc
)
6892 /* Set a breakpoint at callee's start address.
6893 From there we can step once and be back in the caller. */
6894 symtab_and_line sr_sal
;
6895 sr_sal
.pc
= ecs
->stop_func_start
;
6896 sr_sal
.pspace
= get_frame_program_space (frame
);
6897 insert_step_resume_breakpoint_at_sal (gdbarch
,
6898 sr_sal
, null_frame_id
);
6902 /* Set a breakpoint at callee's return address (the address
6903 at which the caller will resume). */
6904 insert_step_resume_breakpoint_at_caller (frame
);
6910 /* Reverse stepping through solib trampolines. */
6912 if (execution_direction
== EXEC_REVERSE
6913 && ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_NONE
)
6915 CORE_ADDR stop_pc
= ecs
->event_thread
->suspend
.stop_pc
;
6917 if (gdbarch_skip_trampoline_code (gdbarch
, frame
, stop_pc
)
6918 || (ecs
->stop_func_start
== 0
6919 && in_solib_dynsym_resolve_code (stop_pc
)))
6921 /* Any solib trampoline code can be handled in reverse
6922 by simply continuing to single-step. We have already
6923 executed the solib function (backwards), and a few
6924 steps will take us back through the trampoline to the
6929 else if (in_solib_dynsym_resolve_code (stop_pc
))
6931 /* Stepped backward into the solib dynsym resolver.
6932 Set a breakpoint at its start and continue, then
6933 one more step will take us out. */
6934 symtab_and_line sr_sal
;
6935 sr_sal
.pc
= ecs
->stop_func_start
;
6936 sr_sal
.pspace
= get_frame_program_space (frame
);
6937 insert_step_resume_breakpoint_at_sal (gdbarch
,
6938 sr_sal
, null_frame_id
);
6944 /* This always returns the sal for the inner-most frame when we are in a
6945 stack of inlined frames, even if GDB actually believes that it is in a
6946 more outer frame. This is checked for below by calls to
6947 inline_skipped_frames. */
6948 stop_pc_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
6950 /* NOTE: tausq/2004-05-24: This if block used to be done before all
6951 the trampoline processing logic, however, there are some trampolines
6952 that have no names, so we should do trampoline handling first. */
6953 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_UNDEBUGGABLE
6954 && ecs
->stop_func_name
== NULL
6955 && stop_pc_sal
.line
== 0)
6957 infrun_log_debug ("stepped into undebuggable function");
6959 /* The inferior just stepped into, or returned to, an
6960 undebuggable function (where there is no debugging information
6961 and no line number corresponding to the address where the
6962 inferior stopped). Since we want to skip this kind of code,
6963 we keep going until the inferior returns from this
6964 function - unless the user has asked us not to (via
6965 set step-mode) or we no longer know how to get back
6966 to the call site. */
6967 if (step_stop_if_no_debug
6968 || !frame_id_p (frame_unwind_caller_id (frame
)))
6970 /* If we have no line number and the step-stop-if-no-debug
6971 is set, we stop the step so that the user has a chance to
6972 switch in assembly mode. */
6973 end_stepping_range (ecs
);
6978 /* Set a breakpoint at callee's return address (the address
6979 at which the caller will resume). */
6980 insert_step_resume_breakpoint_at_caller (frame
);
6986 if (ecs
->event_thread
->control
.step_range_end
== 1)
6988 /* It is stepi or nexti. We always want to stop stepping after
6990 infrun_log_debug ("stepi/nexti");
6991 end_stepping_range (ecs
);
6995 if (stop_pc_sal
.line
== 0)
6997 /* We have no line number information. That means to stop
6998 stepping (does this always happen right after one instruction,
6999 when we do "s" in a function with no line numbers,
7000 or can this happen as a result of a return or longjmp?). */
7001 infrun_log_debug ("line number info");
7002 end_stepping_range (ecs
);
7006 /* Look for "calls" to inlined functions, part one. If the inline
7007 frame machinery detected some skipped call sites, we have entered
7008 a new inline function. */
7010 if (frame_id_eq (get_frame_id (get_current_frame ()),
7011 ecs
->event_thread
->control
.step_frame_id
)
7012 && inline_skipped_frames (ecs
->event_thread
))
7014 infrun_log_debug ("stepped into inlined function");
7016 symtab_and_line call_sal
= find_frame_sal (get_current_frame ());
7018 if (ecs
->event_thread
->control
.step_over_calls
!= STEP_OVER_ALL
)
7020 /* For "step", we're going to stop. But if the call site
7021 for this inlined function is on the same source line as
7022 we were previously stepping, go down into the function
7023 first. Otherwise stop at the call site. */
7025 if (call_sal
.line
== ecs
->event_thread
->current_line
7026 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7028 step_into_inline_frame (ecs
->event_thread
);
7029 if (inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7036 end_stepping_range (ecs
);
7041 /* For "next", we should stop at the call site if it is on a
7042 different source line. Otherwise continue through the
7043 inlined function. */
7044 if (call_sal
.line
== ecs
->event_thread
->current_line
7045 && call_sal
.symtab
== ecs
->event_thread
->current_symtab
)
7048 end_stepping_range (ecs
);
7053 /* Look for "calls" to inlined functions, part two. If we are still
7054 in the same real function we were stepping through, but we have
7055 to go further up to find the exact frame ID, we are stepping
7056 through a more inlined call beyond its call site. */
7058 if (get_frame_type (get_current_frame ()) == INLINE_FRAME
7059 && !frame_id_eq (get_frame_id (get_current_frame ()),
7060 ecs
->event_thread
->control
.step_frame_id
)
7061 && stepped_in_from (get_current_frame (),
7062 ecs
->event_thread
->control
.step_frame_id
))
7064 infrun_log_debug ("stepping through inlined function");
7066 if (ecs
->event_thread
->control
.step_over_calls
== STEP_OVER_ALL
7067 || inline_frame_is_marked_for_skip (false, ecs
->event_thread
))
7070 end_stepping_range (ecs
);
7074 bool refresh_step_info
= true;
7075 if ((ecs
->event_thread
->suspend
.stop_pc
== stop_pc_sal
.pc
)
7076 && (ecs
->event_thread
->current_line
!= stop_pc_sal
.line
7077 || ecs
->event_thread
->current_symtab
!= stop_pc_sal
.symtab
))
7079 if (stop_pc_sal
.is_stmt
)
7081 /* We are at the start of a different line. So stop. Note that
7082 we don't stop if we step into the middle of a different line.
7083 That is said to make things like for (;;) statements work
7085 infrun_log_debug ("infrun: stepped to a different line\n");
7086 end_stepping_range (ecs
);
7089 else if (frame_id_eq (get_frame_id (get_current_frame ()),
7090 ecs
->event_thread
->control
.step_frame_id
))
7092 /* We are at the start of a different line, however, this line is
7093 not marked as a statement, and we have not changed frame. We
7094 ignore this line table entry, and continue stepping forward,
7095 looking for a better place to stop. */
7096 refresh_step_info
= false;
7097 infrun_log_debug ("infrun: stepped to a different line, but "
7098 "it's not the start of a statement\n");
7102 /* We aren't done stepping.
7104 Optimize by setting the stepping range to the line.
7105 (We might not be in the original line, but if we entered a
7106 new line in mid-statement, we continue stepping. This makes
7107 things like for(;;) statements work better.)
7109 If we entered a SAL that indicates a non-statement line table entry,
7110 then we update the stepping range, but we don't update the step info,
7111 which includes things like the line number we are stepping away from.
7112 This means we will stop when we find a line table entry that is marked
7113 as is-statement, even if it matches the non-statement one we just
7116 ecs
->event_thread
->control
.step_range_start
= stop_pc_sal
.pc
;
7117 ecs
->event_thread
->control
.step_range_end
= stop_pc_sal
.end
;
7118 ecs
->event_thread
->control
.may_range_step
= 1;
7119 if (refresh_step_info
)
7120 set_step_info (ecs
->event_thread
, frame
, stop_pc_sal
);
7122 infrun_log_debug ("keep going");
7126 /* In all-stop mode, if we're currently stepping but have stopped in
7127 some other thread, we may need to switch back to the stepped
7128 thread. Returns true we set the inferior running, false if we left
7129 it stopped (and the event needs further processing). */
7132 switch_back_to_stepped_thread (struct execution_control_state
*ecs
)
7134 if (!target_is_non_stop_p ())
7136 struct thread_info
*stepping_thread
;
7138 /* If any thread is blocked on some internal breakpoint, and we
7139 simply need to step over that breakpoint to get it going
7140 again, do that first. */
7142 /* However, if we see an event for the stepping thread, then we
7143 know all other threads have been moved past their breakpoints
7144 already. Let the caller check whether the step is finished,
7145 etc., before deciding to move it past a breakpoint. */
7146 if (ecs
->event_thread
->control
.step_range_end
!= 0)
7149 /* Check if the current thread is blocked on an incomplete
7150 step-over, interrupted by a random signal. */
7151 if (ecs
->event_thread
->control
.trap_expected
7152 && ecs
->event_thread
->suspend
.stop_signal
!= GDB_SIGNAL_TRAP
)
7154 infrun_log_debug ("need to finish step-over of [%s]",
7155 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7160 /* Check if the current thread is blocked by a single-step
7161 breakpoint of another thread. */
7162 if (ecs
->hit_singlestep_breakpoint
)
7164 infrun_log_debug ("need to step [%s] over single-step breakpoint",
7165 target_pid_to_str (ecs
->ptid
).c_str ());
7170 /* If this thread needs yet another step-over (e.g., stepping
7171 through a delay slot), do it first before moving on to
7173 if (thread_still_needs_step_over (ecs
->event_thread
))
7176 ("thread [%s] still needs step-over",
7177 target_pid_to_str (ecs
->event_thread
->ptid
).c_str ());
7182 /* If scheduler locking applies even if not stepping, there's no
7183 need to walk over threads. Above we've checked whether the
7184 current thread is stepping. If some other thread not the
7185 event thread is stepping, then it must be that scheduler
7186 locking is not in effect. */
7187 if (schedlock_applies (ecs
->event_thread
))
7190 /* Otherwise, we no longer expect a trap in the current thread.
7191 Clear the trap_expected flag before switching back -- this is
7192 what keep_going does as well, if we call it. */
7193 ecs
->event_thread
->control
.trap_expected
= 0;
7195 /* Likewise, clear the signal if it should not be passed. */
7196 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7197 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7199 /* Do all pending step-overs before actually proceeding with
7201 if (start_step_over ())
7203 prepare_to_wait (ecs
);
7207 /* Look for the stepping/nexting thread. */
7208 stepping_thread
= NULL
;
7210 for (thread_info
*tp
: all_non_exited_threads ())
7212 switch_to_thread_no_regs (tp
);
7214 /* Ignore threads of processes the caller is not
7217 && (tp
->inf
->process_target () != ecs
->target
7218 || tp
->inf
->pid
!= ecs
->ptid
.pid ()))
7221 /* When stepping over a breakpoint, we lock all threads
7222 except the one that needs to move past the breakpoint.
7223 If a non-event thread has this set, the "incomplete
7224 step-over" check above should have caught it earlier. */
7225 if (tp
->control
.trap_expected
)
7227 internal_error (__FILE__
, __LINE__
,
7228 "[%s] has inconsistent state: "
7229 "trap_expected=%d\n",
7230 target_pid_to_str (tp
->ptid
).c_str (),
7231 tp
->control
.trap_expected
);
7234 /* Did we find the stepping thread? */
7235 if (tp
->control
.step_range_end
)
7237 /* Yep. There should only one though. */
7238 gdb_assert (stepping_thread
== NULL
);
7240 /* The event thread is handled at the top, before we
7242 gdb_assert (tp
!= ecs
->event_thread
);
7244 /* If some thread other than the event thread is
7245 stepping, then scheduler locking can't be in effect,
7246 otherwise we wouldn't have resumed the current event
7247 thread in the first place. */
7248 gdb_assert (!schedlock_applies (tp
));
7250 stepping_thread
= tp
;
7254 if (stepping_thread
!= NULL
)
7256 infrun_log_debug ("switching back to stepped thread");
7258 if (keep_going_stepped_thread (stepping_thread
))
7260 prepare_to_wait (ecs
);
7265 switch_to_thread (ecs
->event_thread
);
7271 /* Set a previously stepped thread back to stepping. Returns true on
7272 success, false if the resume is not possible (e.g., the thread
7276 keep_going_stepped_thread (struct thread_info
*tp
)
7278 struct frame_info
*frame
;
7279 struct execution_control_state ecss
;
7280 struct execution_control_state
*ecs
= &ecss
;
7282 /* If the stepping thread exited, then don't try to switch back and
7283 resume it, which could fail in several different ways depending
7284 on the target. Instead, just keep going.
7286 We can find a stepping dead thread in the thread list in two
7289 - The target supports thread exit events, and when the target
7290 tries to delete the thread from the thread list, inferior_ptid
7291 pointed at the exiting thread. In such case, calling
7292 delete_thread does not really remove the thread from the list;
7293 instead, the thread is left listed, with 'exited' state.
7295 - The target's debug interface does not support thread exit
7296 events, and so we have no idea whatsoever if the previously
7297 stepping thread is still alive. For that reason, we need to
7298 synchronously query the target now. */
7300 if (tp
->state
== THREAD_EXITED
|| !target_thread_alive (tp
->ptid
))
7302 infrun_log_debug ("not resuming previously stepped thread, it has "
7309 infrun_log_debug ("resuming previously stepped thread");
7311 reset_ecs (ecs
, tp
);
7312 switch_to_thread (tp
);
7314 tp
->suspend
.stop_pc
= regcache_read_pc (get_thread_regcache (tp
));
7315 frame
= get_current_frame ();
7317 /* If the PC of the thread we were trying to single-step has
7318 changed, then that thread has trapped or been signaled, but the
7319 event has not been reported to GDB yet. Re-poll the target
7320 looking for this particular thread's event (i.e. temporarily
7321 enable schedlock) by:
7323 - setting a break at the current PC
7324 - resuming that particular thread, only (by setting trap
7327 This prevents us continuously moving the single-step breakpoint
7328 forward, one instruction at a time, overstepping. */
7330 if (tp
->suspend
.stop_pc
!= tp
->prev_pc
)
7334 infrun_log_debug ("expected thread advanced also (%s -> %s)",
7335 paddress (target_gdbarch (), tp
->prev_pc
),
7336 paddress (target_gdbarch (), tp
->suspend
.stop_pc
));
7338 /* Clear the info of the previous step-over, as it's no longer
7339 valid (if the thread was trying to step over a breakpoint, it
7340 has already succeeded). It's what keep_going would do too,
7341 if we called it. Do this before trying to insert the sss
7342 breakpoint, otherwise if we were previously trying to step
7343 over this exact address in another thread, the breakpoint is
7345 clear_step_over_info ();
7346 tp
->control
.trap_expected
= 0;
7348 insert_single_step_breakpoint (get_frame_arch (frame
),
7349 get_frame_address_space (frame
),
7350 tp
->suspend
.stop_pc
);
7353 resume_ptid
= internal_resume_ptid (tp
->control
.stepping_command
);
7354 do_target_resume (resume_ptid
, 0, GDB_SIGNAL_0
);
7358 infrun_log_debug ("expected thread still hasn't advanced");
7360 keep_going_pass_signal (ecs
);
7365 /* Is thread TP in the middle of (software or hardware)
7366 single-stepping? (Note the result of this function must never be
7367 passed directly as target_resume's STEP parameter.) */
7370 currently_stepping (struct thread_info
*tp
)
7372 return ((tp
->control
.step_range_end
7373 && tp
->control
.step_resume_breakpoint
== NULL
)
7374 || tp
->control
.trap_expected
7375 || tp
->stepped_breakpoint
7376 || bpstat_should_step ());
7379 /* Inferior has stepped into a subroutine call with source code that
7380 we should not step over. Do step to the first line of code in
7384 handle_step_into_function (struct gdbarch
*gdbarch
,
7385 struct execution_control_state
*ecs
)
7387 fill_in_stop_func (gdbarch
, ecs
);
7389 compunit_symtab
*cust
7390 = find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7391 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7392 ecs
->stop_func_start
7393 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7395 symtab_and_line stop_func_sal
= find_pc_line (ecs
->stop_func_start
, 0);
7396 /* Use the step_resume_break to step until the end of the prologue,
7397 even if that involves jumps (as it seems to on the vax under
7399 /* If the prologue ends in the middle of a source line, continue to
7400 the end of that source line (if it is still within the function).
7401 Otherwise, just go to end of prologue. */
7402 if (stop_func_sal
.end
7403 && stop_func_sal
.pc
!= ecs
->stop_func_start
7404 && stop_func_sal
.end
< ecs
->stop_func_end
)
7405 ecs
->stop_func_start
= stop_func_sal
.end
;
7407 /* Architectures which require breakpoint adjustment might not be able
7408 to place a breakpoint at the computed address. If so, the test
7409 ``ecs->stop_func_start == stop_pc'' will never succeed. Adjust
7410 ecs->stop_func_start to an address at which a breakpoint may be
7411 legitimately placed.
7413 Note: kevinb/2004-01-19: On FR-V, if this adjustment is not
7414 made, GDB will enter an infinite loop when stepping through
7415 optimized code consisting of VLIW instructions which contain
7416 subinstructions corresponding to different source lines. On
7417 FR-V, it's not permitted to place a breakpoint on any but the
7418 first subinstruction of a VLIW instruction. When a breakpoint is
7419 set, GDB will adjust the breakpoint address to the beginning of
7420 the VLIW instruction. Thus, we need to make the corresponding
7421 adjustment here when computing the stop address. */
7423 if (gdbarch_adjust_breakpoint_address_p (gdbarch
))
7425 ecs
->stop_func_start
7426 = gdbarch_adjust_breakpoint_address (gdbarch
,
7427 ecs
->stop_func_start
);
7430 if (ecs
->stop_func_start
== ecs
->event_thread
->suspend
.stop_pc
)
7432 /* We are already there: stop now. */
7433 end_stepping_range (ecs
);
7438 /* Put the step-breakpoint there and go until there. */
7439 symtab_and_line sr_sal
;
7440 sr_sal
.pc
= ecs
->stop_func_start
;
7441 sr_sal
.section
= find_pc_overlay (ecs
->stop_func_start
);
7442 sr_sal
.pspace
= get_frame_program_space (get_current_frame ());
7444 /* Do not specify what the fp should be when we stop since on
7445 some machines the prologue is where the new fp value is
7447 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
, null_frame_id
);
7449 /* And make sure stepping stops right away then. */
7450 ecs
->event_thread
->control
.step_range_end
7451 = ecs
->event_thread
->control
.step_range_start
;
7456 /* Inferior has stepped backward into a subroutine call with source
7457 code that we should not step over. Do step to the beginning of the
7458 last line of code in it. */
7461 handle_step_into_function_backward (struct gdbarch
*gdbarch
,
7462 struct execution_control_state
*ecs
)
7464 struct compunit_symtab
*cust
;
7465 struct symtab_and_line stop_func_sal
;
7467 fill_in_stop_func (gdbarch
, ecs
);
7469 cust
= find_pc_compunit_symtab (ecs
->event_thread
->suspend
.stop_pc
);
7470 if (cust
!= NULL
&& compunit_language (cust
) != language_asm
)
7471 ecs
->stop_func_start
7472 = gdbarch_skip_prologue_noexcept (gdbarch
, ecs
->stop_func_start
);
7474 stop_func_sal
= find_pc_line (ecs
->event_thread
->suspend
.stop_pc
, 0);
7476 /* OK, we're just going to keep stepping here. */
7477 if (stop_func_sal
.pc
== ecs
->event_thread
->suspend
.stop_pc
)
7479 /* We're there already. Just stop stepping now. */
7480 end_stepping_range (ecs
);
7484 /* Else just reset the step range and keep going.
7485 No step-resume breakpoint, they don't work for
7486 epilogues, which can have multiple entry paths. */
7487 ecs
->event_thread
->control
.step_range_start
= stop_func_sal
.pc
;
7488 ecs
->event_thread
->control
.step_range_end
= stop_func_sal
.end
;
7494 /* Insert a "step-resume breakpoint" at SR_SAL with frame ID SR_ID.
7495 This is used to both functions and to skip over code. */
7498 insert_step_resume_breakpoint_at_sal_1 (struct gdbarch
*gdbarch
,
7499 struct symtab_and_line sr_sal
,
7500 struct frame_id sr_id
,
7501 enum bptype sr_type
)
7503 /* There should never be more than one step-resume or longjmp-resume
7504 breakpoint per thread, so we should never be setting a new
7505 step_resume_breakpoint when one is already active. */
7506 gdb_assert (inferior_thread ()->control
.step_resume_breakpoint
== NULL
);
7507 gdb_assert (sr_type
== bp_step_resume
|| sr_type
== bp_hp_step_resume
);
7509 infrun_log_debug ("inserting step-resume breakpoint at %s",
7510 paddress (gdbarch
, sr_sal
.pc
));
7512 inferior_thread ()->control
.step_resume_breakpoint
7513 = set_momentary_breakpoint (gdbarch
, sr_sal
, sr_id
, sr_type
).release ();
7517 insert_step_resume_breakpoint_at_sal (struct gdbarch
*gdbarch
,
7518 struct symtab_and_line sr_sal
,
7519 struct frame_id sr_id
)
7521 insert_step_resume_breakpoint_at_sal_1 (gdbarch
,
7526 /* Insert a "high-priority step-resume breakpoint" at RETURN_FRAME.pc.
7527 This is used to skip a potential signal handler.
7529 This is called with the interrupted function's frame. The signal
7530 handler, when it returns, will resume the interrupted function at
7534 insert_hp_step_resume_breakpoint_at_frame (struct frame_info
*return_frame
)
7536 gdb_assert (return_frame
!= NULL
);
7538 struct gdbarch
*gdbarch
= get_frame_arch (return_frame
);
7540 symtab_and_line sr_sal
;
7541 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
, get_frame_pc (return_frame
));
7542 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7543 sr_sal
.pspace
= get_frame_program_space (return_frame
);
7545 insert_step_resume_breakpoint_at_sal_1 (gdbarch
, sr_sal
,
7546 get_stack_frame_id (return_frame
),
7550 /* Insert a "step-resume breakpoint" at the previous frame's PC. This
7551 is used to skip a function after stepping into it (for "next" or if
7552 the called function has no debugging information).
7554 The current function has almost always been reached by single
7555 stepping a call or return instruction. NEXT_FRAME belongs to the
7556 current function, and the breakpoint will be set at the caller's
7559 This is a separate function rather than reusing
7560 insert_hp_step_resume_breakpoint_at_frame in order to avoid
7561 get_prev_frame, which may stop prematurely (see the implementation
7562 of frame_unwind_caller_id for an example). */
7565 insert_step_resume_breakpoint_at_caller (struct frame_info
*next_frame
)
7567 /* We shouldn't have gotten here if we don't know where the call site
7569 gdb_assert (frame_id_p (frame_unwind_caller_id (next_frame
)));
7571 struct gdbarch
*gdbarch
= frame_unwind_caller_arch (next_frame
);
7573 symtab_and_line sr_sal
;
7574 sr_sal
.pc
= gdbarch_addr_bits_remove (gdbarch
,
7575 frame_unwind_caller_pc (next_frame
));
7576 sr_sal
.section
= find_pc_overlay (sr_sal
.pc
);
7577 sr_sal
.pspace
= frame_unwind_program_space (next_frame
);
7579 insert_step_resume_breakpoint_at_sal (gdbarch
, sr_sal
,
7580 frame_unwind_caller_id (next_frame
));
7583 /* Insert a "longjmp-resume" breakpoint at PC. This is used to set a
7584 new breakpoint at the target of a jmp_buf. The handling of
7585 longjmp-resume uses the same mechanisms used for handling
7586 "step-resume" breakpoints. */
7589 insert_longjmp_resume_breakpoint (struct gdbarch
*gdbarch
, CORE_ADDR pc
)
7591 /* There should never be more than one longjmp-resume breakpoint per
7592 thread, so we should never be setting a new
7593 longjmp_resume_breakpoint when one is already active. */
7594 gdb_assert (inferior_thread ()->control
.exception_resume_breakpoint
== NULL
);
7596 infrun_log_debug ("inserting longjmp-resume breakpoint at %s",
7597 paddress (gdbarch
, pc
));
7599 inferior_thread ()->control
.exception_resume_breakpoint
=
7600 set_momentary_breakpoint_at_pc (gdbarch
, pc
, bp_longjmp_resume
).release ();
7603 /* Insert an exception resume breakpoint. TP is the thread throwing
7604 the exception. The block B is the block of the unwinder debug hook
7605 function. FRAME is the frame corresponding to the call to this
7606 function. SYM is the symbol of the function argument holding the
7607 target PC of the exception. */
7610 insert_exception_resume_breakpoint (struct thread_info
*tp
,
7611 const struct block
*b
,
7612 struct frame_info
*frame
,
7617 struct block_symbol vsym
;
7618 struct value
*value
;
7620 struct breakpoint
*bp
;
7622 vsym
= lookup_symbol_search_name (sym
->search_name (),
7624 value
= read_var_value (vsym
.symbol
, vsym
.block
, frame
);
7625 /* If the value was optimized out, revert to the old behavior. */
7626 if (! value_optimized_out (value
))
7628 handler
= value_as_address (value
);
7630 infrun_log_debug ("exception resume at %lx",
7631 (unsigned long) handler
);
7633 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7635 bp_exception_resume
).release ();
7637 /* set_momentary_breakpoint_at_pc invalidates FRAME. */
7640 bp
->thread
= tp
->global_num
;
7641 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7644 catch (const gdb_exception_error
&e
)
7646 /* We want to ignore errors here. */
7650 /* A helper for check_exception_resume that sets an
7651 exception-breakpoint based on a SystemTap probe. */
7654 insert_exception_resume_from_probe (struct thread_info
*tp
,
7655 const struct bound_probe
*probe
,
7656 struct frame_info
*frame
)
7658 struct value
*arg_value
;
7660 struct breakpoint
*bp
;
7662 arg_value
= probe_safe_evaluate_at_pc (frame
, 1);
7666 handler
= value_as_address (arg_value
);
7668 infrun_log_debug ("exception resume at %s",
7669 paddress (probe
->objfile
->arch (), handler
));
7671 bp
= set_momentary_breakpoint_at_pc (get_frame_arch (frame
),
7672 handler
, bp_exception_resume
).release ();
7673 bp
->thread
= tp
->global_num
;
7674 inferior_thread ()->control
.exception_resume_breakpoint
= bp
;
7677 /* This is called when an exception has been intercepted. Check to
7678 see whether the exception's destination is of interest, and if so,
7679 set an exception resume breakpoint there. */
7682 check_exception_resume (struct execution_control_state
*ecs
,
7683 struct frame_info
*frame
)
7685 struct bound_probe probe
;
7686 struct symbol
*func
;
7688 /* First see if this exception unwinding breakpoint was set via a
7689 SystemTap probe point. If so, the probe has two arguments: the
7690 CFA and the HANDLER. We ignore the CFA, extract the handler, and
7691 set a breakpoint there. */
7692 probe
= find_probe_by_pc (get_frame_pc (frame
));
7695 insert_exception_resume_from_probe (ecs
->event_thread
, &probe
, frame
);
7699 func
= get_frame_function (frame
);
7705 const struct block
*b
;
7706 struct block_iterator iter
;
7710 /* The exception breakpoint is a thread-specific breakpoint on
7711 the unwinder's debug hook, declared as:
7713 void _Unwind_DebugHook (void *cfa, void *handler);
7715 The CFA argument indicates the frame to which control is
7716 about to be transferred. HANDLER is the destination PC.
7718 We ignore the CFA and set a temporary breakpoint at HANDLER.
7719 This is not extremely efficient but it avoids issues in gdb
7720 with computing the DWARF CFA, and it also works even in weird
7721 cases such as throwing an exception from inside a signal
7724 b
= SYMBOL_BLOCK_VALUE (func
);
7725 ALL_BLOCK_SYMBOLS (b
, iter
, sym
)
7727 if (!SYMBOL_IS_ARGUMENT (sym
))
7734 insert_exception_resume_breakpoint (ecs
->event_thread
,
7740 catch (const gdb_exception_error
&e
)
7746 stop_waiting (struct execution_control_state
*ecs
)
7748 infrun_log_debug ("stop_waiting");
7750 /* Let callers know we don't want to wait for the inferior anymore. */
7751 ecs
->wait_some_more
= 0;
7753 /* If all-stop, but there exists a non-stop target, stop all
7754 threads now that we're presenting the stop to the user. */
7755 if (!non_stop
&& exists_non_stop_target ())
7756 stop_all_threads ();
7759 /* Like keep_going, but passes the signal to the inferior, even if the
7760 signal is set to nopass. */
7763 keep_going_pass_signal (struct execution_control_state
*ecs
)
7765 gdb_assert (ecs
->event_thread
->ptid
== inferior_ptid
);
7766 gdb_assert (!ecs
->event_thread
->resumed
);
7768 /* Save the pc before execution, to compare with pc after stop. */
7769 ecs
->event_thread
->prev_pc
7770 = regcache_read_pc_protected (get_thread_regcache (ecs
->event_thread
));
7772 if (ecs
->event_thread
->control
.trap_expected
)
7774 struct thread_info
*tp
= ecs
->event_thread
;
7776 infrun_log_debug ("%s has trap_expected set, "
7777 "resuming to collect trap",
7778 target_pid_to_str (tp
->ptid
).c_str ());
7780 /* We haven't yet gotten our trap, and either: intercepted a
7781 non-signal event (e.g., a fork); or took a signal which we
7782 are supposed to pass through to the inferior. Simply
7784 resume (ecs
->event_thread
->suspend
.stop_signal
);
7786 else if (step_over_info_valid_p ())
7788 /* Another thread is stepping over a breakpoint in-line. If
7789 this thread needs a step-over too, queue the request. In
7790 either case, this resume must be deferred for later. */
7791 struct thread_info
*tp
= ecs
->event_thread
;
7793 if (ecs
->hit_singlestep_breakpoint
7794 || thread_still_needs_step_over (tp
))
7796 infrun_log_debug ("step-over already in progress: "
7797 "step-over for %s deferred",
7798 target_pid_to_str (tp
->ptid
).c_str ());
7799 global_thread_step_over_chain_enqueue (tp
);
7803 infrun_log_debug ("step-over in progress: resume of %s deferred",
7804 target_pid_to_str (tp
->ptid
).c_str ());
7809 struct regcache
*regcache
= get_current_regcache ();
7812 step_over_what step_what
;
7814 /* Either the trap was not expected, but we are continuing
7815 anyway (if we got a signal, the user asked it be passed to
7818 We got our expected trap, but decided we should resume from
7821 We're going to run this baby now!
7823 Note that insert_breakpoints won't try to re-insert
7824 already inserted breakpoints. Therefore, we don't
7825 care if breakpoints were already inserted, or not. */
7827 /* If we need to step over a breakpoint, and we're not using
7828 displaced stepping to do so, insert all breakpoints
7829 (watchpoints, etc.) but the one we're stepping over, step one
7830 instruction, and then re-insert the breakpoint when that step
7833 step_what
= thread_still_needs_step_over (ecs
->event_thread
);
7835 remove_bp
= (ecs
->hit_singlestep_breakpoint
7836 || (step_what
& STEP_OVER_BREAKPOINT
));
7837 remove_wps
= (step_what
& STEP_OVER_WATCHPOINT
);
7839 /* We can't use displaced stepping if we need to step past a
7840 watchpoint. The instruction copied to the scratch pad would
7841 still trigger the watchpoint. */
7843 && (remove_wps
|| !use_displaced_stepping (ecs
->event_thread
)))
7845 set_step_over_info (regcache
->aspace (),
7846 regcache_read_pc (regcache
), remove_wps
,
7847 ecs
->event_thread
->global_num
);
7849 else if (remove_wps
)
7850 set_step_over_info (NULL
, 0, remove_wps
, -1);
7852 /* If we now need to do an in-line step-over, we need to stop
7853 all other threads. Note this must be done before
7854 insert_breakpoints below, because that removes the breakpoint
7855 we're about to step over, otherwise other threads could miss
7857 if (step_over_info_valid_p () && target_is_non_stop_p ())
7858 stop_all_threads ();
7860 /* Stop stepping if inserting breakpoints fails. */
7863 insert_breakpoints ();
7865 catch (const gdb_exception_error
&e
)
7867 exception_print (gdb_stderr
, e
);
7869 clear_step_over_info ();
7873 ecs
->event_thread
->control
.trap_expected
= (remove_bp
|| remove_wps
);
7875 resume (ecs
->event_thread
->suspend
.stop_signal
);
7878 prepare_to_wait (ecs
);
7881 /* Called when we should continue running the inferior, because the
7882 current event doesn't cause a user visible stop. This does the
7883 resuming part; waiting for the next event is done elsewhere. */
7886 keep_going (struct execution_control_state
*ecs
)
7888 if (ecs
->event_thread
->control
.trap_expected
7889 && ecs
->event_thread
->suspend
.stop_signal
== GDB_SIGNAL_TRAP
)
7890 ecs
->event_thread
->control
.trap_expected
= 0;
7892 if (!signal_program
[ecs
->event_thread
->suspend
.stop_signal
])
7893 ecs
->event_thread
->suspend
.stop_signal
= GDB_SIGNAL_0
;
7894 keep_going_pass_signal (ecs
);
7897 /* This function normally comes after a resume, before
7898 handle_inferior_event exits. It takes care of any last bits of
7899 housekeeping, and sets the all-important wait_some_more flag. */
7902 prepare_to_wait (struct execution_control_state
*ecs
)
7904 infrun_log_debug ("prepare_to_wait");
7906 ecs
->wait_some_more
= 1;
7908 /* If the target can't async, emulate it by marking the infrun event
7909 handler such that as soon as we get back to the event-loop, we
7910 immediately end up in fetch_inferior_event again calling
7912 if (!target_can_async_p ())
7913 mark_infrun_async_event_handler ();
7916 /* We are done with the step range of a step/next/si/ni command.
7917 Called once for each n of a "step n" operation. */
7920 end_stepping_range (struct execution_control_state
*ecs
)
7922 ecs
->event_thread
->control
.stop_step
= 1;
7926 /* Several print_*_reason functions to print why the inferior has stopped.
7927 We always print something when the inferior exits, or receives a signal.
7928 The rest of the cases are dealt with later on in normal_stop and
7929 print_it_typical. Ideally there should be a call to one of these
7930 print_*_reason functions functions from handle_inferior_event each time
7931 stop_waiting is called.
7933 Note that we don't call these directly, instead we delegate that to
7934 the interpreters, through observers. Interpreters then call these
7935 with whatever uiout is right. */
7938 print_end_stepping_range_reason (struct ui_out
*uiout
)
7940 /* For CLI-like interpreters, print nothing. */
7942 if (uiout
->is_mi_like_p ())
7944 uiout
->field_string ("reason",
7945 async_reason_lookup (EXEC_ASYNC_END_STEPPING_RANGE
));
7950 print_signal_exited_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
7952 annotate_signalled ();
7953 if (uiout
->is_mi_like_p ())
7955 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_SIGNALLED
));
7956 uiout
->text ("\nProgram terminated with signal ");
7957 annotate_signal_name ();
7958 uiout
->field_string ("signal-name",
7959 gdb_signal_to_name (siggnal
));
7960 annotate_signal_name_end ();
7962 annotate_signal_string ();
7963 uiout
->field_string ("signal-meaning",
7964 gdb_signal_to_string (siggnal
));
7965 annotate_signal_string_end ();
7966 uiout
->text (".\n");
7967 uiout
->text ("The program no longer exists.\n");
7971 print_exited_reason (struct ui_out
*uiout
, int exitstatus
)
7973 struct inferior
*inf
= current_inferior ();
7974 std::string pidstr
= target_pid_to_str (ptid_t (inf
->pid
));
7976 annotate_exited (exitstatus
);
7979 if (uiout
->is_mi_like_p ())
7980 uiout
->field_string ("reason", async_reason_lookup (EXEC_ASYNC_EXITED
));
7981 std::string exit_code_str
7982 = string_printf ("0%o", (unsigned int) exitstatus
);
7983 uiout
->message ("[Inferior %s (%s) exited with code %pF]\n",
7984 plongest (inf
->num
), pidstr
.c_str (),
7985 string_field ("exit-code", exit_code_str
.c_str ()));
7989 if (uiout
->is_mi_like_p ())
7991 ("reason", async_reason_lookup (EXEC_ASYNC_EXITED_NORMALLY
));
7992 uiout
->message ("[Inferior %s (%s) exited normally]\n",
7993 plongest (inf
->num
), pidstr
.c_str ());
7997 /* Some targets/architectures can do extra processing/display of
7998 segmentation faults. E.g., Intel MPX boundary faults.
7999 Call the architecture dependent function to handle the fault. */
8002 handle_segmentation_fault (struct ui_out
*uiout
)
8004 struct regcache
*regcache
= get_current_regcache ();
8005 struct gdbarch
*gdbarch
= regcache
->arch ();
8007 if (gdbarch_handle_segmentation_fault_p (gdbarch
))
8008 gdbarch_handle_segmentation_fault (gdbarch
, uiout
);
8012 print_signal_received_reason (struct ui_out
*uiout
, enum gdb_signal siggnal
)
8014 struct thread_info
*thr
= inferior_thread ();
8018 if (uiout
->is_mi_like_p ())
8020 else if (show_thread_that_caused_stop ())
8024 uiout
->text ("\nThread ");
8025 uiout
->field_string ("thread-id", print_thread_id (thr
));
8027 name
= thr
->name
!= NULL
? thr
->name
: target_thread_name (thr
);
8030 uiout
->text (" \"");
8031 uiout
->field_string ("name", name
);
8036 uiout
->text ("\nProgram");
8038 if (siggnal
== GDB_SIGNAL_0
&& !uiout
->is_mi_like_p ())
8039 uiout
->text (" stopped");
8042 uiout
->text (" received signal ");
8043 annotate_signal_name ();
8044 if (uiout
->is_mi_like_p ())
8046 ("reason", async_reason_lookup (EXEC_ASYNC_SIGNAL_RECEIVED
));
8047 uiout
->field_string ("signal-name", gdb_signal_to_name (siggnal
));
8048 annotate_signal_name_end ();
8050 annotate_signal_string ();
8051 uiout
->field_string ("signal-meaning", gdb_signal_to_string (siggnal
));
8053 if (siggnal
== GDB_SIGNAL_SEGV
)
8054 handle_segmentation_fault (uiout
);
8056 annotate_signal_string_end ();
8058 uiout
->text (".\n");
8062 print_no_history_reason (struct ui_out
*uiout
)
8064 uiout
->text ("\nNo more reverse-execution history.\n");
8067 /* Print current location without a level number, if we have changed
8068 functions or hit a breakpoint. Print source line if we have one.
8069 bpstat_print contains the logic deciding in detail what to print,
8070 based on the event(s) that just occurred. */
8073 print_stop_location (struct target_waitstatus
*ws
)
8076 enum print_what source_flag
;
8077 int do_frame_printing
= 1;
8078 struct thread_info
*tp
= inferior_thread ();
8080 bpstat_ret
= bpstat_print (tp
->control
.stop_bpstat
, ws
->kind
);
8084 /* FIXME: cagney/2002-12-01: Given that a frame ID does (or
8085 should) carry around the function and does (or should) use
8086 that when doing a frame comparison. */
8087 if (tp
->control
.stop_step
8088 && frame_id_eq (tp
->control
.step_frame_id
,
8089 get_frame_id (get_current_frame ()))
8090 && (tp
->control
.step_start_function
8091 == find_pc_function (tp
->suspend
.stop_pc
)))
8093 /* Finished step, just print source line. */
8094 source_flag
= SRC_LINE
;
8098 /* Print location and source line. */
8099 source_flag
= SRC_AND_LOC
;
8102 case PRINT_SRC_AND_LOC
:
8103 /* Print location and source line. */
8104 source_flag
= SRC_AND_LOC
;
8106 case PRINT_SRC_ONLY
:
8107 source_flag
= SRC_LINE
;
8110 /* Something bogus. */
8111 source_flag
= SRC_LINE
;
8112 do_frame_printing
= 0;
8115 internal_error (__FILE__
, __LINE__
, _("Unknown value."));
8118 /* The behavior of this routine with respect to the source
8120 SRC_LINE: Print only source line
8121 LOCATION: Print only location
8122 SRC_AND_LOC: Print location and source line. */
8123 if (do_frame_printing
)
8124 print_stack_frame (get_selected_frame (NULL
), 0, source_flag
, 1);
8130 print_stop_event (struct ui_out
*uiout
, bool displays
)
8132 struct target_waitstatus last
;
8133 struct thread_info
*tp
;
8135 get_last_target_status (nullptr, nullptr, &last
);
8138 scoped_restore save_uiout
= make_scoped_restore (¤t_uiout
, uiout
);
8140 print_stop_location (&last
);
8142 /* Display the auto-display expressions. */
8147 tp
= inferior_thread ();
8148 if (tp
->thread_fsm
!= NULL
8149 && tp
->thread_fsm
->finished_p ())
8151 struct return_value_info
*rv
;
8153 rv
= tp
->thread_fsm
->return_value ();
8155 print_return_value (uiout
, rv
);
8162 maybe_remove_breakpoints (void)
8164 if (!breakpoints_should_be_inserted_now () && target_has_execution
)
8166 if (remove_breakpoints ())
8168 target_terminal::ours_for_output ();
8169 printf_filtered (_("Cannot remove breakpoints because "
8170 "program is no longer writable.\nFurther "
8171 "execution is probably impossible.\n"));
8176 /* The execution context that just caused a normal stop. */
8183 DISABLE_COPY_AND_ASSIGN (stop_context
);
8185 bool changed () const;
8190 /* The event PTID. */
8194 /* If stopp for a thread event, this is the thread that caused the
8196 struct thread_info
*thread
;
8198 /* The inferior that caused the stop. */
8202 /* Initializes a new stop context. If stopped for a thread event, this
8203 takes a strong reference to the thread. */
8205 stop_context::stop_context ()
8207 stop_id
= get_stop_id ();
8208 ptid
= inferior_ptid
;
8209 inf_num
= current_inferior ()->num
;
8211 if (inferior_ptid
!= null_ptid
)
8213 /* Take a strong reference so that the thread can't be deleted
8215 thread
= inferior_thread ();
8222 /* Release a stop context previously created with save_stop_context.
8223 Releases the strong reference to the thread as well. */
8225 stop_context::~stop_context ()
8231 /* Return true if the current context no longer matches the saved stop
8235 stop_context::changed () const
8237 if (ptid
!= inferior_ptid
)
8239 if (inf_num
!= current_inferior ()->num
)
8241 if (thread
!= NULL
&& thread
->state
!= THREAD_STOPPED
)
8243 if (get_stop_id () != stop_id
)
8253 struct target_waitstatus last
;
8255 get_last_target_status (nullptr, nullptr, &last
);
8259 /* If an exception is thrown from this point on, make sure to
8260 propagate GDB's knowledge of the executing state to the
8261 frontend/user running state. A QUIT is an easy exception to see
8262 here, so do this before any filtered output. */
8264 ptid_t finish_ptid
= null_ptid
;
8267 finish_ptid
= minus_one_ptid
;
8268 else if (last
.kind
== TARGET_WAITKIND_SIGNALLED
8269 || last
.kind
== TARGET_WAITKIND_EXITED
)
8271 /* On some targets, we may still have live threads in the
8272 inferior when we get a process exit event. E.g., for
8273 "checkpoint", when the current checkpoint/fork exits,
8274 linux-fork.c automatically switches to another fork from
8275 within target_mourn_inferior. */
8276 if (inferior_ptid
!= null_ptid
)
8277 finish_ptid
= ptid_t (inferior_ptid
.pid ());
8279 else if (last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8280 finish_ptid
= inferior_ptid
;
8282 gdb::optional
<scoped_finish_thread_state
> maybe_finish_thread_state
;
8283 if (finish_ptid
!= null_ptid
)
8285 maybe_finish_thread_state
.emplace
8286 (user_visible_resume_target (finish_ptid
), finish_ptid
);
8289 /* As we're presenting a stop, and potentially removing breakpoints,
8290 update the thread list so we can tell whether there are threads
8291 running on the target. With target remote, for example, we can
8292 only learn about new threads when we explicitly update the thread
8293 list. Do this before notifying the interpreters about signal
8294 stops, end of stepping ranges, etc., so that the "new thread"
8295 output is emitted before e.g., "Program received signal FOO",
8296 instead of after. */
8297 update_thread_list ();
8299 if (last
.kind
== TARGET_WAITKIND_STOPPED
&& stopped_by_random_signal
)
8300 gdb::observers::signal_received
.notify (inferior_thread ()->suspend
.stop_signal
);
8302 /* As with the notification of thread events, we want to delay
8303 notifying the user that we've switched thread context until
8304 the inferior actually stops.
8306 There's no point in saying anything if the inferior has exited.
8307 Note that SIGNALLED here means "exited with a signal", not
8308 "received a signal".
8310 Also skip saying anything in non-stop mode. In that mode, as we
8311 don't want GDB to switch threads behind the user's back, to avoid
8312 races where the user is typing a command to apply to thread x,
8313 but GDB switches to thread y before the user finishes entering
8314 the command, fetch_inferior_event installs a cleanup to restore
8315 the current thread back to the thread the user had selected right
8316 after this event is handled, so we're not really switching, only
8317 informing of a stop. */
8319 && previous_inferior_ptid
!= inferior_ptid
8320 && target_has_execution
8321 && last
.kind
!= TARGET_WAITKIND_SIGNALLED
8322 && last
.kind
!= TARGET_WAITKIND_EXITED
8323 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8325 SWITCH_THRU_ALL_UIS ()
8327 target_terminal::ours_for_output ();
8328 printf_filtered (_("[Switching to %s]\n"),
8329 target_pid_to_str (inferior_ptid
).c_str ());
8330 annotate_thread_changed ();
8332 previous_inferior_ptid
= inferior_ptid
;
8335 if (last
.kind
== TARGET_WAITKIND_NO_RESUMED
)
8337 SWITCH_THRU_ALL_UIS ()
8338 if (current_ui
->prompt_state
== PROMPT_BLOCKED
)
8340 target_terminal::ours_for_output ();
8341 printf_filtered (_("No unwaited-for children left.\n"));
8345 /* Note: this depends on the update_thread_list call above. */
8346 maybe_remove_breakpoints ();
8348 /* If an auto-display called a function and that got a signal,
8349 delete that auto-display to avoid an infinite recursion. */
8351 if (stopped_by_random_signal
)
8352 disable_current_display ();
8354 SWITCH_THRU_ALL_UIS ()
8356 async_enable_stdin ();
8359 /* Let the user/frontend see the threads as stopped. */
8360 maybe_finish_thread_state
.reset ();
8362 /* Select innermost stack frame - i.e., current frame is frame 0,
8363 and current location is based on that. Handle the case where the
8364 dummy call is returning after being stopped. E.g. the dummy call
8365 previously hit a breakpoint. (If the dummy call returns
8366 normally, we won't reach here.) Do this before the stop hook is
8367 run, so that it doesn't get to see the temporary dummy frame,
8368 which is not where we'll present the stop. */
8369 if (has_stack_frames ())
8371 if (stop_stack_dummy
== STOP_STACK_DUMMY
)
8373 /* Pop the empty frame that contains the stack dummy. This
8374 also restores inferior state prior to the call (struct
8375 infcall_suspend_state). */
8376 struct frame_info
*frame
= get_current_frame ();
8378 gdb_assert (get_frame_type (frame
) == DUMMY_FRAME
);
8380 /* frame_pop calls reinit_frame_cache as the last thing it
8381 does which means there's now no selected frame. */
8384 select_frame (get_current_frame ());
8386 /* Set the current source location. */
8387 set_current_sal_from_frame (get_current_frame ());
8390 /* Look up the hook_stop and run it (CLI internally handles problem
8391 of stop_command's pre-hook not existing). */
8392 if (stop_command
!= NULL
)
8394 stop_context saved_context
;
8398 execute_cmd_pre_hook (stop_command
);
8400 catch (const gdb_exception
&ex
)
8402 exception_fprintf (gdb_stderr
, ex
,
8403 "Error while running hook_stop:\n");
8406 /* If the stop hook resumes the target, then there's no point in
8407 trying to notify about the previous stop; its context is
8408 gone. Likewise if the command switches thread or inferior --
8409 the observers would print a stop for the wrong
8411 if (saved_context
.changed ())
8415 /* Notify observers about the stop. This is where the interpreters
8416 print the stop event. */
8417 if (inferior_ptid
!= null_ptid
)
8418 gdb::observers::normal_stop
.notify (inferior_thread ()->control
.stop_bpstat
,
8421 gdb::observers::normal_stop
.notify (NULL
, stop_print_frame
);
8423 annotate_stopped ();
8425 if (target_has_execution
)
8427 if (last
.kind
!= TARGET_WAITKIND_SIGNALLED
8428 && last
.kind
!= TARGET_WAITKIND_EXITED
8429 && last
.kind
!= TARGET_WAITKIND_NO_RESUMED
)
8430 /* Delete the breakpoint we stopped at, if it wants to be deleted.
8431 Delete any breakpoint that is to be deleted at the next stop. */
8432 breakpoint_auto_delete (inferior_thread ()->control
.stop_bpstat
);
8435 /* Try to get rid of automatically added inferiors that are no
8436 longer needed. Keeping those around slows down things linearly.
8437 Note that this never removes the current inferior. */
8444 signal_stop_state (int signo
)
8446 return signal_stop
[signo
];
8450 signal_print_state (int signo
)
8452 return signal_print
[signo
];
8456 signal_pass_state (int signo
)
8458 return signal_program
[signo
];
8462 signal_cache_update (int signo
)
8466 for (signo
= 0; signo
< (int) GDB_SIGNAL_LAST
; signo
++)
8467 signal_cache_update (signo
);
8472 signal_pass
[signo
] = (signal_stop
[signo
] == 0
8473 && signal_print
[signo
] == 0
8474 && signal_program
[signo
] == 1
8475 && signal_catch
[signo
] == 0);
8479 signal_stop_update (int signo
, int state
)
8481 int ret
= signal_stop
[signo
];
8483 signal_stop
[signo
] = state
;
8484 signal_cache_update (signo
);
8489 signal_print_update (int signo
, int state
)
8491 int ret
= signal_print
[signo
];
8493 signal_print
[signo
] = state
;
8494 signal_cache_update (signo
);
8499 signal_pass_update (int signo
, int state
)
8501 int ret
= signal_program
[signo
];
8503 signal_program
[signo
] = state
;
8504 signal_cache_update (signo
);
8508 /* Update the global 'signal_catch' from INFO and notify the
8512 signal_catch_update (const unsigned int *info
)
8516 for (i
= 0; i
< GDB_SIGNAL_LAST
; ++i
)
8517 signal_catch
[i
] = info
[i
] > 0;
8518 signal_cache_update (-1);
8519 target_pass_signals (signal_pass
);
8523 sig_print_header (void)
8525 printf_filtered (_("Signal Stop\tPrint\tPass "
8526 "to program\tDescription\n"));
8530 sig_print_info (enum gdb_signal oursig
)
8532 const char *name
= gdb_signal_to_name (oursig
);
8533 int name_padding
= 13 - strlen (name
);
8535 if (name_padding
<= 0)
8538 printf_filtered ("%s", name
);
8539 printf_filtered ("%*.*s ", name_padding
, name_padding
, " ");
8540 printf_filtered ("%s\t", signal_stop
[oursig
] ? "Yes" : "No");
8541 printf_filtered ("%s\t", signal_print
[oursig
] ? "Yes" : "No");
8542 printf_filtered ("%s\t\t", signal_program
[oursig
] ? "Yes" : "No");
8543 printf_filtered ("%s\n", gdb_signal_to_string (oursig
));
8546 /* Specify how various signals in the inferior should be handled. */
8549 handle_command (const char *args
, int from_tty
)
8551 int digits
, wordlen
;
8552 int sigfirst
, siglast
;
8553 enum gdb_signal oursig
;
8558 error_no_arg (_("signal to handle"));
8561 /* Allocate and zero an array of flags for which signals to handle. */
8563 const size_t nsigs
= GDB_SIGNAL_LAST
;
8564 unsigned char sigs
[nsigs
] {};
8566 /* Break the command line up into args. */
8568 gdb_argv
built_argv (args
);
8570 /* Walk through the args, looking for signal oursigs, signal names, and
8571 actions. Signal numbers and signal names may be interspersed with
8572 actions, with the actions being performed for all signals cumulatively
8573 specified. Signal ranges can be specified as <LOW>-<HIGH>. */
8575 for (char *arg
: built_argv
)
8577 wordlen
= strlen (arg
);
8578 for (digits
= 0; isdigit (arg
[digits
]); digits
++)
8582 sigfirst
= siglast
= -1;
8584 if (wordlen
>= 1 && !strncmp (arg
, "all", wordlen
))
8586 /* Apply action to all signals except those used by the
8587 debugger. Silently skip those. */
8590 siglast
= nsigs
- 1;
8592 else if (wordlen
>= 1 && !strncmp (arg
, "stop", wordlen
))
8594 SET_SIGS (nsigs
, sigs
, signal_stop
);
8595 SET_SIGS (nsigs
, sigs
, signal_print
);
8597 else if (wordlen
>= 1 && !strncmp (arg
, "ignore", wordlen
))
8599 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8601 else if (wordlen
>= 2 && !strncmp (arg
, "print", wordlen
))
8603 SET_SIGS (nsigs
, sigs
, signal_print
);
8605 else if (wordlen
>= 2 && !strncmp (arg
, "pass", wordlen
))
8607 SET_SIGS (nsigs
, sigs
, signal_program
);
8609 else if (wordlen
>= 3 && !strncmp (arg
, "nostop", wordlen
))
8611 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8613 else if (wordlen
>= 3 && !strncmp (arg
, "noignore", wordlen
))
8615 SET_SIGS (nsigs
, sigs
, signal_program
);
8617 else if (wordlen
>= 4 && !strncmp (arg
, "noprint", wordlen
))
8619 UNSET_SIGS (nsigs
, sigs
, signal_print
);
8620 UNSET_SIGS (nsigs
, sigs
, signal_stop
);
8622 else if (wordlen
>= 4 && !strncmp (arg
, "nopass", wordlen
))
8624 UNSET_SIGS (nsigs
, sigs
, signal_program
);
8626 else if (digits
> 0)
8628 /* It is numeric. The numeric signal refers to our own
8629 internal signal numbering from target.h, not to host/target
8630 signal number. This is a feature; users really should be
8631 using symbolic names anyway, and the common ones like
8632 SIGHUP, SIGINT, SIGALRM, etc. will work right anyway. */
8634 sigfirst
= siglast
= (int)
8635 gdb_signal_from_command (atoi (arg
));
8636 if (arg
[digits
] == '-')
8639 gdb_signal_from_command (atoi (arg
+ digits
+ 1));
8641 if (sigfirst
> siglast
)
8643 /* Bet he didn't figure we'd think of this case... */
8644 std::swap (sigfirst
, siglast
);
8649 oursig
= gdb_signal_from_name (arg
);
8650 if (oursig
!= GDB_SIGNAL_UNKNOWN
)
8652 sigfirst
= siglast
= (int) oursig
;
8656 /* Not a number and not a recognized flag word => complain. */
8657 error (_("Unrecognized or ambiguous flag word: \"%s\"."), arg
);
8661 /* If any signal numbers or symbol names were found, set flags for
8662 which signals to apply actions to. */
8664 for (int signum
= sigfirst
; signum
>= 0 && signum
<= siglast
; signum
++)
8666 switch ((enum gdb_signal
) signum
)
8668 case GDB_SIGNAL_TRAP
:
8669 case GDB_SIGNAL_INT
:
8670 if (!allsigs
&& !sigs
[signum
])
8672 if (query (_("%s is used by the debugger.\n\
8673 Are you sure you want to change it? "),
8674 gdb_signal_to_name ((enum gdb_signal
) signum
)))
8679 printf_unfiltered (_("Not confirmed, unchanged.\n"));
8683 case GDB_SIGNAL_DEFAULT
:
8684 case GDB_SIGNAL_UNKNOWN
:
8685 /* Make sure that "all" doesn't print these. */
8694 for (int signum
= 0; signum
< nsigs
; signum
++)
8697 signal_cache_update (-1);
8698 target_pass_signals (signal_pass
);
8699 target_program_signals (signal_program
);
8703 /* Show the results. */
8704 sig_print_header ();
8705 for (; signum
< nsigs
; signum
++)
8707 sig_print_info ((enum gdb_signal
) signum
);
8714 /* Complete the "handle" command. */
8717 handle_completer (struct cmd_list_element
*ignore
,
8718 completion_tracker
&tracker
,
8719 const char *text
, const char *word
)
8721 static const char * const keywords
[] =
8735 signal_completer (ignore
, tracker
, text
, word
);
8736 complete_on_enum (tracker
, keywords
, word
, word
);
8740 gdb_signal_from_command (int num
)
8742 if (num
>= 1 && num
<= 15)
8743 return (enum gdb_signal
) num
;
8744 error (_("Only signals 1-15 are valid as numeric signals.\n\
8745 Use \"info signals\" for a list of symbolic signals."));
8748 /* Print current contents of the tables set by the handle command.
8749 It is possible we should just be printing signals actually used
8750 by the current target (but for things to work right when switching
8751 targets, all signals should be in the signal tables). */
8754 info_signals_command (const char *signum_exp
, int from_tty
)
8756 enum gdb_signal oursig
;
8758 sig_print_header ();
8762 /* First see if this is a symbol name. */
8763 oursig
= gdb_signal_from_name (signum_exp
);
8764 if (oursig
== GDB_SIGNAL_UNKNOWN
)
8766 /* No, try numeric. */
8768 gdb_signal_from_command (parse_and_eval_long (signum_exp
));
8770 sig_print_info (oursig
);
8774 printf_filtered ("\n");
8775 /* These ugly casts brought to you by the native VAX compiler. */
8776 for (oursig
= GDB_SIGNAL_FIRST
;
8777 (int) oursig
< (int) GDB_SIGNAL_LAST
;
8778 oursig
= (enum gdb_signal
) ((int) oursig
+ 1))
8782 if (oursig
!= GDB_SIGNAL_UNKNOWN
8783 && oursig
!= GDB_SIGNAL_DEFAULT
&& oursig
!= GDB_SIGNAL_0
)
8784 sig_print_info (oursig
);
8787 printf_filtered (_("\nUse the \"handle\" command "
8788 "to change these tables.\n"));
8791 /* The $_siginfo convenience variable is a bit special. We don't know
8792 for sure the type of the value until we actually have a chance to
8793 fetch the data. The type can change depending on gdbarch, so it is
8794 also dependent on which thread you have selected.
8796 1. making $_siginfo be an internalvar that creates a new value on
8799 2. making the value of $_siginfo be an lval_computed value. */
8801 /* This function implements the lval_computed support for reading a
8805 siginfo_value_read (struct value
*v
)
8807 LONGEST transferred
;
8809 /* If we can access registers, so can we access $_siginfo. Likewise
8811 validate_registers_access ();
8814 target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
,
8816 value_contents_all_raw (v
),
8818 TYPE_LENGTH (value_type (v
)));
8820 if (transferred
!= TYPE_LENGTH (value_type (v
)))
8821 error (_("Unable to read siginfo"));
8824 /* This function implements the lval_computed support for writing a
8828 siginfo_value_write (struct value
*v
, struct value
*fromval
)
8830 LONGEST transferred
;
8832 /* If we can access registers, so can we access $_siginfo. Likewise
8834 validate_registers_access ();
8836 transferred
= target_write (current_top_target (),
8837 TARGET_OBJECT_SIGNAL_INFO
,
8839 value_contents_all_raw (fromval
),
8841 TYPE_LENGTH (value_type (fromval
)));
8843 if (transferred
!= TYPE_LENGTH (value_type (fromval
)))
8844 error (_("Unable to write siginfo"));
8847 static const struct lval_funcs siginfo_value_funcs
=
8853 /* Return a new value with the correct type for the siginfo object of
8854 the current thread using architecture GDBARCH. Return a void value
8855 if there's no object available. */
8857 static struct value
*
8858 siginfo_make_value (struct gdbarch
*gdbarch
, struct internalvar
*var
,
8861 if (target_has_stack
8862 && inferior_ptid
!= null_ptid
8863 && gdbarch_get_siginfo_type_p (gdbarch
))
8865 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8867 return allocate_computed_value (type
, &siginfo_value_funcs
, NULL
);
8870 return allocate_value (builtin_type (gdbarch
)->builtin_void
);
8874 /* infcall_suspend_state contains state about the program itself like its
8875 registers and any signal it received when it last stopped.
8876 This state must be restored regardless of how the inferior function call
8877 ends (either successfully, or after it hits a breakpoint or signal)
8878 if the program is to properly continue where it left off. */
8880 class infcall_suspend_state
8883 /* Capture state from GDBARCH, TP, and REGCACHE that must be restored
8884 once the inferior function call has finished. */
8885 infcall_suspend_state (struct gdbarch
*gdbarch
,
8886 const struct thread_info
*tp
,
8887 struct regcache
*regcache
)
8888 : m_thread_suspend (tp
->suspend
),
8889 m_registers (new readonly_detached_regcache (*regcache
))
8891 gdb::unique_xmalloc_ptr
<gdb_byte
> siginfo_data
;
8893 if (gdbarch_get_siginfo_type_p (gdbarch
))
8895 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8896 size_t len
= TYPE_LENGTH (type
);
8898 siginfo_data
.reset ((gdb_byte
*) xmalloc (len
));
8900 if (target_read (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8901 siginfo_data
.get (), 0, len
) != len
)
8903 /* Errors ignored. */
8904 siginfo_data
.reset (nullptr);
8910 m_siginfo_gdbarch
= gdbarch
;
8911 m_siginfo_data
= std::move (siginfo_data
);
8915 /* Return a pointer to the stored register state. */
8917 readonly_detached_regcache
*registers () const
8919 return m_registers
.get ();
8922 /* Restores the stored state into GDBARCH, TP, and REGCACHE. */
8924 void restore (struct gdbarch
*gdbarch
,
8925 struct thread_info
*tp
,
8926 struct regcache
*regcache
) const
8928 tp
->suspend
= m_thread_suspend
;
8930 if (m_siginfo_gdbarch
== gdbarch
)
8932 struct type
*type
= gdbarch_get_siginfo_type (gdbarch
);
8934 /* Errors ignored. */
8935 target_write (current_top_target (), TARGET_OBJECT_SIGNAL_INFO
, NULL
,
8936 m_siginfo_data
.get (), 0, TYPE_LENGTH (type
));
8939 /* The inferior can be gone if the user types "print exit(0)"
8940 (and perhaps other times). */
8941 if (target_has_execution
)
8942 /* NB: The register write goes through to the target. */
8943 regcache
->restore (registers ());
8947 /* How the current thread stopped before the inferior function call was
8949 struct thread_suspend_state m_thread_suspend
;
8951 /* The registers before the inferior function call was executed. */
8952 std::unique_ptr
<readonly_detached_regcache
> m_registers
;
8954 /* Format of SIGINFO_DATA or NULL if it is not present. */
8955 struct gdbarch
*m_siginfo_gdbarch
= nullptr;
8957 /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
8958 TYPE_LENGTH (gdbarch_get_siginfo_type ()). For different gdbarch the
8959 content would be invalid. */
8960 gdb::unique_xmalloc_ptr
<gdb_byte
> m_siginfo_data
;
8963 infcall_suspend_state_up
8964 save_infcall_suspend_state ()
8966 struct thread_info
*tp
= inferior_thread ();
8967 struct regcache
*regcache
= get_current_regcache ();
8968 struct gdbarch
*gdbarch
= regcache
->arch ();
8970 infcall_suspend_state_up inf_state
8971 (new struct infcall_suspend_state (gdbarch
, tp
, regcache
));
8973 /* Having saved the current state, adjust the thread state, discarding
8974 any stop signal information. The stop signal is not useful when
8975 starting an inferior function call, and run_inferior_call will not use
8976 the signal due to its `proceed' call with GDB_SIGNAL_0. */
8977 tp
->suspend
.stop_signal
= GDB_SIGNAL_0
;
8982 /* Restore inferior session state to INF_STATE. */
8985 restore_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
8987 struct thread_info
*tp
= inferior_thread ();
8988 struct regcache
*regcache
= get_current_regcache ();
8989 struct gdbarch
*gdbarch
= regcache
->arch ();
8991 inf_state
->restore (gdbarch
, tp
, regcache
);
8992 discard_infcall_suspend_state (inf_state
);
8996 discard_infcall_suspend_state (struct infcall_suspend_state
*inf_state
)
9001 readonly_detached_regcache
*
9002 get_infcall_suspend_state_regcache (struct infcall_suspend_state
*inf_state
)
9004 return inf_state
->registers ();
9007 /* infcall_control_state contains state regarding gdb's control of the
9008 inferior itself like stepping control. It also contains session state like
9009 the user's currently selected frame. */
9011 struct infcall_control_state
9013 struct thread_control_state thread_control
;
9014 struct inferior_control_state inferior_control
;
9017 enum stop_stack_kind stop_stack_dummy
= STOP_NONE
;
9018 int stopped_by_random_signal
= 0;
9020 /* ID if the selected frame when the inferior function call was made. */
9021 struct frame_id selected_frame_id
{};
9024 /* Save all of the information associated with the inferior<==>gdb
9027 infcall_control_state_up
9028 save_infcall_control_state ()
9030 infcall_control_state_up
inf_status (new struct infcall_control_state
);
9031 struct thread_info
*tp
= inferior_thread ();
9032 struct inferior
*inf
= current_inferior ();
9034 inf_status
->thread_control
= tp
->control
;
9035 inf_status
->inferior_control
= inf
->control
;
9037 tp
->control
.step_resume_breakpoint
= NULL
;
9038 tp
->control
.exception_resume_breakpoint
= NULL
;
9040 /* Save original bpstat chain to INF_STATUS; replace it in TP with copy of
9041 chain. If caller's caller is walking the chain, they'll be happier if we
9042 hand them back the original chain when restore_infcall_control_state is
9044 tp
->control
.stop_bpstat
= bpstat_copy (tp
->control
.stop_bpstat
);
9047 inf_status
->stop_stack_dummy
= stop_stack_dummy
;
9048 inf_status
->stopped_by_random_signal
= stopped_by_random_signal
;
9050 inf_status
->selected_frame_id
= get_frame_id (get_selected_frame (NULL
));
9056 restore_selected_frame (const frame_id
&fid
)
9058 frame_info
*frame
= frame_find_by_id (fid
);
9060 /* If inf_status->selected_frame_id is NULL, there was no previously
9064 warning (_("Unable to restore previously selected frame."));
9068 select_frame (frame
);
9071 /* Restore inferior session state to INF_STATUS. */
9074 restore_infcall_control_state (struct infcall_control_state
*inf_status
)
9076 struct thread_info
*tp
= inferior_thread ();
9077 struct inferior
*inf
= current_inferior ();
9079 if (tp
->control
.step_resume_breakpoint
)
9080 tp
->control
.step_resume_breakpoint
->disposition
= disp_del_at_next_stop
;
9082 if (tp
->control
.exception_resume_breakpoint
)
9083 tp
->control
.exception_resume_breakpoint
->disposition
9084 = disp_del_at_next_stop
;
9086 /* Handle the bpstat_copy of the chain. */
9087 bpstat_clear (&tp
->control
.stop_bpstat
);
9089 tp
->control
= inf_status
->thread_control
;
9090 inf
->control
= inf_status
->inferior_control
;
9093 stop_stack_dummy
= inf_status
->stop_stack_dummy
;
9094 stopped_by_random_signal
= inf_status
->stopped_by_random_signal
;
9096 if (target_has_stack
)
9098 /* The point of the try/catch is that if the stack is clobbered,
9099 walking the stack might encounter a garbage pointer and
9100 error() trying to dereference it. */
9103 restore_selected_frame (inf_status
->selected_frame_id
);
9105 catch (const gdb_exception_error
&ex
)
9107 exception_fprintf (gdb_stderr
, ex
,
9108 "Unable to restore previously selected frame:\n");
9109 /* Error in restoring the selected frame. Select the
9111 select_frame (get_current_frame ());
9119 discard_infcall_control_state (struct infcall_control_state
*inf_status
)
9121 if (inf_status
->thread_control
.step_resume_breakpoint
)
9122 inf_status
->thread_control
.step_resume_breakpoint
->disposition
9123 = disp_del_at_next_stop
;
9125 if (inf_status
->thread_control
.exception_resume_breakpoint
)
9126 inf_status
->thread_control
.exception_resume_breakpoint
->disposition
9127 = disp_del_at_next_stop
;
9129 /* See save_infcall_control_state for info on stop_bpstat. */
9130 bpstat_clear (&inf_status
->thread_control
.stop_bpstat
);
9138 clear_exit_convenience_vars (void)
9140 clear_internalvar (lookup_internalvar ("_exitsignal"));
9141 clear_internalvar (lookup_internalvar ("_exitcode"));
9145 /* User interface for reverse debugging:
9146 Set exec-direction / show exec-direction commands
9147 (returns error unless target implements to_set_exec_direction method). */
9149 enum exec_direction_kind execution_direction
= EXEC_FORWARD
;
9150 static const char exec_forward
[] = "forward";
9151 static const char exec_reverse
[] = "reverse";
9152 static const char *exec_direction
= exec_forward
;
9153 static const char *const exec_direction_names
[] = {
9160 set_exec_direction_func (const char *args
, int from_tty
,
9161 struct cmd_list_element
*cmd
)
9163 if (target_can_execute_reverse
)
9165 if (!strcmp (exec_direction
, exec_forward
))
9166 execution_direction
= EXEC_FORWARD
;
9167 else if (!strcmp (exec_direction
, exec_reverse
))
9168 execution_direction
= EXEC_REVERSE
;
9172 exec_direction
= exec_forward
;
9173 error (_("Target does not support this operation."));
9178 show_exec_direction_func (struct ui_file
*out
, int from_tty
,
9179 struct cmd_list_element
*cmd
, const char *value
)
9181 switch (execution_direction
) {
9183 fprintf_filtered (out
, _("Forward.\n"));
9186 fprintf_filtered (out
, _("Reverse.\n"));
9189 internal_error (__FILE__
, __LINE__
,
9190 _("bogus execution_direction value: %d"),
9191 (int) execution_direction
);
9196 show_schedule_multiple (struct ui_file
*file
, int from_tty
,
9197 struct cmd_list_element
*c
, const char *value
)
9199 fprintf_filtered (file
, _("Resuming the execution of threads "
9200 "of all processes is %s.\n"), value
);
9203 /* Implementation of `siginfo' variable. */
9205 static const struct internalvar_funcs siginfo_funcs
=
9212 /* Callback for infrun's target events source. This is marked when a
9213 thread has a pending status to process. */
9216 infrun_async_inferior_event_handler (gdb_client_data data
)
9218 inferior_event_handler (INF_REG_EVENT
);
9221 void _initialize_infrun ();
9223 _initialize_infrun ()
9225 struct cmd_list_element
*c
;
9227 /* Register extra event sources in the event loop. */
9228 infrun_async_inferior_event_token
9229 = create_async_event_handler (infrun_async_inferior_event_handler
, NULL
);
9231 add_info ("signals", info_signals_command
, _("\
9232 What debugger does when program gets various signals.\n\
9233 Specify a signal as argument to print info on that signal only."));
9234 add_info_alias ("handle", "signals", 0);
9236 c
= add_com ("handle", class_run
, handle_command
, _("\
9237 Specify how to handle signals.\n\
9238 Usage: handle SIGNAL [ACTIONS]\n\
9239 Args are signals and actions to apply to those signals.\n\
9240 If no actions are specified, the current settings for the specified signals\n\
9241 will be displayed instead.\n\
9243 Symbolic signals (e.g. SIGSEGV) are recommended but numeric signals\n\
9244 from 1-15 are allowed for compatibility with old versions of GDB.\n\
9245 Numeric ranges may be specified with the form LOW-HIGH (e.g. 1-5).\n\
9246 The special arg \"all\" is recognized to mean all signals except those\n\
9247 used by the debugger, typically SIGTRAP and SIGINT.\n\
9249 Recognized actions include \"stop\", \"nostop\", \"print\", \"noprint\",\n\
9250 \"pass\", \"nopass\", \"ignore\", or \"noignore\".\n\
9251 Stop means reenter debugger if this signal happens (implies print).\n\
9252 Print means print a message if this signal happens.\n\
9253 Pass means let program see this signal; otherwise program doesn't know.\n\
9254 Ignore is a synonym for nopass and noignore is a synonym for pass.\n\
9255 Pass and Stop may be combined.\n\
9257 Multiple signals may be specified. Signal numbers and signal names\n\
9258 may be interspersed with actions, with the actions being performed for\n\
9259 all signals cumulatively specified."));
9260 set_cmd_completer (c
, handle_completer
);
9263 stop_command
= add_cmd ("stop", class_obscure
,
9264 not_just_help_class_command
, _("\
9265 There is no `stop' command, but you can set a hook on `stop'.\n\
9266 This allows you to set a list of commands to be run each time execution\n\
9267 of the program stops."), &cmdlist
);
9269 add_setshow_zuinteger_cmd ("infrun", class_maintenance
, &debug_infrun
, _("\
9270 Set inferior debugging."), _("\
9271 Show inferior debugging."), _("\
9272 When non-zero, inferior specific debugging is enabled."),
9275 &setdebuglist
, &showdebuglist
);
9277 add_setshow_boolean_cmd ("displaced", class_maintenance
,
9278 &debug_displaced
, _("\
9279 Set displaced stepping debugging."), _("\
9280 Show displaced stepping debugging."), _("\
9281 When non-zero, displaced stepping specific debugging is enabled."),
9283 show_debug_displaced
,
9284 &setdebuglist
, &showdebuglist
);
9286 add_setshow_boolean_cmd ("non-stop", no_class
,
9288 Set whether gdb controls the inferior in non-stop mode."), _("\
9289 Show whether gdb controls the inferior in non-stop mode."), _("\
9290 When debugging a multi-threaded program and this setting is\n\
9291 off (the default, also called all-stop mode), when one thread stops\n\
9292 (for a breakpoint, watchpoint, exception, or similar events), GDB stops\n\
9293 all other threads in the program while you interact with the thread of\n\
9294 interest. When you continue or step a thread, you can allow the other\n\
9295 threads to run, or have them remain stopped, but while you inspect any\n\
9296 thread's state, all threads stop.\n\
9298 In non-stop mode, when one thread stops, other threads can continue\n\
9299 to run freely. You'll be able to step each thread independently,\n\
9300 leave it stopped or free to run as needed."),
9306 for (size_t i
= 0; i
< GDB_SIGNAL_LAST
; i
++)
9309 signal_print
[i
] = 1;
9310 signal_program
[i
] = 1;
9311 signal_catch
[i
] = 0;
9314 /* Signals caused by debugger's own actions should not be given to
9315 the program afterwards.
9317 Do not deliver GDB_SIGNAL_TRAP by default, except when the user
9318 explicitly specifies that it should be delivered to the target
9319 program. Typically, that would occur when a user is debugging a
9320 target monitor on a simulator: the target monitor sets a
9321 breakpoint; the simulator encounters this breakpoint and halts
9322 the simulation handing control to GDB; GDB, noting that the stop
9323 address doesn't map to any known breakpoint, returns control back
9324 to the simulator; the simulator then delivers the hardware
9325 equivalent of a GDB_SIGNAL_TRAP to the program being
9327 signal_program
[GDB_SIGNAL_TRAP
] = 0;
9328 signal_program
[GDB_SIGNAL_INT
] = 0;
9330 /* Signals that are not errors should not normally enter the debugger. */
9331 signal_stop
[GDB_SIGNAL_ALRM
] = 0;
9332 signal_print
[GDB_SIGNAL_ALRM
] = 0;
9333 signal_stop
[GDB_SIGNAL_VTALRM
] = 0;
9334 signal_print
[GDB_SIGNAL_VTALRM
] = 0;
9335 signal_stop
[GDB_SIGNAL_PROF
] = 0;
9336 signal_print
[GDB_SIGNAL_PROF
] = 0;
9337 signal_stop
[GDB_SIGNAL_CHLD
] = 0;
9338 signal_print
[GDB_SIGNAL_CHLD
] = 0;
9339 signal_stop
[GDB_SIGNAL_IO
] = 0;
9340 signal_print
[GDB_SIGNAL_IO
] = 0;
9341 signal_stop
[GDB_SIGNAL_POLL
] = 0;
9342 signal_print
[GDB_SIGNAL_POLL
] = 0;
9343 signal_stop
[GDB_SIGNAL_URG
] = 0;
9344 signal_print
[GDB_SIGNAL_URG
] = 0;
9345 signal_stop
[GDB_SIGNAL_WINCH
] = 0;
9346 signal_print
[GDB_SIGNAL_WINCH
] = 0;
9347 signal_stop
[GDB_SIGNAL_PRIO
] = 0;
9348 signal_print
[GDB_SIGNAL_PRIO
] = 0;
9350 /* These signals are used internally by user-level thread
9351 implementations. (See signal(5) on Solaris.) Like the above
9352 signals, a healthy program receives and handles them as part of
9353 its normal operation. */
9354 signal_stop
[GDB_SIGNAL_LWP
] = 0;
9355 signal_print
[GDB_SIGNAL_LWP
] = 0;
9356 signal_stop
[GDB_SIGNAL_WAITING
] = 0;
9357 signal_print
[GDB_SIGNAL_WAITING
] = 0;
9358 signal_stop
[GDB_SIGNAL_CANCEL
] = 0;
9359 signal_print
[GDB_SIGNAL_CANCEL
] = 0;
9360 signal_stop
[GDB_SIGNAL_LIBRT
] = 0;
9361 signal_print
[GDB_SIGNAL_LIBRT
] = 0;
9363 /* Update cached state. */
9364 signal_cache_update (-1);
9366 add_setshow_zinteger_cmd ("stop-on-solib-events", class_support
,
9367 &stop_on_solib_events
, _("\
9368 Set stopping for shared library events."), _("\
9369 Show stopping for shared library events."), _("\
9370 If nonzero, gdb will give control to the user when the dynamic linker\n\
9371 notifies gdb of shared library events. The most common event of interest\n\
9372 to the user would be loading/unloading of a new library."),
9373 set_stop_on_solib_events
,
9374 show_stop_on_solib_events
,
9375 &setlist
, &showlist
);
9377 add_setshow_enum_cmd ("follow-fork-mode", class_run
,
9378 follow_fork_mode_kind_names
,
9379 &follow_fork_mode_string
, _("\
9380 Set debugger response to a program call of fork or vfork."), _("\
9381 Show debugger response to a program call of fork or vfork."), _("\
9382 A fork or vfork creates a new process. follow-fork-mode can be:\n\
9383 parent - the original process is debugged after a fork\n\
9384 child - the new process is debugged after a fork\n\
9385 The unfollowed process will continue to run.\n\
9386 By default, the debugger will follow the parent process."),
9388 show_follow_fork_mode_string
,
9389 &setlist
, &showlist
);
9391 add_setshow_enum_cmd ("follow-exec-mode", class_run
,
9392 follow_exec_mode_names
,
9393 &follow_exec_mode_string
, _("\
9394 Set debugger response to a program call of exec."), _("\
9395 Show debugger response to a program call of exec."), _("\
9396 An exec call replaces the program image of a process.\n\
9398 follow-exec-mode can be:\n\
9400 new - the debugger creates a new inferior and rebinds the process\n\
9401 to this new inferior. The program the process was running before\n\
9402 the exec call can be restarted afterwards by restarting the original\n\
9405 same - the debugger keeps the process bound to the same inferior.\n\
9406 The new executable image replaces the previous executable loaded in\n\
9407 the inferior. Restarting the inferior after the exec call restarts\n\
9408 the executable the process was running after the exec call.\n\
9410 By default, the debugger will use the same inferior."),
9412 show_follow_exec_mode_string
,
9413 &setlist
, &showlist
);
9415 add_setshow_enum_cmd ("scheduler-locking", class_run
,
9416 scheduler_enums
, &scheduler_mode
, _("\
9417 Set mode for locking scheduler during execution."), _("\
9418 Show mode for locking scheduler during execution."), _("\
9419 off == no locking (threads may preempt at any time)\n\
9420 on == full locking (no thread except the current thread may run)\n\
9421 This applies to both normal execution and replay mode.\n\
9422 step == scheduler locked during stepping commands (step, next, stepi, nexti).\n\
9423 In this mode, other threads may run during other commands.\n\
9424 This applies to both normal execution and replay mode.\n\
9425 replay == scheduler locked in replay mode and unlocked during normal execution."),
9426 set_schedlock_func
, /* traps on target vector */
9427 show_scheduler_mode
,
9428 &setlist
, &showlist
);
9430 add_setshow_boolean_cmd ("schedule-multiple", class_run
, &sched_multi
, _("\
9431 Set mode for resuming threads of all processes."), _("\
9432 Show mode for resuming threads of all processes."), _("\
9433 When on, execution commands (such as 'continue' or 'next') resume all\n\
9434 threads of all processes. When off (which is the default), execution\n\
9435 commands only resume the threads of the current process. The set of\n\
9436 threads that are resumed is further refined by the scheduler-locking\n\
9437 mode (see help set scheduler-locking)."),
9439 show_schedule_multiple
,
9440 &setlist
, &showlist
);
9442 add_setshow_boolean_cmd ("step-mode", class_run
, &step_stop_if_no_debug
, _("\
9443 Set mode of the step operation."), _("\
9444 Show mode of the step operation."), _("\
9445 When set, doing a step over a function without debug line information\n\
9446 will stop at the first instruction of that function. Otherwise, the\n\
9447 function is skipped and the step command stops at a different source line."),
9449 show_step_stop_if_no_debug
,
9450 &setlist
, &showlist
);
9452 add_setshow_auto_boolean_cmd ("displaced-stepping", class_run
,
9453 &can_use_displaced_stepping
, _("\
9454 Set debugger's willingness to use displaced stepping."), _("\
9455 Show debugger's willingness to use displaced stepping."), _("\
9456 If on, gdb will use displaced stepping to step over breakpoints if it is\n\
9457 supported by the target architecture. If off, gdb will not use displaced\n\
9458 stepping to step over breakpoints, even if such is supported by the target\n\
9459 architecture. If auto (which is the default), gdb will use displaced stepping\n\
9460 if the target architecture supports it and non-stop mode is active, but will not\n\
9461 use it in all-stop mode (see help set non-stop)."),
9463 show_can_use_displaced_stepping
,
9464 &setlist
, &showlist
);
9466 add_setshow_enum_cmd ("exec-direction", class_run
, exec_direction_names
,
9467 &exec_direction
, _("Set direction of execution.\n\
9468 Options are 'forward' or 'reverse'."),
9469 _("Show direction of execution (forward/reverse)."),
9470 _("Tells gdb whether to execute forward or backward."),
9471 set_exec_direction_func
, show_exec_direction_func
,
9472 &setlist
, &showlist
);
9474 /* Set/show detach-on-fork: user-settable mode. */
9476 add_setshow_boolean_cmd ("detach-on-fork", class_run
, &detach_fork
, _("\
9477 Set whether gdb will detach the child of a fork."), _("\
9478 Show whether gdb will detach the child of a fork."), _("\
9479 Tells gdb whether to detach the child of a fork."),
9480 NULL
, NULL
, &setlist
, &showlist
);
9482 /* Set/show disable address space randomization mode. */
9484 add_setshow_boolean_cmd ("disable-randomization", class_support
,
9485 &disable_randomization
, _("\
9486 Set disabling of debuggee's virtual address space randomization."), _("\
9487 Show disabling of debuggee's virtual address space randomization."), _("\
9488 When this mode is on (which is the default), randomization of the virtual\n\
9489 address space is disabled. Standalone programs run with the randomization\n\
9490 enabled by default on some platforms."),
9491 &set_disable_randomization
,
9492 &show_disable_randomization
,
9493 &setlist
, &showlist
);
9495 /* ptid initializations */
9496 inferior_ptid
= null_ptid
;
9497 target_last_wait_ptid
= minus_one_ptid
;
9499 gdb::observers::thread_ptid_changed
.attach (infrun_thread_ptid_changed
);
9500 gdb::observers::thread_stop_requested
.attach (infrun_thread_stop_requested
);
9501 gdb::observers::thread_exit
.attach (infrun_thread_thread_exit
);
9502 gdb::observers::inferior_exit
.attach (infrun_inferior_exit
);
9504 /* Explicitly create without lookup, since that tries to create a
9505 value with a void typed value, and when we get here, gdbarch
9506 isn't initialized yet. At this point, we're quite sure there
9507 isn't another convenience variable of the same name. */
9508 create_internalvar_type_lazy ("_siginfo", &siginfo_funcs
, NULL
);
9510 add_setshow_boolean_cmd ("observer", no_class
,
9511 &observer_mode_1
, _("\
9512 Set whether gdb controls the inferior in observer mode."), _("\
9513 Show whether gdb controls the inferior in observer mode."), _("\
9514 In observer mode, GDB can get data from the inferior, but not\n\
9515 affect its execution. Registers and memory may not be changed,\n\
9516 breakpoints may not be set, and the program cannot be interrupted\n\